KR20090088595A - Refrigerant charging apparatus for air-conditioner and the method using it - Google Patents

Abstract

A refrigerant charging apparatus for air-conditioner and a refrigerant charging method using the same are provided to prevent sudden inflow of refrigerant by controlling the flow rate of refrigerant when charging refrigerant in an air conditioner. A refrigerant charging apparatus for air-conditioner comprises a first joint pipe(330), a second joint(340), and a flux control unit(351). The first joint pipe is combined with a first connection pipe which is connected to a refrigerant circuit of an air conditioner. The second joint pipe is combined with a second connection pipe which is connected to a refrigerant storage to let refrigerant flow in. The flux control unit connects the first joint pipe and the second joint pipe and limits the flow rate of the refrigerant flowing in the air conditioner.

Description

Refrigerant charging apparatus for air-conditioner and the method using it}

The present invention provides a refrigerant filling device for an air conditioner and a refrigerant filling method using the same, and more particularly, includes a flow rate control unit for limiting the flow rate of the refrigerant flowing into the air conditioner, and is coupled by a user when filling the refrigerant. The present invention relates to a refrigerant filling apparatus for an air conditioner that can be separated after the refrigerant filling is completed, and a refrigerant filling method using the same.

In general, an air conditioner is classified into an indoor unit installed in an indoor unit and an outdoor unit installed in an outdoor unit. The indoor unit is provided with an indoor heat exchanger and a fan so as to constitute a cooling or heating cycle. The indoor air is heat-exchanged while passing through the indoor heat exchanger by the suction force of the fan, and the air is discharged to the room, thereby cooling or heating is performed. In addition, the outdoor unit is provided with a compressor, a fan, and the like constituting a cycle, and the outdoor air sucked through the fan is exchanged while passing through the outdoor heat exchanger.

On the other hand, conventional air conditioners inevitably cause a loss of refrigerant during use. When the amount of refrigerant decreases, the cooling or heating efficiency of the air conditioner decreases rapidly, and the operator must separately fill the appropriate amount of refrigerant.

A vacuum pump or the like is used to charge a refrigerant of the air conditioner, and when the refrigerant is charged, a plurality of hoses are replaced several times. In the process, a refrigerant loss is accompanied again, and the refrigerant is released into the atmosphere. When the refrigerant of the device is filled, there is a problem that the refrigerant flows rapidly because the inflow rate of the refrigerant being filled is not controlled.

In addition, it is difficult to charge an appropriate amount of refrigerant by relying on manual operation of a user or a manager at the time of starting or terminating the refrigerant filling, and due to the strong fastening between the refrigerant filling apparatus and the air conditioner, the portable filling of the refrigerant filling apparatus is carried out. There is also a problem of poor sex.

The present invention includes a flow control unit for limiting the flow rate of the refrigerant flowing into the air conditioner, the refrigerant filling unit for the air conditioner is coupled by the user when the refrigerant filling, can be separated after the refrigerant filling is completed And to provide a refrigerant filling method using the same.

Refrigerant filling apparatus for an air conditioner of the present invention is for filling a refrigerant stored in the refrigerant storage unit in the air conditioner, the first coupling pipe coupled to the first connection pipe connected to the refrigerant circuit of the air conditioner, A second coupling pipe connected to the refrigerant storage unit and coupled to a second connection pipe through which refrigerant is introduced; And a flow rate control unit connecting the first coupling pipe and the second coupling pipe and limiting a flow rate of the refrigerant flowing into the air conditioner, wherein the refrigerant filling device is configured by the user to fill the refrigerant. And is separated from the air conditioner after the refrigerant filling is completed.

In the present invention, it may further include a check valve installed on the first coupling pipe or the second coupling pipe, and prevents the refrigerant from flowing back from the air conditioner to the refrigerant storage.

In the present invention, the flow control unit may be a pipe having an inner diameter smaller than the first coupling pipe and the second coupling pipe, in particular the flow control unit may be a capillary tube.

In the present invention, it may further include a shut-off valve for blocking the refrigerant flowing into the air conditioner from the refrigerant storage unit.

In the present invention, the air conditioner determines the amount of the insufficient refrigerant in the refrigerant circuit, the air conditioner is the shutoff valve when the insufficient amount of refrigerant is introduced into the refrigerant circuit from the refrigerant storage unit and filled Can be closed.

Refrigerant filling method of the air conditioner of the present invention is for filling the air conditioner with the refrigerant stored in the refrigerant storage unit, determining the amount of insufficient refrigerant in the refrigerant circuit of the air conditioner, the air conditioner In order to fill the refrigerant into the refrigerant, to prepare a refrigerant filling device having a flow rate control unit for connecting the first coupling pipe, the second coupling pipe, the first coupling pipe and the second coupling pipe and limits the flow rate of the refrigerant; step; And connecting the refrigerant circuit of the air conditioner and the first coupling pipe to the first connection pipe, and connecting the refrigerant storage unit and the second coupling pipe to the second connection pipe, thereby preventing the insufficient refrigerant from the refrigerant storage unit. Filling the refrigerant circuit of the air conditioner with the amount of.

In the present invention, the refrigerant filling device further comprises a shutoff valve for blocking the refrigerant flowing into the air conditioner from the refrigerant storage unit, the refrigerant filling method of the air conditioner, the amount of the refrigerant is insufficient. When the air conditioner is filled with a refrigerant circuit, the method may further include closing the shutoff valve.

In the present invention, after filling the refrigerant into the refrigerant circuit of the air conditioner may further comprise the step of separating the refrigerant filling device.

Refrigerant filling apparatus for an air conditioner according to the present invention includes a flow rate control unit for limiting the flow rate of the refrigerant flowing into the air conditioner, and is coupled by the user when the refrigerant is filled, the separation after the refrigerant filling is complete Can be.

In addition, the refrigerant filling method for an air conditioner according to the present invention comprises preparing a refrigerant filling device including the flow control unit and connecting the air conditioner to the amount of refrigerant insufficient from the refrigerant storage unit refrigerant circuit of the air conditioner Filling with a.

Therefore, by appropriately controlling the flow rate of the refrigerant flowing into the air conditioner when the refrigerant is filled in the air conditioner, there is an advantage that can prevent the rapid introduction of the refrigerant. In addition, there is an advantage in that it is possible to automatically determine the start or end time of the refrigerant charge of the air conditioner, to fill the appropriate amount of refrigerant. In addition, since the refrigerant filling device and the air conditioner can be separated by the user, there is an advantage that the portability of the refrigerant filling device is improved.

Hereinafter, an embodiment of a refrigerant filling apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram of a multi-type air conditioner according to the present invention, Figure 2 is an exploded perspective view showing the internal configuration of the outdoor unit of the air conditioner shown in FIG.

Referring to FIG. 1, an outdoor unit 100 of a multi-type air conditioner which has recently been popularized includes a constant speed compressor 120, an inverter compressor 120 ′, an accumulator 132, an outdoor heat exchanger 180, and an outdoor solenoid valve 102. , LEV: linear expansion valve, hereinafter referred to as 'outdoor LEV'), and the indoor unit 200 includes an indoor heat exchanger 202 and an expansion valve 204.

In the multi-type air conditioner, a plurality of indoor units 200 are connected to one or more outdoor units 100. Between the outdoor unit 100 and the indoor units 200, the common liquid pipe 210, which is a single pipe through which liquid refrigerant flows, and The common engine 212, which is a single pipe through which gas refrigerant flows, is formed in communication. And between the two or more outdoor unit 100 is installed in communication with the high and low pressure common pipe 214 to maintain the balance of the refrigerant. The high and low pressure common pipe 214 is installed such that the inlet side of the outdoor heat exchanger 180 provided in the plurality of outdoor units 100 communicates with each other to maintain the balance of the refrigerant between the outdoor units 100. Meanwhile, the refrigerant is also introduced into the outdoor heat exchanger 180 of the outdoor unit 100, which is not used among the plurality of outdoor units 100, resulting in an overall heat exchange efficiency. And the high or low pressure common pipe 214 is a high pressure or low pressure refrigerant flows in accordance with the cooling or heating action.

The indoor unit 200 is formed with a branch liquid pipe 210 'through which a liquid refrigerant flows, and a branch engine 212' through which a gas refrigerant flows, respectively. The branch liquid pipe 210 'and the branch engine 212' have a common liquid pipe ( 210 is in communication with the common engine 212. In addition, the diameters of the plurality of branch liquid pipes 210 'and the branch engine 212' are different depending on the capacity of the indoor unit 200 to be connected.

Referring to FIG. 2, a base fan 110, which forms the bottom surface of the outdoor unit 100, is provided at the bottom of the outdoor unit 100 to support a plurality of components. The front panel 112 is formed to form an appearance. The front grill 114 is installed on the upper side of the front panel 112. Therefore, the outside air is sucked through the front grill 114, and passes through the outdoor heat exchanger 180 to be described later. The upper front bracket 116 is further installed on the upper side of the front grill 114, and the front end bracket 116 is fastened to the front end of the motor mount 174.

Compressors 120 and 120 'are installed on the upper surface of the base fan 110. Compressors (120, 120 ') is to compress the refrigerant to be a high temperature and high pressure, is provided on each side. Here, the constant speed compressor 120 that performs the constant speed operation on the relatively right side, and the inverter compressor 120 'which is a variable speed heat pump (Variable Speed Heat Pump) may be installed on the left side.

Refrigerant injectors 120a are installed at the inlet sides of the compressors 120 and 120 '. The refrigerant injector 120a prevents the compressor from being burned by supplying a refrigerant when the compressors 120 and 120 'are overheated according to operating conditions. The refrigerant used in the refrigerant injection unit 120 may be used. Can be.

A constant oil compressor 121 is installed between the constant speed compressor 120 and the inverter compressor 120 'such that the constant speed compressor 120 and the inverter compressor 120' communicate with each other. Therefore, when oil supply shortage occurs in one of the compressors, the compressor 120 is replenished from the other compressor to prevent burnout of the compressors 120 and 120 'due to the insufficient flow rate.

At the outlet side of the constant speed compressor 120 and the inverter compressor 120 ', a compressor discharge temperature sensor (not shown) and an oil separator 122 for measuring the temperature of the refrigerant discharged from the compressors 120 and 120' may be provided.

The oil separator 122 is configured to communicate with the four-way valve 124 by piping. The four-way valve 124 is arranged to change the flow direction of the refrigerant according to the cooling and heating operation, each port is the outlet (or oil separator) of the compressor (120, 120 '), the inlet of the compressor (120, 120') (Or an accumulator), the outdoor heat exchanger 180 and the indoor unit 200 are connected.

Therefore, the refrigerant discharged from the constant speed compressor 120 and the inverter compressor 120 'is collected in one place, and then flows into the four-way valve 124. The compressors 120 and 120' are provided at the inlet of the four-way valve 124. The high pressure sensor 124 ′ for checking the pressure of the refrigerant discharged from the air may be installed.

The valve support 126 is installed at the center of the first half of the upper surface of the base fan 110. The valve support 126 serves to support and guide the outdoor liquid pipe 210 ", the outdoor engine 212", and the high and low pressure common pipe 214, and the first connection pipe 128 is also installed therein. Here, the pipes 210, 212, 214 supported by the valve support 126 are drawn out through the pipe inlet 188 ′ of the side panel 188 and are connected to the outdoor unit 100.

On the other hand, the air conditioner inevitably causes a loss of refrigerant during the use process, in this case, the user can separately fill the appropriate amount of refrigerant through the first connection pipe (128). The first connection pipe 128 shown in FIG. 2 may be referred to as a 'service pipe' as a pipe for providing a service such as refrigerant filling.

3 is a block diagram showing the outdoor unit 100 and the refrigerant charging device 300 of the air conditioner according to an embodiment of the present invention. 4 is a diagram illustrating each configuration of the refrigerant charging device 300 illustrated in FIG. 3. FIG. 5 is a perspective view illustrating a piping assembly 350 of the refrigerant charging device 300 illustrated in FIG. 4.

Referring to FIG. 3, in order to fill a refrigerant in the air conditioner, the refrigerant stored in the refrigerant storage unit 310 is supplied to the outdoor unit 100 of the air conditioner by using the refrigerant filler 300.

Here, the refrigerant filling apparatus 300 may be coupled by the user when the refrigerant is filled in the air conditioner and separated after the refrigerant filling is completed in the air conditioner. Coupling and separation of the refrigerant filling apparatus 300 and the air conditioner may be performed by combining or releasing the first coupling pipe 330 of the refrigerant filling apparatus 300 and the first connection pipe 128 of the air conditioning apparatus to each other. It is possible by doing. However, the present invention is not limited thereto, and may be possible by coupling or releasing the second coupling pipe 340 and the coolant storage unit 310 of the coolant filling device 300 to be described later, in addition to the coolant filling device 300. It may be possible by uncoupling or uncoupling between the components constituting the piping of each configuration of.

When the refrigerant filling device 300 and the outdoor unit 100 of the air conditioner can be combined or separated by a user, since the portability of the refrigerant filling device 300 is improved, a user or a serviceman may charge the refrigerant filling device 300. By carrying all or part of the, there is an advantage that can provide a refrigerant charging service to a variety of outdoor units.

The refrigerant charging device 300 of the present invention includes a pipe assembly 350, the pipe assembly includes a first coupling pipe 330, the second coupling pipe 340 and the flow control unit 351.

The first coupling pipe 330 is coupled to the first connection pipe 128 connected to the refrigerant circuit of the air conditioner. Here, the first connection pipe 128 refers to the service pipe shown in FIG. 2, and the first coupling pipe 330 is coupled to the first connection pipe 128. Specifically, the first coupling pipe 330 and the first coupling pipe 128 through the first coupling hose 331 connecting one end of the first coupling pipe 330 and one end of the first connecting pipe 128 Combination is possible. Referring to FIG. 5, the other end of the first coupling hose 331 may be connected to the first coupling pipe 330 by being coupled to the first connector 331a formed at one end of the first coupling pipe 330.

Here, the first coupling hose 331 can be omitted, it is also possible to directly combine the first connecting pipe 128 and the first coupling pipe 330.

As shown in FIG. 2, the first connection pipe 128 may be installed at a valve support 126 installed at the center of the first half of the upper surface of the base fan 110. The first connection pipe 128 installed in the valve support 126 is connected to the inlet side, that is, the suction end of the compressor (120, 120 ') shown in FIG. Therefore, the refrigerant introduced into the outdoor unit 100 through the first connection pipe 128 is introduced into the suction ends of the compressors 120 and 120 ', thereby increasing the high temperature and high pressure. However, the present invention is not limited thereto, and the first connection pipe 128 may be connected to any place on the refrigerant circuit through which the refrigerant flows in the air conditioner to supply the refrigerant to the outdoor unit 100.

The manifold gauge 360 may be installed on the first coupling hose 331. The manifold gauge 360 displays the pressure of the refrigerant, but is not limited thereto. The manifold gauge 360 may display the temperature of the refrigerant relative to the pressure of the refrigerant by displaying the temperature of the refrigerant. When filling the refrigerant, the manifold gauge 360 is connected to the air conditioner through various hoses and the like, and the refrigerant is charged until a predetermined operating pressure is reached.

In the case of manually filling the insufficient amount of refrigerant, the pressure is not kept constant immediately when the refrigerant is charged into the air conditioner, but the manifold gauge 360 fluctuates little by little as the air conditioner operates. do. Since the refrigerant must be stabilized to a certain degree (balance pressure) to accurately measure the refrigerant, the refrigerant is charged while the manifold gauge 360 is checked again after a predetermined time after adjusting the pressure of the refrigerant to a predetermined value.

The second connection pipe 311 is connected to the refrigerant storage unit 310, the refrigerant flows from the refrigerant storage unit 310, and the second coupling pipe 340 is coupled to the second connection pipe 311. It is possible to combine the second coupling pipe 340 and the second connection pipe 311 through the second coupling hose 341 connecting one end of the second coupling pipe 340 and one end of the second connection pipe 311. Do. Referring to FIG. 5, the other end of the second coupling hose 341 may be connected to the second coupling pipe 340 by being coupled to the second connector 341a formed at one end of the second coupling pipe 340. Here, the second coupling hose 341 may be omitted, and the second coupling pipe 311 and the second coupling pipe 340 may also be directly coupled.

4 and 5, the flow control unit 351 of the pipe assembly 350 connects the first coupling pipe 330 and the second coupling pipe 340, and the outdoor unit 100 of the air conditioner. Limit the flow rate of refrigerant entering the furnace. That is, when the amount of insufficient refrigerant is to be supplied to the outdoor unit 100, not only does not prevent the refrigerant from flowing during the initial insufficient refrigerant amount, but also when the flow rate of the refrigerant flowing into the outdoor unit 100 is large, the amount is insufficient. Since the possibility of flowing into the outdoor unit 100 by increasing the amount of the refrigerant increases, the flow rate control unit 351 increases the flow rate of the refrigerant so that the refrigerant flowing from the refrigerant storage unit 310 does not rapidly enter the outdoor unit 100. Will be limited.

In order to limit the flow rate of the refrigerant flowing into the outdoor unit 100, the flow control unit 351 may be a pipe having an inner diameter smaller than the first coupling pipe 330 and the second coupling pipe 340, in particular may be a capillary tube have. The diameter of the capillary tube is 1.4 mm or less, and the length of the capillary tube is preferably 1 m or more.

Referring to FIG. 4, the pipe assembly 350 is seated inside the case 353 in which a predetermined internal space is formed. The upper portion of the case 353, the cover 352 forming the upper surface of the case 353 is coupled. Predetermined holes 353a are formed at one side of the case 353 such that the first coupling pipe 330 and the second coupling pipe 340 extend outside the case 353.

Referring to FIG. 5, the refrigerant filling device 300 is installed on the first coupling pipe 330 or the second coupling pipe 340, and prevents the refrigerant from flowing back from the air conditioner to the refrigerant storage unit 310. It may further include a check valve 345. That is, when the pressure of the coolant flowing from the coolant storage unit 310 to the outdoor unit 100 of the air conditioner drops, the coolant flowing through the pipes on the pipe assembly 350 may occur. In this case, by installing the check valve 345 on the first coupling pipe 330 or the second coupling pipe 340, the reverse flow of the refrigerant can be prevented, it is possible to stabilize the refrigerant filling.

On the other hand, the refrigerant filling device 300 may further include a shutoff valve (not shown) for blocking the refrigerant flowing into the air conditioner from the refrigerant storage unit 310.

The air conditioner may determine the amount of refrigerant insufficient in the refrigerant circuit. That is, the microcomputer (not shown) of the outdoor unit 100 of the air conditioner stores logic for determining the amount of the refrigerant insufficient in the refrigerant circuit. As a method of determining the amount of insufficient refrigerant in the refrigerant circuit, it is possible to drive a predetermined cycle (for example, a trial run), measure various parameters on the cycle, and determine whether the values of the parameters are within a normal range. Can be. The parameters include the superheat degree of the compressor, the output temperature of the indoor unit, or the temperature of the outdoor unit, and table the normal range data of the values of the parameters, compare the measured parameters with the table, and determine the insufficient refrigerant amount. Can be. However, the method of determining the insufficient refrigerant amount in the refrigerant circuit is not limited to this.

The microcomputer of the outdoor unit 100 may automatically determine the start or end point of the refrigerant charging of the air conditioner, thereby filling an appropriate amount of refrigerant.

The outdoor unit 100 of the air conditioner may close the shutoff valve (not shown) when the insufficient amount of refrigerant flows into the refrigerant circuit from the refrigerant storage unit 310. The shutoff valve may be provided at any position on the refrigerant filling device 300. Since a sufficient amount of refrigerant is introduced and filled, the refrigerant flowing in the pipe assembly 350 may additionally flow into the refrigerant circuit. By closing the shutoff valve, only the required amount of refrigerant can be filled.

6 is a flowchart illustrating a refrigerant filling process according to an embodiment of the refrigerant filling method of the air conditioner of the present invention.

Refrigerant filling method of the air conditioner of the present invention, the step of determining the amount of insufficient refrigerant in the refrigerant circuit of the air conditioner (step S100), if it is determined that the amount of refrigerant is insufficient (step S200), the refrigerant in the air conditioner In order to fill the step, preparing a refrigerant filling device 300 having a first coupling pipe 330, the second coupling pipe 340, and the flow control unit 351 (S300 step). When the refrigerant filling device 300 is prepared, the refrigerant filling device 300 and the outdoor unit 100 of the air conditioner are combined, which is connected to the refrigerant circuit of the air conditioning device and the first coupling pipe 330 by the first connection pipe ( 128, and the refrigerant storage unit 310 and the second coupling pipe 340 are connected to the second connection pipe 311. After the refrigerant filling apparatus 300 is prepared and the outdoor unit 100 of the air conditioning apparatus is combined, the amount of the insufficient refrigerant is filled from the refrigerant storage unit 310 into the refrigerant circuit of the air conditioning apparatus (S400).

When the amount of insufficient refrigerant is filled into the refrigerant circuit of the air conditioner, the shutoff valve may be closed (step S500), and the refrigerant charge device 300 may be separated from the outdoor unit 100 of the air conditioner.

Although the present invention has been described with reference to the embodiments shown in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a block diagram of a multi-type air conditioner according to the present invention.

FIG. 2 is an exploded perspective view showing the internal configuration of the outdoor unit of the air conditioner shown in FIG. 1.

3 is a block diagram showing an outdoor unit and a refrigerant charging device of the air conditioner according to an embodiment of the present invention.

4 is a block diagram showing each configuration of the refrigerant charging device shown in FIG.

FIG. 5 is a perspective view illustrating a piping assembly of the refrigerant charging device illustrated in FIG. 4.

6 is a flowchart illustrating a refrigerant filling process according to an embodiment of the refrigerant filling method of the air conditioner of the present invention.

<Simple description of the code for the main part of the drawing>

100: outdoor unit 200: indoor unit

300: refrigerant filling device 310: refrigerant storage unit

330: first coupling pipe 340: second coupling pipe

350: pipe assembly 351: flow control unit

Claims (11)

A refrigerant filling device for an air conditioner for filling a refrigerant stored in a refrigerant storage unit into an air conditioner, A first coupling pipe coupled to the first connection pipe connected to the refrigerant circuit of the air conditioner; A second coupling pipe connected to the refrigerant storage unit and coupled to a second connection pipe through which refrigerant is introduced; And It includes a flow control unit for connecting the first coupling pipe and the second coupling pipe, limiting the flow rate of the refrigerant flowing into the air conditioner, The refrigerant filling apparatus is coupled to the air conditioner by the user when the refrigerant filling, refrigerant filling apparatus for an air conditioner is separated from the air conditioning apparatus after the refrigerant filling is completed. The method according to claim 1, And a check valve installed on the first coupling pipe or the second coupling pipe and preventing a backflow of the refrigerant from the air conditioner to the refrigerant storage unit. The method according to claim 1, And the flow control part is a pipe having an inner diameter smaller than that of the first coupling pipe and the second coupling pipe. The method according to claim 3, The flow rate control unit is a capillary tube refrigerant filling device for an air conditioner. The method according to claim 1, And a shut-off valve for blocking the refrigerant flowing into the air conditioner from the coolant storage unit. The method according to claim 5, The air conditioner determines the amount of refrigerant insufficient in the refrigerant circuit, And the air conditioner is configured to close the shutoff valve when the insufficient amount of refrigerant flows into the refrigerant circuit from the refrigerant storage unit. A refrigerant filling method of an air conditioner for filling a refrigerant stored in a refrigerant storage unit into an air conditioner, Determining an amount of insufficient refrigerant in the refrigerant circuit of the air conditioner; In order to fill the air conditioner with a refrigerant, a refrigerant filling unit includes a first coupling pipe, a second coupling pipe, a flow control unit connecting the first coupling pipe and the second coupling pipe and restricting a flow rate of the refrigerant. Preparing the device; And The refrigerant circuit of the air conditioner and the first coupling pipe is connected to the first connection pipe, and the refrigerant storage unit and the second coupling pipe is connected to the second connection pipe, the refrigerant from the refrigerant storage unit Refrigerant filling method comprising the step of filling the refrigerant circuit of the air conditioner. The method according to claim 7, The refrigerant filling device further includes a shutoff valve for blocking the refrigerant flowing into the air conditioner from the refrigerant storage unit. The refrigerant filling method of the air conditioner, And filling the refrigerant circuit of the air conditioner with the insufficient amount of the refrigerant, closing the shutoff valve. The method according to claim 8, And after the refrigerant is filled in the refrigerant circuit of the air conditioner, separating the refrigerant filler. The method according to claim 7, The flow rate control unit is a capillary tube refrigerant filling method of the air conditioner. The method according to claim 7, The refrigerant filling apparatus further includes a check valve installed on the first coupling pipe or the second coupling pipe to block the refrigerant from flowing back from the first coupling pipe to the second coupling pipe. Refrigerant filling method.

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