JP2017150688A - Piping cleaning method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a piping cleaning method capable of efficiently performing cleaning of unit piping between units of a GHP outdoor unit and an EHP outdoor unit.SOLUTION: A piping cleaning method includes: piping 110 for oil discharge connected to an oil port 13c of a GHP compressor 13; an opening/closing valve 111 for discharge provided at the piping 110 for oil discharge; piping 112 for oil injection connected to a middle part of refrigerant piping; an opening/closing valve 113 for injection provided at the piping 112 for oil injection. The piping cleaning method sequentially performs: pump-down operation processing by a heating operation by driving the GHP compressor; oil drain processing for opening the opening/closing valve for discharge of the piping for oil discharge; new oil injection processing for opening the opening/closing valve for injection of the piping for oil injection; and processing for performing the heating operation after releasing the pump-down operation by the heating operation.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pipe cleaning method, and more particularly to a pipe cleaning method for cleaning an inter-unit pipe of an air conditioner that uses both a GHP outdoor unit and an EHP outdoor unit.

In general, when installing an air conditioner, only the outdoor unit or the indoor unit is replaced, and the existing piping in the building is reused as it is. It has been broken.
When the existing piping is used as it is, it may be necessary to clean the existing piping. For example, before installing an outdoor unit or an indoor unit, such an existing pipe can be cleaned by connecting a dedicated cleaning device to the pipe of the existing pipe so that the residual oil of the refrigeration oil attached to the existing pipe, etc. The removal is performed.
However, in the cleaning of existing pipes in a dedicated cleaning device, a work process in which the cleaning device is installed is required before installing the outdoor unit or indoor unit, which increases the number of man-hours for constructing the equipment. There is a problem that the cost and management cost and the labor cost required for the cleaning work are also increased.

  Therefore, conventionally, an engine-driven heat pump that drives a refrigerant compressor with an engine has an operation mode of a pipe cleaning mode that removes residual oil in existing piping of a building, and starts operation in an operation of the pipe cleaning mode. In some cases, a technique is disclosed in which operation is performed with a small amount of refrigerant circulation and automatically switched to the normal operation mode after completion of cleaning of existing piping in the building (see, for example, Patent Document 1). ).

JP 2004-003696 A

Here, in recent years, an air conditioner that drives a plurality of indoor units by using a GHP outdoor unit and an EHP outdoor unit that drive a compressor by an engine is often used.
In such an air conditioner, when one or both of the GHP outdoor unit and the EHP outdoor unit are replaced, when the existing inter-unit piping is reused, the conventional technology uses the GHP. There is a problem that it is necessary to provide a pipe cleaning mode in the outdoor unit or the EHP outdoor unit.
This invention is made | formed in view of an above-described point, and it aims at providing the piping washing | cleaning method which can wash | clean the piping between units of a GHP outdoor unit and an EHP outdoor unit efficiently.

  In order to achieve the above object, the present invention provides an inter-unit connection between a second outdoor unit having a high-capacity compressor, a first outdoor unit having a low-capacity compressor, and an indoor unit. In a pipe cleaning method for cleaning a pipe, an oil discharge pipe connected to an oil port of the high-capacity compressor, a discharge on-off valve provided in the oil discharge pipe, and a refrigerant pipe in the middle An oil injection pipe to be connected and an injection opening / closing valve provided in the oil injection pipe are provided to drive the high-capacity compressor to perform a pump-down operation process by heating operation, and the oil discharge pipe. An oil draining process for opening the discharge on-off valve, a new oil injection process for opening the injection on-off valve of the oil injection pipe, and a heating operation after releasing the pump-down operation by the heating operation And performing a physical, sequentially.

  In the above configuration, the second outdoor unit including the high-capacity compressor is a GHP outdoor unit including a GHP compressor driven by an engine, and the first outdoor unit including the low-capacity compressor is provided. The outdoor unit is an EHP outdoor unit including an EHP compressor driven by a commercial power source.

  According to the pipe cleaning method of the present invention, the inter-unit pipe can be efficiently cleaned in the air conditioner including the GHP outdoor unit and the EHP outdoor unit. Separately, there is no need to prepare a cleaning device and perform work in a separate process, and it is possible to reduce the man-hour and cost for facility construction.

It is a lineblock diagram of the air harmony device concerning an embodiment of the invention. It is a block diagram which shows the functional structure of an air conditioning apparatus.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a configuration diagram showing an embodiment of an air conditioner to which a pipe cleaning method according to the present invention is applied.
The air conditioner 1 is driven by a GHP outdoor unit 2 (second outdoor unit) having a compressor driven by a gas engine as a high-capacity compressor and a commercial power source as a low-capacity compressor. An EHP outdoor unit 3 (first outdoor unit) including a compressor and a plurality of indoor units 4 are provided. The GHP outdoor unit 2, the EHP outdoor unit 3, and each indoor unit 4 are connected via an inter-unit pipe 5 and an oil balance pipe 6, thereby constituting a refrigeration cycle circuit for performing an air conditioning operation.

The GHP outdoor unit 2 includes two external connection valves 10 a and 10 b for connecting to an external inter-unit pipe 5 and an oil connection valve 11 for connecting an oil balance pipe 6.
The GHP outdoor unit 2 is provided with a gas engine 12 as an engine and a GHP compressor 13 (highly capable compressor) that compresses refrigerant by the driving force of the gas engine 12. The GHP compressor 13 includes a first GHP compressor 13a and a second GHP compressor 13b provided in parallel. An oil port 13c is formed in the first GHP compressor 13a.
The gas engine 12 generates a driving force by burning an air-fuel mixture of a fuel such as a gas supplied via a fuel adjustment valve (not shown) and air supplied via a throttle valve (not shown). It is like that.
A drive belt 14 is stretched between the output shaft of the gas engine 12 and the driven shaft of the GHP compressor 13, and the driving force of the gas engine 12 is transmitted via the drive belt 14, so that the GHP The compressor 13 is configured to be driven.

On the discharge side of the GHP compressor 13, an oil separator 15, a four-way valve 16, and two outdoor heat exchangers 17 and 17 are connected in order, and each outdoor heat exchanger 17 is connected to one external connection via a refrigerant pipe 20. It is connected to the valve 10a. In the vicinity of the outdoor heat exchanger 17, an outdoor blower 18 for performing heat exchange between the outdoor heat exchanger 17 and the outside air is provided.
Further, a refrigerant pipe 20 is connected to the other external connection valve 10 b, and this refrigerant pipe 20 is connected to the suction side of the GHP compressor 13 through a midway four-way valve 16 and an accumulator 19.

An electric valve 24 and a check valve 25 are connected in parallel to the middle of the refrigerant pipe 20, and a liquid pipe 22 connected to the inflow side of the accumulator 19 is connected to the refrigerant pipe 20. A dry core 39 is provided between the outdoor heat exchanger 17 and the external connection valve 10a.
In addition, a heat exchange refrigerant pipe 23 that connects the suction side of the GHP compressor 13 and the refrigerant pipe 20 is connected between the suction side of the GHP compressor 13 and the refrigerant pipe 20. An electric valve 26 is provided at 23. A plate-type heat exchanger 27 is provided between the electric valve 26 of the heat exchange refrigerant pipe 23 and the suction side of the GHP compressor 13.

The GHP outdoor unit 2 includes a bypass pipe 28 that connects the discharge side and the suction side of the GHP compressor 13. One end of the bypass pipe 28 is connected between the oil separator 15 and the four-way valve 16, and the other end of the bypass pipe 28 is connected between the accumulator 19 and the four-way valve 16. A part of the refrigerant on the discharge side of the GHP compressor 13 flows to the suction side of the GHP compressor 13 through the bypass pipe 28 due to a pressure difference.
The bypass pipe 28 is provided with a bypass valve 29 that adjusts the flow rate of the bypass pipe 28. The bypass valve 29 is an electric valve that can be opened and closed in stages.

  The GHP outdoor unit 2 includes an oil return pipe 30 that connects the oil separator 15 and the suction side of the GHP compressor 13. The lubricating oil stored in the oil separator 15 flows through the oil return pipe 30 to the suction side due to the pressure difference between the discharge side and the suction side of the GHP compressor 13.

The oil return pipe 30 includes a first return pipe 31 that connects the oil outlet of the oil separator 15 and the suction side of the GHP compressor 13, and a second return provided in parallel to the first return pipe 31. Tube 36.
The first return pipe 31 includes a capillary tube 32.
The second return pipe 36 is connected to the first return pipe 31 so as to bypass the capillary tube 32, and one end of the second return pipe 36 is upstream of the capillary tube 32 in the first return pipe 31. The other end of the second return pipe 36 is connected to the downstream side of the capillary tube 32 in the first return pipe 31.
The second return pipe 36 includes a capillary tube 33 and an oil return valve 34 provided downstream of the capillary tube 33.

  An oil pipe 35 is connected to the oil connection valve 11. The oil pipe 35 branches in the middle, one of which is connected to the downstream side of the oil separator 15 of the refrigerant pipe 20 and the other is between the capillary tube 33 of the second return pipe 32 and the oil return valve 34. Connected between.

One end of the indoor heat exchanger 40 of each indoor unit 4 is connected to the external connection valve 10 a connected to the refrigerant pipe 20 via the inter-unit pipe 5. An expansion valve 41 is provided in the middle of the inter-unit pipe 5.
Inside each indoor unit 4, an indoor blower 42 for performing heat exchange between the indoor heat exchanger 40 and room air is provided.
The other end of each indoor heat exchanger 40 is connected to an external connection valve 10 b connected to the refrigerant pipe 20 via the inter-unit pipe 5.

The GHP outdoor unit 2 includes a cooling water circuit 50 for the gas engine 12.
The cooling water circuit 50 includes a cooling water three-way valve 52 connected in order from the gas engine 12 via a cooling water pipe 51, a plate-type heat exchanger 27, and a radiator 53 disposed in proximity to one of the outdoor heat exchangers 17. And a cooling water pump 54 and an exhaust gas heat exchanger 55 of the gas engine 12, and by driving the cooling water pump 54, the cooling water is circulated in the circuit.
The cooling water pipe 51 of the cooling water circuit 50 is indicated by a double line in FIG. 1, and the flow of the cooling water is indicated by a solid arrow.
In the radiator 53, heat exchange between outside air and cooling water is performed.
In the plate heat exchanger 27, the refrigerant returning to the GHP compressor 13 is heated by the cooling water flowing in the cooling water pipe 51 by the operation of the motor-operated valve 26. Thereby, the low-pressure pressure of the refrigerant increases, and the heating efficiency is improved.

The cooling water circuit 50 can form a first path through which cooling water flows in the order of the gas engine 12, the cooling water three-way valve 52, the radiator 53, the cooling water pump 54, the exhaust gas heat exchanger 55, and the gas engine 12.
In the cooling water circuit 50, the cooling water flows in the order of the gas engine 12, the cooling water three-way valve 52, the plate heat exchanger 27, the cooling water pump 54, the exhaust gas heat exchanger 55, and the gas engine 12. A second path can be formed.

Next, the EHP outdoor unit 3 will be described.
The EHP outdoor unit 3 includes two external connection valves 60 for connecting to an external inter-unit pipe 5 and an oil connection valve 61 for connecting an oil balance pipe 6.
The EHP outdoor unit 32 includes an EHP compressor 62 (low-capacity compressor) driven by a commercial power source. The EHP compressor 62 is, for example, an inverter type compressor whose output can be varied.

On the discharge side of the EHP compressor 62, an oil separator 63, a four-way valve 64, and two outdoor heat exchangers 65, 65 are sequentially connected, and the outdoor heat exchanger 65 is connected to one external connection valve via the refrigerant pipe 21. 60a. In the vicinity of the outdoor heat exchanger 65, an outdoor blower 66 (see FIG. 2) for performing heat exchange between the outdoor heat exchanger 65 and the outside air is provided.
A receiver tank 67 is provided between the outdoor heat exchanger 65 and the external connection valve 60a.
Two channels are formed in the outdoor heat exchanger 65, and the refrigerant pipe 21 on the four-way valve 64 side and the refrigerant pipe 21 on the receiver tank 67 side are branched and connected to the outdoor heat exchanger 65. It is comprised so that. Also, outdoor electronic control valves 68 and 68 are provided on the refrigerant pipe 21 on the receiver tank 67 side of the outdoor heat exchanger 65, respectively.

  The other external connection valve 60b is connected to the suction side of the EHP compressor 62 via the refrigerant pipe 21, and a four-way valve 64 and an accumulator 69 are provided in the middle of the refrigerant pipe.

  A refrigerant return pipe 70 that branches and is connected to the refrigerant pipe 21 between the EHP compressor 62 and the accumulator 69 is provided in the middle of the refrigerant pipe 21 between the EHP compressor 62 and the oil separator 63. It has been. A refrigerant return solenoid valve 71 is provided in the middle of the refrigerant return pipe 70. When the refrigerant return solenoid valve 71 is opened, a part of the refrigerant is guided to the suction side of the EHP compressor 62 without circulating through the refrigeration cycle.

  An oil pipe 72 is connected to the lower part of the oil separator 63, and an oil return pipe 73 connected to the suction side of the EHP compressor 62 is connected to the middle part of the oil pipe 72. The oil return pipe 73 includes two branch pipes 74 and 75 that branch from the oil pipe 72. One branch pipe 74 is provided with an oil return solenoid valve 7631, and the other branch pipe 75 includes A capillary tube 78 is provided. A capillary tube 79 is provided between the connecting portions of the branch pipes 74 and 75 of the oil pipe 27.

  A high-pressure refrigerant pipe 80 that branches in the middle and is connected to the middle part of the oil pipe 72 is connected to the middle part of the refrigerant pipe 21 between the oil separator 63 and the four-way valve 64. A high pressure refrigerant solenoid valve 81 is provided in the middle of the high pressure refrigerant pipe 80.

The accumulator 69 also includes an inflow pipe 82 into which the refrigerant in the refrigerant pipe 21 flows and an outflow pipe 83 that sends the gas refrigerant in the accumulator 69 to the EHP compressor 62. The outflow pipe 83 is configured to open above the interior of the accumulator 69, and is configured to send the gas refrigerant accumulated above the interior of the accumulator 69 to the EHP compressor 62.
In addition, an overflow pipe 84 connected to the suction side of the EHP compressor 62 is connected to the EHP compressor 62. The overflow pipe 84 incorporates a strainer 85 and a throttle 86 for decompressing the oil.
Further, the EHP outdoor unit 3 is provided with an outside air temperature sensor 90 for detecting an external temperature.

  One end of the inter-unit piping 5 is connected to the external connection valve 60 a of the EHP outdoor unit 3, and the other end of the inter-unit piping 5 is a unit that connects the external connection valve 10 a of the GHP outdoor unit 2 and the indoor unit 4. It is connected to the middle part of the intermediate pipe 5. One end of the inter-unit pipe 5 is connected to the external connection valve 60b connected to the refrigerant pipe of the EHP outdoor unit 3, and the other end of the inter-unit pipe 5 is connected to the external connection valve 10b of the GHP outdoor unit 2 and the indoor unit. 4 is connected to a midway part 5 between the units.

The oil connection valve 61 of the EHP outdoor unit 3 and the oil connection valve 11 of the GHP outdoor unit 2 are connected via an oil balance pipe. Accordingly, oil can be supplied to each other between the EHP compressor 62 of the GHP outdoor unit 2 and the EHP compressor 62 of the EHP outdoor unit 3 via the oil balance pipe, and the EHP compression of the GHP outdoor unit 2 The oil quantity balance between the machine 62 and the EHP compressor 62 of the EHP outdoor unit 3 can be maintained.
When the cooling operation is performed, the refrigerant flows as shown by a solid line arrow in FIG. 1, and when the heating operation is performed, the refrigerant flows as shown by a broken line in FIG.

Next, the control configuration of the air conditioning apparatus of the present embodiment will be described. FIG. 2 is a block diagram showing a control configuration in the present embodiment.
As shown in FIG. 2, in this embodiment, the GHP outdoor unit 2 includes a GHP control unit 100, and the EHP outdoor unit 3 includes an EHP control unit 101. Each indoor unit 4 includes an indoor control unit 102. The air conditioner includes a system control unit 103 as a control unit that controls the GHP control unit 100, the EHP control unit 101, and the indoor control unit 102 in an integrated manner.
The GHP control unit 100, the EHP control unit 101, the indoor control unit 102, and the system control unit 103 include, for example, an arithmetic processing circuit such as a CPU, a ROM and a RAM as storage means, and the like, by executing a predetermined program A predetermined control is performed.

As shown in FIG. 2, the GHP control unit 100 is configured to drive and control the gas engine 12 and the outdoor blower 18.
The EHP control unit 101 is configured to drive and control the EHP compressor 62 and the outdoor blower 66 based on the detection value by the outside air temperature sensor 90.
In the present embodiment, the outside air temperature sensor 90 is provided only in the EHP outdoor unit 3, but the outside air temperature sensor 90 may be provided also in the GHP outdoor unit 2.
The indoor control unit 102 is configured to drive and control the indoor blower 42 and the valve operation based on the detection value by the room temperature sensor.
The system control unit 103 controls the GHP outdoor unit 2, the EHP outdoor unit 3, and the indoor unit 4 based on the number of operating indoor units 4, the set temperature, the outside air temperature, and the like, so that the operation by the GHP outdoor unit 2 is performed. A control signal is output to the GHP control unit 100, the EHP control unit 101, and the indoor control unit 102 so that the operation by the EHP outdoor unit 3 is the most energy saving. Accordingly, the GHP control unit 100 efficiently performs the operation control of the GHP outdoor unit 2, the EHP control unit 101 performs the operation control of the EHP outdoor unit 3, and the indoor control unit 102 performs the operation control of the indoor unit 4 efficiently. Yes.

Here, for example, when the GHP outdoor unit 2 is replaced, the existing inter-unit piping 5 connected to the indoor unit 4 is replaced, or the existing inter-unit piping 5 is cleaned and reused or used as it is. Judge whether to do.
Generally, when the pipe diameter of the inter-unit pipe 5 is different or the pipe length is longer than the pipe length limit, the existing inter-unit pipe 5 cannot be used, so the inter-unit pipe 5 needs to be replaced. There is.
However, when the pipe diameters match and the pipe length limit is also satisfied, when the oil used in the air conditioner is different, or when the GHP compressor 13 of the existing GHP outdoor unit 2 is faulty, If the existing inter-unit pipe 5 is contaminated, it can be reused by washing the existing inter-unit pipe 5.
In other cases, the existing inter-unit pipe 5 is used as it is without being washed.

In the present embodiment, when the existing inter-unit pipe 5 is washed and reused, the oil port 13c formed in the GHP compressor 13 is used as a port for oil removal.
As shown in FIG. 1, an oil discharge pipe 110 is connected to the oil port 13 c, and a discharge on-off valve 111 is provided in the oil discharge pipe 110. An oil injection pipe 112 is connected to the refrigerant pipe on the discharge side of the GHP compressor 13, and an injection opening / closing valve 113 is provided in the oil injection pipe 112.
An oil container 114 that receives oil discharged from the oil discharge pipe 110 is provided at the end of the oil discharge pipe 110, and new oil is stored at the end of the oil injection pipe 112. An oil tank 115 is provided.

Next, the pipe cleaning method of the present invention will be described.
First, when replacing the GHP outdoor unit 2, whether to replace the existing inter-unit piping 5 connected to the indoor unit 4, wash the existing inter-unit piping 5, reuse it, or use it as it is. to decide.
When the inter-unit pipe 5 is cleaned, the GHP compressor 13 is driven to perform the pump-down operation process by heating operation, the oil draining process to open the discharge on-off valve 111 of the oil discharge pipe 110, and the discharge After the on-off valve 111 is closed, a new oil injection process for opening the injection on-off valve 113 of the oil injection pipe 112 and a heating operation process for performing the heating operation for 20 to 30 minutes after releasing the pump down are sequentially performed. Each of these processes is repeated a plurality of times.

By performing the pump-down operation by the heating operation, the refrigerant in the refrigerant pipe 20 is accumulated in the indoor heat exchanger 40 of the indoor unit 4, and in this state, the discharge on-off valve 111 is opened to open the GHP compressor 13. It is possible to discharge old oil from the oil port 13c. After closing the discharge on-off valve 111, the injection on-off valve 113 is opened to inject new oil into the refrigerant pipe. By repeating this operation several times, the inter-unit pipe 5 can be cleaned.
By performing such processing, old oil can be discharged from the oil discharge pipe 110 to the oil container 114, and new oil can be injected from the oil tank 115 via the oil injection pipe 112. The pipe 5 can be washed.

When the inter-unit pipe 5 is cleaned, the external connection valves 60a and 60b and the oil connection valve 61 are closed.
The refrigerant and oil sealed in the GHP outdoor unit 2 and the EHP unit 3 are the same. For example, the refrigerant is R410A, and the oil is PVE (polyvinyl ether oil). The refrigerant and the oil are compatible with each other. By using the refrigerant and the oil, the existing pipe can be cleaned relatively quickly. it can.

As described above, in the embodiment to which the present invention is applied, the GHP outdoor unit 2 (second outdoor unit) including the GHP compressor 13 (high capacity compressor) driven by the engine, and the commercial power source Cleaning method for cleaning the inter-unit piping 5 that connects the EHP outdoor unit 3 (first outdoor unit) equipped with the EHP compressor (low-capacity compressor) driven by the unit and the indoor unit 4 2, an oil discharge pipe 110 connected to the oil port 13 c of the GHP compressor 13, a discharge on-off valve 111 provided in the oil discharge pipe 110, and an oil injection pipe 112 connected to the middle part of the refrigerant pipe. And an on-off valve 113 for injection provided in the oil injection pipe 112, driving the GHP compressor and performing pump-down operation processing by heating operation, An oil draining process for opening the discharge on-off valve of the oil discharge pipe, a new oil injection process for opening the injection on-off valve of the oil injection pipe, and a heating operation after releasing the pump-down operation by the heating operation, Are sequentially performed.
According to this, in the air conditioner provided with the GHP outdoor unit 2 and the EHP outdoor unit 3, the inter-unit pipe 5 can be efficiently cleaned. Separately, there is no need to prepare a cleaning device and perform work in a separate process, and it is possible to reduce the man-hour and cost for facility construction.

In addition, the said embodiment shows the one aspect | mode which applied this invention, Comprising: This invention is not limited to the said embodiment.
In the above embodiment, the system control unit 103 controls the GHP control unit 100, the EHP control unit 101, and the indoor control unit 102 in an integrated manner, but the present invention is not limited to this. For example, a management company that manages the system of the air conditioning apparatus may directly control the system control unit 103 or the like via a server or the like.

DESCRIPTION OF SYMBOLS 1 Air conditioning apparatus 2 GHP outdoor unit 3 EHP outdoor unit 4 Indoor unit 5 Inter-unit piping 12 Gas engine 13 GHP compressor 13c Oil port 17,65 Outdoor heat exchanger 40 Indoor heat exchanger 62 EHP compressor 100 GHP control part 101 EHP control unit 102 Indoor control unit 103 System control unit 110 Oil discharge pipe 111 Drain on / off valve 112 Oil injection pipe 113 Injection on / off valve 114 Oil container 115 Oil tank

Claims (2)

In a pipe cleaning method for cleaning a pipe between units connecting a second outdoor unit having a high capacity compressor, a first outdoor unit having a low capacity compressor, and an indoor unit,
An oil discharge pipe connected to the oil port of the high-capacity compressor, a discharge on-off valve provided in the oil discharge pipe, an oil injection pipe connected to a midway portion of the refrigerant pipe, and the oil An on-off valve for injection provided on the injection pipe,
Pumping operation processing by driving the high-capacity compressor to perform heating operation, oil removal processing for opening the discharge on-off valve of the oil discharge pipe, and opening the injection on-off valve of the oil injection pipe A pipe cleaning method characterized by sequentially performing a new oil injection process and a process of performing a heating operation after releasing a pump-down operation by a heating operation. The second outdoor unit including the high-performance compressor is a GHP outdoor unit including a GHP compressor driven by an engine,
2. The pipe cleaning method according to claim 1, wherein the first outdoor unit including the low-capacity compressor is an EHP outdoor unit including an EHP compressor driven by a commercial power source.

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