Vehicular air-conditioner

Abstract

To provide a vehicular air-conditioner capable of improving quick warming performance.SOLUTION: A bypass path in which a refrigerant passing through a compressor 11 detours a heater core 12 and flows into a suction side 11b of the compressor 11, is equipped with refrigerant channels 10a, 10c, 10d, 10e, and 10q as a first path in which the refrigerant passing through the compressor 11 flows to an upstream side of an accumulator 15, and refrigerant channels 10a, 10c, 10f, and 10q as a second path in which the refrigerant passing through the compressor 11 flows to a downstream side of the accumulator 15. A control device 200, when starting a hot gas heating mode, increases a flow rate of the refrigerant flowing in the second path as compared with a flow rate of the refrigerant flowing in the first path.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an air conditioner for a vehicle. [Background technology]

[0002] Air conditioners using heat pumps are known as air conditioners for electric vehicles (EVs) that do not have a combustion heat source such as an engine, or for vehicles with a low amount of heat from a combustion heat source. However, air conditioners using heat pumps have difficulty absorbing heat from outside air when the outside temperature is extremely low, so the heating efficiency decreases. For this reason, for example, Patent Document 1 discloses a technology that employs a heating method called hot gas heating that utilizes the compressor of a heat pump when the outside temperature is extremely low. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2023-075844 Summary of the Invention [Problem to be solved by the invention]

[0004] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide an air conditioner for a vehicle that can improve the quick heating performance. [Means for solving the problem]

[0005] According to one aspect of the present invention, there is provided a vehicle air conditioning system configured to circulate a refrigerant through a compressor, a heater core that heats air supplied to a vehicle cabin, a pressure reducing device, a low-temperature side heat exchanger that causes a refrigerant to absorb heat from a heat medium absorbed from an on-board heat-generating device, and an accumulator, the refrigerant circuit including a bypass path in which the refrigerant that has passed through the compressor bypasses the heater core and flows into the suction side of the compressor, and a control device that can control the system to a hot gas heating mode in which a portion of the refrigerant that has passed through the compressor flows to the heater core and the remaining refrigerant flows to the bypass path, the bypass path including a first path in which the refrigerant that has passed through the compressor flows upstream of the accumulator, and a second path in which the refrigerant that has passed through the compressor flows downstream of the accumulator, and when the hot gas heating mode is activated, the control device increases the flow rate of the refrigerant flowing through the second path more than the flow rate of the refrigerant flowing through the first path. Effect of the Invention

[0006] According to the present invention, it is possible to provide a vehicle air conditioner capable of improving quick heating properties. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is a diagram showing an outline of a configuration example of a vehicle air conditioner according to a first embodiment, and is a diagram showing an example of a state of the vehicle air conditioner when hot gas heating is performed. [Diagram 2] FIG. 2 is a diagram showing an example of a block diagram of a control device in the vehicle air conditioner according to the first and second embodiments. [Diagram 3] FIG. 3 is a diagram showing an example of a flowchart illustrating a process procedure in the hot gas heating mode in the vehicle air conditioner according to the first and second embodiments. [Figure 4] FIG. 4 is a diagram showing an example of a flowchart illustrating a processing procedure in the hot gas heating mode in the vehicle air conditioner according to the first and second embodiments. [Diagram 5]FIG. 5 is a diagram showing an example of a flowchart illustrating a processing procedure in the hot gas heating mode in the vehicle air conditioner according to the first and second embodiments. [Figure 6] FIG. 6 is a diagram showing an outline of a configuration example of a vehicle air conditioner according to the second embodiment, and is a diagram showing an example of a state of the vehicle air conditioner when hot gas heating is performed. [Figure 7] FIG. 7 is a diagram showing an example of a flowchart illustrating a process procedure in the hot gas heating mode in the vehicle air conditioner according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [First embodiment] A first embodiment will be described.

[0009] [Configuration of vehicle air conditioning system] Overview of Vehicle Air Conditioning System The present embodiment relates to a vehicle air conditioner having a refrigerant circuit and a heat medium circuit. The vehicle air conditioner of the present embodiment is mounted on an electric vehicle, and is configured to improve the quick heating performance, prevent a decrease in the suction density of the refrigerant in the compressor, and extend the life of the compressor. Moreover, the vehicle air conditioner of this embodiment is configured to be capable of improving the quick heating property. Moreover, the vehicle air conditioner of this embodiment is configured to be able to increase the heating capacity for the vehicle interior when the heating capacity for the vehicle interior does not reach the target heating capacity. Moreover, the vehicle air conditioner of this embodiment is configured to be capable of preventing the occurrence of liquid backflow. Moreover, the vehicle air conditioner of this embodiment is configured to be able to suppress heat loss.

[0010] FIG. 1 is an explanatory diagram showing an outline of a configuration example of a vehicle air conditioner 1 according to this embodiment.

[0011] The vehicle air conditioner 1 includes a refrigerant circuit 10 configured to circulate a refrigerant. The refrigerant may be, but is not limited to, hydrofluoroolefin. The vehicle air conditioner 1 also includes a battery temperature control circuit 40 configured to circulate a heat transfer medium, such as a fluid such as a coolant.

[0012] The vehicle air conditioner 1 also includes an HVAC (Heating, Ventilation, and Air Conditioning) unit 100. The vehicle air conditioner 1 also includes a control device 200 (see FIG. 2) that controls the operation of various sensors and each part of the vehicle air conditioner 1. The operation of the vehicle air conditioner 1 is controlled based on the detection values ​​of the various sensors, various requests, etc.

[0013] <Refrigerant circuit> The refrigerant circuit 10 includes a compressor 11 that compresses a gaseous refrigerant to a high temperature and high pressure and then discharges it, a heater core 12 that is housed in a case 110 of the HVAC unit 100 and heats the air to be supplied to the vehicle interior, pressure reducing devices 13a, 13b, 13c, 13d, and 13e such as expansion valves that expand the liquid refrigerant to a low pressure, a low-temperature side heat exchanger 14 that evaporates the low-temperature and low-pressure liquid refrigerant to absorb heat, an accumulator 15, a cooler core 16 that is housed in the case 110 of the HVAC unit 100 and cools the air to be supplied to the vehicle interior, and a radiator 17 as an exterior heat exchanger. The refrigerant circuit 10 is configured to function as a heat pump that circulates the refrigerant and repeats compression, condensation, expansion, and evaporation.

[0014] In the low-temperature side heat exchanger 14, the refrigerant exchanges heat with a heat medium circulating in the battery temperature control circuit 40. In the example shown in the figure, the low-temperature side heat exchanger 14 includes a refrigerant passage 14a through which the refrigerant circulating in the refrigerant circuit 10 passes, and a heat medium passage 14b through which the heat medium circulating in the battery temperature control circuit 40 passes.

[0015] The elements of the refrigerant circuit 10 are connected by refrigerant flow paths 10a, 10b, 10c, 10d, 10e, 10f, 10g, 10h, 10i, 10j, 10k, 10m, 10n, 10p, 10q, 10r, 10s, 10t, 10u, 10v, and 10w.

[0016] A discharge side 11a of the compressor 11 is connected to an inlet side 12a of a heater core 12 via a refrigerant flow path 10a connected thereto, a branch point 18a, and a refrigerant flow path 10b downstream of the branch point 18a. A flow path opening / closing valve 20a is provided on the path of the refrigerant flow path 10b.

[0017] The discharge side 11a of the compressor 11 is connected to the inlet side 15a of the accumulator 15 via the refrigerant flow path 10a, the branch point 18a, the refrigerant flow path 10c, the branch point 18b, the refrigerant flow path 10d, the junction point 19a, the refrigerant flow path 10e, the junction point 19b, and the refrigerant flow path 10f downstream thereof. A pressure reducing device 13a serving as a first bypass pressure reducing device is provided on the refrigerant flow path 10c. A flow path opening / closing valve 20b is provided on the refrigerant flow path 10f.

[0018] An outlet side 15b of the accumulator 15 is connected to a suction side 11b of the compressor 11 via a refrigerant flow path 10g connected thereto, a junction 19c, and a refrigerant flow path 10h downstream of the junction 19c. A check valve 21a for preventing the refrigerant from flowing back into the accumulator 15 is provided on the refrigerant flow path 10g.

[0019] The discharge side 11a of the compressor 11 is connected to the suction side 11b of the compressor 11 via the refrigerant flow path 10a, the branch point 18a, the refrigerant flow path 10c, the branch point 18b, the refrigerant flow path 10i, the junction 19c, and the refrigerant flow path 10h downstream thereof. A pressure reducing device 13b serving as a second bypass pressure reducing device is provided on the path of the refrigerant flow path 10i.

[0020] The outlet side 12b of the heater core 12 is connected to the inlet side 16a of the cooler core 16 via the refrigerant flow path 10j, the branch point 18c, the refrigerant flow path 10k, the junction 19d, the refrigerant flow path 10m, the branch point 18d, and the downstream refrigerant flow path 10n. A flow path opening / closing valve 20c is provided on the path of the refrigerant flow path 10k. A pressure reducing device 13c is provided on the path of the refrigerant flow path 10n.

[0021] The outlet side 16b of the cooler core 16 is connected to the inlet side 15a of the accumulator 15 via the refrigerant flow paths 10p, the junction 19e, the refrigerant flow paths 10q, the junction 19a, the refrigerant flow paths 10e, the junction 19b, and the downstream refrigerant flow path 10f. A check valve 21b is provided on the path of the refrigerant flow path 10q to prevent the refrigerant from flowing back to the cooler core 16.

[0022] The outlet side 12b of the heater core 12 is connected to an inlet of a refrigerant passage 14a of the low-temperature side heat exchanger 14 via a refrigerant passage 10j, a branch point 18c, a refrigerant passage 10k, a junction 19d, a refrigerant passage 10m, a branch point 18d, and a downstream refrigerant passage 10r, which are connected to the outlet side 12b. A pressure reducing device 13d is installed on the path of the refrigerant passage 10r.

[0023] The outlet of the refrigerant passage 14a of the low-temperature side heat exchanger 14 is connected to the inlet side 15a of the accumulator 15 via a refrigerant passage 10s connected thereto, a junction 19b, and a refrigerant passage 10f downstream of the junction 19b. A passage opening / closing valve 20d is provided on the path of the refrigerant passage 10s.

[0024] An outlet side 12b of the heater core 12 is connected to an inlet side 17a of a radiator 17 via a refrigerant flow path 10j connected thereto, a branch point 18c, and a downstream refrigerant flow path 10t. A pressure reducing device 13e is installed on the path of the refrigerant flow path 10t.

[0025] The outlet side 17b of the radiator 17 is connected to the inlet side 15a of the accumulator 15 via the refrigerant flow path 10u, the branch point 18e, the refrigerant flow path 10v, the junction 19e, the refrigerant flow path 10q, the junction 19a, the refrigerant flow path 10e, the junction 19b, and the refrigerant flow path 10f downstream thereof. A flow path opening / closing valve 20e is provided on the path of the refrigerant flow path 10v.

[0026] The outlet side 17b of the radiator 17 is connected to the inlet side 16a of the cooler core 16 via the refrigerant flow path 10u, the branch point 18e, the refrigerant flow path 10w, the junction 19d, the refrigerant flow path 10m, the branch point 18d, and the downstream refrigerant flow path 10n. A check valve 21c is provided on the path of the refrigerant flow path 10w to prevent the refrigerant from flowing back to the radiator 17.

[0027] The outlet side 17b of the radiator 17 is connected to the inlet of the refrigerant passage 14a of the low-temperature side heat exchanger 14 via the refrigerant flow path 10u, branch point 18e, refrigerant flow path 10w, junction 19d, refrigerant flow path 10m, branch point 18d, and the downstream refrigerant flow path 10r connected thereto.

[0028] <Battery temperature control circuit> The battery temperature control circuit 40 as an in-vehicle heat-generating device temperature control circuit includes the heat medium passage 14b of the low-temperature side heat exchanger 14 described above and a battery 41 as an in-vehicle heat-generating device. The battery 41 is provided with a battery temperature control unit for controlling the temperature of the battery 41. The battery temperature control circuit 40 can be used to adjust the temperature of the battery 41.

[0029] Note that a configuration similar to that of the battery temperature control circuit 40 can also be applied to other in-vehicle device temperature control circuits having an in-vehicle device temperature control unit for controlling the temperature of other in-vehicle devices that require temperature control in a similar manner, not limited to the battery.

[0030] In the example shown in the figure, the elements of the battery temperature control circuit 40 are connected by heat medium flow paths 40a, 40b. The inlet side 41a of the battery 41 is connected to the outlet of the heat medium passage 14b of the low-temperature side heat exchanger 14 by the heat medium flow path 40a. The outlet side 41b of the battery 41 is connected to the inlet of the heat medium passage 14b of the low-temperature side heat exchanger 14 by the heat medium flow path 40b.

[0031] On the path of the heat medium flow path 40b, a circulation pump P40 and a heat medium heater 42 are installed in this order from the upstream side. The heat medium can be circulated by the circulation pump P40, and the temperature of the battery 41 can be adjusted.

[0032] <HVAC unit> The heater core 12 and the cooler core 16 of the refrigerant circuit 10 are housed in a case 110 of the HVAC unit 100. The case 110 forms the outer shell of the HVAC unit 100, and also forms an air flow passage 120 therein.

[0033] The HVAC unit 100 also has an intake unit 130. The intake unit 130 closes either an outside air intake port that introduces outside air in the vehicle cabin or an inside air intake port that introduces inside air in the vehicle cabin, and switches the air introduced into the case 110 between outside air (outside air intake) and inside air (inside air circulation). The HVAC unit 100 also has a blower 140 installed adjacent to the intake unit 130 so that the air introduced into the case 110 is sent to the air flow passage 120.

[0034] The cooler core 16 is installed at the upstream side of the air flow passage 120. A heater core passage 121 and a bypass passage 122 are formed in parallel at the downstream side of the air flow passage 120. The heater core 12 is provided in the heater core passage 121. Therefore, when the air introduced into the case 110 is guided to the heater core passage 121, the air is ventilated to the cooler core 16 and then ventilated to the heater core 12. On the other hand, when the air introduced into the case 110 is guided to the bypass passage 122, the air is ventilated to the cooler core 16 and then bypasses the heater core 12. The ratio of the air passing through the heater core passage 121 and the air passing through the bypass passage 122 is adjusted by the air mix damper 150.

[0035] Control Device FIG. 2 is an explanatory diagram showing an outline of a configuration example of the control device 200 of the vehicle air conditioner 1 according to this embodiment.

[0036] The control device 200 controls the operation of various sensors and each part of the vehicle air conditioner 1. The control device 200 is an air conditioning ECU (Electronic Control Unit) for executing various control modes of the vehicle air conditioner 1. The various control modes executed by the control device 200 include a hot gas heating mode that executes hot gas heating.

[0037] Detection information is input to the control device 200 from various sensors. In the hot gas heating mode, detection information from a blower temperature sensor 210, an outside air temperature sensor 220, a refrigerant temperature sensor 230, a refrigerant pressure sensor 240, and a vehicle interior temperature sensor 250 is input to the control device 200. The refrigerant temperature sensor 230 and the refrigerant pressure sensor 240 can detect the temperature and pressure of each part of the refrigerant circuit 10, such as the discharge side 11a and the suction side 11b of the compressor 11.

[0038] The control device 200 selects a path in the refrigerant circuit 10 by opening and closing the pressure reducing devices 13a-13e and the flow path opening and closing valves 20a-20d based on detection information from various sensors. While selecting the path, the control device 200 also controls the operation of the compressor 11, the blower 140, the air mix damper 150, the circulation pump P40, and the pressure reducing devices 13a-13e to control the amount of heat released from the refrigerant.

[0039] [Operation of vehicle air conditioning system] A specific operation of the vehicle air conditioner 1 according to this embodiment will be described.

[0040] <Hot gas heating mode> 1 shows the state of the vehicle air conditioner 1 when the outside temperature is extremely low. At this time, the vehicle interior is heated by executing the hot gas heating mode.

[0041] In the hot gas heating mode, the control device 200 fully closes the pressure reducing devices 13c and 13e and opens the flow passage opening / closing valves 20a, 20b, 20c, 20d, and 20e.

[0042] As a result, the refrigerant discharged from the compressor 11 flows into the refrigerant flow paths 10a and 10b and passes through the heater core 12. The refrigerant that has passed through the heater core 12 flows into the refrigerant flow paths 10j, 10k, 10m, and 10r and passes through the refrigerant passage 14a of the low-temperature side heat exchanger 14. The refrigerant that has passed through the refrigerant passage 14a of the low-temperature side heat exchanger 14 flows into the refrigerant flow paths 10s and 10f and flows into the accumulator 15. The refrigerant that has flowed into the accumulator 15 flows into the refrigerant flow paths 10g and 10h and flows into the compressor 11. That is, the refrigerant flow paths 10a, 10b, 10j, 10k, 10m, 10r, 10s, 10f, 10g, and 10h form a circulation path in which the refrigerant that has passed through the compressor 11 passes through the heater core 12.

[0043] In addition, the refrigerant discharged from the compressor 11 flows into the refrigerant flow paths 10a, 10c, 10d, 10e, and 10f and then flows into the accumulator 15. The refrigerant that flows into the accumulator 15 flows into the refrigerant flow paths 10g and 10h and then flows into the compressor 11. That is, the refrigerant flow paths 10a, 10c, 10d, 10e, 10f, 10g, and 10h form a bypass path through which the refrigerant that has passed through the compressor 11 detours without passing through the heater core 12. In addition, this bypass path forms a first path through which the refrigerant that has passed through the compressor 11 flows upstream of the accumulator 15.

[0044] In addition, the refrigerant discharged from the compressor 11 flows into the refrigerant flow paths 10a, 10c, 10i, and 10h and then flows into the compressor 11. That is, the refrigerant flow paths 10a, 10c, 10i, and 10h form a bypass path through which the refrigerant that has passed through the compressor 11 detours without passing through the heater core 12. In addition, this bypass path forms a second path through which the refrigerant that has passed through the compressor 11 flows to the downstream side of the accumulator 15.

[0045] The control device 200 adjusts the throttling amount of the pressure reducing device 13a to cause a portion of the refrigerant discharged from the compressor 11 to flow to the heater core 12 and the remaining refrigerant to flow to the bypass path. As a result, the vehicle interior is heated by the heat of the refrigerant dissipated in the heater core 12. In addition, the refrigerant flowing through the bypass path has a higher temperature when it returns to the suction side 11b of the compressor 11 than the refrigerant passing through the heater core 12. As a result, in the hot gas heating mode, the temperature of the refrigerant discharged from the compressor 11 can be increased to maintain the heating capacity.

[0046] In addition, the control device 200 can flow the refrigerant through the first path and the second path by opening the flow path opening / closing valve 20b and adjusting the throttling amount of the pressure reducing device 13b. As a result, the state of the refrigerant flowing into the suction side 11b of the compressor 11 can be improved by returning the refrigerant discharged from the compressor 11 directly to the suction side 11b of the compressor 11 while warming the refrigerant in the accumulator 15, and the quick heating can be improved. In addition, by flowing the refrigerant circulating through the first path into the accumulator 15, it is possible to increase the circulation amount of the refrigerant, and it is possible to prevent a decrease in the suction density of the refrigerant at the suction side 11b of the compressor 11. In addition, by flowing the refrigerant circulating through the second path downstream of the accumulator 15, it is possible to flow the refrigerant with superheat, so that the refrigerant flowing into the suction side 11b of the compressor 11 can be evaporated reliably, and the occurrence of liquid back to the compressor 11 can be prevented, and the life of the compressor 11 can be extended.

[0047] In addition, it is preferable to configure the second path to branch off from the first path as in this embodiment, and provide pressure reducing device 13a at least in the first path. In addition, by providing pressure reducing device 13b to adjust the flow rate of the refrigerant, it is possible to increase the circulation amount of the refrigerant while preventing the occurrence of liquid backflow.

[0048] In addition, as in this embodiment, it is preferable to provide a pressure reducing device 13a upstream of a branch point 18b where the first path branches into the second path. This makes it easier to adjust the amount of refrigerant bypassing the heater core 12, making it easier to control the hot gas heating mode while maintaining the heating capacity.

[0049] In addition, in the present embodiment, an example has been described in which the pressure reducing device 13a is provided upstream of the branch point 18b where the first path branches into the second path, but the pressure reducing device 13a may be provided downstream of the branch point 18b where the first path branches into the second path, and the pressure reducing device 13b may be provided in the second path. This makes it easy to adjust the flow rate of the refrigerant flowing into the accumulator 15 and the flow rate of the refrigerant bypassing the accumulator 15, and therefore makes it easy to control the density of the refrigerant flowing into the suction side 11b of the compressor 11.

[0050] [Various controls in hot gas heating mode] Next, in the vehicle air conditioner 1 configured as shown in Fig. 1, the control by the control device 200 regarding the adjustment of the flow rate of the refrigerant in the bypass passage will be described with reference to Fig. 3 to Fig. 5. Note that the vehicle air conditioner 1 may be configured to execute one of the controls shown in Fig. 3 to Fig. 5, or may be configured to execute a plurality of controls.

[0051] FIG. 3 is a flowchart showing an example of a specific control process procedure of the control device 200 regarding adjustment of the flow rates of the refrigerant in the first and second paths at the start of the hot gas heating mode.

[0052] 3, when the outside air temperature is extremely low, the control device 200 activates the hot gas heating mode (S1). At this time, the control device 200 fully closes the pressure reducing devices 13c and 13e and opens the flow passage opening / closing valves 20a, 20b, 20c, 20d, and 20e.

[0053] Then, the control device 200 determines whether the suction pressure of the compressor 11 is equal to or higher than a threshold value (S2). As to whether the suction pressure is equal to or higher than the threshold value, for example, it determines whether the pressure is positive, in other words, whether the pressure is not negative.

[0054] When the suction pressure of the compressor 11 is not equal to or higher than the threshold (S2: No), the control device 200 closes the flow passage opening / closing valve 20b. As a result, the second passage is set as a bypass passage that bypasses the heater core 12 (S3). As a result, all of the refrigerant flowing through the bypass passage flows through the second passage. Therefore, the flow rate of the refrigerant is greater through the second passage than through the first passage. As a result, the heat radiation of the refrigerant in the accumulator 15 can be suppressed, and the temperature of the refrigerant sucked into the compressor 11 can be increased. Therefore, it is possible to improve the state of the refrigerant early, and the quick heating performance can be improved. In addition, by flowing all of the refrigerant flowing through the bypass passage through the second passage, the heat radiation of the refrigerant that occurs when the refrigerant flows into the accumulator 15 is eliminated, and the heat loss of the refrigerant can be suppressed.

[0055] When the suction pressure of the compressor 11 is equal to or higher than the threshold (S2: Yes), the control device 200 opens the flow passage opening / closing valve 20b. As a result, the first and second paths are set as bypass paths that bypass the heater core 12 (S4). As a result, the refrigerant flowing through the bypass paths passes through the accumulator 15, so that the density of the refrigerant sucked into the compressor 11 can be increased.

[0056] In this embodiment, an example has been described in which the refrigerant flows only through the second path when the suction pressure of the compressor 11 is not equal to or higher than the threshold value. However, even when the suction pressure of the compressor 11 is not equal to or higher than the threshold value, the flow path opening / closing valve 20b may be opened to allow the refrigerant to flow through the first path and the second path, and the flow rate may be adjusted by the pressure reducing device 13b so that the flow rate of the refrigerant is greater through the second path than through the first path.

[0057] FIG. 4 is a flowchart showing an example of a specific control process procedure of the control device 200 regarding adjustment of the flow rate of the refrigerant in the second path when the hot gas heating mode is performed.

[0058] 4, the control device 200 calculates a target heating capacity for the vehicle interior in the hot gas heating mode (S1). The target heating capacity is calculated as follows. Target heating capacity = (target heater core outlet temperature - heater core inlet air temperature) x air volume The target heater core outlet temperature is calculated based on the difference between the set temperature inside the vehicle compartment and the actual temperature inside the vehicle compartment when the target heating capacity is calculated.

[0059] Next, the control device 200 determines whether the heating capacity for the vehicle interior has reached the target heating capacity (S2). The heating capacity for the vehicle interior is calculated as follows. Heating capacity = (actual heater core outlet temperature when calculating heating capacity - heater core inlet air temperature) x air volume

[0060] Then, if the heating capacity of the vehicle interior has reached the target heating capacity (S2: Yes), the flow rate of the refrigerant flowing through the second path is maintained by adjusting the throttle amount of the pressure reducing device 13b (S3). As a result, the ratio of the flow rate of the refrigerant flowing through the first path to the flow rate of the refrigerant flowing through the second path is maintained. This makes it possible to achieve the target heating capacity by providing an appropriate amount of superheat to the refrigerant flowing through the compressor 11, thereby improving the comfort of the passengers.

[0061] On the other hand, if the heating capacity of the vehicle interior has not reached the target heating capacity (S2: No), the flow rate of the refrigerant flowing through the second path is increased by adjusting the throttle amount of the pressure reducing device 13b (S4). This makes it possible for the refrigerant flowing through the first path from the accumulator 15 to the compressor 11 to be superheated by the refrigerant merging from the second path to the first path, and it is possible to increase the heating capacity of the vehicle interior when the heating capacity of the vehicle interior has not reached the target heating capacity.

[0062] Then, the control device 200 judges whether the heating capacity in the vehicle cabin has decreased (S5). If the heating capacity in the vehicle cabin has decreased (S5: Yes), the flow rate of the refrigerant flowing through the second path is reduced by adjusting the throttling amount of the pressure reducing device 13b (S6). As a result, the flow rate of the refrigerant flowing through the second path is increased too much by increasing the flow rate of the refrigerant flowing through the bypass path, which results in a decrease in the flow rate of the refrigerant passing through the heater core 12. In response to this, the flow rate of the refrigerant flowing through the second path is reduced, thereby making it possible to increase the flow rate of the refrigerant passing through the heater core 12. This makes it possible to improve the heating capacity and suppress deterioration of the comfort of the occupants.

[0063] If the heating capacity for the passenger compartment has not decreased (S5: No), the process ends.

[0064] It is preferable to add a step of determining whether the heating capacity in the vehicle cabin exceeds the target heating capacity to the flow chart shown in Fig. 4. When the control device 200 determines that the heating capacity in the vehicle cabin exceeds the target heating capacity, it is preferable to reduce the flow rate of the refrigerant flowing through the second path by adjusting the throttling amount of the pressure reducing device 13b. This makes it possible to adjust the heating capacity in the vehicle cabin to the target heating capacity, thereby improving the comfort of the occupants.

[0065] FIG. 5 is a flowchart showing an example of a specific control process procedure of the control device 200 regarding adjustment of the flow rate of the refrigerant in the second path when the hot gas heating mode is performed.

[0066] 5, in the hot gas heating mode, the control device 200 estimates the saturated vapor temperature (Tvap) based on the pressure of the refrigerant on the suction side 11b of the compressor 11 (S1). Specifically, the control device 200 has data related to a Ph diagram, and estimates the saturated vapor temperature (Tvap) based on the pressure of the refrigerant on the suction side 11b of the compressor 11 and the Ph diagram.

[0067] Next, the control device 200 determines whether the refrigerant temperature (Ts) on the suction side 11b of the compressor 11 is less than the saturated vapor temperature (Tvap) (S2). If the refrigerant temperature (Ts) is less than the saturated vapor temperature (Tvap) (S2: Yes), the flow rate of the refrigerant flowing through the second path is increased by adjusting the throttle amount of the pressure reducing device 13b (S3). If the refrigerant temperature (Ts) is not less than the saturated vapor temperature (Tvap) (S2: No), the process ends.

[0068] In this way, by increasing the flow rate of the refrigerant in the second path through which the high-temperature refrigerant flows without passing through the accumulator 15, it is possible to prevent the temperature (Ts) of the refrigerant on the suction side 11b of the compressor 11 from becoming lower than the saturated vapor temperature (Tvap) of the refrigerant under the same pressure state. This makes it possible to prevent the compressor 11 from drawing in a refrigerant in a gas-liquid mixed state, which would cause liquid backflow in the compressor 11.

[0069] [Second embodiment] A second embodiment will be described.

[0070] FIG. 6 is an explanatory diagram showing an outline of a configuration example of a vehicle air conditioner 1 according to the second embodiment.

[0071] The vehicle air conditioner 1 according to the second embodiment and the vehicle air conditioner 1 according to the first embodiment have different configurations of the refrigerant circuit 10, but detailed explanations of common configurations will be omitted. Also, the vehicle air conditioner 1 according to the second embodiment and the vehicle air conditioner 1 according to the first embodiment have the same configurations of the battery temperature control circuit 40 and the HVAC unit 100, so explanations of these will be omitted.

[0072] <Refrigerant circuit> In the refrigerant circuit 10 according to the second embodiment, the discharge side 11a of the compressor 11 is connected to the inlet side 15a of the accumulator 15 via a refrigerant flow path 10a, a branch point 18a, a refrigerant flow path 10c, a proportional control three-way valve V30, a refrigerant flow path 10d, a junction 19a, a refrigerant flow path 10e, a junction 19b, and a refrigerant flow path 10f downstream thereof. A flow path opening / closing valve 20b is provided on the path of the refrigerant flow path 10f.

[0073] In addition, the discharge side 11a of the compressor 11 is connected to the suction side 11b of the compressor 11 via the refrigerant flow path 10a, branch point 18a, refrigerant flow path 10c, refrigerant flow path 10i, junction point 19c, and the downstream refrigerant flow path 10h connected thereto.

[0074] As described above, the refrigerant circuit 10 according to the second embodiment differs from the refrigerant circuit 10 according to the first embodiment in that it does not include the branch point 18b and the pressure reducing device 13b included in the refrigerant circuit 10 according to the first embodiment, but does include a proportional control three-way valve V30. In addition, the refrigerant circuit 10 according to the second embodiment has the same other configuration as the refrigerant circuit 10 according to the first embodiment.

[0075] Control Device The vehicle air conditioner 1 according to the second embodiment is controlled by a control device 200 shown in FIG.

[0076] [Operation of vehicle air conditioning system] A specific operation of the vehicle air conditioner 1 according to this embodiment will be described with reference to Fig. 6. Note that only the parts of the operation that differ from the vehicle air conditioner 1 according to the first embodiment will be described, and detailed explanations of the parts of the operation that are common to the vehicle air conditioner 1 according to the first embodiment will be omitted.

[0077] <Hot gas heating mode> 6 shows the state of the vehicle air conditioner 1 when the outside air temperature is extremely low. At this time, the vehicle interior is heated by executing hot gas heating.

[0078] Unlike the vehicle air conditioner 1 according to the first embodiment, in the hot gas heating mode in the vehicle air conditioner 1 according to the second embodiment, the control device 200 can flow the refrigerant through the first path and the second path by adjusting the flow rate of the refrigerant with the proportional control three-way valve V30 instead of the pressure reducing device 13b. As a result, the state of the refrigerant flowing into the suction side 11b of the compressor 11 can be improved by returning the refrigerant discharged from the compressor 11 directly to the suction side 11b of the compressor 11 while warming the refrigerant in the accumulator 15, thereby improving the quick heating performance. In addition, it is possible to increase the circulation amount of the refrigerant by flowing the refrigerant circulating through the first path into the accumulator 15, and it is possible to prevent a decrease in the suction density of the refrigerant on the suction side 11b of the compressor 11. In addition, by flowing the refrigerant circulating through the second path downstream of the accumulator 15, it becomes possible to flow superheated refrigerant, so that the refrigerant flowing into the suction side 11b of the compressor 11 can be evaporated reliably, preventing liquid backflow into the compressor 11 and extending the life of the compressor 11.

[0079] In this embodiment, the second path is branched off from the first path, but it is preferable to provide a pressure reducing device 13a at least in the first path. In addition, by providing a proportional control three-way valve V30 and adjusting the flow rate of the refrigerant, it is possible to increase the circulation amount of the refrigerant while preventing the occurrence of liquid backflow.

[0080] In addition, it is preferable to provide a pressure reducing device 13a upstream of the proportional control three-way valve V30 that branches from the first path to the second path. This makes it easier to adjust the amount of refrigerant that bypasses the heater core 12, making it easier to control the hot gas heating mode while maintaining the heating capacity.

[0081] In addition, in the present embodiment, an example has been described in which the pressure reducing device 13a is provided upstream of the proportional control three-way valve V30 that branches from the first path to the second path, but the pressure reducing device 13a may be provided downstream of the proportional control three-way valve V30 that branches from the first path to the second path, and the pressure reducing device 13b may be provided in the second path. This makes it easy to adjust the flow rate of the refrigerant flowing into the accumulator 15 and the flow rate of the refrigerant bypassing the accumulator 15, and therefore makes it easy to control the density of the refrigerant flowing into the suction side 11b of the compressor 11.

[0082] [Various controls in hot gas heating mode] Next, in the vehicle air conditioner 1 configured as shown in Fig. 6, the control device 200 for adjusting the flow rate of the refrigerant in the first path and the second path can perform the same processing as the control shown in Fig. 3 to Fig. 5. Note that the vehicle air conditioner 1 according to the second embodiment may also be configured to perform any one of the controls shown in Fig. 3 to Fig. 5, or may be configured to perform a plurality of controls.

[0083] In addition, in the vehicle air conditioner 1 according to the first embodiment, the flow rate of the refrigerant in the first path and the second path is adjusted by adjusting the throttling amount by the pressure reducing device 13b in the control shown in Figures 3 to 5. However, in the vehicle air conditioner 1 according to the second embodiment, the flow rate of the refrigerant in the first path and the second path is adjusted by the proportional control three-way valve V30 in the control shown in Figures 3 to 5, unlike the vehicle air conditioner 1 according to the first embodiment.

[0084] Moreover, in the vehicle air conditioner 1 according to the second embodiment, in the hot gas heating mode, the control shown in Fig. 7 can be executed. Fig. 7 is a flowchart showing an example of a specific control process procedure of the control device 200 that can switch to the accumulator bypass path when the hot gas heating mode is executed.

[0085] 7, the control device 200 calculates the refrigerant circulation amount (S1). In calculating the refrigerant circulation amount, first, the refrigerant density is calculated based on the suction pressure and the suction temperature of the compressor 11. Then, the refrigerant circulation amount is calculated based on the calculated refrigerant density and the rotation speed of the compressor 11.

[0086] Next, the control device 200 judges whether the refrigerant circulation amount is appropriate or not (S2). Whether the refrigerant circulation amount is appropriate or not is judged based on the excess or deficiency of the heating capacity caused by the refrigerant circulation amount.

[0087] When the refrigerant circulation amount is appropriate (S2: Yes), the flow passage opening / closing valve 20b is closed (S3). As a result, the refrigerant discharged from the compressor 11 flows into the refrigerant flow passages 10a and 10b and passes through the heater core 12. The refrigerant that has passed through the heater core 12 flows into the refrigerant flow passages 10j, 10k, 10m, and 10r and passes through the refrigerant passage 14a of the low-temperature side heat exchanger 14. The refrigerant that has passed through the refrigerant passage 14a of the low-temperature side heat exchanger 14 flows into the refrigerant flow passages 10s, 10e, 10d, 10i, and 10h to bypass the accumulator 15 and then flows into the compressor 11. As a result, the refrigerant that has flowed into the heater core 12 flows through the refrigerant flow passages 10e and 10d of the first path and the refrigerant flow passages 10c, 10i, and 10h of the second path to bypass the accumulator 15, and then flows through the accumulator bypass path that flows into the suction side 11b of the compressor 11. Furthermore, the refrigerant discharged from the compressor 11 flows into the refrigerant flow paths 10a, 10c, 10i, and 10h and then into the compressor 11.

[0088] In this way, when the refrigerant circulation amount is appropriate, by switching to the accumulator bypass path, heat is not taken from the refrigerant by the accumulator 15, so that heat loss of the refrigerant can be suppressed.

[0089] If the refrigerant circulation amount is not appropriate (S2: No), the flow passage opening / closing valve 20b is opened (S4). As a result, the refrigerant discharged from the compressor 11 flows into the refrigerant flow passages 10a and 10b and passes through the heater core 12. The refrigerant that passes through the heater core 12 flows into the refrigerant flow passages 10j, 10k, 10m, and 10r and passes through the refrigerant passage 14a of the low-temperature side heat exchanger 14. The refrigerant that passes through the refrigerant passage 14a of the low-temperature side heat exchanger 14 flows into the refrigerant flow passages 10s and 10f and flows into the accumulator 15. The refrigerant that flows into the accumulator 15 flows into the refrigerant flow passages 10g and 10h and flows into the compressor 11. Furthermore, the refrigerant discharged from the compressor 11 flows into the refrigerant flow passages 10a, 10c, 10d, 10e, and 10f and flows into the accumulator 15. The refrigerant that flows into the accumulator 15 flows into the refrigerant flow paths 10g and 10h and then flows into the compressor 11. In addition, the refrigerant discharged from the compressor 11 flows into the refrigerant flow paths 10a, 10c, 10i, and 10h and then flows into the compressor 11.

[0090] In this way, when the amount of refrigerant circulating is not appropriate, the amount of refrigerant circulating can be ensured by passing the refrigerant through the accumulator 15.

[0091] The vehicle air conditioner 1 of this embodiment can provide the following advantages.

[0092] (a1) A refrigerant is circulated through a compressor 11, a heater core 12 that heats the air supplied to the vehicle interior, pressure reducing devices 13a to 13e, a low-temperature side heat exchanger 14 that causes a refrigerant to absorb heat of a heat medium absorbed from a battery 41 as an in-vehicle heat generating device, and an accumulator 15. The refrigerant circuit 10 includes a bypass path through which the refrigerant that has passed through the compressor 11 bypasses the heater core 12 and flows into the suction side 11b of the compressor 11. A part of the refrigerant that has passed through the compressor 11 is circulated through the heater core 12. and a control device 200 capable of controlling a hot gas heating mode in which the refrigerant that has passed through the compressor 11 flows to the upstream side of the accumulator 15 and the remaining refrigerant flows to the bypass path. The bypass path includes refrigerant flow paths 10a, 10c, 10d, 10e, 10f, 10g, and 10h as a first path through which the refrigerant that has passed through the compressor 11 flows to the upstream side of the accumulator 15, and refrigerant flow paths 10a, 10c, 10i, and 10h as a second path through which the refrigerant that has passed through the compressor 11 flows to the downstream side of the accumulator 15. Therefore, by returning the refrigerant discharged from the compressor 11 directly to the suction side 11b of the compressor 11 while warming the refrigerant in the accumulator 15, the state of the refrigerant flowing into the suction side 11b of the compressor 11 can be improved, and the heating speed can be improved. In addition, by flowing the refrigerant circulating through the first path into the accumulator 15, it is possible to increase the amount of refrigerant circulating, and it is possible to prevent a decrease in the suction density of the refrigerant at the suction side 11b of the compressor 11. In addition, by flowing the refrigerant circulating through the second path downstream of the accumulator 15, it is possible to flow a superheated refrigerant, so that the refrigerant flowing into the suction side 11b of the compressor 11 can be evaporated reliably, and the occurrence of liquid backflow to the compressor 11 can be prevented, and the life of the compressor 11 can be extended.

[0093] (a2) The second path is a path that branches off from the first path and joins the downstream side of the accumulator 15, and at least the first path is provided with the pressure reducing device 13a as a first bypass pressure reducing device. Therefore, by providing pressure reducing devices 13a and 13b in the first and second paths, respectively, to adjust the flow rate of the refrigerant, it is possible to increase the circulation amount of the refrigerant while preventing liquid backflow.

[0094] (a3) The pressure reducing device 13a serving as the first bypass pressure reducing device is provided upstream of the branch point 18b where the first path branches into the second path. This makes it easier to adjust the amount of refrigerant bypassing the heater core 12, making it easier to control the hot gas heating mode while maintaining the heating capacity.

[0095] (a4) The pressure reducing device 13a serving as the first bypass pressure reducing device is provided downstream of the branch point 18b where the first path branches into the second path, and the pressure reducing device 13b serving as the second bypass pressure reducing device is provided in the second path. This makes it easy to adjust the flow rate of the refrigerant flowing into the accumulator 15 and the flow rate of the refrigerant bypassing the accumulator 15, making it easy to control the density of the refrigerant flowing into the suction side 11b of the compressor 11.

[0096] (b1) A refrigerant is configured to circulate through a compressor 11, a heater core 12 that heats the air supplied to the vehicle interior, pressure reducing devices 13a to 13e, a low-temperature side heat exchanger 14 that causes a refrigerant to absorb heat of a heat medium absorbed from a battery 41 as an in-vehicle heat generating device, and an accumulator 15, and the refrigerant circuit 10 includes a bypass path in which the refrigerant that has passed through the compressor 11 bypasses the heater core 12 and flows into the suction side 11b of the compressor 11, and a hot gas heating mode in which a part of the refrigerant that has passed through the compressor 11 flows into the heater core 12 and the remaining refrigerant flows into the bypass path. The vehicle air conditioning system 1 is equipped with a control device 200 capable of controlling a bypass path, and the bypass path includes refrigerant flow paths 10a, 10c, 10d, 10e, 10f, 10g, and 10h as a first path through which refrigerant that has passed through the compressor 11 flows to the upstream side of the accumulator 15, and refrigerant flow paths 10a, 10c, 10i, and 10h as a second path through which refrigerant that has passed through the compressor 11 flows to the downstream side of the accumulator 15, and when the hot gas heating mode is activated, the control device 200 makes the flow rate of refrigerant flowing through the second path greater than the flow rate of refrigerant flowing through the first path. Therefore, when the suction pressure of the compressor 11 is not equal to or higher than the threshold value, the flow rate of the refrigerant in the second path bypassing the accumulator 15 is made greater than the flow rate of the refrigerant in the first path passing through the accumulator 15, thereby suppressing heat dissipation from the refrigerant in the accumulator 15 and increasing the temperature of the refrigerant sucked into the compressor 11. This makes it possible to improve the condition of the refrigerant early and improve the quick heating performance.

[0097] (b2) When the hot gas heating mode is activated, the control device 200 causes all of the refrigerant flowing through the bypass path to flow through the second path. Therefore, when the suction pressure of the compressor 11 is not equal to or higher than the threshold, all of the refrigerant flowing through the bypass path is made to flow through the second path, thereby eliminating the heat dissipation of the refrigerant that occurs when the refrigerant flows into the accumulator 15, thereby suppressing heat loss of the refrigerant.

[0098] (c1) A refrigerant is configured to circulate through a compressor 11, a heater core 12 that heats the air supplied to the vehicle interior, pressure reducing devices 13a to 13e, a low-temperature side heat exchanger 14 that causes a refrigerant to absorb heat of a heat medium absorbed from a battery 41 as an in-vehicle heat generating device, and an accumulator 15. The refrigerant circuit 10 includes a bypass path in which the refrigerant that has passed through the compressor 11 bypasses the heater core 12 and flows into the suction side 11b of the compressor 11. The refrigerant circuit 10 can be controlled to a hot gas heating mode in which a portion of the refrigerant that has passed through the compressor 11 flows into the heater core 12 and the remaining refrigerant flows into the bypass path. The vehicle air conditioning system 1 is equipped with a control device 200, and the bypass path includes refrigerant flow paths 10a, 10c, 10d, 10e, 10f, 10g, and 10h as a first path through which the refrigerant that has passed through the compressor 11 flows to the upstream side of the accumulator 15, and refrigerant flow paths 10a, 10c, 10i, and 10h as a second path through which the refrigerant that has passed through the compressor 11 flows to the downstream side of the accumulator 15. The control device 200 calculates a target heating capacity, which is a target value for the heating capacity in the vehicle cabin, and controls the flow rate of refrigerant flowing through the second path based on the calculated target heating capacity. Therefore, the refrigerant flowing from the second path to the first path can superheat the refrigerant flowing from the accumulator 15 to the compressor 11 via the first path, thereby making it possible to increase the heating capacity in the passenger compartment when the heating capacity in the passenger compartment has not reached the target heating capacity.

[0099] (c2) The control device 200 increases the flow rate of the refrigerant flowing through the second path when the heating capacity of the vehicle interior has not reached the target heating capacity. Therefore, it becomes possible to superheat the refrigerant flowing from the accumulator 15 to the compressor 11, and the heating capacity for the passenger compartment can be increased when the heating capacity for the passenger compartment has not reached the target heating capacity.

[0100] (c3) The control device 200 maintains the flow rate of the refrigerant flowing through the second path when the heating capacity for the vehicle interior has reached the target heating capacity. Therefore, by providing an appropriate amount of superheat to the refrigerant flowing through the compressor 11, it is possible to achieve the target heating capacity, thereby improving the comfort of the passengers.

[0101] (c4) When the flow rate of the refrigerant flowing through the second path is increased, if the heating capacity of the vehicle interior decreases, the control device 200 reduces the flow rate of the refrigerant flowing through the second path. Therefore, when the flow rate of refrigerant flowing through the second path is increased too much, the flow rate of refrigerant flowing through the bypass path is increased, resulting in a decrease in the heating capacity of the vehicle interior caused by a decrease in the flow rate of refrigerant passing through the heater core 12. However, by reducing the flow rate of refrigerant flowing through the second path, it is possible to increase the flow rate of refrigerant passing through the heater core 12. This improves the heating capacity and suppresses deterioration of passenger comfort.

[0102] (c5) The control device 200 reduces the flow rate of the refrigerant flowing through the second path when the heating capacity for the vehicle interior exceeds the target heating capacity. This makes it possible to adjust the heating capacity of the vehicle interior to the target heating capacity, thereby improving the comfort of the passengers.

[0103] (d1) A refrigerant is configured to circulate through a compressor 11, a heater core 12 that heats air to be supplied into a vehicle cabin, pressure reducing devices 13a to 13e, a low-temperature side heat exchanger 14 that causes a refrigerant to absorb heat of a heat medium absorbed from a battery 41 as an in-vehicle heat generating device, and an accumulator 15, and the refrigerant circuit 10 includes a bypass path in which the refrigerant that has passed through the compressor 11 bypasses the heater core 12 and flows into the suction side 11b of the compressor 11, and a control device 200 that can be controlled to a hot gas heating mode in which a portion of the refrigerant that has passed through the compressor 11 flows into the heater core 12 and the remaining refrigerant flows into the bypass path, The gas path includes refrigerant flow paths 10a, 10c, 10d, 10e, 10f, 10g, and 10h as a first path through which the refrigerant that has passed through the compressor 11 flows to the upstream side of the accumulator 15, and refrigerant flow paths 10a, 10c, 10i, and 10h as a second path through which the refrigerant that has passed through the compressor 11 flows to the downstream side of the accumulator 15.The control device 200 estimates the saturated vapor temperature (Tvap) of the refrigerant on the suction side 11b of the compressor 11 based on the pressure of the refrigerant on the suction side 11b of the compressor 11, and controls the flow rate of the refrigerant flowing through the second path based on the estimated saturated vapor temperature (Tvap) and the temperature (Ts) of the refrigerant on the suction side 11b of the compressor 11. Therefore, by controlling the flow rate of the refrigerant in the second path through which the high-temperature refrigerant flows without passing through the accumulator 15, it is possible to prevent the temperature (Ts) of the refrigerant on the suction side 11b of the compressor 11 from becoming lower than the saturated vapor temperature (Tvap) of the refrigerant under the same pressure state. This makes it possible to prevent the compressor 11 from drawing in a refrigerant in a gas-liquid mixed state, which would cause liquid backflow in the compressor 11.

[0104] (d2) The control device 200 increases the flow rate of the refrigerant flowing through the second path when the temperature of the refrigerant on the suction side 11b of the compressor 11 is lower than the estimated saturated vapor temperature (Tvap). Therefore, by increasing the flow rate of the refrigerant in the second path through which high-temperature refrigerant flows without passing through the accumulator 15, it is possible to prevent the temperature (Ts) of the refrigerant on the suction side 11b of the compressor 11 from becoming lower than the saturated vapor temperature (Tvap) of the refrigerant under the same pressure state. This makes it possible to prevent the compressor 11 from drawing in a refrigerant in a gas-liquid mixed state, which would cause liquid backflow in the compressor 11.

[0105] (e1) A vehicular air conditioner 1 including a compressor 11, a heater core 12 for heating air supplied to a vehicle interior, pressure reducing devices 13a to 13e, a low-temperature side heat exchanger 14 for absorbing heat of a heat medium absorbed from a battery 41 as an in-vehicle heat generating device into a refrigerant, and an accumulator 15, the refrigerant circuit 10 including a bypass path through which the refrigerant that has passed through the compressor 11 bypasses the heater core 12 and flows into the suction side 11b of the compressor 11, and a control device 200 that can be controlled to a hot gas heating mode in which a portion of the refrigerant that has passed through the compressor 11 flows into the heater core 12 and the remaining refrigerant flows into the bypass path. The bypass path includes refrigerant flow paths 10a, 10c, 10d, 10e, 10f, 10g, and 10h as a first path through which the refrigerant that has passed through the compressor 11 flows to the upstream side of the accumulator 15, and refrigerant flow paths 10a, 10c, 10i, and 10h as a second path through which the refrigerant that has passed through the compressor 11 flows to the downstream side of the accumulator 15, and in the hot gas heating mode, the control device 200 is capable of switching to an accumulator bypass path in which the refrigerant that has flowed to the heater core 12 passes through the first path and the second path to bypass the accumulator 15 and then flows into the suction side 11b of the compressor 11. Therefore, the heat of the refrigerant is not taken away by the accumulator 15, and the heat loss of the refrigerant can be suppressed.

[0106] Although the present invention has been described above by showing preferred embodiments, it goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention. [Explanation of symbols]

[0107] 1: Vehicle air conditioning system 10: refrigerant circuit, 11: compressor, 12: heater core, 13a, 13b, 13c, 13d, 13e: pressure reducing device, 14: low-temperature side heat exchanger, 15: accumulator, 16: cooler core, 17: radiator 40: Battery temperature control circuit, 41: Battery, P40: Circulation pump 100: HVAC unit, 110: case, 120: air flow passage, 121: heater core passage, 122: bypass passage, 150: air mix damper

Claims

1. a refrigerant circuit including a compressor, a heater core that heats air to be supplied into a vehicle cabin, a pressure reducing device, a low-temperature side heat exchanger that causes a refrigerant to absorb heat of a heat medium absorbed from an on-board heat generating device, and an accumulator, the refrigerant circulating through the compressor, the refrigerant bypassing the heater core and flowing into a suction side of the compressor; a control device capable of controlling a hot gas heating mode in which a portion of the refrigerant that has passed through the compressor flows to the heater core and the remaining refrigerant flows to the bypass path, The bypass path is a first passage through which the refrigerant that has passed through the compressor flows to an upstream side of the accumulator; a second passage through which the refrigerant that has passed through the compressor flows to a downstream side of the accumulator, The control device includes: When the hot gas heating mode is started, the flow rate of the refrigerant flowing through the second path is made larger than the flow rate of the refrigerant flowing through the first path.

1. A vehicle air conditioning system comprising:

2. The control device includes: When the hot gas heating mode is started, all of the refrigerant flowing through the bypass path is caused to flow through the second path.

2. The vehicle air conditioning system according to claim 1.

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