Air conditioning system

Abstract

To provide a hybrid type air conditioner enabling a high performance operation regardless of required load by making engine cooling water partly bypass when the required load is medium.SOLUTION: An air conditioner includes: an exhaust heat recovery heat exchanger mounted in the middle of an exhaust heat recovery by-pass pipe connecting a first compressor driven by a gas engine and a second compressor driven by an electric motor in parallel and connecting a suction pipe of the second compressor and a liquid refrigerant pipe; a cooling water circuit where the gas engine, the exhaust heat recovery heat exchanger and a pump are annularly connected in order by piping, the cooling water is circulated in the pipe, and the gas engine is cooled; a cooling water by-pass pipe connecting the outflow side and the inflow side of the cooling water of the exhaust heat recovery heat exchanger; and a cooling water flow amount regulating valve provided with the cooling water by-pass pipe.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a hybrid air conditioner that performs air conditioning by connecting a compressor driven by a gas engine (hereinafter referred to as an engine-driven compressor) and a compressor driven by an electric motor (hereinafter referred to as an electric compressor) in parallel.

Background Art

[0002] Patent Document 1 discloses an air conditioner capable of high-efficiency operation regardless of the required load. This air conditioner connects an indoor heat exchanger, an outdoor heat exchanger, an expansion valve, and a four-way valve via refrigerant pipes, and in an air conditioner that connects an engine-driven compressor and an electric compressor in parallel, a bypass pipe that connects the suction pipe of the electric compressor and the liquid refrigerant pipe, an on-off valve provided in the bypass pipe, an exhaust heat recovery heat exchanger, and an on-off valve provided upstream of the connection part between the bypass pipe of the suction pipe of the electric compressor are provided.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The present disclosure provides a hybrid air conditioner capable of high-efficiency operation regardless of the required load by bypassing a part of the engine cooling water when the required load is moderate.

Means for Solving the Problems

[0005] The air conditioning system in this disclosure comprises a first compressor driven by a gas engine and a second compressor driven by an electric motor connected in parallel, and the compressors, an outdoor heat exchanger, an outdoor refrigerant flow control valve, and an indoor heat exchanger connected in a ring in sequence, with refrigerant circulating through the piping, and heat exchange with the indoor air in the indoor heat exchanger to provide indoor air conditioning, wherein the system includes a heat recovery heat exchanger provided in the middle of a heat recovery bypass pipe connecting the suction pipe and liquid refrigerant pipe of the second compressor, and the gas engine, Parallel connected radiators and The aforementioned heat recovery heat exchanger and the pump are connected sequentially in a ring-shaped piping configuration, and cooling water is circulated through the piping to cool the gas engine. This cooling water circuit is connected to the outlet and inlet sides of the cooling water of the heat recovery heat exchanger. And, bypass only the aforementioned heat recovery heat exchanger. The system comprises a cooling water bypass pipe and a cooling water flow control valve provided in the cooling water bypass pipe. The cooling water flow path is used during cooling operation. The aforementioned The radiator side is equipped with a three-way valve that switches between the exhaust heat recovery heat exchanger side or both sides during heating operation. [Effects of the Invention]

[0006] In the air conditioning system described herein, when the air conditioning load decreases to a moderate level and the amount of waste heat from the gas engine decreases, the cooling water flow control valve of the gas engine controls some of the cooling water to flow into the second bypass pipe. As a result, the cooling water that has flowed out of the waste heat recovery heat exchanger merges with the bypassed cooling water and is heated, thereby suppressing the temperature gradient at the gas engine inlet and outlet. Furthermore, because the amount of cooling water flowing into the waste heat recovery heat exchanger decreases, the temperature gradient at the inlet and outlet of the refrigerant heat exchanger becomes smaller, causing the refrigerant heat exchanger outlet temperature to decrease. Therefore, while preventing damage to the gas engine, the amount of cooling water flowing into the heat recovery heat exchanger can be reduced, allowing the refrigerant intake superheat to be maintained below a predetermined temperature while reducing the amount of heat exchanged. As a result, compression power is reduced even under moderate air conditioning loads, and cycle efficiency is improved. [Brief explanation of the drawing]

[0007] [Figure 1] This figure shows the refrigerant flow path and cooling water flow path of an air conditioning system in Embodiment 1 of the present disclosure. [Figure 2]Side view of the outdoor unit in Embodiment 1 of the present disclosure [Figure 3] Front view of the outdoor unit in Embodiment 1 of the present disclosure [Modes for carrying out the invention]

[0008] (Knowledge and other information that formed the basis of this disclosure) Generally, when the air conditioning load decreases to a moderate level, the amount of waste heat from the gas engine decreases. Therefore, the amount of heat exchange between the refrigerant and the cooling water in the waste heat recovery heat exchanger is reduced while the gas engine outlet temperature of the cooling water is controlled to reach the target temperature. In this case, methods to reduce the amount of heat exchange include reducing the amount of cooling water and reducing the amount of refrigerant. However, if the amount of cooling water is reduced, the outlet temperature of the cooling water in the heat exchanger will decrease.

[0009] In conventional configurations, the cooling water circuit lacks a means to raise the cooling water temperature between the outlet of the heat recovery heat exchanger and the gas engine inlet. This results in a large temperature gradient between the gas engine inlet and outlet, causing strain and potentially damaging the gas engine. Therefore, when the amount of refrigerant is reduced while maintaining the amount of cooling water, the refrigerant has a lower specific heat than the cooling water. As a result, the amount of refrigerant reduced is relatively larger than the amount of heat exchanged, and the temperature gradient between the inlet and outlet of the heat recovery heat exchanger for the refrigerant increases. In other words, the outlet temperature of the heat recovery heat exchanger for the refrigerant rises. Consequently, highly superheated refrigerant is drawn into the electric compressor.

[0010] In other words, there is a problem in that it is not possible to maintain the refrigerant intake superheat below a predetermined temperature while reducing the amount of heat exchange. As a result, the inventors discovered that at moderate air conditioning loads, the cycle efficiency decreases due to an increase in compression power, and the subject matter of this disclosure was established in order to solve this problem. Therefore, this disclosure provides a hybrid air conditioning system that enables highly efficient operation regardless of the required load by bypassing some of the engine coolant when the required load is moderate.

[0011] The embodiments will be described in detail below with reference to the drawings. However, unnecessary details may be omitted. For example, detailed explanations of already well-known matters or redundant explanations of substantially identical configurations may be omitted. This is to avoid the following explanation becoming unnecessarily verbose and to facilitate understanding for those skilled in the art. The attached drawings and the following description are provided to enable those skilled in the art to fully understand this disclosure and are not intended to limit the subject matter described in the claims.

[0012] (Embodiment 1) Embodiment 1 will be described below with reference to Figures 1 to 3. [1-1. Structure] [1-1-1. Refrigerant flow path] In Figure 1, the air conditioning system 1 consists of an outdoor unit 100 and an indoor unit 200, and the indoor unit 200 is connected to unit piping 2 extending from the outdoor unit 100. The outdoor unit 100 includes an engine-driven compressor (first compressor) 102 driven by a gas engine 101, an electric compressor (second compressor) 103, an oil separator 104 for separating refrigerant oil contained in the refrigerant discharged from the engine-driven compressor 102 and the electric compressor 103, a four-way valve 105 for switching between cooling and heating refrigeration cycles, an outdoor heat exchanger 106 for exchanging heat between the refrigerant and outside air, and an outdoor refrigerant flow rate control valve 107 for adjusting the flow rate and pressure of the refrigerant. These are connected via refrigerant piping and constitute a part of the refrigerant flow path 3.

[0013] The engine-driven compressor 102 is connected to the gas engine 101 by a power transmission means such as a belt, and is connected in parallel to the electric compressor 103 by piping. The engine-driven compressor 102 employs a compressor with a larger capacity than the electric compressor 103. The accumulator 108 is provided upstream of the branch point between the suction pipe of the engine-driven compressor 102 and the suction pipe of the electric compressor 103, and supplies gas refrigerant to the engine-driven compressor 102 and the electric compressor 103. The liquid refrigerant pipe 109 connects the outdoor heat exchanger 106 and the indoor heat exchanger 201.

[0014] The outdoor fan 110 is provided near the outdoor heat exchanger 106, and promotes heat exchange between the refrigerant and the outside air by introducing the outside air to the outdoor heat exchanger 106. The exhaust heat recovery bypass pipe 111 connects one end to the suction pipe of the electric compressor 103 and the other end to the liquid refrigerant pipe 109, and includes an exhaust heat recovery refrigerant flow rate adjustment valve 112 that adjusts the flow rate and pressure of the refrigerant in order from the upstream side in the refrigerant flow direction, and an exhaust heat recovery heat exchanger 113 that exchanges heat between the refrigerant and the cooling water described later. During heating operation, the refrigerant is configured to be able to absorb heat from the cooling water. The check valve 114 is provided upstream of the connection portion of the suction pipe of the electric compressor 103 with the exhaust heat recovery bypass pipe 111, and prevents the refrigerant flowing out of the exhaust heat recovery bypass pipe from flowing into the suction pipe of the engine-driven compressor 102.

[0015] The indoor unit 200 includes an indoor heat exchanger 201 that exchanges heat between the refrigerant and the air in the space to be air-conditioned, and an indoor refrigerant flow rate adjustment valve 202 that adjusts the flow rate and pressure of the refrigerant. These are connected via a refrigerant pipe and together with the outdoor unit 100, constitute a part of the refrigerant flow path 3. The indoor fan 203 is provided near the indoor heat exchanger 201, and promotes heat exchange between the refrigerant and the air in the space to be air-conditioned by introducing the air in the space to be air-conditioned to the indoor heat exchanger 201. Only one indoor unit 200 is installed, but a plurality of indoor units may be installed in parallel with respect to the outdoor unit 100.

[0016] [1-1-2. Cooling water flow path] In the outdoor unit 100, the cooling water passage 4 includes a cooling water pump 115 that circulates cooling water through the cooling water passage 4, a reservoir tank 116 that temporarily stores excess cooling water to replenish it when cooling water is insufficient, a radiator 117 that exchanges heat between the cooling water and the outside air, a heat recovery heat exchanger 113 that exchanges heat between the cooling water and the refrigerant, and a three-way valve 118 that switches the cooling water passage to the radiator 117 side during cooling operation, to the heat recovery heat exchanger 113 side during heating operation, or to both sides, and the gas engine 101 is cooled by the circulating cooling water. The cooling water bypass pipe 119 has one end connected to the cooling water inlet of the heat recovery heat exchanger 113 and the other end connected to the cooling water outlet of the heat recovery heat exchanger 113, bypassing the heat recovery heat exchanger 113 by allowing a portion of the cooling water to bypass the heat recovery heat exchanger 113 without exchanging heat with the refrigerant. The cooling water flow control valve 120 is installed in the cooling water bypass pipe 119 and adjusts the amount of cooling water flowing into the cooling water bypass pipe 119.

[0017] [1-1-3. Outdoor Unit Configuration] Figure 2 is a side view of the outdoor unit in Embodiment 1 of the present disclosure. Figure 3 is a front view of the outdoor unit in Embodiment 1 of the present disclosure. As shown in Figures 2 and 3, a machine room 121 is provided below the outdoor unit 100, which houses an engine-driven compressor 102, a gas engine 101, an electric compressor 103, an accumulator 108, an oil separator 104 (not shown), a four-way valve 105, an outdoor refrigerant flow control valve 107, a heat recovery heat exchanger 113, etc. A heat exchanger room 122 is provided above the outdoor unit 100, which houses an outdoor heat exchanger 106, an outdoor fan 110, a reservoir tank 116, etc.

[0018] [1-2. Operation] The operation of the air conditioning system 1, configured as described above, will be explained below. [1-2-1. Refrigerant operation] [1-2-1-1. Operation during cooling operation] The outdoor refrigerant flow control valve 107 is opened. The heat recovery refrigerant flow rate control valve 112 and the cooling water flow rate control valve 120 are closed. The three-way valve 118 is switched to a flow path that directs the coolant towards the radiator 117. The high-temperature, high-pressure (e.g., 80°C, 3MPaG) gaseous refrigerant compressed by the engine-driven compressor 102 and the electric compressor 103 merge and flow into the oil separator 104. In the oil separator 104, the highly purified gaseous refrigerant, from which the refrigerant oil has been separated, passes through the four-way valve 105 and flows into the outdoor heat exchanger 106, where it condenses while dissipating heat through heat exchange with the outside air. The liquid refrigerant that flows out of the outdoor heat exchanger 106 then passes through the liquid refrigerant piping 109 and the outdoor refrigerant flow control valve 107 and is supplied to the indoor unit 200.

[0019] The liquid refrigerant flowing into the indoor unit 200 is depressurized by the indoor refrigerant flow control valve 202, becoming a gas-liquid two-phase state, and flows into the indoor heat exchanger 201. In the indoor heat exchanger 201, the gas-liquid two-phase refrigerant exchanges heat with the air in the space to be air-conditioned, absorbing heat and evaporating, and flows out of the indoor unit 200 as a low-temperature, low-pressure (e.g., 16°C, 0.9 MPaG) gaseous refrigerant. The refrigerant gas that has leaked out of the indoor unit 200 flows back into the outdoor unit 100, passes through the four-way valve 105 and the accumulator 108, and returns to the engine-driven compressor 102 and the electric compressor 103, repeating the above process. Furthermore, the refrigerant oil separated by the oil separator 104 passes through an oil return pipe (not shown), flows into the suction pipes of the engine-driven compressor 102 and the electric compressor 103, returns to the engine-driven compressor 102 and the electric compressor 103, and the above process is repeated.

[0020] [1-2-1-2. Operation during rated heating operation] The indoor refrigerant flow control valve 202 is opened. The three-way valve 118 can be switched to a flow path that directs heat to the exhaust heat recovery heat exchanger 113. The high-temperature, high-pressure (e.g., 63°C, 2.2 MPaG) gaseous refrigerant compressed by the engine-driven compressor 102 and the electric compressor 103 merge and flow into the oil separator 104. The highly purified gaseous refrigerant, from which the refrigerant oil has been separated in the oil separator 104, passes through the four-way valve 105 and is supplied to the indoor unit 200. The gaseous refrigerant that flows into the indoor unit 200 condenses in the indoor heat exchanger 201, exchanging heat with the air in the space to be air-conditioned, releasing heat and becoming a high-pressure liquid refrigerant. It then passes through the indoor refrigerant flow control valve 202 and flows out of the indoor unit 200.

[0021] The liquid refrigerant that flows out of the indoor unit 200 flows back into the outdoor unit 100. A portion of the liquid refrigerant that flows into the outdoor unit 100 passes through the heat recovery bypass pipe, is depressurized by the heat recovery refrigerant flow control valve, becomes a gas-liquid two-phase state, and flows into the heat recovery heat exchanger. The remaining liquid refrigerant is depressurized by the outdoor flow control valve 107, becomes a gas-liquid two-phase state, and flows into the outdoor heat exchanger 106.

[0022] The gaseous two-phase refrigerant flowing into the heat recovery heat exchanger 113 evaporates while absorbing heat from the cooling water, becoming a gaseous refrigerant at a medium temperature and medium pressure (e.g., 20°C, 1 MPaG) and a superheat of about 10K, and returns to the electric compressor 103. The gaseous two-phase refrigerant flowing into the outdoor heat exchanger 106 evaporates while exchanging heat with the outside air, becoming a gaseous refrigerant at a low temperature and low pressure (e.g., 2°C, 0.6 MPaG), passing through the four-way valve 105 and the accumulator 108, and returns to the engine-driven compressor 102, and the above process is repeated. Furthermore, the refrigerant oil separated by the oil separator 104 passes through an oil return pipe (not shown), flows into the suction pipes of the engine-driven compressor 102 and the electric compressor 103, returns to the engine-driven compressor 102 and the electric compressor 103, and the above process is repeated.

[0023] [1-2-1-3. Operation during partial load heating operation] The indoor refrigerant flow control valve 202 is opened. The three-way valve 118 can be switched to a flow path that directs heat to the exhaust heat recovery heat exchanger 113. The high-temperature, high-pressure (e.g., 40°C, 1.6 MPaG) gaseous refrigerant compressed by the engine-driven compressor 102 and the electric compressor 103 merge and flow into the oil separator 104. The highly purified gaseous refrigerant, from which the refrigerant oil has been separated in the oil separator 104, passes through the four-way valve 105 and is supplied to the indoor unit 200. The gaseous refrigerant that flows into the indoor unit 200 condenses in the indoor heat exchanger 201, exchanging heat with the air in the space to be air-conditioned, releasing heat and becoming a high-pressure liquid refrigerant. It then passes through the indoor refrigerant flow control valve 202 and flows out of the indoor unit 200.

[0024] The liquid refrigerant that flows out of the indoor unit 200 flows back into the outdoor unit 100. A portion of the liquid refrigerant that flows into the outdoor unit 100 passes through the heat recovery bypass pipe, is depressurized by the heat recovery refrigerant flow control valve, becomes a gas-liquid two-phase state, and flows into the heat recovery heat exchanger. The remaining liquid refrigerant is depressurized by the outdoor flow control valve 107, becomes a gas-liquid two-phase state, and flows into the outdoor heat exchanger 106.

[0025] The gaseous two-phase refrigerant flowing into the heat recovery heat exchanger 113 evaporates while absorbing heat from the cooling water, becoming a gaseous refrigerant at a medium temperature and medium pressure (e.g., 20°C, 1 MPaG) and a superheat of about 10K, and returns to the electric compressor 103. At the same time, the gaseous two-phase refrigerant flowing into the outdoor heat exchanger 106 evaporates while exchanging heat with the outside air, becoming a gaseous refrigerant at a low temperature and low pressure (e.g., 7°C, 0.7 MPaG), passing through the four-way valve 105 and the accumulator 108, and returning to the engine-driven compressor 102, and the above process is repeated. Furthermore, the refrigerant oil separated by the oil separator 104 passes through an oil return pipe (not shown), flows into the suction pipes of the engine-driven compressor 102 and the electric compressor 103, returns to the engine-driven compressor 102 and the electric compressor 103, and the above process is repeated.

[0026] [1-2-2. Operation of the cooling water side] [1-2-2-1. Operation during cooling operation] The three-way valve 118 can be switched to a flow path that directs the coolant towards the radiator 117. The coolant pump 115 pushes the coolant into the exhaust gas heat exchanger 123, which cools the exhaust gas of the gas engine 101. The exhaust gas cooled in the exhaust gas heat exchanger 123 is released into the outside air through the exhaust gas muffler 124. The coolant that flows out of the exhaust gas heat exchanger 123 flows into the gas engine 101, which cools the gas engine 101. The coolant that has cooled the gas engine 101 passes through the three-way valve and flows into the radiator 117. The coolant that flows into the radiator 117 exchanges heat with the outside air to dissipate heat, returns to the coolant pump, and the above process is repeated.

[0027] [1-2-2-2. Operation during rated heating operation] The three-way valve 118 can be switched to a flow path that directs the cooling water towards the heat recovery heat exchanger 113. The cooling water pushed out by the cooling water pump 115 flows into the exhaust gas heat exchanger 123, cooling the exhaust gas of the gas engine 101. The exhaust gas cooled in the exhaust gas heat exchanger 123 is released into the outside air through the exhaust gas muffler 124. The cooling water that flows out of the exhaust gas heat exchanger 123 flows into the gas engine 101, cooling the gas engine 101. The cooling water that has cooled the gas engine 101 (e.g., 60°C) passes through the three-way valve 118 and flows into the waste heat recovery heat exchanger 113. The cooling water that flows into the waste heat recovery heat exchanger 113 exchanges heat with the refrigerant and dissipates heat (e.g., 50°C), then returns to the cooling water pump, and the above process is repeated.

[0028] [1-2-2-3. Operation during partial load heating operation] The three-way valve 118 can be switched to a flow path that directs the cooling water towards the heat recovery heat exchanger 113. The cooling water flow control valve 120 is opened. The cooling water pushed out by the cooling water pump 115 flows into the exhaust gas heat exchanger 123, cooling the exhaust gas of the gas engine 101. The exhaust gas cooled in the exhaust gas heat exchanger 123 is released into the outside air through the exhaust gas muffler 124. The cooling water that flows out of the exhaust gas heat exchanger 123 flows into the gas engine 101, cooling the gas engine 101. The cooling water that has cooled the gas engine 101 (for example, 60°C) passes through the three-way valve 118, with some flowing into the waste heat recovery heat exchanger 113 and the remaining cooling water flowing into the cooling water bypass pipe 119. The cooling water that flows into the heat recovery heat exchanger 113 exchanges heat with the refrigerant and dissipates heat (for example, to 50°C), then merges with the cooling water that flows out from the cooling water bypass pipe 119 (for example, to 60°C), is heated (for example, to 55°C), and then returns to the cooling water pump, repeating the above process.

[0029] [1-3. Effects, etc.] As described above, in this embodiment, the air conditioning system 1 includes an engine-driven compressor 102 driven by a gas engine 101 and an electric compressor 103 driven by an electric motor connected in parallel, a heat recovery heat exchanger 113 provided in the middle of a heat recovery bypass pipe 111 that connects the suction pipe of the electric compressor 103 and the liquid refrigerant pipe 109, a cooling water circuit that connects the gas engine 101, the heat recovery heat exchanger 113 and the pump 115 in a ring shape with cooling water flowing through the pipe to cool the gas engine 101, a cooling water bypass pipe 119 that connects the outlet side and the inlet side of the cooling water of the heat recovery heat exchanger 113, and a cooling water flow rate control valve 120 provided in the cooling water bypass pipe 119. Then, during partial load heating operation, the cooling water flow control valve 120 is opened, allowing the cooling water that has cooled the gas engine 101 to flow to the waste heat recovery heat exchanger 113, and a portion of the cooling water to flow to the cooling water bypass pipe 119.

[0030] As a result, when the air conditioning load decreases to a moderate level and the amount of waste heat decreases, the cooling water flow control valve 120 controls some of the cooling water to flow into the cooling water bypass pipe 119. This causes the cooling water that has flowed out of the waste heat recovery heat exchanger 113 to merge with the bypassed cooling water and be heated, thus suppressing a large increase in the temperature gradient at the inlet and outlet of the gas engine 101. Furthermore, because the amount of cooling water flowing into the heat recovery heat exchanger 113 decreases, the temperature gradient between the refrigerant at the inlet and outlet of the heat recovery heat exchanger 113 becomes smaller, causing the outlet temperature of the refrigerant at the heat recovery heat exchanger 113 to decrease. Therefore, while preventing damage to the gas engine 101, the amount of cooling water flowing into the heat recovery heat exchanger 113 can be reduced, and the refrigerant intake superheat can be maintained at a temperature below a predetermined level while reducing the amount of heat exchange. As a result, compression power is reduced even under moderate air conditioning loads, and cycle efficiency is improved.

[0031] Since the embodiments described above are for illustrative purposes of the technology described herein, various modifications, substitutions, additions, omissions, etc., can be made within the claims or their equivalents. [Industrial applicability]

[0032] This disclosure is applicable to air conditioning systems that are unable to maintain the suction refrigerant superheat of the compressor below a predetermined temperature during partial load operation. Specifically, this disclosure is applicable to hybrid air conditioning systems. [Explanation of symbols]

[0033] 1. Air conditioning system 2 Unit Piping 100 Outdoor Units 101 Gas Engine 102 Engine-driven compressor 103 Electric Compressor 104 Oil Separator 105 Four-way valve 106 Outdoor heat exchanger 107 Outdoor refrigerant flow control valve 108 Accumulator 109 Liquid refrigerant piping 110 Outdoor fan 111 Heat recovery bypass pipe 112 Heat Recovery Refrigerant Flow Control Valve 113 Heat recovery heat exchanger 114 Check valve 115 Cooling water pump 116 Reservoir Tank 117 Radiator 118 Three-way valve 119 Cooling water bypass pipe 120 Cooling water flow control valve 121 Machine room 122 Heat exchanger room 123 Exhaust gas heat exchanger 124 Exhaust gas muffler 200 Indoor Units 201 Indoor heat exchanger 202 Indoor refrigerant flow control valve 203 Indoor Fan

Claims

1. In an air conditioning system that connects a first compressor driven by a gas engine and a second compressor driven by an electric motor in parallel, and connects the compressors, outdoor heat exchanger, outdoor refrigerant flow control valve, and indoor heat exchanger in a ring in sequence, circulates refrigerant through the piping, and performs indoor air conditioning by exchanging heat with the indoor air in the indoor heat exchanger, A heat recovery heat exchanger is provided in the middle of the heat recovery bypass pipe that connects the suction pipe and liquid refrigerant pipe of the second compressor, The gas engine, a radiator and a heat recovery heat exchanger connected in parallel, and a pump are sequentially connected in a ring-shaped piping arrangement, and cooling water is circulated through the piping to cool the gas engine in a cooling water circuit. A cooling water bypass pipe connects the outlet and inlet sides of the cooling water of the aforementioned heat recovery heat exchanger, and bypasses only the heat recovery heat exchanger. The cooling water bypass pipe is provided with a cooling water flow control valve, The system includes a three-way valve that switches the flow path of the cooling water to the radiator side during cooling operation, to the exhaust heat recovery heat exchanger side during heating operation, or to both sides. Air conditioning system.

2. During partial load heating operation, the cooling water flow control valve is opened, allowing the cooling water used to cool the gas engine to flow to the heat recovery heat exchanger, and a portion of the cooling water to flow to the cooling water bypass pipe. The air conditioning device according to claim 1.

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