JP2016080276A - Air conditioning system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air conditioning system in which a refrigerant flow channel is optimized.SOLUTION: Air for air conditioning, exchanging heat with a refrigerant passing through a condenser H2, is supplied to an air-conditioned space. One of refrigerant circulation states is a first heating circulation state in which the refrigerant is divided after passing through the condenser H2, one of the divided refrigerant returns to the condenser H2 after successively passing through a first expansion valve V1, a first evaporator H1 and a first compressor Cg, and the other divided refrigerant returns to the condenser H2 after successively passing through a second expansion valve V2, a second evaporator H1 and a second compressor Ce, and the other one refrigerant circulation state is a second heating circulation state in which the refrigerant is divided after passing through the condenser H2, one of the divided refrigerant returns to the condenser H2 after successively passing through the first expansion valve V1, the first evaporator H1 and the first compressor Cg, and the other divided refrigerant returns to the condenser H2 after successively passing through a third expansion valve V5, a third evaporator H3 and the second compressor Ce.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an air conditioning system that performs an air conditioning operation in which air conditioning air that has exchanged heat with a refrigerant is supplied to an air conditioning target space.

  As an air-conditioning system that performs air-conditioning operation for supplying air-conditioning air heat-exchanged with refrigerant to an air-conditioning target space, a first compressor that is driven by an engine and compresses the refrigerant and a second compressor that is driven by an electric motor and compresses the refrigerant Some use a heat pump in combination with a compressor.

  In Patent Document 1, a first compressor that is driven by an engine and compresses refrigerant and a second compressor that is driven by an electric motor and compresses refrigerant are provided in parallel in the refrigerant circulation path in the heat pump. . That is, the refrigerant sent out from the first compressor and the refrigerant sent out from the second compressor are merged and then flow through the common condenser, the expansion valve, and the evaporator in order.

JP2013-250004A

In the conventional air conditioning system, each of the first compressor driven by the engine and the second compressor driven by the electric motor does not have any dedicated role, but is merely used together.
In other words, the refrigerant sent from the first compressor driven by the engine and the refrigerant sent from the second compressor driven by the electric motor are allowed to flow through what flow path and how. It is not considered whether to use properly.

  The present invention has been made in view of the above problems, and an object thereof is to provide an air conditioning system in which the flow path of the refrigerant is optimized.

In order to achieve the above object, the air-conditioning system according to the present invention is characterized by an engine, a first compressor that is driven by the engine and compresses refrigerant, a generator that is driven by the engine and generates electric power, An electric motor that operates by preferentially consuming the power supplied from the generator and the power supplied from the generator among the power supplied from the generator and the power received from the power system, and compresses the refrigerant driven by the electric motor. A second compressor, a condenser that dissipates heat from the refrigerant, a first expansion valve that expands the refrigerant, a second expansion valve that expands the refrigerant, a third expansion valve that expands the refrigerant, and a first that causes the refrigerant to absorb heat. An evaporator, a second evaporator that absorbs heat into the refrigerant, a third evaporator that absorbs exhaust heat recovered from the engine into the refrigerant, engine control means for controlling the operation of the engine, and front Power generation control means for controlling the operation of the generator, and the electric motor control means for controlling the operation of the electric motor, and a control device having a circulation path control means for switching the circulation path of the refrigerant,
The control device exchanges heat with the refrigerant flowing through the condenser while switching the refrigerant circulation state under the control of the engine control means, the power generation control means, the electric motor control means, and the circulation path control means. It is configured to perform air conditioning operation to supply air conditioning air to the air conditioning target space,
One of the circulating states of the refrigerant is divided after the refrigerant flows through the condenser, and one of the divided refrigerant passes through the first expansion valve, the first evaporator, and the first compressor. The refrigerant is returned to the condenser after flowing in order, and the other of the divided refrigerant flows through the second expansion valve, the second evaporator, and the second compressor in order, and then the condensation is performed. The first heating circulation state returning to the oven,
Another one of the circulation states of the refrigerant is divided after the refrigerant flows through the condenser, and one of the divided refrigerant is the first expansion valve, the first evaporator, and the first. After passing through the compressor in order, the refrigerant is returned to the condenser, and the other of the divided refrigerant passes through the third expansion valve, the third evaporator, and the second compressor in order. It is in the point which is the 2nd heating circulation state which returns to the said condenser after flowing.

According to the above characteristic configuration, when the air-conditioning operation is performed in a state where the refrigerant is circulated in the first heating circulation state, the refrigerant sent from the first compressor and the refrigerant sent from the second compressor are merged. An air conditioning operation, that is, a heating operation is performed in which air conditioning air that is supplied to the condenser and heat-exchanged with the refrigerant flowing through the condenser is supplied to the air conditioning target space.
That is, since the first compressor and the second compressor are provided in parallel to the condenser, the refrigerant amount required for the condenser (that is, the refrigerant amount necessary for the air conditioning load) is the first compressor and the second compressor. What is necessary is just to share with 2 compressors and to send. In addition, since the engine output is supplied to the first compressor and the generator, and the electric power generated by the generator is preferentially consumed by the electric motor that drives the second compressor, the engine output is the first output. It will be used to drive the compressor and the second compressor. By using the first compressor and the second compressor together in such a form, for example, all the output of the engine is supplied to the first compressor, and all of the refrigerant amount required in the condenser is the first. The engine can be operated in a state where a large torque can be obtained by lowering the rotational speed of the engine as compared with the case of supplying from the compressor.

In addition, when the air conditioning operation is performed in a state where the refrigerant is circulated in the second heating circulation state, one of the refrigerants after being divided on the downstream side of the condenser is the first expansion valve, the first evaporator, After passing through the first compressor in order, the refrigerant is returned to the condenser, and the other refrigerant after being divided on the downstream side of the condenser is the third expansion valve, the third evaporator, and the second compressor. And then return to the condenser. That is, in the third evaporator, the exhaust heat recovered from the engine can be effectively used in order to cause the refrigerant to absorb heat. In particular, since the exhaust heat recovered from the engine is higher than the heat recoverable from the atmosphere or the like, the evaporation temperature of the refrigerant in the third evaporator can be increased, and the power of the second compressor can be reduced.
As described above, since the first compressor and the second compressor can be used together and the air conditioning capacity can be gained by the heat absorption of the refrigerant by the third evaporator, for example, the refrigerant amount sent from the first compressor is relatively The engine can be operated in a state where a large torque can be obtained with a small amount (that is, a relatively low rotational speed of the gas engine). As a result, the engine can be operated efficiently.

Another characteristic configuration of the air conditioning system according to the present invention is that the control device verifies the temperature of the refrigerant while circulating the refrigerant in the second heating circulation state at a predetermined timing during the air conditioning operation. Perform refrigerant temperature verification process,
In the refrigerant temperature verification process, when it is determined that the temperature of the refrigerant in the third evaporator is higher than the temperature of the refrigerant in the first evaporator, the refrigerant circulation state is changed to the second heating circulation state and thereafter Let the air conditioning operation
In the refrigerant temperature verification process, when it is determined that the refrigerant temperature in the third evaporator is equal to or lower than the refrigerant temperature in the first evaporator, the refrigerant circulation state is changed to the first heating circulation state and thereafter The air conditioning operation is performed.

  When the refrigerant is circulated in the second heating circulation state and the heating effect on the refrigerant in the third evaporator is greater, the temperature of the refrigerant in the third evaporator is also equal to the heating of the refrigerant. The temperature of the refrigerant in the first evaporator is increased. Therefore, in the refrigerant temperature verification process, when it is determined that the refrigerant temperature in the third evaporator is higher than the refrigerant temperature in the first evaporator, the refrigerant circulation state is changed to the second heating circulation state and the subsequent air conditioning is performed. By performing the operation, an effect of heating the refrigerant by the third evaporator can be obtained.

  In contrast, when the refrigerant is circulating in the second heating circulation state, when the heating effect on the refrigerant by the first evaporator is greater, or when the heating effect on the refrigerant by both is equal The temperature of the refrigerant in the third evaporator is equal to or lower than the temperature of the refrigerant in the first evaporator where the refrigerant is also heated. Therefore, in the refrigerant temperature verification process, when it is determined that the refrigerant temperature in the third evaporator is equal to or lower than the refrigerant temperature in the first evaporator, the refrigerant circulation state is changed to the first heating circulation state and the subsequent air conditioning By performing the operation, the effect of heating the refrigerant by the first evaporator can be obtained.

Still another characteristic configuration of the air conditioning system according to the present invention is a fourth expansion valve for expanding the refrigerant,
A fourth evaporator that causes the refrigerant to absorb the exhaust heat recovered from the engine,
Another one of the circulation states of the refrigerant when the control device performs the air conditioning operation is that the refrigerant is diverted after flowing through the condenser, and the first expansion valve among the diverted refrigerant is used. And the refrigerant that has passed through the first evaporator and the refrigerant that has passed through the fourth expansion valve and the fourth evaporator have joined together and further passed through the first compressor. Returning to the condenser, and among the divided refrigerant, the refrigerant that has passed through the third expansion valve, the third evaporator, and the second compressor in turn returns to the condenser. It is in a heating circulation state.

According to the above characteristic configuration, when the air conditioning operation is performed in a state where the refrigerant is circulated in the third heating circulation state, one of the refrigerants after being divided on the downstream side of the condenser passes through the first compressor. After flowing, the refrigerant returns to the condenser, and the other refrigerant after being divided on the downstream side of the condenser returns to the condenser after flowing through the second compressor.
Furthermore, a part of the refrigerant that flows through the first compressor is refrigerant that has passed through a fourth evaporator that heats the refrigerant by using exhaust heat recovered from the engine. That is, in the fourth evaporator, the exhaust heat recovered from the engine can be effectively utilized in order to cause the refrigerant to absorb heat. In particular, since the exhaust heat recovered from the engine is higher than the heat recoverable from the atmosphere or the like, the evaporation temperature of the refrigerant in the fourth evaporator can be increased, and the power of the first compressor can be reduced.

Still another characteristic configuration of the air conditioning system according to the present invention is that another one of the circulation states of the refrigerant when the control device performs the air conditioning operation is that the refrigerant sent from the second compressor is: A fourth heating circulation state in which the condenser, the second expansion valve, and the second evaporator are sequentially passed and then returned to the second compressor;
The control device performs the air conditioning operation while circulating the refrigerant in the first heating circulation state or the second heating circulation state when a required load required for the air conditioning operation is a reference load or more, and When the required load is less than the reference load, the air conditioning operation is performed while circulating the refrigerant in the fourth heating circulation state without operating the engine.

  According to the above characteristic configuration, when the required load required for the air-conditioning operation is equal to or higher than the reference load, both the first compressor and the second compressor are operated, so that the refrigerant is in the first heating circulation state or the first 2 Circulate in a heated circulation state. As described above, when the required load required for the air conditioning operation is relatively large, that is, when a relatively large amount of refrigerant is required to flow through the condenser that performs heat exchange between the air for air conditioning and the refrigerant. A relatively large output is required for the driven engine. That is, the air conditioning operation can be performed while operating the engine in a state where the efficiency is high.

On the other hand, when the required load required for air-conditioning operation is relatively small, even if the engine is operated, the engine requires only a relatively small output, so the engine is only in a state where the efficiency is low. Can not work.
Therefore, in the present characteristic configuration, when the required load required for the air conditioning operation is less than the reference load, the second compressor is operated with the electric power received from the electric power system without operating the engine, and the refrigerant is the fourth. Circulate with heating circulation. By performing such an operation, the required load required for the air-conditioning operation can be covered while avoiding a decrease in engine efficiency.

Still another characteristic configuration of the air conditioning system according to the present invention is that the condenser is an indoor heat exchanger that exchanges heat with the air-conditioning air supplied into the air-conditioning target space,
The first evaporator and the second evaporator are outdoor heat exchangers that exchange heat with outside air existing outside the air-conditioning target space.

  According to the said characteristic structure, heating of the air-conditioning object space is carried out using the said condenser comprised with an indoor heat exchanger, and the said 1st evaporator and said 2nd evaporator comprised with an outdoor heat exchanger. You can drive.

It is a figure which shows the structure of an air conditioning system. It is a figure explaining the operation state of the engine and electric motor to air-conditioning load. It is a figure explaining the circulation state of the refrigerant | coolant in a 1st cooling circulation state. It is a figure explaining the circulation state of the refrigerant | coolant in a 2nd air conditioning circulation state. It is a figure explaining the circulation state of the refrigerant | coolant in a 3rd air conditioning circulation state. It is a figure explaining the circulation state of the refrigerant | coolant in a 1st heating circulation state. It is a figure explaining the circulation state of the refrigerant | coolant in a 2nd heating circulation state. It is a figure explaining the circulation state of the refrigerant | coolant in a 3rd heating circulation state. It is a figure explaining the circulation state of the refrigerant | coolant in a 4th heating circulation state.

A configuration of an air conditioning system according to the present invention will be described below with reference to the drawings.
FIG. 1 is a diagram illustrating a configuration of an air conditioning system. As illustrated, the air conditioning system includes an engine E, a first compressor Cg, a generator G, an electric motor M, a second compressor Ce, an outdoor heat exchanger H1, and indoor heat exchange. And a vessel H2. The air conditioning system includes an engine-driven heat pump in which the first compressor Cg driven by the engine E delivers the refrigerant, and a motor-driven heat pump in which the second compressor Ce driven by the electric motor M delivers the refrigerant. Air conditioning operation will be performed in combination.

  The engine E is operated by consuming fuel such as gas or light oil. The first compressor Cg is driven by the engine E to compress and send out the refrigerant. The generator G is driven by the engine E to generate power. Although not shown in FIG. 1, the first compressor Cg and power generation are performed after changing the clutch for turning on and off the driving force transmitted from the engine E to the first compressor Cg and the generator G and the rotational speed of the engine E. A transmission mechanism for transmitting to the machine G may be provided. The operation (for example, rotational speed) of the engine E is controlled by the engine control means 11 included in the control device 10.

  The electric power generated by the generator G is supplied to the power line 2 and can be consumed by the electric motor M connected to the power line 2. The power line 2 is also connected to the power system 1, and the electric motor M can consume the power received from the power system 1. The operation of the generator G (electric power supplied to the electric motor M) is controlled by the power generation control means 12 included in the control device 10. That is, the power generation control means 12 controls the power supplied from the generator G to the power line 2 (electric motor M side), so that the output of the engine E to the first compressor Cg and the second compressor Ce is controlled. Distribution is performed.

  The electric motor M operates by preferentially consuming the power supplied from the generator G and the power supplied from the generator G out of the power received from the power system 1. That is, the power line 2 is supplied from the electric power system 1 with the amount of power consumed by the electric motor M that is insufficient for the power generated by the generator G. The second compressor Ce is driven by the electric motor M and compresses the refrigerant. The operation (for example, rotational speed) of the electric motor M is controlled by the electric motor control means 13 included in the control device 10.

  The refrigerant sent from the first compressor Cg and the second compressor Ce flows through the refrigerant flow path L1. A plurality of valves are provided in the middle of the refrigerant flow path L1, and the circulation path of the refrigerant in the refrigerant flow path L1 is switched by switching the open / close state of these valves. The switching of the refrigerant circulation path (that is, the switching of the valve open / close state) is controlled by the circulation path control means 14 of the control device 10.

In the middle of the refrigerant flow path L1, an outdoor heat exchanger H1 that exchanges heat with the outside air existing outside the air conditioning target space, and an indoor heat exchanger H2 that exchanges heat with the air conditioning air supplied into the air conditioning target space, Is provided. As will be described later, by changing the circulation path of the refrigerant, the outdoor heat exchanger H1 and the indoor heat exchanger H2 are caused to function as a condenser that radiates heat from the refrigerant or an evaporator that absorbs heat from the refrigerant. As a result, cooling operation or heating operation of the air-conditioning target space is performed.
The heat exchanger H4 is a device that exchanges heat without mixing two refrigerants, and can function as, for example, a subcooler that further reduces the temperature of the refrigerant supplied to the indoor heat exchanger H2.

  The indoor heat exchanger H2 is provided with an operation switch SW that receives an instruction from the user regarding the air conditioning operation. For example, the operation switch SW receives a command regarding the operation type such as the cooling operation or the heating operation, the set temperature, the air volume, and the like from the user, and transmits the command to the control device 10. In addition, the temperature of the indoor air sucked into the indoor heat exchanger H2 measured by the temperature sensor T6 is also transmitted to the control device 10. And the control apparatus 10 obtains the information regarding the request | requirement load currently requested | required by the air-conditioning driving | operation from the operating capacity of the indoor unit (indoor heat exchanger H2), the temperature information, and the like. In this case, some of the functions of the control device 10 are arithmetic processing units such as an indoor unit microcomputer included in the indoor unit (indoor heat exchanger H2) and an outdoor unit microcomputer included in the outdoor unit (outdoor heat exchanger H1). It is realized using the function. And the control apparatus 10 switches the operation state of the engine E and the electric motor M according to whether the request | requirement load currently requested | required of air-conditioning driving | operation is more than a reference load or less than a reference load. Specifically, when the required load required for the air conditioning operation is equal to or higher than the reference load, the control device 10 controls both the engine E and the electric motor M (that is, both the first compressor Cg and the second compressor Ce). ) To circulate the refrigerant. Thus, when the required load required for the air conditioning operation is relatively large, that is, when a relatively large amount of refrigerant is required, the driven engine E is required to have a relatively large output. . That is, the air conditioning operation can be performed while operating the engine E in a state where the efficiency is high.

  FIG. 2 is a diagram for explaining output states of the engine E and the electric motor M with respect to the air conditioning load. As shown in FIG. 2, when the required load required for the air conditioning operation is less than the reference load, the control device 10 does not operate the engine E (that is, does not operate the generator G), and the second compressor Ce is operated by the electric motor M using the electric power received from the electric power system 1, and the refrigerant is circulated. That is, when the required load required for the air conditioning operation is less than the reference load, the control device 10 is sent from the second compressor Ce while changing the output state of the electric motor M without operating the engine E. Adjust the amount of refrigerant. This is because even when the required load required for the air-conditioning operation is relatively small, even if the engine E is operated, the engine E requires only a relatively small output, so the engine is only in a state where the efficiency is low. This is a solution to the problem that E cannot be operated. That is, when the control device 10 performs the operation as shown in FIG. 2, it is possible to cover the required load required for the air conditioning operation while avoiding a decrease in the efficiency of the engine E.

  On the other hand, the control device 10 operates both the engine E and the electric motor M when the required load required for the air conditioning operation is equal to or higher than the reference load, and outputs the output state of the engine E and the output of the electric motor M. While changing the state, the refrigerant amount sent from the first compressor Cg and the second compressor Ce is adjusted. Note that when both the engine E and the electric motor M are operated, what values are set for the output state of the engine E and the output state of the electric motor M (that is, the refrigerant amount delivered from the first compressor Cg) And what value the refrigerant amount sent from the second compressor Ce is set to can be changed as appropriate.

  The heat released by operating the engine E is recovered by the cooling water flowing through the cooling water flow path L2. The cooling water flow path L2 is arranged so that the cooling water flows through the engine E and the exhaust heat recovery heat exchanger H3 in order. When the refrigerant flows through the heat exchanger H3 for exhaust heat recovery, heat exchange between the cooling water and the refrigerant is performed, so that the exhaust heat recovered from the engine E is transmitted to the refrigerant. Become. That is, the heat exchanger H3 for exhaust heat recovery functions as a fourth evaporator that causes the refrigerant to absorb the exhaust heat recovered from the engine E, as will be described later.

[Cooling operation]
Next, the operation when the air conditioning system performs the cooling operation will be described. For example, when the user operates the operation switch SW provided in the indoor heat exchanger H2 to command the air conditioning system to perform a cooling operation, the command is transmitted to the control device 10 and will be described later. Cooling operation is performed. When the air conditioning system performs cooling operation, the outdoor heat exchanger H1 functions as a condenser, and the indoor heat exchanger H2 functions as an evaporator.
That is, the air conditioning system during the cooling operation includes the engine E, the first compressor Cg, the generator G, the electric motor M, the second compressor Ce, and the first condenser that radiates heat from the refrigerant (for outdoor use). Heat exchanger H1), a second condenser that radiates heat from the refrigerant (outdoor heat exchanger H1), a first expansion valve (valve V4) that expands the refrigerant, and a second expansion valve (valve V3) that expands the refrigerant. ), An evaporator (indoor heat exchanger H2) for absorbing heat by the refrigerant, a heat exchanger H4 for exchanging heat without mixing the two refrigerants, and the control device 10.

  In the present embodiment, the control device 10 is controlled by the engine control means 11, the power generation control means 12, the electric motor control means 13, and the circulation path control means 14, while switching the refrigerant circulation state. Evaporator) An air-conditioning operation (cooling operation) is performed in which air-conditioning air heat-exchanged with the refrigerant flowing through H2 is supplied to the air-conditioning target space.

FIG. 3 is a diagram for explaining the circulation state of the refrigerant in the first cooling circulation state. In FIG. 3, the refrigerant sent from the first compressor Cg is drawn with a thick solid line, and the refrigerant sent from the second compressor Ce is drawn with a thick broken line. In this case, the engine E operates, and the driving force of the engine E is transmitted to both the first compressor Cg and the generator G. The electric power generated by the generator G is supplied to the electric motor M, and the driving force of the electric motor M is transmitted to the second compressor Ce.
In this first cooling circulation state, the four-way valve V7 is switched so that the refrigerant sent from the first compressor Cg first flows into the outdoor heat exchanger H1. The four-way valve V8 is switched so that the refrigerant sent from the second compressor Ce first flows into the outdoor heat exchanger H1. The valve V1 is opened, the valve V2 is opened, the valve V3 is closed, the valve V4 is opened and functions as an expansion valve (first expansion valve), the valve V5 is closed, and the valve V6 is closed. Then, the refrigerant is divided after passing through the valve (first expansion valve) V4 and the indoor heat exchanger (evaporator) H2 in order, and one of the divided refrigerant is used for the first compressor Cg and the outdoor use. After passing through the heat exchanger (first condenser) H1 in order, the heat is returned to the valve (first expansion valve) V4, and the other of the divided refrigerant is exchanged with the second compressor Ce for outdoor heat. After passing through the condenser (second condenser) H1 in order, it returns to the valve (first expansion valve) V4.

  When the air conditioning operation is performed in a state where the refrigerant is circulated in the first cooling circulation state shown in FIG. 3, the refrigerant sent from the first compressor Cg and the refrigerant sent from the second compressor Ce are merged. The air-conditioning air that has passed through the valve (first expansion valve) V4 and the indoor heat exchanger (evaporator) H2 in order and exchanged heat with the refrigerant flowing through the indoor heat exchanger H2 enters the air-conditioning target space. The supplied air conditioning operation, that is, cooling operation is performed. That is, since the first compressor Cg and the second compressor Ce are provided in parallel to the valve (first expansion valve) V4 and the indoor heat exchanger (evaporator) H2, the indoor heat exchanger (evaporation) The refrigerant amount required for H2 (that is, the refrigerant amount necessary for the air conditioning load) may be shared by the first compressor Cg and the second compressor Ce and sent out. In addition, the output of the engine E is supplied to the first compressor Cg and the generator G, and the generated power of the generator G is consumed by the electric motor M that drives the second compressor Ce. Is used to drive the first compressor Cg and the second compressor Ce. Thus, by using together the 1st compressor Cg and the 2nd compressor Ce, for example, all the outputs of the engine E are supplied to the 1st compressor Cg, and it is with the indoor heat exchanger (evaporator) H2. The engine E can be operated in a state where a large torque can be obtained by lowering the rotational speed of the engine E as compared with the case where all of the required refrigerant amount is supplied from the first compressor Cg.

FIG. 4 is a diagram illustrating the refrigerant circulation state in the second cooling circulation state. In this case, the engine E operates, and the driving force of the engine E is transmitted to both the first compressor Cg and the generator G. The electric power generated by the generator G is supplied to the electric motor M, and the driving force of the electric motor M is transmitted to the second compressor Ce.
In this second cooling circulation state, the four-way valve V7 is switched so that the refrigerant sent from the first compressor Cg first flows into the outdoor heat exchanger H1. The four-way valve V8 is switched so that the refrigerant sent from the second compressor Ce first flows into the outdoor heat exchanger H1. The valve V1 is opened, the valve V2 is closed, the valve V3 is opened and functions as an expansion valve (second expansion valve), the valve V4 is opened and functions as an expansion valve (first expansion valve), and the valve V5 Is closed and the valve V6 is closed. The refrigerant sent out from the first compressor Cg includes an outdoor heat exchanger (first condenser) H1, a heat exchanger H4, a valve (first expansion valve) V4, and an indoor heat exchanger (evaporator). After passing through H2 in order, the refrigerant returns to the first compressor Cg and is sent from the second compressor Ce to the outdoor heat exchanger (second condenser) H1 and the valve (second expansion). Valve) V3 and the heat exchanger H4 are sequentially passed, and then returned to the second compressor Ce. In the outdoor heat exchanger H1, the refrigerant sent from the first compressor Cg and the refrigerant sent from the second compressor Ce are not mixed.

Thus, when the air-conditioning operation is performed in a state where the refrigerant is circulated in the second cooling circulation state, the refrigerant that sequentially flows through the first compressor Cg and the outdoor heat exchanger (first condenser) H1. Flows into the heat exchanger H4, and the refrigerant that has passed through the second compressor Ce, the outdoor heat exchanger (second condenser) H1, and the valve (second expansion valve) V3 sequentially flows into the heat exchanger H4. In the heat exchanger H4, heat is exchanged without mixing the two refrigerants. That is, the heat exchanger H4 uses the refrigerant that has passed through the first compressor Cg and the outdoor heat exchanger (first condenser) H1 in order, the second compressor Ce and the outdoor heat exchanger (second condensation). Device) acts as a subcooler that further cools by the refrigerant that has passed through H1 and the valve (second expansion valve) V3 in order. At this time, the control device 10 controls the operation of the valve (second expansion valve) V3 to adjust the temperature of the refrigerant measured by the temperature sensor T1 downstream of the valve (second expansion valve) V3. Can control the effect of supercooling.
In this way, the first compressor Cg and the second compressor Ce can be used together, and the air conditioning capacity can be gained by supercooling by the heat exchanger H4. For example, the amount of refrigerant sent from the first compressor Cg is relatively Therefore, the engine E can be operated in a state where a large torque can be obtained by reducing the rotational speed of the engine E (ie, the rotational speed of the engine E is relatively slow). As a result, the engine E can be operated efficiently.

  The control device 10 performs switching between the first cooling circulation state and the second cooling circulation state described above. Specifically, the control device 10 performs a refrigerant temperature verification process for verifying the temperature of the refrigerant while circulating the refrigerant in the second cooling circulation state at a predetermined timing during the air conditioning operation. In the present embodiment, the refrigerant temperature in the heat exchanger H4 measured by the temperature sensor T1 is compared with the refrigerant temperature in the indoor heat exchanger (evaporator) H2 measured by the temperature sensor T2. . Here, the temperature of the refrigerant in the indoor heat exchanger (evaporator) H2 measured by the temperature sensor T2 is that the refrigerant sent from the first compressor Cg is heated by the outdoor heat exchanger H1, the valve V1, and the heat. It is the temperature of the refrigerant that reaches the indoor heat exchanger (evaporator) H2 through the exchanger H4 and the valve V4, and then flows through the first compressor Cg. The temperature of the refrigerant in the heat exchanger H4 measured by the temperature sensor T1 is such that the refrigerant sent from the second compressor Ce reaches the heat exchanger H4 via the outdoor heat exchanger H1 and the valve V3. Then, the temperature of the refrigerant flowing through the second compressor Ce. In the refrigerant temperature verification process, the control device 10 determines that the refrigerant temperature in the indoor heat exchanger (evaporator) H2 (the refrigerant temperature measured by the temperature sensor T2) is the refrigerant temperature in the heat exchanger H4. When it is determined that the refrigerant temperature is lower than (temperature of the refrigerant measured by the temperature sensor T1), the refrigerant circulation state is changed to the second cooling circulation state, and the subsequent air conditioning operation is performed. In contrast, in the refrigerant temperature verification process, the control device 10 has a refrigerant temperature (T2) in the indoor heat exchanger (evaporator) H2 that is equal to or higher than the refrigerant temperature (T1) in the heat exchanger H4. Is determined, the refrigerant circulation state is changed to the first cooling circulation state, and the subsequent air conditioning operation is performed. As described above, when the refrigerant is circulated in the second cooling circulation state, the temperature of the refrigerant in the heat exchanger H4 measured by the temperature sensor T1 is lowered, and the indoor heat exchange measured by the temperature sensor T2 is performed. When the temperature of the refrigerant in the evaporator (evaporator) H2 is equal to or lower than the temperature of the refrigerant, the power of the second compressor Ce becomes relatively large. However, by switching the refrigerant circulation state to the first cooling circulation state as described above, An increase in power can be suppressed.

  In the drawing, the temperature sensor T1 for measuring the temperature of the refrigerant in the heat exchanger H4 is drawn downstream from the valve V3 and upstream from the heat exchanger H4, and an indoor heat exchanger ( Although the temperature sensor T2 for measuring the temperature of the refrigerant in the evaporator H2 is drawn downstream of the valve V4 and upstream of the indoor heat exchanger (evaporator) H2, the temperature sensor T1 is shown as a heat exchanger. It may be provided downstream of H4, and the temperature sensor T2 may be provided downstream of the indoor heat exchanger (evaporator) H2. However, if the temperature sensor T1 is provided upstream from the heat exchanger H4, the temperature sensor T2 is also provided upstream from the indoor heat exchanger (evaporator) H2, and the temperature sensor T1 is provided from the heat exchanger H4. If provided on the downstream side, the temperature sensor T2 also needs to be provided on the downstream side of the indoor heat exchanger (evaporator) H2. Alternatively, the average value may be derived by providing each temperature sensor on both the upstream side and the downstream side.

FIG. 5 is a diagram illustrating the refrigerant circulation state in the third cooling circulation state. In this case, since the engine E is stopped, the first compressor Cg does not operate. And the electric power received from the electric power grid | system 1 is supplied to the electric motor M, and the driving force of the electric motor M is transmitted to the 2nd compressor Ce.
In this third cooling circulation state, the four-way valve V8 is switched so that the refrigerant sent from the second compressor Ce first flows into the outdoor heat exchanger (second condenser) H1. The valve V1 is closed, the valve V2 is opened, the valve V3 is closed, the valve V4 is opened and functions as an expansion valve (first expansion valve), the valve V5 is closed, and the valve V6 is closed. The refrigerant delivered from the second compressor Ce passes through the outdoor heat exchanger (second condenser) H1, the valve (first expansion valve) V4, and the indoor heat exchanger (evaporator) H2 in order. After flowing, it returns to the second compressor Ce.

When the required load required for the air conditioning operation is equal to or higher than the reference load, the control device 10 performs the air conditioning operation while circulating the refrigerant in the first cooling circulation state or the second cooling circulation state. In addition, as described above, the control device 10 circulates the refrigerant in the first cooling circulation state based on the verification result in the refrigerant temperature verification process, or circulates the refrigerant in the second cooling circulation state. Switch what to do.
On the other hand, when the required load acquired by the operation switch SW is less than the reference load, the control device 10 does not operate the engine E (that is, does not operate the generator G) and operates the second compressor Ce. Operated by the motor M, the refrigerant is circulated in the third cooling circulation state. By performing such an operation, the required load required for the air-conditioning operation can be covered while avoiding a decrease in the efficiency of the engine E.

[Heating operation]
Next, the operation when the air conditioning system performs the heating operation will be described. For example, when the user operates the operation switch SW provided in the indoor heat exchanger H2 to command the air conditioning system to perform a heating operation, the command is transmitted to the control device 10 and will be described later. Heating operation is performed. When the air conditioning system performs heating operation, the outdoor heat exchanger H1 functions as an evaporator, and the indoor heat exchanger H2 functions as a condenser.
That is, the air conditioning system during heating operation includes an engine E, a first compressor Cg, a generator G, an electric motor M, a second compressor Ce, and a condenser that radiates heat from the refrigerant (indoor heat exchange). H2), a first expansion valve (valve V1) for expanding the refrigerant, a second expansion valve (valve V2) for expanding the refrigerant, a third expansion valve (valve V5) for expanding the refrigerant, and the refrigerant absorbing heat. A first evaporator (outdoor heat exchanger H1) to be made, a second evaporator (outdoor heat exchanger H1) to absorb heat in the refrigerant, and a third evaporator (into the refrigerant to absorb the exhaust heat recovered from the engine E) A heat exchanger H3) for exhaust heat recovery and a control device 10 are provided.
In addition, the air conditioning system during heating operation includes a fourth expansion valve (valve V6) that expands the refrigerant, and a fourth evaporator (exhaust heat recovery heat exchanger) that absorbs the exhaust heat recovered from the engine E. H3).

  In the present embodiment, the control device 10 is controlled by the engine control means 11, the power generation control means 12, the electric motor control means 13, and the circulation path control means 14, while switching the refrigerant circulation state. Condenser) An air conditioning operation (heating operation) is performed in which air conditioning air that has exchanged heat with the refrigerant flowing through H2 is supplied to the air conditioning target space.

  FIG. 6 is a diagram for explaining the circulation state of the refrigerant in the first heating circulation state. In this case, the engine E operates, and the driving force of the engine E is transmitted to both the first compressor Cg and the generator G. The electric power generated by the generator G is supplied to the electric motor M, and the driving force of the electric motor M is transmitted to the second compressor Ce. In the first heating circulation state, the four-way valve V7 is switched so that the refrigerant sent from the first compressor Cg first flows into the indoor heat exchanger H2. The four-way valve V8 is switched so that the refrigerant sent from the second compressor Ce first flows into the indoor heat exchanger H2. The valve V1 is opened and functions as an expansion valve (first expansion valve), the valve V2 is opened and functions as an expansion valve (second expansion valve), the valve V3 is closed, the valve V4 is opened, and the valve V5 Is closed and the valve V6 is closed. Then, the refrigerant is divided after flowing through the indoor heat exchanger (condenser) H2, and one of the divided refrigerant is the valve (first expansion valve) V1 and the outdoor heat exchanger (first evaporator). ) After passing H1 and the first compressor Cg in order, they are returned to the indoor heat exchanger (condenser) H2, and the other of the divided refrigerant is the valve (second expansion valve) V2 and the outdoor After passing through the heat exchanger (second evaporator) H1 and the second compressor Ce in order, the air is returned to the indoor heat exchanger (condenser) H2.

  When the air conditioning operation is performed in a state where the refrigerant is circulated in the first heating circulation state shown in FIG. 6, the refrigerant sent out from the first compressor Cg and the refrigerant sent out from the second compressor Ce are merged. Is supplied to the indoor heat exchanger (condenser) H2, and the air-conditioning operation in which the air-conditioning air exchanged with the refrigerant flowing through the indoor heat exchanger (condenser) H2 is supplied to the air-conditioning target space. Heating operation is performed. That is, since the first compressor Cg and the second compressor Ce are provided in parallel to the indoor heat exchanger (condenser) H2, the amount of refrigerant required in the indoor heat exchanger (condenser) H2 (In other words, the amount of refrigerant necessary for the air conditioning load) may be shared and sent by the first compressor Cg and the second compressor Ce. In addition, the output of the engine E is supplied to the first compressor Cg and the generator G, and the generated power of the generator G is consumed by the electric motor M that drives the second compressor Ce. Is used to drive the first compressor Cg and the second compressor Ce. Thus, by using together the 1st compressor Cg and the 2nd compressor Ce, for example, all the output of the engine E is supplied to the 1st compressor Cg, and all the refrigerant | coolants amount required by an evaporator is used. As compared with the case where the engine E is supplied from the first compressor Cg, the rotational speed of the engine E can be lowered and the engine E can be operated in a state where a large torque can be obtained. As a result, the engine E can be operated efficiently.

  FIG. 7 is a diagram illustrating a refrigerant circulation state in the second heating circulation state. In this case, the engine E operates, and the driving force of the engine E is transmitted to both the first compressor Cg and the generator G. The electric power generated by the generator G is supplied to the electric motor M, and the driving force of the electric motor M is transmitted to the second compressor Ce. In the second heating circulation state, the four-way valve V7 is switched so that the refrigerant sent from the first compressor Cg first flows into the indoor heat exchanger H2. The four-way valve V8 is switched so that the refrigerant sent from the second compressor Ce first flows into the indoor heat exchanger H2. The valve V1 is opened and functions as an expansion valve (first expansion valve), the valve V2 is closed, the valve V3 is closed, the valve V4 is opened, and the valve V5 is opened and the expansion valve (third expansion valve). And the valve V6 is closed. Then, the refrigerant is divided after flowing through the indoor heat exchanger (condenser) H2, and one of the divided refrigerant is the valve (first expansion valve) V1 and the outdoor heat exchanger (first Evaporator) H1 and first compressor Cg are sequentially passed through, and then returned to indoor heat exchanger (condenser) H2, and the other refrigerant after the flow-divided is a valve (third expansion valve). ) V5, exhaust heat recovery heat exchanger (third evaporator) H3, and second compressor Ce are sequentially passed, and then returned to the indoor heat exchanger (condenser) H2.

When the air conditioning operation is performed in a state where the refrigerant is circulated in the second heating circulation state, one of the refrigerants after being divided on the downstream side of the indoor heat exchanger (condenser) H2 is a valve (first expansion). Valve) V1, outdoor heat exchanger (first evaporator) H1, and first compressor Cg are passed in order, and then returned to the indoor heat exchanger (condenser) H2, and indoor heat exchange is performed. The other refrigerant after being divided on the downstream side of the condenser (condenser) H2 is the valve (third expansion valve) V5, the exhaust heat recovery heat exchanger (third evaporator) H3, the second compressor Ce, Are sequentially passed through and then returned to the indoor heat exchanger (condenser) H2. That is, in the heat exchanger for recovering exhaust heat (third evaporator) H3, the exhaust heat recovered from the engine E can be effectively used in order to absorb heat by the refrigerant. In particular, since the exhaust heat recovered from the engine E is higher than the heat recoverable from the atmosphere or the like, the evaporation temperature of the refrigerant in the exhaust heat recovery heat exchanger (third evaporator) H3 can be increased. The power of the second compressor Ce can be reduced.
Thus, since the first compressor Cg and the second compressor Ce can be used together and the air conditioning capacity can be gained by the heat absorption of the refrigerant by the exhaust heat recovery heat exchanger (third evaporator) H3, for example, the first compressor The engine E can be operated in a state where a large torque can be obtained by relatively reducing the amount of refrigerant delivered from the compressor Cg (that is, relatively slowing the rotational speed of the engine E). As a result, the engine E can be operated efficiently.

  The control device 10 performs switching between the first heating circulation state and the second heating circulation state described above. Specifically, the control device 10 performs a refrigerant temperature verification process for verifying the temperature of the refrigerant while circulating the refrigerant in the second heating circulation state at a predetermined timing during the air conditioning operation. In the present embodiment, the temperature of the refrigerant in the exhaust heat recovery heat exchanger (third evaporator) H3 measured by the temperature sensor T3 and the outdoor heat exchanger (first evaporator) measured by the temperature sensor T4. ) The refrigerant temperature at H1 is compared. Here, the temperature of the refrigerant in the outdoor heat exchanger (first evaporator) H1 measured by the temperature sensor T4 reaches the outdoor heat exchanger (first evaporator) H1 via the valve V1, and then It is the temperature of the refrigerant flowing through the first compressor Cg. The temperature of the refrigerant in the exhaust heat recovery heat exchanger (third evaporator) H3 measured by the temperature sensor T3 reaches the exhaust heat recovery heat exchanger (third evaporator) H3 via the valve V5. Then, the temperature of the refrigerant flowing through the second compressor Ce. Then, in the refrigerant temperature verification process, the control device 10 determines that the refrigerant temperature in the exhaust heat recovery heat exchanger (third evaporator) H3 (the refrigerant temperature measured by the temperature sensor T3) is an outdoor heat exchanger. (First evaporator) When it is determined that the temperature of the refrigerant in H1 is higher than the temperature of the refrigerant (the temperature of the refrigerant measured by temperature sensor T4), the refrigerant circulation state is changed to the second heating circulation state, and the subsequent air conditioning operation is performed. . On the other hand, in the refrigerant temperature verification process, the control device 10 uses the temperature of the refrigerant in the exhaust heat recovery heat exchanger (third evaporator) H3 (the temperature of the refrigerant measured by the temperature sensor T3) for outdoor use. When it is determined that the temperature of the refrigerant in the heat exchanger (first evaporator) H1 is equal to or lower than the temperature of the refrigerant (the temperature of the refrigerant measured by the temperature sensor T4), the refrigerant is circulated in the first heating circulation state and then air-conditioned. Let's drive.

  In the figure, the temperature sensor T3 for measuring the temperature of the refrigerant in the exhaust heat recovery heat exchanger (third evaporator) H3 is downstream of the valve V5 and the exhaust heat recovery heat exchanger (third evaporation). The temperature sensor T4, which is drawn upstream of the H3 and measures the temperature of the refrigerant in the outdoor heat exchanger (first evaporator) H1, is downstream of the valve V1 and the outdoor heat exchanger. (First evaporator) Although drawn on the upstream side of H1, the temperature sensor T3 may be provided downstream of the exhaust heat recovery heat exchanger (third evaporator) H3, and the temperature sensor T4 is provided outdoors. The heat exchanger (first evaporator) H1 may be provided on the downstream side. However, if the temperature sensor T3 is provided upstream of the exhaust heat recovery heat exchanger (third evaporator) H3, the temperature sensor T4 is also provided upstream of the outdoor heat exchanger (first evaporator) H1. If the temperature sensor T3 is provided downstream of the exhaust heat recovery heat exchanger (third evaporator) H3, the temperature sensor T4 is also provided downstream of the outdoor heat exchanger (first evaporator) H1. It is necessary to provide it. Alternatively, the average value may be derived by providing each temperature sensor on both the upstream side and the downstream side.

  When the refrigerant is circulated in the second heating circulation state shown in FIG. 7 and the heating effect on the refrigerant in the exhaust heat recovery heat exchanger (third evaporator) H3 is greater, the exhaust is recovered. The refrigerant temperature (T3) in the heat recovery heat exchanger (third evaporator) H3 is the same as the refrigerant temperature (T4) in the outdoor heat exchanger (first evaporator) H1 where the refrigerant is also heated. ) Will be higher. Therefore, in the refrigerant temperature verification process, the refrigerant temperature (T3) in the exhaust heat recovery heat exchanger (third evaporator) H3 is equal to the refrigerant temperature (T4) in the outdoor heat exchanger (first evaporator) H1. ) When it is determined that the refrigerant is higher, the refrigerant is in the second heating circulation state and the subsequent air conditioning operation is performed, whereby the exhaust heat recovery heat exchanger (third evaporator) H3 is used to heat the refrigerant. An effect can be obtained.

  In contrast, when the refrigerant circulates in the second heating circulation state, the heating effect on the refrigerant by the outdoor heat exchanger (first evaporator) H1 is greater or the heating by both of the refrigerants. When the effects of the above are equal, the temperature (T3) of the refrigerant in the heat exchanger for recovering exhaust heat (third evaporator) H3 is the same as that for the outdoor heat exchanger (first evaporation) where the refrigerant is also heated. The temperature of the refrigerant at H1 is equal to or lower than the temperature (T4). Therefore, in the refrigerant temperature verification process, the refrigerant temperature (T3) in the exhaust heat recovery heat exchanger (third evaporator) H3 is equal to the refrigerant temperature (T4) in the outdoor heat exchanger (first evaporator) H1. ) When it is determined that the refrigerant is in the following condition, the refrigerant circulation state is changed to the first heating circulation state, and the subsequent air conditioning operation is performed, so that the effect of heating the refrigerant by the outdoor heat exchanger (first evaporator) H1 is achieved. Can be obtained.

FIG. 8 is a diagram illustrating the refrigerant circulation state in the third heating circulation state. In the third heating circulation state, the flow path of the refrigerant sent from the first compressor Cg is different from the second heating circulation state, and the flow path of the refrigerant sent from the second compressor Ce is the second heating heating state. Same as the circulation state.
In this case, the engine E operates, and the driving force of the engine E is transmitted to both the first compressor Cg and the generator G. The electric power generated by the generator G is supplied to the electric motor M, and the driving force of the electric motor M is transmitted to the second compressor Ce. In the third heating circulation state, the four-way valve V7 is switched so that the refrigerant sent from the first compressor Cg first flows into the indoor heat exchanger H2. The four-way valve V8 is switched so that the refrigerant sent from the second compressor Ce first flows into the indoor heat exchanger H2. The valve V1 is opened and functions as an expansion valve (first expansion valve), the valve V2 is closed, the valve V3 is closed, the valve V4 is opened, and the valve V5 is opened and the expansion valve (third expansion valve). The valve V6 is opened and functions as an expansion valve (fourth expansion valve). Then, the refrigerant is divided after flowing through the indoor heat exchanger (condenser) H2, and among the divided refrigerant, the valve (first expansion valve) V1 and the outdoor heat exchanger (first evaporator). ) The refrigerant that has passed through H1 in order, the refrigerant that has passed through the valve (fourth expansion valve) V6 and the heat exchanger for exhaust heat recovery (fourth evaporator) H3 join together, and further the first compressor After flowing through Cg, the flow returns to the indoor heat exchanger (condenser) H2, and among the divided refrigerant, the valve (third expansion valve) V5 and the exhaust heat recovery heat exchanger (third The refrigerant that has passed through the evaporator H3 and the second compressor Ce in turn returns to the indoor heat exchanger (condenser) H2.

  When the air conditioning operation is performed in a state where the refrigerant is circulated in the third heating circulation state shown in FIG. 8, one of the refrigerants after being divided on the downstream side of the indoor heat exchanger (condenser) H2 is 1 After flowing through the compressor Cg, the refrigerant is returned to the indoor heat exchanger (condenser) H2, and the other refrigerant after being divided on the downstream side of the indoor heat exchanger (condenser) H2, After flowing through the second compressor Ce, it returns to the indoor heat exchanger (condenser) H2. Further, a part of the refrigerant flowing through the first compressor Cg sequentially passed through the exhaust heat recovery heat exchanger (fourth evaporator) H3 that heats the refrigerant using the exhaust heat recovered from the engine E. Refrigerant. That is, in the heat exchanger for recovering exhaust heat (fourth evaporator) H3, the exhaust heat recovered from the engine E can be effectively used in order to absorb heat by the refrigerant. In particular, since the exhaust heat recovered from the engine E is higher than the heat recoverable from the atmosphere or the like, the evaporation temperature of the refrigerant in the exhaust heat recovery heat exchanger (fourth evaporator) H3 can be increased. The power of the first compressor Cg can be reduced.

Whether the refrigerant circulates in the second heating circulation state or whether the refrigerant is circulated in the third heating circulation state, is the refrigerant recovering sufficient heat in the outdoor heat exchanger (first evaporator) H1? It can be switched based on whether or not.
For example, the control device 10 causes the refrigerant to circulate in the second heating circulation state if the temperature of the outside air supplied to the outdoor heat exchanger (first evaporator) H1 is equal to or higher than the reference outside air temperature, and the outdoor heat exchanger (First evaporator) When the temperature of the outside air supplied to H1 is lower than the reference outside air temperature, switching is performed such that the refrigerant is circulated in the third heating circulation state.
Alternatively, for example, if the evaporation temperature of the refrigerant in the outdoor heat exchanger (first evaporator) H1 (the refrigerant temperature measured by the temperature sensor T4) is equal to or higher than the reference refrigerant temperature, the control device 10 It is determined that sufficient heat can be recovered by the outdoor heat exchanger (first evaporator) H1, the refrigerant is circulated in the second heating circulation state, and the outdoor heat exchanger (first evaporator) H1 is used. If the evaporation temperature of the refrigerant (the temperature of the refrigerant measured by the temperature sensor T4) is lower than the reference refrigerant temperature, the refrigerant has not recovered sufficient heat in the outdoor heat exchanger (first evaporator) H1. It determines and circulates a refrigerant | coolant in a 3rd heating circulation state.

  FIG. 9 is a diagram illustrating the refrigerant circulation state in the fourth heating circulation state. In this case, since the engine E is stopped, the first compressor Cg does not operate. And the electric power received from the electric power grid | system 1 is supplied to the electric motor M, and the driving force of the electric motor M is transmitted to the 2nd compressor Ce. In the fourth heating circulation state, the four-way valve V8 is switched so that the refrigerant sent from the second compressor Ce first flows into the indoor heat exchanger H2. The valve V1 is closed, the valve V2 is opened and functions as an expansion valve (second expansion valve), the valve V3 is closed, the valve V4 is opened, the valve V5 is closed, and the valve V6 is closed. The refrigerant delivered from the second compressor Ce passes through the indoor heat exchanger (condenser) H2, the valve (second expansion valve) V2, and the outdoor heat exchanger (second evaporator) H1 in this order. After flowing, it returns to the second compressor Ce.

  The control device 10 operates both the first compressor Cg and the second compressor Ce when the required load required for the air-conditioning operation is equal to or higher than the reference load, and causes the refrigerant to be in the first heating circulation state or the first heating state. It circulates in 2 heating circulation state or the said 3rd heating circulation state. As described above, when the required load required for the air conditioning operation is relatively large, that is, the amount of refrigerant to be passed through the indoor heat exchanger (condenser) H2 that performs heat exchange between the air for air conditioning and the refrigerant is small. When a relatively large amount is required, the driven engine E is required to have a relatively large output. That is, the air conditioning operation can be performed while operating the engine E in a state where the efficiency is high. Then, as described above, the control device 10 circulates the refrigerant in the first heating circulation state based on the verification result in the refrigerant temperature verification processing, or the refrigerant is in the second heating circulation state or the second heating circulation state. 3 Switch whether to circulate in the heating circulation state. Furthermore, as described above, the control device 10 switches whether the refrigerant is circulated in the second heating circulation state or the refrigerant is circulated in the third heating circulation state based on, for example, the outside air temperature.

  On the other hand, when the required load required for the air conditioning operation is less than the reference load, the engine E is not operated (that is, the generator G is not operated), and the second compressor Ce is received from the power system 1. The electric power is operated to circulate the refrigerant in the fourth heating circulation state. By performing such an operation, the required load required for the air-conditioning operation can be covered while avoiding a decrease in the efficiency of the engine E.

<Another embodiment>
<1>
In the said embodiment, although the specific example was given and demonstrated about the structure of the air conditioning system of this invention, the structure can be changed suitably. For example, the handling of the refrigerant flow path L1 through which the refrigerant flows, the installation location of each valve, and the like can be changed as appropriate.

<2>
The control device 10 may switch the circulation state of the refrigerant with reference to the measurement result of the temperature sensor T5 that measures the temperature of the cooling water after recovering the exhaust heat from the engine E. For example, when the engine E is started, high-temperature exhaust heat cannot be recovered from the engine E. Therefore, the refrigerant recovers sufficiently high-temperature heat even if heat is exchanged by the exhaust heat recovery heat exchanger H3. I can't. Therefore, the control device 10 prevents the refrigerant from flowing through the exhaust heat recovery heat exchanger H3 when the coolant temperature (exhaust heat temperature) measured by the temperature sensor T5 is equal to or lower than the lower limit temperature. That is, when the cooling water temperature (exhaust heat temperature) measured by the temperature sensor T5 is equal to or lower than the lower limit temperature, the control device 10 performs the air conditioning operation with the refrigerant circulation state set to the first heating circulation state described above. When the coolant temperature (exhaust heat temperature) measured by the sensor T5 is higher than the lower limit temperature, the refrigerant may be circulated in the second heating circulation state or the third heating circulation state described above to perform the air conditioning operation.

<3>
In the above embodiment, an example in which only one indoor heat exchanger H2 is provided has been described. However, a plurality of indoor heat exchangers H2 may be provided. And as the temperature of the refrigerant in the indoor heat exchanger H2 described in the above embodiment (the temperature of the refrigerant measured by the temperature sensor T2), the average value of the refrigerant temperature in the plurality of indoor heat exchangers H2 Etc. may be adopted.

<4>
In the above embodiment, the control device 10 may switch between the first cooling circulation state and the second cooling circulation state based on another determination criterion.
For example, the controller 10 determines that the temperature of the indoor air sucked into the indoor heat exchanger H2 (the temperature of the indoor air measured by the temperature sensor T6) is the temperature of the outdoor air sucked into the outdoor heat exchanger H1 (temperature sensor). When it is determined that the temperature is lower than the temperature of the air measured in T7, the refrigerant circulation state is changed to the second cooling circulation state, and the subsequent air conditioning operation is performed. On the other hand, when the control device 10 determines that the temperature (T6) of the indoor air sucked into the indoor heat exchanger H2 is equal to or higher than the temperature (T7) of the outside air, the circulation state of the refrigerant is changed to the first cooling circulation. The air conditioning operation is performed after that. Here, when a plurality of indoor heat exchangers H2 are provided, the average value of the temperature of the indoor air sucked into each of the plurality of indoor heat exchangers H2 is the temperature of the indoor air described above. May be adopted.

In addition, the control device 10 may switch between the first cooling circulation state and the second cooling circulation state based on whether or not the supercooling effect is obtained.
For example, the control device 10 performs a refrigerant temperature verification process for verifying the temperature of the refrigerant while circulating the refrigerant in the second cooling circulation state at a predetermined timing during the air conditioning operation. In this refrigerant temperature verification process, the control device 10 flows between the outdoor heat exchanger H1 and the heat exchanger (supercooler) H4 in the middle of the circulation system of the refrigerant sent from the first compressor Cg. The temperature of the refrigerant (the temperature of the refrigerant measured by the temperature sensor T4) is compared with the temperature of the refrigerant flowing between the heat exchanger H4 and the valve V4 (the temperature of the refrigerant measured by the temperature sensor T8). Here, the refrigerant temperature (T4) flowing between the outdoor heat exchanger H1 and the heat exchanger (supercooler) H4 is the refrigerant temperature before the supercooling, and the heat exchanger H4 and the valve V4. The temperature (T8) of the refrigerant flowing between the two is the temperature of the refrigerant after being supercooled. That is, the control device 10 compares the refrigerant temperatures before and after the supercooling by the heat exchanger (supercooler) H4. And the control apparatus 10 is the temperature of the refrigerant | coolant which the temperature (T8) of the refrigerant | coolant which flows between the heat exchanger H4 and the valve V4 flows between the outdoor heat exchanger H1 and the heat exchanger (supercooler) H4. When the temperature is lower than the predetermined temperature by (T4) or more, it is determined that a relatively large supercooling effect is obtained, and the air conditioning operation is performed in a state where the refrigerant is circulated in the second cooling circulation state. On the other hand, the control device 10 determines that the temperature (T8) of the refrigerant flowing between the heat exchanger H4 and the valve V4 is between the outdoor heat exchanger H1 and the heat exchanger (supercooler) H4. When the refrigerant temperature (T4) is not lower than the predetermined temperature by a predetermined temperature or more, it is determined that a relatively large supercooling effect is not obtained, and the air conditioning operation is performed with the refrigerant circulated in the first cooling circulation state. Do.

  INDUSTRIAL APPLICABILITY The present invention can be used for an air conditioning system in which the refrigerant flow path is optimized.

1 Power system H1 Outdoor heat exchanger (evaporator, condenser)
H2 Indoor heat exchanger (evaporator, condenser)
H3 Waste heat recovery heat exchanger (evaporator)
H4 subcooler (heat exchanger)
Cg 1st compressor Ce 2nd compressor G Generator E Engine M Electric motor V1 Valve (expansion valve)
V2 valve (expansion valve)
V3 valve (expansion valve)
V4 valve (expansion valve)
V5 valve (expansion valve)
V6 valve (expansion valve)
DESCRIPTION OF SYMBOLS 10 Control apparatus 11 Engine control means 12 Electric power generation control means 13 Electric motor control means 14 Circulation path control means

Claims (5)

Of the engine, the first compressor driven by the engine to compress the refrigerant, the generator driven by the engine to generate power, the power supplied from the generator and the power received from the power system An electric motor that operates by preferentially consuming electric power supplied from the generator, a second compressor that is driven by the electric motor to compress the refrigerant, a condenser that dissipates heat from the refrigerant, and a second that expands the refrigerant. 1 expansion valve, a second expansion valve for expanding the refrigerant, a third expansion valve for expanding the refrigerant, a first evaporator for absorbing heat into the refrigerant, a second evaporator for absorbing heat into the refrigerant, and recovered from the engine A third evaporator that absorbs exhaust heat into the refrigerant, engine control means for controlling the operation of the engine, power generation control means for controlling the operation of the generator, and operations of the electric motor. Gosuru electric motor control means, and a control device having a circulation path control means for switching the circulation path of the refrigerant,
The control device exchanges heat with the refrigerant flowing through the condenser while switching the refrigerant circulation state under the control of the engine control means, the power generation control means, the electric motor control means, and the circulation path control means. It is configured to perform air conditioning operation to supply air conditioning air to the air conditioning target space,
One of the circulating states of the refrigerant is divided after the refrigerant flows through the condenser, and one of the divided refrigerant passes through the first expansion valve, the first evaporator, and the first compressor. The refrigerant is returned to the condenser after flowing in order, and the other of the divided refrigerant flows through the second expansion valve, the second evaporator, and the second compressor in order, and then the condensation is performed. The first heating circulation state returning to the oven,
Another one of the circulation states of the refrigerant is divided after the refrigerant flows through the condenser, and one of the divided refrigerant is the first expansion valve, the first evaporator, and the first. After passing through the compressor in order, the refrigerant is returned to the condenser, and the other of the divided refrigerant passes through the third expansion valve, the third evaporator, and the second compressor in order. The air conditioning system which is the 2nd heating circulation state which returns to the said condenser after flowing. The control device performs a refrigerant temperature verification process for verifying the temperature of the refrigerant while circulating the refrigerant in the second heating circulation state at a predetermined timing during the air conditioning operation,
In the refrigerant temperature verification process, when it is determined that the temperature of the refrigerant in the third evaporator is higher than the temperature of the refrigerant in the first evaporator, the refrigerant circulation state is changed to the second heating circulation state and thereafter Let the air conditioning operation
In the refrigerant temperature verification process, when it is determined that the refrigerant temperature in the third evaporator is equal to or lower than the refrigerant temperature in the first evaporator, the refrigerant circulation state is changed to the first heating circulation state and thereafter The air conditioning system according to claim 1, wherein the air conditioning operation is performed. A fourth expansion valve for expanding the refrigerant;
A fourth evaporator that causes the refrigerant to absorb the exhaust heat recovered from the engine,
Another one of the circulation states of the refrigerant when the control device performs the air conditioning operation is that the refrigerant is diverted after flowing through the condenser, and the first expansion valve among the diverted refrigerant is used. And the refrigerant that has passed through the first evaporator and the refrigerant that has passed through the fourth expansion valve and the fourth evaporator have joined together and further passed through the first compressor. Returning to the condenser, and among the divided refrigerant, the refrigerant that has passed through the third expansion valve, the third evaporator, and the second compressor in turn returns to the condenser. The air conditioning system according to claim 1 or 2, which is in a heating circulation state. Another one of the circulation states of the refrigerant when the control device performs the air conditioning operation is that the refrigerant sent from the second compressor is the condenser, the second expansion valve, and the second evaporator. And the fourth heating circulation state of returning to the second compressor after sequentially passing
The control device performs the air conditioning operation while circulating the refrigerant in the first heating circulation state or the second heating circulation state when a required load required for the air conditioning operation is a reference load or more, and The air conditioning system according to any one of claims 1 to 3, wherein when the required load is less than the reference load, the air conditioning operation is performed while circulating the refrigerant in the fourth heating circulation state without operating the engine. . The condenser is an indoor heat exchanger that exchanges heat with the air-conditioning air supplied into the air-conditioning target space,
The air conditioning system according to any one of claims 1 to 4, wherein the first evaporator and the second evaporator are outdoor heat exchangers that exchange heat with outside air existing outside the air-conditioning target space.

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