Patent Publication Number: US-2023158859-A1

Title: Vehicle air conditioner

Description:
TECHNICAL FIELD 
     This disclosure relates to an air conditioner for a vehicle that can adjust the temperature of a seat provided in a vehicle interior. 
     BACKGROUND ART 
     Systems that can adjust the temperature of a seat in addition to that of an interior of a vehicle have been proposed. 
     For example, in Patent Literature 1, brine is cooled in a brine-refrigerant heat exchanger using evaporation latent heat of a combustible gas. In Patent Literature 1, this low-temperature brine is circulated through a heat exchanger for cooling including a seat installed in a vehicle interior to thereby enhance the comfort of the vehicle interior. Brine refers to water to which a component for lowering the freezing temperature has been added. 
     In Patent Literature 2, air of which the temperature has been adjusted is sent to an air chamber inside a seat through a seat air duct and a wind is blown out of a breathable seat to thereby enhance the comfort of an occupant sitting on the seat. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: JP 4677960 B2 
     Patent Literature 2: JP 6558490 B2 
     SUMMARY OF INVENTION 
     Technical Problem 
     In the proposal of Patent Literature 1, due to the structure in which only a low-temperature brine circuit is connected to an interior heat exchanger, heating of a seat demanded in winter or in cold regions cannot be provided. 
     In the proposal of Patent Literature 2, due to a lack of the amount of accumulated heat of air of which the temperature is adjusted, comfort is immediately lost when getting into or out of the vehicle or when the device is stopped. 
     In view of the above, this disclosure aims to provide a vehicle air conditioner that, in addition to being able to cool and heat a seat, can easily maintain comfort when getting into or out of the vehicle or when the air conditioning device is stopped. 
     Solution to Problem 
     A vehicle air conditioner according to this disclosure includes: a refrigeration cycle in which a refrigerant circulates; a high-temperature cycle in which a first heat medium in liquid form heated by the refrigeration cycle circulates; a low-temperature cycle in which a second heat medium in liquid form cooled by the refrigeration cycle circulates; and a seat that is provided in a vehicle interior and has a warm flow passage and a cold flow passage disposed close to each other. 
     In the vehicle air conditioner according to this disclosure, the warm flow passage is provided on the route of the high-temperature cycle, and the cold flow passage is provided on the route of the low-temperature cycle. 
     Advantageous Effects of Invention 
     According to the vehicle air conditioner of this disclosure, the warm flow passage and the cold flow passage are disposed close to each other in the seat. The seat can be cooled and heated by adjusting the amounts of the first heat medium and the second heat medium flowing through the warm flow passage and the cold flow passage, respectively. Since the first heat medium and the second heat medium supplied to the warm flow passage and the cold flow passage, respectively, of the seat are in liquid form, comfort can be easily maintained when getting into or out of the vehicle or when the device is stopped. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1    is a circuit diagram showing the configuration of a vehicle air conditioner according to an embodiment of this disclosure. 
         FIG.  2    is a circuit diagram when the vehicle air conditioner of  FIG.  1   , with a seat temperature adjustment function added thereto, is performing heating operation. 
         FIG.  3    is a circuit diagram when the vehicle air conditioner of  FIG.  1   , with the seat temperature adjustment function added thereto, is performing dehumidifying and heating operation. 
         FIG.  4    is a circuit diagram when the vehicle air conditioner of  FIG.  1   , with the seat temperature adjustment function added thereto, is performing cooling operation. 
         FIG.  5    is a view showing passages of cold water and warm water in a seat having the temperature adjustment function of  FIG.  2    to  FIG.  4   . 
         FIG.  6    is a circuit diagram of the vehicle air conditioner of  FIG.  1    that includes a function of adjusting the temperatures of a plurality of seats. 
         FIG.  7    is a circuit diagram when the vehicle air conditioner of  FIG.  6    is performing heating operation. 
         FIG.  8    is a circuit diagram when the vehicle air conditioner of  FIG.  6    is performing dehumidifying and heating operation. 
         FIG.  9    is a circuit diagram when the vehicle air conditioner of  FIG.  6    is performing cooling operation. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     A vehicle air conditioner  1  according to an embodiment will be described below with reference to the drawings. 
     The vehicle air conditioner  1  includes a refrigeration cycle  10  constituting a primary loop, and a high-temperature cycle HS and a low-temperature cycle CS that have flow passages independent from the refrigeration cycle  10  and constitute a secondary loop. Thus, comfort can be easily maintained when getting into or out of the vehicle or when the device is stopped, as well as a seat can be cooled and heated. In addition to being used to warm and cool a vehicle interior IN, the vehicle air conditioner  1  is used to heat and cool a seat provided in the vehicle interior IN. In the refrigeration cycle  10 , a refrigerant R circulates. In the high-temperature cycle HS and the low-temperature cycle CS, a first heat medium HW and a second heat medium CW that are each in liquid form circulate. 
     [Overall Configuration] 
     As shown in  FIG.  1   , the vehicle air conditioner  1  includes the refrigeration cycle  10 , a temperature adjustment mechanism  30  that is formed by a heating ventilation and air conditioning unit (HVAC unit) as one example and warms or cools the vehicle interior based on the refrigerant R having been cooled or heated in the refrigeration cycle  10 , and a heat radiation unit  50  that radiates heat of the first heat medium HW to an atmosphere. In the vehicle air conditioner  1 , the high-temperature cycle HS and the low-temperature cycle CS are formed as the refrigeration cycle  10 , the temperature adjustment mechanism  30 , and the heat radiation unit  50  are connected to one another through piping. The first heat medium HW flowing in the high-temperature cycle HS and the second heat medium CW flowing in the low-temperature cycle CS are supplied to a seat  60  provided in the vehicle interior IN. 
     [Refrigeration Cycle  10 ] 
     By having the circulating refrigerant R undergo compression, decompression, etc., the refrigeration cycle  10  absorbs heat from the second heat medium CW circulating in the low-temperature cycle CS and radiates the heat to the first heat medium HW circulating in the high-temperature cycle HS. 
     As shown in  FIG.  1   , the refrigeration cycle  10  includes a compressor  11 , a condenser  13 , a decompression unit  15 , and an evaporator  17 . The condenser  13  and the evaporator  17  are connected to each other by a refrigerant flow passage L 1  and a refrigerant flow passage L 2 . The compressor  11  is provided in the refrigerant flow passage L 1 , and the decompression unit  15  is provided in the refrigerant flow passage L 2 . The refrigeration cycle  10  is provided in a vehicle exterior OUT of the vehicle. 
     As one example, an electrically operated compressor  11  is adopted as the compressor  11 . 
     The compressor  11  suctions and compresses a low-temperature, low-pressure refrigerant R released from the evaporator  17 , and discharges it toward the condenser  13  as a high-temperature, high-pressure refrigerant R in gas form. 
     The condenser  13  condenses the high-temperature, high-pressure refrigerant R in gas form into a high-temperature, high-pressure refrigerant R in liquid form. The condenser  13  is a heat exchanger for heating, and heats the second heat medium CW flowing through a high-temperature-side heat exchanger  23  constituting a part of the high-temperature cycle HS by the heat of the high-temperature, high-pressure refrigerant R. Thus, the condenser  13  is a water-refrigerant heat exchanger that realizes heat exchange between the refrigeration cycle  10  and the high-temperature cycle HS. 
     The decompression unit  15  decompresses and expands the high-temperature, high-pressure refrigerant R in liquid form coming out of the condenser  13  and discharges it toward the evaporator  17 . 
     The evaporator  17  evaporates the refrigerant R having been decompressed by the decompression unit  15  into a low-temperature, low-pressure refrigerant R in gas form. The evaporator  17  is a heat exchanger for cooling, and cools the second heat medium CW flowing through a low-temperature-side heat exchanger  21  constituting a part of the low-temperature cycle CS by evaporating the refrigerant R. Thus, as with the condenser  13 , the evaporator  17  is a water-refrigerant heat exchanger that realizes heat exchange between the refrigeration cycle  10  and the low-temperature cycle CS. 
     [Temperature Adjustment Mechanism  30  (Vehicle Interior IN)] 
     Next, the temperature adjustment mechanism  30  will be described. 
     As shown in  FIG.  1   , the temperature adjustment mechanism  30  includes a blower  31  that pressure-feeds, toward a downstream side, air (inside air or outside air) introduced by switching inside air from the vehicle interior or outside air through an inside-outside air switching damper (not shown). The temperature adjustment mechanism  30  also includes a cooler  33  that continues to the blower  31  and is provided in an air flow passage  39  inside a duct  38 , a heater  35  that is provided farther on the downstream side than the cooler  33 , and a temperature adjustment damper  37  that is provided between the cooler  33  and the heater  35 . 
     The temperature adjustment mechanism  30  is installed, for example, inside an instrument panel at a front part of the vehicle interior IN, and blows out, to the vehicle interior IN, the air of which the temperature has been adjusted by the cooler  33  and the heater  35  according to one of blow-out modes of defrosting blow-out, face blow-out, and foot blow-out, to adjust the vehicle interior to a set temperature, an opening in each of the defrosting blow-out, the face blow-out, and the foot blow-out being directed toward the vehicle interior. 
     [Heat Radiation Unit  50  (Vehicle Exterior OUT)] 
     Next, the heat radiation unit  50  radiates the heat of the second heat medium CW flowing through the low-temperature-side heat exchanger  21  to the outside air. The heat radiation unit  50  includes a radiator  51  provided on an upstream side, and a fan  53  provided on the downstream side of the radiator  51 . 
     In the fan  53 , a motor is driven to rotate to generate an airflow, and this airflow passes through the radiator  51 , thereby promoting heat exchange in the radiator  51 . Thus, in the radiator  51 , heat is exchanged between the outside air and the second heat medium CW flowing through the inside, and the heat is radiated to the outside air. 
     [High-Temperature Cycle HS] 
     The vehicle air conditioner  1  includes the high-temperature cycle HS having, as an element, the high-temperature-side heat exchanger  23  that exchanges heat with the condenser  13  through which the high-temperature, high-pressure refrigerant R flows. The high-temperature cycle HS adjusts the temperature of the vehicle interior using the first heat medium HW having been heated in the high-temperature-side heat exchanger  23 , and also adjusts the temperature of the seat  60  in the vehicle interior. 
     The high-temperature cycle HS includes the heater  35  of the temperature adjustment mechanism  30  as an element, and further includes the following elements. 
     First, the high-temperature cycle HS includes, as flow passages for the first heat medium HW, a high-temperature flow passage HL 1  that connects the high-temperature-side heat exchanger  23  and the heater  35  to each other, and a high-temperature flow passage HL 2  that is connected to the heater  35  on the opposite side from the high-temperature flow passage HL 1 . In the high-temperature flow passage HL 1 , a high-temperature-side pump  34  and a three-way valve  36  are provided in this order from the side of the high-temperature-side heat exchanger  23 . The high-temperature-side pump  34  delivers the first heat medium HW having passed through the high-temperature-side heat exchanger  23  toward the heater  35 . The three-way valve  36  controls the direction of the first heat medium HW flowing through the high-temperature flow passage HL 1 . 
     The high-temperature cycle HS includes a high-temperature flow passage HL 4  that is connected at one end to a connection point P 4  and connected at the other end to a three-way valve  24  that is an element of the low-temperature cycle CS, and a high-temperature flow passage HL 5  that is connected at one end to the three-way valve  36  and connected at the other end to a four-way valve  25  that is an element of the low-temperature cycle CS. 
     The three-way valve  24  includes three flow passages, a flow passage  24 A, a flow passage  24 B, and a flow passage  24 C, each of which opening and closing is independently controlled. The same applies to the other three-way valves  32 ,  36 . 
     The four-way valve  25  includes four flow passages, a flow passage  25 A, a flow passage  25 B, a flow passage  25 C, and a flow passage  25 D, each of which opening and closing is independently controlled. The same applies to the other four-way valve  41 . 
     [Low-Temperature Cycle CS] 
     The vehicle air conditioner  1  includes the low-temperature cycle CS having, as an element, the low-temperature-side heat exchanger  21  that exchanges heat with the evaporator  17  through which the low-temperature, low-pressure refrigerant R flows. The low-temperature cycle CS adjusts the temperature of the vehicle interior using the second heat medium CW having been cooled by the low-temperature-side heat exchanger  21 , and also adjusts the temperature of the seat in the vehicle interior. 
     The low-temperature cycle CS includes the radiator  51  of the heat radiation unit  50  as an element, and further includes the following elements. 
     First, the low-temperature cycle CS includes, as flow passages for the second heat medium CW, a low-temperature flow passage CL 1  that connects the radiator  51  and the low-temperature-side heat exchanger  21  to each other, and a low-temperature flow passage CL 2  that is connected at one end to the low-temperature-side heat exchanger  21  on the opposite side from the low-temperature flow passage CL 1  and connected at the other end to the radiator  51 . In the low-temperature flow passage CL 1 , the four-way valve  25  and a low-temperature-side pump  27  are provided in this order from the side of the radiator  51 . The three-way valve  24  is provided in the low-temperature flow passage CL 2 . Further, the low-temperature cycle CS includes a low-temperature flow passage CL 3  that is connected at one end to the low-temperature flow passage CL 2  at a connection point P 1  and connected at the other end to the cooler  33 , and a low-temperature flow passage CL 5  that is connected at one end to the cooler  33  and connected at the other end to the four-way valve  25 . 
     The first heat medium HW and the second heat medium CW consisting of the same components circulate in the high-temperature cycle HS and the low-temperature cycle CS, respectively. This heat medium does not change in phase within service pressure and temperature ranges. For example, brine, i.e., water containing an antifreeze liquid can be used. In the high-temperature cycle HS (warm flow passage  61 ) and the low-temperature cycle CS (cold flow passage  63 ), the first heat medium HW and the second heat medium CW flow through flow passages that are separate and independent from each other. 
     The high-temperature cycle HS includes, in its configuration, the high-temperature-side pump  34  and the heater  35 . The high-temperature-side pump  34  circulates the first heat medium HW inside the high-temperature cycle HS. A water delivery direction of the high-temperature-side pump  34  is controlled such that the refrigerant R flowing through the condenser  13  and the first heat medium HW flowing through the high-temperature-side heat exchanger  23  form opposing flows. 
     The high-temperature-side pump  34  makes the first heat medium HW having passed through the high-temperature-side heat exchanger  23  flow into the heater  35 . While passing through the high-temperature-side heat exchanger  23 , the first heat medium HW is heated by the high-temperature, high-pressure refrigerant R flowing through the condenser  13 . Thus, the high-temperature first heat medium HW flows into the heater  35 . 
     The low-temperature cycle CS includes, in its configuration, the radiator  51  and the low-temperature-side pump  27 . The low-temperature-side pump  27  circulates the second heat medium CW inside the low-temperature cycle CS. A water delivery direction of the low-temperature-side pump  27  is controlled such that the refrigerant R flowing through the evaporator  17  and the second heat medium CW flowing through the low-temperature-side heat exchanger  21  form opposing flows. 
     The low-temperature-side pump  27  makes the second heat medium CW having passed through the low-temperature-side heat exchanger  21  flow into the radiator  51 . While passing through the low-temperature-side heat exchanger  21 , the second heat medium CW is cooled by the low-temperature, low-pressure refrigerant R flowing through the evaporator  17 . 
     [Seat Temperature Adjustment Function] 
     In this embodiment, an example of adjusting the temperature of the seat  60  provided in the vehicle interior using the vehicle air conditioner  1  shown in  FIG.  1    will be described with reference to  FIG.  2    to  FIG.  5   . 
     First, a configuration different from  FIG.  1    of the vehicle air conditioner  1  having a function of adjusting the temperature of the seat  60  will be described with reference to  FIG.  2   . A three-way valve  32  is provided instead of the flow adjustment valve  29 , and a four-way valve  41  is provided instead of the three-way valve  36 . The connection point P 4  and the four-way valve  41  are connected to each other by a high-temperature flow passage HL 6 . The three-way valve  32  and the connection point P 4  are connected to each other by the low-temperature flow passage CL 4 . 
     As shown in  FIG.  2   , the seat  60  is provided in the vehicle interior, and a warm flow passage  61  and a cold flow passage  63  are provided alongside each other inside the seat  60 . To facilitate understanding, only one seat is extracted and described here. This circuit is the same in  FIG.  3    and  FIG.  4   . The warm flow passage  61  is provided on the route of the high-temperature flow passage HL 6 , and the cold flow passage  63  is provided on the route of the low-temperature flow passage CL 4 . A direction in which the first heat medium HW flows in the warm flow passage  61  and a direction in which the second heat medium CW flows in the cold flow passage  63  are opposite from each other. 
     [Heating Operation] 
     Flows of the refrigerant R, the first heat medium HW, and the second heat medium CW when the vehicle air conditioner  1  performs heating operation will be described with reference to  FIG.  2   . 
     In heating operation of the vehicle air conditioner  1 , the first heat medium HW having been heated by the high-temperature-side heat exchanger  23  is circulated through the high-temperature flow passage HL 1  and the high-temperature flow passage HL 2  to continuously supply the first heat medium HW to the heater  35  and heat the vehicle interior. Since the second heat medium CW is not flowing through the cooler  33 , air pressure-fed by the blower  31  reaches the heater  35  without being cooled by the cooler  33 . 
     In  FIG.  2   , flow passages in which the first heat medium HW and the second heat medium CW flow are depicted thick. The same applies to  FIG.  3    and the subsequent drawings. 
     In addition to the above, in heating operation of the vehicle air conditioner  1 , the temperature of the seat  60  is adjusted as follows. 
     The first heat medium HW having been heated by the high-temperature-side heat exchanger  23  is circulated through the high-temperature flow passage HL 1 , the high-temperature flow passage HL 2 , and the high-temperature flow passage HL 6  to continuously supply the heated first heat medium HW to the warm flow passage  61 . The second heat medium CW having been cooled by the low-temperature-side heat exchanger  21  is circulated through the low-temperature flow passage CL 3 , the low-temperature flow passage CL 4 , the low-temperature flow passage CL 5 , and parts of the low-temperature flow passage CL 1  and the low-temperature flow passage CL 2  to continuously supply the cooled second heat medium CW to the cold flow passage  63 . The vehicle air conditioner  1  adjusts the temperature of the seat  60  by exchanging heat between the warm flow passage  61  and the cold flow passage  63 . 
     During heating operation, the first heat medium HW having passed through the heater  35  flows to the high-temperature-side heat exchanger  23  through the high-temperature flow passage HL 2 . 
     During heating operation, the second heat medium CW having passed through the low-temperature-side heat exchanger  21  flows so as to branch into the low-temperature flow passage CL 2  and the low-temperature flow passage CL 3 , and the second heat medium CW flowing through the low-temperature flow passage CL 2  reaches the radiator  51  and the second heat medium CW flowing through the low-temperature flow passage CL 3  reaches the cold flow passage  63 . The second heat medium CW having passed through the cold flow passage  63  flows into the low-temperature flow passage CL 1  through the four-way valve  25  and reaches the low-temperature-side heat exchanger  21 . 
     Open and closed states of the flow passages of the three-way valve  24 , the four-way valve  25 , the three-way valve  32 , and the four-way valve  41  during heating operation are as follows. In  FIG.  2   , closed flow passages of these valves are blacked out. The same applies to  FIG.  3   ,  FIG.  4   , etc. 
     Three-way valve  24  flow passage  24 A: open, flow passage  24 B: open, flow passage  24 C: closed 
     Four-way valve  25  flow passage  25 A: open, flow passage  25 B: open, flow passage  25 C: open, flow passage  25 D: closed 
     Three-way valve  32  flow passage  32 A: open, flow passage  32 B: open, flow passage  32 C: closed 
     Four-way valve  41  flow passage  41 A: open, flow passage  41 B: open, flow passage  41 C: open, flow passage  41 D: closed 
     [Dehumidifying and Heating] 
     Next, flows of the refrigerant R, the first heat medium HW, and the second heat medium CW when the vehicle air conditioner  1  performs dehumidifying and heating operation will be described with reference to  FIG.  3   . As dehumidifying and heating operation has some parts in common with heating operation having been described with reference to  FIG.  2   , in the following, dehumidifying and heating operation will be described in terms of differences from heating operation. 
     As shown in  FIG.  3   , in dehumidifying and heating operation, the flow passages in three directions of the three-way valve  32  are open. The second heat medium CW flows toward the cooler  33 , and the second heat medium CW having passed through the cooler  33  reaches the four-way valve  25  through the low-temperature flow passage CL 5  and flows into the low-temperature-side heat exchanger  21 . Thus, heating operation and dehumidifying and heating operation can be switched by controlling opening and closing of the flow passages of the three-way valve  32 . 
     As for temperature adjustment of the seat  60 , a difference lies in that, in heating operation, the whole second heat medium CW is supplied to the cold flow passage  63 , whereas in dehumidifying and heating, part of the second heat medium CW is used for dehumidification. 
     Open and closed states of the flow passages of the three-way valve  24 , the four-way valve  25 , the three-way valve  32 , and the four-way valve  41  during dehumidifying and heating operation are as follows. The difference from heating operation shown in  FIG.  2    is opening and closing of the flow passage  32 C of the three-way valve  32 . 
     Three-way valve  24  flow passage  24 A: open, flow passage  24 B: open, flow passage  24 C: closed 
     Four-way valve  25  flow passage  25 A: open, flow passage  25 B: open, flow passage  25 C: open, flow passage  25 D: closed 
     Three-way valve  32  flow passage  32 A: open, flow passage  32 B: open, flow passage  32 C: open 
     Four-way valve  41  flow passage  41 A: open, flow passage  41 B: open, flow passage  41 C: open, flow passage  41 D: closed 
     [Cooling Operation] 
     Next, flows of the refrigerant R, the first heat medium HW, and the second heat medium CW when the vehicle air conditioner  1  performs cooling operation will be described with reference to  FIG.  4   . As cooling operation has some parts in common with dehumidifying and heating operation having been described with reference to  FIG.  3   , in the following, cooling operation will be described in terms of differences from dehumidifying and heating operation. 
     In cooling operation, part of the first heat medium HW having been heated by the high-temperature-side heat exchanger  23  flows into the high-temperature flow passage HL 5  through the four-way valve  41 , and is further supplied to the radiator  51  through the four-way valve  25 . The first heat medium HW having passed through the radiator  51  passes through the three-way valve  24  and flows through the high-temperature flow passage HL 4  to reach the high-temperature-side heat exchanger  23 . 
     As has been described above, in cooling operation, a circulation passage including the low-temperature-side heat exchanger  21  and the cooler  33  is formed for the cooled second heat medium CW. As this circulation passage is formed, cooling operation is realized. For the heated first heat medium HW, a circulation passage including the high-temperature-side heat exchanger  23  of the refrigeration cycle  10  and the warm flow passage  61  of the seat  60 , and a circulation passage including the high-temperature-side heat exchanger  23  of the refrigeration cycle  10  and the radiator  51  of the heat radiation unit  50  are formed. 
     Open and closed states of the flow passages of the three-way valve  24 , the four-way valve  25 , the three-way valve  32 , and the four-way valve  41  during cooling operation are as follows: 
     Three-way valve  24  flow passage  24 A: open, flow passage  24 B: closed, flow passage  24 C: open 
     Four-way valve  25  flow passage  25 A: open, flow passage  25 B: open, flow passage  25 C: open, flow passage  25 D: open 
     Three-way valve  32  flow passage  32 A: open, flow passage  32 B: open, flow passage  32 C: open 
     Four-way valve  41  flow passage  41 A: open, flow passage  41 B: closed, flow passage  41 C: open, flow passage  41 D: open 
     [Flow Passages in Seat  60 ] 
     Next, an example of arrangement of the warm flow passage  61  and the cold flow passage  63  in the seat  60  will be described with reference to  FIG.  5   . The warm flow passage  61  and the cold flow passage  63  in this example are formed by flexible pipe members and are provided close to each other. Being close in this disclosure means that the warm flow passage  61  and the cold flow passage  63  may be in contact with each other or the warm flow passage  61  and the cold flow passage  63  may be spaced a little apart from each other. 
     The seat  60  includes a seating face  60   a , a back support  60   b  rising from the seating face  60   a , and a headrest  60   c  mounted at an upper part of the back support  60   b.    
     As shown in  FIG.  5   , the warm flow passage  61  has an introduction port  61   a  for the heated first heat medium HW and a discharge port  61   b  for the heated first heat medium HW, both provided in the seating face  60   a . For the introduction port  61   a , a pipe  61   c  is provided between the introduction port  61   a  and the discharge port  61   b , and the first heat medium HW supplied from the introduction port  61   a  passes through the pipe  61   c  and is discharged from the discharge port  61   b . The pipe  61   c  is provided so as to meander in the seating face  60   a  and the back support  60   b  in this order, and turns back at an upper part of the back support  60   b  toward a lower side as indicated by the arrow. Then, it meanders in the back support  60   b  and the seating face  60   a  in this order and leads to the discharge port  61   b  in the seating face  60   a.    
     As shown in  FIG.  5   , the cold flow passage  63  has an introduction port  63   a  for the cooled second heat medium CW and a discharge port  63   b  for the cooled second heat medium CW, both provided in the seating face  60   a . For the introduction port  63   a , a pipe  63   c  is provided between the introduction port  63   a  and the discharge port  63   b , and the second heat medium CW supplied from the introduction port  63   a  passes through the pipe  63   c  and is discharged from the discharge port  63   b . The pipe  63   c  is provided so as to meander in the seating face  60   a  and the back support  60   b  in this order, and turns back at an upper part of the back support  60   b  toward the lower side as indicated by the arrow. Then, it meanders in the back support  60   b  and the seating face  60   a  in this order and leads to the discharge port  63   b  in the seating face  60   a.    
     The pipe  61   c  of the warm flow passage  61  and the pipe  63   c  of the cold flow passage  63  are provided adjacent to each other while meandering in the seating face  60   a  and the back support  60   b . Thus, the warm flow passage  61  and the cold flow passage  63  can cool and heat the seat  60  while exchanging heat with each other by adjusting the amounts of the first heat medium HW and the second heat medium CW flowing through the warm flow passage  61  and the cold flow passage  63 , respectively. 
     Effects of First Embodiment 
     Next, the effects of the vehicle air conditioner  1  will be described. 
     [Effect 1] 
     According to the vehicle air conditioner  1  of this disclosure, the warm flow passage  61  and the cold flow passage  63  are disposed close to each other in the seat  60 . The seat  60  can be cooled and heated by adjusting the amounts of the first heat medium HW and the second heat medium CW flowing through the warm flow passage  61  and the cold flow passage  63 , respectively. 
     [Effect 2] 
     According to the vehicle air conditioner  1  of this disclosure, the first heat medium HW and the second heat medium CW supplied to the warm flow passage  61  and the cold flow passage  63 , respectively, of the seat  60  are in liquid form. Since liquids are used as the heat media, the heat accumulation property is high compared with that of air, and comfort can be maintained also when getting into or out of the vehicle or when the device is stopped. 
     [Effect 3] 
     Further, according to the vehicle air conditioner  1  of this disclosure, the warm flow passage  61  and the cold flow passage  63  are separate and independent from each other. 
     Thus, according to the first embodiment, the first heat medium HW and the second heat medium CW are not mixed, which can eliminate the need for a capacity required for mixing. 
     In addition, the roles of the first heat medium HW and the second heat medium CW can be maintained, so that heat management for other on-board devices can be performed. 
     Second Embodiment 
     [Temperature Adjustment of a Plurality of Seats] 
     Next, a second embodiment will be described with reference to  FIG.  6    to  FIG.  9   . The second embodiment proposes a vehicle air conditioner  2  that can separately adjust the temperature of each of a plurality of, specifically, four seats  60  ( 60 A,  60 B,  60 C,  60 D). 
     [Circuit Configuration] 
     First, the circuit configuration of the vehicle air conditioner  2  will be described with reference to  FIG.  6   . As the vehicle air conditioner  2  shares the same circuit configuration with the vehicle air conditioner  1 , in the following, the vehicle air conditioner  2  will be described mainly in terms of differences from the vehicle air conditioner  1 . In  FIG.  6    to  FIG.  9   , the same parts and members as in the vehicle air conditioner  1  are denoted by the same reference signs as those in  FIG.  1   . 
     [High-Temperature Cycle HS] 
     The vehicle air conditioner  2  has the high-temperature cycle HS in which the high-temperature flow passage HL 6  branches into four first branch flow passages HL 6 A, HL 6 B, HL 6 C, and HL 6 D. The high-temperature flow passage HL 6  includes a first total amount valve  43  that adjusts the magnitude of the amount of first heat medium HW flowing into the first branch flow passages HL 6 A, HL 6 B, HL 6 C, and HL 6 D, and this first total amount valve  43  is provided between the four-way valve  41  and a portion where the high-temperature flow passage HL 6  branches. With reference to the flow direction of the first heat medium HW, the first total amount valve  43  is provided farther upstream than the portion where the high-temperature flow passage HL 6  branches. Upstream and downstream in the high-temperature flow passage HL 6  are based on this reference. 
     In the first branch flow passages HL 6 A, HL 6 B, HL 6 C, and HL 6 D, first separate valves  65 A,  65 B,  65 C,  65 D are provided on the upstream side of the seats  60 A,  60 B,  60 C,  60 D, respectively. The first separate valves  65 A,  65 B,  65 C,  65 D adjust the magnitudes of the amounts of first heat medium HW flowing into the warm flow passages  61 A,  61 B,  61 C,  61 D, respectively, that are provided in the seats  60 A,  60 B,  60 C,  60 D. Thus, the vehicle air conditioner  2  can separately adjust the amounts of first heat medium HW flowing through the warm flow passages  61 A,  61 B,  61 C,  61 D. 
     [Low-Temperature Cycle CS] 
     The vehicle air conditioner  2  has the low-temperature cycle CS in which the low-temperature flow passage CL 4  branches into four second branch flow passages CL 4 A, CL 4 B, CL 4 C, and CL 4 D. The low-temperature flow passage CL 4  includes a second total amount valve  45  that adjusts the magnitude of the amount of second heat medium CW flowing into the second branch flow passages CL 4 A, CL 4 B, CL 4 C, and CL 4 D. The second total amount valve  45  is provided between the four-way valve  41  and a portion where the low-temperature flow passage CL 4  branches. With reference to the flow direction of the second heat medium CW, the second total amount valve  45  is provided farther upstream than the portion where the low-temperature flow passage CL 4  branches. Upstream and downstream in the low-temperature flow passage CL 4  are based on this reference. 
     In the second branch flow passages CL 4 A, CL 4 B, CL 4 C, and CL 4 D, second separate valves  67 A,  67 B,  67 C,  67 D are provided on the upstream side of the seats  60 A,  60 B,  60 C,  60 D, respectively. The second separate valves  67 A,  67 B,  67 C,  67 D adjust the magnitudes of the amounts of second heat medium CW flowing into the cold flow passages  63 A,  63 B,  63 C,  63 D, respectively, that are provided in the seats  60 A,  60 B,  60 C,  60 D. Thus, the vehicle air conditioner  2  can separately adjust the amounts of second heat medium CW flowing through the cold flow passages  63 A,  63 B,  63 C,  63 D. 
     [Heating, Dehumidifying and Heating, and Cooling Operations] 
     Next, heating operation, dehumidifying and heating, and cooling operation in the vehicle air conditioner  2  will be described with reference to  FIG.  7    to  FIG.  9   . Also these operations will be described mainly in terms of differences from the vehicle air conditioner  1 . 
     As with the vehicle air conditioner  1 , the vehicle air conditioner  2  can perform heating operation ( FIG.  7   ), dehumidifying and heating operation ( FIG.  8   ), and cooling operation ( FIG.  9   ) by activating the refrigeration cycle  10 . The temperatures of the seats  60 A,  60 B,  60 C,  60 D are adjusted as the first heat medium HW and the second heat medium CW flow in the high-temperature cycle HS and the low-temperature cycle CS in each operation as will be described below. 
     [High-Temperature Cycle HS] 
     In heating operation, the flow passage  41 A and the flow passage  41 C of the four-way valve  41  are open, so that the first heat medium HW passes through the first total amount valve  43  and flows to the warm flow passages  61 A,  61 B,  61 C,  61 D. Here, the amount of first heat medium HW flowing to the warm flow passages  61 A,  61 B,  61 C,  61 D as a whole is adjusted by the first total amount valve  43 . The amount of the first heat medium HW flowing to each of the warm flow passages  61 A,  61 B,  61 C,  61 D is also adjusted. 
     [Low-Temperature Cycle CS] 
     In heating operation, the flow passage  32 A and the flow passage  32 B of the three-way valve  32  are open, so that the second heat medium CW flows to the cold flow passages  63 A,  63 B,  63 C,  63 D through the second total amount valve  45 . Here, the amount of second heat medium CW flowing to the cold flow passages  63 A,  63 B,  63 C,  63 D as a whole is adjusted by the second total amount valve  45 . The amount of first heat medium HW flowing to each of the cold flow passages  63 A,  63 B,  63 C,  63 D is also adjusted. 
     As has been described above, the vehicle air conditioner  2  can adjust the temperatures of the seats  60 A,  60 B,  60 C,  60 D by adjusting the amounts of second heat medium CW flowing to the warm flow passages  61 A,  61 B,  61 C,  61 D and the cold flow passages  63 A,  63 B,  63 C,  63 D while performing heating operation, dehumidifying and heating, or cooling operation by the temperature adjustment mechanism  30 . In particular, the vehicle air conditioner  2  can adjust the amount of second heat medium CW flowing through each of the warm flow passages  61 A,  61 B,  61 C,  61 D and the cold flow passages  63 A,  63 B,  63 C,  63 D. 
     Effects of Second Embodiment 
     The vehicle air conditioner  2  according to the second embodiment achieves the following Effect 5 and Effect 6 in addition to Effect 1 to Effect 4 of the vehicle air conditioner  1 . 
     [Effect 5] 
     According to the vehicle air conditioner  2 , the amount of second heat medium CW flowing through each of the warm flow passages  61 A,  61 B,  61 C,  61 D and the cold flow passages  63 A,  63 B,  63 C,  63 D can be adjusted. Thus, the temperature of each of the plurality of seats  60 A,  60 B,  60 C,  60 D can be adjusted according to the preference of an occupant. 
     [Additional Statement] 
     The vehicle air conditioner  1  described in the above embodiments can be understood as follows. 
     [Configuration of Vehicle Air Conditioner  1  According to First Aspect] 
     The vehicle air conditioner  1  according to a first aspect includes: the refrigeration cycle  10  in which a refrigerant circulates; the high-temperature cycle HS in which the first heat medium HW heated by the refrigeration cycle  10  circulates; the low-temperature cycle CS in which the second heat medium CW cooled by the refrigeration cycle  10  circulates; and the seat  60  that is provided in the vehicle interior and has the warm flow passage  61  and the cold flow passage  63  disposed close to each other. 
     In the vehicle air conditioner  1 , the warm flow passage  61  is provided on the route of the high-temperature cycle HS, and the cold flow passage  63  is provided on the route of the low-temperature cycle CS. 
     [Effects of Vehicle Air Conditioner  1  According to First Aspect] 
     In the vehicle air conditioner  1  according to the first aspect, the warm flow passage  61  and the cold flow passage  63  are disposed close to each other in the seat  60 . The seat  60  can be cooled and heated by adjusting the amounts of the first heat medium HW and the second heat medium CW flowing through the warm flow passage  61  and the cold flow passage  63 , respectively. 
     According to the vehicle air conditioner  1 , the first heat medium HW and the second heat medium CW supplied to the warm flow passage  61  and the cold flow passage  63 , respectively, of the seat  60  are in liquid form. Since liquids are used as the heat media, the heat accumulation property is high compared with that of air, and comfort can be maintained also when getting into or out of the vehicle or when the device is stopped. 
     Further, according to the vehicle air conditioner  1 , the warm flow passage  61  and the cold flow passage  63  are separate and independent from each other. Thus, according to the first embodiment, the first heat medium HW and the second heat medium CW are not mixed, which can eliminate the need for a capacity required for mixing. In addition, the roles of the first heat medium HW and the second heat medium CW can be maintained, so that heat management for other on-board devices can be performed. 
     [Configuration of Vehicle Air Conditioner  1  According to Second Aspect] 
     The vehicle air conditioner  1  according to a second aspect includes the temperature adjustment mechanism  30  that is provided in the vehicle interior IN and configured to adjust the temperature of air supplied to the vehicle interior. The temperature adjustment mechanism  30  includes the heater  35  configured to heat the air to be supplied and the cooler  33  configured to cool the air to be supplied. The heater  35  is provided on the route of the high-temperature cycle HS, parallel to the warm flow passage  61 , and the cooler  33  is provided on the route of the low-temperature cycle CS, parallel to the cold flow passage  63 . 
     [Effects of Vehicle Air Conditioner  1  According to Second Aspect] 
     The vehicle air conditioner  1  according to the second aspect can cool and heat the seat  60  while performing temperature adjustment, such as heating or cooling, of the vehicle interior IN. 
     [Configuration of Vehicle Air Conditioner  1  According to Third Aspect] 
     The refrigeration cycle  10  in the vehicle air conditioner  1  according to a third aspect includes: the compressor  11  configured to compress the refrigerant; the condenser  13  configured to condense the refrigerant having been compressed by the compressor  11 ; the decompression unit  15  configured to decompress the refrigerant having been condensed by the condenser  13 ; and the evaporator  17  configured to evaporate the refrigerant having been decompressed by the decompression unit  15 . 
     The high-temperature cycle HS includes the high-temperature-side heat exchanger  23  configured to make the refrigerant flowing through the condenser  13  and the first heat medium exchange heat with each other, and the low-temperature cycle CS includes the low-temperature-side heat exchanger  21  configured to make the refrigerant flowing through the evaporator  17  and the second heat medium exchange heat with each other. 
     [Effects of Vehicle Air Conditioner  1  According to Third Aspect] 
     The vehicle air conditioner  1  according to the third aspect can cool and heat the seat  60  while performing temperature adjustment, such as heating or cooling, of the vehicle interior IN. 
     [Configuration of Vehicle Air Conditioner  1  According to Fourth Aspect] 
     In the vehicle air conditioner  1  according to a fourth aspect, the direction in which the first heat medium HW flows in the warm flow passage  61  and the direction in which the second heat medium CW flows in the cold flow passage  63  are opposite from each other. 
     [Effects of Vehicle Air Conditioner  1  According to Fourth Aspect] 
     The vehicle air conditioner  1  according to the fourth aspect can eliminate the need for a fan that generates a convection flow. 
     [Configuration of Vehicle Air Conditioner  1  According to Fifth Aspect] 
     The vehicle air conditioner  1  according to a fifth aspect includes: a plurality of seats  60  provided in the vehicle interior; the warm flow passage  61  and the cold flow passage  63  provided in each of the seats  60 ; the first total amount valve  43  configured to adjust the amount of first heat medium HW supplied from the high-temperature cycle HS to the plurality of seats  60 ; and the second total amount valve  45  configured to adjust the amount of second heat medium CW supplied from the low-temperature cycle CS to the plurality of seats  60 . 
     [Effects of Vehicle Air Conditioner  1  According to Fifth Aspect] 
     The vehicle air conditioner  1  according to the fifth aspect allows each individual to set the temperature according to his or her preference, without depending on the temperature of air blown out of the temperature adjustment mechanism  30 , by adjusting the balance between the flow rates of the first heat medium HW and the second heat medium CW in the plurality of seats  60 . 
     [Configuration of Vehicle Air Conditioner  1  According to Sixth Aspect] 
     The vehicle air conditioner  1  according to a sixth aspect includes the first branch flow passages HL 6 A, HL 6 B, HL 6 C, HL 6 D in which the plurality of warm flow passages  61  is respectively provided, and the second branch flow passages CL 4 A, CL 4 B, CL 4 C, CL 4 D in which the plurality of cold flow passages  63  is respectively provided. In addition, the vehicle air conditioner  1  includes the first separate valves  65 A,  65 B,  65 C,  65 D that are provided in the first branch flow passages HL 6 A, HL 6 B, HL 6 C, HL 6 D, respectively, and adjust the flow rates of the first heat medium HW supplied to the plurality of first branch flow passages HL 6 A, HL 6 B, HL 6 C, HL 6 D, and the second separate valves  67 A,  67 B,  67 C,  67 D that are provided in the second branch flow passages CL 4 A, CL 4 B, CL 4 C, CL 4 D, respectively, and adjust the flow rates of the second heat medium CW supplied to the plurality of second branch flow passages CL 4 A, CL 4 B, CL 4 C, CL 4 D. 
     [Effects of Vehicle Air Conditioner  1  According to Sixth Aspect] 
     The vehicle air conditioner  1  according to the sixth aspect adjusts the total flow rate of the heat media required for individual temperature adjustment through opening degrees of the first total amount valve  43  and the second total amount valve  45 . Thus, the effect of a change in the flow rate balance resulted from a change of the temperature of the seat made by one occupant on temperature adjustment of the other seats can be minimized. Since energy is consumed only in seats where occupants are present, an energy saving effect can be expected. 
     Other than the above, configurations presented in the embodiments may be selectively adopted or changed to other configurations as necessary. 
     REFERENCE SINGS LIST 
     
         
         
           
               1 ,  2  Vehicle air conditioner 
             L 1  Refrigerant flow passage 
             L 2  Refrigerant flow passage 
             HS High-temperature cycle 
             HL 1 , HL 2 , HL 4 , HL 5 , HL 6  High-temperature flow passage 
             HL 6 A, HL 6 B, HL 6 C, HL 6 D First branch flow passage 
             CS Low-temperature cycle 
             CL 1 , CL 2 , CL 3 , CL 4 , CL 5  Low-temperature flow passage 
             CL 4 A, CL 4 B, CL 4 C, CLOD Second branch flow passage 
             R Refrigerant 
             HW First heat medium 
             CW Second heat medium 
               10  Refrigeration cycle 
               21  Low-temperature-side heat exchanger 
               23  High-temperature-side heat exchanger 
               24 ,  32 ,  36  Three-way valve 
               25 ,  41  Four-way valve 
               27  Low-temperature-side pump 
               30  Temperature adjustment mechanism 
               31  Blower 
               43  First total amount valve 
               45  Second total amount valve 
               60 ,  60 A,  60 B,  60 C,  60 D Seat 
               61 ,  61 A,  61 B,  61 C,  61 D Warm flow passage 
               63 ,  63 A,  63 B,  63 C,  63 D Cold flow passage 
               65 A,  65 B,  65 C,  65 D First separate valve 
               67 A,  67 B,  67 C,  67 D Second separate valve