JP6379633B2 - Engine driven air conditioner - Google Patents

Description

  The present invention relates to an engine-driven air conditioner.

  An engine-driven air conditioner having a water-cooled engine has an engine exhaust heat exchanger that makes thermal contact between a refrigerant and engine cooling water. By recovering the engine exhaust heat in the refrigerant by the engine exhaust heat exchanger, an efficient air conditioning operation can be performed.

  In addition, the engine-driven air conditioner is equipped with a radiator, and when the temperature of the cooling water is too high, the cooling water temperature is lowered by flowing the cooling water through the radiator, which causes problems such as engine seizure. Occurrence is prevented. Therefore, the cooling water circuit provided in the engine-driven air conditioner has a flow path for flowing cooling water to the engine exhaust heat exchanger side and a flow path for flowing to the radiator side. In this case, the cooling water flow path is a temperature-sensitive flow path so that the cooling water flows through the engine exhaust heat exchanger when the cooling water temperature is low and the cooling water flows through the radiator when the cooling water temperature is high. It is switched by a switching valve.

  Patent Document 1 discloses an engine-driven air conditioner including a cooling water circuit configured to switch a cooling water flow path using two flow path switching valves (a low temperature valve and a high temperature valve). The cooling water circuit described in Patent Document 1 includes a first flow path in which the cooling water that has cooled the engine flows into the engine again without heat exchange, and the cooling water that has cooled the engine is an engine exhaust heat exchanger (waste A second flow path that flows into the engine after heat exchange in the heat recovery unit, and a third flow path that flows into the engine after the cooling water that has cooled the engine has been heat exchanged with the radiator.

  According to Patent Document 1, the cooling water that has cooled the engine is first introduced into the low-temperature valve. If the temperature of the cooling water introduced into the low-temperature valve is equal to or lower than a predetermined low temperature, the cooling water flows through the cooling water circuit along the first flow path. On the other hand, if the cooling water introduced into the low temperature valve is at or above a predetermined low temperature, the cooling water is then introduced into the high temperature valve. If the temperature of the cooling water introduced into the high temperature valve is below a predetermined high temperature, the cooling water flows through the cooling water circuit along the second flow path. On the other hand, if the temperature of the cooling water introduced into the high temperature valve is equal to or higher than a predetermined high temperature, the cooling water follows the third flow path and flows through the cooling water circuit. In this way, the flow path of the cooling water is switched to one of the three flow paths by the two valves.

JP 2006-308277 A (FIG. 1)

(Problems to be solved by the invention)
Since the cooling water circuit described in Patent Document 1 uses two flow path switching valves to switch the flow path, there is a problem that the cost for configuring the cooling water circuit is high. A temperature-sensitive wax valve is generally used as the flow path switching valve, but the temperature responsiveness of the wax valve is poor, so that the flow path cannot be switched reliably according to the temperature. For example, in Patent Document 1, when the switching temperature of the flow path in the low temperature valve is Ta, the low temperature valve starts the switching operation of the flow path only after the temperature of the cooling water reaches the temperature Ta from a temperature lower than the temperature Ta. Therefore, when the switching of the flow path is completed, that is, when the switching operation of the low temperature valve is completed, the temperature of the cooling water is stabilized at a temperature Tb higher than Ta. In this case, when the temperature of the cooling water is Ta to Tb, a sufficient amount of cooling water does not flow to the exhaust heat exchanger, and the engine exhaust heat cannot be sufficiently recovered. That is, in the conventional method, the temperature of the cooling water flowing into the engine exhaust heat exchanger cannot be maintained at an appropriate temperature, specifically, an optimum temperature at which the heat exchange efficiency is most improved.

  An object of the present invention is to provide an engine-driven air conditioner that can be configured at low cost and can sufficiently recover engine exhaust heat.

(Means for solving the problem)
The present invention includes a refrigerant circuit formed by connecting a compressor, a condenser, an expansion valve, and an evaporator driven by a water-cooled engine, and cooling water enclosed therein, and the enclosed cooling water is An engine that exchanges heat between the cooling water circuit configured to recirculate through the engine to cool the engine and the cooling water that has cooled the engine so that the refrigerant flowing in the refrigerant circuit is heated. When the temperature of the exhaust water heat exchanger, the radiator that dissipates the cooling water that has cooled the engine, and the temperature of the cooling water that has cooled the engine is equal to or lower than a predetermined first temperature, the cooling water that has cooled the engine is the engine exhaust heat heat exchange When the temperature of the cooling water that has cooled the engine is equal to or higher than the first temperature, the cooling water that has cooled the engine passes through the radiator and passes through the radiator. A flow path switching valve for switching the flow path of the cooling water flowing in the cooling water circuit so as to flow through the inflow flow path, and the temperature of the cooling water that has cooled the engine approaches a second temperature lower than the first temperature. A control device that controls the flow rate of the refrigerant flowing through the engine exhaust heat exchanger or the flow rate of the cooling water flowing through the cooling water circuit based on the temperature of the cooling water that has cooled the engine , and the control device cools the engine The coolant temperature is higher than an appropriate temperature range set on the basis of the second temperature as a temperature range in which the heat of the coolant can be efficiently transferred to the refrigerant in the engine exhaust heat exchanger, and the refrigerant If the degree of superheat of the refrigerant flowing through the circuit is lower than the proper range, the flow rate of the cooling water flowing through the cooling water circuit Ru is configured to increase, to provide an engine driving type air conditioner.

  In this case, when the temperature of the cooling water that has cooled the engine is lower than the second temperature, the control device flows through the engine exhaust heat exchanger so that the flow rate of the refrigerant flowing through the engine exhaust heat exchanger decreases. The flow rate of the refrigerant may be controlled. The second temperature may be a temperature that is predetermined as a temperature at which the efficiency of heat exchange between the refrigerant and the cooling water by the engine exhaust heat exchanger is the highest. The engine-driven air conditioner according to the present invention also includes a refrigerant flow rate adjustment valve that adjusts the flow rate of the refrigerant that flows to the engine exhaust heat exchanger, and the flow of the cooling water in the cooling water circuit and the flow of the cooling water circuit. And a cooling water pump capable of adjusting a flow rate of the cooling water. The control device then opens the opening of the refrigerant flow rate adjustment valve based on the temperature of the cooling water that has cooled the engine so that the temperature of the cooling water that has cooled the engine is maintained at a second temperature lower than the first temperature. It is preferable to control the discharge flow rate of the cooling water pump. The engine exhaust heat exchanger may be interposed in the refrigerant circuit so that the refrigerant that has flowed out of the condenser is in thermal contact with the cooling water that has cooled the engine. In this case, the engine exhaust heat exchanger may be interposed in a bypass pipe connecting a refrigerant pipe connecting the condenser and the evaporator and a refrigerant pipe connecting the evaporator and the compressor.

  According to the present invention, the flow path of the cooling water is switched between the flow path through the radiator and the flow path through the engine exhaust heat exchanger by one flow path switching valve. Further, the control device controls the flow rate of the refrigerant flowing through the engine exhaust heat exchanger or the flow rate of the cooling water flowing through the cooling water circuit so that the temperature of the cooling water that has cooled the engine approaches the second temperature. Since the second temperature is lower than the first temperature, the cooling water whose temperature is controlled so as to approach the second temperature mainly flows through the exhaust heat exchanger. That is, according to the present invention, the temperature of the cooling water flowing through the exhaust heat exchanger can be maintained at the second temperature. Therefore, by setting the second temperature to a temperature at which the heat exchange efficiency in the engine exhaust heat exchanger is highest, the engine exhaust heat is sufficiently recovered in the engine exhaust heat exchanger.

  Further, when the temperature of the cooling water that has cooled the engine (that is, that has flowed out of the engine) is lower than the second temperature, the flow rate of the refrigerant flowing to the engine exhaust heat exchanger is reduced by the control device. The amount of heat exchange with is reduced. Thereby, the temperature fall of the cooling water by an engine exhaust heat exchanger is restrict | limited, and a cooling water can be raised to an appropriate temperature rapidly. That is, according to the present invention, the low temperature valve described in Patent Document 1 is eliminated, and instead, the engine exhaust heat heat when the coolant temperature is low by the flow rate control of the refrigerant flowing through the engine exhaust heat exchanger. Restricts heat exchange in the exchanger. Therefore, the flow path switching valve (the low temperature valve described in Patent Document 1) that is necessary when the cooling water temperature is low can be eliminated.

  Thus, according to the present invention, it is possible to provide an engine-driven air conditioner that can be configured at low cost and can sufficiently recover engine exhaust heat.

  The second temperature may be a temperature region having a predetermined temperature range. The control device controls the flow rate of the refrigerant flowing into the engine exhaust heat exchanger or the flow rate of the cooling water so that the cooling water temperature is maintained within a temperature range having a predetermined temperature range. Occurrence of problems such as control hunting due to changes or frequent changes in the coolant flow rate can be prevented.

  Further, the control device is configured to control the flow rate of the refrigerant flowing into the engine exhaust heat exchanger or the cooling water circuit based on the degree of superheat so that the degree of superheat of the refrigerant flowing in the refrigerant circuit falls within a predetermined range. It is better to control the flow rate of the cooling water flowing through. In this case, the superheat degree is the superheat degree of the refrigerant flowing out from the engine exhaust heat exchanger or the superheat degree of the refrigerant sucked into the compressor, that is, the superheat degree of the refrigerant on the suction side of the compressor. It is good. The predetermined range may be a range between a lower limit value and an upper limit value of the degree of superheat set in advance. Here, the lower limit value of the degree of superheat is a value that does not cause the compressor to cause liquid compression of the refrigerant because the refrigerant sucked into the compressor is wet. Further, the upper limit value of the degree of superheat is such a value that the density of the refrigerant sucked into the compressor is not lowered and the operation efficiency is not significantly lowered. An example of such a range of superheat is a range of greater than 0 ° C. and less than 10 ° C.

  According to this, in addition to maintaining the appropriate temperature of the cooling water flowing through the engine exhaust heat exchanger, the superheat degree of the refrigerant can also be maintained in an appropriate range, so the temperature control of the cooling water according to the present invention When the above is executed, the occurrence of problems due to the degree of superheat becoming too small or too large, for example, the liquid compression in the compressor described above, or the reduction in operating efficiency is effectively prevented. Can be prevented.

It is a figure which shows the structure of the engine drive type air conditioner concerning this embodiment. It is a flowchart which shows the control routine which a control apparatus performs. It is a flowchart which shows the control routine which a control apparatus performs. It is a flowchart which shows the control routine which a control apparatus performs.

(First embodiment)
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating a configuration of an engine-driven air conditioner according to the present embodiment. As shown in FIG. 1, the engine-driven air conditioner 1 according to this embodiment includes a water-cooled gas engine 10, a refrigerant circuit 20, a cooling water circuit 40, and a control device 50.

  The refrigerant circuit 20 includes a compressor 21, an oil separator 22, a four-way valve 23, an indoor heat exchanger 24, an outdoor heat exchanger 25, an expansion valve 26, an accumulator 28, and a refrigerant pipe 29 connecting them. Is provided. The refrigerant is filled in the refrigerant pipe 29. The refrigerant pipe 29 includes a first refrigerant pipe 291, a second refrigerant pipe 292, a third refrigerant pipe 293, a fourth refrigerant pipe 294, a fifth refrigerant pipe 295, and a bypass pipe 296. The refrigerant pipe 29 is filled with a refrigerant. As shown in FIG. 1, the refrigerant circuit 20 is formed by connecting at least a compressor 21, an indoor heat exchanger 24, an expansion valve 26, and an outdoor heat exchanger 25.

  The compressor 21 is connected to the gas engine 10 and operates using the driving force of the gas engine 10 as a power source. The compressor 21 has a suction port 21a and a discharge port 21b. The suction port 21 a is connected to one end of the fifth refrigerant pipe 295, and the discharge port 21 b is connected to one end of the first refrigerant pipe 291. The compressor 21 operates to suck the refrigerant gas from the suction port 21a, compress the refrigerant gas therein, and discharge the compressed refrigerant gas from the discharge port 21b.

  The oil separator 22 is interposed in the first refrigerant pipe 291. The oil separator 22 collects the lubricating oil discharged from the discharge port 21 b of the compressor 21 and returns the collected lubricating oil to the suction port 21 a side of the compressor 21.

  The four-way valve 23 is connected to the other end of the first refrigerant pipe 291. In addition to the first refrigerant pipe 291, a second refrigerant pipe 292, a fourth refrigerant pipe 294, and a fifth refrigerant pipe 295 are connected to the four-way valve 23. The four-way valve 23 includes a switching state during heating in which the first refrigerant pipe 291 is connected to the second refrigerant pipe 292 and the fourth refrigerant pipe 294 is connected to the fifth refrigerant pipe, and the first refrigerant pipe 291 is the fourth refrigerant pipe. The cooling state switching state in which the second refrigerant pipe 292 is connected to the second refrigerant pipe 295 and the second refrigerant pipe 292 is connected to the second refrigerant pipe 295 is selectively realized.

  The second refrigerant pipe 292 connects the four-way valve 23 and the indoor heat exchanger 24. The indoor heat exchanger 24 exchanges heat between the refrigerant flowing into the interior and the room air. The third refrigerant pipe 293 connects the indoor heat exchanger 24 and the outdoor heat exchanger 25. The outdoor heat exchanger 25 exchanges heat between the refrigerant flowing into the interior and the outside air. Further, the expansion valve 26 is interposed in the middle of the third refrigerant pipe 293. The refrigerant flowing through the third refrigerant pipe 293 is expanded by passing through the expansion valve 26.

  The fourth refrigerant pipe 294 connects the four-way valve 23 and the outdoor heat exchanger 25. The fifth refrigerant pipe 295 connects the four-way valve 23 and the suction port 21 a of the compressor 21. Accordingly, the fifth refrigerant pipe 295 connects the outdoor heat exchanger 25 and the suction port 21a of the compressor 21 during heating. The accumulator 28 is interposed in the middle of the fifth refrigerant pipe 295. The liquid refrigerant flowing through the fifth refrigerant pipe 295 is accumulated by the accumulator 28. Therefore, only the gas refrigerant is sucked into the suction port 21a.

  Further, in the third refrigerant pipe 293 that connects the indoor heat exchanger 24 and the outdoor heat exchanger 25, a portion between the indoor heat exchanger 24 and the expansion valve 26, the outdoor heat exchanger 25, and the compressor 21 A portion between the four-way valve 23 and the accumulator 28 in the fifth refrigerant pipe 295 connecting the suction port 21 a is connected by a bypass pipe 296. An engine exhaust heat exchanger 27 and a refrigerant flow rate adjustment valve 31 are interposed in the bypass pipe 296. By controlling the opening degree of the refrigerant flow rate adjusting valve 31, the flow rate of the refrigerant flowing through the engine exhaust heat exchanger 27 can be controlled.

  The cooling water circuit 40 is a circuit in which cooling water is enclosed, and is configured so that the enclosed cooling water flows back through the gas engine in order to cool the gas engine 10. The cooling water circuit 40 includes a cooling water inflow pipe 41, a cooling water outflow pipe 42, a first cooling water pipe 43, a second cooling water pipe 44, and a cooling water pump 46.

  The cooling water inflow pipe 41 is connected to the gas engine 10 so that the cooling water flowing into the gas engine 10 flows. The cooling water outflow pipe 42 is connected to the gas engine 10 so that the cooling water outflowed from the gas engine 10 flows. A cooling water passage is formed in the gas engine 10. The cooling water flowing into the gas engine 10 from the cooling water inflow pipe 41 passes through the cooling water passage, whereby the gas engine 10 is cooled. And the cooling water which passed through the cooling water passage from the cooling water outflow piping 42 flows out.

  The first cooling water pipe 43 connects the end of the cooling water outflow pipe 42 and the end of the cooling water inflow pipe 41. The second cooling water pipe 44 also connects the end of the cooling water outflow pipe 42 and the end of the cooling water inflow pipe 41. That is, the flow path branches into the first cooling water pipe 43 and the second cooling water pipe 44 at the end of the cooling water outflow pipe 42. The branched flow paths merge at the end of the cooling water inflow pipe 41.

  An engine exhaust heat exchanger 27 is interposed in the middle of the first coolant pipe 43. Therefore, the cooling water flowing through the first cooling water pipe 43 transfers heat to the refrigerant in the engine exhaust heat exchanger 27. On the other hand, a radiator 47 is interposed in the middle of the second cooling water pipe 44. Accordingly, the cooling water flowing through the second cooling water pipe 44 is radiated by the radiator 47.

  A flow path switching valve 45 is interposed at the end of the cooling water outflow pipe 42, that is, at a branch position between the first cooling water pipe 43 and the second cooling water pipe 44. The flow path switching valve 45 switches whether the cooling water flows to the first cooling water pipe 43 or the second cooling water pipe 44. An example of the flow path switching valve 45 is a wax valve configured to switch the flow path at a predetermined temperature.

  A cooling water pump 46 is interposed in the middle of the cooling water inflow pipe 41. When the cooling water pump 46 is driven, the cooling water flows in the cooling water circuit 40. The cooling water pump 46 may be interposed in the middle of the cooling water outflow pipe 42. The cooling water pump 46 is configured so that its discharge flow rate can be adjusted by the number of rotations. That is, the flow rate of the cooling water flowing in the cooling water circuit 40 can be controlled by controlling the rotation speed (discharge flow rate) of the cooling water pump 46. The gas engine 10 may be used as a drive source of the cooling water pump 46, or an electric motor or the like may be used.

  Further, as shown in FIG. 1, a refrigerant temperature sensor 32 is attached to the bypass pipe 296. The refrigerant temperature sensor 32 detects the temperature Tr of the refrigerant flowing out from the engine exhaust heat exchanger 27 interposed in the bypass pipe 296. A refrigerant pressure sensor 33 is attached to the middle of the fifth refrigerant pipe 295 and between the four-way valve 23 and the accumulator 28. The refrigerant pressure sensor 33 detects the pressure P of the refrigerant flowing through the fifth refrigerant pipe 295. Further, a cooling water temperature sensor 34 is attached in the middle of the cooling water outflow pipe 42. The cooling water temperature sensor 34 detects the temperature of the cooling water flowing through the cooling water outflow pipe 42, that is, the cooling water Tw that has cooled the gas engine 10.

  The control device 50 is mainly composed of a microcomputer including a CPU, a ROM, and a RAM. The control device 50 acquires the temperature Tr from the refrigerant temperature sensor 32, the pressure P from the refrigerant pressure sensor 33, and the temperature Tw from the coolant temperature sensor 34, respectively. And based on the acquired temperature information and pressure information, the opening degree of the refrigerant | coolant flow control valve 31 and the rotation speed (flow volume) of the cooling water pump 46 are controlled.

  Next, the air conditioning operation of the engine-driven air conditioner having the above configuration will be briefly described. First, the heating operation will be described. When the compressor 21 is actuated by driving the gas engine 10, the compressor 21 sucks the low-pressure gas refrigerant in the fifth refrigerant pipe 295 from the suction port 21a and compresses the sucked low-pressure gas refrigerant to convert the high-temperature high-pressure gas refrigerant. Generate. And the produced | generated high temperature / high pressure gas refrigerant | coolant is discharged from the discharge outlet 21b. The high-temperature and high-pressure gas refrigerant discharged from the discharge port 21 b flows through the first refrigerant pipe 291 and enters the four-way valve 23.

  During heating, the four-way valve 23 is switched to the heating state. Accordingly, the first refrigerant pipe 291 is connected to the second refrigerant pipe 292 by the four-way valve 23. Therefore, the high-temperature high-pressure gas refrigerant in the first refrigerant pipe 291 flows to the second refrigerant pipe 292 via the four-way valve 23. The high-temperature and high-pressure gas refrigerant that has flowed into the second refrigerant pipe 292 flows into the indoor heat exchanger 24. The high-temperature and high-pressure gas refrigerant that has flowed into the indoor heat exchanger 24 condenses by discharging heat to the indoor air while flowing through the indoor heat exchanger 24. That is, the indoor heat exchanger 24 functions as a condenser during heating. At this time, the room air is warmed by the heat discharged from the high-temperature and high-pressure gas refrigerant, and the room is heated.

  The refrigerant that exhausts heat to the indoor air and is condensed is partially liquefied and flows out from the indoor heat exchanger 24 to the third refrigerant pipe 293. And it is pressure-reduced so that it may evaporate easily by expanding with the expansion valve 26 interposed in the middle of the 3rd refrigerant | coolant piping 293. FIG. Thereafter, it flows into the outdoor heat exchanger 25. While flowing through the outdoor heat exchanger 25, the refrigerant flowing into the outdoor heat exchanger 25 takes outside heat and evaporates. That is, the outdoor heat exchanger 25 functions as an evaporator during heating.

  A part of the refrigerant evaporated by taking heat of the outside air is vaporized and flows out from the outdoor heat exchanger 25 to the fourth refrigerant pipe 294. Then, the four-way valve 23 is entered. During heating, the fourth refrigerant pipe 294 is connected to the fifth refrigerant pipe 295 by the four-way valve 23. Therefore, the refrigerant in the fourth refrigerant pipe 294 flows to the fifth refrigerant pipe 295 via the four-way valve 23 and is further introduced into the accumulator 28. In the accumulator 28, the introduced refrigerant is gas-liquid separated. Then, only the low-temperature and low-pressure gas refrigerant is taken out and returned to the suction port 21 a of the compressor 21. By repeating such a refrigerant circulation cycle, room heating is continued.

  Next, the cooling operation will be described. When the compressor 21 is operated by driving the gas engine 10, high-temperature and high-pressure gas refrigerant is discharged from the discharge port 21 b of the compressor 21 to the first refrigerant pipe 291. The high-temperature high-pressure gas refrigerant flows through the first refrigerant pipe 291 and enters the four-way valve 23. At the time of cooling, the four-way valve 23 is switched to the cooling state. Accordingly, the first refrigerant pipe 291 is connected to the fourth refrigerant pipe 294 by the four-way valve 23. Therefore, the high-temperature and high-pressure gas refrigerant in the first refrigerant pipe 291 flows to the fourth refrigerant pipe 294 via the four-way valve 23. The high-temperature and high-pressure gas refrigerant that has flowed into the fourth refrigerant pipe 294 flows into the outdoor heat exchanger 25. The high-temperature and high-pressure gas refrigerant that has flowed into the outdoor heat exchanger 25 is condensed while discharging heat to the outside air while flowing through the outdoor heat exchanger 25. That is, the outdoor heat exchanger 25 functions as a condenser during cooling.

  The refrigerant that is condensed by discharging heat to the outside air is partially liquefied and flows out from the outdoor heat exchanger 25 to the third refrigerant pipe 293. And it is pressure-reduced so that it may evaporate easily by expanding with the expansion valve 26 interposed in the middle of the 3rd refrigerant | coolant piping 293. FIG. Thereafter, it flows into the indoor heat exchanger 24. The refrigerant that has flowed into the indoor heat exchanger 24 evaporates by taking the heat of the indoor air while flowing through the indoor heat exchanger 24. That is, the indoor heat exchanger 24 functions as an evaporator during cooling. At this time, the refrigerant removes heat from the room air, thereby cooling the room air and cooling the room.

  The refrigerant that has evaporated the heat of the room air partially vaporizes and flows out from the indoor heat exchanger 24 to the second refrigerant pipe 292. Then, the four-way valve 23 is entered. During cooling, the four-way valve 23 connects the second refrigerant pipe 292 to the fifth refrigerant pipe 295. Therefore, the refrigerant in the second refrigerant pipe 292 flows to the fifth refrigerant pipe 295 via the four-way valve 23 and is further introduced into the accumulator 28. In the accumulator 28, the introduced refrigerant is gas-liquid separated. Only the low-temperature and low-pressure gas refrigerant returns to the suction port 21 a of the compressor 21. By repeating such a refrigerant circulation cycle, room cooling is continued.

  During the heating operation, the refrigerant that has flowed out of the indoor heat exchanger 24 flows into the outdoor heat exchanger 25 through the expansion valve 26 as described above, but apart from that, some of the refrigerant flows through the bypass pipe 296. . Then, it is introduced into the engine exhaust heat exchanger 27 provided in the bypass pipe 296. The refrigerant introduced into the engine exhaust heat exchanger 27 is heated by taking heat of the cooling water heated by cooling the gas engine 10. The refrigerant thus heated flows out of the engine exhaust heat exchanger 27, then flows through the bypass pipe 296, enters the fifth refrigerant pipe 295, and is then introduced into the accumulator 28. Thus, the exhaust heat of the cooling water is recovered by the engine exhaust heat exchanger 27 and the refrigerant is heated, so that the efficient engine-driven air conditioner can be operated.

  Further, the cooling water pump 46 is driven while the gas engine 10 is driven. When the cooling water pump 46 is driven, cooling water is introduced into the gas engine 10 from the cooling water inflow pipe 41. The introduced cooling water flows through a cooling passage formed in the gas engine 10. Thereby, the gas engine 10 is cooled. The cooling water heated by cooling the gas engine 10 flows from the gas engine 10 to the cooling water outflow pipe 42. Then, it is introduced into the flow path switching valve 45 ahead.

  The flow path switching valve 45 allows the cooling water flowing in from the cooling water inflow piping 41 to flow to the first cooling water piping 43 or the second cooling water piping 44. In the present embodiment, the flow path switching valve 45 is a temperature-sensitive wax valve, and is configured such that the flow path switching operation is performed by the temperature of the cooling water flowing through itself. Specifically, when the cooling water temperature is higher than a predetermined first temperature T1, the cooling water flows to the second cooling water pipe 44, and when lower than the first temperature T1, the cooling water is supplied to the first cooling water pipe. It flows to 43. Since the temperature responsiveness of the wax valve is poor, the flow path is actually switched in the temperature range including the first temperature T1. Therefore, when the cooling water temperature is near the first temperature T 1, the cooling water flows through both the first cooling water pipe 43 and the second cooling water pipe 44.

  The cooling water that has flowed through the first cooling water pipe 43 is introduced into the engine exhaust heat exchanger 27. In the engine exhaust heat exchanger 27, the heated cooling water after cooling the gas engine 10 is brought into thermal contact with the refrigerant that has been condensed and cooled in the indoor heat exchanger 24, whereby the heat of the cooling water is increased. Deprived of refrigerant. The cooling water cooled by the refrigerant flows out from the engine exhaust heat exchanger 27 and then flows into the gas engine 10 again.

  The cooling water that has flowed into the second cooling water pipe 44 is introduced into the radiator 47. In the radiator 47, the heated cooling water after cooling the gas engine 10 is brought into thermal contact with the outdoor air (outside air), whereby the heat of the cooling water is taken away by the outside air. The cooling water cooled by the outside air flows out of the radiator 47 and then flows into the gas engine 10 again.

  That is, when the temperature of the cooling water that has cooled the gas engine 10 is considerably high, specifically, when the cooling water temperature Tw is higher than the first temperature T1, occurrence of problems such as seizure of the gas engine 10 is prevented. Accordingly, the cooling water is caused to flow through the second cooling water pipe 44 and the cooling water is cooled by the radiator 47 having excellent heat radiation efficiency. Further, when the temperature of the cooling water that has cooled the gas engine 10 is not so high, specifically, when the cooling water temperature Tw is equal to or lower than the first temperature T1, the engine exhaust heat transferred to the cooling water is used as the refrigerant. In order to recover, the cooling water is caused to flow through the first cooling water pipe 43, and the cooling water is cooled by the engine exhaust heat heat exchanger 27.

  In the case where the cooling water temperature Tw is equal to or lower than the first temperature T1, in order to recover the engine exhaust heat most efficiently by the engine exhaust heat exchanger 27, the opening degree of the refrigerant flow rate adjustment valve 31 is controlled by the controller 50. And the discharge flow rate (rotation speed) of the cooling water pump 46 is controlled. Hereinafter, control of the opening degree of the refrigerant flow rate adjustment valve 31 and the discharge flow rate (rotation speed) of the cooling water pump 46 by the control device 50 will be described.

  2, 3, and 4 are flowcharts showing the flow of a control routine for controlling the opening degree of the refrigerant flow rate adjustment valve 31 and the rotation speed of the cooling water pump 46 by the control device 50. This routine is repeatedly executed every predetermined minute time. When this routine is started, the control device 50 first calculates the degree of superheat ΔT on the suction side of the compressor 21 in step 1 (hereinafter, step is abbreviated as S) 1 in FIG.

  The degree of superheat ΔT is, for example, the refrigerant pressure (low pressure side) detected by the refrigerant pressure sensor 33 from the refrigerant temperature Tr (temperature of the superheated steam) on the outlet side of the engine exhaust heat exchanger 27 detected by the refrigerant temperature sensor 32. It can be obtained from the difference (Tr−Ts) from the saturated vapor temperature Ts of the refrigerant at (refrigerant pressure) P. If the degree of superheat ΔT is too small, the possibility of liquid compression occurring in the compressor 21 increases, which is not preferable. On the other hand, if the degree of superheat ΔT is too large, the density of the refrigerant sucked from the suction port 21a of the compressor 21 is lowered and the air conditioning capability is lowered, which is not preferable. For example, the appropriate range of the degree of superheat ΔT is 0 ° C. <ΔT <10 ° C.

  After calculating the degree of superheat ΔT in S1, the control device 50 determines in S2 whether or not the coolant temperature Tw is less than the optimum coolant temperature Topt. The optimum cooling water temperature Topt is lower than the first temperature T1, and is the cooling water temperature that can exchange heat most efficiently in the engine exhaust heat exchanger 27, that is, cooling that maximizes the amount of exhaust heat recovery. It is the temperature of water. The optimum coolant temperature Topt is a temperature determined in advance based on the structure of the engine exhaust heat heat exchanger 27, the heat transfer coefficient, and the like. The optimum cooling water temperature Topt corresponds to the second temperature of the present invention.

  When it is determined in S2 that the cooling water temperature Tw is lower than the optimum cooling water temperature Topt (S2: Yes), the control device 50 proceeds to S8 and outputs an opening degree reduction signal to the refrigerant flow rate adjustment valve 31. . Thereby, the opening degree of the refrigerant flow rate adjustment valve 31 is decreased by a predetermined amount, and the flow rate of the refrigerant flowing through the bypass pipe 296, that is, the flow rate of the refrigerant flowing through the engine exhaust heat exchanger 27 is decreased. Thereafter, the control device 50 ends this routine.

  When the flow rate of the refrigerant flowing through the engine exhaust heat exchanger 27 is reduced by the process of S8, the amount of heat that the coolant is deprived by the refrigerant in the engine exhaust heat exchanger 27 decreases. For this reason, the temperature fall of the cooling water by passing the engine exhaust heat heat exchanger 27 is suppressed. For this reason, the cooling water temperature Tw rises. That is, when the flow rate of the refrigerant flowing through the engine exhaust heat exchanger 27 decreases, the coolant temperature Tw increases. Thereby, the cooling water temperature Tw can be brought close to the optimum cooling water temperature Topt.

  Further, when it is determined in S2 that the cooling water temperature Tw is equal to or higher than the optimum cooling water temperature Topt (S2: No), the control device 50 determines whether or not the superheat degree ΔT is in an appropriate range in S3. That is, it is determined whether the degree of superheat ΔT is greater than 0 ° C. and less than 10 ° C.

  In S3, when it is determined that the degree of superheat ΔT is in an appropriate range, that is, the degree of superheat ΔT is greater than 0 ° C. and less than 10 ° C. (S3: Yes), the control device 50 advances the process to S5. In S5, the control device 50 determines whether or not the cooling water temperature Tw is less than the optimum cooling water upper limit temperature that is 2 ° C. higher than the optimum cooling water temperature Topt. When the temperature of the cooling water is within the temperature range from the optimum cooling water temperature Topt to the optimum cooling water upper limit temperature (Top + 2 ° C.), the engine exhaust heat exchanger 27 receives the cooling water heat to the refrigerant very efficiently. Can pass.

  When it is determined in S5 that the cooling water temperature Tw is lower than the optimum cooling water upper limit temperature (Top + 2 ° C.) (S5: Yes), the control device 50 ends this routine as it is. That is, the superheat degree ΔT is in an appropriate superheat degree range (0 ° C. <ΔT <10 ° C.) (S3: Yes), and the cooling water temperature Tw is in an appropriate cooling water temperature range (Top ≦ Tw <Top + 2 ° C.). In some cases (S2: No, S5: Yes), neither the cooling water temperature Tw nor the superheat degree ΔT needs to be changed. Therefore, in this case, the control device 50 ends this routine without doing anything.

  In S5, when it is determined that the cooling water temperature Tw is equal to or higher than the optimum cooling water upper limit temperature (Top + 2 ° C.) (S5: No), the control device 50 proceeds to S9 and cools the rotation speed increase signal. Output to the water pump 46. Thereby, the rotation speed of the cooling water pump 46 increases, and the discharge flow rate of the cooling water pump 46 increases. For this reason, the flow volume of the cooling water which flows through the cooling water circuit 40 increases. After outputting the rotation speed increase signal in S9, the control device 50 ends this routine.

  When the determination result of S5 is No, the superheat degree ΔT is in the appropriate superheat degree range (S3: Yes), but the cooling water temperature is higher than the appropriate cooling water temperature range (S2: No, S5: No ). In such a case, if the flow rate of the cooling water flowing through the cooling water circuit 40 is increased by increasing the number of rotations of the cooling water pump 46 by the process of S9, the residence time of the cooling water in the gas engine 10 is reduced. In addition, the temperature rise of the cooling water can be suppressed. For this reason, the cooling water is cooled in the engine exhaust heat heat exchanger 27, and the cooling water temperature Tw is lowered. That is, when the cooling water flow rate increases, the cooling water temperature Tw decreases. Thereby, the cooling water temperature Tw can be brought close to the optimum cooling water temperature Topt.

  In S3, when the degree of superheat ΔT is not in an appropriate range, that is, when the degree of superheat ΔT is a value outside the range of greater than 0 ° C. and less than 10 ° C. (S3: No), the control device 50 The process proceeds to S4 of 3. In S4, the controller 50 determines whether or not the degree of superheat ΔT exceeds 10 ° C., that is, whether or not the degree of superheat ΔT exceeds an appropriate upper limit value (upper limit degree of superheat). When the superheat degree ΔT exceeds the upper limit superheat degree (10 ° C.) (S4: Yes), the control device 50 advances the process to S6, and whether the cooling water temperature Tw is less than the optimum cooling water upper limit temperature (Top + 2 ° C.). Judge whether or not. When the cooling water temperature Tw is less than the optimum cooling water upper limit temperature (S6: Yes), the control device outputs a rotation speed decrease signal to the cooling water pump 46 (S10). As a result, the rotational speed of the cooling water pump 46 decreases, and the discharge flow rate of the cooling water pump 46 decreases. For this reason, the flow rate of the cooling water flowing through the cooling water circuit 40 decreases. Thereafter, the control device 50 ends this routine.

  When the determination result of S6 is Yes, the cooling water temperature Tw is in an appropriate cooling water temperature range (Top ≦ Tw <Top + 2 ° C.) (S2: No, S6: Yes), but the superheat degree ΔT is too high ( S3: No, S4: Yes). In such a case, if the number of rotations of the cooling water pump 46 is reduced by the process of S10 to reduce the flow rate of the cooling water, the cooling water flowing into the engine exhaust heat exchanger 27 becomes insufficient. The amount of heat transferred to For this reason, the degree of superheat of the refrigerant passing through the engine exhaust heat exchanger 27 decreases. As a result, the superheat degree ΔT of the refrigerant on the suction side of the compressor 21 decreases. That is, when the cooling water flow rate decreases, the degree of superheat ΔT decreases. For this reason, the degree of superheat ΔT can be brought close to an appropriate range (0 ° C. to 10 ° C.).

  If it is determined in S6 that the cooling water temperature is not within the appropriate cooling water temperature range (S6: No), the control device 50 proceeds to S11 and sends an opening increase signal to the refrigerant flow rate adjustment valve 31. Output. Thereby, the opening degree of the refrigerant | coolant flow control valve 31 increases. When the opening degree of the refrigerant flow rate adjustment valve 31 increases, the refrigerant flow rate flowing through the bypass pipe 296 increases, and the refrigerant flow rate flowing through the engine exhaust heat exchanger 27 also increases. Thereafter, the control device 50 ends this routine.

  When the determination result of S6 is No, the cooling water temperature Tw is higher than the appropriate cooling water temperature range (S2: No, S6: No), and the degree of superheat ΔT is too high (S3: No , S4: Yes). In such a case, if the flow rate of the refrigerant flowing through the engine exhaust heat exchanger 27 is increased by the process of S11, the amount of heat transferred from the coolant to the refrigerant in the engine exhaust heat exchanger 27 increases. That is, the amount of exhaust heat recovery increases and the cooling water is sufficiently cooled. For this reason, the cooling water temperature Tw is lowered, and the cooling water temperature Tw can be brought close to the optimum cooling water temperature Topt.

  When it is determined in S4 that the degree of superheat ΔT is not greater than 10 ° C. (S4: No), the degree of superheat ΔT is less than 0 ° C., that is, the degree of superheat ΔT is smaller than the appropriate superheat range. It is. In this case, the control device 50 advances the process to S7 in FIG. In S7, it is determined whether or not the cooling water temperature Tw is less than the optimum cooling water upper limit temperature (Top + 2 ° C.). When the cooling water temperature Tw is less than the optimum cooling water upper limit temperature (S7: Yes), the control device 50 advances the process to S12 and outputs an opening degree reduction signal to the refrigerant flow rate adjustment valve 31. Thereby, the opening degree of the refrigerant | coolant flow control valve 31 reduces. As the opening degree of the refrigerant flow rate adjustment valve 31 decreases, the flow rate of the refrigerant flowing through the engine exhaust heat exchanger 27 decreases. Thereafter, the control device 50 ends this routine.

  When the determination result of S7 is Yes, the cooling water temperature Tw is in an appropriate cooling water temperature range (S2: No, S7: Yes), but the superheat degree ΔT is too low (S3: No, S4: No). . In such a case, if the flow rate of the refrigerant flowing through the engine exhaust heat exchanger 27 is decreased by the process of S12, the time during which the refrigerant stays in the engine exhaust heat exchanger 27 increases. The amount of heat delivered increases. For this reason, the degree of superheat ΔT increases. That is, when the flow rate of the refrigerant flowing through the engine exhaust heat exchanger 27 decreases, the degree of superheat ΔT increases. Thereby, the degree of superheat ΔT can be brought close to an appropriate range.

  In S7, when the cooling water temperature Tw is equal to or higher than the optimum cooling water upper limit temperature (S7: No), the control device 50 outputs a rotation speed increase signal to the cooling water pump 46 (S13). Thereby, the rotation speed of the cooling water pump 46 increases, the discharge flow rate of the cooling water pump 46 increases, and the flow rate of the cooling water flowing through the cooling water circuit 40 increases. Thereafter, the control device 50 ends this routine.

  When the determination result of S7 is No, the cooling water temperature Tw is higher than the appropriate cooling water temperature range (S2: No, S7: No), and the superheat degree ΔT is too low (S3: No, S4: No). In such a case, if the rotation speed of the cooling water pump 46 is increased by the process of S13 to increase the flow rate of the cooling water, the residence time of the cooling water in the gas engine 10 decreases, so the temperature of the cooling water rises. Is suppressed. For this reason, the cooling water temperature Tw is lowered by heat exchange in the engine exhaust heat exchanger 27. Therefore, the cooling water temperature Tw can be brought close to an appropriate cooling water temperature range.

The control method of the opening degree of the refrigerant flow rate adjustment valve 31 and the rotation speed of the cooling water pump 46 by the control device 50 described above is summarized as follows.
(1) The controller 50 opens the refrigerant flow rate adjustment valve 31 so that the flow rate of the refrigerant flowing through the engine exhaust heat exchanger 27 decreases when the cooling water temperature Tw is lower than the optimum cooling water temperature Topt. Decrease. This raises the cooling water temperature.
(2) When the superheat degree ΔT is in an appropriate range and the cooling water temperature Tw is higher than the appropriate range (Top to Top + 2 ° C.), the control device 50 increases the number of rotations of the cooling water pump 46 to increase the cooling water circuit. The flow rate of the cooling water flowing through 40 is increased. This lowers the cooling water temperature.
(3) When the degree of superheat ΔT is higher than the appropriate range and the cooling water temperature Tw is in the appropriate range (Top to Top + 2 ° C.), the control device 50 decreases the number of rotations of the cooling water pump 46 to reduce the cooling water. The flow rate of the cooling water flowing through the circuit 40 is decreased. As a result, the degree of superheat ΔT is reduced.
(4) When the degree of superheat ΔT is higher than the appropriate range and the coolant temperature Tw is higher than the appropriate range, the control device 50 increases the opening of the refrigerant flow rate adjustment valve 31 to increase the engine exhaust heat heat exchanger. The flow rate of the refrigerant flowing through 27 is increased. Thereby, the cooling water temperature is lowered.
(5) When the degree of superheat ΔT is lower than the appropriate range and the cooling water temperature Tw is within the appropriate range (Top to Top + 2 ° C.), the control device 50 reduces the opening of the refrigerant flow rate adjustment valve 31 to reduce the engine The flow rate of the refrigerant flowing through the exhaust heat exchanger 27 is decreased. As a result, the degree of superheat ΔT is increased.
(6) When the degree of superheat ΔT is lower than the appropriate range and the coolant temperature Tw is higher than the appropriate range, the control device 50 increases the number of rotations of the coolant pump 46 and flows in the coolant circuit 40. Increase the flow rate of cooling water. Thereby, the cooling water temperature is lowered.

  As can be seen from the above, the control device 50 reduces the opening of the refrigerant flow rate adjustment valve 31 in order to increase the cooling water temperature Tw, and the rotation of the cooling water pump 46 in order to decrease the cooling water temperature Tw. The number is increased or the opening degree of the refrigerant flow rate adjustment valve 31 is increased. Further, the degree of opening of the refrigerant flow rate adjustment valve 31 is decreased to increase the degree of superheat ΔT, and the rotational speed of the cooling water pump 46 is decreased to decrease the degree of superheat ΔT. Further, as shown in the above (4) and (6), when both the cooling water temperature Tw and the superheat degree ΔT are not in the proper range, the control device 50 brings the cooling water temperature Tw close to the proper range. Such control is prioritized.

  When the control device 50 executes such control, it is possible to maintain both the appropriate cooling water temperature Tw and the appropriate superheat degree ΔT.

  As described above, according to the present embodiment, the flow path of the cooling water is changed into the flow path that passes through the radiator 47 and the flow path that passes through the engine exhaust heat exchanger 27 by one flow path switching valve 45. Can be switched. Further, the control device 50 determines that the temperature Tw of the cooling water that has cooled the gas engine 10 is an optimum cooling water temperature Topt (or an appropriate temperature in the vicinity of Top) so that the efficiency of heat exchange in the engine exhaust heat exchanger 27 is maximized. The flow rate of the refrigerant flowing through the engine exhaust heat exchanger 27 or the flow rate of the cooling water flowing through the cooling water circuit 40 is controlled so as to approach the temperature range. For this reason, the temperature of the cooling water flowing through the engine exhaust heat heat exchanger 27 can be maintained at a temperature near the optimum cooling water temperature Topt. Therefore, the engine exhaust heat is sufficiently recovered by the engine exhaust heat exchanger 27.

  When the temperature Tw of the cooling water that has cooled the gas engine 10 is lower than the optimum cooling water temperature Topt (S2: Yes), the control device 50 decreases the opening of the refrigerant flow rate adjustment valve 31 (S8). As a result, the flow rate of the refrigerant flowing through the engine exhaust heat exchanger 27 is reduced, so that the amount of heat exchange between the refrigerant and the cooling water by the engine exhaust heat exchanger 27 is reduced. Thereby, the temperature drop of the cooling water due to heat exchange in the engine exhaust heat exchanger 27 is limited, and the cooling water temperature Tw can be quickly raised to the optimum cooling water temperature Topt. That is, according to this embodiment, the low-temperature valve described in Patent Document 1 is abolished, and instead, the flow rate of the refrigerant flowing through the engine exhaust heat exchanger 27 is controlled, and the cooling water temperature is low. Heat exchange in the engine exhaust heat exchanger 27 is limited. Therefore, the flow path switching valve (the low temperature valve described in Patent Document 1), which has been conventionally required when the cooling water temperature is low, can be eliminated.

  Further, according to the present embodiment, the control device 50 flows into the engine exhaust heat exchanger 27 based on the superheat degree ΔT so that the superheat degree ΔT on the suction side of the compressor 21 falls within a predetermined range. The flow rate of the coolant or the flow rate of the coolant flowing through the coolant circuit 40 is controlled. Therefore, in addition to maintaining an appropriate temperature of the cooling water flowing through the engine exhaust heat exchanger 27, the superheat degree ΔT of the refrigerant can also be maintained in an appropriate range. Therefore, when the temperature control of the cooling water is executed, troubles caused by the degree of superheat ΔT becoming too small or too large, such as liquid compression in the compressor or reduction in operating efficiency, are caused. Generation | occurrence | production can be prevented effectively.

In addition, the following technical ideas can also be grasped from the above embodiment.
The water-cooled gas engine 10 has a suction port 21a and a discharge port 21b, compresses the refrigerant sucked from the suction port 21a and discharges it from the discharge port 21b, and is discharged from the compressor 21 during heating. An indoor heat exchanger 24 that condenses the refrigerant, an expansion valve 26 that expands the refrigerant that flows out of the indoor heat exchanger 24, an outdoor heat exchanger 25 that evaporates the refrigerant expanded in the expansion valve 26 during heating, The refrigerant circuit 20 is filled with the refrigerant and includes the compressor 21, the indoor heat exchanger 24, the expansion valve 26, and the refrigerant pipe 29 that connects the outdoor heat exchanger 25, and the indoor heat exchanger 24 is heated during heating. A bypass pipe 296 connected to the refrigerant pipe 29 and the bypass pipe 296 are interposed so that the outflowed refrigerant bypasses the outdoor heat exchanger 25 and is sucked into the suction port 21a of the compressor 21. The engine exhaust heat exchanger 27 that exchanges heat between the refrigerant flowing through the pipe 296 and the cooling water that has cooled the gas engine 10, and the refrigerant flow rate that is interposed in the bypass pipe 296 and adjusts the flow rate of the refrigerant flowing through the bypass pipe 296. The regulating valve 31, the radiator 47 that radiates the cooling water that has cooled the gas engine 10, the cooling water inflow pipe 41 through which the cooling water flowing into the gas engine 10 circulates, and the cooling water that has flowed out from the gas engine 10 circulates. The cooling water inflow piping 42 and the cooling water inflow piping so that the cooling water that has cooled the gas engine 10 flows into the gas engine 10 through the engine exhaust heat exchanger 27 are formed. The cooling water that has cooled the gas engine 10 is connected to the gas engine via the radiator 47. 10, a second cooling water pipe 44 that connects the cooling water inflow pipe 41 and the cooling water outflow pipe 42, and the cooling water inflow pipe 41 or the cooling water outflow pipe. 42, the cooling water pump 46 with adjustable flow rate, and when the cooling water temperature Tw for cooling the gas engine 10 is equal to or higher than the first temperature T1, the cooling water flows through the second cooling water pipe 44, and the cooling water The temperature of the cooling water that has cooled the gas engine 10 and the flow path switching valve 45 that switches the flow path of the cooling water so that the cooling water flows through the first cooling water pipe 43 when the temperature Tw is lower than the first temperature T1. A control device 50 that controls the opening degree of the refrigerant flow rate adjustment valve 31 or the discharge flow rate (the number of rotations) of the cooling water pump 46 based on the temperature Tw so that Tw approaches the optimum cooling water temperature Topt that is lower than the first temperature T1. And A gin-driven air conditioner.

  As mentioned above, although embodiment of this invention was described, this invention should not be limited to the said embodiment. For example, in the above embodiment, an engine-driven air conditioner using a gas engine is shown, but an engine using a liquid fuel such as gasoline may be used. Moreover, in the said embodiment, in order to control the cooling water temperature Tw and the superheat degree (DELTA) T, either the opening degree of the refrigerant | coolant flow rate adjustment valve 31 or the rotation speed of the cooling water pump 46 is controlled, but it is air conditioning. Either may be controlled as long as there is no influence. For example, in the above embodiment, the flow rate of the refrigerant flowing through the engine exhaust heat exchanger 27 is decreased in order to increase the cooling water temperature Tw, but instead (or in combination), the cooling water circuit 40 flows. The cooling water flow rate may be decreased. Moreover, in the said embodiment, in order to raise superheat degree (DELTA) T, the flow volume of the refrigerant | coolant which flows through the engine exhaust-heat heat exchanger 27 is decreased, but cooling which flows through the cooling water circuit 40 instead of this (or with this) is carried out. The water flow rate may be increased. Further, in the above-described embodiment, the flow rate of the cooling water flowing through the cooling water circuit 40 is decreased in order to reduce the degree of superheat ΔT, but instead of (or with) the flow of the engine exhaust heat exchanger 27. The flow rate of the refrigerant may be increased. In the above embodiment, the temperature Tr of the refrigerant that has flowed out of the engine exhaust heat exchanger 27 is detected to calculate the degree of superheat ΔT, but the temperature of the refrigerant that flows into the engine exhaust heat exchanger 27 is detected. Alternatively, the temperature of the refrigerant sucked into the suction port 21a of the compressor 21 may be detected, and the superheat degree ΔT on the suction side of the compressor 21 may be calculated based on the detected temperature information. Thus, the present invention can be modified without departing from the gist thereof.

DESCRIPTION OF SYMBOLS 1 ... Engine-driven air conditioner, 10 ... Gas engine, 20 ... Refrigerant circuit, 21 ... Compressor, 21a ... Inlet, 21b ... Discharge port, 22 ... Oil separator, 23 ... Four-way valve, 24 ... Indoor heat exchanger 25 ... Outdoor heat exchanger, 26 ... Expansion valve, 27 ... Engine exhaust heat exchanger, 28 ... Accumulator, 29 ... Refrigerant piping, 31 ... Refrigerant flow rate adjustment valve, 32 ... Refrigerant temperature sensor, 33 ... Refrigerant pressure sensor, 34 ... Cooling water temperature sensor, 40 ... Cooling water circuit, 41 ... Cooling water inflow piping, 42 ... Cooling water outflow piping, 43 ... First cooling water piping, 44 ... Second cooling water piping, 45 ... Channel switching valve, 46 ... Cooling water pump, 47 ... Radiator, 50 ... Control device, 291 ... First refrigerant pipe, 292 ... Second refrigerant pipe, 293 ... Third refrigerant pipe, 294 ... Fourth refrigerant pipe, 295 ... Fifth refrigerant pipe, 296 ... Bypass distribution , Topt ... optimum coolant temperature, Tw ... coolant temperature, [Delta] T ... superheat

Claims (4)

A refrigerant circuit formed by connecting a compressor, a condenser, an expansion valve, and an evaporator driven by a water-cooled engine;
A cooling water circuit configured to enclose cooling water therein and to recirculate the encapsulated cooling water via the engine to cool the engine;
An engine exhaust heat exchanger that exchanges heat between the refrigerant and the cooling water that has cooled the engine so that the refrigerant flowing in the refrigerant circuit is heated;
A radiator that dissipates heat from cooling water that has cooled the engine;
When the temperature of the cooling water that has cooled the engine is equal to or lower than a predetermined first temperature, the cooling water that has cooled the engine flows through the flow path through which the engine flows into the engine via the engine exhaust heat exchanger, When the temperature of the cooling water that has cooled the engine is equal to or higher than the first temperature, the cooling water that has cooled the engine flows in the cooling water circuit so that the cooling water flows through the flow path that flows into the engine via the radiator. A flow path switching valve for switching the flow path of the flowing cooling water,
The flow rate of the refrigerant flowing through the engine exhaust heat exchanger based on the temperature of the cooling water that has cooled the engine so that the temperature of the cooling water that has cooled the engine approaches a second temperature that is lower than the first temperature, or A control device for controlling the flow rate of the cooling water flowing through the cooling water circuit;
Equipped with a,
The controller is set based on the second temperature as a temperature range in which the temperature of the cooling water that has cooled the engine can efficiently transfer the heat of the cooling water to the refrigerant in the engine exhaust heat exchanger. that higher than the appropriate temperature range, and, if the degree of superheat of the refrigerant flowing in the refrigerant circuit is lower than the appropriate range, Ru is configured to increase the flow rate of the cooling water flowing through the cooling water circuit,
Engine-driven air conditioner. The engine-driven air conditioner according to claim 1,
When the temperature of the cooling water that has cooled the engine is lower than the second temperature, the control device is configured to reduce the flow rate of the refrigerant flowing through the engine exhaust heat heat exchanger. Engine-driven air conditioner that controls the flow rate of refrigerant flowing through The engine-driven air conditioner according to claim 1 or 2,
The engine-driven air conditioner, wherein the second temperature is a temperature that is predetermined as a temperature at which the efficiency of heat exchange between the refrigerant and the cooling water by the engine exhaust heat exchanger is the highest. The engine-driven air conditioner according to any one of claims 1 to 3,
A refrigerant flow rate adjustment valve that adjusts the flow rate of the refrigerant flowing through the engine exhaust heat heat exchanger;
A cooling water pump capable of adjusting the flow rate of the cooling water flowing through the cooling water circuit while circulating the cooling water in the cooling water circuit,
The controller controls the refrigerant flow rate adjustment valve based on the temperature of the cooling water that has cooled the engine so that the temperature of the cooling water that has cooled the engine is maintained at a second temperature that is lower than the first temperature. An engine-driven air conditioner that controls an opening degree or a discharge flow rate of the cooling water pump.

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