Vehicle air conditioning device

Abstract

The purpose of the present invention is to improve the comfort of an occupant by suppressing fluctuations in the discharge temperature when transferring from hot-gas heating to heat-absorbing heating while stably continuing a hot-gas heating mode. A vehicle air-conditioning device including a refrigerant circuit, an air-conditioning unit, and a control device for controlling the refrigerant circuit and the air-conditioning unit is capable of executing a heat-absorbing heating mode and a hot-air heating mode. In the vehicle interior heating mode, the refrigerant, the heat of which has been dissipated by heating in the vehicle interior, absorbs heat from a heat-absorbing object such as outside air in the external heat exchanger, and in the hot-air heating mode, a portion of the refrigerant compressed by the compressor is bypassed and returned to the compressor, and the vehicle interior is heated by the heat dissipation of the remaining refrigerant. When transitioning from the hot-gas heating mode to the heat-absorbing heating mode, if the difference between the current heating capacity in the hot-gas heating mode and the heating capacity in the heat-absorbing heating mode estimated on the basis of the temperature of the heat-absorbing object is equal to or greater than a prescribed value, the damper is driven to reduce the current heating capacity in the hot-gas heating mode.

Description

TECHNICAL FIELD

[0001] The present application relates to a vehicle air-conditioning device. BACKGROUND

[0002] In recent years, hybrid vehicles, electric vehicles, and the like in which a traveling motor is driven by electric power supplied from a battery mounted on a vehicle are becoming widespread. As a vehicle air-conditioning device mounted on such a vehicle, a vehicle air-conditioning device in which a heat pump (refrigerant circuit) is used as a heat source is known.

[0003] In a vehicle air-conditioning device using a heat pump, during heating operation, an outside heat exchanger such as an outdoor heat exchanger disposed outside the vehicle cabin functions as a heat absorber to obtain a heating heat source from outside air or the like (absorption heating). Therefore, if the outside air temperature becomes extremely low, it is difficult to absorb heat from outside air or the like, and the heating capacity is greatly reduced. In contrast, as an effective heating method in an extremely low temperature environment, hot gas heating using the heat of high-temperature, high-pressure refrigerant discharged from a compressor without absorbing heat from outside air or the like is known.

[0004] For example, in the vehicle air-conditioning device of Patent Literature 1, a hot gas heating mode is executed in which a part of high-temperature, high-pressure refrigerant discharged from the compressor is depressurized after flowing through a bypass passage and then returned to the compressor, and the remaining refrigerant is depressurized after heat-exchanging with the air supplied to the vehicle cabin in an indoor heat exchanger, and then returned to the compressor without passing through an outside heat exchanger. PRIOR ART DOCUMENTS PATENT LITERATURE

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2023-46604 SUMMARY PROBLEMS TO BE SOLVED BY THE INVENTION

[0006] In the vehicle air-conditioning device described above, in the case where heating in the vehicle cabin is performed, for example, control is sometimes performed in which the hot gas heating mode is executed at the time of startup to raise the temperature in the vehicle cabin as quickly as possible, and the absorption heating mode is shifted to after the desired temperature in the vehicle cabin is reached. In this case, in the hot gas heating mode and the absorption heating mode in the same environment, the difference in heating capacity is large, and therefore, when shifting from the hot gas heating mode to the absorption heating mode, the blowing temperature sometimes greatly fluctuates, which impairs the comfort of the occupants.

[0007] On the other hand, in order to suppress variation in the blow-out temperature at the time of transition, it is considered to transition to the heat-absorption heating mode after reducing the blow-out temperature in the hot-gas heating mode. In the case where the high-pressure side refrigerant pressure of the refrigerant circuit is reduced, that is, the rotation speed of the compressor is reduced, in order to reduce the blow-out temperature, there is a lower limit to the rotation speed of the compressor in which stable operation can be continued in the hot-gas heating mode, and thus the blow-out temperature cannot necessarily be reduced to a desired temperature. In the hot-gas heating mode, in the case where the compressor is driven at a rotation speed lower than the above lower limit, the balance between the input heat and the heat dissipation in the refrigerant circuit cannot be maintained, the operation state becomes unstable, and the vehicle air-conditioner can stop.

[0008] The present application has been achieved in view of such circumstances, and aims to stably continue the hot-gas heating mode and improve the comfort of an occupant or the like by suppressing variation in the blow-out temperature at the time of transition from the hot-gas heating mode to the heat-absorption heating mode. Means for solving the problem

[0009] The present application provides a vehicle air-conditioner including: a refrigerant circuit including a compressor, an indoor heat exchanger, an external heat exchanger, and a hot-gas bypass that depressurizes at least a part of refrigerant compressed by the compressor without passing through the indoor heat exchanger and the external heat exchanger and returns the refrigerant to the compressor; an air-conditioning unit in which the indoor heat exchanger is disposed inside, having a blower and a regulation damper that adjusts a proportion of air blown by the blower to the indoor heat exchanger; and a control device that controls the refrigerant circuit and the air-conditioning unit, capable of executing a heat-absorption heating mode in which refrigerant compressed by the compressor is heat-dissipated in the indoor heat exchanger and then heat-absorbed in the external heat exchanger, and a hot-gas heating mode in which a part of the refrigerant compressed by the compressor flows in the hot-gas bypass and returns to the compressor, and the remaining refrigerant is heat-dissipated in the indoor heat exchanger, the control device, at the time of transition from the hot-gas heating mode to the heat-absorption heating mode, in the case where a difference between a current heating capacity in the hot-gas heating mode and a heating capacity in the heat-absorption heating mode estimated based on a temperature of an object of heat absorption of the external heat exchanger is equal to or greater than a predetermined value, controls to drive the regulation damper to reduce the current heating capacity in the hot-gas heating mode. Effects of the Invention

[0010] According to the present application, it is possible to stably continue the hot-gas heating mode and improve the comfort of an occupant by suppressing variation in the blow-out temperature at the time of transition from the hot-gas heating mode to the heat-absorption heating mode. BRIEF DESCRIPTION OF DRAWINGS

[0011] Figure 1is a diagram showing a system configuration example of a vehicle air-conditioning device according to an embodiment of the present application. Figure 2 is a diagram showing a control device of a vehicle air-conditioning device according to an embodiment of the present application. Figure 3 is a diagram showing a configuration of a control device and the like of an electric vehicle (EV) according to an embodiment of the present application. Figure 4 is a diagram showing an operation of a refrigerant circuit in a hot-gas heating mode of a vehicle air-conditioning device according to an embodiment of the present application. Figure 5 is a flowchart showing a flow of processing of Embodiment 1 for a shift from a hot-gas heating mode to a heat-absorption heating mode by a control device in a vehicle air-conditioning device according to an embodiment of the present application. Figure 6 is a flowchart showing a flow of processing of Embodiment 2 for a shift from a hot-gas heating mode to a heat-absorption heating mode by a control device in a vehicle air-conditioning device according to an embodiment of the present application. DETAILED DESCRIPTION

[0012] Hereinafter, an embodiment of the present application will be described with reference to the drawings. In the following description, the same reference numerals are used for the same functions in different drawings, and repeated description will be omitted as appropriate in each drawing. In addition, in the drawings, a black thick line in the refrigerant circuit 10 represents a refrigerant flow path in which high-pressure refrigerant flows, and a hollow line represents a refrigerant flow path in which refrigerant after pressure reduction flows. Further, a broken line in the refrigerant circuit 10 represents a refrigerant flow path in which refrigerant does not flow.

[0013] [Structure of Refrigerant Circuit and the Like] Figure 1 is a diagram showing a structure example of a vehicle air-conditioning device 1 according to an embodiment of the present application. The structure example shown here is one example, and the specific structure is not particularly limited.

[0014] The air-conditioning device 1 for a vehicle is provided with a refrigerant circuit 10 and an air-conditioning unit 20. The refrigerant circuit 10 includes a compressor 2, indoor heat exchangers 21, 22 provided inside the air-conditioning unit 20, and an outdoor heat exchanger 11 provided outside the vehicle cabin, which are arranged along a refrigerant flow path. The indoor heat exchangers 21, 22 are provided to exchange heat between air flowing inside the air-conditioning unit 20 and refrigerant, and the outdoor heat exchanger 11 is provided to exchange heat between outside air outside the vehicle cabin and refrigerant. The indoor heat exchanger 21 is used for heating of air, and the indoor heat exchanger 22 is used for cooling of air. A refrigerant pressure sensor 44B that detects outlet refrigerant pressure Pci (high-pressure-side refrigerant pressure) from the indoor heat exchanger 21 and a refrigerant temperature sensor 43B that detects outlet refrigerant temperature Tc (high-pressure-side refrigerant temperature) are provided immediately downstream of the indoor heat exchanger 21.

[0015] The compressor 2 compresses refrigerant and circulates it in the refrigerant circuit 10. Refrigerant compressed by the compressor 2 is depressurized to a desired pressure in a refrigerant flow path selected as appropriate, via, for example, a first pressure-reducing portion V1, a second pressure-reducing portion V2, a third pressure-reducing portion V3, and a fourth pressure-reducing portion V4, which are expansion valves. The refrigerant circuit 10 is provided with flow path switching valves 12, 13 for switching the refrigerant flow path, and check valves 14, 15 for limiting the flow direction of refrigerant.

[0016] A receiver 16 that recovers liquid refrigerant and separates refrigerant into gas and liquid is provided immediately upstream of the compressor 2 in the refrigerant circuit 10. A refrigerant pressure sensor 44A that detects suction refrigerant pressure Ps (low-pressure-side refrigerant pressure) that is sucked into the compressor 2 and a refrigerant temperature sensor 43A that detects suction refrigerant temperature Ts (low-pressure-side refrigerant temperature) are provided between the receiver 16 and the compressor 2.

[0017] As described above, the air-conditioning unit 20 is provided with the indoor heat exchangers 21, 22 inside, and is provided with a blower 23 that introduces air inside or outside the vehicle cabin into the inside, and an adjustment damper 24 that adjusts the proportion of air introduced by the blower 23 that passes through the indoor heat exchanger 21. Further, the air-conditioning unit 20 is provided with an adjustment damper 25 that is provided at a position upstream of the blower 23 in the inflow direction of air, and switches air introduced into the blower 23 to either the inside or the outside of the vehicle cabin.

[0018] In the air-conditioning unit 20, air introduced by the blower 23 is blown out to the inside of the vehicle cabin through the indoor heat exchangers 21, 22. In Figure 1When the regulating damper 24 is fully open, the air introduced by the blower 23 passes through the indoor heat exchanger 22 and then is blown into the room through the indoor heat exchanger 21. Furthermore, when the regulating damper 24 is fully closed, the inflow side of the indoor heat exchanger 21 is sealed off, and the air introduced by the blower 23 is blown into the vehicle interior only through the indoor heat exchanger 22.

[0019] In the air conditioning unit 20, by selectively closing the air inlet 25A connected to the outside and the air inlet 25B connected to the inside by adjusting the damper 25, air can be drawn in from either side. Furthermore, in the air conditioning unit 20, by positioning the damper 25 at a desired position between the air inlet 25A and the air inlet 25B, air from the outside of the vehicle or from the outside can be drawn in at a desired ratio from both the air inlets 25A and 25B.

[0020] Furthermore, in the aforementioned external heat exchanger 11 and indoor heat exchangers 21 and 22, an example of direct heat exchange between the refrigerant and air has been described. However, the refrigerant and air can also exchange heat indirectly via a heat medium that has exchanged heat with the refrigerant. That is, it can also be configured such that the refrigerant absorbs heat from the air via a heat medium or releases heat from the refrigerant to the air via a heat medium.

[0021] like Figure 1 As shown, the vehicle air conditioning unit 1 includes a heat medium circuit 30. The heat medium circuit 30 circulates the heat medium via a circulation pump 31, heats the heat medium via a heater (ECH: Electric Coolant Heater) 32, or recovers waste heat from a temperature-regulated object such as a battery via a temperature-regulated object heat exchanger 33. Furthermore, a refrigerant heat medium heat exchanger 34 is provided in both the refrigerant circuit 10 and the heat medium circuit 30, allowing heat exchange between the refrigerant and the heat medium via a flow path 34A for refrigerant flow and a flow path 34B for heat medium flow. The heat medium circuit 30 is configured as needed.

[0022] [Control Device] Vehicle air conditioning unit 1 has Figure 2 The control device 100 shown. The control device 100 controls the refrigerant circuit 10, the air conditioning unit 20 and the heat medium circuit 30 based on various input signals 60 (air conditioning indicator signal, charger connection signal, etc.) and detection signals from the sensor unit 40.

[0023] The sensor section 40 that inputs the detection signals to the control device 100 includes, for example, an outside air sensor 41 that detects the outside air temperature, outside air humidity, and the like, a compressor current sensor 42 that detects the consumed power (consumed energy) of the compressor 2, a refrigerant temperature sensor 43 and a refrigerant pressure sensor 44 that detect the state of the refrigerant, an occupant sensor 45 that detects the presence or absence of an occupant in the vehicle cabin, a supply air temperature sensor 46 that detects the supply air temperature of the air conditioning unit 20, an inside air sensor 47 that detects the inside air temperature, inside air humidity, and the like in the vehicle cabin, and the like.

[0024] In particular, the refrigerant temperature sensor 43 includes a refrigerant temperature sensor 43A that detects the suction refrigerant temperature Ts (low-pressure-side refrigerant temperature) of the refrigerant sucked into the compressor 2, and a refrigerant temperature sensor 43B that detects the outlet refrigerant temperature Tc (high-pressure-side refrigerant temperature) of the indoor heat exchanger 21 (see FIG. 1) (refer to Figure 1 ).

[0025] Further, the refrigerant pressure sensor 44 includes a refrigerant pressure sensor 44A that detects the suction refrigerant pressure Ps (low-pressure-side refrigerant pressure) of the refrigerant sucked into the compressor 2, and a refrigerant pressure sensor 44B that detects the outlet refrigerant pressure Pci (high-pressure-side refrigerant pressure) of the indoor heat exchanger 21 (see FIG. 1) (refer to Figure 1 ). These sensors are examples, and the sensor section 40 includes various sensors that detect information required when the control device 100 performs various controls.

[0026] The control objects of the control device 100 are the compressor 2, the first pressure-reducing section V1, the second pressure-reducing section V2, the third pressure-reducing section V3, the fourth pressure-reducing section V4, and the flow path switching valves 12, 13, and the like in the refrigerant circuit 10, the supply fan 23 and the damper 24, 25, and the like in the air conditioning unit 20, and the circulating pump 31 and the like in the heat medium circuit 30. Further, the control device 100 controls the vehicle air conditioning device 1 in accordance with the processing result of the control device 100. In the vehicle air conditioning device 1, various operation modes including a heat-absorption heating mode in which the refrigerant is caused to absorb heat in the outside heat exchanger 11 and a hot-gas heating mode in which the refrigerant is not caused to absorb heat in the outside heat exchanger 11 but the refrigerant compressed by the compressor 2 is caused to radiate heat in the indoor heat exchanger 21, thereby heating the vehicle cabin, can be executed by the control device 100.

[0027] [Structure of Control Device in Electric Vehicle (EV)] As Figure 3As shown, the control device 100 provided in the vehicle air conditioning device 1 is configured as one ECU connected to various ECUs (Electronic Control Unit) that control the electric vehicle EV via the in-vehicle network L. The control device 100 includes a CPU (Central Processing Unit) 101, a ROM (Read Only Memory) 102, a RAM (Random Access Memory) 103, an I / F (Interface) 104 for input and output, an I / F (Interface) 105 for in-vehicle communication, and the like, which are connected to each other via a bus 106.

[0028] The CPU 101 performs control of the control device 100 by executing various programs stored in the ROM 102. The ROM 102 is a nonvolatile memory. For example, the ROM 102 stores programs executed by the CPU 101, data required for the CPU 101 to execute the programs, and the like. The RAM 103 is a main storage device such as a DRAM (Dynamic Random Access Memory) or a SRAM (Static Random Access Memory).

[0029] For example, the RAM 103 functions as a work area used when the CPU 101 executes the programs. The I / F 104 for input and output is connected to various sensors and monitors provided in the EV, and inputs data to the CPU 101 and outputs data obtained by the CPU 101 from the operation processing. The I / F 105 for in-vehicle communication controls transmission and reception of data with other ECUs provided in the EV by being connected to the in-vehicle network L.

[0030] The control device 100 is inputted with data related to environmental information around the vehicle or data related to the operation state of the EV via the I / F 104 for input and output and the I / F 105 for in-vehicle communication, and thus performs control of the vehicle air conditioning device 1 by the programs executed by the CPU 101.

[0031] The battery B is provided in the EV. The battery B is charged by connecting a plug PS of a charger to a battery socket BP, and power is supplied to the vehicle air conditioning device 1 via the battery B. The state in which the plug PS is connected to the battery socket BP is transmitted to the control device 100 as a charger connection signal via the in-vehicle network L.

[0032] [Hot air heating mode] At an extremely low temperature, it is difficult to perform heat absorption using the external heat exchanger 11, and therefore the hot gas heating mode is used. The hot gas heating mode is an operation mode in which the refrigerant is not caused to absorb heat in the external heat exchanger 11, and a part or all of the refrigerant compressed by the compressor 2 is caused to radiate heat in the indoor heat exchanger 21, thereby performing heating of the vehicle cabin.

[0033] In Figure 4 In the operation, a part of the high-temperature and high-pressure refrigerant discharged from the compressor 2 passes through the indoor heat exchanger 21 and the flow path switching valve 12, is depressurized by the third pressure reducing portion V3 to become low-pressure refrigerant, passes through the refrigerant heat medium heat exchanger 34, is subjected to gas-liquid separation by the accumulator 16, and returns to the compressor 2. At this time, in the refrigerant circuit 10, the first pressure reducing portion VI is fully closed so that the refrigerant is not caused to flow to the external heat exchanger 11. Further, the fourth pressure reducing portion V4 is fully closed so that the refrigerant is not caused to flow to the indoor heat exchanger 22.

[0034] The refrigerant circuit 10 has a hot gas bypass 10V that depressurizes at least a part of the refrigerant compressed by the compressor 2 without passing through the indoor heat exchanger 21 and the external heat exchanger 11, and returns to the compressor 2. In the hot gas bypass 10V, a part of the high-temperature and high-pressure refrigerant is branched at a branching point PI immediately downstream of the compressor 2, is depressurized by the second pressure reducing portion V2, and is merged with the low-pressure refrigerant depressurized by the third pressure reducing portion V3 at a merging point P2 immediately upstream of the accumulator 16.

[0035] By providing such a hot gas bypass 10V, the gaseous refrigerant after passing through the hot gas bypass 10V can be mixed with the liquid refrigerant condensed by heat radiation in the indoor heat exchanger 21, and returned to the compressor 2 as gas-rich refrigerant. Further, by increasing the flow rate of the refrigerant flowing through the hot gas bypass 10V, the amount of heat radiation in the indoor heat exchanger 21 can be suppressed, and the flow rate of the refrigerant flowing through the hot gas bypass 10V is adjusted by opening and closing of the second pressure reducing portion V2, so that the balance between the amount of heat radiation of the refrigerant circuit 10 and the input heat amount input to the compressor 2 can be maintained. That is, the second pressure reducing portion V2 functions as a flow rate adjusting portion that adjusts the flow rate of the refrigerant flowing in the hot gas bypass 10V.

[0036] In the hot gas heating mode, the refrigerant flowing in the refrigerant circuit 10 is decompressed by the 3rd decompression portion V3 in the flow path via the indoor heat exchanger 21, and thus becomes high-pressure refrigerant on the upstream side of the 3rd decompression portion V3 and low-pressure refrigerant on the downstream side of the 3rd decompression portion V3. At this time, it is important in maintaining the heating capacity that the refrigerant in the low-pressure side flow path does not perform heat exchange in the refrigerant heat medium heat exchanger 34. Also, in the air conditioning unit 20, the air introduced by the blow fan 23 is heated by heat radiation at the indoor heat exchanger 21 and blown out to the vehicle cabin.

[0037] [Heat-absorption heating mode] In the heat-absorption heating mode, in the refrigerant circuit 10, the refrigerant is caused to absorb heat from the outside air as a heat absorption target by causing the refrigerant to flow in the outside heat exchanger 11, thereby obtaining a heat source for heating. In addition, regarding the flow of the refrigerant in the refrigerant circuit 10 in the heat-absorption heating mode, the illustration is omitted.

[0038] In the refrigerant circuit 10 in the heat-absorption heating mode, the 2nd decompression portion V2, the 3rd decompression portion V3, the 4th decompression portion V4, and the flow path switching valve 12 are all fully closed. On the other hand, the flow path switching valve 13 is fully open, and the 1st decompression portion V1 is open.

[0039] Also, in the heat-absorption heating mode, the high-temperature high-pressure refrigerant discharged from the compressor 2 passes through the indoor heat exchanger 21 in the air conditioning unit 20, is decompressed by the 1st decompression portion V1, and the low-pressure refrigerant passes through the outside heat exchanger 11, via the flow path switching valve 13, the check valve 14, and the accumulator 16, and returns to the compressor 2. At this time, the high-pressure refrigerant coming out of the compressor 2 is condensed, radiates heat at the indoor heat exchanger 21, is decompressed by the 1st decompression portion V1 to become low-pressure refrigerant, absorbs heat at the outside heat exchanger 11, evaporates, and returns to the compressor 2. Also, in the air conditioning unit 20, the air introduced by the blow fan 23 is heated by heat radiation at the indoor heat exchanger 21 and blown out to the vehicle cabin.

[0040] [Switching control of operation mode by control device] Hereinafter, the switching control of the operation mode by the control device 100 in the case where heating in the vehicle cabin is performed by the vehicle air conditioning device 1 of the present embodiment will be described. In the case where the vehicle interior is heated by the vehicle air-conditioning device 1, the control device 100 executes either the heat-absorption heating mode or the hot-gas heating mode in accordance with the outside environment, such as the outside air temperature Tam, and the set temperature Tset, and the like. The hot-gas heating mode has a higher heating capacity than the heat-absorption heating mode, and therefore, in the control device 100, the heat-absorption heating mode is normally executed in the case where the outside air temperature Tam is equal to or higher than a prescribed temperature (for example, -10°C), and the hot-gas heating mode is executed in the case where the outside air temperature Tam is lower than the prescribed temperature in an extremely low-temperature environment.

[0041] On the other hand, for example, in the case where the vehicle air-conditioning device 1 is started in an outside environment in which the outside air temperature Tam is within a prescribed temperature range including the prescribed temperature and either the heat-absorption heating mode or the hot-gas heating mode can be executed, the control device 100 can be controlled to execute the hot-gas heating mode at the time of start, and then shift to the heat-absorption heating mode. By such control, the temperature of the vehicle interior is raised as quickly as possible by the hot-gas heating mode to ensure prompt heating, and then, in the case where the target temperature (for example, the set temperature Tset described later) is reached in the vehicle interior, and the like, the shift to the heat-absorption heating mode is made, whereby the power consumption can be suppressed.

[0042] However, as described above, there is a difference in heating capacity between the hot-gas heating mode and the heat-absorption heating mode, and therefore, at the time of shift from the hot-gas heating mode to the heat-absorption heating mode, the blow temperature to the vehicle interior can greatly change. Therefore, in the control device 100, control is made at the time of shift from the hot-gas heating mode to the heat-absorption heating mode to reduce the difference in heating capacity between the two, and suppress the change in blow temperature due to the difference in heating capacity.

[0043] Hereinafter, the processing related to the shift from the hot-gas heating mode to the heat-absorption heating mode by the control device 100 of the vehicle air-conditioning device 1 of the present embodiment will be described with reference to the flowcharts of Figs. 9 and 10. Figure 5 In the example shown in Fig. 9, the control device 100 mainly controls the expansion valve 24 (Example 1), and in the example shown in Fig. 10, the control device 100 mainly controls the compressor 2 and the expansion valve 24 (Example 2). Figure 6 Figure 5 In the example shown in Fig. 9, the control device 100 mainly controls the expansion valve 24 (Example 1), and in the example shown in Fig. 10, the control device 100 mainly controls the compressor 2 and the expansion valve 24 (Example 2). Figure 6

[0044] (Example 1) As shown in Fig. 9, the control device 100 of the vehicle air-conditioning device 1 of the present embodiment controls the expansion valve 24 to be opened at the time of start of the hot-gas heating mode, and then controls the expansion valve 24 to be closed at a prescribed timing after the start of the hot-gas heating mode. Figure 5 ​​When the heating of the vehicle cabin is started by the vehicle air-conditioning apparatus 1, the hot-gas heating mode is executed (step Sll). The control device 100 fully closes the first pressure-reducing portion VI and the fourth pressure-reducing portion V4 and opens the second pressure-reducing portion V2 and the third pressure-reducing portion V3 in the refrigerant circuit 10. The control device 100 drives the compressor 2 in this state, and causes a part of the high-temperature and high-pressure refrigerant discharged from the compressor 2 to flow in the indoor heat exchanger 21 to exchange heat with the air supplied to the vehicle cabin and then return to the compressor 2, and causes the remaining part of the high-temperature and high-pressure refrigerant discharged from the compressor 2 to flow in the hot-gas bypass 10V and then return to the compressor 2.

[0045] In addition, at this time, in order to stabilize the operation state of the hot-gas heating mode, it is desirable to make the inside / outside air ratio a fixed ratio (for example, 20% of outside air and 80% of inside air, which is set taking into account the suppression of the increase in carbon dioxide concentration and the opening of the window) by adjusting the damper 25.

[0046] The control device 100 compares the set temperature Tset and the temperature of the vehicle cabin, that is, the indoor temperature Tin, which is acquired from the inside air sensor 47 at a predetermined cycle, in the execution of the hot-gas heating mode, and monitors whether the indoor temperature Tin is a temperature equal to the set temperature Tset (step S12). In the process of step S12, the control device 100 determines a predetermined temperature range including the set temperature Tset as an allowable temperature range, and if the indoor temperature Tin is within the allowable temperature range, it can be considered that the indoor temperature Tin is a temperature equal to the set temperature Tset.

[0047] The control device 100 continues the hot-gas heating mode if the indoor temperature Tin is not within the allowable temperature range including the set temperature Tset (NO in step S12). On the other hand, the control device 100 proceeds to step S13 if the indoor temperature Tin is within the allowable temperature range including the set temperature Tset (YES in step S12).

[0048] The control device 100 determines whether it is preferable to shift from the hot-gas heating mode to the heat-absorption heating mode in step S13 (step S13). In this determination, the control device 100 determines whether it is preferable to shift the operation mode in order to reduce the power consumption of the vehicle air-conditioning apparatus 1 in view of the outside air temperature Tam, the indoor temperature Tin, and the operation state of the hot-gas heating mode, the current heating capacity, and the like. The control device 100 continues the hot-gas heating mode and monitors whether the indoor temperature Tin is a temperature equal to the set temperature Tset (step S12) if it is not preferable to shift the operation mode (NO in step S13).

[0049] The control device 100 proceeds to step S14 in the case where it is determined that the shift from the hot gas heating mode to the heat-recovery heating mode is performed (YES in step S13). In addition, the control device 100 preferably controls the adjustment damper 25 so as to make the internal air ratio higher than the internal / external air ratio in the above step Sll in the case where it is determined that the shift from the hot gas heating mode to the heat-recovery heating mode is performed. By increasing the internal air ratio, it is possible to reduce the heating load.

[0050] In step S14, the current heating capacity in the hot gas heating mode and the heating capacity in the heat-recovery heating mode estimated on the basis of the outside air temperature Tam of the heat-recovery target of the outside heat exchanger 11 are acquired, the difference (hereinafter, difference ΔQ) between these heating capacities is calculated, and it is determined whether the difference ΔQ is equal to or greater than a prescribed value Qth. In the case where the difference ΔQ is equal to or greater than the prescribed value Qth (YES in step S14), the control device 100 performs control so as to drive the adjustment damper 24 so as to make the difference ΔQ smaller, that is, so as to reduce the heating capacity in the hot gas heating mode (step S15). In addition, in the case where the difference ΔQ is smaller than the prescribed value Qth (NO in step S14), the shift to the heat-recovery heating mode is performed (step S17).

[0051] With respect to the range of the heating capacity obtained by the control of the compressor 2, in the case where the hot gas heating mode and the heat-recovery heating mode are compared, the lowest heating capacity in the hot gas heating mode and the highest heating capacity in the heat-recovery heating mode do not overlap with each other, and the lowest heating capacity in the hot gas heating mode is higher than the highest heating capacity in the heat-recovery heating mode. Therefore, the control device 100 controls the adjustment damper 24 so as to make the proportion of the air supply to the indoor heat exchanger 21 smaller in step S15, whereby it is possible to reduce the heating capacity in the hot gas heating mode and to reduce the difference ΔQ.

[0052] By thus controlling the adjustment damper 24, the proportion of the air supply to the flow path that bypasses the indoor heat exchanger 21 increases, and therefore it is possible to reduce the blow-out temperature to the vehicle cabin. Therefore, by controlling the adjustment damper 24, it is possible to reduce the blow-out temperature in the hot gas heating mode on the basis of the reduction of the difference ΔQ, and therefore it is possible to suppress a large variation at the time of the shift of the operation mode.

[0053] In the control device 100, the difference ΔQ is monitored while the adjustment damper 24 is driven (step S16), and the adjustment damper 24 is driven until the difference ΔQ is smaller than the prescribed value Qth (NO in step S16). The control device 100 shifts from the hot gas heating mode to the heat-recovery heating mode in the case where the difference ΔQ is smaller than the prescribed value Qth (YES in step S16) (step S17).

[0054] Thus, in the vehicle air conditioning unit 1 of this embodiment, when transitioning from a hot air heating mode to a heat absorption heating mode, the control device 100 controls the process to minimize the difference in heating capacity between the hot air heating mode and the heat absorption heating mode. This suppresses large fluctuations in the blow-out temperature caused by the difference in heating capacity, improving passenger comfort. Specifically, by controlling the regulating damper 24 to reduce the difference in heating capacity, the operating state of the hot air heating mode does not fluctuate significantly, allowing for stable and continuous operation in the hot air heating mode and a smooth transition to the heat absorption heating mode.

[0055] (Example 2) like Figure 6 As shown, when heating of the vehicle interior is initiated by the vehicle air conditioning unit 1, the hot gas heating mode is executed (step S21). In the refrigerant circuit 10, the control device 100 fully closes the first pressure reducing section V1 and the fourth pressure reducing section V4, and opens the second pressure reducing section V2 and the third pressure reducing section V3. By driving the compressor 2 in this state, the control device 100 causes a portion of the high-temperature, high-pressure refrigerant discharged from the compressor 2 to flow in the indoor heat exchanger 21, exchange heat with the air supplied to the vehicle interior, and then return to the compressor 2. The remaining portion of the high-temperature, high-pressure refrigerant discharged from the compressor 2 flows in the hot gas bypass 10V and returns to the compressor 2.

[0056] In addition, at this time, in order to stabilize the operation of the hot air heating mode, it is desirable to adjust the damper 25 to make the ratio of internal and external air a fixed ratio (for example, taking into account the suppression of the rise in carbon dioxide concentration and opening windows, the ratio is set to 20% external air and 80% internal air).

[0057] During the execution of the hot air heating mode, the control device 100 compares the set temperature Tset with the interior temperature Tin obtained from the internal air sensor 47 at predetermined intervals, and monitors whether the interior temperature is equal to the set temperature Tset (step S22). In the process of step S22, the control device 100 determines the predetermined temperature range including the set temperature Tset as the allowable temperature range. If the interior temperature Tin is within the allowable temperature range, it can be considered that the interior temperature Tin is equal to the set temperature Tset.

[0058] The control device 100 continues the hot-gas heating mode in a case where the indoor temperature Tin is not within the allowable temperature range including the set temperature Tset (NO in step S22). On the other hand, the control device 100 proceeds to step S23 in a case where the indoor temperature Tin is within the allowable temperature range including the set temperature Tset (YES in step S22). The control device 100 gradually or stepwise reduces the rotation speed TGNC of the compressor 2 in step S23 to reduce the current heating capacity in the hot-gas heating mode.

[0059] The hot-gas heating mode can continue stable operation by maintaining the balance between the input heat and the heat dissipation in the refrigerant circuit 10, and there is a lower limit value of the rotation speed TGNC of the compressor 2 required to maintain the balance. The control device 100 calculates or previously holds in the ROM 102 or the like, for example, the minimum rotation speed TGNC_LL which is the lower limit value of the rotation speed TGNC of the compressor 2 that enables the operating state of the hot-gas heating mode to continue stably.

[0060] Therefore, the control device 100 monitors whether the rotation speed TGNC of the compressor 2 reaches the minimum rotation speed TGNC_LL so that the rotation speed TGNC is not lower than the minimum rotation speed TGNC_LL (step S24). The control device 100 reduces the rotation speed TGNC of the compressor 2 until it becomes the minimum rotation speed TGNC_LL (NO in step S24), and proceeds to step S25 in a case where the rotation speed TGNC becomes the minimum rotation speed TGNC_LL (YES in step S24). In this way, it is possible to reduce the heating capacity in the hot-gas heating mode as much as possible by the control of the compressor 2, and it is possible to enable the operating state of the hot-gas heating mode to continue stably.

[0061] In step S25, the control device 100 determines whether it is preferable to perform the shift from the hot-gas heating mode to the heat-absorption heating mode (step S25). That is, in this determination, the control device 100 determines whether it is preferable to shift the operating mode in order to reduce the power consumption of the vehicle air-conditioning device 1 in view of, among other things, the outdoor air temperature Tam, the indoor temperature Tin, and the operating state of the hot-gas heating mode and the current heating capacity. The control device 100 continues the hot-gas heating mode in a case where the shift of the operating mode is not performed (NO in step S25) (step S22).

[0062] The control device 100 proceeds to step S26 in the case where it is determined that the shift from the heat-generating heating mode to the heat-absorbing heating mode is performed (YES in step S25). In addition, the control device 100 preferably controls the adjustment damper 25 so as to make the internal air ratio higher than the internal / external air ratio in the above step S21 in the case where it is determined that the shift from the heat-generating heating mode to the heat-absorbing heating mode is performed. By increasing the internal air ratio, it is possible to reduce the heating load.

[0063] In step S26, the current heating capacity in the heat-generating heating mode and the heating capacity in the heat-absorbing heating mode estimated on the basis of the external air temperature Tam of the heat-absorbing target of the external heat exchanger 11 are acquired, the difference (hereinafter, difference ΔQ) between these heating capacities is calculated, and it is determined whether the difference ΔQ is equal to or greater than a prescribed value Qth.

[0064] In the present embodiment, since the rotational speed TGNC of the compressor 2 is reduced to the minimum rotational speed TGNC_LL in the heat-generating heating mode, the current heating capacity in the heat-generating heating mode acquired in step S26 becomes the lowest heating capacity that can be achieved by controlling the rotational speed TGNC of the compressor 2. In the case where the difference ΔQ is equal to or greater than the prescribed value Qth (YES in step S26) when shifting from this state to the heat-absorbing heating mode, the control device 100 performs control so as to make the difference ΔQ smaller, that is, to reduce the heating capacity in the heat-generating heating mode, by driving the adjustment damper 24 (step S27). In the case where the difference ΔQ is smaller than the prescribed value Qth (NO in step S26), the shift to the heat-absorbing heating mode is performed (step S29).

[0065] As described above, with respect to the range of the heating capacity obtained by the control of the compressor 2, in the case where the heat-generating heating mode and the heat-absorbing heating mode are compared, the lowest heating capacity in the heat-generating heating mode and the highest heating capacity in the heat-absorbing heating mode do not overlap with each other, and the lowest heating capacity in the heat-generating heating mode is higher than the highest heating capacity in the heat-absorbing heating mode.

[0066] In the present embodiment, since the rotational speed TGNC of the compressor 2 is reduced to the minimum rotational speed TGNC_LL, the control device 100 controls the adjustment damper 24 so as to make the air supply ratio to the indoor heat exchanger 21 smaller in step S27, whereby it is possible to further reduce the heating capacity in the heat-generating heating mode and to reduce the difference ΔQ.

[0067] By thus controlling the adjustment damper 24, the air supply ratio to the flow path that bypasses the indoor heat exchanger 21 is increased, and therefore it is possible to reduce the blow-out temperature to the vehicle cabin. Therefore, by controlling the adjustment damper 24, it is possible to reduce the blow-out temperature in the heat-generating heating mode on the basis of reducing the difference ΔQ, and therefore it is possible to suppress a large variation at the time of the shift of the operation mode.

[0068] In the control device 100, the above difference AQ is monitored while the damper 24 is driven (step S28), and the damper 24 is driven until the difference AQ is smaller than the prescribed value Qth (NO in step S28). The control device 100 shifts from the hot-gas heating mode to the heat-absorption heating mode (step S29) when the difference AQ is smaller than the prescribed value Qth (YES in step S28).

[0069] Thus, in the vehicle air-conditioner 1 of the present embodiment, when shifting from the hot-gas heating mode to the heat-absorption heating mode, the control device 100 controls so that the difference between the heating capacity of the hot-gas heating mode and the heating capacity of the heat-absorption heating mode becomes small. Thus, the large variation in the blow temperature due to the difference in the heating capacity is suppressed, and the comfort of the occupant can be improved.

[0070] In the control device 100, the heating capacity is reduced as much as possible by controlling the rotation speed TGNC of the compressor 2, and further, the damper 24 is controlled to reduce the difference in the heating capacity. Thus, the operating state of the hot-gas heating mode does not vary greatly, the hot-gas heating mode can be stably continued, and the shift to the heat-absorption heating mode can be smoothly performed, and the comfort of the occupant can be improved.

[0071] As described above, according to the present embodiment, the hot-gas heating mode is stably continued, and the variation in the blow temperature at the time of shifting from the hot-gas heating mode to the heat-absorption heating mode is suppressed, and the comfort of the occupant is improved.

[0072] The embodiments of the present application have been described in detail with reference to the accompanying drawings, but the specific configuration is not limited to these embodiments, and design changes and the like within a range not departing from the gist of the present application are included in the present application. Explanation of Reference Numerals:

[0073] 1: vehicle air-conditioner; 2: compressor; 10: refrigerant circuit; 10V: hot-gas bypass; 11: external heat exchanger; 12, 13: flow switching valve; 14, 15: check valve; 16: accumulator; 20: air-conditioning unit; 21, 22: indoor heat exchanger; 23: blower fan; 24, 25: damper; 25A, 25B: air introduction port; 30: heat medium circuit; 31: circulating pump; 33: temperature adjustment target heat exchanger; 34: refrigerant heat medium heat exchanger; 34A, 34B: flow path; 40: sensor section; 41: outside air sensor; 42: compressor current sensor; 43, 43A, 43B: refrigerant temperature sensor; 44, 44A, 44B: refrigerant pressure sensor; 45: occupant sensor; 46: blow temperature sensor; 47: inside air sensor; 60: input signal; 100: control device.

Claims

1. A vehicle air conditioning device, wherein, Possessing: a refrigerant circuit including: a compressor; an indoor heat exchange portion; an outdoor heat exchange portion; and a hot gas bypass that depressurizes at least a portion of refrigerant compressed by the compressor without passing through the indoor heat exchange portion and the outdoor heat exchange portion and returns the refrigerant to the compressor; an air conditioning unit that internally configures the indoor heat exchange portion, has: a blower; and a regulation damper that adjusts a proportion of supply air supplied by the blower to the indoor heat exchange portion; and a control device that controls the refrigerant circuit and the air conditioning unit, can execute a heat absorption heating mode in which refrigerant compressed by the compressor is heat-absorbed in the outdoor heat exchange portion after being heat-dissipated in the indoor heat exchange portion, and a hot gas heating mode in which a portion of the refrigerant compressed by the compressor flows in the hot gas bypass and returns to the compressor, and the remaining refrigerant is heat-dissipated in the indoor heat exchange portion, the control device is, when shifting from the hot gas heating mode to the heat absorption heating mode, in a case where a difference between a current heating capacity in the hot gas heating mode and a heating capacity in the heat absorption heating mode estimated based on a temperature of a heat absorption target of the outdoor heat exchange portion is a predetermined value or more, control is performed so as to drive the regulation damper to reduce the current heating capacity in the hot gas heating mode.

2. The vehicle air conditioning device according to claim 1, wherein the control device is, when shifting from the hot gas heating mode to the heat absorption heating mode, in a case where a difference between a heating capacity in the hot gas heating mode in a case where the compressor is driven at a minimum rotation speed set in advance and a heating capacity in the heat absorption heating mode estimated based on a temperature of a heat absorption target of the outdoor heat exchange portion is a predetermined value or more, control is performed so as to drive the compressor at the minimum rotation speed and drive the regulation damper to reduce the current heating capacity in the hot gas heating mode.

3. The vehicle air conditioning device according to claim 1 or 2, wherein the control device controls the regulation damper to reduce the proportion of supply air to the indoor heat exchange portion.

4. The vehicle air conditioning device according to claim 1 or 2, wherein the air conditioning unit has an inside / outside air switching damper that controls a proportion of introduction of air inside a vehicle cabin and air outside the vehicle cabin, the control device increases the proportion of introduction of air inside the vehicle cabin by the inside / outside air switching damper when shifting from the hot gas heating mode to the heat absorption heating mode.

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