阅读说明：本技术 热泵 (Heat pump ) 是由 冈田秀志 奥田宪弘 吉村智也 于 2015-11-18 设计创作，主要内容包括：热泵的室外机具有：压缩机；机油分离器,其设置于压缩机的排出路径；室外机连接管,其用于将压缩机的吸入路径和其他热泵的室外机连接起来、且向其他热泵的室外机供给制冷剂；供油管,其从机油分离器的规定位置延伸、且与室外机连接管连接；开闭阀,其设置于供油管；膨胀阀,其设置于与吸入路径连接的连接部和与供油管连接的连接部之间的室外机连接管的一部分；以及制冷剂填充用端口,其设置于连接部和膨胀阀之间的室外机连接管的一部分。(The outdoor unit of the heat pump has: a compressor; an oil separator provided in a discharge path of the compressor; an outdoor unit connection pipe for connecting a suction path of the compressor to an outdoor unit of another heat pump and supplying a refrigerant to the outdoor unit of the other heat pump; an oil supply pipe extending from a predetermined position of the oil separator and connected to the outdoor unit connection pipe; an opening/closing valve provided in the oil supply pipe; an expansion valve provided in a part of the outdoor unit connection pipe between a connection part connected to the suction path and a connection part connected to the oil supply pipe; and a refrigerant charging port provided in a part of the outdoor unit connection pipe between the connection unit and the expansion valve.)

1. A heat pump has an outdoor unit, wherein,

the outdoor unit is provided with:

a compressor;

an outdoor unit connection pipe for connecting a suction path of the compressor to an outdoor unit of another heat pump and supplying a refrigerant to the outdoor unit of the other heat pump; and

and a refrigerant charging port provided in the outdoor unit connection pipe.

2. A heat pump has an outdoor unit, wherein,

the outdoor unit is provided with:

a compressor;

a refrigerant filling pipe for connecting a suction path of the compressor and an outdoor unit of another heat pump and filling the suction path of the compressor with refrigerant supplied from the outdoor unit of the other heat pump; and

and a refrigerant charging port provided in a part of the refrigerant charging pipe.

Technical Field

The present invention relates to heat pumps.

Background

Currently, heat pumps of the following structure are known: when a plurality of heat pumps are used, the outdoor unit of each heat pump can exchange refrigerant with the indoor units of the plurality of heat pumps (see, for example, patent document 1). In the case of patent document 1, outdoor units of a plurality of heat pumps are connected to each other via a connection path, and an on-off valve is provided in the connection path. The outdoor units can exchange the refrigerant with each other by the connection path and the on-off valve.

Prior art documents

Patent document

Patent document 1: japanese patent No. 4764850

Disclosure of Invention

However, patent document 1 does not disclose a port for filling refrigerant into each heat pump after installing, for example, a plurality of heat pumps.

Accordingly, an object of the present invention is to provide a heat pump including an outdoor unit and an indoor unit, the heat pump having the following configuration: when a plurality of heat pumps are used, the outdoor unit of each heat pump can exchange refrigerant with the indoor units of the plurality of heat pumps, and has a refrigerant charging port.

In order to solve the above-mentioned technical problem, according to one aspect of the present invention,

there is provided a heat pump having an outdoor unit,

the outdoor unit is provided with:

a compressor;

an oil separator provided in a discharge path of the compressor;

an outdoor unit connection pipe for connecting a suction path of the compressor to an outdoor unit of another heat pump and supplying a refrigerant to the outdoor unit of the other heat pump;

an oil supply pipe extending from a predetermined position of the oil separator and connected to the outdoor unit connection pipe;

an opening/closing valve provided in the oil supply pipe;

an expansion valve provided in a part of the outdoor unit connection pipe between a connection part connected to the suction path and a connection part connected to the oil supply pipe; and

and a refrigerant filling port provided in a part of the outdoor unit connection pipe between the connection portion connected to the oil supply pipe and the expansion valve.

In addition, according to another mode of the present invention,

there is provided a heat pump having an outdoor unit,

the outdoor unit is provided with:

a compressor;

an oil separator provided in a discharge path of the compressor;

a refrigerant filling pipe for connecting a suction path of the compressor and an outdoor unit of another heat pump and filling the suction path of the compressor with refrigerant supplied from the outdoor unit of the other heat pump;

an oil supply pipe extending from a predetermined position of the oil separator and connected to the refrigerant filling pipe;

an opening/closing valve provided in the oil supply pipe;

an expansion valve provided in a part of the refrigerant filling pipe between a connection portion connected to the suction path and a connection portion connected to the oil supply pipe; and

and a refrigerant filling port provided in a part of the refrigerant filling pipe between the expansion valve and a connection portion connected to the oil supply pipe.

Effects of the invention

According to the present invention, there is provided a heat pump including an outdoor unit and an indoor unit, the heat pump having the following configuration: when a plurality of heat pumps are used, the outdoor unit of each heat pump can exchange refrigerant with the indoor units of the plurality of heat pumps, and the heat pump has a port for filling refrigerant.

Drawings

Fig. 1 is a circuit diagram showing a structure of a heat pump according to an embodiment of the present invention.

Fig. 2 is a perspective view showing a part of a heat pump according to an embodiment of the present invention.

Detailed Description

Embodiments of the present invention will be described below with reference to the drawings.

Fig. 1 is a circuit diagram showing a structure of a heat pump according to an embodiment of the present invention. Fig. 2 is a perspective view showing a part of the heat pump. In the circuit diagram shown in fig. 1, components of the heat pump such as a filter are omitted for simplicity of explanation.

Fig. 1 also shows a plurality of heat pumps, specifically, 2 heat pumps 10A, 10B, and these 2 heat pumps 10A, 10B respectively have 1 outdoor unit 12A, 12B that exchanges heat with the outside air and 2 indoor units 14A, 14B that exchange heat with the indoor air.

The outdoor units 12A and 12B of the heat pumps 10A and 10B exchange refrigerant with the indoor units 14A and 14B of the plurality of heat pumps 10A and 10B, which will be described in detail later.

The outdoor units 12A and 12B have substantially the same configuration, and the indoor units 14A and 14B have substantially the same configuration. Therefore, the outdoor unit 12B is simplified in fig. 1.

The outdoor units 12A, 12B of the heat pumps 10A, 10B have: a compressor 16 that compresses and discharges a refrigerant; a heat exchanger 18 that exchanges heat with outside air; and a four-way valve 20. On the other hand, the indoor units 14A and 14B have heat exchangers 22 that exchange heat with the indoor air.

The compressor 16 is driven by a drive source 24 such as a gas engine (gas engine). In the present embodiment, 2 compressors 16 and 1 gas engine 24 are mounted on the outdoor units 12A and 12B. As shown in fig. 2, the compressor 16 is coupled to a flywheel 30 attached to an output shaft of the gas engine 24 via a clutch 26 and a transmission belt 28. At least one of the compressors 16 can be selectively driven by 1 gas engine 24 via the clutch 26.

The high-temperature, high-pressure gas refrigerant discharged from the discharge port 16a of the compressor 16 is caused to flow to the heat exchanger 18 of the outdoor unit 12A, 12B or the heat exchanger 22 of the indoor unit 14A, 14B by the four-way valve 20. In the heating operation, the gaseous refrigerant discharged from the compressor 16 is sent to the heat exchanger 22 of the indoor unit 14A, 14B. On the other hand, in the cooling operation, the gaseous refrigerant is sent to the heat exchangers 18 of the outdoor units 12A and 12B.

An oil separator 32 that separates refrigerating machine oil (oil) contained in the refrigerant is provided in a discharge path of the compressor 16, that is, in a refrigerant path between the discharge port 16a of the compressor 16 and the four-way valve 20. The oil separated from the refrigerant and accumulated in the bottom portion 32a of the oil separator 32 is returned to the sliding portion in the compressor 16 through an oil return path (not shown).

In the heating operation, the high-temperature, high-pressure gas refrigerant discharged from the compressor 16 and passing through the four-way valve 20 (solid line) exchanges heat with the indoor air in the heat exchanger 22 of the indoor units 14A, 14B. That is, heat is transferred from the refrigerant to the indoor air by the heat exchanger 22. As a result, the refrigerant turns into a low-temperature high-pressure liquid state.

The accumulator 36 is provided in the outdoor units 12A and 12B. The accumulator 36 is a buffer tank (buffer tank) for temporarily accumulating the low-temperature and high-pressure liquid refrigerant after the heat exchange with the indoor air in the heat exchanger 22 of the indoor unit 14A or 14B. The liquid refrigerant flowing out of the heat exchangers 22 of the indoor units 14A and 14B passes through the check valve 34 and flows into the accumulator 36.

The low-temperature high-pressure liquid refrigerant in the accumulator 36 is sent to the heat exchangers 18 of the outdoor units 12A and 12B. A check valve 38 and an expansion valve 40 are provided in a path between the bottom 36a of the accumulator 36 and the heat exchanger 18. The low-temperature high-pressure liquid refrigerant flowing out of the bottom portion 36a of the accumulator 36 is expanded by the expansion valve 40 to become a low-temperature low-pressure liquid (mist).

The low-temperature, low-pressure liquid refrigerant passing through the expansion valve 40 exchanges heat with the outside air in the heat exchanger 18 of the outdoor units 12A, 12B. That is, heat is transferred from the outside air to the refrigerant by the heat exchanger 18. As a result, the refrigerant is changed to a low-temperature, low-pressure gas state.

The gas-liquid separator 42 is provided in the outdoor units 12A and 12B, and temporarily accumulates low-temperature low-pressure gaseous refrigerant after heat exchange with the outside air in the heat exchangers 18 of the outdoor units 12A and 12B. The gas-liquid separator 42 is provided in a suction path of the compressor 16 (a path between the suction port 16b of the compressor 16 and the four-way valve 20).

The low-temperature low-pressure gas refrigerant in the gas-liquid separator 42 is sucked into the compressor 16 and compressed. As a result, the refrigerant turns into a high-temperature and high-pressure gas state, and is sent again to the heat exchanger 22 of the indoor unit 14A, 14B.

While the low-temperature and low-pressure gas refrigerant is temporarily retained in the gas-liquid separator 42, a small amount of liquid refrigerant contained in the gas refrigerant is separated. The liquid refrigerant is stored in the gas-liquid separator 42.

On the other hand, in the cooling operation, the high-temperature, high-pressure gas refrigerant discharged from the discharge port 16a of the compressor 16 moves to the heat exchangers 18 of the outdoor units 12A, 12B via the four-way valve 20 (two-dot chain line). The refrigerant is changed into a low-temperature high-pressure liquid state by heat exchange with the outside air in the heat exchanger 18. The refrigerant flowing out of the heat exchanger 18 passes through the expansion valve 40 and turns into a low-temperature low-pressure liquid state (mist state). The refrigerant passing through the expansion valve 40 passes through the check valve 44, the accumulator 36, and the check valve 46 in this order, and reaches the heat exchanger 22 of the indoor unit 14A, 14B. The refrigerant is changed into a low-temperature, low-pressure gas state by heat exchange with the indoor air in the heat exchanger 22. The refrigerant flowing out of the heat exchanger 22 passes through the four-way valve 20 and the gas-liquid separator 42 and returns to the compressor 16.

In order to improve the cooling efficiency, the outdoor units 12A and 12B of the heat pumps 10A and 10B include cooling heat exchangers 48 for cooling the refrigerant flowing from the accumulator 36 to the check valves 46.

The cooling heat exchanger 48 is configured to exchange heat between the liquid refrigerant flowing from the accumulator 36 to the check valve 46 and the mist refrigerant, that is, to cool the liquid refrigerant by the mist refrigerant. The atomized refrigerant is formed by atomizing a part of the liquid refrigerant flowing from the cooling heat exchanger 48 to the check valve 46 by the expansion valve 50. The expansion valve 50 is a valve whose opening degree can be adjusted to selectively cool the liquid refrigerant in the cooling heat exchanger 48.

When the expansion valve 50 is controlled so that at least a part of the expansion valve 50 is open by a control device (not shown) of the heat pump 10A or 10B, a part of the liquid refrigerant that has passed through the cooling heat exchanger 48 and the check valve 46 before passing through the expansion valve 50 is atomized. The refrigerant atomized by the expansion valve 50 flows into the cooling heat exchanger 48, and takes heat from the liquid refrigerant flowing out of the accumulator 36 and before flowing through the check valve 46, thereby achieving vaporization. As a result, the liquid refrigerant having a temperature lower than the temperature when the expansion valve 50 is in the closed state flows into the heat exchanger 22 of the indoor unit 14A, 14B.

On the other hand, the gaseous refrigerant after extracting heat from the liquid refrigerant flowing out of the accumulator 36 and flowing through the check valve 46 is directly returned from the cooling heat exchanger 48 to the compressor 16. The gas refrigerant is used to evaporate the liquid refrigerant stored in the gas-liquid separator 42. That is, by opening the opening/closing valve 52, the liquid refrigerant in the gas-liquid separator 42 is mixed with the gaseous refrigerant returned from the cooling heat exchanger 48 to the compressor 16, and is vaporized, and these are returned to the compressor 16.

The heat pumps 10A and 10B each include an auxiliary evaporation heat exchanger 54 for vaporizing a liquid refrigerant contained in a gas refrigerant returned from the four-way valve 20 to the compressor 16.

In order to determine whether or not the gaseous refrigerant returned to the compressor 16 contains a liquid refrigerant, a temperature sensor 56 and a pressure sensor 58 that detect the temperature and pressure of the refrigerant are provided on a path between the four-way valve 20 and the gas-liquid separator 42. The temperature sensor 56 and the pressure sensor 58 output detection signals corresponding to the detection results to a control device (not shown) of the heat pumps 10A and 10B. The control device determines whether or not the gaseous refrigerant returned to the compressor 16 contains liquid refrigerant based on detection signals from the temperature sensor 56 and the pressure sensor 58. That is, if the pressure of the refrigerant detected by the pressure sensor 58 is substantially the same as the vapor pressure corresponding to the temperature detected by the temperature sensor 56, it is determined that the gaseous refrigerant returned to the compressor 16 contains almost no liquid refrigerant (the liquid refrigerant is substantially zero).

The auxiliary evaporative heat exchanger 54 utilizes a portion of the low temperature, high pressure liquid refrigerant exiting the accumulator 36 and prior to flowing through the check valve 38. Therefore, an expansion valve 60 whose opening degree can be adjusted is provided between the receiver 36 and the auxiliary evaporation heat exchanger 54.

When the control device (not shown) of the heat pump 10A, 10B determines that the gas refrigerant returned to the compressor 16 contains a predetermined amount or more of liquid refrigerant, the expansion valve 60 is controlled. Thereby, at least a part of the expansion valve 60 is opened.

When at least a part of the expansion valve 60 is opened, a part of the low-temperature and high-pressure liquid refrigerant flowing out of the accumulator 36 and before flowing through the check valve 38 flows through the expansion valve 60 and turns into a low-temperature and low-pressure mist.

The mist refrigerant passing through the expansion valve 60 is heated by, for example, high-temperature exhaust gas of the gas engine 24, a coolant, and the like in the auxiliary evaporation heat exchanger 54. Thereby, the refrigerant mist that passes through the expansion valve 60 and flows into the auxiliary evaporation heat exchanger 54 is changed into a high-temperature low-pressure gas state. The high-temperature gas refrigerant heated in the auxiliary evaporation heat exchanger 54 is fed into a path between the four-way valve 20 and the gas-liquid separator 42. Thereby, the liquid refrigerant contained in the gas refrigerant that has passed through the four-way valve 20 and returned to the compressor 16 is heated and evaporated (vaporized) by the high-temperature gas refrigerant from the auxiliary evaporation heat exchanger 54. As a result, the refrigerant flowing into the gas-liquid separator 42 becomes substantially gaseous.

Next, the components of the heat pump used when a plurality of heat pumps are used will be described.

First, as shown in fig. 1, the indoor units 14A and 14B of the heat pumps 10A and 10B are connected to the common refrigerant pipes 62 and 64, respectively. The outdoor units 12A and 12B of the heat pumps 10A and 10B are also connected to the common refrigerant pipes 62 and 64. Thus, at least one of the outdoor unit 14A of the heat pump 10A and the outdoor unit 14B of the heat pump 10B can exchange refrigerant with at least one of the indoor units 14A and 14B via the common refrigerant pipes 62 and 64.

For example, both the outdoor units 12A and 12B (the compressors 16 thereof) may be operated, and at least one of the indoor units 14A and 14B may be operated. The indoor units 14A and 14B are each provided with an expansion valve 66 whose opening degree can be adjusted. When the expansion valve 66 is opened, the refrigerant flows into the heat exchanger 22, and the indoor units 14A and 14B operate. The output of the indoor units 14A and 14B is adjusted by adjusting the opening degree of the expansion valve 66.

For example, only one of the outdoor units 12A and 12B (the compressor 16 thereof) may be operated, and at least one of the indoor units 14A and 14B may be operated. Specifically, the output of either one of the outdoor units 12A and 12B may be sufficient for the total output of at least one of the indoor units 14A and 14B. In this case, one of the outdoor units 12A and 12B (the compressor 16 thereof) is operated, and the other is stopped. This is because: when only one of the gas engines 24 of the outdoor units 12A, 12B is driven at the rated output and the other is stopped, the fuel consumption, energy efficiency, life, and the like are excellent as compared with the case where both the gas engines 24 of the outdoor units 12A, 12B are driven at an output lower than the rated output.

However, when only one of the outdoor units 12A and 12B (the compressor 16 thereof) is operated, the refrigerant may be insufficient in the outdoor unit during operation. This is because there is a tendency that: the refrigerant flowing out of the heat exchangers 22 of the indoor units 14A and 14B flows into the outdoor unit during operation, as compared with the outdoor unit during stoppage as one of the outdoor units 12A and 12B.

Further, if the refrigerant of the outdoor unit in operation of either of the outdoor units 12A and 12B is insufficient, the oil for lubricating the compressor 16 of the outdoor unit in operation may be insufficient. This is because: the refrigerant discharged from the compressor 16 of the outdoor unit in operation and containing oil flows out of the heat exchangers 22 of the indoor units 14A and 14B, and then flows into the outdoor unit in a stopped state together with the oil.

In order to cope with this, the outdoor unit of the heat pump of the present embodiment is configured such that: when a plurality of outdoor units are used, a refrigerant and engine oil can be supplied from the outdoor unit that is stopped to the outdoor unit that is in operation.

The case where the outdoor unit 12B is in operation and the outdoor unit 12A is in a stop will be described as an example. Note that, if the suffixes "a" and "B" of the symbols are interchanged, the following description can also be applied to a case where the outdoor unit 12A is in operation and the outdoor unit 12B is in a stop state.

As shown in fig. 1, when the outdoor unit 12B (the compressor 16 thereof) is operated, the refrigerant (and the oil contained therein) flowing out of the outdoor unit 12B flows into the heat exchanger 22 of at least one of the indoor units 14A and 14B through the common refrigerant pipe 62. Most of the refrigerant having exchanged heat with the indoor air in the heat exchanger 22 flows to the outdoor unit 12B side by the suction of the compressor 16 of the outdoor unit 12B in operation, but a part of the refrigerant flows to the outdoor unit 12A side in a stop state. The part of the refrigerant remains in the outdoor unit 12A that is stopped. Therefore, it is necessary to supply a part of the refrigerant from the outdoor unit 12A that is stopped to the outdoor unit 12B that is in operation.

The outdoor unit 12A that is stopped has an outdoor unit connection pipe 70 for connecting to the outdoor unit 12B that is in operation, in order to supply the refrigerant from the outdoor unit 12A that is stopped to the outdoor unit 12B that is in operation.

The outdoor unit connecting pipe 70 of the outdoor unit 12A that is in a stopped state connects the suction path of the compressor 16 to the outdoor unit 12B that is in operation. In the present embodiment, one end of the outdoor unit connecting pipe 70 of the outdoor unit 12A that is in a stopped state is connected to a path portion between the auxiliary evaporation heat exchanger 54 and the expansion valve 60, which is a part of the suction path of the compressor 16 (a connecting portion 70 a). On the other hand, an on-off valve 72 that can be manually opened and closed is provided near the other end thereof.

As shown in fig. 2, a connector 74 for connecting to the outdoor unit 12B in operation is provided at the other end of the outdoor unit connecting pipe 70 of the outdoor unit 12A in a stopped state. Specifically, the connector 74 of the outdoor unit connection pipe 70 of the outdoor unit 12A that is in a stopped state is connected to the connector 74 of the outdoor unit connection pipe 70 of the outdoor unit 12B that is in an operating state via the connection pipe 76 shown in fig. 1. As a result, the refrigerant can flow from the outdoor unit connection pipe 70 of the outdoor unit 12A that is in a stopped state to the outdoor unit connection pipe 70 of the outdoor unit 12B that is in an operating state via the connection pipe 76. That is, in the outdoor unit 12B during operation, the outdoor unit connecting pipe 70 functions as a refrigerant filling pipe for filling the suction path of the compressor 16 with the refrigerant supplied from the outdoor unit 12A during stoppage.

In the outdoor unit 12A that is stopped, most of the refrigerant is stored in the accumulator 36 and the heat exchanger 18. A first refrigerant supply pipe 78, which directly connects the accumulator 36 and the outdoor unit connection pipe 70, is provided in the outdoor unit 12A in order to supply the refrigerant in the accumulator 36 of the outdoor unit 12A that is in a stopped state to the outdoor unit 12B that is in operation.

The first refrigerant supply pipe 78 is connected to the side surface 36b of the accumulator 36. Specifically, the first refrigerant supply pipe 78 is connected to a side surface 36b of the accumulator 36 located at a predetermined height with respect to the bottom 36 a. Thus, the refrigerant stored in the accumulator 36 of the outdoor unit 12A that is in a stopped state can be supplied to the outdoor unit 12B that is in operation via the first refrigerant supply pipe 78 and the outdoor unit connection pipe 70. Further, a predetermined amount of refrigerant necessary for the operation of the outdoor unit 12A during stoppage can be stored in the accumulator 36.

Further, an on-off valve 80 and a check valve 82 are provided in the first refrigerant supply pipe 78. When the outdoor unit 12A (the compressor 16 thereof) is in operation, the on-off valve 80 is in a closed state. The check valve 82 prevents: the refrigerant flows backward through the first refrigerant supply pipe 78 toward the accumulator 36.

The second refrigerant supply pipe 84 is provided in the outdoor unit 12A so as to supply the refrigerant in the heat exchanger 18 of the outdoor unit 12A that is in a stopped state to the outdoor unit 12B that is in operation.

One end of the second refrigerant supply pipe 84 is connected to a path between the four-way valve 20 and the heat exchanger 18. Specifically, an on-off valve 86 that is closed during stoppage of the compressor 16 so that the refrigerant does not flow backward from the heat exchanger 18 to the discharge path (discharge port 16a) of the compressor 16 is provided in the path between the four-way valve 20 and the heat exchanger 18. One end of the second refrigerant supply pipe 84 is connected between the on-off valve 86 and the heat exchanger 18.

On the other hand, the other end of the second refrigerant supply pipe 84 is connected to a path between the auxiliary evaporation heat exchanger 54 and the expansion valve 60.

Thus, the refrigerant stored in the heat exchanger 18 of the outdoor unit 12A that is in a stopped state can be supplied to the outdoor unit 12B that is in operation via the second refrigerant supply pipe 84 and the outdoor unit connection pipe 70.

Further, an opening/closing valve 88 and a check valve 90 are provided in the second refrigerant supply pipe 84. When the outdoor unit 12A (the compressor 16 thereof) is in operation, the on-off valve 88 is in a closed state. The check valve 90 prevents: the refrigerant flows backward through the second refrigerant supply pipe 84 to the heat exchanger 18.

As described above, a part of the refrigerant in the accumulator 36 of the outdoor unit 12A and the refrigerant in the heat exchanger 18 that are stopped are supplied to the outdoor unit 12B that is in operation via the first and second refrigerant supply pipes 78 and 84 and the outdoor unit connection pipe 70. However, even in this case, the refrigerant may be insufficient in the outdoor unit 12B during operation.

At this time, the refrigerant is further supplied from the accumulator 36 of the outdoor unit 12A that is stopped to the outdoor unit 12B that is in operation.

Specifically, during the heating operation, the on-off valve 100 of the outdoor unit 12A that is in a stopped state is opened to suck the refrigerant discharged from the outdoor unit 12B that is in an operating state, and the refrigerant accumulated in the accumulator 36 is pressed against the check valve 46 and the first refrigerant supply pipe 78. The refrigerant pressed against the check valve 46 flows through the common refrigerant pipe 64 to the outdoor unit 12B in operation. The refrigerant pushed toward the first refrigerant supply pipe 78 flows from the connection pipe 76 to the outdoor unit 12B through the opening/closing valve 80 and the check valve 82. At this time, the opening degree of the expansion valve 110 of the outdoor unit 12B is controlled to adjust the amount of refrigerant flowing from the connection pipe 76.

On the other hand, during the cooling operation, the on-off valve 88 of the outdoor unit 12A that is in a stopped state is opened, and the refrigerant accumulated in the heat exchanger 18 is sucked into the outdoor unit 12B that is in operation via the check valve 88, the second refrigerant supply pipe 84, the auxiliary evaporation heat exchanger 54, the four-way valve 20, and the common pipe 62.

The refrigerant is supplied from the outdoor unit 12A to the operating outdoor unit 12B via the first and second refrigerant supply pipes 78 and 84 (and, depending on the case, the third and fourth refrigerant supply pipes 92 and 98) of the outdoor unit 12A that is in a stopped state. In addition, oil for lubricating the compressor 16 of the outdoor unit 12B in operation is supplied from the outdoor unit 12A in a stopped state.

For this purpose, an oil supply pipe 104 extending from a predetermined position of the oil separator and connected to the outdoor unit connection pipe 70 is provided in the outdoor unit 12A.

On the other hand, one end of the oil supply pipe 104 is connected to a part of the outdoor unit connection pipe 70 (connection portion 70b) between the connection portion 70a connected to the suction path of the compressor 16 and the manual opening/closing valve 72.

On the other hand, the other end of the oil supply pipe 104 is connected to a predetermined position of the side surface 32b of the oil separator 32 located at a predetermined height with respect to the bottom 32a of the oil separator 32. This allows the oil stored in the oil separator 32 of the outdoor unit 12A that is stopped to be supplied to the outdoor unit 12B that is operating via the oil supply pipe 104 and the outdoor unit connection pipe 70. Further, a predetermined amount of oil required for future operation of the outdoor unit 12A (the compressor 16 thereof) that is stopped can be retained in the oil separator 32.

The oil supply pipe 104 of the outdoor unit 12A that is stopped is provided with an on-off valve 106 and a check valve 108. The opening/closing valve 106 is closed when the outdoor unit 12A is in operation. The check valve 108 prevents the refrigerant from flowing into the oil separator 32 from the outdoor unit connection pipe 70.

Next, the outdoor unit 12B in operation after the refrigerant and the oil are supplied from the outdoor unit 12A in a stop state will be described. As described above, the outdoor units 12A and 12B have substantially the same configuration. Therefore, in order to understand the configuration of the outdoor unit 12B, the configuration of the outdoor unit 12A shown in fig. 1 may be used.

The refrigerant supplied from the outdoor unit 12A that is stopped flows into the outdoor unit connecting pipe 70 (i.e., refrigerant filling pipe) of the outdoor unit 12B that is in operation. In the indoor unit 12B in operation, the on-off valve 80 in the first refrigerant supply pipe 78, the on-off valve 88 in the second refrigerant supply pipe 84, the on-off valve 94 in the third refrigerant supply pipe 92, the on-off valve 100 in the fourth refrigerant supply pipe 98, and the on-off valve 106 in the oil supply pipe 104 are closed. Therefore, the refrigerant flowing into the outdoor unit connecting pipe 70 of the outdoor unit 12B in operation passes through the auxiliary evaporation heat exchanger 54 and the gas-liquid separator 42 in this order and enters the suction port 16B of the compressor 16.

The outdoor unit connecting pipe 70 of the outdoor unit 12B during operation is provided with an expansion valve 110 whose opening degree can be adjusted. The expansion valve 110 is provided in a part of the outdoor unit connection pipe 70 between the connection portion 70a connected to the suction path of the compressor 16 and the connection portion 70b connected to the oil supply pipe 104. When the refrigerant is exchanged between the outdoor unit 12A in a stopped state and the outdoor unit 12B in an operating state via the outdoor unit connection pipe 70, the expansion valve 110 is opened.

The refrigerant supplied from the outdoor unit 12A being stopped and flowing into the outdoor unit connecting pipe 70 in the outdoor unit 12B being operated is atomized by the expansion valve 110. The refrigerant atomized by the expansion valve 110 is heated and vaporized by the auxiliary evaporation heat exchanger 54. As a result, the refrigerant supplied from the outdoor unit 12A that is stopped can flow into the compressor 16 of the outdoor unit 12B that is in operation in a gaseous state.

The oil supplied from the outdoor unit 12A that is in a stopped state flows into the outdoor unit connection pipe 70 (i.e., the refrigerant filling pipe) of the outdoor unit 12B that is in operation along with the refrigerant supplied from the outdoor unit 12A. Therefore, the outdoor unit connection pipe 70 (i.e., the refrigerant filling pipe) functions as an oil supply path for supplying not only the refrigerant but also the oil.

The oil flowing into the outdoor unit connection pipe 70 of the operating outdoor unit 12B enters the compressor 16 together with the refrigerant, is discharged from the compressor 16 together with the gaseous refrigerant, and is collected by the oil separator 32. The oil recovered in the oil separator 32 is supplied to the sliding portion of the compressor 16 via an oil return circuit (not shown).

When the control device of the outdoor unit 12B in operation determines that the refrigerant is insufficient, it transmits a signal requesting the refrigerant to the control device of the outdoor unit 12A in a stop state. On the other hand, the controller of the outdoor unit 12A that is stopped and receives the refrigerant request signal opens at least 1 of the on-off valve 80 of the first refrigerant supply pipe 78, the on-off valve 88 of the second refrigerant supply pipe 84, the on-off valve 94 of the third refrigerant supply pipe 92, the on-off valve 100 of the fourth refrigerant supply pipe 98, and the on-off valve 106 of the oil supply pipe 104, and supplies the refrigerant to the outdoor unit 12B that is in operation.

The outdoor unit connection pipe 70 of the outdoor units 12A and 12B is provided with a refrigerant charging port 112 for charging the refrigerant. Specifically, the refrigerant charging port 112 is provided in a part of the outdoor unit connection pipe 70 between the connection portion 70b connected to the oil supply pipe 104 and the expansion valve 110.

Specifically, the refrigerant charging port 112 is provided with, for example, a plurality of heat pumps 10A and 10B, and then a plurality of outdoor units 12A and 12B and a plurality of indoor units 14A and 14B, and connects these units, and then uses them for charging the outdoor units 12A and 12B of the heat pumps 10A and 10B with refrigerant.

When the outdoor units 12A and 12B are respectively filled with the refrigerant via the refrigerant filling port 112, the manual opening/closing valve 72 of the outdoor unit connection pipe 70 is closed by an operator. In addition, in a state where the compressors 16 of the outdoor units 12A and 12B are operated, the refrigerant is charged through the refrigerant charging port 112. That is, the outdoor unit connection pipe 70 provided with the refrigerant charging port 112 functions as a refrigerant charging path.

Further, since the manual on-off valve 72 and the refrigerant charging port 112 are provided in the outdoor unit connecting pipe 70, the manual on-off valve 72 and the refrigerant charging port 112 are close to each other as shown in fig. 2. As a result, the operator can check the state where the manual on-off valve 72 is closed, and then can fill the outdoor units 12A and 12B with the refrigerant through the refrigerant filling port 112.

The refrigerant filled into the outdoor unit connecting pipe 70 through the refrigerant filling port 112 is atomized by the expansion valve 110, and is vaporized by the auxiliary evaporation heat exchanger 54. The vaporized refrigerant flows into the compressor 16. The refrigerant is then discharged to the compressor 16 and fills the entire path.

As described above, according to the present embodiment, it is possible to provide heat pumps 10A and 10B including outdoor units 12A and 12B and indoor units 14A and 14B, and the heat pumps 10A and 10B have the following configurations: when a plurality of heat pumps are used, the outdoor units 12A and 12B of the heat pumps 10A and 10B exchange refrigerant with the indoor units 14A and 14B of the plurality of heat pumps 10A and 10B, respectively, and have refrigerant charging ports 112.

The present invention has been described above by taking the above embodiments as examples, but the present invention is not limited thereto.

For example, although the present invention has been described with reference to 2 heat pumps 10A and 10B in the above embodiment, the present invention is not limited to 2 heat pumps. For example, 3 or more heat pumps may be used.

In the case of the above embodiment, the heat pumps 10A and 10B have 1 outdoor unit 12A and 12B and 2 indoor units 14A and 14B, respectively, but the present invention is not limited to this. More than 3 indoor units may be provided for 1 outdoor unit of the heat pump.

The heat pumps 10A and 10B according to the above embodiments may be used individually. At this time, the manual on-off valve 72, the on-off valve 80 in the first refrigerant supply pipe 78, the on-off valve 88 in the second refrigerant supply pipe 84, the on-off valve 94 in the third refrigerant supply pipe 92, the on-off valve 100 in the fourth refrigerant supply pipe 98, and the on-off valve 106 in the oil supply pipe 104 are maintained in the closed state.

The heat pump according to the present invention is not limited to the heat pumps 10A and 10B of the above embodiments. In broad terms, a heat pump according to the present invention is a heat pump having an outdoor unit, the outdoor unit including: a compressor; an oil separator provided in a discharge path of the compressor; an outdoor unit connection pipe for connecting a suction path of the compressor to an outdoor unit of another heat pump and supplying a refrigerant to the outdoor unit of the other heat pump; an oil supply pipe extending from a predetermined position of the oil separator and connected to the outdoor unit connection pipe; an opening/closing valve provided in the oil supply pipe; an expansion valve provided in a part of the outdoor unit connection pipe between a connection part connected to the suction path and a connection part connected to the oil supply pipe; and a refrigerant filling port provided in a part of the outdoor unit connection pipe between the connection portion connected to the oil supply pipe and the expansion valve.

In a broad sense, another heat pump according to the present invention includes an outdoor unit including: a compressor; an oil separator provided in a discharge path of the compressor; a refrigerant filling pipe for connecting a suction path of the compressor and an outdoor unit of another heat pump and filling the suction path of the compressor with refrigerant supplied from the outdoor unit of the other heat pump; an oil supply pipe extending from a predetermined position of the oil separator and connected to the refrigerant filling pipe; an opening/closing valve provided in the oil supply pipe; an expansion valve provided in a part of the refrigerant filling pipe between a connection portion connected to the suction path and a connection portion connected to the oil supply pipe; and a refrigerant filling port provided in a part of the refrigerant filling pipe between the expansion valve and a connection portion connected to the oil supply pipe.

The present invention is applicable to a heat pump in which an oil separator is provided in a discharge path of a compressor.

Although the disclosure herein has been described in connection with the preferred embodiments with reference to the accompanying drawings, it will be apparent to those skilled in the art that various changes and modifications may be made. Such changes and modifications are to be understood as included in the present invention, unless they depart from the scope of the present invention as defined by the appended claims.

The disclosures of the specification, drawings and claims of japanese patent application No. 2014-237145, filed on 21/11/2014, are incorporated herein by reference in their entirety.

Description of the reference numerals

10A heat pump

10B heat pump

12A outdoor unit

12B outdoor unit

16 compressor

32 machine oil separator

70 outdoor machine connecting pipe

70a connecting part

70b connecting part

104 oil supply pipe

106 opening and closing valve

110 expansion valve

112 port for refrigerant charging