JP5430634B2 - Refrigeration cycle apparatus and refrigerant recovery method for refrigeration cycle apparatus - Google Patents

Description

  The present invention relates to a refrigeration cycle apparatus and a refrigerant recovery method for the refrigeration cycle apparatus.

  In order to collect the refrigerant circulating in the refrigeration cycle apparatus, a refrigeration cycle apparatus that can be connected to the refrigerant collection apparatus has been conventionally proposed. As a refrigeration cycle apparatus that can connect such a refrigerant recovery apparatus, for example, “this refrigerant recovery apparatus 1 includes a compressor 2 whose suction side 2A is connected to a recovery port 5 via a heat exchanger 3; A shutoff valve 6 is provided connected to the discharge side 2B of the compressor 2. The shutoff valve 6 is connected to the discharge port 7 via the heat exchanger 3. The discharge port 7 is In order to recover the refrigerant of the refrigerator 100 with the refrigerant recovery apparatus 1, first, the recovery port 5 is connected between the compressor 101 and the outdoor heat exchanger 106. To the connection port 108 provided in the refrigerant pipe 110 of the above "(for example, see Patent Document 1).

Japanese Unexamined Patent Publication No. 2000-199660 (paragraphs 0019, 0021, FIG. 1)

  However, although the conventional refrigeration cycle apparatus prevents the refrigerant from leaking into the atmosphere in the refrigerant recovery operation, there is a problem that the refrigerant leaks into the atmosphere as described below in the refrigerant charging operation. .

  When the refrigerant is filled in the refrigerant circuit of the conventional refrigeration cycle apparatus, the following work is required. First, a vacuum source such as a vacuum pump is connected to a refrigerant recovery connection port (for example, connection port 108 of Patent Document 1) provided in the refrigerant circuit, and the refrigerant circuit is evacuated. Thereafter, the vacuum source is removed from the connection port, and the connection port and the connection hose connected to the refrigerant cylinder are connected. By doing so, the refrigerant is filled in the refrigerant circuit of the refrigeration cycle apparatus. However, in order to maintain the vacuum state in the refrigerant circuit, it is necessary to remove the air in the connection hose before connecting the connection port and the refrigerant hose. For this reason, before the connection port and the refrigerant hose are connected, the work of extruding the air in the connection hose by the refrigerant in the refrigerant cylinder through the connection hose is performed, and a small amount of refrigerant may leak into the atmosphere. there were.

By the way, in recent years, in order to suppress global warming, for example, it is desired to use a refrigerant having a low global warming coefficient such as tetrafluoropropene for the refrigeration cycle apparatus. However, tetrafluoropropene or the like has a lower condensation pressure or evaporation pressure than conventional refrigerants (for example, R410A and R407C). For this reason, a non-azeotropic refrigerant mixture in which a condensation pressure or an evaporation pressure is adjusted by mixing tetrafluoropropene or the like with a refrigerant having a lower boiling point than tetrafluoropropene or the like (for example, HFC-32) is often used. However, since HFC-32 is a flammable refrigerant, there is a problem that when HFC-32 leaks into the atmosphere, HFC-32 may be ignited. Moreover, since HFC-32 has a high global warming potential of 550, there is a problem that when HFC-32 leaks into the atmosphere, it adversely affects the global environment.
In addition, when recovering such a non-azeotropic refrigerant mixture from the refrigeration cycle apparatus, a conventional refrigerant recovery apparatus has an HFC refrigerant having a boiling point lower than that of tetrafluoropropene (for example, flammable and leaks to the atmosphere) Then, HFC-32), which has a large impact on the global environment (greenhouse), was not configured to focus on recovery.

  The present invention has been made on the basis of the above-described background. From a refrigerant circuit in which a non-azeotropic refrigerant mixture containing tetrafluoropropene and an HFC refrigerant having a boiling point lower than that of the tetrafluoropropene is circulated, It is an object of the present invention to obtain a refrigeration cycle apparatus capable of intensively collecting an HFC refrigerant having a boiling point lower than that of propene and a refrigerant recovery method for the refrigeration cycle apparatus.

  The global warming potential is the ratio of the effect of each greenhouse gas that causes global warming to the effect of carbon dioxide, which is approved by the Intergovernmental Panel on Climate Change (IPCC) This is the value agreed by the Conference of the Parties. This global warming potential is a value that is updated from time to time, and the Kyoto Protocol determines that the global warming potential is the value from the 1955 IPCC Second Assessment Report. The global warming potential shown in the present application is a value determined by the Kyoto Protocol.

The refrigeration cycle apparatus according to the present invention includes a compressor, a condenser, a throttling device, an evaporator, and an accumulator, which are connected by refrigerant piping, and includes a non-common that includes tetrafluoropropene and an HFC refrigerant having a boiling point lower than that of the tetrafluoropropene. A refrigerant circuit in which the boiling mixed refrigerant circulates, a branch pipe having one end connected between the compressor and the condenser, and a first refrigerant circuit connected to the other end of the branch pipe Side opening / closing device, a refrigerant flow rate adjusting unit provided in the branch pipe, and provided between the refrigerant flow rate adjusting unit and the first refrigerant circuit side opening / closing device, and flows between the accumulator and the compressor. A high- and low-pressure heat exchanger that exchanges heat between the non-azeotropic refrigerant mixture and the non-azeotropic refrigerant flowing through the branch pipe, and a first refrigerant circuit side opening / closing device that is detachably connected. Has receiver-side opening and closing device And receiver, provided in the refrigerant circuit includes a connection port connectable to a vacuum source, and the rear placing the refrigerant circuit in a state of non-azeotropic mixed refrigerant is not filled, the installation place of the refrigerant circuit The non-azeotropic refrigerant mixture is stored and the first receiver-side opening / closing device is closed, and the closed first receiver circuit-side opening / closing device is connected to the first receiver-side opening / closing device. By connecting to the refrigerant circuit, opening the first refrigerant circuit side opening / closing device, sucking the inside of the refrigerant circuit with a vacuum source connected to the connection port, the first receiver side opening / closing device And the refrigerant circuit is filled with the non-azeotropic refrigerant stored in the receiver .

  In the present invention, when the compressor is started, the evaporation amount of the HFC refrigerant having a low boiling point increases among the non-azeotropic refrigerants stored in the accumulator. For this reason, a non-azeotropic refrigerant mixture having a high HFC refrigerant ratio (hereinafter referred to as an HFC-rich non-azeotropic refrigerant mixture) circulates in the refrigerant circuit. The HFC-rich non-azeotropic refrigerant mixture flows into the refrigerant flow rate adjustment unit via the branch pipe, and the flow rate is adjusted by the refrigerant flow rate adjustment unit and flows into the high-low pressure heat exchanger. The non-azeotropic mixed refrigerant in the HFC-rich gas state flowing into the high-low pressure heat exchanger releases heat to the HFC-rich non-azeotropic mixed refrigerant sucked into the compressor and is stored in the receiver. Therefore, in the present invention, an HFC refrigerant having a boiling point lower than that of tetrafluoropropene is obtained from a refrigerant circuit in which a non-azeotropic refrigerant mixture containing tetrafluoropropene and an HFC refrigerant having a boiling point lower than that of tetrafluoropropene is circulated. It can be collected with priority.

1 is an example of a refrigerant circuit diagram of a refrigeration cycle apparatus according to Embodiment 1. FIG. 2 is an example illustrating a refrigerant recovery method of the refrigerant circuit diagram of the refrigeration cycle apparatus according to Embodiment 1. FIG. 6 is an example of a refrigerant circuit diagram of a refrigeration cycle apparatus according to Embodiment 2. FIG. It is an example of the refrigerant circuit figure which shows the state before performing refrigerant | coolant collection | recovery of the refrigeration cycle apparatus which concerns on Embodiment 2. FIG.

Embodiment 1 FIG.
(Constitution)
FIG. 1 is an example of a refrigerant circuit diagram of a refrigeration cycle apparatus according to Embodiment 1 of the present invention.
In the refrigeration cycle apparatus 100, a refrigerant circuit is configured by connecting a compressor 1, a four-way valve 2, an indoor heat exchanger 3, an expansion device 4, an outdoor heat exchanger 5, and an accumulator 6 with refrigerant piping. And the vacuum pump 9 is connected to the connection port 9a provided in the piping which connects the compressor 1 and the accumulator 6. FIG.
Note that the connection port 9 a is not necessarily provided in a pipe that connects the compressor 1 and the accumulator 6. If it is in the refrigerant circuit of the refrigerating cycle apparatus 100, the connection port 9a can be provided in arbitrary positions. Further, the vacuum source is not limited to the vacuum pump.

  The refrigeration cycle apparatus 100 according to the first embodiment is provided with a first branch pipe 13a having one end connected between the compressor 1 and the four-way valve 2. A first two-way valve 14a that can be opened and closed is connected to the other end of the first branch pipe 13a. Further, a second branch pipe 13 b having one end connected between the four-way valve 2 and the accumulator 6 is provided. A second two-way valve 14b that can be opened and closed is connected to the other end of the second branch pipe 13b. Here, the first two-way valve 14a and the second two-way valve 14b correspond to the first refrigerant circuit side opening / closing device and the second refrigerant circuit side opening / closing device of the present invention.

  Further, the refrigeration cycle apparatus 100 according to Embodiment 1 is provided with a receiver 7 capable of storing a refrigerant. The receiver 7 is provided with pipes on, for example, an upper part and a lower part of the receiver 7. Further, an openable / closable third two-way valve 8a is connected to the upper pipe of the receiver 7, and a openable / closable fourth two-way valve 8b is connected to the lower pipe of the receiver 7. Yes. Here, the third two-way valve 8a and the fourth two-way valve 8b correspond to the first receiver-side opening / closing device and the second receiver-side opening / closing device of the present invention.

  The first two-way valve 14a, the third two-way valve 8a, the second two-way valve 14b, and the fourth two-way valve 8b are detachably connected by the connection pipe 17a and the connection pipe 17b, respectively. Has been.

In addition, instead of the first branch pipe 13a and the first two-way valve 14a of the first embodiment, for example, a three-way valve may be directly provided between the compressor 1 and the four-way valve 2. If the connection port to the connection pipe 17a is a three-way valve that can be opened and closed, the same function as that of the first branch pipe 13a and the first two-way valve 14a is achieved. Further, instead of the second branch pipe 13b and the second two-way valve 14b, for example, a three-way valve may be directly provided between the four-way valve 2 and the accumulator 6. If the connection port with the connection pipe 17b is a three-way valve that can be opened and closed, the same function as the second branch pipe 13b and the second two-way valve 14b is achieved.
Further, instead of the third two-way valve 8a and the fourth two-way valve 8b, a connection port that can be opened and closed may be directly provided in the receiver 7.

(Used refrigerant)
In the refrigeration cycle apparatus 100 according to Embodiment 1, tetrafluoropropene (for example, 2,3,3,3-tetrafluoropropene) and an HFC refrigerant (for example, HFC-32) having a boiling point lower than that of tetrafluoropropene are used. And a combustible non-azeotropic refrigerant mixture 30 is used. Tetrafluoropropene has a low global warming potential (hereinafter referred to as GWP) of 4, and even if it leaks into the atmosphere, it has little impact on the global environment. On the other hand, HFC-32 has a high GWP of 550, and has a characteristic of having a great influence on the global environment (greenhouse) when leakage to the atmosphere occurs.

(Refrigerant filling method)
A refrigerant charging method of the refrigeration cycle apparatus 100 according to Embodiment 1 will be described.
First, a receiver 7 filled with a combustible non-azeotropic refrigerant mixture 30 in a safe place in advance is prepared. At this time, the third two-way valve 8a and the fourth two-way valve 8b are in a closed state. Next, the first two-way valve 14a and the third two-way valve 8a are connected by a connection pipe 17a, and the second two-way valve 14b and the fourth two-way valve 8b are connected by a connection pipe 17b. . Then, the first two-way valve 14a and the second two-way valve 14b are opened. Next, the inside of the refrigerant circuit of the refrigeration cycle apparatus 100 is sucked by the vacuum pump 9 connected to the connection port 9a. Then, the fourth two-way valve 8b is opened, and the refrigerant circuit is filled with the combustible non-azeotropic refrigerant mixture 30 filled in the receiver 7.

  With this configuration, the receiver 7 can be filled with the non-azeotropic refrigerant mixture 30 in a safe place in advance, so that the non-azeotropic refrigerant mixture 30 is prevented from leaking at the place where the refrigeration cycle apparatus 100 is installed. it can. Further, when the receiver 7 is connected to the refrigerant circuit of the refrigeration cycle apparatus 100, the first two-way valve 14a, the second two-way valve 14b, the third two-way valve 8a, and the fourth two-way valve 8b are closed. Therefore, it is possible to prevent the non-azeotropic refrigerant mixture 30 from leaking at the place where the refrigeration cycle apparatus 100 is installed. The first two-way valve 14a and the second two-way valve 14b are opened, and the third two-way valve 8a and the fourth two-way valve 8b are closed, and the inside of the refrigerant circuit of the refrigeration cycle apparatus 100 Can be sucked. For this reason, it is not necessary to perform the operation | work with the possibility of the refrigerant | coolant leakage for extracting the air inside the connection piping 17a and the connection piping 17b like the past. Therefore, when the refrigerant circuit of the refrigeration cycle apparatus 100 is filled with the refrigerant, the non-azeotropic mixed refrigerant 30 can be prevented from leaking into the atmosphere. For this reason, it is possible to prevent ignition of the leaked HFC-32. Moreover, the influence on the global environment by the refrigerant | coolant leak of HFC-32 with high GWP can also be suppressed.

(Refrigerant recovery method)
Next, a refrigerant recovery method for the refrigeration cycle apparatus 100 according to Embodiment 1 will be described.
FIG. 2 is an example showing a refrigerant recovery method of the refrigerant circuit diagram of the refrigeration cycle apparatus according to Embodiment 1 of the present invention. In FIG. 2, an external cooling device 40 is provided on the outer periphery of the receiver 7.
A receiver 7 whose inside is sucked in advance is prepared. At this time, the third two-way valve 8a and the fourth two-way valve 8b are in a closed state. Next, the first two-way valve 14a and the third two-way valve 8a are connected by a connection pipe 17a, and the second two-way valve 14b and the fourth two-way valve 8b are connected by a connection pipe 17b. . Then, the first two-way valve 14a, the second two-way valve 14b, the third two-way valve 8a, and the fourth two-way valve 8b are opened, and the refrigerant circuit of the refrigeration cycle apparatus 100 and the receiver 7 are communicated. .

  By connecting the refrigerant circuit of the refrigeration cycle apparatus 100 and the receiver 7, the non-azeotropic refrigerant mixture 30 in the refrigerant circuit of the refrigeration cycle apparatus 100 flows into the receiver 7. Next, the receiver 7 is cooled by the external cooling device 40 provided on the outer periphery of the receiver 7, and the gaseous non-azeotropic refrigerant mixture 30 that has flowed into the receiver 7 is condensed and liquefied. When the refrigerant circuit of the refrigeration cycle apparatus 100 has been filled but has flowed into the receiver 7, the third two-way valve 8a and the fourth two-way valve 8b are closed. Thereafter, the receiver 7 is removed from the refrigerant circuit of the refrigeration cycle apparatus 100 by removing each of the third two-way valve 8a and the fourth two-way valve 8b and each of the connection pipe 17a and the connection pipe 17b. The recovery of the boiling mixed refrigerant 30 is completed.

  In the present embodiment, the non-azeotropic refrigerant mixture 30 in the refrigerant circuit of the refrigeration cycle apparatus 100 is cooled after flowing into the receiver 7, but the receiver 7 is cooled. The cooling of the receiver 7 may be started before the boiling mixed refrigerant 30 flows into the receiver 7. Moreover, you may provide the external cooling device 40 in places other than the receiver 7, such as the connection piping 17a and the connection piping 17b, for example. It is also possible to collect the non-azeotropic refrigerant mixture 30 in the refrigerant circuit of the refrigeration cycle apparatus 100 in the receiver 7 without providing the external cooling device 40 in the receiver 7.

With this configuration, the receiver can be removed from the refrigerant circuit of the refrigeration cycle apparatus 100 after the third two-way valve 8a and the fourth two-way valve 8b are closed. When recovering the refrigerant from the circuit, the non-azeotropic refrigerant mixture 30 can be prevented from leaking into the atmosphere. For this reason, it is possible to prevent ignition of the leaked HFC-32. Moreover, the influence on the global environment by the refrigerant | coolant leak of HFC-32 with high GWP can also be suppressed.
In addition, by cooling the receiver 7 with the external cooling device 40, the condensed and liquefied refrigerant can be collected in the receiver 7.

  In the first embodiment, a piping path including the first branch pipe 13a, the first two-way valve 14a, the connection pipe 17a, and the third two-way valve 8a, the second branch pipe 13b, and the second The refrigerant circuit of the refrigeration cycle apparatus 100 and the receiver 7 are connected by two piping paths including a two-way valve 14b, a connecting pipe 17b, and a fourth two-way valve 8b, but only one of the piping paths However, it is possible to implement the present invention. Further, the connection positions of the first branch pipe 13a and the second branch pipe 13b and the refrigerant circuit of the refrigeration cycle apparatus 100 are not limited to the positions of the present embodiment.

Embodiment 2. FIG.
In the refrigerant recovery operation of the refrigeration cycle apparatus 100, the non-azeotropic refrigerant mixture 30 is focused on recovering HFC-32 that is flammable and has a great impact on the global environment (greenhouse) when leakage to the atmosphere occurs. Also good.

  FIG. 3 is an example of a refrigerant circuit diagram of the refrigeration cycle apparatus according to Embodiment 2 of the present invention. FIG. 4 is an example of a refrigerant circuit diagram showing a state before the refrigerant recovery of the refrigeration cycle apparatus. In the second embodiment, items that are not particularly described are the same as those in the first embodiment, and the same functions and configurations are described using the same reference numerals.

(Constitution)
In the refrigeration cycle apparatus 100 according to the second embodiment, the capillary 15 and the high / low pressure heat exchanger 16 are provided in the refrigeration cycle apparatus 100 according to the first embodiment. Here, the capillary 15 corresponds to the refrigerant flow rate adjusting unit of the present invention. The capillary tube 15 is provided in the first branch tube 13 a corresponding to the branch tube of the present invention, and has a function of adjusting the amount of the refrigerant flowing into the receiver 7. The high / low pressure heat exchanger 16 is provided between the capillary 15 of the first branch pipe 13a and the first two-way valve 14a. In the high-low pressure heat exchanger 16, the high-temperature gaseous refrigerant flowing through the first branch pipe 13 a and the low-temperature refrigerant flowing from the accumulator 6 to the compressor 1 perform heat exchange. The refrigeration cycle apparatus 100 according to Embodiment 2 also includes tetrafluoropropene (for example, 2,3,3,3-tetrafluoropropene) and an HFC refrigerant (for example, HFC-32) having a boiling point lower than that of tetrafluoropropene. A flammable non-azeotropic refrigerant mixture is used.

(Refrigerant filling method)
A refrigerant charging method of the refrigeration cycle apparatus 100 according to Embodiment 2 will be described.
First, a receiver 7 filled with a flammable non-azeotropic refrigerant mixture 30 (liquid) in a safe place is prepared in advance. At this time, the third two-way valve 8a and the fourth two-way valve 8b are in a closed state. Next, the first two-way valve 14a and the third two-way valve 8a are connected by a connection pipe 17a, and the second two-way valve 14b and the fourth two-way valve 8b are connected by a connection pipe 17b. . Then, the first two-way valve 14a and the second two-way valve 14b are opened. Next, the inside of the refrigerant circuit of the refrigeration cycle apparatus 100 is sucked by the vacuum pump 9 connected to the connection port 9a. Then, the fourth two-way valve 8b is opened, and the refrigerant circuit is filled with the combustible non-azeotropic refrigerant mixture 30 (liquid) filled in the receiver 7.

  With this configuration, the receiver 7 can be filled with the non-azeotropic refrigerant mixture 30 in a safe place in advance, so that the non-azeotropic refrigerant mixture 30 is prevented from leaking at the place where the refrigeration cycle apparatus 100 is installed. it can. Further, when the receiver 7 is connected to the refrigerant circuit of the refrigeration cycle apparatus 100, the first two-way valve 14a, the second two-way valve 14b, the third two-way valve 8a, and the fourth two-way valve 8b are closed. Therefore, it is possible to prevent the non-azeotropic refrigerant mixture 30 from leaking at the place where the refrigeration cycle apparatus 100 is installed. The first two-way valve 14a and the second two-way valve 14b are opened, and the third two-way valve 8a and the fourth two-way valve 8b are closed, and the inside of the refrigerant circuit of the refrigeration cycle apparatus 100 Can be sucked. For this reason, it is not necessary to perform the operation | work with the possibility of the refrigerant | coolant leakage for extracting the air inside the connection piping 17a and the connection piping 17b like the past. Therefore, when the refrigerant circuit of the refrigeration cycle apparatus 100 is filled with the refrigerant, the non-azeotropic mixed refrigerant 30 can be prevented from leaking into the atmosphere. For this reason, it is possible to prevent ignition of the leaked HFC-32. Moreover, the influence on the global environment by the refrigerant | coolant leak of HFC-32 with high GWP can also be suppressed.

(Refrigerant recovery method)
Next, a refrigerant recovery method for the refrigeration cycle apparatus 100 according to Embodiment 1 will be described.
In a state before the compressor 1 is started, an excess non-azeotropic refrigerant mixture 30 is stored in the accumulator 6. First, the compressor 1 is started with the first two-way valve 14a and the third two-way valve 8a opened and the second two-way valve 14b and the fourth two-way valve 8b closed. When the compressor 1 is started, the pressure of the accumulator 6 decreases. When the pressure of the accumulator 6 decreases, the non-azeotropic refrigerant mixture 30 (liquid) evaporates inside the accumulator 6. At this time, since the amount of evaporation of HFC-32 having a low boiling point increases, the compressor 1 has a non-azeotropic refrigerant mixture 30 (hereinafter referred to as HFC-32-rich non-azeotropic refrigerant mixture 32) having a high HFC-32 ratio. ) Will be inhaled.

  The HFC-32 rich non-azeotropic refrigerant mixture 32 sucked into the compressor 1 is compressed by the compressor 1 and discharged as a high-temperature and high-pressure gaseous refrigerant. A part of the HFC-32 rich non-azeotropic refrigerant mixture 32 that has become high temperature and pressure passes through the four-way valve 2 and flows into the outdoor heat exchanger 5 that functions as a condenser. Then, the outdoor heat exchanger 5 condenses and liquefies while dissipating heat to the outdoor air, and the HFC-32 rich non-azeotropic mixed refrigerant 32 becomes a high-pressure liquid refrigerant. The HFC-32 rich non-azeotropic refrigerant mixture 32 that has become a high-pressure liquid refrigerant in the outdoor heat exchanger 5 flows into the expansion device 4. The HFC-32 rich non-azeotropic refrigerant mixture 32 that has become a high-pressure liquid refrigerant is squeezed and expanded (depressurized) by the expansion device 4, and a low-temperature low-pressure refrigerant (gas-liquid) having a dryness of 0.2 to 0.3. Two-phase state).

  The HFC-32 rich non-azeotropic refrigerant mixture 32 that has become a low-temperature low-pressure gas-liquid two-phase state in the expansion device 4 flows into the indoor heat exchanger 3 that functions as an evaporator. Then, while the indoor heat exchanger 3 absorbs heat from room air, the HFC-32 rich non-azeotropic refrigerant mixture 32 becomes a low-temperature low-pressure refrigerant (gas-liquid two-phase state) with a dryness of 0.9 to 1.0. The HFC-32 rich non-azeotropic refrigerant mixture 32 that has become a low-temperature low-pressure refrigerant in the indoor heat exchanger 3 passes through the four-way valve 2. A part of the low-temperature, low-pressure, HFC-32 rich non-azeotropic refrigerant mixture 32 flowing out of the four-way valve 2 flows into the accumulator 6, and is separated into a gaseous refrigerant and a liquid refrigerant by the accumulator 6. Then, the HFC-32 rich non-azeotropic mixed refrigerant 32 that has become gaseous in the accumulator 6 flows into the high-low pressure heat exchanger 16. The HFC-32 rich non-azeotropic mixed refrigerant 32 flowing into the high-low pressure heat exchanger 16 absorbs heat from the high-temperature high-pressure HFC-32 rich non-azeotropic mixed refrigerant 32 flowing through the first branch pipe 13a, and the compressor 1 is aspirated.

  On the other hand, the remaining part of the HFC-32 rich non-azeotropic refrigerant mixture 32 that has become a high-temperature gas in the compressor 1 flows into the first branch pipe 13a. The HFC-32 rich non-azeotropic refrigerant mixture 32 is adjusted in flow rate when passing through the capillary tube 15 and flows into the high-low pressure heat exchanger 16. The high-temperature HFC-32 rich non-azeotropic mixed refrigerant 32 (gaseous) flowing into the high-low pressure heat exchanger 16 is converted into the low-temperature HFC-32 rich non-azeotropic mixed refrigerant 32 (gas) sucked into the compressor 1. To form a non-azeotropic refrigerant 32 rich in HFC-32 that is liquid at low temperatures. The liquid HFC-32 rich non-azeotropic refrigerant mixture 32 that has become low temperature in the high / low pressure heat exchanger 16 flows into the receiver 7 and is stored in the receiver 7.

  If the operation of the compressor 1 is continued, tetrafluoropropene having a high boiling point also starts to evaporate and circulates through the refrigeration cycle apparatus 100. Since the HFC-32 having a low boiling point is stored in the receiver 7 as described above, the refrigerant circulating in the refrigeration cycle apparatus 100 is in a state where the ratio of tetrafluoropropene is gradually high (hereinafter, tetrafluoropropene-rich non-covalent Called boiling mixed refrigerant).

  After the refrigerant circulating in the refrigeration cycle apparatus 100 becomes a tetrafluoropropene-rich non-azeotropic refrigerant mixture, the first two-way valve 14a and the third two-way valve 8a are closed, and the compressor 1 is stopped. Then, the receiver 7 is removed from the refrigerant circuit of the refrigeration cycle apparatus 100 by removing each of the third two-way valve 8a and the fourth two-way valve 8b and each of the connection pipe 17a and the connection pipe 17b. The recovery of the 32-rich non-azeotropic refrigerant mixture 32 is completed.

  The tetrafluoropropene-rich non-azeotropic mixed refrigerant remaining in the refrigerant circuit of the refrigeration cycle apparatus 100 is recovered by connecting a conventional recovery device to the connection port 9a, for example. Further, a new receiver 7 is connected to the refrigerant circuit of the refrigeration cycle apparatus 100, and the tetrafluoropropene-rich non-azeotropic mixed refrigerant remaining in the refrigerant circuit of the refrigeration cycle apparatus 100 is removed by the refrigerant recovery method shown in the first embodiment. It may be recovered.

  By adopting such a configuration, it is possible to collect the HFC-32 rich non-azeotropic refrigerant mixture having a high GWP mainly to the receiver 7. For this reason, the tetrafluoropropene-rich non-azeotropic refrigerant mixture having a low GWP can be recovered from the refrigerant circuit of the refrigeration cycle apparatus 100 by a method similar to the conventional method.

  In the second embodiment, a pipe path including the first branch pipe 13a, the capillary tube 15, the high / low pressure heat exchanger 16, the first two-way valve 14a, the connection pipe 17a, and the third two-way valve 8a The refrigerant circuit of the refrigeration cycle apparatus 100 and the receiver 7 are connected by two pipe paths including a second branch pipe 13b, a second two-way valve 14b, a connection pipe 17b, and a fourth two-way valve 8b. However, the present invention is carried out only by a piping path including the first branch pipe 13a, the capillary tube 15, the high / low pressure heat exchanger 16, the first two-way valve 14a, the connection pipe 17a, and the third two-way valve 8a. It is possible.

  In the refrigerant circuit diagram shown in FIGS. 1 to 4 of the present invention, the receiver 7 forms a part of the circuit. However, the refrigerant circuit side switchgear provided on the refrigerant circuit side as shown in FIG. 1 is a first refrigerant circuit side switchgear 14a (first two sides) connected between the compressor 1 and the condenser 5. A valve 14a) and a second refrigerant circuit side opening / closing device 14b (second two-way valve 14b) connected between the evaporator 3 and the compressor 1, and a receiver provided on the one receiver side The side opening / closing device has a pipe connection part between the first two-way valve 14a, and this connection part is fixed with a seal as a countermeasure against refrigerant leakage and a bolt / nut as a connection means. It is detachably connected by removing the connection part. With the same connection structure as the connection structure of the first receiver side opening / closing device 8a (third two-way valve 8a), the second refrigerant circuit side opening / closing device 14b (second two-way valve 14b) is detachable. A second receiver-side opening / closing device 8b (fourth two-way valve 8b) to be connected is provided. In this refrigerant circuit diagram configuration, after the receiver 7 collects the refrigerant from the refrigerant circuit, the compressor 1, the outdoor heat exchanger 5, the expansion device 4, the indoor heat exchanger 3, the accumulator 6, and the four-way valve 2 are refrigerant pipes. Sequentially connected and left. However, the refrigerant circuit has a first connection port (connection port 9a) that can be connected to a vacuum source, and a first refrigerant circuit side opening / closing device that is disposed in the refrigerant circuit and can be opened and closed when the receiver 7 is attached to and detached from the refrigerant circuit. 14a (first two-way valve 14a) and the second connection port and the second connection port of the refrigerant circuit are arranged at different positions, can be connected to the receiver 7, and between the receiver 7 The third connection port having the second refrigerant circuit side opening / closing device 14b (second two-way valve 14b) provided and opened and closed when the receiver 7 is attached to and detached from the refrigerant circuit remains. In such a state where the receiver is removed, it is preferable to close all the opening / closing devices provided in any of the connection ports.

  DESCRIPTION OF SYMBOLS 1 Compressor, 2 Four way valve, 3 Indoor heat exchanger, 4 Throttling device, 5 Outdoor heat exchanger, 6 Accumulator, 7 Receiver, 8a 3rd two way valve, 8b 4th two way valve, 9 Vacuum pump, 9a connection port, 13a first branch pipe, 13b second branch pipe, 14a first two-way valve, 14b second two-way valve, 15 capillary, 16 high / low pressure heat exchanger, 17a connection pipe, 17b connection Piping, 30 non-azeotropic refrigerant mixture, 32 HFC-32 rich non-azeotropic refrigerant mixture, 40 external cooling device, 100 refrigeration cycle device.

Claims (3)

A refrigerant circuit in which a compressor, a condenser, a throttling device, an evaporator, and an accumulator are connected by a refrigerant pipe, and a non-azeotropic mixed refrigerant containing tetrafluoropropene and an HFC refrigerant having a boiling point lower than that of the tetrafluoropropene is circulated; ,
A branch pipe having one end connected between the compressor and the condenser;
A first refrigerant circuit side opening / closing device connected to the other end of the branch pipe;
A refrigerant flow rate adjusting portion provided in the branch pipe;
The non-azeotropic mixed refrigerant flowing between the accumulator and the compressor, and the non-azeotropic mixed refrigerant flowing between the branch pipes, provided between the refrigerant flow rate adjusting unit and the first refrigerant circuit side opening / closing device. A high and low pressure heat exchanger that exchanges heat with
A receiver having a first receiver-side opening / closing device detachably connected to the first refrigerant circuit-side opening / closing device;
A connection port provided in the refrigerant circuit and connectable to a vacuum source;
Equipped with a,
After installing the refrigerant circuit in a state where the non-azeotropic refrigerant mixture is not filled, at the installation location of the refrigerant circuit,
The receiver in which the non-azeotropic refrigerant mixture is stored and the first receiver side opening / closing device is closed is connected to the first refrigerant circuit side opening / closing device in the closed state and the first receiver side opening / closing device. Connected to the refrigerant circuit by
Open the first refrigerant circuit side opening and closing device, suck the inside of the refrigerant circuit with a vacuum source connected to the connection port,
The refrigeration cycle apparatus, wherein the first receiver-side opening / closing device is opened, and the refrigerant circuit is filled with the non-azeotropic refrigerant mixture stored in the receiver . A refrigerant circuit in which a compressor, a condenser, a throttling device, an evaporator, and an accumulator are connected by a refrigerant pipe, and a non-azeotropic mixed refrigerant containing tetrafluoropropene and an HFC refrigerant having a boiling point lower than that of the tetrafluoropropene is circulated; ,
A branch pipe having one end connected between the compressor and the condenser;
A first refrigerant circuit side opening / closing device connected to the other end of the branch pipe;
A refrigerant flow rate adjusting portion provided in the branch pipe;
The non-azeotropic mixed refrigerant flowing between the accumulator and the compressor, and the non-azeotropic mixed refrigerant flowing between the branch pipes, provided between the refrigerant flow rate adjusting unit and the first refrigerant circuit side opening / closing device. A high and low pressure heat exchanger that exchanges heat with
A receiver having a first receiver-side opening / closing device detachably connected to the first refrigerant circuit-side opening / closing device;
A refrigerant recovery method for a refrigeration cycle apparatus comprising:
Opening the first refrigerant circuit side opening / closing device and the first receiver side opening / closing device, starting the compressor, and allowing the gaseous non-azeotropic mixed refrigerant inside the accumulator to flow into the branch pipe When,
Storing the non-azeotropic refrigerant mixture condensed and liquefied in the high-low pressure heat exchanger provided in the branch pipe in the receiver;
Closing at least the first receiver-side switchgear, removing the refrigerant circuit-side switchgear and the receiver-side switchgear, and collecting the non-azeotropic refrigerant mixture;
Cooling the receiver with an external cooling device;
A refrigerant recovery method for a refrigeration cycle apparatus, comprising: A refrigerant circuit in which a compressor, a condenser, a throttling device, an evaporator, and an accumulator are connected by a refrigerant pipe, and a non-azeotropic mixed refrigerant containing tetrafluoropropene and an HFC refrigerant having a boiling point lower than that of the tetrafluoropropene is circulated; ,
A branch pipe having one end connected between the compressor and the condenser;
A first refrigerant circuit side opening / closing device connected to the other end of the branch pipe and connectable to a receiver;
A refrigerant flow rate adjusting portion provided in the branch pipe;
The non-azeotropic mixed refrigerant flowing between the accumulator and the compressor, and the non-azeotropic mixed refrigerant flowing between the branch pipes, provided between the refrigerant flow rate adjusting unit and the first refrigerant circuit side opening / closing device. A high and low pressure heat exchanger that exchanges heat with
A connection port provided in the refrigerant circuit and connectable to a vacuum source;
Equipped with a,
After installing the refrigerant circuit in a state where the non-azeotropic refrigerant mixture is not filled, at the installation location of the refrigerant circuit,
By connecting the first refrigerant circuit side opening / closing device in the closed state and the first receiver side opening / closing device in the closed state provided in the receiver, the receiver in which the non-azeotropic refrigerant mixture is stored is used as the refrigerant. Connected to the circuit,
Open the first refrigerant circuit side opening and closing device, suck the inside of the refrigerant circuit with a vacuum source connected to the connection port,
The refrigeration cycle apparatus, wherein the first receiver-side opening / closing device is opened, and the refrigerant circuit is filled with the non-azeotropic refrigerant mixture stored in the receiver .

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