JP5658635B2 - Air conditioner and air conditioner construction method using existing refrigerant piping - Google Patents

Description

  The present invention relates to an air conditioner and an air conditioner construction method that reuses existing refrigerant piping.

  From the conventional air conditioner that uses CFC refrigerant or HCFC refrigerant as the refrigerant and mineral oil as the refrigerating machine oil, the HFC refrigerant and HFC There is an increasing demand for replacement with a new air conditioner (hereinafter referred to as a new machine) that uses refrigeration oil for a refrigerant. At the time of this replacement, the existing refrigerant piping that connects the old indoor unit and the outdoor unit is reused.

  Here, in the existing refrigerant pipe, a large amount of solid foreign matters resulting from wear of the sliding parts of the compressor mounted on the old machine remain. If no measures are taken against such solid foreign matters and the existing refrigerant piping is reused, the solid foreign matters enter the compressor installed in the new machine and promote wear of the sliding parts of the compressor. The reliability of the machine may be significantly impaired.

  Patent Document 1 describes that a filter having a net made of a metal body formed of a twilled weave is installed in a refrigerant pipe of an air conditioner. According to this, it is supposed that the fine foreign material which has a bad influence on an air-conditioning equipment can be caught reliably.

JP 2002-224513 A

  However, although the technique described in the cited document 1 describes that the filter is provided in the refrigerant pipe of the air conditioner, the specific installation mode is not described. For example, it is conceivable to protect the compressor by installing a filter in a liquid refrigerant pipe or a gas refrigerant pipe connecting an indoor unit and an outdoor unit and capturing solid foreign matters circulating with the refrigerant. However, in the air conditioner, the direction of refrigerant circulation is reversed between the cooling operation and the heating operation. Therefore, once trapped solid foreign substances may be separated from the filter and enter the compressor when the refrigerant flows backward.

  An object of the present invention is to effectively reuse existing refrigerant pipes without impairing the reliability of the air conditioner.

In order to solve the above problems, an air conditioner according to a first aspect of the present invention includes an outdoor unit including a compressor, a four-way valve, and an outdoor heat exchanger, and an indoor unit including an indoor expansion valve and an indoor heat exchanger. Are connected by a liquid refrigerant pipe and a gas refrigerant pipe to form a refrigeration cycle.In the outdoor unit, a blocking valve is provided at each connection port to which the liquid refrigerant pipe and the gas refrigerant pipe are connected, Each strainer is formed so as to be connectable to each other, and a liquid refrigerant pipe and a gas refrigerant pipe are formed so as to be directly connectable. The minimum clearance of the compressor bearing is 1 to 20 μm. has a screen size of the aperture portion is formed smaller than the minimum gap, characterized in that it is capable of capturing constructed of solid foreign matter or openings.

  That is, since a strainer that captures solid foreign matters is provided in each of the liquid refrigerant pipe and the gas refrigerant pipe, the solid foreign matters remaining in the liquid refrigerant pipe and the gas refrigerant pipe are on the gas refrigerant pipe side during the cooling operation. And is captured by the strainer on the liquid refrigerant piping side during heating operation. Therefore, even if the direction of refrigerant circulation is switched, it is possible to suppress solid foreign matter from entering the compressor. Further, since each strainer is provided at each connection port between the outdoor unit and each refrigerant pipe, solid foreign matters remaining in the liquid refrigerant pipe and the gas refrigerant pipe are surely captured by each strainer, and the compressor There is no risk of intrusion. As a result, the existing refrigerant pipe can be effectively reused without impairing the reliability of the air conditioner.

In this case, the strainer formed so that the gas refrigerant pipe can be connected preferably has a screen formed of at least one of a porous metal, a metal nonwoven fabric, and a polyester nonwoven fabric.

  Since the screen formed of these materials has a high ability to capture fine particles, it can capture solid foreign substances having a small particle size. Therefore, it can suppress that a solid foreign material penetrate | invades further into a compressor.

Further, it is desirable to dispose a magnet in each strainer, and it is desirable to dispose a neodymium magnet in a strainer formed so as to be connectable to the gas refrigerant pipe .

  Since the solid foreign matters remaining in the existing piping are mainly wear powder at the sliding portion of the refrigerant compressor, the ratio of iron adsorbed on the magnet is large. Therefore, by disposing a magnet in each strainer, part of the solid foreign matter can be adsorbed to the magnet, and the amount of solid foreign matter captured by the screen placed in each strainer can be reduced. As a result, clogging on the screen can be suppressed, and solid foreign matter can be prevented from entering the compressor. Further, the strainer attached to the gas refrigerant pipe is at a low temperature during the cooling operation. For this reason, it is effective to use a neodymium magnet that does not easily demagnetize even at low temperatures, as the magnet disposed in the strainer.

  Further, it is desirable that the strainer provided at the connection port between the outdoor unit and the liquid refrigerant pipe is initially filled with refrigeration oil for the compressor.

  This is because inside the existing refrigerant pipe, in addition to solid foreign substances, refrigeration oil (mineral oil, alkylbenzene, etc.) sealed in the old machine, oxidative degradation reaction products of refrigeration oil, pollutants such as chlorinated compounds (hereinafter referred to as chlorinated compounds) This is because impurities may deteriorate the refrigerating machine oil used in the new machine and cause the reliability of the air conditioner to be impaired.

  That is, although the refrigerating machine oil is previously enclosed in the outdoor unit of the normal air conditioner, the refrigerating machine oil for the compressor is further connected to the strainer provided at the connection port between the outdoor unit and the liquid refrigerant pipe. Is initially sealed. According to this, when the refrigerant circulates during the initial operation, the refrigeration oil sealed in the strainer circulates in the refrigeration cycle while gradually dissolving in the liquid refrigerant, and remains in the existing refrigerant piping for the refrigeration oil used in the new machine. Impurity ratio can be less than the allowable value. Therefore, deterioration of the refrigeration oil in the new machine can be prevented while effectively reusing the existing refrigerant pipe, and the reliability of the air conditioner can be maintained.

  This is because when an additional amount of refrigeration oil is enclosed in the refrigeration cycle during the construction of the air conditioner, a special hose is required to prevent contamination from entering, and the construction by adding the refrigeration oil filling work Compared to this, the time required for the installation is longer, and the sealing work during construction can be omitted, which is effective in reducing the construction burden. In addition, when the additional amount of refrigerating machine oil is enclosed in advance in the outdoor unit, etc., it is necessary to develop and manufacture the outdoor unit that encloses the additional amount of refrigerating machine oil separately from the outdoor unit that is not additionally enclosed. Compared to, development and manufacturing burden can be reduced.

  In addition, each strainer is preferably provided in the casing of the outdoor unit. This is because, if each strainer is provided outside the housing of the outdoor unit, it is necessary to apply heat insulation to the strainer itself to prevent condensation on the strainer, which increases the cost of the member and the manufacturing cost. Because. In other words, if it is inside the housing of the outdoor unit, even if condensation occurs and drops, there is no problem, so no heat insulating material is necessary, and the cost of the member and the manufacturing cost can be suppressed.

The second aspect of the present invention is the construction of an air conditioner that connects the new outdoor unit and the new indoor unit by reusing the existing liquid refrigerant piping and the existing gas refrigerant piping that connect the old outdoor unit and the old indoor unit. In the method, the new outdoor unit is provided with a blocking valve at each connection port to which the existing liquid refrigerant pipe and the existing gas refrigerant pipe are connected, and a strainer for capturing solid foreign substances in the refrigerant is formed at the connection port so that each can be connected. each strainer existing liquid refrigerant pipe and the existing gas refrigerant pipe is directly connectable to form a minimum gap of a bearing of the compressor is 1 to 20 [mu] m, each strainer, than the minimum gap size of the aperture portion It has a small screen, is configured to be able to capture solid foreign matters beyond the opening , and connects the existing liquid refrigerant pipe directly to a strainer formed so that the existing liquid refrigerant pipe can be connected. Connectable formed And wherein the connecting strainer to the existing gas refrigerant pipe directly to.

  According to this, since the new outdoor unit is connected to each of the existing liquid refrigerant pipe and the existing gas refrigerant pipe via the strainer that captures solid foreign matters circulating in the refrigeration cycle together with the refrigerant, Similarly to the first aspect, even if the direction of refrigerant circulation is switched, it is possible to prevent solid foreign matter from entering the compressor in the outdoor unit. As a result, the existing refrigerant pipe can be effectively reused without impairing the reliability of the air conditioner.

In this case, the strainer formed so that the existing gas refrigerant pipe can be connected preferably has a screen formed of at least one of a porous metal, a metal nonwoven fabric, and a polyester nonwoven fabric, Moreover, it is desirable that the strainer formed so that the existing liquid refrigerant pipe can be connected is preliminarily filled with refrigerating machine oil for the compressor of the new outdoor unit before construction.

  According to this, since solid foreign matters having a small particle diameter can be captured, solid foreign matters can be further prevented from entering the compressor, and impurities remaining in the existing refrigerant piping for the refrigerating machine oil in the new machine can be suppressed. Therefore, the deterioration of the refrigerating machine oil in the new machine can be prevented. As a result, the existing refrigerant pipe can be effectively reused without impairing the reliability of the air conditioner.

  ADVANTAGE OF THE INVENTION According to this invention, the existing refrigerant | coolant piping can be reused effectively, without impairing the reliability of an air conditioner.

It is a figure which shows the whole structure of the air conditioner of this invention. It is a figure which shows the structure of a strainer. It is a figure which shows the other structure of a strainer. It is an external view at the time of attaching a strainer in an outdoor unit. It is a figure explaining the strainer connected to the liquid refrigerant piping side. It is a figure explaining the exchange method of a strainer. It is a figure which shows the whole structure of the air conditioner of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of an air conditioner to which the present invention is applied and an air conditioner construction method that reuses an existing refrigerant pipe will be described with reference to FIGS. In the following description, the same functional parts are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a diagram showing an overall configuration of an air conditioner according to the present invention. The air conditioner 1 includes an outdoor unit 2, an indoor unit 3, and a liquid refrigerant pipe 4 and a gas refrigerant pipe 5 that connect them. The outdoor unit 2 includes a compressor 7, a four-way valve 8, an outdoor heat exchanger 9, an outdoor expansion valve 10, a receiver 11, a liquid blocking valve 16, a gas blocking valve 17, and the like. The machine 3 includes an indoor expansion valve 13 and an indoor heat exchanger 14.

  The suction port and the discharge port of the compressor 7 are formed so that they can be switched and connected to the outdoor heat exchanger 9 or the gas blocking valve 17 via the four-way valve 8 in reverse. The other end of the outdoor heat exchanger 9 is connected to the liquid blocking valve 16 via the outdoor expansion valve 10 and the receiver 11. The liquid blocking valve 16 and the gas blocking valve 17 are connected to one end of the liquid refrigerant pipe 4 and the gas refrigerant pipe 5 via strainers 18 and 19, respectively. The other end of the liquid refrigerant pipe 4 is connected to the indoor expansion valve 13. The other end of the gas refrigerant pipe 5 is connected to the indoor heat exchanger 14.

  As shown in FIG. 2, the strainers 18 and 19 are provided with a cylindrical screen 23 inside a cylindrical pressure vessel 20, one of the screens 23 is sealed with a sealing cap 21, and the other Is connected to an introduction cap 22 having an open central portion.

  Here, in the document ““ Lubrication ”, Vol. 17, No. 11 (1972) 741 to 746”, the minimum clearance in the sliding bearing also used in the refrigerant compressor is 1 to 20 μm. "Tribology and the environment", Shinkisha, page 53, Fig. 2, 2, 3 and 7 (b) "shows that the wear of the sliding part is the most under the condition that the particle size of the solid foreign material is equal to the minimum clearance of the bearing. There is a statement that it will be promoted. From such a description, it is preferable to use a screen 23 that can capture a solid foreign matter of 1 μm or more. Specifically, the screen 23 is formed of at least one of a porous metal, a metallic nonwoven fabric, a polyester nonwoven fabric, and the like. Has been.

  Further, the connection between the sealing cap 21 and the screen 23 and the connection between the introduction cap 22 and the screen 23 are realized by caulking all in the circumferential direction. Thereby, the inflow and outflow of solid foreign matters from the connecting portion between the sealing cap 21 and the introduction cap 22 and the screen 23 are prevented. Furthermore, the connection between the inner surface of the pressure vessel 20 and the introduction cap 22 is also realized by caulking the circumferential direction or welding all of the circumferential direction, thereby preventing inflow and outflow of solid foreign matters. A pipe 26 and a flare nut 27 are provided at one end of the pressure vessel 20, and a pipe 28 and a flare union 29 are provided at the other end.

  In addition, in order to endure the fluid force from a refrigerant | coolant and refrigerator oil, you may reinforce the inner periphery and outer periphery of the screen 23 with high intensity | strength members, such as a punching metal.

  Next, the operation of the air conditioner 1 and the capture of solid foreign matters by the strainers 18 and 19 will be described. When the air conditioner 1 is in cooling operation, the refrigerant circulates in the direction of the solid arrow in FIG. As the refrigerant circulates, solid foreign matters remaining in the liquid refrigerant pipe 4 and the gas refrigerant pipe 5 circulate. At this time, the solid foreign matter flows in the direction indicated by the solid line arrow in FIG. 2 on the screen 23 of the strainer 19 provided on the gas refrigerant pipe 5 side, and the solid foreign matter having a particle size larger than the opening portion of the screen 23 , And is captured by the inner surface of the screen 23. Further, the refrigerant and the refrigerating machine oil dissolved in the refrigerant flow out from the pipe 26 side through the opening portion of the screen 23.

  During the heating operation, the connection of the four-way valve 8 is switched to the direction indicated by the dotted line, and the refrigerant, the refrigerating machine oil, and the solid foreign material circulate in the direction indicated by the dotted arrow in FIG. At this time, the refrigerant and the refrigerating machine oil flow on the screen 23 of the strainer 19 in the direction indicated by the dotted arrow in FIG. 2, so that the solid foreign matter once captured on the inner surface of the screen 23 is piped by the fluid force of the refrigerant and the refrigerating machine oil. There is a possibility of flowing out of the strainer 19 from the 28 side. However, in the strainer 18 provided on the liquid refrigerant pipe 4 side, the flare union 29 on the pipe 28 side and the liquid refrigerant pipe 4 shown in FIG. 2 are connected, and the flare nut 27 and the liquid blocking valve 16 on the pipe 26 side are connected. Are connected to each other, and the solid foreign matter is captured by the screen 23 of the strainer 18.

  Thus, since the strainers 18 and 19 for capturing solid foreign substances are provided in the liquid refrigerant pipe 4 and the gas refrigerant pipe 5, respectively, the solid foreign substances remaining in the liquid refrigerant pipe 4 and the gas refrigerant pipe 5 are During the cooling operation, it is captured by the strainer 19 on the gas refrigerant pipe 5 side, and during the heating operation, it is captured by the strainer 18 on the liquid refrigerant pipe 4 side. Therefore, even if the air conditioner 1 switches between the cooling operation and the heating operation and the refrigerant circulation method is switched, it is possible to prevent the solid foreign matter from entering the compressor 7. Moreover, since each strainer 18 and 19 is provided in each connection port of the outdoor unit 2 and each refrigerant | coolant piping 4 and 5, the solid foreign material remaining in the liquid refrigerant piping 4 and the gas refrigerant piping 5 is ensured. In other words, there is no risk of being caught by the strainers 18 and 19 and entering the compressor.

  In addition, although the fine solid foreign matter not captured by the screen 23 enters the compressor 7, the document “Tribology and Environment”, Shinkisha, p. 53, FIG. 2, 2, 3, 7 (c) ”. According to the description, the amount of wear of the bearing portion increases as the amount of foreign matter supplied to the bearing sliding portion increases. Therefore, an allowable value for the amount of solid foreign matter intrusion is set as a specification of the compressor 7, and the solid foreign matter remaining in the liquid refrigerant pipe 4 and the gas refrigerant pipe 5 if the solid foreign matter intrusion amount is less than the allowable value. There is no problem even if part of the gas passes through the screen 23 and flows into the compressor 7. That is, the capture rate of the screen 23 employed in the strainers 18 and 19 may not be 100%.

  Here, as shown in FIG. 3, the strainers 18 and 19 may be configured by disposing a magnet 30 at a substantially central portion on the screen 23 side of the sealing cap 21 that seals one end of the screen 23.

  That is, the solid foreign matter remaining in the existing piping is mainly wear powder at the sliding portion of the refrigerant compressor, and therefore the ratio of iron adsorbed on the magnet is large. Therefore, by arranging the magnet 30 in the strainers 18 and 19 and adsorbing part of the solid foreign matter to the magnet, the amount of solid foreign matter captured by the screen 23 placed in the strainer 18 and 19 can be reduced. Clogging at the screen 23 can be suppressed.

  In this case, by making the material of the screen 23 a SUS non-woven fabric or a polyester non-woven fabric that does not adsorb to the magnet 30, it is possible to suppress the adsorption of iron to the screen 23, so that more iron is adsorbed to the magnet 30. And clogging at the screen 23 can be suppressed.

  Further, the strainer 19 attached to the gas refrigerant pipe 5 side becomes a low temperature during the cooling operation. Therefore, it is effective to use a neodymium magnet that is less likely to be demagnetized even at low temperatures as the magnet 30 disposed in the strainer 19.

  Next, the construction method of the air conditioner which reused existing refrigerant piping is demonstrated. When a conventional air conditioner using a CFC refrigerant or an HCFC refrigerant ages, first, in order to remove the old outdoor unit and the old indoor unit from the liquid refrigerant pipe 4 and the gas refrigerant pipe 5, the CFC refrigerant or HCFC The system refrigerant is recovered by a refrigerant recovery device. After recovering the refrigerant and removing the old outdoor unit and the old indoor unit, the liquid blocking valve 16 and the liquid refrigerant pipe 4 are connected via the strainer 18 inside the casing 31 of the outdoor unit 2 as shown in FIG. The gas blocking valve 17 and the gas refrigerant pipe 5 are connected via a strainer 19. At this time, the strainers 18 and 19 and the blocking valves 16 and 17 are directly flared, and the strainers 18 and 19 and the refrigerant pipes 4 and 5 are also directly flared.

  Thus, since each strainer 16 and 17 is arrange | positioned in the housing | casing 31 of an outdoor unit, compared with the case where each strainer is provided outside the housing | casing of an outdoor unit, it prevents that a strainer produces | generates condensation. Therefore, it is not necessary to apply a heat insulating material or the like, and the cost and manufacturing cost of the member can be suppressed.

  Further, in the strainer 18 connected to the liquid refrigerant pipe 4 side, as shown in FIG. 5, an on-off valve 33 is attached to the pipe 28, the pipe 26 is sealed with a cap 34, and the compression mounted on the outdoor unit 2. A pre-enclosed refrigerating machine oil 35 for the machine 7 is used. At the time of construction, after the flare union 29 is connected to the liquid refrigerant pipe 4, the on-off valve 33 is opened and the refrigerating machine oil 35 in the pressure vessel 20 is introduced into the liquid refrigerant pipe 4.

  The amount of the refrigerating machine oil 35 previously enclosed in the strainer 18 is such that deterioration due to impurities remaining in the liquid refrigerant pipe 4 and the gas refrigerant pipe 5 can be suppressed, that is, a refrigerating machine oil (not shown) enclosed in the outdoor unit 2 in advance. The ratio of impurities (impurity concentration) with respect to the whole of the refrigerating machine oil 35 enclosed in advance in the strainer 18 may be such that it is not more than an allowable value.

  The refrigerating machine oil 35 enclosed in advance in the strainer 18 is gradually dissolved in a liquid refrigerant such as an HFC refrigerant enclosed as a new refrigerant at the start of the initial operation and quickly discharged out of the strainer 18. Thereby, since the ratio of the impurity with respect to the refrigerating machine oil of the whole refrigerating cycle becomes below an allowable value, deterioration of refrigerating machine oil can be suppressed, As a result, the reliability of an air conditioner can be maintained.

  Compared to the case where additional refrigeration oil is enclosed in the refrigeration cycle during the construction of the air conditioner, a special hose for preventing contamination from entering the refrigeration oil is not required, and the addition of refrigeration oil is added. Since the construction time is shortened, it is effective in reducing the construction burden. In addition, when the additional amount of refrigerating machine oil is enclosed in advance in the outdoor unit, etc., it is necessary to develop and manufacture the outdoor unit that encloses the additional amount of refrigerating machine oil separately from the outdoor unit that is not additionally enclosed. Compared to, development and manufacturing burden can be reduced.

  It should be noted that the refrigerating machine oil is enclosed in the strainer 18 before carrying it into the construction site, and preferably before the strainer 18 is shipped from the factory. When the refrigerating machine oil 35 is sealed in the pressure resistant container 20, the piping 26 is first sealed with the cap 34, and then the open / close valve 33 is opened to evacuate the pressure resistant container 20. Thereafter, the refrigerating machine oil 35 is sealed from the flare union 29 side. Finally, an inert gas (for example, nitrogen gas) is sealed in the pressure vessel 20 and the pressure in the pressure vessel 20 is set to be equal to or higher than the atmospheric pressure, and then the on-off valve 33 may be closed. An on-off valve 33 may be attached instead of the cap 34.

  Thus, by using the on-off valve 33, it is possible to prevent the refrigerating machine oil 35 in the pressure-resistant container 20 from flowing out of the liquid refrigerant pipe 4 during construction, so that workability can be improved.

  When a necessary amount of refrigerating machine oil is held between the non-woven fibers by adopting a polyester non-woven fabric as the material of the screen 23 of the strainer 18, the on-off valve 33 and the cap 34 for preventing the refrigerating machine oil from flowing out. Etc. may not be used.

  Next, a method for replacing the strainers 18 and 19 will be described with reference to FIG. The screen 23 of the strainers 18 and 19 is assumed to be the amount of solid foreign matter remaining in the refrigerant pipes 4 and 5 from the pipe length and the like, and an appropriate one corresponding to that amount is used. For example, the strainers 18 and 19 are attached. At this time, foreign substances may be erroneously mixed in the refrigerant pipes 4 and 5. In addition, the amount of remaining solid foreign matter may be larger than expected. At this time, the amount of solid foreign matter in each of the refrigerant pipes 4 and 5 is larger than the initially assumed amount, so the screen 23 is closed or the pressure loss at the screen 23 is remarkably increased. Then, the suction pressure of the compressor 7 is remarkably reduced, and the performance and reliability of the air conditioner may be remarkably lowered, such as insufficient capacity and a rise in the temperature of the compressor 7.

  Therefore, foreign matter capturing kits 42 and 43 incorporating strainers 18 and 19 and on-off valves 40 and 41 are attached between the outdoor unit 2 and the refrigerant pipes 4 and 5, and the strainers 18 and 19 are further connected by flaring. Thus, the strainers 18 and 19 can be removed from the foreign matter capturing kits 42 and 43.

  When the strainers 18 and 19 are replaced, first, the respective stop valves 16 and 17 and the on-off valves 40 and 41 are closed, and the check valves 16 and 17 and the on-off valves 40 and 41 are checked by the refrigerant recovery device from the check joints 44 and 45. Then, the strainers 18 and 19 are removed. Then, a new strainer or a removed strainer from which foreign matter has been removed is mounted in the foreign matter catching kits 42 and 43, and after evacuating from the check joints 44 and 45, each of the blocking valves 16, 17 and the on-off valve 40, 41 can be opened.

  As a result, even if a large amount of solid foreign matter is trapped on the screens 23 of the strainers 18 and 19 and closed or pressure loss occurs, the strainer can be easily replaced.

  The air conditioner of the present invention is intended to suppress the solid foreign matters remaining in the refrigerant pipes 4 and 5 from mainly entering the compressor 7, so the installation mode of the strainers 18 and 19 is as follows. As shown in FIG. 1, the present invention is not limited to this, and the following installation mode may be employed. As shown in FIG. 7, in addition to the strainers 18 and 19, strainers 48 and 49 are provided in the vicinity of the connection port of the indoor unit 3. In other words, the liquid refrigerant pipe 4 and the connection port on the indoor expansion valve 13 side of the indoor unit 3 are connected via the strainer 48, and the gas refrigerant pipe 5 and the connection port on the indoor heat exchanger 14 side of the indoor unit 3 are connected. Are connected via a strainer 49.

  Thereby, it can suppress that the solid foreign material which remained in each refrigerant | coolant piping 4 and 5 penetrate | invades in the indoor unit 3. FIG. As a result, even if the flow path inner diameter of the refrigerant distribution capillary of the indoor heat exchanger 14 or the indoor expansion valve 13 which is a component of the indoor unit 3 is not sufficiently larger than the particle size of the solid foreign matter, the indoor unit It is possible to prevent clogging from occurring within 3.

  As mentioned above, although embodiment of the construction method of the air conditioner and the air conditioner which reused existing refrigerant piping of the present invention was described, in the above explanation, HFC refrigerant was mainly used from the old machine which used HCFC refrigerant. The renewal to the new machine is described. However, the present invention is not limited to the type of refrigerant used, such as renewal from an old machine using HCFC refrigerant to a new machine using HCFC refrigerant, or from an old machine using HFC refrigerant to a new machine using HFC refrigerant. It is applicable without limitation.

DESCRIPTION OF SYMBOLS 1 Air conditioner 2 Outdoor unit 3 Indoor unit 4 Liquid refrigerant piping 5 Gas refrigerant piping 7 Compressor 8 Four-way valve 9 Outdoor heat exchanger 13 Indoor expansion valve 14 Indoor heat exchangers 18 and 19 Strainer 23 Screen 30 Magnet 31 Outdoor unit Enclosure

Claims (12)

A refrigerating cycle is formed by connecting an outdoor unit equipped with a compressor, a four-way valve and an outdoor heat exchanger, and an indoor unit equipped with an indoor expansion valve and an indoor heat exchanger with existing liquid refrigerant pipes and gas refrigerant pipes. In the air conditioner
The outdoor unit, the liquid refrigerant pipe and the gas refrigerant pipe, each blocking valve is provided in the connection port to be connected, a strainer for capturing the solid foreign matters in the refrigerant to the connection port is connected respectively, each strainers the gas refrigerant pipe and the liquid refrigerant pipe is connected directly,
The air conditioner is characterized in that a minimum clearance of a bearing of the compressor is 1 to 20 μm, and each strainer is configured to be able to capture a solid foreign matter of 1 μm or more.   The strainer formed so that the gas refrigerant pipe can be connected has a screen formed of at least one of a porous metal, a metallic nonwoven fabric, and a polyester nonwoven fabric. Air conditioner.   The air conditioner according to claim 2, wherein a magnet is disposed in each strainer.   The air conditioner according to claim 3, wherein the magnet disposed in the strainer formed so that the gas refrigerant pipe is connectable is a neodymium magnet.   5. The air conditioner according to claim 1, wherein the strainer formed so that the liquid refrigerant pipe is connectable is initially filled with refrigeration oil for the compressor.   The air conditioner according to any one of claims 1 to 5, wherein each strainer is provided in a casing of the outdoor unit.   The air conditioner according to any one of claims 1 to 6, wherein a check joint is provided in each flow path between the blocking valve and the strainer at each connection port. In the construction method of the air conditioner that connects the new outdoor unit and the new indoor unit by reusing the existing liquid refrigerant piping and the existing gas refrigerant piping that connect the old outdoor unit and the old indoor unit,
Said new outdoor unit, the existing liquid refrigerant pipe and the existing gas refrigerant pipe, each blocking valve is provided in the connection port to be connected, a strainer for capturing the solid foreign matters in the refrigerant to the connection port is connected respectively , each strainer said existing gas refrigerant pipe and the existing liquid refrigerant pipe is connected directly,
The minimum gap of the bearing of the compressor is 1 to 20 μm, and each strainer is configured to be able to capture solid foreign matters of 1 μm or more,
The existing liquid refrigerant pipe is directly connected to a strainer formed so that the existing liquid refrigerant pipe can be connected, and the existing gas refrigerant pipe is directly connected to a strainer formed so that the existing gas refrigerant pipe can be connected. An air conditioner construction method that reuses existing refrigerant piping.   The strainer formed so that the existing gas refrigerant pipe can be connected has a screen formed of at least one of a porous metal, a metal nonwoven fabric, and a polyester nonwoven fabric. Method of air conditioner that reuses existing refrigerant piping.   The construction method of the air conditioner which reused the existing refrigerant | coolant piping of Claim 9 by which a magnet is arrange | positioned in each said strainer.   The construction method of the air conditioner which reused the existing refrigerant | coolant piping of Claim 10 characterized by the magnet arrange | positioned in the strainer formed so that the said existing gas refrigerant | coolant piping is connectable.   The strainer formed so that the existing liquid refrigerant pipe can be connected is preliminarily filled with refrigerating machine oil for the compressor of the new outdoor unit before construction. The construction method of the air conditioner which reused the existing refrigerant | coolant piping as described in a term.

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