Vehicle air conditioning system

Abstract

This vehicle air conditioning system comprises: a refrigerant flow path that circulates a refrigerant across a condenser and an evaporator; a coolant flow path for circulating a coolant that exchanges heat with the refrigerant in the condenser and the evaporator; and a heat exchanger that performs heat exchange between air and the coolant in order to heat and cool the interior of a vehicle compartment.

Description

Vehicle air conditioning system

[0001] The present invention relates to a vehicle air conditioning system.

[0002] 2. Description of the Related Art Conventionally, vehicle air conditioning systems are used to cool and heat the interior of a vehicle. Technologies relating to such vehicle air conditioning systems are disclosed in, for example, Patent Documents 1 and 2, the sources of which are listed below.

[0003] Patent Document 1 describes a refrigeration cycle device. This refrigeration cycle device is applied to a vehicle air conditioner. The vehicle air conditioner is configured to be switchable between a cooling mode and a heating mode. In the cooling mode, an interior evaporator cools the blown air and supplies cool air to the passenger compartment. In the heating mode, heat is exchanged between a refrigerant that has been brought to a high-temperature, high-pressure state by a compressor and the heat-exchanged coolant via a heater core, heating the blown air and supplying warm air to the passenger compartment. An air mix door is disposed between the downstream side of the interior evaporator in the blown air flow and the upstream side of the heater core in the blown air flow. The air mix door adjusts the ratio of the amount of blown air that passes through the heater core to the amount of blown air that passes through the cool air bypass passage after passing through the interior evaporator.

[0004] The vehicle air conditioning system described in Patent Document 2 is configured to be switchable between a cooling mode and a heating mode using a coolant that has undergone heat exchange with a refrigerant circulating through a condenser and an evaporator of a heat pump cycle. This vehicle air conditioning system includes a first heat exchanger that exchanges heat between air and the coolant cooled through the evaporator, and a second heat exchanger that exchanges heat between the air that has undergone heat exchange in the first heat exchanger and the coolant heated through the condenser. As a result, dehumidifying and heating operation can be achieved by dehumidifying the air in the first heat exchanger and then heating the air in the second heat exchanger, eliminating the need for a desiccant or other drying material.

[0005] JP 2019-60580 A JP 2015-16706 A

[0006] As described above, the vehicle air conditioner described in Patent Document 1 is configured to include an interior evaporator, a heater core, and an air mix door to supply cool air and warm air to the vehicle interior. The vehicle air conditioner described in Patent Document 1 has room for improvement in terms of size and cost reduction.

[0007] Furthermore, as described above, the vehicle air conditioning system equipped with the first heat exchanger and the second heat exchanger described in Patent Document 2 can be made smaller because it does not require a desiccant or other desiccant. However, for example, in cooling mode, if the coolant cooled through the evaporator becomes too cold, the air is dehumidified too much and becomes dry air with extremely low humidity before being introduced into the vehicle cabin. In other words, it has been difficult to adjust the humidity of the air blown into the vehicle cabin.

[0008] Therefore, there is a demand for a vehicle air conditioning system that is small and inexpensive, and that is capable of adjusting the humidity of the blown air.

[0009] The characteristic configuration of the vehicle air conditioning system of the present invention is that it comprises a refrigerant flow path that circulates refrigerant between a condenser and an evaporator, a coolant flow path that circulates coolant that exchanges heat with the refrigerant in the condenser and the evaporator, and a heat exchanger that exchanges heat between air and the coolant to cool and heat the vehicle interior.

[0010] With this characteristic configuration, when heating the vehicle interior, the coolant warmed by the condenser flows through the heat exchanger to perform heat exchange, and when cooling the vehicle interior, the coolant cooled by the evaporator flows through the heat exchanger to perform heat exchange. This allows the interior evaporator and heater core of conventional vehicle air conditioning systems to be replaced with a single heat exchanger, thereby reducing the size and cost of the vehicle air conditioning system. Therefore, a small and inexpensive vehicle air conditioning system can be realized.

[0011] Furthermore, a characteristic configuration of the vehicle air conditioning system according to the present invention is that it comprises a refrigerant flow path that circulates refrigerant between a condenser and an evaporator, a coolant flow path that circulates coolant that exchanges heat with the refrigerant in the condenser and the evaporator, a first heat exchanger that can exchange heat between air and the coolant, and a second heat exchanger that can exchange heat between the air and the coolant after heat exchange in the first heat exchanger, and the coolant flow path has a switching mechanism that can switch between a first state in which the coolant is circulated between the evaporator and the first heat exchanger, and a second state in which the coolant is circulated between the evaporator and the first heat exchanger and the second heat exchanger.

[0012] With this configuration, the cooling mode is performed in the first state as in the conventional system, and the coolant cooled through the evaporator can be distributed to the first and second heat exchangers in the second state. In this second state, the heat capacity of the coolant cooled through the evaporator is distributed to the first and second heat exchangers, so the air passing through the first heat exchanger is not rapidly cooled, and the decrease in air humidity can be suppressed compared to when the air is cooled only by the first heat exchanger as in the first state. Furthermore, by adjusting the flow rate of the coolant circulating through the first and second heat exchangers, the humidity of the air introduced into the vehicle cabin can be adjusted. Thus, a vehicle air conditioning system capable of adjusting the humidity of the air being blown in can be realized.

[0013] 1 is a circuit configuration diagram of a vehicle air conditioning system according to a first embodiment; FIG. 2 is a plan view showing the layout of the vehicle air conditioning system according to the first embodiment; FIG. 3 is a side view showing the layout of the vehicle air conditioning system according to the first embodiment; FIG. 4 is a diagram showing the flow of coolant in a first state according to the first embodiment; FIG. 5 is a diagram showing the flow of coolant in a second state according to the first embodiment; FIG. 6 is a diagram showing the state of a switching valve according to the first embodiment; FIG. 7 is a circuit configuration diagram of a vehicle air conditioning system according to a second embodiment; FIG. 8 is a diagram showing the flow of coolant when the vehicle air conditioning system according to the second embodiment is in a first state; FIG. 9 is a diagram showing the flow of coolant when the vehicle air conditioning system according to the second embodiment is in a second state; FIG. 10 is a diagram showing the flow of coolant when the vehicle air conditioning system according to the second embodiment is in a third state; FIG. 11 is a circuit configuration diagram of a vehicle air conditioning system according to a third embodiment; FIG. 12 is a circuit configuration diagram of a vehicle air conditioning system according to a fourth embodiment; FIG. 13 is a diagram showing the flow of coolant in a first state according to the fourth embodiment; FIG. 14 is a diagram showing the flow of coolant in a second state according to the fourth embodiment. 10 is a diagram showing a flow of coolant in a third state according to a fourth embodiment; FIG. 11 is a diagram showing a flow of coolant in a fourth state according to the fourth embodiment; FIG. 12 is a circuit configuration diagram of a vehicle air conditioning system according to a fifth embodiment.

[0014] [First Embodiment] A vehicle air conditioning system according to the present invention is configured to be able to cool and heat a vehicle cabin. A vehicle air conditioning system A according to this embodiment will be described below. However, the vehicle air conditioning system A is not limited to the following embodiment, and various modifications are possible without departing from the spirit and scope of the invention.

[0015] FIG. 1 is a diagram showing the circuit configuration of a vehicle air conditioning system A. The vehicle air conditioning system A is mounted on a vehicle and, as shown in FIG. 1, includes a refrigerant module B, a coolant module C, and an HVAC (Heating, Ventilation, and Air Conditioning) unit D (an example of an "air conditioning unit"). The refrigerant module B is provided with a refrigerant flow path B1 and configured as a refrigerant manifold. The coolant module C is provided with a coolant flow path C1 and configured as a coolant manifold. Here, the manifold is a flow path housing formed by laminating and sealing a plate member on a housing main body in which the coolant flow path C1 and the refrigerant flow path B1 are engraved. The flow path housing is formed of a metal material with high thermal conductivity, including aluminum.

[0016] A refrigerant such as a hydrofluorocarbon (HFC) or a hydrofluoroolefin (HFO) flows through the refrigerant flow path B1, and a coolant such as an antifreeze or long-life coolant primarily composed of ethylene glycol or the like, or a coolant composed of insulating oil such as paraffin, flows through the coolant flow path C1. Figures 2A and 2B show the arrangement of the refrigerant module B, the coolant module C, and the HVAC unit D in the vehicle air conditioning system A. Figure 2A is a plan view, and Figure 2B is a side view. In Figures 2A and 2B, the front side of the vehicle in the direction of travel when the vehicle air conditioning system A is installed on the vehicle is indicated as F, and the rear side is indicated as R. The coolant module C has ports PO1 and PO2 for introducing and discharging the coolant.

[0017] 1, 2A, and 2B, a refrigerant flow path B1 circulates a refrigerant through a water-cooled condenser (an example of a "condenser") 12 and a chiller (an example of an "evaporator") 14. The refrigerant module B is configured to allow a refrigerant to flow between an accumulator 10, a compressor 11, the water-cooled condenser 12, an expansion valve 13, and the chiller 14 via the refrigerant flow path B1.

[0018] The accumulator 10 stores a liquid refrigerant and separates the stored refrigerant into gas and liquid. The gas refrigerant separated by the accumulator 10 flows through a first refrigerant passage 21 and is sent to the compressor 11.

[0019] The compressor 11 compresses the refrigerant from the accumulator 10. As a result, the refrigerant becomes a high-temperature compressed gas. The compressor 11 sends this high-temperature compressed gas to the water-cooled condenser 12 via the second refrigerant path 22. Therefore, the compressor 11 pressure-feeds the refrigerant from the accumulator 10 to the water-cooled condenser 12.

[0020] The refrigerant that has passed through the compressor 11 flows through the water-cooled condenser 12. The water-cooled condenser 12 is configured so that the coolant flows in through a first coolant flow path 31 and flows out through a second coolant flow path 32. The first coolant flow path 31 and the second coolant flow path 32 are configured separately from the second coolant path 22. The refrigerant from the second coolant path 22 is condensed and liquefied as heat is absorbed by the coolant. The liquefied refrigerant is sent to the third coolant path 23. Like the second coolant path 22, the third coolant path 23 is also configured separately from the first coolant flow path 31 and the second coolant flow path 32.

[0021] In the expansion valve 13, the refrigerant (liquefied refrigerant) flowing through the third refrigerant passage 23 is expanded and converted into a low-temperature, low-pressure mist. The mist-like refrigerant is sent to the fourth refrigerant passage 24.

[0022] The refrigerant flows through the chiller 14 via the fourth refrigerant passage 24. As described above, the refrigerant expanded by the expansion valve 13 and converted into a low-temperature, low-pressure atomized refrigerant flows through the fourth refrigerant passage 24, and this refrigerant is sent to the chiller 14. The chiller 14 is configured such that the coolant that has undergone heat exchange in the heat exchanger 52 flows into it from the third coolant passage 33, and the coolant flows out from the fourth coolant passage 34. The third coolant passage 33 and the fourth coolant passage 34 are configured separately from the fourth refrigerant passage 24. In the chiller 14, the atomized refrigerant absorbs heat from the coolant and evaporates. The evaporated refrigerant flows to the accumulator 10 via the fifth refrigerant passage 25.

[0023] The coolant flow path C1 carries the coolant that exchanges heat with the refrigerant in the water-cooled condenser 12 and the chiller 14. The coolant module C is configured so that the coolant can flow through the coolant flow path C1 among the water-cooled condenser 12, the chiller 14, the switching valve 42, the radiator 43, and the heat exchanger 52 by the first pump P1 and the second pump P2.

[0024] As described above, the water-cooled condenser 12 is configured so that the coolant flows in through the first coolant flow path 31 and flows out through the second coolant flow path 32. The first coolant flow path 31 is provided with a first pump P1, and the coolant is delivered by this first pump P1.

[0025] The switching valve 42 is disposed in the coolant flow path C1 and is configured to allow the coolant to flow from the water-cooled condenser 12 and the chiller 14. The coolant is sent to the switching valve 42 from the water-cooled condenser 12 via the second coolant flow path 32, and the coolant is sent from the chiller 14 via the fourth coolant flow path 34. A second pump P2 is provided in the fourth coolant flow path 34, and the coolant is sent from the chiller 14 to the switching valve 42 by this second pump P2.

[0026] The switching valve 42 is configured to be able to send the coolant to the fifth coolant flow path 35 and the sixth coolant flow path 36. The coolant sent from the switching valve 42 to the fifth coolant flow path 35 flows through the heat exchanger 52. The coolant sent to the heat exchanger 52 is configured to be able to be sent to the water-cooled condenser 12 via the first coolant flow path 31, and is also configured to be able to be sent to the chiller 14 via the third coolant flow path 33.

[0027] The coolant sent from the switching valve 42 to the sixth coolant flow path 36 flows to the radiator 43. In the radiator 43, heat exchange with outside air occurs, and the coolant is cooled. After heat exchange, the coolant is sent to the first coolant flow path 31 via the seventh coolant flow path 37.

[0028] The switching valve 42 is configured to switch the flow state of the coolant in the coolant flow path C1 between a first state and a second state. The first state is a state in which the coolant is circulated through the water-cooled condenser 12. The flow state of the coolant in this first state is shown in FIG. 3. As shown in FIG. 3, in the first state, the coolant is circulated by the first pump P1 through the water-cooled condenser 12, the second coolant flow path 32, the switching valve 42, the fifth coolant flow path 35, the heat exchanger 52, and the first coolant flow path 31.

[0029] At this time, the coolant may be sent from the switching valve 42 to the sixth coolant flow path 36 , and then circulated so as to return to the first coolant flow path 31 via the radiator 43 and the seventh coolant flow path 37 .

[0030] The second state is a state in which the coolant is circulated through the chiller 14. The flow of the coolant in this second state is shown in Fig. 4. As shown in Fig. 4, in the second state, the coolant is circulated by the second pump P2 through the chiller 14, the fourth coolant flow path 34, the switching valve 42, the fifth coolant flow path 35, the heat exchanger 52, and the third coolant flow path 33.

[0031] The switching valve 42 is switched between a first state and a second state by a control unit (not shown) of the vehicle air conditioning system A or a higher-level system of the vehicle air conditioning system A.

[0032] 1 , the HVAC unit D includes a blower 51, a heat exchanger 52, a desiccant 53, and a heater (electric heater) 54. The blower 51 draws in outside air and sends the drawn outside air to the heat exchanger 52.

[0033] The heat exchanger 52 exchanges heat between air and coolant to cool or heat the vehicle cabin. The air is outside air drawn in by the blower 51. The coolant is introduced into the heat exchanger 52 via the fifth coolant flow path 35 as described above. The coolant is then sent to one or both of the first coolant flow path 31 and the third coolant flow path 33 depending on the state of the switching valve 42 (details will be described later). Therefore, in the heat exchanger 52, heat exchange occurs between the outside air sent from the blower 51 and the coolant supplied via the fifth coolant flow path 35, and the air after the heat exchange is introduced into the vehicle cabin. Specifically, when the outside air is cooled in the heat exchanger 52, cool air is introduced into the vehicle cabin. When the outside air is heated in the heat exchanger 52, warm air is introduced into the vehicle cabin. This allows the vehicle cabin to be cooled or heated.

[0034] The desiccant 53 adsorbs moisture contained in the moisture-containing air to generate heated, dry air. The desiccant 53 functions as an adsorption section that adsorbs moisture and can be made using an adsorbent such as zeolite, silica gel, or activated carbon. The desiccant 53 is provided between the blower 51 and the heat exchanger 52. Therefore, the outside air sent from the blower 51 passes through the desiccant 53 and is discharged to the heat exchanger 52.

[0035] The electric heater 54 evaporates the moisture adsorbed in the desiccant 53 to generate cooled and humidified air. The electric heater 54 functions as a heating unit that evaporates the moisture adsorbed in the desiccant 53. As shown in FIG. 1 , the electric heater 54 is attached to the desiccant 53, for example (integrated with the desiccant 53). In this case, the desiccant 53 is heated by the electric heater 54, thereby evaporating the moisture adsorbed in the desiccant 53. Of course, the electric heater 54 may not be attached to the desiccant 53, but may be located upstream of the desiccant 53 (between the blower 51 and the desiccant 53) and spaced apart from the desiccant 53 (or may be provided separately from the desiccant 53). In this case, the air from the blower 51 is heated by the electric heater 54, and the heated air is supplied to the desiccant 53, thereby evaporating the moisture adsorbed in the desiccant 53. The air supplied to the desiccant 53 is humidified by the moisture evaporated from the desiccant 53, generating cooled and humidified air. The heating unit that evaporates the moisture adsorbed in the desiccant 53 may be an air heating device other than the electric heater 54.

[0036] When moisture-containing air is supplied from the blower 51 to the desiccant 53 without moisture being adsorbed on the desiccant 53, the desiccant 53 adsorbs the moisture in the moisture-containing air to reduce the humidity of the moisture-containing air. As a result, the moisture-containing air supplied to the desiccant 53 is dehumidified by the desiccant 53 and becomes dry air, which is then discharged to the heat exchanger 52.

[0037] On the other hand, when air heated by the electric heater 54 or high-temperature air from the blower 51 is supplied to the desiccant 53 while moisture is adsorbed on the desiccant 53, the desiccant 53 desorbs the adsorbed moisture. The desorbed moisture humidifies the high-temperature air. As a result, the high-temperature air supplied to the desiccant 53 becomes moist air humidified by the desiccant 53 and is discharged to the heat exchanger 52.

[0038] The heat exchanger 52 exchanges heat between the heated dry air or cooled humidified air and the coolant to generate air for cooling or heating the vehicle cabin. Thus, the heat exchanger 52 exchanges heat between the dry air and the coolant introduced through the fifth coolant flow path 35 to generate air for cooling the vehicle cabin. The heat exchanger 52 also exchanges heat between the humid air and the coolant introduced through the fifth coolant flow path 35 to generate air for heating the vehicle cabin. Furthermore, the heat exchanger 52 can also exchange heat between the dry air and the coolant introduced through the fifth coolant flow path 35 to generate air for heating the vehicle cabin. In this case, dehumidified heated air can be supplied to the vehicle cabin when the defroster function is activated, for example, in winter. By introducing such air for cooling or heating the vehicle cabin into the vehicle cabin, the humidity inside the vehicle cabin can be adjusted.

[0039] As described above, the switching valve 42 is configured to allow the coolant from the water-cooled condenser 12 and the coolant from the chiller 14 to flow through. When the coolant from the water-cooled condenser 12 is compared with the coolant from the chiller 14, the temperature of the coolant from the water-cooled condenser 12 is relatively higher than the temperature of the coolant from the chiller 14. Therefore, when heating the vehicle interior, the switching valve 42 is set to a first state in which the coolant is circulated through the water-cooled condenser 12, and when cooling the vehicle interior, the switching valve 42 is set to a second state in which the coolant is circulated through the chiller 14.

[0040] In this embodiment, the switching valve 42 is configured to change its opening degree so as to simultaneously achieve the first state and the second state. Therefore, the switching valve 42 can mix the relatively high-temperature coolant from the water-cooled condenser 12 and the relatively low-temperature coolant from the chiller 14 and deliver the mixture to the fifth coolant flow path 35. As shown in FIG. 5 , when the set temperature of the air conditioning in the vehicle cabin is high, the ratio of the coolant from the chiller 14 to the coolant from the water-cooled condenser 12 can be reduced. When the set temperature of the air conditioning in the vehicle cabin is low, the ratio of the coolant from the chiller 14 to the coolant from the water-cooled condenser 12 can be increased. In this way, by changing the opening degree of the switching valve 42 in accordance with the set temperature of the air conditioning in the vehicle cabin and controlling the flow rates of the coolant from the second coolant flow path 32 and the fourth coolant flow path 34, the temperature of the coolant delivered to the fifth coolant flow path 35 can be adjusted, and the temperature in the vehicle cabin can be adjusted to the set temperature of the air conditioning.

[0041] In this embodiment, as shown in FIGS. 2A and 2B , the refrigerant module B and the coolant module C are integrated with the HVAC unit D. Here, "integration" refers to a state in which the refrigerant module B and the coolant module C are fixed to the HVAC unit D with bolts or the like. Note that "integration" also includes forming the HVAC unit D, the refrigerant module B, and the coolant module C from the same material into a single case. Specifically, as shown in FIG. 2A , when the HVAC unit D is mounted on a vehicle, the refrigerant module B is located on the front side of the HVAC unit D in the direction of travel of the vehicle. By integrating the refrigerant module B and the coolant module C with the HVAC unit D in this manner, the routing of the flow paths through which the coolant flows between the refrigerant module B and the HVAC unit D and the coolant module C can be simplified and shortened compared to when the refrigerant module B and the coolant module C are not integrated with the HVAC unit D. This allows for a more compact vehicle air conditioning system A, thereby improving power efficiency. 2A and 2B, the water-cooled condenser 12, the expansion valve 13, and the chiller 14 can be disposed in the front of the vehicle, so that as the vehicle travels, wind can be blown onto the water-cooled condenser 12, the expansion valve 13, and the chiller 14. This makes it possible to prevent condensation on the water-cooled condenser 12, the expansion valve 13, and the chiller 14.

[0042] 2B, when the HVAC unit D is mounted on a vehicle, the coolant module C is provided on the left side of the vehicle in the HVAC unit D. This makes it possible to easily secure coolant introduction and discharge routes in the coolant module C by providing ports PO1 and PO2, as shown in FIG. 2B. Furthermore, by arranging the first pump P1, the second pump P2, and the switching valve 42 on the side of the HVAC unit D, it becomes possible to improve maintainability.

[0043] [Alternative to First Embodiment] Next, an alternative embodiment of the vehicle air conditioning system A of the first embodiment will be described.

[0044] In the above embodiment, the vehicle air conditioning system A is described as being provided with a switching valve 42 in the coolant flow path C1 that can be switched between a first state in which the coolant is circulated through the water-cooled condenser 12 and a second state in which the coolant is circulated through the chiller 14. However, the vehicle air conditioning system A can also be configured without the switching valve 42. In this case, a flow path for circulating the coolant between the water-cooled condenser 12 and the heat exchanger 52 and a flow path for circulating the coolant between the chiller 14 and the heat exchanger 52 may be provided separately (independently), and an on-off valve may be provided for each flow path. By switching these on-off valves between an open state and a closed state, the coolant from the water-cooled condenser 12 and the coolant from the chiller 14 can be circulated through the heat exchanger 52. Alternatively, the coolant from the water-cooled condenser 12 and the coolant from the chiller 14 can be simultaneously circulated through the heat exchanger 52.

[0045] In the above embodiment, the switching valve 42 is described as being capable of changing the opening degree so as to simultaneously realize the first state and the second state. However, the switching valve 42 may also be configured so as not to simultaneously realize the first state and the second state.

[0046] In the above embodiment, the coolant module C having the coolant flow path C1 has a heat exchanger 52 and is integrated with the HVAC unit D that cools and heats the vehicle cabin. However, it is also possible to configure the coolant module C without integrating it with the HVAC unit D. Furthermore, in the above embodiment, the refrigerant module B having the refrigerant flow path B1 has a heat exchanger 52 and is integrated with the HVAC unit D that cools and heats the vehicle cabin. However, it is also possible to configure the refrigerant module B without integrating it with the HVAC unit D.

[0047] Second Embodiment Circuit Configuration of Vehicle Air Conditioning System Next, the circuit configuration of a vehicle air conditioning system 100A according to a second embodiment will be described. The vehicle air conditioning system 100A is mounted on a vehicle and is configured to be switchable between a cooling mode and a heating mode. As shown in FIG. 6 , the vehicle air conditioning system 100A includes a refrigerant module 100B, a coolant module 100C, and an HVAC (Heating, Ventilation, and Air Conditioning) unit 100D. The refrigerant module 100B is provided with a refrigerant flow path 100B1, which constitutes a refrigerant manifold. The coolant module 100C is provided with a coolant flow path 100C1, which constitutes a coolant manifold. The manifold is a flow path housing formed by laminating and sealing a plate member on a housing main body in which the coolant flow path 100C1 and at least a portion of the refrigerant flow path 100B1 are formed. The flow path housing is formed of a metal material, including aluminum, or a resin with high thermal conductivity. The HVAC unit 100D includes a blower 151, a first heat exchanger 152 (an example of a heat exchanger), and a second heat exchanger 153 (an example of a heat exchanger).

[0048] A refrigerant such as a hydrofluorocarbon (HFC) or a hydrofluoroolefin (HFO) flows through the refrigerant flow path 100B1. A coolant flow path 100C1 is a cooling water such as an antifreeze or long-life coolant mainly containing ethylene glycol or the like, or a coolant composed of insulating oil such as paraffin.

[0049] As shown in FIG. 6 , the refrigerant module 100B includes an accumulator 110, a compressor 111, a water-cooled condenser 112, an expansion valve 113, a chiller 114, and a refrigerant flow path 100B1 that circulates a refrigerant among these components. The refrigerant flow path 100B1 includes a first refrigerant flow path 121, a second refrigerant flow path 122, a third refrigerant flow path 123, a fourth refrigerant flow path 124, and a fifth refrigerant flow path 125. The first refrigerant flow path 121 is disposed between the accumulator 110 and the compressor 111. The second refrigerant flow path 122 is disposed between the compressor 111 and the water-cooled condenser 112. The third refrigerant flow path 123 is disposed between the water-cooled condenser 112 and the expansion valve 113. The fourth refrigerant flow path 124 is disposed between the expansion valve 113 and the chiller 114. The fifth refrigerant flow path 125 is disposed between the chiller 114 and the accumulator 110. The coolant flow path 100B1 is an annular flow path.

[0050] The coolant module 100C includes a first pump 100P1, a second pump 100P2, a first switching valve 142, a second switching valve 144, a reserve tank 146 (an example of a reservoir), and a portion of a coolant flow path 100C1 that circulates the coolant between these components. The coolant flow path 100C1 includes a first coolant flow path 131, a second coolant flow path 132, a third coolant flow path 133, a fourth coolant flow path 134, a fifth coolant flow path 135, a sixth coolant flow path 136, a seventh coolant flow path 137, an eighth coolant flow path 138, a ninth coolant flow path 139, a tenth coolant flow path 140, and an eleventh coolant flow path 141. The first pump 100P1 is disposed midway through the first coolant flow path 131, and the second pump 100P2 is disposed midway through the third coolant flow path 133, both of which pump the coolant. The operations of the first pump 100P1, the second pump 100P2, the first switching valve 142, and the second switching valve 144 are controlled by a control unit 160.

[0051] The first coolant flow path 131 is arranged between the second switching valve 144 and the water-cooled condenser 112. The second coolant flow path 132 is arranged between the water-cooled condenser 112 and the first switching valve 142. The third coolant flow path 133 is arranged between the first heat exchanger 152 and the chiller 114. The fourth coolant flow path 134 is arranged between the reserve tank 146 and the second heat exchanger 153. The fifth coolant flow path 135 is arranged between the chiller 114 and the first switching valve 142. The sixth coolant flow path 136 is arranged between the first switching valve 142 and the reserve tank 146. The seventh coolant flow path 137 is arranged between the first switching valve 142 and a radiator 143 (described later). The eighth coolant flow path 138 is arranged between the radiator 143 and the first coolant flow path 131 upstream of the first pump 100P1. The ninth coolant flow path 139 is arranged between the second heat exchanger 153 and the second switching valve 144. The tenth coolant flow path 140 is arranged between the second switching valve 144 and the third coolant flow path 133 upstream of the second pump 100P2. The eleventh coolant flow path 141 is arranged between the chiller 114 and the first heat exchanger 152.

[0052] In this embodiment, the first switching valve 142 is a four-way valve, and the second switching valve 144 is a three-way valve. The first switching valve 142 switches the flow path between three switching positions, first to third. In the first switching position, the coolant flowing in from the second coolant flow path 132 flows out to the seventh coolant flow path 137 and the flow of the coolant flowing in from the fifth coolant flow path 135 is blocked (in a first state described below). In the second switching position, the coolant flowing in from the fifth coolant flow path 135 flows out to the sixth coolant flow path 136 and the flow of the coolant flowing in from the second coolant flow path 132 is blocked (in a second state described below). In the third switching position, the coolant flowing in from the second coolant flow path 132 flows out to the sixth coolant flow path 136 and the flow of the coolant flowing in from the fifth coolant flow path 135 is blocked (in a third and fourth states described below).

[0053] The second switching valve 144 switches the flow path between two switching positions, a first and a second. In the first switching position, the coolant flowing in from the ninth coolant flow path 139 flows out to the tenth coolant flow path 140 (in the second state). In the second switching position, the coolant flowing in from the ninth coolant flow path 139 flows out to the first coolant flow path 131 (in the third and fourth states). The switching of the first switching valve 142 and the second switching valve 144 is controlled by the control unit 160.

[0054] The reserve tank 146 is an insulating container with a large heat capacity. The coolant that has flowed through the sixth coolant flow path 136 flows into the container and is stored therein in an insulated state. The stored coolant then flows out to the fourth coolant flow path 134. In this embodiment, the reserve tank 146 is formed integrally with the coolant module 100C. In this embodiment, "integrally formed" refers to both a case in which the reserve tank 146 is formed integrally with a housing that constitutes the coolant manifold, and a case in which the separate reserve tank 146 is fixed to the coolant manifold with bolts or the like and integrated therewith. In this embodiment, the "insulated state" refers to a state in which the temperature change per unit time of the coolant stored inside the reserve tank 146 is smaller than the temperature change per unit time of the coolant present in the coolant flow path 100C1. An example of the structure of the reserve tank 146 is one in which the reserve tank 146 has a double structure consisting of an inner case and an outer case, with the space between the inner case and the outer case being a vacuum, or one in which the reserve tank 146 is made of a material with low thermal conductivity, such as resin.

[0055] Because the reserve tank 146 is an insulated container, the temperature of the coolant stored therein is not easily affected by the temperature (air temperature) outside the vehicle. Therefore, even long periods of time after the vehicle air conditioning system 100A has stopped operating, the temperature of the coolant stored in the reserve tank 146 remains substantially the same as the temperature of the coolant when it flowed through the sixth coolant flow path 136 during operation before the vehicle air conditioning system 100A was stopped. Therefore, immediately after the vehicle air conditioning system 100A is restarted, it becomes possible to cause the coolant to flow into the fourth coolant flow path 134 at substantially the same temperature as when it flowed through the sixth coolant flow path 136.

[0056] In the HVAC unit 100D, outside air, which is air outside the vehicle, is introduced and dehumidified, cooled, heated, etc. in the first heat exchanger 152 and / or the second heat exchanger 153 before being sent to the passenger compartment 154 to cool or heat the passenger compartment 154. In the HVAC unit 100D, a blower 151, a first heat exchanger 152, and a second heat exchanger 153 are arranged in this order from upstream of the flow of outside air toward the passenger compartment 154. The blower 151 draws in outside air and sends it toward the first heat exchanger 152. The first heat exchanger 152 exchanges heat between the coolant flowing in from the chiller 114 and the outside air sent from the blower 151. The second heat exchanger 153 exchanges heat between the coolant flowing in from the water-cooled condenser 112 or the chiller 114 and the outside air that has passed through the first heat exchanger 152. In this embodiment, the first heat exchanger 152 is provided for dehumidifying and cooling, and the second heat exchanger 153 is provided for dehumidifying, cooling, and heating.

[0057] [Operation of Vehicle Air Conditioning System] Next, the operation of the vehicle air conditioning system A according to this embodiment will be described. The vehicle air conditioning system A is configured to be switchable between four states, a first state, a second state, and a fourth state, which will be described later, depending on the cooling and heating states. In Figures 7 to 10, the coolant flow path C1 through which the coolant flows is indicated by a thick line.

[0058] The refrigerant flow path 100B1 of the refrigerant module 100B will now be described. The accumulator 110 stores the liquid refrigerant. Hereinafter, unless otherwise specified as "liquid" or the like, the refrigerant refers to "gaseous refrigerant." The accumulator 110 separates the liquid refrigerant contained in the refrigerant that flows in from the chiller 114. After the liquid refrigerant has been separated by the accumulator 110, the refrigerant flows through the first refrigerant flow path 121 and flows into the compressor 111.

[0059] The compressor 111 compresses the refrigerant that has flowed in from the accumulator 110. As a result, the refrigerant becomes a high-temperature compressed gas. The compressor 111 pressure-feeds this high-temperature compressed gas to the water-cooled condenser 112 via the second refrigerant flow path 122.

[0060] The refrigerant flowing from the compressor 111 through the second refrigerant flow path 122 flows into the water-cooled condenser 112 and flows out into the third refrigerant flow path 123. The coolant also flows into the water-cooled condenser 112 from the first coolant flow path 131 of the coolant flow path 100C1 and flows out into the second coolant flow path 132. The refrigerant flowing in from the second refrigerant flow path 122 exchanges heat with the coolant flowing in from the first coolant flow path 131 within the water-cooled condenser 112. Specifically, the refrigerant is condensed and liquefied as heat is absorbed by the coolant. The liquefied refrigerant flows out into the third refrigerant flow path 123. The coolant flowing in from the first coolant flow path 131 is heated by the refrigerant and flows out into the second coolant flow path 132.

[0061] In the expansion valve 113, the liquid refrigerant flowing in from the third refrigerant flow path 123 is expanded and converted into a low-temperature, low-pressure mist of refrigerant. The mist of refrigerant flows out into the fourth refrigerant flow path 124.

[0062] Atomized refrigerant flowing through the fourth refrigerant flow path 124 flows into the chiller 114 and flows out into the fifth refrigerant flow path 125. Furthermore, the coolant flows into the chiller 114 from the third coolant flow path 133 of the coolant flow path 100C1 and flows out into only the eleventh coolant flow path 141 or into the fifth coolant flow path 135 and the eleventh coolant flow path 141. The atomized refrigerant flowing in from the fourth refrigerant flow path 124 exchanges heat with the coolant flowing in from the third coolant flow path 133 within the chiller 114. Specifically, the atomized refrigerant absorbs heat from the coolant and evaporates. The evaporated refrigerant flows out into the fifth refrigerant flow path 125 and flows into the accumulator 110. The vaporized refrigerant may include atomized (liquid) refrigerant that was not completely vaporized. The coolant flowing in from the third coolant flow passage 133 is cooled by the atomized refrigerant and flows out only to the eleventh coolant flow passage 141 or to both the fifth coolant flow passage 135 and the eleventh coolant flow passage 141 .

[0063] Next, the coolant flow path 100C1 will be described. The coolant flow path 100C1 carries coolant that exchanges heat with the refrigerant in the water-cooled condenser 112 and the chiller 114. In the coolant flow path 100C1, the coolant pumped by the first pump 100P1 and the second pump 100P2 flows among the water-cooled condenser 112, the chiller 114, the first switching valve 142, the radiator 143, the second switching valve 144, the reserve tank 146, the first heat exchanger 152, and the second heat exchanger 153.

[0064] As described above, the water-cooled condenser 112 is configured so that the coolant flows in through the first coolant flow path 131 and flows out through the second coolant flow path 132. The first coolant flow path 131 is provided with a first pump 100P1, and the coolant is pressure-fed by this first pump 100P1 to circulate.

[0065] The first switching valve 142 is configured to allow the flow of coolant from the water-cooled condenser 112 and the chiller 114. The coolant flows into the first switching valve 142 from the water-cooled condenser 112 via the second coolant flow path 132, or the coolant flows into the first switching valve 142 from the chiller 114 via the fifth coolant flow path 135. The first switching valve 142 is configured to allow the coolant to flow out to the sixth coolant flow path 136 or the seventh coolant flow path 137.

[0066] The coolant that flows out from the first switching valve 142 to the sixth coolant flow path 136 flows into the reserve tank 146. The coolant stored in the reserve tank 146 flows out, passes through the fourth coolant flow path 134, and flows into the second heat exchanger 153. The coolant that flows into the second heat exchanger 153 flows through the ninth coolant flow path 139 and into the second switching valve 144. The second switching valve 144 switches the flow path between two cases: when the coolant flows into the tenth coolant flow path 140, and when the coolant flows into the first coolant flow path 131. When the coolant flows into the tenth coolant flow path 140, it flows through the third coolant flow path 133 and flows into the chiller 114 (in the second state shown in FIG. 8 ). Furthermore, when the coolant flows out into the first coolant flow path 131, it flows through the first coolant flow path 131 and into the water-cooled condenser 112 (in the third state shown in FIG. 9 and the fourth state shown in FIG. 10 ). In this way, the second switching valve 144 is switched so that the coolant that flows in from the second heat exchanger 153 flows out to either the chiller 114 or the water-cooled condenser 112.

[0067] 7 , the coolant that flows in from the second coolant flow path 132 and flows out to the seventh coolant flow path 137 due to flow path switching by the first switching valve 142 flows into the radiator 143. In the radiator 143, heat exchange occurs between the coolant and the outside air, and the coolant is cooled. After heat exchange, the coolant flows through the eighth coolant flow path 138 and merges with the first coolant flow path 131 upstream of the first pump 100P1.

[0068] Next, the HVAC unit 100D will be described. The first heat exchanger 152 and the second heat exchanger 153 exchange heat between the air and the coolant to cool and heat the vehicle interior 154. The air is outside air drawn in by the blower 151. As described above, the coolant that has flowed through the eleventh coolant flow path 141 flows into the first heat exchanger 152 and flows out into the third coolant flow path 133. As described above, the coolant that has flowed through the fourth coolant flow path 134 flows into the second heat exchanger 153 and flows out into the ninth coolant flow path 139. Therefore, in the first heat exchanger 152, heat exchange occurs between the outside air sent from the blower 151 and the coolant that has flowed through the eleventh coolant flow path 141 and flowed in. In addition, in the second heat exchanger 153, heat exchange may or may not occur between the outside air after heat exchange has been or is not performed in the first heat exchanger 152 and the coolant that has flowed through the fourth coolant flow path 134, and the air after passing through the second heat exchanger 153 is introduced into the passenger compartment 154.

[0069] [First State] Next, the first to fourth states of the vehicle air conditioning system 100A will be described in order. The refrigerant module 100B is operating in all four states. The first state of the vehicle air conditioning system 100A is a cooling mode that dehumidifies and cools the passenger compartment 154, particularly in summer. In the first state of the coolant module 100C, as shown in FIG. 7 , the control unit 160 controls the first switching valve 142 to allow the coolant flowing from the second coolant flow path 132 to flow to the seventh coolant flow path 137 and to stop the flow of the coolant flowing from the fifth coolant flow path 135. Therefore, no coolant flows through the sixth coolant flow path 136, and no coolant flows through the fourth coolant flow path 134, the second heat exchanger 153, or the ninth coolant flow path 139. Therefore, the second switching valve 144 does not switch the flow path. Under the control of the control unit 160, both the first pump 100P1 and the second pump 100P2 are in operation.

[0070] Therefore, the coolant that flows through the first coolant flow path 131 and flows into the water-cooled condenser 112 exchanges heat with the refrigerant that has flowed into the water-cooled condenser 112, is heated, and flows out into the second coolant flow path 132. Thereafter, the coolant flows through the seventh coolant flow path 137 and flows into the radiator 143, is cooled in the radiator 143, flows through the eighth coolant flow path 138 and the first coolant flow path 131, and flows into the water-cooled condenser 112 again.

[0071] Because the second pump 100P2 is operating, the coolant flows through the third coolant flow path 133. The coolant that flows through the third coolant flow path 133 and enters the chiller 114 exchanges heat with the refrigerant that has flowed into the chiller 114, is cooled, and flows out into the eleventh coolant flow path 141. Because flow is stopped by the first switching valve 142, the coolant does not flow through the fifth coolant flow path 135. The coolant then flows into the first heat exchanger 152, where it dehumidifies, cools, and heats the outside air introduced from the blower 151. After being heated in the first heat exchanger 152, the coolant flows through the third coolant flow path 133 via the second pump 100P2 and flows back into the chiller 114. The outside air that has been dehumidified and cooled by heat exchange in the first heat exchanger 152 is sent toward the second heat exchanger 153.

[0072] Since no coolant flows into the second heat exchanger 153, the outside air introduced from the blower 151 and heat exchanged in the first heat exchanger 152 is not heat exchanged in the second heat exchanger 153, but is instead supplied as dehumidified cool air to the passenger compartment 154. This dehumidifies and cools the passenger compartment 154.

[0073] When the outside air temperature is high, if the vehicle air conditioning system 100A is stopped for a long time, the coolant temperature will rise. In the first state, cool air for cooling is generated using only the first heat exchanger 152. Therefore, if the vehicle air conditioning system 100A is restarted after a long time has passed, heat exchange occurs in the first heat exchanger 152 with coolant that has not been sufficiently cooled by the chiller 114 immediately after restart. As a result, the outside air sent to the passenger compartment 154 is not sufficiently cooled, making it difficult to quickly cool the passenger compartment 154. Furthermore, because the outside air temperature must be lowered using only the first heat exchanger 152, a large amount of condensation forms on the surface of the first heat exchanger 152.

[0074] [Second State] The second state of the vehicle air conditioning system 100A, like the first state, is a cooling mode for cooling the passenger compartment 154, particularly in summer. In the second state, as shown in FIG. 8 , the control unit 160 controls the first switching valve 142 of the coolant module 100C to allow the coolant flowing in from the fifth coolant flow path 135 to flow into the sixth coolant flow path 136 and to stop the flow of the coolant flowing in from the second coolant flow path 132. Therefore, no coolant flows through the seventh coolant flow path 137. The second switching valve 144 also controls the second switching valve 144 to allow the coolant flowing in from the ninth coolant flow path 139 to flow into the tenth coolant flow path 140. Under the control of the control unit 160, the first pump 100P1 is stopped and the second pump 100P2 is operating.

[0075] As described above, since the coolant does not flow through the first coolant flow path 131 and the second coolant flow path 132, in the second state, heat exchange does not occur in the water-cooled condenser 112, and heat exchange occurs only in the chiller 114. The coolant that flows through the third coolant flow path 133 and flows into the chiller 114 exchanges heat with the refrigerant that flows into the chiller 114, is cooled, and flows out into the fifth coolant flow path 135 and the eleventh coolant flow path 141. The coolant that flows through the eleventh coolant flow path 141 flows into the first heat exchanger 152, where it dehumidifies, cools, and heats the outside air. After being heated in the first heat exchanger 152, the coolant flows through the third coolant flow path 133 via the second pump 100P2 and flows back into the chiller 114. The outside air that has been dehumidified and cooled by heat exchange in the first heat exchanger 152 is sent toward the second heat exchanger 153.

[0076] The coolant that flows out of the chiller 114 and flows through the fifth coolant flow path 135 flows through the sixth coolant flow path 136 via the first switching valve 142 and is stored in the reserve tank 146. The reserve tank 146 stores low-temperature coolant that was stored during the previous flow, and the coolant that was stored previously flows out, followed by the coolant that has newly flowed into the reserve tank 146. The coolant that flows out of the reserve tank 146 flows through the fourth coolant flow path 134 and into the second heat exchanger 153. In the second heat exchanger 153, the low-temperature coolant exchanges heat with the outside air cooled in the first heat exchanger 152, further dehumidifying and cooling the outside air. This heats the coolant. The heated coolant flows out of the second heat exchanger 153, passes through the ninth coolant flow path 139, the second switching valve 144, the tenth coolant flow path 140, and the second pump 100P2, flows through the third coolant flow path 133, and then flows back into the chiller 114.

[0077] In this way, the outside air introduced from the blower 151 is dehumidified and cooled by heat exchange in both the first heat exchanger 152 and the second heat exchanger 153, and is supplied as dehumidified cool air to the passenger compartment 154. In this way, the inside of the passenger compartment 154 is dehumidified and cooled.

[0078] As in the first state, when the outside air temperature is high, if the vehicle air conditioning system 100A is temporarily stopped and left for a long period of time, the coolant temperature will rise. However, unlike the first state, in the second state, both the first heat exchanger 152 and the second heat exchanger 153 are used to generate cool air for cooling. The reserve tank 146 is located upstream of the second heat exchanger 153. As described above, the reserve tank 146 stores coolant at approximately the same temperature as the coolant that flowed through the sixth coolant flow path 136 when the vehicle air conditioning system 100A was operating in the second state before the vehicle air conditioning system 100A was stopped. In other words, the temperature of the coolant stored in the reserve tank 146 is low, approximately the same as the temperature cooled by the chiller 114.

[0079] Therefore, when the vehicle air-conditioning system 100A is restarted a long time after it was shut down, immediately after the restart, coolant that has not been sufficiently cooled by the chiller 114 flows into the first heat exchanger 152, and sufficiently cooled coolant stored in the reserve tank 146 flows into the second heat exchanger 153. As a result, the outside air that has undergone heat exchange in the first heat exchanger 152 is not sufficiently cooled, but the outside air is dehumidified and cooled by heat exchange with the sufficiently cooled, low-temperature coolant in the second heat exchanger 153. Then, the outside air that has been sufficiently dehumidified and cooled by heat exchange in the second heat exchanger 153 is sent to the passenger compartment 154 as cool air, thereby quickly dehumidifying and cooling the passenger compartment 154. After the chiller 114 is started again, sufficiently cooled, low-temperature coolant continues to flow into the first heat exchanger 152 and the second heat exchanger 153, thereby continuously dehumidifying and cooling the passenger compartment 154. In this way, the vehicle air conditioning system 100A can quickly perform its cooling function immediately after restarting.

[0080] In the second state, the heat capacity of the coolant cooled through the chiller 114 is distributed to the first heat exchanger 152 and the second heat exchanger 153, so the air passing through the first heat exchanger 152 is not rapidly cooled, and a decrease in air humidity can be suppressed compared to the first state. Therefore, the amount of condensation that forms on the surfaces of the first heat exchanger 152 and the second heat exchanger 153 in the second state is smaller than the amount of condensation that forms on the first heat exchanger 152 in the first state.

[0081] [Third State] The third state of the vehicle air conditioning system A is a heating mode for heating the passenger compartment 154, particularly in winter. In the third state, as shown in FIG. 9 , the control unit 160 controls the first switching valve 142 of the coolant module 100C to allow the coolant flowing in from the second coolant flow path 132 to flow into the sixth coolant flow path 136 and to stop the flow of the coolant flowing in from the fifth coolant flow path 135. Therefore, no coolant flows through the seventh coolant flow path 137. In addition, the second switching valve 144 controls the coolant flowing in from the ninth coolant flow path 139 to flow into the first coolant flow path 131. Under the control of the control unit 160, the first pump 100P1 is operating and the second pump 100P2 is stopped.

[0082] As described above, because the operation of the second pump 100P2 is stopped, the coolant does not flow through the third coolant flow path 133 and the fifth coolant flow path 135. Therefore, in the third state, heat exchange does not occur in the chiller 114, and heat exchange occurs only in the water-cooled condenser 112. Also, in the third state, the coolant does not flow into the first heat exchanger 152, and therefore, heat exchange does not occur in the first heat exchanger 152. Therefore, the outside air introduced from the blower 151 is sent directly to the second heat exchanger 153 without being heat exchanged in the first heat exchanger 152.

[0083] The coolant flowing through the first coolant flow path 131 is pumped by the first pump 100P1 and flows into the water-cooled condenser 112. The coolant that flows into the water-cooled condenser 112 exchanges heat with the refrigerant that has flowed into the water-cooled condenser 112, is heated, and flows out into the second coolant flow path 132. The coolant that flows through the second coolant flow path 132 flows through the sixth coolant flow path 136 via the first switching valve 142 and is stored in the reserve tank 146. The reserve tank 146 stores high-temperature coolant that was stored during the previous flow, and the coolant that was stored during the previous flow flows out, followed by the coolant that has newly flowed into the reserve tank 146. The coolant that flows out of the reserve tank 146 flows through the fourth coolant flow path 134 and flows into the second heat exchanger 153. In the second heat exchanger 153, the high-temperature coolant exchanges heat with the outside air cooled in the first heat exchanger 152, heating the outside air. This cools the coolant. The cooled coolant flows out of the second heat exchanger 153, passes through the ninth coolant flow path 139, the second switching valve 144, the first coolant flow path 131, and the first pump 100P1, and then flows into the water-cooled condenser 112 again.

[0084] In this way, since no coolant flows into the first heat exchanger 152, the outside air introduced from the blower 151 does not undergo heat exchange in the first heat exchanger 152, but undergoes heat exchange and is heated in the second heat exchanger 153. The heated outside air is supplied to the passenger compartment 154 as heated warm air. In this way, the inside of the passenger compartment 154 is heated.

[0085] When the outside air temperature is low, if the vehicle air conditioning system 100A is stopped for a long period of time, the coolant temperature will drop. However, the reserve tank 146 is located upstream of the second heat exchanger 153. As described above, the reserve tank 146 stores coolant at approximately the same temperature as the coolant that flowed through the sixth coolant flow path 136 when the vehicle air conditioning system 100A was operating in the third state before the vehicle air conditioning system 100A was stopped. In other words, the temperature of the coolant stored in the reserve tank 146 is high, approximately the same as the temperature to which the coolant was heated by the water-cooled condenser 112.

[0086] Therefore, when the vehicle air-conditioning system 100A is restarted after a long time has elapsed since the system was shut down, the sufficiently heated, high-temperature coolant stored in the reserve tank 146 flows into the second heat exchanger 153 immediately after the restart. The outside air is heated by heat exchange with the sufficiently heated coolant in the second heat exchanger 153. The sufficiently heated outside air is then sent to the passenger compartment 154 as warm air, thereby quickly heating the passenger compartment 154. This allows the vehicle air-conditioning system 100A to quickly perform its heating function. After the water-cooled condenser 112 is activated after the system is restarted, the sufficiently heated, high-temperature coolant continues to flow into the second heat exchanger 153, allowing the passenger compartment 154 to be continuously heated.

[0087] [Fourth State] The fourth state of the vehicle air conditioning system 100A is a heating mode that dehumidifies and heats the passenger compartment 154, particularly in winter. In the fourth state, as shown in FIG. 10 , the control unit 160 controls the first switching valve 142 of the coolant module 100C to allow the coolant flowing in from the second coolant flow path 132 to flow into the sixth coolant flow path 136 and to stop the flow of the coolant flowing in from the fifth coolant flow path 135. Therefore, no coolant flows through the seventh coolant flow path 137. The second switching valve 144 is also controlled to allow the coolant flowing in from the ninth coolant flow path 139 to flow into the first coolant flow path 131. Under the control of the control unit 160, both the first pump 100P1 and the second pump 100P2 are operating.

[0088] Because the second pump 100P2 is operating, the coolant flows through the third coolant flow path 133. The coolant that flows through the third coolant flow path 133 and enters the chiller 114 exchanges heat with the refrigerant that has flowed into the chiller 114, is cooled, and flows out into the eleventh coolant flow path 141. Because flow is stopped by the first switching valve 142, the coolant does not flow through the fifth coolant flow path 135. The coolant then flows into the first heat exchanger 152, where it dehumidifies, cools, and heats the outside air introduced from the blower 151. After being heated in the first heat exchanger 152, the coolant flows through the third coolant flow path 133 via the second pump 100P2 and flows back into the chiller 114. The outside air that has been dehumidified and cooled by heat exchange in the first heat exchanger 152 is sent toward the second heat exchanger 153.

[0089] Meanwhile, the coolant flowing through the first coolant flow path 131 is pumped by the first pump 100P1 and flows into the water-cooled condenser 112. The coolant that flows into the water-cooled condenser 112 exchanges heat with the refrigerant that has flowed into the water-cooled condenser 112, is heated, and flows out into the second coolant flow path 132. The coolant that flows through the second coolant flow path 132 flows through the sixth coolant flow path 136 via the first switching valve 142 and is stored in the reserve tank 146. The reserve tank 146 stores high-temperature coolant that was stored during the previous flow, and the coolant that was stored during the previous flow flows out, followed by the coolant that has newly flowed into the reserve tank 146. The coolant that flows out of the reserve tank 146 flows through the fourth coolant flow path 134 and flows into the second heat exchanger 153. In the second heat exchanger 153, the high-temperature coolant exchanges heat with the outside air that has been dehumidified and cooled in the first heat exchanger 152, heating the outside air. This heats the coolant in a dehumidified state. The cooled coolant flows out of the second heat exchanger 153, passes through the ninth coolant flow path 139, the second switching valve 144, the first coolant flow path 131, and the first pump 100P1, and then flows again into the water-cooled condenser 112.

[0090] In this way, the outside air introduced from the blower 151 is dehumidified and cooled by the first heat exchanger 152, and then heated in a dehumidified state by the second heat exchanger 153. The dehumidified warm air is then supplied to the passenger compartment 154. In this way, the inside of the passenger compartment 154 is dehumidified and heated.

[0091] When the outside air temperature is low, if the vehicle air conditioning system 100A is temporarily stopped and left for a long period of time, the coolant temperature will drop. However, the reserve tank 146 is located upstream of the second heat exchanger 153. As described above, the reserve tank 146 stores coolant at approximately the same temperature as the coolant that flowed through the sixth coolant flow path 136 when the vehicle air conditioning system 100A was operating in the fourth state before the vehicle air conditioning system 100A was stopped. In other words, the temperature of the coolant stored in the reserve tank 146 is high, approximately the same as the temperature to which the coolant was heated by the water-cooled condenser 112.

[0092] Therefore, when the vehicle air-conditioning system 100A is restarted after a long time has elapsed since the system was shut down, the sufficiently heated, high-temperature coolant stored in the reserve tank 146 flows into the second heat exchanger 153 immediately after the restart. The outside air dehumidified and cooled by the first heat exchanger 152 is heated by heat exchange with the sufficiently heated coolant in the second heat exchanger 153. The sufficiently heated outside air is then sent to the passenger compartment 154 as dehumidified, heated warm air, thereby quickly dehumidifying and heating the passenger compartment 154. This allows the vehicle air-conditioning system 100A to quickly perform its heating function. After the water-cooled condenser 112 is activated after the system is restarted, the sufficiently heated, high-temperature coolant continues to flow into the second heat exchanger 153, allowing the passenger compartment 154 to be continuously dehumidified and heated.

[0093] 11 , in a vehicle air conditioning system 100A according to a third embodiment, a flow control valve 145 is disposed at a branch point of an eleventh coolant flow path 141 through which coolant flows out from a chiller 114 and a fifth coolant flow path 135. The flow control valve 145 is configured to be able to control the amount of coolant flowing through each of the eleventh coolant flow path 141 and the fifth coolant flow path 135. Other configurations are the same as those in the second embodiment.

[0094] The vehicle air conditioning system 100A is provided with the flow control valve 145, which makes it possible to easily change the amount of coolant flowing into the first heat exchanger 152 and the amount of coolant flowing into the second heat exchanger 153. This makes it possible to appropriately adjust the degree of cooling and heating by the first heat exchanger 152 and the second heat exchanger 153, thereby optimizing dehumidification, cooling, and heating.

[0095] [Another embodiment of the second and third embodiments] In the above embodiment, the reserve tank 146 is formed integrally with the coolant module 100C. Alternatively, the reserve tank 146 may be formed integrally with the HVAC unit 100D.

[0096] In the above embodiment, the vehicle air conditioning system 100A is configured to include, as the switching mechanism, the first switching valve 142 and the second switching valve 144. Although not shown, the vehicle air conditioning system 100A may be configured to include a plurality of on-off valves as the switching mechanism.

[0097] Fourth Embodiment FIG. 12 is a diagram showing the circuit configuration of a vehicle air conditioning system 200A according to a fourth embodiment. The vehicle air conditioning system 200A is mounted on a vehicle and, as shown in FIG. 12, includes a refrigerant module 200B, a coolant module 200C, and an HVAC (Heating, Ventilation, and Air Conditioning) unit 200D. The refrigerant module 200B is provided with a refrigerant flow path 200B1 and configured as a refrigerant manifold. The coolant module 200C is provided with a coolant flow path 200C1 and configured as a coolant manifold. Here, the manifold is a flow path housing formed by laminating and sealing a plate member on a housing main body in which the coolant flow path 200C1 and the refrigerant flow path 200B1 are engraved. The flow path housing is formed of a metal material with high thermal conductivity, including aluminum. The HVAC unit 200D is provided with a first heat exchanger 252 capable of exchanging heat with the chiller 214, and a second heat exchanger 253 capable of exchanging heat with the water-cooled condenser 212.

[0098] A refrigerant such as a hydrofluorocarbon (HFC) or a hydrofluoroolefin (HFO) flows through the refrigerant flow path 200B1, and a cooling liquid such as antifreeze or long-life coolant whose main component is ethylene glycol, or a cooling liquid composed of insulating oil such as paraffin, flows through the cooling liquid flow path 200C1.

[0099] 12, refrigerant flow path 200B1 circulates refrigerant between water-cooled condenser 212 and chiller 214. Refrigerant module 200B is configured to allow refrigerant to flow between accumulator 210, compressor 211, water-cooled condenser 212 (an example of a "condenser"), expansion valve 213, and chiller 214 (an example of an "evaporator") via refrigerant flow path 200B1.

[0100] The accumulator 210 stores a liquid refrigerant and separates the stored refrigerant into gas and liquid. The gas refrigerant separated by the accumulator 210 flows through a first refrigerant passage 221 and is sent to the compressor 211.

[0101] The compressor 211 compresses the refrigerant from the accumulator 210. As a result, the refrigerant becomes a high-temperature compressed gas. The compressor 211 sends this high-temperature compressed gas to the water-cooled condenser 212 via the second refrigerant path 222. Therefore, the compressor 211 pressure-feeds the refrigerant from the accumulator 210 to the water-cooled condenser 212.

[0102] The refrigerant that has passed through the compressor 211 flows through the water-cooled condenser 212. The water-cooled condenser 212 is configured so that the coolant flows in through a first coolant flow path 231 and flows out through a second coolant flow path 232. The first coolant flow path 231 and the second coolant flow path 232 are configured separately from the second coolant path 222. The refrigerant from the second coolant path 222 is condensed and liquefied as heat is absorbed by the coolant. The liquefied refrigerant is sent to the third coolant path 223. Like the second coolant path 222, the third coolant path 223 is also configured separately from the first coolant flow path 231 and the second coolant flow path 232.

[0103] In the expansion valve 213, the refrigerant (liquefied refrigerant) flowing through the third refrigerant passage 223 is expanded and converted into a low-temperature, low-pressure mist. The mist-like refrigerant is sent to the fourth refrigerant passage 224.

[0104] The refrigerant flows through the chiller 214 via a fourth refrigerant path 224. As described above, the refrigerant expanded by the expansion valve 213 and converted into a low-temperature, low-pressure atomized refrigerant flows through the fourth refrigerant path 224, and this refrigerant is sent to the chiller 214. The chiller 214 is configured such that the coolant that has undergone heat exchange in the first heat exchanger 252 flows into the chiller 214 from the third coolant path 233, and the coolant flows out from the fourth coolant path 234 and the fifth coolant path 235. The third coolant path 233, the fourth coolant path 234, and the fifth coolant path 235 are configured separately from the fourth refrigerant path 224. In the chiller 214, the atomized refrigerant absorbs heat from the coolant and evaporates. The evaporated refrigerant flows through the fifth refrigerant path 225 to the accumulator 210.

[0105] The coolant flow path 200C1 carries coolant that exchanges heat with the refrigerant in the water-cooled condenser 212 and the chiller 214. The coolant module 200C is configured so that the coolant can flow through the coolant flow path 200C1 between the water-cooled condenser 212, the chiller 214, the first switching valve 242, the radiator 243, the second heat exchanger 253, and the second switching valve 244 by a first pump 200P1 and a second pump 200P2.

[0106] The coolant flow path 200C1 has a switching mechanism 200E that can switch between a first state in which the coolant is circulated through the chiller 214 and the first heat exchanger 252, and a second state in which the coolant is circulated through the chiller 214 and the first and second heat exchangers 252 and 253. The switching mechanism 200E includes a first switching valve 242 and a second switching valve 244. In this embodiment, the first switching valve 242 is a four-way valve, and the second switching valve 244 is a three-way valve.

[0107] The first switching valve 242 switches the direction in which the coolant discharged from the chiller 214 flows, to either the first heat exchanger 252 only or to both the first heat exchanger 252 and the second heat exchanger 253. The second switching valve 244 switches the direction in which the coolant discharged from the second heat exchanger 253 flows, to either the chiller 214 or the water-cooled condenser 212.

[0108] As described above, the water-cooled condenser 212 is configured so that the coolant flows in through the first coolant flow path 231 and flows out through the second coolant flow path 232. The first coolant flow path 231 is provided with a first pump 200P1, and the coolant is delivered by this first pump 200P1.

[0109] The first switching valve 242 is configured to allow the coolant to flow from the water-cooled condenser 212 and the chiller 214. The coolant is sent to the first switching valve 242 from the water-cooled condenser 212 via the second coolant flow path 232, and the coolant is sent from the chiller 214 via the fifth coolant flow path 235. A second pump 200P2 is provided in the third coolant flow path 233, and the second pump 200P2 sends the coolant from the second heat exchanger 253 to the chiller 214. The first switching valve 242 is configured to allow the coolant to be sent to the sixth coolant flow path 236 and the seventh coolant flow path 237.

[0110] The coolant sent from the first switching valve 242 to the sixth coolant flow path 236 flows through the second heat exchanger 253. The coolant sent to the second heat exchanger 253 is configured to be able to be sent to the water-cooled condenser 212 via the ninth coolant flow path 239, the second switching valve 244, and the first coolant flow path 231. In addition, the coolant sent to the second heat exchanger 253 is configured to be able to be sent to the chiller 214 via the ninth coolant flow path 239, the second switching valve 244, the tenth coolant flow path 240, and the third coolant flow path 233.

[0111] The coolant sent from the first switching valve 242 to the seventh coolant flow path 237 flows to the radiator 243. In the radiator 243, heat exchange with outside air occurs, and the coolant is cooled. After heat exchange, the coolant is sent to the first coolant flow path 231 via the eighth coolant flow path 238.

[0112] The HVAC unit 200D includes a blower 251, a first heat exchanger 252, and a second heat exchanger 253. The blower 251 draws in outside air and sends the drawn outside air to the first heat exchanger 252.

[0113] The first heat exchanger 252 and the second heat exchanger 253 exchange heat between air and coolant to cool or heat the vehicle cabin. The air is outside air drawn in by the blower 251. As described above, coolant is introduced into the first heat exchanger 252 via the fourth coolant flow path 234 and sent to the third coolant flow path 233. As described above, coolant is introduced into the second heat exchanger 253 via the sixth coolant flow path 236 and sent to the first coolant flow path 231. Therefore, in the first heat exchanger 252, heat exchange occurs between the outside air sent from the blower 251 and the coolant supplied via the fourth coolant flow path 234. In the second heat exchanger 253, heat exchange occurs between the air that has passed through the first heat exchanger 252 and the coolant supplied via the sixth coolant flow path 236, and the air after heat exchange is introduced into the vehicle cabin.

[0114] 13 , in the first state, the first switching valve 242 blocks the flow from the fifth coolant flow path 235 to the sixth coolant flow path 236, and the second switching valve 244 blocks the flow from the ninth coolant flow path 239 to the tenth coolant flow path 240. Note that in the first state and second to fourth states described below, the switching of the first switching valve 242 and the second switching valve 244 and the operation control of the first pump 200P1 and the second pump 200P2 are performed by the control unit 260. In the first state, the first pump 200P1 and the second pump 200P2 are driven.

[0115] When the first pump 200P1 is driven, the coolant that flows through the first coolant flow path 231 and into the water-cooled condenser 212 exchanges heat with the refrigerant that has flowed into the water-cooled condenser 212, is heated, and flows out into the second coolant flow path 232. Thereafter, the coolant flows through the seventh coolant flow path 237 and into the radiator 243, is cooled by the radiator 243, flows through the eighth coolant flow path 238 and the first coolant flow path 231, and flows into the water-cooled condenser 212 again.

[0116] Furthermore, by driving the second pump 200P2, the coolant from the chiller 214 is supplied to the first heat exchanger 252, the outside air is cooled by the first heat exchanger 252, and no coolant is supplied to the second heat exchanger 253. In other words, the vehicle air conditioning system 200A introduces cool air into the vehicle cabin by cooling using only the first heat exchanger 252.

[0117] [Second State] As shown in FIG. 14 , in the second state, the first switching valve 242 allows flow from the fifth coolant flow path 235 to the sixth coolant flow path 236, and the second switching valve 244 allows flow from the ninth coolant flow path 239 to the tenth coolant flow path 240. Furthermore, the second pump 200P2 is driven. In contrast, the first pump 200P1 is stopped. As a result, coolant from the chiller 214 is supplied to the first heat exchanger 252, and the outside air is cooled by the first heat exchanger 252. In addition, coolant from the chiller 214 is also supplied to the second heat exchanger 253, and the outside air cooled by the first heat exchanger 252 is cooled. In other words, the vehicle air conditioning system 200A introduces cool air into the vehicle cabin by cooling using the first heat exchanger 252 and the second heat exchanger 253.

[0118] In the second state, the heat capacity of the coolant cooled through the chiller 214 is distributed to the first heat exchanger 252 and the second heat exchanger 253, so the air passing through the first heat exchanger 252 is not cooled rapidly. Therefore, it is possible to suppress a decrease in humidity in the air compared to when cooling is performed only by the first heat exchanger 252 as in the first state.

[0119] 15 , in the third state, the first switching valve 242 blocks the flow from the fifth coolant flow path 235 to the sixth coolant flow path 236 and allows the flow from the second coolant flow path 232 to the sixth coolant flow path 236. The second switching valve 244 also allows the flow from the ninth coolant flow path 239 to the first coolant flow path 231 and blocks the flow from the ninth coolant flow path 239 to the tenth coolant flow path 240. Furthermore, the first pump 200P1 is driven and the second pump 200P2 is stopped. As a result, the coolant from the chiller 214 is not supplied to the first heat exchanger 252, and the outside air is not cooled by the first heat exchanger 252. Meanwhile, the coolant from the water-cooled condenser 212 is supplied to the second heat exchanger 253, heating the outside air. That is, in the vehicle air conditioning system 200A, warm air is introduced into the vehicle compartment by heating using the second heat exchanger 253.

[0120] 16 , in the fourth state, the first switching valve 242 blocks the flow from the fifth coolant flow path 235 to the sixth coolant flow path 236 and allows the flow from the second coolant flow path 232 to the sixth coolant flow path 236. The second switching valve 244 also allows the flow from the ninth coolant flow path 239 to the first coolant flow path 231 and blocks the flow from the ninth coolant flow path 239 to the tenth coolant flow path 240. Furthermore, the first pump 200P1 and the second pump 200P2 are driven. As a result, the coolant from the chiller 214 is supplied to the first heat exchanger 252, and the outside air is cooled by the first heat exchanger 252. Meanwhile, the coolant from the water-cooled condenser 212 is supplied to the second heat exchanger 253, and the outside air is heated. That is, in the vehicle air conditioning system 200A, the air dehumidified by the first heat exchanger 252 is heated by the second heat exchanger 253. Thus, in the fourth state, dehumidifying and heating is performed and warm air is introduced into the vehicle cabin. In this case, dehumidified and heated air can be supplied into the vehicle cabin when the defroster function is used, for example, in winter.

[0121] As described above, the first switching valve 242 is configured to allow the coolant from the water-cooled condenser 212 and the coolant from the chiller 214 to flow through it. When the coolant from the water-cooled condenser 212 is compared with the coolant from the chiller 214, the temperature of the coolant from the water-cooled condenser 212 is relatively higher than the temperature of the coolant from the chiller 214. Therefore, when the second heat exchanger 253 is used to heat the vehicle cabin, the first switching valve 242 and the second switching valve 244 are set to the third state or the fourth state in which the coolant is circulated through the water-cooled condenser 212, and when the second heat exchanger 253 is used to cool the vehicle cabin, the first switching valve 242 and the second switching valve 244 are set to the first state or the second state in which the coolant is circulated through the chiller 214.

[0122] In the present embodiment, the first switching valve 242 may be configured to change its opening degree so as to simultaneously realize the first state and the second state. In this case, the first switching valve 242 can mix the relatively high-temperature coolant from the water-cooled condenser 212 and the relatively low-temperature coolant from the chiller 214 and send the mixed coolant to the sixth coolant flow path 236.

[0123] 17 , in a vehicle air conditioning system 200A according to the fifth embodiment, a flow control valve 245 is disposed at a branch point of a fourth coolant flow path 234 and a fifth coolant flow path 235 through which coolant flows out from a chiller 214. The flow control valve 245 is configured to be able to control the amount of coolant flowing through each of the fourth coolant flow path 234 and the fifth coolant flow path 235. Other configurations are the same as those of the fourth embodiment.

[0124] The vehicle air conditioning system 200A is provided with the flow control valve 245, which makes it possible to easily change the amount of coolant flowing through the first heat exchanger 252 and the amount of coolant flowing through the second heat exchanger 253. This makes it possible to appropriately adjust the cooling power of the first heat exchanger 252 and the second heat exchanger 253, thereby optimizing dehumidification and cooling.

[0125] [Alternative to the Fourth and Fifth Embodiments] Next, an alternative to the vehicle air conditioning system 200A of the fourth and fifth embodiments will be described.

[0126] In the above embodiment, the vehicle air conditioning system 200A has been described as an example in which the switching mechanism 200E controls the switching of the first switching valve 242 and the second switching valve 244. Alternatively, the vehicle air conditioning system 200A may be configured to include sensors capable of detecting the temperature and humidity of the air introduced into the first heat exchanger 252 and the temperature of the coolant introduced into the first heat exchanger 252, and the following control may be performed by the control unit 260. The control unit 260 controls the switching to the second state when the predicted humidity of the air after heat exchange in the first heat exchanger 252, which is predicted based on the temperature and humidity of the air introduced into the first heat exchanger 252 and the temperature of the coolant introduced into the first heat exchanger 252 detected by the various sensors, becomes equal to or lower than a predetermined value (e.g., 10%).

[0127] In this embodiment, the humidity of the air introduced into the vehicle cabin after heat exchange in the first heat exchanger 252 is predicted based on the temperature and humidity of the air introduced into the first heat exchanger 252 and the temperature of the coolant introduced into the first heat exchanger 252, making it possible to adjust the humidity of the air introduced into the vehicle cabin in real time. Furthermore, when this predicted humidity becomes equal to or lower than a predetermined value, the control unit 260 switches the switching mechanism E to the second state, thereby maintaining the vehicle cabin in an optimal air-conditioned state.

[0128] In the above embodiment, the vehicle air conditioning system 200A has been described as an example in which the switching mechanism 200E includes the first switching valve 242 and the second switching valve 244. Although not shown, the vehicle air conditioning system 200A may have the switching mechanism 200E configured by a plurality of on-off valves.

[0129] In the above embodiment, the first switching valve 242 is described as being capable of changing its opening degree so as to simultaneously realize the first state and the second state. However, the first switching valve 242 may be configured so as not to simultaneously realize the first state and the second state. For example, by changing the period during which the coolant circulates through the first heat exchanger 252 and the second heat exchanger 253, the air conditioning temperature can be changed in multiple stages.

[0130] [Outline of the above embodiment] The vehicle air conditioning systems A, 100A, and 200A described above will now be outlined.

[0131] (1) The vehicle air conditioning system A is configured to include a refrigerant flow path B1 that circulates refrigerant between the water-cooled condenser 12 (condenser) and the chiller 14 (evaporator), a coolant flow path C1 that circulates coolant that exchanges heat with the refrigerant in the water-cooled condenser 12 (condenser) and the chiller 14 (evaporator), and a heat exchanger 52 that exchanges heat between air and coolant to cool and heat the vehicle interior.

[0132] According to this configuration, when heating the vehicle interior, the coolant warmed by the water-cooled condenser 12 flows through the heat exchanger 52 to perform heat exchange, and when cooling the vehicle interior, the coolant cooled by the chiller 14 flows through the heat exchanger 52 to perform heat exchange. This allows the interior evaporator and heater core provided in conventional vehicle air conditioning systems to be replaced by a single heat exchanger 52, thereby making it possible to reduce the size and cost of the vehicle air conditioning system A. Therefore, a vehicle air conditioning system A with a small and inexpensive configuration can be realized.

[0133] (2) In the vehicle air conditioning system A described in (1), it is preferable that a switching valve 42 is arranged in the coolant flow path C1, which can be switched between a first state in which the coolant is circulated to the water-cooled condenser 12 and a second state in which the coolant is circulated to the chiller 14.

[0134] According to this configuration, when the vehicle interior is heated, the switching valve 42 is switched to the first state, allowing the coolant warmed in the water-cooled condenser 12 to flow through the heat exchanger 52, and when the vehicle interior is cooled, the switching valve 42 is switched to the second state, allowing the coolant cooled in the chiller 14 to flow through the heat exchanger 52. In this way, the switching valve 42 makes it possible to easily switch the coolant to be circulated through the heat exchanger 52.

[0135] (3) In the vehicle air conditioning system A described in (2), it is preferable that the switching valve 42 is capable of changing the opening degree so as to simultaneously realize the first state and the second state.

[0136] For example, when heating the vehicle interior, if only coolant that has been warmed by the water-cooled condenser 12 is circulated through the heat exchanger 52, the heating intensity may be too strong. Also, when cooling the vehicle interior, if only coolant that has been cooled by the chiller 14 is circulated through the heat exchanger 52, the cooling intensity may be too strong. Therefore, with this configuration, the switching valve 42 can circulate both coolant that has been warmed by the water-cooled condenser 12 and coolant that has been cooled by the chiller 14 through the heat exchanger 52, making it possible to adjust the intensity of heating or cooling the vehicle interior.

[0137] (4) In the vehicle air conditioning system A described in (3), it is preferable that the switching valve 42 adjusts the ratio of the flow rate of the coolant from the chiller 14 to the flow rate of the coolant from the water-cooled condenser 12 .

[0138] According to this configuration, by controlling the flow rate of the coolant from the water-cooled condenser 12 and the flow rate of the coolant from the chiller 14, the temperature of the coolant sent to the heat exchanger 52 can be adjusted, thereby making it possible to adjust the temperature inside the vehicle cabin.

[0139] (5) In the vehicle air conditioning system A described in (3), it is preferable that the opening degree of the switching valve 42 is changed according to the set temperature of the air conditioning in the vehicle compartment.

[0140] According to this configuration, by controlling the flow rate of the coolant from the water-cooled condenser 12 and the flow rate of the coolant from the chiller 14 according to the set temperature of the air conditioning in the vehicle cabin, the temperature of the coolant sent to the heat exchanger 52 is adjusted, and the temperature in the vehicle cabin can be adjusted to the set temperature of the air conditioning.

[0141] (6) In the vehicle air conditioning system 100A described in (1), it is preferable to further include a reserve tank 146 (storage section) that is arranged upstream of the heat exchangers 152, 153 in the coolant flow path 100C1 and stores the coolant in an insulated state.

[0142] According to this configuration, low-temperature coolant can be stored in the reserve tank 146 in the summer, and high-temperature coolant can be stored in the reserve tank 146 in the winter. As a result, when it is desired to quickly start cooling or heating the vehicle after starting it, the low-temperature or high-temperature coolant stored in the reserve tank 146 can be introduced into the heat exchangers 152, 153, and cool or warm air can be quickly sent into the passenger compartment 154.

[0143] (7) In the vehicle air conditioning system 100A described in (6), the insulated state is a state in which the amount of temperature change per unit time of the coolant stored inside the reserve tank 146 is smaller than the amount of temperature change per unit time of the coolant present in the coolant flow path 100C1.

[0144] According to this configuration, the temperature of the coolant stored inside the reserve tank 146 can be maintained at approximately the same temperature as the temperature of the coolant when the vehicle air conditioning system 100A was operating before being stopped, even long after the vehicle air conditioning system 100A has stopped operating. Therefore, immediately after the vehicle air conditioning system 100A is subsequently restarted, it becomes possible to use coolant at approximately the same temperature as the temperature of the coolant when the vehicle air conditioning system 100A was operating before being stopped.

[0145] In the vehicle air conditioning system 100A described in (8) (6) or (7), the heat exchangers 152, 153 have a first heat exchanger 152 capable of exchanging heat between air and coolant, and a second heat exchanger 153 capable of exchanging heat between the air and coolant after heat exchange in the first heat exchanger 152, and it is preferable that the reserve tank 146 stores the coolant to be introduced into the second heat exchanger 153.

[0146] This configuration includes a first heat exchanger 152 capable of exchanging heat between air and coolant, and a second heat exchanger 153 capable of exchanging heat between the air and coolant after heat exchange in the first heat exchanger 152, eliminating the need for a desiccant or other drying material and enabling downsizing. Furthermore, the reserve tank 146 of this embodiment stores the coolant to be introduced into the second heat exchanger 153, thereby adjusting the temperature of the air immediately before it is introduced into the passenger compartment 154, and enabling cool or warm air to be quickly sent into the passenger compartment 154.

[0147] (9) The vehicle air conditioning system 200A includes a refrigerant flow path 200B1 that circulates refrigerant between the water-cooled condenser 212 and the chiller 214, a coolant flow path 200C1 that circulates coolant that exchanges heat with the refrigerant in the water-cooled condenser 212 and the chiller 214, a first heat exchanger 252 that can exchange heat between air and the coolant, and a second heat exchanger 253 that can exchange heat between the air and the coolant after heat exchange in the first heat exchanger 252, and the coolant flow path 200C1 has a switching mechanism 200E that can switch between a first state in which the coolant is circulated between the chiller 214 and the first heat exchanger 252 and a second state in which the coolant is circulated between the chiller 214 and the first heat exchanger 252 and the second heat exchanger 253.

[0148] According to this configuration, in the first state, the same cooling mode as in the conventional system is performed. In the second state, the coolant cooled through the chiller 214 can be distributed to the first heat exchanger 252 and the second heat exchanger 253. In this second state, the heat capacity of the coolant cooled through the chiller 214 is distributed to the first heat exchanger 252 and the second heat exchanger 253. This prevents the air passing through the first heat exchanger 252 from being cooled rapidly, thereby suppressing a decrease in humidity compared to when the air is cooled only by the first heat exchanger 252, as in the first state. Furthermore, by adjusting the flow rate of the coolant circulating through the first heat exchanger 252 and the second heat exchanger 253, it is possible to adjust the humidity of the air introduced into the vehicle cabin. Thus, a vehicle air conditioning system 200A capable of adjusting the humidity of the blown air can be realized.

[0149] (10) In the vehicle air conditioning system 200A described in (9), it is preferable that the switching mechanism 200E includes a first switching valve 242 that switches the direction in which the coolant discharged from the chiller 214 flows to only the first heat exchanger 252 or to both the first heat exchanger 252 and the second heat exchanger 253, and a second switching valve 244 that switches the direction in which the coolant discharged from the second heat exchanger 253 flows to the chiller 214 or the water-cooled condenser 212.

[0150] According to this configuration, if the first switching valve 242 is set to direct the flow direction of the coolant discharged from the chiller 214 to both the first heat exchanger 252 and the second heat exchanger 253, and the second switching valve 244 is set to direct the flow direction of the coolant discharged from the second heat exchanger 253 to the chiller 214, it is possible to adjust the humidity of the blown air in the cooling mode. In this way, if the switching mechanism 200E is formed with two switching valves (the first switching valve 242 and the second switching valve 244), the device configuration can be simplified.

[0151] The technology disclosed herein can be used in a vehicle air conditioning system installed in a vehicle.

[0152] [First embodiment] 12: water-cooled condenser (condenser), 14: chiller (evaporator), 42: switching valve, 52: heat exchanger, A: vehicle air conditioning system, B1: refrigerant flow path, C1: coolant flow path,

[0153] [Second embodiment, third embodiment] 146: reserve tank (storage portion), 152: first heat exchanger (heat exchanger), 153: second heat exchanger (heat exchanger), 100A: vehicle air conditioning system, 100C1: coolant flow path,

[0154] [Fourth and Fifth Embodiments] 212: Water-cooled condenser (condenser), 214: Chiller (evaporator), 242: First switching valve, 244: Second switching valve, 252: First heat exchanger, 253: Second heat exchanger, 200A: Vehicle air conditioning system, 200B1: Refrigerant flow path, 200C1: Coolant flow path, 200E: Switching mechanism

Claims

1. A vehicle air conditioning system comprising: a refrigerant flow path that circulates a refrigerant between a condenser and an evaporator; a coolant flow path that circulates a coolant that exchanges heat with the refrigerant in the condenser and the evaporator; and a heat exchanger that exchanges heat between air and the coolant to cool or heat an interior of a vehicle.

2. A vehicle air conditioning system as described in claim 1, wherein a switching valve is disposed in the cooling liquid flow path, which can be switched between a first state in which the cooling liquid is circulated through the condenser and a second state in which the cooling liquid is circulated through the evaporator.

3. The vehicle air conditioning system according to claim 2, wherein the degree of opening of the switching valve is changeable so as to simultaneously realize the first state and the second state.

4. The vehicle air conditioning system according to claim 3, wherein the switching valve adjusts the ratio of the flow rate of the coolant from the evaporator to the flow rate of the coolant from the condenser.

5. A vehicle air conditioning system according to claim 3, wherein the opening degree of the switching valve is changed in accordance with a set temperature of the air conditioning in the vehicle compartment.

6. The vehicle air conditioning system according to claim 1, further comprising a reservoir section arranged upstream of the heat exchanger in the coolant flow path, for storing the coolant in an insulated state.

7. A vehicle air conditioning system as described in claim 6, wherein the insulated state is a state in which the amount of temperature change per unit time of the coolant stored inside the storage portion is smaller than the amount of temperature change per unit time of the coolant present in the coolant flow path.

8. A vehicle air conditioning system as described in claim 6 or 7, wherein the heat exchanger has a first heat exchanger capable of exchanging heat between the air and the coolant, and a second heat exchanger capable of exchanging heat between the air and the coolant after heat exchange in the first heat exchanger, and the storage section stores the coolant to be introduced into the second heat exchanger.

9. A vehicle air conditioning system comprising: a refrigerant flow path that circulates refrigerant between a condenser and an evaporator; a coolant flow path that circulates a coolant that exchanges heat with the refrigerant in the condenser and the evaporator; a first heat exchanger that can exchange heat between air and the coolant; and a second heat exchanger that can exchange heat between the air and the coolant after heat exchange in the first heat exchanger, wherein the coolant flow path has a switching mechanism that can be switched between a first state in which the coolant is circulated between the evaporator and the first heat exchanger, and a second state in which the coolant is circulated between the evaporator and the first heat exchanger and the second heat exchanger.

10. The vehicle air conditioning system of claim 9, wherein the switching mechanism includes a first switching valve that switches the direction in which the cooling liquid discharged from the evaporator flows to only the first heat exchanger or to both the first heat exchanger and the second heat exchanger, and a second switching valve that switches the direction in which the cooling liquid discharged from the second heat exchanger flows to the evaporator or the condenser.

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