JP6984046B2 - Refrigeration cycle device - Google Patents

Description

The present invention relates to a refrigeration cycle device.

The refrigeration cycle device includes a compressor that compresses and raises the temperature of the gaseous refrigerant, a condenser that dissipates and condenses the pressurized and heated gaseous refrigerant to liquefy it, and decompresses and expands the liquefied refrigerant. It is equipped with an expansion valve that evaporates a part of the refrigerant and an evaporator that evaporates and vaporizes the remaining liquid refrigerant to remove heat from the surroundings. Further, the refrigerant vaporized in the evaporator is returned to the compressor. Thus, in the refrigeration cycle device, the refrigerant circulates between the compressor, the condenser, the expansion valve, and the evaporator. The refrigerant also releases heat to the external environment of the condenser while passing through the condenser. The refrigerant absorbs heat from the evaporator's external environment while passing through the evaporator. Both the condenser and the evaporator are heat exchangers that exchange heat between the refrigerant and the external environment, and have a common basic mechanical configuration.

The refrigeration cycle device is used as a heat source for refrigerators or freezers, but is also used as a heat source for air conditioners. In a refrigerating cycle device used as a heat source of a refrigerator or the like, the evaporator is always arranged in the refrigerator or the like, and the condenser is always arranged outside the refrigerator.

When the air conditioner is used as a cooler, it is necessary to make the heat exchanger arranged in the room function as an evaporator and the heat exchanger arranged outside the room to function as a condenser. When the air conditioner is used as a heater, it is necessary to make the heat exchanger arranged in the room function as a condenser and the heat exchanger arranged outside the room to function as an evaporator. Therefore, in the refrigeration cycle device used as a heat source of the air conditioner, it is necessary to provide a flow path switching device that changes the flow direction of the refrigerant between the cooling operation and the heating operation. In the refrigeration cycle device used as a heat source of the air conditioner, the heat exchanger arranged indoors is called a user side heat exchanger, and the heat exchanger arranged outdoors is called a heat source side heat exchanger. ..

Conventionally, in a refrigeration cycle device used as a heat source for an air conditioner, a four-way valve is often used as a flow path switching device. For example, Patent Document 1 discloses a vehicle air conditioner provided with a four-way valve as a flow path switching device.

The specific configuration of the four-way valve is shown in Patent Document 2. The four-way valve described in Patent Document 2 is arranged in a valve housing in which the first to fourth ports are opened and inside the valve housing, and rotates about an axis perpendicular to the plane in which the first to fourth ports are arranged. It is equipped with a valve body. In this four-way valve, by rotating the valve body around an axis, the first port and the second port are communicated with each other, and the third port and the fourth port are communicated with each other. It is possible to switch between a state in which the first port and the fourth port are communicated with each other and the second port and the third port are communicated with each other.

Japanese Unexamined Patent Publication No. 2002-316531 Japanese Unexamined Patent Publication No. 2002-22041

Conventionally, in an air conditioner for a vehicle, a fluorocarbon-based refrigerant called R407C has been frequently used. However, since R407C has a large GWP (Global Warming Potential), it is required to replace it with a low GWP from the viewpoint of preventing global warming. Therefore, carbon dioxide, which has both nonflammability and low GWP properties, is regarded as promising as an alternative refrigerant for air conditioners for vehicles. It is also described in Patent Document 1 that carbon dioxide is used as a refrigerant for an air conditioner for a vehicle.

When carbon dioxide is used as a refrigerant for a refrigeration cycle device, the design pressure is 14.0 Mpa, which is considerably larger than the design pressure of 2.94 Mpa for R407C. Therefore, when carbon dioxide is used as a refrigerant, it is necessary to improve the pressure resistance performance of the refrigeration cycle device. Naturally, it is necessary to improve the withstand voltage performance of the flow path switching device.

However, since the structure of a four-way valve is complicated, there is a problem that the external dimensions and mass of the four-way valve increase when trying to improve the pressure resistance performance of the four-way valve used as a flow path switching device. As a result, the external dimensions and mass of the entire refrigeration cycle device increase. In particular, since there are strict demands for miniaturization and weight reduction of air conditioners for vehicles, there is a strong demand for miniaturization and weight reduction of flow path switching devices.

Further, depending on the four-way valve, the inflow of the refrigerant into the compressor when the refrigeration cycle device is stopped cannot be blocked, so that a phenomenon called refrigerant stagnation in which the refrigerant stays in the compressor occurs. When the refrigerant slumps, the refrigerant dissolves in the lubricating oil in the compressor and the viscosity of the lubricating oil decreases, resulting in poor lubrication. Further, if the compressor is restarted after the refrigerant has fallen, the refrigerant dissolved in the lubricating oil may be gasified at once, and the lubricating oil may be in a foamed state and sufficient refueling may not be possible.

The present invention has been made in view of the above problems, and is a refrigerating cycle apparatus capable of using a high-pressure refrigerant, which can be made smaller and lighter, and can suppress refrigerant stagnation. The purpose is to provide.

The refrigeration cycle apparatus according to the present invention has an inflow port for inflow of refrigerant, an outflow port for outflow of refrigerant, first and second inflow / outflow ports for inflow or outflow of refrigerant, an inflow port and a first inflow / outflow port. Between the first communication flow path connecting the ports, the second communication flow path connecting the first inflow / outflow port and the outflow port, and the outflow port and the second inflow / outflow port. A third communication flow path connecting the two, a fourth communication flow path connecting the second inflow / outflow port and the inflow port, and a first communication flow path arranged in each of the first to fourth communication channels. A flow path switching device including first to fourth two-way valves that open and close each of the connecting flow paths 1 to 4, and a compressor arranged between the outflow port and the inflow port of the flow path switching device. , The user-side heat exchanger connected to the first inflow / outflow port of the flow path switching device, the heat source-side heat exchanger connected to the second inflow / outflow port of the flow path switching device, and the user-side heat exchanger. A first annular flow that departs from the expansion valve located between the heat exchanger and the outflow port of the flow path switching device, passes through the compressor, and returns to the inflow port of the flow path switching device. Starting from the path and the first inflow / outflow port of the flow path switching device, passing through the user side heat exchanger, the expansion valve, and the heat source side heat exchanger in order, the second inflow / outflow port of the flow path switching device. A second annular flow path is provided , and a plurality of first to fourth two-way valves are arranged in parallel in each of the first to fourth communication flow paths .

In the refrigeration cycle device according to the present invention, the flow path switching device is configured by four two-way valves instead of the conventional four-way valves. Since the two-way valve has a simpler structure than the four-way valve, the pressure resistance can be improved relatively easily. Therefore, the increase in external dimensions and mass when the withstand voltage performance is improved is small. Further, since the first to fourth connecting channels can be closed at the same time, the compressor can be isolated from the second annular channel when the refrigeration cycle device is stopped, and the refrigerant can be prevented from falling asleep.

Explanatory drawing which shows the structure of the refrigerating cycle apparatus which concerns on 1st Embodiment of this invention. Explanatory drawing which shows the structure of the flow path switching apparatus provided in the refrigeration cycle apparatus according to FIG. FIG. 2 is a diagram showing the configuration and operation of the electromagnetic on-off valve provided in the flow path switching device shown in FIG. 2, and is a cross-sectional view of the electromagnetic on-off valve in the closed state. FIG. 2 is a diagram showing the configuration and operation of the electromagnetic on-off valve provided in the flow path switching device shown in FIG. 2, and is a cross-sectional view of the electromagnetic on-off valve in the valve-opened state. Explanatory drawing which shows operation of the refrigerating cycle apparatus when the refrigerating cycle apparatus shown in FIG. 1 is operated in a cooling mode. Explanatory drawing which shows operation of the refrigerating cycle apparatus when the refrigerating cycle apparatus shown in FIG. 1 is operated in a heating mode. Explanatory drawing which shows the structure of the flow path switching apparatus provided in the refrigerating cycle apparatus which concerns on 2nd Embodiment Explanatory drawing which shows the structure of the refrigerating cycle apparatus which concerns on 1st modification Explanatory drawing which shows the structure of the refrigerating cycle apparatus which concerns on 2nd modification Explanatory drawing which shows the structure of the refrigerating cycle apparatus which concerns on 3rd modification Explanatory drawing which shows the structure of the refrigerating cycle apparatus which concerns on 4th modification

Hereinafter, the configuration and operation of the refrigeration cycle apparatus according to the embodiment of the present invention will be described in detail with reference to the drawings. In each drawing, the same or equivalent parts are designated by the same reference numerals.

(First Embodiment)
FIG. 1 is an explanatory diagram showing a configuration of a refrigeration cycle device 1 according to a first embodiment of the present invention. The refrigeration cycle device 1 is a device mounted on a vehicle (not shown) to adjust the temperature of the air in the vehicle interior of the vehicle, that is, to cool and heat the vehicle interior. Further, the refrigerating cycle device 1 uses carbon dioxide as a refrigerant.

As shown in FIG. 1, the refrigerating cycle device 1 includes a flow path switching device 2 that changes the direction in which the refrigerant flows. The flow path switching device 2 includes an inflow port 2a into which the refrigerant flows in, an outflow port 2b in which the refrigerant flows out, and first and second inflow / outflow ports 2c and 2d in which the refrigerant flows in and out. The detailed configuration of the flow path switching device 2 will be described later.

A compressor 3 is arranged between the inflow port 2a and the outflow port 2b of the flow path switching device 2. A pipeline 4a is arranged between the outflow port 2b and the compressor 3. Therefore, the refrigerant flowing out from the outflow port 2b flows into the inside of the compressor 3 through the pipeline 4a. Further, a pipeline 4b is arranged between the compressor 3 and the inflow port 2a. Therefore, the refrigerant compressed inside the compressor 3 and having a high temperature and high pressure flows into the inflow port 2a through the pipeline 4b. In this way, the refrigerant circulates between the flow path switching device 2 and the compressor 3. Further, according to the pipeline 4a and the pipeline 4b, the first ring that starts from the outflow port 2b of the flow path switching device 2, passes through the compressor 3, and returns to the inflow port 2a of the flow path switching device 2. The flow path 4 is formed.

Further, as shown in FIG. 1, the refrigerating cycle device 1 includes a user-side heat exchanger 5, a heat source-side heat exchanger 6, and an expansion valve 7. The user-side heat exchanger 5 is connected to the first inflow / outflow port 2c of the flow path switching device 2 via the pipeline 8a. The heat source side heat exchanger 6 is connected to the second inflow / outflow port 2d of the flow path switching device 2 via the pipeline 8d. The expansion valve 7 is arranged between the user side heat exchanger 5 and the heat source side heat exchanger 6. The expansion valve 7 is connected to the heat exchanger 5 on the utilization side via the pipe line 8b, and to the heat exchanger 6 on the heat source side via the pipe line 8c, respectively. As described above, according to the pipelines 8a, 8b, 8c, 8d, the heat exchanger 5, the expansion valve 7, and the heat source side heat exchange on the user side depart from the first inflow / outflow port 2c of the flow path switching device 2. A second annular flow path 8 is formed, which passes through the vessels 6 in order and returns to the second inflow / outflow port 2d of the flow path switching device 2. The direction in which the refrigerant flows in the second annular flow path 8 is changed by the flow path switching device 2. The operation of the flow path switching device 2 will be described in detail later.

The user-side heat exchanger 5 is a heat exchanger installed in a section to be air-adjusted to cool or heat the air in the section. Further, the user-side heat exchanger 5 includes a fan (not shown). The heat source side heat exchanger 6 is a heat exchanger that is installed outside the section that is the target of air adjustment and releases the heat carried by the refrigerant to the atmosphere or releases the heat carried by the atmosphere to the refrigerant. .. The heat source side heat exchanger 6 also includes a fan (not shown).

The expansion valve 7 is a device that decompresses and expands the liquefied refrigerant discharged from the user-side heat exchanger 5 or the heat source-side heat exchanger 6 to evaporate a part thereof.

Further, as shown in FIG. 1, the refrigerating cycle device 1 includes a control device 9. The control device 9 is a computer that controls the entire refrigeration cycle device 1. The flow path switching device 2, the compressor 3, the user-side heat exchanger 5, the heat source-side heat exchanger 6, and the expansion valve 7 are controlled by the control device 9.

FIG. 2 is an explanatory diagram showing a configuration of a flow path switching device 2 included in the refrigeration cycle device 1. As shown in FIG. 2, the flow path switching device 2 has a first communication flow path 21 for communicating between the inflow port 2a and the first inflow / outflow port 2c, and a first inflow / outflow port 2c and an outflow port. A second communication flow path 22 that communicates with 2b, a third communication flow path 23 that communicates between the outflow port 2b and the second outflow / inflow port 2d, and a second outflow / inflow port 2d. It is provided with a fourth communication flow path 24 that communicates with the inflow port 2a. Further, the first to fourth communication channels 21 to 24 are provided with the first to fourth electromagnetic on-off valves SV1 to SV4, respectively. The first to fourth electromagnetic on-off valves SV1 to SV4 are two-way valves controlled by the control device 9 to open and close each of the first to fourth communication channels 21 to 24. In FIG. 2, IN indicates the inflow port of the first to fourth electromagnetic on-off valves SV1 to SV4, and OUT indicates the outflow port of the first to fourth electromagnetic on-off valves SV1 to SV4. As will be described later, when the first to fourth electromagnetic on-off valves SV1 to SV4 are opened, the refrigerant flows from the inflow port IN toward the outflow port OUT.

3A and 3B are diagrams showing the configuration and operation of the first to fourth electromagnetic on-off valves SV1 to SV4. 3A is a cross-sectional view of the first to fourth electromagnetic on-off valves SV1 to SV4 in the closed state, and FIG. 3B is a cross-sectional view of the first to fourth electromagnetic on-off valves SV1 to SV4 in the open state. As shown in FIGS. 3A and 3B, the first to fourth electromagnetic on-off valves SV1 to SV4 include a casing 31, and the casing 31 is formed with an inlet IN and an outlet OUT. A valve body 32 and a spring 33 are arranged inside the casing 31. The spring 33 is an elastic member that urges the valve body 32 in the direction toward the valve seat 34.

In the state shown in FIG. 3A, the valve body 32 is pushed by the spring 33 and is in contact with the valve seat 34. Therefore, since the flow path from the casing 31 to the outlet OUT is blocked, the refrigerant that has flowed into the inside of the casing 31 through the inlet IN does not flow to the outlet OUT. Further, in the state shown in FIG. 3A, the fluid pressure of the refrigerant inside the casing 31 acts in the direction of bringing the valve body 32 into contact with the valve seat 34.

As shown in FIGS. 3A and 3B, a rod 35 made of a magnetic material is fixed to the back side of the valve body 32, that is, the surface opposite to the surface of the valve body 32 in contact with the valve seat 34. Further, a solenoid coil 36 is fixed to the casing 31. A rod 35 is inserted in the center of the solenoid coil 36. Therefore, when the solenoid coil 36 is energized under the control of the control device 9, the rod 35 is attracted to the solenoid coil 36 and moves upward in FIG. 3B, as shown in FIG. 3B. As a result, the valve body 32 separates from the valve seat 34. As a result, the refrigerant that has flowed into the inside of the casing 31 through the inlet IN flows out through the outlet OUT.

As shown in FIG. 1, the inflow port 2a of the flow path switching device 2 is connected to the discharge port of the compressor 3, and the outflow port 2b is connected to the inflow port of the compressor 3. Therefore, when the compressor 3 is operating, that is, when the refrigerating cycle device 1 is operating, the fluid pressure of the refrigerant in the inflow port 2a of the flow path switching device 2 is higher than the fluid pressure of the refrigerant in the outflow port 2b. , Always high. Further, as shown in FIG. 2, in the first to fourth electromagnetic on-off valves SV1 to SV4, the inflow port IN is located near the inflow port 2a and the outflow port OUT is located near the outflow port 2b. There is. Therefore, the fluid pressure of the refrigerant acting on the valve body 32 when the first to fourth electromagnetic on-off valves SV1 to SV4 are closed acts in the direction of pressing the valve body 32 against the valve seat 34. That is, the fluid pressure of the refrigerant acting on the valve body 32 acts in the direction of maintaining the valve closed state. As described above, since the closed state of the first to fourth electromagnetic on-off valves SV1 to SV4 is maintained by the fluid pressure of the refrigerant, the first to fourth electromagnetic on-off valves SV1 to SV4 may be inadvertently opened. It is suppressed.

As described above, the flow path switching device 2 is controlled by the control device 9, and the first to fourth electromagnetic on-off valves SV1 to SV4 are controlled by the control device 9 to be opened and closed. Further, the control device 9 can set the open / closed states of the first to fourth electromagnetic on-off valves SV1 to SV4 to correspond to the cooling operation mode, the heating operation mode, the pressure equalizing mode, the oil return mode, and the stop mode. .. The mode can be changed by manual operation of the control device 9.

(Cooling operation mode)
When operating the refrigerating cycle device 1 in the cooling operation mode, that is, when the refrigerating cycle device 1 functions as a cooling machine, the second electromagnetic on-off valve SV2 and the fourth electromagnetic on-off valve SV4 are opened, and the first The electromagnetic on-off valve SV1 and the third electromagnetic on-off valve SV3 are closed. Then, as shown in FIG. 4, in the flow path switching device 2, a flow path through which the refrigerant flows is formed between the inflow port 2a and the second inflow / outflow port 2d. Further, a flow path through which the refrigerant flows is formed between the outflow port 2b and the first outflow / inflow port 2c. Therefore, the refrigerant discharged from the compressor 3 follows the pipeline 4b, the flow path switching device 2, and the pipeline 8d in this order, and flows into the heat source side heat exchanger 6. After that, the refrigerant flows from the heat source side heat exchanger 6 through the pipeline 8c, the expansion valve 7, and the pipeline 8b in order, and flows into the utilization side heat exchanger 5. The refrigerant that has flowed into the user-side heat exchanger 5 flows into the flow path switching device 2 through the pipeline 8a. The refrigerant that has flowed into the flow path switching device 2 passes through the pipeline 4a and returns to the compressor 3. In this way, the refrigerant circulates in the second annular flow path 8 counterclockwise, that is, in the direction indicated by the arrow in FIG.

As described above, in the cooling mode, the refrigerant circulates counterclockwise in the second annular flow path 8, so that the heat source side heat exchanger 6 functions as a condenser. Further, the user-side heat exchanger 5 functions as an evaporator. Therefore, in the heat source side heat exchanger 6, the heat carried by the refrigerant is released to the atmosphere. In the user-side heat exchanger 5, the heat carried in the air in the section in which the user-side heat exchanger 5 is arranged is absorbed by the refrigerant. As a result, the air in the section where the user-side heat exchanger 5 is arranged is cooled.

(Heating operation mode)
When operating the refrigerating cycle device 1 in the heating operation mode, that is, when the refrigerating cycle device 1 functions as a heater, the first electromagnetic on-off valve SV1 and the third electromagnetic on-off valve SV3 are opened, and the second. The electromagnetic on-off valve SV2 and the fourth electromagnetic on-off valve SV4 are closed. Then, as shown in FIG. 5, in the flow path switching device 2, a flow path through which the refrigerant flows is formed between the inflow port 2a and the first inflow / outflow port 2c. Further, a flow path through which the refrigerant flows is formed between the outflow port 2b and the second outflow / inflow port 2d. Therefore, the refrigerant discharged from the compressor 3 follows the pipeline 4b, the flow path switching device 2, and the pipeline 8a in this order, and flows into the heat exchanger 5 on the user side. After that, the refrigerant flows from the user side heat exchanger 5 into the heat source side heat exchanger 6 by following the pipe line 8b, the expansion valve 7, and the pipe line 8c in order. The refrigerant that has flowed into the heat source side heat exchanger 6 flows into the flow path switching device 2 through the pipeline 8d. The refrigerant that has flowed into the flow path switching device 2 passes through the pipeline 4a and returns to the compressor 3. In this way, the refrigerant circulates in the second annular flow path 8 clockwise, that is, in the direction indicated by the arrow in FIG.

As described above, in the heating operation mode, the refrigerant circulates clockwise in the second annular flow path 8, so that the user-side heat exchanger 5 functions as a condenser. Further, the heat source side heat exchanger 6 functions as an evaporator. Therefore, in the user-side heat exchanger 5, the heat carried by the refrigerant is released to the air in the section in which the user-side heat exchanger 5 is arranged. In the heat source side heat exchanger 6, the heat carried in the atmosphere is absorbed by the refrigerant. As a result, the air in the section where the user-side heat exchanger 5 is arranged is heated.

(Pressure equalization mode)
In the cooling operation mode, the refrigerant in the heat source side heat exchanger 6 is in a higher pressure state than the refrigerant in the user side heat exchanger 5. On the other hand, in the heating operation mode, the refrigerant in the heat source side heat exchanger 6 is in a lower pressure state than the refrigerant in the user side heat exchanger 5. Therefore, when the cooling operation mode is directly switched to the heating operation mode or the heating operation mode is directly switched to the cooling operation mode, the high-pressure refrigerant flows into the compressor 3, so that an excessive load is applied to the compressor 3. In order to avoid such a phenomenon, in the refrigerating cycle apparatus 1, the cooling operation mode and the heating operation mode are switched to each other through the pressure equalizing mode described below.

In the pressure equalization mode, all of the first to fourth electromagnetic on-off valves SV1 to SV4 are opened under the control of the control device 9. When all of the first to fourth electromagnetic on-off valves SV1 to SV4 are opened, the pressure of the refrigerant in the first annular flow path 4 and the second annular flow path 8 becomes equal. After that, when the cooling operation mode or the heating operation mode is selected, each of the first to fourth electromagnetic on-off valves SV1 to SV4 is opened or closed, and then the compressor 3 is operated, the compressor 3 is operated. High-pressure refrigerant does not flow into the room. Therefore, an excessive load is not applied to the compressor 3.

(Oil return mode)
When the refrigeration cycle device 1 is operated, a part of the lubricating oil of the compressor 3 is mixed with the refrigerant and flows out into the first annular flow path 4 and the second annular flow path 8. As a result, poor lubrication may occur in the compressor 3. In order to avoid such a phenomenon, in the refrigerating cycle apparatus 1, the oil return mode described below is selected as necessary, and the inside of the first annular flow path 4 and the second annular flow path 8 is selected. The lubricating oil that has flowed out to the compressor 3 can be returned to the compressor 3.

In the oil return mode, the first electromagnetic on-off valve SV1 is closed and the second to fourth electromagnetic on-off valves SV2 to SV4 are opened under the control of the control device 9. When the oil return mode is selected with the compressor 3 stopped, the lubricating oil flowing out into the first annular flow path 4 and the second annular flow path 8 is returned to the compressor 3.

(Stop mode)
When the refrigerating cycle device 1 is stopped, the stop mode can be selected. When the stop mode is selected, all of the first to fourth electromagnetic on-off valves SV1 to SV4 are closed under the control of the control device 9. When all of the first to fourth electromagnetic on-off valves SV1 to SV4 are closed, the compressor 3 is isolated from the second annular flow path 8. That is, the flow of the refrigerant between the compressor 3 and the second annular flow path 8 is cut off. As a result, since the refrigerant does not flow into the compressor 3, the refrigerant does not stay in the compressor 3. Therefore, the occurrence of the refrigerant stagnation in the compressor 3 is prevented.

(Second embodiment)
In the first embodiment described above, an example in which one electromagnetic on-off valve SV1 to SV4 of the first to fourth valves SV1 to SV4 are arranged in each of the connecting flow paths 21 to 24 of the first to fourth flow path switching devices 2. showed that. However, the flow path switching device 2 is not limited to the one in which one of the first to fourth electromagnetic on-off valves SV1 to SV4 is arranged in each of the first to fourth communication flow paths 21 to 24. The flow path switching device 2 may arrange a plurality of first to fourth electromagnetic on-off valves SV1 to SV4 in parallel in each of the first to fourth communication flow paths 21 to 24. For example, as shown in FIG. 6, two first electromagnetic on-off valves SV1a and SV1b are provided in the first communication flow path 21, and two second electromagnetic on-off valves SV2a, are used in the second communication flow path 22. SV2b is arranged, two third electromagnetic on-off valves SV3a and SV3b are arranged in the third communication flow path 23, and two fourth electromagnetic on-off valves SV4a and SV4b are arranged in the fourth communication flow path 24, respectively. May be. In this way, if a plurality of electromagnetic on-off valves SV1 to SV4 of the first to fourth units are arranged in parallel in each of the first to fourth communication channels 21 to 24, the first to fourth communication channels 21 to 4 are arranged in parallel. Since the flow path resistance in 24 is reduced, the efficiency of the refrigeration cycle device 1 is improved.

(First modification)
The refrigerating cycle device 1 according to the first and second embodiments may be provided with a sensor for determining the direction in which the refrigerant flows in the second annular flow path 8. For example, as shown in FIG. 7, the pressure sensor P1 is connected to the conduit between the inflow port 2a and the compressor 3, that is, the conduit 4a, and the pipe between the first inflow / outflow port 2c and the user-side heat exchanger 5. The pressure sensor P2 in the path, that is, the conduit 8a, the pressure sensor P3 in the conduit between the outflow port 2b and the compressor 3, that is, the conduit 4a, and the second inflow / outflow port 2d and the heat source side heat exchanger 6. A pressure sensor P4 may be provided in each of the intervening pipelines, that is, the conduit 8d. The pressure sensors P1, P2, P3, and P4 are sensors that detect the magnitude of the pressure of the refrigerant flowing in each pipeline.

In the refrigeration cycle apparatus 1 shown in FIG. 7, if the pressure values p1 to p4 measured by the pressure sensors P1 to P4 have a relationship of p1 ≧ p4> p2 ≧ p3, the refrigerant is the second refrigerant in FIG. It can be determined that the annular flow path 8 circulates counterclockwise. That is, it can be determined that the refrigerating cycle device 1 is operated in the cooling operation cycle.

Further, in the refrigerating cycle apparatus 1 shown in FIG. 7, if the pressure values p1 to p4 measured by the pressure sensors P1 to P4 have a relationship of p1 ≧ p2> p4 ≧ p3, the refrigerant is the first in FIG. It can be determined that the ring-shaped flow path 8 of No. 2 circulates clockwise. That is, it can be determined that the refrigeration cycle device 1 is operated in the heating operation cycle.

(Second modification)
The sensor for determining the direction in which the refrigerant flows in the second annular flow path 8 is not limited to the set of the four pressure sensors P1 to P4 shown in FIG. 7. As shown in FIG. 8, the refrigeration cycle device 1 may be provided with two pressure sensors P2 and P4.

In the refrigeration cycle apparatus 1 shown in FIG. 8, if the pressure values p2 and p4 measured by the pressure sensors P2 and P4 have a relationship of p4> p2, in FIG. 8, the refrigerant is the second annular flow path 8 It can be judged that the inside is circulated counterclockwise. That is, it can be determined that the refrigerating cycle device 1 is operated in the cooling operation cycle.

Further, in the refrigeration cycle apparatus 1 shown in FIG. 8, if the pressure values p2 and p4 measured by the pressure sensors P2 and P4 have a relationship of p2> p4, in FIG. 8, the refrigerant is a second annular flow. It can be determined that the road 8 circulates clockwise. That is, it can be determined that the refrigeration cycle device 1 is operated in the heating operation cycle.

(Third modification example)
The sensor for determining the direction in which the refrigerant flows in the second annular flow path 8 is not limited to the pressure sensors P1 to P4. As shown in FIG. 9, the temperature sensor T1 is connected to the pipeline between the first inflow / outflow port 2c and the user side heat exchanger 5, that is, the conduit 8a, and the second inflow / outflow port 2d and the heat source side heat exchanger are connected. The temperature sensor T2 may be provided in each of the pipelines between No. 6, that is, the conduit 8d. The temperature sensors T1 and T2 are sensors that measure the temperature of the refrigerant flowing in each pipeline.

In the refrigeration cycle apparatus 1 shown in FIG. 9, if the temperatures t1 and t2 measured by the temperature sensors T1 and T2 have a relationship of t2> t1, in FIG. 9, the refrigerant flows in the second annular flow path 8. It can be judged that it circulates counterclockwise. That is, it can be determined that the refrigerating cycle device 1 is operated in the cooling operation cycle.

Further, in the refrigerating cycle apparatus 1 shown in FIG. 9, if the temperatures t1 and t2 measured by the temperature sensors T1 and T2 have a relationship of t1> t2, in FIG. 9, the refrigerant is the second annular flow path 8 It can be judged that the inside is circulated clockwise. That is, it can be determined that the refrigeration cycle device 1 is operated in the heating operation cycle.

(Fourth modification)
The sensor for determining the direction in which the refrigerant flows in the second annular flow path 8 is not limited to the pressure sensors P1 to P4 or the temperature sensors T1 and T2. Instead of these, the flow velocity sensors F1 and F2 that directly measure the flow velocity and the flow direction of the refrigerant flowing in the second annular flow path 8 may be provided. That is, as shown in FIG. 10, the flow velocity sensor F1 is connected to the pipeline between the first inflow / outflow port 2c and the user-side heat exchanger 5, that is, the conduit 8a, and the second inflow / outflow port 2d and the heat source side heat. The flow path sensor F2 may be provided in each of the conduits between the exchangers 6, that is, the conduit 8d.

In the above, an example in which both the flow velocity sensor F1 and the flow velocity sensor F2 are provided in the refrigeration cycle device 1 is shown, but either one of the flow velocity sensors F1 and F2 may be omitted. If the refrigeration cycle device 1 is provided with either one of the flow velocity sensors F1 and F2, the direction in which the refrigerant flows in the second annular flow path 8 can be determined.

As described above, the refrigerating cycle device 1 according to the first and second embodiments described above is the flow path switching device 2 in which the first to fourth electromagnetic on-off valves SV1 to SV4 are used instead of the conventional four-way valves. It is equipped with. The first to fourth electromagnetic on-off valves SV1 to SV4 are two-way valves and have a simpler structure than the four-way valve, so that the withstand voltage performance can be easily enhanced. Therefore, even when a refrigerant circulated at high pressure is used, it becomes easy to configure the flow path switching device 2 in a small size and a light weight. As a result, the refrigerating cycle device 1 can be easily reduced in size and weight.

Further, since the first to fourth electromagnetic on-off valves SV1 to SV4 constituting the flow path switching device 2 can be opened and closed independently of each other, the flow path switching device 2 is added to the heating operation mode and the cooling operation mode. You can select the stop mode, transformation mode, and oil return mode. Therefore, the occurrence of refrigerant stagnation or poor lubrication in the compressor 3 is suppressed.

Further, the refrigeration cycle device 1 according to each of the above modifications includes the pressure sensors P1 to P4, the temperature sensors T1 and T2, or the flow velocity sensors F1 and F2 in the second annular flow path 8, and the second annular flow. It is possible to confirm the direction in which the refrigerant flows in the road 8. Therefore, it is easy to control.

The technical scope of the present invention is not limited to the above embodiments. The present invention can be freely applied, modified, or improved as far as the technical idea shown in the claims is concerned.

In particular, the technical scope of the present invention is not limited to the refrigeration cycle apparatus using carbon dioxide as a refrigerant.

Further, in the description of the background technology, the air conditioner for a vehicle is exemplified, but the application of the refrigeration cycle device according to the present invention is not limited to the air conditioner for a vehicle.

The present invention allows for various embodiments and modifications without departing from the broad spirit and scope of the invention. Further, the above-described embodiments are for explaining the present invention, and do not limit the scope of the present invention. That is, the scope of the present invention is shown not by the embodiment but by the claims. And, various modifications made within the scope of the claims and within the scope of the equivalent invention are considered to be within the scope of the present invention.

This application is based on Japanese Patent Application No. 2018-24670 filed on December 25, 2018. The specification of Japanese Patent Application No. 2018-240670, the scope of claims, and the entire drawing shall be incorporated into this specification as a reference.

The present invention can be suitably used as a refrigeration cycle device.

1 Refrigeration cycle device, 2 Flow path switching device, 2a Inflow port, 2b Outflow port, 2c First inflow / outflow port, 2d Second inflow / outflow port, 3 Compressor, 4 First annular flow path, 4a, 4b Pipeline, 5 Utilization side heat exchanger, 6 Heat source side heat exchanger, 7 Expansion valve, 8 Second annular flow path, 8a, 8b, 8c, 8d pipeline, 9 Control device, 21 First communication flow path , 22 2nd communication flow path, 23 3rd communication flow path, 24 4th communication flow path, 31 casing, 32 valve body, 33 spring, 34 valve seat, 35 rod, 36 solenoid coil, SV1, SV1a, SV1b 1st solenoid on-off valve, SV2, SV2a, SV2b 2nd solenoid on-off valve, SV3, SV3a, SV3b 3rd solenoid on-off valve, SV4, SV4a, SV4b 4th solenoid on-off valve, IN inlet port, OUT outlet Port, P1, P2, P3, P4 pressure sensor, T1, T2 temperature sensor, F1, F2 flow velocity sensor

Claims (6)

The inflow port where the refrigerant flows in and
The outflow port from which the refrigerant flows out and
The first and second inflow / outflow ports into which the refrigerant flows in or out, and
A first communication flow path connecting the inflow port and the first inflow / outflow port,
A second communication flow path connecting the first outflow / inflow port and the outflow port,
A third communication flow path connecting the outflow port and the second outflow / inflow port,
A fourth communication flow path connecting the second inflow / outflow port and the inflow port,
A two-way valve arranged in each of the first to fourth communication channels and opening and closing each of the first to fourth communication channels, and a first to fourth two-way valve.
A flow path switching device equipped with
A compressor arranged between the outflow port and the inflow port of the flow path switching device, and
A user-side heat exchanger connected to the first inflow / outflow port of the flow path switching device, and
A heat source side heat exchanger connected to the second inflow / outflow port of the flow path switching device, and
An expansion valve arranged between the user-side heat exchanger and the heat source-side heat exchanger,
A first annular flow path that departs from the outflow port of the flow path switching device, passes through the compressor, and returns to the inflow port of the flow path switching device.
Starting from the first inflow / outflow port of the flow path switching device, passing through the utilization side heat exchanger, the expansion valve, and the heat source side heat exchanger in order, the second of the flow path switching device. A second annular flow path that returns to the inflow / outflow port of the
A plurality of the first to fourth two-way valves are arranged in parallel in each of the first to fourth communication channels .
Refrigeration cycle equipment. The pipeline connected to the flow path switching device is provided with a sensor for determining the direction in which the refrigerant flows in the second annular flow path.
The refrigeration cycle apparatus according to claim 1. The sensor is
The pipeline between the inflow port and the compressor, the pipeline between the first inflow / outflow port and the utilization side heat exchanger, and between the second inflow / outflow port and the heat source side heat exchanger. Arranged in each of the conduit, the conduit between the outflow port and the compressor,
A pressure sensor that detects the magnitude of the pressure of the refrigerant flowing in each of the above pipelines.
The refrigeration cycle apparatus according to claim 2. The sensor is
Arranged in each of the pipeline between the first inflow / outflow port and the utilization side heat exchanger, and the conduit between the second inflow / outflow port and the heat source side heat exchanger.
A pressure sensor that detects the magnitude of the pressure of the refrigerant flowing in each of the above pipelines.
The refrigeration cycle apparatus according to claim 2. The sensor is
Arranged in each of the pipeline between the first inflow / outflow port and the utilization side heat exchanger, and the conduit between the second inflow / outflow port and the heat source side heat exchanger.
A temperature sensor that detects the temperature of the refrigerant flowing in each of the pipelines.
The refrigeration cycle apparatus according to claim 2. The sensor is
Arranged in the pipeline between the first inflow / outflow port and the utilization side heat exchanger, or in the conduit between the second inflow / outflow port and the heat source side heat exchanger.
A flow velocity sensor that detects the direction in which the refrigerant flows in each of the pipelines.
The refrigeration cycle apparatus according to claim 2.

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