HFC mixed refrigerant component separation and recovery device and component separation and recovery method using the HFC mixed refrigerant component separation and recovery device

Abstract

To provide an HFC mixed refrigerant component separation and recovery device capable of separating R410A into R125 and R32 without temperature adjustment. [Solution] An HFC mixed refrigerant component separation and recovery device having an R410A filled container 2, an R32 recovery container 3, and an R125 recovery container 4, an R32 recovery pipe 31 connected to the R410A filled container 2 and a filter unit 1 and having an R410A supply valve SV1, an expansion valve 22, an evaporator 23, and an R410A compressor 5 in its path, connected to the filter unit 1 and the R32 recovery container 3 and having an R32 buffer tank 34 and an R32 compressor 6 in its path, a filter non-permeating gas pipe 11 connected to the filter unit 1, an R125 recovery pipe 41 branching off from the filter non-permeating gas pipe 11 and connecting to the R125 recovery container 4, and an R410A circulation pipe 71 branching off from the filter non-permeating gas pipe 11 and connecting to the R410A supply pipe between the R410A supply valve SV1 and the expansion valve 22.

Description

[Technical field]

[0001] The present invention relates to an HFC (hydrofluorocarbon) mixed refrigerant component separation and recovery device used in thermal control systems such as air conditioners and heat pump systems, and is particularly specialized for the component separation and recovery of R410A refrigerant. More specifically, the present invention relates to an HFC mixed refrigerant component separation and recovery device and a component separation and recovery method using the same, for efficiently separating and recovering pentafluoroethane (R125) and difluoromethane (R32) that constitute R410A. [Background technology]

[0002] R410A has an ozone depletion potential (ODP) of zero and is superior to R22 in terms of protecting the ozone layer, so it has been widely used as the standard UFC mixed refrigerant in thermal control systems such as air conditioners and heat pump systems. When equipment that uses R410A is discarded, the R410A is collected and regenerated / recycled. However, if regeneration is not possible, it is detoxified through high-temperature incineration or chemical decomposition for disposal, but these processes have a greater environmental impact than regeneration / recycling. In addition, fluorite (calcium fluoride), the raw material for fluorocarbons, is produced in a limited number of countries, and demand for it in other industries is also increasing, so in the future it will be necessary to regenerate and recycle R410A as much as possible without disposing of it.

[0003] Meanwhile, as the problem of global warming becomes more serious, the environmental impact of refrigerants used in heat treatment systems has been attracting international attention in recent years. In particular, the global warming potential (GWP) of refrigerants has become an important indicator, and reducing the use of high-GWP refrigerants has become a global issue.

[0004] R410A is an HFC refrigerant mixture made of equal parts pentafluoroethane (R125) and difluoromethane (R32), and has a relatively high GWP value of approximately 2088, which is currently a major environmental issue. There is a significant difference in GWP values ​​between R125 and R32 contained in R410A. The GWP value of R125 is 3500, which means it has a large impact on long-term climate change. On the other hand, the GWP value of R32 is 675, which is significantly lower than R125, and its environmental impact is relatively small. As R32 has a significantly lower GWP value than R125, if they could be separated and recovered, various environmental benefits could be expected. R32, a low-GWP refrigerant, could be reused, and R125 could be appropriately treated or repurposed for uses with less environmental impact.

[0005] Patent Document 1 describes a method for recovering a specific fluorocarbon from recovered fluorocarbons containing two or more types of fluorocarbons. Moreover, Patent Documents 2 and 3 describe methods for separating a target gas from a plurality of types of gas bodies. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2005-9715 A [Patent Document 2] JP 2016-67972 A [Patent Document 3] JP 2017-196601 A Summary of the Invention [Problem to be solved by the invention]

[0007] The method of Patent Document 1 separates and recovers the fluorocarbons contained in the recovered fluorocarbons by utilizing the difference in boiling points. However, R410A is an azeotropic mixture of R125 and R32, and it is difficult to separate them by distillation utilizing the difference in boiling points.

[0008] In addition, Patent Documents 2 and 3 disclose a method for separating and recovering gases by changing the molecular diameter of each gas by changing the temperature and passing the gas through a filter made of a porous material. However, since R410A is stored in a high-pressure gas container in a liquid state, it is difficult to adjust the temperature of the stored R410A. In addition, a temperature control device is required to adjust the temperature. Note that neither Patent Documents 2 nor 3 disclose any specific temperature control means.

[0009] The present invention aims to provide an HFC mixed refrigerant component separation and recovery device that can separate R410A into R125 and R32 without temperature adjustment, and a component separation and recovery method using the HFC mixed refrigerant component separation and recovery device. [Means for solving the problem]

[0010] The present invention, which has been made to achieve the above object, comprises an R410A filling container filled with R410A, an R32 recovery container for recovering R32 separated from R410A, an R125 recovery container for recovering R125 separated from R410A, an R410A supply pipe connected to the R410A filling container and a filter unit and having an R410A supply valve, an expansion valve, an evaporator, and an R410A compressor in its path, an R32 recovery pipe connected to the filter unit and the R32 recovery container and having an R32 buffer tank and an R32 compressor in its path, a filter non-permeating gas pipe connected to the filter unit, and a gas supply pipe branching off from the filter non-permeating gas pipe. the R410A circulation pipe branching off from the filter non-permeated gas pipe and connected to the R410A supply pipe between the R410A supply valve and the expansion valve and having a first R410A circulation valve, an R410A buffer tank, and a second R410 circulation valve in its path; a permeate side pressure switch provided in the R32 recovery pipe between the filter unit and the R32 buffer tank; and a non-permeate side pressure switch provided in the R410A circulation pipe between the first R410A circulation valve and the R410A buffer tank. The filter unit may have a double-tube structure of an outer tube and a filter tube housed in the outer tube, the filter tube being made of a molecular sieve membrane, the R410A supply pipe being connected to one end of the filter unit so as to communicate with the inside of the filter tube, the filter non-permeating gas pipe being connected to the other end of the filter unit so as to communicate with the inside of the filter tube, and the R32 recovery pipe being connected to the outer circumferential surface of the outer tube so as to communicate with the inside of the outer tube. The R410 supply pipe may have a pressure reducing valve between the evaporator and the R410A compressor.

[0011] The present invention also provides an R410A supply process, which comprises: (1) starting the R410A compressor while opening the R410A supply valve and the first R410A circulation valve and closing the R125 recovery valve and the second R410 circulation valve to supply R410A from the R410A filling container and storing the R410A in the R410A buffer tank; and (2) closing the R410A supply valve, opening the second R410 circulation valve, and transferring the R410A stored in the R410A buffer tank to the filter. an R410A circulation and R32 recovery process in which the R410A containing R125 that does not permeate the filter unit is stored in the R410A buffer tank and circulated; and (3) a process in which the first R410A circulation valve is closed, the R125 recovery valve is opened, and the R410A containing R125 after separation of the R32 stored in the R410A buffer tank is circulated as the R125 recovery valve. Tubeand a R125 recovery process in which the R125 is passed through the non-permeate side pressure switch in step (1) and stored in the R125 recovery container via the non-permeate side pressure switch, the process is activated to transition to step (2), and in step (2) the process returns to step (1) when the non-permeate side pressure switch drops below the predetermined pressure. In step (2), the process starts up the R32 compressor to send the R32 stored in the R32 buffer tank to the R32 recovery container, and is activated to stop the R32 compressor when the permeate side pressure switch drops below the predetermined pressure. The process proceeds to step (3) when the cumulative time of steps (1) and (2) reaches a certain value or more. Effect of the Invention

[0012] The present invention provides at least one of the following effects by solving the above-mentioned problems. <1> Since the temperature of the R410A to be separated is not controlled, there is no need for a temperature control device or a heat transfer medium for heating or cooling. <2> Separation is performed using a molecular sieve membrane, utilizing the molecular sieve effect, making it possible to separate and recover the azeotropic mixtures R125 and R32. <3> By installing a pressure reducing valve between the evaporator and the R410A compressor, the suction pressure of the R410A compressor can be maintained at an appropriate pressure. [Brief description of the drawings]

[0013] [Figure 1] Overall schematic diagram of the HFC mixed refrigerant component separation and recovery device of the present invention [Diagram 2] Diagram of separation by filter unit [Diagram 3] An explanatory diagram of the component separation and recovery method using the HFC mixed refrigerant component separation and recovery device of the present invention (1) [Figure 4] An explanatory diagram (2) of the component separation and recovery method using the component separation and recovery device for HFC mixed refrigerants of the present invention [Diagram 5]An explanatory diagram (3) of the component separation and recovery method using the component separation and recovery device for HFC mixed refrigerants of the present invention DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. EXAMPLES

[0015] <1> Overview of HFC mixed refrigerant component separation and recovery equipment (Figure 1) The HFC mixed refrigerant component separation and recovery device of the present invention separates and recovers the components R125 and R32 of the HFC mixed refrigerant R410A. The HFC mixed refrigerant component separation and recovery device of the present invention utilizes the difference in molecular diameter between R125 and R32 to separate them by supplying R410A to a filter unit 1 having a molecular sieve membrane. In addition, the R410A to be separated is circulated within the device and passed through the filter unit 1 multiple times, thereby increasing the reliability of separation of R125 and R32.

[0016] <2> Overall configuration of HFC mixed refrigerant component separation and recovery equipment (Figure 1) The HFC mixed refrigerant component separation and recovery device of the present invention has an R410A filled container 2 filled with R410A to be separated, and an R32 recovery container 3 and an R125 recovery container 4 for respectively recovering R32 and R125 separated from R410A. The R410A filled container 2, the R32 recovery container 3, and the R125 recovery container 4 are appropriately connected by piping consisting of a charge hose, a SUS tube, or the like, as described below. An R410A supply pipe 21 is connected to the R410A filling container 2, and the R410A supply pipe 21 is connected to one end of the filter unit 1 via an R410A supply valve SV1 that opens and closes the pipe line, an expansion valve 22, an evaporator 23, a pressure reducing valve 24, and an R410A compressor 5. The filter unit 1 has an R32 recovery pipe 31 connected to its outer circumferential surface, and the R32 recovery pipe 31 is connected to an R32 recovery container 3 via an R32 buffer tank 34 and an R32 compressor 6. A permeate side pressure switch PS1 is provided between the filter unit 1 and the R32 buffer tank 34. A check valve 33 may also be provided between the filter unit 1 and the R32 buffer tank 34. A filter non-permeate gas pipe 11 is connected to the other end of the filter unit 1. The filter non-permeated gas pipe 11 branches into an R125 recovery pipe 41 and an R410A circulation pipe 71, and the R125 recovery pipe 41 is connected to the R125 recovery container 4 via an R125 recovery valve SV2 that opens and closes the pipe. The R410A circulation pipe 71 is connected to between the R410A supply valve SV1 and the expansion valve 22 of the R410A supply pipe 21 via a first R410A circulation valve SV3 that opens and closes the pipe, an R410A buffer tank 7, and a second R410 circulation valve SV4 that opens and closes the pipe. The R410A circulation pipe 71 is provided with a non-permeated side pressure switch PS2 before the R410A buffer tank 7 (between the first R410A circulation valve SV3 and the R410A buffer tank 7). The R410A supply valve SV1, the R125 recovery valve SV2, the first R410A circulation valve SV3 and the second R410 circulation valve SV4 shall be motorized valves, solenoid valves or the like that open and close automatically by signals.

[0017] <3> Separation by filter unit 1 (Figure 2) The R410A to be separated is stored in a liquid state in an R410A filled container 2, and is passed through an expansion valve 22 and an evaporator 23 to be supplied in a gaseous state to the filter unit 1. No temperature control is performed, and the R410A is converted into a gas by the expansion valve 22 and the evaporator 23 using the heat of the surrounding air, so there is no need for a temperature control device or a heat medium for heating or cooling. The filter unit 1 has a double-tube structure consisting of an outer tube 12 and a filter tube 13 housed in the outer tube 12. The filter tube 13 is made of a molecular sieve membrane made of an organic polymer. R410A is an azeotropic mixture of R125 and R32, and separation by distillation is difficult. In the present invention, the difference in molecular diameter between R125 and R32 is utilized, and separation is performed by the molecular sieve effect using a molecular sieve membrane having pores of a size that allows only R32 to pass through. The theoretical molecular diameter of R32 at 25°C and 0.6 MPa is 0.362 nm, and the theoretical molecular diameter of R125 is 0.446 nm. The R410A supply pipe 21 connected to one end of the filter unit 1 and the filter non-permeate gas pipe 11 connected to the other end each communicate with the inside of the filter tube 13. The R32 recovery pipe 31 is connected to the outer peripheral surface of the outer tube 12 and communicates with the inside of the outer tube 12, which is the outside of the filter tube 13. When R410A is supplied from the R410A supply pipe 21 to the filter tube 13, which is the inner tube of the filter unit 1, only R32 permeates from the filter tube 13 to the outside and is sent to the R32 recovery pipe 31. The R125 that does not permeate the filter tube 13 passes through the inside of the filter tube 13 and is sent to the filter non-permeate gas pipe 11.

[0018] <4> Method for separating and recovering components using HFC mixed refrigerant component separation and recovery equipment Next, a component separation and recovery method using the HFC mixed refrigerant component separation and recovery device of the present invention will be described.

[0019] <4.1> Process 1: R410A supply process (Fig. 3) The R410A supply valve SV1 and the first R410A circulation valve SV3 are opened, and the R125 recovery valve SV2 and the second R410 circulation valve SV4 are closed. With this in place, the R410A compressor 5 is started to supply R410A from the R410A filling container 2 into the device. Liquid R410A supplied from the R410A filled container 2 passes through the expansion valve 22 and the evaporator 23 to become gas, which is compressed by the R410A compressor 5 and supplied to the filter unit 1 at a predetermined pressure. Note that by providing a pressure reducing valve 24 between the evaporator 23 and the R410A compressor 5, the suction pressure of the R410A compressor 5 is kept at an appropriate pressure. A portion of the R32 in the R410A supplied to the filter unit 1 permeates the filter tube 13 and is sent from the R32 recovery pipe 31 to the R32 buffer tank 34. Then, the R410A, which contains the R125 that does not permeate the filter tube 13 and the R32 that does not permeate the filter tube 13, passes through the filter non-permeating gas pipe 11 and the R410A circulation pipe 71 and is stored as a liquid in the R410A buffer tank 7. As the amount of R410A stored in the R410A buffer tank 7 increases, the pressure in the R410A circulation pipe 71 before the R410A buffer tank 7 increases. Then, when the R410A in the R410A buffer tank 7 reaches a predetermined amount, the pressure in the R410A circulation pipe 71 before the R410A buffer tank 7 exceeds a predetermined value, and the non-permeation side pressure switch PS2 before the R410A buffer tank 7 is activated. Then, the process moves to the next R410A separation process.

[0020] <4.2> Process 2: R410A circulation and R32 recovery process (Figure 4) The R410A supply valve SV1 is closed to stop the supply from the R410A filling container 2, and the second R410A circulation valve SV4 is opened to circulate the R410A in the R410A buffer tank 7 within the device. Liquid R410A stored in the R410A buffer tank 7 passes through the expansion valve 22 and the evaporator 23 to become a gas, which is compressed by the R410A compressor 5 and supplied to the filter unit 1 at a predetermined pressure. Then, a portion of the R32 in the R410A supplied to the filter unit 1 permeates the filter tube 13 and is sent from the R32 recovery pipe 31 to the R32 buffer tank 34. Then, the R410A, which contains the R125 that does not permeate the filter tube 13 and the R32 that does not permeate the filter tube 13, passes through the filter non-permeating gas pipe 11 and the R410A circulation pipe 71, is stored as a liquid in the R410A buffer tank 7, and is circulated again within the device. By circulating the R410A within the device and passing it through the filter unit 1 multiple times, the reliability of the separation of R125 and R32 is increased. In addition, the R32 compressor 6 is started to send the R32 in the R32 buffer tank 34 to the R32 recovery container 3 for storage, and the R32 is recovered from the device. When the R32 compressor 6 is started, the R32 recovery pipe 31 connected to the suction side of the R32 compressor 6 and the outer periphery side (after permeation through the filter pipe 13) in the filter unit 1 are depressurized, so the amount of R32 permeating the filter pipe 13 increases, and the separation of R125 and R32 becomes more reliable. When the amount of R32 in the R32 buffer tank 34 and the amount of R32 permeating through the filter pipe 13 decreases, the pressure in the permeate side pressure switch PS1 between the filter unit 1 and the R32 buffer tank 34 decreases. When the pressure falls below a predetermined pressure, the permeate side pressure switch PS1 operates and the R32 compressor 6 is stopped. As the separation and recovery of R32 progresses and the amount of R410A in the device decreases, the pressure in the R410A circulation pipe 71 before the R410A buffer tank 7 decreases. Therefore, when the pressure in the R410A circulation pipe 71 before the R410A buffer tank 7 falls below a predetermined pressure, the non-permeation side pressure switch PS2 operates and the process returns to step 1 of <4.1>.

[0021] <4.3> Step 3: R125 recovery step (Figure 5) After separating R32 from R410A through steps 1 and 2, only R125 is circulated within the device. Therefore, when the cumulative time of process 1 and process 2 reaches a certain amount, the process moves to the R125 recovery process. In this process, the first R410A circulation valve SV3 is closed and the R125 recovery valve SV2 is opened, and the R125 in the R410A buffer tank 7 and the device is sent by the R410A compressor 5 through the filter unit 1, the filter non-permeating gas pipe 11, the R410A circulation pipe 71, and the R125 recovery pipe 41 to the R125 recovery container 4 for storage, and the R125 is recovered from the device. After a certain period of time has elapsed, the process returns to step 1, and steps 1 to 3 are repeated to separate and recover all of the R410A in the R410A filling container 2.

[0022] <5> Other applications for HFC mixed refrigerants In this embodiment, the R410A consisting of R125 and R32 has been described, but the R410A, which is of inferior quality, may contain other fluorocarbons. Since the molecular diameter of R32 is small among fluorocarbons, other fluorocarbons do not pass through the filter tube 13. Therefore, by using this device, it is possible to recover high-purity R32. In addition, even with other combinations of HFC mixed refrigerants, separation can be performed using this device by selecting the pore size of the organo-based separation membrane of the filter tube 13 according to the difference in molecular size. [Explanation of symbols]

[0023] 1 filter unit, 11 filter non-permeable gas pipe, 12 outer cylinder, 13 filter tube, 2 R410A filling container, 21 R410A supply pipe, 22 expansion valve, 23 evaporator, 24 pressure reducing valve, 3 R32 recovery container, 31 R32 recovery pipe, 33 check valve, 34 R32 buffer tank, 4 R125 recovery container, 41 R125 recovery pipe, 5 R410A compressor, 6 R32 compressor, 7 R410A buffer tank, 71 R410A circulation pipe PS1 Permeate side pressure switch, PS2 Non-permeate side pressure switch SV1 R410A supply valve, SV2 R125 recovery valve, SV3 First R410A circulation valve SV4 Second R410A circulation valve

Claims

1. An R410A filled container filled with R410A; an R32 recovery container for recovering R32 separated from R410A; an R125 recovery container for recovering R125 separated from R410A; an R410A supply pipe connected to the R410A filled container and the filter unit and having an R410A supply valve, an expansion valve, an evaporator, and an R410A compressor in its path; an R32 recovery pipe connected to the filter unit and the R32 recovery container, the R32 recovery pipe having an R32 buffer tank and an R32 compressor in the path; A non-filter permeable gas pipe connected to the filter unit; an R125 recovery pipe branching off from the non-filtered gas pipe and connected to the R125 recovery container, the R125 recovery pipe having an R125 recovery valve in the path; an R410A circulation pipe that branches off from the filter non-permeating gas pipe and is connected to the R410A supply pipe between the R410A supply valve and the expansion valve, and has a first R410A circulation valve, an R410A buffer tank, and a second R410 circulation valve in its path; A permeation side pressure switch provided between the filter unit of the R32 recovery pipe and the R32 buffer tank; and a non-permeation side pressure switch provided between the first R410A circulation valve and the R410A buffer tank of the R410A circulation pipe. HFC mixed refrigerant component separation and recovery equipment.

2. The filter unit has a double-tube structure including an outer tube and a filter tube housed in the outer tube, The filter tube is made of a molecular sieve membrane, The R410A supply pipe is connected to one end of the filter unit so as to communicate with the inside of the filter tube, the filter non-permeable gas pipe is connected to the other end of the filter unit so as to communicate with the inside of the filter tube; The R32 recovery pipe is connected to the outer circumferential surface of the outer cylinder and communicates with the inside of the outer cylinder.

2. The component separation and recovery device for an HFC mixed refrigerant according to claim 1.

3. The R410 supply pipe has a pressure reducing valve between the evaporator and the R410A compressor.

2. The component separation and recovery device for an HFC mixed refrigerant according to claim 1.

4. (1) an R410A supply process, in which the R410A supply valve and the first R410A circulation valve are opened, and the R125 recovery valve and the second R410 circulation valve are closed, the R410A compressor is started to supply R410A from the R410A filling container, and the R410A is stored in the R410A buffer tank; (2) an R410A circulation / R32 recovery process in which the R410A supply valve is closed, the second R410 circulation valve is opened, and the R410A stored in the R410A buffer tank is sent to the filter unit, the R32 separated by passing through the filter unit is stored in the R32 recovery container, and the R410A containing R125 that does not pass through the filter unit is stored in the R410A buffer tank and circulated; (3) an R125 recovery process in which the first R410A circulation valve is closed, the R125 recovery valve is opened, and the R410A containing R125 is separated from the R32 stored in the R410A buffer tank and then stored in the R125 recovery container via the R125 recovery pipe; In the step (1), when the non-permeation side pressure switch reaches a predetermined pressure or more, the process proceeds to the step (2), and in the step (2), when the non-permeation side pressure switch reaches a predetermined pressure or less, the process returns to the step (1), In the step (2), the R32 compressor is started to send the R32 stored in the R32 buffer tank to the R32 recovery container, and when the permeation side pressure switch becomes equal to or lower than a predetermined pressure, the switch is activated to stop the R32 compressor; When the cumulative total time of the steps (1) and (2) reaches a certain amount, the process proceeds to the step (3). A method for separating and recovering components of an HFC mixed refrigerant, using the apparatus for separating and recovering components of an HFC mixed refrigerant according to any one of claims 1 to 3.

Images