CN100462649C - air conditioner - Google Patents

Abstract

An air conditioning device capable of controlling the temperature of cooling water without using a wax-lined three-way valve. An auxiliary evaporator (15) is provided in the refrigerant circuit, and the cooling water circuit is provided with a main cooling path, a flow channel for the cooling water flowing through the engine (31) to flow back into the cooling water pump (39) via the radiator (20). The cooling water from the engine (31) flows back through the auxiliary evaporator (15) into the secondary cooling path of the cooling water pump (39) and the electric three-way valve (37) that distributes the cooling water to the main cooling path and the secondary cooling path. When the cooling water temperature is lower than the target temperature, based on the temperature difference between the cooling water temperature and the target temperature, the cooling water is allocated to both the main cooling path and the secondary cooling path, or all the cooling water is allocated to the secondary cooling path, and at the same time , reduce the rotating speed of the cooling water pump (39).

Description

air conditioner

technical field

The present invention relates to a gas heat pump type air conditioner in which a compressor is driven by a gas engine; in particular, it relates to a technique for maintaining the temperature of cooling water for cooling the gas engine.

Background technique

Now, it is well known that there is a refrigerant circuit that connects a compressor driven by an internal combustion engine, that is, a gas engine, a four-way valve, an outdoor heat exchanger, and a room heat exchanger, and a cooling water circuit that sends cooling water to the above-mentioned engine by a cooling water pump to cool the gas engine. Loop gas heat pump air conditioning unit. (For example, refer to Patent Document 1).

In addition, it is also known that in the above-mentioned air-conditioning device, in order to control the cooling water temperature, a wax-lined three-way valve (automatic temperature control valve) is provided on the outlet side of the engine, and is used to The temperature of the cooling water should be raised, the engine outlet side of the cooling water and the suction side of the cooling water pump should be short-circuited, and the cooling water should not flow through the outdoor heat exchanger.

[Patent Document 1]

Japanese Patent Application Publication No. 2003-232582.

However, in the prior art, there is a problem that the cost is increased because the wax-lined three-way valve is used to control the temperature of the cooling water; Cooling water temperature problem.

Contents of the invention

In view of the above problems, the present invention aims to provide an air conditioner capable of controlling the temperature of cooling water without using a wax-lined three-way valve.

In order to achieve the above object, the present invention is an air conditioner, which has: a refrigerant circuit connected with a compressor driven by an engine, a four-way valve, an outdoor heat exchanger, and an indoor heat exchanger, and is sent to the engine by a cooling water pump for cooling. water to cool the cooling water circuit of the above-mentioned engine. In this air conditioner, in the above-mentioned refrigerant circuit, an auxiliary evaporator for cooling the cooling water circulation of the above-mentioned engine is provided; Flow into the main cooling path of the cooling water pump, the cooling water flowing through the engine flows back into the auxiliary cooling path of the cooling water pump through the auxiliary evaporator, and the electric tee that distributes the cooling water to the main cooling path and the auxiliary cooling path Valve, when the temperature of the cooling water is lower than the target temperature, based on the temperature difference between the temperature of the cooling water and the target temperature, the electric three-way valve is controlled, so that the cooling water is distributed between the main cooling path and the secondary cooling path or distribute all of the cooling water to the sub-cooling path, and reduce the rotation speed of the cooling water pump.

In addition, in the present invention, in the above invention, when the temperature of the cooling water is higher than the target temperature, the rotation speed of the cooling water pump is increased based on the temperature difference between the cooling water temperature and the target temperature.

In addition, according to the present invention, in one of the above-mentioned inventions, a bypass path for bypassing the auxiliary evaporator while dividing the cooling water flowing in the sub-cooling path is provided in the sub-cooling path.

In addition, in the present invention, in one of the above-mentioned inventions, the refrigerant circuit has an expansion valve for changing the flow rate of the refrigerant flowing into the auxiliary evaporator via the outdoor heat exchanger, and when the temperature of the cooling water is lower than the target temperature, the refrigerant circuit is reduced. By reducing the opening degree of the expansion valve, the flow rate of the refrigerant flowing into the auxiliary evaporator is reduced.

According to the present invention, the temperature of cooling water can be controlled without using a wax-lined three-way valve.

Description of drawings

FIG. 1 is a schematic diagram showing the structure of an air-conditioning apparatus according to an embodiment of the present invention;

Fig. 2 is a graph for explaining maintaining cooling water temperature control;

Fig. 3 is a graph for explaining the control to maintain the cooling water temperature.

Detailed ways

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a schematic structural diagram of a gas heat pump air conditioner 100 . In this figure, the refrigerant circuit is indicated by a thick dotted line, and the cooling water circuit is indicated by a thick solid line. The air conditioner 100 has an indoor unit 1 and an outdoor unit 3 ; the indoor unit 1 is provided with an indoor heat exchanger 7 with a flow divider 5 , a fan 9 , and the like. In addition, on the side of the outdoor unit 3, as the main components of the refrigerant circuit, a compressor 11, an electromagnetic four-way valve 13, an auxiliary evaporator 15 (sub-evaporator), an outdoor heat exchanger 19 with a flow divider 17, and a fan are installed. 21. Expansion valve 72, etc.; as the main components of the cooling water circuit, an engine 31, an exhaust heat exchanger 33, an electric three-way valve 37, an electric AC pump that is a cooling water pump 39, and a radiator (air heat exchanger) 20 are provided. wait. In the figure, 43 is an exhaust pipe connected to the exhaust heat exchanger 33, 45 is a frequency converter for controlling the speed of the cooling water pump 39, 47 is a fan motor for driving the fan 21, and 49 is connected to the engine 31 and the compressor 11. flexible couplings. The expansion valve 72 adjusts the flow rate of the refrigerant flowing back from the indoor heat exchanger 7 to the outdoor heat exchanger 19, and the radiator 20 radiates heat from the cooling water. In order to suppress the thermal influence on the outdoor heat exchanger 19 , the radiator 20 is disposed downwind of the fan 21 with respect to the outdoor heat exchanger 19 .

A control unit 61 is provided inside the outdoor unit 3, which drives and controls the four-way valve 13, the electric three-way valve 37, the frequency converter 45, the fan motor 47, and the like. The control unit 61 is firstly composed of a CPU, and is composed of an input/output interface, a ROM, a RAM, a timer, etc., and the water temperature detector 63 provided on the cooling water pipe 87 on the outlet side of the engine 31 is connected to the input interface. , the heat exchange temperature detector 65 installed on the outdoor heat exchanger 19, the exhaust temperature detector 67 arranged on the exhaust pipe 43, the outside air temperature detector 69 installed on the outer wall surface, etc. In addition, the control unit 61 is connected to a control unit (not shown) on the side of the indoor unit 1, and mutually performs signal reception and transmission.

Next, the flow of the refrigerant will be described. During heating operation, the liquid refrigerant flows from the refrigerant pipe 71 to the side of the outdoor unit 3, passes through the expansion valve 72, the flow divider 17, the outdoor heat exchanger 19, the refrigerant pipe 75, the four-way valve 13, and the refrigerant pipe 77, and then flows into the auxiliary evaporator 15. , is heated between passing through two heat exchangers 19,15. In addition, in the auxiliary evaporator 15, a double-pipe type in which cooling water passes through the refrigerant piping is adopted; in the outdoor heat exchanger 19, a plate fin type structure is adopted in which the refrigerant piping and the cooling water piping are connected through plate fins (refer to FIG. 1 outdoor heat exchanger 19 and radiator 20). The gas refrigerant heated in both heat exchangers 19 and 15 flows into the compressor 11 through the refrigerant piping 78 and is further heated by being compressed there. The high-temperature gas refrigerant discharged from the compressor 11 flows into the indoor heat exchanger 7 on the side of the indoor unit 1 through the refrigerant piping 79, the four-way valve 13, and the refrigerant piping 81, and releases heat to the air discharged into the room by the fan 9 for heating. It becomes liquid refrigerant, and flows into the outdoor unit 3 side from the refrigerant piping 71 again.

In this way, inside the outdoor unit 3, the auxiliary evaporator 15 for utilizing the heat of the cooling water of the engine 31 during the heating operation and the exhaust gas heat exchanger for utilizing the heat of the exhaust gas of the engine 31 during the heating operation are provided. 33, therefore, during heating operation, sufficient heating can be performed even when the outside air temperature is low.

In addition, during cooling operation, the four-way valve 6 is switched. That is, the high-temperature gas refrigerant discharged from the compressor 11 flows into the outdoor heat exchanger 19 through the refrigerant piping 79 , the four-way valve 13 , and the refrigerant piping 75 , where it is cooled and liquefied by the low-temperature external air. The liquefied refrigerant flows into the indoor heat exchanger 7 on the side of the indoor unit 1 through the refrigerant piping 71, absorbs heat from the indoor air and evaporates, flows into the outdoor unit 3 through the refrigerant piping 81, passes through the four-way valve 13, the refrigerant piping 77, The auxiliary evaporator 15 , the refrigerant piping 78 , and then flows into the compressor 78 . Here, during the cooling operation, except during the warm-up operation and when the cooling water temperature is low, the cooling water circulation to the auxiliary evaporator 15 is stopped, and the refrigerant heating is not performed in the auxiliary evaporator 15 .

Hereinafter, the configuration of the cooling water circuit will be described in more detail.

As shown in Figure 1, the cooling water circuit has the following functions: the cooling water discharged from the cooling water pump 39 passes through the exhaust heat exchanger 33, the engine 31, the electric three-way valve 37, and the radiator 20 in turn, and flows back into the main circuit of the cooling water pump 39. In addition to the cooling path, there is also a secondary cooling water path in which the cooling water discharged from the engine 31 flows back into the cooling water pump 39 via the electric three-way valve 37 and the auxiliary evaporator 15 .

Now, the flow of cooling water during the heating operation will be described. The cooling water discharged from the cooling water pump 39 flows into the exhaust heat exchanger 33 through the cooling water pipe 85 , is heated by the exhaust gas, and then flows into the engine 31 . The engine 31 is cooled to become high-temperature cooling water, and the high-temperature cooling water flows into the radiator 20 through the cooling water pipe 87, the electric three-way valve 37, and the cooling water pipe 89 to release heat energy. Further, the cooling water that has released thermal energy in the radiator 20 flows back into the cooling water pump 39 through the cooling water pipe 91 .

Here, during the heating operation, the high-temperature cooling water not only passes through the radiator 20 but also passes through the auxiliary evaporator 15 as will be described later to auxiliary heat the refrigerant. In addition, during the cooling operation, high-temperature cooling water passes only through the radiator 20, where heat energy is released.

In addition, the structure in which the radiator 20 is integrally assembled on the outdoor heat exchanger 19 can also be regarded as a single outdoor heat exchanger that also serves as a condenser for refrigerant and a radiator for cooling water.

On the other hand, in the sub cooling path, the cooling water discharged from the cooling water pump 39 flows into the exhaust heat exchanger 33 through the cooling water pipe 85 , and flows into the engine 31 after being heated by the exhaust gas. Cool the engine 31 and turn it into high-temperature cooling water. During the heating operation, the high-temperature cooling water flows into the auxiliary evaporator 15 through the cooling water pipe 87, the electric three-way valve 37, and the cooling water pipe 95, and releases heat energy by heating the refrigerant. Then, the cooling water released from the auxiliary evaporator 15 joins the cooling water pipe 91 via the cooling water pipes 97 and 91 , and flows back into the cooling water pump 39 via the cooling water pipe 91 .

However, in general, in a gas heat pump type air conditioner, when it is started after a long-term stop, since the cooling water temperature is low, heat exchange with the refrigerant hardly occurs in the auxiliary evaporator, so there is a problem that the heating operation takes time. question. Especially during the severe winter period, the start-up time of the heating operation is long.

Therefore, in the present embodiment, when the temperature of the cooling water is low, the cooling water is circulated only in the sub-cooling passage, so that the temperature of the cooling water is raised rapidly.

More specifically, when starting the engine 31 after a long-time stop, the control unit 61 closes the radiator of the electric three-way valve 37 when the cooling water temperature at the outlet of the engine 31 is lower than the target temperature (70° C. in this embodiment). 20 side and the auxiliary evaporator 15 side is opened to circulate all the cooling water in the auxiliary cooling water path. That is, the auxiliary evaporator 15 has a smaller amount of heat dissipation than the radiator 20 arranged in the main cooling path. Therefore, when the cooling water circulates in the auxiliary cooling path, the drop in water temperature is suppressed, and the temperature drop is smaller than that when the cooling water circulates in the main cooling path. The temperature rises.

Here, using the auxiliary evaporator 15 with a smaller heat dissipation amount than the radiator 20 can not only reduce the heat dissipation amount when the cooling water circulates in the auxiliary cooling path, but also promote a higher temperature rise of the cooling water. However, when the auxiliary evaporator 15 uses an evaporator with too little heat dissipation, depending on the type of the outdoor heat exchanger 19, the pressure loss of the refrigerant may increase, resulting in a decrease in the capacity of the refrigerant circuit.

Therefore, in the present embodiment, as shown in FIG. 1 , a bypass pipe 99 is provided in the above-mentioned sub-cooling path so as to divide the cooling water in front of the auxiliary evaporator 15 so that a part of the cooling water flows through the auxiliary evaporator. 15 bypass (detour), therefore, without increasing the pressure loss of the refrigerant, the amount of heat dissipation of the cooling water in the sub-cooling path can be further suppressed, and the temperature of the cooling water can be raised rapidly. In addition, in the structure in which the bypass pipe 99 is provided in this way, by appropriately changing the diameter of the bypass pipe 99 and changing the ratio of the respective amounts of cooling water flowing into the auxiliary evaporator 15 and the bypass pipe 99, the auxiliary evaporator 15 can be easily adjusted. The amount of heat dissipation in the cooling path.

In this way, when the cooling water temperature is lower than the target temperature, the electric three-way valve 37 is controlled to circulate all the cooling water in the secondary cooling path with a smaller heat dissipation than the main cooling path. Therefore, the cooling water temperature can be raised to reach the target temperature quickly. temperature.

Furthermore, in this embodiment, when the cooling water temperature is lower than the target temperature, in addition to the above-mentioned switching control of the cooling path, the cooling water pump 39 is also driven at the lowest speed lower than the pump speed during normal operation, reducing the number of cooling water circuits. The flow rate of cooling water in the engine 31 is increased, thereby prolonging the residence time of the cooling water in the engine 31 and promoting the temperature of the cooling water to rise. In this way, the cooling water temperature can be brought to the target temperature more quickly.

Moreover, after the cooling water temperature reaches the target temperature, the control unit 61 gradually opens the radiator 20 side of the electric three-way valve 37 , so that the cooling water with a higher temperature will flow into the radiator 20 . As described above, in the present embodiment, since the temperature of the cooling water can be quickly raised to the target temperature after the startup, the warm-up operation can be quickly completed. In addition, even in severe winter when the temperature is low, waste heat can be recovered by the auxiliary evaporator during warming up of the cooling water during the warm-up operation, thereby improving the start-up characteristics of the heating operation.

In addition, in this embodiment, after the cooling water temperature reaches the target temperature, that is, after the warm-up is completed, in order to prevent the moisture contained in the exhaust gas of the engine 31 from being trapped in the exhaust path and the cover of the engine 31 (where the exhaust gas is discharged from the engine 31 Part) condenses and mixes with the engine oil to produce precipitation, and the rotation speed of the cooling water pump 39 is also controlled based on the atmospheric temperature and the cooling water temperature, thereby adjusting the cooling water flow rate and keeping the cooling water temperature at the target temperature.

Specifically, as shown in FIG. 2 , in this embodiment, five judgment temperatures A to E that specify the cooling water temperature range are set, and the cooling water temperature is judged to be one of A to E according to the current cooling water temperature, and the cooling is controlled. The rotating speed of water pump 39. Regarding the judgment temperatures A to E, the details are as follows: the judgment temperature is C when the current cooling water temperature is the target temperature, that is, when the temperature control of the cooling water temperature is not required, and the judgment temperature is when the current cooling water temperature is lower than the target temperature. It is B, when it is lower than the specified temperature, the temperature is judged as A, and based on the current cooling water temperature ratio target, when the temperature is only higher than the specified temperature, it is judged as D, and when it is higher than the specified temperature, it is judged as E.

In addition, during cooling operation and during heating operation, the water temperature conditions required for cooling water such as whether to use cooling water for refrigerant heating are different. Therefore, for the determination temperatures A to E, set different temperature ranges. Furthermore, even during the heating operation, different temperature ranges are set according to the outside air temperature. Specifically, when the air temperature is higher than 5°C during the cooling operation or during the heating operation, the temperature is judged as C when the cooling water temperature is the target temperature, and B is judged as the temperature when the cooling water temperature is 2°C lower than the target temperature, which is 10°C lower than the target temperature. °C, the judgment temperature is A, and when the cooling water temperature is 10 °C higher than the target temperature, the judgment temperature is D, and when the cooling water temperature is 20 °C higher, the judgment temperature is E. In addition, when the air temperature is lower than 5°C during heating operation, the temperature is judged to be C when the cooling water temperature is 2°C lower than the target temperature, B is judged to be when the cooling water temperature is 5°C lower than the target temperature, and B is judged to be when the cooling water temperature is 10°C lower than the target temperature. A, and when the cooling water temperature is the target temperature, the judgment temperature is D, and when it is 10°C higher, the judgment temperature is E.

As described above, when the cooling water temperature is determined to be B or A, it means that the cooling water temperature is lower than the target temperature. Therefore, the rotation speed of the cooling water pump 39 is gradually decreased in order to increase the cooling water temperature. For example, when the current judging temperature of the cooling water temperature is between B and C, the rotation speed of the cooling water pump 39 is reduced by 100 rpm every 200 seconds until the cooling water temperature is above the judging temperature C. In addition, when the cooling water temperature is between A and B, the rotation speed of the cooling water pump 39 is further reduced by 100 rpm, and when the cooling water temperature is below the determination temperature A, the rotation speed of the cooling water pump 39 is further reduced by 200 rpm. As a result, the lower the cooling water temperature is than the target temperature, the more the rotation speed of the cooling water pump 39 is reduced, and the cooling water temperature rises faster, so that the cooling water temperature can quickly reach the target temperature.

On the other hand, when the cooling water temperature is at the determination temperature D, E, it means that the cooling water temperature is higher than the target temperature, so the rotation speed of the cooling water pump 39 is gradually increased in order to suppress the increase in the cooling water temperature. For example, when the current judging temperature of the cooling water temperature is between D and E, the rotation speed of the cooling water pump 39 is increased by 100 rpm every 200 seconds until the cooling water temperature falls below the judging temperature E. In addition, when the cooling water temperature is equal to or higher than the determination temperature E, the rotation speed of the cooling water pump 39 is further increased by 100 rpm. As a result, the higher the cooling water temperature is higher than the target temperature, the more the rotation speed of the cooling water pump 39 is increased to suppress the increase in the cooling water temperature, so that the cooling water temperature can be quickly lowered to the target temperature.

In addition, the setting of the determination temperatures A to E shown in FIG. 2 and the increase (decrease) of the cooling water pump 39 shown in FIG. to change. In addition, during the cooling operation, the cooling water is only circulated in the radiator 20 of the main cooling path, not in the secondary cooling path, and the rotation speed control of the cooling water pump 39 is given priority, thereby performing the control of maintaining the cooling water temperature; When the speed of the cooling water pump 39 is controlled and the temperature of the cooling water does not rise, the cooling water is diverted to the auxiliary cooling path to increase the temperature of the cooling water.

As described above, according to the present embodiment, the following structure is formed: in the refrigerant circuit, the auxiliary evaporator 15 for circulating the cooling water of the engine 31 is provided; The main cooling path of the cooling water pump 39 from the device 20, the cooling water flowing through the engine 31 flows back into the secondary cooling path of the cooling water pump 39 through the auxiliary evaporator 15, and the electric motor that distributes the cooling water to the primary cooling path and the secondary cooling path. Three-way valve 37; when the cooling water temperature is lower than the target temperature, the electric three-way valve 37 is controlled based on the temperature difference between the cooling water temperature and the target temperature. Accordingly, the cooling water is distributed to both the main cooling path and the sub cooling path, or all the cooling water is distributed to the sub cooling path, and at the same time, the rotation speed of the cooling water pump 39 is reduced. Therefore, the following effects are obtained.

That is, the cooling water is also distributed to the sub-cooling path which has a smaller heat dissipation amount than the main cooling path, and further, the cooling water flow rate is reduced by reducing the rotation speed of the cooling water pump 39, thereby suppressing the heat dissipation amount in the radiator 20, and prolonging the cooling time in the engine. 31 residence time, and increase the amount of heat recovery from the engine 31, therefore, to achieve a reduction in cooling water heat dissipation and an increase in heating, as a result, the cooling water temperature rises rapidly.

In particular, during the warm-up operation, all the cooling water is distributed to the sub-cooling path, and the heat dissipation of the cooling water is minimized, so that the temperature of the cooling water can quickly reach the specified target temperature, so that the completion of the warm-up can be shortened. run time.

Also, even if the cooling water temperature drops due to the decrease in the rotation speed of the engine 31 after completion of the warm-up operation, the cooling water temperature can be promoted to increase by reducing the rotation speed of the cooling water pump 39 . At this time, during the heating operation, based on the temperature difference between the cooling water temperature and the target temperature, the cooling water is distributed to both the main cooling path and the sub cooling path, or all the cooling water is distributed to the sub cooling path, thus adjusting the heat dissipation of the cooling water. The amount can correctly control the cooling water temperature.

On the other hand, during cooling operation, in order not to hinder the cooling capacity, when the cooling water temperature is low, all of the cooling water is continuously circulated in the radiator 20 of the main cooling path, and the rotating speed of the cooling water pump 39 is reduced to promote cooling. When the water temperature rises, when the cooling water temperature cannot rise, the cooling water is also distributed to the secondary cooling path, and the heat dissipation of the cooling water is suppressed, and the cooling water temperature is promoted.

In this way, according to the present embodiment, by distributing the cooling water to the main cooling path and the sub cooling path and controlling the rotation speed of the cooling water pump 39, the temperature of the cooling water can be controlled. cut costs.

In addition, according to this embodiment, when the cooling water temperature is higher than the target temperature, the rotation speed of the cooling water pump 39 is increased based on the temperature difference between the cooling water temperature and the target temperature. . Thereby, the cooling water temperature can be maintained at the target temperature.

In addition, according to the present embodiment, the sub-cooling path is provided with a bypass pipe 99 for branching the cooling water flowing through the sub-cooling path and bypassing the sub-evaporator 15 . Therefore, without increasing the pressure loss of the refrigerant, the heat dissipation amount of the cooling water in the sub-cooling path can be further suppressed, and the temperature of the cooling water can be raised rapidly.

The above-mentioned embodiment is merely an example of the present invention and can be modified arbitrarily within the scope of the present invention. For example, in the above-described embodiment, the bypass pipe 99 is provided in the sub-cooling path, thereby reducing the heat dissipation amount of the cooling water in the sub-evaporator 15 . However, it is not limited thereto. When the cooling water temperature is lower than the target temperature, the opening of the expansion valve 72 may be reduced to reduce the flow rate of the refrigerant flowing into the auxiliary evaporator 15. With such a structure, the auxiliary evaporation can be suppressed. The heat dissipation of the cooling water in the device 15. In addition, a bypass pipe 99 may be provided in the sub-cooling path, and the opening degree of the expansion valve 72 may also be controlled.

In addition, in the above-described embodiment, an AC pump is used for the cooling water pump 39 , and the inverter 45 controls the rotation amount of the cooling water pump 39 . However, it is not limited to this, and a DC pump may be used for the cooling water pump 39, and a structure in which the rotation speed can be controlled without using the inverter 45 is also possible.

In addition, a plate heat exchanger may also be used as the auxiliary heat exchanger 15 .

Claims (4)

1. An air conditioner, which has: a refrigerant circuit that is connected to a compressor driven by an engine, a four-way valve, an outdoor heat exchanger, and an indoor heat exchanger, and a cooling water pump is used to input cooling water to the engine to cool the above-mentioned engine. The water circuit is characterized in that: in the above-mentioned refrigerant circuit, an auxiliary evaporator for cooling the cooling water circulation of the above-mentioned engine is provided; The cooling water that flows into the main cooling path of the cooling water pump, the cooling water flowing through the engine flows back into the auxiliary cooling path of the cooling water pump through the auxiliary evaporator, and the electric tee that distributes the cooling water to the main cooling path and the auxiliary cooling path valve, when the temperature of the cooling water is lower than the target temperature, based on the temperature difference between the temperature of the cooling water and the target temperature, the electric three-way valve is controlled, thereby distributing the cooling water to the main cooling path and the secondary cooling Both paths, or all of the cooling water is distributed to the sub-cooling path, and the rotation speed of the cooling water pump is reduced. 2. The air conditioner according to claim 1, wherein when the cooling water temperature is higher than a target temperature, the rotation speed of the cooling water pump is increased based on a temperature difference between the cooling water temperature and the target temperature. 3. The air conditioning apparatus according to claim 1 or 2, wherein a bypass path for bypassing the auxiliary evaporator while diverting the cooling water flowing in the sub cooling path is provided in the sub cooling path. 4. The air conditioning device according to any one of claims 1 or 2, wherein the refrigerant circuit has an expansion valve for changing the flow rate of the refrigerant flowing into the auxiliary evaporator via the outdoor heat exchanger; When the cooling water temperature is lower than the target temperature, the opening degree of the expansion valve is reduced to reduce the flow rate of the refrigerant flowing into the auxiliary evaporator.

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