Abstract:
A device for climate control of a vehicle is provided which includes a coolant circuit in which coolant flows through a compressor, a condenser, and an evaporator; a heat transfer medium circuit in which heat transfer medium flows through a heat source and a heat exchanger; and a heat/cold reservoir in which the evaporator and the heat exchanger are located. The device of the present invention provides an improved and comparatively economical approach to climate control in the area of a driver&#39;s bed in a motor vehicle interior by, at least in part, using a heating/cooling surface for a driver&#39;s bed and/or vehicle interior wall, which is integrated into the heat transfer medium circuit such that the heat transfer medium can flow selectively through the heating/cooling surface, or the heat transfer medium which is conveyed by the heat source can flow through the heating/cooling surface.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a device for climate control of a vehicle interior with a coolant circuit, in which coolant flows through a compressor, a condenser, and an evaporator, with a heat transfer medium circuit in which heat transfer medium flows through a heat source and a heat exchanger, and a heat/cold reservoir in which the evaporator and the heat exchanger are located. 
   2. Description of Related Art 
   A device of this type is known from German patent 100 65 279 C1 and corresponding U.S. Patent Application Publication 2002/0100290. In this climate control means, a coolant circuit and a heat transfer medium circuit are coupled in terms of themral engineering using a reservoir which is used to store both heat and cold. In particular, the device has a comparatively simple structure and furthermore has an especially fast response behavior. 
   German patent application 196 45 544 A1 discloses a climate controlled driver&#39;s seat which has at least one combined heating/cooling element which for climate control of the vehicle seat can be connected to the secondary circuit of a heat exchanger which is supplied on the primary side by at least one on-board heat generator, or to the secondary circuit of a heat exchanger which is supplied on the primary side by at least one onboard cold generator. It is furthermore proposed that alternative heating/cooling of the driver&#39;s seat is possible by it being selectively connectable via the heat exchanger to the vehicle heating system or the auxiliary heating system or to the vehicle air conditioning system or auxiliary air conditioning system. 
   SUMMARY OF THE INVENTION 
   One object of the present invention is to make available a device for climate control of the vehicle interior, with which especially an improved, and moreover comparatively economical, approach to climate control in the area of a driver&#39;s bed in the vehicle interior or a vehicle interior wall is possible. 
   This object, and other objects, are achieved by providing a device for climate control of the vehicle interior, in which there is a heating/cooling surface for a driver&#39;s bed and/or vehicle interior wall, i.e., a surface heating system integrated into the heat transfer medium circuit such that the heat transfer medium which is transported by the heat exchanger can flow selectively through it, or the heat transfer medium which is conveyed by the heat source can flow through it. 
   The climate control of a driver&#39;s bed in the vehicle interior or a vehicle interior wall or cab wall has a major effect on the well-being of the driver with respect to his resting during rest breaks. It has therefore long been desired that the vehicle interior or the sleeping berth of motor vehicles be comprehensively temperature-controlled. 
   In the climate control of driver&#39;s bed or the rear wall of the cab, in the past, air was used as the heat transfer medium resulting in the driver&#39;s bed or the rear wall of the cab having to be made technically complex. Temperature control of the driver&#39;s bed or the rear wall of the cab via so-called surface heaters with a manageable technology is more advantageous. 
   Compared to these prior climate control systems, the device of the present invention offers the advantage that a cooling/heating surface through which especially a liquid heat transfer medium flows is used. With a liquid heat transfer medium, large amounts of energy can be transported and therefore it is possible for the driver&#39;s bed to be rapidly heated and cooled to the required amount. The cooling/heating surface of the present invention is moreover integrated into the device such that the cooling/heating surface can transport the same heat transfer medium, one time cooling being possible and then another time, heating. Thus the driver&#39;s bed of the present invention or the interior wall of the vehicle can be cooled as well as heated in an especially simple manner. Therefore, the present invention permits abandonment of a complex technology for switching and rerouting of coolant or heat transfer medium. 
   With the present invention, the same heat transfer medium is transported on the one hand by the heat source in order to directly heat the driver&#39;s bed or the interior wall of the vehicle, and on the other, the same heat transfer medium can be transported by the heat exchanger in the reservoir, in order especially to cool. In addition, the device of the present invention has the advantage that the driver&#39;s bed and/or the vehicle interior wall can also be heated out of the reservoir, specifically in the case in which the reservoir has to be charged beforehand with the thermal energy of the heat source by the heat exchanger. In this way, the driver&#39;s bed of the present invention, or the vehicle interior wall, can be brought to the desired temperature quickly. 
   In one advantageous embodiment of the invention, the heating/cooling surface for the driver&#39;s bed and/or the vehicle interior wall is arranged in a parallel connection to the heat exchanger in the heat transfer medium circuit. The parallel connection enables three basic flow paths which can be cleared individually, or also in combination, in an especially simple manner for flowing heat transfer medium. A first flow path leads from the engine cooling circuit as a heat source through the heat exchanger in the reservoir and back into the engine cooling circuit. A second flow path leads from the engine cooling circuit through the heating/cooling surface and back into the engine cooling circuit. The third flow path leads out of the heat exchanger in the reservoir into the heating/cooling surface and back into the reservoir. Alternatively to a parallel connection, the heat exchanger in the reservoir and the heating/cooling surface in the heat transfer medium circuit can be connected in series. In this series connection, a bypass line and possibly a line with a second heat exchanger are advantageously connected parallel to the heating/cooling surface. 
   In the device of the present invention, a valve is furthermore assigned to the heating/cooling surface and it can remotely control the flow of the heat transfer medium through the heating/cooling surface. With the valve, the flow of heat transfer medium through the heating/cooling surface is controlled and, in this way, the temperature on the driver&#39;s bed or the interior wall of the vehicle is adapted as desired. 
   Several driver&#39;s beds and/or vehicle interior walls can be simultaneously controlled especially easily by an individual device as provided by the present invention by the use of a second heating/cooling surface for a second driver&#39;s bed or a second vehicle interior wall which is located in a parallel connection to the first heating/cooling surface. 
   Two or more heating/cooling surfaces for driver&#39;s beds or vehicle interior walls can be individually controlled with respect to their temperature by each of the two heating/cooling surfaces being assigned its own valve with which the flow through the respective heating/cooling surface can be remotely controlled. 
   For one economical approach to the device of the present invention, alternatively to the parallel connection, a common valve can be assigned to the heating/cooling surfaces, whereby the flow of heat transfer medium through the two heating/cooling surfaces can be remotely controlled. 
   The device of the present invention can moreover be used to heat the air itself in the passenger compartment. This is possible via a second heat exchanger which is integrated into the heat transfer medium circuit and through which air can flow. The second heat transfer medium can be located in the front and/or rear area of the vehicle interior. The temperature in the vehicle interior or the sleeping berth can then be set via the heat transfer medium flow in the second heat exchanger and the air flow through this heat exchanger. In addition, the driver&#39;s bed itself is temperature-controlled by the same heat transfer medium flow, and the temperature of the driver&#39;s bed can be influenced by the amount of heat transfer medium flowing therethrough. 
   At least one heating/cooling surface is advantageously series-connected to the aforementioned second heat exchanger. A bypass line for the heating/cooling surface is formed with an adjustable flow cross section. In this series connection, heat energy is withdrawn in a controlled manner from the heat transfer medium flow first from one of the two means, while already colder heat transfer medium is flowing through the means which is located downstream in the series connection. It is advantageous in this arrangement if at least one heating/cooling surface for heating is located in front of the second heat exchanger in the flow direction from the engine cooling circuit. When flow takes place through the arrangement, the heat transfer medium then heats first the driver&#39;s bed before the remainder of its thermal energy is released to the air in the vehicle interior with the second heat exchanger. The driver&#39;s bed is then heated first. The aforementioned bypass line is used for flow around the heating/cooling surface when it has been blocked by one of the aforementioned valves. When the driver&#39;s bed and the vehicle interior are cooled in turn the focus is on the means through which the heat transfer medium flows first. 
   Alternatively, at least one heating/cooling surface can also be advantageously located in a parallel connection to the second heat exchanger. In the parallel connection, hot or cold heat transfer medium flows simultaneously through the heating/cooling surface and the pertinent second heat exchanger. Accordingly, the aforementioned heating or cooling of the driver&#39;s bed and the air in the vehicle interior takes place therefore uniformly. Both means are therefore operated to the same degree. 
   In addition, advantageously, a circulation pump is integrated into the heat transfer medium circuit such that it conveys the heat transfer medium through the heat exchanger and the heating/cooling surface and especially also through the second heat exchanger. The circulation pump is used to charge the reservoir with thermal energy and, moreover, enables heating and cooling from the reservoir into the heating/cooling surface of the driver&#39;s bed and/or into the second heat exchanger. Besides this circulation pump, using the coolant pump of the internal combustion engine, which is used as a heat source, the liquid heat transfer medium can likewise be conveyed in the heat transfer medium circuit. The coolant pump can likewise convey the heat transfer medium through the heating/cooling surface and/or the heat exchanger, in this case the driver&#39;s bed and the air being heated in the vehicle interior by the exhaust heat of the internal combustion engine. Besides an internal combustion engine, an auxiliary heater with a burner and possibly its own circulation pump, an electrical heater and/or a fuel cell (APU means) can be used as the heat source. 
   In the coolant circuit, a second evaporator is advantageously provided through which preferably air can flow. Using the second evaporator, during operation of the coolant circuit, the air in the motor vehicle interior can be directly cooled. This function is used during operation of the vehicle engine, during which the compressor in the coolant circuit is driven by the engine. The other aforementioned functions in which the reservoir is used, are provided preferably, for auxiliary climate control while the engine of the vehicle is off. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  shows a simplified representation of a first embodiment of a device of the present invention while driving or in auxiliary operation; 
       FIG. 2  shows a simplified representation of a second embodiment of a device of the present invention in auxiliary operation; 
       FIG. 3  shows a simplified representation of a third embodiment of a device of the present invention while driving or in auxiliary operation; 
       FIG. 4  shows a simplified representation of a fourth embodiment of a device as claimed in the invention while driving or in auxiliary operation, 
       FIG. 5  shows a simplified representation of a fifth embodiment of the device of the present invention in auxiliary operation; 
       FIG. 6  shows a simplified representation of a sixth embodiment of the device of the present invention in auxiliary operation; 
       FIG. 7  shows a simplified representation of a seventh embodiment of the device of the present invention while driving or in auxiliary operation; 
       FIG. 8  shows a simplified representation of an eighth embodiment of the device of the present invention while driving or in auxiliary operation; and 
       FIG. 9  is a broken-away view of a truck cab showing the driver&#39;s bed or the interior wall of the driver&#39;s cab. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1  shows a device  10  for climate control of a vehicle interior (not shown), and preferably for the sleeping birth of a truck. The device  10  has a coolant circuit  12  and a heat transfer medium circuit  14  as important components. 
   The coolant circuit  12  is used to cool a coolant and includes a line  18  proceeding from a compressor  16  and leading to a condenser  20  and further to a collector/drier  22 . In the line  18 , there is a branch  24  from which a line  26  leads to a valve  28  and then to an expansion valve  30 . In the flow direction behind the expansion valve  30 , there is an evaporator  32  in a cold/heat reservoir  34 . From the evaporator  32 , a line  36  leads to a check valve  38  and further to a branch  40  at which the line  36  again meets the line  18 . 
   Between the branch  24  and the branch  40 , there is a second line  42  parallel to the evaporator  32 , in which proceeding from the branch  24  there are a valve  44 , an expansion valve  46  and an evaporator  48 . The evaporator  48  is located as a so-called front HVAC in the vehicle interior. Air can be transported through the evaporator  48  and also the condenser  20  by a fan. 
   The coolant circuit enables the following operating modes: during operation of the compressor  16  which is driven by the internal combustion engine of the truck (not shown), heat is removed from the coolant at the condenser  20  and is subsequently conveyed to the branch  24 . At the branch  24 , the coolant can be routed by switching the valves  28  and/or  44  selectively into the evaporator  32  and/or the evaporator  48 . In the evaporators  32  and  48 , heat is supplied to the coolant and thus the vicinity of the evaporators  32  and  48  is cooled. 
   Air flows through the evaporator  48  and is subsequently routed into the motor vehicle interior to directly cool the air in the interior. This direct cooling of the vehicle interior corresponds to the operation of an ordinary air conditioner. 
   The evaporator  32  is located in the reservoir  34  so that this reservoir  34  can be cooled and charged by the coolant flowing through the evaporator  32 . In the reservoir  34 , using the coolant circuit during operation of the compressor  16 , “cold” can be stored. 
   The heat transfer medium circuit  14  is preferably used to heat a liquid heat transfer medium and moreover to cool the driver&#39;s bed and/or the vehicle interior or cab wall  144 . A feed inlet  50  leads into the heat transfer medium circuit  14  and makes available heat transfer medium from an engine cooling circuit (not shown). From the inlet  50 , a line  52  leads to a valve  54  and further to a branch  56 . From branch  56 , a line  58  leads to another branch  60  from which a line  62  leads to a circulation pump  64  and further to a heat exchanger  66 . The heat exchanger  66  is located in the aforementioned cold/heat reservoir  34 . In the flow direction downstream of the heat exchanger  66 , a compensation tank  70  is connected to the line  62  at the branch  68 . A valve  72  is located in the line  62  which leads further to a branch  74 . From the branch  74 , a line  76  leads to another branch  78 . From branch  78 , finally a line  80  leads to an outlet  82  which discharges into the engine cooling circuit. 
   In the engine cooling circuit, on the one hand, there is an internal combustion engine (not shown); its exhaust heat is released to the engine cooling circuit. Furthermore, in the engine cooling circuit, there is an auxiliary heater with a burner and/or an electrical heater. In an embodiment of the device  10  which is not shown, a fuel cell is located in the engine cooling circuit. 
   Between the branch  56  and the branch  78 , a line  88  is formed in which a valve  90  and the heating/cooling surface  92  of a driver&#39;s bed  144  ( FIG. 9 ) are located. Between the branch  60  and the branch  74 , there is a line  84  in which there is a heat exchanger  86 . Air flows through the heat exchanger  86 , which is also called a rear/front heater (HE), by use of a fan, and into the motor vehicle interior. 
   Using the heat transfer medium circuit  14 , the following functions of the device  10  can be made available on the heating/cooling surface  92  of the driver&#39;s bed  144  and the heat exchanger  86 . Both the heating/cooling surface  92  and also the heat exchanger  86  can be directly heated with a hot heat transfer medium which is made available from the engine cooling circuit by a coolant pump or delivery pump in the auxiliary heater which is not shown. For this direct heating, the valve  54  is opened and the valve  88  selectively closed. With the valve  88  in particular, the amount of heat transfer medium delivered by the heating/cooling surface  92  per unit of time can be influenced, by which the temperature of the driver&#39;s bed  144  can be adjusted. For heating/cooling as provided by the invention, a temperature of the driver&#39;s bed 1K to 5K above or below the ambient temperature at a heat output of roughly 30-100 W/m 2 , especially 50-80 W/m 2 , is desirable. To prevent flow through the heat exchanger  66  during direct heating, the valve  72  can be closed. In the engine cooling circuit, the heat transfer medium can be heated with the exhaust heat of the internal combustion engine and/or the auxiliary heater. 
   In addition to direct heating, it is also possible to charge the reservoir  34  with thermal energy from the engine cooling circuit. To do this, with the valve  54  open and the valve  72  open, the heat transfer medium is transported by the circulation pump  64  through the heat exchanger  66 . During charging of the reservoir  34  with thermal energy, moreover, the heat transfer medium can be transported by the heat exchanger  86  to heat the air in the vehicle interior or the heat transfer medium can be routed through the heating/cooling surface  92  to heat the driver&#39;s bed  144 . 
   In addition, with the heat transfer medium circuit  14 , indirect heating can also be enabled by discharging a charged hot reservoir  34  again and by its thermal energy being routed to the heat exchanger  86  and/or the heating/cooling surface  92 . The reservoir  34  is discharged in this way using the circulation pump  64  which, with the valve  72  opened, delivers the heat transfer medium to the heat exchanger  86  and, with the valve  90  opened, also to the heating/cooling surface  92 . Direct and indirect heating can take place at the same time with both the valve  72  and also the valve  54  being opened. 
   Finally, with the heat transfer medium circuit  14 , a charged cold reservoir  34  can also be discharged and its cold can be conveyed to the heat exchanger  86  and/or especially to the heating/cooling surface  92  of the driver&#39;s bed  144 . In these operating modes of indirect cooling, using the circulation pump  64 , the heat transfer medium is conveyed through the cold reservoir  34 . With the valve  72  open, the heat transfer medium travels to the heat exchanger  86  and, with the valve  90  open, also travels to the heating/cooling surface  92 . The cold heat transfer medium can be prevented from flowing into the engine cooling circuit by closing the valves  54  and  102 . Indirect cooling is carried out preferably when the internal combustion engine is off, during which the compressor  16  is not driven. 
   Overall, the following operating modes can be implemented with the coolant circuit  12 : 
   1. only cooling at the evaporator  48  (air conditioner function); 
   2. only charging of the reservoir  34  at the evaporator  32  (charging while driving); 
   3. simultaneous cooling on the evaporator  48  and charging at the evaporator  32 . 
   The following operating modes can be implemented with the heat transfer medium circuit  14 : 
   1. only discharging of the cold reservoir  34  at the heat exchanger  86 ; 
   2. only discharging of the cold reservoir  34  at the heating/cooling surface; 
   3. simultaneous discharging of the cold reservoir  34  at the heat exchanger  86  and at the heating/cooling surface  92 ; 
   4. only charging of the reservoir  34  with the heat exchanger  66 ; 
   5. only heating at the heat exchanger  86 ; 
   6. only heating at the heating/cooling surface  92 ; 
   7. simultaneous charging of the reservoir  34  and heating at the heat exchanger  86  and/or at the heating/cooling surface  92 ; 
   8. only heating at the heat exchanger  86  and/or at the heating/cooling surface  92 . 
   These diverse operating modes of the device  10  can moreover be extensively varied by combining the functions of the coolant circuit  12  with those of the heat transfer medium circuit  14 . In this way, for example, during operation of the compressor  16 , the vehicle interior can be cooled, for example, via the evaporator  48  and, at the same time, via the reservoir  34  and the heat exchanger  86 . Moreover, the heating/cooling surface  92  of the driver&#39;s bed  144  can be cooled from the reservoir  66 . 
   The different heating functions of the heat transfer medium circuit  14  can be further varied by the exhaust heat of the internal combustion engine and the heat output of the auxiliary heater or a heater being used in the engine cooling circuit. 
   The device  10  enables simple, reliable and moreover highly flexible climate control of the heating/cooling surface of a driver&#39;s bed  144 . The heating and cooling of the driver&#39;s bed  144  takes place in combination with the heating and cooling of air in the motor vehicle interior so that overall the level of comfort for the driver of the vehicle is greatly increased. 
     FIG. 2  shows an embodiment of the device  10  in which the heat transfer medium circuit  14  is made slightly differently. Instead of the valve  72  as shown in  FIG. 1 , in the line  84  as shown in  FIG. 2 , a valve  96  is located next to the heat exchanger  86 . Furthermore, in the line  88 , the valve  90  as shown in  FIG. 1  is replaced by the valve  94  on the side of the heating/cooling surface  92 , which is the left one in  FIG. 2 . The two valves  92  and  94  enable dedicated control of the flows of the heat transfer medium through the heat exchanger  86  and the heating/cooling surface  92  such that the aforementioned operating modes can be controlled with especially high temperature control accuracy. 
     FIG. 3  illustrates a device  10  in which, in contrast to the device as shown in  FIG. 2 , a line  98  is connected parallel to the heating/cooling surface  92  wherein there is a second heating/cooling surface  100 . To control the flow of the heat transfer medium through the two heating/cooling surfaces  92  and  100 , a valve  94  is provided downstream of the union of the lines  88  and  98 . 
   Furthermore, in the device as shown in  FIG. 3 , in the line  80 , there is another valve  102  by means of which the heat transfer medium circuit  14  can also be closed at the outlet  82  relative to the engine cooling circuit. 
     FIG. 4  shows a device  10  in which, instead of the joint control of the flow through the two heating/cooling surfaces  92  and  100  using only one valve  94 , there is another valve  106 . While the valve  94  in the line  88  is assigned to the heating/cooling surface  92 , using the valve  106 , the line  98  of the second heating/cooling surface  100  can be closed. In this way the individual flows in the heating/cooling surfaces  92  or  100  can be controlled individually. There is another branch  104  as the discharge of the line  98  into the line  80 . 
     FIGS. 5 and 6  each show a device  10  in which with the heating/cooling surface  92  and the heat exchanger  86 , a series connection is formed within the heat transfer medium circuit  14 . This series connection is made in the line  110  which extends from the branch  56  as shown in  FIG. 1  in the direction to the branch  78  as shown in  FIG. 1 . In the line  110 , there are a heating/cooling surface  92  and furthermore a valve  112  with which the flow through the heating/cooling surface  92  can be controlled. Furthermore, on the branch  114  in the line  52 , a line  116  branches off in which selectively, as shown in  FIG. 5 , a second heating/cooling surface  100  and the pertinent valve  118  may be provided. The two heating/cooling surface  92  and  100  in this way, within the series connection, form a parallel connection. For the heating/cooling surface  92 , there is furthermore as shown in  FIG. 5  and also  FIG. 6 , a bypass line  120  in which the valve or a choke  122  is located. Using the bypass line  120 , the heat transfer medium can be routed around the heating/cooling surface  92  and also the heating/cooling surface  100  when, with the flowing heat transfer medium solely or to an increased degree, the heat exchanger  86  can be controlled. The heat exchanger  86  is located in a line  124  in the flow direction behind the heating/cooling surfaces  92  and  100 . 
   In the series connection shown in  FIGS. 5 and 6 , during heating out of the engine cooling circuit, upstream of the heat exchanger  86 , the heating/cooling surface  92  and  100  can be started with the hot heat exchanger. This leads to an especially rapid heat-up of the heating/cooling surfaces  92  and  100 , especially while driving. When hot or cold is discharged from the reservoir using the circulation pump  64 , conversely first the heat exchanger  86  and subsequently the heating/cooling surfaces  92  and  100  are started with the hot or cold heat transfer medium. Accordingly especially during auxiliary operation of the device  10 , the heat exchanger  86  is operated to an intensified degree. The heating/cooling performance of the heat exchanger  86  can be influenced both by means of the flow of heat transfer medium transported by it and also by means of the amount of air delivered per unit of time by the heat exchanger  86 . 
     FIG. 7  shows a device  10  which is structured essentially like the device as shown in  FIG. 5 . However, as shown in  FIG. 7 , the bypass line  120  is made in a direct continuation of the line  124 . Furthermore, in the bypass line  120 , there is no valve so that the flow of heat transfer medium is conveyed essentially by the heat exchanger  86 . Heating and cooling on the heat exchanger  86  are controlled solely by the corresponding operation of its fan. The heating/cooling surfaces  92  and  100  are connected in parallel to the bypass line  120  analogously to  FIG. 5 . 
   Finally,  FIG. 8  shows the device  10  in which, in the line  52  of heat transfer medium circuit  14 , a branch  126  is formed from which a line  128  leads continuously to a branch  130  which is located in the line  80  at the outlet  82 . In the device  10  as shown in  FIG. 8 , furthermore in the flow direction downstream of the branch  126  proceeding from the triple junction  136 , a parallel connection is formed from the line  134 , the line  136  and the line  138 . In the line  138 , there are a valve  140  and the heating/cooling surface  92 . The line  136  extends continuously from the branch  132  to a branch  142  at which the three lines  134 ,  136  and  138  come together. 
   The parallel connection of the three lines  134 ,  136 ,  138  selectively enables flow through the heat exchanger  86 , direct diversion to the reservoir  34  and/or flow through the heating/cooling surface  92 . Moreover, the line  128  can deliver the heat transfer medium directly back into the engine cooling circuit without it flowing further through the heat transfer medium circuit  14 . In this way, the engine cooling circuit can be heated up especially quickly after the starting of the internal combustion engine.