Patent Publication Number: US-2019198954-A1

Title: Device temperature regulator

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation application of International Patent Application No. PCT/JP2017/028063 filed on Aug. 2, 2017, which designated the United States and claims the benefit of priority from Japanese Patent Application No. 2016-176794 filed on Sep. 9, 2016. The entire disclosures of all of the above applications are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a device temperature regulator that can regulate a temperature of at least one temperature regulation target device. 
     BACKGROUND 
     In a battery temperature regulator, heat is absorbed from a battery in an evaporator as a battery temperature regulation part to thereby evaporate a refrigerant in the battery temperature regulation part, and the evaporated refrigerant is condensed in a condenser, so as to cool a battery. 
     SUMMARY 
     The present disclosure is for a device temperature regulator that can regulate a temperature of at least one temperature regulation target device. 
     According to at least one embodiment of the present disclosure, a device temperature regulator includes: a device heat exchanger configured to function as an evaporator in which a liquid working fluid is evaporated by absorbing heat from the temperature regulation target device at the time of cooling the temperature regulation target device, and to function as a heat radiator in which a gaseous working fluid is condensed to radiate heat to the temperature regulation target device at the time of warming up the temperature regulation target device; a condenser that is disposed above the device heat exchanger to condense a gaseous working fluid evaporated in the device heat exchanger at the time of cooling the temperature regulation target device; a gas passage part configured to guide the gaseous working fluid evaporated in the device heat exchanger to the condenser; a liquid passage part configured to guide the liquid working fluid condensed in the condenser to the device heat exchanger; at least one heater configured to heat the working fluid in a device fluid circuit that is configured to include the device heat exchanger, the condenser, the gas passage part, and the liquid passage part; and a liquid amount regulator configured to regulate a liquid amount of the working fluid collecting in the device heat exchanger. 
     The device heat exchanger may be configured to include a heat exchange portion disposed opposite to the temperature regulation target device to exchange heat with the temperature regulation target device. The liquid amount regulator may be configured to regulate the liquid amount of the liquid working fluid collecting in the device heat exchanger such that an occupancy rate of the gaseous working fluid inside the heat exchange portion becomes larger at the time of warming up the temperature regulation target device as compared with that at the time of cooling the temperature regulation target device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic general configuration diagram of a device temperature regulator of a first embodiment. 
         FIG. 2  is a graph to show input/output characteristics of a battery pack. 
         FIG. 3  is a schematic diagram of the device temperature regulator of the first embodiment. 
         FIG. 4  is a schematic diagram to show an interior of a device heat exchanger of the device temperature regulator of the first embodiment. 
         FIG. 5  is a flow chart to show a flow of control processing performed by a control device of the device temperature regulator of the first embodiment. 
         FIG. 6  is a diagram to illustrate an operation at the time of a cooling mode of the device temperature regulator of the first embodiment. 
         FIG. 7  is a diagram to illustrate an operation at the time of a warming-up mode of the device temperature regulator of the first embodiment. 
         FIG. 8  is a diagram to illustrate a detailed operation at the time of the warming-up mode of the device temperature regulator of the first embodiment. 
         FIG. 9  is a schematic diagram of a device temperature regulator of a first modification of the first embodiment. 
         FIG. 10  is a schematic diagram of a device temperature regulator of a second modification of the first embodiment. 
         FIG. 11  is a schematic diagram of a device temperature regulator of a third modification of the first embodiment. 
         FIG. 12  is a schematic diagram of a device temperature regulator of a fourth modification of the first embodiment. 
         FIG. 13  is a schematic diagram of a device temperature regulator of a fifth modification of the first embodiment. 
         FIG. 14  is a schematic diagram of a device temperature regulator of a sixth modification of the first embodiment. 
         FIG. 15  is a schematic diagram to show a main portion of a device temperature regulator of a seventh modification of the first embodiment. 
         FIG. 16  is a schematic diagram to show a main portion of a device temperature regulator of an eighth modification of the first embodiment. 
         FIG. 17  is a flow chart to show a flow of control processing performed by a control device of a device temperature regulator of a ninth modification of the first embodiment. 
         FIG. 18  is a schematic general configuration diagram of a device temperature regulator of a second embodiment. 
         FIG. 19  is a flow chart to show a flow of control processing performed by a control device of the device temperature regulator of the second embodiment. 
         FIG. 20  is a schematic general configuration diagram of a device temperature regulator of a third embodiment. 
         FIG. 21  is a schematic diagram of the device temperature regulator of the third embodiment. 
         FIG. 22  is a flow chart to show a flow of control processing performed by a control device of the device temperature regulator of the third embodiment. 
         FIG. 23  is a schematic diagram of a device temperature regulator of a modification of the third embodiment. 
         FIG. 24  is a schematic general configuration diagram of a device temperature regulator of a fourth embodiment. 
         FIG. 25  is a schematic diagram of the device temperature regulator of the fourth embodiment. 
         FIG. 26  is a flow chart to show a flow of control processing performed by a control device of the device temperature regulator of the fourth embodiment. 
         FIG. 27  is a schematic diagram of a device temperature regulator of a fifth embodiment. 
         FIG. 28  is a cross-sectional view taken on a line XXVIII-XXVIII in  FIG. 27 . 
         FIG. 29  is a diagram to illustrate a liquid surface position of a device heat exchanger at the time of a warming-up mode of the device temperature regulator of the fifth embodiment. 
         FIG. 30  is a diagram to illustrate an operation at the time of a cooling mode of the device temperature regulator of the fifth embodiment. 
         FIG. 31  is a diagram to illustrate an operation at the time of the warming-up mode of the device temperature regulator of the fifth embodiment. 
         FIG. 32  is a diagram to illustrate a liquid surface change in the device heat exchanger at the time of the cooling mode and at the time of the warming-up mode of the device temperature regulator of the fifth embodiment. 
         FIG. 33  is a schematic diagram of a device temperature regulator of a sixth embodiment. 
         FIG. 34  is a diagram to illustrate a liquid surface position of a device heat exchanger at the time of a warming-up mode of the device temperature regulator of the sixth embodiment. 
         FIG. 35  is a diagram to illustrate an operation at the time of a cooling mode of the device temperature regulator of the sixth embodiment. 
         FIG. 36  is a diagram to illustrate an operation at the time of the warming-up mode of the device temperature regulator of the sixth embodiment. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     A battery temperature regulator may be configured such that a liquid refrigerant in a battery temperature regulation part is evaporated by a heating member arranged in the battery temperature regulation part and the evaporated refrigerant is condensed in the battery temperature regulation part, so as to heat a battery. 
     For example, the battery temperature regulation part is opposed to a side of the battery. In other words, a portion on an upper side of the battery is opposed to a position in which a gas refrigerant collects in the battery temperature regulation part and that a portion on a lower side of the battery is opposed to a position in which the liquid refrigerant collects in the battery temperature regulation part. 
     In a portion in which the liquid refrigerant collects in the battery temperature regulation part, the refrigerant is not condensed at the time of warming-up the battery as a temperature regulation target device. In other words, in the battery as the temperature regulation target device, a portion close to the portion in which the liquid refrigerant collects in the battery temperature regulation part is not sufficiently heated. 
     If a wide range of the battery is opposed to a portion in which the liquid refrigerant collects in the battery temperature regulation part, the portion is not sufficiently heated and hence a temperature variation of the battery at the time of warming up the battery will be enlarged. In particular, when the battery is heated, an amount of the liquid refrigerant in the battery temperature regulation part is larger as compared with a case where the battery is cooled, and the temperature variation of the battery is easily enlarged at the time of warming up the battery. An expansion of the temperature variation in the battery will have a large effect on the input/output characteristics of the battery and hence is not preferable. The expansion of the temperature variation at the time of warming up the battery will be caused not only in the battery but also in the other device. 
     An object of the present disclosure is to provide a device temperature regulator that can suppress a temperature variation of a temperature regulation target device from being enlarged at the time of warming up the temperature regulation target device. 
     Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In the respective embodiments below, the same or equivalent parts will be denoted by the same reference characters, and their descriptions will be omitted in some cases. In a case where only a part of constituent elements is described in the embodiment, the constituent elements described in the preceding embodiment can be applied to other parts of the constituent elements. In the following embodiments, the respective embodiments can be combined with each other within a range in which a combination of them does not cause a matter especially, even if the combination of them is not especially clearly described. 
     First Embodiment 
     A first embodiment will be described on the basis of  FIG. 1  to  FIG. 8 . The first embodiment will describe an example in which a device temperature regulator  1  of the present disclosure is applied to a device to regulate a battery temperature Tb of a battery pack BP mounted on a vehicle. An electric vehicle, a hybrid vehicle, or the like, which can travel by a travelling electric motor (not shown in the figure) having the battery pack BP as an electric power supply, is assumed as a vehicle mounted with the device temperature regulator  1  shown in  FIG. 1 . 
     The battery pack BP is configured of a stack in which a plurality of battery cells BC are stacked, the battery cell BC being formed in a shape of a rectangular parallelepiped. The plurality of battery cells BC to configure the battery pack BP are electrically connected to each other in series. Each battery cell BC to configure the battery pack BP is configured of a secondary battery capable of charging or discharging (for example, a lithium-ion battery, a lead acid battery). A shape of the battery cell BC is not limited to the shape of rectangular parallelepiped but may be another shape such as a cylindrical shape. The battery pack BP may be configured so as to include the battery cells BC electrically connected to each other in parallel. 
     The battery pack BP is connected to a power converter and a motor generator (not shown in the figure). The power converter is, for example, a device that converts a direct current supplied from the battery pack BP to an alternating current and that supplies (that is, discharges) the converted alternating current to various kinds of electric loads such as the travelling electric motor. Further, the motor generator is a device that, when the vehicle is regenerated, inversely converts a travelling energy of the vehicle to an electric energy and supplies the inversely converted electric energy to the battery pack BP as a regenerative electric power via a power converter or the like. 
     When the battery pack BP supplies the electric power or the like while the vehicle is travelling, the battery pack BP is self-heated and hence is brought into an excessively high temperature in some cases. When the battery pack BP is brought into the excessively high temperature, as shown in  FIG. 2 , a deterioration of the battery cells BC is advanced and hence an output and an input need to be limited so as to reduce a degree of self-heating. Thus, a cooling means for keeping the temperature of the battery pack BP at a specified temperature or less is required so as to ensure the output and the input of the battery cells BC. 
     Further, as to the battery pack BP, also while the vehicle is parking in the summer or the like, the battery temperature Tb of the battery pack BP becomes the excessively high temperature in some cases. In other words, an electrical storage device including the battery pack BP is disposed under a floor of the vehicle or on the lower side of a trunk room in many cases, so not only during the time when the vehicle is travelling but also during the time when the vehicle is parking in the summer, the battery temperature Tb of the battery pack BP is gradually increased and the battery pack BP is brought into an excessively high temperature in some cases. When the battery pack BP is left unattended under a high temperature environment, the deterioration of the battery cells BC is advanced to greatly reduce a battery lifetime. Thus, it is preferred that the battery temperature Tb of the battery pack BP is held at a specified temperature or less even while the vehicle is parking or the like. 
     Still further, the battery pack BP is configured of the plurality of battery cells BC, and if the respective battery cells BC are varied in their temperatures, the respective battery cells BC cause unevenness in a degree of progress of deterioration, which hence will reduce the input and output characteristics of the whole of the battery pack BP. This is because of the following reasons: that is, the battery pack BP includes a series connection body of the battery cells BC, so that the input and output characteristics of the whole of the battery pack BP are determined according to the battery characteristics of the battery cell BC which has the most advanced degree of progress of deterioration among the battery cells BC. For this reason, so as to cause the battery pack BP to exert a preferred performance for a long time, it is important to reduce variations in the temperatures of the respective battery cells BC, that is, to equalize the temperatures of the respective battery cells BC. 
     A cooling means of an air-cooling type using a blower and a cooling means using a cold heat of a refrigeration cycle of a vapor compression type are generally used as a cooling means for cooling the battery pack BP. 
     However, the cooling means of an air-cooling type using a blower only sends air or the like in a vehicle compartment to the battery pack BP and hence cannot get a cooling capacity capable of sufficiently cooling the battery pack BP in some cases. 
     Further, the cooling means using a cold heat of a refrigeration cycle of a vapor compression type has a high cooling capacity of the battery pack BP but needs to drive a compressor or the like, which is high in a power consumption, while the vehicle is parking. This is not preferable because of causing an increase in the power consumption and an increase in noises. 
     Hence, the device temperature regulator  1  of the present embodiment employs a thermosiphon system which regulates the battery temperature of the battery pack BP not by a forced circulation of a refrigerant by a compressor but by a natural circulation of a working fluid. 
     The device temperature regulator  1  is a device for regulating a battery temperature Tb of the battery pack BP mounted on the vehicle, the battery pack BP being the temperature regulation target device. As shown in  FIG. 1 , the device temperature regulator  1  is provided with the device fluid circuit  10  in which the working fluid is circulated and the control device  100 . The refrigerant or the like used in the refrigeration cycle of a steam compression type can be employed as the working fluid circulated in the device fluid circuit  10 . 
     In the present embodiment, a refrigerant (for example, R134a, R1234yf) having a property in which a density ratio dr of a saturated liquid density dl to a saturated gas density dg becomes larger as a saturation temperature becomes lower is employed as a working fluid. The density ratio dr of the saturated liquid density dl to the saturated gas density dg is defined by the following mathematical formula F1. Hereinafter, the saturated gas density and the saturated liquid density are simply referred to as a gas density and a liquid density in some cases. 
         dr=dl/dg    (F1)
 
     The device fluid circuit  10  is a heat pipe which transfers heat by the evaporation and the condensation of the working fluid and is configured so as to form a thermosiphon of a loop type in which a flow passage in which a gaseous working fluid flows is separated from a flow passage in which a liquid working fluid flows. 
     As shown in  FIG. 3 , the device fluid circuit  10  is configured of a device heat exchanger  12 , a condenser  14 , a gas passage part  16 , and a liquid passage part  18 . An arrow DRg shown in  FIG. 3  shows a direction in which a vertical line extends, that is, a vertical direction. 
     The device fluid circuit  10  of the present embodiment has the device heat exchanger  12 , the condenser  14 , the gas passage part  16 , and the liquid passage part  18  connected to each other, thereby being configured as a fluid circuit shaped like a closed ring. The device fluid circuit  10  is filled with a specified amount of working fluid with its interior evacuated. 
     The device heat exchanger  12  functions as an evaporator that absorbs heat from the battery pack BP to thereby evaporate the liquid working fluid at the time of cooling the battery pack BP of the temperature regulation target device. Further, the device heat exchanger  12  functions as a radiator that condenses the gaseous working fluid therein to thereby transfer heat to the battery pack BP at the time of warming up the battery pack BP. The device heat exchanger  12  is arranged at a position opposed to a bottom surface part side of the battery pack BP. The device heat exchanger  12  has a shape of a thin and flat rectangular parallelepiped. 
     In the device heat exchanger  12 , a device proximity part  121  proximate to a bottom surface part of the battery pack BP configures a heat transfer part to transfer heat between the battery pack BP and the device heat exchanger  12 . In the present embodiment, the device proximity part  121  configures a heat exchange portion to exchange heat with the battery pack BP in the device heat exchanger  12 . The device proximity part  121  has a size to cover the whole of the bottom surface part of the battery pack BP so as to prevent a temperature variation from being caused in the respective battery cells BC to configure the battery pack BP. 
     In the device heat exchanger  12 , the device proximity part  121  is in contact with the bottom surface portion of the battery pack BP so as to be able to transfer heat between the device heat exchanger  12  and the battery pack BP. In the device heat exchanger  12 , the device proximity part  121  may be configured so as to be arranged separately from the bottom surface portion of the battery pack BP if the device proximity part  121  can transfer heat between the device heat exchanger  12  and the battery pack BP. 
     In a case where a liquid surface of the working fluid in the device heat exchanger  12  is separate from the device proximity part  121  of the device heat exchanger  12 , the heat of the battery pack BP is not easily transferred to the liquid working fluid in the device heat exchanger  12 . In other words, in the case where the liquid surface of the working fluid in the device heat exchanger  12  is separate from the device proximity part  121  of the device heat exchanger  12 , the liquid working fluid collecting in the device heat exchanger  12  is limited from evaporating. 
     For this reason, the device fluid circuit  10  of the present embodiment is configured such that the liquid surface of the working fluid is in contact with the device proximity part  121  so as to transfer the heat of the battery pack BP to the liquid working fluid collecting in the device heat exchanger  12 . In other words, the device fluid circuit  10  of the present embodiment is configured such that an internal space of the device heat exchanger  12  is filled with the liquid working fluid to contain bubbles at the time of cooling the battery pack BP. 
     For example, as shown in  FIG. 4 , in a case where the device heat exchanger  12  is configured of a hollow container, a liquid surface LS of the working fluid collecting in the device heat exchanger  12  is proximate to the device proximity part  121  at the time of cooling the battery pack BP. The device heat exchanger  12  is not limited to the hollow container but may be configured so as to have a plurality of flow passages formed by heat exchange tubes or the like. 
     Returning to  FIG. 3 , the device heat exchanger  12  includes a gas outlet part  122 , to which an end portion on a lower side of the gas passage part  16  is connected, and a liquid inlet part  123 , to which an end portion on a lower side of the liquid passage part  18  is connected. The device heat exchanger  12  of the present embodiment has the gas outlet part  122  and the liquid inlet part  123  provided on its side parts opposite to each other. Further, the device heat exchanger  12  of the present embodiment has the gas outlet part  122  and the liquid inlet part  123  provided at positions of the same level in the vertical direction DRg. In the present embodiment, the gas outlet part  122  configures a gas-side connection part to which the gas passage part  16  is connected in the device heat exchanger  12  and the liquid inlet part  123  configures a liquid-side connection part to which the liquid passage part  18  is connected in the device heat exchanger  12 . 
     The device heat exchanger  12  is configured of metal or alloy having an excellent thermal conductivity such as aluminum and copper. The device heat exchanger  12  can be configured of a material other than the metal but at least the device proximity part  121  to configure a heat transfer part is preferred to be configured of a material having an excellent thermal conductivity. 
     The condenser  14  is a heat exchanger which condenses the gaseous working fluid evaporated in the device heat exchanger  12 . The condenser  14  is configured of an air-cooling type heat exchanger which exchanges heat between the air sent from the blower fan BF and the gaseous working fluid to thereby condense the gaseous working fluid. 
     The condenser  14  is arranged on an upper side of the device heat exchanger  12  in the vertical direction DRg such that the liquid working fluid condensed in the condenser  14  moves to the device heat exchanger  12  by its own weight. 
     The condenser  14  includes a gas inlet part  141 , to which an end portion on an upper side of the gas passage part  16  is connected, and a liquid outlet part  142 , to which an end portion on an upper side of the liquid passage part  18  is connected. In the condenser  14  of the present embodiment, the gas inlet part  141  and the liquid outlet part  142  are provided on portions opposed to the each other in the vertical direction DRg. 
     Further, in the condenser  14  of the present embodiment, the gas inlet part  141  is arranged on an upper side of the liquid outlet part  142  in the vertical direction DRg. Specifically, in the condenser  14  of the present embodiment, the gas inlet part  141  is provided on an upper end part in the condenser  14  and the liquid outlet part  142  is provided on a lower end part in the condenser  14 . 
     The condenser  14  is configured of metal or alloy having an excellent thermal conductivity such as aluminum and copper. The condenser  14  may be configured so as to include a material other than the metal, but at least a portion to exchange heat with air is preferred to be configured of a material having an excellent thermal conductivity. 
     The blower fan BF is a device to blow off air inside the vehicle compartment or air outside the vehicle compartment toward the device heat exchanger  12 . The blower fan BF functions as a heat radiation amount regulator for regulating a heat radiation amount of the working fluid collecting in the condenser  14 . The blower fan BF is configured of an electric fan operated when energized. The blower fan is connected to the control device  100  and has its blowing capacity controlled on the basis of a control signal from the control device  100 . 
     The gas passage part  16  guides the gaseous working fluid evaporated in the device heat exchanger  12  to the condenser  14 . The gas passage part  16  has its lower end portion connected to the gas outlet part  122  of the device heat exchanger  12  and has its upper end portion connected to the gas inlet part  141  of the condenser  14 . The gas passage part  16  of the present embodiment is configured of a pipe having a flow passage formed therein, the flow passage causing the working fluid to flow in itself. The gas passage part  16  shown in the figure is only one example. The gas passage part  16  can be changed as appropriate in consideration of ease of mounting on the vehicle. 
     The liquid passage part  18  guides the liquid working fluid condensed in the condenser  14  to the device heat exchanger  12 . The liquid passage part  18  has its lower end portion connected to the liquid inlet part  123  of the device heat exchanger  12  and has its upper end portion connected to the liquid outlet part  142  of the condenser  14 . The liquid passage part  18  of the present embodiment is configured of a pipe having a flow passage formed therein, the flow passage causing the working fluid to flow in itself. 
     In the liquid passage part  18  of the present embodiment, a portion on the condenser  14  side is located above a portion on the device heat exchanger  12  side. Further, the liquid passage part  18  of the present embodiment is configured such that a portion on the device heat exchanger  12  side is located at the same level or on an upper side of a portion on a lowermost side of the device heat exchanger  12 . The liquid passage part  18  shown in the figure is only one example. The liquid passage part  18  can be changed as appropriate in consideration of an ease of mounting on the vehicle. 
     In the device temperature regulator  1  of the thermosiphon system, when the temperature of the working fluid collecting on the condenser  14  side is higher than the battery temperature Tb of the battery pack BP, the working fluid in the condenser  14  is hardly condensed and the working fluid in the device heat exchanger  12  is hardly evaporated. In other words, in the device temperature regulator  1 , in a case where the temperature of the working fluid on the condenser  14  side in the device fluid circuit  10  is higher than the battery temperature Tb of the battery pack BP, the cooling of the battery pack BP is substantially stopped. 
     On the other hand, in the device temperature regulator  1  of the thermosiphon system, when the temperature of the working fluid collecting on the condenser  14  side is lower than the battery temperature Tb of the battery pack BP, the working fluid is evaporated in the device heat exchanger  12  and the working fluid is condensed in the condenser  14 . In other words, in the device temperature regulator  1 , in a case where the temperature of the working fluid on the condenser  14  side in the device fluid circuit  10  is lower than the battery temperature Tb of the battery pack BP, the cooling of the battery pack BP is continued even if the battery temperature Tb of the battery pack BP is within an optimum temperature range. 
     For this reason, in the device temperature regulator  1  of the thermosiphon system, in a case where the temperature of the working fluid in the condenser  14  is lower than the battery temperature Tb of the battery pack BP, the battery temperature Tb of the battery pack BP is decreased to a level equal to or lower than the optimum temperature range in some cases. 
     As shown in  FIG. 2 , when the battery temperature Tb of the battery pack BP is decreased excessively, an internal resistance of the battery pack BP is increased to thereby reduce the input/output characteristics of the battery pack BP. For this reason, it is necessary to take measures so as to prevent the battery temperature Tb of battery pack BP from being excessively decreased. 
     In contrast to this, the device temperature regulator  1  of the present embodiment is configured so as to be able to increase the battery temperature Tb of the battery pack BP. In other words, the device temperature regulator  1  of the present embodiment, as shown in  FIG. 1  and  FIG. 3 , is provided with a heater  20  that heats the working fluid collecting in the device fluid circuit  10 . 
     The heater  20  is a device that heats the working fluid collecting in the device fluid circuit  10  to thereby evaporate the liquid working fluid. The heater  20  of the present embodiment is arranged at a portion on a lower side of the device proximity part  121  proximate to the battery pack BP in the device heat exchanger  12  of the device fluid circuit  10 . 
     Specifically, the heater  20  is arranged on a lower side of both of the gas outlet part  122  and the liquid inlet part  123  of the device heat exchanger  12 . In a case where the gas outlet part  122  and the liquid inlet part  123  of the device heat exchanger  12  are arranged at different positions in the vertical direction DRg, the heating pat  20  is arranged on a lower side of at least one of the gas outlet part  122  and the liquid inlet part  123 . 
     The heater  20  of the present embodiment is arranged on a lower surface part of a tank part  161  provided in the gas passage  16  of the device fluid circuit  10 . The tank part  161  stores a portion of the liquid working fluid collecting in the device fluid circuit  10 . The tank part  161  is provided on a portion on a lower side in the gas passage  16  of the device fluid circuit  10 . 
     In the present embodiment, a portion opposite to a lower surface part of the tank part  161  in the heater  20  configures a heat radiation portion HA. In the heater  20 , the heat radiation portion HA is set so as to be located on a lower side of an upper end of the heat exchange portion to exchange heat with the battery pack BP of the device heat exchanger  12 . Specifically, the heat radiation portion HA of the present embodiment is set so as to be located below a lower end of the device proximity part  121 . 
     The heater  20  of the present embodiment is configured of an electric heater that generates heat when it is energized. The heater  20  has its operation controlled by the control device  100  which will be described later. The heater  20  may be configured of not only the electric heater but also, for example, a power converter, a travelling motor, a heat radiator to radiate an exhaust heat of an engine, and the like. 
     In the device temperature regulator  1 , the temperature variation of the battery pack BP is expanded at the time of warming up the battery pack BP in some cases. The present inventors have earnestly studied causes to cause the temperature variation of the battery pack BP at the time of warming up the battery pack BP. As a result, the present inventors have found that the temperature variation of the battery pack BP is caused by the fact that the heat of the working fluid cannot be sufficiently radiated to the battery pack BP side because the liquid working fluid is put into contact with a portion in a wide range in the device proximity part  121  of the device heat exchanger  12 . 
     The present inventors have considered that the temperature variation of the battery pack BP can be limited by regulating a liquid amount of the working fluid in the device heat exchanger  12  at the time of warming up the battery pack BP and have invented a configuration that can regulate the liquid amount of the working fluid in the device heat exchanger  12 . 
     The device temperature regulator  1  of the present embodiment is provided in the liquid passage part  18  with a liquid passage opening/closing valve  30  that opens or closes the liquid passage part  18  so as to regulate the liquid amount of the working fluid in the device heat exchanger  12 . The liquid passage opening/closing valve  30  is configured of an electric valve mechanism controlled by the control device  100 . Specifically, the liquid passage opening/closing valve  30  of the present embodiment is configured of a normal open type electromagnetic valve that is closed when energized and opened when not energized. 
     When the liquid passage part  18  is opened by the liquid passage opening/closing valve  30 , the device heat exchanger  12  is supplied with the liquid working fluid condensed in the condenser  14 . Further, when the liquid passage part  18  is closed by the liquid passage opening/closing valve  30 , the supply of the liquid working fluid condensed in the condenser  14  to the device heat exchanger  12  is stopped. For this reason, the liquid passage opening/closing valve  30  functions as a liquid amount regulator that regulates the liquid amount of the liquid working fluid collecting in the device heat exchanger  12 . 
     In the device temperature regulator  1  of the present embodiment, when a condition for eliminating the need for warming up the battery pack BP is satisfied, the liquid passage part  18  is closed such that a part of a portion located on an upper side of the liquid passage opening/closing valve  30  in the device fluid circuit  10  functions as a liquid reservoir. 
     The condenser  14  of the present embodiment has the gas inlet part  141  arranged on an upper side of the liquid outlet part  142  so as to be able to store the liquid working fluid when the condition for eliminating the need for the temperature regulation of the battery pack BP is satisfied. In other words, the condenser  14  of the present embodiment is arranged on the upper side of the liquid passage opening/closing valve  30  and the gas inlet part  141  is arranged on the upper side of the liquid outlet part  142 . For this reason, when the condition for eliminating the need for the temperature regulation of the battery pack BP is satisfied and when the liquid passage part  18  is closed by the liquid passage opening/closing valve  30 , the condenser  14  functions as the liquid reservoir LR for storing the liquid working fluid. 
     In the device temperature regulator  1  of the present embodiment, an internal volume of the liquid reservoir for storing the liquid working fluid is set such that when the liquid passage part  18  is closed by the liquid passage opening/closing valve  30 , a liquid surface of the working fluid in the device heat exchanger  12  is located at a specified position. 
     The liquid surface of the working fluid in the device heat exchanger  12  is varied according to an internal volume of the liquid reservoir. Then, the internal volume of the liquid reservoir is varied according to a position at which the liquid passage opening/closing valve  30  is provided in the liquid passage part  18 . 
     For this reason, the liquid passage opening/closing valve  30  is provided in the liquid passage part  18  such that the liquid surface of the working fluid in the device heat exchanger  12  when the liquid working fluid is stored in the liquid reservoir is located between the device proximity part  121  and the heat radiation portion HA of the heater  20  in the vertical direction DRg. In this way, the device temperature regulator  1  is configured so as to regulate the liquid amount of the working fluid in the device heat exchanger  12  such that the liquid surface of the working fluid in the device heat exchanger  12  is located between the device proximity part  121  and the heat radiation portion HA of the heater  20  in the vertical direction DRg. 
     The liquid passage opening/closing valve  30  of the present embodiment is configured so as to regulate the liquid amount of the working fluid in the device heat exchanger  12  such that an occupancy rate of the gaseous working fluid inside the device heat exchanger  12  becomes larger at the time of warming up the battery pack BP than at the time of cooling the battery pack BP. Further, the liquid passage opening/closing valve  30  of the present embodiment is configured so as to regulate the liquid amount of the working fluid collecting in the device heat exchanger  12  such that the liquid working fluid collects in at least one portion of a heat receiving portion  200  that receives heat from the heater  20  at the time of warming up the battery pack BP. 
     Specifically, the liquid passage opening/closing valve  30  is configured so as to regulate the liquid amount of the working fluid in the device heat exchanger  12  such that the liquid surface of the working fluid in the device heat exchanger  12  is located above at least one of the gas outlet part  122  and the liquid inlet part  123  at the time of warming up the battery pack BP. 
     Subsequently, the control device  100  to configure an electronic control part of the device temperature regulator  1  will be described with reference to  FIG. 1 . The control device  100  shown in  FIG. 1  is configured of a microcomputer including a processor and a storage part (for example, a ROM, a RAM) and its peripheral circuit. The storage part of the control device  100  is configured of a non-transitive substantial storage medium. 
     The control device  100  performs various calculations and processing on the basis of a control program stored in the storage part. The control device  100  controls operations of various kinds of devices connected to the output side thereof such as the blower fan BF, the heater  20 , and the liquid passage opening/closing valve  30 . 
     The control device  100  has a group of various sensors, which includes a battery temperature detection part  101  and a condenser temperature detection part  102 , connected to its input side. 
     The battery temperature detection part  101  is configured of a temperature sensor for detecting the battery temperature Tb of the battery pack BP. The battery temperature detection part  101  may be configured of a plurality of temperature sensors. In this case, the battery temperature detection part  101  may be configured so as to output an average value of the detected values of the plurality of temperature sensors to the control device  100 . 
     The condenser temperature detection part  102  is configured of a temperature sensor for detecting a temperature of the working fluid collecting in the condenser  14 . The condenser temperature detection part  102  is not necessarily configured so as to directly detect the temperature of the working fluid collecting in the condenser  14  but may be configured so as to detect a surface temperature of the condenser  14  as the temperature of the working fluid collecting in the condenser  14 . 
     The control device  100  of the present embodiment is a device into which a plurality of control parts, which are configured of hardware and software to control various kinds of devices connected to the output side thereof, are integrated. The control device  100  has a fan control part  100   a,  a heating control part  100   b,  and a valve control part  100   c  integrated thereinto, the fan control part  100   a  controlling the number of revolutions of the blower fan BF, the heating control part  100   b  controlling the heater  20 , the valve control part  100   c  controlling an opening/closing state of the liquid passage opening/closing valve  30 . 
     Next, an operation of the device temperature regulator  1  of the present embodiment will be described with reference to a flow chart shown in  FIG. 5 . Control processing shown in  FIG. 5  is performed at a specified cycle by the control device  100  while the vehicle is travelling. Needless to say, the device temperature regulator  1  may be configured such that the control processing shown in  FIG. 5  is performed by the control device  100  while the vehicle is parking. Each control step shown in  FIG. 5  configures a function realization part which realizes each of various functions performed by the control device  100 . 
     As shown in  FIG. 5 , the control device  100  reads various sensor signals first in step S 110 . Specifically, in the processing of step S 110 , the control device  100  reads the battery temperature Tb of the battery pack BP detected by the battery temperature detection part  101  and the temperature of the working fluid collecting in the condenser  14  detected by the condenser temperature detection part  102 . 
     Subsequently, the control device  100  determines whether or not a condition that requires the battery pack BP to be warmed up is satisfied. In the present embodiment, a condition which is satisfied when the battery temperature Tb of the battery pack BP is lower than a previously-set allowable lower limit temperature Tbmin of the battery pack BP is employed as the condition that requires the battery pack BP to be warmed up. In other words, the control device  100  determines in step S 112  whether or not the battery temperature Tb of the battery pack BP is lower than the previously-set allowable lower limit temperature Tbmin of the battery pack BP. The allowable lower limit temperature Tbmin is set to, for example, a temperature (for example, 10° C.) at which the input/output characteristics of the battery pack BP are not easily impaired even if the battery temperature Tb of the battery pack BP is decreased. 
     In a case where it is determined from a result of determination processing in step S 112  that the battery temperature Tb of the battery pack BP is the allowable lower limit temperature Tbmin or more, the control device  100  determines in step S 114  whether or not the battery temperature Tb of the battery pack BP is higher than a previously-set cooling necessary temperature Tbth. The cooling necessary temperature Tbth is set a temperature (for example, 40 ° C.) at which the input/output characteristics of the battery pack BP are not easily impaired even if the battery temperature Tb of the battery pack BP is increased. 
     In a case where it is determined from a result of the determination processing in step S 114  that the battery temperature Tb of the battery pack BP is higher than the temperature requiring cooling Tbth, the device temperature regulator  1  proceeds to a cooling mode for cooling the battery pack BP. In other words, in a case where it is determined from the result of the determination processing in step S 114  that the battery temperature Tb of the battery pack BP is higher than the temperature requiring cooling Tbth, the control device  100  brings the liquid passage opening/closing valve  30  into an open state in step S 116  and stops heating the working fluid by the heater  20 . Further, the control device  100  operates the blower fan BF in step S 118  to thereby start radiating the heat of the working fluid collecting in the condenser  14 . 
     In the device temperature regulator  1 , at the time of the cooling mode, when the battery temperature Tb of the battery pack BP is increased by the self-heating or the like when the vehicle travels, the heat of the battery pack BP is transferred to the device heat exchanger  12 . In the device heat exchanger  12 , heat is absorbed from the battery pack BP and hence a portion of the liquid working fluid is evaporated. The battery pack BP is cooled by a latent heat of evaporation of the working fluid collecting in the device heat exchanger  12  and hence has its temperature decreased. 
     The gaseous working fluid evaporated in the device heat exchanger  12  flows out to the gas passage part  16  from the gas outlet part  122  of the device heat exchanger  12  and moves to the condenser  14  via the gas passage part  16 , as shown by an arrow Fcg in  FIG. 6 . 
     In the condenser  14 , the gaseous working fluid radiates heat to the blown air from the blower fan BF, thereby being condensed. In the condenser  14 , the gaseous working fluid is liquefied and hence a specific gravity of the working fluid is increased. In this way, the working fluid liquefied in the condenser  14  is moved down toward the liquid outlet part  142  of the condenser  14  by its own weight. 
     The liquid working fluid condensed in the condenser  14  flows out to the liquid passage part  18  from the liquid outlet part  142  of the condenser  14  and moves to the device heat exchanger  12  via the liquid passage part  18  as shown by an arrow Fc 1  in  FIG. 6 . Then, in the device heat exchanger  12 , a portion of the liquid working fluid flowing into the device heat exchanger  12  from the liquid inlet part  123  via the liquid passage part  18  absorbs heat from the battery pack BP, thereby being evaporated. 
     In this way, in the device temperature regulator  1 , at the time of the cooling mode, the working fluid is circulated between the device heat exchanger  12  and the condenser  14  while changing its phase into a gas state and a liquid state and the heat is transported to the condenser  14  from the device heat exchanger  12 , and thereby the battery pack BP is cooled. 
     At the time of the cooling mode, the liquid passage opening/closing valve  30  is opened. For this reason, at the time of the cooling mode, the internal space of the device heat exchanger  12  is filled with the liquid working fluid containing bubbles. In other words, at the time of the cooling mode, the liquid working fluid is brought into contact with an inside of a portion to exchange heat with the battery pack BP of the device heat exchanger  12 . For this reason, at the time of the cooling mode, the battery pack BP can be sufficiently cooled by a heat absorption effect produced by the evaporation of the liquid working fluid collecting in the device heat exchanger  12 . 
     The device temperature regulator  1  is configured such that the working fluid is naturally circulated in the device fluid circuit  10  even if there is not a driving force required for circulating the working fluid by a compressor or the like. For this reason, the device temperature regulator  1  can realize the temperature regulation of the battery pack BP, which depresses both of a power consumption and noises and is efficient as compared with a refrigeration cycle or the like. 
     Returning to  FIG. 5 , in a case where it is determined from the result of the determination processing in step S 114  that the battery temperature Tb of the battery pack BP is the cooling necessary temperature Tbth or lower, the device temperature regulator  1  stops the heat radiation of the working fluid in the condenser  14 . 
     Specifically, in a case where it is determined from the result of the determination processing in step S 114  that the battery temperature Tb of the battery pack BP is the temperature requiring cooling Tbth or lower, the control device  100  brings the liquid passage opening/closing valve  30  into an open state and stops heating the working fluid by the heater  20  in step S 120 . Further, the control device  100  stops the operation of the blower fan BF to thereby stop the heat radiation of the working fluid collecting in the condenser  14  in step S 122 . 
     In the device temperature regulator  1 , even if the operation of the blower fan BF is stopped, in a case where the temperature of the working fluid collecting in the condenser  14  is higher than the battery temperature Tb of the battery pack BP, the heat is transferred to the condenser  14  from the device heat exchanger  12 , and thereby the battery pack BP is cooled. In other words, in the device temperature regulator  1 , if the temperature of the working fluid collecting in the condenser  14  is higher than the battery temperature Tb of the battery pack BP, as is the case with the cooling mode, the battery pack BP is held cooled. 
     For this reason, in a case where the surrounds of the condenser  14  becomes a low temperature in the winter or the like and hence the temperature of the condenser  14  becomes the low temperature, the battery pack BP is held cooled by the device temperature regulator  1 , so that the temperature Tb of the battery pack BP may become lower than the allowable lower limit temperature Tbmin. 
     In contrast to this, if the battery temperature Tb of the battery pack BP becomes lower than the allowable lower limit temperature Tbmin, the device temperature regulator  1  of the present embodiment proceeds to a warming-up mode so as to prevent the battery pack BP from becoming excessively cooled. In other words, in a case where it is determined from the result of the determination processing in step S 112  that the battery temperature Tb of the battery pack BP is lower than the allowable lower limit temperature Tbmin, the control device  100  brings the liquid passage opening/closing valve  30  into a closed state and starts heating the working fluid by the heater  20  in step S 124 . Further, the control device  100  operates the blower fan BF to thereby start radiating heat of the working fluid collecting in the condenser  14  in step S 126 . 
     The device temperature regulator  1  of the present embodiment has the liquid passage part  18  closed by the liquid passage opening/closing valve  30  at the time of the warming-up mode. In other words, in the device temperature regulator  1  of the present embodiment, at the time of the warming-up mode, the supply of the liquid working fluid to the device heat exchanger  12  is stopped. Then, when the working fluid collecting in the condenser  14  starts radiating heat, the liquid working liquid is stored in the condenser  14 . 
     In the device temperature regulator  1 , as the liquid working fluid stored in the condenser  14  increases, the liquid working liquid collecting in the device heat exchanger  12  decreases. In this way, in the device temperature regulator  1  of the present embodiment, as shown in  FIG. 7 , a liquid surface LS of the working fluid in the device heat exchanger  12  goes down to a lower side of the device proximity part  121 . In other words, in the device temperature regulator  1  of the present embodiment, the liquid passage opening/closing valve  30  is closed at the time of the warming-up mode, so that the occupancy rate of the gaseous working fluid inside the device proximity part  121  of the device heat exchanger  12  becomes larger as compared with at the time of the cooling mode. 
     In addition, in the device temperature regulator  1  of the present embodiment, even if the liquid passage opening/closing valve  30  is closed, the liquid working fluid collects in the heat receiving portion  200  to receive heat from the heater  20 . For this reason, in the device temperature regulator  1 , the working fluid, which is heated by the heater  20  and hence is evaporated, is condensed near the device proximity part  121  of the device heat exchanger  12 . In other words, in the device temperature regulator  1 , at the time of the warming-up mode, the working fluid is condensed near the device proximity part  121  of the device heat exchanger  12  and the heat of the working fluid at that time is radiated to the battery pack BP, and thereby the battery pack BP is heated. 
     Hereinafter, a detailed operation of the device temperature regulator  1  of the present embodiment will be described with reference to  FIG. 8 . In  FIG. 8 , operation states in an initial stage ES, a first middle stage MS 1 , a second middle stage MS 2 , and a stable stage SS of warming up the battery pack BP will be shown in an upper left space, an upper right space, a lower left space, and a lower right space, respectively. In the device temperature regulator  1 , at the time of the warming-up mode, an operation state proceeds in order of the initial stage ES, the first middle stag MS 1 , the second middle stage MS 2 , and the stable stage SS. 
     As shown in  FIG. 8 , at the initial stage ES, the liquid working fluid is heated by the heater  20  and the liquid working fluid stored in the tank part  161  is evaporated. At this time, the liquid working fluid collects near the device proximity part  121  of the device heat exchanger  12  and hence the heat of the working fluid is not sufficiently radiated to the battery pack BP side. 
     In the next first middle stage MS 1 , the condenser  14  is cooled in a state where the liquid passage part  18  is closed by the liquid passage opening/closing valve  30 , so that the liquid working fluid is gradually stored in the condenser  14 . In this way, the liquid amount of the working fluid collecting in the device heat exchanger  12  is decreased. Further, in the first middle stage MS 1 , the liquid working fluid collecting in the device heat exchanger  12  flows into the tank part  161 , and thereby the evaporation of the liquid working fluid stored in the tank part  161  is continued. 
     In the next second middle stage MS 2 , the liquid working fluid is increased in the condenser  14 , and thereby the liquid surface LS of the working fluid colleting in the device heat exchanger  12  is decreased below the device proximity part  121 . In this way, the working fluid, which is heated by the heater  20  and is evaporated, is condensed near the device proximity part  121  of the device heat exchanger  12 , and thereby the heating of the battery pack BP is started. 
     In the next stable stage SS, the liquid working fluid is stored in the whole of the condenser  14 , so that the condensation of the working fluid in the condenser  14  is stopped. In other words, in the stable stage SS, the condensation of the working fluid is caused only in the device heat exchanger  12 . 
     In this way, in the stable stage SS, almost all of a heat amount from the heater  20  is used for warming up the battery pack BP, which hence improves an energy efficiency at the time of the warming-up mode of the battery pack BP as compared with in the initial stage or the like. 
     The device temperature regulator  1  of the present embodiment described above is provided with the heater  20 , which heats the working fluid collecting in the device fluid circuit  10 , and the liquid passage opening/closing valve  30 , which functions as the liquid amount regulator for regulating the liquid amount of the working fluid collecting in the device heat exchanger  12 . Then, the liquid passage opening/closing valve  30  regulates the liquid amount of the working fluid collecting in the device heat exchanger  12  such that the occupancy rate of the gaseous working fluid inside the portion to exchange heat with the battery pack BP of the device heat exchanger  12  becomes large. 
     According to this, the device temperature regulator  1  can regulate the liquid amount of the working fluid in the device heat exchanger  12  by the liquid passage opening/closing valve  30  so as to prevent the liquid working fluid from collecting in a portion proximate to the battery pack BP in the device heat exchanger  12  at the time of warming up the battery pack BP. 
     In this way, at the time of warming up the battery pack BP, the device temperature regulator  1  of the present embodiment can suppress the temperature variation from being expanded at the time of warming up the battery pack BP by regulating the liquid amount of the working fluid in the device heat exchanger  12 . 
     In particular, in the device temperature regulator  1  of the present embodiment, an area in which the gaseous working fluid is in contact with an inside of the portion to exchange heat with the battery pack BP in the device heat exchanger  12  is increased and hence a range in which the working fluid is condensed inside the device proximity part  121  can be expanded. 
     Thus, according to the device temperature regulator  1  of the present embodiment, at the time of warming up the battery pack BP, the battery pack BP can be heated in a wide range, which can hence suppress the temperature variation from being expanded at the time of warming up the battery pack BP. 
     Further, at the time of cooling the battery pack BP, an area in which the liquid working fluid is in contact with an inside of the portion to exchange heat with the battery pack BP in the device heat exchanger  12  is increased and hence the refrigerant can be evaporated inside the device proximity part  121 . In this way, the battery pack BP can be sufficiently cooled by a heat absorption effect produced by the evaporation of the liquid working fluid. 
     Further, in the device temperature regulator  1 , the heat radiation portion HA of the heater  20  is located below an upper end of the device proximity part  121  of the device heat exchanger  12 . Then, the liquid passage opening/closing valve  30  is configured so as to regulate the liquid amount of the working fluid collecting in the device heat exchanger  12  such that the working fluid collects in at least a portion of the heat receiving portion  200  to receive heat from the heater  20  at the time of warming up the battery pack BP. In other words, the device temperature regulator  1  of the present embodiment has the heater  20  arranged at a portion located below the device proximity part  121  of the device heat exchanger  12  and hence is configured so as to heat the liquid working fluid by the heater  20  when the condition that requires the battery pack BP to be warmed up is satisfied. 
     According to this, at the time of warming up the battery pack BP, the liquid working fluid collecting in the heat receiving portion  200  can be evaporated by the heater  20  and the evaporated gaseous working fluid can be condensed by the device proximity part  121  of the device heat exchanger  12 . Thus, the battery pack BP can be efficiently warmed up. 
     Specially, in the present embodiment, the heat radiation portion HA of the heater  20  is located on a lower side of at least one of the gas outlet part  122  and the liquid inlet part  123  in the device heat exchanger  12  in the vertical direction DRg. 
     According to this, the liquid working fluid collecting in the device fluid circuit  10  can easily flow to the heater  20  side and the gaseous working fluid, which is heated by the heater  20  and is evaporated, can easily flow to the device heat exchanger  12  side. For this reason, in the device temperature regulator  1  of the present embodiment, at the time of warming up the battery pack BP, the heat of the working fluid can be radiated to the battery pack BP via the device heat exchanger  12 . 
     Further, the device temperature regulator  1  regulates the liquid amount of the working fluid collecting in the device heat exchanger  12  by the liquid passage opening/closing valve  30  such that the liquid surface of the working fluid in the device heat exchanger  12  is located between the heat radiation portion HA of the heater  20  and the device proximity part  121 . 
     According to this, at the time of warming up the battery pack BP, the gaseous working fluid evaporated by the heater  20  can be condensed by the device proximity part  121  proximate to the battery pack BP, so that the heat of the working fluid can be radiated to the battery pack BP via the device heat exchanger  12 . At this time, at the time of warming up the battery pack BP, the battery pack BP is close to a portion in which the gaseous working fluid in the device heat exchanger  12  collects and hence the temperature variation of the battery pack BP can be sufficiently inhibited. 
     Specifically, the device temperature regulator  1  is configured so as to regulate the liquid amount in the device heat exchanger  12  by the liquid passage opening/closing valve  30  such that the liquid surface of the device heat exchanger  12  is located above at least one of the gas outlet part  122  and the liquid inlet part  123  at the time of warming up the battery pack BP. 
     According to this, at the time of warming up the battery pack BP, the liquid working fluid collecting in the device heat exchanger  12  can easily flow to a side of the heater  20  via at least one of the gas outlet part  122  and the liquid inlet part  123 . For this reason, in the device temperature regulator  1 , the liquid working fluid can be heated by the heater  20  and hence can be evaporated. 
     Further, the device temperature regulator  1  of the present embodiment is configured so as to close the liquid passage part  18  by the liquid passage opening/closing valve  30  such that the supply of the liquid working fluid to the device heat exchanger  12  is stopped when the condition that requires the battery pack BP to be warmed up is satisfied. 
     In this configuration, the supply of the liquid working fluid to the device heat exchanger  12  is stopped and the liquid working fluid is stored on the upper side of the liquid passage opening/closing valve  30 , and thereby the liquid amount of the working fluid in the device heat exchanger  12  can be decreased. In this way, at the time of warming up the battery pack BP, the gaseous working fluid evaporated by the heater  20  can be condensed by the device proximity part  121  proximate to the battery pack BP and hence the heat of the working fluid can be radiated to the battery pack BP via the device heat exchanger  12 . 
     Here, the device temperature regulator  1  of the present embodiment is configured so as to operate the blower fan BF such that the heat radiation amount of the working fluid in the condenser  14  is increased when the condition that requires the battery pack BP to be warmed up is satisfied. According to this, at the time of warming up the battery pack BP, the storage amount of liquid working fluid in the condenser  14  is increased and hence the liquid amount of the working fluid in the device heat exchanger  12  can be decreased early. 
     Further, in the present embodiment, the refrigerant (for example, R134a, R1234yf) having a property in which a density ratio of the liquid density to a gas density becomes larger as the saturation temperature decreases is employed. In a case where the working fluid having this property is used, the liquid amount in the device fluid circuit  10  decreases under an environmental condition in which the battery temperature Tb of the battery pack BP decreases. For this reason, at the time of warming up the battery pack BP, a volume necessary for storing the liquid working fluid in the device fluid circuit  10  can be reduced. In other words, in a case where a working fluid having the property in which the density ratio of the gas density to the liquid density becomes larger as the saturation temperature decreases is used, the device temperature regulator  10  can be reduced in size 
     Modifications of the First Embodiment 
     Hereinafter, a first modification to a ninth modification of the device temperature regulator  1  of the first embodiment will be described with reference to  FIG. 9  to  FIG. 17 . Contents described in the present modifications can be applied to the device temperature regulator  1  of the second embodiment to the fourth embodiment, which will be described later, within a range in which a trouble will be not caused in particular. 
     First Modification 
     In the first embodiment described above, the configuration in which the gas passage part  16  of the device fluid circuit  10  is provided with the tank part  161  and in which the heater  20  is arranged on the lower surface part of the tank part  161  has been shown as an example, but the present disclosure is not limited to this. 
     The device temperature regulator  1  may be configured such that, for example, as shown in  FIG. 9 , the gas passage part  16  is not provided with the tank part  161 . In this case, the heater  20  may be arranged simply at a portion on a lower side of the gas passage part  16 . According to this, the gas passage part  16  does not need to be provided with the tank part  161 , so that the device temperature regulator  1  can be simplified. 
     Second Modification 
     Further, the device temperature regulator  1  may be configured such that, for example, as shown in  FIG. 10 , a portion on a lower side in the gas passage part  16  is provided with a portion bent in a shape of a letter U and is provided with the heater  20 . In this way, if the device temperature regulator  1  is configured such that the portion which is bent in the shape of the letter U and into which the liquid working fluid easily flows is heated by the heater  20 , at the time of warming up the battery pack BP, the gaseous working fluid can be supplied to the device heat exchanger  12  sufficiently. 
     Third Modification 
     In the first embodiment described above, a configuration in which the liquid working fluid collecting in the gas passage part  16  in the device fluid circuit  10  is heated by the heater  20  has been shown as an example, but the present disclosure is not limited to this. 
     The device temperature regulator  1  may be configured such that, for example, as shown in  FIG. 11 , the heater  20  is arranged on the lower surface part of the device heat exchanger  12  and that the liquid working fluid collecting on the lower surface part side of the device heat exchanger  12  in the device fluid circuit  10  is heated by the heater  20 . 
     Fourth Modification 
     Further, the device temperature regulator  1  may be configured such that, for example, as shown in  FIG. 12 , the liquid passage part  18  is provided with the tank part  181  and that the heater  20  is arranged on a lower surface part of the tank part  181  and that the liquid working fluid collecting in the liquid passage part  18  is heated by the heater  20 . The device temperature regulator  1  may be configured such that the liquid passage part  18  is not provided with the tank part  181 . In this case, the heater  20  should be arranged only at a portion on a lower side of the liquid passage part  18 . 
     Fifth Modification 
     In the first embodiment described above, the configuration in which the working fluid collecting in the device fluid circuit  10  is heated by a single heater  20  has been shown as an example, but the present disclosure is not limited to this. 
     The device temperature regulator  1  may be configured such that the working fluid collecting in the device fluid circuit  10  is heated by a plurality of heaters  20 . For example, the device temperature regulator  1  may be configured such that, as shown in  FIG. 13 , both of the gas passage part  16  and the liquid passage part  18  are provided with tank parts  161 ,  181 , respectively, and that heaters  20 A,  20 B are arranged on the respective lower surface parts of the tank parts  161 ,  181 . Heat receiving portions  200 A,  200 B in the present modification become the lower surface parts of the respective tank parts  161 ,  181 . 
     Sixth Modification 
     Further, the device temperature regulator  1  may be configured such that, for example, as shown in  FIG. 14 , neither of the gas passage part  16  nor the liquid passage part  18  is provided with the tank parts  161 ,  181 . In this case, the heaters  20 A,  20 B should be arranged simply at portions on a lower side of each of the gas passage part  16  and the liquid passage part  18 . The heat receiving portions  200 A,  200 B in the present modification are portions opposite to the heaters  20 A,  20 B in the gas passage part  16  and the liquid passage part  18 . 
     Seventh Modification 
     In the first embodiment described above, the blower fan BF has been shown as the heat radiation amount regulator for regulating a heat radiation amount of the working fluid collecting in the condenser  14 , but the heat radiation amount regulator is not limited to the blower fan BF. 
     The heat radiation amount regulator, as shown in  FIG. 15 , may be configured of a refrigerant-side heat exchanger HEC in which the low-temperature refrigerant of a refrigeration cycle of a vapor compression type flows. In this case, the heat radiation amount in the condenser  14  is varied by increasing or decreasing the number of revolutions of a compressor in the refrigeration cycle. For this reason, in a case where the refrigerant-side heat exchanger HEC shown in  FIG. 15  is made the heat radiation amount regulator, a configuration for controlling the number of revolutions of the compressor becomes a control part for controlling the heat radiation amount regulator. 
     Eighth Modification 
     Further, the heat radiation amount regulator, as shown in  FIG. 16 , may be configured of a water-side heat exchanger HEL in which a low-temperature antifreeze flows in a cooling water circuit. In this case, the heat radiation amount in the condenser  14  is varied by increasing or decreasing the number of revolutions of a pump in the cooling water circuit. For this reason, in a case where the water-side heat exchanger HEL shown in  FIG. 16  is made the heat radiation amount regulator, a configuration for controlling the number of revolutions of the pump becomes a control part for controlling the heat radiation amount regulator. 
     Ninth Modification 
     In the first embodiment described above, an example in which the heat radiation amount in the condenser  14  is increased in a state where the supply of the liquid working fluid to the device heat exchanger  12  is stopped when the condition that requires the battery pack BP to be warmed up is satisfied has been described, but the present disclosure is not limited to this. 
     The device temperature regulator  1  of the present modification is configured so as to decrease the heat radiation amount of the working fluid in the condenser  14  when the condition that requires the battery pack BP to be warmed up is satisfied and when the condition in which the liquid amount of the working fluid in the device heat exchanger  12  becomes lower than a specified reference liquid amount is satisfied. 
     Hereinafter, an operation of the device temperature regulator  1  of the present modification will be described with reference to a flow chart shown in  FIG. 17 . Control processing shown in  FIG. 17  is performed by the control device  100 . Of the control processing shown in  FIG. 17 , the processing shown in steps S 110  to S 126  are the same as the processing shown in steps S 110  to S 126  shown in  FIG. 5 , which are described in the first embodiment. For this reason, in the present embodiments, as to the processing shown in steps S 110  to S 126 , their descriptions will be omitted or simplified. 
     As shown in  FIG. 17 , the control device  100  operates the blower fan BF in step S 126  to start the heat radiation of the working fluid collecting in the condenser  14  and then determines in step S 128  whether or not a regulation of the liquid amount of the working fluid collecting in the device heat exchanger  12  is finished. In other words, the control device  100  determines in step S 128  whether or not a condition in which the liquid amount of the working fluid in the device heat exchanger  12  becomes lower than a specified reference liquid amount is satisfied. 
     Specifically, when a specified reference time elapses after the control device  100  of the present modification operates the blower fan BF, the control device  100  determines in step S 128  that the regulation of the liquid amount of the working fluid collecting in the device heat exchanger  12  is finished. 
     Here, the processing in step S 128  may be processing for determining whether or not the regulation of the liquid amount of the working fluid collecting in the device heat exchanger  12  is finished regardless of an elapsed time from when the blower fan BF is operated in step S 126 . 
     For example, the control device  100  may be configured in the following manner: that is, the control device  100  operates the blower fan BF in step S 126  and then when the battery temperature Tb of the battery pack BP increases to a specified temperature, the control device  100  determines that the regulation of the liquid amount of the working fluid collecting in the device heat exchanger  12  is finished. 
     Further, the control device  100  may be configured to monitor an actual liquid amount of the working fluid in the device heat exchanger  12 , and the control device  100  may determine that the regulation of the liquid amount of the working fluid flowing in the device heat exchanger  12  is finished when the actual liquid amount becomes more than a specified reference amount. 
     In a case where it is determined in step S 128  that the regulation of the liquid amount of the working fluid collecting in the device heat exchanger  12  is finished, the control device  100  stops operating the blower fan BF in step S 130  to stop radiating the heat of the working fluid collecting in the condenser  14 . 
     The other configuration is the same as the first embodiment. The device temperature regulator  1  of the present modification is configured so as to decrease the heat radiation amount of the working fluid in the condenser  14  when the condition that requires the battery pack BP to be warmed up is satisfied and when the condition in which the liquid amount of the working fluid in the device heat exchanger  12  becomes lower than the specified reference amount is satisfied. In other words, in the device temperature regulator  1  of the present modification, when the supply of the liquid working fluid to the device heat exchanger  12  is stopped and then the liquid amount of the working fluid in the device heat exchanger  12  becomes lower than the specified reference amount, the heat radiation amount of the working fluid in the condenser  14  is decreased. 
     In this configuration, the gaseous working fluid heated and evaporated by the heater  20  is limited from flowing into the condenser  14  side, so that the liquid amount of the working fluid in the device heat exchanger  12  can be held at a suitable amount. 
     Second Embodiment 
     Next, a second embodiment will be described with reference to  FIG. 18  and  FIG. 19 . The present embodiment is different from the first embodiment in that the device temperature regulator  1  is provided with a gas passage opening/closing valve  32  for opening or closing the gas passage part  16 . 
     As shown in  FIG. 18 , in the device temperature regulator  1  of the present embodiment, the gas passage part  16  is provided with the gas passage opening/closing valve  32  for opening or closing the gas passage part  16 . The gas passage opening/closing valve  32  is configured of an electric valve mechanism controlled by the control device  100 . Specifically, the gas passage opening/closing valve  32  of the present embodiment is configured of an electromagnetic valve of a normal open type which is closed when energized and which is opened when not energized. 
     The gas passage opening/closing valve  32  of the present embodiment is provided at a portion closer to the condenser  14  side than the tank part  161  in the gas passage part  16  such that the gaseous working fluid heated and evaporated by the heater  20  does not flow into the condenser  14  via the gas passage part  16 . 
     In the device heat exchanger  12  of the present embodiment, when the gas passage part  16  is opened by the gas passage opening/closing valve  32 , the gaseous working fluid is supplied to the condenser  14 , whereas when the gas passage part  16  is closed by the gas passage opening/closing valve  32 , the supply of the gaseous working fluid to the condenser  14  is stopped. 
     Hereinafter, an operation of the device temperature regulator  1  of the present embodiment will be described with reference to a flow chart shown in  FIG. 19 . Control processing shown in  FIG. 19  is performed by the control device  100 . Of the control processing shown in  FIG. 19 , the processing shown in steps S 110  to S 114  are the same as the processing shown in steps S 110  to S 114  shown in  FIG. 5 , which are described in the first embodiment. For this reason, in the present embodiment, as to the processing shown in steps S 110  to S 114 , their descriptions will be omitted or simplified. 
     As shown in  FIG. 19 , in a case where it is determined as a result of the determination processing in step S 114  that the battery temperature Tb of the battery pack BP is higher than a temperature requiring cooling Tbth, the device temperature regulator  1  of the present modification proceeds to a cooling mode for cooling the battery pack BP. In other words, in the case where it is determined as a result of the determination processing in step S 114  that the battery temperature Tb of the battery pack BP is higher than the temperature requiring cooling Tbth, the control device  100  opens the respective passage opening/closing valves  30 ,  32  in step S 116 A and stops the heating of the working fluid by the heater  20 . Further, the control device  100  operates the blower fan BF in step S 118  to start the heat radiation of the working fluid collecting in the condenser  14 . 
     On the other hand, in a case where it is determined as the result of the determination processing in step S 114  that the battery temperature Tb of the battery pack BP is the temperature requiring cooling Tbth or lower, the control device  100  opens the respective passage opening/closing valves  30 ,  32  in step S 120 A and stops the heating of the working fluid by the heater  20 . Further, the control device  100  stops operating the blower fan BF in step S 122  to stop the heat radiation of the working fluid collecting in the condenser  14 . 
     Further, in a case where it is determined as a result of the determination processing in step S 112  that the battery temperature Tb of the battery pack BP is the allowable lower limit temperature Tbmin or lower, the device temperature regulator  1  of the present embodiment proceeds to a warming-up mode. In other words, in step S 124 A, the control device  100  closes the liquid passage opening/closing valve  30  and opens the gas passage opening/closing valve  32  and then starts the heating of the working fluid by the heater  20 . Then, in step S 126 , the control device  100  operates the blower fan BF to start the heat radiation of the working fluid in the condenser  14 . 
     The control device  100  operates the blower fan BF in step S 126  and then determines in step S 128  whether or not the regulation of the liquid amount of the working fluid collecting in the device heat exchanger  12  is finished. In other words, the control device  100  determines in step S 128  whether or not the condition in which the liquid amount of the working fluid collecting in the device heat exchanger  12  is lower than the specified reference liquid amount is satisfied. 
     In a case where it is determined in step S 128  that the regulation of the liquid amount of the working fluid collecting in the device heat exchanger  12  is finished, the control device  100  stops the operation of the blower fan BF in step S 130 A to stop the heat radiation of the working fluid collecting in the condenser  14  and controls the gas passage opening/closing valve  32  to a closed state. 
     The other configuration is the same as the first embodiment. The device temperature regulator  1  of the present embodiment is configured so as to close the gas passage  16  by the gas passage opening/closing valve  32  when the condition that requires the battery pack BP to be warmed up is satisfied and the condition in which the liquid amount of the working fluid collecting in the device heat exchanger  12  is lower than the specified reference liquid amount is satisfied. 
     According to this, when the liquid amount of the working fluid in the device heat exchanger  12  becomes lower than the specified reference liquid amount, the gaseous working fluid heated and evaporated by the heater  20  is limited from flowing into the condenser  14  side. In this way, the liquid amount of the working fluid in the device heat exchanger  12  can be held at a suitable amount at the time of warming up the battery pack BP. 
     Further, after the gas passage part  16  is closed by the gas passage opening/closing valve  32 , almost all of the heat amount from the heater  20  is used for warming up the battery pack BP, so that an energy efficiency at the time of warming up the battery pack BP can be improved. 
     Third Embodiment 
     Next, a third embodiment will be described with reference to  FIG. 20  to  FIG. 22 . The present embodiment is different from the first embodiment in that the liquid amount regulator, which regulates the liquid amount of the working fluid collecting in the device heat exchanger  12 , is not configured of the liquid passage opening/closing valve  30  but is configured of a volume regulation part  40  which regulates an internal volume of the device fluid circuit  10 . 
     As shown in  FIG. 20  and  FIG. 21 , the device temperature regulator  1  of the present embodiment is provided with the volume regulation part  40  so as to regulate the liquid amount of the working fluid in the device heat exchanger  12 . The device temperature regulator  1  of the present embodiment is not provided with the liquid passage opening/closing valve  30 . 
     The volume regulation part  40  of the present embodiment is provided with a liquid reservoir  41  for storing the liquid working fluid, a volume variation part  42  which slides in the liquid reservoir to thereby vary an internal volume of the liquid reservoir  41 , and an actuator  43  for driving the volume variation part  42 . 
     The liquid reservoir  41  of the present embodiment is provided in a lower portion of the device heat exchanger  12 . Specifically, the liquid reservoir  41  of the present embodiment is configured of a portion formed by bulging a portion of the device heat exchanger  12  to a lower side. 
     The liquid reservoir  41  of the present embodiment is provided on a lower side of the device proximity part  121  of the device heat exchanger  12 . Specifically, the liquid reservoir  41  of the present embodiment is provided on a lower side of the device proximity part  121  in the device heat exchanger  12  and on a lower side of both of the gas outlet part  122  and the liquid inlet part  123  in the vertical direction DRg. 
     The volume variation part  42  of the present embodiment is configured of a block-shaped member located on a lower side of the liquid reservoir  41 . The actuator  43  changes a position of the volume variation part  42  in the liquid reservoir  41  to thereby increase or decrease the internal volume of the liquid reservoir  41 . 
     Specifically, the volume regulation part  40  is configured such that when the volume variation part  42  is moved to an uppermost position by the actuator  43 , the internal volume of the liquid reservoir  41  becomes substantially zero. Further, the volume regulation part  40  is configured such that when the volume variation part  42  is moved to a lowermost position by the actuator  43 , the internal volume of the liquid reservoir  41  becomes a maximum volume. The volume regulation part  40  of the present embodiment has its operation controlled by the control device  100 . 
     In the device temperature regulator  1  of the present embodiment, the liquid amount of the working fluid collecting in the device heat exchanger  12  is increased or decreased by changing a position of the volume variation part  42  to increase or decrease a liquid storage amount of the working fluid in the liquid reservoir  41 . 
     Specifically, in the device temperature regulator  1  of the present embodiment, when the internal volume of the liquid reservoir  41  is decreased, the liquid amount of the working fluid colleting in the device heat exchanger  12  is increased. Further, in the device temperature regulator  1  of the present embodiment, when the internal volume of the liquid reservoir  41  is increased, the liquid amount of the working fluid colleting in the device heat exchanger  12  is decreased. 
     In this way, in the device temperature regulator  1  of the present embodiment, the volume regulation part  40  functions as a liquid amount regulator that regulates the liquid amount of the working fluid collecting in the device heat exchanger  12 . The volume regulation part  40  described in the present embodiment is only an example and may be realized by the other configuration. 
     The volume regulation part  40  of the present embodiment has its maximum volume set such that the liquid surface of the working fluid in the device heat exchanger  12  when the liquid working fluid is stored in the liquid reservoir  41  is positioned between the device proximity part  121  and the heat radiation portion HA of the heater  20  in the vertical direction DRg. 
     In this way, the volume regulation part  40  can regulate the liquid amount of the working fluid in the device heat exchanger  12  such that, at the time of warming up the battery pack BP, the liquid surface of the working fluid in the device heat exchanger  12  is located between the device proximity part  121  and the heat radiation portion HA of the heater  20  in the vertical direction DRg. 
     The volume regulation part  40  of the present embodiment is configured so as to regulate the liquid amount of the working fluid in the device heat exchanger  12  such that, at the time of warming up the battery pack BP, an occupancy rate of the gaseous working fluid inside the device proximity part  121  becomes larger as compared with at the time of cooling the battery pack BP. 
     The volume regulation part  40  of the present embodiment is configured so as to regulate the liquid amount of the working fluid collecting in the device heat exchanger  12  such that, at the time of warming up the battery pack BP, the liquid working fluid collects at least in a portion of the heat receiving portion  200  receiving heat from the heater  20 . 
     Specifically, the volume regulation part  40  is configured so as to regulate the liquid amount of the working fluid in the device heat exchanger  12  such that, at the time of warming up the battery pack BP, the liquid surface of the working fluid in the device heat exchanger  12  is located above at least one of gas outlet part  122  and the liquid inlet part  123 . 
     The heater  20  of the present embodiment is located at a position close to the liquid reservoir  41  such that the working fluid collecting in the liquid reservoir  41  of the volume regulation part  40  is heated. Specifically, the heater  20  of the present embodiment is located on a lower surface part of the liquid reservoir  41  of the volume regulation part  40 . The heat receiving portion  200  of the present embodiment becomes the lower surface part of the liquid reservoir  41 . 
     Subsequently, the control device  100  of the device temperature regulator  1  of the present embodiment will be described with reference to  FIG. 20 . The control device  100  controls the operations of various kinds of instruments connected to an output side thereof, for example, the blower fan BF and the volume regulation part  40 . Not only a fan control part  100   a  for controlling the number of revolutions of the blower fan BF but also a volume control part  100   d  for controlling an operation of the volume regulation part  40  are integrated into the control device  100  of the present embodiment. 
     The other configuration is the same as the first embodiment. Hereinafter, an operation of the device temperature regulator  1  of the present embodiment will be described with reference to a flow chart shown in  FIG. 22 . Control processing shown in  FIG. 22  is performed by the control device  100  at a specified period. Of the control processing shown in  FIG. 22 , the processing shown in steps S 210  to S 214  are the same as the processing shown in steps S 110  to S 114  shown in  FIG. 5 , which are described in the first embodiment. For this reason, in the present embodiment, as to the processing shown in steps S 210  to S 214 , their descriptions will be omitted or simplified. 
     As shown in  FIG. 22 , first, the control device  100  reads various sensor signals in step S 210 . Subsequently, the control device  100  determines in step S 212  whether or not the battery temperature Tb of the battery pack BP is lower than the previously set allowable lower limit temperature Tbmin of the battery pack BP. 
     In a case where it is determined as a result of the determination processing of step S 212  that the battery temperature Tb of the battery pack BP is the allowable lower limit temperature Tbmin or more, the control device  100  determines in step S 214  whether or not the battery temperature Tb of the battery pack BP is higher than the previously set temperature requiring cooling Tbth. 
     In a case where it is determined as a result of the determination processing of step S 214  that the battery temperature Tb of the battery pack BP is higher than the temperature requiring cooling Tbth, the device temperature regulator  1  proceeds to the cooling mode for cooling the battery pack BP. In other words, in step S 216 , the control device  100  minimizes the internal volume of the liquid reservoir  41  of the volume regulation part  40  and stops heating the working fluid by the heater  20 . Further, in step  218 , the control device  100  operates the blower fan BF to start the heat radiation of the working fluid collecting in the condenser  14 . Specifically, in the processing of step S 216 , the control device  100  controls the position of the volume variation part  42  such that the internal volume of the liquid reservoir  41  becomes a minimum volume. 
     In the device temperature regulator  1 , when the battery temperature Tb of the battery pack BP is increased by self-heating or the like when the vehicle travels, the heat of the battery pack BP is transferred to the device heat exchanger  12 . In the device heat exchanger  12 , heat is absorbed from the battery pack BP and hence a portion of the liquid working fluid is evaporated. The battery pack BP is cooled by a latent heat of evaporation of the working fluid collecting in the device heat exchanger  12  and hence has its temperature decreased. At this time, since the internal volume of the liquid reservoir  41  is minimized, the liquid working fluid is evaporated near the device proximity part  121  in the device heat exchanger  12 . 
     The gaseous working fluid evaporated in the device heat exchanger  12  flows out to the gas passage part  16  from the gas outlet part  122  of the device heat exchanger  12  and moves to the condenser  14  via the gas passage part  16  as shown by an arrow Fcg of  FIG. 21 . 
     In the condenser  14 , heat is radiated to air blown from the blower fan BF, and the gaseous working fluid is thereby condensed. In the condenser  14 , the gaseous working fluid is liquefied and a specific gravity of the working fluid is increased. In this way, the working fluid liquefied in the condenser  14  goes down toward a liquid outlet part  142  of the condenser  14  by its own weight. 
     The liquid working fluid condensed in the condenser  14  flows out to the liquid passage part  18  from the liquid outlet part  142  of the condenser  14  and moves to the device heat exchanger  12  via the liquid passage part  18  as shown by an arrow Fc 1  of  FIG. 21 . 
     In this way, at the time of the cooling mode, in the device temperature regulator  1 , the working fluid is circulated between the device heat exchanger  12  and the condenser  14  while changing the phase between the gas state and the liquid state and heat is transferred from the device heat exchanger  12  to the condenser  14 , and thereby the battery pack BP is cooled. 
     Here, at the time of the cooling mode, the internal volume of the liquid reservoir  41  of the volume regulation part  40  is minimized, so that the internal space of the device heat exchanger  12  is filled with the liquid working fluid containing bubbles. In other words, at the time of the cooling mode, the liquid working fluid is in contact with an inside of the device proximity part  121  of the device heat exchanger  12 . For this reason, at the time of the cooling mode, the battery pack BP can be sufficiently cooled by a heat adsorption effect produced by the evaporation of the liquid working fluid collecting in the device heat exchanger  12 . 
     Returning to  FIG. 22 , in a case where it is determined as a result of the determination processing of step S 214  that the battery temperature Tb of the battery pack BP is the temperature requiring cooling Tbth or lower, the device temperature regulator  1  stops the heat radiation of the working fluid in the condenser  14 . 
     Specifically, in step S 220 , the control device  100  minimizes the internal volume of the liquid reservoir  41  and stops heating the working fluid by the heater  20 . Further, in step S 222 , the control device  100  stops the operation of the blower fan BF to thereby stop the heat radiation of the working fluid collecting in the condenser  14 . 
     In the device temperature regulator  1 , in a case where even if the operation of the blower fan BF is stopped, when the temperature of the working fluid collecting in the condenser  14  is higher than the battery temperature Tb of the battery pack BP, the heat is transferred to the condenser  14  from the device heat exchanger  12  and hence the battery pack BP is cooled. 
     Here, if the battery temperature Tb of the battery pack BP becomes lower than the allowable lower limit temperature Tbmin, the device temperature regulator  1  of the present embodiment proceeds to the warming-up mode so as to prevent the battery pack BP from being excessively cooled. In other words, in a case where it is determined as a result of the determination processing of step S 212  that the battery temperature Tb of the battery pack BP is lower than the allowable lower limit temperature Tbmin, the control device  100  maximizes the internal volume of the liquid reservoir  41  and starts heating the working fluid by the heater  20  in step S 224 . Then, in step S 226 , the control device  100  stops operating the blower fan BF to thereby stop the heat radiation of the working fluid collecting in the condenser  14 . Specifically, in the processing of step S 224 , the control device  100  controls the volume variation part  42  so as to maximize the internal volume of the liquid reservoir  41 . 
     In the device temperature regulator  1 , at the time of the warming-up mode, the internal volume of the liquid reservoir  41  becomes the maximum volume. For this reason, in the device temperature regulator  1 , as shown in  FIG. 20 , the liquid surface of the working fluid in the device heat exchanger  12  goes down to a lower side of the device proximity part  121 . In other words, in the device temperature regulator  1  of the present embodiment, the internal volume of the liquid reservoir  41  is maximized at the time of the warming-up mode, so that the occupancy rate of the gaseous working fluid inside the device proximity part  121  of the device heat exchanger  12  becomes larger as compared with at the time of the cooling mode. 
     In addition, in the device temperature regulator  1  of the present embodiment, even if the internal volume of the liquid reservoir  41  is maximized, the liquid working fluid collects in the heat receiving portion  200  to receive the heat from the heater  20 . For this reason, in the device temperature regulator  1 , the working fluid heated and evaporated by the heater  20  is condensed near the device proximity part  121  of the device heat exchanger  12 . In other words, in the device temperature regulator  1 , at the time of the warming-up mode, the working fluid is condensed near the device proximity part  121  of the device heat exchanger  12  and the heat of the working fluid at that time is radiated to the battery pack BP and hence the battery pack BP is heated. 
     The device temperature regulator  1  of the present embodiment described above can produce the same operations and effects produced by the configuration common to the first embodiment as is the case with the first embodiment. In particular, the device temperature regulator  1  of the present embodiment is configured so as to increase the internal volume of the device fluid circuit  10  by the volume regulation part  40  when the condition that requires the battery pack BP to be warmed up is satisfied. 
     In this way, if the device temperature regulator  1  of the present embodiment is configured to increase the internal volume of the device fluid circuit  10  at the time of warming up the battery pack BP, the liquid working fluid is stored in a space increased by the volume regulation part  40  and hence the liquid amount of the working fluid in the device heat exchanger  12  can be decreased. In other words, in the device temperature regulator  1  of the present embodiment, the occupancy rate of the gaseous working fluid inside the device proximity part  121  of the device heat exchanger  12  can be made larger at the time of the warming-up mode as compared with at the time of the cooling mode by the volume regulation part  40 . 
     According to this, at the time of warming up the battery pack BP, the gaseous working fluid evaporated by the heater  20  can be condensed by the device proximity part  121  proximate to the battery pack BP, so that the heat of the working fluid can be radiated to the battery pack BP via the device heat exchanger  12 . As a result, in the warming up of the battery pack BP, the battery pack BP comes close to a portion in which the gaseous working fluid in the device heat exchanger  12  collects, so that the temperature variation of the battery pack BP can be sufficiently limited. 
     In particular, at the time of warming up the battery pack BP, an area in which the gaseous working fluid evaporated by the heater  20  is in contact with the gaseous working fluid at an inside portion of the device proximity part  121 , exchanging heat with the battery pack BP, is increased, thereby increasing a range in which gaseous working fluid inside the device proximity part  121  is condensed. 
     Thus, according to the device temperature regulator  1  of the present embodiment, at the time of warming up the battery pack BP, the battery pack BP can be heated in a wide range, so that the temperature variation of the battery pack BP can be sufficiently limited. 
     Further, at the time of cooling the battery pack BP, the area in which the liquid working fluid is in contact with the inside portion to exchange heat with the battery pack BP in the device heat exchanger  12  is increased, so that the liquid working fluid can be evaporated on the inside of the device proximity part  121 . According to this, the battery pack BP can be sufficiently cooled by the heat absorption effect produced by the evaporation of the liquid working fluid. 
     Further in the device temperature regulator  1  of the present embodiment, the liquid reservoir  41  of the variable volume type in which the internal volume can be varied is provided on the lower side of the device proximity part  121  of the device heat exchanger  12  in the vertical direction DRg. According to this, the liquid working fluid collecting in the device heat exchanger  12  can easily flow to the liquid reservoir  41  by its own weight, so that the liquid amount of the working fluid in the device heat exchanger  12  can be suitably reduced at the time of warming up the battery pack BP. 
     Specifically, in the device temperature regulator  1  of the present embodiment, the liquid reservoir  41  is provided on the lower side of at least one of the gas outlet part  122  and the liquid inlet part  123  in the device heat exchanger  12  in the vertical direction DRg. According to this, the liquid working fluid collecting in the device heat exchanger  12  can easily flow into the liquid reservoir  41 , so that the liquid working fluid can be transferred to the liquid reservoir  41  from the device heat exchanger  12  at the time of warming up the battery pack BP. 
     Further, in the device temperature regulator  1  of the present embodiment, the heater  20  is located on the lower side of the liquid reservoir  41  in the vertical direction DRg. According to this, the gaseous working fluid heated and evaporated by the heater  20  can easily flow to the device heat exchanger  12  side from the liquid reservoir  41 , so that the heat of the working fluid can be transferred to the battery pack BP via the device heat exchanger  12 . 
     Modification of the Third Embodiment 
     In the third embodiment described above, the configuration in which the liquid reservoir  41  of the volume regulation part  40  is provided on the lower side of the device heat exchanger  12  has been shown, but the present disclosure is not limited to this. 
     The device temperature regulator  1 , for example, as shown in  FIG. 23 , may be configured such that a liquid reservoir  41 A is provided on a portion on the lower side of the gas passage part  16 . In this case, it is preferable that the liquid reservoir  41 A is provided on the lower side of the device proximity part  121  in the device heat exchanger  12 . 
     Although not shown in the figure, the device temperature regulator  1  may be configured such that the liquid reservoir  41  is provided on a portion on the lower side of the liquid passage part  18 . In this case, it is preferable that the liquid reservoir  41  is provided on the lower side of the device proximity part  121  in the device heat exchanger  12 . 
     Fourth Embodiment 
     Next, a fourth embodiment will be described with reference to  FIG. 24  and  FIG. 26 . The present embodiment is different from the first embodiment in that the liquid amount regulator for regulating the liquid amount of the working fluid collecting in the device heat exchanger  12  includes not the liquid passage opening/closing valve  30  but a liquid reservoir  51  and a cooling device  54 . 
     As shown in  FIG. 24  and  FIG. 25 , the device temperature regulator  1  of the present embodiment is provided with the liquid reservoir  51 , a branch passage part  52 , a branch connection part  53 , the cooling device  54 , and a branch passage opening/closing valve  55  so as to regulate the liquid amount of the working fluid collecting in the device heat exchanger. 
     The liquid reservoir  51  stores the liquid working fluid collecting in the device fluid circuit  10 . The liquid reservoir  51  is configured of a fixed-volume type container having a constant internal volume. The liquid reservoir  51  is connected to the device fluid circuit  10  via the branch passage part  52  and the branch connection part  53 . Specifically, the liquid reservoir  51  is connected to the gas passage part  16  of the device fluid circuit  10  via the branch passage part  52  and the branch connection part  53 . 
     The branch connection part  53  is configured of a three-way joint provided in the device fluid circuit  10 . The branch connection part  53  of the present embodiment is provided at a portion located on an upper side of a portion Hu located uppermost in the vertical direction DRg of the device heat exchanger  12  of the device fluid circuit  10 . Further, the branch passage part  52  has its one end side connected to an upper surface part of the liquid reservoir  51  and has the other end side connected to the branch connection part  53 . 
     The cooling device  54  is a device which cools the liquid reservoir  51  to condense the gaseous working fluid collecting in the liquid reservoir  51 . The cooling device  54  is provided next to a lower surface part of the liquid reservoir  51 . 
     The cooling device  54  of the present embodiment is configured of a Peltier element to generate cold heat when energized. The cooling device  54  has its operation controlled by the control device  100 . The cooling device  54  may be configured of not only the Peltier element but also, for example, a heat exchanger in which a low-temperature refrigerant of a refrigeration cycle of a vapor compression type is circulated. 
     Here, the gaseous working fluid collecting in the device fluid circuit  10  is condensed at a portion brought into a low temperature in the device fluid circuit  10 . For this reason, when the liquid reservoir  51  is cooled by the cooling device  54 , the gaseous working fluid collecting in the device fluid circuit  10  is condensed and stored in the liquid reservoir  51 . 
     For this reason, in the device temperature regulator  1 , when the liquid reservoir  51  is cooled by the cooling device  54 , the liquid amount of the working fluid collecting in the device fluid circuit  10  is decreased. Then, in the device heat exchanger  12 , as the liquid amount of the working fluid in the device fluid circuit  10  is decreased, the liquid amount of the working fluid in the device heat exchanger  12  is also decreased. 
     On the other hand, when the cooling of the liquid reservoir  51  by the cooling device  54  is stopped, the liquid working fluid stored in the liquid reservoir  51  is transferred to the device fluid circuit  10  as the temperature is increased, so that the liquid amount of the working fluid collecting in the device fluid circuit  10  is increased. As the liquid amount of the working fluid collecting in the device fluid circuit  10  is increased, the liquid amount of the working fluid collecting in the device heat exchanger  12  is also increased. 
     The cooling device  54  of the present embodiment is configured so as to increase the liquid storage amount of the liquid working fluid in the liquid reservoir  41  such that when the condition that requires the battery pack BP to be warmed up is satisfied, the liquid surface of the working fluid in the device heat exchanger  12  is located on the lower side of the device proximity part  121 . 
     In the device temperature regulator  1  of the present embodiment, a maximum volume of the liquid reservoir  51  is set such that, when the liquid reservoir  51  stores the liquid working fluid, the liquid surface of the working fluid in the device heat exchanger  12  is located between the device proximity part  121  and the heat radiation portion HA of the heater  20  in the vertical direction DRg. 
     In other words, the device temperature regulator  1  can regulate the liquid amount of the working fluid in the device heat exchanger  12  such that at the time of warming up the battery pack BP, the liquid surface of the working fluid in the device heat exchanger  12  is located between the device proximity part  121  and the heat radiation portion HA of the heater  20  in the vertical direction DRg. 
     The device temperature regulator  1  of the present embodiment regulates the liquid amount of the working fluid in the device heat exchanger  12  such that at the time of warming up the battery pack BP, the occupancy rate of the gaseous working fluid inside the portion to exchange heat with the battery pack BP of the device heat exchanger  12  becomes larger as compared with at the time of cooling the battery pack BP. 
     Further, the device temperature regulator  1  of the present embodiment is configured so as to regulate the liquid amount of the working fluid collecting in the device heat exchanger  12  such that at the time of warming up the battery pack BP, the liquid working fluid collects in at least one portion of the heat receiving portion  200  to receive heat from the heater  20 . 
     Specifically, the device temperature regulator  1  of the present embodiment can regulate the liquid amount of the working fluid in the device heat exchanger  12  such that at the time of warming up the battery pack BP, the liquid surface of the liquid working fluid in the device heat exchanger  12  is located above at least one of the gas outlet part  122  and the liquid inlet part  123 . 
     Subsequently, the branch passage opening/closing valve  55  is a fluid shutter to shut a movement of the working fluid between the liquid reservoir  51  and the device fluid circuit  10 . The branch passage opening/closing valve  55  of the present embodiment is provided in the branch passage part  52 . The branch passage opening/closing valve  55  of the present embodiment is configured of an electric valve mechanism controlled by the control device  100 . Specifically, the branch passage opening/closing valve  55  of the present embodiment is configured of a normally-open type electromagnetic valve which is closed when energized and is opened when not energized. 
     Subsequently, the control device  100  of the device temperature regulator  1  of the present embodiment will be described with reference to  FIG. 24 . The control device  100  controls the operations of various devices connected to its outside such as the blower fan BF, the cooling device  54 , and the branch passage opening/closing valve  55 . The control device  100  of the present embodiment has not only a BF control part  100   a  but also a cooling control part  100   e  and a valve control part  100   f  integrated thereinto, the fan control part  100   a  controlling the number of revolutions of the blower fan BF, the cooling control part  100   e  controlling an operation of the cooling device  54 , the valve control part  100   f  controlling the branch passage opening/closing valve  55 . 
     The other configuration is the same as the first embodiment. Hereinafter, an operation of the device temperature regulator  1  of the present embodiment will be described with reference to a flow chart shown in  FIG. 26 . Control processing shown in  FIG. 26  is performed at a specified period by the control device  100 . Of the control processing shown in  FIG. 26 , the processing shown in steps S 310  to S 314  are the same as the processing shown in steps S 110  to S 114  shown in  FIG. 5 , which are described in the first embodiment. For this reason, in the present embodiment, as to the processing shown in steps S 310  to S 314 , their descriptions will be omitted or simplified. 
     As shown in  FIG. 26 , first, the control device  100  reads various sensor signals in step S 310 . Subsequently, the control device  100  determines in step S 312  whether or not the battery temperature Tb of the battery pack BP is lower than the previously set allowable lower limit temperature Tbmin of the battery pack BP. 
     In a case where it is determined as a result of the determination processing of step S 312  that the battery temperature Tb of the battery pack BP is the allowable lower limit temperature Tbmin or more, the control device  100  determines in step S 314  whether or not the battery temperature Tb of the battery pack BP is higher than the previously set temperature requiring cooling Tbth. 
     In a case where it is determined as a result of the determination processing of step S 314  that the battery temperature Tb of the battery pack BP is higher than the temperature requiring cooling Tbth, the device temperature regulator  1  proceeds to the cooling mode for cooling the battery pack BP. In other words, in step S 316 , the control device  100  stops cooling the liquid reservoir  51  by the cooling device  54  and controls the branch passage opening/closing valve  55  to an open state and further stops heating the working fluid by the heater  20 . Further, in step  318 , the control device  100  operates the blower fan BF to start the heat radiation of the working fluid collecting in the condenser  14 . 
     In the device temperature regulator  1 , at the time of the cooling mode, when the battery temperature Tb of the battery pack BP is increased by the self-heating developed when the vehicle is travelling, the heat of the battery pack BP is transferred to the device heat exchanger  12 . In the device heat exchanger  12 , heat is absorbed from the battery pack BP and hence a portion of the liquid working fluid is evaporated. The battery pack BP is cooled by a latent heat of evaporation of the working fluid collecting in the device heat exchanger  12 , thereby having its temperature cooled. 
     The gaseous working fluid evaporated in the device heat exchanger  12  flows out to the gas passage part  16  from the gas outlet part  122  of the device heat exchanger  12  and moves to the condenser  14  via the gas passage part  16  as shown by arrows Fcg of  FIG. 25 . 
     The condenser  14  radiates heat to the air blown from the blower fan BF, and thereby the gaseous working fluid is condensed. In the condenser  14 , the gaseous working fluid is liquefied to increase a specific gravity of the working fluid. In this way, the working fluid liquefied in the condenser  14  goes down to the liquid outlet part  142  of the condenser  14  by its own weight. 
     The liquid working fluid condensed in the condenser  14  flows out to the liquid passage part  18  from the liquid outlet part  142  of the condenser  14  and moves to the device heat exchanger  12  via the liquid passage part  18  as shown by an arrow Fc 1 . At the time of the cooling mode, the cooling of the liquid reservoir  51  by the cooling device  54  is stopped, so that the working fluid is hardly condensed in the liquid reservoir  51 . 
     In this way, in the device temperature regulator  1 , at the time of the cooling mode, the working fluid is circulated between the device heat exchanger  12  and the condenser  14  while changing its phase between the gas state and the liquid state and heat is transferred from the device heat exchanger  12  to the condenser  14 , and thereby the battery pack BP is cooled. 
     Here, at the time of the cooling mode, the liquid working fluid is hardly stored in the liquid reservoir  51 , so that an internal space of the device heat exchanger  12  is filled with the liquid working fluid containing bubbles. In other words, at the time of the cooling mode, the liquid working fluid is brought into contact with an inside of the device proximity part  121  of the device heat exchanger  12 . For this reason, at the time of the cooling mode, the battery pack BP can be sufficiently cooled by a heat absorption effect produced by the evaporation of the liquid working fluid collecting in the device heat exchanger  12 . 
     Returning to  FIG. 26 , in a case where it is determined as the result of the determination processing of step S 314  that the battery temperature Tb of the battery pack BP is the temperature requiring cooling Tbth or less, the device temperature regulator  1  stops the heat radiation of the working fluid in the condenser  14 . 
     Specifically, in step S 320 , the control device  100  stops cooling the liquid reservoir  51  by the cooling device  54  and controls the branch passage opening/closing valve  55  to an open state and further stops heating the working fluid by the heater  20 . Further, in step S 322 , the control device  100  stops operating the blower fan BF to stop the heat radiation of the working fluid collecting in the condenser  14 . 
     In the device temperature regulator  1 , even if the operation of the blower fan BF is stopped, when the temperature of the working fluid collecting in the condenser  14  is higher than the battery temperature Tb of the battery pack BP, the heat is transferred to the condenser  14  from the device heat exchanger  12 , and thereby the battery pack BP is cooled. 
     When the battery temperature Tb of the battery pack BP becomes lower than the allowable lower limit temperature Tbmin, the device temperature regulator  1  of the present embodiment proceeds to the warming-up mode so as to prevent the battery temperature BP from being excessively cooled. In other words, in step S 324 , the control device  100  starts cooling the liquid reservoir  51  by the cooling device  54  and controls the branch passage opening/closing valve  55  to an open state and further starts heating the working fluid by the heater  20 . Further, in step S 326 , the control device  100  stops operating the blower fan BF to stop the heat radiation of the working fluid collecting in the condenser  14 . 
     In the device temperature regulator  1  of the present embodiment, at the time of the warming up-mode, the branch passage part  52  is opened by the branch passage opening/closing valve  55  and the cooling of the liquid reservoir  51  is started by the cooling device  54  in a state where the heating of the working fluid by the heater  20  is started. At this time, the control device  100  controls the cooling device  54  such that the temperature of the liquid reservoir  51  becomes lower than the temperature of the condenser  14 . 
     In the device temperature regulator  1 , when the liquid reservoir  51  is cooled by the cooling device  54 , the gaseous working fluid collecting in the device fluid circuit  10  is condensed in the liquid reservoir  51 . In this way, in the device temperature regulator  1 , as shown in  FIG. 24 , the liquid working fluid condensed in the liquid reservoir  51  is stored in the liquid reservoir  51 . 
     In the device temperature regulator  1 , as the liquid working fluid stored in the liquid reservoir  51  is increased, the liquid working fluid collecting in the device heat exchanger  12  is decreased. In this way, in the device temperature regulator  1 , the liquid surface of the working fluid in the device heat exchanger  12  goes down to the lower side of the device proximity part  121 . In other words, in the device temperature regulator  1  of the present embodiment, the liquid working fluid is stored in the liquid reservoir  51  at the time of the warming-up mode, so that the occupancy rate of the gaseous working fluid inside the device proximity part  121  of the device heat exchanger  12  becomes larger compared with at the time of the cooling mode. 
     In addition, in the device temperature regulator  1  of the present embodiment, even if the liquid working fluid is stored in the liquid reservoir  51 , the liquid working fluid collects at the heat receiving portion  200  to receive the heat from the heater  20 . For this reason, in the device temperature regulator  1 , the working fluid heated and evaporated by the heater  20  is condensed near the device proximity part  121  of the device heat exchanger  12 . In short, in the device temperature regulator  1 , at the time of the warming-up mode, the working fluid is condensed near the device proximity part  121  of the device heat exchanger  12  and the heat of the working fluid at that time is radiated to the battery pack BP, and thereby the battery pack BP is heated. 
     Returning to  FIG. 26 , after the processing of step S 326 , the control device  100  determines in step S 328  whether or not the regulation of the liquid amount of the working fluid collecting in the device heat exchanger  12  is finished. In other words, the control device  100  determines in step S 328  whether or not the condition in which the liquid amount of the working fluid in the device heat exchanger  12  becomes lower than a specified reference liquid amount is satisfied. 
     When a specified reference time elapses after the cooling of the liquid reservoir  51  by the cooling device  54  is started in step S 324 , the control device  100  of the present embodiment determines in step S 328  that the regulation of the liquid amount of the working fluid collecting in the device heat exchanger  12  is finished. 
     The processing of step S 328  may be processing for determining whether or not the regulation of the liquid amount of the working fluid collecting in the device heat exchanger  12  is finished regardless of an elapsed time from the time when the cooling of the liquid reservoir  51  by the cooling device  54  is started in step S 324 . 
     For example, the control device  100  may be configured to determine that the regulation of the liquid amount of the working fluid in the device heat exchanger  12  is finished when the battery temperature Tb of the battery pack BP is increased to a specified temperature after the cooling of the liquid reservoir  51  by the cooling device  54  is started in step S 324 . 
     Further, the control device  100  may be configured so as to monitor an actual liquid amount of the working fluid in the device heat exchanger  12  and to determine that the regulation of the liquid amount of the working fluid collecting in the device heat exchanger  12  is finished when the actual liquid amount becomes more than a specified reference amount. 
     In a case where it is determined in step S 328  that the regulation of the liquid amount of the working fluid collecting in the device heat exchanger  12  is finished, in step S 330 , the control device  100  stops cooling the liquid reservoir  51  by the cooling device  54  and controls the branch passage opening/closing valve  55  to a closed state. 
     The device temperature regulator  1  of the present embodiment described above can produce the same operations and effects produced by the configuration common to the first embodiment as is the case with the first embodiment. In particular, the device temperature regulator  1  of the present embodiment is configured so as to cool the liquid reservoir  51  by the cooling device  54  to increase the liquid storage amount of the liquid working fluid in the liquid reservoir  51  when the condition that requires the battery pack BP to be warmed up is satisfied. 
     In this way, if the device temperature regulator  1  of the present embodiment is configured so as to increase the liquid storage amount of the liquid working fluid stored in the liquid reservoir  51  at the time of warming up the battery pack BP, the liquid amount of the working fluid in the device heat exchanger  12  can be decreased. In other words, the device temperature regulator  1  of the present embodiment can increase the occupancy rate of the gaseous working fluid inside the portion to exchange heat with the battery pack BP of the device heat exchanger  12  at the time of the warming-up mode as compared with at the time of the cooling mode by regulating the liquid storage amount of the working fluid in the liquid reservoir  51 . 
     According to this, at the time of warming up the battery pack BP, the gaseous working fluid evaporated by the heater  20  can be condensed by the device proximity part  121  proximate to the battery pack BP, so that the heat of the working fluid can be radiated to the battery pack BP via the device heat exchanger  12 . At the time of warming up the battery pack BP, the battery pack BP is proximate to the portion in the device heat exchanger  12  in which the gaseous working fluid collects, so that the temperature variation of the battery pack BP can be sufficiently limited. 
     In particular, at the time of warming up the battery pack BP, an area in which the gaseous working fluid evaporated by the heater  20  is in contact with the gaseous working fluid at the inside portion of the device proximity part  121 , exchanging heat with the battery pack BP, is increased, thereby increasing a range in which the gaseous working fluid on the inside of the device proximity part  121  is condensed. 
     Thus, according to the device temperature regulator  1  of the present embodiment, at the time of warming up the battery pack BP, the battery pack BP can be heated in a wide range, which hence can sufficiently suppress the temperature variation of the battery pack BP. 
     Further, the device temperature regulator  1  of the present embodiment is configured so as to close the branch passage part  52  by the branch passage opening/closing valve  55  when the liquid storage amount of the liquid working fluid in the liquid reservoir  51  reaches a specified reference amount at the time of the warming-up mode. 
     According to this, the working fluid is limited from moving between the liquid reservoir  51  and the device fluid circuit  10  after the liquid working fluid is stored in the liquid reservoir  51 , which hence can prevent the working fluid in the liquid reservoir  51  from unintentionally moving to the device fluid circuit  10 . 
     The device temperature regulator  1  is preferable to be configured such that the branch passage part  52  can be opened or closed by the branch passage opening/closing valve  55 , but the present disclosure is not limited to this. The device temperature regulator  1  may be configured so as not to be provided with the branch passage opening/closing valve  55 . 
     Further, as described above, the cooling device  54  is preferable to be provided adjacently to the lower surface part of the liquid reservoir  51 , but the present disclosure is not limited to this. The cooling device  54  may be provided, for example, in at least one portion of the side surface of the liquid reservoir  51  or the branch passage part  52 . 
     Fifth Embodiment 
     Next, a fifth embodiment will be described with reference to  FIG. 27  to  FIG. 32 . The present embodiment is different from the first embodiment in that the device heat exchanger  12  is arranged at a position opposite to a side surface part of the battery pack BP. In the present embodiment, parts different from the first embodiment will be mainly described. 
     As shown in  FIG. 27  and  FIG. 28 , the device heat exchanger  12  of the present embodiment is configured so as to include a cylindrical upper tank  124 , a cylindrical lower tank  125 , and a plurality of tubes  126  to make the upper tank  124  communicate with the lower tank  125 . The device heat exchanger  12  may be configured so as to make the upper tank  124  communicate with the lower tank  125  by a hollow member having a plurality of flow passages formed therein in place of the plurality of tubes  126 . 
     The respective members to configure the device heat exchanger  12  are configured of metal having an excellent thermal conductivity, for example, aluminum or copper. The respective members to configure the device heat exchanger  12  may be configured of a material having an excellent thermal conductivity other than the metal. 
     The upper tank  124  is provided on a portion on an upper side in the vertical direction DRg of the device heat exchanger  12 . The upper tank  124  has a gas outlet part  122  provided on its one side in a longitudinal direction, the gas outlet part  122  having an end portion on a lower side of the gas passage part  16  connected thereto. The gas outlet part  122  configures a gas-side connection part to which the gas passage part  16  in the device heat exchanger  12  is connected. 
     The lower tank  125  is provided on a portion on the lower side in the vertical direction DRg of the device heat exchanger  12 . The lower tank  125  has a liquid inlet part  123  provided on its one side in the longitudinal direction, the liquid inlet part  123  having an end portion on the lower side of the liquid passage part  18  connected thereto. The liquid inlet part  123  configures a liquid-side connection part to which the liquid passage part  18  in the device heat exchanger  12  is connected. 
     The battery pack BP is provided on the outside of the device heat exchanger  12  via a thermal conductive sheet  13  having an electric insulation. The device heat exchanger  12  has insulation from the battery pack BP secured and has a thermal resistance to the battery pack BP reduced by the thermal conductive sheet  13 . 
     The device heat exchanger  12  is arranged so as to oppose to the battery pack BP in a direction orthogonal to the vertical direction DRg. In the device heat exchanger  12  of the present embodiment, a portion opposed to the battery pack BP in the direction orthogonal to the vertical direction DRg configures the device proximity part  12  to exchange heat with the battery pack BP. The device proximity part  121  is a heat transfer part to transfer heat between the battery pack BP and the device heat exchanger  12 . In the present embodiment, the device proximity part  121  configures a heat exchange part to exchange heat with the battery pack BP in the device heat exchanger  12 . The device proximity part  121  has a size large enough to cover the whole of the side surface part of the battery pack BP so as not to cause a temperature variation in the respective battery cells to configure the battery pack BP. The device proximity part  121  of the present embodiment extends along the vertical direction DRg. 
     The battery pack BP of the present embodiment is located such that a surface on a side opposite to a surface provided with a terminal TE is opposed to the device proximity part  121  of the device heat exchanger  12  via the thermal conductive sheet  13 . The respective battery cells BC to configure the battery pack BP are arranged in a direction intersecting the vertical direction DRg. 
     In the device temperature regulator  1  of the present embodiment, the liquid passage part  18  is provided with the liquid passage opening/closing valve  30 . The liquid passage opening/closing valve  30  functions as a liquid amount regulator that regulates the liquid amount of the liquid working fluid collecting in the device heat exchanger  12 , as is the case with the first embodiment. 
     The liquid passage opening/closing valve  30  of the present embodiment is configured so as to regulate the liquid amount of the working fluid in the device heat exchanger  12  such that, at the time of warming up the battery pack BP, the occupancy rate of the gaseous working fluid inside the device proximity part  121  becomes larger as compared with at the time of cooling the battery pack BP. 
     Further, the liquid passage opening/closing valve  30  of the present embodiment is configured so as to regulate the liquid amount of the working fluid collecting in the device heat exchanger  12  such that, at the time of warming up the battery pack BP, the liquid working fluid collects in at least one portion of the heat receiving portion  200  to receive heat from the heater  20 . 
     As shown in  FIG. 29 , the liquid passage opening/closing valve  30  of the present embodiment is configured so as to regulate the liquid amount of the working fluid collecting in the device heat exchanger  12  such that, at the time of warming up the battery pack BP, the liquid surface in the device heat exchanger  12  is located below an upper end position Pe 1  of a heat exchange portion. 
     Here, it is preferable that the liquid passage opening/closing valve  30  is configured so as to regulate the liquid amount of the working fluid collecting in the device heat exchanger  12  such that, at the time of warming up the battery pack BP, the liquid surface in the device heat exchanger  12  is located below a lower end position Pe 2  of the heat exchange portion. According to this, a range in which the working fluid on the inside of the device proximity part  121  is condensed can be most expanded. 
     Further, the liquid passage opening/closing valve  30  of the present embodiment is configured so as to regulate the liquid amount of the working fluid collecting in the device heat exchanger  12  such that, at the time of warming up the battery pack BP, the liquid surface in the device heat exchanger  12  is positioned above a lower end position Ph 1  of a heat radiation portion HA of the heater  20 . 
     Here, it is preferable that the liquid passage opening/closing valve  30  is configured so as to regulate the liquid amount of the working fluid collecting in the device heat exchanger  12  such that, at the time of warming up the battery pack BP, the liquid surface in the device heat exchanger  12  is located above an upper end position Ph 2  of the heat radiation portion HA of the heater  20 . According to this, an area in which heat is transferred to the liquid working fluid from the heater  20  can be sufficiently ensured. 
     Next, an operation of the device temperature regulator  1  of the present embodiment will be described with reference to  FIG. 30  to  FIG. 32 . In the device temperature regulator  1  of the present embodiment, as shown in  FIG. 30 , at the time of the cooling mode, the liquid passage opening/closing valve  30  is brought into the open state and the blower fan BF is operated in a state where the heating of the working fluid by the heater  20  is stopped. 
     In this way, in the device heat exchanger  12 , the liquid working fluid absorbs heat from the battery pack BP and a portion of the liquid working fluid is evaporated. The battery pack BP is cooled by the latent heat of evaporation of the working fluid collecting in the device heat exchanger  12  and hence has its temperature decreased. 
     The gaseous working fluid evaporated in the device heat exchanger  12  flows out to the gas passage part  16  from the gas outlet part  122  of the device heat exchanger  12  and moves to the condenser  14  via the gas passage part  16  as shown by an arrow Fcg in  FIG. 30 . 
     In the condenser  14 , the gaseous working fluid radiates heat to air blown from the blower fan BF, thereby being condensed. In the condenser  14 , the gaseous working fluid is liquefied and hence a specific gravity of the working fluid is increased. In this way, the working fluid liquefied in the condenser  14  goes down toward the liquid outlet part  142  of the condenser  14  by its own weight. 
     The liquid working fluid condensed in the condenser  14  flows out to the liquid passage part  18  from the liquid outlet part  142  of the condenser  14  and moves to the device heat exchanger  12  via the liquid passage part  18  as shown by an arrow Fcl in  FIG. 30 . Then, in the device heat exchanger  12 , a portion of the liquid working fluid flowing into the device heat exchanger  12  from the liquid inlet part  123  via the liquid passage part  18  absorbs heat from the battery pack BP, thereby being evaporated. 
     In this way, in the device temperature regulator  1 , at the time of the cooling mode, the working fluid is circulated between the device heat exchanger  12  and the condenser  14  while changing the phase between the gas phase and the liquid phase and hence the heat is transferred from the device heat exchanger  12  to the condenser  14 , and thereby the battery pack BP is cooled. 
     Here, at the time of the cooling mode, the liquid passage opening/closing valve  30  is opened. For this reason, at the time of the cooling mode, the internal space of the device heat exchanger  12  is filled with the liquid working fluid containing the bubbles. In other words, at the time of the cooling mode, the liquid working fluid is brought into contact with the inside of the device proximity part  121  of the device heat exchanger  12 . For this reason, at the time of the cooling mode, the battery pack BP can be sufficiently cooled by a heat absorption effect produced by the evaporation of the liquid working fluid collecting in the device heat exchanger  12 . 
     Further, in the device temperature regulator  1  of the present embodiment, as shown in  FIG. 31 , at the time of the warming-up mode, the blower fan BF is operated in a state where the liquid passage opening/closing valve  30  is closed and where the heating of the working fluid by the heater  20  is started. 
     When the heat radiation of the working fluid collecting in the condenser  14  is started by operating the blower fan BF, the liquid working fluid is stored in the condenser  14 , and thereby the liquid surface of the working fluid in the device heat exchanger  12  goes down to a position below an upper end of the device proximity part  121 . 
     In this way, as shown in  FIG. 32 , in the device temperature regulator  1 , at the time of the warming-up mode, the occupancy rate of the gaseous working fluid on the inside of the device proximity part  121  of the device heat exchanger  12  becomes larger as compared with at the time of the cooling mode. 
     In addition, in the device temperature regulator  1  of the present embodiment, even if the liquid passage opening/closing valve  30  is closed, the liquid working fluid collects in the heat receiving portion  200  to receive heat from the heater  20 . For this reason, in the device temperature regulator  1 , the working fluid heated and evaporated by the heater  20  is condensed near the device proximity part  121  of the device heat exchanger  12 . In other words, in the device temperature regulator  1 , at the time of the warming-up mode, the working fluid is condensed near the device proximity part  121  of the device heat exchanger  12  and the heat of the working fluid is radiated to the battery pack BP at the time, so that the battery pack BP is heated. 
     The other configuration is the same as the first embodiment. In the device temperature regulator  1  of the present embodiment, at the time of warming up the battery pack BP, the area in which the gaseous working fluid is in contact with the inside portion, exchanging heat with the battery pack BP in the device heat exchanger  12 , becomes larger, so that the area in which the working fluid on the inside of the device proximity part  121  is condensed can be expanded. For this reason, also by the device temperature regulator  1  of the present embodiment, at the time of warming up the battery pack BP, the battery pack BP can be heated in a wide range, so that it is possible to suppress the temperature variation of the battery pack BP from being expanded at the time of the warming-up of the battery pack BP. 
     Here, in the present embodiment, the example in which the liquid amount regulator is configured of the liquid passage opening/closing valve  30  has been described, but the present disclosure is not limited to this. The liquid amount regulator may be configured of those shown in the second embodiment to the fourth embodiment. 
     Sixth Embodiment 
     Next, a sixth embodiment will be described with reference to  FIG. 33  to  FIG. 36 . The present embodiment is different from the fifth embodiment in that the device fluid circuit  10  is additionally provided with a bypass passage part  19 . In the present embodiment, parts different from the fifth embodiment will be mainly described. 
     As shown in  FIG. 33 , the device fluid circuit  10  of the present embodiment is configured so as to include the bypass passage part  19  that causes the upper tank  124  and the lower tank  125  of the device heat exchanger  12  to communicate with each other without using the condenser  14 . 
     The bypass passage part  19  has its one end side connected to an upper connection part  127  provided in the upper tank  124  and has its other end side connected to a lower connection part  128  provided in the lower tank  125 . The bypass passage  19  may be configured so as to connect a middle portion of the gas passage part  16  to a middle portion of the liquid passage part  18 . 
     The bypass passage part  19  is provided with the heater  20  that heats the working fluid collecting in the bypass passage part  19 . The heater  20  is located such that the heat radiation portion HA is located below an upper end of the device proximity part  121  in the device heat exchanger  12 . 
     The liquid passage opening/closing valve  30  of the present embodiment is configured so as to regulate the liquid amount of the working fluid in the device heat exchanger  12  such that, at the time of warming up the battery pack BP, the occupancy rate of the gaseous working fluid on the inside of the device proximity part  121  becomes larger as compared with at the time of cooling the battery pack BP. 
     Further, the liquid passage opening/closing valve  30  of the present embodiment is configured so as to regulate the liquid amount of the working fluid collecting in the device heat exchanger  12  such that, at the time of warming up the battery pack BP, the liquid working fluid collects in at least one portion of the heat receiving portion  200  to receive heat from the heater  20 . 
     As shown in  FIG. 34 , the liquid passage opening/closing valve  30  of the present embodiment is configured so as to regulate the liquid amount of the working fluid collecting in the device heat exchanger  12  such that, at the time of warming up the battery pack BP, the liquid surface in the device heat exchanger  12  is located below the upper end position Pe 1  of the heat exchange portion. 
     Further, the liquid passage opening/closing valve  30  of the present embodiment is configured so as to regulate the liquid amount of the working fluid collecting in the device heat exchanger  12  such that, at the time of warming up the battery pack BP, the liquid surface in the device heat exchanger  12  is located above the lower end position Ph 1  of the heat radiation portion HA of the heater  20 . 
     Next, an operation of the device temperature regulator  1  of the present embodiment will be described with reference to  FIG. 35  and  FIG. 36 . In the device temperature regulator  1  of the present embodiment, as shown in  FIG. 35 , at the time of the cooling mode, the blower fan BF is operated in a state where the liquid passage opening/closing valve  30  is opened and where the heating of the working fluid by the heater  20  is stopped. 
     In this way, in the device heat exchanger  12 , the liquid working fluid absorbs heat from the battery pack BP and a portion of the liquid working fluid is evaporated. The battery pack BP is cooled by the latent heat of evaporation of the working fluid collecting in the device heat exchanger  12  and hence has its temperature decreased. 
     The gaseous working fluid evaporated in the device heat exchanger  12  flows out to the gas passage part  16  from the gas outlet part  122  of the device heat exchanger  12  and moves to the condenser  14  via the gas passage part  16  as shown by an arrow Fcg in  FIG. 35 . 
     In the condenser  14 , the gaseous working fluid radiates heat to air blown from the blower fan BF, thereby being condensed. In the condenser  14 , the gaseous working fluid is liquefied and hence a specific gravity of the working fluid is increased. In this way, the working fluid liquefied in the condenser  14  goes down toward the liquid outlet part  142  of the condenser  14  by its own weight. 
     The liquid working fluid condensed in the condenser  14  flows out to the liquid passage part  18  from the liquid outlet part  142  of the condenser  14  and moves to the device heat exchanger  12  via the liquid passage part  18  as shown by an arrow Fcl in  FIG. 35 . Then, in the device heat exchanger  12 , a portion of the liquid working fluid flowing into the device heat exchanger  12  from the liquid inlet part  123  via the liquid passage part  18  absorbs heat from the battery pack BP, thereby being evaporated. 
     Here, a portion of the liquid working fluid condensed in the condenser  14  flows in the bypass passage part  19  but the heater  20  is stopped, so that the liquid working fluid is not evaporated in the bypass passage  19 . For this reason, at the time of cooling mode, a flow of the working fluid is hardly caused in the bypass passage part  19 . 
     In this way, in the device temperature regulator  1 , at the time of the cooling mode, the working fluid is circulated between the device heat exchanger  12  and the condenser  14  while changing the phase between the gas phase and the liquid phase and the heat is transferred to the condenser  14  from the device heat exchanger  12 , and thereby the battery pack BP is cooled. 
     At the time of cooling mode, the liquid passage opening/closing valve  30  is opened. For this reason, at the time of the cooling mode, the internal space of the device heat exchanger  12  is filled with the liquid working fluid containing the bubbles. In other words, at the time of the cooling mode, the liquid working fluid is brought into contact with the inside of the device proximity part  121  of the device heat exchanger  12 . For this reason, at the time of the cooling mode, the battery pack BP can be sufficiently cooled by a heat absorption effect produced by the evaporation of the liquid working fluid collecting in the device heat exchanger  12 . 
     Further, in the device temperature regulator  1  of the present embodiment, as shown in  FIG. 36 , at the time of the warming-up mode, the blower fan BF is operated in a state where the liquid passage opening/closing valve  30  is closed and where the heating of the working fluid by the heater  20  is started. 
     When the blower fan BF is operated and the heat radiation of the working fluid collecting in the condenser  14  is started, the liquid working fluid is stored in the condenser  14 , and thereby the liquid surface of the working fluid in the device heat exchanger  12  goes down to a position below an upper end of the device proximity part  121 . In this way, in the device temperature regulator  1 , at the time of the warming-up mode, the occupancy rate of the gaseous working fluid on the inside of the device proximity part  121  of the device heat exchanger  12  becomes larger as compared with at the time of the cooling mode. 
     In this state, the working fluid collecting in the bypass passage part  19  is heated by the heater  20 . Then, the working fluid heated and evaporated by the heater  20  flows into the device heat exchanger  12  from the upper connection part  127 . Almost all of the gaseous working fluid flowing into the device heat exchanger  12 , except for the gaseous working fluid flowing to the condenser  14  side, is condensed near the device proximity part  121  of the device heat exchanger  12 . In short, in the device temperature regulator  1 , at the time of the warming-up mode, the working fluid is condensed near the device proximity part  121  of the device heat exchanger  12  and the heat of the working fluid at that time is radiated to the battery pack BP, so that the battery pack is heated. Then, the working fluid condensed near the device proximity part  121  of the device heat exchanger  12  flows out to the bypass passage part  19  via the lower connection part  128  and is again heated by the heater  20 . 
     The other configuration is the same as the first embodiment. In the device temperature regulator  1  of the present embodiment, at the time of warming up the battery pack BP, the area in which the gaseous working fluid is in contact with the inside portion to exchange heat with the battery pack BP in the device heat exchanger  12  becomes larger, so that the area in which the working fluid on the inside of the device proximity part  121  is condensed can be expanded. For this reason, also by the device temperature regulator  1  of the present embodiment, at the time of warming up the battery pack BP, the battery pack BP can be heated in a wide range, so that it is possible to suppress the temperature variation of the battery pack BP from being expanded at the time of the warming-up of the battery pack BP. 
     In the present embodiment, the example in which the liquid amount regulator is configured of the liquid passage opening/closing valve  30  has been described, but the present disclosure is not limited to this. The liquid amount regulator may be configured of those shown in the second embodiment to the fourth embodiment. 
     Further, in the present embodiment, an example in which at the time of warming up the battery pack BP, the heat radiation amount in the condenser  14  is increased by operating the blower fan BF has been described, but the present invention is not limited to this. In a case where the temperature around the condenser  14  is low, even if the blower fan BF is not operated, the working fluid is condensed in the condenser  14  in some cases. For this reason, the device temperature regulator  1  may be configured so as not to increase the heat radiation amount in the condenser  14  at the time of warming up the battery pack BP. This is the same also in the first embodiment and the like. 
     Other Embodiments 
     Up to this point, typical embodiments of the present disclosure have been described, and the present disclosure is not limited to the embodiments described above but, for example, can be variously modified as will be described below. 
     In the first embodiment, the example in which the liquid passage opening/closing valve  30  is configured of the electromagnetic valve has been described, but the liquid passage opening/closing valve  30  may be configured of, for example, a mechanical valve having a valve mechanism operated without being energized. This is the same also in the gas passage opening/closing valve  32  of the second embodiment and in the branch passage opening/closing valve  55  of the fourth embodiment. 
     In the respective embodiments described above, the examples in which the gas outlet part  122  and the liquid inlet part  123  of the device heat exchanger  12  are provided on the side surface portions opposed to each other have been described, but the present disclosure is not limited to this. The gas outlet part  122  and the liquid inlet part  123  may be provided, for example, on an upper surface part of the device heat exchanger  12 . 
     Further, the gas outlet part  122  and the liquid inlet part  123  of the device heat exchanger  12  may be different from each other in a height in the vertical direction DRg. In this case, it is preferred that the gas outlet part  122  is provided at a position higher than the liquid inlet part  123 . 
     As described in the respective embodiments, it is preferable that the liquid amount of the working fluid of the device heat exchanger  12  is regulated by the liquid amount regulator such that, at the time of warming up the battery pack BP, the liquid surface of the working fluid in the device heat exchanger  12  is located between the device proximity part  121  and the heat radiation portion HA of the heater  20 , but the present disclosure is not limited to this. The liquid amount regulator may be configured so as to regulate the liquid amount of the working fluid in the device heat exchanger  12  such that, at the time of warming up the battery pack BP, the liquid surface of the working fluid in the device heat exchanger  12  is located at least on the lower side of the device proximity part  121 . 
     In the respective embodiments described above, the examples in which the temperature of the single battery pack BP is regulated by the device temperature regulator  1  have been described, but the present disclosure is not limited to this. The device temperature regulator  1  can regulate the temperatures of a plurality of devices. 
     In the respective embodiments, the condition satisfied when the battery temperature Tb of the battery pack BP is lower than the previously set allowable lower limit temperature Tbmin of the battery pack BP is employed as the condition in which the battery pack BP needs to be warmed up, but the present disclosure is not limited to this. The condition in which the battery pack BP needs to be warmed up may be, for example, a condition satisfied when an ambient temperature around the battery pack BP becomes a specified temperature or less. 
     In the respective embodiments described above, the examples in which the device temperature regulator  1  of the present disclosure is applied to a device for regulating the battery temperature Tb of the battery pack BP mounted on the vehicle have been described, but the present disclosure is not limited to this. In other words, the device temperature regulator  1  of the present disclosure can be widely applied not only to the battery pack BP but also to a device for regulating a temperature of the other instrument. 
     In the embodiments described above, needless to say, elements configuring the embodiments are not necessarily essential except where the elements are specified to be especially essential and except where the elements are clearly essential in principle. 
     In the embodiments described above, in a case where numerical values such as a number, a numerical value, an amount, and a range of the constituent element of the embodiment are referred to, except where the numerical values are specified to be especially essential or except where the numerical values are clearly limited to the specified numbers in principle, the numerical values are not limited to the specified numerical values. 
     In the embodiments described above, when a shape and a position relation of the constituent element or the like are referred to, except where the shape and the position relation are specified to be especially essential or except where the shape and the position relation are limited to a specified shape and a specified position relation in principle, the shape and the position relation are not limited to the specified shape and the specified position relation. 
     According to a first aspect shown in a part or all of the embodiments described above, the device temperature regulator is provided with at least one heater for heating the working fluid collecting in the device fluid circuit  10  and the liquid amount regulator for regulating the liquid amount of the working fluid collecting in the device heat exchanger. 
     Accordingly, at the time of warming up the temperature regulation target device, the liquid amount of the working fluid in the device heat exchanger can be regulated by the liquid amount regulator for example, so as to suppress a liquid working fluid from collecting in a heat exchanging part exchanging heat with a temperature regulation target space in the device heat exchanger. For this reason, in the device temperature regulator of the present disclosure, by regulating the liquid amount of the working fluid in the device heat exchanger at the time of warming up the temperature regulation target device, a temperature variation in the temperature regulation target device can be limited from being expanded at the time of warming up the temperature regulation target device. 
     According to a second aspect, in the device temperature regulator, at least a part of the heat receiving portion configured to receive heat from the heater in the device fluid circuit is located below an upper end of the heat exchange portion. Then, the liquid amount regulator is configured to regulate the liquid amount of the working fluid collecting in the device heat exchanger such that, when the condition in which the temperature regulation target device needs to be warmed up is satisfied, the liquid working fluid collects at least in the part of the heat receiving portion. 
     According to this, at the time of warming up the temperature regulation target device, the liquid working fluid collecting in the heat receiving portion can be evaporated by the heater and the evaporated gaseous working fluid can be condensed by the heat exchange portion. In other words, according to this configuration, the heat of the working fluid can be easily radiated to the temperature regulation target device via the device heat exchanger. For this reason, the temperature regulation target device can be efficiently warmed up. 
     According to a third aspect, the heater includes a heat radiation portion configured to radiate the heat to the working fluid and is arranged on the lower side of at least one of the gas-side connection part or the liquid-side connection part in the vertical direction. Here, the gas-side connection part of the device heat exchanger is connected to the gas passage part, and the liquid-side connection part of the device heat exchanger is connected to the liquid passage part. 
     According to this, the liquid working fluid collecting in the device heat exchanger can easily flow to the heater side and the gaseous working fluid, which is heated and evaporated by the heater, can easily flow to the device heat exchanger side. For this reason, in the device temperature regulator of the present disclosure, the heat of the working fluid can be radiated to the temperature regulation target device via the device heat exchanger. 
     According to a fourth aspect, the liquid amount regulator of the device temperature regulator can regulate the liquid amount of the working fluid in the device heat exchanger such that, at the time of warming up the temperature regulation target device, the liquid surface of the working fluid in the device heat exchanger is located above at least one of the respective connection parts. 
     According to this, at the time of warming up the temperature regulation target device, the liquid working fluid collecting in the device heat exchanger can easily flow to the side of the heater via at least one of the gas-side connection part and the liquid-side connection part, so that the liquid working fluid can be evaporated suitably by the heating of the heater. 
     According to a fifth aspect, the device temperature regulator is provided with the liquid passage opening/closing valve that opens or closes the liquid passage part to regulate the supply amount of the liquid working fluid to the device heat exchanger. Then, the liquid passage opening/closing valve is configured so as to close the liquid passage part such that when the condition that requires the temperature regulation target device to be warmed up is satisfied, the supply of the liquid working fluid to the device heat exchanger is stopped. 
     In this configuration, the supply of the liquid working fluid to the device heat exchanger is stopped and the liquid working fluid is stored on the upper side of the liquid passage opening/closing valve, so that the liquid amount of the working fluid in the device heat exchanger can be reduced. In this way, at the time of warming up the temperature regulation target device, the gaseous working fluid evaporated by the heater can be condensed at the heat exchange portion to exchange heat with the temperature regulation target device, so that the heat of the working fluid can be radiated to the temperature regulation target device via the device heat exchanger. 
     According to a sixth aspect, the liquid amount regulator of the device temperature regulator is configured to include the heat radiation amount regulator that regulates the heat radiation amount of the working fluid in the condenser. The heat radiation amount regulator is configured to increase the heat radiation amount of the working fluid in the condenser when the condition that requires the temperature regulation target device to be warmed up is satisfied. According to this, at the time of warming up the temperature regulation target device, the liquid storage amount of the working fluid in the condenser is increased, and thereby the liquid amount of the working fluid in the device heat exchanger can be quickly reduced. 
     According to a seventh aspect, the heat radiation amount regulator of the device temperature regulator is configured to reduce the heat radiation amount of the working fluid in the condenser when the condition in which the liquid amount of the working fluid in the device heat exchanger becomes lower than the specified reference liquid amount is satisfied at the time of warming up the temperature regulation target device. 
     According to this, when the supply of the liquid working fluid to the device heat exchanger is stopped and then the liquid amount of the working fluid in the device heat exchanger becomes lower than the specified reference liquid amount, the heat radiation amount in the condenser is reduced. In this way, the gaseous working fluid, which is heated and evaporated by the heater, is restricted from flowing into a side of the condenser, so that the liquid amount of the working fluid in the device heat exchanger can be held at a suitable amount. 
     According to an eighth aspect, the device temperature regulator is configured so as to include the gas passage opening/closing valve which opens or closes the gas passage part. The gas passage opening/closing valve is configured so as to close the gas passage part such that when the condition in which the liquid amount of the working fluid in the device heat exchanger becomes lower than the specified reference liquid amount is satisfied at the time of warming up the temperature regulation target device, the supply of the gaseous working fluid to the condenser is stopped. 
     According to this, when the liquid amount of the working fluid in the device heat exchanger becomes lower than the specified reference liquid amount at the time of warming up the temperature regulation target device, the gaseous working fluid which is heated and evaporated by the heater is limited from flowing into the side of the condenser. In this way, the liquid amount of the working fluid in the device heat exchanger at the time of warming up the temperature regulation target device can be held at a suitable amount. 
     Further, after the gas passage part  16  is closed by the gas passage opening/closing valve  32 , almost all of the heat amount from the heater  20  is used for warming up the temperature regulation target device, so that an energy efficiency at the time of warming up the temperature regulation target device is improved. 
     According to a ninth aspect, the liquid amount regulator of the device temperature regulator is configured to include the volume regulation part for regulating an internal volume of the device fluid circuit. Then, the volume regulation part is configured so as to increase the internal volume of the device fluid circuit when the condition that requires the temperature regulation target device to be warmed up is satisfied. 
     In this way, if the volume regulation part is configured to increase the internal volume of the device fluid circuit at the time of warming up the temperature regulation target device, the liquid working fluid is stored in a space increased by the volume regulation part and hence the liquid amount of the working fluid in the device heat exchanger can be reduced. 
     According to this, at the time of warming up the temperature regulation target device, the gaseous working fluid evaporated by the heater can be condensed by the heat exchange portion to exchange heat with the temperature regulation target device, so that the heat of the working fluid can be radiated to the temperature regulation target device via the device heat exchanger. 
     Further, according to a tenth aspect, the volume regulation part of the device temperature regulator is configured to include the liquid reservoir of the variable volume type in which the internal volume can be varied. Then, the liquid reservoir is provided on the lower side of the heat exchange portion to exchange heat with the temperature regulation target device in the device heat exchanger in the vertical direction. 
     According to this, the liquid working fluid collecting in the device heat exchanger can easily flow to the liquid reservoir by its own weight, so that the liquid amount of the working fluid in the device heat exchanger can be suitably reduced at the time of the warming up of the temperature regulation target device. 
     Further, according to an eleventh aspect, the liquid reservoir of the device temperature regulator is provided at the lower side of at least one of the gas-side connection part connected to the gas passage part or the liquid-side connection part connected to the liquid-side connection part in the vertical direction, in the device heat exchanger. 
     According to this, the liquid working fluid collecting in the device heat exchanger can easily flow into the liquid reservoir, so that the liquid working fluid can be moved to the tank part from the device heat exchanger at the time of warming up the temperature regulation target device. 
     According to a twelfth aspect, the heater of the device temperature regulator includes the heat radiation part configured to radiate the heat to the working fluid, and the heat radiation part is arranged on the lower side of the liquid reservoir in the vertical direction. According to this, the gaseous working fluid heated and evaporated by the heater can easily flow to the device heat exchanger from the liquid reservoir, so that the heat of the working fluid can be transferred to the temperature regulation target device via the device heat exchanger. 
     According to a thirteenth aspect, the liquid amount regulator of the device temperature regulator is configured to include the liquid reservoir and the cooling device which are provided so as to be branched in the device fluid circuit. The liquid reservoir stores the working fluid collecting in the device fluid circuit. The cooling device is configured to cool the working fluid collecting in the liquid reservoir by the cooling device to thereby increase the liquid storage amount of the liquid working fluid in the liquid reservoir when the condition that requires the temperature regulation target device to be warmed up is satisfied. 
     In this way, if the device temperature regulator is configured so as to cool the liquid reservoir by the cooling device to thereby increase the liquid storage amount of the liquid working fluid in the liquid reservoir at the time of warming up the temperature regulation target device, the liquid working fluid collecting in the device fluid circuit can be reduced. 
     According to this, at the time of warming up the temperature regulation target device, the gaseous working fluid evaporated by the heater can be condensed at the heat exchange portion to exchange heat with the temperature regulation target device, so that the heat of the working fluid can be radiated to the temperature regulation target device via the device heat exchanger. 
     According to a fourteenth aspect, the liquid amount regulator of the device temperature regulator is configured so as to include the liquid shutter which shuts the movement of the working fluid between the liquid reservoir and the device fluid circuit. Then, the liquid shutter is configured so as to shut the movement of the working fluid between the liquid reservoir and the device fluid circuit after the condition that requires the temperature regulation target device to be warmed up is satisfied. 
     According to this, after the liquid working fluid is stored in the liquid reservoir, the movement of the working fluid between the liquid reservoir and the device fluid circuit is shut, so that it is possible to prevent the working fluid in the liquid reservoir from flowing into the device fluid circuit after the liquid working fluid is stored in the liquid reservoir. 
     According to a fifteenth aspect, in the device temperature regulator, the temperature regulation target device is configured of the battery pack mounted on the vehicle. According to this, it is possible to suppress the temperature of the battery pack from being excessively lowered and hence to avoid the input characteristics from being impaired by an increase in the internal resistance which is caused by a suppression of a chemical change in the battery pack. 
     According to a sixteenth aspect, in the device temperature regulator, the working fluid has a characteristic in which the density ratio of the saturated liquid density to the saturated gas density becomes larger as the saturated temperature becomes lower. In a case where the working fluid having such a characteristic is used, the liquid amount in the device fluid circuit becomes smaller under an environmental condition in which the temperature of the temperature regulation target device is decreased. For this reason, at the time of warming up the temperature regulation target device, the volume necessary for storing the liquid working fluid in the device fluid circuit can be reduced. In other words, in a case where the working fluid having the characteristic such that the density ratio of the saturated liquid density to the saturated gas density becomes larger as the saturated temperature becomes lower is used as the working fluid, the device temperature regulator can be reduced in size.