JP7092169B2 - Refrigeration cycle device - Google Patents

Description

The present invention relates to a refrigeration cycle apparatus.

In the refrigeration cycle apparatus, it has been proposed to use an R466A refrigerant as a refrigerant having a low global warming potential (GWP) (Patent Document 1). The R466A refrigerant is a _three -kind mixed refrigerant of R32 refrigerant, R125 refrigerant, and trifluoroiodomethane (CF 3I), and is decomposed in a high temperature environment to generate acid. Metal parts may corrode and damage the refrigeration cycle equipment. Therefore, as a related technique, there is one in which an acid capture filter for capturing an acid generated by the R466A refrigerant is provided in the refrigerant circuit (Patent Document 2).

Japanese Unexamined Patent Publication No. 2020-34261 Japanese Unexamined Patent Publication No. 2018-96571

In the related art described above, the acid capture filter is located between the expansion valve and the evaporator, or between the expansion valve and the condenser, and the gas-liquid two-phase refrigerant passes through the acid capture filter. The acid trapping filter has a structure having a large flow resistance in order to increase the contact area with the refrigerant. Therefore, there is a problem that a pressure loss occurs when the gas-liquid two-phase refrigerant passes through the acid capture filter, and the refrigerating capacity of the refrigerating cycle apparatus is lowered.

The disclosed technique has been made in view of the above, and provides a refrigerating cycle apparatus capable of suppressing a pressure loss of a refrigerant passing through a filter member and suppressing a decrease in the refrigerating capacity of the refrigerating cycle apparatus having the filter member. The purpose is to do.

One aspect of the refrigeration cycle apparatus disclosed in the present application is provided in a refrigerant circuit having a flow path through which a liquid single-phase refrigerant flows and a flow path through which the liquid single-phase refrigerant flows, and captures acid contained in the passing refrigerant. The refrigerant circuit includes a filter member and a supercooler provided on the upstream side of the filter member in the flow direction of the refrigerant and changing the gas-liquid two-phase refrigerant into a liquid single-phase supercooled refrigerant. .. The supercooler has a high-pressure side flow path and a low-pressure side flow path provided inside the supercooler, and sends the refrigerant flowing out of the high-pressure side flow path to the filter member to the refrigerant circuit. Is provided with a supercooling expansion valve in which the refrigerant before flowing into the filter member flows in and flows out to the low pressure side flow path of the supercooler.

According to one aspect of the refrigerating cycle apparatus disclosed in the present application, it is possible to suppress the pressure loss of the refrigerant passing through the filter member and suppress the decrease in the refrigerating capacity of the refrigerating cycle apparatus having the filter member.

FIG. 1 is a schematic view showing the entire refrigeration cycle apparatus of the first embodiment. FIG. 2 is a schematic view showing a first acid trap and a second acid trap included in the refrigeration cycle apparatus of Example 1. FIG. 3 is a schematic view showing a main part of the refrigeration cycle apparatus of the second embodiment. FIG. 4 is a schematic view showing a main part of the refrigeration cycle apparatus of the third embodiment. FIG. 5 is a schematic view showing a main part of the refrigeration cycle apparatus of the fourth embodiment.

Hereinafter, examples of the refrigeration cycle apparatus disclosed in the present application will be described in detail with reference to the drawings. The following examples do not limit the refrigeration cycle apparatus disclosed in the present application.

As the refrigerating cycle device of the embodiment, an air conditioner is taken as an example, and one indoor unit is connected to one outdoor unit so that the indoor unit can perform cooling operation or heating operation. explain. FIG. 1 is a schematic view showing the entire refrigeration cycle apparatus of the first embodiment.

(Refrigerant)
First, the refrigerant used in the refrigeration cycle device 1 of the embodiment will be described. In the refrigerating cycle device 1 of the embodiment, the R466A refrigerant is used as the refrigerant. The R466A refrigerant is a _three -component mixed refrigerant of R32 refrigerant, R125 refrigerant, and trifluoroiodomethane (CF 3I). The R466A refrigerant may be decomposed in a high temperature environment to generate acid after being compressed by the compressor of the compressor, and the acid may corrode the refrigerant circuit and damage the refrigeration cycle device. Therefore, in the refrigerating cycle device 1 of the embodiment, the acid contained in the refrigerant is captured by the first acid trap 34A and the second acid trap 34B, which will be described later, and the acid is removed from the refrigerant to remove the acid from the refrigerating cycle device 1. The damage is suppressed.

The refrigerant is not limited to the R466A refrigerant, and other refrigerants may be used as long as they may generate acid. For example, in a refrigerant containing HFO (hydrofluoroolefin), the steam pressure [kPa] of the refrigerant is low, and a region where the pressure becomes more negative than the atmospheric pressure is likely to occur during operation in the refrigerant circuit, so that the high-pressure refrigerant is depressurized. Since there is a tendency for oxygen to easily enter the refrigerant by sucking outside air into the refrigerant circuit in the section, the refrigerant is easily oxidatively decomposed to generate acid. Even when such a refrigerant is used, the present embodiment 1 may be applied, and the effects described later can be obtained as in the present embodiment 1.

(Configuration of refrigeration cycle equipment)
As shown in FIG. 1, the refrigerating cycle device 1 includes a refrigerant circuit 2 in which a refrigerant circulates, and an outdoor unit 3 and an indoor unit 4 provided in the refrigerant circuit 2. In FIG. 1, the flow of the refrigerant when the indoor unit 4 is cooled and operated is indicated by an arrow. The refrigerant circuit 2 has a liquid pipe 6 and a gas pipe 7 that connect the outdoor unit 3 and the indoor unit 4. One end of the liquid pipe 6 is connected to the closing valve (liquid two-way valve) 16 of the outdoor unit 3, and the other end is connected to the indoor unit 4. One end of the gas pipe 7 is connected to the closing valve (gas three-way valve) 17 of the outdoor unit 3, and the other end is connected to the indoor unit 4.

(Outdoor unit configuration)
First, the outdoor unit 3 will be described. The outdoor unit 3 includes a compressor 10, an accumulator 11, a four-way valve 12, an outdoor heat exchanger 13, an outdoor fan 14, an outdoor expansion valve 15, and a closing valve 16 to which one end of a liquid pipe 6 is connected. It includes a closing valve 17 to which one end of the gas pipe 7 is connected, and an accumulator 18 which is a refrigerant reservoir.

The compressor 10 is a rotary compressor having a variable capacity capable of varying the operating capacity by being driven by a motor (not shown) whose rotation speed is controlled by an inverter. Inside the compressor 10, refrigerating machine oil 9 as a lubricating oil for lubricating a sliding portion (not shown) is stored. The refrigerant discharge side of the compressor 10 is connected to an oil separator 22 that separates the refrigerating machine oil 9 from the refrigerant discharged from the compressor 10 via a discharge pipe 21a. Further, the oil separator 22 is connected to the port a of the four-way valve 12 described later via the refrigerant pipe 21b, and the refrigerant separated from the refrigerating machine oil 9 is sent to the four-way valve 12. Further, the oil separator 22 is connected to a refrigerant pipe 21c connected to the refrigerant inflow side of the accumulator 18, and the refrigerating machine oil 9 separated from the refrigerant is combined with the gas refrigerant sent from the accumulator 18 to the compressor accumulator 11. Will be sent to. The refrigerant pipe 21c is provided with a pressure reducing valve 23 for reducing the pressure of the refrigerating machine oil 9 from the oil separator 22. The refrigerant pipe 21c may be provided with a capillary tube (not shown) instead of the pressure reducing valve 23. The refrigerant suction side of the compressor 10 is connected to the refrigerant outflow side of the accumulator 18 and the refrigerant pipe 21c via the suction pipe 24. In this way, the compressor 10 is connected to the refrigerant circuit 2 filled with the refrigerant.

The four-way valve 12 is a switching valve for switching the flow direction of the refrigerant, and has four ports a, b, c, and d. The port a is connected to the refrigerant discharge side of the compressor 10 by the discharge pipe 21a via the oil separator 22 connected by the refrigerant pipe 21b as described above. The port b is connected to one of the refrigerant inlets and outlets of the outdoor heat exchanger 13 by a refrigerant pipe 26. The other refrigerant inlet / outlet of the outdoor heat exchanger 13 is connected to the liquid pipe 6 by the outdoor unit liquid pipe 29. The port c is connected to the refrigerant inflow side of the accumulator 18 via the refrigerant pipe 27. The port d is connected to the closing valve 17 by an outdoor unit gas pipe 28.

The outdoor heat exchanger 13 exchanges heat between the outside air taken into the inside of the outdoor unit 3 by the outdoor fan 14 and the refrigerant. One of the refrigerant inlets and outlets of the outdoor heat exchanger 13 is connected to the port b of the four-way valve 12 by a refrigerant pipe 26 as described above, and the other refrigerant inlet and outlet is connected to the closing valve 16 via the outdoor unit liquid pipe 29. Has been done.

The outdoor expansion valve 15 is provided in the outdoor unit liquid pipe 29. The outdoor expansion valve 15 is an electronic expansion valve, and by adjusting its opening degree, the amount of refrigerant flowing into the outdoor heat exchanger 13 or the amount of refrigerant flowing out of the outdoor heat exchanger 13 is adjusted. The opening degree of the outdoor expansion valve 15 is fully opened when the refrigerating cycle device 1 is performing the cooling operation. Further, when the refrigerating cycle device 1 is in the heating operation, the refrigerant discharge temperature is set to the compressor by controlling the opening degree of the outdoor expansion valve 15 according to the refrigerant discharge temperature from the compressor 10. It is adjusted so as not to exceed the upper limit of 10 in use.

The refrigerant inflow side of the accumulator 18 is connected to the port c of the four-way valve 12 via the refrigerant pipe 27, and the refrigerant outflow side of the accumulator 18 is connected to the refrigerant suction side of the compressor 10 via the suction pipe 24. In this way, the accumulator 18 is connected to the refrigerant circuit 2 and the compressor 10. The accumulator 18 separates the refrigerant flowing into the accumulator 18 from the refrigerant pipe 27 into a gas refrigerant and a liquid refrigerant. The separated gas refrigerant is sucked into the compressor 10 via the accumulator 11 for the compressor.

Further, the outdoor unit 3 includes an outdoor unit control circuit 30 as a control unit. Although not shown, the outdoor unit control circuit 30 is mounted on a control board housed in an electrical component box (not shown) of the outdoor unit 3. The outdoor unit control circuit 30 controls the drive of the compressor 10 and the outdoor fan 14 based on the detection results and control signals detected by various sensors (not shown) of the outdoor unit 3. Further, the outdoor unit control circuit 30 controls switching of the four-way valve 12 and adjusts the opening degree of the outdoor expansion valve 15 based on the detection results and control signals detected by various sensors of the outdoor unit 3.

(Main part of Example 1)
Further, in the refrigerant circuit 2, an outdoor unit liquid pipe 29 located between the outdoor heat exchanger 13 and the closing valve 16 is provided with a supercooler that changes a gas-liquid two-phase refrigerant into a liquid single-phase supercooling refrigerant. The overcooling heat exchanger 31 is provided. Further, the refrigerant circuit 2 extends a part of the refrigerant flowing between the overcooling heat exchanger 31 and the closing valve 16 from the port c of the four-way valve 12 to the accumulator 18 via the overcooling expansion valve 32. A refrigerant pipe 33 is provided. The supercooling heat exchanger 31 includes a high-pressure side flow path and a low-pressure side flow path (not shown). The refrigerant that has flowed out from the outdoor expansion valve 15 when the indoor unit 4 is operated for cooling flows into the high-pressure side flow path. The refrigerant flowing into the high-pressure side flow path exchanges heat with the refrigerant in the low-pressure side flow path, and then flows out to the closing valve 16 side. The low-pressure side flow path is provided in the refrigerant pipe 33, and the refrigerant flowing out from the supercooling expansion valve 32 flows into the flow path. The refrigerant flowing into the low-pressure side flow path exchanges heat with the refrigerant in the high-pressure side flow path, and then flows out to the refrigerant pipe 27 side. Further, the outdoor unit liquid pipe 29 is provided with a supercooling expansion valve 32 on the upstream side of the supercooling heat exchanger 31 in the flow direction F2 of the refrigerant when the indoor unit 4 is heated. With these configurations, the downstream side of the supercooling heat exchanger 31 in the outdoor unit liquid pipe 29 becomes a flow path 29a through which the liquid single-phase refrigerant flows.

As described above, the refrigerant circuit 2 has a flow path 29a through which the liquid single-phase refrigerant flows, and this flow path 29a corresponds to one section of the outdoor unit liquid pipe 29 in the refrigerant circuit 2. When the indoor unit 4 is cooled, the section between the supercooling heat exchanger 31 and the closing valve 16 in the outdoor unit liquid pipe 29 is the flow path 29a through which the liquid single-phase refrigerant flows. When the indoor unit 4 is heated, the section between the supercooling heat exchanger 31 and the outdoor expansion valve 15 in the outdoor unit liquid pipe 29 is the flow path 29a through which the liquid single-phase refrigerant flows.

Then, as shown in FIG. 1, the flow path 29a of the refrigerant circuit 2 has a first acid trap 34A and a second acid trap having an acid capture filter 35 as a filter member for capturing the acid contained in the passing refrigerant. Each vessel 34B is provided. The filter member includes an acid capture filter 35 of the first acid trap 34A as the first filter member and an acid capture filter 35 of the second acid trap 34B as the second filter member.

The first acid trap 34A is located on the downstream side of the supercooling heat exchanger 31 in the refrigerant flow direction F1 when the indoor unit 4 is cooled, that is, between the supercooling heat exchanger 31 and the closing valve 16. Have been placed. The second acid trap 34B is located on the downstream side of the supercooling heat exchanger 31 in the refrigerant flow direction F2 when the indoor unit 4 is heated, that is, between the supercooling heat exchanger 31 and the outdoor expansion valve 15. Is located in.

In other words, in the flow path 29a of the refrigerant circuit 2, the gas and liquid are on the upstream side of the refrigerant flow direction F1 when the indoor unit 4 is cooled and operated with respect to the first acid trap 34A having the acid capture filter 35. An overcooling heat exchanger 31 that changes a two-phase refrigerant into a liquid single-phase overcooling refrigerant is provided. Further, in the flow path 29a of the refrigerant circuit 2, gas and liquid 2 are located upstream of the refrigerant flow direction F2 when the indoor unit 4 is heated and operated with respect to the second acid trap 34B having the acid capture filter 35. An overcooling heat exchanger 31 that changes the phase refrigerant into a liquid single-phase overcooling refrigerant is provided.

FIG. 2 is a schematic view showing a first acid trap 34A and a second acid trap 34B included in the refrigeration cycle device 1 of the first embodiment. The first acid trap 34A and the second acid trap 34B have the same structure. As shown in FIG. 2, the first acid trap 34A and the second acid trap 34B have a container 36 through which the refrigerant flows in one direction, and an acid trap filter 35 is provided in the container 36. The acid capture filter 35 is, for example, a porous body formed by molding activated alumina particles, and captures acid by the adsorption action of the porous body. As a result, the refrigerating cycle device 1 is less likely to be damaged by the acid generated by the decomposition of the refrigerant in a high temperature environment.

In the first embodiment, the liquid single-phase refrigerant containing no gas phase passes through the acid capture filter 35. Considering the flow resistance when the refrigerant passes through the inside of the porous body which is the acid trapping filter 35, the liquid single phase refrigerant is compared with the case where the gas-liquid two-phase refrigerant passes through the inside of the acid trapping filter 35. The pressure loss due to the flow resistance when the refrigerant passes through the inside of the acid capture filter 35 is reduced. This is because the flow resistance when the gas phase refrigerant passes through the acid capture filter 35 is larger than the flow resistance when the liquid phase refrigerant passes through the acid capture filter 35. Since the flow resistance when the liquid single-phase refrigerant passes through the acid trapping filter is reduced in this way, the pressure loss due to the first acid trapping device 34A and the second acid trapping device 34B can be suppressed, so that the acid trapping filter 35 Even in the structure using the above, the decrease in the refrigerating capacity of the refrigerating cycle apparatus 1 can be suppressed.

Further, the flow resistance of the refrigerant passing through the acid capture filter 35 becomes small. When the flow resistance becomes small, the turbulent flow of the refrigerant in the acid capture filter 35 can be suppressed, so that the noise generated when the refrigerant passes through the acid capture filter 35 can be reduced.

Further, the upstream side and the downstream side of the first acid trap 34A in the flow path 29a are connected via the first detour flow path (bypass flow path) 37A. Similarly, the upstream side and the downstream side of the second acid trap 34B in the flow path 29a are connected via the second detour flow path (bypass flow path) 37B.

Between the first acid trap 34A and the closing valve 16, on the downstream side of the first acid trap 34A in the refrigerant flow direction F1 when the indoor unit 4 is cooled, from the overcooling heat exchanger 31 side. A check valve 38a for flowing the refrigerant only in the flow direction F1 toward the closing valve 16 side (indoor expansion valve 52 side described later) is provided. The first detour flow path 37A is provided with a check valve 38b that shuts off the refrigerant in the flow direction F1.

Between the outdoor expansion valve 15 and the second acid trap 34B, the overcooling heat exchanger 31 side is located downstream of the second acid trap 34B in the refrigerant flow direction F2 when the indoor unit 4 is heated. A check valve 38c for flowing the refrigerant only in the flow direction F2 toward the outdoor expansion valve 15 side is provided. The second detour flow path 37B is provided with a check valve 38d that shuts off the refrigerant in the flow direction F2.

Therefore, when the indoor unit 4 is cooled, the two-phase refrigerant that has passed through the outdoor expansion valve 15 passes through the second detour flow path 37B without passing through the second acid trap 34B, and the supercooling heat exchanger 31 The refrigerant that has passed through the above passes through the first acid trap 34A without passing through the first detour flow path 37A. Further, when the indoor unit 4 is heated, the refrigerant that has passed through the closing valve 16 has passed through the first detour flow path 37A without passing through the first acid trap 34A, and has passed through the overcooling heat exchanger 31. The two-phase refrigerant passes through the second acid trap 34B without passing through the second detour flow path 37B. As described above, the refrigerant passes through only one of the first acid trap 34A and the second acid trap 34B during the cooling operation and the heating operation.

As described above, the first acid trap 34A, the first detour flow path 37A, the check valves 38a, and 38b are cooling filter circuits 39A for removing the acid contained in the refrigerant when the indoor unit 4 is cooled. Consists of. Similarly, the second acid trap 34B, the second detour flow path 37B, the check valves 38c, and 38d provide a heating filter circuit 39B for removing the acid contained in the refrigerant when the indoor unit 4 is heated. It is composed.

(Composition of indoor unit)
Next, the indoor unit 4 will be described. The indoor unit 4 includes an indoor heat exchanger 51, an indoor expansion valve 52, and an indoor fan 53. In the indoor unit 4, one refrigerant inlet / outlet of the indoor heat exchanger 51 and the liquid pipe 6 are connected by the indoor unit liquid pipe 54, and the other refrigerant inlet / outlet of the indoor heat exchanger 51 and the gas pipe 7 are connected to the indoor unit. It is connected by a gas pipe 55.

The indoor heat exchanger 51 exchanges heat between the indoor air taken into the interior of the indoor unit 4 and the refrigerant from the suction port (not shown) by the indoor fan 53. The indoor heat exchanger 51 functions as an evaporator when the air conditioner 1 performs a cooling operation, and functions as a condenser when the indoor unit 4 performs a heating operation.

The indoor expansion valve 52 is provided in the indoor unit liquid pipe 54. The indoor expansion valve 52 is an electronic expansion valve, and when the indoor heat exchanger 51 functions as an evaporator, that is, when the indoor unit 4 performs a cooling operation, the degree of refrigerant superheat at the refrigerant outlet of the indoor heat exchanger 51 is high. It is adjusted to the target refrigerant superheat degree. Here, the target refrigerant superheat degree is the refrigerant superheat degree for the indoor unit 4 to exhibit sufficient cooling capacity. Further, in the indoor expansion valve 52, when the indoor heat exchanger 51 functions as a condenser, that is, when the indoor unit 4 performs a heating operation, the degree of cooling of the refrigerant excess at the refrigerant outlet of the indoor heat exchanger 51 is predetermined. It is adjusted to the target value.

Further, the indoor unit 4 includes an indoor unit control circuit 60. The indoor unit control circuit 60 is mounted on a control board housed in an electrical component box (not shown) of the indoor unit 4. The indoor unit control circuit 60 adjusts the opening degree of the indoor expansion valve 52 and the indoor fan 53 based on the detection results detected by various sensors (not shown) of the indoor unit 4 and the signals transmitted from the remote controller and the outdoor unit 3. Control the drive of. The control circuit of the refrigeration cycle device 1 is composed of the outdoor unit control circuit 30 and the indoor unit control circuit 60 described above.

(Operation of refrigeration cycle device)
Next, the flow of the refrigerant and the operation of each part in the refrigerant circuit 2 during the air conditioning operation of the refrigeration cycle device 1 in the present embodiment will be described with reference to FIG. Hereinafter, the case where the indoor unit 4 performs the cooling / dehumidifying operation will be described, and the detailed description will be omitted when the indoor unit 4 performs the heating operation. Further, the arrow along the refrigerant flow direction F1 in FIG. 1 indicates the flow of the refrigerant during the cooling operation.

As shown in FIG. 1, when the indoor unit 4 performs the cooling operation, the outdoor unit control circuit 30 communicates the four-way valve 12 with a solid line in FIG. 1, that is, the port a and the port b of the four-way valve 12. Then, the port c and the port d are switched so as to communicate with each other. As a result, the refrigerant circuit 2 becomes a cooling cycle in which the outdoor heat exchanger 13 functions as a condenser and the indoor heat exchanger 51 functions as an evaporator.

The high-pressure refrigerant discharged from the compressor 10 flows through the discharge pipe 21a and the refrigerant pipe 21b and flows into the four-way valve 12, and from the four-way valve 12, the refrigerant pipe 26, the outdoor heat exchanger 13, the outdoor expansion valve 15, the second. The detour flow path 37B, the overcooling heat exchanger 31, the first acid trap 34A, the closing valve 16, and the liquid pipe 6 flow in this order and flow into the indoor unit 4. The refrigerant that has flowed into the indoor unit 4 flows through the indoor unit liquid pipe 54, flows into the indoor heat exchanger 51, and exchanges heat with the indoor air taken into the indoor unit 4 by the rotation of the indoor fan 53 to evaporate. do. In this way, the indoor heat exchanger 51 functions as an evaporator, and the indoor heat exchanger 51 exchanges heat with the refrigerant to blow out the cooled indoor air from the outlet (not shown) into the room. , The room in which the indoor unit 4 is installed is cooled.

The refrigerant flowing out of the indoor heat exchanger 51 flows through the indoor unit gas pipe 55 and flows into the gas pipe 7. The refrigerant flowing through the gas pipe 7 flows into the outdoor unit 3 through the closing valve 17. The refrigerant flowing into the outdoor unit 3 flows in the order of the outdoor unit gas pipe 28, the four-way valve 12, the refrigerant pipe 27, the accumulator 18, the suction pipe 24, and the accumulator 11 for the compressor, and is sucked into the compressor 10 and compressed again. ..

When the indoor unit 4 heats the four-way valve 12, the four-way valve 12 is shown by a broken line in FIG. 1, that is, the port a and the port d of the four-way valve 12 are connected, and the port b and the port d are connected. Switch to. As a result, the refrigerant circuit 2 becomes a heating cycle in which the outdoor heat exchanger 13 functions as an evaporator and the indoor heat exchanger 51 functions as a condenser.

(Control of expansion valve)
Here, the control of the outdoor expansion valve 15 and the indoor expansion valve 52 in the refrigeration cycle device 1 of the first embodiment will be described. Hereinafter, regarding the temperature of the refrigerant, for example, the high temperature is about 90 ° C, the medium temperature is about 40 ° C, and the low temperature is about 10 ° C. Regarding the pressure of the refrigerant, for example, the high pressure is about 3.0 MPa, the medium pressure is about 2.8 MPa, and the low pressure is about 0.9 MPa.

During the cooling operation, the medium-temperature and high-pressure refrigerant flows into the inlet of the outdoor expansion valve 15, and the medium-temperature and high-pressure refrigerant flows out from the outlet of the outdoor expansion valve 15. As a result, the high-pressure refrigerant flows into the supercooling heat exchanger 31 located on the downstream side of the outdoor expansion valve 15 in the refrigerant flow direction F1, and the liquid single-phase refrigerant flows out from the supercooling heat exchanger 31. At this time, in order to send the refrigerant to the inlet of the indoor expansion valve 52 while ensuring the supercooled state, the outdoor unit control circuit 30 of the refrigeration cycle device 1 controls so that the opening degree of the outdoor expansion valve 15 is fully opened. .. That is, the outdoor expansion valve 15 does not reduce the pressure of the refrigerant during the cooling operation.

Further, during the cooling operation, the medium-temperature and medium-pressure refrigerant flows into the inlet of the indoor expansion valve 52, and the low-temperature and low-pressure refrigerant flows out from the outlet of the indoor expansion valve 52. At this time, the indoor unit control circuit 60 of the refrigeration cycle device 1 decompresses the refrigerant to the evaporation temperature at which the indoor heat exchanger 51 can obtain an appropriate evaporation capacity, and controls the flow rate of the refrigerant. Further, the indoor unit control circuit 60 determines the degree of refrigerant superheat at the outlet of the indoor heat exchanger 51 (from the temperature of the refrigerant at the outlet of the indoor heat exchanger 51 (evaporator) to the temperature of the refrigerant at the inlet of the indoor heat exchanger 51). The subtracted value) is controlled to be kept at a predetermined target value.

During the heating operation, the medium-temperature and high-pressure refrigerant flows into the inlet of the indoor expansion valve 52, and the medium-temperature and high-pressure refrigerant flows out from the outlet of the indoor expansion valve 52. As a result, the high-pressure refrigerant flows into the supercooling heat exchanger 31 located on the downstream side of the indoor expansion valve 52 in the refrigerant flow direction F2, and the liquid single-phase refrigerant flows out from the supercooling heat exchanger 31. Further, the indoor unit control circuit 60 controls to keep the degree of refrigerant supercooling (a value obtained by subtracting the temperature of the refrigerant at the outlet of the indoor heat exchanger 51 (condenser) from the high-pressure saturation temperature) at a predetermined target value. ..

Further, during the heating operation, the medium-temperature and medium-pressure refrigerant flows into the inlet of the outdoor expansion valve 15, and the low-temperature and low-pressure refrigerant flows out from the outlet of the outdoor expansion valve 15. At this time, the outdoor unit control circuit 30 of the refrigeration cycle device 1 decompresses the refrigerant to the evaporation temperature at which the outdoor heat exchanger 13 can obtain an appropriate evaporation capacity by adjusting the opening degree of the outdoor expansion valve 15, and the refrigerant is charged. Control the flow rate.

(Effect of Example 1)
As described above, the refrigerating cycle apparatus 1 of the first embodiment has a refrigerant circuit 2 having a flow path 29a through which a liquid single-phase refrigerant flows, and an acid provided in the flow path 29a to capture an acid contained in the passing refrigerant. A capture filter 35 is provided. By passing the liquid single-phase refrigerant through the acid capture filter 35 in this way, the flow when the refrigerant passes through the acid capture filter 35 as compared with the case where the gas-liquid two-phase refrigerant passes through the acid capture filter 35. Pressure loss due to resistance is reduced. As a result, it becomes possible to suppress the pressure loss of the refrigerant passing through the acid trapping filter 35, and it is possible to suppress the decrease in the refrigerating capacity of the refrigerating cycle device 1 having the acid trapping filter 35.

Further, in the refrigeration cycle device 1, the flow resistance when the liquid single-phase refrigerant passes through the acid capture filter 35 is smaller than that in the case where the gas-liquid two-phase refrigerant passes through the acid capture filter 35. When the flow resistance becomes small, the turbulent flow of the refrigerant in the acid capture filter 35 can be suppressed, so that the noise generated when the refrigerant passes through the acid capture filter 35 can be reduced.

Further, in the refrigerant circuit 2 of the refrigeration cycle device 1 of the first embodiment, supercooling that changes the gas-liquid two-phase refrigerant into a liquid single-phase supercooling refrigerant on the upstream side in the flow direction of the refrigerant with respect to the acid capture filter 35. A heat exchanger 31 is provided. This makes it possible to reliably send the liquid single-phase refrigerant to the acid capture filter 35. Further, according to the first embodiment, by arranging the acid trapping filter 35 on the downstream side of the supercooling heat exchanger 31, for example, a part of the refrigerant is caused by the pressure loss in the outdoor unit liquid pipe 29. Even when so-called flash gas, which is vaporized and bubbles are generated in the refrigerant, is generated, the refrigerant is overcooled in the overcooling heat exchanger 31, so that the liquid single-phase refrigerant is suitable for the acid capture filter 35. Can be sent to.

Further, the acid capture filter 35 included in the refrigeration cycle device 1 of the first embodiment is the acid capture filter 35 of the first acid capture device 34A as the first filter member and the second acid capture device 34B as the second filter member. Includes acid capture filter 35. The refrigerant circuit 2 includes a first detour flow path 37A connecting the upstream side of the first acid catcher 34A and the downstream side of the first acid catcher 34A in the flow directions F1 and F2 of the refrigerant, and a second acid catcher. A second detour flow path 37B connecting the upstream side of the 34B and the downstream side of the second acid trap 34B is provided, and the refrigerant is the first acid trap 34A and the first acid trap 34A during the heating operation and the cooling operation of the indoor unit 4. Only one of the two acid traps 34B is passed. As a result, the refrigerant passes through the acid capture filter 35 on the downstream side of the overcooling heat exchanger 31 in both the refrigerant flow direction F1 during cooling operation and the refrigerant flow direction F2 during heating. Further, since only one of the first acid trap 34A and the second acid trap 34B is passed, the influence of the flow resistance by the acid trap 35 during operation is only one, so that the refrigeration cycle device 1 It is possible to suppress a decrease in the refrigerating capacity of.

Further, according to the first embodiment, since the liquid single-phase refrigerant passes through the acid capture filter 35, the lubricating oil 9 contained in the refrigerant is suppressed from staying in the acid capture filter 35, so that the lubricating oil 9 in the compressor 10 is suppressed. The decrease in the amount of the lubricating oil 9 is suppressed, and the operation of the compressor 10 can be properly maintained by the lubricating oil 9. In the case of a gas-liquid two-phase state refrigerant containing a gas-phase refrigerant, the lubricating oil 9 may separate and stay in the acid capture filter 35, but in the case of a liquid single-phase refrigerant, the lubricating oil 9 is combined with the liquid refrigerant. Since it passes through the acid capture filter 35, it does not stay in the acid capture filter 35.

In Example 1 described above, the supercooling heat exchanger 31 was used to send the liquid single-phase refrigerant to the flow path 29a, but instead of the supercooling heat exchanger 31, a liquid single-phase refrigerant was used. A gas-liquid separator that separates from the gas-single-phase refrigerant may be used. When a gas-liquid separator is used in place of the overcooling heat exchanger 31 in the refrigerant circuit 2 shown in FIG. 1, the liquid-single-phase refrigerant is sent to the flow path 29a through the gas-liquid separator and the gas-liquid. A single-phase refrigerant from the separator is sent to the refrigerant pipe 27 through the refrigerant pipe 33. However, the gas-liquid separator tends to have a higher enthalpy of the liquid single-phase refrigerant flowing out of the gas-liquid separator as compared with the case where the supercooling heat exchanger 31 is used. Since the refrigerant having a high enthalpy is sent to the evaporator (outdoor heat exchanger 13 or indoor heat exchanger 51), the coefficient of performance (COP) in the refrigeration cycle apparatus 1 decreases, so that the gas-liquid separator is used. It is preferable to use a supercooled heat exchanger rather than using it.

Hereinafter, other embodiments will be described with reference to the drawings. In another embodiment, the same components as those in the first embodiment are designated by the same reference numerals as those in the first embodiment, and the description thereof will be omitted.

FIG. 3 is a schematic view showing a main part of the refrigeration cycle apparatus of the second embodiment. Example 2 differs from Example 1 in that it has a bridge circuit provided with a single acid trap.

As shown in FIG. 3, the refrigerant circuit 2 of the refrigeration cycle apparatus of the second embodiment includes a bridge circuit 61 having a supercooling heat exchanger 31 and an acid trap 34. The bridge circuit 61 is provided with a single acid trap 34, and the refrigerant flows in only one direction with respect to the acid trap 34 as described later. The acid trap 34 is configured in the same manner as the first acid trap 34A and the second acid trap 34B in Example 1, and has an acid trap filter 35. Although not shown in FIG. 3, a refrigerant pipe 33 that sends a gas refrigerant to the refrigerant pipe 27 is connected to the low-pressure side flow path of the supercooling heat exchanger 31 (see FIG. 1). The refrigerant pipe 33 transfers a part of the refrigerant flowing between the supercooling heat exchanger 31 and the acid trap 34 from the port c of the four-way valve 12 to the accumulator 18 via the supercooling expansion valve 32 and the low pressure side flow path. It flows into the extending refrigerant pipe 27.

In the second embodiment, the portion A including the bridge circuit 61 having the supercooled heat exchanger 31 and the acid trap 34 is the supercooled heat exchanger 31, the first acid trap 34A, and the second acid trap 34B in FIG. It has the same function as the portion A including the above.

The bridge circuit 61 has a first flow path 61a, a second flow path 61b, a third flow path 61c, a fourth flow path 61d, and a fifth flow path 61e, and the first flow path excluding the third flow path 61c. Check valves 62 are provided in the passage 61a, the second flow path 61b, the fourth flow path 61d, and the fifth flow path 61e, respectively. Specifically, the check valve 62 provided in the first flow path 61a regulates the flow of the refrigerant from the supercooling heat exchanger 31 to the outdoor expansion valve 15. The check valve 62 provided in the second flow path 61b regulates the flow of the refrigerant from the outdoor expansion valve 15 to the acid trap 34. The check valve 62 provided in the fourth flow path 61d regulates the flow of the refrigerant from the supercooling heat exchanger 31 to the indoor expansion valve 52. The check valve 62 provided in the fifth flow path 61e regulates the flow of the refrigerant from the indoor expansion valve 52 to the acid trap 34. In the bridge circuit 61, the supercooling heat exchanger 31 and the acid trap 34 are arranged in this order along the third flow path 61c through which the refrigerant flows in only one direction. In the third flow path 61c of the bridge circuit 61, one section on the downstream side of the supercooling heat exchanger 31 in the flow direction of the refrigerant corresponds to the flow path 29a through which the liquid single-phase refrigerant flows. In the bridge circuit 61, the liquid single-phase refrigerant that has passed through the supercooling heat exchanger 31 flows into the acid trapping filter 35 of the acid trapping device 34.

When the indoor unit 4 is cooled, the refrigerant flowing into the bridge circuit 61 from the outdoor expansion valve 15 flows in the flow direction F1 of the refrigerant in the order of the first flow path 61a, the third flow path 61c, and the fifth flow path 61e. Is sent to the indoor expansion valve 52. On the other hand, when the indoor unit 4 is heated, the refrigerant flowing into the bridge circuit 61 from the indoor expansion valve 52 is the refrigerant flow direction F2 in the order of the fourth flow path 61d, the third flow path 61c, and the second flow path 61b. And is sent to the outdoor expansion valve 15.

(Effect of Example 2)
The refrigeration cycle apparatus of the second embodiment includes the bridge circuit 61, so that one acid trap 34 can be used without using the two first acid traps 34A and the second acid traps 34B as in the first embodiment. The refrigerant circuit 2 can be compactly configured by using the refrigerant circuit 2.

Further, also in the second embodiment, as in the first embodiment, the liquid single-phase refrigerant passes through the acid capture filter 35, so that the gas-liquid two-phase refrigerant passes through the acid capture filter 35, as compared with the case where the liquid single-phase refrigerant passes through the acid capture filter 35. Since it is possible to suppress the pressure loss of the refrigerant passing through the acid trapping filter 35, it is possible to suppress a decrease in the refrigerating capacity of the refrigerating cycle apparatus having the acid trapping filter 35. Further, also in the second embodiment, the noise generated when the liquid single-phase refrigerant passes through the acid capture filter 35 can be reduced as compared with the case where the gas-liquid two-phase refrigerant passes through the acid capture filter 35.

FIG. 4 is a schematic view showing a main part of the refrigeration cycle apparatus of the third embodiment. Example 3 is different from Example 2 in that it has a bridge circuit 61 provided with a gas-liquid separator.

As shown in FIG. 4, the refrigeration cycle apparatus of Example 3 includes a bridge circuit 61 having a gas-liquid separator 64 and an acid trap 34. In Example 3, a gas-liquid separator 64 is used instead of the supercooling heat exchanger 31 in Example 2. The gas-liquid separator 64 is arranged on the upstream side of the acid trap 34 so that the liquid outlet is connected to the acid trap 34 side. The gas-liquid separator 64 separates the liquid single-phase refrigerant from the gas-liquid two-phase refrigerant, and sends the liquid single-phase refrigerant to the acid capture filter 35. Although not shown in FIG. 4, the gas outlet of the gas-liquid separator 64 is connected to a refrigerant pipe 33 that sends the separated gas phase refrigerant (gas refrigerant) to the refrigerant pipe 27 (see FIG. 1). In the refrigerant pipe 33, a part of the refrigerant flowing between the gas-liquid separator 64 and the acid trap 34 is passed through the bypass expansion valve (corresponding to the supercooling expansion valve 32 of the first embodiment) of the four-way valve 12. It flows into the refrigerant pipe 27 extending from the port c to the accumulator 18. In the third flow path 61c of the bridge circuit 61, one section on the downstream side of the gas-liquid separator 64 in the flow direction of the refrigerant corresponds to a flow path through which the liquid single-phase refrigerant separated from the gas phase refrigerant flows. As described above, in the bridge circuit 61, the liquid single-phase refrigerant sent from the gas-liquid separator 64 passes through the acid capture filter 35 of the acid trap 34.

Also in the third embodiment, the portion A including the bridge circuit 61 having the gas-liquid separator 64 and the acid trap 34 is the supercooled heat exchanger 31, the first acid trap 34A, and the second acid trap 34B in FIG. It has the same function as the portion A including the above.

(Effect of Example 3)
The refrigerating cycle apparatus of the third embodiment is provided with the bridge circuit 61 as in the second embodiment, so that the refrigerant does not use the two first acid traps 34A and the second acid traps 34B as in the first embodiment. The circuit 2 can be configured compactly.

Further, in the third embodiment, since the liquid single-phase refrigerant separated by the gas-liquid separator 64 can be sent to the acid trap 34, the gas-liquid two-phase refrigerant is the acid capture filter as in the first embodiment. Since it is possible to suppress the pressure loss of the refrigerant passing through the acid trapping filter 35 as compared with the case of passing through the acid trapping filter 35, it is possible to suppress a decrease in the refrigerating capacity of the refrigerating cycle apparatus having the acid trapping filter 35. Further, also in the second embodiment, the noise generated when the liquid single-phase refrigerant passes through the acid capture filter 35 can be reduced as compared with the case where the gas-liquid two-phase refrigerant passes through the acid capture filter 35.

In Example 1 (FIG. 1), the gas-liquid separator 64 may be used as in Example 3. For example, the upstream side of the first acid trap 34A in the flow direction F1 of the refrigerant and the refrigerant. A gas-liquid separator 64 may be provided on the upstream side of the second acid trap 34B in the flow direction F2. In this case, the two gas-liquid separators 64 are arranged so that the refrigerant can bypass the one gas-liquid separator 64 and the first acid trap 34A by the first detour flow path 37A, and the second detour flow path. The 37B is arranged so that the refrigerant can bypass the other gas-liquid separator 64 and the secondary acid trap 34B. Further, one gas-liquid separator 64 is arranged so that the liquid outlet is connected to the first acid trap 34A side, and the other gas-liquid separator 64 has a liquid outlet outlet of the second acid trap 34B. Arranged to be connected to the side.

FIG. 5 is a schematic view showing a main part of the refrigeration cycle apparatus of the fourth embodiment. The fourth embodiment is different from the second embodiment in that the receiver 65 is added to the bridge circuit 61 provided with the supercooled heat exchanger.

As shown in FIG. 5, the refrigeration cycle apparatus of Example 4 includes a bridge circuit 61 having a receiver 65, a supercooled heat exchanger 31 and an acid trap 34. The receiver 65 is arranged on the upstream side of the supercooling heat exchanger 31 in the flow direction of the refrigerant in the third flow path 61c, and the liquid single-phase refrigerant separated by the receiver 65 is transferred to the supercooling heat exchanger 31. Sent. Although not shown in FIG. 5, a refrigerant pipe 33 that sends a gas refrigerant to the refrigerant pipe 27 is connected to the low-pressure side flow path of the supercooling heat exchanger 31 (see FIG. 1). The refrigerant pipe 33 transfers a part of the refrigerant flowing between the supercooling heat exchanger 31 and the acid trap 34 from the port c of the four-way valve 12 to the accumulator 18 via the supercooling expansion valve 32 and the low pressure side flow path. It flows into the extending refrigerant pipe 27.

Also in the fourth embodiment, the portion A including the receiver 65, the supercooled heat exchanger 31 and the bridge circuit 61 having the acid trap 34 is the supercooled heat exchanger 31, the first acid trap 34A, the second in FIG. It has the same function as the portion A including the acid trap 34B.

(Effect of Example 4)
Since the refrigerating cycle apparatus of the fourth embodiment has a receiver 65 having a function of adjusting the amount of the refrigerant flowing through the refrigerant circuit 2 on the upstream side of the supercooling heat exchanger 31, the environmental load may fluctuate. I can handle it.

Further, also in the fourth embodiment, as in the first embodiment, the liquid single-phase refrigerant passes through the acid capture filter 35, so that the gas-liquid two-phase refrigerant passes through the acid capture filter 35, as compared with the case where the liquid single-phase refrigerant passes through the acid capture filter 35. Since it is possible to suppress the pressure loss of the refrigerant passing through the acid trapping filter 35, it is possible to suppress a decrease in the refrigerating capacity of the refrigerating cycle apparatus having the acid trapping filter 35. Further, also in the fourth embodiment, the noise generated when the liquid single-phase refrigerant passes through the acid capture filter 35 can be reduced as compared with the case where the gas-liquid two-phase refrigerant passes through the acid capture filter 35.

In Example 1 (FIG. 1), the receiver 65 may be used as in Example 4. For example, the upstream side of the first acid trap 34A in the refrigerant flow direction F1 and the refrigerant flow direction. The receiver 65 may be provided on either side of the upstream side of the second acid trap 34B in F2.

1 Refrigerant cycle device 2 Refrigerant circuit 15 Outdoor expansion valve 29 Outdoor unit liquid pipe 29a Flow path 31 Supercooling heat exchanger (supercooler)
34A 1st acid trap (acid trap)
34B second acid trap (acid trap)
35 Acid capture filter (filter member, first filter member, second filter member)
37A 1st detour flow path 37B 2nd detour flow path 52 Indoor expansion valve 61 Bridge circuit 64 Gas-liquid separator 65 Receiver

Claims (7)

A refrigerant circuit having a flow path through which a liquid single-phase refrigerant flows,
A filter member provided in the flow path and capturing an acid contained in the passing refrigerant,
In the refrigerant circuit, a supercooler provided on the upstream side of the filter member in the flow direction of the refrigerant and changing the gas-liquid two-phase refrigerant into a liquid single-phase supercooling refrigerant.
Equipped with
The supercooler has a high-pressure side flow path and a low-pressure side flow path provided inside the supercooler, and sends the refrigerant flowing out of the high-pressure side flow path to the filter member.
The refrigerating cycle apparatus is provided with a supercooling expansion valve in which the refrigerant before flowing into the filter member flows into the refrigerant circuit and flows out to the low pressure side flow path of the supercooler. A refrigerant circuit having a flow path through which a liquid single-phase refrigerant flows,
A filter member provided in the flow path and capturing an acid contained in the passing refrigerant,
In the refrigerant circuit, the liquid single-phase refrigerant is separated from the gas-liquid two-phase refrigerant provided on the upstream side of the filter member in the flow direction of the refrigerant, and the liquid single-phase refrigerant is used as the filter member. The gas-liquid separator to send and
Equipped with
The refrigerating cycle device is provided with a bypass expansion valve in which the refrigerant of the gas phase flowing out of the gas-liquid separator flows into the refrigerant circuit. A refrigerant circuit having a flow path through which a liquid single-phase refrigerant flows,
A filter member provided in the flow path and capturing an acid contained in the passing refrigerant,
Equipped with
The filter member includes a first filter member and a second filter member.
The refrigerant circuit includes a first detour flow path connecting the upstream side of the first filter member and the downstream side of the first filter member in the flow direction of the refrigerant, and the upstream side and the second filter member. A second detour flow path connecting the downstream side of the second filter member is provided.
A refrigerating cycle device in which the refrigerant passes through only one of the first filter member and the second filter member during heating operation and cooling operation of the indoor unit connected to the refrigerant circuit. In the refrigerant circuit, the liquid single-phase refrigerant is separated from the gas-liquid two-phase refrigerant on the upstream side in the flow direction of the refrigerant with respect to the supercooler, and the liquid single-phase refrigerant is used in the supercooler. There is a receiver to send to,
The refrigeration cycle apparatus according to claim 1. The filter member includes a first filter member and a second filter member.
The refrigerant circuit includes a first detour flow path connecting the upstream side of the first filter member and the downstream side of the first filter member in the flow direction of the refrigerant, and the upstream side and the second filter member. A second detour flow path connecting the downstream side of the second filter member is provided.
The refrigerant passes through only one of the first filter member and the second filter member during the heating operation and the cooling operation of the indoor unit connected to the refrigerant circuit.
The refrigeration cycle apparatus according to claim 1 or 2. The refrigerant circuit has a bridge circuit provided with the single filter member.
The bridge circuit includes a first flow path and a second flow path separated from one end side of the flow path, a third flow path connecting the first flow path and the second flow path in the previous period, and the other end of the flow path. The refrigerant is formed in only one direction with respect to the filter member provided in the third flow path, which is formed by the fourth flow path and the fifth flow path which are separated from the side and connected by the third flow path. The refrigerating cycle apparatus according to claim 1 or 2, which flows. The refrigerant is an R466A refrigerant.
The refrigeration cycle apparatus according to any one of claims 1 to 6.

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