Vehicle air conditioning system

Abstract

To continue hot gas heating to continue heating under a cryogenic environment for a predetermined time without using auxiliary heating such as a PTC heater in a vehicle air conditioner using a heat pump.SOLUTION: A vehicle air conditioner includes: a refrigerant circuit which includes at least a compressor and circulates a high-temperature refrigerant discharged from the compressor; an air heater which heats air in a passenger compartment with heat radiated from the refrigerant; and a control device which controls an amount of heat radiated from the refrigerant. The control device has a hot gas heating continuation mode in which the amount of heat radiated from the refrigerant is smaller than or equal to a heat gain from the compressor.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to an air conditioning system for vehicles. [Background technology]

[0002] For electric vehicles (EVs) that do not have a combustion system heat source such as an engine, or for vehicles with a low heat output from a combustion system heat source, air conditioning systems that use a heat pump as a heat source are well known.

[0003] In air conditioning systems using heat pumps, the external heat exchanger functions as a heat absorber during heating operation, obtaining heating heat from the outside air. Therefore, when the outside temperature becomes extremely low, heat absorption from the outside air becomes difficult, and the heating capacity decreases significantly. In contrast, if an electric heater such as a PTC heater is used to secure the heat source, battery consumption increases, raising concerns about adverse effects on the driving range of electric vehicles, and also increasing the manufacturing cost of the air conditioning system.

[0004] Hot gas heating, which utilizes the compressor of a heat pump, is a heating method that does not involve absorbing heat from the outside air. In this hot gas heating system, the high-temperature refrigerant discharged from the compressor is sent to the heat dissipation section, which is an in-vehicle heat exchanger, and the refrigerant discharged from the heat dissipation section is depressurized and returned to the compressor without passing through an external heat exchanger (see Patent Document 1 below). [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2014-196017 [Overview of the project] [Problems that the invention aims to solve]

[0006] In vehicle air conditioning systems utilizing heat pumps, when employing the aforementioned hot gas heating system for heating in extremely low-temperature environments, the compressor is typically operated at a rotational speed close to its capacity limit. In this case, as the amount of heat released from the in-vehicle heat exchanger increases in response to heating demands, if the amount of heat released becomes greater than the energy consumed (heat input) of the compressor, it becomes impossible to continue hot gas heating even if the compressor is continuously operated at its upper limit rotational speed.

[0007] This invention addresses these problems and aims to provide a solution for continuously utilizing hot gas heating. Specifically, in a vehicle air conditioning system using a heat pump, the objective of this invention is to enable continuous heating for a predetermined period of time in an extremely low-temperature environment without the need for auxiliary heating such as a PTC heater, by continuously providing hot gas heating. [Means for solving the problem]

[0008] To solve these problems, the present invention has the following configuration. A vehicle air conditioning system comprising at least a compressor and a refrigerant circuit for circulating high-temperature refrigerant discharged from the compressor, an air heating device for heating the air inside the vehicle by the heat radiated by the refrigerant, and a control device for controlling the amount of heat radiated by the refrigerant, wherein the control device has a hot gas heating continuous mode that keeps the amount of heat radiated by the refrigerant less than or equal to the amount of heat input from the compressor. [Effects of the Invention]

[0009] The present invention, with these characteristics, makes it possible to continue hot gas heating in an extremely low-temperature environment for a predetermined period of time, thereby improving the practicality of vehicle air conditioning systems that utilize heat pumps. Furthermore, since heating in an extremely low-temperature environment can be performed without using auxiliary heating such as PTC heaters, the manufacturing cost of air conditioning systems can be reduced. [Brief explanation of the drawing]

[0010] [Figure 1]An explanatory diagram showing the configuration and refrigerant flow of a vehicle air conditioning system according to an embodiment of the present invention. [Figure 2] An explanatory diagram showing the configuration and refrigerant flow of a vehicle air conditioning system according to an embodiment of the present invention. [Figure 3] A block diagram of a control device in a vehicle air conditioning system according to an embodiment of the present invention. [Figure 4] An explanatory diagram showing the basic control flow for the continuous hot gas heating mode. [Figure 5] The timing chart diagram shows an example of control in continuous hot gas heating mode ((a) is an example of controlling the fan output voltage based on the amount of heat radiated from the indoor air conditioning unit's heat radiating section, and (b) is an example of controlling the heat transfer fluid flow rate based on the amount of heat radiated from the refrigerant-heat transfer fluid heat exchanger). [Figure 6] An explanatory diagram showing another example of a control flow for executing the hot gas heating continuous mode. [Figure 7] The timing chart diagram of the control example in Figure 6 ((a) shows control based on the time-series change of the heat dissipation amount Qicnd of the heat dissipation unit, and (b) shows control based on the time-series change of the compressor discharge pressure Pci). [Figure 8] A flowchart showing a specific control example of a vehicle air conditioning system according to an embodiment of the present invention. [Figure 9] An explanatory diagram showing an example of the configuration of a control system in an electric vehicle (EV) equipped with an in-vehicle air conditioning system. [Modes for carrying out the invention]

[0011] Embodiments of the present invention will now be described with reference to the drawings. In the following description, the same reference numerals in different figures indicate parts with the same function, and redundant explanations in each figure will be omitted as appropriate.

[0012] Figure 1 shows an example of the configuration of a vehicle air conditioning system according to an embodiment of the present invention. The vehicle air conditioning system 1 comprises an interior air conditioning unit 10 that functions as an air heating device for heating the air inside the vehicle, and a refrigerant circuit 20.

[0013] The vehicle air conditioning unit 10 shown in Figure 1 is equipped with indoor heat exchangers 11 and 12. The indoor air conditioning unit 10 is also equipped with a blower 13 in the air supply layer 10A upstream of the indoor heat exchanger 11, which blows air from inside the vehicle into the indoor heat exchangers 11 and 12, and an air supply passage to the vehicle interior is provided in the air receiving layer 10B downstream of the indoor heat exchanger 12, which is not shown. The indoor air conditioning unit 10 is also equipped with an air damper 14 which is opened and closed by an air damper drive unit 14A. The amount of air supplied through the indoor heat exchangers 11 and 12 can be adjusted by controlling the air supply volume of the blower 13 and the opening and closing of the air damper 14.

[0014] The refrigerant circuit 20 of the vehicle air conditioning system 1 shown in Figure 1 can perform heating or cooling operations by configuring a heat pump, and is equipped with a refrigerant flow path switching means that allows switching to a heat pump cycle. By selecting the refrigerant flow path shown by the thick line in the figure, hot gas heating can be performed.

[0015] The refrigerant circuit 20 includes a compressor 2 that compresses and discharges vaporized refrigerant, a pressure reducing valve 22 (22A, 22B, 22C, 22D) that reduces the pressure of the refrigerant compressed by the compressor 2 to a predetermined pressure, a flow path switching valve 23 (23A, 23B, 23C, 23D) that switches the flow path of the refrigerant, and an accumulator 21 provided upstream of the compressor 2.

[0016] Furthermore, the refrigerant flow path of the refrigerant circuit 20 is connected to the indoor heat exchangers 11 and 12 mentioned above, as well as to an external heat exchanger 24 for the refrigerant to exchange heat with the outside air, and a refrigerant-heat transfer medium heat exchanger 25 for the refrigerant to exchange heat with the heat transfer medium flowing through the heat transfer medium circuit 30. In addition, the refrigerant circuit 20 is equipped with a check valve 26 and the like as needed.

[0017] In the illustrated example, by closing the flow path switching valves 23C and 23D, hot gas heating can be performed using the refrigerant flow path shown by the thick line in the illustration. When hot gas heating is performed, the high-temperature refrigerant discharged from the compressor 2 flows through the indoor heat exchanger 12, which functions as a heat dissipation unit. The refrigerant that exits the indoor heat exchanger 12 returns to the compressor 2 via the flow path switching valve 23A, pressure reducing valve 22A, refrigerant-heat transfer medium heat exchanger 25, and accumulator 21. The refrigerant that exits the compressor 2 also passes through a bypass flow path 3 that bypasses the indoor heat exchanger 12, etc., and returns to the compressor 2 via the accumulator 21.

[0018] In the example shown in Figure 1, only the indoor heat exchanger 12 is used as the heat dissipation unit in the indoor air conditioning unit 10, and the refrigerant flow path passes through the refrigerant-heat transfer medium heat exchanger 25. However, as shown in Figure 2, by completely closing the pressure reducing valve 22A, both the indoor heat exchangers 11 and 12 of the indoor air conditioning unit 10 can be used as the heat dissipation unit, and hot gas heating can be performed with a refrigerant flow path that bypasses the refrigerant-heat transfer medium heat exchanger 25.

[0019] In the example shown in Figure 1, the refrigerant circuit 20 allows adjustment of the flow rate ratio between the bypass passage 3 and the other passages by adjusting the throttling amounts of the pressure reducing valves 22A and 22B. Similarly, in the example shown in Figure 2, the aforementioned flow rate ratio can be adjusted by adjusting the throttling amounts of the pressure reducing valves 22C and 22B. By adjusting the flow rate ratio so that the flow rate of the bypass passage 3 increases, the flow rate of refrigerant returning to the compressor 2 with less heat dissipation increases, thereby reducing the amount of heat dissipated by the refrigerant.

[0020] Furthermore, as shown in Figure 3, the vehicle air conditioning system 1 includes a control device 4. The control device 4 is an air conditioning ECU (Electronic Control Unit) for executing various control modes of the vehicle air conditioning system 1, and when hot gas heating is performed, it has a hot gas heating continuation mode that controls the amount of heat released from the refrigerant to continue hot gas heating.

[0021] In order to grasp the operating status of the vehicle air conditioner 1, the control device 4 acquires detection information from various sensors. In the hot gas heating continuous mode described above, as shown in FIG. 3, detection information from the blower temperature sensors Ta1, Ta2, the outside air temperature sensor Ta3, the refrigerant temperature sensors Tr1, Tr2, and the refrigerant pressure sensors Pr1, Pr2 is input to the control device 4. The control device 4 controls the flow path switching valve drive units S1 to S4 to open and close the flow path switching valves 23 (23A to 23D), thereby selecting the refrigerant flow path, and controls the compressor 2, the blower 13, the air damper drive unit 14A, the heat medium circulation pump 31, and the pressure reducing valve drive units E1 to E4 to control the heat radiation amount of the refrigerant.

[0022] The basic control flow of the control device 4 in the hot gas heating continuous mode is shown in FIG. 4. From the start of control, the heat input amount (Q comp ) from the compressor 2 is grasped (step S1), and the heat radiation amount (Q out ) of the refrigerant in the refrigerant circuit 20 is grasped (step S2). The heat input amount (Q comp ) and the heat radiation amount (Q out ) are compared (step S3). When Q comp ≧Q out is established (step S3: YES), it is assumed that the hot gas heating can be continued, and in response to the heating request (step S4), the control cycle is terminated.

[0023] Also, when Q comp ≧Q out is not established (step S3: NO), it is assumed that the continuation of the hot gas heating is impossible, and after performing a process (step S5) to reduce the heat radiation amount (Q out ) of the refrigerant, the control cycle is terminated. In the hot gas heating continuous mode, by repeating the control cycle of this basic control flow, when Q comp ≧Q out is not established, a process to reduce the heat radiation amount (Q out ) of the refrigerant is performed to return to a state where Q comp ≧Q out is established, thereby enabling the continuation of the hot gas heating.

[0024] Here, the amount of heat input from compressor 2 (Q) comp The amount of heat input (Q) can be determined by monitoring the power consumption of compressor 2. comp This can be determined by multiplying the power consumption of compressor 2 by a predetermined coefficient, etc.

[0025] The amount of heat dissipated by the refrigerant in the refrigerant circuit 20 (Q) out Understanding the following can be done by individually or comprehensively considering (1) to (3) below.

[0026] (1) Amount of heat dissipated by the heat dissipation section (indoor heat exchangers 11, 12) in the indoor air conditioning unit 10, (2) Amount of ambient heat dissipated by the refrigerant circuit 20, and (3) Amount of heat dissipated from the refrigerant-heat transfer medium heat exchanger 25 to the heat transfer medium circuit 30.

[0027] In (1) to (3) above, the most important heat dissipation when continuing hot gas heating is the heat dissipation amount of the heat dissipation part of the indoor air conditioning unit 10 in (1) above. The heat dissipation amount of the refrigerant (Q) out When determining the amount of heat dissipation, it is preferable to first determine the amount of heat dissipation in (1) above, then, if necessary, take into account the effect of the amount of heat dissipation in (2) above as a disturbance, and further take into account the amount of heat dissipation in (3) above when the heat transfer medium circuit 30 is in operation.

[0028] First, the amount of heat dissipated by the refrigerant (Q) out ) is roughly equal to the amount of heat (Q) dissipated by the heat dissipation section (indoor heat exchanger 12 in Figure 1) of the indoor air conditioning unit 10. icnd This explains the cases that fall under the category of ).

[0029] The amount of heat dissipated by the heat dissipation section of the indoor air conditioning unit 10 (Q icnd ) can be calculated using the following formula. Q icnd = (Thp-Te)×Ga×K Here, Thp: outlet air temperature, Te: intake air temperature, Ga: airflow rate through the heat dissipation section, and K: calculation constant.

[0030] Here, the outlet air temperature (Thp) is the value detected by the airflow temperature sensor Ta2, and the intake air temperature (Te) is the value detected by the airflow temperature sensor Ta1. The airflow rate Ga passing through the heat dissipation section is a calculated value determined by the output of the blower 13 and the opening degree of the air damper 14. The calculation constant (K) is a preset value in the system.

[0031] And in step S3 above, Q comp ≧Q icnd To determine if it is true, Q comp ≧Q icnd If the above condition is not met, the amount of heat released by the refrigerant (Q) is used. out The process to reduce (step S4) is performed by (a) to (c) below.

[0032] (a) Reduction of the airflow rate Ga passing through the heat dissipation section, (b) Increase in the flow rate ratio of the refrigerant flowing through the bypass channel 3, and (c) Reduction in the flow rate of the heat transfer medium flowing through the refrigerant-heat transfer medium heat exchanger 25.

[0033] Here, (a) above can be achieved by appropriately combining the reduction in output of the blower 13 and the increase in the opening of the air damper 14, or by controlling either one of them. By reducing the amount of airflow Ga passing through the heat dissipation section, the amount of heat dissipated by the heat dissipation section in the indoor air conditioning unit 10 is reduced, and the amount of heat dissipated by the refrigerant (Q) is reduced. out ) can be reduced.

[0034] The above (b) can be achieved by adjusting the throttling amount of pressure reducing valves 22A and 22B in the flow path state shown in Figure 1 (and by adjusting the throttling amount of pressure reducing valves 22C and 22B in the flow path state shown in Figure 2). By increasing the flow rate ratio of the refrigerant flowing through the bypass flow path 3, the amount of refrigerant flowing through the heat dissipation section of the indoor air conditioning unit 10 is reduced, and the amount of heat dissipated by the refrigerant (Q out ) can be reduced.

[0035] The above (c) can be achieved by reducing the rotational speed of the heat medium circulation pump 31 when the heat medium circuit 30 is in operation. By reducing the flow rate of the heat medium flowing through the refrigerant-heat medium heat exchanger 25 during the operation of the heat medium circuit 30, the heat dissipation amount of the refrigerant-heat medium heat exchanger 25 in the heat medium circuit 30 decreases, and the heat dissipation amount (Q out ) of the refrigerant can be reduced.

[0036] FIG. 5 shows an example of control. In the example shown in FIG. 5(a), the heat dissipation amount (Q out ) of the refrigerant is grasped by the heat dissipation amount (Q icnd ) of the heat dissipation part in the indoor air-conditioning unit 10, and the comparison between Q comp and Q icnd is made. When Q comp ≧Q icnd no longer holds, control is performed to reduce the output voltage of the blower 13. In the example shown in the figure, at the timing T1 when Q icnd -Q comp ≧α, the output voltage of the blower 13 is lowered from V1 to V2 (V1>V2), thereby reducing the heat dissipation amount (Q icnd ) and making Q comp ≧Q icnd hold.

[0037] Also, in the example shown in the figure, after Q comp ≧Q icnd holds, the output voltage of the blower 13 is raised from V2 to V3 (V2<V3) at a predetermined timing T2 to meet the desired heating requirement. Here, the blower air volume Ga passing through the heat dissipation part is controlled by controlling the output voltage of the blower 13. Instead of this or in addition to this, the blower air volume Ga passing through the heat dissipation part may be controlled by controlling the opening degree of the air damper 14.

[0038] In the example shown in FIG. 5(b), the heat dissipation amount (Q out ) of the refrigerant is grasped by the heat dissipation amount (Q chil ) in the heat medium circuit 30, and the comparison between Q comp and Q chil is made. When Q comp ≧Q chilWhen is no longer satisfied, control is performed to reduce the rotational speed of the heat medium circulation pump 31 and thereby reduce the heat medium flow rate. In the illustrated example, at timing T1 when Q chil -Q comp ≧α, the heat medium flow rate is decreased from L1 to L2 (L1 > L2), thereby reducing the heat dissipation amount (Q chil ) and making Q comp ≧Q chil hold. Also, in the illustrated example, after Q comp ≧Q chil holds, the heat medium flow rate is increased from L2 to L3 (L2 < L3) at a predetermined timing T2 to meet the temperature control requirement of the heat medium circuit 30.

[0039] FIG. 6 shows another control flow example for executing the hot gas heating continuous mode. Here, on the premise that the rotational speed of the compressor 2 is constant (upper limit value), based on the time-series change of the heat dissipation amount (Q icnd ) of the heat dissipation part or the discharge pressure (P ci ) of the compressor 2, the relationship between the heat input amount (Q comp ) and the heat dissipation amount (Q out ) is estimated.

[0040] In the example of FIG. 6, the current value of the heat dissipation amount (Q icnd ) of the heat dissipation part or the discharge pressure (P ci ) of the compressor 2 is acquired from the start of control (step S01) and stored in the memory (step S02). Then, the previous value Q icndz (or P ciz ) stored in the memory in the previous cycle in the control cycle is compared with the current value Q icnd (or P ci ) (step S03). When Q icnd ≧Q icndz (or P ci ≧P ciz ) holds (step S03: YES), it is considered that the continuation of hot gas heating is possible, and in response to the heating requirement (step S04), the current control cycle is terminated.

[0041] Also, the previous value Q icndz (or P ciz) and the current value Q icnd (or P ci ) are compared (step S03). If Q icnd ≧Q icndz (or P ci ≧P ciz is not satisfied (step S03: NO), the reduction process of the heat dissipation amount (Q) of the refrigerant described above is performed (step S05), and the process of returning to a state where hot gas heating can continue is performed, and the current control cycle is terminated.

[0042] By performing the control shown in FIG. 6, a time chart as shown in FIG. 7 can be obtained. FIG. 7(a) is based on the time-series change of the heat dissipation amount Q icnd of the heat dissipation part. At the timing T01 when the current value of Q icnd drops below the previous value, the output voltage of the blower 13 is reduced from V01 to V02 to reduce Q icnd . At this time, by reducing the output voltage of the blower 13 and reducing the air volume Ga passing through the heat dissipation part, the absolute value of Q icnd decreases, but the time-series change is suppressed and Q icnd becomes stable.

[0043] The state where the current value of Q icnd here drops below the previous value is exactly a state where the heat dissipation amount (Q comp ) exceeds the heat input amount (Q out ), and the continuous condition of hot gas heating is broken. Here, this state is detected, and by performing the process of reducing the heat dissipation amount (Q out ), the continuation of hot gas heating is ensured.

[0044] By performing the process of step S05, when the time-series change of the heat dissipation amount Q icnd becomes stable and the continuous condition of hot gas heating is maintained, the output voltage of the blower 13 is increased from V02 to V03 at a predetermined timing T02, and the heat dissipation amount Q icnd corresponding to the heating requirement is obtained as appropriate.

[0045] FIG. 7(b) shows the discharge pressure P of the compressor 2 ci ​due to the time series change, P ci at the timing T10 when the current value of ci drops below the previous value, the output voltage of the blower 13 is decreased from V11 to V12, and Q icnd (heat dissipation amount Q out ) is decreased. At this time, by decreasing the heat dissipation amount Q out , the discharge pressure P ci of the compressor 2 returns to a predetermined pressure and becomes a stable time series change state. Note that the discharge pressure P ci of the compressor 2 here is detected by the refrigerant pressure sensor Pr2 in the refrigerant circuit 20 shown in FIG. 1.

[0046] And, in order to respond to the heating request in step S4 in the control flow of FIG. 3 or step S04 in the control flow of FIG. 7, control is performed to bring the blown air temperature (Thp) closer to the target heating temperature (TCO).

[0047] In the case of considering the continuity of hot gas heating for such a heating request, on the premise that the rotation speed of the compressor 2 is set near the upper limit value, when the difference between the target heating temperature (TCO) and the blown air temperature (Thp) is larger than the set value α1 (that is, (TCO - α1)> Tph, α1> 0), in order to lower the heat dissipation amount Q out (O icnd ), the output voltage of the blower 13 is decreased to perform control to enhance the continuity of hot gas heating. And, on the same premise, when the blown air temperature (Tph) exceeds the target heating temperature (TCO) by the set value β (that is, TOC ≦ Thp - β, β> 0), using the capacity surplus in that case, the output voltage of the blower 13 is increased to increase the heat dissipation amount Q out (O icnd ) to increase the heat utilization efficiency during hot gas heating.

[0048] The control example shown in FIG. 8 is an example of executing the hot gas heating continuous mode by combining the control of the output voltage of the blower 13 (control of the air volume Ga passing through the heat dissipation part) described above and the control of adjusting the flow rate ratio of the bypass flow path 3 described above.

[0049] In this example, the heat input amount Q from the compressor 2 from the start of controlcomp and the amount of heat dissipated by the heat dissipation section Q icnd Understand (Step S10) the conditions for continuing hot gas heating, Q comp ≧Q icnd Determine whether the condition is met (Step S11). Then, Q comp ≧Q icnd If this condition is not met (Step S11: NO), the output voltage of the fan 13 is reduced (Step S16) in an attempt to continue hot gas heating, and the heat dissipation amount Q out It reduces.

[0050] Furthermore, in step S11, the condition for continuing hot gas heating is Q. comp ≧Q icnd If the condition is met (Step S11: YES), the output voltage of the blower 13 is maintained (Step S12), and a determination is made as to whether the discharged air temperature (Thp) has reached the target heating temperature (TCO) according to the heating requirement (Step S13). If the discharged air temperature (Thp) has not reached the target heating temperature (TCO) (Step 13: NO), the flow rate ratio of the refrigerant flowing through the bypass channel 3 is increased to increase the heat dissipation amount Q. out This reduces the (step S17). This improves the continuity of the hot gas heating.

[0051] Then, in step S13, if the discharged air temperature (Thp) has reached the target heating temperature (TCO) (step S17: YES), it is determined whether there is a capacity surplus (step S14). If there is no capacity surplus (step S14: NO), that state is maintained. If there is a capacity surplus (step S14: YES), the flow rate ratio of the refrigerant flowing through the bypass channel 3 is reduced (step S15), and the heat dissipation amount Q is reduced. out To increase.

[0052] The control unit 4 of the vehicle air conditioning system 1 is configured as a single ECU connected via the in-vehicle network L to various ECUs (Electronic Control Units) that control the electric vehicle (EV), as shown in Figure 9. The control unit 4 includes a CPU (Central Processing Unit) 41, ROM (Read Only Memory) 42, RAM (Random Access Memory) 43, input / output I / F (Interface) 44, in-vehicle communication I / F (Interface) 45, etc., and each piece of hardware is interconnected via the bus 46.

[0053] The CPU 41 controls the control device 4 by executing various programs stored in the ROM 42. The ROM 42 is a non-volatile memory. For example, the ROM 42 stores programs executed by the CPU 41, data necessary for the CPU 41 to execute programs, etc. The RAM 43 is a main memory such as DRAM (Dynamic Random Access Memory) or SRAM (Static Random Access Memory). For example, the RAM 43 functions as a workspace used by the CPU 41 when executing programs. The input / output I / F 44 is connected to various sensors and monitors installed in the EV, inputting data to the CPU 41 and outputting data processed by the CPU 41. The in-vehicle communication I / F 45 is connected to the in-vehicle network L and controls data transmission and reception with other ECUs set up in the EV.

[0054] The control device 4 receives data related to the surrounding environment or the driving status of the EV via the input / output interface 44 and the in-vehicle communication interface 45, and the CPU 41 executes a program to control the aforementioned vehicle air conditioning system 1.

[0055] As described above, according to the embodiment of the present invention, it becomes possible to continue hot gas heating in the refrigerant circuit 20 including the heat pump compressor 2, so that even in an extremely low temperature environment, a sufficient amount of heating can be maintained with low power consumption without using electric heaters such as PCT heaters. This improves the practicality of vehicle air conditioning systems that utilize heat pumps.

[0056] Although embodiments of the present invention have been described in detail above with reference to the drawings, the specific configurations are not limited to these embodiments, and any design changes, etc., that do not depart from the gist of the present invention are also included. Furthermore, the above-described embodiments can be combined by utilizing each other's technologies, as long as there are no particular contradictions or problems in their purpose and configuration. [Explanation of Symbols]

[0057] 1: Vehicle air conditioning system, 2: Compressor, 3: Bypass channel, 4: Control device, 10: Indoor air conditioning unit (air heating device), 10A: Air blower layer, 10B: Air receiving layer, 11,12: Indoor heat exchanger (heat radiation part), 13: Blower, 14: Air damper, 14A: Air damper drive unit, 20: Refrigerant circuit, 21: Accumulator, 22 (22A~22D): Pressure reducing valve, 23 (23A~23D): Flow path switching valve, 24: External heat exchanger, 25: Refrigerant-heat transfer fluid heat exchanger, 26: Check valve, 30: Heat transfer fluid circuit, 31: Heat transfer fluid circulation pump, 41:CPU, 42:ROM, 43:RAM, 44: Input / Output Interface, 45: In-vehicle communication interface, 46: Bus, L: In-vehicle network

Claims

1. A vehicle air conditioning system comprising at least a compressor and a refrigerant circuit for circulating high-temperature refrigerant discharged from the compressor, an air heating device for heating the air inside the vehicle by the heat dissipation of the refrigerant, and a control device for controlling the amount of heat dissipated by the refrigerant, The control device is Based on the power consumption of the compressor, the amount of heat input from the compressor is determined. A vehicle air conditioning system characterized by having a hot gas heating continuous mode in which the amount of heat dissipated by the refrigerant is less than or equal to the amount of heat input from the compressor.

2. The air heating device blows air into the vehicle cabin to the heat dissipation section of the refrigerant circuit provided in the air heating device. The vehicle air conditioning system according to claim 1, characterized in that the control device controls the amount of air passing through the heat dissipation section.

3. The vehicle air conditioning system according to claim 2, characterized in that the control device reduces the amount of air passing through when the amount of heat dissipated by the heat dissipation section is higher than the amount of heat input from the compressor.

4. The vehicle air conditioning system according to claim 3, characterized in that the control device determines the amount of heat dissipated by the heat dissipation unit (Qicnd) in each control cycle, and reduces the amount of air passing through when the amount of heat dissipated (Qicndz) determined in the current cycle is lower than the amount of heat dissipated (Qicndz) determined in the previous cycle.

5. The vehicle air conditioning system according to claim 3, characterized in that the control device acquires the discharge pressure (Pci) of the compressor in each control cycle, and reduces the amount of air passing through when the discharge pressure (Pci) of the compressor acquired in the current cycle is lower than the discharge pressure (Pciz) of the compressor acquired in the previous cycle.

6. The vehicle air conditioning system according to any one of claims 2 to 5, characterized in that the control of the amount of air passing through is performed by the output of the blower in the air heating device or the opening degree of the air damper.

7. The refrigerant circuit includes a bypass channel that circulates the refrigerant to the air heating device, The vehicle air conditioning system according to any one of claims 1 to 6, characterized in that the control device controls the amount of heat dissipated by the refrigerant by controlling the flow rate ratio of the refrigerant flow rate through the bypass channel and the refrigerant flow rate passing through the air heating device.

8. The refrigerant circuit includes a refrigerant-heat transfer medium heat exchanger, The vehicle air conditioning system according to any one of claims 1 to 7, characterized in that the control device controls the amount of heat released by the refrigerant by controlling the flow rate of the heat transfer medium.

9. The vehicle air conditioning system according to any one of claims 1 to 8, characterized in that the refrigerant circuit is provided with a refrigerant flow path switching means that can switch to a heat pump cycle.

Images