JP2007187369A - Repair method for refrigerant circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a repair method for a refrigerant circuit especially using a carbon dioxide having high working pressure as a refrigerant inside the refrigerant circuit. <P>SOLUTION: A low pressure side of the refrigerant circuit 30 is provided with a valve connection part 40 allowing a refrigerant purge. The refrigerant inside the refrigerant circuit 30 is purged from the valve connection part 40, and an opening/closing valve 42 is connected to the valve connection part 40 before repair work or after the repair work. The inside of the refrigerant circuit 30 is evacuated in an open state of the opening/closing valve 42 after the repair work, the refrigerant is filled in the refrigerant circuit 30, and thereafter the opening/closing valve is closed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for repairing a refrigerant circuit, particularly a refrigerant circuit in which a carbon dioxide refrigerant is sealed.

  2. Description of the Related Art Conventionally, a refrigerant circuit in which a compressor, a radiator, a decompression device, an evaporator, and the like are sequentially connected by piping, for example, a refrigeration device in which a refrigerant having a low operating pressure is sealed is known. On the low pressure side (suction side) of the compressor provided in such a refrigeration apparatus, a refrigerant charge valve (a valve commonly called “musi”) is provided. When the refrigerant is injected into the refrigerant circuit, a refrigerant tank filled with the refrigerant is connected to the refrigerant charge valve. Next, opening / closing control of the refrigerant charge valve was performed, and a predetermined amount of refrigerant was sealed from the refrigerant tank (see Patent Document 1).

Further, when a failure occurs in the refrigerant circuit and repair is performed, a suction device and an empty refrigerant tank are connected to the refrigerant charge valve. Then, opening / closing control of the refrigerant charge valve is performed, and the refrigerant is sucked from the refrigerant circuit by the suction device and sealed in the refrigerant tank. Since the refrigerant circuit uses a refrigerant having a low operating pressure, a refrigerant charge valve having a low pressure resistance and a relatively low price has been used. The refrigerant charge valve is attached to each of a large number of refrigeration apparatuses produced for purging the refrigerant sealed in the refrigerant circuit and injecting the refrigerant into the refrigerant circuit when a problem occurs in the refrigerant circuit.
JP-A-8-136091

  However, since CFC-based refrigerants have been regarded as a problem due to the destruction of the global environment, in recent years, carbon dioxide refrigerants having a favorable characteristic of a warming coefficient of 1 and a high operating pressure have been used as refrigerants. . When carbon dioxide having such a high operating pressure is used as a refrigerant in a cooling device, if a refrigerant charge valve having a low pressure resistance is used for purging the refrigerant enclosed in the refrigerant circuit, the refrigerant charge valve will be destroyed. Therefore, it is necessary to install an on-off valve that is several times more expensive than the refrigerant charge valve. For this reason, there was a problem that the cost of the refrigeration apparatus would increase.

  The present invention has been made to solve the problems of the related art, and provides a method for repairing a refrigerant in a refrigerant circuit, in particular, a refrigerant circuit using carbon dioxide having a high operating pressure as the refrigerant. Objective.

  That is, the refrigerant circuit repair method of the present invention is provided with a valve connecting portion capable of purging the refrigerant on the low pressure side of the refrigerant circuit, and purging the refrigerant in the refrigerant circuit from the valve connecting portion before repair work or repair. After the operation, an on-off valve is connected to the valve connection part, and after repair work, the inside of the refrigerant circuit is evacuated with the on-off valve opened, and after the refrigerant circuit is filled with the refrigerant, the on-off valve is closed. And

  According to a second aspect of the present invention, there is provided a refrigerant circuit repair method, wherein the on-off valve is sealed with a sealing plug after the on-off valve is closed.

  According to a third aspect of the present invention, there is provided a method for repairing a refrigerant circuit according to the first or second aspect, wherein the valve connecting portion provided on the low-pressure side of the refrigerant circuit is constituted by a nut and a sealing plug. It is characterized in that it is loosened and the refrigerant is purged.

  According to a fourth aspect of the present invention, there is provided the refrigerant circuit repair method according to the first or second aspect, wherein the valve connecting portion provided on the low pressure side of the refrigerant circuit is constituted by a pipe whose end is sealed. A perforation is formed in the substrate to purge the refrigerant.

  Furthermore, the method for repairing a refrigerant circuit according to claim 5 is characterized in that, in claims 1 to 4, the refrigerant enclosed in the refrigerant circuit is carbon dioxide.

  According to the present invention, a valve connecting portion capable of purging the refrigerant is provided on the low pressure side of the refrigerant circuit, the refrigerant in the refrigerant circuit is purged from the valve connecting portion, the valve connecting portion before or after the repair work. Since the on-off valve is connected to the valve, and after opening the on-off valve after repair work, the inside of the refrigerant circuit is evacuated, and after the refrigerant circuit is filled with the refrigerant, the on-off valve is closed. Even when a refrigerant such as carbon dioxide with a high operating pressure is used in the refrigerant circuit as in item 5, all the refrigerators, air conditioners, car air conditioners, package air conditioners, etc. that produce relatively expensive on-off valves It does not have to be provided. Thereby, repair work can be easily performed only by attaching an on-off valve to a refrigerator, an air conditioner, a car air conditioner, or a packaged air conditioner provided with a refrigerant circuit. Accordingly, it is possible to prevent inconveniences such as a cost increase of a refrigerator, an air conditioner, a car air conditioner, or a packaged air conditioner per unit.

  In particular, since an on-off valve is attached to a valve connection provided in a refrigerant circuit such as a refrigerator, an air conditioner, a car air conditioner, or a packaged air conditioner, when the refrigerant circuit fails and repairs, The refrigerant circuit can be repaired on site by simply bringing a pulling device, a welding device such as a burner, and a refrigerant. Thereby, it is possible to save the trouble of taking the refrigerator, air conditioner, car air conditioner, packaged air conditioner, etc. back to the repair shop and repairing it. Therefore, the labor of reciprocating between the repair site and the repair shop can be saved, and the refrigerant circuit can be repaired quickly.

  According to the invention of claim 2, in the above, since the on-off valve is sealed with the sealing plug after the on-off valve is closed, dust or dust adheres to the on-off valve. It is possible to prevent the refrigerant sealed in the refrigeration circuit from leaking even if the on-off valve is loosened due to vibration or the like. As a result, for example, it is possible to prevent inconveniences such as damage to the compressor constituting the refrigerant circuit due to mixed dust or dust.

  According to a third aspect of the present invention, in the first or second aspect, the valve connecting portion provided on the low pressure side of the refrigerant circuit is constituted by a nut and a sealing plug, and the sealing plug is loosened. Since the refrigerant is purged, for example, even when a refrigerant such as carbon dioxide having a high operating pressure is used in the refrigerant circuit as in claim 5, if the sealing plug is loosened gradually, The refrigerant purge enclosed in can be performed little by little. As a result, it is possible to avoid the danger that the high-pressure refrigerant in the refrigerant circuit blows out at a stroke and the repair worker is injured, and the purge operation of the refrigerant enclosed in the refrigerant circuit can be performed with peace of mind. It can be carried out.

  According to a fourth aspect of the present invention, there is provided the refrigerant circuit repair method according to the first or second aspect, wherein the valve connecting portion provided on the low pressure side of the refrigerant circuit is constituted by a pipe whose end is sealed. Therefore, even when a refrigerant such as carbon dioxide having a high operating pressure is used in the refrigerant circuit, a relatively expensive on-off valve is formed. Even if it is not attached to all the refrigerators, air conditioners, car air conditioners, or packaged air conditioners to be produced, there is no problem in repairing the refrigerant circuit. In addition, after purging the refrigerant sealed in the refrigerant circuit, if the pipe is removed and the on-off valve is installed, it is only necessary to attach the on-off valve to a refrigerator, air conditioner, car air conditioner, or packaged air conditioner that repairs the refrigerant circuit. That's it. Accordingly, it is possible to prevent inconvenience that the cost of a refrigerator, an air conditioner, a car air conditioner, a packaged air conditioner, etc. per unit rises.

  In particular, since a perforation is formed in the pipe so that the refrigerant sealed in the refrigerant circuit can be purged from the perforation, a refrigerant such as carbon dioxide having a high operating pressure is provided in the refrigerant circuit. Even when it is used, it is possible to purge the refrigerant sealed in the refrigerant circuit little by little by gradually drilling using a drilling jig. As a result, it is possible to avoid the danger that the high-pressure refrigerant in the refrigerant circuit blows out at a stroke and the repair worker is injured, and the purge operation of the refrigerant enclosed in the refrigerant circuit can be performed with peace of mind. Will be able to do.

  The present invention is characterized in that an open / close valve provided on the low pressure side of the refrigerant circuit for repairing the refrigerant circuit is not provided in all the refrigerators, air conditioners, car air conditioners, or packaged air conditioners to be produced. To do. The purpose of not providing an open / close valve in all the refrigerators, air conditioners, car air conditioners, or packaged air conditioners that were produced was realized by providing an open / close valve on the low pressure side of the refrigerant circuit only during repair work of the refrigerant circuit. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a refrigerant circuit diagram of one embodiment illustrating a method for repairing a refrigerant circuit of the present invention.

  In the figure, reference numeral 1 denotes an internal intermediate pressure multistage (two-stage) compression rotary compressor that uses carbon dioxide as a refrigerant. The rotary compressor 1 includes a cylindrical sealed container 2 made of a steel plate, and an interior of the sealed container 2. An electric element 4 disposed on the upper side of the space, a first rotary compression element 10 (first stage) disposed on the lower side of the electric element 4 and driven by the rotating shaft 6 of the electric element 4; The rotary compression mechanism unit 14 is composed of the second rotary compression element 12 (second stage).

  The sealed container 2 includes a container main body 2A that houses the electric element 4 and the rotary compression mechanism section 14, and a substantially bowl-shaped end cap (lid body) 2B that closes an end opening (upper opening) of the container main body 2A. It is configured. A terminal (wiring is omitted) 16 for supplying power to the electric element 4 is attached to the center of the upper surface of the end cap 2B.

  One end of a refrigerant introduction pipe 18 for introducing refrigerant gas is inserted and connected to the second rotary compression element 12, and one end of the refrigerant introduction pipe 18 is connected to a suction passage (not shown) of the second rotary compression element 12. Z)). The other end of the refrigerant introduction pipe 18 passes through the outside of the sealed container 2 and communicates with the sealed container 2. One end of a refrigerant introduction pipe 20 for introducing refrigerant gas is inserted and connected to the first rotary compression element 10, and one end of the refrigerant introduction pipe 20 is connected to a suction passage (not shown) of the first rotary compression element 10. Z)). A refrigerant discharge pipe 22 is inserted and connected to the second rotary compression element 12, and one end of the refrigerant discharge pipe 22 communicates with a discharge silencer chamber (not shown).

  And the rotary compressor 1 comprised in this way is used for refrigerant circuits 30, such as a refrigerator, an air conditioner, a car air conditioner, or a packaged air conditioner. That is, the refrigerant discharge pipe 22 of the rotary compressor 1 is connected to the inlet of the radiator 24, and the pipe exiting the radiator 24 reaches the inlet of the evaporator 28 through the expansion valve 25 as a pressure reducing device, and the outlet of the evaporator 28. Is connected to the refrigerant introduction pipe 20 to form an annular refrigerant circuit 30. The refrigerant circuit 30 is filled with carbon dioxide refrigerant, which is a natural refrigerant.

  Next, the operation will be described. The rotary compressor 1 is energized to the electric element 4 via the terminal 16 and wiring (not shown), and the electric element 4 is activated. Due to the activation of the electric element 4, the low-pressure (3 to 4 MPaG) refrigerant gas sucked from the refrigerant introduction pipe 20 to the low-pressure chamber side of the first rotary compression element 10 (corresponding to the low-pressure side of the refrigerant circuit 30 of the present invention). Is compressed there to an intermediate pressure (8 to 10 MPaG). The intermediate-pressure refrigerant gas compressed by the first rotary compression element 10 passes through a communication path (not shown) and an intermediate discharge pipe into the sealed container 2 (between the second rotary compression element 12 and the electric element 4 side). Discharged.

  Then, the refrigerant gas discharged into the sealed container 2 is sucked into the low pressure chamber side of the second rotary compression element 12 via the refrigerant introduction pipe 18. The refrigerant gas sucked into the low-pressure chamber side of the second rotary compression element 12 is compressed there to become a high-temperature and high-pressure (12 to 13 MPaG) refrigerant gas, and the high-pressure chamber side (relative to the low-pressure side of the refrigerant circuit 30 of the present invention). From the high pressure side) into the radiator 24 via the refrigerant discharge pipe 22.

  The refrigerant gas that has flowed into the radiator 24 radiates heat therein, is decompressed by the expansion valve 25, and then flows into the evaporator 28. The refrigerant flowing into the evaporator 28 evaporates there and absorbs heat from the surroundings, thereby exerting a cooling action for a refrigerator, an air conditioner, a car air conditioner or a packaged air conditioner. The refrigerant exiting the evaporator 28 repeats the cycle of being sucked into the first rotary compression element 10 from the refrigerant introduction pipe 20.

  On the other hand, the refrigerant introduction pipe 20 of the refrigerant circuit 30 is provided with a valve connection portion 40 that is branched from the refrigerant introduction pipe 20. That is, the valve connecting portion 40 is connected to the refrigerant introduction pipe 20 on the low pressure side of the refrigerant circuit 30, and is connected to the branch pipe 32 that is substantially equivalent to the refrigerant introduction pipe 20 and the end of the branch pipe 32. And a pipe 36. The branch pipe 32 is configured with a length (about 100 mm to 200 mm) that does not interfere with assembly and handling of the rotary compressor 1, and a connecting portion 34 (shown in FIG. 2) is provided at the tip. The connecting portion 34 is configured so that a pipe 36 equivalent to the branch pipe 32 can be inserted and welded. The refrigerant introduction pipe 20 has an outer diameter of about 6.35 mm, a wall thickness of about 1.00 mm, and an inner diameter of about 5.35 mm.

  That is, the connecting portion 34 is formed to have a diameter larger than that of the connecting portion 34 by inserting a tube expansion jig (not shown) at the end of the branch pipe 32 and pushing it from the inside. The inner diameter of the connecting portion 34 is provided with a gap of about 0.07 mm with respect to the outer diameter of the pipe 36, and this gap is formed at an interval suitable for brazing (welding material) welding. And although not shown in figure, the pipe 36 is inserted in the connection part 34, a brazing material (welding material) is filled between the connection part 34 and the pipe 36, and the brazing material is melted by a welding device such as a burner, The connecting portion 34 and the pipe 36 are welded.

  Thereby, the branch pipe 32 and the pipe 36 are connected without a gap. Further, the end portion 36A of the pipe 36 (on the side away from the connecting portion 34) is crushed by a press (not shown) or the like and is brought into close contact with the brazing material. After that, the brazing material is melted by a welding device such as a burner. As a result, the end 36A is sealed. Thereby, the inside of the pipe 36 and the inside of the refrigerant introduction pipe 20 are communicated, and the inside of the refrigerant circuit 30 is sealed. As described above, a refrigerator, an air conditioner, a car air conditioner, a packaged air conditioner, or the like is shipped in a state where the valve connection portion 40 is provided on the low pressure side of the refrigerant circuit 30, and is installed at a predetermined position in a store, factory, or home. The

  On the other hand, as shown in FIG. 3, the valve connecting part 40 is configured to be connectable with an opening / closing valve 42 having an opening / closing lever 44. The on-off valve 42 fills the refrigerant in the refrigerant circuit 30 and expels (purges) the refrigerant enclosed in the refrigerant circuit 30 into the air and seals the inside of the refrigerant circuit 30. A connection pipe 46 is provided on one side of the valve 42 so as to extend a predetermined distance. The connection pipe 46 is configured to be insertable into the connection portion 34 of the branch pipe 32 and is configured to have a length of about 50 mm to 100 mm. The connection pipe 46 is configured substantially the same as the pipe 36 except for its length.

  Then, the connection pipe 46 of the on-off valve 42 is inserted into the connection portion 34, and the brazing material is melted by a welding device such as a burner, so that the on-off valve 42 can be fixed to the branch pipe 32 by welding. . Further, the other side of the on-off valve 42 is configured so that a sealing plug 48 (shown in FIG. 8) can be screwed, and a screw portion (not shown) that can be tightened between the sealing plug 48 and the on-off valve 42. Is provided. The other end of the on-off valve 42 is configured so that the sealing plug 48 is screwed by the screw portion and the other side of the on-off valve 42 is sealed to seal the inside of the refrigerant circuit 30.

Next, a method for repairing the refrigerant circuit 30 with the above configuration will be described in (1) to (10).
(1) Start of repair If a failure occurs for some reason during operation of a refrigerator, an air conditioner, a car air conditioner, a packaged air conditioner, etc. installed at a predetermined position in a store, factory or home, the repair operator must use the rotary compressor 1 Stop driving.

(2) Pipe perforation and refrigerant purge in the refrigerant circuit A perforation 38 is provided in the pipe 36 of the valve connecting portion 40 using a drill jig (not shown) prepared in advance as shown in FIG. Purge the enclosed refrigerant. At this time, the perforation 38 is gradually performed, and the refrigerant sealed in the refrigerant circuit 30 is gradually purged into the air. The hole 38 has a hole diameter of about 1 mm to 3 mm.

  Thereby, the danger that the high pressure refrigerant | coolant in the refrigerant circuit 30 will blow out from the perforation 38 at a stretch, and a repair worker will be injured can be avoided beforehand. Since carbon dioxide, which is a natural refrigerant, is enclosed in the refrigerant circuit 30, even when such a natural refrigerant is purged into the air, it becomes a serious problem due to the destruction of the global environment, such as a fluorocarbon refrigerant. The refrigerant sealed in the refrigerant circuit can be purged into the air without any trouble.

(3) Refrigerant circuit repair After the purge of the refrigerant enclosed in the refrigerant circuit 30 is completed, the repair operator repairs the refrigerant circuit 30.
(4) Removing the pipe from the valve connection portion After the repair work of the refrigerant circuit 30 is completed, the repair worker as shown in FIG. 5 is a brazing material in which the connection portion 34 of the branch pipe 32 and the pipe 36 are welded by a welding device such as a burner. And the pipe 36 is removed from the connecting portion 34.

(5) Attach the on-off valve to the valve connection part. Insert the connection pipe 46 of the on-off valve 42 into the connection part 34, and fill a brazing material (welding material) between the connection part 34 and the connection pipe 46. The brazing material is melted with a welding device to weld the connecting portion 34 and the connecting pipe 46 (FIG. 6). Thereby, the branch pipe 32 and the on-off valve 42 are fixed by welding. At this time, the open / close lever 44 keeps the open / close valve 42 in the open state (state shown in FIG. 6). The welding and fixing of the branch pipe 32 and the on-off valve 42 may be performed before the refrigerant circuit 30 is repaired.

(6) A vacuum evacuation device is attached to the on-off valve. A refrigerant evacuation device 60 provided with a evacuation device 62 and a refrigerant tank 64 filled with a refrigerant (carbon dioxide) in advance is prepared (FIG. 7). The vacuuming device 62 and the refrigerant tank 64 provided in the refrigerant filling device 60 are connected by a pipe 68 via a switching valve 66, and the pipe 68 is connected to the other side of the on-off valve 42. Then, a pipe 64 provided in the refrigerant filling device 60 is connected to the on-off valve 42 (screwed into a screw part provided on the opposite side of the connection pipe 46). That is, the on-off valve 42 communicates with the refrigerant tank 64 from the pipe 68 through the switching valve 66 and communicates with the refrigerant tank 64 through the switching valve 66. In FIG. 7, the pipe 64 is illustrated by a single line, but the pipe 64 is configured in the same manner as the pipe 36.

(7) Vacuum evacuation in the refrigerant circuit After the switching valve 66 is operated to connect the vacuum evacuation device 62 with the on-off valve 42 and the refrigerant circuit 30, the vacuum evacuation device 62 is driven to evacuate. As a result, the air in the refrigerant circuit 30, the moisture in the air, or the refrigerant is evacuated to make the inside of the refrigerant circuit 30 vacuum. In addition, about the technique of evacuating the refrigerant circuit 30 with the vacuum drawing apparatus 62, since it is a conventionally well-known technique, detailed description is abbreviate | omitted.

(8) Filling the refrigerant circuit with refrigerant When the refrigerant circuit 30 is evacuated, the switching valve 66 is switched to connect the refrigerant tank 64 and the on-off valve 42. At this time, the refrigerant filling device 60 switches the switching valve 66 and switches the refrigerant tank 64 and the on-off valve 42 in a state where the vacuum circuit 62 and the on-off valve 42 are communicated with each other through the pipe 64 and the inside of the refrigerant circuit 30 is evacuated. And communicate with. This prevents air, moisture in the air, dust and the like from entering the pipe 64.

(9) Closing of the open / close valve After the refrigerant (carbon dioxide refrigerant) is filled into the refrigerant circuit 30 from the refrigerant tank 64, the switching valve 66 is closed and the open / close lever 44 is closed (the white arrow in FIG. 7).
(10) Remove the refrigerant filling device and seal the other side of the on-off valve. Remove the refrigerant filling device 60 from the on-off valve 42 and screw the sealing plug 48 into the screw portion of the on-off valve 42 from which the refrigerant filling device 60 is removed. Then, the other side of the on-off valve 42 is sealed (FIG. 8). As a result, the refrigerant circuit 30 is filled with a refrigerant (carbon dioxide refrigerant) and enclosed.

  When the refrigerant circuit 30 fails again and is repaired, the sealing plug 48 sealing the other side of the on-off valve 42 is gradually loosened, and the refrigerant sealed in the refrigerant circuit 30 is Purge gradually into the air little by little through the gap between the screw portions of the on-off valve 42 and the sealing plug 48. Thereby, the danger that the high pressure refrigerant | coolant in the refrigerant circuit 30 will blow out at a stretch and a repair worker will be injured can be avoided beforehand. Then, after the purge of the refrigerant enclosed in the refrigerant circuit 30 is completed, the repair work is performed on the refrigerant circuit 30 by a repair worker. After the repair work is completed, the refrigerant filling device 60 is connected to the other side of the on-off valve 42, the inside of the refrigerant circuit 30 is evacuated as described above, and then the refrigerant is filled from the refrigerant tank 64 into the refrigerant circuit 30 and sealed. .

  As described above, the valve connecting portion 40 capable of purging the refrigerant sealed in the refrigerant circuit 30 is provided on the low pressure side of the refrigerant circuit 30. Then, the refrigerant sealed in the refrigerant circuit 30 is purged from the valve connection part 40, and the opening / closing valve 42 is connected to the valve connection part 40 before or after the repair work. Then, after the repair work, the open / close lever 44 is operated to open the open / close valve 42 and the refrigerant circuit 30 is evacuated, and after the refrigerant circuit 30 is filled with the refrigerant, the open / close lever 44 is operated to open the open / close valve. 42 is closed.

  As a result, even when a refrigerant such as carbon dioxide having a high operating pressure is used in the refrigerant circuit 30, the relatively expensive on-off valve 42 can be used for all the refrigerators, air conditioners, car air conditioners, packaged air conditioners and the like that are produced. It is only necessary to attach the on-off valve 42 to those that repair the refrigerant circuit 30 without attaching them. Moreover, since the on-off valve 42 is only attached to a refrigerator, an air conditioner, a car air conditioner, a packaged air conditioner or the like that requires repair of the refrigerant circuit 30, it is possible to prevent the cost per unit from rising.

  In addition, since the sealing plug 48 can be sealed on the other side of the on-off valve 42 after the on-off valve 42 is closed, it is possible to prevent dust and dirt from adhering to the on-off valve 42. It is possible to prevent the refrigerant sealed in the refrigeration circuit from leaking even if the on-off valve is loosened due to vibration or the like. As a result, for example, the rotary compressor 1 constituting the refrigerant circuit 30 can be prevented from being damaged by the dust or dust mixed therein.

  On the other hand, in the repair methods (1) to (10) of the refrigerant circuit 30 described above, the evacuation device 62 and the refrigerant filling device 60 are integrally configured. There are different things. Therefore, a method for repairing the refrigerant circuit 30 will be described below, in which the vacuuming device 62 and the refrigerant filling device 60 are separate.

In this case, the refrigerant circuit 30 has substantially the same configuration as the above-described embodiment. The repair method of the refrigerant circuit 30 will be described below with reference to (1) to (10) of the repair method. The same parts as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted.
(1) to (5) are the same as the repair method described above. (6) A vacuuming device is attached to the on-off valve, and a pipe (not shown) provided on the vacuuming device 62 is connected to the other side of the on-off valve 42.

(7) Vacuum evacuation in the refrigerant circuit The open / close valve 42 is opened by operating the opening / closing lever 44 to connect the vacuum drawing device 62, the open / close valve 42, and the refrigerant circuit 30, and then the vacuum drawing device 62 is driven to perform vacuum drawing. To do. As a result, the air in the refrigerant circuit 30, the moisture in the air, or the refrigerant is evacuated to make the inside of the refrigerant circuit 30 vacuum. When the inside of the refrigerant circuit 30 is evacuated, the open / close lever 44 is operated to close the open / close valve 42.

  Next, the vacuuming device 62 is removed from the on-off valve 42. At this time, since the on-off valve 42 is closed, outside air does not enter the refrigerant circuit 30 from the on-off valve 42. Then, instead of the vacuuming device 62, a refrigerant charging device 60 provided with a refrigerant tank 64 filled with a refrigerant (carbon dioxide) on the other side of the on-off valve 42 is connected.

(8) Filling the refrigerant circuit with refrigerant After connecting the refrigerant filling device 60, the air remaining in the pipe 68 connected to the on-off valve 42 is evacuated, or purged with the refrigerant filled in the refrigerant tank 64. Then, the on-off lever 44 is operated to open the on-off valve 42, the refrigerant tank 64 and the on-off valve 42 are communicated, and the refrigerant (carbon dioxide refrigerant) is charged into the refrigerant circuit 30 from the refrigerant tank 64.
(9) Closing of the open / close valve After filling the refrigerant into the refrigerant circuit 30, the switching valve 66 is closed and the open / close lever 44 is closed. Thereafter, the above-described (10) is performed.

  As described above, even if the vacuuming device 62 and the refrigerant charging device 60 are separate, the refrigerant circuit 30 is effective until the refrigerant charging device 60 is attached after the refrigerant circuit 30 is evacuated, in addition to the same effects as described above. It is possible to reliably prevent outside air from entering the inside. Thereby, even if the vacuuming device 62 and the refrigerant filling device 60 are different, the refrigerant circuit 30 can be repaired efficiently.

  Next, FIG. 9 shows a valve connecting portion 40 applied to a method for repairing the refrigerant circuit 30 according to another embodiment of the present invention. The refrigerant circuit 30 has substantially the same configuration as the above-described embodiment. Hereinafter, different parts will be described. The same parts as those in the above-described embodiment are denoted by the same reference numerals, and description thereof is omitted. The valve connecting portion 40 is composed of a branch pipe 32 and a sealing plug 48 provided at the end of the branch pipe 32.

  A nut 50 is fixed to the end of the branch pipe 32, and a sealing plug 48 is detachably screwed onto the nut 50. The on-off valve 42 is provided with a screw portion (not shown), and this screw portion is provided on one side of the on-off valve 42 (the connection pipe 46). The screw portion on one side of the on-off valve 42 is configured in the same manner as the sealing plug 48 screwed into a nut 50 provided at the end of the branch pipe 32.

  Then, in a state where the sealing plug 48 is removed from the end of the branch pipe 32, a screw portion provided on one side of the on-off valve 42 can be detachably screwed into the nut 50 at the end of the branch pipe 32. It is configured. In addition, the other sealing plug 48 is configured to be detachably screwed to the other side of the on-off valve 42.

Next, the repair method of the refrigerant circuit 30 with the above configuration will be described in (20) to (28).
(20) Start of repair When a failure occurs for some reason during operation of a refrigerator, an air conditioner, a car air conditioner, a packaged air conditioner, etc. installed at a predetermined position in a store, factory, or home, the repair operator must use the rotary compressor 1 Stop driving.

(21) Refrigerant purge in refrigerant circuit The sealing plug 48 screwed into the nut 50 at the end of the branch pipe 32 is gradually loosened with a nut turning jig prepared in advance. Thereby, the refrigerant sealed in the refrigerant circuit 30 can be gradually purged into the air from the gap between the screw portions of the nut 50 and the sealing plug 48. Therefore, it is possible to avoid the danger that the high-pressure refrigerant in the refrigerant circuit 30 is blown out at a stroke and the repair worker is injured.

(22) Refrigerant Circuit Repair After the purge of the refrigerant sealed in the refrigerant circuit 30 is completed, the repair operator performs a repair work on the refrigerant circuit 30.
(23) Removing the sealing plug After the repair work of the refrigerant circuit 30 is completed, the sealing plug 48 is removed from the nut 50. The operation of removing the sealing plug 48 from the nut 50 may be performed after the refrigerant purge and before the refrigerant circuit 30 is repaired.
(24) Attach the on-off valve to the valve connection part. Screw the screw part into the nut 50 at the end of the branch pipe 32, and fix the on-off valve 42 to the nut 50. At this time, the open / close lever 44 positions the open / close valve 42 in the open state. It should be noted that the connection between the nut 50 at the end of the branch pipe 32 and the on-off valve 42 may be made before the refrigerant circuit 30 is repaired.

(25) A vacuuming device is attached to the on-off valve, as in the previous embodiment (see FIG. 7). The pipe 68 of the refrigerant filling device 60 is connected to the other side of the on-off valve 42.
(26) Vacuum pulling in refrigerant circuit The switching valve 66 is operated to open the valve, and the vacuum pulling device 62 and the opening / closing valve 42 are communicated with each other. As a result, the air in the refrigerant circuit 30, the moisture in the air, or the refrigerant is evacuated to make the inside of the refrigerant circuit 30 vacuum.

(27) Filling the refrigerant circuit with refrigerant and closing the on-off valve When the refrigerant circuit 30 is evacuated, the switching valve 66 is switched to connect the refrigerant tank 64 and the on-off valve 42. Next, after the refrigerant circuit 30 is filled with refrigerant (carbon dioxide refrigerant), the switching valve 66 is closed and the open / close lever 44 is closed (the white arrow in FIG. 10).

(28) Remove the refrigerant filling device and seal the other side of the on-off valve. Remove the refrigerant filling device 60 from the on-off valve 42, and screw the sealing plug 48 into the screw portion of the on-off valve 42 from which the refrigerant filling device 60 is removed. (FIG. 8). As a result, the refrigerant circuit 30 is filled with a refrigerant (carbon dioxide refrigerant) and enclosed. In addition, when a failure occurs again in the refrigerant circuit 30 and repair is performed, the same operation as in the embodiment is performed.

  The valve connecting portion 40 provided on the low pressure side of the refrigerant circuit 30 is constituted by the nut 50 and the sealing plug 48, and the sealing plug 48 is loosened to purge the refrigerant sealed in the refrigerant circuit 30. Therefore, for example, even when a refrigerant such as carbon dioxide having a high operating pressure is used in the refrigerant circuit 30, if the sealing plug 48 is gradually loosened, the refrigerant purged in the refrigerant circuit is gradually purged. Can be done. Thereby, the danger that the high-pressure refrigerant in the refrigerant circuit 30 is blown out at a stroke and the operator is injured can be avoided, and the purge operation of the refrigerant can be performed with confidence.

  In addition, since a screw portion on which the sealing plug 48 can be detachably screwed is provided on the other side of the on-off valve 42, the sealing plug 48 removed from the nut 50 is attached before or after the repair work of the refrigerant circuit 30. The other side of the on-off valve 42 can be screwed and sealed. Thereby, the inside of the refrigerant circuit 30 can be reliably sealed. Further, since the sealing plug 48 removed from the nut 50 is screwed to the other side of the on-off valve 42, the sealing plug 48 can be effectively used. Therefore, the workability of repairing the refrigerant circuit 30 can be greatly improved.

  Further, even when a refrigerant such as carbon dioxide having a high operating pressure is used in the refrigerant circuit 30, the relatively expensive on-off valve 42 is attached to all the refrigerators, air conditioners, car air conditioners, package air conditioners, etc. to be produced. Instead, it is only necessary to attach the opening / closing valve 42 to the one that repairs the refrigerant circuit 30. Thereby, it is possible to prevent the cost per unit from rising, such as a refrigerator provided with a refrigerant circuit, an air conditioner, a car air conditioner, or a packaged air conditioner.

  In addition, although the Example demonstrated the repair method of the refrigerant circuit 30 by providing the valve connection part 40 in the low voltage | pressure side of the refrigerant circuit 30 of a refrigerator, an air conditioner, a car air conditioner, or a packaged air conditioner, the repair of the refrigerant circuit 30 was demonstrated. The method is not limited to a refrigerator, an air conditioner, a car air conditioner, a packaged air conditioner, or the like, and the method for repairing the refrigerant circuit 30 of the present invention is applied to a water heater using a refrigerant circuit or a refrigerant circuit provided in another device. There is no problem.

  The refrigerant circuit repair method has been described using carbon dioxide refrigerant having a high operating pressure. However, the refrigerant circuit repair method is not limited to a carbon dioxide refrigerant having a high operating pressure, and other refrigerants using a refrigerant having a high operating pressure. The present invention is also effective when applied to a circuit, a chlorofluorocarbon refrigerant circuit having a low operating pressure, and the like.

  Further, although the valve connecting portion 40 is provided on the low pressure side of the refrigerant circuit 30, the valve connecting portion 40 is not limited to the low pressure side, and may be provided on the high pressure side of the refrigerant circuit 30. Of course, the present invention is not limited to the above-described embodiments, and the present invention is effective even when various other modifications are made without departing from the scope of the present invention.

It is a refrigerant circuit figure of one Example explaining the repair method of the refrigerant circuit of this invention (Example 1). It is a front view of the valve | bulb connection part provided in the refrigerant circuit explaining the repair method of the refrigerant circuit of this invention. It is a front view of the on-off valve used with the repair method of the refrigerant circuit of this invention. It is a front view of the valve | bulb connection part which shows the state which is performing the refrigerant | coolant purge from the perforation formed in the pipe. It is a front view of the valve | bulb connection part which shows the state which removed the pipe from the connection part. It is a front view of the valve connection part which shows the state which attached the on-off valve to the connection part which removed the pipe of FIG. It is a front view of the valve connection part which shows the state which attached the refrigerant | coolant filling apparatus to the on-off valve attached to the connection part of the pipe of FIG. It is a front view of the valve | bulb connection part which shows the state which complete | finished repair and sealed the other side of the on-off valve with the sealing plug. It is a front view of the valve | bulb connection part provided in the refrigerant circuit explaining other one Example of this invention (Example 2). FIG. 10 is a front view of the valve connecting portion showing a state where the on-off valve is attached to the nut from which the sealing plug of FIG. 9 is removed. It is a front view of the valve | bulb connection part which shows the state which complete | finished repair and sealed the other side of the on-off valve with the sealing plug.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotary compressor 2 Sealed container 4 Electric element 14 Rotation compression mechanism part 20 Refrigerant introduction pipe 30 Refrigerant circuit 32 Branch pipe 34 Connection part 36 Pipe 36A End part 38 Perforation 40 Valve connection part 42 On-off valve 48 Sealing plug 60 Refrigerant filling apparatus 62 Evacuation device 64 Refrigerant tank 66 Switching valve

Claims (5)

  A valve connecting part capable of purging the refrigerant is provided on the low pressure side of the refrigerant circuit, the refrigerant in the refrigerant circuit is purged from the valve connecting part, and an opening / closing valve is provided at the valve connecting part before or after the repair work. A method of repairing a refrigerant circuit, comprising: connecting, evacuating the refrigerant circuit with the on-off valve opened after repair work, filling the refrigerant circuit with the refrigerant, and then closing the on-off valve.   The method for repairing a refrigerant circuit according to claim 1, wherein after closing the on-off valve, the on-off valve is sealed with a sealing plug.   The valve connection part provided in the low-pressure side of the refrigerant circuit is constituted by a nut and a sealing plug, and the sealing plug is loosened to purge the refrigerant. Refrigerant circuit repair method.   The valve connecting portion provided on the low pressure side of the refrigerant circuit is constituted by a pipe whose end is sealed, and the refrigerant is purged by forming a perforation in the pipe. 3. A method for repairing a refrigerant circuit according to 2.   The refrigerant circuit repair method according to claim 1, wherein the refrigerant sealed in the refrigerant circuit is carbon dioxide.

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