JP6895653B2 - Air conditioner - Google Patents

Description

The present invention relates to an air conditioner.

As a prior art, in an air conditioner including an indoor unit and an outdoor unit, an air conditioner capable of effectively utilizing the exhaust heat of an engine used as a power source of a compressor has been proposed (see, for example, Patent Document 1). According to this air conditioner, if the outdoor heat exchanger is likely to frost or frosts during heating operation, the exhaust heat exchanger is used instead of absorbing heat from the air using the outdoor heat exchanger. Heating is continued by absorbing heat from the cooling water of the engine.

Japanese Unexamined Patent Publication No. 2003-56932

However, the technique of Patent Document 1 has a problem that heat cannot be absorbed from the outdoor air at the time of frost formation.
The present invention solves the above-mentioned conventional problems, and an object of the present invention is to provide an air conditioner capable of absorbing heat from air at the time of frost formation.

This specification includes all the contents of the Japanese patent application / Japanese Patent Application No. 2016-212725 filed on October 31, 2016.
In order to solve the conventional problems, the air conditioner of the present invention includes a first compressor driven by an engine, a second compressor connected in parallel with the first compressor, and the first compressor. A switching circuit for switching the flow path of the refrigerant discharged from the second compressor, a medium-pressure refrigerant circuit provided between the indoor heat exchanger and the outdoor heat exchanger, and a medium-pressure refrigerant circuit through which the medium-pressure refrigerant passes, and the first The low-pressure refrigerant circuit provided on the suction side of the 1 compressor and the 2nd compressor through which the low-pressure refrigerant passes, the intermediate bypass pipe connecting the medium-pressure refrigerant circuit and the low-pressure refrigerant circuit, and the intermediate bypass pipe The first exhaust heat exchanger, which is provided and transfers the exhaust heat of the engine to a refrigerant, is provided, and the switching circuit is provided to at least one of the indoor heat exchanger and the outdoor heat exchanger. The refrigerant discharged from the compressor is flowed, and the flow path is switched to a flow path for flowing the refrigerant discharged from the second compressor to one of the other. The switching circuit transfers the refrigerant discharged from the first compressor into the room. The first switching means for switching to a flow path for flowing to either the heat exchanger or the outdoor heat exchanger, and the indoor heat exchanger and the outdoor heat exchanger for the refrigerant discharged from the second compressor. With reference to the second switching means for switching to the flow path to flow to either the other and the flow path of the refrigerant evaporated in the indoor heat exchanger or the outdoor heat exchanger, the first switching means or the downstream of the second switching means. The low-pressure refrigerant circuit is a circuit downstream of the opening / closing means.
The switching circuit is between the second switching means and the indoor heat exchanger, and the second opening / closing means provided on the circuit through which only the discharged refrigerant of the second compressor flows during the heating operation, and the first opening / closing means. It is between the switching means and said outdoor heat exchanger, obtaining further Bei third switching means provided on the circuit only flow discharge refrigerant of the first compressor during the cooling operation, the.
As a result, when the outdoor heat exchanger is frosted, a part of the refrigerant discharged from the first compressor or the second compressor is flowed to the indoor heat exchanger, and a part is flowed to the outdoor heat exchanger to be indoors. The refrigerant that has passed through the heat exchanger and the refrigerant that has passed through the outdoor heat exchanger can be merged and returned to the first compressor and the second compressor via the intermediate bypass pipe.
Therefore, it is possible to provide an air conditioner capable of performing defrosting operation by the refrigerant flowing in the outdoor heat exchanger while continuing the heating operation by the refrigerant flowing in the indoor heat exchanger and absorbing heat from the air even at the time of frost formation. it can.
According to the present invention, the refrigerant discharged from the first compressor can be flowed to either the indoor heat exchanger or the outdoor heat exchanger by the first switching means, and is discharged from the second compressor. The refrigerant can flow to either the indoor heat exchanger or the outdoor heat exchanger, and the refrigerant that has passed through the indoor heat exchanger and the refrigerant that has passed through the outdoor heat exchanger are merged and passed through the intermediate bypass pipe. It can be returned to the 1st compressor and the 2nd compressor.
Therefore, it is possible to provide an air conditioner capable of performing defrosting operation by the refrigerant flowing in the outdoor heat exchanger while continuing the heating operation by the refrigerant flowing in the indoor heat exchanger and absorbing heat from the air even at the time of frost formation. it can.
According to the present invention, the refrigerant discharged from the first compressor can be flowed to the indoor heat exchanger or the outdoor heat exchanger by the first switching means, and the refrigerant discharged from the second compressor is the first. The refrigerant discharged from the compressor can flow to a heat exchanger different from the heat exchanger in which the refrigerant flows, and the refrigerant that has passed through the indoor heat exchanger and the refrigerant that has passed through the outdoor heat exchanger are combined to form an intermediate bypass pipe. It can be returned to the first compressor and the second compressor via.
Therefore, it is possible to provide an air conditioner capable of performing defrosting operation by the refrigerant flowing in the outdoor heat exchanger while continuing the heating operation by the refrigerant flowing in the indoor heat exchanger and absorbing heat from the air even at the time of frost formation. it can.

According to the air conditioner of the present invention, heat can be absorbed from the outdoor air during the heating operation even when frost is formed.

FIG. 1 shows the configuration of the air conditioner according to the first embodiment of the present invention. FIG. 2 shows a refrigerant flow path during the cooling operation according to the first embodiment of the present invention. FIG. 3 shows a refrigerant flow path during the heating operation according to the first embodiment of the present invention. FIG. 4 shows a refrigerant flow path during heating / defrosting parallel operation according to the first embodiment of the present invention. FIG. 5 is a compressor efficiency curve of an engine compressor and a motor compressor. FIG. 6 shows the configuration of the air conditioner according to the second embodiment of the present invention. FIG. 7 shows the configuration of the air conditioner according to the third embodiment of the present invention.

The first invention relates to a first compressor driven by an engine, a second compressor connected in parallel with the first compressor, and a refrigerant discharged from the first compressor and the second compressor. A switching circuit for switching the flow path, a medium-pressure refrigerant circuit provided between the indoor heat exchanger and the outdoor heat exchanger and through which the medium-pressure refrigerant passes, and the suction side of the first compressor and the second compressor. A low-pressure refrigerant circuit provided in the above, a low-pressure refrigerant circuit through which the low-pressure refrigerant passes, an intermediate bypass pipe connecting the medium-pressure refrigerant circuit and the low-pressure refrigerant circuit, and an intermediate bypass pipe provided in the intermediate bypass pipe to transfer the exhaust heat of the engine to the refrigerant. The switching circuit is provided with an exhaust heat exchanger for flowing the refrigerant discharged from the first compressor to at least one of the indoor heat exchanger and the outdoor heat exchanger. The switching circuit switches to a flow path through which the refrigerant discharged from the second compressor flows to the other side, and the switching circuit transfers the refrigerant discharged from the first compressor to either the indoor heat exchanger or the outdoor heat exchanger. A first switching means for switching to a flow path for flowing to one side, and a second switching for switching the refrigerant discharged from the second compressor to a flow path for flowing the refrigerant to either the indoor heat exchanger or the outdoor heat exchanger. The low pressure is provided with means and opening / closing means provided downstream of the first switching means or the second switching means with reference to the flow path of the refrigerant evaporated in the indoor heat exchanger or the outdoor heat exchanger. The refrigerant circuit is a circuit downstream of the opening / closing means, and the switching circuit is between the second switching means and the indoor heat exchanger, and only the discharged refrigerant of the second compressor flows during the heating operation. A third opening / closing means provided on the circuit between the second opening / closing means, the first switching means, and the outdoor heat exchanger, and through which only the discharged refrigerant of the first compressor flows during cooling operation. It means an air conditioner, wherein the obtaining further Bei a.
According to the present invention, when frost is formed on the outdoor heat exchanger, a part of the refrigerant discharged from the first compressor or the second compressor flows into the indoor heat exchanger, and a part is sent to the outdoor heat exchanger. The flow, the refrigerant that has passed through the indoor heat exchanger and the refrigerant that has passed through the outdoor heat exchanger can be merged and returned to the first compressor and the second compressor via the intermediate bypass pipe.
Therefore, when the outdoor heat exchanger is frosted during the heating operation, the refrigerant flowing through the indoor heat exchanger continues the heating operation, while the refrigerant flowing through the outdoor heat exchanger defrosts the frost. Even if it does, it will be able to absorb heat from the outdoor air.
According to the present invention, the refrigerant discharged from the first compressor can be flowed to either the indoor heat exchanger or the outdoor heat exchanger by the first switching means, and is discharged from the second compressor. The refrigerant can flow to either the indoor heat exchanger or the outdoor heat exchanger, and the refrigerant that has passed through the indoor heat exchanger and the refrigerant that has passed through the outdoor heat exchanger are merged and passed through the intermediate bypass pipe. It can be returned to the 1st compressor and the 2nd compressor.
Therefore, it is possible to provide an air conditioner capable of performing defrosting operation by the refrigerant flowing in the outdoor heat exchanger while continuing the heating operation by the refrigerant flowing in the indoor heat exchanger and absorbing heat from the air even at the time of frost formation. it can.
According to the present invention, the refrigerant discharged from the first compressor can be flowed to the indoor heat exchanger or the outdoor heat exchanger by the first switching means, and the refrigerant discharged from the second compressor is the first. The refrigerant discharged from the compressor can flow to a heat exchanger different from the heat exchanger in which the refrigerant flows, and the refrigerant that has passed through the indoor heat exchanger and the refrigerant that has passed through the outdoor heat exchanger are combined to form an intermediate bypass pipe. It can be returned to the first compressor and the second compressor via.
Therefore, it is possible to provide an air conditioner capable of performing defrosting operation by the refrigerant flowing in the outdoor heat exchanger while continuing the heating operation by the refrigerant flowing in the indoor heat exchanger and absorbing heat from the air even at the time of frost formation. it can.

According to the second invention, the switching circuit does not combine the refrigerant discharged from the first compressor and the refrigerant discharged from the second compressor during the parallel heating / defrosting operation, and the indoor heat exchanger It is characterized in that the refrigerant discharged from the first compressor flows to either one of the outdoor heat exchanger and the outdoor heat exchanger, and the flow path is switched to a flow path through which the refrigerant discharged from the second compressor flows to one of the other. It is an air conditioner.
According to the present invention, since the pressures of the refrigerant discharged from the first compressor and the refrigerant discharged from the second compressor are not uniform, the indoor heat exchanger does not increase the load of the low-load compressor. While continuing the heating operation with the refrigerant flowing through the outdoor heat exchanger, defrosting can be performed with the refrigerant flowing through the outdoor heat exchanger.

In a third aspect of the invention, the switching circuit supplies the refrigerant discharged from the first compressor and the second compressor, which has a higher capacity, to the indoor heat exchanger, and supplies the first compressor and the second compressor with the discharge refrigerant. It is an air conditioner characterized by supplying the refrigerant discharged from a compressor having a low capacity among the second compressors to the outdoor heat exchanger.
According to the present invention, the heating operation can be performed by the compressor having a higher capacity among the first compressor and the second compressor, and it becomes easy to maintain the air conditioning temperature in the room.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The present invention is not limited to the present embodiment.

(Embodiment 1)
FIG. 1 shows the configuration of an air conditioner according to the first embodiment of the present invention.
The air conditioner according to the first embodiment includes an outdoor unit 111 and an indoor unit 202.
The outdoor unit 111 includes an engine 100a whose drive source is gas, a first compressor 101 which obtains a driving force by the engine 100a to compress the refrigerant, and a second compressor 102 whose drive source is a motor 100b. ..
As the first compressor 101, one having a higher capacity than that of the second compressor 102 is selected.
The second compressor 102 may be a compressor that compresses the refrigerant by obtaining a driving force from a gas engine.

The first discharge pipe 121 is connected to the discharge port of the first compressor 101. A second discharge pipe 122 is connected to the discharge port of the second compressor 102.
The first discharge pipe 121 is connected to the first refrigerant pipe 123 at the location of the four-way valve (first switching means) 110b via the first oil separator 103a. The first refrigerant pipe 123 is connected to one end of the indoor heat exchanger 200. The oil separated in the first oil separator 103a is returned to the first suction pipe 134 connected to the suction port of the first compressor 101 through an oil return pipe (not shown). The four-way valve 110b provided downstream of the first oil separator 103a is for switching the refrigeration cycle between cooling and heating together with the three-way valve (second switching means) 110a described later. In FIG. 1, when the refrigerant flows along the solid line, the heating operation is performed, and when the refrigerant flows along the dotted line, the cooling operation is performed.

A second refrigerant pipe 124 is connected to the other end of the indoor heat exchanger 200. The second refrigerant pipe 124 is connected to one end of the outdoor heat exchanger 105 via the indoor expansion valve 201 and the outdoor expansion valve 107. A radiator 106 is provided on the leeward side of the outdoor heat exchanger 105, and the engine cooling water is dissipated by an outdoor fan (not shown).

Here, the medium-pressure refrigerant circuit refers to a circuit through which the medium-temperature and medium-pressure refrigerant passes. In the first embodiment, of the second refrigerant pipe 124, the pipe between the indoor expansion valve 201 and the outdoor expansion valve 107 is the medium pressure refrigerant circuit.

A third refrigerant pipe 125 is connected to the other end of the outdoor heat exchanger 105. The third refrigerant pipe 125 is connected to the fourth refrigerant pipe 126 via the four-way valve 110b. The fourth refrigerant pipe 126 is connected to the first suction pipe 134 connected to the suction port of the first compressor 101 via an on-off valve (opening / closing means) 110c. Further, the fourth refrigerant pipe 126 is connected to the second suction pipe 135 connected to the suction port of the second compressor 102 via the on-off valve 110c.
The first suction pipe 134 is connected to the suction port of the first compressor 101 via the first accumulator 104a.
The second suction pipe 135 is connected to the suction port of the second compressor 102 via the second accumulator 104b.

The second discharge pipe 122 is connected to the first refrigerant pipe 123 via the second oil separator 103b and the three-way valve (second switching means) 110a. Further, the second discharge pipe 122 is connected to the third refrigerant pipe 125 via the three-way valve 110a. The three-way valve 110a, together with the four-way valve 110b, is for switching the refrigeration cycle between cooling and heating.

The four-way valve (first switching means) 110b that switches the flow of the refrigerant so that the refrigerant discharged from the first compressor 101 flows to the indoor heat exchanger 200 or the outdoor heat exchanger 105, and the refrigerant discharged from the second compressor 102. A three-way valve (second switching means) 110a that switches the flow of the refrigerant so as to flow the refrigerant to the indoor heat exchanger 200 or the outdoor heat exchanger 105, and the indoor heat exchanger 200 or the outdoor heat exchanger. With reference to the flow path of the refrigerant evaporated in 105, the on-off valve (opening / closing means) 110c provided downstream of the four-way valve 110b or the three-way valve 110a constitutes the switching circuit 110.

In the first embodiment including the switching circuit 110, the circuit downstream of the on-off valve 110c is the low-pressure refrigerant circuit. That is, when the flow of the refrigerant during the heating operation is used as a reference, the pipe downstream of the on-off valve 110c, the first suction pipe 134, and the second suction pipe 135 of the fourth refrigerant pipe 126 are low-pressure refrigerant circuits. ..

The second refrigerant pipe (medium pressure refrigerant circuit) 124 and the fourth refrigerant pipe (low pressure refrigerant circuit) 126 are connected by an intermediate bypass pipe 127.
The intermediate bypass pipe 127 connects the second refrigerant pipe 124 and the fourth refrigerant pipe 126 from the side of the second refrigerant pipe 124, which is the medium pressure side during heating, via the exhaust heat expansion valve 109a and the exhaust heat exchanger 108a. Connecting.
The intermediate bypass pipe 127 may be any one that connects the medium-pressure refrigerant circuit and the low-pressure refrigerant circuit.

The operation and operation of the air conditioner configured as described above will be described below.
FIG. 2 shows the refrigerant flow path during the cooling operation according to the first embodiment of the present invention. During the cooling operation, the four-way valve 110b and the three-way valve 110a are switched so that the refrigerant flows as shown by the solid line, and the on-off valve 110c is opened.
As a result, the circuit on the high pressure side where the high pressure refrigerant compressed by the first compressor 101 and the second compressor 102 exists is connected to the outdoor heat exchanger 105 side, while the circuit on the low pressure side where the low pressure refrigerant exists is indoors. It is connected to the heat exchanger 200 side.

A high-temperature and high-pressure gas refrigerant compressed by the first compressor 101 by the power of the engine 100a and passed through the first oil separator 103a, and a high-temperature and high-pressure gas refrigerant compressed by the second compressor 102 and passed through the second oil separator 103b. Does not merge upstream of the four-way valve 110b and the three-way valve 110a. Then, the high-temperature and high-pressure refrigerant discharged from the first compressor 101 is flowed to the outdoor heat exchanger 105 side by the four-way valve 110b, and the high-temperature and high-pressure refrigerant discharged from the second compressor 102 is flown to the outdoor heat exchanger 105 by the three-way valve 110a. It flows to the 105 side, joins in the third refrigerant pipe 125 downstream from the four-way valve 110b and the three-way valve 110a, and flows into the outdoor heat exchanger 105. The refrigerant condensed to medium temperature and medium pressure by exchanging with air in the outdoor heat exchanger 105 flows into the indoor heat exchanger 200, exchanges heat with the indoor air in the indoor heat exchanger 200, and evaporates. It becomes a low temperature and low pressure state. After that, the refrigerant that has passed through the indoor heat exchanger 200 flows through the four-way valve 110b as shown by the solid line, passes through the on-off valve 110c, and passes through the first accumulator 104a and the second accumulator 104b, and then the first compressor 101. And it is compressed again by the second compressor 102.

Further, FIG. 5 shows the compression efficiency curves of the first compressor 101 and the second compressor 102.
The engine efficiency is high after medium load, while the motor efficiency is high in the low to medium load range. Therefore, in FIG. 5, the efficiency of the second compressor 102 driven by the motor 100b increases in the low load region, and the efficiency of the first compressor 101 driven by the engine 100a increases after the medium load. When the load is small, only the second compressor 102, which is highly efficient in operation with a small load, is driven, and when the load is medium or more, the first compressor 101 mainly supplies air conditioning, depending on the load. Efficient operation is possible by selecting the compressor to be driven.

FIG. 3 shows the refrigerant flow path during the heating operation according to the first embodiment of the present invention. During the heating operation, the four-way valve 110b and the three-way valve 110a are switched so that the refrigerant flows as shown by the solid line, and the on-off valve 110c is opened.
As a result, the circuit on the high pressure side where the high pressure refrigerant compressed by the first compressor 101 and the second compressor 102 exists is connected to the indoor heat exchanger 200 side, while the circuit on the low pressure side where the low pressure refrigerant exists is connected. It is connected to the outdoor heat exchanger 105 side.

The high temperature and high pressure gas refrigerant compressed by the first compressor 101 by the power of the engine 100a and passed through the first oil separator 103a, and the high temperature compressed by the second compressor 102 by the power of the motor 100b and passed through the second oil separator 103b. The high-pressure gas refrigerant does not merge upstream of the four-way valve 110b and the three-way valve 110a. Then, the high-temperature and high-pressure refrigerant discharged from the first compressor 101 is flowed to the indoor heat exchanger 200 side by the four-way valve 110b, and the high-temperature and high-pressure refrigerant discharged from the second compressor 102 is sent to the indoor heat exchanger by the three-way valve 110a. It is flowed to the 200 side, merges in the first refrigerant pipe 123 downstream of the four-way valve 110b and the three-way valve 110a, and flows into the indoor unit 202. The refrigerant condensed to medium temperature and medium pressure by exchanging with the indoor air in the indoor heat exchanger 200 in the indoor unit 202 flows into the outdoor unit 111 and exchanges heat with the outdoor air in the outdoor heat exchanger 105. Then it evaporates and becomes a low temperature and low pressure state. After that, the refrigerant that has passed through the outdoor heat exchanger 105 flows through the four-way valve 110b as shown by the solid line, passes through the on-off valve 110c, and passes through the first accumulator 104a and the second accumulator 104b, and then the first compressor 101. And it is compressed again by the second compressor 102.

When the outside air temperature is low, the medium-temperature and medium-pressure refrigerant flowing in from the indoor unit 202 can be absorbed and evaporated not only in the outdoor heat exchanger 105 but also in the first exhaust heat exchanger 108. .. Further, as in the case of cooling operation, efficient operation is possible by selecting a compressor to be driven according to the load.

FIG. 4 shows a refrigerant flow path during heating / defrosting parallel operation according to the first embodiment of the present invention. During the heating / defrosting parallel operation, the four-way valve 110b and the three-way valve 110a are switched so that the refrigerant flows as shown by the solid line, and the on-off valve 110c is closed.
As a result, the circuit on the high pressure side where the high pressure refrigerant compressed by the first compressor 101 exists is connected to the indoor heat exchanger 200 side, while the high pressure side where the high pressure refrigerant compressed by the second compressor 102 exists. Circuit is connected to the outdoor heat exchanger 105 side.

If frost is detected or is likely to frost during the heating operation, the high-temperature and high-pressure gas refrigerant compressed by the first compressor 101 by the power of the engine 100a and passed through the first oil separator 103a passes through the four-way valve 110b. It flows into the indoor unit 202. Then, the refrigerant flowing into the indoor unit 202 is condensed in the indoor heat exchanger 200 to become a medium-temperature medium-pressure refrigerant, and returns to the outdoor unit 111. On the other hand, the high-temperature and high-pressure gas refrigerant compressed by the second compressor 102 by the power of the motor 100b and passed through the second oil separator 103b does not merge with the refrigerant compressed by the first compressor 101 via the three-way valve 110a. It flows into the outdoor heat exchanger 105. Then, the refrigerant flowing into the outdoor heat exchanger 105 exchanges heat with the outdoor air or the frost generated in the outdoor heat exchanger 105 and condenses to become a medium-temperature medium-pressure refrigerant. Then, the refrigerant that has reached medium temperature and medium pressure in the outdoor heat exchanger 105 merges with the medium temperature and medium pressure refrigerant condensed in the indoor heat exchanger 200 at the intermediate bypass pipe 127. The combined refrigerant evaporates in the exhaust heat exchanger 108a due to the exhaust heat of the engine 100a to become a low-pressure gas refrigerant, and after passing through the first accumulator 104a and the second accumulator 104b, the first compressor 101 and the second compressor are compressed. It is compressed again by the machine 102.

As described above, the air exchanger according to the first embodiment of the present invention includes the first compressor 101 driven by the engine 100a, the second compressor 102 connected in parallel with the first compressor 101, and the first compressor. A second switching circuit 110 for switching the flow path of the refrigerant discharged from the compressor 101 and the second compressor 102, provided between the indoor heat exchanger 200 and the outdoor heat exchanger 105, and through which the medium pressure refrigerant passes. The refrigerant pipe (medium pressure refrigerant circuit) 124, the fourth compressor pipe (low pressure refrigerant circuit) 126 provided on the suction side of the first compressor 101 and the second compressor 102 and through which the low pressure refrigerant passes, and the second refrigerant pipe An intermediate bypass pipe 127 connecting the 124 and the fourth refrigerant pipe 126, and an exhaust heat expansion valve 109a and an exhaust heat exchanger 108a provided in the intermediate bypass pipe 127 in this order from the medium pressure side during the heating operation. The switching circuit 110 allows at least one of the indoor heat exchanger 200 and the outdoor heat exchanger 105 to flow the refrigerant discharged from the first compressor 101, and at least one of the other from the second compressor 102. Switch to the flow path through which the discharged refrigerant flows.
When frost is formed on the outdoor heat exchanger 105 during the heating operation, a part of the refrigerant discharged from the first compressor 101 or the second compressor 102 flows into the indoor heat exchanger 200, and a part of the outdoor heat exchanger The refrigerant flowing through the indoor heat exchanger 200 and the refrigerant passing through the outdoor heat exchanger 105 can be merged and returned to the first compressor 101 and the second compressor 102 via the intermediate bypass pipe 127. ..
Since the defrosting is performed by the discharged refrigerant of the second compressor 102 flowing into the outdoor heat exchanger 105, heat can be absorbed from the outdoor air even when the outdoor heat exchanger 105 is frosted.

Further, according to the first embodiment, the switching circuit 110 does not combine the refrigerant discharged from the first compressor 101 and the refrigerant discharged from the second compressor 102 during the parallel heating / defrosting operation. A flow path through which the refrigerant discharged from the first compressor 101 flows to either the indoor heat exchanger 200 or the outdoor heat exchanger 105, and the refrigerant discharged from the second compressor 102 flows to one of the other. It is a switching circuit.
In this case, since the pressures of the refrigerant discharged from the first compressor 101 and the refrigerant discharged from the second compressor 102 are not uniform, the load of the second compressor 102, which is a low load, is not increased, and the room is indoors. While continuing the heating operation with the refrigerant flowing through the heat exchanger 200, defrosting can be performed with the refrigerant flowing through the outdoor heat exchanger 105.

Further, according to the first embodiment, the switching circuit 110 supplies the refrigerant discharged from the first compressor 101 having a high capacity to the indoor heat exchanger 200, and the second compressor 101 has a lower capacity than the first compressor 101. This is a circuit capable of supplying the refrigerant discharged from the compressor 102 to the outdoor heat exchanger 105.
In this case, the heating operation can be covered by the first compressor 101, which has a higher capacity than the second compressor 102, and it becomes easy to maintain the air conditioning temperature in the room.
Further, in this case, since the first compressor 101 is operated by driving the engine 100a, the exhaust heat is increased by driving the first compressor 101, and the exhaust heat exchanger 108a can be effectively used.

Further, according to the first embodiment, the switching circuit 110 switches the refrigerant discharged from the first compressor 101 to a flow path for flowing the refrigerant to either the indoor heat exchanger 200 or the outdoor heat exchanger 105. A three-way valve (second switching means) that switches the valve (first switching means) 110b and the flow path through which the refrigerant discharged from the second compressor 102 flows to either the indoor heat exchanger 200 or the outdoor heat exchanger 105. ) 110a and an on-off valve (opening / closing means) 110c provided downstream of the four-way valve 110b or the three-way valve 110a with reference to the flow path of the refrigerant evaporated in the indoor heat exchanger 200 or the outdoor heat exchanger 105. The circuit downstream of the on-off valve (opening / closing means) 110c is a low-pressure refrigerant circuit.
By providing the switching circuit 110, the refrigerant discharged from the first compressor 101 can be flowed to the indoor heat exchanger 200 by the four-way valve 110b, and the refrigerant discharged from the second compressor 102 can be flowed to the three-way valve 110a. The refrigerant that has passed through the indoor heat exchanger 200 and the refrigerant that has passed through the outdoor heat exchanger 105 are merged with each other, and the first compressor 101 and the second compressor 101 and the second compressor are merged through the intermediate bypass pipe 127. It can be returned to the compressor 102.
Therefore, it is possible to perform the defrosting operation by the refrigerant flowing in the outdoor heat exchanger 105 while continuing the heating operation by the refrigerant flowing in the indoor heat exchanger 200, and to provide an air conditioner capable of absorbing heat from the air even at the time of frost formation. be able to.

Even if the refrigerant discharged from the first compressor 101 is passed through the outdoor heat exchanger 105 by the four-way valve 110b and the refrigerant discharged from the second compressor 102 is flowed through the indoor heat exchanger 200 by the three-way valve 110a. Good.

Further, according to the first embodiment, the second discharge pipe 122 connected to the second compressor 102 driven by the motor 100b is provided with a three-way valve 110a and is connected to the first compressor 101 driven by the engine 100a. The first discharge pipe 121 is provided with a four-way valve 110b.
When the heating / defrosting parallel operation is performed during the heating operation, the three-way valve (second switching means) 110a is switched. The switching of the second switching means can be performed smoothly with the three-way valve, which has a shorter switching time than the four-way valve.
Therefore, according to the first embodiment, the heating operation is performed by using the three-way valve (second switching means) 110a as the second replacement means for switching when the heating / defrosting parallel operation is performed during the heating operation. It is possible to smoothly switch between heating and defrosting parallel operations.

(Embodiment 2)
FIG. 6 shows the configuration of the air conditioner according to the second embodiment of the present invention. In the second embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.
In the second embodiment, a three-way valve (first switching means) 210b is provided instead of the four-way valve (first switching means) 110b in the first embodiment. Further, a four-way valve (second switching means) 210a is provided instead of the three-way valve (second switching means) 110a in the first embodiment.

In the second embodiment, a three-way valve (first switching means) 210b that switches the flow of the refrigerant so that the refrigerant discharged from the first compressor 101 flows to the indoor heat exchanger 200 or the outdoor heat exchanger 105, and the first 2 A four-way valve (second switching means) 210a that switches the flow of the refrigerant so as to flow the refrigerant discharged from the compressor 102 to the indoor heat exchanger 200 or the outdoor heat exchanger 105, and the indoor heat exchange. The on-off valve (opening / closing means) 110c provided downstream of the four-way valve 110b or the three-way valve 110a constitutes the switching circuit 210 with reference to the flow path of the refrigerant evaporated in the device 200 or the outdoor heat exchanger 105.

Also in the second embodiment including the switching circuit 210, the circuit downstream of the on-off valve 110c is the low-pressure refrigerant circuit. That is, when the flow of the refrigerant during the heating operation is used as a reference, the pipe downstream of the on-off valve 110c, the first suction pipe 134, and the second suction pipe 135 of the fourth refrigerant pipe 126 are low-pressure refrigerant circuits. ..
Further, of the second refrigerant pipe 124, the pipe between the indoor expansion valve 201 and the outdoor expansion valve 107 is a medium pressure refrigerant circuit.

The operation and operation of the air conditioner configured as described above will be described below.
In the cooling operation, the refrigerant discharged from the first compressor 101 flows into the outdoor heat exchanger 105 side through the three-way valve 210b set to allow the refrigerant to flow along the dotted line. Further, the refrigerant discharged from the second compressor 102 flows into the outdoor heat exchanger 105 side through the four-way valve 210a set so that the refrigerant flows along the dotted line, and the discharged refrigerant discharged from the first compressor 101. Meet with. At this time, the on-off valve 110c is opened. The subsequent refrigerant flow path is the same as that of the first embodiment.

In the case of the heating operation, the refrigerant discharged from the first compressor 101 flows into the indoor unit 202 via the three-way valve 210b set to allow the refrigerant to flow in the solid line. Further, the refrigerant discharged from the second compressor 102 flows into the indoor unit 202 via the four-way valve 210a set to allow the refrigerant to flow in the solid line, and merges with the discharged refrigerant discharged from the first compressor 101. .. At this time, the on-off valve 110c is opened. The subsequent refrigerant flow path is the same as that of the first embodiment.

If frost is detected or is likely to frost during the heating operation, the on-off valve 110c is closed first, and the refrigerant discharged from the first compressor 101 is a three-way valve 210b set so that the refrigerant flows in the solid line. It flows into the indoor unit 202 via. Further, the refrigerant discharged from the second compressor 102 flows into the outdoor heat exchanger 105 via the four-way valve 210a set so that the refrigerant flows along the dotted line. At this time, the on-off valve 110c is closed. The subsequent refrigerant flow path is the same as that of the first embodiment.

As described above, in the second embodiment of the present invention, the three-way valve (first switching means) 210b is provided instead of the four-way valve (first switching means) 110b in the first embodiment. Further, the outdoor heat exchanger 105 was frosted during the heating operation by the switching circuit 210 provided with the four-way valve (second switching means) 210a instead of the three-way valve (second switching means) 110a in the first embodiment. At that time, a part of the refrigerant discharged from the first compressor 101 or the second compressor 102 was passed through the indoor heat exchanger 200, and a part of the refrigerant was passed through the outdoor heat exchanger 105 and passed through the indoor heat exchanger 200. The refrigerant and the refrigerant that have passed through the outdoor heat exchanger 105 can be merged and returned to the first compressor 101 and the second compressor 102 via the intermediate bypass pipe 127.
Also in the second embodiment, since the defrosting is performed by the discharged refrigerant of the second compressor 102 flowing into the outdoor heat exchanger 105, heat can be absorbed from the outdoor air even when the outdoor heat exchanger 105 is frosted. Therefore, the same effect as that of the first embodiment is obtained.

(Embodiment 3)
FIG. 7 shows the configuration of the air conditioner according to the third embodiment of the present invention. In the third embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.
In the third embodiment, the second four-way valve (second switching means) 110d is provided in place of the three-way valve (second switching means) 110a in the first embodiment.

The second discharge pipe 122 is connected to the first refrigerant pipe 123 via the second oil separator 103b, the second four-way valve 110d, and the second on-off valve (second on-off means) 110e.
The second on-off valve 110e is between the second four-way valve 110d and the indoor heat exchanger 200, and can be provided on a circuit through which only the discharged refrigerant of the second compressor 102 flows during the heating operation. In the third embodiment, the second on-off valve 110e is provided downstream of the second four-way valve 110d in the second discharge pipe 122.

The third refrigerant pipe 125 is branched into a first third refrigerant pipe 400 and a second third refrigerant pipe 500. The first third refrigerant pipe 400 joins the second third refrigerant pipe 500 via the third on-off valve (third on-off means) 110f and the four-way valve 110b. The second third refrigerant pipe 500 joins the first third refrigerant pipe 400 via the second four-way valve 110d. The fourth refrigerant pipe 126 is connected to the connection point between the first third refrigerant pipe 400 and the second third refrigerant pipe 500.
The third on-off valve 110f is between the four-way valve 110b and the outdoor heat exchanger 105, and can be provided on a circuit through which only the discharged refrigerant of the first compressor 101 flows during the cooling operation. In the third embodiment, the third on-off valve 110f is provided downstream of the four-way valve 110b in the first third refrigerant pipe 400 with reference to the flow of the refrigerant during the cooling operation.

A four-way valve (first switching means) 110b that switches the flow of the refrigerant so that the refrigerant flows from the first discharge pipe 121 to the indoor heat exchanger 200 or the outdoor heat exchanger 105, and the indoor heat exchanger 200 from the second discharge pipe 122. Alternatively, the flow path of the refrigerant evaporated in the indoor heat exchanger 200 or the outdoor heat exchanger 105 is used as a reference with the second four-way valve (second switching means) 110d that switches the flow of the refrigerant so that the refrigerant flows to the outdoor heat exchanger 105. It is between the on-off valve (opening / closing means) 110c provided downstream of the four-way valve 110b or the three-way valve 110a, the second four-way valve 110d, and the indoor heat exchanger 200, and discharges the second compressor 102 during the heating operation. It is between the second on-off valve (second on-off means) 110e provided on the circuit through which only the refrigerant flows, the four-way valve 110b and the outdoor heat exchanger 105, and only the discharged refrigerant of the first compressor 101 during the cooling operation. A third on-off valve (third on-off means) 110f provided on the flowing circuit constitutes a switching circuit 310.

Also in the third embodiment including the switching circuit 310, the circuit downstream of the on-off valve 110c is the low-pressure refrigerant circuit. That is, when the flow of the refrigerant during the heating operation is used as a reference, the pipe downstream of the on-off valve 110c, the first suction pipe 134, and the second suction pipe 135 of the fourth refrigerant pipe 126 are low-pressure refrigerant circuits. ..
Further, of the second refrigerant pipe 124, the pipe between the indoor expansion valve 201 and the outdoor expansion valve 107 is a medium pressure refrigerant circuit.

The operation and operation of the air conditioner configured as described above will be described below.
In the case of cooling operation, the on-off valve 110c and the third on-off valve 110f are opened. The refrigerant discharged from the first compressor 101 flows into the outdoor heat exchanger 105 via a four-way valve 110b set to allow the refrigerant to flow along the dotted line. Further, the refrigerant discharged from the second compressor 102 flows into the outdoor heat exchanger 105 via the second four-way valve 110d set so that the refrigerant flows along the dotted line, and the refrigerant discharged from the first compressor 101. Meet with. The subsequent refrigerant flow path is the same as that of the first embodiment.

In the case of heating operation, the on-off valve 110c and the second on-off valve 110e are opened. The refrigerant discharged from the first compressor 101 flows into the indoor unit 202 via a four-way valve 110b set to allow the refrigerant to flow along the solid line. Further, the refrigerant discharged from the second compressor 102 flows into the indoor unit 202 via the second four-way valve 110d set to flow the refrigerant along the solid line, and merges with the discharged refrigerant from the first compressor 101. The subsequent refrigerant flow path is the same as that of the first embodiment.

If frost is detected or is likely to frost during the heating operation, the on-off valve 110c, the second on-off valve 110e, and the third on-off valve 110f are closed first, and the refrigerant discharged from the first compressor 101 is a solid line. It flows into the indoor unit 202 through a four-way valve 110b set to allow the refrigerant to flow through the room. Further, the refrigerant discharged from the second compressor 102 flows into the outdoor heat exchanger 105 via the second four-way valve 110d set so that the refrigerant flows along the dotted line. The subsequent refrigerant flow path is the same as that of the first embodiment.

As described above, in the third embodiment of the present invention, the switching circuit 310 is a flow path for flowing the refrigerant discharged from the first compressor 101 to either the indoor heat exchanger 200 or the outdoor heat exchanger 105. A four-way valve (first switching means) 110b that switches to, and a second four-way valve that switches the refrigerant discharged from the second compressor 102 to a flow path that flows to either the indoor heat exchanger 200 or the outdoor heat exchanger 105. An on-off valve (opening / closing means) 110c provided downstream of the four-way valve 110b or the three-way valve 110a with reference to the flow path of the refrigerant evaporated in the (second switching means) 110d and the indoor heat exchanger 200 or the outdoor heat exchanger 105. And the second on-off valve (second on-off means) 110e, which is between the second four-way valve 110d and the indoor heat exchanger 200 and is provided on the circuit through which only the discharged refrigerant of the second compressor 102 flows during the heating operation. , A third on-off valve (third on-off means) 110f between the four-way valve 110b and the outdoor heat exchanger 105 and provided on a circuit through which only the discharged refrigerant of the first compressor 101 flows during cooling operation. did.
According to this, when the outdoor heat exchanger 105 is frosted during the heating operation, a part of the refrigerant discharged from the first compressor 101 or the second compressor 102 is partially discharged from the indoor heat exchanger 200 by the switching circuit 310. A part of the refrigerant flows through the outdoor heat exchanger 105, and the refrigerant that has passed through the indoor heat exchanger 200 and the refrigerant that has passed through the outdoor heat exchanger 105 are merged with each other, and the first compressor 101 and the first compressor 101 and the like are passed through the intermediate bypass pipe 127. It can be returned to the second compressor 102.
Since the defrosting is performed by the discharged refrigerant of the second compressor 102 flowing into the outdoor heat exchanger 105, heat can be absorbed from the outdoor air even when the outdoor heat exchanger 105 is frosted.

Further, also in the third embodiment, the switching circuit 310 does not combine the refrigerant discharged from the first compressor 101 and the refrigerant discharged from the second compressor 102 during the parallel heating / defrosting operation, and is indoors. The refrigerant discharged from the first compressor 101 flows to either one of the heat exchanger 200 and the outdoor heat exchanger 105, and the flow path is switched to flow the refrigerant discharged from the second compressor 102 to one of the other. .. Therefore, without increasing the load of the second compressor 102, which has a low load, the heating operation can be continued by the refrigerant flowing in the indoor heat exchanger 200, and the defrosting can be performed by the refrigerant flowing in the outdoor heat exchanger 105. it can.

Further, also in the third embodiment, the discharged refrigerant of the first compressor 101 having a high capacity flows into the indoor heat exchanger 200, and the discharged refrigerant of the second compressor 102 having a low capacity flows into the outdoor heat exchanger 105. Therefore, the heating operation can be covered by the first compressor 101, which has a higher capacity than the second compressor 102, and it becomes easy to maintain the air conditioning temperature in the room.

Although the present invention has been described above based on the present embodiment, the present invention is not limited to these embodiments. Since this is merely an example of the embodiment of the present invention, it can be arbitrarily modified and applied without departing from the spirit of the present invention.

For example, in the switching circuit, a part of the refrigerant discharged from the first compressor 101 or the second compressor 102 is passed through the indoor heat exchanger 200, and one of the refrigerants discharged from the first compressor 101 or the second compressor 102. The unit may have a circuit configuration that allows the air to flow through the outdoor heat exchanger 105, and is not limited to that of the present embodiment.
Further, the low-pressure refrigerant circuit may be any circuit that allows the refrigerant to flow from the medium-pressure refrigerant circuit via the intermediate bypass pipe.

Further, for example, a fourth on-off valve is provided on the upstream side of the second compressor 102, and one end is connected to the downstream side of the connection end of the intermediate bypass pipe 127 in the medium pressure refrigerant circuit through which the medium pressure refrigerant passes. A second intermediate bypass is provided between the compressor 102 and the valve with the other end connected, and the second intermediate bypass is provided by the second exhaust heat expansion valve, the cooling water of the engine 100a, and the refrigerant from the medium pressure side during heating. Second exhaust heat exchangers for heat exchange may be provided in order, and a fifth on-off valve may be provided between the connection end of the intermediate bypass pipe 127 and the connection end of the second intermediate bypass in the intermediate refrigerant circuit.
In this case, by closing the 4th on-off valve and the 5th on-off valve when defrosting, the low-voltage circuit of the defrosting cycle by the second compressor 102 and the low-voltage circuit of the heating cycle by the first compressor 101 The circuit becomes independent. Therefore, the pressure on the suction side of the second compressor 102 is not lowered by the low pressure of the first compressor 101, and the load on the second compressor 102 is reduced. Therefore, the efficiency of the second compressor 102 during the defrosting operation is increased, and as a result, the efficiency of the heating operation is increased.

As described above, the air conditioner according to the present invention enables highly efficient heating operation to be continued even when the outside air is low, and not only a heat pump of a type that pumps heat from air to air, but also hot water that pumps heat from air to water. It is also possible to develop into a heat pump of the type that produces.

100b Motor 101 1st compressor 102 2nd compressor 105 Outdoor heat exchanger 107 Outdoor expansion valve 108a Exhaust heat exchanger 109a Exhaust heat expansion valve 110, 210, 310 Switching circuit 110a Three-way valve (second switching means)
110b four-way valve (first switching means)
110c on-off valve (opening and closing means)
110d 2nd four-way valve (2nd switching means)
110e 2nd on-off valve (2nd on-off means)
110f 3rd on-off valve (3rd on-off means)
111 Outdoor unit 121 1st discharge pipe 122 2nd discharge pipe 123 1st refrigerant pipe 124 2nd refrigerant pipe (medium pressure refrigerant circuit)
125 3rd Refrigerant Piping 126 4th Refrigerant Piping (Low Pressure Refrigerant Circuit)
127 Intermediate bypass pipe 134 First suction pipe (low pressure refrigerant circuit)
135 Second suction pipe (low pressure refrigerant circuit)
200 Indoor heat exchanger 201 Indoor expansion valve 202 Indoor unit 210a Three-way valve (first switching means)
210b Four-way valve (second switching means)
400 1st 3rd refrigerant pipe 500 2nd 3rd refrigerant pipe

Claims (3)

The first compressor driven by the engine and
A second compressor connected in parallel with the first compressor,
A switching circuit that switches the flow path of the refrigerant discharged from the first compressor and the second compressor, and
A medium-pressure refrigerant circuit that is installed between the indoor heat exchanger and the outdoor heat exchanger and through which the medium-pressure refrigerant passes,
A low-pressure refrigerant circuit provided on the suction side of the first compressor and the second compressor through which the low-pressure refrigerant passes, and
An intermediate bypass pipe connecting the medium-pressure refrigerant circuit and the low-pressure refrigerant circuit,
The intermediate bypass pipe is provided with an exhaust heat exchanger that transfers the exhaust heat of the engine to the refrigerant.
The switching circuit is
A flow in which the refrigerant discharged from the first compressor flows to at least one of the indoor heat exchanger and the outdoor heat exchanger, and the refrigerant discharged from the second compressor flows to one of the other. Switch to the road,
The switching circuit is
A first switching means for switching the refrigerant discharged from the first compressor to a flow path for flowing the refrigerant to either the indoor heat exchanger or the outdoor heat exchanger.
A second switching means for switching the refrigerant discharged from the second compressor to a flow path for flowing the refrigerant to either the indoor heat exchanger or the outdoor heat exchanger.
With reference to the flow path of the refrigerant evaporated in the indoor heat exchanger or the outdoor heat exchanger, the first switching means or the opening / closing means provided downstream of the second switching means is provided.
The low-pressure refrigerant circuit is a circuit downstream of the opening / closing means.
The switching circuit is
A second opening / closing means between the second switching means and the indoor heat exchanger, which is provided on a circuit through which only the discharged refrigerant of the second compressor flows during the heating operation.
Is between the outdoor heat exchanger and said first switching means, and wherein the obtaining further Bei third switching means provided on the circuit only flow discharge refrigerant of the first compressor during the cooling operation, the Air conditioner. The switching circuit is
During parallel heating and defrosting operation
Discharge from the first compressor to either the indoor heat exchanger or the outdoor heat exchanger without merging the refrigerant discharged from the first compressor and the refrigerant discharged from the second compressor. The air conditioner according to claim 1, wherein the flow of the refrigerant is switched to a flow path for flowing the refrigerant discharged from the second compressor to one of the other. The switching circuit is
The refrigerant discharged from the first compressor and the second compressor having a higher capacity is supplied to the indoor heat exchanger.
The air conditioner according to claim 2, wherein the refrigerant discharged from the first compressor and the second compressor having a lower capacity is supplied to the outdoor heat exchanger.

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