JP4006390B2 - Air conditioner - Google Patents

Description

  The present invention relates to an air conditioner that circulates a refrigerant with a compressor to perform indoor air conditioning.

  2. Description of the Related Art Conventionally, there has been an air conditioner that performs indoor air conditioning by providing heat exchangers both indoors and outdoors and circulating refrigerant while changing the phase between them. Some of these air conditioners use a gas engine to drive a compressor that compresses the refrigerant in the gas phase. However, the gas engine has a limitation on the number of revolutions that can be operated. There was a limit to the air conditioning load. On the other hand, an air conditioner that includes a plurality of compressors and speed change means and transmits the driving force of the gas engine to the plurality of compressors has been proposed (for example, see Patent Document 1). According to this air conditioner, the range of the air conditioning load that can be handled can be increased by adjusting the speed ratio of the speed change means.

Alternatively, in order to cope with a smaller air conditioning load, an air conditioner using a compressor having an opening in the intermediate pressure portion has also been proposed (see, for example, Patent Document 2). In this air conditioner, when the air conditioning load is small, the refrigerant gas flows out from the opening of the compressor to the low pressure flow path. This reduces the amount of refrigerant that actually contributes to air conditioning and improves controllability when the air conditioning load is small.
JP 2002-206913 A (page 3-4) Japanese Patent Laid-Open No. 10-115292

  The conventional air conditioners described above are intended to increase the range of air conditioning loads that can be accommodated. Therefore, a device for dealing with a larger air conditioning load and a smaller air conditioning load has been devised. On the other hand, the air-conditioning load range used frequently is often near the center. In general, in a gas engine, if the work is the same, the higher torque region is a more efficient operation region, so operation in a higher torque region is desirable. That is, it is desired to increase the operation efficiency in the partial load region without reducing the applicable air conditioning load range. However, conventional air conditioners have not taken much consideration into the operating efficiency of gas engines.

  For example, FIG. 16 shows an example of the change state of the engine torque in a system having two compressors and controlling the number of operating units and the engine speed control, such as the air conditioner described in Patent Document 1. Show. In this figure, the setting state of the engine torque (change in the number of compressors) and the change in the engine speed with respect to the output air conditioning capacity are shown in a graph. Note that the engine speed for the same air conditioning capacity may be different between when the number of drive compressors is reduced and when it is increased, but this figure and the following similar figures are shown as the same for simplicity. .

  The conventional air conditioner will be described in the direction of decreasing the air conditioning load in descending order. First, at the maximum rating of the air conditioning load, two compressors are driven and the engine speed is high. From here, the engine speed is decreased as the partial load is reached. When the engine speed reaches the lower limit engine speed, one compressor is driven. At the same time, the engine speed is increased in order to maintain the continuity of the refrigerant circulation rate as a whole. Furthermore, when the air-conditioning load is lowered, the engine speed is lowered while keeping one drive compressor. That is, as can be seen from this figure, when the number of driving compressors is one, the engine torque becomes small, so that there is a problem that the operating efficiency of the engine suddenly decreases.

  The present invention has been made to solve the problems of the conventional air conditioners described above. That is, an object of the present invention is to provide an air conditioner that can use an area where the operating efficiency of a gas engine is high by simple control.

An air conditioner of the present invention made for the purpose of solving this problem is an air conditioner that performs air conditioning by circulating a refrigerant in a refrigerant circulation path including a heat exchanger, and includes a plurality of air conditioners provided in parallel in the refrigerant circulation path. It has a multistage capacity compressor and a prime mover that drives a plurality of multistage capacity compressors, and the multistage capacity compressor is provided with an opening that can be opened and closed at a location that is an intermediate pressure between the suction port and the discharge port. at least, the opening of the rest of the multi-stage capacity compressor with use in all the first mode to be used in a state of being closed the opening of the multi-stage capacity compressor, state closes the opening of the part of the multi-stage capacity compressor has and the second mode to be used in a state where the open and a third mode used in a state of opening the opening of all the multi-stage capacity compressor, a part of the multi-stage capacity con A fourth mode for halting the rest of the multi-stage capacity compressor with use in a state of closing the said opening of the suppressor, the rest of the multi-stage capacity compressor with use in opening the opening of the part of the multi-stage capacity compressor state The operation is performed by selecting any one mode from the mode group including the fifth mode to be paused.

The air conditioner of the present invention can be operated by selecting from at least five types of operation modes by having a plurality of multistage capacity compressors. Here, the multistage capacity compressor is a compressor capable of changing the volume of gas to be compressed. This as a multi-stage capacity compressor, an opening is provided in the portion which becomes an intermediate pressure between the suction port and the discharge port, to use a compressor which enables opening and closing the opening. When such a compressor is used, the torque of the driven engine varies depending on the compressor capacity. That is, the larger the compressor capacity, the greater the torque that should be generated by the engine. In general, the larger the engine torque, the higher the operating efficiency. Therefore, the larger the compressor capacity, the better the engine operating efficiency. Therefore, by selecting a large-capacity mode within the range of engine speeds that can be output from the engine according to the air conditioning load from a large number of operation modes, it is possible to achieve an operating state in a region where engine operating efficiency is better. Can do. As a result, the air conditioner can use an area where the operating efficiency of the gas engine is high by simple control.

Furthermore, in the present invention, it is desirable to have mode control means for switching the mode selection so that high prime mover efficiency can be obtained according to the operating conditions, and the mode control means desirably selects the first mode during rated operation.
In this way, the mode control means selects a mode with high prime mover efficiency, and an operation mode with the largest air conditioning capacity is selected during rated operation. Therefore, it is only necessary to switch to a mode in which the capacity of the compressor is increased in order as the air conditioning capacity increases, so that control is easy.

Furthermore, the present invention is an air conditioner that performs air conditioning by circulating a refrigerant in a refrigerant circuit including a heat exchanger, and includes a plurality of multistage compressors provided in parallel with the refrigerant circuit, and a plurality of multistage compressors. 1st mode that uses a gas engine to drive, and at least uses all multistage capacity compressors in a large capacity state, and uses some multistage capacity compressors in a large capacity state and the remaining multistage capacity compressors in small capacity A second mode that is used in the state, a third mode that uses all the multistage capacity compressors in a small capacity state, and a fourth mode in which some multistage capacity compressors are used in a large capacity state and the remaining multistage capacity compressors are deactivated. Mode, and use some multistage compressors in a small capacity state and suspend the remaining multistage compressors. It operates to select any one mode of the mode group including a chromatography de has a mode control unit for switching the selection mode to be higher the efficiency of the gas engine in accordance with the operating conditions, the mode control means it may be one that selects the second mode, third mode, and one of the fourth mode one in rated operation.
In general, in a gas engine, the change in the maximum torque with respect to the rotational speed is a mountain-shaped graph, and the maximum torque during operation at the maximum rotational speed is slightly smaller than the maximum torque during operation at a medium rotational speed. It has become. Therefore, if the mode with the maximum torque is selected at the time of a medium partial air conditioning load and the medium rotation speed region is used, the operation efficiency in this region can be further increased. In reality, since this partial air conditioning load region is often used, the overall operation efficiency is increased by doing so. In this case, an operation mode other than the operation mode that provides the maximum torque during rated operation is selected. In particular, it is preferable to select an operation mode that provides the second torque level.

  According to the air conditioner of the present invention, a region where the operating efficiency of the gas engine is high can be used by simple control.

"First form"
DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the best mode for embodying the present invention will be described in detail with reference to the accompanying drawings. This embodiment is an air conditioner that circulates refrigerant in various places while changing the phase, thereby cooling and heating the room.

  As shown in FIG. 1, the air conditioner 1 of the present embodiment is connected to the output shaft of the gas engine 11 with two multistage capacity compressors 22 and 23 via a drive switching device 21. The air conditioner 1 further includes two heat exchangers (condenser 13 and evaporator 14) and an expansion valve 15, which are connected to each other by a refrigerant flow path 16. Further, two check valves 24 and two on-off valves 25 and 26 are connected to the refrigerant flow path 16 to control the inflow of refrigerant to the multistage compressors 22 and 23.

  The gas engine 11 rotates the output shaft using city gas or the like as fuel, and drives the multistage capacity compressors 22 and 23. The condenser 13 releases heat and condenses (liquefies) the refrigerant. The evaporator 14 absorbs heat and evaporates (vaporizes) the refrigerant. The expansion valve 15 depressurizes the liquid refrigerant. These configurations are the same as those of a conventional general air conditioner. In addition to this configuration, the air conditioner 1 further includes various valves, accumulators, and the like. However, these are general ones, and a description thereof is omitted here.

  The drive switching device 21 is a clutch, for example, and switches the connection between the output shaft of the gas engine 11 and the drive shafts of the two multistage capacity compressors 22 and 23. By switching the drive switching device 21, the gas engine 11 is switched between a state in which only one of the two multistage compressors 22 and 23 is driven and a state in which both are driven. The drive switching device 21 may be further provided with a speed change function so that the two multistage capacity compressors 22 and 23 can be driven at different rotational speeds.

  The two multistage compressors 22 and 23 have the same configuration. Each of these is provided with three openings, suction ports 31 and 32, discharge ports 33 and 34, and suction amount adjustment ports 35 and 36. The intake amount adjusting ports 35 and 36 are openings provided in the intermediate pressure portion of the multistage compressors 22 and 23, and the on-off valves 25 and 26 are connected to the intake amount adjusting ports 35 and 36.

  That is, for example, in the multistage capacity compressor 22, the refrigerant of the entire capacity from the suction port 31 to the discharge port 33 is compressed in the same manner as when the intake amount adjustment port 35 is not provided when the on-off valve 25 is closed. On the other hand, when the on-off valve 25 is in the open state, the refrigerant is input from the suction amount adjustment port 35 as well as the suction port 31, and since these are communicated, the pressure is the same. That is, the portion from the suction port 31 to the suction amount adjustment port 35 is not compressed. The refrigerant to be compressed is only the capacity portion between the suction amount adjustment port 35 and the discharge port 33. That is, the capacity required for compression of the multistage compressors 22 and 23 is changed by opening and closing the on-off valves 25 and 26.

  The multistage capacity compressors 22 and 23 are, for example, scroll compressors, and suction amount adjusting ports 35 and 36 so as to communicate with the compression chambers at a predetermined angle inside from the end of the fixed scroll and the point symmetrical positions. Can be used. Here, the suction amount adjusting ports 35 and 36 are provided at positions corresponding to about one-fourth of the entire volume from the suction ports 31 and 32. For this reason, the capacity of the multistage compressors 22 and 23 is about three-quarters of that when the on-off valves 25 and 26 are closed. The two multistage compressors 22 and 23 may be different from each other in terms of the total capacity and the positions of the suction amount adjusting ports 35 and 36.

  The check valve 24 is provided in the refrigerant flow path 16 between the discharge ports 33 and 34 of the multistage capacity compressors 22 and 23 and their junctions. The check valve 24 prevents the refrigerant from flowing back from the discharge ports 33 and 34 into the multistage compressors 22 and 23.

  In this air conditioner 1, as indicated by arrows in FIG. 1, the refrigerant is circulated through the refrigerant flow path 16, and the state of the refrigerant is changed at various places, whereby heat is released and absorbed. Therefore, during cooling, the evaporator 14 is used as an indoor unit and the condenser 13 is used as an outdoor unit. During heating, the evaporator 14 is used as an outdoor unit and the condenser 13 is used as an indoor unit. It can be carried out. Further, the number of multistage capacity compressors 22 and 23 driven by the drive switching device 21 is selected, and the capacity of each of the multistage capacity compressors 22 and 23 is selected by the on-off valves 25 and 26. Operation mode is possible. Therefore, the optimum one can be selected according to the required air conditioning capacity. Below, the total of the internal capacity concerning compression of the driven multistage capacity compressors 22 and 23 is called effective capacity.

  Next, each operation mode will be described. In each of the following modes, the multistage capacity compressors 22 and 23 may be reversed. The first mode is a mode in which both the multistage compressors 22 and 23 are used with a large capacity. The second mode is a mode in which the multistage compressor 22 is used with a large capacity and the multistage compressor 23 is used with a small capacity. The third mode is a mode in which both the multistage capacity compressors 22 and 23 are used with a small capacity. The fourth mode is a mode in which the multistage capacity compressor 22 is stopped and the multistage capacity compressor 23 is used with a large capacity. The fifth mode is a mode in which the multistage capacity compressor 22 is stopped and the multistage capacity compressor 23 is used with a small capacity.

  By providing each operation mode in this way, the effective capacity is as follows: first mode> second mode> third mode> fourth mode> fifth mode. Here, since the small capacity of each of the multistage compressors 22 and 23 is about three-quarters of the large capacity, only one small capacity of both units has a larger effective capacity than the large capacity.

  In order to execute each of these operation modes, operation control may be performed as follows. To enter the first mode, as shown in FIG. 2, both the on-off valves 25 and 26 are closed, and the drive switching device 21 is connected to both of the multistage capacity compressors 22 and 23. In order to enter the second mode, as shown in FIG. 3, the on-off valve 25 is closed, the on-off valve 26 is opened, and the drive switching device 21 is connected to both of the multistage capacity compressors 22, 23.

  In order to enter the third mode, as shown in FIG. 4, both the on-off valves 25 and 26 are opened, and the drive switching device 21 is connected to both the multistage capacity compressors 22 and 23. In order to enter the fourth mode, as shown in FIG. 5, the on-off valve 26 is closed, and the drive switching device 21 is connected only to the multistage capacity compressor 23. In order to enter the fifth mode, as shown in FIG. 6, the on-off valve 26 is opened, and the drive switching device 21 is connected only to the multistage capacity compressor 23. In the fourth and fifth modes, the state of the on-off valve 25 may be any.

  By switching in this way, one mode is selected from each operation mode. At this time, an operation mode with a larger effective capacity is an operation mode with a larger torque of the gas engine 11, that is, an air-conditioning operation with better operation efficiency of the gas engine 11. Therefore, control is performed so as to select an operation mode having the largest torque (large effective capacity) within the range of the allowable number of revolutions of the gas engine 11 in accordance with the air conditioning load.

  Next, FIG. 7 shows a schematic configuration of the control system 2 that controls the operation mode of the air conditioner 1. In the control system 2, a gas engine 11, various sensors 42, a drive switching device 21, and on-off valves 25 and 26 are connected with a controller 41 as a center.

  In this control system 2, the controller 41 detects the output torque and rotation speed of the gas engine 11. Alternatively, the torque of the gas engine 11 to be output may be calculated by detecting the outside air temperature, the indoor environment temperature, the set temperature, the supply status of the condensed water or the evaporating water from the outside using the various sensors 42. Next, the maximum torque at the rotational speed is obtained from the standard of the gas engine 11, and the difference between the maximum torque and the current output torque is calculated. The optimum operation mode is selected so that the torque difference falls within a predetermined range, and the drive switching device 21, the on-off valves 25 and 26, and the gas engine 11 are controlled.

  In the control system 2 of the air conditioner 1 of this embodiment, the first mode is selected during rated operation. That is, the first mode with the largest effective capacity is selected during rated operation that exhibits the greatest air conditioning capability. Accordingly, the capacities of the multistage capacity compressors 22 and 23 are selected so that the maximum effective capacity obtained by adding the large capacities of the multistage capacity compressors 22 and 23 is an effective capacity corresponding to the set rated air conditioning capacity. That is, the capacity of each of the multistage compressors 22 and 23. The minimum size required for rated operation can be selected.

  The graph of FIG. 8 shows the setting condition of the torque of the engine 11 by the combination of the compressor with respect to the air conditioning capacity by the control system 2 and the relationship between the rotational speed of the engine 11 at that time. As shown in this figure, when the air conditioning capability operated in the second mode to the fifth mode is about 30 to 60%, the operation mode is switched in accordance with the air conditioning capability, and the mode with the optimum torque is selected. As a result, the engine speed is kept low. Here, in the lowest engine speed state of the fifth mode, the amount of refrigerant that substantially contributes to air conditioning is changed to correspond to an air conditioning capability that is smaller than about 30%. This part of the control is general and will not be described.

  Next, the processing of the control system 2 will be described with reference to the flowchart of FIG. In the air conditioner 1, in general, control completely different from that after the steady state is performed from the start of operation to the steady state. The control process by the control system 2 is executed after the air conditioner 1 is in a steady state. Therefore, when this process is executed, the engine speed and operation mode are set to a predetermined initial state.

  When the execution of this process is started, it is first determined whether or not the requested air conditioning load has changed from the initial state (S101). When it is determined that the air conditioning load has not changed (S101: No), the operation is continued with the setting as it is. When it is determined that the air conditioning load has changed from the previous setting state (S101: Yes), the next step is divided depending on whether the direction of change has decreased or increased (S102).

  If it is determined in S102 that the air conditioning load has decreased (S102: Yes), it is determined whether the air conditioning load has become smaller than the set value in the operation mode due to the decrease (S103). Each operation mode has an appropriate air-conditioning load range. If the operation mode becomes smaller than that range (S103: Yes), the operation mode is changed. Then, by reducing the effective capacity, the air conditioning load is reduced (S104).

  Alternatively, if it is within the proper load range in the operation mode (S103: No), it is determined whether the change width is within a predetermined range (S105). If the change is greater than the predetermined width (S105: No), the engine speed is decreased (S106). However, when the change width is small and within the predetermined width (S105: Yes), the operation at the engine speed is continued as it is.

  If the direction of change is an increasing direction (S102: No), it is determined whether the air conditioning load has increased beyond the set value in the operation mode due to the increase (S107). When it becomes larger than the appropriate air conditioning load range (S107: Yes), the operation mode is changed to increase the effective capacity and the engine torque is increased (S108). This further increases the efficiency of operation.

  Or when it is in the suitable load range in the operation mode (S107: No), it is judged whether a change width is in a predetermined range (S109). If the change is greater than the predetermined width (S109: No), the engine speed is increased (S110). However, when the change width is small and within the predetermined width (S109: Yes), the operation at the engine speed is continued as it is. In this manner, the selection of the operation mode and the control for changing the engine speed are continued until the operation of the air conditioner 1 is stopped. In S104 and S108, when the operation mode is changed, the engine speed is also changed simultaneously with the air conditioning load.

  Here, if the air conditioning output is not so finely controlled, the range of change as a criterion in S105 and S109 may be increased. For example, as shown in FIG. 10, control may be performed in which the engine speed in each mode is not changed between the second mode and the fifth mode. That is, while the air conditioning load is within a certain range, the engine is operated without changing the engine speed at the minimum speed in a predetermined mode. When the air conditioning load changes beyond a predetermined limit, the air conditioning output is changed in steps by changing the effective capacity. In the air conditioner 1 of this embodiment, since there are many types of operation modes, the change width of the step change is not so large. Therefore, such a control method can be realized. Only the switching of the number of compressors in two stages as shown in FIG. 16 makes the change range too large, so that such a control method is not practical.

  As described above in detail, according to the air conditioner 1 of the present embodiment, the effective capacity of the multistage capacity compressors 22 and 23 is changed by opening and closing the on-off valves 25 and 26. Further, the drive switching device 21 selects the number of units to be driven among the multistage capacity compressors 22 and 23. Thus, the operation mode of the air conditioner 1 can be selected from the first to fifth modes. Then, the control system 2 selects an operation mode with larger torque and higher operation efficiency in accordance with the air conditioning load. Therefore, in the partial load air-conditioning area of about 30 to 60%, which is frequently used, the air-conditioning apparatus can use the area where the operation efficiency of the gas engine is high by simple control.

"Second form"
The air conditioner of this embodiment is the same in configuration as the air conditioner 1 of the first embodiment, and only the control method is slightly different, so only the different parts will be described.

  The control system 3 of the present embodiment selects the second mode during rated operation. That is, during the rated operation with the largest air conditioning capacity, the second mode with the second largest torque is selected. This is because the relationship between the maximum shaft torque and the rotational speed of the gas engine 11 is approximately a mountain-shaped change as shown in FIG. Therefore, a larger torque can be output in the middle rotation speed region than in the high rotation speed region, and the operation efficiency is improved when the torque is larger. Therefore, as the mode with the largest effective capacity of the first mode, a torque mode corresponding to the maximum torque in the medium rotation speed range that is larger than that during rated operation is set in advance.

  In this way, by selecting the first mode with the largest torque in the partial load air-conditioning region of about 60 to 80%, which is slightly below the rating, the torque can be increased in this portion as compared with the first embodiment. In addition, the torque in the partial load air conditioning region of 60% or less also increases. This further increases the operating efficiency in this partial load region. During rated operation, the second mode with the second torque may be selected and the high speed range may be used.

  The graph of FIG. 12 shows the setting condition of the torque of the engine 11 by the combination of the compressors with respect to the air conditioning capacity by the control system 3 and the relationship between the rotational speed of the engine 11 at that time. As shown in this figure, from the lowest air conditioning capability to about 60%, the operation mode is switched according to the air conditioning capability, and the mode with the optimum torque is selected. As a result, the engine speed is kept low. When the air conditioning capacity is increased to about 80%, the maximum torque decreases from the increase in engine speed. Therefore, the engine speed is increased from the first mode to the second mode to avoid engine stall due to insufficient torque. To do. As a result, the control system is able to effectively use the region where the maximum torque is large and the efficiency is high.

  Next, the process of the control system 3 will be described with reference to the flowcharts of FIGS. Similar to the control system 2 of the first embodiment, this process is also executed after a steady state is reached after the operation is started. When this process is executed, first, in S201, it is determined whether or not the air conditioning load requested at that time is greater than or equal to a predetermined value. This is because, as described above, since the maximum torque decreases in a region where the air conditioning load is large, it is necessary to monitor the engine torque state.

  In the operation region where the air conditioning load is small (S201: No), the operation mode and the engine speed are controlled while watching the change in the air conditioning load. This is the same as the control in the first embodiment. That is, S101 to S110 in FIG. 13 are the same as the steps with the same symbols in the control system 2 in FIG. However, when the air conditioning load decreases, the process may return to S101. However, when the air conditioning load increases, the process returns to S201 to determine again whether the air conditioning load is within a predetermined value.

  Next, when it is determined in S201 that the air conditioning load is equal to or greater than the predetermined value (S201: Yes), the process proceeds to “A” in FIG. Then, the difference between the maximum torque stored as the standard of the gas engine 11 and the current output torque of the gas engine 11 at the engine speed at that time is obtained, and the value (engine torque margin) is appropriate. It is determined whether it is within the range (S211). This is because if it is not within the proper range, it is necessary to change to a more appropriate operation mode.

  If it is determined that the engine torque margin is not within the appropriate range (S211: No), it is first determined whether the margin is smaller than a predetermined value (S212). If it is determined to be small (S212: Yes), the engine may be stalled, so the operation mode is switched to one with a small effective capacity in order to provide more margin (S213). Alternatively, if it is determined that the margin is not smaller than the predetermined value (S212: No), that is, the margin is too large, and the operation mode is set to a large effective capacity in order to achieve a more efficient operation. Switching (S214).

  Thus, when the engine torque margin is within an appropriate range (S211: Yes), the operation in that state is continued while the air conditioning load is not changing (S215: No). If the air conditioning load changes (S215: Yes), control is performed as follows according to the direction of the change. That is, when the air conditioning load decreases (S216: Yes), the engine speed is decreased (S217). Alternatively, when the air conditioning load increases (S216: No), the engine speed is increased (S218). In any case, after changing the engine speed, the process proceeds to “B” in FIG. 13 and the determination in S201 is performed again.

  Also in this embodiment, if the fine control of the air-conditioning output is not necessary, the range of change that becomes the determination criterion in S105 and S109 may be increased. For example, as shown in FIG. 15, step control may be performed in which the engine speed in each mode is not changed between the second mode and the fifth mode. However, in this embodiment, it is desirable to use the engine speed control in combination with the switching between the first mode and the second mode in the portion where the air conditioning capacity is large.

  In the air conditioner of this embodiment, in order to obtain an air conditioner having a rated operation capacity equivalent to that of the first embodiment, the effective capacity in the operation in the second mode is the same as that in the first mode of the first embodiment. It must be equivalent to the effective capacity during operation. For this purpose, it is necessary to use at least one of the multistage compressors 22 and 23 having a capacity slightly larger than that of the first embodiment, or to increase the maximum rotational speed. However, the operation efficiency as a whole increases, and high-efficiency operation is possible particularly in the 60 to 80% partial load air-conditioning region, which is frequently used.

  As described above in detail, the control system 3 according to the present embodiment is an air conditioner that can use a region where the operating efficiency of the gas engine is high by simple control, similarly to the control system 2 according to the first embodiment. .

In addition, each said form is only a mere illustration and does not limit this invention at all. Therefore, the present invention can naturally be improved and modified in various ways without departing from the gist thereof.
For example, the number of connected compressors and the number of switchable capacity stages may be further increased than those shown in this embodiment. In that case, the number of modes can be increased.
Further, for example, in the above embodiment, the scroll type compressor is used as the compressor to be used, but the present invention is not limited to this, and other types such as a multi-vane type may be used.

It is explanatory drawing which shows schematic structure of the air conditioner of a 1st form. It is explanatory drawing which shows the driving | running state in a 1st mode. It is explanatory drawing which shows the driving | running state in a 2nd mode. It is explanatory drawing which shows the driving | running state in a 3rd mode. It is explanatory drawing which shows the driving | running state in a 4th mode. It is explanatory drawing which shows the driving | running state in a 5th mode. It is a block diagram which shows schematic structure of the control system of an air conditioner. It is a graph which shows the relationship of the engine torque and engine speed with respect to the air-conditioning capability by the control system of a 1st form. It is a flowchart which shows the control processing by the control system of a 1st form. It is a graph which shows the relationship of the engine torque with respect to the air-conditioning capability by another control system of a 1st form, and an engine speed. It is a graph which shows the relationship between the rotation speed of a gas engine, and maximum torque. It is a graph which shows the relationship of the engine torque with respect to the air-conditioning capability by the control system of a 2nd form, and an engine speed. It is a flowchart which shows the control processing by the control system of a 2nd form. It is a flowchart which shows the control processing by the control system of a 2nd form. It is a graph which shows the relationship of the engine torque with respect to the air-conditioning capability by another control system of a 2nd form, and an engine speed. It is a graph which shows the relationship of the engine torque and engine speed with respect to the air-conditioning capability by the conventional air conditioning apparatus.

Explanation of symbols

1 Air conditioner 2, 3 Control system (mode control means)
11 Gas engine (motor)
13 Condenser (heat exchanger)
14 Evaporator (heat exchanger)
16 Refrigerant flow path (refrigerant circulation path)
22,23 Multistage capacity compressor

Claims (3)

In an air conditioner that performs air conditioning by circulating a refrigerant in a refrigerant circuit including a heat exchanger,
A plurality of multistage capacity compressors provided in parallel with the refrigerant circuit;
A prime mover for driving the plurality of multistage capacity compressors,
The multi-stage capacity compressor is provided with an openable and closable opening at a location where the intermediate pressure between the suction port and the discharge port is obtained,
at least,
A first mode for use with all the multistage capacity compressors with the opening closed ;
A second mode that is used in a state in which the openings of some of the multistage capacity compressors are closed and is used in a state in which the openings of the remaining multistage capacity compressors are opened ;
A third mode in which all the multistage compressors are used with the openings opened ;
A fourth mode in which some of the multi-stage capacity compressors are used with the opening closed, and the remaining multi-stage capacity compressors are deactivated;
The operation is performed by selecting any one mode of a mode group including a fifth mode in which a part of the multistage capacity compressor is used in a state where the opening of the part of the multistage capacity compressor is opened and the remaining multistage capacity compressor is stopped. Air conditioner to do. In the air conditioner according to claim 1,
It has mode control means to switch the mode selection so that high prime mover efficiency can be obtained according to the driving situation,
The air conditioner characterized in that the mode control means selects the first mode during rated operation. In an air conditioner that performs air conditioning by circulating a refrigerant in a refrigerant circuit including a heat exchanger,
A plurality of multistage capacity compressors provided in parallel with the refrigerant circuit;
A gas engine that drives the plurality of multistage compressors,
at least,
A first mode in which all multistage compressors are used in a large capacity state;
A second mode in which some multistage compressors are used in a large capacity state and the remaining multistage compressors are used in a small capacity state;
A third mode in which all multistage compressors are used in a small capacity state;
A fourth mode in which some multistage capacity compressors are used in a large capacity state and the remaining multistage capacity compressors are deactivated;
Select and operate any one of a mode group including a fifth mode in which some multistage capacity compressors are used in a small capacity state and the remaining multistage capacity compressors are deactivated,
Mode control means for switching the selection of the mode so as to increase the efficiency of the gas engine according to the operating situation;
The air conditioner characterized in that the mode control means selects one of a second mode, a third mode, and a fourth mode during rated operation.

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