Gas liquid separator and vehicular heat pump cycle using the same

Abstract

To provide a gas liquid separator having a function for securely supplying a gas-phase refrigerant to a compressor during a heating operation and a function for securely supplying a liquid-phase refrigerant to an expansion valve provided on an inflow side of a heat absorber during cooling operation without requiring increase in the number of components and additionally securing an installation space, and a vehicular heat pump cycle using the gas liquid separator.SOLUTION: A gas liquid separator 1 that is used includes: a refrigerant inflow part 4 for causing a refrigerant to flow into a refrigerant storage space 2; a liquid-phase refrigerant outflow part 5 that is opened in a liquid-phase region of the refrigerant storage space 2 and enables outflow of the liquid-phase refrigerant; and a gas-phase refrigerant outflow part 6 that is opened in a gas-phase region of the refrigerant storage space 2 and enables outflow of the gas-phase refrigerant. The refrigerant inflow part 4 is connected to a refrigerant outflow side 14b of a cabin exterior heat exchanger 14, and a gas-phase refrigerant outflow part 6 is connected to a gas-phase refrigerant passage 17 leading to a compressor 11. The liquid-phase refrigerant outflow part 5 is connected to a refrigerant path leading to a cabin interior absorber expansion valve 15 provided on an inflow side of a cabin interior heat absorber 22.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a gas-liquid separation device that functions as an accumulator that separates a refrigerant into gas and liquid and supplies a gas-phase refrigerant, and also functions as a liquid tank that separates a refrigerant into gas and liquid and supplies a liquid-phase refrigerant, and to a vehicle heat pump cycle using the same. [Background technology]

[0002] 2. Description of the Related Art Conventionally, there has been known a vehicle air conditioner that cools and heats the interior of a vehicle using a heat pump type refrigeration cycle. For example, a heat pump cycle 900 shown in Patent Document 1 (JP Patent Publication 2012-254670) is configured by connecting a compressor 901 that draws in and discharges a refrigerant, a condenser 902, a first expansion valve 903, an outdoor heat exchanger 904, a second expansion valve 905, an evaporator (heat absorber) 906, and an accumulator 907 in a circular manner through refrigerant passages, as shown in Fig. 10. The cycle also includes a first bypass passage 908 that connects an outlet side passage of the condenser 902 and an inlet side passage of the second expansion valve 905, a first solenoid valve 909 that opens and closes the first bypass passage 908, and a check valve 910 that prevents the refrigerant flowing from the outlet side of the condenser 902 through the first bypass passage 908 from flowing back to the outdoor heat exchanger 904. The heat pump cycle 900 further includes a second bypass passage 911 connecting an outlet side passage of the outdoor heat exchanger 904 and an outlet side passage of the evaporator 906, and a second solenoid valve 912 for opening and closing the second bypass passage 911.

[0003] In such a heat pump cycle 900, during cooling operation, the first expansion valve 903 is fully opened, the opening degree of the second expansion valve 905 is controlled, the first solenoid valve 909 is closed, and the second solenoid valve 912 is closed. Note that the air mix door in front of the condenser 902 is set to a full cool position (a position that does not allow air to be ventilated to the condenser 902). 11(a), a loop path is formed of the compressor 901 → condenser 902 → first expansion valve 903 → outdoor heat exchanger 904 → second expansion valve 905 → evaporator 906 → accumulator 907 → compressor 901. That is, the refrigerant discharged from the compressor does not dissipate heat in the condenser 902, but is liquefied by dissipating heat in the outdoor heat exchanger 904 and is then guided to the second expansion valve 905, where it is decompressed and expanded and then absorbs heat in the evaporator 906. Thereafter, gas and liquid are separated in the accumulator 907, and only the gas-phase refrigerant is returned to the compressor 901.

[0004] During heating operation, the opening degree of the first expansion valve 903 is controlled, the second expansion valve 905 is closed, the first solenoid valve 909 is closed, and the second solenoid valve 912 is opened. The air mix door in front of the condenser 902 is set to the full hot position (a position that maximizes the ventilation ratio to the condenser 902). 11(b), a refrigerant path is formed as follows: compressor 901 → condenser 902 → first expansion valve 903 → outdoor heat exchanger 904 → second bypass passage 911 (second solenoid valve 912) → accumulator 907 → compressor 901. That is, the refrigerant discharged from the compressor dissipates heat in the condenser 902, is guided to the first expansion valve 903, is decompressed and expanded by the first expansion valve 903, and absorbs heat in the outdoor heat exchanger 904. Thereafter, the refrigerant is separated into gas and liquid in the accumulator 907, and only the gas-phase refrigerant is returned to the compressor 901. As described above, in the conventional heat pump cycle, the accumulator 907 is disposed upstream of the compressor 901 to reliably prevent the liquid refrigerant from being drawn into the compressor. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2012-254670 A Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the above-described conventional heat pump cycle 900, the refrigerant that has dissipated heat by the outdoor heat exchanger 904 is supplied to the second expansion valve 905 during cooling operation, so the state of the refrigerant supplied to the second expansion valve 905 depends on the heat dissipation capacity of the outdoor heat exchanger 904. For this reason, the refrigerant is often supplied to the second expansion valve 905 as a gas-liquid mixed refrigerant without being sufficiently liquefied, which makes it difficult to ensure a stable supply of liquid refrigerant to the second expansion valve 905.

[0007] To solve this problem, it would be effective to add a separate gas-liquid separator (liquid tank) upstream of second expansion valve 905, but providing a separate liquid tank would increase the number of parts and require space to accommodate the liquid tank. A liquid tank could be placed in outdoor heat exchanger 904 as a subcooling condenser, but this would unavoidably increase the number of parts and there would also be concerns about increased passage resistance.

[0008] It is also possible to provide an internal heat exchanger as a heat absorber to exchange heat between the refrigerant flowing out of the evaporator 906 and the refrigerant flowing in to the second expansion valve 905, thereby promoting liquefaction of the refrigerant flowing in to the expansion valve, but this does not guarantee complete liquefaction of the refrigerant flowing into the second expansion valve 905.

[0009] The present invention has been made in consideration of the above circumstances, and has as its main objective the provision of a gas-liquid separation device that combines the function of reliably supplying gas phase refrigerant to the compressor during heating operation and the function of reliably supplying liquid phase refrigerant to an expansion valve provided on the refrigerant inlet side of the heat absorber during cooling operation, without increasing the number of parts or requiring new installation space, and a vehicle heat pump cycle using the same. [Means for solving the problem]

[0010] In order to achieve the above-mentioned object, the gas-liquid separation device of the present invention is characterized by comprising a tank (3) having a refrigerant storage space (2) formed therein, a refrigerant inlet portion (4) through which refrigerant flows into the refrigerant storage space (2), a liquid phase refrigerant outlet portion (5) that opens into a liquid phase region (2a) of the refrigerant storage space (2) and allows the liquid phase refrigerant stored in the refrigerant storage space (2) to flow out, and a gas phase refrigerant outlet portion (6) that opens into a gas phase region (2b) of the refrigerant storage space (2) and allows the gas phase refrigerant in the refrigerant storage space (2) to flow out.

[0011] Therefore, during cooling operation, the liquid phase refrigerant flowing out from the liquid phase refrigerant outlet port is guided to the expansion valve provided on the refrigerant inlet side of the heat absorber, allowing the gas-liquid separation device to function as a liquid tank, and during heating operation, the gas phase refrigerant flowing out from the gas phase refrigerant outlet port is guided to the compressor, allowing the gas-liquid separation device to function as an accumulator.

[0012] The vehicle heat pump cycle that achieves this is as follows: a refrigerant cycle (10) in which a compressor (11), a passenger compartment heat radiating section (12), an expansion valve (13) for an exterior heat exchanger, a passenger compartment exterior heat exchanger (14), the gas-liquid separation device (1) according to claim 1, an expansion valve (15) for a passenger compartment heat absorber, and a passenger compartment heat absorber (22) are connected by piping at least in this order, and in which a refrigerant is circulated; a gas-phase refrigerant passage (17) connected to a refrigerant path between the passenger compartment heat sink (22) and the compressor (11), through which a gas-phase refrigerant flows and which is provided with a gas-phase refrigerant on-off valve (18); an on-off valve (16) for a passenger compartment heat sink, the on-off valve (16) being provided in a refrigerant path between the passenger compartment heat sink expansion valve (15) and the gas-liquid separation device (1), or in a refrigerant path downstream of the passenger compartment heat sink (22) and between the gas-phase refrigerant passage (17) and the gas-phase refrigerant path; Equipped with the passenger compartment heat radiating section (12) has at least a passenger compartment radiator (23), and the passenger compartment radiator (23) and the passenger compartment heat absorber (22) are disposed in an air blowing space (21) of an air conditioning unit (20); The refrigerant inlet portion 4 of the gas-liquid separation device (1) is connected to a refrigerant outlet side (14b) of the passenger compartment exterior heat exchanger (14), The gas-phase refrigerant outlet (6) is connected to the gas-phase refrigerant passage (17), The liquid phase refrigerant outlet (5) may be connected to a refrigerant path leading to the passenger compartment heat absorber expansion valve (15).

[0013] By using such a heat pump cycle, a single gas-liquid separation device can be used as a liquid tank to supply liquid refrigerant to the expansion valve for the passenger compartment heat absorber during cooling operation, and as an accumulator to supply gas phase refrigerant to the compressor during heating operation.

[0014] The gas phase refrigerant on-off valve (18) and the passenger compartment heat absorber on-off valve (16) may be integrated into a three-way valve (19). Using one gas-liquid separation device, it is possible to supply liquid phase refrigerant to the passenger compartment heat absorber expansion valve as a liquid tank during cooling operation, and to supply gas phase refrigerant to the compressor as an accumulator during heating operation. Effect of the Invention

[0015] As described above, according to the present invention, the gas-liquid separation device is configured to include a tank having a refrigerant storage space formed therein, a refrigerant inlet portion through which refrigerant flows into the refrigerant storage space, a liquid-phase refrigerant outlet portion that opens into a liquid phase region of the refrigerant storage space and allows the liquid-phase refrigerant stored in the refrigerant storage space to flow out, and a gas-phase refrigerant outlet portion that opens into a gas phase region of the refrigerant storage space and allows the gas-phase refrigerant in the refrigerant storage space to flow out. Therefore, without increasing the number of parts or requiring additional installation space, a single gas-liquid separation device can provide both a function of supplying gas-phase refrigerant to the compressor during heating operation and a function of supplying liquid-phase refrigerant to an expansion valve provided on the refrigerant inlet side of a heat absorber during cooling operation. [Brief description of the drawings]

[0016] [Figure 1] 1 is a configuration diagram showing a first embodiment of a heat pump cycle for a vehicle according to the present invention. [Diagram 2] 1 is a schematic diagram showing a configuration example of a gas-liquid separation device according to the present invention. [Diagram 3] 2A is a diagram explaining the flow of refrigerant in a cooling operation mode of the heat pump cycle for a vehicle shown in FIG. 1, and FIG. 2B is a diagram explaining the flow of refrigerant in a heating operation mode of the heat pump cycle for a vehicle shown in FIG. 1. [Figure 4] 1A and 1B are diagrams showing a first modified example of a heat pump cycle for a vehicle according to the first embodiment, in which (a) is a diagram explaining the flow of refrigerant in a cooling operation mode, and (b) is a diagram explaining the flow of refrigerant in a heating operation mode. [Diagram 5] FIG. 4 is a diagram showing a second modified example of the vehicle heat pump cycle according to the first embodiment. [Figure 6] FIG. 11 is a diagram showing a third modified example of the vehicle heat pump cycle according to the first embodiment. [Figure 7] FIG. 4 is a diagram showing a second embodiment of a heat pump cycle for a vehicle according to the present invention. [Figure 8] FIG. 4 is a diagram showing a third embodiment of a heat pump cycle for a vehicle according to the present invention. [Figure 9] 11A and 11B are diagrams illustrating the flow of refrigerant in each operation mode using a heat pump cycle for a vehicle according to the third embodiment, where (a) shows the state in a cooling operation mode, and (b) shows the state in a heating operation mode. [Figure 10] FIG. 1 is a diagram showing a conventionally known heat pump cycle. [Figure 11] 11A and 11B are diagrams illustrating the flow of refrigerant in each operation mode of the conventional heat pump cycle shown in FIG. 10, where (a) is a diagram illustrating the flow of refrigerant in a refrigerant operation mode, and (b) is a diagram illustrating the flow of refrigerant in a heating operation mode. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0018] (First embodiment) 1 shows a first embodiment of a heat pump cycle 100 for a vehicle according to the present invention. The heat pump cycle 100 for a vehicle may be simply called a heat pump cycle 100. The heat pump cycle 100 for a vehicle is mounted on, for example, an automobile, and includes a passenger compartment heat absorber 22 and a passenger compartment radiator 23 disposed in an air blowing space 21 in an air conditioning unit 20, and a passenger compartment exterior heat exchanger 14 disposed outside the air conditioning unit 20 and capable of exchanging heat with outside air.

[0019] <Air conditioning unit> First, the air conditioning unit 20 will be described. An inside / outside air switching device 24 is provided on the most upstream side of the air conditioning unit 20. This inside / outside air switching device 24 has an inside air inlet 25a and an outside air inlet 25b that are selectively opened by an intake door 26. The inside air or outside air selectively introduced into the air conditioning unit 20 is sucked in by the rotation of a blower 27 and sent to the passenger compartment heat absorber 22 and the passenger compartment radiator 23, where the air is heat exchanged and supplied into the passenger compartment from desired outlets 28a to 28c.

[0020] The passenger compartment radiator 23 is disposed downstream of the passenger compartment heat absorber 22 in the air flow direction inside the air conditioning unit 20, and a damper 29 is provided upstream of the passenger compartment radiator 23 in the air flow direction. The damper 29 can be adjusted from a position where the amount of air passing through the passenger compartment radiator 23 is maximum (heating position: opening degree 100%) to a position where it is minimum (cooling position: opening degree 0%), and by adjusting the opening degree, the ratio of air passing through the passenger compartment radiator 23 and bypass air can be adjusted. The damper 29 is also called an air mix door. An electric heating device (PTC) may be disposed downstream of the passenger compartment radiator 23 in the air conditioning unit 20.

[0021] <Heat pump cycle> Next, the heat pump cycle 100 will be described. This heat pump cycle 100 includes a refrigerant cycle 10 in which a compressor 11, a passenger compartment radiator 23, an expansion valve 13 for the passenger compartment exterior heat exchanger, a passenger compartment exterior heat exchanger 14, a gas-liquid separation device 1, an expansion valve 15 for the passenger compartment heat absorber, a passenger compartment heat absorber 22, an opening / closing valve 16 for the passenger compartment heat absorber, and a compressor 11 are connected by piping in a loop in this order to circulate a refrigerant therein.

[0022] That is, the refrigerant inlet side 23a of the passenger compartment radiator 23 is connected to the discharge side α of the compressor 11, and the refrigerant outlet side 23b of the passenger compartment radiator 23 is connected to the refrigerant inlet side 13a of the expansion valve 13 for the passenger compartment exterior heat exchanger. The refrigerant outflow side 13b of the passenger compartment exterior heat exchanger expansion valve 13 is connected to the refrigerant inflow side 14a of the passenger compartment exterior heat exchanger 14, and the refrigerant outflow side 14b of the passenger compartment exterior heat exchanger 14 is connected to the gas-liquid separation device 1 and is connected to the refrigerant inflow side 22a of the passenger compartment heat absorber 22 via the gas-liquid separation device 1 and the passenger compartment heat absorber expansion valve 15. The refrigerant outflow side 22b of the passenger compartment heat absorber 22 is connected to the suction side β of the compressor 11 via the passenger compartment heat absorber on-off valve 16.

[0023] Here, the passenger compartment radiator 23 is shown as an example of a system in which the refrigerant discharged from the compressor 11 flows in directly to directly heat the air flowing through the air supply space 21 of the air conditioning unit 20, but it may also be a system in which the air in the air supply space 21 is indirectly heated by a heat medium that exchanges heat with the refrigerant from the compressor 11 (this point will be described later).Since the heat pump cycle 100 is applicable to both of these systems, the passenger compartment radiator 23 may also be broadly regarded as the passenger compartment heat dissipation section 12. The passenger compartment radiator 23 is also called an inner condenser.

[0024] In the refrigerant cycle 10 constituting the heat pump cycle 100, a gas-phase refrigerant passage 17 that connects the gas-liquid separation device 1 is connected between the passenger compartment heat absorber 22 and the compressor 11 (in the middle of the pipe that connects the passenger compartment heat absorber 22 and the compressor 11). The gas-phase refrigerant passage 17 is opened and closed by a gas-phase refrigerant on-off valve 18. In this example, the passenger compartment heat absorber on-off valve 16 is provided in the refrigerant path downstream of the passenger compartment heat absorber 22 and between the passenger compartment heat absorber 22 and a connection site J to which the gas-phase refrigerant passage 17 is connected.

[0025] <Gas-liquid separation equipment> As also shown in Figure 2, the gas-liquid separation device 1 comprises a tank 3 having a refrigerant storage space 2 formed therein, a refrigerant inlet portion 4 through which the refrigerant flows into the refrigerant storage space 2, a liquid phase refrigerant outlet portion 5 that opens into a liquid phase region 2a of the refrigerant storage space 2 and allows the liquid phase refrigerant stored in the refrigerant storage space 2 to flow out, and a gas phase refrigerant outlet portion 6 that opens into a gas phase region 2b located above the liquid phase region 2a of the refrigerant storage space 2 and allows the gas phase refrigerant in the refrigerant storage space 2 to flow out.

[0026] The tank 3 may have any shape, but may have, for example, a cylindrical peripheral wall 3a with a cylindrical refrigerant storage space 2 formed therein, with the lower end closed by a bottom wall 3b and the upper end closed by an upper wall 3c. The refrigerant inlet 4, liquid phase refrigerant outlet 5, and gas phase refrigerant outlet 6 are formed of pipes inserted and fixed into the refrigerant storage space 2 of the tank 3, for example, via the upper wall 3c.

[0027] The refrigerant inlet section 4 is formed by a straight pipe 4a inserted and fixed through the upper wall 3c of the tank 3, and the open end inserted into the refrigerant storage space 2 faces downward and opens into the gas phase region 2b while maintaining a sufficient distance from the liquid phase region 2a.

[0028] The liquid phase refrigerant outflow portion 5 is formed by a straight pipe 5a inserted and fixed through the upper wall 3c of the tank 3, and the open end inserted into the refrigerant storage space 2 is positioned near the bottom of the refrigerant storage space 2 and is always open to the liquid phase region 2a stored in the refrigerant storage space 2.

[0029] The gas phase refrigerant outflow section 6 is formed by a U-shaped tube 6a inserted and fixed through the upper wall 3c of the tank 3, and the open end inserted into the refrigerant storage space 2 faces upward and is always open to the gas phase region 2b of the refrigerant storage space 2. This U-shaped tube 6a is formed so as to extend from the upper wall 3c of the tank 3 through the vicinity of the bottom of the refrigerant storage space 2 and then upward, and an oil suction hole 8 is formed near the bottom of this U-shaped tube 6a to suck in the oil 2a-oil stored at the bottom (below the liquid phase region 2a) of the refrigerant storage space 2.

[0030] An inflow refrigerant receiving section 7 is disposed between the end of the refrigerant inlet section 4 of the refrigerant storage space 2 that opens into the gas phase region 2b and the end of the gas phase refrigerant outlet section 6 that opens into the gas phase region 2b. This inflow refrigerant receiving portion 7 can be formed into any shape, but here it comprises a circular flat portion 7a arranged approximately horizontally between the opening end of the refrigerant inlet portion 4 and the opening end of the gas phase refrigerant outlet portion 6, and a flange portion 7b extending downward from the periphery of this flat portion 7a, with the opening end of the refrigerant inlet portion 4 facing the upper surface of the flat portion 7a, the opening end of the gas phase refrigerant outlet portion 6 facing the lower surface of the flat portion 7a, and the opening end of the gas phase refrigerant outlet portion 6 being fixed so as to open at a position higher than the lower end of the flange portion 7b.

[0031] This causes the refrigerant flowing from the refrigerant inlet 4 into the refrigerant storage space 2 to collide with the flat portion 7a of the inflow refrigerant receiving portion 7, promoting gas-liquid separation of the refrigerant, while also preventing the liquid refrigerant flowing from the refrigerant inlet 4 from flowing directly into the gas-phase refrigerant outlet 6.

[0032] The refrigerant inlet section 4 of the gas-liquid separation device 1 is connected to the refrigerant outlet side 14b of the passenger compartment exterior heat exchanger 14, i.e., a refrigerant path leading to the refrigerant outlet section of the passenger compartment exterior heat exchanger 14, the gas phase refrigerant outlet section 6 is connected to the gas phase refrigerant passage 17, and the liquid phase refrigerant outlet section 5 is connected to the refrigerant inlet side of the passenger compartment heat sink expansion valve 15, i.e., a refrigerant path leading to the passenger compartment heat sink expansion valve 15.

[0033] Therefore, the refrigerant flowing out from the passenger compartment exterior heat exchanger 14 flows into the refrigerant storage space 2 of the gas-liquid separation device 1 through the refrigerant inlet portion 4, but the refrigerant flowing in from the refrigerant inlet portion 4 collides with the upper surface of the flat plate portion 7a of the inflow refrigerant receiving portion 7 to cause gas-liquid separation, and the separated liquid-phase refrigerant is guided downward into the refrigerant storage space 2 through a gap between the flange portion 7b provided around the flat plate portion 7a and the peripheral wall 3a of the tank 3. Also, part of the gas-phase refrigerant from which the liquid-phase refrigerant has been separated remains above the inflow refrigerant receiving portion 7 in the gas-phase region 2b, and the rest passes through a gap between the flange portion 7b provided around the flat plate portion 7a and the peripheral wall 3a of the tank 3 to be guided downward into the flat plate portion 7a in the gas-phase region 2b.

[0034] The liquid-phase refrigerant guided downward into the refrigerant storage space 2 is introduced into the liquid-phase refrigerant outlet portion 5 and supplied to the expansion valve 15 for the passenger compartment heat absorber in a cooling operation mode described later.

[0035] The gas-phase refrigerant guided to below the flat plate portion 7a of the inflow refrigerant receiving portion 7 within the upper portion of the refrigerant storage space 2 is introduced into the gas-phase refrigerant outflow portion 6 and sucked into the compressor 11 in the heating operation mode described below.

[0036] <Cooling operation mode> In the above configuration, when the heat pump cycle 100 is operated in the cooling operation mode, the passenger compartment heat absorber on-off valve 16 is opened, the gas phase refrigerant on-off valve 18 is closed, and the passenger compartment exterior heat exchanger expansion valve 13 is fully opened. In addition, the inside / outside air switching device 24 is set to introduce outside air, the damper 29 is set to the cooling position where the amount of air passing through the passenger compartment radiator 23 is minimized, and the compressor 11 and the blower 27 are started.

[0037] 3(a), the high-temperature, high-pressure refrigerant discharged from the compressor 11 is guided to the exterior heat exchanger 14 via the exterior heat exchanger expansion valve 13 without exchanging heat with the air in the air blowing space 21 in the interior radiator 23. Since the exterior heat exchanger expansion valve 13 is fully open, the high-temperature, high-pressure refrigerant passes through the exterior heat exchanger expansion valve 13 without being decompressed and expanded therein, has heat dissipated by the exterior heat exchanger 14, and is introduced as a gas-liquid mixed refrigerant from the refrigerant inlet portion 4 of the gas-liquid separation device 1 into the refrigerant storage space 2. The refrigerant guided to the gas-liquid separation device 1 then collides with the inflow refrigerant receiving portion 7 and is separated into gas and liquid, and the liquid-phase refrigerant is supplied from the liquid-phase refrigerant outlet portion 5 to the interior heat absorber expansion valve 15.

[0038] The passenger compartment heat absorber expansion valve 15 is controlled in terms of opening degree. That is, the valve opening degree of the passenger compartment heat absorber expansion valve 15 is in a throttled state. The liquid phase refrigerant guided to the passenger compartment heat absorber expansion valve 15 is decompressed and expanded there, and then flows into the passenger compartment heat absorber 22. The passenger compartment heat absorber 22 absorbs heat from the air flowing through the air blowing space 21 of the air conditioning unit 20, and then the liquid phase refrigerant is returned to the compressor 11.

[0039] Therefore, the air introduced into the air conditioning unit 20 from the outside air inlet 25b is cooled as it passes through the passenger compartment heat absorber 22, and is then supplied into the passenger compartment from desired outlets 28a-28c (for example, vent outlet 28b) to cool the passenger compartment. At this time, the refrigerant supplied to the passenger compartment heat absorber expansion valve 15 is only liquid phase refrigerant separated from the gas phase refrigerant by the gas-liquid separation device 1, so a stable supply of liquid phase refrigerant is ensured and there is no problem of a decrease in cooling capacity.

[0040] Although the inside / outside air switching device 24 has been described as introducing outside air, it may introduce both outside and inside air.

[0041] <Heating operation mode> On the other hand, when the heat pump cycle 100 is operated in the heating operation mode, the passenger compartment heat absorber on-off valve 16 is closed, the gas phase refrigerant on-off valve 18 is opened, and the opening degree of the passenger compartment exterior heat exchanger expansion valve 13 is controlled. That is, the valve opening degree of the passenger compartment exterior heat exchanger expansion valve 13 is narrowed. Also, the inside / outside air switching device 24 is set to introduce inside air, the damper 29 is set to the heating position where the amount of air passing through the passenger compartment radiator 23 is maximized, and the compressor 11 and the blower 27 are started.

[0042] Then, as shown in Figure 3 (b), the high-temperature, high-pressure refrigerant discharged from the compressor 11 exchanges heat with the air in the ventilation space 21 in the passenger compartment radiator 23, dissipating heat, and is then guided to the passenger compartment exterior heat exchanger 14 via the passenger compartment exterior heat exchanger expansion valve 13. Since the opening degree of the passenger compartment exterior heat exchanger expansion valve 13 is controlled, the refrigerant passing therethrough is decompressed and expanded, and absorbs heat from the outside air passing therethrough in the passenger compartment exterior heat exchanger 14. Therefore, the refrigerant is evaporated by the passenger compartment exterior heat exchanger 14, but if the refrigerant is not completely evaporated, it flows into the gas-liquid separation device 1 through the refrigerant inlet portion 4 as a gas-liquid mixed refrigerant. The refrigerant that has flowed into the gas-liquid separation device 1 is separated into gas and liquid here, and only the gas-phase refrigerant is sucked into the compressor 11 through the gas-phase refrigerant outlet portion 6.

[0043] Therefore, the air introduced into the air conditioning unit 20 from the inside air inlet 25a is guided to the passenger compartment radiator 23 without being heat exchanged in the passenger compartment heat absorber 22, heated as it passes through this passenger compartment radiator 23, and then supplied into the vehicle cabin from the desired outlets 28a to 28c (for example, foot outlet 28c) to warm the vehicle cabin. At this time, the refrigerant guided to the compressor 11 is only the gas-phase refrigerant from which the liquid-phase refrigerant has been separated by the gas-liquid separation device 1, so there is no risk of the compressor 11 compressing the liquid-phase refrigerant.

[0044] Although the inside / outside air switching device 24 has been described as introducing inside air, it may introduce a mixture of outside air and inside air. Alternatively, the inside / outside air switching device 24 may be set to introduce outside air.

[0045] In this way, the gas-liquid separation device 1 functions as a liquid tank that supplies only liquid phase refrigerant to the passenger compartment heat sink expansion valve 15 during cooling operation, and functions as an accumulator that supplies only gas phase refrigerant to the compressor 11 during heating operation. This eliminates the need to provide multiple gas-liquid separation devices, avoiding the inconvenience of an increased number of parts, and also eliminates the need to secure installation space for an additional gas-liquid separation device.

[0046] <First dehumidification mode> When the heat pump cycle 100 is operated in the first dehumidification operation mode, the passenger compartment heat absorber on-off valve 16 is opened, the gas phase refrigerant on-off valve 18 is closed, and the passenger compartment exterior heat exchanger expansion valve 13 is fully opened, although not shown. In addition, the inside / outside air switching device 24 is set to introduce outside air, the damper 29 is set to a position where the amount of air passing through the passenger compartment radiator 23 is maximized, and the compressor 11 and the blower 27 are started. As a result, the refrigerant discharged from the compressor 11 radiates heat in the passenger compartment radiator 23 and the passenger compartment exterior heat exchanger 14, and absorbs heat in the passenger compartment heat absorber 22. The air sent from the blower 27 to the air blowing space 21 is cooled and dehumidified at the passenger compartment heat absorber 22, and then heated in the passenger compartment radiator 23 to dehumidify the passenger compartment. The dehumidified air is supplied to the vehicle interior from desired outlets 28a to 28c (for example, vent outlet 28b and foot outlet 28c). The first dehumidification operation mode is a dehumidification operation mode in which the cooling capacity of the passenger compartment heat absorber 22 is higher than the heating capacity of the passenger compartment radiator 23, and the cooling capacity is higher than that of a second dehumidification operation mode described later.

[0047] <Second dehumidification operation mode> When the heat pump cycle 100 is operated in the second dehumidification operation mode, the passenger compartment heat absorber on-off valve 16 is opened, the gas-phase refrigerant on-off valve 18 is closed, and the passenger compartment exterior heat exchanger expansion valve 13 is controlled to have an opening degree, although not shown in the figure. In addition, the inside / outside air switching device 24 is set to introduce outside air, the damper 29 is set to a position where the amount of air passing through the passenger compartment radiator 23 is maximized, and the compressor 11 and the blower 27 are started. As a result, the refrigerant discharged from the compressor 11 radiates heat in the passenger compartment radiator 23 and absorbs heat in the passenger compartment exterior heat exchanger 14 and the passenger compartment heat absorber 22. The air sent from the blower 27 to the air blowing space 21 is cooled and dehumidified at the passenger compartment heat absorber 22, and then heated in the passenger compartment radiator 23 to dehumidify the passenger compartment. The dehumidified air is supplied to the vehicle interior from desired outlets 28a to 28c (for example, vent outlet 28b and foot outlet 28c). The second dehumidification operation mode is a dehumidification operation mode in which the heating capacity of the passenger compartment radiator 23 is higher than the cooling capacity of the passenger compartment heat absorber 22, and the heating capacity is higher than that of the first dehumidification operation mode.

[0048] Although the inside / outside air switching device 24 has been described as introducing outside air, it may introduce a mixture of outside air and inside air. Alternatively, the inside / outside air switching device 24 may be set to introduce inside air depending on the situation.

[0049] In this way, the gas-liquid separation device 1 can also function as a liquid tank that supplies only liquid-phase refrigerant to the passenger compartment heat absorber expansion valve 15 during dehumidification operation.

[0050] (First Modification) In the illustrated example, the passenger compartment heat sink opening / closing valve 16 is disposed in the refrigerant path downstream of the passenger compartment heat sink 22 (the refrigerant path between the passenger compartment heat sink 22 and the compressor 11) and upstream of the connection point J to which the gas phase refrigerant passage 17 is connected. However, since the purpose of this is to control the supply / stop of refrigerant to the passenger compartment heat sink 22, it may also be disposed upstream of the passenger compartment heat sink expansion valve 15 on the refrigerant path between the gas-liquid separation device 1.

[0051] (Second Modification) Moreover, when the passenger compartment heat absorber on-off valve 16 is disposed downstream of the passenger compartment heat absorber 22 and between the passenger compartment heat absorber 22 and the connection site J to which the gas phase refrigerant passage 17 is connected, the passenger compartment heat absorber on-off valve 16 and the gas phase refrigerant on-off valve 18 may be replaced with one three-way valve 19 as shown in Fig. 4. With such a configuration, in addition to obtaining the same effects as those of the heat pump cycle 100 shown in Fig. 1, it is possible to eliminate the on-off valves 16 and 18, thereby simplifying the cycle configuration.

[0052] (Third Modification) Furthermore, in order to enhance the cooling effect during cooling operation and to more reliably supply liquid refrigerant to the passenger compartment heat absorber expansion valve 15, as shown in FIG. 5, an internal heat exchanger 50 may be further provided to exchange heat between the refrigerant flowing between the liquid phase refrigerant outflow portion 5 of the gas-liquid separation device 1 and the passenger compartment heat absorber expansion valve 15 and the refrigerant flowing out from the passenger compartment heat absorber 22.

[0053] (Fourth Modification) 6, the passenger compartment heat absorber expansion valve 15 may be configured as an electronic expansion valve that can be controlled to an arbitrary opening degree and can be fully closed. In such a configuration, the passenger compartment heat absorber expansion valve 15 can be provided with a throttling function and an on-off valve function, so that the same action and effect can be obtained even if the passenger compartment heat absorber on-off valve 16 is omitted, and the cycle configuration can be simplified.

[0054] Second embodiment In the above-described vehicle heat pump cycle 100, as an example of the passenger compartment radiator 12 that uses the high-temperature, high-pressure refrigerant compressed by the compressor 11 to heat the blown air to be supplied to the vehicle cabin, a configuration example (direct type heat pump cycle) has been shown in which the high-temperature, high-pressure refrigerant discharged from the compressor 11 is directly supplied to the passenger compartment radiator 23 arranged in the air blowing space 21 of the air conditioning unit 20, and the air flowing through the air blowing space 21 is heated by this passenger compartment radiator 23. However, the present invention is not limited to this, and the passenger compartment radiator 12 may be configured to transfer the heat of the refrigerant discharged from the compressor 11 to a first heat medium cycle 30 to which it is thermally coupled, as shown in FIG. 7, and to heat the air flowing through the air blowing space 21 of the air conditioning unit 20 via this first heat medium cycle 30 (indirect type heat pump cycle).

[0055] That is, the first heat medium cycle 30 includes a first pump 31 that circulates the heat medium, a first refrigerant heat medium heat exchanger 32 into which the circulating heat medium flows and which exchanges heat with the refrigerant discharged from the compressor 11 of the refrigerant cycle 10A, and a heat medium radiator 33 that is accommodated in the air blowing space 21 of the air conditioning unit 20 and serves as the passenger compartment radiator 23 into which the circulating heat medium flows and which radiates heat from the heat medium.

[0056] The first refrigerant / heat medium heat exchanger 32 includes a refrigerant passage portion 32a through which the refrigerant of the refrigerant cycle 10A flows, and a heat medium passage portion 32b through which the heat medium of the first heat medium cycle 30 flows, and transfers heat between the refrigerant flowing in the refrigerant passage portion 32a and the heat medium flowing in the heat medium passage portion 32b. When the heat medium is water, the first refrigerant / heat medium heat exchanger 32 is also called a water condenser. Other configurations of the refrigerant cycle 10A are similar to those shown in FIG. 1, so the same components are given the same reference numerals and the description thereof will be omitted.

[0057] Even in such a configuration, the gas-liquid separation device 1 can function as a receiver tank in the cooling operation mode and as an accumulator in the heating operation mode, making it possible to simplify the cycle configuration.

[0058] Third embodiment 8 shows a third embodiment of a heat pump cycle 100 for a vehicle including a gas-liquid separation device 1 according to the present invention. The heat pump cycle 100 for a vehicle includes a refrigerant cycle 10B and a second heat medium cycle 40. The refrigerant cycle 10B has the same configuration as that shown in FIG. 1, except that the passenger compartment exterior heat exchanger 14 of the refrigerant cycle 10 shown in FIG. 1 is a second refrigerant / heat medium heat exchanger 42 that is thermally coupled to a second heat medium cycle 40 described below. Therefore, the same reference numerals are used for the same parts and their descriptions are omitted.

[0059] The second heat medium cycle 40 is formed in a loop shape by sequentially piping connections of a second pump 41 through which a heat medium circulates and which pumps out the heat medium, a second refrigerant heat medium heat exchanger 42 into which the heat medium flowing out of the second pump 41 flows and which is thermally coupled to the refrigerant cycle 10B, a heat source heat exchanger 44 into which the heat medium flowing out of the second refrigerant heat medium heat exchanger 42 flows and which is capable of absorbing heat generated by a heat source 43 such as a battery, and a radiator 45 which exchanges heat with outside air. The heat source 43 may be a battery or a motor or inverter for driving a vehicle.

[0060] The second refrigerant / heat medium heat exchanger 42 includes a refrigerant passage portion 42a through which the refrigerant of the refrigerant cycle 10B flows, and a heat medium passage portion 42b through which the heat medium of the heat medium cycle 40 flows. The second refrigerant / heat medium heat exchanger 42 transfers heat between the refrigerant flowing in the refrigerant passage portion 42a and the heat medium flowing in the heat medium passage portion 42b, and is sometimes referred to as a water condenser.

[0061] The second heat medium cycle 40 also includes a bypass passage 46 that bypasses the radiator 45. A three-way valve 47 is provided at a branch point between the heat generating element heat exchanger 44 and the radiator 45 to which the bypass passage 46 is connected, making it possible to switch between passing the heat medium flowing out from the heat generating element heat exchanger 44 through the radiator 45 or bypassing it.

[0062] In such a configuration, when the operation mode is set to the cooling operation mode, the refrigerant cycle 10B is set in the same manner as in FIG. 3(a), and in the second heat medium cycle 40, the second pump 41 is operated and the three-way valve 47 is switched so as to pass the heat medium flowing out of the heat exchanger 44 through the radiator 45.

[0063] As a result, as shown in Figure 9(a), the high-temperature, high-pressure refrigerant discharged from the compressor 11 flows into the second refrigerant heat medium heat exchanger 42 without being heat exchanged in the passenger compartment radiator 23 and without being reduced in pressure and expanded in the passenger compartment exterior heat exchanger expansion valve 13, and dissipates heat in this second refrigerant heat medium heat exchanger 42 to the heat medium circulating in the second heat medium cycle 40. On the other hand, in the second heat medium cycle 40, the heat medium discharged from the second pump 41 absorbs heat of the refrigerant in the second refrigerant heat medium heat exchanger 42 and also absorbs heat from the heating element 43, and then dissipates the heat to the outside air in the radiator 45. That is, the heat absorbed from the blown air by the passenger compartment heat absorber 22 is dissipated to the heat medium of the second heat medium cycle 40 via the second refrigerant heat medium heat exchanger 42, and is dissipated to the outside of the vehicle together with the heat recovered from the heating element 43 via the radiator 45, so that the air introduced into the air conditioning unit 20 (air blown from the blower 27) can be efficiently cooled.

[0064] On the other hand, when the operation mode is set to the heating mode, the refrigerant cycle 10B is set as in FIG. 3(b), and the second heat medium cycle 40 is switched so that the second pump 41 is operated and the three-way valve 47 causes the heat medium flowing out of the heat exchanger 44 to bypass the radiator 45.

[0065] 9(b), the high-temperature, high-pressure refrigerant discharged from the compressor 11 dissipates heat to the air flowing through the air blowing space 21 of the air conditioning unit 20 in the passenger compartment radiator 23, and then is decompressed and expanded in the passenger compartment exterior heat exchanger expansion valve 13 and flows into the second refrigerant heat medium heat exchanger 42. In the second heat medium cycle 40, the heat medium that has recovered heat from the heat generating element 43 by the heat generating element heat exchanger 44 flows into the second refrigerant heat medium heat exchanger 42 through the bypass passage 46 without dissipating heat in the radiator 45. Therefore, the refrigerant that has flowed into the second refrigerant heat medium heat exchanger 42 absorbs heat from the heat medium and is evaporated and vaporized, and after gas-liquid separation by the gas-liquid separation device 1, only the gas-phase refrigerant is drawn into the compressor 11. Therefore, the heat recovered by the heating element heat exchanger 44 is recovered into the refrigerant via the second refrigerant heat medium heat exchanger 42, making it possible to efficiently heat the air introduced into the air conditioning unit 20 (air blown from the blower 27).

[0066] Even in such a configuration, the gas-liquid separation device 1 provided in the refrigerant cycle 10B can function as a receiver tank in the cooling operation mode and as an accumulator in the heating operation mode, thereby simplifying the cycle configuration.

[0067] (Other embodiments) As long as the effects of the present invention can be achieved, the above-mentioned embodiments and modifications can be appropriately combined. For example, the heat pump cycle 100 may be configured to have a first heat medium cycle 30 and a second heat medium cycle 40. The second modification of the first embodiment may be adopted simultaneously with the first and third modifications. The first, second, and third modifications of the first embodiment may be adopted in the second and third embodiments, respectively. [Industrial Applicability]

[0068] The gas-liquid separation device 1 and the vehicular heat pump cycle 100 of the present invention are suitable for installation in a passenger vehicle. [Explanation of symbols]

[0069] 1 Gas-liquid separator 2 Refrigerant storage space 2a Liquid phase region 2b Gas phase region 3. Tank 4. Refrigerant inlet 5. Liquid refrigerant outlet 6. Gas phase refrigerant outlet 10, 10A, 10B Refrigerant cycle 11 Compressor 12 Passenger compartment heat dissipation section 13 Expansion valve for passenger compartment heat exchanger 14 Passenger compartment exterior heat exchanger 15 Expansion valve for passenger compartment heat sink 16 Passenger compartment heat sink opening / closing valve 17 Gas phase refrigerant passage 18 Gas phase refrigerant on-off valve 20 Air Conditioning Unit 21 Ventilation space 22 Passenger compartment heat sink 23 Passenger compartment radiator 30 First heat transfer medium cycle 32 1st refrigerant heat medium heat exchanger 40 Second heat transfer medium cycle 42 Second refrigerant heat medium heat exchanger 100 Heat pump cycle (vehicle heat pump cycle)

Claims

1. A tank (3) having a refrigerant storage space (2) formed therein; a refrigerant inlet (4) for introducing a refrigerant into the refrigerant storage space (2); a liquid-phase refrigerant outlet (5) that opens into a liquid-phase region (2a) of the refrigerant storage space (2) and allows the liquid-phase refrigerant stored in the refrigerant storage space (2) to flow out; a gas-phase refrigerant outlet (6) that opens into a gas-phase region (2b) located above the liquid-phase region (2a) of the refrigerant storage space (2) and allows the gas-phase refrigerant in the refrigerant storage space (2) to flow out; A gas-liquid separation device (1), comprising:

2. a refrigerant cycle (10) in which a compressor (11), a passenger compartment heat dissipation section (12), an expansion valve for a passenger compartment exterior heat exchanger (13), a passenger compartment exterior heat exchanger (14), the gas-liquid separation device (1) according to claim 1, an expansion valve for a passenger compartment heat absorber (15), and a passenger compartment heat absorber (22) are connected by piping at least in this order, and in which a refrigerant is circulated; a gas-phase refrigerant passage (17) connected to a refrigerant path between the passenger compartment heat sink (22) and the compressor (11), through which a gas-phase refrigerant flows and which is provided with a gas-phase refrigerant on-off valve (18); an on-off valve (16) for a passenger compartment heat absorber, the on-off valve (16) being provided in a refrigerant path between the passenger compartment heat absorber expansion valve (15) and the gas-liquid separation device (1), or in a refrigerant path downstream of the passenger compartment heat absorber (22) and between the gas-phase refrigerant passage (17) and a portion of the refrigerant path; Equipped with the passenger compartment heat radiating section (12) has at least a passenger compartment radiator (23), and the passenger compartment radiator (23) and the passenger compartment heat absorber (22) are disposed in an air blowing space (21) of an air conditioning unit (20); The refrigerant inlet portion (4) of the gas-liquid separation device (1) is connected to a refrigerant outlet side (14b) of the passenger compartment exterior heat exchanger (14), The gas-phase refrigerant outlet (6) is connected to the gas-phase refrigerant passage (17), The liquid-phase refrigerant outlet (5) is connected to a refrigerant path leading to the passenger compartment heat absorber expansion valve (15). A heat pump cycle (100) for a vehicle.

3. 3. The heat pump cycle (100) for a vehicle according to claim 2, wherein the gas-phase refrigerant on-off valve (18) and the passenger compartment heat absorber on-off valve (16) are integrated into a three-way valve (19).

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