JP4661289B2 - Engine driven air conditioner - Google Patents

Description

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

  GHP (gas heat pump) is a kind of air conditioner, and performs air conditioning using a gas engine. Specifically, the compressor (compressor) connected to the refrigerant passage by the gas engine is driven to circulate the refrigerant in the refrigerant passage, and the indoor heat exchanger and the outdoor heat exchanger interposed in the refrigerant passage Thus, the refrigerant is condensed and evaporated, and the air is conditioned by the movement of heat associated with the action.

  Specifically, during heating, the refrigerant discharged from the compressor passes through an indoor heat exchanger (condensation), an expansion valve (expansion), and an outdoor heat exchanger (evaporation) in this order through the refrigerant passage and returns to the compressor. However, at this time, the indoor heat exchanger condenses the refrigerant to generate condensation heat, which is used for indoor heating. On the other hand, during cooling, the refrigerant discharged from the compressor passes through the outdoor heat exchanger (condensation), the expansion valve, and the indoor heat exchanger (evaporation) in this order through the refrigerant passage, and returns to the compressor. The refrigerant evaporates in the exchanger, and the surrounding space is cooled by taking away heat from the surroundings as evaporating heat by the evaporating action, and the cooling heat generated by this cooling is supplied to the indoor cooling.

  By the way, during heating, there may be little outdoor heat obtained from an outdoor heat exchanger installed outdoors, and there may be a case where heat cannot be efficiently applied to the refrigerant by the outdoor heat exchanger. In order to cope with such a case, in addition to the outdoor heat exchanger, a refrigerant-cooling water heat exchanger capable of exchanging heat with engine cooling water is provided as an apparatus for heating the refrigerant during heating. Some water heat exchangers also have a refrigerant passage configured to allow the refrigerant to flow (see, for example, Patent Document 1). Specifically, a bypass passage is branched from a portion upstream of the portion of the refrigerant passage where the outdoor heat exchanger is interposed (upstream portion during heating), and refrigerant-cooling water heat exchange is performed in this bypass passage. A configuration with a vessel interposed is adopted. With such a parallel passage configuration, during heating, the refrigerant exchanges heat with both the outdoor heat exchanger and the refrigerant-cooling water heat exchanger. Therefore, heat exchange that cannot be covered by heat exchange in the outdoor heat exchanger can be supplemented by the refrigerant-cooling water heat exchanger, and heat exchange efficiency can be improved.

In the parallel passage configuration as described above, it is necessary to set the amount of refrigerant flowing through both passages. For this reason, conventionally, an orifice or capillary is interposed in the refrigerant passage, and the amount of refrigerant flowing through the refrigerant passage is limited by the orifice or capillary so that excess refrigerant flows through the bypass passage.
JP 2004-347306 A

  As described above, in conventional engine-driven air conditioners, the amount of refrigerant flowing in the refrigerant passage is adjusted by an orifice or capillary, so in engine-driven air conditioners with different capacities, adjustment of the amount of refrigerant corresponding to each is adjusted. It was necessary to install orifices with different orifice diameters or capillaries with capillary diameters for each model. For this reason, the operation | work which selects an orifice and a capillary for every model generate | occur | produced, and the effort in manufacturing has arisen. Further, once the orifice or capillary is attached, it is difficult to further adjust the amount of refrigerant flowing to the outdoor heat exchanger side, and there is a problem that the refrigerant adjustment capability is lacking. Furthermore, in the case of heating at a low temperature where the outside air temperature is extremely low, the heat exchange efficiency of the outdoor heat exchanger is extremely low, so it is better not to let the refrigerant flow to the outdoor heat exchanger. Then, since the refrigerant flows into the outdoor heat exchanger through a throttle mechanism such as an orifice, there is a problem that the refrigerant dissipates heat in the outdoor heat exchanger and the heating capacity is further reduced.

 Therefore, it is a technical object of the present invention to solve the above problems.

The invention of claim 1 devised to solve the technical problem is:
Engine,
A compressor that includes a suction port for sucking refrigerant and a discharge port for discharging refrigerant, and that is driven by the engine to compress the refrigerant sucked from the suction port and discharge the refrigerant from the discharge port;
An outdoor heat exchanger that evaporates the supplied refrigerant during heating and condenses the supplied refrigerant during cooling;
An indoor heat exchanger that condenses the supplied refrigerant during heating and evaporates the supplied refrigerant during cooling;
A refrigerant passage communicating the compressor, the outdoor heat exchanger, and the indoor heat exchanger;
A bypass passage provided by branching from the refrigerant passage so that the refrigerant in the refrigerant passage bypasses the outdoor heat exchanger during heating;
A refrigerant that is interposed in the middle of the bypass passage and performs heat exchange between the refrigerant and the cooling water that cools the engine, and a cooling water heat exchanger, and an amount of the refrigerant that is interposed in the middle of the bypass passage and flows through the bypass passage In an engine-driven air conditioner equipped with a sub expansion valve for adjusting
A main expansion valve capable of adjusting the amount of refrigerant flowing into the outdoor heat exchanger during heating is installed in the refrigerant passage ;
A control means for controlling the valve opening of the main expansion valve and the valve opening of the sub expansion valve;
The control means is calculated by an upper limit opening calculation step for calculating an upper limit opening of the main expansion valve and an upper limit opening of the sub expansion valve from the rotation speed of the compressor, and the upper limit opening calculation step. A total opening calculation step of calculating the total opening by adding the upper limit opening of the main electronic expansion valve and the upper opening of the sub electronic expansion valve, and the necessity of the sub expansion valve from the state of the refrigerant in the refrigerant passage Sub electronic expansion valve opening setting step for setting the opening, and main electronic expansion valve opening for setting the opening obtained by subtracting the required opening of the sub expansion valve from the total opening as the opening of the main expansion valve An engine-driven air conditioner characterized by comprising a setting step .

According to the invention of claim 1, since the main electronic expansion valve capable of adjusting the amount of refrigerant flowing into the outdoor heat exchanger is interposed in the refrigerant passage, the opening degree of the main electronic expansion valve is adjusted. The amount of refrigerant flowing into the outdoor heat exchanger can be adjusted. For this reason, when the model is different, it can be dealt with only by changing the opening setting of the electronic expansion valve, and the trouble of setting the orifice diameter for each model in the manufacturing process can be saved. Furthermore, since the opening degree once set can be changed and adjusted again, the refrigerant flow rate can be adjusted flexibly according to the refrigerant conditions. Further, the control means first calculates the total opening obtained by summing the valve opening of the main expansion valve and the valve opening of the sub expansion valve, and then the required opening of the sub expansion valve from the state of the refrigerant in the refrigerant passage. Then, the opening obtained by subtracting the required opening of the sub expansion valve from the total opening is set as the opening of the main expansion valve. Thus, by setting each valve opening degree, the opening degree of both expansion valves will be controlled in relation to each other, and refrigerant flow control can be uniquely determined. In particular, in the present invention, the valve opening of the main expansion valve is obtained by subtracting the valve opening of the sub expansion valve set from the calculated total opening, and assigning the remaining opening to the opening of the main expansion valve. Since the valve opening is determined, it is possible to realize control giving priority to circulating the refrigerant through the refrigerant-cooling water heat exchanger by a simple control step.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

 FIG. 1 is a schematic configuration diagram of an engine-driven air conditioner in this example. In FIG. 1, the engine-driven air conditioner 100 in this example is roughly divided into an outdoor unit 200 and an indoor unit 300.

 The outdoor unit 200 includes an engine 201, a compressor 202, a four-way switching valve 203, an outdoor heat exchanger 204, an accumulator 206, a refrigerant passage 207 that connects these, a refrigerant-cooling water heat exchanger 205, a refrigerant-cooling water heat exchanger. A bypass passage 208 in which 205 is interposed is a main component, and these are housed in a housing (not shown) of the outdoor unit.

 The engine 201 may be any engine as long as it can act as a prime mover. However, in an engine-driven air conditioner, a gas engine driven by gas fuel is often used.

 The compressor 202 is connected to the output shaft of the engine 201 via a clutch mechanism (not shown), and operates by receiving the driving force of the engine 201. The compressor 202 has a suction port 202a and a discharge port 202b that are communication ports with the outside. The compressor 202 sucks refrigerant from the suction port 202a, increases the pressure of the refrigerant sucked inside, and discharges the increased pressure of the refrigerant to the discharge port 202b. More discharged.

  The discharge port 202b of the compressor 202 communicates with the four-way switching valve 203 through the refrigerant passage 207a. The four-way switching valve 203 includes a compressor input port 203a, a first output port 203b, a second output port 203c, and an accumulator output port 203d. The compressor input port 203a and the first output port 203b communicate with each other, and the second A first state in which the output port 203c and the accumulator output port 203d communicate with each other, a second state in which the compressor input port 203a and the second output port 203c communicate with each other, and the first output port 203b and the accumulator output port 203d communicate with each other. It is a valve that can be switched to a state. When the four-way switching valve 203 is in the first state, indoor heating is performed, and when the four-way switching valve 203 is in the second state, indoor cooling is performed.

 A refrigerant passage 207 b communicates with the first output port 203 b of the four-way switching valve 203. A ball valve 41b is connected to the end of the refrigerant passage 207b.

  A refrigerant passage 207 c communicates with the second output port 203 c of the four-way switching valve 203. The refrigerant passage 207c is provided with an outdoor heat exchanger 204 and a main electronic expansion valve 209 in the middle, and a ball valve 41c is connected to the end thereof.

 The outdoor heat exchanger 204 exchanges heat between the refrigerant introduced into the outside and the outside air. Specifically, the outdoor heat exchanger 204 is provided with a meandering channel through which the refrigerant flows and fins connected to the meandering channel. The aspect which laminated | stacked the flat plate is taken. Further, the meandering flow path through which the refrigerant circulates enters the adjacent plate at the side end of each plate, so that the refrigerant flows through the meandering flow path in each plate. ing. And while a refrigerant | coolant flows through the meandering flow path in each plate, the heat collected from the surrounding air is transmitted to the refrigerant | coolant in a meandering flow path from a fin, and heat exchange is performed. In this example, four layers of this plate are laminated, and the innermost plate is a flow path different from the flow path of the refrigerant flowing in the remaining three layers, and functions as a radiator. I am letting.

 The main electronic expansion valve 209 is a valve whose valve opening can be adjusted by electrical control, and the flow rate of the refrigerant passing through the refrigerant passage 207c can be controlled by adjusting the valve opening.

 Further, as can be seen from the figure, one end of the cooling passage 207f is connected to the point C which is the portion between the outdoor heat exchanger 204 and the main electronic expansion valve 209 in the refrigerant passage 207c. The other end of the cooling passage 207f is connected to a point D that is located across the main electronic expansion valve 209 in the refrigerant passage 207c from the point C, and the refrigerant passes through the cooling passage 207f. The main electronic expansion valve 209 is bypassed. Furthermore, a one-way valve 211 that allows refrigerant to flow from point C to point D and blocks refrigerant from point D to point C is provided in the middle of the cooling passage 207f. ing. For this reason, only the refrigerant flowing from the outdoor heat exchanger 204 side flows through the cooling passage 207f. The main electronic expansion valve 209 and the sub electronic expansion valve 210 are electrically connected to the control means 212. The control means 212 has a function of setting the valve opening degree of both expansion valves 209 and 210 based on the state of the refrigerant flowing in each refrigerant passage, the state of each device, and the like.

 A refrigerant passage 207 d is connected to the accumulator output port 203 d of the four-way switching valve 203. The end of the refrigerant passage 207d enters the accumulator 206. A return passage 207 e is connected from the accumulator 206, and this return passage 207 e is connected to the suction port 202 a of the compressor 202.

 Further, as can be seen from the figure, one end of the bypass passage 208 branched from the refrigerant passage 207c is connected to the point A in the refrigerant passage 207c. A refrigerant / cooling water heat exchanger 205 and a sub electronic expansion valve 210 are interposed in the bypass passage 208. Further, the other end of the bypass passage 208 is configured to merge with the refrigerant passage 207d at a point B in the figure.

 The refrigerant-cooling water heat exchanger 205 exchanges heat between the cooling water that cools the engine 201 and the refrigerant that flows through the bypass passage 208. In this example, the plate-type heat is formed by folding a plurality of plate-like flat plates. An exchanger is used. The cooling water introduced into the refrigerant-cooling water heat exchanger 205 is the cooling water after cooling the engine 201 and is heated. Therefore, in the refrigerant-cooling water heat exchanger 205, the refrigerant is heated by the heated cooling water.

 The sub electronic expansion valve 210 is a valve whose valve opening can be adjusted by electrical control, like the main electronic expansion valve 209, and the flow rate of the refrigerant passing through the bypass passage 208 can be controlled by adjusting the valve opening. It is supposed to be.

 On the other hand, the indoor unit 300 mainly includes an indoor heat exchanger 302, an expansion valve 303, and a refrigerant passage 301 that connects them.

 The refrigerant passage in the indoor unit 300 includes a refrigerant passage 301c connected to the ball valve 41c, a refrigerant passage 301b connected to the ball valve 41b, and a refrigerant passage 301d that connects the refrigerant passages 301c and 301b. The refrigerant passages 301d are required for the number of indoor heat exchangers installed. For example, if there are two indoor heat exchangers, two refrigerant passages 301d are required.

 An indoor heat exchanger 302 and an expansion valve 303 are interposed in the refrigerant passage 301d. The indoor heat exchanger 302 exchanges heat between the refrigerant introduced into the interior and the room air, and its specific structure is similar to that of the outdoor heat exchanger. Moreover, the expansion valve 303 expands the refrigerant | coolant which distribute | circulates there by restricting a flow path, and makes it low pressure.

 As can be seen from the above description, the refrigerant passage on the outdoor unit 200 side and the refrigerant passage on the indoor unit 300 side communicate with each other at the ball valves 41b and 41c. Thereby, the compressor 202, the outdoor heat exchanger 204, the indoor heat exchanger 301, and the expansion valve 302 are connected by the refrigerant passages.

 In the above configuration, the operation of the engine-driven air conditioner 100 in this example will be described. First, the operation during heating will be described.

(When heating)
When the compressor 202 is driven by driving the engine 201, the compressor 202 sucks gaseous refrigerant from the suction port 202a side, compresses it inside, and discharges a predetermined high-pressure gaseous refrigerant from the discharge port 202b. The refrigerant discharged from the compressor 202 enters the compressor input port 203a of the four-way switching valve 203 through the refrigerant passage 207a. During heating, since the four-way switching valve 203 is in the first state, the refrigerant entering the compressor input port 203a exits the four-way switching valve 203 from the first output port 203b and passes through the refrigerant passage 207b ahead of it. Flowing. Then, the air enters the indoor unit 300 from the refrigerant passage 301b through the ball valve 41b at the end of the refrigerant passage 207b.

 Since the refrigerant passage 301d is connected to the refrigerant passage 301b, the refrigerant flows into the refrigerant passage 301d. The refrigerant that has flowed into the refrigerant passage 301d further enters the indoor heat exchanger 302. The refrigerant introduced into the indoor heat exchanger 302 is a high-pressure gaseous refrigerant compressed by the compressor 202, and this gaseous refrigerant exchanges heat with the surrounding air in the indoor heat exchanger 302 to condense (liquefy). To do. As the refrigerant condenses, the refrigerant discharges the heat of condensation around, so the surrounding air is heated. In this way, the indoor air is heated by heating the indoor air by the condensing action of the refrigerant operated in the indoor heat exchanger 302 during heating.

 The refrigerant condensed in the indoor heat exchanger 302 exits the indoor heat exchanger 302 in a liquid phase state or a gas-liquid two phase state. Next, the refrigerant is expanded by an expansion valve 303 installed on the downstream side (downstream side during heating) of the indoor heat exchanger 302, and the pressure is reduced to become a low-pressure refrigerant. Then, the low-pressure refrigerant flows from the refrigerant passage 301d to the refrigerant passage 301c, and enters the outdoor unit 200 from the refrigerant passage 207c via the ball valve 41c.

 The refrigerant that has entered the refrigerant passage 207 c is split at point A into a refrigerant that flows through the refrigerant passage 207 c and a refrigerant that flows through the bypass passage 208. The refrigerant flowing from the point A toward the refrigerant passage 207c further enters the main electronic expansion valve 209 installed on the downstream side (downstream side during heating). As described above, the main electronic expansion valve 209 is a valve that operates based on an electrical input signal and is capable of adjusting the opening degree. Therefore, the amount of refrigerant entering the outdoor heat exchanger 204 through the refrigerant passage 207c can be adjusted by adjusting the opening of the main electronic expansion valve 209. In this regard, conventionally, as shown in FIG. 2, since the upstream side of the outdoor heat exchanger (upstream side at the time of heating) is not provided with an electronic expansion valve but an orifice or a capillary, Although the flow rate of the refrigerant entering the exchanger could be limited, it could not be increased or decreased. On the other hand, in this example, an electronic expansion valve is attached on the upstream side (upstream side during heating) of the outdoor heat exchanger so that the flow rate can be controlled, thereby increasing or decreasing the flow rate of the refrigerant entering the outdoor heat exchanger. be able to. For this reason, the same electronic expansion valve can be applied to various models with different amounts of refrigerant flowing to the outdoor heat exchanger, and the flow rate can be adjusted by adjusting the opening of the electronic expansion valve. Therefore, there is no need for the troublesome work of attaching different orifices for each model as in the prior art. Furthermore, the amount of refrigerant flowing through the refrigerant passage can be adjusted according to the load of the indoor heat exchanger, and the amount of refrigerant in the refrigerant passage can be appropriately adjusted even in various situations.

 The low-pressure liquid refrigerant or the gas-liquid two-phase refrigerant entering the outdoor heat exchanger 204 via the main electronic expansion valve 209 from the refrigerant passage 207c exchanges heat with the outside air in the outdoor heat exchanger 204, and the heat of the outside air And evaporates. The refrigerant is vaporized by such an evaporating action to be a gaseous refrigerant. Then, it leaves the outdoor heat exchanger 204.

 On the other hand, the refrigerant flowing from the point A to the bypass passage 208 side enters the sub electronic expansion valve 210. Similarly to the main electronic expansion valve 209, the sub electronic expansion valve 210 is also a valve that operates based on an electrical input signal and can be adjusted in opening. Therefore, the flow rate of the refrigerant flowing through the bypass passage 208 is adjusted by adjusting the opening degree of the sub electronic expansion valve 210.

 The refrigerant whose flow rate is adjusted by the sub electronic expansion valve 210 further enters the refrigerant-cooling water heat exchanger 205 installed on the downstream side (downstream side during heating). In this refrigerant-cooling water heat exchanger 205, the refrigerant receives heat from the cooling water that has cooled the engine and evaporates. The refrigerant evaporates by this evaporating action and becomes a gaseous refrigerant. Then, the refrigerant-cooling water heat exchanger 205 exits.

 The refrigerant that has exited the outdoor heat exchanger 204 enters the four-way switching valve 203 through the second output port 203c. As described above, since the four-way switching valve is in the first state during heating, the refrigerant that has entered the second output port 203c exits the four-way switching valve 203 from the accumulator output port 203d, and is further ahead. It flows through the refrigerant passage 207d. On the other hand, the refrigerant that has exited the refrigerant-cooling water heat exchanger 205 further flows to the downstream side (downstream side during heating) through the bypass passage 208. A downstream end (downstream side during heating) of the bypass passage 208 joins the refrigerant passage 207d at point B. Therefore, at the point B, the refrigerant exiting the outdoor heat exchanger 204 and the refrigerant exiting the refrigerant-cooling water heat exchanger 205 are merged. The merged refrigerant further flows to the downstream side (downstream side during heating) through the refrigerant passage 207d and enters the accumulator 206. In the accumulator 206, the refrigerant is separated into a gas phase portion and a liquid phase portion. In the accumulator 206, only the refrigerant in the gas phase (gas refrigerant) is sucked into the compressor 202 from the suction port 202 a of the compressor 202.

 During heating, the above cycle is repeated to generate heat in the indoor heat exchanger and to perform indoor heating.

 In the heating operation described above, the opening degrees of the main expansion valve 209 and the sub expansion valve 210 are set by the control means 212 and controlled so as to be the set opening degrees. The opening control of these valves in this example is as follows.

(1) Upper limit opening calculation step First, the upper limit opening of the main electronic expansion valve 209 and the upper limit opening of the sub electronic expansion valve 210 are respectively calculated from the rotational speed of the compressor.

(2) Total opening degree calculation step The upper limit opening degree of the main electronic expansion valve 209 and the upper limit opening degree of the sub electronic expansion valve 210 calculated in the upper limit opening degree calculation step are summed to calculate the total opening degree.

(3) Sub electronic expansion valve opening setting step The required amount of refrigerant-cooling water heat exchanger 205 is determined from the degree of superheat at the outlet of refrigerant-cooling water heat exchanger 205 or the temperature of the refrigerant liquid flowing to outdoor heat exchanger 204. The valve opening degree of the sub electronic expansion valve 210 through which the refrigerant can flow is calculated and set. In this setting, when the temperature at the suction port 202a of the compressor 202 or the temperature at the discharge port 202b is high, these conditions may be set in consideration.

(4) Main electronic expansion valve opening setting step An opening obtained by subtracting the valve opening of the sub electronic expansion valve 210 calculated in the sub electronic expansion valve opening setting step from the total opening calculated in the total opening calculation step. The degree of opening is calculated and this opening degree is set as the opening degree of the main electronic expansion valve 209. In this setting, a corrected value may be set in consideration of the temperature of the refrigerant flowing through the outdoor heat exchanger 204, the outside air temperature, and the suction pressure of the refrigerant into the compressor 202.

 Thus, in this example, the valve opening degree of the sub expansion valve is first determined by the control means, and then the valve opening degree of the main expansion valve is determined with reference to the determined opening degree of the sub expansion valve. Therefore, the opening degrees of both expansion valves are controlled in relation to each other, and the refrigerant flow control can be uniquely determined. In particular, since the valve opening degree of the main expansion valve is determined based on the valve opening degree of the sub expansion valve, it is possible to take control giving priority to circulating the refrigerant through the refrigerant-cooling water heat exchanger. Sometimes a thermally efficient operation can be realized.

 Next, the operation during cooling will be described.

(When cooling)
When the compressor 202 is driven by driving the engine 201, the compressor 202 sucks gaseous refrigerant from the suction port 202a side, compresses it inside, and discharges a predetermined high-pressure gaseous refrigerant from the discharge port 202b. The refrigerant discharged from the compressor 202 enters the compressor input port 203a of the four-way switching valve 203 through the refrigerant passage 207a. Since the four-way switching valve 203 is in the second state during cooling, the refrigerant that has entered the compressor input port 203a exits the four-way switching valve 203 from the second output port 203c, and the refrigerant passage 207c ahead of it. Flowing. Then, it enters the outdoor heat exchanger 204 installed on the downstream side (downstream side during cooling). The refrigerant introduced into the outdoor heat exchanger 204 is a high-pressure gaseous refrigerant compressed by the compressor 201, and this gaseous refrigerant exchanges heat with the outside air in the outdoor heat exchanger 204 and condenses (liquefies).

 The refrigerant condensed in the outdoor heat exchanger 204 enters a liquid phase state or a gas-liquid two phase state and exits the outdoor heat exchanger 204. A main electronic expansion valve 209 is installed on the downstream side (downstream side during cooling) of the indoor heat exchanger 204. During cooling, the electronic expansion valve 209 is fully closed. Therefore, the refrigerant flows from the point C through the cooling passage 207f. A one-way valve 211 is interposed in the middle of the cooling passage 207f. The one-way valve 211 allows a flow from the point C to the point D, and therefore flows from the point C. The refrigerant passes through the one-way valve and goes to point D.

 The refrigerant that has passed through the cooling passage 207f from the point C joins the refrigerant passage 207c again at the point D. Then, the refrigerant further flows through the refrigerant passage 207c, enters the indoor unit 200 through the refrigerant passage 301c via the ball valve 41.

 The refrigerant that has entered the indoor unit 200 flows from the refrigerant passage 301c through the refrigerant passage 301d to the expansion valve 303 interposed in the refrigerant passage 301d. In the expansion valve 303, the refrigerant is expanded to a low pressure. The refrigerant whose pressure has been reduced by the expansion valve 303 further reaches the indoor heat exchanger 302 installed on the downstream side (downstream during cooling).

 The low-pressure liquid refrigerant or gas-liquid two-phase refrigerant introduced into the indoor heat exchanger 302 exchanges heat with the indoor air in the indoor heat exchanger 302, and evaporates by receiving heat from the outside air. The refrigerant evaporates by such an evaporation action. The heat of vaporization at this time causes the refrigerant to take away heat from the surroundings and cool the surrounding air. In this way, the room air is cooled and a cooling action is performed.

 The refrigerant evaporated in the indoor heat exchanger 302 flows through the refrigerant passage 301b further downstream (downstream during cooling), and enters the outdoor unit 200 via the ball valve 41 from the refrigerant passage 207b. The refrigerant further flows through the refrigerant passage 207b on the outdoor unit 200 side, and enters the four-way switching valve 203 from the first output port 203b. As described above, since the four-way switching valve is in the second state at the time of cooling, the refrigerant entering the first output port 203b exits the four-way switching valve 203 from the accumulator output port 204d and is further ahead. It flows through the refrigerant passage 207d and enters the accumulator 206. In the accumulator 206, the refrigerant is separated into a gas phase portion and a liquid phase portion. In the accumulator 206, only the refrigerant in the gas phase (gas refrigerant) is sucked into the compressor 202 from the suction port 202 a of the compressor 202.

 During cooling, the above cycle is repeated to generate heat in the indoor heat exchanger and to cool the room.

 As described above, according to this example, the electronic expansion valve 209 that can control the amount of refrigerant flowing into the outdoor heat exchanger 205 during heating is disposed upstream of the outdoor heat exchanger 205 in the refrigerant passage 207c (during heating). It is inserted in the part on the upstream side. For this reason, the amount of the refrigerant flowing into the outdoor heat exchanger 205 can be freely controlled by the electronic expansion valve 209. Therefore, when the model is different, it can be dealt with only by changing the opening setting of the electronic expansion valve. For this reason, the manufacturing effort can be saved. Furthermore, since the opening degree once set can be changed and adjusted again, the refrigerant flow rate can be adjusted flexibly according to each situation.

It is a schematic structure figure of an engine drive type air harmony machine in an embodiment of the present invention. It is a figure which shows the structure of the refrigerant path near an outdoor heat exchanger in a prior art.

Explanation of symbols

100: engine-driven air conditioner, 200: outdoor unit, 300: indoor unit, 201: engine, 202: compressor (compressor), 202a: suction port, 202b: discharge port, 203: four-way switching valve, 204 : Outdoor heat exchanger, 205: refrigerant-cooling water heat exchanger, 206: accumulator, 207a, 207b, 207c, 207d, 207e: refrigerant passage, 207f: cooling passage, 208: bypass passage, 209: main electronic expansion valve 210: Sub electronic expansion valve, 212: Control means, 301b, 301c, 301d: Refrigerant passage, 302: Indoor heat exchanger

Claims (1)

Engine,
A compressor that includes a suction port for sucking refrigerant and a discharge port for discharging refrigerant, and that is driven by the engine to compress the refrigerant sucked from the suction port and discharge the refrigerant from the discharge port;
An outdoor heat exchanger that evaporates the supplied refrigerant during heating and condenses the supplied refrigerant during cooling;
An indoor heat exchanger that condenses the supplied refrigerant during heating and evaporates the supplied refrigerant during cooling;
A refrigerant passage communicating the compressor, the outdoor heat exchanger, and the indoor heat exchanger;
A bypass passage provided by branching from the refrigerant passage so that the refrigerant in the refrigerant passage bypasses the outdoor heat exchanger during heating;
A refrigerant that is interposed in the middle of the bypass passage and performs heat exchange between the refrigerant and the cooling water that cools the engine, and a cooling water heat exchanger, and an amount of the refrigerant that is interposed in the middle of the bypass passage and flows through the bypass passage In an engine-driven air conditioner equipped with a sub expansion valve for adjusting
A main expansion valve capable of adjusting the amount of refrigerant flowing into the outdoor heat exchanger during heating is installed in the refrigerant passage ;
A control means for controlling the valve opening of the main expansion valve and the valve opening of the sub expansion valve;
The control means is calculated in an upper limit opening calculation step for calculating an upper limit opening of the main expansion valve and an upper limit opening of the sub expansion valve from the rotation speed of the compressor, and the upper limit opening calculation step. A total opening calculation step of calculating the total opening by adding the upper limit opening of the main electronic expansion valve and the upper limit opening of the sub electronic expansion valve, and the necessary opening of the sub expansion valve from the state of the refrigerant in the refrigerant passage. A sub electronic expansion valve opening setting step for setting the degree, and a main electronic expansion valve opening setting for setting the opening obtained by subtracting the required opening of the sub expansion valve from the total opening as the opening of the main expansion valve and having a step, the engine driving type air conditioner.

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