WO2012137260A1

WO2012137260A1 - Refrigerant recovery method for refrigeration cycle device and refrigeration cycle device

Info

Publication number: WO2012137260A1
Application number: PCT/JP2011/002098
Authority: WO
Inventors: 山下　浩司
Original assignee: 三菱電機株式会社
Priority date: 2011-04-08
Filing date: 2011-04-08
Publication date: 2012-10-11

Abstract

Provided is a refrigerant recovery method that is for a refrigeration cycle device and that is able to safely recover refrigerant without igniting the refrigerant when recovering the combustible refrigerant using a normal refrigerant recovery device for Freon. A refrigeration cycle device (100) generates a non-combustible mixed refrigerant by mixing a predetermined quantity of non-combustible refrigerant and the combustible refrigerant within the refrigeration cycle, and recovers the combustible refrigerant from the generated non-combustible mixed refrigerant.

Description

Refrigerant recovery method for refrigeration cycle apparatus and refrigeration cycle apparatus

The present invention relates to a refrigerant recovery method and a refrigeration cycle apparatus for a refrigeration cycle apparatus such as a room air conditioner or a building multi-air conditioner using a flammable refrigerant as a refrigerant.

Conventionally, in refrigeration cycle apparatuses such as room air conditioners and multi air conditioners for buildings, refrigerant circulating in the refrigeration cycle is often recovered using a refrigerant recovery apparatus.

In addition, after collecting the refrigerant in the refrigeration and air-conditioning cycle to the outdoor unit by pump down operation, when collecting the refrigerant remaining in the indoor unit and connection pipe using a vacuum pump, connect a refrigerant collection container to the exhaust port of the vacuum pump, There is also a refrigerant recovery method for the refrigeration cycle system that recovers the refrigerant discharged from the exhaust port to reliably recover a small amount of refrigerant at the time of refrigerant recovery or relocation, and reliably avoids the risk of refrigerant leakage. Exists (see, for example, Patent Document 1).

JP 2004-116885 A (7th page, FIG. 4 etc.)

Fluorocarbon refrigerant recovery devices usually do not have an explosion-proof structure that can recover flammable refrigerants. Therefore, if a combustible refrigerant is recovered using such a conventional refrigerant recovery device for CFC, there is a possibility of causing ignition or explosion.

Further, in the refrigerant recovery method of the refrigeration cycle apparatus described in Patent Document 1, the refrigerant exhausted from the vacuum pump is recovered to prevent ignition, and the vacuum pump and the refrigerant recovery apparatus itself are the ignition source. In such a case, there was a problem that ignition could not be prevented.

The present invention was made in order to solve the above-described problems, and when recovering a flammable refrigerant using a normal refrigerant recovery device for Freon, the refrigerant does not ignite, An object of the present invention is to provide a refrigerant recovery method and a refrigeration cycle apparatus for a refrigeration cycle apparatus that can be safely recovered.

The refrigerant recovery method of the refrigeration cycle apparatus according to the present invention includes a compressor, a first heat exchanger, a first expansion device, and a second heat exchanger connected by a refrigerant pipe to circulate a flammable refrigerant, A refrigerant recovery method for a refrigeration cycle for recovering a flammable refrigerant, wherein a predetermined amount of a nonflammable refrigerant is mixed with the flammable refrigerant circulating in the refrigeration cycle to generate a nonflammable mixed refrigerant. The combustible refrigerant is recovered as the non-combustible mixed refrigerant.

The refrigeration cycle apparatus according to the present invention includes a refrigeration cycle in which a compressor, a first heat exchanger, a first expansion device, and a second heat exchanger are connected by a refrigerant pipe to circulate a combustible refrigerant, and the refrigeration cycle A refrigerant outlet connected to the refrigerant outlet, a refrigerant mixing device connected to the refrigerant outlet, an incombustible refrigerant cylinder detachably connected to the refrigerant outlet via the refrigerant mixer, and the refrigerant mixer The non-combustible refrigerant and the combustible refrigerant circulating in the refrigerating cycle are detachably connected to the refrigerant take-out portion via the non-combustible cylinder and sealed in the refrigerating cycle via the non-combustible cylinder. A refrigerant recovery device that recovers the mixed refrigerant, and the nonflammable mixed refrigerant that is connected to the refrigerant recovery device and in which the combustible refrigerant and the nonflammable refrigerant are mixed in the refrigerant mixing device by the action of the refrigerant recovery device The A refrigerant recovery cylinder is cut, in those having a refrigerant recovery mechanism configured.

According to the refrigerant recovery method and the refrigeration cycle apparatus of the present invention, the flammable refrigerant in the refrigeration cycle can be recovered safely without igniting.

It is a schematic circuit diagram which shows an example of the refrigerant circuit structure of the refrigerating-cycle apparatus which concerns on Embodiment 1 of this invention. It is a system block diagram for demonstrating the refrigerant | coolant collection | recovery operation | movement which the refrigeration cycle apparatus which concerns on Embodiment 1 of this invention performs. It is a flowchart which shows the flow of a process of the refrigerant | coolant collection | recovery operation | movement which the refrigeration cycle apparatus which concerns on Embodiment 1 of this invention performs. It is a schematic circuit diagram which shows an example of another refrigerant circuit structure of the refrigeration cycle apparatus which concerns on Embodiment 1 of this invention. It is a schematic circuit diagram which shows an example of another refrigerant circuit structure of the refrigeration cycle apparatus which concerns on Embodiment 1 of this invention. It is a refrigerant circuit diagram which shows the refrigerant circuit structure of the refrigerating-cycle apparatus which concerns on Embodiment 2 of this invention. It is a flowchart which shows the flow of a process of the refrigerant | coolant collection | recovery operation | movement which the refrigeration cycle apparatus which concerns on Embodiment 2 of this invention performs.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1 FIG.
FIG. 1 is a schematic circuit diagram showing an example of a refrigerant circuit configuration of a refrigeration cycle apparatus 100 according to Embodiment 1 of the present invention. Based on FIG. 1, the configuration, operation, and refrigerant recovery method of the refrigeration cycle apparatus 100 will be described. In addition, in the following drawings including FIG. 1, the relationship of the size of each component may be different from the actual one. Further, in the following drawings including FIG. 1, the same reference numerals denote the same or equivalent parts, and this is common throughout the entire specification. Furthermore, the forms of the constituent elements shown in the entire specification are merely examples, and are not limited to these descriptions.

The refrigeration cycle apparatus 100 according to Embodiment 1 can perform a cooling operation (for example, a cooling operation) or a heating operation (for example, a heating operation) by using a refrigeration cycle in which a refrigerant is circulated. It is used for freezers, vending machines, air conditioners, showcases, heat pump water heaters, and the like. In the following description, a state where the refrigeration cycle apparatus 100 is applied to an air conditioner will be described as an example.

[Configuration of refrigeration cycle apparatus 100]
In FIG. 1, the refrigeration cycle apparatus 100 includes an outdoor unit 1 that is a heat source unit and an indoor unit 2 that is a use side unit. The outdoor unit 1 and the indoor unit 2 are connected by a refrigerant pipe 4 (refrigerant pipe 4 (1) and refrigerant pipe 4 (2) that conducts the refrigerant, and the cold or hot heat generated by the outdoor unit 1 is the indoor unit. The refrigerant recovery mechanism 50 is connected to the refrigerant pipe 4 (2) between the expansion device 16 and the use side heat exchanger 13.

The outdoor unit 1 is normally disposed in an outdoor space (for example, a rooftop) of a building or the like, and the indoor unit 2 supplies cold or hot heat to the indoor unit 2. The indoor unit 2 is disposed at a position where cooling air or heating air can be supplied to an indoor space (for example, a living room) inside the building, and supplies the cooling air or heating air to the indoor space that is the air-conditioning target space. To do. The refrigerant recovery mechanism 50 is used when recovering the refrigerant circulating in the refrigeration cycle.

In the refrigeration cycle apparatus 100, a flammable refrigerant is used as the refrigerant. The flammable refrigerant, for example, (HFO1234yf represented by CF ₃ CF = CH _2, HFO1234ze like represented by CF ₃ CH = CHF) chemical formula C ₃ H _{2-tetrafluoropropene} represented by F ₄ and Formula Is known such as difluoromethane (R32) represented by CH ₂ F ₂ . Moreover, you may use the mixed refrigerant containing these. In the case of a mixed refrigerant, for example, HFO1234yf may be mixed at a ratio of 80%, R32 may be mixed at 20%, etc., but the mixing ratio is not particularly limited, and any mixing ratio may be used. Further, a highly flammable refrigerant such as R290 (propane) may be used.

[Outdoor unit 1]
In the outdoor unit 1, a compressor 10, a refrigerant flow switching device 11 such as a four-way valve, a heat source side heat exchanger (first heat exchanger) 12, and a throttle device 16 are connected in series by a refrigerant pipe 4. Has been installed.

The compressor 10 sucks the refrigerant and compresses the refrigerant to a high temperature / high pressure state, and may be composed of, for example, an inverter compressor capable of capacity control. The refrigerant flow switching device 11 switches the refrigerant flow during the heating operation and the refrigerant flow during the cooling operation. The heat source side heat exchanger 12 functions as an evaporator during heating operation, functions as a condenser (or radiator) during cooling operation, and between air supplied from a blower such as a fan (not shown) and the heat source side refrigerant. Heat exchange is performed to evaporate or condense the heat-source-side refrigerant. The expansion device 16 has a function as a pressure reducing valve or an expansion valve, and expands the refrigerant by reducing the pressure. For example, the expansion device 16 may be composed of an electronic expansion valve or the like.

[Indoor unit 2]
The indoor unit 2 is equipped with a use side heat exchanger (second heat exchanger) 13. The use side heat exchanger 13 is connected to the expansion device 16 and the refrigerant flow switching device 11 mounted in the outdoor unit 1 by the refrigerant pipe 4 (refrigerant pipe 4 (1), refrigerant pipe 4 (2)). It is like that. The use side heat exchanger 13 exchanges heat between air supplied from a blower such as a fan (not shown) and a heat medium, and generates heating air or cooling air to be supplied to the indoor space. Is.

[Refrigerant recovery mechanism 50]
The refrigerant recovery mechanism 50 includes an extraction pipe (refrigerant extraction part) 31, a connection valve (open / close valve) 32, a hose 33, a refrigerant recovery device 34, a refrigerant recovery cylinder 35, and an incombustible refrigerant cylinder 36. ing.

The extraction pipe 31 is connected to the refrigerant pipe 4 (2) between the expansion device 16 and the use-side heat exchanger 13, and the refrigerant conducts when the refrigerant is sealed or collected. The connection valve 32 is installed in the extraction pipe 31 and opens and closes the extraction pipe 31 when enclosing the refrigerant or collecting the refrigerant. The hose 33 connects the connection valve 32 and the refrigerant recovery device 34 so that the refrigerant is conducted when the refrigerant is recovered. The refrigerant recovery device 34 is driven to cause the refrigerant to conduct from the refrigerant pipe 4 (2) to the extraction pipe 31 and the hose 33. The refrigerant recovery cylinder 35 recovers the refrigerant that has flowed through the extraction pipe 31 and the hose 33 by driving the refrigerant recovery device 34. The non-combustible refrigerant cylinder 36 is one in which an incombustible refrigerant sealed in the refrigeration cycle is stored.

[Operation during cooling operation of refrigeration cycle apparatus 100]
When the refrigeration cycle apparatus 100 performs the cooling operation, in the outdoor unit 1, the refrigerant flow switching device 11 is switched so that the refrigerant discharged from the compressor 10 flows into the heat source side heat exchanger 12.

A low-temperature / low-pressure refrigerant is compressed by the compressor 10 and discharged as a high-temperature / high-pressure gas refrigerant. The high-temperature and high-pressure gas refrigerant discharged from the compressor 10 flows into the heat source side heat exchanger 12 via the refrigerant flow switching device 11. Then, the heat source side heat exchanger 12 condenses and liquefies while radiating heat to the outdoor air, and becomes a high-pressure liquid refrigerant. The high-pressure liquid refrigerant that has flowed out of the heat source side heat exchanger 12 is expanded by the expansion device 16 and becomes a low-temperature, low-pressure two-phase refrigerant. This two-phase refrigerant flows out of the outdoor unit 1 and flows into the indoor unit 2 through the refrigerant pipe 4 (2).

The two-phase refrigerant that has flowed into the indoor unit 2 flows into the use-side heat exchanger 13 that acts as an evaporator. The two-phase refrigerant that has flowed into the use-side heat exchanger 13 absorbs heat from the indoor air in the use-side heat exchanger 13 to be evaporated and becomes a low-temperature / low-pressure gas refrigerant. At this time, the indoor unit 2 cools the indoor space. The low-temperature and low-pressure gas refrigerant that has flowed out of the use-side heat exchanger 13 flows out of the indoor unit 2 and flows into the outdoor unit 1 again through the refrigerant pipe 4 (1). The gas refrigerant that has flowed into the outdoor unit 1 is again sucked into the compressor 10 via the refrigerant flow switching device 11.

[Operation during heating operation of refrigeration cycle apparatus 100]
When the refrigeration cycle apparatus 100 performs a heating operation, in the outdoor unit 1, the refrigerant flow switching device 11 causes the refrigerant discharged from the compressor 10 to flow into the use side heat exchanger 13 instead of the heat source side heat exchanger 12. Switch to let

A low-temperature / low-pressure refrigerant is compressed by the compressor 10 and discharged as a high-temperature / high-pressure gas refrigerant. The high-temperature and high-pressure gas refrigerant discharged from the compressor 10 flows out of the outdoor unit 1 through the refrigerant flow switching device 11, and flows into the indoor unit 2 through the refrigerant pipe 4 (1). The high-temperature and high-pressure gas refrigerant that has flowed into the indoor unit 2 flows into the use-side heat exchanger 13. The high-temperature and high-pressure gas refrigerant that has flowed into the use-side heat exchanger 13 is condensed and liquefied while dissipating heat to the indoor air in the use-side heat exchanger 13, and becomes high-pressure liquid refrigerant. At this time, the indoor unit 2 heats the indoor space 7.

The high-pressure liquid refrigerant that has flowed out of the use-side heat exchanger 13 flows out of the indoor unit 2 and flows into the outdoor unit 1 again through the refrigerant pipe 4 (2). The high-pressure liquid refrigerant flowing into the outdoor unit 1 is expanded by the expansion device 16 and becomes a low-temperature / low-pressure two-phase refrigerant. This two-phase refrigerant flows into the heat source side heat exchanger 12 acting as an evaporator. The two-phase refrigerant that has flowed into the heat source side heat exchanger 12 absorbs heat from outdoor air in the heat source side heat exchanger 12 to be evaporated and gasified into a low-temperature / low-pressure gas refrigerant, and through the refrigerant flow switching device 11, It is sucked into the compressor 10 again.

[Refrigerant recovery operation]
FIG. 2 is a system configuration diagram for explaining the refrigerant recovery operation executed by the refrigeration cycle apparatus 100. FIG. 3 is a flowchart showing the flow of the refrigerant recovery operation performed by the refrigeration cycle apparatus 100. The refrigerant recovery operation when recovering the combustible refrigerant from the refrigeration cycle apparatus 100 will be described with reference to FIGS.

When a part used in the refrigeration cycle apparatus 100 installed on site, for example, the compressor 10 or the like fails, the refrigerant circulating inside the refrigerant pipe 4 is recovered in a recovery cylinder and then failed. Parts need to be repaired. If the refrigerant is released into the atmosphere without being collected, the global warming will progress. Therefore, the global warming can be prevented from being accelerated by collecting the refrigerant. Also, when the refrigeration cycle apparatus 100 is deteriorated and discarded, it is necessary to recover the refrigerant from the viewpoint of suppressing global warming.

The refrigerant recovery mechanism 50 is connected to the refrigeration cycle apparatus 100 as described above. When the refrigeration cycle apparatus 100 is performing a normal operation (cooling operation or heating operation), the refrigerant recovery device 34 is stopped and the connection valve 32 is closed so that the refrigerant does not flow outside. It has become. On the other hand, when the refrigeration cycle apparatus 100 executes the refrigerant recovery operation, the refrigerant recovery apparatus 34 is driven, the connection valve 32 is opened, and the refrigerant is recovered in the refrigerant recovery cylinder 35 via the extraction pipe 31 and the hose 33. It is like that.

Here, the refrigerant recovery device 34 used for recovery of the chlorofluorocarbon refrigerant is usually not explosion-proof. Therefore, if a flammable refrigerant is used as the refrigerant and the refrigerant is recovered using the refrigerant recovery device 34, the refrigerant may ignite and explode. Therefore, when recovering the flammable refrigerant, a new countermeasure for recovering the refrigerant is required. Therefore, the refrigeration cycle apparatus 100 takes measures as described below.

The flow of the refrigerant recovery operation will be described with reference to FIGS.
First, with the refrigerant recovery device 34 and the refrigerant recovery cylinder 35 removed, a procedure for recovering the combustible refrigerant from the refrigeration cycle apparatus 100 is started (ST1). When the process is started, as shown in FIG. 2, the nonflammable refrigerant cylinder 36 is connected to the connection valve 32 via the hose 33 (ST2). Then, the connection valve 32 is opened to secure the flow path of the combustible refrigerant, and the incombustible refrigerant is enclosed in the refrigeration cycle in which the combustible refrigerant is already enclosed from the incombustible refrigerant cylinder 36 (ST3). A combustible refrigerant has a property of becoming nonflammable when a specific amount or more of a specific nonflammable refrigerant is mixed. The combination of the incombustible combustible refrigerant and the incombustible refrigerant will be described later.

When a non-flammable refrigerant is mixed more than a specified amount (ST4; Yes), the flammable refrigerant circulating in the refrigeration cycle apparatus 100 becomes a mixed refrigerant with the nonflammable refrigerant and becomes nonflammable. Thereafter, the connection valve 32 is closed, and the nonflammable refrigerant cylinder 36 is removed from the connection valve 32 (ST5). At this time, unless the pressure inside the incombustible refrigerant cylinder 36 is higher than the pressure inside the refrigeration cycle, the refrigerant cannot be sealed from the incombustible refrigerant cylinder 36 into the refrigeration cycle. Therefore, the processing (ST3, ST4) is performed after the compressor 10 is stopped or the refrigerant flow switching device 11 is operated so that the position of the extraction pipe 31 is low.

Next, as shown in FIG. 1, the refrigerant recovery device 34 is connected to the connection valve 32 via the hose 33 (ST6). Then, the connection valve 32 is opened to secure a non-flammable mixed refrigerant flow path, and the non-flammable mixed refrigerant generated in the refrigeration cycle is supplied to the refrigerant recovery cylinder 35 by the action of the refrigerant recovery device 34. (ST7). Then, the refrigerant is recovered until the pressure in the refrigeration cycle becomes less than the set pressure (ST8). When the pressure in the refrigeration cycle becomes less than the set pressure (ST8; Yes), the refrigerant recovery device 34 is removed from the connection valve 32 (ST9). The refrigerant recovery operation is completed by this series of processes (ST10).

In addition, although the description that the refrigerant recovery in the refrigeration cycle is completed when the pressure in the refrigeration cycle falls below the set pressure is described here, the present invention is not limited to this. For example, when the amount of refrigerant sealed in the refrigeration cycle of the refrigeration cycle apparatus 100 is known in advance, the refrigerant in the refrigeration cycle also depends on whether or not the recovered refrigerant amount has exceeded a specified amount (specified weight). It can be confirmed that is fully recovered.

[Types and mixing ratios of combustible and non-combustible refrigerants]
A nonflammable mixed refrigerant produced by mixing a nonflammable refrigerant with a combustible refrigerant will be described.
In general, R410A, which is a refrigerant often used in a refrigeration cycle apparatus such as an air conditioner, is a nonflammable mixed refrigerant in which R125, which is a flammable refrigerant, is mixed with R125, which is a nonflammable refrigerant. . Since the boiling point of R32 is −51.8 ° C., the boiling point of R125 is −48.5 ° C., and the boiling points of R32 and R125 are close to each other, R410A is called a pseudo-azeotropic refrigerant.

In this R410A, R32 is mixed with 50% by mass and R125 is mixed with 50% by mass. There is also a non-flammable mixed refrigerant R410B having the same refrigerant component as R410A but having a different mixing ratio. In this R410B, R32 is mixed by 45 mass% and R125 is mixed by 55 mass%. That is, in the mixed refrigerant produced by mixing the flammable refrigerant R32 and the non-flammable refrigerant R125, it is possible to obtain a non-flammable mixed refrigerant by mixing 50 mass% or more of R125.

It has also been found that a pseudo-azeotropic incombustible mixed refrigerant can be produced by mixing 62% by mass of HFO1234yf, which is a combustible refrigerant, and 38% by mass of R134a, which is an incombustible refrigerant. Since the boiling point of HFO1234yf is −29 ° C. and the boiling point of R134a is −26.2 ° C., this mixed refrigerant also becomes a pseudo-azeotropic mixed refrigerant. Note that in the mixed refrigerant of HFO1234yf and R134a, an incombustible mixed refrigerant is naturally produced even if R134a, which is an incombustible refrigerant, is mixed in an amount greater than 38% by mass.

In addition, there are the following non-flammable mixed refrigerants in which R32, which is a flammable refrigerant, R125, which is a non-flammable refrigerant, and R134a, which is a non-flammable refrigerant, are mixed. For example, R407A (R32: R125: R134a = 20 mass%: 40 mass%: 40 mass%), R407B (R32: R125: R134a = 10 mass%: 70 mass%: 20 mass%), R407C (R32: R125: R134a = 23 mass%: 25 mass%: 52 mass%), R407D (R32: R125: R134a = 15 mass%: 15 mass%: 70 mass%), R407E (R32: R125: R134a = 25 mass%: 15 mass) %: 60% by mass).

In these refrigerants, R32 has a boiling point of −51.8 ° C., R125 has a boiling point of −48.5 ° C., R134a has a boiling point of −26.2 ° C., and refrigerants having greatly different boiling points are mixed. It becomes a non-azeotropic refrigerant mixture. That is, in the mixed refrigerant of R32, R125, and R134a, if the mixed refrigerant has a mixture ratio that is less than the above-mentioned component ratio or the above-mentioned component ratio, the component ratio of R32 that is a flammable refrigerant is incombustible. Can be a mixed refrigerant.

From the above, nonflammable refrigerants can be produced by mixing nonflammable refrigerants with flammable refrigerants in the refrigeration cycle and having a refrigerant component ratio similar to these prescribed nonflammable mixed refrigerants, The refrigerant can be recovered safely. In addition, as a result of mixing the flammable refrigerant and the non-flammable refrigerant, if the mixing ratio is similar to that of the specified non-flammable mixed refrigerant, even if the mixing ratio is not completely the same, the same characteristics are exhibited. There is no particular problem.

Here, in the case of generating a nonflammable mixed refrigerant, only a few examples of the components and mixing ratios of the combustible refrigerant and the nonflammable refrigerant to be mixed are shown, and the present invention is not limited to the combinations described here. Absent. Even if it is a thing other than the combination described here, as long as it can produce a nonflammable mixed refrigerant by combining a combustible refrigerant and a nonflammable refrigerant, any component and mixing ratio may be used. The mixed refrigerant may be a pseudo-azeotropic mixed refrigerant or a non-azeotropic mixed refrigerant. For example, even when a mixed refrigerant (flammable) of R32 and HFO1234yf is enclosed in the refrigeration cycle, R125, R1234a and other nonflammable refrigerants are mixed and recovered as a nonflammable mixed refrigerant. May be.

As described above, when a flammable refrigerant circulates in the refrigeration cycle of the refrigeration cycle apparatus 100, a refrigeration cycle apparatus is provided by enclosing a specified amount of non-flammable refrigerant in the refrigeration cycle of the refrigeration cycle apparatus 100 from the outside. Incombustible mixed refrigerant can be produced in 100 refrigeration cycles. Therefore, even if the refrigerant recovery device 34 used for refrigerant recovery of the chlorofluorocarbon refrigerant is used, the refrigerant can be recovered safely.

[Another circuit configuration of the refrigeration cycle apparatus 100]
4 and 5 are schematic circuit diagrams illustrating an example of another refrigerant circuit configuration of the refrigeration cycle apparatus 100. FIG. Based on FIG.4 and FIG.5, enclosure of a nonflammable refrigerant | coolant is demonstrated. FIG. 4 shows a refrigerant circuit configuration in which an accumulator 18 is installed on the suction side of the compressor 10. FIG. 5 shows a refrigerant circuit configuration in which a receiver (intermediate pressure receiver) 19 is installed between the heat source side heat exchanger 12 and the use side heat exchanger 13. A diaphragm device (a diaphragm device 16a, a diaphragm device 16b) is installed before and after the receiver 19.

For example, when producing R410A, the mixing ratio of R32 and R125 needs to be 50% by mass to 50% by mass. That is, it is necessary to enclose the same amount of R125 refrigerant as the R32 refrigerant circulating in the refrigeration cycle in the refrigeration cycle. In the refrigeration cycle apparatus 100 shown in FIG. 1, the refrigerant changes into liquid, two-phase, and gas, and the density is the largest in liquid refrigerant, then the two-phase refrigerant, and the smallest is the gas refrigerant. The density ratio of the gas refrigerant is about 1000 times. Therefore, it is technically possible to stop the compressor 10 and enclose the liquid refrigerant in a place where the refrigerant exists in a gas state or a two-phase state.

On the other hand, in the state of functioning as a refrigeration cycle, there is no place for storing the nonflammable refrigerant sealed from the outside, which is difficult. Therefore, as shown in FIG. 4, by providing the accumulator 18 on the suction side of the compressor 10, a large amount of liquid refrigerant can be stored in the accumulator 18. Therefore, the nonflammable refrigerant can be easily enclosed. 1 shows an example in which the expansion device 16 is accommodated in the outdoor unit 1 and FIG. 4 shows an example in which the expansion device 16 is accommodated in the indoor unit 2, but the expansion device 16 is included in the outdoor unit. 1 and indoor unit 2 may be accommodated.

In addition, as shown in FIG. 5, by providing the receiver 19 in the pipe between the heat source side heat exchanger 12 and the use side heat exchanger 13, that is, the pipe through which the liquid refrigerant flows, a large amount of liquid is contained in the receiver 19. The refrigerant can be stored. Therefore, it becomes possible to easily enclose the nonflammable refrigerant.

Further, the description has been given by taking the refrigeration cycle apparatus 100 as being provided with the extraction pipe 31 and the connection valve 32 as an example. By the way, in a normal refrigeration cycle apparatus, an extraction pipe that can put refrigerant into and out of the refrigeration cycle and a connection valve that can open and close the flow path are integrated. In addition, it has a service valve that also has the function of connecting an extension pipe. Therefore, it is sufficient to use such a service valve, and it is not necessary to newly provide another one. In addition, any material may be used as long as the refrigerant in the refrigeration cycle can be taken in and out and the flow path can be opened and closed.

Furthermore, between the extraction pipe 31 and the connection valve 32, between the connection valve 32 and the refrigerant recovery device 34, between the connection valve 32 and the non-combustible refrigerant cylinder 36, and between the refrigerant recovery device 34 and the refrigerant recovery cylinder 35. The hose 33 is used as an example for the connection, but any connection method may be used as long as the refrigerant is connected so as not to leak to the outside, and the connection is made using copper piping. Alternatively, it may be directly connected using a special connection joint.

The refrigerant flow switching device 11 may be a four-way valve, or a plurality of three-way valves or two-way valves may be used.

In general, the heat source side heat exchanger 12 and the use side heat exchanger 13 are provided with a blower, and in many cases, condensation or evaporation is promoted by blowing air, but this is not restrictive. For example, as the use side heat exchanger 13, a panel heater using radiation can be used, and as the heat source side heat exchanger 12, a water-cooled type in which heat is transferred by water or antifreeze. Any material can be used as long as it has a structure capable of radiating or absorbing heat.

Moreover, the installation position of the outdoor unit 1 is not limited to the outdoor space, but may be installed in an enclosed space such as a machine room with a vent, and if it is ventilated outdoors, It can be installed.

The indoor unit 2 includes a ceiling cassette type, a ceiling-embedded type, a ceiling-suspended type, a wall-mounted type, and the like, so that heating air or cooling air can be blown directly into the indoor space 7 or by a duct or the like. Any kind of material can be used.

In addition, here, the number of connected outdoor units 1 and indoor units 2 is shown as one, but the number is not limited to this, and a plurality of indoor units 2 may be attached to one outdoor unit 1, A plurality of outdoor units 1 may be connected to one refrigeration cycle.

In addition, a repeater is installed between the outdoor unit 1 and the indoor unit 2, and both the cooling and heating are generated by the repeater, and the cooling and heating can be freely selected by the plurality of indoor units 2, and the cooling and heating can be performed simultaneously. The circuit may be configured to operate.

The refrigeration cycle apparatus 100 may be a room air conditioner, a packaged air conditioner, or a multi air conditioner for buildings, and includes a refrigeration cycle in which a refrigerant is circulated. Any device can be used.

Also, it is not limited to the direct expansion cycle in which the refrigerant circulates directly to the indoor unit 2. Installed between the outdoor unit 1 and the indoor unit 2 is a heat medium converter that houses a heat exchanger for heat medium in which a heat medium such as refrigerant and water exchanges heat, and the outdoor unit 1 and the heat medium converter The circuit may be configured so that the refrigerant is circulated between them and the heat medium is circulated between the heat medium converter and the indoor unit.

Moreover, the heat exchanger between heat media which heat-exchanges heat medium, such as a refrigerant | coolant and water, is accommodated in the inside of the outdoor unit 1, a refrigerant | coolant is circulated in the outdoor unit 1, and between the outdoor unit 1 and the indoor unit 2 is accommodated. A circuit such as a chiller in which the heat medium circulates may be configured.

As described above, according to the refrigeration cycle apparatus 100, the non-flammable refrigerant is temporarily sealed in the refrigeration cycle in which the flammable refrigerant circulates, and the generated non-flammable mixed refrigerant is used as the action of the refrigerant recovery apparatus 34. Thus, the flammable refrigerant can be safely recovered by collecting the refrigerant in the refrigerant collection cylinder 35.

Embodiment 2. FIG.
FIG. 6 is a refrigerant circuit diagram showing a refrigerant circuit configuration of the refrigeration cycle apparatus 200 according to Embodiment 2 of the present invention. Based on FIG. 6, the structure, operation | movement, and refrigerant | coolant collection | recovery method of the refrigerating-cycle apparatus 200 are demonstrated. In the second embodiment, the difference from the first embodiment described above will be mainly described, and parts having the same functions as those in the first embodiment will be denoted by the same reference numerals and description thereof will be omitted. And

Refrigeration cycle apparatus 200 according to Embodiment 2 is different from refrigeration cycle apparatus 100 according to Embodiment 1 in that refrigerant mixing apparatus 37 is connected. The refrigerant mixing device 37 is connected to the connection valve 32 via the hose 33. The refrigerant mixing device 37 is connected to an incombustible refrigerant cylinder 36 and a refrigerant recovery device 34 via a hose 33. A refrigerant recovery cylinder 35 is connected to the refrigerant recovery device 34 via a hose 33.

That is, in the refrigeration cycle apparatus 200, an extraction pipe (refrigerant extraction part) 31, a connection valve (open / close valve) 32, a hose 33, a refrigerant recovery apparatus 34, a refrigerant recovery cylinder 35, an incombustible refrigerant cylinder 36, and a refrigerant The mixing device 37 constitutes a refrigerant recovery mechanism 50A.

The refrigerant mixing device 37 is driven by, for example, a stepping motor or the like, and changes the opening area of the flow path opened on the connection valve 32 side and the opening area of the flow path opened on the nonflammable refrigerant cylinder 36 side. It is good to comprise by the three-way valve etc. which are made to do. If the refrigerant mixing device is constituted by such a three-way valve, the amount of the combustible refrigerant flowing from the connection valve 32 and the nonflammability flowing from the nonflammable refrigerant cylinder 36 are adjusted by adjusting the opening of the refrigerant mixing device 37. The amount of refrigerant can be adjusted to a specified ratio. Therefore, according to the refrigeration cycle apparatus 200, the removal and connection of the non-combustible refrigerant cylinder 36, the refrigerant recovery apparatus 34, and the refrigerant recovery cylinder 35 can be omitted, and the refrigerant can be easily recovered accordingly. Become.

[Refrigerant recovery operation]
FIG. 7 is a flowchart showing the flow of the refrigerant recovery operation performed by the refrigeration cycle apparatus 200. Based on FIG.6 and FIG.7, the refrigerant | coolant collection | recovery operation | movement at the time of collect | recovering combustible refrigerant | coolants from the refrigerating-cycle apparatus 200 is demonstrated. The types and mixing ratios of the flammable refrigerant and the nonflammable refrigerant are the same as those described in the first embodiment.

First, treatment for recovering the combustible refrigerant from the refrigeration cycle apparatus 100 is started (GT1). When the processing is started, as shown in FIG. 6, the refrigerant mixing device 37 is connected to the connection valve 32, the refrigerant collecting device 34 and the incombustible refrigerant cylinder 36 are connected to the refrigerant mixing device 37, and the refrigerant collecting cylinder 35 is connected to the refrigerant collecting device 34. Each is connected (GT2). Then, the connection valve 32 is opened, the opening degree of the refrigerant mixing device 37 is adjusted, the amount of flammable refrigerant flowing into the refrigerant mixing device 37 from the inside of the refrigeration cycle, and the refrigerant mixing device 37 flowing from the nonflammable refrigerant cylinder 36. The ratio to the amount of non-combustible refrigerant to be set is set to a predetermined specified value (GT3).

The mixed refrigerant of the nonflammable combustible refrigerant and the nonflammable refrigerant generated by the refrigerant mixing device 37 is recovered in the refrigerant recovery cylinder 35 via the refrigerant recovery device 34 (GT4). Then, recovery of the refrigerant is continued until the pressure in the refrigeration cycle becomes less than the set pressure (GT5). When the pressure in the refrigeration cycle becomes lower than the set pressure (GT5; Yes), the refrigerant recovery is completed, and the refrigerant mixing device 37 is removed from the connection valve 32 (GT6). The refrigerant recovery operation is completed by this series of processes (GT7). By performing such a refrigerant recovery method, only the non-combustible mixed refrigerant flows into the refrigerant recovery device 34, so that the refrigerant can be safely recovered in the refrigerant recovery cylinder 35.

Note that as the refrigerant in the refrigeration cycle is recovered, the pressure in the refrigeration cycle decreases. Therefore, an unillustrated pressure sensor (first pressure detection device) that measures the pressure of the refrigerant in the refrigeration cycle, and an unillustrated pressure sensor (second pressure detection device) that measures the pressure of the refrigerant in the incombustible refrigerant cylinder 36. ), And based on both pressures, the opening degree of the refrigerant mixing device 37 having a specified mixing ratio is calculated, and the refrigerant mixing device 37 can be controlled. By doing so, even if the pressure of the refrigerant in the refrigeration cycle and the pressure of the refrigerant in the incombustible refrigerant cylinder 36 change, the refrigerant flowing into the refrigerant recovery device 34 can always be an incombustible mixed refrigerant. It will be safer to use.

In addition, a refrigerant flow rate detection device (first refrigerant flow rate detection device) capable of measuring the flow rate of the combustible refrigerant flowing from the refrigeration cycle device 200 to the refrigerant mixing device 37, and a non-flammable refrigerant cylinder 36 for refrigerant mixing. You may make it provide the refrigerant | coolant flow rate detection apparatus (2nd refrigerant | coolant flow rate detection apparatus) which can measure the flow volume of the nonflammable refrigerant | coolant which flows into the apparatus 37. FIG. If it does so, it will become possible to calculate the opening degree of the refrigerant | coolant mixing apparatus 37 used as a prescription | regulation mixing ratio based on both detection values (detection flow volume), and to control the refrigerant | coolant mixing apparatus 37. FIG.

In the refrigerant recovery process, for example, if the pressure in the refrigeration cycle apparatus 200 falls below a predetermined value, the refrigerant recovery may be completed assuming that the refrigerant has been sufficiently recovered. When a refrigerant flow rate detection device (first refrigerant flow rate detection device, second refrigerant flow rate detection device) is installed, detection based on a detection flow rate of the first refrigerant flow rate detection device and / or a detection flow rate of the third refrigerant flow rate detection device When the pressure falls below a predetermined value, the refrigerant recovery may be completed.

By performing the refrigerant recovery method of the refrigeration cycle apparatus 200, the refrigerant recovery operation procedure is reduced, and there is an advantage that the refrigerant can be recovered safely and in a short time.

The refrigerant mixing device 37 has been described as an example of a three-way valve. However, the refrigerant mixing device 37 is not limited to this, and the refrigerant mixing device 37 may have a structure such as an ejector that can suck and mix a fluid from another flow path by a main flow. Good. In addition, two open / close valves (two-way valves) and expansion valves driven by a stepping motor or the like may be combined, or a three-way valve or two open / close valves that are manually operated may be combined to suck and mix two fluids. Any structure can be used.

In addition, the case where the refrigerant mixing device 37 is different from the connection valve 32 and is connected to the connection valve 32 has been described as an example, but the present invention is not limited to this. For example, if the refrigerant mixing device 37 has a structure that can completely close the connection port between the refrigerant mixing device 37 and the refrigerant recovery device 34 and the mixing port between the refrigerant mixing device 37 and the nonflammable refrigerant, the refrigerant mixing device The apparatus 37 may be incorporated in the refrigeration cycle apparatus 200 instead of the connection valve 32.

As described above, according to the refrigeration cycle apparatus 200, a flammable refrigerant circulating in the refrigeration cycle is mixed with a specified amount of an incombustible refrigerant to generate an incombustible mixed refrigerant, and a refrigerant recovery apparatus. The refrigerant can be recovered in the non-combustible refrigerant cylinder 36 via 34, and the refrigerant recovery device 34 can prevent the occurrence of ignition or explosion and can recover the refrigerant safely.

In addition, although the refrigerating and air-conditioning apparatus according to the present invention has been described separately for each embodiment, the refrigerating and air-conditioning apparatus may be configured by appropriately combining the features of each embodiment. If the embodiments are appropriately combined, the effects of the features of the embodiments can be obtained in a superimposed manner.

1 outdoor unit, 2 indoor unit, 4 refrigerant piping, 7 indoor space, 10 compressor, 11 refrigerant flow switching device, 12 heat source side heat exchanger, 13 use side heat exchanger, 16 expansion device, 16a expansion device, 16b Throttle device, 18 accumulator, 19 receiver, 31 outlet piping, 32 connection valve, 33 hose, 34 refrigerant recovery device, 35 refrigerant recovery cylinder, 36 nonflammable refrigerant cylinder, 37 refrigerant mixing device, 50 refrigerant recovery mechanism, 50A refrigerant recovery mechanism , 100 refrigeration cycle equipment, 200 refrigeration cycle equipment.

Claims

A refrigerant recovery method for a refrigeration cycle in which the combustible refrigerant is recovered from a refrigeration cycle in which the compressor, the first heat exchanger, the first expansion device, and the second heat exchanger are connected by refrigerant piping to circulate the combustible refrigerant. There,
A predetermined amount of non-flammable refrigerant is mixed with the combustible refrigerant circulating in the refrigeration cycle to generate a non-flammable mixed refrigerant, and the combustible refrigerant is recovered as the generated non-flammable mixed refrigerant. A refrigerant recovery method for a cycle device.
A refrigerant take-out part capable of taking in and out the refrigerant is provided at any position of the refrigerant pipe,
The non-flammable refrigerant is sealed in the refrigeration cycle via the refrigerant take-out section, the flammable refrigerant circulating in the refrigeration cycle is mixed with the non-flammable refrigerant, and then the refrigerant take-out section is passed through. The refrigerant recovery method for the refrigeration cycle apparatus according to claim 1, wherein the non-combustible mixed refrigerant is recovered.
Connecting a non-flammable refrigerant cylinder that encloses the non-flammable refrigerant to the refrigeration cycle to the refrigeration cycle;
Enclosing the incombustible refrigerant from the incombustible refrigerant cylinder into the refrigeration cycle;
Connecting a refrigerant recovery device for taking out the non-combustible mixed refrigerant from the refrigeration cycle to the refrigeration cycle;
The refrigerant recovery of the refrigeration cycle apparatus according to claim 1, further comprising a step of recovering the incombustible mixed refrigerant in a refrigerant recovery cylinder connected to the refrigerant recovery apparatus by driving the refrigerant recovery apparatus. Method.
A refrigerant take-out unit installed at any position of the refrigerant pipe and capable of taking in and out the refrigerant;
A refrigerant mixing device connected to the refrigerant take-out unit and capable of adjusting a mixing ratio of the flammable refrigerant and the non-flammable refrigerant,
The flammable refrigerant circulating in the refrigeration cycle and the non-flammable refrigerant are mixed through the refrigerant take-out section and the refrigerant mixing device, and then the non-flammable through the refrigerant take-out portion and the refrigerant mixing device. The refrigerant | coolant collection method of the refrigerating-cycle apparatus of Claim 1.
A non-flammable refrigerant cylinder that encloses the non-flammable refrigerant in the refrigeration cycle via the refrigerant mixing device; and a refrigerant recovery device that extracts the non-flammable mixed refrigerant from the refrigeration cycle via the refrigerant mixing device. Connecting to the refrigeration cycle;
The step of mixing the flammable refrigerant and the non-flammable refrigerant in the refrigerant mixing device by the action of the refrigerant recovery device, and collecting the non-flammable mixed refrigerant in a refrigerant recovery cylinder attached to the refrigerant recovery device. The refrigerant | coolant collection method of the refrigerating-cycle apparatus of Claim 4.
The refrigerant mixing device includes:
The refrigerant recovery method for the refrigeration cycle apparatus according to claim 4, wherein the refrigerant ratio is configured to be capable of adjusting a mixing ratio of the combustible refrigerant and the non-combustible refrigerant.
The refrigerant mixing device includes:
The refrigerant recovery method for the refrigeration cycle apparatus according to claim 4, comprising a three-way valve or two on-off valves.
A first pressure detector for measuring the pressure of the refrigeration cycle;
A second pressure detection device for measuring the pressure of the non-combustible refrigerant cylinder,
The refrigerant recovery method for a refrigeration cycle apparatus according to any one of claims 4 to 7, wherein the refrigerant mixing device is controlled based on a detection pressure of the first pressure detection device and a detection pressure of the second pressure detection device. .
The refrigerant recovery method for a refrigeration cycle apparatus according to claim 8, wherein the refrigerant recovery operation is completed when the pressure detected by the first pressure detection apparatus falls below a predetermined value set.
A first refrigerant flow rate detection device for measuring a flow rate of the combustible refrigerant flowing from the refrigeration cycle device to the refrigerant mixing device;
A second refrigerant flow rate detection device that measures the flow rate of the non-combustible refrigerant flowing from the non-combustible refrigerant cylinder to the refrigerant mixing device,
The refrigerant of the refrigeration cycle apparatus according to any one of claims 4 to 9, wherein the refrigerant mixing device is controlled based on a detection flow rate of the first refrigerant flow rate detection device and a detection flow rate of the second refrigerant flow rate detection device. Collection method.
The refrigeration cycle apparatus according to claim 10, wherein the refrigerant recovery operation is completed when at least one detection flow rate detected by the first refrigerant flow rate detection device and the second refrigerant flow rate detection device falls below a predetermined value. Refrigerant recovery method.
The combustible refrigerant is R32;
The non-flammable refrigerant is R125;
The refrigerant recovery method for a refrigeration cycle apparatus according to any one of claims 1 to 11, wherein the non-flammable refrigerant is mixed so that a ratio of the non-flammable refrigerant in the non-flammable mixed refrigerant is 50% or more.
The non-flammable mixed refrigerant is
The refrigerant recovery method of the refrigeration cycle apparatus according to claim 12, which is similar to a component ratio of the R410A refrigerant or the R410B refrigerant.
The combustible refrigerant is HFO1234yf;
The non-flammable refrigerant is R134a;
The refrigerant recovery method for a refrigeration cycle apparatus according to any one of claims 1 to 11, wherein the non-flammable refrigerant is mixed so that a ratio of the non-flammable refrigerant in the non-flammable mixed refrigerant is 38% or more.
A compressor, a first heat exchanger, a first expansion device, and a second heat exchanger having a refrigeration cycle for circulating a flammable refrigerant by connecting refrigerant pipes;
A refrigerant outlet connected to the refrigeration cycle;
A refrigerant mixing device connected to the refrigerant outlet, and
A non-combustible refrigerant cylinder detachably connected to the refrigerant outlet through the refrigerant mixing device;
The flammable refrigerant that is detachably connected to the refrigerant take-out section via the refrigerant mixing device and is enclosed in the refrigeration cycle via the nonflammable cylinder, and the flammable refrigerant circulating in the refrigeration cycle; A refrigerant recovery device for recovering the combustible refrigerant as a non-combustible mixed refrigerant;
A refrigerant recovery cylinder connected to the refrigerant recovery device and storing the nonflammable mixed refrigerant in which the combustible refrigerant and the nonflammable refrigerant are mixed in the refrigerant mixing device by the operation of the refrigerant recovery device; A refrigeration cycle apparatus equipped with a refrigerant recovery mechanism.