JP2000039236A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an air conditioner in which a water remover can be changed while a refrigerant is sealed therein after the water remover is disposed, and the concentration of water in a refrigerating cycle can be reduced without wearing a dehumidifying agent in the water remover. SOLUTION: An air conditioner comprises a refrigerating cycle including an outdoor machine having a compressor 1, a four-way valve 2, a heat exchanger 3 for an outdoor machine, a check valve 8 for a gas piping and a check valve 9 for a liquid piping, an indoor machine having a heat exchanger 10 for an indoor machine and an expander 12, and a gas connecting piping 15 and a liquid connecting piping 16 for connecting the outdoor machine and the indoor machine together so as to use HFC refrigerant a working refrigerant. The air conditioner further includes a liquid valve 14 provided in the liquid connecting piping 16, and a water remover 13 attached between the check valve 9 for the liquid piping and the liquid valve 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating and air-conditioning apparatus, and is suitable for an air conditioner for removing moisture mixed in a refrigerating cycle.

[0002]

2. Description of the Related Art Conventionally, for example, as described in Japanese Patent Application Laid-Open No. 8-75321, moisture removal during a refrigeration cycle is performed by installing a moisture remover in a liquid pipe which is a main pipe between a condenser and an expansion valve. There is known a refrigeration apparatus having a configuration in which a bypass pipe having a smaller diameter than the main pipe is provided.

[0003] Japanese Patent Laid-Open No. Hei 7-253 discloses that a moisture remover is provided in a liquid line of a refrigeration cycle, and further provided in a pipe bypassing the moisture remover via a stop valve.
No. 259 is known.

[0004] During the refrigeration cycle, moisture may be mixed in during installation of the refrigeration / air-conditioning apparatus, particularly when connecting pipes connecting the indoor unit and the outdoor unit. In some cases, moisture is mixed in the refrigerating machine oil used for lubricating a portion of the compressor bearing or the like where mechanical wear occurs.

[0005] If water is mixed in the refrigeration cycle, the water is frozen and the narrowed portion of the flow path of the expansion device or the like is blocked with ice, resulting in insufficient capacity or abnormal increase in the pressure in the refrigeration cycle.
Abnormal drop occurs. In addition, deterioration of the refrigerating machine oil occurs.
For this reason, a moisture remover is provided in the refrigeration cycle to remove moisture in the refrigeration cycle.

[0006] Conventionally, CFC-based refrigerant (chlorofluorocarbon),
HCFC-based refrigerants (hydrochlorofluorocarbons) have been used. However, since these fluorocarbons cause ozone destruction, HFC-based refrigerants (hydrofluorocarbons) have come to be used as alternative refrigerants that do not use chlorine. Mineral oil that has been used as a refrigerating machine for refrigeration and air-conditioning systems using HCFC-based refrigerant (hydrochlorofluorocarbon) has a problem of poor compatibility with HFC-based refrigerant, and ester oil or ether having good compatibility with HFC-based refrigerant. Oil is used. These refrigerating machine oils have high hygroscopicity, and there is a risk that more moisture is mixed into the refrigerating cycle through the refrigerating machine oil than before.

[0007]

In recent years, it has become clear that chlorine-containing refrigerants used in refrigeration and air-conditioning systems destroy the ozone layer, and from the viewpoint of environmental protection, the production of chlorine-containing refrigerants is restricted worldwide. Is in the direction of prohibition. For this reason, the use of HFC-based refrigerants that do not contain chlorine has been shifted to, but there is a problem that synthetic oil, which is a refrigerating machine oil having good compatibility with the present refrigerant, easily absorbs moisture. Is frozen and the part of the flow path, such as the expansion device, in which the flow path is narrowed is blocked by ice, resulting in insufficient capacity or abnormal increase or decrease in the pressure in the refrigeration cycle. In addition, deterioration of the refrigerating machine oil occurs. Therefore, poor lubrication of the compressor may occur, and in some cases, a burnout accident of the compressor may occur.

As a method of removing water on site, a method of removing moisture by arranging a moisture remover in an outdoor unit and shipping the same to complete a refrigeration cycle on site via an indoor unit and a connection pipe and circulating a refrigerant. And a method of providing a moisture remover outside the outdoor unit at the site is known. In any case, even if moisture is absorbed by the moisture remover, the moisture in the refrigeration cycle is transferred to the refrigeration cycle. If it cannot be removed by the attached water remover, it is necessary to recover the refrigerant from the refrigeration cycle and attach a new water remover to the pipe again.

In this case, since the refrigeration cycle is opened to the air, there arises a problem that moisture enters the cycle during the operation. In addition, since the refrigerant is once removed from the refrigeration cycle, a refrigerant recovery device is required, which requires a long working time and requires a recovery cylinder. In addition, when the moisture remover performs a brazing operation or the like with a liquid pipe, it is necessary to remove the used moisture remover by a burner and to attach a replacement moisture remover.

Further, after the refrigerant is collected, a vacuuming operation, a refrigerant charging operation, and an additional operation of the refrigerating machine oil are required in some cases. As described above, removal of the existing water remover requires a great deal of construction time. Further, HFC refrigerants are currently more expensive than CFC refrigerants and HCFC refrigerants, and ester oils and ether oils, which are refrigerating machine oils having good compatibility with HFC refrigerants, are synthetic oils and are more expensive than mineral oils. Therefore, the construction cost of conventional refrigerant CF
The cost is higher than the replacement work of the C-based and HCFC-based refrigerants.

In the method described in Japanese Patent Application Laid-Open No. Hei 7-253259, a moisture removing device is provided in the main pipe, and the moisture absorbing material is worn during the moisture removing operation, and the worn pieces spread during the refrigeration cycle. There is a possibility that the expansion valve or the like in the refrigeration cycle is clogged.

Furthermore, the amount of water in the refrigeration cycle before moisture absorption is unknown in most cases, and the amount of water after the water remover cannot be grasped as in the above-described prior art. . If the evacuation cannot be performed, it is expected that moisture is still mixed in the refrigeration cycle. However, even if the evacuation can be performed, a very small amount of moisture cannot be detected.

[0013] Furthermore, the water remover has been used in refrigerators in the past, and since it is used only for cooling operation, a type in which the refrigerant flows in one direction in the water remover is mainly used in the market. . For this reason, when a refrigerant flows in both directions in a liquid pipe like a heat pump type air conditioner, there is a problem that a conventional moisture remover cannot be used.

An object of the present invention is to provide a method for removing moisture in a refrigeration cycle, in which the moisture remover can be replaced in a refrigerant-filled state after the moisture remover is provided, and the dehumidifier in the moisture remover is not worn. Another object of the present invention is to provide an air conditioner capable of reducing the moisture concentration in a refrigeration cycle.

[0015]

To achieve the above object, the present invention relates to an outdoor unit having a compressor, a four-way valve, a heat exchanger for an outdoor unit, a check valve for a gas pipe, and a check valve for a liquid pipe, and an indoor unit. An indoor unit having a heat exchanger for expansion and an expansion unit is connected sequentially with a gas connection pipe and a liquid connection pipe to form a refrigeration cycle,
An air conditioner using a system refrigerant as a working refrigerant, comprising: a liquid valve provided at the liquid connection pipe; and a water remover attached between the liquid pipe check valve and the liquid valve. is there.

With this arrangement, if the moisture concentration in the refrigeration cycle does not decrease even when the moisture removal operation in the refrigeration cycle is performed by the moisture eliminator after charging the refrigerant, the refrigeration cycle operation is stopped and the liquid piping check valve in the outdoor unit is stopped. Close the liquid valve outside the machine, disconnect the liquid piping check valve and the liquid valve from the refrigeration cycle, remove the moisture remover placed between them, and install the replacement moisture remover again to remove the refrigerant. It is possible to replace the water remover without collecting the water.

Further, the main body of the water remover is branched from the liquid connection pipe, which is the main pipe, and is provided in the bypass circuit of the main pipe. By circulating through the inside and clogging the expansion valve in the refrigeration cycle, it is possible to prevent operation abnormality from occurring.

Further, by attaching a sight glass having an indicator function of a moisture concentration to a liquid pipe which is a main pipe so as to be in parallel with the moisture remover, the moisture concentration in the refrigeration cycle before and after the attachment of the moisture remover is detected. it can.

Further, the workability at the site can be improved by forming the water remover and the sight glass in a parallel structure, and furthermore, by flaring both ends to the liquid pipe which is the main pipe.

Further, by allowing the refrigerant to flow in the water remover in both directions, even when the refrigerant flow in the liquid pipe connection pipe is reversed in the cooling operation and the heating operation, the refrigerant in the water remover can be removed. It is made possible to flow a refrigerant through the dehumidifier and absorb moisture in the refrigeration cycle.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to a package type air conditioner as an embodiment.

FIG. 1 is a refrigeration cycle system diagram showing a first embodiment of a heat pump type air conditioner according to the present invention. The air conditioner is a separate type air conditioner combining an indoor unit and an outdoor unit. Machine. A refrigeration cycle is constituted by an indoor unit and an outdoor unit, and a cooling operation and a heating operation can be performed by a signal from a control device.

The refrigerating cycle mainly includes a compressor 1, a four-way valve 2, an outdoor unit heat exchanger 3, a subcooler 4, an outdoor unit blower 5, an accumulator 6, an outdoor unit expansion device 7, a gas pipe blocking valve 8, It comprises a liquid pipe blocking valve 9, an indoor unit heat exchanger 10, an indoor unit blower 11, an indoor unit expansion device 12, a moisture remover 13, a liquid valve 14, and the like. And a refrigeration cycle connected by the liquid pipe connection pipe 16 and the like.

Next, the operation during the refrigeration cycle operation will be described. During the cooling operation, the high-temperature and high-pressure gas refrigerant discharged from the compressor 1 passes through the four-way valve 2 and is cooled by the air blown by the outdoor unit blower 5 in the outdoor unit heat exchanger 3 to condense the gas refrigerant. Liquefy. The liquid refrigerant is further subcooled by the subcooler 4, and after passing through the liquid piping check valve 9, a part of the refrigerant is branched to the water remover 13 side to remove water mixed in the refrigerant. It joins with the liquid refrigerant flowing through the liquid pipe connection pipe 16 which is a pipe. The liquid refrigerant having a reduced moisture concentration passes through the liquid valve 14, is decompressed by the indoor unit expansion device 12 through the liquid pipe connection pipe 16, and is sent by the indoor unit blower 11 by the indoor unit heat exchanger 10. By absorbing heat from air and evaporating, it becomes a low-temperature and low-pressure gas refrigerant. This low-temperature and low-pressure gas refrigerant is connected to the gas pipe connecting pipe 1.
After returning to the outdoor unit side via 5 and passing through the gas piping check valve 8 and the four-way valve 2, gas-liquid separation is performed by the accumulator 6, the flow returns to the compressor 1, and the same cycle is repeated again.

At the time of heating, the high-temperature and high-pressure gas discharged from the compressor 1 passes through the four-way valve 2, passes through the gas pipe blocking valve 8, passes through the gas pipe connection pipe 15, enters the indoor unit, and enters the indoor unit side. The gas refrigerant is cooled by the air blown from the indoor unit blower 11 in the heat exchanger 10, and the gas refrigerant is condensed and liquefied. The liquid refrigerant passes through the liquid pipe connection pipe 16 and the liquid valve 14, and a part of the refrigerant is branched to the water remover 13 side to remove water mixed in the refrigerant, and then the liquid pipe connection pipe serving as a main pipe. It merges with the liquid refrigerant flowing in 16. The liquid refrigerant having a reduced moisture concentration returns to the outdoor unit again, passes through the liquid piping check valve 9 and the sub-cooler 4, and then passes through the air blown from the outdoor unit blower 5 by the outdoor unit heat exchanger 3 in the outdoor unit heat exchanger 3. After absorbing and evaporating, the refrigerant becomes a low-temperature and low-pressure gas refrigerant, gas-liquid separated by the accumulator 6 via the four-way valve 2, returns to the compressor 1, and repeats the same cycle again.

Next, FIG. 2 shows a schematic diagram of the water removal kit. The structure is composed of a union 17 and a main pipe 18 connected by a flare ring to a connection pipe 16 for a liquid pipe, which is a main pipe, and a water remover 13 branched from the main pipe. Is in.

FIG. 3 shows a sight glass 20 provided in the main pipe 18 in the water removal kit shown in FIG. 2, and FIG. 4 shows an installation construction diagram. The moisture removal kit flares the end of the liquid pipe connection pipe 16 coming out of the liquid piping check valve 9 in the outdoor unit, flares and connects the moisture removal kit with the union 17, and further connects the union 17 on the opposite side of the moisture removal kit to the fluid valve 14. Is fixed by flare connection. The liquid valve 14 is connected to the indoor unit via a liquid pipe connection pipe 16. As shown in FIG. 4, the water removal kit requires that the bypassed water remover 13 be located below the connection pipe 16 for the liquid pipe, so that the liquid refrigerant always passes through the moisture remover. become.

Next, a method of removing water during the refrigeration cycle will be described. As shown in FIG. 4, after the water remover 13 is disposed in the connection pipe 16 for the liquid pipe to complete the refrigeration cycle piping work, a test operation of the refrigeration cycle is performed in the cooling operation or the heating operation, and the water in the refrigeration cycle is removed. It is made to adsorb | suck to the hygroscopic agent 19 in the water removal device 13, and water is removed. At this time, it is necessary to operate for several days in order for the moisture absorbent 19 to absorb moisture.

After a test run of the refrigeration cycle for several days,
The moisture concentration indicator attached to the sight glass 20 is used to check whether or not moisture remains in the refrigeration cycle. If the moisture has decreased to a specified value or less, the construction is completed. On the other hand, if the water concentration has not fallen below the specified value, the refrigeration cycle operation is stopped, the outdoor unit liquid piping check valve 9 and the liquid valve 14 are closed, and the water removal kit is separated from the refrigeration cycle at the flare portion and replaced. The flare nut is tightened again and fixed so that there is no leakage, a vacuum is drawn from the check joint 21 provided on the outdoor unit liquid piping check valve 9, and the outdoor unit liquid piping check valve 9 and the liquid valve 1 are replaced.
Remove air and moisture between the four. At this time, it was confirmed by the moisture concentration indicator attached to the sight glass 20 that the vacuum was released. If the moisture concentration had fallen to a specified value, the liquid piping check valve 9 and the liquid valve 14 in the outdoor unit were opened, and the freezing was performed again. The cycle operation is performed, and the moisture in the refrigeration cycle is removed by the replaced moisture removal kit.

As described above, since the refrigerant in the refrigeration cycle is not taken out of the refrigeration cycle and the refrigeration cycle is opened to the outside air, moisture does not enter when the moisture remover 13 is replaced. In addition, since the replacement work is easy and does not take much time, the service time can be reduced.

Further, by providing the water removing device 13 in a bypass circuit branched from the main pipe, wear of the dehumidifying agent 19 can be reduced, reliability of the compressor can be ensured, and pressure loss in the connection pipe 16 for the liquid pipe can be reduced. The performance can be improved with the water remover attached in the refrigeration cycle.

Further, by installing the sight glass 20, it is possible to confirm the water concentration in the refrigeration cycle and easily determine whether it is necessary to replace the water removal kit.

Further, by allowing the refrigerant to flow in the water remover in both directions, even when the refrigerant flow in the liquid pipe connection pipe is reversed in the cooling operation and the heating operation, the refrigerant in the water remover can be removed. A refrigerant is made to flow through the dehumidifier, thereby enabling moisture in the refrigeration cycle to be absorbed. Therefore, the water removal operation can be performed immediately after the air conditioner is installed regardless of the summer or winter season.

As described above, according to the above, the moisture removal kit is provided between the liquid piping check valve in the outdoor unit and the liquid valve outside the unit.
After a trial operation after the initially installed moisture remover is filled with the refrigerant, the moisture removal kit can be removed without taking the refrigerant out of the refrigeration cycle and replacing it. Therefore, it is not necessary to bring a cylinder for charging the refrigerant or a cylinder for collecting the refrigerant to the site.

Furthermore, HFC-based refrigerants are currently more expensive than CFC-based refrigerants and HCFC-based refrigerants, and ester oils and ether oils, which are refrigerating machine oils having good compatibility with HFC-based refrigerants, are more expensive than mineral oils. Although the construction cost is higher than the replacement work cost of the conventional CFC-based and HCFC-based refrigerants, according to the present invention, the water in the refrigeration cycle can be removed at a low cost.

Further, since the water removal kit is flared with the connection pipe for the liquid pipe, there is no need to remove the brazing connection by using a burner or the like on site, so that the work time can be reduced, and the water removal can be performed by the brazing work. Damage to the dehumidifier in the vessel can be avoided.

Further, by attaching the moisture remover to the main pipe, which is a connecting pipe for a liquid pipe, it is possible to prevent the dehumidifier in the moisture remover from being worn out. Damage to the compressor due to no supply of the refrigerating machine oil can be avoided, and the reliability of the refrigerating cycle can be improved.

Further, it is difficult to grasp the water concentration in the refrigeration cycle on site, and almost all cases are evaluated based on the time required for evacuation. For this reason, by attaching a sight glass having a moisture concentration indicator function as in the present invention, the moisture concentration in the refrigeration cycle before and after the attachment of the moisture removal kit can be grasped, and the moisture removal kit is replaced on site. It is possible to easily determine whether or not it is necessary to do so.

[0039]

As described above, according to the present invention, as a method for removing moisture in a refrigeration cycle, it is possible to replace the moisture remover in a state in which refrigerant is charged after the moisture remover is installed, Ensure that the dehumidifier does not wear,
An air conditioner capable of reducing the water concentration in the refrigeration cycle can be obtained.

[Brief description of the drawings]

FIG. 1 is a refrigeration cycle system diagram according to one embodiment.

FIG. 2 is a configuration diagram of a water removal kit according to one embodiment.

FIG. 3 is a configuration diagram of a moisture removal kit with a sight glass according to one embodiment.

FIG. 4 is a construction view showing an installation state according to one embodiment.

[Explanation of symbols]

1 ... Compressor, 2 ... Four-way valve, 3 ... Outdoor heat exchanger, 4 ...
..Sub-cooler, 5 ... outdoor blower, 6 ... accumulator, 7 ... outdoor expansion device, 8 ... blocking valve for gas piping, 9
... Restriction valve for liquid piping, 10 ... Heat exchanger for indoor use, 11 ...
Indoor blower, 12 Indoor control device, 13 Water remover, 14 Liquid valve, 15 Connection pipe for gas pipe, 16
... connection pipe for liquid pipe, 17 ... union, 18 ... main pipe, 19 ... hygroscopic agent, 20 ... sight glass, 21 ... check joint.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Tsuyoshi Endo 390 Muramatsu, Shimizu-shi, Shizuoka Prefecture Inside the Air Conditioning Systems Division, Hitachi, Ltd. Inside

Claims (5)

[Claims] An outdoor unit having a compressor, a four-way valve, a heat exchanger for an outdoor unit, a check valve for a gas pipe, a check valve for a liquid pipe, a heat exchanger for an indoor unit, and an indoor unit having an expansion device are gas-connected. A refrigeration cycle is constructed by connecting pipes and liquid connection pipes one after another
An air conditioner using a system refrigerant as a working refrigerant, comprising: a liquid valve provided in the liquid connection pipe, and a water remover attached between the liquid pipe check valve and the liquid valve. A characteristic air conditioner. 2. A device according to claim 1, further comprising a bypass circuit branched from said liquid connection pipe and passing through a moisture remover, wherein said bypass circuit is provided between said liquid pipe check valve and said liquid valve. An air conditioner characterized by being arranged. 3. The air according to claim 1, wherein the moisture remover after moisture absorption is replaced with a moisture remover before moisture absorption in a state where the working refrigerant is sealed and the refrigerant is sealed. Harmony machine. 4. The air conditioner according to claim 2, wherein a sight glass having a moisture concentration indicator function is arranged in the connection pipe for the liquid pipe in parallel with the moisture remover. 5. The air conditioner according to claim 2, wherein the refrigerant can flow in both directions in the moisture remover.