Vehicular temperature control system and method for controlling vehicular temperature control system

Abstract

Provided is a vehicular temperature control system (100) characterized by comprising: an HVAC unit (30) including a first low-pressure–side heat exchanger (14), a second low-pressure–side heat exchanger (24), and a blower (32); and a switching damper for switching between a recirculation state and an outside air intake state. In the recirculation state, a second flow rate of air passing through the second low-pressure–side heat exchanger (24) is greater than a first flow rate of air passing through the first low-pressure–side heat exchanger (14).

Description

Vehicle temperature control system and control method for vehicle temperature control system

[0001] The present disclosure relates to a vehicle temperature control system and a method for controlling a vehicle temperature control system.

[0002] There is an example of a temperature control system equipped with two refrigeration cycles for performing air conditioning for the vehicle cabin and temperature management for the battery (Patent Document 1). The temperature control system described in Patent Document 1 includes a first refrigerant circuit including an electric compressor, an air-cooled condenser, a vehicle cabin evaporator, and an auxiliary chiller for the battery, and a second refrigerant circuit including an engine-driven compressor, an air-cooled condenser, and a main chiller for the battery. The main chiller of the second refrigerant circuit cools the coolant supplied to the battery while the engine is running.

[0003] U.S. Pat. No. 10,639,957

[0004] When conditioning the interior of a vehicle cabin in a temperature control system equipped with two refrigeration cycles, a first refrigeration cycle and a second refrigeration cycle, there are cases where the air inside the vehicle cabin is circulated and cases where outside air is introduced. When outside air is introduced and the temperature difference between the outside air and a target temperature is large, it is desirable to control the temperature of the air using both the first heat exchanger whose temperature is controlled by the first refrigeration cycle and the second heat exchanger whose temperature is controlled by the second refrigeration cycle. On the other hand, when the air inside the vehicle cabin is circulated and the temperature difference between the inside air and a target temperature is small, it is desirable to control the temperature of the air using only one of the first heat exchanger whose temperature is controlled by the first refrigeration cycle and the second heat exchanger whose temperature is controlled by the second refrigeration cycle.

[0005] However, when circulating air inside the vehicle cabin, if the air passes through one of the first and second heat exchangers that is not used for temperature control, the heat exchanger will create ventilation resistance, resulting in a decrease in the energy consumption efficiency (COP).

[0006] The present disclosure has been made in consideration of the above circumstances, and aims to provide a vehicle temperature control system and a control method for a vehicle temperature control system that can improve the COP in a vehicle temperature control system equipped with multiple refrigeration cycles.

[0007] In order to solve the above problems, the present disclosure provides a vehicle temperature control system and a method for controlling the vehicle temperature control system, the vehicle temperature control system including: a first heat exchanger whose temperature is controlled by a first refrigeration cycle in which a first refrigerant circulates; a second heat exchanger whose temperature is controlled by a second refrigeration cycle in which a second refrigerant circulates; a temperature control unit having a blower that passes air through the first heat exchanger and the second heat exchanger and directs the air into the vehicle cabin; and a switching unit that switches between an inside air circulation state in which air inside the vehicle cabin is introduced into the temperature control unit and an outside air introduction state in which air outside the vehicle cabin is introduced into the temperature control unit, wherein in the inside air circulation state, a second flow rate of air passing through the second heat exchanger is greater than a first flow rate of air passing through the first heat exchanger.

[0008] In a control method for a vehicle temperature control system according to one aspect of the present disclosure, the vehicle temperature control system includes a temperature control unit having a first heat exchanger whose temperature is controlled by a first refrigeration cycle in which a first refrigerant is circulated, a second heat exchanger whose temperature is controlled by a second refrigeration cycle in which a second refrigerant is circulated, a blower that passes air through the first heat exchanger and the second heat exchanger and guides it into a vehicle compartment, and a flow rate adjustment damper that changes the flow rate of air passing through the second heat exchanger when the blower is operating; and an inside air circulation state in which air inside the vehicle compartment is introduced into the temperature control unit and air outside the vehicle compartment is introduced into the temperature control unit. and a control step of controlling the first refrigeration cycle and the second refrigeration cycle so as to set a first temperature control state in which the temperatures of both the first heat exchanger and the second heat exchanger are controlled in the outside air introduction state and a second temperature control state in which the temperature of the first heat exchanger is not controlled but the temperature of the second heat exchanger is controlled in the inside air circulation state, the control step controlling the flow rate adjustment damper so that a second flow rate of air passing through the second heat exchanger is greater than a first flow rate of air passing through the first heat exchanger in the inside air circulation state. In addition, in the inside air circulation state, there are cases where all of the air introduced into the temperature control unit is air inside the vehicle cabin and cases where some of the air is air outside the vehicle cabin (when the inside / outside air switching damper is set between an inside air position and an outside air position).

[0009] According to the present disclosure, it is possible to provide a vehicle temperature control system and a method for controlling a vehicle temperature control system that can improve the COP in a vehicle temperature control system equipped with multiple refrigeration cycles.

[0010] FIG. 1 is a schematic configuration diagram showing a vehicle temperature control system according to a first embodiment of the present disclosure, showing a state in which the vehicle temperature control system introduces air from outside the vehicle cabin to perform cooling operation. FIG. 2 is a schematic configuration diagram showing a vehicle temperature control system according to a first embodiment of the present disclosure, showing a state in which the vehicle temperature control system circulates air inside the vehicle cabin to perform cooling operation. FIG. 3 is a block diagram showing a control configuration of the vehicle temperature control system according to the first embodiment of the present disclosure. FIG. 4 is a flowchart showing a control method for the vehicle temperature control system according to the first embodiment of the present disclosure. FIG. 5 is a schematic configuration diagram showing a vehicle temperature control system according to a second embodiment of the present disclosure, showing a state in which the vehicle temperature control system introduces air from outside the vehicle cabin to perform cooling operation. FIG. 6 is a schematic configuration diagram showing a vehicle temperature control system according to a second embodiment of the present disclosure, showing a state in which the vehicle temperature control system circulates air inside the vehicle cabin to perform cooling operation. FIG. 7 is a schematic configuration diagram showing a vehicle temperature control system according to a third embodiment of the present disclosure, showing a state in which the vehicle temperature control system introduces air from outside the vehicle cabin to perform heating operation. 10 is a schematic diagram showing a vehicle temperature control system according to a third embodiment of the present disclosure, illustrating a state in which the vehicle temperature control system is performing heating operation by circulating air in the vehicle cabin. FIG.

[0011] First Embodiment A vehicle temperature control system 100 according to a first embodiment of the present disclosure will be described with reference to the drawings. The vehicle temperature control system 100 of this embodiment is installed in a vehicle (not shown), such as an electric vehicle that does not have an engine and obtains driving force for running the vehicle from an electric motor, or a so-called hybrid vehicle that obtains driving force for running the vehicle from an engine and an electric motor.

[0012] The vehicle temperature control system 100 is responsible for air conditioning such as heating and cooling, dehumidification, and ventilation of the passenger compartment, as well as heat management and waste heat recovery for on-board devices such as the battery (not shown), traction motor (not shown), and heat-generating electronic devices installed in the vehicle. Conditioning the air to an appropriate temperature and humidity, and maintaining on-board devices at an appropriate temperature, are collectively referred to as "thermal management."

[0013] Fig. 1 is a schematic diagram showing a vehicle temperature control system 100 according to a first embodiment of the present disclosure, illustrating a state in which the vehicle temperature control system 100 is operating in cooling mode by introducing air from outside the vehicle cabin. Fig. 2 is a schematic diagram showing a vehicle temperature control system 100 according to a first embodiment of the present disclosure, illustrating a state in which the vehicle temperature control system 100 is operating in cooling mode by circulating air from inside the vehicle cabin. Fig. 3 is a block diagram showing the control configuration of the vehicle temperature control system 100 according to the first embodiment of the present disclosure.

[0014] As shown in FIG. 1 , the vehicle temperature control system 100 includes a first refrigeration cycle 10, a second refrigeration cycle 20, an HVAC unit (temperature control unit) 30, a switching damper (switching unit) 40, and a control unit 50.

[0015] The first refrigeration cycle 10 includes a first compressor 11, a first high-pressure heat exchanger 12, a first expansion valve 13, a first low-pressure heat exchanger (first heat exchanger) 14, and a first refrigerant flow path 14a. The first refrigeration cycle 10 is connected by the first refrigerant flow path 14a, and circulates a first refrigerant R1 between the first compressor 11, the first high-pressure heat exchanger 12, the first expansion valve 13, and the first low-pressure heat exchanger 14 when the vehicle temperature control system 100 is operating in cooling mode with outside air introduced. The first low-pressure heat exchanger 14 is a heat exchanger whose temperature is controlled by the first refrigeration cycle 10.

[0016] The first compressor 11 compresses the first refrigerant R1 guided from the first low-pressure side heat exchanger 14 and discharges it to the first high-pressure side heat exchanger 12. The first high-pressure side heat exchanger 12 is supplied with the first refrigerant R1 compressed by the first compressor 11 and exchanges heat between the first refrigerant R1 and outside air. The first expansion valve 13 expands the first refrigerant R1 supplied from the first high-pressure side heat exchanger 12 and supplies it to the first low-pressure side heat exchanger 14. The first low-pressure side heat exchanger 14 is supplied with the first refrigerant R1 expanded by the first expansion valve 13 and exchanges heat between the decompressed first refrigerant R1 and air blown by the blower 32. The first refrigerant R1 that has passed through the first low-pressure side heat exchanger 14 is guided to the first compressor 11.

[0017] The second refrigeration cycle 20 includes a second compressor 21, a second high-pressure heat exchanger 22, a second expansion valve 23, a second low-pressure heat exchanger (second heat exchanger) 24, a refrigerant flow path 25, an expansion valve 26, and a low-pressure heat exchanger 27. The second refrigeration cycle 20 is connected by the refrigerant flow path 25, and circulates a second refrigerant R2 between the second compressor 21, the second high-pressure heat exchanger 22, the second expansion valve 23, and the second low-pressure heat exchanger 24 when the vehicle temperature control system 100 is operating in cooling mode in the inside air circulation mode or the outside air circulation mode. The second low-pressure heat exchanger 24 is a heat exchanger whose temperature is controlled by the second refrigeration cycle 20.

[0018] The second compressor 21 compresses the second refrigerant R2 guided from the second low-pressure side heat exchanger 24 and discharges it to the second high-pressure side heat exchanger 22. The second high-pressure side heat exchanger 22 is supplied with the second refrigerant R2 compressed by the second compressor 21 and performs heat exchange between the high-temperature, high-pressure second refrigerant R2 and a heat exchange medium HM (e.g., water) circulating through the exterior heat exchanger 60. The supply state of the heat exchange medium HM is switched by a switching valve 28b.

[0019] The second expansion valve 23 expands the second refrigerant R2 supplied from the second high-pressure side heat exchanger 22 and supplies the expanded refrigerant to the second low-pressure side heat exchanger 24. The second low-pressure side heat exchanger 24 is supplied with the second refrigerant R2 expanded by the second expansion valve 23, and exchanges heat between the decompressed second refrigerant R2 and air blown by the blower 32. The second refrigerant R2 that has passed through the second low-pressure side heat exchanger 24 is guided to the second compressor 21.

[0020] The HVAC unit 30 includes a first low-pressure heat exchanger 14, a second low-pressure heat exchanger 24, an interior heat exchanger 31, a blower 32, and a flow rate adjustment damper (flow rate adjustment mechanism) 33. The blower 32 is a device that passes air through the first low-pressure heat exchanger 14 and the second low-pressure heat exchanger 24 to guide temperature-adjusted air into the vehicle cabin.

[0021] When the vehicle temperature control system 100 is in heating operation, the interior heat exchanger 31 is supplied with a heat exchange medium (e.g., water) that has exchanged heat with the second refrigerant R2 in the second high-pressure heat exchanger 22. The pump 28 circulates the heat exchange medium between the second high-pressure heat exchanger 22 and the interior heat exchanger 31. The interior heat exchanger 31 heats air blown by the blower 32 by exchanging heat between the heat exchange medium and the air. The heat exchange medium that has exchanged heat with the second refrigerant R2 in the low-pressure heat exchanger 27 passes through a heat exchange medium passage (not shown) and absorbs heat from the exterior heat exchanger 60. When the vehicle temperature control system 100 is in heating operation, the second refrigerant R2 circulates between the second compressor 21, the second high-pressure heat exchanger 22, the expansion valve 26, and the low-pressure heat exchanger 27.

[0022] The first low-pressure heat exchanger 14 is disposed upstream of the second low-pressure heat exchanger 24 in the flow direction AD of the air guided by the blower 32. The interior heat exchanger 31 is disposed downstream of the second low-pressure heat exchanger 24 in the flow direction AD of the air guided by the blower 32.

[0023] When the vehicle temperature control system 100 is operating in cooling mode with outside air introduced, the first refrigerant R1 expanded by the first expansion valve 13 is supplied to the first low-pressure side heat exchanger 14. The first low-pressure side heat exchanger 14 exchanges heat between the air blown by the blower 32 and the first refrigerant R1 to cool the air.

[0024] When the vehicle temperature control system 100 is in cooling operation, the second refrigerant R2 expanded by the second expansion valve 23 is supplied to the second low-pressure side heat exchanger 24. The second low-pressure side heat exchanger 24 exchanges heat between the air blown by the blower 32 and the second refrigerant R2 to cool the air.

[0025] The flow rate adjustment damper 33 is a device that changes the flow rate of air passing through the first low-pressure side heat exchanger 14 when the blower 32 is operating. The flow rate adjustment damper 33 is disposed between the blower 32 and the first low-pressure side heat exchanger 14 in the flow direction AD of air circulating through the HVAC unit 30. The flow rate adjustment damper 33 is controlled by the control unit 50 so that the second flow rate of air passing through the second low-pressure side heat exchanger 24 is greater than the first flow rate of air passing through the first low-pressure side heat exchanger 14 in the internal air circulation state shown in FIG. 2 .

[0026] The switching damper 40 is a device that switches between an inside air circulation state in which air inside the vehicle cabin is introduced into the HVAC unit 30 and an outside air introduction state in which air outside the vehicle cabin is introduced into the HVAC unit 30. The switching damper 40 switches between the inside air circulation state and the outside air introduction state based on a control command from the control unit 50. The switching damper 40 switches between an inside air circulation state in which air flowing through the inside air circulation flow path 30a that introduces air inside the vehicle cabin into the HVAC unit 30 is introduced into the second low-pressure side heat exchanger 24, and an outside air introduction state in which air flowing through the outside air introduction flow path 30b is introduced into the second low-pressure side heat exchanger 24.

[0027] The control unit 50 is a device that controls the vehicle temperature control system 100. The control unit 50 controls each part of the vehicle temperature control system 100, including the first refrigeration cycle 10, the second refrigeration cycle 20, the HVAC unit 30, and the switching damper 40.

[0028] Next, a control method for the vehicle temperature control system 100 according to this embodiment will be described with reference to Figures 4 and 5. Figures 4 and 5 are flowcharts showing the control method for the vehicle temperature control system 100 according to the first embodiment of the present disclosure. Figures 4 and 5 show the control method when the vehicle temperature control system 100 performs cooling operation.

[0029] In step S101, the control unit 50 determines whether the operator has specified the outside air introduction state or the inside air introduction state, and if the answer is YES (outside air introduction), the process proceeds to step S102, and if the answer is NO (inside air introduction), the process proceeds to step S111.

[0030] In step S102, the control unit 50 determines whether the air conditioning capacity required by the HVAC unit 30 is greater than the specified capacity based on the temperature difference between the temperature of the introduced outside air and the set temperature set by the operator, and if the answer is YES, proceeds to step S103, and if the answer is NO, proceeds to step S107.

[0031] In step S103, the control unit 50 sets the first refrigeration cycle 10 to an operating state and circulates the first refrigerant R1 between the first compressor 11, the first high-pressure side heat exchanger 12, the first expansion valve 13, and the first low-pressure side heat exchanger 14.

[0032] In step S104, the control unit 50 sets the second refrigeration cycle 20 to an operating state, and circulates the second refrigerant R2 between the second compressor 21, the second high-pressure side heat exchanger 22, the second expansion valve 23, and the second low-pressure side heat exchanger 24. The control unit 50 controls the first refrigeration cycle 10 and the second refrigeration cycle 20 to a first temperature control state in which the temperatures of both the first low-pressure side heat exchanger 14 and the second low-pressure side heat exchanger 24 are controlled.

[0033] In step S105 , the control unit 50 sets the switching damper 40 to the outside air introduction state, thereby introducing air outside the vehicle compartment (outside air Ae) into the HVAC unit 30 .

[0034] In step S106, the control unit 50 sets the flow rate adjustment damper 33 to the first heat exchanger ventilation state so that most of the outside air Ae introduced into the HVAC unit 30 passes through the first low-pressure side heat exchanger 14. As shown in Fig. 1 , the control unit 50 places the flow rate adjustment damper 33 at a position indicated by a solid line, spaced apart from the upstream side of the first low-pressure side heat exchanger 14 in a direction perpendicular to the air flow direction AD, so as not to block the upstream side of the first low-pressure side heat exchanger 14 in the air flow direction AD.

[0035] In step S107, the control unit 50 sets the first refrigeration cycle 10 to a stopped state, so that the first refrigerant R1 does not circulate between the first compressor 11, the first high-pressure side heat exchanger 12, the first expansion valve 13, and the first low-pressure side heat exchanger 14. Note that the first compressor 11 may be set to an operating state, so that the first refrigerant R1 circulates so as to bypass the first low-pressure side heat exchanger 14 through a bypass refrigerant flow path (not shown).

[0036] In step S108, the control unit 50 sets the second refrigeration cycle 20 to an operating state, and circulates the second refrigerant R2 between the second compressor 21, the second high-pressure side heat exchanger 22, the second expansion valve 23, and the second low-pressure side heat exchanger 24. The control unit 50 controls the first refrigeration cycle 10 and the second refrigeration cycle 20 to a second temperature control state in which the first low-pressure side heat exchanger 14 is not temperature-controlled and the second low-pressure side heat exchanger 24 is temperature-controlled.

[0037] In step S109 , the control unit 50 sets the switching damper 40 to the outside air introduction state, thereby bringing about a state in which air outside the vehicle compartment (outside air Ae) is introduced into the HVAC unit 30 .

[0038] In step S110, the control unit 50 sets the flow rate adjustment damper 33 to the first heat exchanger bypass state so that most of the outside air Ae introduced into the HVAC unit 30 does not pass through the first low-pressure side heat exchanger 14. As shown in Fig. 1 , the control unit 50 places the flow rate adjustment damper 33 at the position indicated by the dotted line upstream of the first low-pressure side heat exchanger 14 so as to block the upstream side of the first low-pressure side heat exchanger 14 in the air flow direction AD.

[0039] In step S111, the control unit 50 determines whether the air conditioning capacity required by the HVAC unit 30 is greater than a predetermined capacity based on the temperature difference between the temperature of the introduced inside air and the set temperature set by the operator, and if the answer is YES, proceeds to step S112, and if the answer is NO, proceeds to step S116.

[0040] In step S112, the control unit 50 sets the first refrigeration cycle 10 to an operating state and circulates the first refrigerant R1 between the first compressor 11, the first high-pressure side heat exchanger 12, the first expansion valve 13, and the first low-pressure side heat exchanger 14.

[0041] In step S113, the control unit 50 sets the second refrigeration cycle 20 to an operating state, and circulates the second refrigerant R2 between the second compressor 21, the second high-pressure side heat exchanger 22, the second expansion valve 23, and the second low-pressure side heat exchanger 24. The control unit 50 controls the first refrigeration cycle 10 and the second refrigeration cycle 20 to a first temperature control state in which the temperatures of both the first low-pressure side heat exchanger 14 and the second low-pressure side heat exchanger 24 are controlled.

[0042] In step S114 , the control unit 50 sets the switching damper 40 to the inside air circulation state, so that the air inside the vehicle compartment (inside air Ai) is introduced into the HVAC unit 30 .

[0043] In step S115, the control unit 50 sets the flow rate adjustment damper 33 to the first heat exchanger ventilation state so that most of the inside air Ai introduced into the HVAC unit 30 passes through the first low-pressure side heat exchanger 14. As shown in Fig. 2 , the control unit 50 places the flow rate adjustment damper 33 at a position indicated by a dotted line, spaced apart from the upstream side of the first low-pressure side heat exchanger 14 in a direction perpendicular to the air flow direction AD, so as not to block the upstream side of the first low-pressure side heat exchanger 14 in the air flow direction AD.

[0044] In step S116, the control unit 50 sets the first refrigeration cycle 10 to a stopped state, so that the first refrigerant R1 does not circulate between the first compressor 11, the first high-pressure side heat exchanger 12, the first expansion valve 13, and the first low-pressure side heat exchanger 14. Note that the first compressor 11 may be set to an operating state, so that the first refrigerant R1 circulates so as to bypass the first low-pressure side heat exchanger 14 through a bypass refrigerant flow path (not shown).

[0045] In step S117, the control unit 50 sets the second refrigeration cycle 20 to an operating state, and circulates the second refrigerant R2 between the second compressor 21, the second high-pressure side heat exchanger 22, the second expansion valve 23, and the second low-pressure side heat exchanger 24. The control unit 50 controls the first refrigeration cycle 10 and the second refrigeration cycle 20 to a second temperature control state in which the first low-pressure side heat exchanger 14 is not temperature-controlled and the second low-pressure side heat exchanger 24 is temperature-controlled.

[0046] In step S118 , the control unit 50 sets the switching damper 40 to the inside air circulation state, so that the air inside the vehicle compartment (inside air Ai) is introduced into the HVAC unit 30 .

[0047] In step S119, the control unit 50 sets the flow rate adjustment damper 33 to an internal air circulation state so that most of the internal air Ai introduced into the HVAC unit 30 does not pass through the first low-pressure side heat exchanger 14. As shown in Fig. 2 , the control unit 50 places the flow rate adjustment damper 33 at a position indicated by a solid line upstream of the first low-pressure side heat exchanger 14 so as to block the upstream side of the first low-pressure side heat exchanger 14 in the air flow direction AD.

[0048] After executing steps S106, S110, S115, and S119, the control unit 50 ends the process of this flowchart and repeats the process from step S101 again.

[0049] In the embodiment described above, the vehicle temperature control system 100 includes the flow rate adjustment damper 33 that changes the flow rate of air passing through the first low-pressure heat exchanger 14 when the blower 32 is operating, in addition to the switching damper 40 that switches between an interior air circulation mode in which air inside the vehicle cabin is introduced into the HVAC unit 30 and an outside air introduction mode in which air outside the vehicle cabin is introduced into the HVAC unit 30. However, other configurations are also possible. For example, the switching damper 40 may have both the function of switching between the interior air circulation mode and the outside air introduction mode and the function of changing the flow rate of air passing through the first low-pressure heat exchanger 14 when the blower 32 is operating. The vehicle temperature control system 100 of this modified example does not include the flow rate adjustment damper 33 shown in FIGS. 1 and 2 .

[0050] In the vehicle temperature control system 100 of this embodiment described above, the first low-pressure side heat exchanger 14 may be arranged in the outside air intake passage 30b that introduces outside air into the second low-pressure side heat exchanger 24 of the HVAC unit 30.

[0051] The operation and effects of the vehicle temperature control system 100 of the present embodiment described above will now be described.

[0052] Passing air through the first low-pressure heat exchanger 14, which is not temperature-controlled in the interior air recirculation mode, generates ventilation resistance and reduces the coefficient of performance (COP). Therefore, in the vehicle temperature control system 100 of this embodiment, the flow rate adjustment damper 33 is controlled so that the second flow rate of air passing through the second low-pressure heat exchanger 24 is greater than the first flow rate of air passing through the first low-pressure heat exchanger 14, which is temperature-controlled by the first refrigeration cycle 10, in the interior air recirculation mode. By using the flow rate adjustment damper 33 to reduce the ventilation resistance when air passes through the first low-pressure heat exchanger 14, the COP of the vehicle temperature control system 100, which has multiple refrigeration cycles, can be improved.

[0053] According to the vehicle temperature control system 100 of this embodiment, the first low-pressure heat exchanger 14 is disposed in the outside air intake passage, and in the internal air recirculation state, air does not pass through the first low-pressure heat exchanger 14, causing no ventilation resistance. Therefore, in the internal air recirculation state, it is possible to prevent a decrease in COP due to air passing through the first low-pressure heat exchanger 14.

[0054] According to the vehicle temperature control system 100 of this embodiment, the switching damper 40 can switch between an internal air circulation state in which air circulating through the internal air circulation flow path is introduced into the second low-pressure side heat exchanger 24, and an external air introduction state in which air circulating through the external air introduction flow path is introduced into the second low-pressure side heat exchanger 24.

[0055] According to the vehicle temperature control system 100 of this embodiment, by arranging the flow control damper 33 downstream of the first low-pressure side heat exchanger 14 in the air flow direction AD, it is possible to reliably prevent air from being directed to the first low-pressure side heat exchanger 14 in the internal air circulation state.

[0056] Second Embodiment Next, a vehicle temperature control system 100A according to a second embodiment of the present disclosure will be described with reference to the drawings. The second embodiment is a modification of the first embodiment, and is similar to the first embodiment except where specifically described below, and therefore will not be described again.

[0057] In the vehicle temperature control system 100 according to the first embodiment, the HVAC unit 30 includes a first low-pressure heat exchanger 14 whose temperature is controlled by a first refrigerant R1 circulating through a first refrigeration cycle 10, and a second low-pressure heat exchanger 24 whose temperature is controlled by a second refrigerant R2 circulating through a second refrigeration cycle 20. In contrast, the vehicle temperature control system 100A according to the present embodiment includes a first heat exchanger 15 whose temperature is controlled by a heat exchange medium M1 that has exchanged heat with the first refrigerant R1 circulating through the first refrigeration cycle 10, and a second heat exchanger 24A whose temperature is controlled by a heat exchange medium M2 that has exchanged heat with a second refrigerant R2 circulating through a second refrigeration cycle 20.

[0058] Fig. 6 is a schematic diagram showing a vehicle temperature control system 100A according to a second embodiment of the present disclosure, illustrating a state in which the vehicle temperature control system 100A is operating in cooling mode by introducing air from outside the vehicle cabin. Fig. 7 is a schematic diagram showing a vehicle temperature control system 100A according to a second embodiment of the present disclosure, illustrating a state in which the vehicle temperature control system 100A is operating in cooling mode by circulating air from inside the vehicle cabin.

[0059] The first refrigeration cycle 10 includes a first heat exchanger 15 whose temperature is controlled by a heat exchange medium M1 that has exchanged heat with a first refrigerant R1 in a first low-pressure side heat exchanger 14, and a pump 16. The heat exchange medium M1 is circulated by the pump 16 through a first heat exchange medium flow path 16a between the first low-pressure side heat exchanger 14 and the first heat exchanger 15.

[0060] The second refrigeration cycle 20 includes a second heat exchanger 24A whose temperature is controlled by a heat exchange medium M2 that has exchanged heat with a second refrigerant R2 in a low-pressure side heat exchanger 27, and a pump 29. The heat exchange medium M2 is circulated by the pump 29 through a second heat exchange medium flow path 29a between the low-pressure side heat exchanger 27 and the second heat exchanger 24A.

[0061] As shown in Figure 6, the control unit 50 controls the first refrigeration cycle 10 and the second refrigeration cycle 20 to enter a first temperature control state in which both the first low-pressure side heat exchanger 14 and the second low-pressure side heat exchanger 24 are temperature-controlled in the outside air introduction state.

[0062] 6, the control unit 50 sets the switching damper 40 to the outside air introduction state so that all of the outside air Ae introduced into the HVAC unit 30 passes through the first heat exchanger 15. As shown in Fig. 5, the control unit 50 places the switching damper 40 at a position spaced apart from the downstream side of the first heat exchanger 15 in a direction perpendicular to the air flow direction AD so as not to block the downstream side of the first heat exchanger 15 in the air flow direction AD.

[0063] 7, the control unit 50 sets the switching damper 40 to the internal air circulation state so that most of the internal air Ai introduced into the HVAC unit 30 does not pass through the first heat exchanger 15. As shown in FIG. 7, the control unit 50 arranges the switching damper 40 downstream of the first heat exchanger 15 so as to block the downstream side of the first heat exchanger 15 in the air flow direction AD.

[0064] As shown in Figure 7, when the control unit 50 controls the switching damper 40 to the internal air circulation state, the second flow rate of air passing through the second heat exchanger 24A is greater than the first flow rate of air passing through the first heat exchanger 15.

[0065] Third Embodiment Next, a vehicle temperature control system 100B according to a third embodiment of the present disclosure will be described with reference to the drawings. The third embodiment is a modification of the first embodiment, and is similar to the first embodiment except where specifically described below, and therefore will not be described below.

[0066] In the vehicle temperature control system 100 according to the first embodiment, when performing cooling operation, the flow rate adjustment damper 33 is controlled so that the second flow rate of air passing through the second low-pressure heat exchanger 24 is greater than the first flow rate of air passing through the first low-pressure heat exchanger 14 in the interior air circulation state. In contrast, in the vehicle temperature control system 100B according to the present embodiment, when performing heating operation, the second flow rate of air passing through the interior heat exchanger 31 is greater than the first flow rate of air passing through the first heat exchanger 15 when the control unit 50 controls the switching damper 40 to the interior air circulation state.

[0067] Fig. 8 is a schematic diagram showing a vehicle temperature control system 100B according to a third embodiment of the present disclosure, illustrating a state in which the vehicle temperature control system 100B is operating in a heating mode by introducing air from outside the vehicle cabin. Fig. 9 is a schematic diagram showing a vehicle temperature control system 100B according to a third embodiment of the present disclosure, illustrating a state in which the vehicle temperature control system 100B is operating in a heating mode by circulating air from inside the vehicle cabin.

[0068] The first refrigeration cycle 10 includes a first heat exchanger 15 whose temperature is regulated by a heat exchange medium M1 that has exchanged heat with a first refrigerant R1 in a first high-pressure side heat exchanger 12, and a pump 16. The heat exchange medium M1 is circulated through a first heat exchange medium flow path 16a between the first high-pressure side heat exchanger 12 and the first heat exchanger 15 by the pump 16. The first high-pressure side heat exchanger 12 exchanges heat between the first refrigerant R1 and the heat exchange medium M1. By supplying the heat exchange medium M1 heated by the first refrigerant R1 to the first heat exchanger 15, outside air Ae can be heated in the first heat exchanger 15, thereby providing heating.

[0069] The second refrigeration cycle 20 includes a heat exchanger (second heat exchanger) 31 for vehicle interior air conditioning, whose temperature is adjusted by a heat exchange medium M2 that has exchanged heat with the second refrigerant R2 in the second high-pressure side heat exchanger 22, and a pump 28. The heat exchange medium M2 is circulated by the pump 28 through a second heat exchange medium flow path 28a between the second high-pressure side heat exchanger 22 and the vehicle interior heat exchanger 31.

[0070] As shown in Figure 8, the control unit 50 controls the first refrigeration cycle 10 and the second refrigeration cycle 20 to enter a first temperature control state in which both the first heat exchanger 15 and the interior heat exchanger 31 are temperature controlled in the outside air introduction state.

[0071] 8, the control unit 50 sets the switching damper 40 to the outside air introduction state so that most of the outside air Ae introduced into the HVAC unit 30 passes through the first heat exchanger 15. As shown in Fig. 8, the control unit 50 places the switching damper 40 at a position spaced apart from the downstream side of the first heat exchanger 15 in a direction perpendicular to the air flow direction AD so as not to block the downstream side of the first heat exchanger 15 in the air flow direction AD.

[0072] 9, the control unit 50 sets the switching damper 40 to the inside air circulation state so that most of the outside air Ae introduced into the HVAC unit 30 does not pass through the first heat exchanger 15. As shown in Fig. 9, the control unit 50 arranges the switching damper 40 downstream of the first heat exchanger 15 so as to block the downstream side of the first heat exchanger 15 in the air flow direction AD. Note that in the second temperature control state, the first compressor 11 may be set to an operating state so that the heat exchange medium is circulated so as to bypass the first heat exchanger 15 through a bypass heat exchange medium flow path (not shown).

[0073] As shown in Figure 9, when the control unit 50 controls the switching damper 40 to the internal air circulation state, the second flow rate of air passing through the in-vehicle heat exchanger 31 is greater than the first flow rate of air passing through the first heat exchanger 15.

[0074] The vehicle temperature control system according to each of the above-described embodiments can be understood as follows, for example: A vehicle temperature control system according to a first aspect of the present disclosure is a vehicle temperature control system (100) including a first heat exchanger (14) whose temperature is controlled by a first refrigeration cycle (10) through which a first refrigerant (R1) circulates, a second heat exchanger (24) whose temperature is controlled by a second refrigeration cycle (20) through which a second refrigerant (R2) circulates, a temperature control unit (30) having a blower (32) that passes air through the first heat exchanger and the second heat exchanger and guides it into a vehicle cabin, and a switching unit (40) that switches between an interior air circulation state in which air inside the vehicle cabin is introduced into the temperature control unit and an outside air introduction state in which air outside the vehicle cabin is introduced into the temperature control unit, and is characterized by having an operating mode in which a second flow rate of air passing through the second heat exchanger is greater than a first flow rate of air passing through the first heat exchanger in the interior air circulation state.

[0075] In the vehicle temperature control system according to the first aspect of the present disclosure, the second flow rate of air passing through the second heat exchanger is greater than the first flow rate of air passing through the first heat exchanger in the internal air recirculation state. By reducing the airflow resistance when air passes through the first heat exchanger, the COP of the vehicle temperature control system having multiple refrigeration cycles can be improved.

[0076] The vehicle temperature control system according to a second aspect of the present disclosure is the same as the first aspect, but further includes the following configuration: the temperature control unit has a flow rate adjustment mechanism that changes the flow rate of air passing through the first heat exchanger when the blower is operating.

[0077] A vehicle temperature control system according to a third aspect of the present disclosure is the first or second aspect, further including the following configuration: the first heat exchanger is disposed in an outside air introduction flow path that introduces outside air into the second heat exchanger.

[0078] In the vehicle temperature control system according to the third aspect of the present disclosure, the first heat exchanger is disposed in the outside air intake passage, and air does not pass through the first heat exchanger in the internal air recirculation state, causing no ventilation resistance. Therefore, it is possible to prevent a decrease in COP due to air passing through the first heat exchanger in the internal air recirculation state.

[0079] A vehicle temperature control system according to a fourth aspect of the present disclosure is the first or second aspect, further including the following configuration: the flow rate control damper is disposed downstream of the first heat exchanger in the flow direction of air flowing through the temperature control unit.

[0080] According to the vehicle temperature control system relating to the fourth aspect of the present disclosure, by arranging a flow control damper downstream of the first heat exchanger in the air flow direction, it is possible to reliably prevent air from being directed to the first heat exchanger in an internal air circulation state.

[0081] The vehicle temperature control system according to a fifth aspect of the present disclosure is the first or second aspect, further including the following configuration: the switching unit changes the flow rate of air passing through the first heat exchanger when the blower is operating.

[0082] The vehicle temperature control system according to a sixth aspect of the present disclosure is the first or second aspect, and further includes the following configuration: an operating mode in the outside air introduction state in which the temperatures of both the first heat exchanger and the second heat exchanger are controlled in a first temperature control state, and an operating mode in the inside air circulation state in which the temperature of the first heat exchanger is not controlled but the temperature of the second heat exchanger is controlled in a second temperature control state.

[0083] A vehicle temperature control system according to a seventh aspect of the present disclosure is the sixth aspect, further including the following configuration: a control unit that controls the first refrigeration cycle to stop circulation of the first refrigerant in the second temperature control state.

[0084] According to the vehicle temperature control system relating to the seventh aspect of the present disclosure, the COP of the vehicle temperature control system can be improved by controlling the first refrigeration cycle to stop the circulation of the first refrigerant in the second temperature control state.

[0085] The vehicle temperature control system according to an eighth aspect of the present disclosure is the first or second aspect, and further includes the following configuration: the first refrigeration cycle includes a first high-pressure side heat exchanger and a first low-pressure side heat exchanger that exchanges heat with air blown by the blower, the second refrigeration cycle includes a second high-pressure side heat exchanger that exchanges heat with a heat exchange medium circulating through an exterior heat exchanger or an interior heat exchanger, and a second low-pressure side heat exchanger that exchanges heat with the air blown by the blower, and the first low-pressure side heat exchanger is disposed upstream of the second low-pressure side heat exchanger in the flow direction of air guided by the blower.

[0086] In a control method for a vehicle temperature control system according to a ninth aspect of the present disclosure, the vehicle temperature control system includes a first heat exchanger whose temperature is controlled by a first refrigeration cycle in which a first refrigerant (R1) circulates, a second heat exchanger whose temperature is controlled by a second refrigeration cycle in which a second refrigerant (R2) circulates, a temperature control unit having a blower that passes air through the first heat exchanger and the second heat exchanger and guides it into a vehicle compartment, a switching unit that switches between an inside air circulation state in which air inside the vehicle compartment is introduced into the temperature control unit and an outside air introduction state in which air outside the vehicle compartment is introduced into the temperature control unit, and a flow of air passing through the second heat exchanger when the blower is operating. and a flow rate adjustment damper that changes the amount of air passing through the first refrigeration cycle and the second refrigeration cycle, and includes a control step (S102, S103, S106, S107) that controls the first refrigeration cycle and the second refrigeration cycle so that in the outside air introduction state, a first temperature control state is established in which the temperatures of both the first heat exchanger and the second heat exchanger are controlled, and in the internal air circulation state, a second temperature control state is established in which the temperature of the first heat exchanger is not controlled but the temperature of the second heat exchanger is controlled, and the control step controls the flow rate adjustment damper so that in the internal air circulation state, a second flow rate of air passing through the second heat exchanger is greater than a first flow rate of air passing through the first heat exchanger.

[0087] In the control method for a vehicle temperature control system according to a ninth aspect of the present disclosure, the second flow rate of air passing through the second heat exchanger is greater than the first flow rate of air passing through the first heat exchanger in the internal air recirculation state. By reducing the airflow resistance when air passes through the first heat exchanger, the COP of the vehicle temperature control system having multiple refrigeration cycles can be improved.

[0088] REFRIGERATION CYCLE 10 First refrigeration cycle 11 First compressor 12 First high-pressure side heat exchanger 13 First expansion valve 14 First low-pressure side heat exchanger (first heat exchanger) 14a First refrigerant flow path 15 First heat exchanger 16 Pump 20 Second refrigeration cycle 21 Second compressor 22 Second high-pressure side heat exchanger 23 Second expansion valve 24 Second low-pressure side heat exchanger (second heat exchanger) 24A Second heat exchanger 25 Refrigerant flow path 26 Expansion valve 27 Low-pressure side heat exchanger 28 Pump 28a Second heat exchange medium flow path 29 Pump 29a Second heat exchange medium flow path 30 HVAC unit (temperature control unit) 31 In-vehicle heat exchanger 32 Blower 33 Flow rate adjustment damper (flow rate adjustment mechanism) 40 Switching damper (switching unit) 50 Control unit 100, 100A, 100B Vehicle temperature control system AD Direction Ae Outside air Ai Inside air M1, M2 Heat exchange medium R1 First refrigerant R2 Second refrigerant

Claims

1. A vehicle temperature control system comprising: a first heat exchanger whose temperature is controlled by a first refrigeration cycle in which a first refrigerant circulates; a second heat exchanger whose temperature is controlled by a second refrigeration cycle in which a second refrigerant circulates; a temperature control unit having a blower that passes air through the first heat exchanger and the second heat exchanger and leads it into the vehicle cabin; and a switching unit that switches between an internal air circulation state in which air inside the vehicle cabin is introduced into the temperature control unit and an external air introduction state in which air outside the vehicle cabin is introduced into the temperature control unit, wherein the vehicle temperature control system has an operating mode in which the second flow rate of air passing through the second heat exchanger is greater than the first flow rate of air passing through the first heat exchanger in the internal air circulation state.

2. A vehicle temperature control system according to claim 1, wherein the temperature control unit has a flow rate adjusting mechanism that changes the flow rate of air passing through the first heat exchanger when the blower is operating.

3. A vehicle temperature control system according to claim 1 or 2, wherein the first heat exchanger is disposed in an outside air intake passage that introduces outside air into the second heat exchanger.

4. A vehicle temperature control system as described in claim 2, wherein the flow rate adjustment mechanism is a damper disposed between the blower and the first heat exchanger in the flow direction of air flowing through the temperature control unit.

5. A vehicle temperature control system according to claim 1 or 2, wherein the switching unit changes the flow rate of air passing through the first heat exchanger when the blower is operating.

6. A vehicle temperature control system as described in claim 1 or claim 2, having an operating mode in which a first temperature control state is set in which both the first heat exchanger and the second heat exchanger are temperature controlled in the outside air introduction state, and an operating mode in which a second temperature control state is set in which the first heat exchanger is not temperature controlled but the second heat exchanger is temperature controlled in the internal air circulation state.

7. The vehicle temperature control system according to claim 6, further comprising a control unit that controls the first refrigeration cycle so as to stop the circulation of the first refrigerant in the second temperature control state.

8. A temperature control system for a vehicle as described in claim 1 or claim 2, wherein the first refrigeration cycle comprises a first high-pressure side heat exchanger and a first low-pressure side heat exchanger that exchanges heat with the air blown by the blower, and the second refrigeration cycle comprises a second high-pressure side heat exchanger that exchanges heat with a heat exchange medium circulating through an exterior heat exchanger or an interior heat exchanger, and a second low-pressure side heat exchanger that exchanges heat with the air blown by the blower, and the first low-pressure side heat exchanger is arranged upstream of the second low-pressure side heat exchanger in the flow direction of the air guided by the blower.

9. A control method for a vehicle temperature control system, the vehicle temperature control system comprising: a first heat exchanger whose temperature is controlled by a first refrigeration cycle in which a first refrigerant is circulated; a second heat exchanger whose temperature is controlled by a second refrigeration cycle in which a second refrigerant is circulated; a temperature control unit having: a blower that passes air through the first heat exchanger and the second heat exchanger and leads it into the vehicle cabin; and a flow rate control damper that changes the flow rate of air passing through the second heat exchanger when the blower is operating; and a switching unit that switches between an inside air circulation state in which air inside the vehicle cabin is introduced into the temperature control unit and an outside air introduction state in which air outside the vehicle cabin is introduced into the temperature control unit, the control method comprising a control step of controlling the first refrigeration cycle and the second refrigeration cycle so as to set a first temperature control state in which both the first heat exchanger and the second heat exchanger are controlled in the outside air introduction state, and a second temperature control state in which the first heat exchanger is not controlled in temperature but the second heat exchanger is controlled in the inside air circulation state, The control step is a control method for a vehicle temperature control system that controls the flow rate control damper so that the second flow rate of air passing through the second heat exchanger is greater than the first flow rate of air passing through the first heat exchanger in the internal air circulation state.

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