JP6051946B2 - Engine-driven air conditioner - Google Patents

Description

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

  The engine-driven air conditioner includes a refrigerant circulation circuit formed by connecting a compressor driven by an engine, a four-way switching valve, an outdoor heat exchanger, an expansion valve, and an indoor heat exchanger via a refrigerant pipe, Air conditioning (cooling, heating) is performed by circulating the refrigerant in the refrigerant circulation circuit. By switching the flow of the refrigerant in the refrigerant circuit with the four-way switching valve, the cooling operation and the heating operation are switched. During the cooling operation, the refrigerant outlet (high pressure side) of the compressor is connected to the outdoor heat exchanger and the refrigerant inlet (low pressure side) of the compressor is connected to the indoor heat exchanger. During the heating operation, the refrigerant discharge of the compressor The four-way switching valve is used during cooling operation and heating operation so that the outlet (high pressure side) is connected to the indoor heat exchanger and the refrigerant suction port (low pressure side) of the compressor is connected to the outdoor heat exchanger. Can be switched.

  During the heating operation of the engine-driven air conditioner when the outside air temperature is extremely low, the temperature of the refrigerant discharged from the outdoor heat exchanger (refrigerant evaporation temperature) may drop below the freezing point and below the dew point. In this case, frost is formed on the heat exchange fins of the outdoor heat exchanger. When the heating operation is continued with frost on the heat exchange fins, frost grows and the heat exchange fins are covered with frost. In addition, the ventilation area decreases due to the growth of frost. For this reason, the heat exchange performance in the outdoor heat exchanger is impaired.

  Therefore, when the outdoor heat exchanger is frosted, generally the heating operation is temporarily stopped and the defrosting operation is started. In the defrosting operation, the switching state of the four-way switching valve is changed from the switching state during heating to the switching state during cooling, and the indoor fan and the outdoor fan are stopped. Then, the outdoor heat exchanger functions as a condenser and discharges heat to the outside air. As a result, the outside air is warmed and the frost attached to the heat exchange fins is melted.

  When the switching state of the four-way switching valve is changed from the switching state during heating to the switching state during cooling when starting the defrosting operation, outdoor heat exchange connected to the refrigerant inlet (low pressure side) of the compressor Suddenly connected to the refrigerant outlet (high pressure side) of the compressor, and the indoor heat exchanger connected to the refrigerant outlet (high pressure side) of the compressor suddenly connected to the refrigerant inlet (low pressure side) of the compressor Is done. Therefore, when the differential pressure ΔP between the refrigerant pressure at the refrigerant intake port of the compressor and the refrigerant pressure at the refrigerant discharge port is large, a sudden pressure change at the time of switching of the four-way switching valve causes the outdoor heat exchanger and the indoor heat exchanger to The heat exchange fins may be distorted. Further, when the differential pressure ΔP is large, a large refrigerant flow noise is generated when the four-way switching valve is switched, which may impair comfort.

  Patent Document 1 discloses an air conditioner in which the rotation speed of the compressor is controlled so that the rotation speed of the compressor is reduced to a predetermined rotation speed when switching from the heating operation to the defrosting operation. According to the air conditioner described in Patent Literature 1, the pressure difference between the refrigerant pressure at the refrigerant discharge port (high-pressure side) and the refrigerant pressure at the refrigerant suction port (low-pressure side) of the compressor is reduced by reducing the rotation speed of the compressor. ΔP decreases. For this reason, it is possible to reduce the refrigerant flow noise generated when the four-way switching valve is switched.

JP 2011-52849 A

(Problems to be solved by the invention)
In recent years, a self-supporting engine-driven air conditioner including a generator that generates electric power using engine power has been proposed. The electric power generated by the generator is a component part of the engine-driven air conditioner and is supplied to a part (electrically driven part) driven by the electric power or an external load. For this reason, the self-supporting engine-driven air conditioner can continue air-conditioning operation independently without being supplied with power from an external power source such as a commercial power source, and can supply power to an external load. It is also possible to perform a self-sustaining power generation operation in which the engine and the compressor are separated to stop the air conditioning operation, and the generator is operated by the engine to supply power to an external load.

  Even in such a self-supporting engine-driven air conditioner, the defrosting operation is started when the outside air temperature is extremely lowered during the heating operation and the outdoor heat exchanger is frosted. At this time, when the four-way switching valve is switched, the engine speed is decreased in order to suppress the occurrence of the above-described problems caused by the large differential pressure ΔP between the refrigerant pressure at the refrigerant inlet of the compressor and the refrigerant pressure at the refrigerant outlet. As a result, the rotational speed of the compressor is reduced to a predetermined rotational speed. However, the magnitude of the electric power generated by the generator decreases as the engine speed decreases. If the actual power generated by the generator falls below the total power (required power) to be supplied to the external load and electric drive parts, the external load or engine-driven air conditioner may stop due to insufficient power supply .

  An object of the present invention is to provide a self-supporting engine-driven air conditioner that does not cause a shortage of power supply even when the engine speed is reduced when switching a four-way switching valve.

(Means for solving the problem)
The present invention is an engine-driven air conditioner configured to perform a heating operation and a defrosting operation, and has an engine, a refrigerant suction port, and a refrigerant discharge port, and is driven by the power of the engine to generate a low pressure. Heat exchange is performed between the compressor that sucks gas refrigerant from the refrigerant inlet and discharges high-pressure gas refrigerant from the refrigerant outlet, and the indoor air that is installed indoors and discharged from the refrigerant outlet of the compressor during heating operation Indoor heat exchangers that are installed outdoors, outdoor heat exchangers that exchange heat between the refrigerant flowing out of the indoor heat exchanger during heating operation and the outside air, and the refrigerant outlet of the compressor during indoor heating operation And the refrigerant suction port of the compressor is connected to the outdoor heat exchanger. During the defrosting operation, the refrigerant discharge port of the compressor is connected to the outdoor heat exchanger and the refrigerant suction port of the compressor is connected to the indoor heat exchanger. Connect to heat exchanger As described above, the refrigerant discharge port and the refrigerant suction port of the compressor, the four-way switching valve configured to be able to switch the connection state between the indoor heat exchanger and the outdoor heat exchanger, and power generation by the engine power, A generator configured to be able to supply generated electric power to an external load and an electric drive part that is driven by electric power and is a component of an engine-driven air conditioner, and the generator supplies electric power to the electric drive part. When a request for switching the four-way switching valve is input to change the operating state from the heating operation to the defrosting operation, the engine speed is set in advance before the four-way switching valve switches. The engine speed and the generator to the electric drive component so that the power is supplied to the electric drive component from the generator and the first set speed that is a predetermined low speed is reduced. And a control unit for executing a self defrosting before control for controlling the magnitude of power supplied, to provide an engine-driven air conditioning system.

  In this case, the control unit lowers the engine speed to the first set speed in the self-defrosting pre-control, and the actual generated power of the generator is predetermined as the minimum power to be supplied to the external load. The engine speed and the amount of power supplied from the generator to the electric drive components are controlled so that the required power, which is the sum of the power (externally supplied power) and the electric power to be supplied to the electric drive components, is not reduced. It is good.

  Further, in this case, the first set rotational speed is caused by the above-described problem (heat) due to the differential pressure ΔP between the refrigerant pressure at the refrigerant outlet of the compressor and the refrigerant pressure at the refrigerant inlet of the compressor when the four-way switching valve is switched. It is preferable that the pressure difference be reduced to such an extent that distortion of the exchange fins and a large flow noise) do not occur, and the actual generated power does not fall below the required power.

  According to the present invention, when the generator is supplying electric power to the electric drive component, the control unit performs the self-defrosting pre-control when switching from the heating operation to the defrosting operation. In the control before self-defrosting, the engine speed is reduced to the first set speed before the four-way switching valve is switched. For this reason, the differential pressure ΔP between the refrigerant pressure at the refrigerant discharge port of the compressor driven by the engine and the refrigerant pressure at the refrigerant suction port decreases. Therefore, it is possible to suppress the occurrence of the above-described problems (distortion of heat exchange fins, large flow noise) caused by the large differential pressure ΔP. Further, as the engine speed decreases, the amount of power supplied from the generator to the electric drive parts decreases. For this reason, even if the amount of power generated by the generator decreases as the engine speed decreases, the power supply from the generator to the electric drive parts is reduced to the external load by the reduced amount. Supply power, in particular, external supply power predetermined as the minimum power supplied to the external load can be ensured. Therefore, it is possible to prevent occurrence of insufficient power supply to the external load. In addition, it is necessary for continuation of operation by controlling the amount of power supplied from the generator to the electric drive parts so that the actual generated power of the generator does not fall below the required power in the self-defrosting control. The power supplied to the electric drive parts can be ensured. Therefore, it is possible to prevent the engine-driven air conditioner from being stopped due to insufficient power supply to these electric drive parts, and consequently the engine-driven air conditioner from being stopped and power supply to the external load being cut off.

  The engine-driven air conditioner of the present invention is preferably provided with an outdoor fan as an electric drive component that blows air to the outdoor heat exchanger. Then, in the control before the self-defrosting, the control unit reduces the engine speed to the first set speed and stops the supply of electric power from the generator to the outdoor fan. The power supply from the unit to the outdoor fan should be controlled. In this case, it is preferable that the control unit controls the power supply from the generator to the outdoor fan so that the power supply from the generator to the outdoor fan decreases immediately after the start of the self-defrosting control. In the defrosting operation, it is not necessary to drive the outdoor fan. Thus, by stopping power supply to electric drive parts that do not require power supply for the subsequent defrosting operation, supply to electric drive parts that require external load and power supply while suppressing wasteful power consumption Electric power can be secured.

  The engine-driven air conditioner of the present invention preferably includes an indoor fan as an electrically driven component that blows air to the indoor heat exchanger. And a control part continues the electric power supply from a generator to an indoor fan until the rotation speed of an engine falls to the 2nd setting rotation speed higher than a 1st setting rotation speed by control before independent defrost. The engine speed and the power supply from the generator to the indoor fan may be controlled so that the power supply from the generator to the indoor fan stops when the engine speed decreases to the second set speed.

  It is not necessary to drive the indoor fan in the defrosting operation. However, when the driving of the indoor fan is suddenly stopped during the heating operation, condensation of the refrigerant in the indoor heat exchanger suddenly stops. When the condensation of the refrigerant in the indoor heat exchanger suddenly stops, the pressure of the refrigerant flowing out from the indoor heat exchanger suddenly increases, and the engine-driven air conditioner may stop due to a pressure abnormality. For this reason, when the indoor fan is stopped, the refrigerant pressure at the refrigerant discharge port of the compressor (that is, the refrigerant pressure flowing into the indoor heat exchanger) is reduced as much as possible, and the indoor heat exchanger is stopped even if the indoor fan stops. It is recommended that the pressure of the refrigerant flowing out of the tank is not as high as possible. With regard to this point, in the present invention, power is supplied to the indoor fan until the engine speed is reduced to the second set speed in the self-defrosting pre-control, and the time when the engine speed is reduced to the second set speed. For the first time, the power supply to the indoor fans is stopped. For this reason, when the drive of the indoor fan is stopped, the engine speed can be lowered as much as possible, thereby reducing the refrigerant pressure at the refrigerant discharge port of the compressor. As a result, it is possible to avoid an abnormal stop due to a sudden rise in the refrigerant pressure flowing out from the indoor heat exchanger when the indoor fan is stopped.

  The second set rotational speed is higher than the first set rotational speed, and covers the electric power to be supplied to the necessary electric drive parts other than the outdoor fan and the externally supplied power by the self-defrost pre-control. It can be determined in advance as the engine speed required to generate as little electric power as possible with the generator. In this case, the second set rotational speed can be determined as follows, for example. When the engine speed is decreased while the power supply to the indoor fan is continued in the control before self-defrosting, the difference between the actual generated power A and the required power B (AB) as the engine speed decreases. ) Gradually shrinks. The engine speed when the difference (A−B) becomes 0 or when the difference (A−B) becomes equal to or less than a predetermined power difference can be determined as the second set speed.

  In addition, the controller controls the engine speed after the four-way switching valve is switched to change the operating state from the defrosting operation to the heating operation when the generator is supplying electric power to the electric drive component. When the engine speed reaches a third preset speed, which is a predetermined high speed, a stop of power supply to the outdoor fan and the indoor fan is released. It is good to execute the control after the self-defrosting that controls the rotational speed and the power supply from the generator to the outdoor fan and the indoor fan.

  According to this, in the case where the generator supplies power to the electric drive component, the control unit performs the self-defrosting control after switching from the defrosting operation to the heating operation. In the control after self-defrosting, the engine speed is increased after the four-way switching valve is switched. Then, when the engine speed reaches the third set speed, which is a predetermined high speed, the stop of power supply to the outdoor fan and the indoor fan is released. As described above, since the power supply to the outdoor fan and the indoor fan is started after the engine speed has sufficiently increased and the actual generated power of the generator has sufficiently increased, the actual engine power increases in the process of increasing the engine speed. It is prevented that the generated power falls below the required power and the power supply is insufficient.

  The third set speed is a higher speed than the first set speed. Further, the third set rotational speed may be higher than the second set rotational speed. The third set rotational speed may be a rated rotational speed of the engine when the engine-driven air conditioner is performing a heating operation.

It is the schematic which shows the structure of the engine drive type air conditioner which concerns on this embodiment. It is a schematic block diagram of an air-conditioning unit in case a four-way switching valve is a cooling connection state. It is a flowchart which shows the flow in case an engine drive type air conditioner starts an air conditioning driving | operation, when the electric power from a commercial power source cannot be utilized. It is a flowchart which shows the self-defrosting defrost start control routine which a controller performs. It is a flowchart which shows the independent defrost termination | finish control routine performed by the controller. In the engine-driven air conditioner according to the present embodiment, the engine speed R and the compressor of the compressor when the operating state changes from the self-sustained heating operation to the self-supporting defrosting operation, and further from the self-supporting defrosting operation to the self-supporting heating operation. It is a graph which shows the change of the difference (differential pressure (DELTA) P) of the refrigerant | coolant pressure in a refrigerant | coolant suction port, and the refrigerant | coolant pressure in a refrigerant | coolant discharge port. In the engine-driven air conditioner according to the present embodiment, the engine speed R, the actual generated power, and the power when the operating state changes from the self-sustained heating operation to the self-supporting defrosting operation and further from the self-supporting defrosting operation to the self-supporting heating operation. It is a graph which shows the change of required electric power. In the conventional self-contained engine-driven air conditioner, the engine speed R, the actual generated power and the power when the operating state changes from the self-sustained heating operation to the self-sustained defrosting operation and further from the self-sustained defrosting operation to the self-sustaining heating operation. It is a graph which shows the change of required electric power.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration of an engine-driven air conditioner according to this embodiment. As shown in FIG. 1, the engine-driven air conditioner 1 includes a gas engine 10, an air conditioning unit 20, an indoor unit remote controller 30, a generator 40, a battery 50, a controller 60, and a starter motor 70. Prepare.

  The gas engine 10 is driven by the supply of gas fuel from the gas pipe 11. The gas engine 10 includes an output shaft 12, and the driving force of the gas engine 10 is taken out from the output shaft 12. A first pulley 13 and a second pulley 14 are connected to the output shaft 12 coaxially with the output shaft 12. The gas engine 10 is configured to be started by a starter motor 70.

  The air conditioning unit 20 is a component that contributes to air conditioning, and includes a compressor 21, a refrigerant pipe 22, an indoor heat exchanger 23, an indoor fan 231, an outdoor heat exchanger 24, an outdoor fan 241, and an expansion valve 25. A four-way switching valve 26, an accumulator 27, and a clutch 28. The indoor heat exchanger 23, the outdoor heat exchanger 24, the expansion valve 25, and the four-way switching valve 26 are interposed in the refrigerant pipe 22. The compressor 21, the refrigerant pipe 22, the indoor heat exchanger 23, the outdoor heat exchanger 24, the expansion valve 25, the four-way switching valve 26, and the accumulator 27 constitute a refrigerant circulation circuit. A refrigerant flows through the refrigerant pipe 22. In the present embodiment, the refrigerant pipe 22 is a first refrigerant pipe 221, a second refrigerant pipe 222, a third refrigerant pipe 223, a fourth refrigerant pipe 224, a fifth refrigerant pipe 225, and a sixth refrigerant pipe 226. With.

  The compressor 21 includes a first input shaft 211 and a second input shaft 212 that are coaxially arranged. When the second input shaft 212 rotates, the compressor 21 is driven. A third pulley 213 is coaxially connected to the first input shaft 211. A belt is wound between the first pulley 13 and the third pulley 213. Therefore, the rotational driving force of the output shaft 12 of the gas engine 10 is transmitted to the first input shaft 211 via the first pulley 13 and the third pulley 213.

  The clutch 28 is attached midway between the first input shaft 211 and the second input shaft 212. For example, the clutch 28 may be configured such that two clutch plates face each other, and may be configured to be able to adopt a contact state in which the respective clutch plates are in contact with each other and a separated state in which the clutch plates are separated from each other. The operation of the clutch 28 is controlled by a controller 60 described later.

  In this case, when the clutch 28 is in a contact state, the rotation of the first input shaft 211 is transmitted to the second input shaft 212. Therefore, the power of the gas engine 10 is transmitted to the compressor 21. On the other hand, when the clutch 28 is in the disengaged state, the rotation of the first input shaft 211 is not transmitted to the second input shaft 212. Therefore, the power of the gas engine 10 is not transmitted to the compressor 21.

  The compressor 21 has a refrigerant suction port 21a and a refrigerant discharge port 21b. The refrigerant discharge port 21 b is connected to one end of the first refrigerant pipe 221, and the refrigerant suction port 21 a is connected to one end of the sixth refrigerant pipe 226. Therefore, when the compressor 21 is driven, the compressor 21 sucks the low-pressure gas refrigerant in the sixth refrigerant pipe 226 from the refrigerant suction port 21a, compresses the sucked low-pressure gas refrigerant inside, and compresses the high-pressure gas refrigerant. The gas refrigerant is discharged from the refrigerant discharge port 21b to the first refrigerant pipe 221.

  The indoor heat exchanger 23 is installed indoors. The indoor heat exchanger 23 includes a heat exchange tube and is configured so that a refrigerant can flow through the heat exchange tube. The refrigerant flowing through the heat exchange tube exchanges heat with room air. The indoor heat exchanger 23 has a first inlet 23a through which refrigerant flows during heating operation and a first outlet 23b through which refrigerant flows out during heating operation. During the cooling operation, the refrigerant flows in from the first outlet 23b and flows out from the first inlet 23a. One end of the second refrigerant pipe 222 is connected to the first inflow port 23a. One end of the third refrigerant pipe 223 is connected to the first outlet 23b.

  The outdoor heat exchanger 24 is installed outdoors. The outdoor heat exchanger 24 includes a heat exchange tube, and is configured so that a refrigerant can flow through the heat exchange tube. The refrigerant circulating in the heat exchange tube exchanges heat with the outside air. The outdoor heat exchanger 24 has a second inlet 24a through which refrigerant flows during heating operation, and a second outlet 24b through which refrigerant flows out during heating operation. During the cooling operation, the refrigerant flows in from the second outlet 24b and flows out from the second inlet 24a. The other end of the third refrigerant pipe 223 is connected to the second inlet 24a. Accordingly, the third refrigerant pipe 223 connects the first outlet 23 b of the indoor heat exchanger 23 and the second inlet 24 a of the outdoor heat exchanger 24. One end of a fourth refrigerant pipe 224 is connected to the second outlet 24b.

  An expansion valve 25 is interposed in the middle of the third refrigerant pipe 223. Therefore, the third refrigerant pipe 223 is constituted by the indoor pipe 223a closer to the indoor heat exchanger 23 and the outdoor pipe 223b closer to the outdoor heat exchanger 24 than the expansion valve 25 as a boundary. The The expansion valve 25 expands (low pressure) the refrigerant in the refrigerant pipe 22 passing therethrough.

  The accumulator 27 is configured to gas-liquid separate the refrigerant introduced therein to discharge only the gas-phase refrigerant. The accumulator 27 is connected to one end of a fifth refrigerant pipe 225 as a refrigerant introduction pipe and the other end of a sixth refrigerant pipe 226 as a refrigerant discharge pipe. Therefore, the sixth refrigerant pipe 226 connects the accumulator 27 and the refrigerant suction port 21 a of the compressor 21.

  The four-way switching valve 26 includes a hollow fixed portion having four ports (a first port 261, a second port 262, a third port 263, and a fourth port 264), and a drive portion movable within the fixed portion. . The space in the fixed part is partitioned so that two specific ports and the other two ports are connected by the drive part. As shown in FIG. 1, the other end of the first refrigerant pipe 221 having one end connected to the refrigerant discharge port 21 b of the compressor 21 is connected to the first port 261 of the fixed portion of the four-way switching valve 26. The The other end of the second refrigerant pipe 222 whose one end is connected to the first inlet 23 a of the indoor heat exchanger 23 is connected to the second port 262. The third port 263 is connected to the other end of the fifth refrigerant pipe 225 whose one end is connected to the accumulator 27. The fourth port 264 is connected to the other end of the fourth refrigerant pipe 224 whose one end is connected to the second outlet 24 b of the outdoor heat exchanger 24.

  The drive unit of the four-way switching valve 26 is movably disposed in the fixed unit so that the position can be selectively switched between the heating connection position and the cooling connection position. When the position of the drive unit is the heating connection position, the four-way switching valve 26 is in the heating connection state, and when the position of the drive unit is the cooling connection position, the four-way switching valve 26 is in the cooling connection state. FIG. 1 shows a case where the four-way switching valve 26 is in a heating connection state. When in the heating connection state, the first port 261 and the second port 262 are communicated, and the third port 263 and the fourth port 264 are communicated. Therefore, when in the heating connection state, the refrigerant discharge port 21b (high-pressure side) of the compressor 21 and the indoor heat exchanger 23 are connected via the four-way switching valve 26, and the refrigerant suction port 21a (low-pressure side) of the compressor 21 is connected. ) And the outdoor heat exchanger 24 are connected via a four-way switching valve 26.

  FIG. 2 is a schematic configuration diagram of the air conditioning unit 20 when the four-way switching valve 26 is in a cooling connection state. As shown in FIG. 2, when the four-way switching valve 26 is in the cooling connection state, the first port 261 and the fourth port 264 are connected, and the second port 262 and the third port 263 are connected. Therefore, in the cooling connection state, the refrigerant discharge port 21b (high pressure side) of the compressor 21 and the outdoor heat exchanger 24 are communicated with each other via the four-way switching valve 26, and the refrigerant suction port 21a (low pressure side) of the compressor 21 is connected. ) And the indoor heat exchanger 23 are communicated with each other via a four-way switching valve 26. During the heating operation, the four-way switching valve 26 is in a heating connection state, and during the cooling operation, the four-way switching valve 26 is in a cooling connection state. Incidentally, during the defrosting operation, the four-way switching valve 26 is in a cooling connection state. Therefore, when the operating state changes from the heating operation to the defrosting operation, the four-way switching valve 26 is switched from the heating connection state to the cooling connection state. Further, when the operating state changes from the defrosting operation to the heating operation, the four-way switching valve 26 is switched from the cooling connection state to the heating connection state.

  Here, the air conditioning operation (heating operation, cooling operation) of the engine-driven air conditioner 1 will be briefly described. First, the heating operation will be described. When the compressor 21 is driven by the gas engine 10, the low-pressure gas refrigerant in the sixth refrigerant pipe 226 is sucked into the compressor 21 from the refrigerant suction port 21a and the sucked low-pressure gas refrigerant is compressed. The compressed high-temperature high-pressure gas refrigerant is discharged from the refrigerant discharge port 21b to the first refrigerant pipe 221. The high-temperature high-pressure gas refrigerant discharged from the refrigerant discharge port 21 b flows through the first refrigerant pipe 221 and enters the first port 261 of the four-way switching valve 26. In the heating connection state, the first port 261 communicates with the second port 262. A second refrigerant pipe 222 is connected to the second port 262. Therefore, the high-temperature and high-pressure gas refrigerant entering the four-way switching valve 26 from the first port 261 exits the four-way switching valve 26 from the second port 262 and flows to the second refrigerant pipe 222. The high-temperature high-pressure gas refrigerant that has flowed into the second refrigerant pipe 222 flows into the indoor heat exchanger 23 from the first inflow port 23a. The high-temperature and high-pressure gas refrigerant that has flowed into the indoor heat exchanger 23 is condensed by discharging heat to the indoor air while flowing through the indoor heat exchanger 23. At this time, the indoor 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 first outlet 23 b of the indoor heat exchanger 23 to the third refrigerant pipe 223. And it is pressure-reduced so that it may evaporate easily by expanding with the expansion valve 25 interposed in the middle of the 3rd refrigerant | coolant piping 223. FIG. Thereafter, it flows into the outdoor heat exchanger 24 from the second inflow port 24a. That is, the refrigerant heat expanded by the expansion valve 25 flows into the outdoor heat exchanger 24 after flowing out of the indoor heat exchanger 23 during the heating operation. While flowing into the outdoor heat exchanger 24, the refrigerant flowing into the outdoor heat exchanger 24 takes away the heat of the outside air and evaporates.

  A part of the refrigerant evaporated by taking the heat of the outside air is vaporized and flows out from the second outlet 24b of the outdoor heat exchanger 24 to the fourth refrigerant pipe 224. Then, it enters the fourth port 264 of the four-way switching valve 26. In the heating connection state, the fourth port 264 communicates with the third port 263. The third port 263 is connected to the fifth refrigerant pipe 225. Therefore, the refrigerant that has entered the four-way switching valve 26 from the fourth port 264 exits the four-way switching valve 26 from the third port 263, flows to the fifth refrigerant pipe 225, and is further introduced into the accumulator 27. In the accumulator 27, the introduced refrigerant is gas-liquid separated. Then, only the low-temperature and low-pressure gas refrigerant flows through the sixth refrigerant pipe 226 and returns to the refrigerant inlet 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 driven by the gas engine 10, high-temperature and high-pressure gas refrigerant is discharged from the refrigerant discharge port 21 b of the compressor 21 to the first refrigerant pipe 221. The high-temperature high-pressure gas refrigerant discharged from the refrigerant discharge port 21 b flows through the first refrigerant pipe 221 and enters the first port 261 of the four-way switching valve 26. In the cooling connection state, the first port 261 communicates with the fourth port 264 as shown in FIG. A fourth refrigerant pipe 224 is connected to the fourth port 264. Therefore, the high-temperature and high-pressure gas refrigerant entering the four-way switching valve 26 from the first port 261 exits the four-way switching valve 26 from the fourth port 264 and flows to the fourth refrigerant pipe 224. The high-temperature and high-pressure gas refrigerant that has flowed into the fourth refrigerant pipe 224 flows into the outdoor heat exchanger 24 from the second outlet 24b. The high-temperature and high-pressure gas refrigerant that has flowed into the outdoor heat exchanger 24 is condensed by discharging heat to the outside air while flowing through the outdoor heat exchanger 24.

  The refrigerant that is condensed by discharging heat to the outside air is partially liquefied and flows out from the second inlet 24 a of the outdoor heat exchanger 24 to the third refrigerant pipe 223. And it is pressure-reduced so that it may evaporate easily by expanding with the expansion valve 25 interposed in the middle of 3rd refrigerant | coolant piping. Then, it flows into the indoor heat exchanger 23 from the first outlet 23b. While flowing into the indoor heat exchanger 23, the refrigerant flowing into the indoor heat exchanger 23 takes the heat of the indoor air and evaporates. 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 first inlet 23 a of the indoor heat exchanger 23 to the second refrigerant pipe 222. Then, it enters the second port 262 of the four-way switching valve 26. In the cooling connection state, the second port 262 communicates with the third port 263. The third port 263 is connected to the fifth refrigerant pipe 225. Therefore, the refrigerant that has entered the four-way switching valve 26 from the second port 262 exits the four-way switching valve 26 from the third port 263, flows to the fifth refrigerant pipe 225, and is further introduced into the accumulator 27. In the accumulator 27, the introduced refrigerant is gas-liquid separated. Then, only the low-temperature and low-pressure gas refrigerant flows through the sixth refrigerant pipe 226 and returns to the refrigerant inlet 21 a of the compressor 21. By repeating such a refrigerant circulation cycle, room cooling is continued.

  As shown in FIG. 1, the indoor fan 231 is disposed facing the indoor heat exchanger 23, and exchanges heat between the refrigerant flowing in the indoor heat exchanger 23 and the indoor air by sending air to the indoor heat exchanger 23. Promote. The outdoor fan 241 is disposed facing the outdoor heat exchanger 24 and promotes heat exchange between the refrigerant flowing in the outdoor heat exchanger 24 and the outside air by sending air to the outdoor heat exchanger 24. The indoor fan 231 and the outdoor fan 241 are components that constitute the engine-driven air conditioner 1 and are driven by electric power, that is, electric drive components.

  The generator 40 has an input shaft 41. A fourth pulley 42 is coaxially connected to the input shaft 41. A belt is wound between the second pulley 14 and the fourth pulley 42. Therefore, the rotation of the output shaft 12 of the gas engine 10 is transmitted to the input shaft 41 of the generator 40 via the second pulley 14 and the fourth pulley 42. When the input shaft 41 is rotationally driven, power is generated by the generator 40.

  The generator 40 is a component of the engine-driven air conditioner 1 and is electrically connected to a component (electrically driven component) that is driven by electric power, and is configured to be able to supply electric power to these electrically driven components. Is done. For example, the indoor fan 231, the outdoor fan 241, and the controller 60 are electrically connected. In addition, although not illustrated, the generator 40 is also electrically connected to a cooling pump or the like provided in a cooling unit for cooling the gas engine 10. The generator 40 is also electrically connected to the battery 50. Furthermore, the generator 40 is also electrically connected to an external load so that the external load can be driven by the power generated by the generator 40. In FIG. 1, the generator 40 is electrically connected to external loads 101, 102, 103.

  The battery 50 stores the electric power generated by the generator 40. The battery 50 is configured to be electrically connected to the controller 60 and the starter motor 70 so as to supply electric power thereto.

  The indoor unit remote controller 30 operates when power is supplied from a commercial power source. The indoor unit remote controller 30 is configured to be able to perform instructions for starting and stopping the operation of the engine-driven air conditioner 1 when a commercial power source is available, and to set air conditioning conditions. The indoor unit remote controller 30 is configured to be able to communicate with the controller 60 so that the set condition can be received by the controller 60.

  The starter motor 70 is electrically connected to the battery 50 as described above, and is also electrically connected to a commercial power source. Accordingly, the starter motor 70 is driven by being supplied with power from a commercial power source or the battery 50 to start the gas engine 10. When power can be supplied from both the commercial power source and the battery 50, the starter motor 70 is driven by power supplied from the commercial power source.

  The controller 60 is electrically connected to the generator 40, the battery 50, and the commercial power source. The controller 60 controls the engine-driven air conditioner 1 based on conditions set by the indoor unit remote controller 30 and information from various sensors provided in the engine-driven air conditioner 1. In particular, the controller 60 controls the operation of the clutch 28, the switching operation of the four-way switching valve 26, and the rotational speed of the gas engine 10. Furthermore, the controller 60 supplies power to the electric drive components and external loads in the engine-driven air conditioner 1 from the generator 40 during the self-sustaining operation in which the engine-driven air conditioner 1 is operating with the power generated by the generator 40. Control the magnitude of power.

  Moreover, as shown in FIG. 1, the 1st temperature sensor 281 is attached to the part near the indoor heat exchanger 23 among the 2nd refrigerant | coolant piping 222, and indoor heat exchange is carried out among the 3rd refrigerant | coolant piping 223 (indoor side piping 223a). A second temperature sensor 282 is attached to a portion close to the vessel 23. Furthermore, a third temperature sensor 283 is attached to a portion of the third refrigerant pipe 223 (outdoor pipe 223b) close to the outdoor heat exchanger 24, and a third temperature sensor 283 is attached to a portion of the fourth refrigerant pipe 224 close to the outdoor heat exchanger 24. A four temperature sensor 284 is attached. The temperature information detected by these temperature sensors is transferred to the controller 60. In addition, although not illustrated, for example, a temperature sensor or a pressure sensor may be provided in the vicinity of the refrigerant suction port 21a and the refrigerant discharge port 21b of the compressor 21. Furthermore, pressure sensors may be provided at various locations on the refrigerant pipe. Information detected by these sensors is transferred to the controller 60.

  The engine-driven air conditioner 1 according to this embodiment can be started by being supplied with electric power from a commercial power source and can be continuously operated with power supplied from the commercial power source. In addition to starting spontaneously, the operation can be continued independently without receiving power supply from a commercial power source. FIG. 3 is a flowchart showing a flow when the engine-driven air conditioner 1 starts the air-conditioning operation when the electric power from the commercial power source cannot be used. When starting operation of the engine-driven air conditioner 1 when the commercial power source cannot be used, first, as shown in step (hereinafter abbreviated as S) 1 in FIG. A start switch of an external device (not shown) (this external device is supplied with power from the battery 50) is pressed (ON operation), and an air conditioning start signal is transmitted to the controller 60. Then, the controller 60 (the controller 60 is also supplied with power from the battery 50) outputs an air conditioning activation signal to the starter motor 70. When the starter motor 70 receives the air conditioning activation signal, power is supplied from the battery 50 to the starter motor 70 (S2). The starter motor 70 is driven by being supplied with power from the battery 50. The gas engine 10 is started by driving the starter motor 70 (S3). Once the gas engine 10 is started, the driving is continued by supplying gas fuel thereafter, so that it is not necessary to drive the starter motor 70. Therefore, the power supply from the battery 50 to the starter motor 70 is stopped (S4).

  When the gas engine 10 is started in S3, the generator 40 connected to the gas engine 10 so as to be able to transmit power is also driven to generate power (S5). Further, after the gas engine 10 is started in S3, the controller 60 operates the clutch 28 so that the connection state between the gas engine 10 and the compressor 21 becomes the transmission state (S7). As a result, the compressor 21 connected to the gas engine 10 so as to be able to transmit power is driven (S8). When the compressor 21 is driven, the refrigerant flows through the refrigerant pipe 22 and the air conditioning operation is started.

  In the present embodiment, each electric drive component constituting the engine-driven air conditioner 1 is electrically connected to the generator 40. Therefore, when the commercial power source cannot be used, the generator 40 supplies power to each electric drive component as in S6. In this case, when the connection state between the gas engine 10 and the compressor 21 is a transmission state, the engine-driven air conditioner 1 simultaneously performs air conditioning and power supply to each electric drive component and an external load. Such an operation is referred to as an independent air-conditioning operation (an independent heating operation or an independent cooling operation) in this specification. On the other hand, when the connection state of the gas engine 10 and the compressor 21 is in the cut-off state, the engine-driven air conditioner 1 uses electric power to the electric drive parts and external loads that need to be supplied with power in order to continue the current operation. Supply only. Such an operation is referred to as a self-sustained power generation operation in this specification. In any independent operation, the gas engine 10 is driven.

  When the engine-driven air conditioner 1 is operating independently, the electric power generated by the generator 40 is also supplied to the external loads 101, 102, 103 as described above. Therefore, for example, at the time of a power failure, the engine-driven air conditioner 1 (generator 40) supplies power to an external load instead of the commercial power supply. In addition, when the engine-driven air conditioner 1 is operating independently, the gas engine 10 is driven to rotate at a rated speed. In this embodiment, the rated rotational speed is 2400 rpm. When the gas engine 10 is driven at the rated rotational speed (2400 rpm), the generator 40 generates electric power having a magnitude of about 4.5 kW. Among these, the electric power more than the electric power (external supply electric power) predetermined as the minimum electric power supplied to an external load is provided to an external load, and the remaining electric power is provided to the electric drive component of the engine drive type air conditioner 1. In the present embodiment, the external supply power is set to 2 kW. Further, most of the electric power provided to the engine-driven air conditioner 1 is consumed by the indoor fan 231 and the outdoor fan 241. For example, the maximum power consumption of the indoor fan 231 is about 0.7 kW, and the maximum power consumption of the outdoor fan 241 is about 0.7 kW.

  When the engine-driven air conditioner 1 is in a self-sustained heating operation, the outside air temperature is extremely low and the refrigerant in the outdoor heat exchanger 24 cannot sufficiently take heat from the outside air, and the refrigerant evaporation temperature is 0 ° C. When it falls to less than, there exists a possibility that the outdoor heat exchanger 24 may frost. When the outdoor heat exchanger 24 is frosted, the heat exchange performance of the outdoor heat exchanger 24 is deteriorated. Therefore, in this case, the independent heating operation is temporarily stopped and the independent defrosting operation is started. When switching the operation state from the independent heating operation to the independent defrosting operation, the switching state of the four-way switching valve 26 is switched from the heating connection state to the cooling connection state. Further, when switching the operation state from the self-sustained defrosting operation to the self-sustained heating operation, the switching state of the four-way switching valve 26 is switched from the cooling connection state to the heating connection state. In the present embodiment, when the operation state is switched from the self-sustained heating operation to the self-sustained defrosting operation, the controller 60 executes the pre-self-defrosting control and the operation state is switched from the self-sustained defrosting operation to the self-sustained heating operation. In addition, the controller 60 executes the control after self-defrosting.

  FIG. 4 is a flowchart showing a control routine before self-defrosting executed by the controller 60. This control routine before self-defrosting is performed at predetermined minute intervals when the engine-driven air conditioner 1 is performing a self-heating operation. When the control routine before self-defrosting is started, the controller 60 first determines whether or not the outdoor heat exchanger 24 is frosted in S11 of FIG. This frost formation determination can be performed based on whether or not the evaporation temperature of the refrigerant in the outdoor heat exchanger 24 (the temperature detected by the fourth temperature sensor 284) is, for example, 0 ° C. or higher.

  When the frost is not formed (S11: No), the controller 60 determines that the self-sustained defrosting operation is not necessary and once ends this routine. On the other hand, when the frost is formed (S11: Yes), the controller 60 recognizes that the switching operation request of the four-way switching valve 26 has been input in order to change the operation state from the independent heating operation to the independent defrosting operation. In this case, the controller 60 advances the process to S12 and stops the power supply from the generator 40 to the outdoor fan 241. As a result, the driving of the outdoor fan 241 stops. Next, the controller 60 reduces the rotational speed R of the gas engine 10 gradually or stepwise (S13). Subsequently, the controller 60 determines whether or not the engine speed R has decreased to a predetermined second set speed R2 (S14). The second set rotational speed R2 will be described later.

  When it is determined in S14 that the engine speed R is equal to or higher than the second set speed R2 (S14: No), the controller 60 returns the process to S13 and continues to decrease the engine speed R. On the other hand, when it is determined that the engine speed R has decreased to the second set speed R2 (S14: Yes), the controller 60 proceeds to S15 and stops the power supply from the generator 40 to the indoor fan 231. . As a result, the amount of power supplied from the generator 40 to the electric drive component is reduced, and the drive of the indoor fan 231 is stopped.

  Subsequently, the controller 60 determines whether or not the engine speed R has decreased to the first set speed R1 (S16). The first set rotational speed R1 is predetermined as a rotational speed smaller than the second set rotational speed R2 (in other words, the second set rotational speed R2 is a rotational speed larger than the first set rotational speed R1).

  Here, how to determine the first set rotational speed R1 will be described. If the engine speed decreases during the self-supporting air-conditioning operation of the self-supporting engine-driven air conditioner, the compressor speed also decreases, so the difference between the refrigerant pressure at the refrigerant discharge port and the refrigerant pressure at the refrigerant suction port The pressure ΔP decreases. The first set rotational speed R1 moderately suppresses the occurrence of the above-mentioned problems (distortion of heat exchange fins, large refrigerant flow noise) caused by a large differential pressure ΔP when the switching state of the four-way switching valve 26 is changed. This is a rotational speed that is defined in advance as an engine rotational speed for generating such a differential pressure ΔP. The first set rotational speed R1 can be set, for example, to the minimum rotational speed during the independent heating operation, for example, 1200 rpm.

  When it is determined in S16 that the engine speed R is equal to or higher than the first set speed R1 (S16: No), the controller 60 waits until the engine speed R decreases to the first set speed R1. If the engine speed R has decreased to the first set speed R1 (S16: Yes), the controller 60 proceeds to S17 and stops the decrease in the engine speed R. Thereafter, the controller 60 ends this routine.

  The controller 60 performs the switching operation of the four-way switching valve 26 after the determination result of S11 is Yes and the execution of the control before the independent defrosting is finished. As a result, the refrigerant discharge port 21b of the compressor 21 is connected to the indoor heat exchanger 23, and the refrigerant suction port 21a of the compressor 21 is connected to the outdoor heat exchanger 24. The switching state of the four-way switching valve 26 changes to a cooling connection state in which the discharge port 21b is connected to the outdoor heat exchanger 24 and the refrigerant suction port 21a of the compressor 21 is connected to the indoor heat exchanger 23. The self-supporting defrosting operation is started when the switching operation of the four-way switching valve 26 is completed. Thus, according to this embodiment, when the switching operation request | requirement of the four-way switching valve 26 is input in order to change an operation state from a self-sustained heating operation to a self-supporting defrosting operation, the four-way switching valve 26 performs a switching operation. Before, the rotational speed R of the gas engine 10 and the power generation are reduced so that the rotational speed R of the gas engine 10 is reduced to the first set rotational speed R1 and the magnitude of the power supplied from the generator 40 to the electric drive parts is reduced. A self-defrosting pre-control for controlling the magnitude of power supplied from the machine 40 to the electric drive parts is executed.

  When the self-sustained defrosting control is finished and the self-sustaining defrosting operation is started, the high-temperature and high-pressure gas refrigerant flows into the outdoor heat exchanger 24 through the four-way switching valve 26. Then, the high-temperature and high-pressure gas refrigerant condenses in the outdoor heat exchanger 24 and discharges heat to the outside air. For this reason, the frost adhering to the outdoor heat exchanger 24 melts. This defrosts. Then, after continuing the defrosting operation for a predetermined time, the controller 60 switches the four-way switching valve 26 to change the operation state from the self-sustained defrosting operation to the self-sustained heating operation. As a result, the refrigerant discharge port 21b of the compressor 21 is connected to the outdoor heat exchanger 24, and the refrigerant suction port 21a of the compressor 21 is connected to the indoor heat exchanger 23. The switching state of the four-way switching valve 26 changes to a heating connection state in which the discharge port 21b is connected to the indoor heat exchanger 23 and the refrigerant suction port 21a of the compressor 21 is connected to the outdoor heat exchanger 24. When the switching operation of the four-way switching valve 26 is completed, the self-supporting defrosting operation is finished.

  Then, the controller 60 performs control after self-defrosting. FIG. 5 is a flowchart showing a control routine after self-defrosting executed by the controller 60. When the control routine after the self-supporting defrosting is started, the controller 60 increases the rotational speed R of the gas engine 10 in S21 of FIG.

  Subsequently, the controller 60 determines whether or not the engine speed R is larger than the third set speed R3 (S22). The third set rotational speed R3 will be described later, but may be set to the rated rotational speed (2400 rpm) of the gas engine 10, for example. When it is determined in S22 that the engine speed R is equal to or less than the third set speed R3 (S22: No), the controller 60 returns the process to S21 and continues to increase the engine speed R. On the other hand, when it is determined that the engine speed R has increased to the third set speed R3 (S22: Yes), the controller 60 proceeds to S23 and stops the power supply from the generator 40 to the outdoor fan 241. Next, the stop of the power supply from the generator 40 to the indoor fan 231 is released (S24). Subsequently, the controller 60 advances the process to S25, and returns the control of the engine speed R to the control during the independent heating operation (normal control). Thereafter, the controller 60 ends this routine. Thus, according to the present embodiment, after the four-way switching valve 26 is switched in order to change the operating state from the self-sustained defrosting operation to the self-sustaining heating operation, the rotational speed R of the gas engine 10 is increased, and the gas When the rotational speed R of the engine 10 reaches the third set rotational speed R3, from the rotational speed R of the gas engine 10 and the generator 40 so as to cancel the stop of power supply to the outdoor fan 241 and the indoor fan 231. Control after independent defrosting that controls power supply to the outdoor fan 241 and the indoor fan 231 is executed. After the controller 60 performs the control after self-defrosting, the operation state of the engine-driven air conditioner 1 is switched to the self-heating operation.

  FIG. 6 shows the engine speed R and the refrigerant pressure at the refrigerant inlet 21a of the compressor 21 when the operation state changes from the self-sustained heating operation to the self-sustained defrosting operation and from the self-sustained defrosting operation to the self-sustained heating operation. It is a graph which shows the change of differential pressure | voltage (DELTA) P with the refrigerant | coolant pressure in the refrigerant | coolant discharge port 21b. In FIG. 6, line A represents the change in engine speed R, and line B represents the change in differential pressure ΔP.

  As shown in FIG. 6, the engine speed R is the rated speed of 2400 rpm during the self-sustained heating operation. At this time, the differential pressure ΔP is about 2.5 MPa. When the four-way switching valve 26 is switched when the differential pressure ΔP is 2.5 MPa, the above-described problems (distortion of heat exchange fins, large flow noise) occur because the differential pressure ΔP is large. To do. In the present embodiment, the range of the differential pressure ΔP for sufficiently suppressing the occurrence of the above-described problems when switching the four-way switching valve 26 is 1.5 MPa or less. If the differential pressure ΔP is too small, the four-way switching valve 26 will not operate. For these reasons, the differential pressure ΔP is preferably a minimum operating differential pressure (for example, 0.5 MPa) to 1.5 MPa of the four-way switching valve 26. That is, when the four-way switching valve 26 is switched, the differential pressure ΔP needs to be kept within the range of the minimum operating differential pressure of the four-way switching valve 26 to 1.5 MPa.

  In FIG. 6, it is determined that frost is formed at time T1. That is, at time T1, a request for switching the four-way switching valve 26 is input to the controller 60. Then, the self-defrost pre-defrost control is executed thereafter, and the engine speed R is reduced. When the engine speed R decreases, the speed of the compressor 21 also decreases, so that the capacity of the compressor 21 decreases. Therefore, the differential pressure ΔP also decreases. When the engine speed R decreases to 1200 rpm, the differential pressure ΔP falls below 1.5 MPa. In the present embodiment, the first set rotational speed R1 is 1200 rpm. Therefore, the decrease in the engine speed R is stopped at the time T2 when the engine speed R becomes 1200 rpm, and the control before the self-defrosting is finished. Thereafter, the four-way switching valve 26 is switched to start the self-supporting defrosting operation.

  The self-supporting defrosting operation is continued for a predetermined time, and at time T3, the four-way switching valve 26 is switched and the self-supporting defrosting operation is terminated. Thereafter, the control after self-defrosting is executed, and the engine speed R is increased. When the engine speed R increases, the speed of the compressor 21 also increases, so that the capacity of the compressor 21 is improved. Therefore, the differential pressure ΔP also increases. Then, when the engine speed R increases to 2400 rpm, the control after the self-defrosting is finished and the self-heating operation is started.

  FIG. 7 shows the engine speed R and the power generated by the generator 40 (actual power generation) when the operating state changes from the self-sustained heating operation to the self-supporting defrosting operation and from the self-supporting defrosting operation to the self-supporting heating operation. ) And a change in required power, which is the sum of the power supplied to each electric drive component in order to operate the externally supplied power and the engine-driven air conditioner 1. In FIG. 7, the upper graph represents a change in engine speed R, and the lower graph represents a change in electric power. In the lower graph, line A represents a change in actual generated power, and line B represents a change in required power.

  As shown in FIG. 7, during the self-sustained heating operation, the engine speed R is about 2400 rpm, and the actual generated power of the generator 40 is about 4.5 kW. Further, the required power at this time is about 3.7 kW. When the independent pre-defrost control is executed at the time point T1 and the engine speed R decreases, the rotational speed of the generator 40 also decreases accordingly, so the actual generated power also decreases. In addition, the power supply from the generator 40 to the outdoor fan 241 is stopped immediately after the pre-independent defrost control is performed at the time point T1, so that the amount of power to be supplied from the generator 40 to the electric drive component is large. Is reduced. For this reason, the required power is reduced to 3.0 kW at T5 after T1.

  At the time of execution of the control before self-defrosting, the required power changes at 3.0 kW until the time T6 after the time T5. During this time, power supply from the generator 40 to the outdoor fan 241 is stopped as described above, but power is continuously supplied from the generator 40 to the indoor fan 231. For this reason, the indoor fan 231 continues to drive.

  On the other hand, since the actual generated power gradually decreases after the time point T5, the difference between the actual generated power and the required power becomes small. And the magnitude | size of request | requirement electric power and the magnitude | size of real power generation power become equal at the time of T6 after T5. That is, the required power and the actual generated power are 3.0 kW at the time of T6. At time T6, power supply from the generator 40 to the indoor fan 231 is stopped. The engine speed at this time, that is, the engine speed when the actual generated power and the required power are equal is the second set speed R2 of the present embodiment. The second set rotational speed R2 may be set as the engine rotational speed when the difference (A−B) between the actual generated power A and the required power B becomes a predetermined minute power ΔV. That is, the second set rotational speed R2 is the engine speed corresponding to the smallest possible power out of the power that can supply the required power (power to be supplied to the electric drive parts other than the outdoor fan + externally supplied power) in the control before the self-defrosting. It is predetermined as a number.

  Since the power supply from the generator 40 to the indoor fan 231 is stopped when the engine speed R decreases to the second set speed R2, that is, when the actual generated power and the required power become equal, the required power is reduced. It decreases from 3.0 kW to 2.3 kW. Then, the control before the independent defrosting is finished at the time point T2. The engine speed at the time of T2 is 1200 rpm, and the actual power generation at this time is 2.7 kW. As can be seen from FIG. 7, the actual generated power does not fall below the required power during the period from T1 to T2, that is, during the execution of the pre-independent defrost control. Therefore, there is no shortage of power supply.

  As can be seen from FIG. 6, the target value of the rotational speed of the gas engine 10 that is reduced by the control before the self-defrosting, that is, the first set rotational speed R1 (1200 rpm in the present embodiment) is 1.5 MPa or less. As shown in FIG. 7, it is possible to suppress the occurrence of problems caused by the large differential pressure ΔP (distortion of heat exchange fins during switching operation of the four-way switching valve 26 and large flow noise). The rotation speed is such that the generated power does not fall below the required power. That is, it is possible to suppress the occurrence of problems caused by the large differential pressure ΔP (distortion of heat exchange fins and large flow noise during switching operation of the four-way switching valve 26), and the actual generated power falls below the required power. The first set rotational speed R1 is determined in advance as the rotational speed that does not exist.

  At the time of T2, the control before the self-defrosting is completed, the four-way switching valve 26 is switched and the self-defrosting operation is started. The actual generated power of the generator 40 during the self-supporting defrosting operation is 2.7 kW, and the required power B is 2.3 kW. That is, during the self-supporting defrosting operation, externally supplied power (2 kW) is provided to the external load, and the operation of the engine-driven air conditioner 1 (defrosting operation) is continued with the remaining power. Even during this self-sustaining defrosting operation, the actual generated power does not fall below the required power. Therefore, there is no shortage of power supply.

  At time T3, the four-way switching valve 26 is switched to complete the defrosting operation, and the control after the self-defrosting is executed. For this reason, the engine speed R is increased. Along with this, the actual generated power also increases. However, since the power supply from the generator 40 to the indoor fan 231 and the outdoor fan 241 is stopped, the required power does not increase. Therefore, the actual generated power does not fall below the required power, and there is no shortage of power supply.

  When the engine speed increases to 2400 rpm, which is the third set speed R3, at time T4, the power supply from the generator 40 to the indoor fan 231 and the outdoor fan 241 is stopped, and the control after self-defrosting is performed. The self-sustained heating operation is started. Since the actual power generation is already 4.5 kW at this time, even if the required power increases by supplying power to the indoor fan 231 and the outdoor fan 241 thereafter, the required power exceeds the actual power generation and is supplied. There is no shortage. That is, the engine speed at which the self-sustained heating operation can be started without falling into power supply is the third set speed R3. In other words, the third set rotational speed R3 is such that the actual generated power does not fall below the required power when the stop of power supply to the indoor fan 231 and the outdoor fan 241 is canceled and the independent heating operation is started. It is predetermined as a number.

  As can be seen from the above description and FIG. 7, in the present embodiment, when the operating state changes from the self-sustained defrosting operation to the self-sustaining defrosting operation, and when the operating state changes from the self-sustained defrosting operation to the self-sustained heating operation. Even if the actual power generated by the generator 40 decreases due to a decrease in the engine speed, the actual power generated does not fall below the required power. For this reason, at least external power supply (2 kW) can be stably supplied to the external load, and power can be stably supplied to the electric drive parts necessary for continued operation to operate the engine-driven air conditioner 1 independently. Can continue.

  FIG. 8 shows a conventional self-contained engine-driven air conditioner in which the engine speed R when the operating state changes from the self-sustained heating operation to the self-supporting defrosting operation, and further from the self-supporting defrosting operation to the self-supporting heating operation, It is a graph which shows the change of an actual generated electric power and request | requirement electric power. In FIG. 8, the upper graph represents a change in engine speed R, and the lower graph represents a change in electric power. In the lower graph, line A represents a change in actual generated power, and line B represents a change in required power.

  As shown in FIG. 8, when it is determined that frost formation has occurred at time T1, the engine speed is subsequently reduced. As the engine speed decreases, the actual power generated by the generator 40 also decreases. However, the power supply to the indoor fan and the outdoor fan is not stopped. Therefore, the actual generated power is lower than the required power at time T7.

  At the time T2, the decrease in the engine speed is completed, the four-way switching valve is switched, and the self-sustaining defrosting operation is started. At this time, since the power supply from the generator to the indoor fan and the outdoor fan is stopped, the actual generated power exceeds the required power at time T7. However, in the section C between T7 and T8, since the actual power generation is less than the required power, power supply shortage occurs.

  In addition, the self-supporting defrosting operation ends at time T3. Then, the engine speed is then increased. Along with this, the actual generated power also increases. Further, when the self-supporting defrosting operation is finished, power is immediately supplied from the generator to the indoor fan and the indoor fan. For this reason, the required power also increases. The required power exceeds the actual generated power at time T9. Thereafter, the required power becomes constant at about 3.9 kW, but the actual generated power increases as the engine speed increases, and the actual generated power exceeds the required power at time T10. However, in the section D between T9 and T10, the actual power generation is less than the required power, resulting in insufficient power supply.

  Thus, in the conventional self-supporting engine-driven air conditioner, power shortage occurs at the time of switching from the self-sustained heating operation to the self-supporting defrosting operation and at the time of switching from the self-supporting defrosting operation to the self-supporting heating operation. . On the other hand, in the self-supporting engine-driven air conditioner 1 according to the present embodiment, both at the time of switching from the self-supporting heating operation to the self-supporting defrosting operation and at the time of switching from the self-supporting defrosting operation to the self-supporting heating operation. Therefore, there will be no shortage of power supply. For this reason, it is possible to prevent the driving of the external load or the engine-driven air conditioner from being stopped due to insufficient power supply.

  As described above, the engine-driven air conditioner 1 of the present embodiment includes the gas engine 10, the compressor 21, the indoor heat exchanger 23, the outdoor heat exchanger 24, the four-way switching valve 26, and the generator 40. And a controller 60 (control unit). The compressor 21 has a refrigerant suction port 21a and a refrigerant discharge port 21b. The compressor 21 is driven by the power of the gas engine 10 to suck a low-pressure gas refrigerant from the refrigerant suction port 21a and a high-pressure gas refrigerant from the refrigerant discharge port 21b. Discharge. The indoor heat exchanger 23 is installed indoors, and exchanges heat between the refrigerant discharged from the refrigerant discharge port 21b of the compressor 21 and the room air during the heating operation. The outdoor heat exchanger 24 is installed outside, and flows out of the indoor heat exchanger 23 during heating operation, and exchanges heat between the refrigerant expanded by the expansion valve 25 and the outside air. In the heating operation, the four-way switching valve 26 is in a heating connection state in which the refrigerant discharge port 21b of the compressor 21 is connected to the indoor heat exchanger 23 and the refrigerant suction port 21a of the compressor 21 is connected to the outdoor heat exchanger 24. During cooling operation and defrosting operation, the refrigerant discharge port 21b of the compressor 21 is connected to the outdoor heat exchanger 24 and the refrigerant suction port 21a of the compressor 21 is connected to the indoor heat exchanger 23. The connection state between the refrigerant discharge port 21b and the refrigerant suction port 21a of the compressor 21 and the indoor heat exchanger 23 and the outdoor heat exchanger 24 can be switched so that the connection state is established. The generator 40 is configured to generate electric power using the power of the gas engine 10 and to supply the generated electric power to an external load and an electric drive component that is a component of the engine-driven air conditioner 1 and is driven by the electric power. The And the controller 60, when the switching operation request | requirement of the four-way switching valve 26 is input in order to change an operation state from heating operation to defrost operation, when the generator 40 is supplying electric power to electric drive parts, That is, when a switching operation request of the four-way switching valve 26 for switching the operation state to the self-sustaining defrosting operation is input during the self-sustained heating operation, the control before the self-defrosting is executed before the four-way switching valve 26 performs the switching operation. . In the control before self-defrosting, the controller 60 reduces the rotational speed of the gas engine 10 to a first preset rotational speed R1 that is a predetermined low rotational speed and supplies power from the generator 40 to the electric drive component. The number of revolutions of the gas engine 10 and the magnitude of power supplied from the generator 40 to the electric drive parts are controlled so that the magnitude of the power is reduced.

  In addition, the controller 60 reduces the rotational speed R of the gas engine 10 to the first set rotational speed R1 and controls the actual power generated by the generator 40 as the minimum power supplied to the external load in the control before the self-defrosting. The rotational speed R of the gas engine 10 and the generator 40 to the electric drive parts are set so as not to fall below the required electric power, which is the sum of the predetermined external supply power (2.0 kW) and the electric power to be supplied to the electric drive parts. Control the magnitude of the power supply.

  According to the present embodiment, when switching from the self-sustained heating operation to the self-sustained defrosting operation, the controller 60 executes the pre-self-defrosting control before the four-way switching valve 26 is switched. Although the engine speed R is reduced to the first set speed R1 by the execution of the control before the self-sustaining defrosting, the magnitude of the power supplied from the generator 40 to the electric drive parts is also reduced. Occurrence of supply shortage can be prevented, and stable power supply to an external load can be realized. In addition, in order to control the amount of power that should be supplied from the generator 40 to the electric drive parts so that the actual generated power of the generator 40 does not fall below the required power in the control before self-defrosting, the operation is continued. Electric power to necessary electric drive parts can be secured. Therefore, it is possible to prevent the operation of the engine-driven air conditioner 1 from being stopped due to insufficient power supply to the electric drive parts, and the power supply to the external load from being interrupted due to the engine-driven air conditioner 1 being stopped. .

  Further, the controller 60 reduces the rotation speed R of the gas engine 10 to the first set rotation speed R1 and stops the supply of power from the generator 40 to the outdoor fan 241 in the control before the self-defrosting. The rotational speed R of the gas engine 10 and the power supply from the generator 40 to the outdoor fan 241 are controlled. Thus, by stopping power supply to the outdoor fan 241 that does not require power supply in the self-supporting defrosting operation, electric drive that requires power supply from the generator 40 in the self-supporting defrosting operation is suppressed while suppressing wasteful power consumption. The electric power supplied to the components (for example, the controller 60) can be secured.

  In addition, the controller 60 supplies the necessary electric drive parts other than the outdoor fan 241 with the rotation speed R of the gas engine 10 being higher than the first set rotation speed R1 in the self-defrosting control. Until the electric power to be supplied and the electric power that can cover the externally supplied electric power are reduced to the second set rotational speed R2 that is set in advance as the rotational speed that is necessary for the generator 40 to generate as little electric power as possible. 40 so that the power supply from the generator 40 to the indoor fan 231 is stopped when the power supply from the generator 40 to the indoor fan 231 is continued and the rotational speed R of the gas engine 10 decreases to the second set rotational speed R2. The number of revolutions R of the engine 10 and the power supply from the generator 40 to the indoor fan 231 are controlled. For this reason, when the drive of the indoor fan 231 stops, the engine speed R can be lowered as much as possible. Therefore, when the indoor fan 231 is stopped, the pressure of the refrigerant discharge port 21b of the compressor 21 (that is, the pressure of the refrigerant flowing into the indoor heat exchanger 23) can be reduced.

  It is not necessary to drive the indoor fan in the defrosting operation. However, when the driving of the indoor fan is suddenly stopped during the heating operation, condensation of the refrigerant in the indoor heat exchanger suddenly stops. When the condensation of the refrigerant in the indoor heat exchanger suddenly stops, the pressure of the refrigerant flowing out from the indoor heat exchanger suddenly increases, and the engine-driven air conditioner may stop due to a pressure abnormality. In this regard, in the present embodiment, as described above, the refrigerant pressure at the refrigerant discharge port 21b of the compressor 21 (that is, the refrigerant pressure flowing into the indoor heat exchanger 23) can be reduced when the indoor fan 231 is stopped. Therefore, an abnormal stop due to a sudden rise in the refrigerant pressure flowing out from the indoor heat exchanger 23 when the indoor fan 231 is stopped can be avoided.

  Further, after the self-standing defrosting, the controller 60 switches the four-way switching valve 26 so as to change the operation state from the defrosting operation to the heating operation when the generator 40 is supplying electric power to the electric drive parts. Execute control. In the control after self-defrosting, the controller 60 increases the rotational speed of the gas engine 10 and the rotational speed R of the gas engine 10 has reached a third preset rotational speed R3 that is a predetermined high rotational speed. In some cases, the rotational speed of the gas engine 10 and the power supply from the generator 40 to the outdoor fan 241 and the indoor fan 231 are controlled so as to cancel the stop of the power supply to the outdoor fan 241 and the indoor fan 231. With this post-independent defrosting control, power supply to the outdoor fan 241 and the indoor fan 231 is started after the engine speed R is sufficiently increased and the actual generated power of the generator 40 is sufficiently increased. Therefore, it is possible to prevent the actual generated power from falling below the required power in the process of increasing the engine speed R, resulting in insufficient power supply.

  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 example in which a gas engine is used as the engine has been described. However, an engine using liquid fuel such as gasoline may be used. Further, the values of the first set rotation speed R1 and the third set rotation speed R3 shown in the present embodiment are examples and can be changed as appropriate. Thus, the present invention can be changed without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Engine-driven air conditioner, 10 ... Gas engine, 20 ... Air conditioning unit, 21 ... Compressor, 21a ... Refrigerant suction port, 21b ... Refrigerant discharge port, 22 ... Refrigerant piping, 23 ... Indoor heat exchanger, 23a ... No. 1 inflow port, 23b ... first outflow port, 231 ... indoor fan, 24 ... outdoor heat exchanger, 24a ... second inflow port, 24b ... second outflow port, 241 ... outdoor fan, 25 ... expansion valve, 26 ... four-way Switch valve 261 ... 1st port, 262 ... 2nd port, 263 ... 3rd port, 264 ... 4th port, 40 ... Generator, 50 ... Battery, 60 ... Controller (control part), 70 ... Starter motor, 101 , 102, 103 ... external load, A ... actual generated power, B ... required power, R ... engine speed, R1 ... first set speed, R2 ... second set speed, R3 ... third set speed, ΔP …Differential pressure

Claims (5)

An engine-driven air conditioner configured to perform heating operation and defrosting operation,
Engine,
A compressor having a refrigerant suction port and a refrigerant discharge port, driven by the power of the engine, sucking low-pressure gas refrigerant from the refrigerant suction port, and discharging high-pressure gas refrigerant from the refrigerant discharge port;
An indoor heat exchanger that is installed indoors and exchanges heat between the refrigerant discharged from the refrigerant discharge port of the compressor and room air during heating operation;
An outdoor heat exchanger that is installed outdoors and exchanges heat between the refrigerant flowing out of the indoor heat exchanger and the outside air during heating operation,
During the heating operation, the refrigerant outlet of the compressor is connected to the indoor heat exchanger and the refrigerant inlet of the compressor is connected to the outdoor heat exchanger, and during the defrosting operation, the compressor of the compressor The refrigerant discharge port and the refrigerant suction port of the compressor, such that a refrigerant discharge port is connected to the outdoor heat exchanger and the refrigerant suction port of the compressor is connected to the indoor heat exchanger; A four-way switching valve configured to be able to switch the connection state between the indoor heat exchanger and the outdoor heat exchanger;
A generator configured to generate electric power using the engine power, and to be able to supply the generated electric power to an external load and an electric drive component that is a component of the engine-driven air conditioner and is driven by the electric power;
When the switching operation request of the four-way switching valve is input in order to change the operation state from the heating operation to the defrosting operation when the generator is supplying electric power to the electric drive component, the four-way switching valve Before the engine is switched, the engine speed is reduced to a first preset speed which is a predetermined low speed, and the power supplied from the generator to the electric drive component is reduced. A control unit that performs a self-defrosting pre-control for controlling the number of revolutions of the engine and the amount of electric power supplied from the generator to the electric drive parts;
An engine-driven air conditioner. The engine-driven air conditioner according to claim 1,
In the pre-self-defrosting control, the control unit reduces the engine speed to the first set speed, and the actual generated power of the generator is set in advance as the minimum power to be supplied to the external load. Control the number of revolutions of the engine and the amount of power supplied from the generator to the electric drive parts so as not to fall below the required power, which is the sum of the predetermined power and the power to be supplied to the electric drive parts. An engine-driven air conditioner. The engine-driven air conditioner according to claim 1 or 2,
An outdoor fan as the electric drive part for blowing air to the outdoor heat exchanger;
The control unit is configured to reduce the engine speed to the first set speed and to stop supplying power from the generator to the outdoor fan in the control before the self-defrosting. An engine-driven air conditioner that controls the number of revolutions and power supply from the generator to the outdoor fan. The engine-driven air conditioner according to claim 3,
An indoor fan as the electric drive component for blowing air to the indoor heat exchanger;
The controller controls the power from the generator to the indoor fan until the engine speed decreases to a second set speed higher than the first set speed in the self-defrosting control. The supply of power from the generator to the indoor fan is stopped when the supply is continued and the rotation speed of the engine is reduced to the second set rotation speed. An engine-driven air conditioner that controls power supply to indoor fans. The engine-driven air conditioner according to claim 4,
The control unit rotates the engine after the four-way switching valve is switched to change the operating state from the defrosting operation to the heating operation when the generator is supplying electric power to the electric drive component. When the number of revolutions of the engine reaches a third preset number of revolutions, which is a predetermined high number of revolutions, the stop of power supply to the outdoor fan and the indoor fan is released. As described above, an engine-driven air conditioner that performs a self-defrosting control that controls the rotational speed of the engine and the power supply from the generator to the outdoor fan and the indoor fan.

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