WO2018047599A1

WO2018047599A1 - Heat pump cycle, vehicle air conditioning device comprising same, and refrigeration cycle

Info

Publication number: WO2018047599A1
Application number: PCT/JP2017/029580
Authority: WO
Inventors: めぐみ重田
Original assignee: サンデン・オートモーティブクライメイトシステム株式会社
Priority date: 2016-09-06
Filing date: 2017-08-10
Publication date: 2018-03-15
Also published as: JP2018040518A

Abstract

Provided is a heat pump cycle (HP) that comprises a refrigerant circuit (R) having: a compressor (2) that compresses a refrigerant; a heat exchanger for heat radiation (a radiator (4) and an outdoor heat exchanger (7)) that radiates heat from the refrigerant; a pressure reducer (an outdoor expansion valve (6) and an indoor expansion valve (7)); and a heat exchanger for heat absorption (an outdoor heat exchanger (7) and a heat sink (9)) that absorbs heat from the refrigerant. The heat pump cycle comprises an accumulator (12) that is connected to the refrigerant intake side of the compressor (2). A service valve (64) is provided on inlet piping (refrigerant piping (13C)) of the accumulator (12). Thus, oil is prevented from being drawn out when recovering refrigerant in the refrigerant circuit (R).

Description

Heat pump cycle, vehicle air conditioner equipped with the same, and refrigeration cycle

The present invention relates to a heat pump cycle including a compressor, a radiator, a decompressor, and a heat exchanger for heat absorption, an air conditioner for a vehicle that includes the same and air-conditions a vehicle interior, and a refrigeration cycle. .

Conventionally, this type of heat pump cycle, particularly a heat pump cycle that constitutes an air conditioner for vehicles, includes a compressor that compresses a refrigerant, a radiator that radiates the refrigerant (a heat exchanger for heat dissipation), and an expansion valve as a pressure reducing device. And an outdoor heat exchanger (an endothermic heat exchanger or a heat dissipation heat exchanger) and an indoor evaporator (an endothermic heat exchanger) are sequentially connected to form a refrigerant circuit. The supplied air is heated and the vehicle interior is heated by absorbing heat with an outdoor heat exchanger, and the vehicle interior is cooled by absorbing heat of the refrigerant with an indoor evaporator (see, for example, Patent Document 1). ).
In addition, an accumulator as a gas-liquid separator is connected to the refrigerant suction side of the compressor. Especially in a vehicle air conditioner that is subject to vibration during traveling, refrigerant leakage from the refrigerant circuit becomes a problem. A service valve called a charging port was attached to the piping from the outlet side of the accumulator to the compressor. Then, when the refrigerant is filled in the refrigerant circuit, the refrigerant in the circuit is once evacuated and collected from the service valve and then filled.

Japanese Patent Laying-Open No. 2015-137779

Here, the accumulator is equipped with a tank with a predetermined capacity, and an outlet pipe that opens at the upper part of the tank and that has the other end drawn out of the tank and connected to the compressor. The inlet pipe is connected to the tank. And open at the top of the tank. Then, the liquid refrigerant out of the refrigerant flowing in from the inlet pipe is temporarily stored in the tank, and the two-phase refrigerant mixed with part of the liquid refrigerant in which the gas refrigerant and oil are dissolved flows out from the opening at one end of the outlet pipe. It is supposed to be a structure that allows
The tank also stores oil circulating in the refrigerant circuit together with the refrigerant. Since this oil also needs to be returned to the compressor, the outlet pipe has a shape that descends from the opening at one end to the bottom of the tank, forms an oil return hole at the lowest point, and this oil return hole enters the tank. It was configured to return the accumulated oil to the compressor.
However, conventionally, since the service valve is attached to the outlet pipe of the accumulator, the oil in the accumulator is also sucked when evacuating and the oil in the refrigerant circuit is exhausted. .
The present invention was made in order to solve the conventional technical problem, and a heat pump cycle capable of preventing oil from being sucked out when recovering the refrigerant in the refrigerant circuit, An object is to provide a vehicle air conditioner and a refrigeration cycle using the same.

The heat pump cycle of the present invention includes a refrigerant circuit having a compressor that compresses a refrigerant, a heat exchanger for heat dissipation that dissipates the refrigerant, a decompression device, and a heat exchanger that absorbs heat from the refrigerant. An accumulator connected to the refrigerant suction side of the compressor is provided, and a service valve is provided in an inlet pipe of the accumulator.
In the heat pump cycle according to the second aspect of the present invention, in the above invention, the accumulator includes a tank having a predetermined capacity inside and an outlet pipe that opens at an upper part of the tank, and the inlet pipe is connected to the upper part of the tank. While opening in the said tank, outlet piping has an oil return hole opened in the bottom part in a tank, It is characterized by the above-mentioned.
A vehicle air conditioner according to a third aspect of the invention includes an air flow passage through which air to be supplied into the passenger compartment flows in addition to the heat pump cycle of each of the above inventions, and a heat exchanger for heat dissipation is provided in the air flow passage. The endothermic heat exchanger is provided outside the passenger compartment, and the refrigerant discharged from the compressor is radiated by the heat radiating heat exchanger, and the radiated refrigerant is decompressed by the decompression device, and then the heat absorbing heat exchanger. The vehicle interior is heated by absorbing heat.
A vehicle air conditioner according to a fourth aspect of the invention includes an air flow passage through which air to be supplied into the vehicle compartment flows in addition to the heat pump cycle of the first or second aspect of the invention, and the heat absorption heat exchanger is an air The heat dissipation heat exchanger is provided outside the passenger compartment, and the refrigerant discharged from the compressor is radiated by the heat dissipation heat exchanger. The interior of the vehicle is cooled by absorbing heat with a heat exchanger.
The refrigeration cycle of the invention of claim 5 comprises at least a compressor, a radiator, a decompressor, a heat exchanger for heat absorption, and an accumulator, comprising an accumulator connected to the refrigerant suction side of the compressor, A service valve is provided in the inlet pipe of the accumulator.

According to the first or fifth aspect of the invention, the accumulator connected to the refrigerant suction side of the compressor is provided, and the service valve is provided in the inlet pipe of the accumulator. It is possible to avoid the disadvantage that the oil is sucked out.
This is because, for example, as in the invention of claim 2, the accumulator includes a tank having a predetermined capacity inside and an outlet pipe opened at the upper part of the tank, and the inlet pipe is connected to the upper part of the tank. This is extremely effective when the outlet pipe has an oil return hole that opens at the bottom of the tank.
As a result, it is possible to eliminate the disadvantage that the oil in the circuit is exhausted due to the recovery of the refrigerant from the refrigerant circuit. This is particularly effective in a vehicle air conditioner that heats or cools the passenger compartment as in the inventions of

claims

3 and 4.

It is a block diagram of one Example of the air conditioning apparatus for vehicles provided with the heat pump cycle to which this invention is applied. It is a block diagram of the electric circuit of the controller of the vehicle air conditioner of FIG. It is a perspective view of the accumulator of the air conditioning apparatus for vehicles of FIG. It is a schematic sectional drawing of the accumulator of the vehicle air conditioner of FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a configuration diagram of an embodiment of a vehicle air conditioner 1 provided with a heat pump cycle HP as an example of the refrigeration cycle of the present invention. The vehicle according to the embodiment to which the vehicle air conditioner 1 of FIG. 1 is applied is an electric vehicle (EV) in which an engine (internal combustion engine) is not mounted, and an electric motor for traveling with electric power charged in a battery is used. The vehicle is driven and driven (none of which is shown), and the vehicle air conditioner 1 is also driven by the power of the battery. That is, the vehicle air conditioner 1 of the embodiment performs a heating mode by a heat pump operation using a refrigerant circuit in an electric vehicle that cannot be heated by engine waste heat, and further includes a dehumidifying heating mode, a dehumidifying cooling mode, a cooling mode, And each operation mode of MAX cooling mode is selectively performed.
The present invention is effective not only for electric vehicles but also for so-called hybrid vehicles that use an engine and an electric motor for traveling, and is also applicable to ordinary vehicles that run on an engine. Needless to say.
The vehicle air conditioner 1 according to the embodiment performs air conditioning (heating, cooling, dehumidification, and ventilation) in a vehicle interior of an electric vehicle, and includes an electric compressor 2 that compresses refrigerant and vehicle interior air. Is provided in the air flow passage 3 of the HVAC unit 10 through which air is circulated, and the high-temperature and high-pressure refrigerant discharged from the compressor 2 flows in through the refrigerant pipe 13G and dissipates the refrigerant into the passenger compartment. A radiator 4 as an exchanger, an outdoor expansion valve 6 as a decompression device comprising a motor-operated valve that decompresses and expands the refrigerant during heating, and functions as a heat-dissipating heat exchanger that is provided outside the passenger compartment during cooling and absorbs heat during heating An outdoor heat exchanger 7 for exchanging heat between the refrigerant and the outside air so as to function as a heat exchanger, an indoor expansion valve 8 as a decompression device comprising an electric valve for decompressing and expanding the refrigerant, and the air flow passage 3 It is provided in the air conditioner A heat absorber 9 as a heat exchanger for heat absorption to absorbed by the refrigerant from the cabin outside when fine dehumidification, the accumulator 12 and the like are provided sequentially connected heat pump cycle HP of the refrigerant circuit R is constituted by a refrigerant pipe 13.
The refrigerant circuit R of the heat pump cycle HP is filled with a predetermined amount of refrigerant and lubricating oil. Note that an outdoor fan 15 is provided in the outdoor heat exchanger 7 (a heat exchanger for heat dissipation or a heat exchanger for heat absorption). The outdoor blower 15 exchanges heat between the outside air and the refrigerant by forcibly passing outside air through the outdoor heat exchanger 7, so that the outdoor air blower 15 can also be used outdoors even when the vehicle is stopped (that is, the vehicle speed is 0 km / h). It is comprised so that external air may be ventilated by the heat exchanger 7. FIG.
The outdoor heat exchanger 7 has a receiver dryer unit 14 and a supercooling unit 16 in order on the downstream side of the refrigerant, and the refrigerant pipe 13A exiting from the outdoor heat exchanger 7 includes a dehumidifying heating mode, a dehumidifying cooling mode, a cooling mode, The refrigerant pipe 13B on the outlet side of the supercooling section 16 is connected to the inlet of the heat absorber 9 via the indoor expansion valve 8 via a cooling electromagnetic valve 17 opened in the MAX cooling mode. Connected to the side. In addition, the receiver dryer part 14 and the supercooling part 16 structurally constitute a part of the outdoor heat exchanger 7.
The refrigerant pipe 13B between the subcooling section 16 and the indoor expansion valve 8 is provided in a heat exchange relationship with the refrigerant pipe 13C on the outlet side of the heat absorber 9, and constitutes an internal heat exchanger 19 together. Thus, the refrigerant flowing into the indoor expansion valve 8 through the refrigerant pipe 13B is cooled (supercooled) by the low-temperature refrigerant that has exited the heat absorber 9.
Further, the refrigerant pipe 13A exiting from the outdoor heat exchanger 7 is branched into a refrigerant pipe 13D, and the branched refrigerant pipe 13D is connected to the internal heat exchanger via a heating electromagnetic valve 21 opened in the heating mode. 19 is connected to a refrigerant pipe 13 C on the downstream side. The refrigerant pipe 13 C is connected to the accumulator 12 as an inlet pipe as described later, and the accumulator 12 is connected to the refrigerant suction side of the compressor 2. Further, the refrigerant pipe 13E on the outlet side of the radiator 4 is connected to the inlet side of the outdoor heat exchanger 7 via the outdoor expansion valve 6.
In addition, the refrigerant pipe 13G between the discharge side of the compressor 2 and the inlet side of the radiator 4 is reheated in the heating mode, the dehumidifying cooling mode, and the cooling mode, and closed in the dehumidifying heating mode and the MAX cooling mode. An electromagnetic valve 30 is provided. In this case, the refrigerant pipe 13G is branched into a bypass pipe 35 on the upstream side of the electromagnetic valve 30, and the bypass pipe 35 is opened in the dehumidifying heating mode and the MAX cooling mode, and is heated, dehumidified and cooled, and cooled. The refrigerant pipe 13E is connected to the downstream side of the outdoor expansion valve 6 through a bypass electromagnetic valve 40 that is closed in the mode. Bypass pipe 45, solenoid valve 30 and solenoid valve 40 constitute bypass device 45.
The air flow passage 3 on the air upstream side of the heat absorber 9 is formed with each of an outside air inlet and an inside air inlet (represented by the inlet 25 in FIG. 1). 25 is provided with a suction switching damper 26 for switching the air introduced into the air flow passage 3 between the inside air (inside air circulation mode) which is air inside the passenger compartment and the outside air (outside air introduction mode) which is outside the passenger compartment. Yes. Furthermore, an indoor blower (blower fan) 27 for supplying the introduced inside air or outside air to the air flow passage 3 is provided on the air downstream side of the suction switching damper 26.
Moreover, in FIG. 1, 23 is an auxiliary heater provided in the vehicle air conditioner 1 of the embodiment. The auxiliary heater 23 of the embodiment is composed of a PTC heater which is an electric heater, and is provided in the air flow passage 3 on the air upstream side of the radiator 4 with respect to the air flow in the air flow passage 3. Yes. When the auxiliary heater 23 is energized and generates heat, the air in the air flow passage 3 flowing into the radiator 4 through the heat absorber 9 is heated. In other words, the auxiliary heater 23 serves as a so-called heater core, which heats or complements the passenger compartment.
In addition, air in the air flow passage 3 on the upstream side of the auxiliary heater 23 flows into the air flow passage 3 and assists air (inside air or outside air) in the air flow passage 3 after passing through the heat absorber 9. An air mix damper 28 is provided for adjusting the ratio of ventilation through the heater 23 and the radiator 4. Further, FOOT (foot), VENT (vent), and DEF (def) outlets (represented by the outlet 29 as a representative in FIG. 1) are formed in the air flow passage 3 on the air downstream side of the radiator 4. The air outlet 29 is provided with an air outlet switching damper 31 that performs switching control of air blowing from the air outlets.
Here, FIGS. 3 and 4 show a perspective view and a sectional view of the accumulator 12 described above. The accumulator 12 is a so-called gas-liquid separator for separating the liquid refrigerant and the gas refrigerant flowing in via the refrigerant pipe 13C, and has a tank 57 having upper and lower predetermined dimensions and a predetermined capacity inside, and the tank 57 The baffle plate 58 disposed in the upper part of the tank 57 and spaced apart from the side wall and the upper wall of the tank 57, and enters the inside from the upper wall of the tank 57, penetrates the baffle plate 58, and once reaches the bottom of the tank 57. And the outlet pipe 61 is opened at one end (tip) that is opened at a distance below the baffle plate 58. That is, one end of the outlet pipe 61 is opened at the upper part in the tank 57 below the baffle plate 58.
The lowermost part of the outlet pipe 61 is located immediately above the bottom wall of the tank 57 with a small clearance, and an oil return hole 62 formed of a small hole is formed at the lowermost part. That is, the oil return hole 62 opens at the bottom of the tank 57. Further, the other end of the outlet pipe 61 exits from the upper wall of the tank 57 and is connected to the suction side of the compressor 2.
A refrigerant pipe 13 C serving as an inlet pipe of the accumulator 12 enters the tank 57 from the upper wall and opens above the baffle plate 58. That is, the refrigerant pipe 13 C is connected to the upper part of the tank 57, and opens at the upper part in the tank 57 above the baffle plate 58. Further, a service valve 64 is attached to the refrigerant pipe 13C (inlet pipe), which is a little before the portion connected to the accumulator 12. The service valve 64 is a valve used when evacuating the refrigerant from the refrigerant circuit R of the heat pump cycle HP and filling the refrigerant into the refrigerant circuit R as will be described later.
Next, in FIG. 2, reference numeral 32 denotes a controller (ECU) as a control device composed of a microcomputer which is an example of a computer provided with a processor. The controller 32 detects the outside air temperature (Tam) of the vehicle. The outside air temperature sensor 33 for detecting the outside air humidity, the HVAC suction temperature sensor 36 for detecting the temperature of the air sucked into the air flow passage 3 from the suction port 25, and the air (inside air) in the passenger compartment. An inside air temperature sensor 37 that detects the temperature, an inside air humidity sensor 38 that detects the humidity of the air in the vehicle interior, an indoor CO2 concentration sensor 39 that detects the carbon dioxide concentration in the vehicle interior, and an air outlet 29 is blown into the vehicle interior. A discharge temperature sensor 41 for detecting the temperature of the air to be discharged, a discharge pressure sensor 42 for detecting the discharge refrigerant pressure Pd of the compressor 2, and a pressure A discharge temperature sensor 43 that detects a discharge refrigerant temperature Td of the compressor 2, a suction pressure sensor 44 that detects a suction refrigerant pressure Ps of the compressor 2, and a suction that is the temperature of the refrigerant that comes out of the accumulator 12 and is sucked into the compressor 2 A suction temperature sensor 55 that detects the refrigerant temperature Ts, and a radiator temperature sensor 46 that detects the temperature of the radiator 4 (the temperature of the air that has passed through the radiator 4 or the temperature of the radiator 4 itself: the radiator temperature TH). The radiator pressure sensor 47 for detecting the refrigerant pressure of the radiator 4 (in the radiator 4 or immediately after exiting the radiator 4: the pressure of the radiator: PCI) and the temperature of the heat absorber 9 (the heat absorber) The temperature of the air that has passed through the heat sink 9 or the temperature of the heat absorber 9 itself: the heat absorber temperature sensor 48, and the refrigerant pressure of the heat absorber 9 (within the heat absorber 9 or the heat absorber 9 The refrigerant pressure immediately after Pressure sensor 49, photosensor type solar radiation sensor 51 for detecting the amount of solar radiation into the passenger compartment, vehicle speed sensor 52 for detecting the moving speed (vehicle speed) of the vehicle, set temperature and operation mode An air conditioning (air conditioner) operation unit 53 for setting the switching, and the temperature of the outdoor heat exchanger 7 (the temperature of the refrigerant immediately after coming out of the outdoor heat exchanger 7 (the refrigerant flowing into the accumulator 12 in the heating mode described later) Temperature: outdoor heat exchanger temperature sensor 54 for detecting the outdoor heat exchanger temperature TXO) and the refrigerant pressure of the outdoor heat exchanger 7 (in the outdoor heat exchanger 7 or immediately after it has come out of the outdoor heat exchanger 7) Each output of the outdoor heat exchanger pressure sensor 56 for detecting refrigerant pressure: outdoor heat exchanger pressure PXO) is connected to the controller 32. Further, the input of the controller 32 further includes the temperature of the auxiliary heater 23 (auxiliary heater 23). Also connected to the output of the auxiliary heater temperature sensor 50 for detecting the temperature of the air immediately after being heated or the temperature of the auxiliary heater 23 itself: the auxiliary heater temperature Tptc).
On the other hand, the output of the controller 32 includes the compressor 2, the outdoor blower 15, the indoor blower (blower fan) 27, the suction switching damper 26, the air mix damper 28, the outlet switching damper 31, and the outdoor expansion. The solenoid valve, the indoor expansion valve 8, the auxiliary heater 23, the solenoid valve 30 (for reheating), the solenoid valve 17 (for cooling), the solenoid valve 21 (for heating), and the solenoid valve 40 (for bypass) are connected. Has been. And the controller 32 controls these based on the output of each sensor, and the setting input in the air-conditioning operation part 53. FIG.
Next, the operation of the vehicle air conditioner 1 having the above-described configuration will be described. In the embodiment, the controller 32 switches between the operation modes of the heating mode, the dehumidifying heating mode, the dehumidifying cooling mode, the cooling mode, and the MAX cooling mode. First, an outline of refrigerant flow and control in each operation mode will be described.
(1) Heating mode
When the heating mode is selected by the controller 32 (auto mode) or by manual operation (manual mode) to the air conditioning operation unit 53, the controller 32 opens the electromagnetic valve 21 (for heating) and the electromagnetic valve 17 (for cooling). Close. Further, the electromagnetic valve 30 (for reheating) is opened, and the electromagnetic valve 40 (for bypass) is closed.
Then, the compressor 2 and each of the

blowers

15 and 27 are operated, and the air mix damper 28 is blown out from the indoor blower 27 and passes through the heat absorber 9 as shown by a broken line in FIG. It is assumed that air is passed through the auxiliary heater 23 and the radiator 4. As a result, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4 from the refrigerant pipe 13G via the electromagnetic valve 30. Since the air in the airflow passage 3 is passed through the radiator 4, the air in the airflow passage 3 is converted into the high-temperature refrigerant in the radiator 4 (when the auxiliary heater 23 operates, the auxiliary heater 23 and the radiator 4. On the other hand, the refrigerant in the radiator 4 is cooled by being deprived of heat by the air, and is condensed and liquefied.
The refrigerant liquefied in the radiator 4 exits the radiator 4 and then reaches the outdoor expansion valve 6 through the refrigerant pipe 13E. The refrigerant flowing into the outdoor expansion valve 6 is decompressed there and then flows into the outdoor heat exchanger 7. The refrigerant flowing into the outdoor heat exchanger 7 evaporates, and pumps up heat from the outside air that is ventilated by traveling or by the outdoor blower 15. That is, the outdoor heat exchanger 7 becomes a heat exchanger for heat absorption. Then, the low-temperature refrigerant exiting the outdoor heat exchanger 7 enters the accumulator 12 from the refrigerant pipe 13C via the refrigerant pipe 13A, the electromagnetic valve 21 and the refrigerant pipe 13D.
In this case, the gas refrigerant evaporated in the outdoor heat exchanger 7 and the non-evaporated liquid refrigerant pass through the refrigerant pipe 13A, the electromagnetic valve 21, and the refrigerant pipe 13D as described above from the refrigerant pipe 13C with arrows in FIG. It enters into the tank 57 of the accumulator 12 as shown. The refrigerant in the gas-liquid mixed state flowing into the tank 57 first collides with the baffle plate 58 and spreads outward, and flows down between the outer edge of the baffle plate 58 and the tank 57 as shown by the arrows and into the lower part of the tank 57. To do.
The liquid refrigerant is stored in the lower part of the tank 57, and the gas refrigerant and the gas refrigerant in which the liquid refrigerant has evaporated in the accumulator 12 pass through the gap between the tip of the outlet pipe 61 and the baffle plate 58 as shown by the arrows. After entering the outlet pipe 61 from the opening at the tip and flowing down, it rises again and exits from the accumulator 12. The tank 57 also stores oil (for lubricating the compressor 2) circulating in the refrigerant circuit R together with the refrigerant. The oil and a part of the liquid refrigerant enter the outlet pipe 61 from the oil return hole 62 formed at the lowermost part of the outlet pipe 61 and rise and exit from the accumulator 12.
The refrigerant and oil thus separated into gas and liquid are sucked into the compressor 2 through the outlet pipe 61 of the accumulator 12, and this circulation is repeated thereafter. Since the air heated by the radiator 4 (heat dissipation heat exchanger) or the auxiliary heater 23 is blown out from the outlet 29, the vehicle interior is thereby heated.
(2) Dehumidification heating mode
Next, in the dehumidifying and heating mode, the controller 32 opens the electromagnetic valve 17 and closes the electromagnetic valve 21. Further, the electromagnetic valve 30 is closed, the electromagnetic valve 40 is opened, and the valve opening degree of the outdoor expansion valve 6 is fully closed. Then, the compressor 2 and each of the

blowers

15 and 27 are operated, and the air mix damper 28 is blown out from the indoor blower 27 and passes through the heat absorber 9 as shown by a broken line in FIG. It is assumed that air is passed through the auxiliary heater 23 and the radiator 4.
Accordingly, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 to the refrigerant pipe 13G flows into the bypass pipe 35 without going to the radiator 4, passes through the electromagnetic valve 40, and is connected to the refrigerant pipe on the downstream side of the outdoor expansion valve 6. 13E. At this time, since the outdoor expansion valve 6 is fully closed, the refrigerant flows into the outdoor heat exchanger 7. The refrigerant flowing into the outdoor heat exchanger 7 is cooled and condensed by running there or by the outside air ventilated by the outdoor blower 15. The refrigerant that has exited the outdoor heat exchanger 7 sequentially flows from the refrigerant pipe 13 A through the electromagnetic valve 17 into the receiver dryer unit 14 and the supercooling unit 16. Here, the refrigerant is supercooled.
The refrigerant that has exited the supercooling section 16 of the outdoor heat exchanger 7 enters the refrigerant pipe 13 B, reaches the indoor expansion valve 8 through the internal heat exchanger 19. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. The air blown out from the indoor blower 27 by the heat absorption action at this time is cooled, and moisture in the air condenses and adheres to the heat absorber 9, so that the air in the air flow passage 3 is cooled, and Dehumidified. The refrigerant evaporated in the heat absorber 9 passes through the internal heat exchanger 19 and reaches the accumulator 12 through the refrigerant pipe 13C, and repeats circulation that is separated into gas and liquid and sucked into the compressor 2 as described above.
At this time, since the valve opening degree of the outdoor expansion valve 6 is fully closed, it is possible to suppress or prevent inconvenience that the refrigerant discharged from the compressor 2 flows backward from the outdoor expansion valve 6 into the radiator 4. It becomes. Thereby, the fall of a refrigerant | coolant circulation amount can be suppressed or eliminated and air-conditioning capability can be ensured now. Further, in this dehumidifying and heating mode, the controller 32 energizes the auxiliary heater 23 to generate heat. As a result, the air cooled and dehumidified by the heat absorber 9 is further heated in the process of passing through the auxiliary heater 23 and the temperature rises, so that the dehumidifying heating in the passenger compartment is performed.
(3) Dehumidifying and cooling mode
Next, in the dehumidifying and cooling mode, the controller 32 opens the electromagnetic valve 17 and closes the electromagnetic valve 21. Further, the electromagnetic valve 30 is opened and the electromagnetic valve 40 is closed. Then, the compressor 2 and each of the

blowers

15 and 27 are operated, and the air mix damper 28 is blown out from the indoor blower 27 and passes through the heat absorber 9 as shown by a broken line in FIG. It is assumed that air is passed through the auxiliary heater 23 and the radiator 4. As a result, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4 from the refrigerant pipe 13G via the electromagnetic valve 30. Since the air in the air flow passage 3 is passed through the radiator 4, the air in the air flow passage 3 is heated by the high-temperature refrigerant in the radiator 4, while the refrigerant in the radiator 4 heats the air. It is deprived and cooled, and condensates.
The refrigerant that has exited the radiator 4 reaches the outdoor expansion valve 6 through the refrigerant pipe 13E, and flows into the outdoor heat exchanger 7 through the outdoor expansion valve 6 that is controlled to open. The refrigerant flowing into the outdoor heat exchanger 7 is cooled and condensed by running there or by the outside air ventilated by the outdoor blower 15. The refrigerant that has exited the outdoor heat exchanger 7 sequentially flows from the refrigerant pipe 13 A through the electromagnetic valve 17 into the receiver dryer unit 14 and the supercooling unit 16. Here, the refrigerant is supercooled.
The refrigerant that has exited the supercooling section 16 of the outdoor heat exchanger 7 enters the refrigerant pipe 13 B, reaches the indoor expansion valve 8 through the internal heat exchanger 19. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. Since the moisture in the air blown out from the indoor blower 27 by the heat absorption action at this time condenses and adheres to the heat absorber 9, the air is cooled and dehumidified.
The refrigerant evaporated in the heat absorber 9 passes through the internal heat exchanger 19 and reaches the accumulator 12 through the refrigerant pipe 13C, and repeats circulation that is separated into gas and liquid and sucked into the compressor 2 as described above. In this dehumidifying and cooling mode, since the controller 32 does not energize the auxiliary heater 23, the air cooled by the heat absorber 9 is reheated (reheated in the process of passing through the radiator 4). ) As a result, dehumidifying and cooling in the passenger compartment is performed.
(4) Cooling mode
Next, in the cooling mode, the controller 32 fully opens the valve opening degree of the outdoor expansion valve 6 in the dehumidifying and cooling mode. The controller 32 controls the air mix damper 28, and the air in the air flow passage 3 after being blown out from the indoor blower 27 and passing through the heat absorber 9 as shown by a solid line in FIG. The rate of ventilation through the vessel 4 is adjusted. Further, the controller 32 does not energize the auxiliary heater 23.
As a result, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 flows into the radiator 4 from the refrigerant pipe 13G via the electromagnetic valve 30, and the refrigerant exiting the radiator 4 passes through the refrigerant pipe 13E and the outdoor expansion valve 6. To. At this time, since the outdoor expansion valve 6 is fully opened, the refrigerant passes through it and flows into the outdoor heat exchanger 7 as it is, where it is cooled by air or by outside air that is ventilated by the outdoor blower 15 and condensed. Liquefaction. That is, the outdoor heat exchanger 7 serves as a heat exchanger for heat dissipation. The refrigerant that has exited the outdoor heat exchanger 7 sequentially flows from the refrigerant pipe 13 A through the electromagnetic valve 17 into the receiver dryer unit 14 and the supercooling unit 16. Here, the refrigerant is supercooled.
The refrigerant that has exited the supercooling section 16 of the outdoor heat exchanger 7 enters the refrigerant pipe 13 B, reaches the indoor expansion valve 8 through the internal heat exchanger 19. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. The air blown out from the indoor blower 27 by the heat absorption action at this time is cooled. Further, moisture in the air condenses and adheres to the heat absorber 9.
The refrigerant evaporated in the heat absorber 9 passes through the internal heat exchanger 19 and reaches the accumulator 12 via the refrigerant pipe 13C, and after being gas-liquid separated as described above, the circulation sucked into the compressor 2 is repeated. Air that has been cooled and dehumidified by the heat absorber 9 (heat exchanger for heat absorption) is blown out from the air outlet 29 into the vehicle interior (partly passes through the radiator 4 to exchange heat), so that the vehicle Indoor cooling will be performed.
(5) MAX cooling mode
Next, in the MAX cooling mode, the controller 32 opens the electromagnetic valve 17 and closes the electromagnetic valve 21. Further, the electromagnetic valve 30 is closed, the electromagnetic valve 40 is opened, and the valve opening degree of the outdoor expansion valve 6 is fully closed. Then, the compressor 2 and the

blowers

15 and 27 are operated, and the air mix damper 28 is in a state in which the air in the air flow passage 3 is not passed through the auxiliary heater 23 and the radiator 4. However, there is no problem even if it is ventilated somewhat. Further, the controller 32 does not energize the auxiliary heater 23.
Accordingly, the high-temperature and high-pressure gas refrigerant discharged from the compressor 2 to the refrigerant pipe 13G flows into the bypass pipe 35 without going to the radiator 4, passes through the electromagnetic valve 40, and is connected to the refrigerant pipe on the downstream side of the outdoor expansion valve 6. 13E. At this time, since the outdoor expansion valve 6 is fully closed, the refrigerant flows into the outdoor heat exchanger 7. The refrigerant flowing into the outdoor heat exchanger 7 is cooled and condensed by running there or by the outside air ventilated by the outdoor blower 15. The refrigerant that has exited the outdoor heat exchanger 7 sequentially flows from the refrigerant pipe 13 A through the electromagnetic valve 17 into the receiver dryer unit 14 and the supercooling unit 16. Here, the refrigerant is supercooled.
The refrigerant that has exited the supercooling section 16 of the outdoor heat exchanger 7 enters the refrigerant pipe 13 B, reaches the indoor expansion valve 8 through the internal heat exchanger 19. After the refrigerant is depressurized by the indoor expansion valve 8, it flows into the heat absorber 9 and evaporates. The air blown out from the indoor blower 27 by the heat absorption action at this time is cooled. In addition, since moisture in the air condenses and adheres to the heat absorber 9, the air in the air flow passage 3 is dehumidified. The refrigerant evaporated in the heat absorber 9 reaches the accumulator 12 through the refrigerant pipe 13C through the internal heat exchanger 19, and repeats circulation that is sucked into the compressor 2 there through. At this time, since the outdoor expansion valve 6 is fully closed, similarly, it is possible to suppress or prevent the disadvantage that the refrigerant discharged from the compressor 2 flows backward from the outdoor expansion valve 6 into the radiator 4. . Thereby, the fall of a refrigerant | coolant circulation amount can be suppressed or eliminated and air-conditioning capability can be ensured now.
Here, since the high-temperature refrigerant flows through the radiator 4 in the cooling mode described above, direct heat conduction from the radiator 4 to the HVAC unit 10 occurs not a little, but in this MAX cooling mode, the refrigerant flows into the radiator 4. Therefore, the air in the air flow passage 3 from the heat absorber 9 is not heated by the heat transmitted from the radiator 4 to the HVAC unit 10. Therefore, powerful cooling of the passenger compartment is performed, and particularly in an environment where the outside air temperature Tam is high, the passenger compartment can be quickly cooled to realize comfortable air conditioning in the passenger compartment.
(6) Switching each operation mode
The air flowing through the air flow passage 3 is subjected to cooling from the heat absorber 9 and heating action from the heat radiator 4 (and the auxiliary heater 23) (adjusted by the air mix damper 28) in each of the above operation modes. Is blown out into the passenger compartment. The controller 32 is set by the air-conditioning operation unit 53, the outside air temperature Tam detected by the outside air temperature sensor 33, the temperature in the vehicle interior detected by the inside air temperature sensor 37, the blower voltage, the amount of solar radiation detected by the solar radiation sensor 51, and the like. The target blowout temperature TAO is calculated based on the target passenger compartment temperature (set temperature) in the passenger compartment, and the temperature of the air blown from the blowout port 29 is controlled to this target blowout temperature TAO by switching each operation mode.
In this case, the controller 32 determines whether the outside air temperature Tam, the humidity in the vehicle interior, the target outlet temperature TAO, the radiator temperature TH, the target radiator temperature TCO, the heat absorber temperature Te, the target heat absorber temperature TEO, or the dehumidification request in the vehicle interior. By switching each operation mode based on parameters such as, etc., it switches between heating mode, dehumidifying heating mode, dehumidifying cooling mode, cooling mode and MAX cooling mode accurately according to the environmental conditions and necessity of dehumidification. In addition, efficient cabin air conditioning is realized.
(7) Vacuum drawing and refrigerant filling using service valve 64
Next, the refrigerant evacuation and refrigerant filling operation from the refrigerant circuit R using the service valve 64 described above will be described. Since the vehicle air conditioner 1 as in the embodiment is exposed to relatively large vibrations during traveling, refrigerant leakage from the refrigerant circuit R occurs. In that case, refrigerant filling is performed using the service valve 64.
In this case, first, the outdoor expansion valve 6 and the indoor expansion valve 8 are fully opened, and the

electromagnetic valves

17, 21, 30, and 40 are opened. Next, an evacuation device (not shown) is connected to the service valve 64 to evacuate the refrigerant from the refrigerant circuit R. At this time, the service valve 64 is attached to the refrigerant pipe 13 C serving as the inlet pipe of the accumulator 12, and the refrigerant pipe 13 C opens at the upper part in the tank 57 of the accumulator 12. The gasified liquid refrigerant is sucked, and the oil stored in the bottom of the tank 57 is not sucked out or the amount sucked out is minimized.
After the refrigerant in the refrigerant circuit R is evacuated in this manner, a refrigerant filling device (not shown) is connected to the service valve 64 and a predetermined amount of refrigerant is filled in the refrigerant circuit R.
As described above, according to the present invention, the accumulator 12 connected to the refrigerant suction side of the compressor 2 that compresses the refrigerant is provided, and the service valve 64 is provided in the refrigerant pipe 13C that is the inlet pipe of the accumulator 12, A tank 57 having a predetermined capacity is provided inside, and an outlet pipe 61 opened at the upper part of the tank 57. The refrigerant pipe 13C is connected to the upper part of the tank 57 and opens into the tank 57. Even when the accumulator 12 having the oil return hole 62 opened at the bottom in the tank 57 is used, the inconvenience that the oil in the accumulator 12 is sucked out when the service valve 64 is used for evacuation. It can be avoided.
Thereby, the problem that the oil in the circuit is exhausted due to the recovery of the refrigerant from the refrigerant circuit R can be solved. This is particularly effective in the vehicle air conditioner 1 that performs heating or cooling of the vehicle interior as in the embodiment.
In the embodiment, the present invention is applied to the heat pump cycle HP of the vehicle air conditioner 1 that air-conditions the interior of the vehicle. However, the present invention is not limited to this, and the compressor 2 that compresses the refrigerant, the heat exchanger for heat dissipation (the radiator 4, The present invention is effective for various heat pump cycles including a refrigerant circuit R having an outdoor heat exchanger 7), a pressure reducing device (expansion valves 6, 8), and a heat absorbing heat exchanger (heat absorbing device 9, outdoor heat exchanger 7). It is.
Furthermore, the present invention is also effective for a refrigeration facility having a refrigeration cycle including at least a compressor, a radiator, a decompressor, a heat exchanger for heat absorption, and an accumulator, a refrigeration facility, and the like.
In the above-described embodiment, the operation mode of the vehicle air conditioner 1 has been described as an example of switching each operation mode of the heating mode, the dehumidifying heating mode, the dehumidifying cooling mode, the cooling mode, and the MAX cooling mode. The present invention is also effective for a vehicle air conditioner that executes only the heating mode or only the cooling mode. Furthermore, the configuration of the refrigerant circuit R described in the embodiments is not limited thereto, and can be changed without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Vehicle air conditioner 2 Compressor 3 Air flow path 4 Radiator (Heat dissipation heat exchanger)
6 Outdoor expansion valve (pressure reduction device)
7 Outdoor heat exchanger (heat exchanger for heat dissipation, heat exchanger for heat absorption)
8 Indoor expansion valve (pressure reduction device)
9 Heat absorber (heat exchanger for heat absorption)
12 Accumulator 13C Refrigerant piping (inlet piping)
17, 21, 30, 40 Solenoid valve 32 Controller (control device)
57 Tank 61 Outlet piping 62 Oil return hole 64 Service valve HP Heat pump cycle (refrigeration cycle)
R refrigerant circuit

Claims

In a heat pump cycle including a compressor that compresses a refrigerant, a heat exchanger for heat dissipation that dissipates the refrigerant, a decompression device, and a refrigerant circuit that includes a heat exchanger for heat absorption that absorbs heat from the refrigerant,
An accumulator connected to the refrigerant suction side of the compressor;
A heat pump cycle, wherein a service valve is provided in an inlet pipe of the accumulator.
The accumulator includes a tank having a predetermined capacity inside, and an outlet pipe that opens at an upper portion in the tank,
The said inlet piping is connected to the upper part of the said tank, and while it opens in the said tank, the said outlet piping has an oil return hole opened in the bottom part in the said tank. Heat pump cycle.
An air flow passage through which air to be supplied into the passenger compartment flows is provided.
The heat dissipating heat exchanger is provided in the air flow passage, the heat absorbing heat exchanger is provided outside the passenger compartment,
The refrigerant discharged from the compressor is radiated by the heat radiating heat exchanger, the radiated refrigerant is depressurized by the pressure reducing device, and then is absorbed by the heat absorbing heat exchanger, thereby heating the vehicle interior. The vehicle air conditioner provided with the heat pump cycle according to claim 1 or 2.
An air flow passage through which air to be supplied into the passenger compartment flows is provided.
The heat-absorbing heat exchanger is provided in the air flow passage, and the heat-dissipating heat exchanger is provided outside the passenger compartment,
The refrigerant discharged from the compressor is radiated by the heat radiating heat exchanger, the radiated refrigerant is depressurized by the decompression device, and is then absorbed by the heat absorbing heat exchanger, thereby cooling the vehicle interior. The vehicle air conditioner provided with the heat pump cycle according to claim 1 or 2.
At least in a refrigeration cycle including a compressor, a radiator, a decompressor, a heat exchanger for heat absorption, and an accumulator,
An accumulator connected to the refrigerant suction side of the compressor;
A refrigeration cycle, wherein a service valve is provided in an inlet pipe of the accumulator.