Air conditioner for vehicle

Abstract

To provide an air conditioner for a vehicle which can avoid occurrence of vibration and noise.SOLUTION: A control device 200 determines whether or not vibration exceeding a predetermined allowable range in a hot gas heating mode occurs, and changes a target suction pressure within an establishment range of target heating capability when having determined that the vibration exceeding the predetermined allowable range occurs. A plurality of conditions to achieve the target heating capability exist in the hot gas heating mode, and accordingly operation in the hot gas heating mode is performed by the combination of conditions different from the combination of the condition when it is determined that the vibration exceeding the predetermined allowable range occurs, which can avoid occurrence of vibration and noise accompanied by the vibration while maintaining the target heating capability.SELECTED DRAWING: Figure 10

Description

[Technical field]

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

[0002] Air conditioners using a heat pump 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 heat capacity of the combustion heat source. However, air conditioners using a heat pump have difficulty absorbing heat from the 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 a hot gas heating mode, in which, when the outside temperature is extremely low, a portion of the refrigerant that has passed through the compressor is made to flow to a heater core and the remaining refrigerant is made to flow to a bypass path. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 201568 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide an air conditioner for a vehicle that can prevent the generation of vibrations and noise. [Means for solving the problem]

[0005] According to one aspect of the present invention, there is provided a vehicle air conditioning system including a refrigerant circuit configured to circulate through a compressor, a heater core for heating air supplied to a vehicle cabin, a pressure reducing device, a low-temperature side heat exchanger for causing 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 capable of control in a hot gas heating mode in which a portion of the refrigerant that has passed through the compressor flows into the heater core and the remaining refrigerant flows into the bypass path, the control device determining whether vibrations exceeding a predetermined allowable range are occurring during the hot gas heating mode, and if it is determined that vibrations exceeding the predetermined allowable range are occurring, changing the target suction pressure within the range in which a target heating capacity is achieved. Effect of the Invention

[0006] According to the present invention, it is possible to provide a vehicle air conditioner that can prevent the generation of vibrations and noise. [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, 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 block diagram showing an example of a control device in a vehicle air conditioner. [Diagram 3] FIG. 3 is a diagram showing an example of a flowchart illustrating a procedure of a process when the hot gas heating mode is ended in the vehicle air conditioner. [Figure 4] FIG. 4 is an explanatory diagram showing the transition of each element when a pressure reduction process is performed at the end of the hot gas heating mode in the vehicle air conditioner. [Diagram 5] FIG. 5 is an enlarged view of a portion of the compressor in FIG. 4 where the pressure drops on the suction side. [Figure 6] FIG. 6 is a diagram showing an example of a flowchart illustrating a procedure of a process when the hot gas heating mode is ended in the vehicle air conditioner. [Figure 7] FIG. 7 is an explanatory diagram showing the transition of each element when the pressure reduction process is performed at the end of the hot gas heating mode in the vehicle air conditioner. [Figure 8] FIG. 8 is a diagram showing an example of a flowchart illustrating a procedure of processing when the hot gas heating mode is ended in the vehicle air conditioner. [Figure 9] FIG. 9 is a diagram showing an example of a flowchart illustrating a procedure of a process when the hot gas heating mode is ended in the vehicle air conditioner. [Figure 10] FIG. 10 is a diagram showing an example of a flowchart illustrating a procedure of a process in the hot gas heating mode in the vehicle air conditioner. [Figure 11] FIG. 11 is a diagram showing an example of a flowchart illustrating a procedure of a process in the hot gas heating mode in the vehicle air conditioner. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] [Configuration of vehicle air conditioning system] Overview of Vehicle Air Conditioning System The vehicle air conditioner of this embodiment is configured to be able to suppress wear on the components. Moreover, the vehicle air conditioner of this embodiment is configured so as to be able to prevent the generation of vibrations and noise. Moreover, the vehicle air conditioner of this embodiment is configured to be capable of suppressing the generation of vibrations and noise due to resonance or the like.

[0009] FIG. 1 is an explanatory diagram showing an outline of a configuration example of a vehicle air conditioner 1 according to this embodiment.

[0010] 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.

[0011] The vehicle air conditioner 1 also includes an HVAC (Heating, Ventilation, and Air Conditioning) unit 100 as an air conditioning unit. 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.

[0012] <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, and 13d 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.

[0013] 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.

[0014] The elements of the refrigerant circuit 10 are connected by refrigerant flow paths 10a, 10b, 10c, 10e, 10f, 10g, 10j, 10k, 10m, 10n, 10p, 10q, 10r, 10s, 10t, 10u, 10v, and 10w.

[0015] 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.

[0016] 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 junction 19a, the refrigerant flow path 10e, the junction 19b, and the downstream refrigerant flow path 10f, which are connected to the discharge side 11a. A pressure reducing device 13a is installed on the path of the refrigerant flow path 10c.

[0017] 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.

[0018] 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 18b, the refrigerant flow path 10k, the junction 19d, the refrigerant flow path 10m, the branch point 18c, and the downstream refrigerant flow path 10n. A flow path opening / closing valve 20a is provided on the path of the refrigerant flow path 10k. A pressure reducing device 13b is provided on the path of the refrigerant flow path 10n.

[0019] 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.

[0020] 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 18b, a refrigerant passage 10k, a junction 19d, a refrigerant passage 10m, a branch point 18c, and a downstream refrigerant passage 10r, which are connected to the outlet side 12b. A pressure reducing device 13c is installed on the path of the refrigerant passage 10r.

[0021] 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.

[0022] 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 18b, and a downstream refrigerant flow path 10t. A pressure reducing device 13d is installed on the path of the refrigerant flow path 10t.

[0023] 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 18d, 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 20b is provided on the path of the refrigerant flow path 10v.

[0024] 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 18d, the refrigerant flow path 10w, the junction 19d, the refrigerant flow path 10m, the branch point 18c, 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.

[0025] 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 18d, refrigerant flow path 10w, junction 19d, refrigerant flow path 10m, branch point 18c, and the downstream refrigerant flow path 10r connected thereto.

[0026] <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.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] <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 defines an air flow passage 120 therein. The air flow passage 120 is an air flow passage for air that exchanges heat in the heater core 12 and the cooler core 16.

[0031] The HVAC unit 100 also has an intake unit 130 as an inside / outside air switching device. The intake unit 130 can close either an outside air intake port for introducing outside air into the vehicle cabin or an inside air intake port for introducing air inside the vehicle cabin to switch the air introduced into the case 110 between outside air (outside air intake) and inside air (inside air circulation). The intake unit 130 can adjust the ratio of the air introduced into the vehicle cabin and the air introduced into the vehicle cabin by closing either the outside air intake port or the inside air intake port to switch between outside air intake and inside air circulation to introduce air into the case 110, or by adjusting the ratio of the outside air intake and the inside air circulation to an arbitrary ratio and introducing air into the case 110. 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 fed to the air flow passage 120. The blower 140 blows the air to be heat exchanged in the heater core 12 and the cooler core 16 into the vehicle interior.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] Detection information from various sensors is input to the control device 200. 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, an interior temperature sensor 250, and a rotation speed detection sensor 260 for the compressor 11 is input to the control device 200.

[0036] The refrigerant temperature sensor 230 and the refrigerant pressure sensor 240 are capable of detecting the temperature and pressure of each portion of the refrigerant circuit 10, such as the temperature and pressure on the low pressure side and the temperature and pressure on the high pressure side.

[0037] The refrigerant temperature sensor 230 is composed of a plurality of sensors that detect the refrigerant temperature at various points in the refrigerant circuit 10, and includes a low-pressure side refrigerant temperature sensor 230a that detects the temperature of the refrigerant on the low-pressure side of the refrigerant circuit 10 and a high-pressure side refrigerant temperature sensor 230b that detects the temperature of the refrigerant on the high-pressure side of the refrigerant circuit 10. The low-pressure side refrigerant temperature sensor 230a is disposed, for example, on the suction side 11b of the compressor 11. The high-pressure side refrigerant temperature sensor 230b is disposed, for example, on the outlet side 12b of the heater core 12.

[0038] The refrigerant pressure sensor 240 is composed of a plurality of sensors that detect the refrigerant pressure at various points in the refrigerant circuit 10, and includes a low-pressure side refrigerant pressure sensor 240a that detects the pressure of the refrigerant on the low-pressure side of the refrigerant circuit 10 and a high-pressure side refrigerant pressure sensor 240b that detects the pressure of the refrigerant on the high-pressure side of the refrigerant circuit 10. The low-pressure side refrigerant pressure sensor 240a is disposed, for example, on the suction side 11b of the compressor 11. The high-pressure side refrigerant pressure sensor 240b is disposed, for example, on the outlet side 12b of the heater core 12.

[0039] 1 refers to the pressure of the refrigerant in the path from the discharge side 11a of the compressor 11 to the pressure reducing device 13a, and the pressure of the refrigerant in the path from the discharge side 11a of the compressor 11 to the pressure reducing device 13c. In other words, the pressure of the high pressure side of the refrigerant circuit 10 refers to the pressure of the refrigerant on the discharge side 11a of the compressor 11.

[0040] 1 refers to the pressure of the refrigerant in the path from the pressure reducing device 13a to the suction side 11b of the compressor 11, and the pressure of the refrigerant in the path from the pressure reducing device 13c to the suction side 11b of the compressor 11. In other words, the pressure on the low pressure side of the refrigerant circuit 10 refers to the pressure of the refrigerant on the suction side 11b of the compressor 11.

[0041] The control device 200 selects a path in the refrigerant circuit 10 by opening and closing the pressure reducing devices 13a-13d and the flow path opening and closing valves 20a, 20b 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-13d to control the amount of heat released from the refrigerant.

[0042] [Operation of vehicle air conditioning system] A specific operation of the vehicle air conditioner 1 according to this embodiment will be described.

[0043] <Hot gas heating mode> 1 shows the state of the vehicle air conditioner 1 when the outside air temperature is extremely low (for example, −20° C. to −30° C.) At this time, the vehicle interior is heated by executing the hot gas heating mode.

[0044] In the hot gas heating mode, the control device 200 fully closes the pressure reducing devices 13b and 13d and opens the flow passage opening / closing valves 20a and 20b.

[0045] 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 path 10g and then flows into the compressor 11. In other words, the refrigerant flow paths 10a, 10b, 10j, 10k, 10m, 10r, 10s, 10f, and 10g form a circulation path through which the refrigerant that has passed through the compressor 11 passes through the heater core 12.

[0046] In addition, the refrigerant discharged from the compressor 11 flows into the refrigerant flow paths 10a, 10c, 10e, and 10f and then flows into the accumulator 15. The refrigerant that flows into the accumulator 15 flows into the refrigerant flow path 10g and then flows into the compressor 11. In other words, the refrigerant flow paths 10a, 10c, 10d, 10e, 10f, and 10g form a bypass path through which the refrigerant that has passed through the compressor 11 detours without passing through the heater core 12.

[0047] The control device 200 adjusts the opening degree of the pressure reducing device 13a, i.e., 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 by 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.

[0048] [Various controls in vehicle air conditioning systems] Various control processes in the vehicle air conditioner 1 will be described with reference to Fig. 3 to Fig. 11. Note that any one of the processes in Fig. 3, Fig. 5, Fig. 8, Fig. 9, Fig. 10, and Fig. 11 may be executed, or a plurality of processes may be executed.

[0049] <Pressure reduction process on the low pressure side> In the hot gas heating mode, the compressor 11 mostly operates so that the pressure on the low pressure side of the refrigerant circuit 10 is kept near the upper limit in order to increase the heating capacity. On the other hand, when the operation of the compressor 11 is stopped, the pressure on the high pressure side of the refrigerant circuit 10 decreases and the pressure on the low pressure side of the refrigerant circuit 10 increases. Therefore, when the operation of the compressor 11 is stopped while the hot gas heating mode is being executed, the pressure on the low pressure side of the refrigerant circuit 10 temporarily exceeds the upper limit, and parts such as the compressor 11 and the accumulator 15 may be worn out. For this reason, the control device 200 can execute a pressure reduction process to reduce the pressure on the low pressure side of the refrigerant circuit 10 when the hot gas heating mode is ended. This makes it possible to stop the compressor 11 so that the pressure on the low pressure side of the refrigerant circuit 10 does not exceed the upper limit, thereby suppressing wear on parts of the vehicle air conditioner 1, such as the compressor 11 and the accumulator 15, which are installed on the low pressure side of the refrigerant circuit 10.

[0050] 3, 5, 8, and 9 all show pressure reduction processes by the control device 200, but any one of them may be executed, or a configuration may be adopted in which a plurality of processes are executed.

[0051] <Example 1 of low pressure side pressure reduction treatment> FIG. 3 is a flowchart showing an example of a procedure of the pressure reduction process performed by the control device 200.

[0052] 3, the control device 200 determines whether or not the hot gas heating mode is to end (S1). The hot gas heating mode ends, for example, when the operation mode of the vehicle air conditioner 1 is turned off or when the vehicle system is turned off.

[0053] When the control device 200 determines that the hot gas heating mode is not ending (S1: No), it ends the process. When the control device 200 determines that the hot gas heating mode is ending (S1: Yes), it gradually reduces the rotation speed of the compressor 11 (S2).

[0054] Next, the control device 200 determines whether or not the pressure on the low pressure side of the refrigerant circuit 10 has increased (S3). When the control device 200 determines that the pressure on the low pressure side of the refrigerant circuit 10 has not increased (S3: No), the control device 200 waits until the pressure on the low pressure side of the refrigerant circuit 10 increases.

[0055] When the control device 200 determines that the pressure on the low pressure side of the refrigerant circuit 10 has increased (S3: Yes), it reduces the opening of the pressure reducing device 13a to reduce the pressure on the low pressure side of the refrigerant circuit 10 (S4). Specifically, if an expansion valve is used for the pressure reducing device 13a, the expansion valve is throttled. Note that the low pressure side of the refrigerant circuit 10 may be reduced by reducing the opening of both the pressure reducing devices 13a and 13b.

[0056] Next, the control device 200 judges whether the pressure on the low pressure side of the refrigerant circuit 10 will not exceed the upper limit when the operation of the compressor 11 is stopped (S5). When the control device 200 judges that the pressure on the low pressure side of the refrigerant circuit 10 will exceed the upper limit when the operation of the compressor 11 is stopped (S5: No), it waits until it judges that the pressure on the low pressure side of the refrigerant circuit 10 will not exceed the upper limit when the operation of the compressor 11 is stopped. Then, when the control device 200 judges that the pressure on the low pressure side of the refrigerant circuit 10 will not exceed the upper limit when the operation of the compressor 11 is stopped (S5: Yes), it stops the operation of the compressor 11 (S6). Next, the control device 200 stops the operation of the blower 140 (S7). Note that even if it waits in the process of step S5, if the pressure on the low pressure side of the refrigerant circuit 10 exceeds the upper limit when the operation of the compressor 11 is stopped, it is possible to return to the process of step S2 and repeat the processes of steps S2 to S4 again.

[0057] In the process of FIG. 3, it is possible to stop the compressor 11 so that the pressure on the low pressure side of the refrigerant circuit 10 does not exceed the upper limit, thereby reducing wear on the components of the vehicle air conditioner 1, such as the compressor 11 and the accumulator 15.

[0058] In addition, the process of FIG. 3 makes it possible to gradually reduce the pressure and temperature on the low-pressure side of the refrigerant circuit 10, thereby reducing the load on components of the vehicle air conditioner 1, such as the compressor 11 and the accumulator 15.

[0059] In addition, in the process of FIG. 3, after the rotation speed of the compressor 11 is reduced, pressure reduction control is performed on the low-pressure side of the refrigerant circuit 10, so that it is possible to prevent the pressure of the refrigerant on the high-pressure side from increasing, and to reduce the load on components such as the compressor 11 and the accumulator 15.

[0060] Here, an example of changes in the rotation speed NC of the compressor 11, the opening degree ECCVdis_rate of the pressure reducing device 13a, the pressure Pd on the high pressure side of the refrigerant circuit 10, and the pressure Ps on the low pressure side of the refrigerant circuit 10 in the results of the processing in Fig. 3 will be described with reference to Fig. 4 and Fig. 5. Fig. 5 is an enlarged view of a portion in Fig. 4 where the pressure on the low pressure side of the refrigerant circuit 10 fluctuates. Figs. 4 and 5 will also be used to explain an example of pressure reduction control of the refrigerant circuit 10 in which the opening degree of the pressure reducing device 13a is reduced while the opening degree of the pressure reducing device 13b is maintained.

[0061] 4 and 5, when the rotation speed NC of the compressor 11 is reduced, the pressure Pd on the high pressure side of the refrigerant circuit 10 decreases, while the pressure Ps on the low pressure side of the refrigerant circuit 10 increases. Then, when the opening degree ECCVdis_rate of the pressure reducing device 13a is reduced when the pressure Ps on the low pressure side of the refrigerant circuit 10 increases, the pressure Ps on the low pressure side of the refrigerant circuit 10 decreases over time. Furthermore, when the opening degree ECCVdis_rate of the pressure reducing device 13a is reduced, the pressure Pd on the high pressure side of the refrigerant circuit 10 increases, but by gradually reducing the rotation speed of the compressor 11 over time, the pressure Pd on the high pressure side of the refrigerant circuit 10 also decreases over time.

[0062] That is, by gradually reducing the rotation speed of the compressor 11 and reducing the pressure on the low pressure side of the refrigerant circuit 10, the pressure Pd on the high pressure side of the refrigerant circuit 10 and the pressure Ps on the low pressure side of the refrigerant circuit 10 are reduced over time as a whole while the increase and decrease in the pressure Pd on the high pressure side of the refrigerant circuit 10 and the increase and decrease in the pressure Ps on the low pressure side of the refrigerant circuit 10 are offset. Then, if the pressure Ps on the low pressure side of the refrigerant circuit 10 does not exceed the upper limit Psmax when the operation of the compressor 11 is stopped, the operation of the compressor 11 is stopped. As a result, the pressure Ps on the low pressure side of the refrigerant circuit 10 temporarily increases, but the pressure Ps on the low pressure side of the refrigerant circuit 10 subsequently decreases without exceeding the upper limit Psmax.

[0063] <Specific example 2 of pressure reduction treatment on the low pressure side> FIG. 6 is a flow chart showing a procedure of the pressure reduction process by the control device 200, which is an example of a procedure of the pressure reduction process different from that shown in FIG.

[0064] 6, the control device 200 determines whether or not the hot gas heating mode is to end (S1). The hot gas heating mode ends, for example, when the operation mode of the vehicle air conditioner 1 is turned off or when the vehicle system is turned off.

[0065] If the hot gas heating mode is not ending (S1: No), the control device 200 ends the process. If the hot gas heating mode is ending (S1: Yes), the control device 200 starts the circulation pump P40 of the battery temperature control circuit 40 (S2). This causes the heat medium to circulate through the battery temperature control circuit 40 by the pushing of the circulation pump P40. Therefore, the heat of the refrigerant flowing through the refrigerant passage 14a of the low-temperature side heat exchanger 14 is dissipated to the heat medium flowing through the heat medium passage 14b of the low-temperature side heat exchanger 14. This causes the pressure on the low-pressure side of the refrigerant circuit 10 to decrease.

[0066] Next, the control device 200 determines whether the pressure on the low pressure side of the refrigerant circuit 10 has fallen below a predetermined pressure (S3). The predetermined pressure is, for example, a pressure that does not exceed an upper limit even if the rotation speed of the compressor 11 is reduced. When the control device 200 determines that the pressure on the low pressure side of the refrigerant circuit 10 has not fallen below the predetermined pressure (S3: No), it waits until it determines that the pressure on the low pressure side of the refrigerant circuit 10 has fallen below the predetermined pressure. When the control device 200 determines that the pressure on the low pressure side of the refrigerant circuit 10 has fallen below the predetermined pressure (S3: Yes), it gradually reduces the rotation speed of the compressor 11 (S4). In other words, the rotation speed of the compressor 11 is reduced in stages.

[0067] Next, the control device 200 judges whether the pressure on the low pressure side of the refrigerant circuit 10 will not exceed the upper limit when the operation of the compressor 11 is stopped (S5). When the control device 200 judges that the pressure on the low pressure side of the refrigerant circuit 10 will exceed the upper limit when the operation of the compressor 11 is stopped (S5: No), it waits until it judges that the pressure on the low pressure side of the refrigerant circuit 10 will not exceed the upper limit when the operation of the compressor 11 is stopped. Then, when the control device 200 judges that the pressure on the low pressure side of the refrigerant circuit 10 will not exceed the upper limit when the operation of the compressor 11 is stopped (S5: Yes), it stops the operation of the compressor 11 (S6). Next, the control device 200 stops the operation of the circulation pump P40 and the blower 140 (S7). Note that even if it waits in the process of step S5, if the pressure on the low pressure side of the refrigerant circuit 10 exceeds the upper limit when the operation of the compressor 11 is stopped, it is possible to return to the process of step S4 and repeat the process of step S4 again.

[0068] In the process of FIG. 6, it is possible to stop the compressor 11 so that the pressure on the low pressure side of the refrigerant circuit 10 does not exceed the upper limit, thereby reducing wear on the components of the vehicle air conditioner 1, such as the compressor 11 and the accumulator 15.

[0069] 6, the pressure and temperature of the refrigerant on the low-pressure side of the refrigerant circuit 10 can be reduced, thereby reducing the load on components such as the compressor 11 and the accumulator 15. In addition, the heat medium can store the heat of the refrigerant, so the stored heat can be used as a heat source when restarting the vehicle air conditioner.

[0070] FIG. 7 will now be used to explain an example of changes in the rotation speed NC of the compressor 11, the opening degree ECCVdis_rate of the pressure reducing device 13a, the pressure Pd on the high-pressure side of the refrigerant circuit 10, the pressure Ps on the low-pressure side of the refrigerant circuit 10, the cooling capacity ChillerCapacity of the refrigerant in the low-temperature side heat exchanger 14, the temperature Tw_ch_in of the heat medium at the inlet of the heat medium passage 14b of the low-temperature side heat exchanger 14, and the temperature Tw_ch_out of the heat medium at the outlet of the heat medium passage 14b of the low-temperature side heat exchanger 14, as a result of the processing in FIG. 6.

[0071] As shown in Fig. 7, when the circulation pump P40 of the battery temperature control circuit 40 starts at the end of the hot gas heating mode, the heat medium flows through the heat medium passage 14b of the low-temperature side heat exchanger 14. As a result, the heat of the refrigerant flowing through the refrigerant passage 14a of the low-temperature side heat exchanger 14 is dissipated to the heat medium flowing through the heat medium passage 14b of the low-temperature side heat exchanger 14. As a result, the refrigerant is cooled, and the cooling capacity ChillerCapacity of the refrigerant of the low-temperature side heat exchanger 14 increases.

[0072] Accordingly, the pressure of the refrigerant in the refrigerant circuit 10 decreases, so that the pressure Pd on the high pressure side of the refrigerant circuit 10 and the pressure Ps on the low pressure side of the refrigerant circuit 10 decrease. In addition, the temperature Tw_ch_out of the heat medium at the outlet of the heat medium passage 14b increases due to the heat dissipation from the refrigerant to the heat medium. In addition, the temperature of the heat medium as a whole increases due to the heat dissipation from the refrigerant to the heat medium, so that the temperature Tw_ch_in of the heat medium at the inlet of the heat medium passage 14b also increases over time. In addition, the pressure Pd on the high pressure side of the refrigerant circuit 10 and the pressure Ps on the low pressure side of the refrigerant circuit 10 decrease due to the heat dissipation of the refrigerant flowing through the low pressure side of the refrigerant circuit 10, so that the temperature of the refrigerant flowing into the refrigerant passage 14a of the low temperature side heat exchanger 14 decreases. As a result, the temperature difference between the refrigerant and the heat medium becomes smaller, and the amount of heat exchange in the low temperature side heat exchanger 14 decreases. Therefore, the temperature Tw_ch_out of the heat medium at the outlet of the heat medium passage 14b decreases over time. Therefore, the temperature difference between the temperature Tw_ch_out of the heat medium at the outlet of the heat medium passage 14b and the temperature Tw_ch_in of the heat medium at the inlet of the heat medium passage 14b almost disappears.

[0073] Then, as the rotation speed of the compressor 11 is gradually reduced, the pressure Pd on the high pressure side of the refrigerant circuit 10 gradually decreases. As described above, when the temperature of the refrigerant decreases due to heat dissipation from the refrigerant flowing through the low pressure side of the refrigerant circuit 10 and the heat medium is warmed, the temperature difference between the refrigerant and the heat medium decreases, and the temperatures of the two approach almost the same. At this time, heat dissipation from the refrigerant to the heat medium in the low temperature side heat exchanger 14 is almost no longer performed, so the pressure Ps on the low pressure side of the refrigerant circuit 10 stops decreasing. When heat is being dissipated from the refrigerant to the heat medium, the relationship is maintained such that the temperature Tw_ch_out of the heat medium at the outlet of the heat medium passage 14b is higher than the temperature Tw_ch_in of the heat medium at the inlet of the heat medium passage 14b. However, as is clear from FIG. 7 , the timing at which the pressure Ps on the low-pressure side of the refrigerant circuit 10 stops decreasing is the same as the timing at which heat dissipation from the refrigerant to the heat medium almost ceases to occur and the temperature difference between the temperature Tw_ch_in of the heat medium at the inlet of the heat medium passage 14b and the temperature Tw_ch_out of the heat medium at the outlet of the heat medium passage 14b almost disappears. This also means that the pressure Ps on the low-pressure side of the refrigerant circuit 10 stops decreasing due to a decrease in the amount of heat exchange in the low-temperature side heat exchanger 14.

[0074] After that, since there is almost no heat dissipation from the low-pressure side refrigerant to the heat medium, the pressure Ps on the low-pressure side of the refrigerant circuit 10 starts to tend to rise. That is, as in the hot gas heating mode, the refrigerant on the low-pressure side of the refrigerant circuit 10 does not exchange heat, so the pressure Ps on the low-pressure side of the refrigerant circuit 10 starts to tend to rise.

[0075] However, at the stage where the pressure Ps on the low pressure side of the refrigerant circuit 10 stops decreasing, the pressure Ps on the low pressure side of the refrigerant circuit 10 has sufficiently decreased. Therefore, even if the pressure Ps on the low pressure side of the refrigerant circuit 10 starts to increase, the pressure Pd on the high pressure side of the refrigerant circuit 10 is decreased by gradually decreasing the number of operations of the compressor 11, thereby preventing the pressure Ps on the low pressure side of the refrigerant circuit 10 from exceeding the upper limit Psmax when the operation of the compressor 11 is stopped. Therefore, even if the operation of the compressor 11 is stopped, the pressure Ps on the low pressure side of the refrigerant circuit 10 temporarily increases, but the pressure Ps on the low pressure side of the refrigerant circuit 10 subsequently decreases without exceeding the upper limit Psmax.

[0076] <Example 3 of pressure reduction process on the low pressure side> FIG. 8 is a flow chart showing a procedure of the pressure reduction process by the control device 200, which is an example of a procedure of the pressure reduction process different from those in FIG. 3 and FIG.

[0077] 8, the control device 200 determines whether or not the hot gas heating mode is to end (S1). The hot gas heating mode ends, for example, when the operation mode of the vehicle air conditioner 1 is turned off or when the vehicle system is turned off.

[0078] When the hot gas heating mode is not ending (S1: No), the control device 200 ends the process. When the hot gas heating mode is ending (S1: Yes), the control device 200 increases the rotation speed of the blower 140 to increase the amount of air sent by the blower 140 (S2). As a result, the amount of heat released by the refrigerant becomes greater than the amount of heat of the refrigerant flowing into the compressor 11, and the balance between the workload of the compressor 11 and the heating capacity of the heater core 12 and the heat loss in the flow path is lost, and the heating cycle is reduced, so that the overall pressure of the refrigerant circulating through the refrigerant circuit 10 decreases. As a result, the pressure on the low pressure side of the refrigerant circuit 10 decreases.

[0079] Next, the control device 200 determines whether the pressure on the low pressure side of the refrigerant circuit 10 has fallen below a predetermined pressure (S3). The predetermined pressure is, for example, a pressure that does not exceed an upper limit even if the rotation speed of the compressor 11 is reduced. When the control device 200 determines that the pressure on the low pressure side of the refrigerant circuit 10 has not fallen below the predetermined pressure (S3: No), it waits until it determines that the pressure on the low pressure side of the refrigerant circuit 10 has fallen below the predetermined pressure. When the control device 200 determines that the pressure on the low pressure side of the refrigerant circuit 10 has fallen below the predetermined pressure (S3: Yes), it gradually reduces the rotation speed of the compressor 11 (S4).

[0080] Next, the control device 200 judges whether the pressure on the low pressure side of the refrigerant circuit 10 will not exceed the upper limit when the operation of the compressor 11 is stopped (S5). When the control device 200 judges that the pressure on the low pressure side of the refrigerant circuit 10 will exceed the upper limit when the operation of the compressor 11 is stopped (S5: No), it waits until it judges that the pressure on the low pressure side of the refrigerant circuit 10 will not exceed the upper limit when the operation of the compressor 11 is stopped. Then, when the control device 200 judges that the pressure on the low pressure side of the refrigerant circuit 10 will not exceed the upper limit when the operation of the compressor 11 is stopped (S5: Yes), it stops the operation of the compressor 11 (S6). Next, the control device 200 stops the operation of the blower 140 (S7). Note that even if it waits in the process of step S5, if the pressure on the low pressure side of the refrigerant circuit 10 exceeds the upper limit when the operation of the compressor 11 is stopped, it is possible to return to the process of step S2 and repeat the processes of steps S2 to S4 again.

[0081] In the process of FIG. 8, it is possible to stop the compressor 11 so that the pressure on the low pressure side of the refrigerant circuit 10 does not exceed the upper limit, thereby reducing wear on the components of the vehicle air conditioner 1, such as the compressor 11 and the accumulator 15.

[0082] 8, by increasing the airflow rate of the blower 140, the amount of heat released by the refrigerant becomes greater than the amount of heat of the refrigerant flowing into the compressor 11, and the heating cycle is reduced, so that the pressure on the low-pressure side of the refrigerant circuit 10 can be made lower than the upper limit pressure. That is, the pressure on the suction side 11b of the compressor 11 can be made lower than the allowable pressure.

[0083] 8, it is preferable to blow air into the vehicle cabin from a defroster (DEF) outlet in order to prevent a decrease in passenger comfort due to an increase in the airflow rate of the blower 140. In addition, it is preferable not to operate the blower 140 at the maximum airflow rate while the hot gas heating mode is being executed so that the pressure in the refrigerant circuit 10 can be reduced in the event of an emergency.

[0084] <Specific example 4 of pressure reduction process on the low pressure side> Figure 9 is a flowchart showing a specific processing procedure by the control device 200 for reducing the pressure on the low pressure side of the refrigerant circuit 10 when the hot gas heating mode ends, and is an example of a procedure in a control process that differs from Figures 3, 4, and 8.

[0085] 9, the control device 200 determines whether or not it is time to end the hot gas heating mode (S1). The hot gas heating mode ends, for example, when the operation mode of the vehicle air conditioner 1 is turned off or when the vehicle system is turned off.

[0086] When the hot gas heating mode is not ending (S1: No), the control device 200 ends the process. When the hot gas heating mode is ending (S1: Yes), the control device 200 increases the ratio of outside air introduced into the vehicle cabin (S2). That is, the control device 200 has the intake unit 130 adjust the ratio of the air inside the vehicle cabin and the air outside the vehicle cabin so that the ratio of the air outside the vehicle cabin introduced into the vehicle cabin increases. As a result, the extremely low temperature outside air flows in, and the amount of heat released by the refrigerant becomes greater than the amount of heat of the refrigerant flowing into the compressor 11, which disrupts the balance between the workload of the compressor 11 and the heating capacity of the heater core 12 and the heat loss in the flow path, and the heating cycle is reduced, so that the overall pressure of the refrigerant circulating through the refrigerant circuit 10 decreases. As a result, the pressure on the low pressure side of the refrigerant circuit 10 decreases.

[0087] Next, the control device 200 determines whether the pressure on the low pressure side of the refrigerant circuit 10 has fallen below a predetermined pressure (S3). The predetermined pressure is, for example, a pressure that does not exceed an upper limit even if the rotation speed of the compressor 11 is reduced. When the control device 200 determines that the pressure on the low pressure side of the refrigerant circuit 10 has not fallen below the predetermined pressure (S3: No), it waits until it determines that the pressure on the low pressure side of the refrigerant circuit 10 has fallen below the predetermined pressure. When the control device 200 determines that the pressure on the low pressure side of the refrigerant circuit 10 has fallen below the predetermined pressure (S3: Yes), it gradually reduces the rotation speed of the compressor 11 (S4).

[0088] Next, the control device 200 judges whether the pressure on the low pressure side of the refrigerant circuit 10 will not exceed the upper limit when the operation of the compressor 11 is stopped (S5). When the control device 200 judges that the pressure on the low pressure side of the refrigerant circuit 10 will exceed the upper limit when the operation of the compressor 11 is stopped (S5: No), it waits until it judges that the pressure on the low pressure side of the refrigerant circuit 10 will not exceed the upper limit when the operation of the compressor 11 is stopped. Then, when the control device 200 judges that the pressure on the low pressure side of the refrigerant circuit 10 will not exceed the upper limit when the operation of the compressor 11 is stopped (S5: Yes), it stops the operation of the compressor 11 (S6). Next, the control device 200 stops the operation of the blower 140 (S7). Note that even if it waits in the process of step S5, if the pressure on the low pressure side of the refrigerant circuit 10 exceeds the upper limit when the operation of the compressor 11 is stopped, it may return to the process of step S2 and repeat the processes of steps S2 to S4 again, or it may return to the process of step S4 and repeat the process of step S4 again.

[0089] In the process of FIG. 9, it is possible to stop the compressor 11 so that the pressure on the low pressure side of the refrigerant circuit 10 does not exceed the upper limit, thereby reducing wear on the components of the vehicle air conditioner 1, such as the compressor 11 and the accumulator 15.

[0090] In addition, in an extremely low-temperature environment in which the hot gas heating mode is executed, the temperature of the air outside the vehicle cabin is lower than the temperature of the air inside the vehicle cabin. Therefore, in the process of FIG. 9, regardless of the air volume blown by the blower 140, the amount of heat radiation of the refrigerant can be increased by increasing the ratio of the outside air introduced, which has a lower temperature than the air inside the vehicle cabin. As a result, the amount of heat radiation of the refrigerant becomes greater than the amount of heat of the refrigerant flowing into the compressor 11, and the heating cycle is reduced, so that the pressure on the low-pressure side of the refrigerant circuit 10 can be made lower than the upper limit pressure. In other words, the pressure on the suction side 11b of the compressor 11 can be made lower than the allowable pressure.

[0091] In the example of FIG. 9, it is preferable to blow air into the vehicle compartment from a defroster (DEF) outlet in order to prevent a decrease in passenger comfort due to an increase in the ratio of outside air introduced into the vehicle compartment.

[0092] <Vibration and noise reduction treatment> In the hot gas heating mode, vibrations and noises may occur in the vehicle due to resonance between the rotation of the compressor 11 and each element constituting the refrigerant circuit 10, or due to an increase in the rotation speed of the compressor 11 for increasing the heating capacity. Therefore, the control device 200 can execute control for reducing vibrations and noises as shown in Fig. 10 and Fig. 11. Note that only one of the processes in Fig. 10 and Fig. 11 may be executed, or both of the processes may be executed.

[0093] <Example 1 of vibration and noise reduction treatment> FIG. 10 is a flowchart showing an example of a specific processing procedure of the control device 200 regarding the processing for reducing vibration and noise in the hot gas heating mode.

[0094] As shown in FIG. 10, the control device 200 determines whether or not the system is in the hot gas heating mode (S1).

[0095] When the hot gas heating mode is not in progress (S1: No), the control device 200 ends the process. When the hot gas heating mode is in progress (S1: Yes), the control device 200 determines whether or not vibrations exceeding a predetermined allowable range are occurring (S2). Vibrations exceeding a predetermined allowable range are vibrations with a frequency that is expected to cause resonance.

[0096] In this embodiment, the rotation speed of the compressor 11 when vibration exceeding a predetermined tolerance occurs is measured in advance, and the control device 200 stores the rotation speed of the compressor 11 when vibration exceeding the predetermined tolerance occurs as data. The control device 200 then monitors the actual rotation speed of the compressor 11 to detect whether or not vibration exceeding the predetermined tolerance occurs. Note that a sensor for detecting vibration may be provided to detect whether or not vibration exceeding the predetermined tolerance occurs.

[0097] When vibration exceeding a predetermined tolerance range is not occurring (S2: No), the control device 200 ends the process. When vibration exceeding a predetermined tolerance range is occurring (S2: Yes), the control device 200 determines whether the target suction pressure of the compressor 11 is maximum within the range in which the target heating capacity can be achieved (S3).

[0098] The target heating capacity is a heating capacity required to achieve the interior temperature set by the occupant, and is calculated as follows. Target heating capacity = (target heater core downwind air temperature - heater core upwind air temperature) x air volume The target heater core downwind air temperature is calculated based on the difference between the set temperature in the vehicle interior and the actual temperature in the vehicle interior when the target heating capacity is calculated. In addition, the target suction pressure is a target value of the suction pressure of the compressor 11 for obtaining the target heater core downwind air temperature required to achieve the target heating capacity, and can vary in relation to the heater core upwind air temperature and air volume.

[0099] When the control device 200 determines that the target suction pressure of the compressor 11 is not the maximum within the range in which the target heating capacity is achieved (S3: No), it increases the target suction pressure of the compressor 11 within the range in which the target heating capacity is achieved (S4). As the target suction pressure increases, the suction pressure of the compressor 11 increases, and the rotation speed of the compressor 11 decreases. This makes it possible to set the rotation speed of the compressor 11 to a value different from the rotation speed at which vibrations exceeding a predetermined tolerance range occur. As a result, it is possible to avoid the occurrence of vibrations exceeding a predetermined tolerance range. At this time, the control device 200 changes each target value so as to maintain the target heating capacity.

[0100] When the control device 200 determines that the target suction pressure of the compressor 11 is maximum within the range in which the target heating capacity can be achieved (S3: Yes), it reduces the target suction pressure of the compressor 11 within the range in which the target heating capacity can be achieved (S5). As the target suction pressure is reduced, the suction pressure of the compressor 11 is reduced, and the rotation speed of the compressor 11 is increased. This makes it possible to set the rotation speed of the compressor 11 to a value different from the rotation speed at which vibrations exceeding a predetermined tolerance range occur. As a result, it is possible to avoid the occurrence of vibrations exceeding a predetermined tolerance range. At this time, the control device 200 changes each target value so as to maintain the target heating capacity.

[0101] In hot gas heating mode, there are multiple conditions for achieving the target heating capacity. Therefore, in the process of Fig. 10, by operating in hot gas heating mode under a combination of conditions different from the combination of conditions when it is determined that vibration exceeding a predetermined tolerance has occurred, it is possible to avoid the occurrence of vibration and noise associated with vibration while maintaining the target heating capacity.

[0102] Moreover, by making the target suction pressure higher than the target value, it is possible to reduce the rotation speed of the compressor 11, thereby reducing power consumption. In addition, the load on the compressor 11 can be reduced, thereby extending the life of the compressor 11.

[0103] In addition, since it is possible to operate under conditions different from those under which resonance occurs while maintaining the target heating capacity, it is possible to avoid the occurrence of vibrations and noise.

[0104] <Example 2 of vibration and noise reduction treatment> FIG. 11 is a flowchart showing an example of a specific processing procedure of the control device 200 regarding the processing for reducing vibration and noise in the hot gas heating mode.

[0105] As shown in Fig. 11, the control device 200 determines whether or not the system is in hot gas heating mode (S1). If the system is not in hot gas heating mode (S1: No), the control device 200 ends the process. If the system is in hot gas heating mode (S1: Yes), the control device 200 determines whether or not the rotation speed of the compressor 11 is equal to or higher than a predetermined rotation speed (S2). The predetermined rotation speed is, for example, a rotation speed at which vibration or noise is estimated to occur.

[0106] In this embodiment, the rotation speed of the compressor 11 when vibration or noise occurs is measured in advance, and the control device 200 stores the rotation speed of the compressor 11 when vibration or noise occurs as data. The control device 200 then detects whether vibration or noise is occurring by monitoring whether the actual rotation speed of the compressor 11 is equal to or higher than a predetermined rotation speed. Note that a sensor for detecting vibration or noise may be provided to detect whether vibration or noise that exceeds a predetermined allowable range is occurring.

[0107] When the rotation speed of the compressor 11 is not equal to or higher than the predetermined rotation speed (S2: No), the control device 200 ends the process. When the rotation speed of the compressor 11 is equal to or higher than the predetermined rotation speed (S2: Yes), the control device 200 reduces the opening degree of the pressure reducing device 13a and the pressure reducing device 13b to reduce the pressure on the low pressure side of the refrigerant circuit 10 (S4). Specifically, when an expansion valve is used as the pressure reducing device 13a and the pressure reducing device 13b, the expansion valve is throttled. This reduces the temperature of the refrigerant on the low pressure side of the refrigerant circuit 10. The low pressure side of the refrigerant circuit 10 may be reduced by reducing the opening degree of either the pressure reducing device 13a or the pressure reducing device 13b.

[0108] Next, the control device 200 starts the circulation pump P40 and the heat medium heater 42 (S3). As a result, the heat medium heated by the heat medium heater 42 is circulated through the battery temperature control circuit 40 by the circulation pump P40, and passes through the heat medium passage 14b of the low-temperature side heat exchanger 14. As a result, the heat of the heat medium flowing through the heat medium passage 14b of the low-temperature side heat exchanger 14 is dissipated to the refrigerant flowing through the refrigerant passage 14a of the low-temperature side heat exchanger 14. At this time, the temperature of the refrigerant has been reduced by the process in S2, so the efficiency of heat dissipation to the refrigerant is increased.

[0109] When the temperature of the refrigerant passing through the refrigerant passage 14a is higher than the temperature of the heat medium passing through the heat medium passage 14b of the low-temperature side heat exchanger 14, the control device 200 first warms the heat medium by using the heat of the refrigerant. Specifically, the control device 200 controls the rotation speed of the circulation pump P40 to reduce the amount of heat medium passing through the heat medium passage 14b, thereby increasing the efficiency of heat dissipation from the refrigerant to the heat medium, and warms the heat medium by using the heat of the refrigerant. Then, when the temperature of the heat medium becomes higher than the temperature of the refrigerant due to heat dissipation from the refrigerant or heating by the heat medium heater 42, the control device 200 increases the amount of heat medium passing through the heat medium passage 14b, causing the heat medium to dissipate heat to the refrigerant.

[0110] Next, the control device 200 judges whether the temperature of the refrigerant is equal to or higher than a predetermined temperature (S6). The predetermined temperature is a temperature measured in advance, and is a temperature at which the pressure on the low-pressure side of the refrigerant circuit 10 increases and the rotation speed of the compressor 11 decreases. The control device 200 stores the predetermined temperature as data. When the control device 200 judges that the temperature of the refrigerant is not equal to or higher than the predetermined temperature, it waits until the temperature of the refrigerant is equal to or higher than the predetermined temperature. When the control device 200 judges that the temperature of the refrigerant is equal to or higher than the predetermined temperature, it stops the operation of the circulation pump P40 and the heat medium heater 42 (S7). When the temperature of the refrigerant is equal to or higher than the predetermined temperature, the rotation speed of the compressor 11 decreases, so that the rotation speed of the compressor 11 can be made lower than the predetermined rotation speed. As a result, it is possible to suppress the occurrence of vibrations and noise such as resonance caused by the rotation of the compressor 11.

[0111] In the process of Fig. 11, the heat source in the hot gas heating mode is increased by dissipating heat from the heat medium to the refrigerant, so the temperature of the refrigerant can be increased. Therefore, the pressure on the low pressure side of the refrigerant circuit 10 can be increased while maintaining the heating capacity, and the rotation speed of the compressor 11 can be reduced. This makes it possible to suppress the generation of vibrations and noise due to resonance, etc.

[0112] Furthermore, by providing the heat medium heater 42, the temperature of the heat medium can be made higher than the temperature of the refrigerant, which makes it easier to increase the pressure on the low pressure side of the refrigerant circuit 10 and therefore makes it easier to reduce the rotation speed of the compressor 11. This makes it possible to more effectively avoid the generation of vibrations and noise.

[0113] Furthermore, by making the temperature of the heat medium higher than the temperature of the refrigerant by the heat medium heater 42, it becomes possible to more suitably cause the refrigerant to absorb heat in the low-temperature side heat exchanger 14, and therefore it becomes easier to reduce the rotation speed of the compressor 11. As a result, the rotation speed of the compressor 11 can be further reduced.

[0114] [Effects of this embodiment] (a1) A vehicular air conditioning device 1 including a refrigerant circuit 10 configured to circulate through a compressor 11, a heater core 12 that heats air supplied to a vehicle cabin, pressure reducing devices 13a to 13e, a low-temperature side heat exchanger 14 that causes a refrigerant to absorb heat from a heat medium absorbed from a battery 41 as an on-board heat generating device, and an accumulator 15, the refrigerant circuit including a bypass path that causes the refrigerant that has passed through the compressor 11 to bypass the heater core 12 and flow into the suction side 11b of the compressor 11, and a control device 200 capable of control in 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, and the control device 200 executes a pressure reduction process to reduce the pressure on the low-pressure side of the refrigerant circuit 10 when the hot gas heating mode is terminated. Therefore, it is possible to stop the compressor 11 so that the pressure on the low pressure side of the refrigerant circuit 10 does not exceed the upper limit, thereby reducing wear on the components of the vehicle air conditioner 1, such as the compressor 11 and the accumulator 15. (a2) A pressure reducing device 13a is provided in the bypass path, and the control device 200 executes a process of reducing the pressure on the low pressure side of the refrigerant circuit 10 by the pressure reducing devices 13a, 13b and gradually reducing the rotation speed of the compressor 11 as a pressure reduction process. This allows the pressure and temperature of the refrigerant on the low-pressure side of the refrigerant circuit 10 to be gradually reduced, thereby reducing the load on the components of the vehicle air conditioner 1, such as the compressor 11 and the accumulator 15. (a3) As the pressure reduction process, the control device 200 executes a process of gradually reducing the rotation speed of the compressor 11 and then reducing the pressure on the low-pressure side of the refrigerant circuit 10 by the pressure reducing devices 13a, 13b. Therefore, it is possible to prevent the pressure of the refrigerant on the high-pressure side of the refrigerant circuit 10 from increasing, and the load on components such as the compressor 11 and the accumulator 15 can be reduced. (a4) In the pressure reduction process, the controller 200 executes a process of dissipating heat of the refrigerant to the heat medium in the low-temperature side heat exchanger 14. This allows the pressure and temperature of the refrigerant on the low-pressure side of the refrigerant circuit 10 to be reduced, thereby reducing the load on components such as the compressor 11 and the accumulator 15. In addition, the heat of the refrigerant can be stored in the heat medium, so the stored heat can be used as a heat source when restarting the vehicle air conditioner. (a5) The vehicle is provided with an HVAC unit 100 as an air conditioning unit that houses a heater core 12 and includes an intake unit 130 as an inside / outside air switching device that adjusts the ratio of inside and outside air introduced into an air flow passage 120 for air that exchanges heat in the heater core 12, and a blower 140 that blows the air that exchanges heat in the heater core 12 into the vehicle cabin, and a control device 200 executes a process to increase the amount of air blown by the blower 140 during a pressure reduction process. Therefore, by increasing the blowing amount of the blower 140, the amount of heat released by the refrigerant becomes greater than the amount of heat of the refrigerant flowing into the compressor 11, and the heating cycle is reduced, so that the pressure on the low-pressure side of the refrigerant circuit 10 can be made lower than the upper limit pressure. In other words, the pressure on the suction side 11b of the compressor 11 can be made lower than the allowable pressure. (a6) The vehicle is equipped with an HVAC unit 100 as an air conditioning unit that houses a heater core 12 and includes an intake unit 130 as an inside / outside air switching device that adjusts the ratio of inside and outside air introduced into an air flow passage 120 for air that exchanges heat in the heater core 12, and a blower 140 that blows the air that exchanges heat in the heater core 12 into the vehicle cabin, and a control device 200 performs a process of adjusting the ratio of outside air introduced by the intake unit 130 so that the ratio of outside air introduced is increased during a pressure reduction process. Therefore, it is possible to increase the amount of heat dissipated by the refrigerant by increasing the ratio of the outside air introduced, which has a lower temperature than the air inside the vehicle compartment, regardless of the amount of air blown by the blower 140. As a result, the amount of heat dissipated by the refrigerant becomes greater than the amount of heat of the refrigerant flowing into the compressor 11, and the heating cycle is reduced, so that the pressure on the low-pressure side of the refrigerant circuit 10 can be made lower than the upper limit pressure. In other words, the pressure on the suction side 11b of the compressor 11 can be made lower than the allowable pressure.

[0115] (b1) A vehicular air conditioning device 1 including a refrigerant circuit 10 configured to circulate through a compressor 11, a heater core 12 that heats air supplied to a vehicle cabin, pressure reducing devices 13a to 13e, a low-temperature side heat exchanger 14 that causes a refrigerant to absorb heat from a heat medium absorbed from a battery 41 as an on-board heat generating device, and an accumulator 15, the refrigerant circuit including 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 capable of control in 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 control device 200 determines whether or not vibrations exceeding a predetermined allowable range are occurring during the hot gas heating mode, and if it is determined that vibrations exceeding the predetermined allowable range are occurring, changes the target suction pressure within the range in which the target heating capacity is established. Therefore, since there are multiple conditions for achieving the target heating capacity in hot gas heating mode, by operating in hot gas heating mode under a combination of conditions different from the combination of conditions when it is determined that vibrations exceeding a specified tolerance range have occurred, it is possible to maintain the target heating capacity while avoiding the generation of vibrations and noise associated with vibrations. (b2) When it is possible to increase the target suction pressure within the range in which the target heating capacity is achieved, the control device 200 increases the target suction pressure within the range in which the target heating capacity is achieved when it determines that vibration exceeding a predetermined tolerance range is occurring. Therefore, by setting the target suction pressure higher than the target value, it is possible to reduce the rotation speed of the compressor 11, thereby reducing power consumption. In addition, the load on the compressor 11 can be reduced, thereby extending the life of the compressor 11. (b3) When the target suction pressure is maximum within the range in which the target heating capacity is achieved, the control device 200 reduces the target suction pressure if it determines that vibration exceeding a predetermined allowable range is occurring. Therefore, since it is possible to operate under conditions different from those under which resonance occurs while maintaining the target heating capacity, it is possible to avoid the occurrence of vibrations and noise.

[0116] (c1) A vehicular air conditioning device 1 including a refrigerant circuit 10 configured to circulate through a compressor 11, a heater core 12 that heats air supplied to a vehicle cabin, pressure reducing devices 13a to 13e, a low-temperature side heat exchanger 14 that causes a refrigerant to absorb heat from a heat medium absorbed from a battery 41 as an in-vehicle heat generating device, and an accumulator 15, the refrigerant circuit 10 including a bypass path where 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 capable of control in 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 control device 200 determines whether the rotation speed of the compressor 11 is equal to or greater than a predetermined rotation speed during the hot gas heating mode, and when it is determined that the rotation speed of the compressor 11 is equal to or greater than the predetermined rotation speed, causes the heat of the heat medium to be dissipated to the refrigerant in the low-temperature side heat exchanger 14. Therefore, the heat source in the hot gas heating mode increases by dissipating heat from the heat medium to the refrigerant, and the temperature of the refrigerant can be increased. Therefore, the pressure on the low pressure side of the refrigerant circuit 10 can be increased while maintaining the heating capacity, and the rotation speed of the compressor 11 can be reduced. This makes it possible to suppress the generation of vibrations and noise due to resonance, etc.

[0117] (c2) The battery temperature control circuit 40 includes a heat medium heating device 42 capable of heating a heat medium and a temperature control unit that controls the temperature of a battery 41 as an in-vehicle heat-generating device, and is configured so that the heat medium circulates. The control device 200 dissipates heat from the heat medium heated by the heat medium heating device 42 to the refrigerant in the low-temperature side heat exchanger 14. Therefore, by providing the heat medium heating device 42, the temperature of the heat medium can be made higher than the temperature of the refrigerant, which makes it easier to increase the pressure on the low pressure side of the refrigerant circuit 10 and therefore makes it easier to reduce the rotation speed of the compressor 11. This makes it possible to more effectively avoid the generation of vibrations and noise.

[0118] (c3) The temperature of the heat medium is made higher than the temperature of the refrigerant flowing through the low-temperature side heat exchanger 14 by the heat medium heater 42. Therefore, by making the temperature of the heat medium higher than the temperature of the refrigerant by the heat medium heater 42, it becomes possible to more suitably cause the refrigerant to absorb heat in the low-temperature side heat exchanger 14, and accordingly, it becomes easier to reduce the rotation speed of the compressor 11. As a result, the rotation speed of the compressor 11 can be further reduced.

[0119] 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]

[0120] 1: Vehicle air conditioning system 10: refrigerant circuit, 11: compressor, 12: heater core, 13a, 13b, 13c, 13d: 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 in a hot gas heating mode in which a part of the refrigerant that has passed through the compressor is caused to flow to the heater core and the remaining refrigerant is caused to flow to the bypass path, The control device includes: A determination is made as to whether or not vibration exceeding a predetermined allowable range occurs during the hot gas heating mode, and if it is determined that vibration exceeding the predetermined allowable range occurs, a target suction pressure is changed within a range in which a target heating capacity is established.

1. A vehicle air conditioning system comprising:

2. The control device includes: When it is possible to increase the target suction pressure within the range in which the target heating capacity is realized, if it is determined that vibration exceeding the predetermined allowable range is occurring, the target suction pressure is increased within the range in which the target heating capacity is realized.

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

3. The control device includes: When the target suction pressure is maximum within the range in which the target heating capacity is established, the target suction pressure is reduced if it is determined that vibration exceeding the predetermined allowable range is occurring.

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

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