CN113939698A - Refrigeration cycle device - Google Patents

Abstract

The refrigeration cycle device (10) is provided with a compressor (11), a radiator (12) which heats supply air using a refrigerant discharged from the compressor as a heat source when heating the interior of a room, and a pressure reduction unit (13) which reduces the pressure of the refrigerant passing through the radiator. The refrigeration cycle device is provided with an evaporator (14) which functions as a cooler for cooling the heat generating equipment when the equipment is cooled and functions as a heat absorber when the room is heated, and an opening degree control unit (80a) which controls the throttle opening degree of the decompression unit. The radiator has a condensing unit (121) for condensing the refrigerant and a liquid storage unit (122) for storing the liquid refrigerant remaining in the cycle by gas-liquid separation of the refrigerant having passed through the condensing unit. The opening degree control unit controls the throttle opening degree of the decompression unit so as to maintain the refrigerant state on the refrigerant outlet side of the evaporator in a saturated state or a wet state during indoor heating. The lower limit of the throttle opening of the adjustment region for heating the room is smaller than the adjustment region of the throttle opening of the decompression section for cooling the device.

Description

Refrigeration cycle device

Cross reference to related applications

The present application is based on japanese patent application No. 2019-107327 filed on 7.6.2019, the contents of which are incorporated herein by reference.

Technical Field

The present invention relates to a refrigeration cycle apparatus capable of performing indoor heating for heating supply air to be blown into an air-conditioned space and equipment cooling for cooling heat-generating equipment.

Background

Conventionally, a vapor compression refrigeration cycle device is known that heats air blown into a vehicle interior by exchanging heat between a refrigerant discharged from a compressor and the air blown into the vehicle interior (see, for example, patent document 1). In general, such a refrigeration cycle apparatus mixes oil for lubricating a compressor with a refrigerant to circulate the refrigerant containing the oil in a cycle.

Documents of the prior art

Patent document

Patent document 1: japanese patent application laid-open No. 2010-42698

However, the refrigeration cycle device of patent document 1 has a cycle structure in which an excess refrigerant in the cycle is stored in an accumulator disposed on the refrigerant suction side of the compressor (so-called accumulator cycle). This cycle structure can supply the gas refrigerant to the compressor while returning the oil to the compressor, but cannot grasp the state of the refrigerant on the refrigerant outlet side of the evaporator, and it is difficult to bring the refrigerant state on the refrigerant outlet side of the evaporator into an overheated state. This results in a decrease in the cooling capacity of the evaporator, and is therefore not preferable.

In contrast, a cycle configuration (so-called receiver cycle) may be considered in which a receiver for storing excess refrigerant in the cycle is provided on the refrigerant outlet side of the radiator. In this cycle structure, the refrigerant state on the refrigerant outlet side of the evaporator can be brought into a superheated state. On the other hand, in the receiver cycle, when the blowing air blown into the room is heated by the refrigerant discharged from the compressor, the refrigerant evaporation pressure in the evaporator is lowered. This reduces the flow rate of the refrigerant passing through the evaporator, and increases the viscosity of the oil flowing into the evaporator, so that the oil is likely to accumulate in the evaporator.

Disclosure of Invention

An object of the present invention is to provide a refrigeration cycle apparatus capable of returning oil to a refrigerant suction side of a compressor without disposing an accumulator on the refrigerant suction side of the compressor when heating indoor.

In accordance with one aspect of the present invention,

a kind of refrigeration cycle device is disclosed,

the disclosed device cooling device is capable of performing indoor heating for heating supply air to be blown into a space to be air-conditioned, and cooling heat-generating devices, and is provided with:

a compressor compressing and discharging a refrigerant containing oil;

a radiator that heats, in indoor heating, the air blown into the air-conditioned space using, as a heat source, a refrigerant discharged from the compressor;

a decompression unit that decompresses the refrigerant that has passed through the radiator;

an evaporator that functions as a cooler for cooling the heat generating equipment by using latent heat of evaporation of the refrigerant decompressed by the decompression unit when the equipment is cooled, and functions as a heat absorber when the indoor heat is generated; and

an opening degree control unit for controlling the throttle opening degree of the decompression unit,

the radiator has a condensing part for condensing the refrigerant and a receiver part for gas-liquid separating the refrigerant passing through the condensing part and storing the remaining liquid refrigerant in the cycle,

the opening degree control unit controls the throttle opening degree of the decompression unit to maintain the refrigerant state at the refrigerant outlet side of the evaporator in a saturated state or a wet state during indoor heating,

the lower limit of the throttle opening adjustment region of the pressure reducing section in the indoor heating is smaller than the throttle opening adjustment region of the pressure reducing section in the equipment cooling.

In this way, the refrigerant at the refrigerant outlet side of the evaporator can be brought into an overheated state due to the cycle configuration in which the radiator is provided with the receiver for storing the surplus refrigerant in the cycle.

In addition, during indoor heating, the throttle opening of the decompression section is controlled so as to maintain the refrigerant state on the refrigerant outlet side of the evaporator in a saturated state or a wet state. The lower limit of the throttle opening adjustment region of the pressure reducing section in the indoor heating is smaller than the throttle opening adjustment region of the pressure reducing section in the equipment cooling. Therefore, during indoor heating, the refrigerant in a gas-liquid two-phase state is sucked into the compressor, and therefore, the oil in the cycle is easily returned to the compressor together with the refrigerant.

As described above, according to the refrigeration cycle apparatus of the present aspect, it is possible to return oil to the refrigerant suction side of the compressor without disposing an accumulator on the refrigerant suction side of the compressor when heating the room.

Here, the "saturated state" refers to an equilibrium state in which a liquid refrigerant and a gas refrigerant are stably coordinated. In other words, the "saturated state" is a state in which the refrigerant state exists on the saturated vapor line on the mollier diagram. The term "wet state" refers to a state in which the refrigerant is in a wet vapor state. In other words, the "wet state" is a state in which the dryness of the refrigerant exceeds 0% and is 100% or less. Further, the "superheated state" refers to a state in which the refrigerant is dry vapor. In other words, the "superheated state" is a state in which the refrigerant has a degree of superheat.

In accordance with another aspect of the present invention,

a kind of refrigeration cycle device is disclosed,

indoor heating for heating the air blown into the air-conditioned space, equipment cooling for cooling the heat generating equipment, and indoor cooling for cooling the air blown into the air-conditioned space can be performed, and the air-conditioning apparatus is provided with:

a compressor compressing and discharging a refrigerant containing oil;

a radiator that heats, in indoor heating, the air blown into the air-conditioned space using, as a heat source, a refrigerant discharged from the compressor;

a first decompression unit configured to decompress the refrigerant having passed through the radiator;

a second decompression section arranged in parallel with the first decompression section on the downstream side of the radiator in the refrigerant flow;

a device cooler that functions as a cooler for cooling the heat generating device by using latent heat of evaporation of the refrigerant decompressed by the first decompression unit when the device is cooled, and functions as a heat absorber when the device is heated indoors;

a cooler for an air conditioner; the air conditioning cooler cools the air by using latent heat of evaporation of the refrigerant decompressed by the second decompression unit; and

an opening degree control section that controls throttle opening degrees of the first pressure reducing section and the second pressure reducing section,

the radiator has a condensing part for condensing the refrigerant and a receiver part for gas-liquid separating the refrigerant passing through the condensing part and storing the remaining liquid refrigerant in the cycle,

the opening degree control unit controls the throttle opening degree of the first decompression unit so as to maintain the refrigerant state at the refrigerant outlet side of the equipment cooler in a saturated state or a wet state during indoor heating,

the lower limit of the throttle opening degree of the adjustment region of the throttle opening degree of the first pressure reducing portion in the indoor heating is smaller than the adjustment region of the throttle opening degree of the first pressure reducing portion in the equipment cooling.

In this way, the cycle configuration is provided in which the radiator is provided with the reservoir portion for storing the surplus refrigerant in the cycle, and therefore, the refrigerant state on the refrigerant outlet side of the equipment cooler and the air conditioning cooler can be brought into an overheated state.

In addition, during indoor heating, the throttle opening degree of the first decompression section is controlled so as to maintain the refrigerant state on the refrigerant outlet side of the equipment cooler in a saturated state or a wet state. The lower limit of the throttle opening of the adjustment range of the throttle opening of the first pressure reducing unit during indoor heating is smaller than the adjustment range of the throttle opening of the first pressure reducing unit during equipment cooling. Therefore, during indoor heating, the refrigerant in a gas-liquid two-phase state is sucked into the compressor, and therefore, the oil in the cycle is easily returned to the compressor together with the refrigerant.

As described above, according to the refrigeration cycle apparatus of the present aspect, it is possible to return oil to the refrigerant suction side of the compressor without disposing an accumulator on the refrigerant suction side of the compressor when heating the room.

The parenthesized reference numerals for each component and the like indicate an example of the correspondence between the component and the like and the specific component and the like described in the embodiment described later.

Drawings

Fig. 1 is a schematic configuration diagram of an air conditioner including a refrigeration cycle apparatus according to a first embodiment.

Fig. 2 is a schematic view showing a first expansion valve used in the refrigeration cycle apparatus.

Fig. 3 is a schematic diagram showing a valve body of the first expansion valve.

Fig. 4 is a schematic view showing the valve element in the direction indicated by the arrow IV of fig. 2.

Fig. 5 is an explanatory diagram for explaining a relationship between the throttle opening degree and the opening area in the first expansion valve.

Fig. 6 is a schematic block diagram of a control device of the refrigeration cycle device.

Fig. 7 is an explanatory diagram for explaining a control method of the decompression units for each operation mode in the refrigeration cycle apparatus according to the first embodiment.

Fig. 8 is a mollier diagram for explaining the state of the refrigerant when the apparatus is cooled and when the room is heated.

Fig. 9 is an explanatory diagram for explaining the high-low pressure difference of the refrigerant in the cycle at the time of cooling the device and at the time of heating the room.

Fig. 10 is an explanatory diagram for explaining a control method of the decompression units for each operation mode in the refrigeration cycle apparatus according to the second embodiment.

Fig. 11 is a schematic configuration diagram of a device cooling system including the refrigeration cycle apparatus according to the third embodiment.

Fig. 12 is an explanatory diagram for explaining a control method of the decompression units for each operation mode in the refrigeration cycle apparatus according to the third embodiment.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent portions as those described in the preceding embodiments are denoted by the same reference numerals and the description thereof may be omitted. In the embodiment, when only a part of the components is described, the components described in the previous embodiment can be applied to other parts of the components. The following embodiments may be partially combined with each other unless otherwise explicitly indicated, as long as the embodiments do not cause any particular combination failure.

(first embodiment)

The present embodiment will be described below with reference to fig. 1 to 9. In the present embodiment, an example will be described in which the refrigeration cycle apparatus 10 of the present invention is applied to an air conditioner 1 that adjusts the vehicle interior space to an appropriate temperature. In the present embodiment, the vehicle interior space is an air conditioning target space.

Although not shown, the refrigeration cycle apparatus 10 shown in fig. 1 is mounted on a hybrid vehicle that obtains a driving force for vehicle running from an engine and a motor for vehicle running. This hybrid vehicle is configured as a plug-in hybrid vehicle capable of charging a battery BT mounted on the vehicle with electric power supplied from an external power supply when the vehicle is stopped. The driving force output from the engine is used not only for running of the vehicle but also for generating electric power by the motor generator. The electric power generated by the motor generator and the electric power supplied from the external power supply are stored in the battery BT. The electric power stored in the battery BT is supplied not only to the electric motor for running but also to various in-vehicle devices including the constituent devices of the refrigeration cycle apparatus 10.

The refrigeration cycle apparatus 10 can perform indoor heating for heating the air blown into the vehicle interior, indoor cooling for cooling the air blown into the vehicle interior, and equipment cooling for cooling the battery BT.

The refrigeration cycle apparatus 10 is constituted by a vapor compression refrigeration cycle. The refrigeration cycle device 10 has a refrigerant circuit 100 through which a refrigerant circulates. The refrigeration cycle apparatus 10 includes a compressor 11, a radiator 12, a first decompression section 13, an equipment cooler 14, a second decompression section 15, an air-conditioning cooler 16, and an evaporation pressure adjustment valve 17 in a refrigerant circuit 100.

A freon refrigerant (for example, HFO134a) is contained as a refrigerant in the refrigerant circuit 100. The refrigerant circuit 100 is a subcritical cycle in which the pressure on the high pressure side of the cycle does not exceed the critical pressure of the refrigerant. As the refrigerant, a refrigerant other than HFO134a may be used.

Oil (i.e., refrigerator oil) for lubricating the compressor 11 is mixed into the refrigerant. As the oil, for example, polyalkylene glycol oil (i.e., PAG oil) having compatibility with the liquid refrigerant is used. A portion of the oil circulates in the cycle with the refrigerant.

The refrigerant circuit 100 includes a first refrigerant flow path 100a, a second refrigerant flow path 100b, and a third refrigerant flow path 100c as flow paths through which the refrigerant flows. In the refrigerant circuit 100, the second refrigerant flow path 100b and the third refrigerant flow path 100c are connected to the first refrigerant flow path 100a so that the refrigerants flow in parallel with each other.

In the first refrigerant flow path 100a, the compressor 11 and the radiator 12 are arranged in series. Specifically, in the first refrigerant flow path 100a, the radiator 12 is disposed downstream of the compressor 11.

In the second refrigerant flow path 100b, the first decompression section 13 and the equipment cooler 14 are arranged in series. Specifically, the equipment cooler 14 is disposed downstream of the first decompression section 13 in the second refrigerant flow path 100 b.

In the third refrigerant flow path 100c, the second decompression section 15 and the air conditioning cooler 16 are arranged in series. Specifically, the air conditioning cooler 16 is disposed downstream of the second decompression section 15 in the third refrigerant flow path 100 c.

The compressor 11 is a device that compresses and discharges refrigerant. The compressor 11 is constituted by an electric compressor that rotates a compression mechanism that compresses a refrigerant by a motor. The compressor 11 controls the rotation speed of the motor based on a control signal output from a control device 80 described later.

A radiator 12 is connected to the refrigerant discharge side of the compressor 11. The radiator 12 radiates heat from the refrigerant discharged from the compressor 11. The radiator 12 is a heat exchanger that radiates heat from a high-temperature and high-pressure refrigerant (hereinafter, also referred to as a high-pressure refrigerant) discharged from the compressor 11 to a high-temperature heat medium circulating in the high-temperature heat medium circuit 30.

The radiator 12 includes a condensing unit 121, a liquid storage unit 122, and a supercooling unit 123. The condenser 121 condenses the high-pressure refrigerant by radiating heat to the high-temperature heat medium. The receiver 122 separates the refrigerant having passed through the condenser 121 into a gas and a liquid, and stores the separated liquid refrigerant as an excess refrigerant in the cycle. The subcooling unit 123 subcools the liquid refrigerant stored in the reservoir 122 by radiating heat to the high-temperature heat medium before flowing into the condensing unit 121.

The radiator 12 heats the air blown into the vehicle interior using the refrigerant discharged from the compressor 11 as a heat source. Specifically, the radiator 12 can heat the air blown into the vehicle interior by radiating the high-pressure refrigerant to the air through the high-temperature heat medium circuit 30.

Here, the high-temperature heat medium circuit 30 is a circuit for circulating a high-temperature heat medium. As the high-temperature heat medium, for example, a solution containing ethylene glycol, an antifreeze, or the like is used. In the present embodiment, the high-temperature heat medium constitutes the first heat medium. In the high-temperature heat medium circuit 30, a radiator 12, a high-temperature-side pump 31, a heater core 32, a high-temperature-side radiator 33, a high-temperature-side flow rate adjustment valve 34, and the like are disposed.

The high-temperature-side pump 31 is a pump for feeding the high-temperature heat medium to the radiator 12 under pressure in the high-temperature heat medium circuit 30. The high-temperature-side pump 31 is an electric pump whose rotation speed is controlled in accordance with a control signal output from the control device 80.

The heater core 32 is disposed in a casing 61 of an indoor air conditioning unit 60 described later. The heater core 32 is a heat exchanger that heats the air-sending air by exchanging heat between the high-temperature heat medium heated by the radiator 12 and the air-sending air passing through the air-conditioning cooler 16, which will be described later.

The high-temperature-side radiator 33 is a heat exchanger that radiates the high-temperature heat medium heated by the radiator 12 to the outside air. The high-temperature side radiator 33 is disposed on the front side of the vehicle that contacts the traveling wind when the vehicle travels. In the high-temperature heat medium circuit 30, the high-temperature-side radiator 33 and the heater core 32 are connected in parallel with respect to the flow of the high-temperature heat medium.

The high-temperature-side flow rate adjustment valve 34 is a flow rate adjustment valve that adjusts the flow rate ratio of the flow rate of the high-temperature heat medium flowing into the heater core 32 and the flow rate of the high-temperature heat medium flowing into the high-temperature-side radiator 33, among the high-temperature heat medium heated by the radiator 12. The high temperature side flow rate adjustment valve 34 is a three-way valve type flow rate adjustment valve. The high-temperature-side flow rate adjustment valve 34 is disposed at a connection portion between the inlet side of the heater core 32 and the inlet side of the high-temperature-side radiator 33 in the high-temperature heat medium circuit 30.

In the high-temperature heat medium circuit 30 configured as described above, the high-pressure refrigerant usage mode can be changed by adjusting the flow rate ratio by the high-temperature-side flow rate adjustment valve 34. The high-temperature heat medium circuit 30 can use the heat of the high-temperature heat medium for heating the air to heat the vehicle interior by increasing the flow rate of the high-temperature heat medium flowing into the heater core 32 by the high-temperature-side flow rate adjustment valve 34, for example. On the other hand, the high-temperature heat medium circuit 30 can discharge the heat of the high-temperature heat medium to the outside air by increasing the flow rate of the high-temperature heat medium flowing into the high-temperature side radiator 33 by the high-temperature side flow rate adjustment valve 34, for example.

The refrigerant outlet side of the radiator 12 branches into the second refrigerant flow path 100b and the third refrigerant flow path 100 c. The first decompression section 13 and the equipment cooler 14 are disposed in the second refrigerant flow path 100 b. The second decompression section 15 and the air conditioning cooler 16 are disposed in the third refrigerant flow path 100 c.

The first decompression portion 13 includes a fully closed or fully opened first opening/closing valve 131 and a first expansion valve 132. The first on-off valve 131 is an electromagnetic valve that opens and closes the second refrigerant flow path 100 b. The first opening/closing valve 131 is controlled to open and close in accordance with a control signal from the control device 80 described later.

The first expansion valve 132 is an expansion valve that decompresses the refrigerant flowing through the second refrigerant flow path 100 b. The first expansion valve 132 is constituted by an electric expansion valve. The first expansion valve 132 controls the throttle opening degree in accordance with a control signal from a control device 80 described later. The first expansion valve 132 will be described in detail later.

The facility cooler 14 is an evaporator (i.e., a chiller) that evaporates the refrigerant decompressed by the first decompression section 13 by exchanging heat between the refrigerant and the low-temperature heat medium circulating in the low-temperature heat medium circuit 40. In the equipment cooler 14, the refrigerant absorbs heat from the low-temperature heat medium and evaporates, thereby cooling the low-temperature heat medium. The equipment cooler 14 is formed of a stacked heat exchanger in which a plurality of refrigerant flow paths through which a refrigerant flows and a plurality of heat medium flow paths through which a low-temperature heat medium flows are alternately stacked.

The facility cooler 14 of the present embodiment functions as a cooler for cooling the battery BT by using the latent heat of evaporation of the refrigerant decompressed by the first decompression section 13 when the facility is cooled, and functions as a heat absorber when the room is heated. Specifically, the facility cooler 14 cools the battery BT via the low-temperature heat medium circuit 40 when the facility is cooled, and absorbs heat from the outside air when the room is heated.

Here, the low-temperature heat medium circuit 40 is a circuit for circulating the low-temperature heat medium. As the low-temperature heat medium, for example, a solution containing ethylene glycol, an antifreeze, or the like is used. In the present embodiment, the low-temperature heat medium constitutes the second heat medium. In the low-temperature heat medium circuit 40, the equipment cooler 14, the low-temperature-side pump 41, the battery cooling unit 42, the low-temperature-side radiator 43, the first channel switching valve 44, the second channel switching valve 45, and the like are arranged.

The low-temperature-side pump 41 is a pump for feeding the low-temperature heat medium under pressure to the facility cooler 14 in the low-temperature heat medium circuit 40. The low temperature side pump 41 is an electric pump whose rotation speed is controlled in accordance with a control signal output from the control device 80.

The battery cooling unit 42 cools the battery BT by the low-temperature heat medium flowing through the low-temperature heat medium circuit 40. The battery BT is electrically connected to an inverter and a charger, not shown. The battery BT supplies electric power to the inverter and stores electric power supplied from the charger. The battery BT is constituted by, for example, a lithium ion battery.

The low-temperature-side radiator 43 is a heat exchanger that exchanges heat between the low-temperature heat medium cooled by the equipment cooler 14 and the outside air to absorb heat from the outside air. The low temperature side radiator 43 is disposed on the front side of the vehicle, which comes into contact with the traveling wind during traveling of the vehicle, together with the high temperature side radiator 33. The low-temperature side radiator 43 and the battery cooling unit 42 are connected in parallel to the flow of the low-temperature heat medium in the low-temperature heat medium circuit 40.

The first channel switching valve 44 switches between a state in which the low-temperature heat medium flows into the battery cooling portion 42 and a state in which the low-temperature heat medium does not flow into the battery cooling portion 42. The first channel switching valve 44 is constituted by an electromagnetic valve whose opening and closing operations are controlled in accordance with a control signal output from the control device 80.

The second channel switching valve 45 switches between a state in which the low-temperature thermal medium flows to the low-temperature-side radiator 43 and a state in which the low-temperature thermal medium does not flow to the low-temperature-side radiator 43. The second channel switching valve 45 is constituted by an electromagnetic valve whose opening and closing operations are controlled in accordance with a control signal output from the control device 80.

In the low-temperature heat medium circuit 40 configured as described above, the use mode of the low-pressure refrigerant can be changed by changing the flow path of the low-temperature heat medium by the first flow path switching valve 44 and the second flow path switching valve 45. The low-temperature heat medium circuit 40 can cool the battery BT by the low-temperature heat medium cooled by the facility cooler 14 by opening the first channel switching valve 44, for example. On the other hand, the low-temperature heat medium circuit 40 can absorb heat from the outside air by, for example, opening the second channel switching valve 45 and allowing the low-temperature heat medium to flow to the low-temperature side radiator 43.

The second decompression section 15 is arranged in parallel with the first decompression section 13 on the downstream side of the radiator 12 in the refrigerant flow. The second decompression portion 15 has a second opening/closing valve 151 and a second expansion valve 152 that are fully closed or fully opened. The second opening/closing valve 151 is an electromagnetic valve that opens and closes the third refrigerant flow path 100 c. The second opening/closing valve 151 is controlled to open and close in accordance with a control signal from the control device 80 described later.

The second expansion valve 152 is an expansion valve that decompresses the refrigerant flowing through the third refrigerant flow path 100 c. The second expansion valve 152 is constituted by an electric expansion valve having a valve element and an electric actuator. The valve body is configured to be capable of changing a throttle opening degree, which is an opening degree of the refrigerant flow path. The electric actuator includes a stepping motor that displaces a valve body to change the throttle opening degree of the second expansion valve 152. The second expansion valve 152 controls the throttle opening degree in accordance with a control signal from a control device 80 described later.

The air conditioning cooler 16 is disposed in a casing 61 of an indoor air conditioning unit 60 described later. The air conditioning cooler 16 is a heat exchanger that evaporates the refrigerant decompressed by the second decompression section 15 by exchanging heat between the refrigerant and the blown air blown into the vehicle interior. The air conditioning cooler 16 cools the feed air using the latent heat of evaporation of the refrigerant decompressed by the second decompression section 15. That is, the air conditioning cooler 16 cools the feed air by the low-pressure refrigerant absorbing heat from the feed air and evaporating the heat.

An evaporation pressure regulating valve 17 is disposed on the refrigerant outlet side of the air conditioning cooler 16. The evaporation pressure adjustment valve 17 is a pressure adjustment valve for maintaining the pressure of the refrigerant on the refrigerant outlet side of the air conditioning cooler 16 at a pressure higher than the pressure of the refrigerant on the refrigerant outlet side of the equipment cooler 14. Specifically, the evaporation pressure adjustment valve 17 is configured to maintain the temperature of the refrigerant on the refrigerant outlet side of the air conditioning cooler 16 at a temperature (for example, 1 ℃) or higher at which frost formation in the air conditioning cooler 16 can be suppressed.

In the refrigeration cycle device 10 configured as described above, the second refrigerant flow path 100b and the third refrigerant flow path 100c are connected to the first refrigerant flow path 100a on the downstream side of the evaporation pressure adjustment valve 17. The refrigeration cycle apparatus 10 has a cycle structure in which the equipment cooler 14 and the air conditioning cooler 16 are connected to the refrigerant suction side of the compressor 11 without passing through the liquid reservoir (i.e., no-reservoir cycle). Specifically, the refrigeration cycle apparatus 10 has a cycle structure in which the receiver cycle is not provided with the reservoir 122 on the high-pressure side and the reservoir 122 on the low-pressure side in the cycle.

Next, the indoor air conditioning unit 60 will be described with reference to fig. 1. The indoor air conditioning unit 60 shown in fig. 1 is a member for adjusting the temperature of the supply air blown into the vehicle interior to an appropriate temperature. The indoor air conditioning unit 60 is disposed inside the instrument panel at the forefront in the vehicle interior. The indoor air conditioning unit 60 houses the air conditioning cooler 16, the heater core 32, and the like inside a case 61 forming a housing.

The casing 61 is a passage forming portion that forms an air flow path of the blowing air to be blown into the vehicle interior. Although not shown, an inside and outside air box for adjusting the ratio of the inside air to the outside air introduced into the casing 61 is disposed on the upstream side of the casing 61 in the air flow.

A blower 62 for blowing air introduced from the inside and outside air boxes into the vehicle interior is disposed inside the casing 61. The blower 62 is constituted by an electric blower that rotates a centrifugal fan by a motor. The blower 62 controls the rotation speed based on a control signal output from a control device 80 described later.

The air conditioning cooler 16 is disposed inside the casing 61 on the downstream side of the air flow of the blower 62. The downstream side of the air flow of the air conditioning cooler 16 is divided into a warm air passage 63 and a cool air passage 64 inside the casing 61. The heater core 32 is disposed in the warm air flow path 63. The cool air flow path 64 is a flow path for allowing the air having passed through the air conditioning cooler 16 to flow while bypassing the heater core 32.

An air mix door 65 is disposed between the air conditioning cooler 16 and the heater core 32 inside the case 61. The air mix door 65 is a member that adjusts the air volume ratio between the air passing through the warm air flow path 63 and the air passing through the cool air flow path 64. An air mixing space 66 for mixing the warm air having passed through the warm air flow path 63 and the cool air having passed through the cool air flow path 64 is formed on the downstream side of the warm air flow path 63 and the cool air flow path 64 inside the casing 61. Although not shown, a plurality of openings for blowing the feed air adjusted to a desired temperature in the air mixing space 66 into the vehicle interior are formed in the most downstream portion of the air flow inside the casing 61.

Next, the first expansion valve 132 of the present embodiment will be described. As shown in fig. 2, the first expansion valve 132 includes a main body 133, a shaft 134, a valve body 135, and a stepping motor 136.

The main body 13 is formed of a substantially hollow metal block. The body 133 is formed with a refrigerant inflow portion 133a, a decompression chamber 133b, and a refrigerant outflow portion 133 c. The refrigerant inflow portion 133a is a portion into which the refrigerant flowing out of the radiator 12 flows. The decompression chamber 133b is a portion for decompressing the refrigerant flowing into the refrigerant inflow portion 133 a. The refrigerant outflow portion 133c is a portion that allows the refrigerant decompressed by the decompression chamber 133b to flow out to the outside.

A valve seat 133d that is in contact with and separated from the valve body 135 is formed in the decompression chamber 133 b. The valve seat 133d is formed on the refrigerant outflow portion 133c side.

The stepping motor 136 is an actuator for displacing the shaft 134 in the axial direction DRa. The stepping motor 136 rotates the output shaft at a constant angle gradually in accordance with a control signal (i.e., a pulse signal) from the control device 80 described later. The axial direction DRa is a direction in which the axial center CL of the shaft 134 extends.

The shaft 134 is formed of a rod-shaped member made of metal. One side of the shaft 134 in the axial direction DRa is coupled to a linear motion conversion mechanism, not shown. The linear motion conversion mechanism converts the rotational motion of the output shaft of the stepping motor 136 into linear motion. Thereby, the shaft 134 is displaced in the axial direction DRa when the output shaft of the stepping motor 136 rotates.

A portion on the other side of the shaft 134 in the axial direction DRa is positioned in the decompression chamber 133 b. The other side of the shaft 134 in the axial direction DRa is coupled to the spool 135. The shaft 134 and the valve body 135 of the present embodiment are formed as an integrally molded product. The shaft 134 may be formed separately from the valve body 135.

The valve body 135 is formed in a disk shape. The valve body 135 is moved in the axial direction DRa by the shaft 134 to contact and separate from the valve seat 133 d. The throttle opening degree of the first expansion valve 132 decreases when the valve body 135 approaches the valve seat 133d, and increases when the valve body 135 moves away from the valve seat 133 d. The throttle opening degree is a distance (i.e., a lift amount) between the valve seat 133d and the valve body 135.

As shown in fig. 3 and 4, a drain port 135a having a constant opening area is formed in the spool 135. The drain port 135a is a communication hole that depressurizes the refrigerant flowing from the refrigerant inflow portion 133a side and flows toward the refrigerant outflow portion 133c side even in a state where the valve body 135 is in contact with the valve seat 133 d.

Since the first expansion valve 132 configured as described above is provided with the bleed port 135a, as shown in fig. 5, when the throttle opening degree is lower than the predetermined opening degree, the opening area is defined by the bleed port 135 a. The opening area shown in fig. 5 is the cross-sectional area of the refrigerant flow path in the decompression chamber 133 b.

Next, an outline of the electronic control unit of the air conditioner 1 will be described with reference to fig. 6. The control device 80 has a computer including a processor, a memory, and peripheral circuits thereof. The control device 80 performs various calculations and processes based on programs stored in the memory, and controls various devices connected to the output side. Further, the memory of the control device 80 is constituted by a non-transitory physical storage medium.

The output side of the control device 80 is connected to various devices including the constituent devices of the refrigeration cycle apparatus 10. Specifically, the compressor 11, the first decompression section 13, the second decompression section 15, the high temperature side pump 31, the high temperature side flow rate adjustment valve 34, the low temperature side pump 41, the flow path switching valves 44 and 45, the blower 62, the air mix door 65, and the like are connected to the output side of the controller 80.

The input side of the control device 80 is connected to a sensor group 81 for air conditioning control. The sensor group 81 includes an inside air temperature sensor, an outside air temperature sensor, a solar radiation sensor, a PT sensor that detects the pressure and temperature on the refrigerant outlet side of each of the coolers 14, 16, and the like.

Therefore, the detection signal of the sensor group 81 is input to the control device 80. Thus, the refrigeration cycle apparatus 10 can adjust the temperature of the feed air blown into the vehicle interior in accordance with the physical quantity detected by the sensor group 81, and can realize comfortable air conditioning.

An input side of the control device 80 is connected to an operation panel 82 for various input operations. The operation panel 82 is disposed near the instrument panel and includes various operation switches. Operation signals from various operation switches provided on the operation panel 82 are input to the control device 80.

The various operation switches of the operation panel 82 include an automatic switch, an operation mode changeover switch, an air volume setting switch, a temperature setting switch, an air blowing mode changeover switch, and the like. The refrigeration cycle apparatus 10 can appropriately switch the operation mode of the refrigeration cycle apparatus 10 by receiving an input to the operation panel 82.

Here, the control device 80 integrally constitutes a control unit that controls various devices connected to the output side. The control device 80 of the present embodiment includes an opening degree control unit 80a that controls the throttle opening degrees of the first and second decompression units 13 and 15. The opening degree control unit 80a may be configured separately from the control device 80.

Hereinafter, the operation of the air conditioner 1 will be described. The air conditioner 1 is configured to be capable of performing indoor cooling, equipment cooling, and indoor heating as an operation mode. Therefore, in the present embodiment, the operation of the air conditioning apparatus 1 will be described separately for indoor cooling, equipment cooling, and indoor heating.

< indoor refrigeration >

The indoor cooling is an operation mode in which air cooled to a desired temperature by the indoor air conditioning unit 60 is blown into the vehicle interior. The control device 80 uses the detection signals of the sensor group 81 and the operation signals of the operation panel 82 to appropriately determine the operation states of various devices during cooling of the room.

For example, as shown in fig. 7, the controller 80 controls the decompression units 13 and 15 such that the first opening/closing valve 131 is fully closed, the second opening/closing valve 151 is fully opened, and the second expansion valve 152 is in a variable throttle state. That is, the controller 80 controls the first decompression unit 13 to be in the fully closed state, and controls the second decompression unit 15 to perform the decompression function. Specifically, the control device 80 controls the throttle opening degree of the second expansion valve 152 so that the refrigerant state on the refrigerant outlet side of the air-conditioning cooler 16 becomes an overheated state having an overheat degree during indoor cooling.

The controller 80 controls the high-temperature-side flow rate adjustment valve 34 so that the entire amount of the high-temperature heat medium passing through the radiator 12 flows to the high-temperature-side radiator 33. Further, the controller 80 controls the air mix door 65 to a position where the warm air flow path 63 is fully closed and the cool air flow path 64 is fully opened. The control device 80 uses the detection signals of the sensor group 81 and the operation signals of the operation panel 82 to appropriately determine control signals for other devices.

In the refrigeration cycle apparatus 10 for cooling the interior, the high-pressure refrigerant discharged from the compressor 11 flows into the condensation portion 121 of the radiator 12. The refrigerant having flowed into the condensing portion 121 radiates heat to the high-temperature heat medium flowing through the high-temperature heat medium circuit 30 and is condensed. Thereby, the high-temperature heat medium flowing through the high-temperature heat medium circuit 30 is heated and increased in temperature.

The high-temperature heat medium heated by the condenser 121 flows through the high-temperature side radiator 33, and radiates heat to the outside air. That is, during indoor cooling, the high-pressure refrigerant in the cycle radiates heat to the outside air via the high-temperature heat medium.

On the other hand, the refrigerant having passed through the condenser 121 flows into the receiver 122 and is separated into gas and liquid. Then, the liquid refrigerant separated in the receiver 122 flows into the subcooling part 123. The refrigerant having flowed into the subcooling part 123 is subcooled by radiating heat to the high-temperature heat medium flowing through the high-temperature heat medium circuit 30.

The refrigerant flowing out of the subcooling part 123 flows into the second decompression part 15, and is decompressed by the second expansion valve 152 of the second decompression part 15. Further, during indoor cooling, the first opening/closing valve 131 is fully closed, so the refrigerant does not flow into the first expansion valve 132, and the entire amount of the refrigerant is decompressed by the second decompression section 15.

The refrigerant decompressed by the second decompression section 15 flows into the air conditioning cooler 16. The refrigerant flowing into the air conditioning cooler 16 absorbs heat from the air blown from the blower 62 and evaporates. Thereby, the blowing air from the blower 62 is cooled.

The refrigerant having passed through the air conditioning cooler 16 is sucked into the compressor 11 via the evaporation pressure adjustment valve 17. The refrigerant sucked into the compressor 11 is compressed again by the compressor 11 until it becomes a high-pressure refrigerant.

As described above, when the vehicle interior is cooled, the air cooled by the air conditioning cooler 16 is blown into the vehicle interior, whereby the vehicle interior can be cooled.

< Cooling of the apparatus >

The device cooling is an operation mode in which the battery BT as a heat generating device is cooled using latent heat of evaporation of the refrigerant. The control device 80 uses the detection signals of the sensor group 81 and the operation signals of the operation panel 82 to appropriately determine the operation states of the various devices when the devices are cooled.

For example, as shown in fig. 7, the controller 80 controls the decompression units 13 and 15 such that the second opening/closing valve 151 is fully closed, the first opening/closing valve 131 is fully opened, and the first expansion valve 132 is in a variable throttle state. That is, the controller 80 controls the second decompression unit 15 to be in the fully closed state, and controls the first decompression unit 13 to perform the decompression function.

The control device 80 controls the throttle opening degree of the first expansion valve 132 so that the refrigerant state on the refrigerant outlet side of the equipment cooler 14 becomes an overheated state having an overheat degree when the equipment is cooled. Specifically, the controller 80 controls the throttle opening degree of the first expansion valve 132 in the adjustment region Xb shown in fig. 5 when the device is cooled. As shown in fig. 5, the adjustment range Xb of the throttle opening degree of the first expansion valve 132 during the cooling of the device is set to a range in which the opening area is not defined by the bleed port 135 a. That is, the adjustment range Xb of the throttle opening degree of the first expansion valve 132 when the device is cooled is set to a range in which the lower limit Xbmin of the adjustment range Xb is larger than the predetermined position Xs at which the opening area is defined by the bleed port 135 a.

The controller 80 controls the high-temperature-side flow rate adjustment valve 34 so that the entire amount of the high-temperature heat medium passing through the radiator 12 flows to the high-temperature-side radiator 33. Further, the controller 80 controls the first channel switching valve 44 to be fully opened and the second channel switching valve 45 to be fully closed so that the entire amount of the low-temperature heat medium passing through the equipment cooler 14 flows to the battery cooling unit 42. The control device 80 uses the detection signals of the sensor group 81 and the operation signals of the operation panel 82 to appropriately determine control signals for other devices.

In the refrigeration cycle apparatus 10 when the equipment is cooled, the high-pressure refrigerant discharged from the compressor 11 flows into the condensation portion 121 of the radiator 12. As shown by the solid line in fig. 8, the refrigerant that has flowed into the condensation portion 121 radiates heat to the high-temperature heat medium flowing through the high-temperature heat medium circuit 30 and condenses (i.e., point a1 → point a2 in fig. 8). Thereby, the high-temperature heat medium flowing through the high-temperature heat medium circuit 30 is heated and increased in temperature.

The high-temperature heat medium heated by the condenser 121 flows to the high-temperature side radiator 33, and radiates heat to the outside air. That is, when the equipment is cooled, the high-pressure refrigerant in the cycle radiates heat to the outside air via the high-temperature heat medium.

On the other hand, the refrigerant having passed through the condenser 121 flows into the receiver 122 and is separated into gas and liquid. Then, the liquid refrigerant separated in the receiver 122 flows into the subcooling part 123. The refrigerant having flowed into the subcooling part 123 is subcooled by radiating heat to the high-temperature heat medium flowing through the high-temperature heat medium circuit 30 (i.e., point a2 → point A3 in fig. 8).

The refrigerant flowing out of the subcooling part 123 flows into the first decompression part 13, and is decompressed by the first expansion valve 132 of the first decompression part 13 (i.e., point A3 → point a4 in fig. 8). Further, when the equipment is cooled, the second opening/closing valve 151 is fully closed, and therefore the refrigerant does not flow into the second expansion valve 152, and the entire amount of the refrigerant is decompressed by the first decompression section 13.

The refrigerant decompressed by the first decompression section 13 flows into the equipment cooler 14. The refrigerant flowing into the equipment cooler 14 absorbs heat from the low-temperature heat medium flowing through the low-temperature heat medium circuit 40 and evaporates (i.e., point a4 → point a5 in fig. 8). Thereby, the low-temperature heat medium is cooled.

When the equipment is cooled, the throttle opening degree of the first decompression section 13 is set so that the refrigerant state on the refrigerant outlet side of the equipment cooler 14 becomes an overheated state. Therefore, the refrigerant having passed through the equipment cooler 14 becomes a gas refrigerant having a superheat degree and is sucked into the compressor 11. The refrigerant sucked into the compressor 11 is compressed again by the compressor 11 until it becomes a high-pressure refrigerant.

Here, the low-temperature heat medium cooled by the equipment cooler 14 flows to the battery cooling unit 42, and absorbs heat from the battery BT. Thereby, the battery BT is cooled. That is, when the equipment is cooled, the battery BT is cooled by the latent heat of evaporation of the refrigerant in the equipment cooler 14.

As described above, when the facility is cooled, the battery BT can be cooled by supplying the low-temperature heat medium cooled by the facility cooler 14 to the battery cooling unit 42.

Here, in the above-described equipment cooling, the high-temperature-side flow rate adjustment valve 34 is controlled so that the entire amount of the high-temperature heat medium passing through the radiator 12 flows to the high-temperature-side radiator 33, but the present invention is not limited thereto. For example, when heating in the vehicle interior is required when the equipment is cooled, the controller 80 may control the high-temperature-side flow rate adjustment valve 34 so that the high-temperature heat medium that has passed through the radiator 12 flows to the heater core 32. This makes it possible to cool the apparatus and heat the room at the same time.

In the above-described equipment cooling, the second opening/closing valve 151 is fully closed, the first opening/closing valve 131 is fully opened, and the throttle opening degree of the first expansion valve 132 is set to a predetermined opening degree by controlling the pressure reducing portions 13 and 15, respectively, but the present invention is not limited thereto. For example, when the indoor cooling is required during the cooling of the equipment, the controller 80 may control the second decompression unit 15 such that the second opening/closing valve 151 is fully opened and the throttle opening degree of the second expansion valve 152 is a predetermined opening degree. Thereby, the equipment cooling and the indoor cooling can be simultaneously performed.

< indoor heating >

The indoor heating is an operation mode in which air heated to a desired temperature by the indoor air conditioning unit 60 is blown into the vehicle interior. The control device 80 uses the detection signals of the sensor group 81 and the operation signals of the operation panel 82 to appropriately determine the operation states of various devices during indoor heating.

For example, as shown in fig. 7, the controller 80 controls the decompression units 13 and 15 such that the second opening/closing valve 151 is fully closed and the first opening/closing valve 131 is fully opened, and further, the first expansion valve 132 is in a throttled state. That is, the controller 80 controls the second decompression unit 15 to be in the fully closed state, and controls the first decompression unit 13 to perform the decompression function.

The controller 80 controls the throttle opening degree of the first expansion valve 132 so that the refrigerant state on the refrigerant outlet side of the equipment cooler 14 becomes a saturated state or a wet state during indoor heating. Specifically, the control device 80 controls the throttle opening degree of the first expansion valve 132 in the adjustment region Xh shown in fig. 5 during indoor heating. As shown in fig. 5, the adjustment region Xb of the throttle opening degree of the first expansion valve 132 during indoor heating is set to a region including an opening area defined by the drain port 135 a. That is, the lower limit of the adjustment region Xh of the throttle opening degree of the first expansion valve 132 during indoor heating is smaller than the lower limit of the adjustment region Xb during appliance cooling. To describe in detail, the upper limit Xhmax of the adjustment range Xh of the throttle opening degree of the first expansion valve 132 during indoor heating is smaller than the lower limit xmin of the adjustment range Xb during equipment cooling so as not to overlap the adjustment range Xb during equipment cooling.

Here, the controller 80 controls the throttle opening degree of the first expansion valve 132 such that the frequency of adjusting the throttle opening degree of the first expansion valve 132 during heating of the room is smaller than the frequency of adjusting the throttle opening degree of the first expansion valve 132 during cooling of the device. Specifically, the controller 80 controls the first expansion valve 132 so as to be in a fixed throttle state in which the throttle opening degree is fixed. The controller 80 of the present embodiment controls the first expansion valve 132 to a predetermined throttle opening degree (for example, a throttle opening degree around a predetermined position Xs) in the adjustment region Xh.

The controller 80 controls the high-temperature-side flow rate adjustment valve 34 so that the entire amount of the high-temperature heat medium passing through the radiator 12 flows to the heater core 32. Further, the controller 80 controls the first channel switching valve 44 to be fully closed and the second channel switching valve 45 to be fully opened so that the entire amount of the low-temperature heat medium passing through the equipment cooler 14 flows to the low-temperature side radiator 43.

The controller 80 controls the air mix door 65 to a position where the cool air passage 64 is fully closed and the warm air passage 63 is fully opened. The control device 80 uses the detection signals of the sensor group 81 and the operation signals of the operation panel 82 to appropriately determine control signals for other devices.

In the refrigeration cycle apparatus 10 for heating a room, a high-pressure refrigerant discharged from the compressor 11 flows into the condenser 121 of the radiator 12. As indicated by the broken line in fig. 8, the refrigerant having flowed into the condenser 121 radiates heat to the high-temperature heat medium flowing through the high-temperature heat medium circuit 30 and condenses (i.e., B1 → B2 in fig. 8). Thereby, the high-temperature heat medium flowing through the high-temperature heat medium circuit 30 is heated and increased in temperature.

The high-temperature heat medium heated by the condenser 121 flows into the heater core 32, and radiates heat to the air blown into the vehicle interior. That is, during indoor heating, the high-pressure refrigerant in the cycle radiates heat to the air blown into the vehicle interior via the high-temperature heat medium.

On the other hand, the refrigerant having passed through the condenser 121 flows into the receiver 122 and is separated into gas and liquid. Then, the liquid refrigerant separated in the receiver 122 flows into the subcooling part 123. The refrigerant having flowed into the subcooling part 123 is subcooled by radiating heat to the high-temperature heat medium flowing through the high-temperature heat medium circuit 30 (i.e., B2 → B3 in fig. 8).

The refrigerant flowing out of the subcooling part 123 flows into the first decompression part 13, and is decompressed by the first expansion valve 132 of the first decompression part 13 (i.e., B3 → B4 in fig. 8). In addition, during indoor heating, the second opening/closing valve 151 is fully closed, and therefore the refrigerant does not flow into the second expansion valve 152, and the entire amount of the refrigerant is decompressed by the first decompression section 13.

Here, during indoor heating, the throttle opening degree of the first expansion valve 132 is smaller than during equipment cooling. As a result, as shown in fig. 9, during indoor heating, the pressure Pd of the low-pressure refrigerant becomes higher than that during equipment cooling (i.e., Pd1 > Pd2), and the pressure Ps of the low-pressure refrigerant becomes lower than that during equipment cooling (i.e., Ps1 < Ps 2). In other words, the high-low pressure difference Δ P1 of the refrigerant in the cycle during indoor heating is greater than the high-low pressure difference Δ P2 of the refrigerant in the cycle during equipment cooling.

Therefore, during indoor heating, the temperature of the refrigerant decompressed by the first decompression section 13 may become extremely low. In this case, the density of the refrigerant flowing through the low-pressure side of the cycle decreases, and the flow rate of the refrigerant passing through the low-pressure side heat exchanger decreases. In addition, on the low-pressure side in the cycle, the viscosity of the oil increases due to the decrease in the temperature of the refrigerant.

The refrigerant decompressed by the first decompression section 13 flows into the equipment cooler 14. The refrigerant flowing into the equipment cooler 14 absorbs heat from the low-temperature heat medium flowing through the low-temperature heat medium circuit 40 and evaporates (i.e., point B4 → point B5 in fig. 8). Thereby, the low-temperature heat medium is cooled. The low-temperature heat medium cooled by the equipment cooler 14 flows to the low-temperature side radiator 43, and absorbs heat from the outside air.

In the indoor heating, the throttle opening degree of the first expansion valve 132 is set so that the refrigerant state on the refrigerant outlet side of the equipment cooler 14 becomes a saturated state or a wet state. Therefore, the refrigerant having passed through the equipment cooler 14 is a two-phase gas-liquid refrigerant and is sucked into the compressor 11. The refrigerant sucked into the compressor 11 is compressed again by the compressor 11 until it becomes a high-pressure refrigerant.

As described above, when heating the vehicle interior, the air heated by the heater core 32 is blown into the vehicle interior, whereby the vehicle interior can be heated. In the indoor heating, the oil in the equipment cooler 14 is returned to the compressor 11 together with the liquid refrigerant.

Here, the first channel switching valve 44 is controlled to be fully closed so that the low-temperature heat medium does not pass through the battery cooling unit 42 during the indoor heating described above, but the present invention is not limited thereto. In the case of indoor heating, the controller 80 may control the first channel switching valve 44 to be fully opened so that the low-temperature heat medium passes through the battery cooling unit 42.

This allows the refrigerant to absorb the exhaust heat of the battery BT via the low-temperature heat medium in the facility cooler 14. Therefore, the exhaust heat of the battery BT can be used as a heat source for heating the air blown into the vehicle interior.

The refrigeration cycle apparatus 10 described above has a cycle configuration in which the receiver 122 for storing the surplus refrigerant in the cycle is provided to the radiator 12. As a result, the refrigerant states at the refrigerant outlet sides of the equipment cooler 14 and the air-conditioning cooler 16 can be brought into an overheated state during cooling of the room and during cooling of the equipment.

During indoor heating, the throttle opening degree of the first expansion valve 132 is controlled so as to maintain the refrigerant state on the refrigerant outlet side of the equipment cooler 14 in a saturated state or a wet state. The lower limit of the throttle opening degree of the adjustment region Xh of the throttle opening degree of the first expansion valve 132 during indoor heating is smaller than the adjustment region Xb of the throttle opening degree of the first expansion valve 132 during appliance cooling. Thus, during indoor heating, the refrigerant in a gas-liquid two-phase state is sucked into the compressor 11, and therefore, the oil in the cycle is easily returned to the compressor 11 together with the refrigerant.

Therefore, according to the refrigeration cycle apparatus 10 of the present embodiment, it is possible to return oil to the refrigerant suction side of the compressor 11 during indoor heating without disposing an accumulator on the refrigerant suction side of the compressor 11.

The second decompression section 15 of the refrigeration cycle apparatus 10 of the present embodiment includes a second opening/closing valve 151 and is configured to be fully closable. The controller 80 controls the second decompression unit 15 to be fully closed and controls the first decompression unit 13 to perform a decompression function during indoor heating. Thus, when heating the room, the refrigerant having absorbed heat in the equipment cooler 14 is discharged to the radiator 12 via the compressor 11, whereby the air blown into the vehicle interior can be heated using the refrigerant passing through the radiator 12 as a heat source.

However, the refrigeration cycle apparatus 10 of the present embodiment reduces the throttle opening degree of the first expansion valve 132 during indoor heating. At this time, if the dryness of the refrigerant on the refrigerant outlet side of the equipment cooler 14 becomes too small, the amount of the liquid refrigerant sucked into the compressor 11 increases. In this case, since the liquid compression occurs in the compressor 11, the compression efficiency of the compressor 11 deteriorates.

In contrast, the first decompression section 13 of the refrigeration cycle apparatus 10 is provided with the discharge port 135a in the first expansion valve 132, and is configured such that the refrigerant is decompressed when passing through the discharge port 135 a. As described above, if the discharge port 135a is provided in the first expansion valve 132 of the first decompression section 13, the refrigerant flows through the discharge port 135a during indoor heating, and thus the dryness of the refrigerant on the refrigerant outlet side of the equipment cooler 14 can be suppressed from becoming excessively small.

The control device 80 of the present embodiment controls the throttle opening degree of the first pressure reducing section 13 so that the frequency of adjusting the throttle opening degree of the first pressure reducing section 13 during indoor heating is smaller than the frequency of adjusting the throttle opening degree of the first pressure reducing section 13 during equipment cooling. If the frequency of adjusting the throttle opening of the first decompression unit 13 is reduced, the refrigerant state on the refrigerant outlet side of the equipment cooler 14 is easily stabilized. Therefore, by reducing the frequency of adjusting the throttle opening degree of the first decompression section 13 during indoor heating, the refrigerant state on the refrigerant outlet side of the equipment cooler 14 during indoor heating can be maintained in a saturated state or a wet state.

Further, the control device 80 controls the throttle opening degree of the first decompression section 13 so as to maintain the state of the refrigerant on the refrigerant outlet side of the equipment cooler 14 in a saturated state or an overheated state when the equipment is cooled. In the configuration in which the refrigerant state on the refrigerant outlet side of the equipment cooler 14 is maintained in the saturated state or the superheated state, enthalpy on the refrigerant outlet side of the equipment cooler 14 can be increased compared to the case in which the refrigerant state is maintained in the moist state. Therefore, by controlling the throttle opening degree of the first decompression section 13 so as to maintain the state of the refrigerant on the refrigerant outlet side of the equipment cooler 14 in a saturated state or an overheated state when the equipment is cooled, the heat generating equipment can be sufficiently cooled by the refrigerant passing through the equipment cooler 14.

The radiator 12 of the refrigeration cycle apparatus 10 includes a supercooling portion 123 that radiates heat from the liquid refrigerant stored in the liquid reservoir portion 122. Thereby, the refrigerant state on the refrigerant outlet side of the radiator 12 becomes a supercooled state, and the enthalpy on the refrigerant outlet side of the radiator 12 decreases. Therefore, during indoor heating, the air blown into the space to be air-conditioned can be sufficiently heated by the refrigerant passing through the radiator 12.

(modification of the first embodiment)

In the first embodiment described above, the configuration in which the drain port 135a is provided in the valve body 135 is exemplified as the first expansion valve 132, but the present invention is not limited to this. The first expansion valve 132 may have a bleed port 135a formed in the body 133, for example. Further, the drain port 135a is not limited to the communication hole, and may be constituted by a communication groove.

The first expansion valve 132 is preferably provided with the drain port 135a, but is not limited thereto. The first expansion valve 132 may be configured without the drain port 135 a.

In the first embodiment described above, the adjustment region Xh in which the upper limit of the adjustment region Xh is smaller than the lower limit of the adjustment region Xb in the device cooling operation is exemplified as the adjustment region Xh in which the throttle opening degree of the first expansion valve 132 is adjusted during indoor heating, but the present invention is not limited thereto. The adjustment region Xh of the throttle opening degree of the first expansion valve 132 during indoor heating may be such that the upper limit Xhmax is larger than the lower limit Xbmin of the adjustment region Xb during equipment cooling, for example, so that the adjustment region Xb during equipment cooling overlaps with a part of the adjustment region Xh.

In the first embodiment described above, the example in which the first expansion valve 132 is set to the fixed throttle state during indoor heating has been described, but the present invention is not limited to this. The controller 80 may change the throttle opening degree of the first expansion valve 132 within the adjustment range Xh during indoor heating, for example.

In the first embodiment described above, the example in which the first expansion valve 132 is set to the variable throttle state when the equipment is cooled has been described, but the present invention is not limited to this. The controller 80 may fix the throttle opening degree of the first expansion valve 132 in the adjustment region Xb during cooling of the device, for example. In this case, the frequency of adjusting the throttle opening degree of the first expansion valve 132 during indoor heating can be made the same as the frequency of adjusting the throttle opening degree of the first expansion valve 132 during equipment cooling. These modifications are also applied to the following embodiments.

In the first embodiment described above, the radiator 12 having the supercooling unit 123 is exemplified, but the present invention is not limited thereto. The radiator 12 may be constituted by a member having no supercooling unit 123, for example.

(second embodiment)

Next, a second embodiment will be described with reference to fig. 10. In the present embodiment, the description will be mainly given of portions different from those of the first embodiment, and the description of portions identical to those of the first embodiment may be omitted.

The first expansion valve 132 in the present embodiment is controlled in a different manner from the first embodiment. As shown in fig. 10, the controller 80 controls the decompression units 13 and 15 such that the second opening/closing valve 151 is fully closed, the first opening/closing valve 131 is fully opened, and the first expansion valve 132 is in a fixed throttle state. Specifically, the controller 80 controls the first expansion valve 132 to the minimum throttle opening degree (i.e., the minimum opening degree) in the adjustment region Xh during indoor heating. Thereby, the opening area of the first expansion valve 132 coincides with the opening area of the drain port 135 a. The opening area of the drain port 135a is set to an area in which the refrigerant outlet side of the equipment cooler 14 is in a saturated state or a wet state when indoor heating is performed under standard environmental conditions, for example.

The other structure is the same as that of the first embodiment. The refrigeration cycle apparatus 10 of the present embodiment has a configuration common to that of the first embodiment. Therefore, the operational advantages and effects of the configuration common to the first embodiment can be obtained as in the first embodiment.

The control device 80 of the refrigeration cycle device 10 of the present embodiment controls the first expansion valve 132 to the minimum opening degree during indoor heating. Thus, during indoor heating, the refrigerant in a gas-liquid two-phase state is easily returned to the compressor 11, and therefore, the oil in the cycle can be returned to the compressor 11 together with the refrigerant.

(third embodiment)

Next, a third embodiment will be described with reference to fig. 11. In the present embodiment, the description will be mainly given of portions different from those of the first embodiment, and the description of portions identical to those of the first embodiment may be omitted.

In the present embodiment, an example will be described in which the refrigeration cycle apparatus 10A of the present invention is applied to a device cooling system for cooling a battery BT as a heat generating device. The refrigeration cycle apparatus 10A shown in fig. 11 can perform equipment cooling and indoor heating.

The refrigeration cycle apparatus 10A includes a compressor 11A, a radiator 12A, a decompression unit 13A, an equipment cooler 14A, and a control device 80. In the refrigerant circuit 100 of the refrigeration cycle apparatus 10A, a compressor 11A, a radiator 12A, a pressure reducing unit 13A, and an equipment cooler 14A are arranged in this order. The compressor 11A is configured similarly to the compressor 11 described in the first embodiment.

The radiator 12A radiates heat from the refrigerant discharged from the compressor 11A. The radiator 12A is a heat exchanger that radiates heat from the high-pressure refrigerant discharged from the compressor 11 to the high-temperature heat medium flowing through the high-temperature heat medium circuit 30A. Specifically, the radiator 12A includes a condensation unit 121A for condensing the refrigerant, and a receiver 122A for gas-liquid separating the refrigerant having passed through the condensation unit 121A and storing the liquid refrigerant remaining in the cycle. The condenser 121A and the reservoir 122A are configured in the same manner as those described in the first embodiment.

Here, the high-temperature heat medium circuit 30A includes the radiator 12A, the high-temperature-side pump 31A, the heater core 32A, the high-temperature-side radiator 33A, the high-temperature-side flow rate adjustment valve 34A, and the like, as in the first embodiment. The high-temperature-side pump 31A, the heater core 32A, the high-temperature-side radiator 33A, and the high-temperature-side flow rate adjustment valve 34A are configured in the same manner as those described in the first embodiment.

The outlet side of the radiator 12 is connected to the decompression section 13A. The decompression section 13A is an expansion valve that decompresses the refrigerant after passing through the radiator 12. The decompression section 13A is configured in the same manner as the first expansion valve 132 described in the first embodiment. That is, the decompression portion 13A is constituted by an electric expansion valve in which a bleed port 135a is formed in a valve body 135.

The facility cooler 14A is an evaporator that evaporates the refrigerant decompressed by the decompression unit 13A by exchanging heat between the refrigerant and the low-temperature heat medium circulating in the low-temperature heat medium circuit 40A. The facility cooler 14A functions as a cooler for cooling the battery BT by latent heat of evaporation of the refrigerant decompressed by the decompression unit 13A when the facility is cooled, and functions as a heat absorber when the room is heated.

Here, the low-temperature heat medium circuit 40A includes the facility cooler 14A, the low-temperature side pump 41A, the battery cooling unit 42A, the low-temperature side radiator 43A, the first channel switching valve 44A, the second channel switching valve 45A, and the like, as in the first embodiment. The low temperature side pump 41A, the battery cooling unit 42A, the low temperature side radiator 43A, the first channel switching valve 44A, and the second channel switching valve 45A are configured in the same manner as those described in the first embodiment.

Hereinafter, the operation of the facility cooling system will be described. The facility cooling system is configured to be capable of performing facility cooling and indoor heating as an operation mode.

< Cooling of the apparatus >

The device cooling is an operation mode in which the battery BT as a heat generating device is cooled using latent heat of evaporation of the refrigerant. The control device 80 uses the detection signals of the sensor group 81 and the operation signals of the operation panel 82 to appropriately determine the operation states of the various devices when the devices are cooled.

For example, as shown in fig. 12, the controller 80 controls the decompression section 13A to be in a variable throttle state. That is, the controller 80 controls the throttle opening degree of the decompression section 13A so that the refrigerant state on the refrigerant outlet side of the equipment cooler 14A becomes an overheated state having an overheating degree when the equipment is cooled. Specifically, the controller 80 controls the throttle opening of the decompression unit 13A in the adjustment region Xb shown in fig. 5 when the device is cooled. That is, the controller 80 controls the throttle opening degree of the decompression section 13A during the cooling of the device, similarly to the first expansion valve 132 of the first embodiment.

Thus, in the refrigeration cycle apparatus 10A when the equipment is cooled, the high-pressure refrigerant discharged from the compressor 11A flows into the condensation portion 121A of the radiator 12A. The refrigerant having flowed into the condensing portion 121A radiates heat to the high-temperature heat medium flowing through the high-temperature heat medium circuit 30A and is condensed.

The refrigerant having passed through the condenser 121A flows into the receiver 122A and is separated into gas and liquid. Then, the liquid refrigerant separated in the receiver 122A flows into the decompression section 13A, and is decompressed by the decompression section 13A.

The refrigerant decompressed by the decompression unit 13A flows into the facility cooler 14A. The refrigerant flowing into the equipment cooler 14A absorbs heat from the low-temperature heat medium flowing through the low-temperature heat medium circuit 40A and evaporates. Thereby, the low-temperature heat medium is cooled.

When the equipment is cooled, the throttle opening degree of the pressure reducing portion 13A is set so that the refrigerant state on the refrigerant outlet side of the equipment cooler 14A becomes an overheated state. Therefore, the refrigerant having passed through the equipment cooler 14A becomes a gas refrigerant having a superheat degree and is sucked into the compressor 11A. The refrigerant sucked into the compressor 11A is compressed again by the compressor 11A until it becomes a high-pressure refrigerant.

Here, the low-temperature heat medium cooled by the equipment cooler 14A flows to the battery cooling portion 42A, and absorbs heat from the battery BT. Thereby, the battery BT is cooled. That is, when the equipment is cooled, the battery BT is cooled by the latent heat of evaporation of the refrigerant in the equipment cooler 14A.

As described above, when the facility is cooled, the battery BT can be cooled by supplying the low-temperature heat medium cooled by the facility cooler 14A to the battery cooling unit 42A.

< indoor heating >

The indoor heating is an operation mode in which air heated to a desired temperature by the indoor air conditioning unit 60A is blown into the vehicle interior. The control device 80 uses the detection signals of the sensor group 81 and the operation signals of the operation panel 82 to appropriately determine the operation states of various devices during indoor heating.

For example, as shown in fig. 12, the controller 80 controls the decompression section 13A to be in the fixed throttle state. That is, the controller 80 controls the throttle opening degree of the decompression section 13A so that the refrigerant state on the refrigerant outlet side of the equipment cooler 14A becomes a saturated state or a wet state when the equipment is cooled. Specifically, during indoor heating, the controller 80 controls the throttle opening degree of the decompression section 13A in the adjustment region Xh shown in fig. 5. That is, the controller 80 controls the throttle opening degree of the decompression section 13A during indoor heating in the same manner as the first expansion valve 132 of the first embodiment.

Thus, in the refrigeration cycle apparatus 10A, the high-pressure refrigerant discharged from the compressor 11A flows into the condenser 121A of the radiator 12A during indoor heating. The refrigerant having flowed into the condensing portion 121A radiates heat to the high-temperature heat medium flowing through the high-temperature heat medium circuit 30A and is condensed. Thereby, the high-temperature heat medium flowing through the high-temperature heat medium circuit 30A is heated and increased in temperature.

The high-temperature heat medium heated by the condenser 121A flows into the heater core 32A, and radiates heat to the air blown into the vehicle interior. That is, during indoor heating, the high-pressure refrigerant in the cycle radiates heat to the air blown into the vehicle interior via the high-temperature heat medium.

On the other hand, the refrigerant having passed through the condenser 121A flows into the receiver 122A and is separated into gas and liquid. Then, the liquid refrigerant separated in the receiver 122A flows into the decompression section 13A, and is decompressed by the decompression section 13A.

The refrigerant decompressed by the decompression unit 13A flows into the facility cooler 14A. The refrigerant flowing into the equipment cooler 14A absorbs heat from the low-temperature heat medium flowing through the low-temperature heat medium circuit 40A and evaporates. Thereby, the low-temperature heat medium is cooled. The low-temperature heat medium cooled by the equipment cooler 14A flows to the low-temperature side radiator 43A, and absorbs heat from the outside air.

Here, the throttle opening degree of the pressure reducing portion 13A is set so that the refrigerant state on the refrigerant outlet side of the equipment cooler 14A becomes a saturated state or a wet state during indoor heating. Therefore, the refrigerant having passed through the equipment cooler 14A is a two-phase gas-liquid refrigerant and is sucked into the compressor 11A. The refrigerant sucked into the compressor 11A is compressed again by the compressor 11A until it becomes a high-pressure refrigerant.

As described above, when heating the vehicle interior, the air heated by the heater core 32A is blown into the vehicle interior, whereby the vehicle interior can be heated. In the indoor heating, the oil in the equipment cooler 14A returns to the compressor 11 together with the liquid refrigerant.

The refrigeration cycle apparatus 10A of the present embodiment has a configuration common to that of the first embodiment. Therefore, the operational advantages and effects of the configuration common to the first embodiment can be obtained as in the first embodiment.

Specifically, since the refrigeration cycle apparatus 10A has a cycle configuration in which the receiver 12A is provided with the receiver 122A for storing the surplus refrigerant in the cycle, the refrigerant on the refrigerant outlet side of the equipment cooler 14A can be brought into an overheated state when the equipment is cooled.

In addition, during indoor heating, the throttle opening degree of the decompression section 13A is controlled so as to maintain the refrigerant state on the refrigerant outlet side of the equipment cooler 14A in a saturated state or a wet state. The lower limit of the throttle opening degree adjustment region Xh of the decompression section 13A during indoor heating is smaller than the throttle opening degree adjustment region Xb of the decompression section 13A during equipment cooling. Thus, during indoor heating, the refrigerant in a gas-liquid two-phase state is sucked into the compressor 11A, and therefore the oil in the cycle is easily returned to the compressor 11A together with the refrigerant.

The decompression section 13A has the following structure: a discharge port 135a is provided, the discharge port 135a having a constant opening area, and the refrigerant is decompressed when passing through the discharge port 135 a. Thus, even if the throttle opening degree of the decompression section 13A is reduced during indoor heating, by flowing the refrigerant through the discharge port 135a, the dryness of the refrigerant on the refrigerant outlet side of the equipment cooler 14A can be suppressed from becoming too low.

The controller 80 controls the throttle opening degree of the decompressor 13A so that the adjustment frequency of the throttle opening degree of the decompressor 13A during indoor heating is smaller than the adjustment frequency of the throttle opening degree of the decompressor 13A during equipment cooling. This can maintain the refrigerant state on the refrigerant outlet side of the equipment cooler 14A in a saturated state or a wet state during indoor heating.

The control device 80 controls the throttle opening degree of the decompression section 13A so as to maintain the state of the refrigerant on the refrigerant outlet side of the equipment cooler 14A in a saturated state or an overheated state when the equipment is cooled. Thereby, the enthalpy of the refrigerant outlet side of the equipment cooler 14A can be increased as compared with the case where the throttle opening degree of the decompression portion 13A is controlled to maintain the refrigerant state in a moist state. Therefore, by controlling the throttle opening degree of the decompression portion 13A so as to maintain the refrigerant outlet side of the equipment cooler 14A in the refrigerant state, the saturated state, or the superheated state when the equipment is cooled, the battery BT can be sufficiently cooled by the refrigerant passing through the equipment cooler 14A.

(other embodiments)

While the present invention has been described with reference to the exemplary embodiments, the present invention is not limited to the embodiments described above, and various modifications such as the following may be made.

In the above-described embodiment, as the refrigeration cycle apparatus 10, an apparatus capable of performing indoor cooling, equipment cooling, and indoor heating is exemplified, but the present invention is not limited thereto. The refrigeration cycle apparatus 10 may be configured to be able to perform dehumidification and heating in a vehicle interior, for example.

In the above-described embodiment, as the refrigeration cycle apparatus 10, an apparatus capable of performing indoor cooling, equipment cooling, and indoor heating is exemplified, but the present invention is not limited thereto. The refrigeration cycle apparatus 10 may be configured to be able to perform only indoor cooling and indoor heating, for example. The refrigeration cycle apparatus 10 may be configured to be able to perform dehumidification and heating in the vehicle interior.

The respective configurations of the refrigeration cycle apparatus 10 described in the above embodiments are not limited to those disclosed in the above embodiments. The compressor 11 may be driven by an internal combustion engine, for example. The heat sink 12 may be configured to include only the condensing unit 121 without the liquid reservoir 122 or the supercooling unit 123, for example. The second expansion valve 152 may be constituted by, for example, a mechanical expansion valve or a fixed throttle member. The first opening/closing valve 131 and the second opening/closing valve 151 may be disposed downstream of the first expansion valve 132 and the second expansion valve 152, for example. The first opening/closing valve 131 and the second opening/closing valve 151 may be arranged in parallel with the first expansion valve 132 and the second expansion valve 152, for example. The first decompression section 13 and the second decompression section 15 may be formed of electric expansion valves having a fully closing function. The evaporation pressure adjustment valve 17 may be disposed in the second refrigerant flow path 100b instead of the third refrigerant flow path 100c, for example.

In the above-described embodiment, the example of using the liquid such as the antifreeze as the high-temperature heat medium and the low-temperature heat medium has been described, but the present invention is not limited thereto. As long as the high-temperature heat medium and the low-temperature heat medium have excellent thermal conductivity, a gas may be used.

The respective configurations of the high-temperature heat medium circuit 30 described in the above-described embodiments are not limited to those disclosed in the above-described embodiments. The high-temperature heat medium circuit 30 may be configured to adjust the flow rate ratio of the refrigerant flowing through the heater core 32 and the high-temperature-side radiator 33 by providing two flow rate adjustment valves corresponding to the heater core 32 and the high-temperature-side radiator 33, respectively, for example.

The configuration of the low-temperature heat medium circuit 40 described in the above embodiment is not limited to that disclosed in the above embodiment. The low-temperature heat medium circuit 40 may be configured to switch the flow path by a three-way valve type flow path switching valve.

The device cooled by the low-temperature heat medium flowing through the low-temperature heat medium circuit 40 may be a device other than the battery BT as long as it is a heat generating device that generates heat when operating.

In addition to the battery BT, the vehicle-mounted heat generating device includes a motor that outputs driving force for traveling, an inverter that converts the frequency of electric power supplied to the motor, a charger that charges the battery BT, and the like.

Therefore, the low-temperature heat medium circuit 40 can be configured to cool not only the battery BT but also the motor, the inverter, the charger, and the like. Such a structure can be realized by connecting various heat generating devices in parallel or in series with respect to the flow of the low-temperature heat medium.

In the above-described embodiment, although the relationship between the high temperature side radiator 33 and the low temperature side radiator 43 is not mentioned, the high temperature side radiator 33 and the low temperature side radiator 43 are not limited to the independent structures. For example, the high temperature side radiator 33 and the low temperature side radiator 43 may be integrated so that heat of the high temperature heat medium and heat of the low temperature heat medium can be thermally moved to each other. Specifically, the heat mediums may be integrated so as to be thermally movable with each other by commonly using components (for example, heat exchange fins) constituting part of the high temperature side radiator 33 and the low temperature side radiator 43.

In the above-described embodiment, the example in which the refrigeration cycle device 10 is applied to the air conditioner 1 and the equipment cooling system of the hybrid vehicle has been described, but the present invention is not limited thereto. The refrigeration cycle apparatus 10 can be applied to, for example, an air conditioner 1 and a facility cooling system of an electric vehicle. The refrigeration cycle apparatus 10 can be applied not only to a mobile body such as a vehicle but also to a stationary type apparatus and system.

In the above-described embodiments, it is needless to say that constituent elements of the embodiments are not necessarily essential, unless explicitly stated otherwise or clearly considered essential in principle.

In the above-described embodiments, when numerical values such as the number, numerical value, number, range, and the like of the constituent elements of the embodiments are mentioned, the number is not limited to a specific number unless explicitly stated to be particularly necessary or if it is apparently considered to be limited to a specific number in principle.

In the above-described embodiments, when referring to the shape, positional relationship, and the like of the constituent elements and the like, the shape, positional relationship, and the like are not limited to those unless specifically stated or limited to a specific shape, positional relationship, and the like in principle.

In the above-described embodiment, when it is described that the external environment information of the vehicle (for example, the humidity outside the vehicle) is acquired from the sensor, the sensor may be eliminated and the external environment information may be received from a server or cloud outside the vehicle. Alternatively, the sensor may be eliminated, the related information related to the external environment information may be acquired from a server or cloud outside the vehicle, and the external environment information may be estimated from the acquired related information.

The control apparatus and method thereof described in the present invention can be realized by a special purpose computer provided by constituting a processor and a memory programmed to execute one or more functions embodied by a computer program. Alternatively, the control device and the method described in the present invention may be realized by a special purpose computer provided by a processor including one or more dedicated hardware logic circuits. Alternatively, the control device and the method thereof described in the present invention may be implemented by one or more special purpose computers configured by combining a processor programmed to execute one or more functions, a memory, and a processor configured by one or more hardware logic circuits. The computer program may be stored as instructions to be executed by a computer in a non-transitory tangible computer-readable storage medium.

(conclusion)

In accordance with a first aspect of some or all of the above embodiments, the refrigeration cycle apparatus includes a compressor, a radiator, a decompression unit, an evaporator, and an opening degree control unit that controls a throttle opening degree of the decompression unit. The radiator includes a condensing portion for condensing the refrigerant and a reserve portion for storing the liquid refrigerant remaining in the cycle by gas-liquid separation of the refrigerant having passed through the condensing portion. The opening degree control unit controls the throttle opening degree of the decompression unit so as to maintain the refrigerant state on the refrigerant outlet side of the evaporator in a saturated state or a wet state during indoor heating. The lower limit of the throttle opening adjustment region of the pressure reducing section in the indoor heating is smaller than the throttle opening adjustment region of the pressure reducing section in the equipment cooling.

According to a second aspect, the decompression section has the following configuration: a bleed port is provided having a constant opening area, and the refrigerant is depressurized as it passes through the bleed port.

When the dryness of the refrigerant on the refrigerant outlet side of the evaporator becomes too small during indoor heating, the amount of the liquid refrigerant sucked into the compressor increases. In this case, since the liquid compression occurs in the compressor, the compression efficiency of the compressor deteriorates.

In contrast, if the relief portion is provided with the bleed port, even if the throttle opening degree of the relief portion is reduced during indoor heating, the dryness of the refrigerant on the refrigerant outlet side of the evaporator can be suppressed from becoming too low by flowing the refrigerant through the bleed port.

According to the third aspect, the opening degree control unit controls the throttle opening degree of the pressure reducing unit such that the frequency of adjusting the throttle opening degree of the pressure reducing unit during indoor heating is smaller than the frequency of adjusting the throttle opening degree of the pressure reducing unit during equipment cooling. If the frequency of adjusting the throttle opening of the decompression section is reduced, the refrigerant state on the refrigerant outlet side of the evaporator is easily stabilized. Therefore, by reducing the frequency of adjusting the throttle opening of the decompression section during indoor heating, the refrigerant state on the refrigerant outlet side of the evaporator during indoor heating can be maintained in a saturated state or a wet state.

According to a fourth aspect, the opening degree control unit controls the throttle opening degree of the decompression unit so as to maintain the refrigerant state on the refrigerant outlet side of the evaporator in a saturated state or an overheated state when the equipment is cooled.

If the throttle opening degree of the decompression portion is controlled so as to maintain the refrigerant state at the refrigerant outlet side of the evaporator in a saturated state or an overheated state, the enthalpy at the refrigerant outlet side of the evaporator can be increased as compared with the case where the throttle opening degree of the decompression portion is controlled so as to maintain the refrigerant state in a moist state. Therefore, by controlling the throttle opening of the decompression section so as to maintain the refrigerant state on the refrigerant outlet side of the evaporator in a saturated state or a superheated state when the equipment is cooled, the heat generating equipment can be sufficiently cooled by the refrigerant passing through the evaporator.

According to a fifth aspect, the refrigeration cycle apparatus includes a compressor, a radiator, a first decompression section, a second decompression section, a device cooler, an air conditioning cooler, and an opening degree control section that controls the throttle opening degrees of the first decompression section and the second decompression section. The radiator includes a condensing portion that condenses the refrigerant, and a receiver portion that separates the refrigerant having passed through the condensing portion into gas and liquid, and stores the remaining liquid refrigerant in the cycle. The opening degree control unit controls the throttle opening degree of the first decompression unit so as to maintain the refrigerant state on the refrigerant outlet side of the equipment cooler in a saturated state or a wet state during indoor heating. The lower limit of the throttle opening degree of the adjustment region of the throttle opening degree of the first pressure reducing portion in the indoor heating is smaller than the adjustment region of the throttle opening degree of the first pressure reducing portion in the equipment cooling.

According to a sixth aspect, the second decompression portion is configured to be fully closable. The opening degree control unit controls the second decompression unit to be fully closed and controls the first decompression unit to perform a decompression function during indoor heating. In this way, the refrigerant having absorbed heat in the equipment cooler is discharged to the radiator via the compressor, and the air blown into the space to be air-conditioned can be heated using the refrigerant passing through the radiator as a heat source.

According to a seventh aspect, the first decompression section has the following configuration: a discharge port is provided having a constant opening area through which refrigerant is depressurized as it passes. As described above, if the discharge port is provided in the first pressure reducing portion, the dryness of the refrigerant on the refrigerant outlet side of the equipment cooler can be suppressed from becoming excessively small by flowing the refrigerant through the discharge port during indoor heating.

According to the eighth aspect, the opening degree control unit controls the throttle opening degree of the first pressure reducing unit such that the frequency of adjusting the throttle opening degree of the first pressure reducing unit during heating of the room is smaller than the frequency of adjusting the throttle opening degree of the first pressure reducing unit during cooling of the equipment.

When the frequency of adjusting the throttle opening of the first decompression unit is reduced, the refrigerant state on the refrigerant outlet side of the equipment cooler is easily stabilized. Therefore, by reducing the frequency of adjusting the throttle opening degree of the first decompression section in the indoor heating, the refrigerant state on the refrigerant outlet side of the equipment cooler in the indoor heating can be maintained in the saturated state or the wet state.

According to a ninth aspect, the opening degree control unit controls the throttle opening degree of the first decompression unit when the equipment is cooled so as to maintain the state of the refrigerant on the refrigerant outlet side of the equipment cooler in a saturated state or an overheated state.

In the configuration in which the state of the refrigerant on the refrigerant outlet side of the equipment cooler is maintained in the saturated state or the superheated state, the enthalpy on the refrigerant outlet side of the equipment cooler can be increased as compared with the case where the state of the refrigerant is maintained in the moist state. Therefore, by controlling the throttle opening degree of the first decompression portion so as to maintain the state of the refrigerant on the refrigerant outlet side of the equipment cooler in a saturated state or an overheated state when the equipment is cooled, the heat generating equipment can be sufficiently cooled by the refrigerant passing through the equipment cooler.

According to a tenth aspect, the radiator includes a supercooling portion that radiates heat from the liquid refrigerant stored in the liquid reservoir. Thereby, the refrigerant state on the refrigerant outlet side of the radiator becomes a supercooled state, and enthalpy on the refrigerant outlet side of the radiator decreases. Therefore, during indoor heating, the air blown into the space to be air-conditioned can be sufficiently heated by the refrigerant passing through the radiator. The "supercooled state" refers to a state in which the refrigerant becomes a supercooled liquid.

Claims (10)

1. A refrigeration cycle apparatus capable of performing indoor heating for heating supply air blown into a space to be air-conditioned and equipment cooling for cooling a heat generating equipment (BT), the refrigeration cycle apparatus comprising:

a compressor (11A) that compresses and discharges a refrigerant containing oil;

a radiator (12A) that heats the air supply using, as a heat source, the refrigerant discharged from the compressor during heating of the room;

a decompression unit (13A) that decompresses the refrigerant that has passed through the radiator;

an evaporator (14A) that functions as a cooler for cooling the heat-generating equipment by using latent heat of evaporation of the refrigerant decompressed by the decompression unit when the equipment is cooled, and functions as a heat absorber when the indoor space is heated; and

an opening degree control unit (80a) that controls the throttle opening degree of the pressure reducing unit,

the radiator has a condensing unit (121A) for condensing the refrigerant and a receiver unit (122A) for gas-liquid separating the refrigerant having passed through the condensing unit and storing the liquid refrigerant remaining in the cycle,

the opening degree control unit controls a throttle opening degree of the decompression unit to maintain a refrigerant state at a refrigerant outlet side of the evaporator in a saturated state or a wet state during the indoor heating,

a lower limit of the throttle opening of the adjustment region in the indoor heating is smaller than a region of adjustment of the throttle opening of the decompression section in the equipment cooling.

2. The refrigeration cycle apparatus according to claim 1,

the decompression part has the following structure: a discharge port (135a) is provided having a constant opening area, and the refrigerant is depressurized as it passes therethrough.

3. The refrigeration cycle apparatus according to claim 1 or 2,

the opening degree control unit controls the throttle opening degree of the decompression unit such that an adjustment frequency of the throttle opening degree of the decompression unit during indoor heating is smaller than the adjustment frequency during equipment cooling.

4. The refrigeration cycle apparatus according to any one of claims 1 to 3,

the opening degree control unit controls a throttle opening degree of the decompression unit so as to maintain a refrigerant state on a refrigerant outlet side of the evaporator in a saturated state or an overheated state when the equipment is cooled.

5. A refrigeration cycle apparatus capable of performing indoor heating for heating supply air blown into a space to be air-conditioned, equipment cooling for cooling a heat-generating equipment (BT), and indoor cooling for cooling the supply air, the refrigeration cycle apparatus comprising:

a compressor (11) that compresses and discharges a refrigerant containing oil;

a radiator (12) that heats the air to be blown into the space to be air-conditioned using, as a heat source, the refrigerant discharged from the compressor during the indoor heating;

a first decompression unit (13) that decompresses the refrigerant that has passed through the radiator;

a second decompression unit (15) that is arranged in parallel with the first decompression unit on the downstream side of the radiator in the refrigerant flow;

a facility cooler (14) that functions as a cooler for cooling the heat generating facility by using latent heat of evaporation of the refrigerant decompressed by the first decompression unit when the facility is cooled, and functions as a heat absorber when the room is heated;

a cooler (16) for an air conditioner; the air conditioning cooler cools the air by using latent heat of evaporation of the refrigerant decompressed by the second decompression unit; and

an opening degree control unit (80a) that controls the throttle opening degrees of the first and second pressure reducing units,

the radiator has a condensing unit (121) for condensing the refrigerant and a receiver (122) for gas-liquid separating the refrigerant passing through the condensing unit and storing the remaining liquid refrigerant in the cycle,

the opening degree control unit controls a throttle opening degree of the first decompression unit so as to maintain a refrigerant state at a refrigerant outlet side of the equipment cooler in a saturated state or a wet state during the indoor heating,

a lower limit of the throttle opening degree of the adjustment region in the indoor heating is smaller than a region of adjustment of the throttle opening degree of the first decompression section in the equipment cooling.

6. The refrigeration cycle apparatus according to claim 5,

the second decompression portion is configured to be fully closable,

the opening degree control unit controls the second decompression unit to be fully closed when the room is heated, and controls the first decompression unit to perform a decompression function.

7. The refrigeration cycle apparatus according to claim 5 or 6,

the first decompression part has the following structure: a discharge port (135a) is provided having a constant opening area, and the refrigerant is depressurized as it passes therethrough.

8. The refrigeration cycle apparatus according to any one of claims 5 to 7,

the opening degree control unit controls the throttle opening degree of the first pressure reducing unit such that an adjustment frequency of the throttle opening degree of the first pressure reducing unit during heating of the room is smaller than the adjustment frequency during cooling of the equipment.

9. The refrigeration cycle apparatus according to any one of claims 5 to 8,

the opening degree control unit controls the throttle opening degree of the first decompression unit so as to maintain a refrigerant state on a refrigerant outlet side of the equipment cooler in a saturated state or an overheated state when the equipment is cooled.

10. The refrigeration cycle apparatus according to any one of claims 1 to 9,

the radiator is provided with a supercooling unit (123) which dissipates heat from the refrigerant stored in the liquid storage unit.

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