Air conditioning device, method for controlling air conditioning device, and computer program product

Abstract

The present invention provides an air conditioning device capable of appropriately switching between separate operation of a second compressor and simultaneous operation of the first compressor and the second compressor, the first compressor driven by a gas engine and the second compressor driven by a motor are connected in parallel, and a refrigerant is circulated to perform air conditioning. Comprising a control unit for controlling the driving of the first compressor and the second compressor, the control unit comprising: a first drive control unit for driving only the first compressor during a first period and calculating a first air-conditioning load, which is an air-conditioning load during the first period, when the air-conditioning device is started; and a second drive control unit that, on the basis of the first air-conditioning load, determines to drive both the first compressor and the second compressor or only the second compressor, and the second drive control unit determines to drive only the second compressor when the intake differential temperature is equal to or less than a predetermined threshold value during the first period.

Description

Technical Field

[0001] This disclosure relates to air conditioning devices, control methods for air conditioning devices, and computer program products. Background Technology

[0002] Patent document 1 discloses an air conditioning device, which includes an outdoor unit and an indoor unit. The outdoor unit includes a gas engine driven by gas, a first compressor that obtains driving force from the gas engine and compresses refrigerant, and a second compressor driven by an electric motor.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2019-15435 Summary of the Invention

[0006] The problem that the invention aims to solve

[0007] This disclosure provides an air conditioning device that appropriately switches between the individual operation of a second compressor and the combined operation of a first compressor and a second compressor, a control method for the air conditioning device, and a computer program product.

[0008] Technical solutions for solving the problem

[0009] This disclosure provides an air conditioning device that connects a first compressor driven by a gas engine and a second compressor driven by a motor in parallel to circulate refrigerant for air conditioning. The device includes a control unit that controls the driving of the first compressor and the second compressor. The control unit comprises: a first drive control unit that, when starting the air conditioning device, drives only the first compressor during a first period and calculates the air conditioning load (i.e., the first air conditioning load) during the first period; and a second drive control unit that, based on the first air conditioning load, determines whether to drive both the first compressor and the second compressor, or only the second compressor. The second drive control unit determines to drive only the second compressor if the suction temperature difference is below a predetermined threshold during the first period. If the suction temperature difference is below the predetermined threshold during the first period, the second drive control unit determines to drive only the second compressor during a second period and calculates the air conditioning load (i.e., the second air conditioning load) during the second period. Based on the second air conditioning load, the second drive control unit determines whether to drive both the first compressor and the second compressor, or only the second compressor.

[0010] This disclosure provides a control method for an air conditioning device, wherein the air conditioning device connects a first compressor driven by a gas engine and a second compressor driven by a motor in parallel to circulate refrigerant for air conditioning. The method includes a control unit that controls the driving of the first compressor and the second compressor. In the method, the control unit performs: a first control step, when starting the air conditioning device, driving only the first compressor during a first period and calculating the air conditioning load (i.e., the first air conditioning load) during the first period; and a second control step, based on the first air conditioning load, determining whether to drive both the first compressor and the second compressor or only the second compressor. In the second control step, if the suction temperature difference is below a predetermined threshold during the first period, it is determined that only the second compressor is driven; if the suction temperature difference is below the predetermined threshold during the first period, only the second compressor is driven during a second period, and the air conditioning load (i.e., the second air conditioning load) during the second period is calculated. Based on the second air conditioning load, it is determined whether to drive both the first compressor and the second compressor or only the second compressor.

[0011] A computer program product records a control program for an air conditioning device, wherein the air conditioning device connects a first compressor driven by a gas engine and a second compressor driven by a motor in parallel to circulate refrigerant for air conditioning. In the computer program product, a processor controlling the drives of the first compressor and the second compressor functions as both a first drive control unit and a second drive control unit. When the air conditioning device is started, the first drive control unit drives only the first compressor during a first period and calculates the air conditioning load (i.e., the first air conditioning load) during the first period. Based on the first air conditioning load, the second drive control unit determines whether to drive both the first compressor and the second compressor, or only the second compressor. If the suction temperature difference is below a predetermined threshold during the first period, the second drive control unit determines to drive only the second compressor. If the suction temperature difference is below the predetermined threshold during the first period, the second drive control unit drives only the second compressor during a second period and calculates the air conditioning load (i.e., the second air conditioning load) during the second period. Based on the second air conditioning load, the second drive control unit determines whether to drive both the first compressor and the second compressor, or only the second compressor.

[0012] Invention Effects

[0013] The air conditioning device, the control method for the air conditioning device, and the computer program product disclosed herein can appropriately switch between the individual operation of the second compressor and the concurrent operation of the first compressor and the second compressor. Attached Figure Description

[0014] Figure 1 This is a refrigerant circuit diagram representing the air conditioning device of Embodiment 1.

[0015] Figure 2 This is a block diagram showing the structure of the control unit in Embodiment 1.

[0016] Figure 3 This is a graph showing the relationship between air conditioning load and efficiency in Implementation Method 1.

[0017] Figure 4 This is a timing diagram illustrating an example of the transition of the compressor's state in Implementation 1.

[0018] Figure 5 This is a timing diagram illustrating another example of the transition of the compressor's state in Implementation 1.

[0019] Figure 6 This is a flowchart illustrating an example of the processing of the outdoor unit control unit in Embodiment 1. Detailed Implementation

[0020] (Insights, etc., that form the basis of this disclosure)

[0021] When the inventors conceived of this disclosure, they had an air conditioning device comprising a gas engine driven by gas, a first compressor that obtains driving force from the gas engine and compresses refrigerant, and a second compressor driven by an electric motor.

[0022] In addition, for example, it is proposed that when the air conditioning device is started, only the first compressor is driven in the first period, and the air conditioning load in the first period is calculated, i.e., the first air conditioning load. Based on the first air conditioning load, the individual operation of the second compressor and the combined operation of the first compressor and the second compressor are appropriately switched.

[0023] However, in the aforementioned air conditioning device, the first compressor has a higher capacity than the second compressor. Therefore, during the first period (e.g., 5 minutes), thermal disconnection (thermo-off / thermal protection shutdown) sometimes occurs. Thus, the inventors have discovered the following problem: in the event of thermal disconnection occurring within a short period, the overall space may not reach the target temperature, potentially hindering user comfort. To solve this problem, the subject of this disclosure is formed.

[0024] This disclosure provides an air conditioning device capable of appropriately switching between the individual operation of a second compressor and the combined operation of a first compressor and a second compressor, a control method for the air conditioning device, and a computer program product.

[0025] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. However, sometimes necessary detailed descriptions are omitted. For example, detailed descriptions of well-known matters or repeated descriptions of substantially the same structures are sometimes omitted. This is to avoid making the following description too lengthy and to facilitate understanding by those skilled in the art.

[0026] Furthermore, the accompanying drawings and the following description are provided to enable those skilled in the art to fully understand this disclosure, and are not intended to limit the scope of the subject matter described in the claims.

[0027] (Implementation Method 1)

[0028] Hereinafter, Embodiment 1 will be described using the accompanying drawings.

[0029] [1-1. Structure, etc.]

[0030] [1-1-1. Structure of the refrigerant circuit]

[0031] First, refer to Figure 1 The refrigerant circuit constituting the air conditioning unit 1 will be described. Figure 1 This is a refrigerant circuit diagram of the air conditioning device 1 in Embodiment 1.

[0032] like Figure 1 As shown, the air conditioning device 1 of this embodiment includes an outdoor unit 10 and an indoor unit 30. Furthermore, in Figure 1 In this case, only one indoor unit 30 is provided, but multiple indoor units 30 can also be provided in parallel with the outdoor unit 10.

[0033] The outdoor unit 10 includes a gas engine 11, a first compressor 12, a motor 13, and a second compressor 14.

[0034] The gas engine 11 drives the first compressor 12. The first compressor 12, driven by the gas engine 11, compresses the refrigerant.

[0035] Motor 13 drives the second compressor 14. The second compressor 14, driven by motor 13, compresses the refrigerant.

[0036] The first compressor 12 and the second compressor 14 are connected in parallel.

[0037] In this embodiment, the first compressor 12 has a higher capacity than the second compressor 14.

[0038] Furthermore, in the following description, "driving the first compressor" means driving the first compressor 12 with the gas engine 11. Additionally, "driving the second compressor" means driving the second compressor 14 with the motor 13.

[0039] The refrigerant injection sides of the first compressor 12 and the second compressor 14 converge, and an oil separator 15 is installed there. The oil separator 15 separates the oil contained in the refrigerant gas injected from the first compressor 12 and the second compressor 14.

[0040] Downstream of the oil separator 15, it is connected to the outdoor heat exchanger 17 via a four-way valve 16. The four-way valve 16 switches the refrigeration cycle between cooling and heating operations. That is, in Figure 1 In the heating operation, the refrigerant flows in the direction indicated by the solid arrow, and in the cooling operation, the refrigerant flows in the direction indicated by the dashed arrow.

[0041] A radiator 18 for cooling the cooling water of the gas engine 11 is disposed on the lower side of the outdoor heat exchanger 17. In addition, an outdoor fan 19 for ventilating outside air to the outdoor heat exchanger 17 and the radiator 18 is disposed near the radiator 18.

[0042] An outdoor expansion valve 20 is installed on one side of the outdoor heat exchanger 17. The outdoor expansion valve 20 is connected to the indoor unit 30 via a refrigerant pipe.

[0043] The indoor unit 30 includes an indoor heat exchanger 31, an indoor fan 32, and an indoor expansion valve 33. The refrigerant piping 35 is connected to one end of the indoor heat exchanger 31 via the indoor expansion valve 33.

[0044] The other end of the indoor heat exchanger 31 is connected to the suction pipe 36 of the first compressor 12 and the second compressor 14 via a four-way valve 16 and an accumulator 21.

[0045] Indoor unit 30 corresponds to an example of "indoor unit".

[0046] A bypass pipe 22 is connected midway through the refrigerant piping 35 connecting the outdoor heat exchanger 17 and the indoor heat exchanger 31. This bypass pipe 22 is connected to the suction side of the first compressor 12 and the second compressor 14. A heat recovery pressure reducing device 23 and a heat recovery heat exchanger 24 are installed on the bypass pipe 22.

[0047] Additionally, one end of the oil return pipe 25 is connected below the oil separator 15, and the other end of the oil return pipe 25 is connected to the suction pipe 36 of the first compressor 12 and the second compressor 14.

[0048] In addition, refrigerant temperature sensors 26 for detecting the temperature of the sprayed refrigerant are provided on the discharge side of the first compressor 12 and the second compressor 14.

[0049] [1-1-2. Control Structure]

[0050] Next, refer to Figure 2The control structure of this embodiment will be described. Figure 2 This is a block diagram showing the control structure of the air conditioning device 1 in this embodiment.

[0051] like Figure 2 As shown, the air conditioning unit 1 includes an outdoor unit control unit 40 and an indoor unit control unit 50. The outdoor unit control unit 40 controls each part of the outdoor unit 10. The indoor unit control unit 50 controls each part of the indoor unit 30.

[0052] The outdoor unit control section 40 corresponds to an example of "control section".

[0053] First, the structure of the outdoor unit control unit 40 will be explained.

[0054] The outdoor unit control unit 40 includes an outdoor unit communication circuit 41, an outdoor unit processor 42, and an outdoor unit memory 43.

[0055] The outdoor unit communication circuit 41 communicates with the indoor unit communication circuit 51 according to instructions from the outdoor unit processor 42. The outdoor unit communication circuit 41 receives the temperature difference signal SG from the indoor unit communication circuit 51. The temperature difference signal SG represents the intake temperature difference ΔTP of the indoor unit 30.

[0056] The outdoor unit processor 42 is a CPU (Central Processing Unit) or MPU (Micro Processing Unit) processor.

[0057] The outdoor unit processor 42 can consist of a single processor or multiple processors.

[0058] The outdoor unit processor 42 corresponds to an example of "processor".

[0059] The outdoor unit memory 43 is a memory for storing programs and data. The outdoor unit memory 43 stores the outdoor unit control program 431. The outdoor unit memory 43 has non-volatile storage areas. Alternatively, the outdoor unit memory 43 may also include volatile storage areas, constituting the working area of ​​the outdoor unit processor 42. The outdoor unit memory 43 may be composed of, for example, ROM (Read Only Memory) or RAM (Random Access Memory).

[0060] The outdoor unit control program 431 corresponds to an example of the "control program".

[0061] The outdoor unit control unit 40 controls the first compressor 12, the second compressor 14, the outdoor fan 19, the outdoor expansion valve 20, etc. of the outdoor unit 10 of the air conditioning device 1.

[0062] A refrigerant temperature sensor 26 is connected to the outdoor unit control section 40.

[0063] The outdoor unit processor 42 functions as both the first drive control unit 421 and the second drive control unit 422. Specifically, the outdoor unit processor 42 reads and executes the outdoor unit control program 431 from the outdoor unit memory 43, thus functioning as both the first drive control unit 421 and the second drive control unit 422.

[0064] When the first drive control unit 421 starts the air conditioning unit 1, it drives only the first compressor 12 during the first period P1 and calculates the air conditioning load LD, i.e., the first air conditioning load L1, during the first period P1. The first period P1 is, for example, 5 minutes.

[0065] In this way, when the air conditioning unit 1 is started, only the first compressor 12 is driven. Therefore, even if liquid refrigerant enters the compressor, damage to the compressor can be suppressed. This is because the second compressor 14 is more likely to be damaged when compressing liquid refrigerant compared to the first compressor 12.

[0066] In addition, the first drive control unit 421 calculates the first air conditioning load L1 based on, for example, the rated output of the first compressor 12, the rated output of the second compressor 14, the output of the first compressor 12, the output of the second compressor 14, the suction temperature difference ΔTP of the indoor unit 30, etc.

[0067] The intake temperature difference ΔTP represents the difference between the target temperature and the intake temperature. The target temperature is set, for example, by the remote control 90. The intake temperature is the temperature of the air drawn into the indoor unit 30. The intake temperature is detected by the intake temperature sensor 34.

[0068] The outdoor unit communication circuit 41 receives a signal representing the intake temperature difference ΔTP from the indoor unit communication circuit 51. The first drive control unit 421 obtains the intake temperature difference ΔTP from the outdoor unit communication circuit 41.

[0069] In addition, the second drive control unit 422 determines, based on the first air conditioning load L1, whether to drive both the first compressor 12 and the second compressor 14, or only the second compressor 14.

[0070] For example, when the first air conditioning load L1 is above the first threshold TH1, the second drive control unit 422 determines to drive both the first compressor 12 and the second compressor 14. Alternatively, when the first air conditioning load L1 is below the first threshold TH1, the second drive control unit 422 determines to drive only the second compressor 14.

[0071] The first threshold TH1 is, for example, "30%" of the maximum load. The maximum load is, for example, the sum of the rated capacity of the first compressor 12 and the rated capacity of the second compressor 14.

[0072] In addition, if the second drive control unit 422 determines that only the second compressor 14 is driven when the intake temperature difference ΔTP in the indoor unit 30 is below the predetermined threshold ΔTHA during the first period P1.

[0073] The intake temperature difference ΔTP represents the difference between the target temperature and the intake temperature. The target temperature is set, for example, by the remote control 90. The intake temperature is the temperature of the air drawn into the indoor unit 30. The intake temperature is detected by the intake temperature sensor 34.

[0074] Furthermore, during the first period P1, when the outdoor unit communication circuit 41 receives the temperature difference signal SG from the indoor unit communication circuit 51, the second drive control unit 422 determines whether the intake temperature difference ΔTP within the indoor unit 30 is below a predetermined threshold ΔTHA. The temperature difference signal SG represents the intake temperature difference ΔTP. The predetermined threshold ΔTHA is, for example, "2°C".

[0075] The specified threshold ΔTHA is set to a value larger than the transition threshold ΔTHB, which will be described later.

[0076] In addition, when the suction temperature difference ΔTP during the first period P1 is below the predetermined threshold ΔTHA, the second drive control unit 422 drives only the second compressor 14 during the second period P2 after the first period P1, and calculates the air conditioning load, i.e., the second air conditioning load L2, during the second period P2.

[0077] The second period P2 is, for example, a period of the same length as the first period P1. In other words, the second period P2 is, for example, "5 minutes".

[0078] The second drive control unit 422 calculates the second air conditioning load L2, for example, based on the rated output of the first compressor 12, the rated output of the second compressor 14, the output of the first compressor 12, the output of the second compressor 14, the suction temperature difference ΔTP of the indoor unit 30, etc.

[0079] The outdoor unit communication circuit 41 receives a temperature difference signal SG representing the intake temperature difference ΔTP from the indoor unit communication circuit 51. The second drive control unit 422 obtains the intake temperature difference ΔTP from the outdoor unit communication circuit 41.

[0080] Furthermore, the second drive control unit 422 determines, based on the second air conditioning load L2, whether to drive both the first compressor 12 and the second compressor 14, or only the second compressor 14.

[0081] For example, if the second air conditioning load L2 is above the second threshold TH2, the second drive control unit 422 determines to drive both the first compressor 12 and the second compressor 14. Alternatively, if the second air conditioning load L2 is below the second threshold TH2, the second drive control unit 422 determines to drive only the second compressor 14.

[0082] The second threshold TH2 is, for example, the same value as the first threshold TH1. In other words, the second threshold TH2 is, for example, 30% of the maximum load. The maximum load is, for example, the sum of the rated capacity of the first compressor 12 and the rated capacity of the second compressor 14.

[0083] Next, the structure of the indoor unit control unit 50 will be explained.

[0084] The indoor unit control unit 50 includes an indoor unit communication circuit 51, an indoor unit processor 52, and an indoor unit memory 53.

[0085] The indoor unit communication circuit 51 communicates with the outdoor unit communication circuit 41 according to instructions from the indoor unit processor 52. The indoor unit communication circuit 51 sends a differential temperature signal SG, etc., to the outdoor unit communication circuit 41. The differential temperature signal SG represents the intake differential temperature ΔTP.

[0086] The indoor unit processor 52 is a CPU or MPU processor.

[0087] The indoor unit processor 52 can consist of a single processor or multiple processors.

[0088] The indoor unit memory 53 is a memory for storing programs and data. The indoor unit memory 53 stores the indoor unit control program 531. The indoor unit memory 53 has non-volatile storage areas. Alternatively, the indoor unit memory 53 may also include volatile storage areas, constituting the working area of ​​the indoor unit processor 52. The indoor unit memory 53 is, for example, composed of ROM or RAM.

[0089] The indoor unit control unit 50 controls the indoor fan 32, indoor expansion valve 33, etc. of the indoor unit 30 of the air conditioning device 1.

[0090] The indoor unit processor 52 functions as both a drive control unit 521 and a transmission unit 522. Specifically, the indoor unit processor 52 reads and executes the indoor unit control program 531 from the indoor unit memory 53, thus functioning as both a drive control unit 521 and a transmission unit 522.

[0091] The drive control unit 521 controls each part of the indoor unit 30 according to the setting information from the remote controller 90.

[0092] The drive control unit 521 receives, for example, instruction information from the remote controller 90 and switches the indoor unit 30 on / off.

[0093] Additionally, the drive control unit 521 receives, for example, instruction information from the remote controller 90 and controls the operating mode of the indoor unit 30. The operating modes include heating mode, cooling mode, and fan operation mode. The heating mode is the mode in which the drive control unit 521 causes the indoor unit 30 to perform heating operation.

[0094] The cooling operation mode is the operation mode in which the drive control unit 521 causes the indoor unit 30 to perform cooling operation. The air supply operation mode is the operation mode in which the drive control unit 521 causes the indoor unit 30 to perform air supply operation.

[0095] In addition, the drive control unit 521 receives target temperature information from the remote controller 90, and controls each part of the indoor unit 30 based on the target temperature.

[0096] The drive control unit 521, for example, switches to air supply operation when the intake temperature difference ΔTP falls below the transition threshold ΔTHB during heating or cooling operation. The intake temperature difference ΔTP represents the difference between the target temperature and the intake temperature. The target temperature is set, for example, by the remote control 90. The intake temperature is the temperature of the air drawn into the indoor unit 30. The intake temperature is detected by the intake temperature sensor 34. The transition threshold ΔTHB is, for example, "1°C".

[0097] In the operating mode of the indoor unit 30 controlled by the drive control unit 521, the transmitting unit 522 transmits the differential temperature signal SG to the outdoor unit communication circuit 41 relative to the indoor unit communication circuit 51. The differential temperature signal SG represents the intake differential temperature ΔTP.

[0098] In this embodiment, only one indoor unit 30 is provided in the air conditioning unit 1, or multiple indoor units 30 may be provided in the air conditioning unit 1. In this case, for example, if the intake temperature difference ΔTP of at least one indoor unit 30 among the multiple indoor units 30 falls below a predetermined threshold ΔTHA during the first period P1, the second drive control unit 422 determines to drive only the second compressor 14.

[0099] [1-1-3. Relationship between air conditioning load and efficiency]

[0100] Next, refer to Figure 3 The relationship between air conditioning load LD and efficiency EF is explained. Figure 3 This is a graph showing the relationship between air conditioning load LD and efficiency EF.

[0101] Figure 3 The horizontal axis represents the air conditioning load LD, and the vertical axis represents the efficiency EF.

[0102] Chart G1 shows the relationship between air conditioning load LD and efficiency EF when only the second compressor 14 is driven. Chart G2 shows the relationship between air conditioning load LD and efficiency EF when only the first compressor 12 is driven. Chart G3 shows the relationship between air conditioning load LD and efficiency EF when both the first compressor 12 and the second compressor 14 are driven.

[0103] By comparing charts G1, G2, and G3, we can see the following.

[0104] That is, when the air conditioning load LD is within the first range LA, the efficiency EF is optimal when only the second compressor 14 is driven. The first range LA is the range below the first load LD1.

[0105] Furthermore, when the air conditioning load LD is within the second range LB, the efficiency EF is optimal when only the first compressor 12 is driven. The second range LB is the range between the first load LD1 and the second load LD2.

[0106] Furthermore, when the air conditioning load LD is within the third range LC, the efficiency EF is optimal when both the first compressor 12 and the second compressor 14 are driven. The third range LC is the range above the second load LD2.

[0107] The load THL represents the air conditioning load LD at the intersection of chart G1 and chart G3. The first threshold TH1 and the second threshold TH2 are set, for example, based on the load THL.

[0108] Therefore, from the perspective of efficiency EF, it is preferable to drive only the second compressor 14 when the air conditioning load LD is in the first range LA, drive only the first compressor 12 when the air conditioning load LD is in the second range LB, and drive both the first compressor 12 and the second compressor 14 when the air conditioning load LD is in the third range LC.

[0109] However, the first compressor 12 is driven by the gas engine 11, so it is efficient when driven at medium to high output, but less efficient when driven at low output.

[0110] Therefore, in this embodiment, the second drive control unit 422 determines, based on the first air conditioning load L1, whether to drive both the first compressor 12 and the second compressor 14, or only the second compressor 14. Furthermore, the second drive control unit 422 determines, based on the second air conditioning load L2, whether to drive both the first compressor 12 and the second compressor 14, or only the second compressor 14.

[0111] [1-2. Actions, etc.]

[0112] [1-2-1. Operation of the refrigerant circuit]

[0113] Next, refer to Figure 1 The operation of the air conditioning device in the embodiment will be explained.

[0114] (Refrigeration operation)

[0115] During cooling operation, at least one of the first compressor 12 and the second compressor 14 is driven according to the air conditioning load LD. The four-way valve 16 is configured to allow refrigerant to flow in the direction indicated by the dashed arrow.

[0116] High-temperature, high-pressure gaseous refrigerant, compressed by at least one of the first compressor 12 and the second compressor 14, flows into the oil separator 15. The gaseous refrigerant, having had its oil separated by the oil separator 15, enters the outdoor heat exchanger 17 through the four-way valve 16. The gaseous refrigerant exchanges heat with the outside gas using the outdoor heat exchanger 17 and condenses after heat dissipation, becoming a high-pressure liquid refrigerant, which is then supplied to the indoor unit 30 through the outdoor expansion valve 20.

[0117] The high-pressure liquid refrigerant entering the indoor unit 30 is depressurized by the indoor expansion valve 33, becoming a gas-liquid two-phase state, and flows into the indoor heat exchanger 31. The gas-liquid two-phase refrigerant exchanges heat with the air in the space to be conditioned using the indoor heat exchanger 31, and evaporates after absorbing heat, becoming a gaseous refrigerant, which flows out from the indoor unit 30.

[0118] The refrigerant flowing out of the indoor unit 30 returns to the outdoor unit 10. The refrigerant flowing into the outdoor unit 10 returns to at least one of the first compressor 12 and the second compressor 14 through the four-way valve 16 and the accumulator 21, and repeats the above process.

[0119] (Heating operation)

[0120] During heating operation, the first compressor 12 and the second compressor 14 are driven together, or only the second compressor 14, depending on the air conditioning load LD. The four-way valve 16 is set to allow refrigerant to flow in the direction indicated by the solid arrow.

[0121] The high-temperature, high-pressure gaseous refrigerant, compressed by both the first compressor 12 and the second compressor 14, or by the second compressor 14, flows into the oil separator 15. The gaseous refrigerant, after the oil has been separated by the oil separator 15, is supplied to the indoor unit 30 through the four-way valve 16.

[0122] The high-temperature, high-pressure gaseous refrigerant entering the indoor unit 30 flows into the indoor heat exchanger 31, where it exchanges heat with the air in the space that is being conditioned and condenses after dissipating heat, becoming liquid refrigerant, which then flows out of the indoor unit 30 through the indoor expansion valve 33.

[0123] The liquid refrigerant flowing out of the indoor unit 30 returns to the outdoor unit 10. The liquid refrigerant flowing into the outdoor unit 10 is depressurized by the outdoor expansion valve 20, becoming a gas-liquid two-phase state, and flows into the outdoor heat exchanger 17. The gas-liquid two-phase refrigerant exchanges heat with the external gas in the outdoor heat exchanger 17 and evaporates after absorbing heat, becoming a gaseous refrigerant. It then returns to either the first compressor 12 or the second compressor 14, or the second compressor 14, through the four-way valve 16 and the accumulator 21, repeating the above process.

[0124] [1-2-2. Transition of the compressor's state]

[0125] Next, refer to Figure 4 - Figure 5 The transition of the compressor's state is explained.

[0126] Figure 4 This is a timing diagram illustrating an example of the transition of the compressor's state in Implementation 1. Figure 4 It is a time series diagram when the inhalation temperature difference ΔTP does not fall below the specified threshold ΔTHA during the first period P1.

[0127] Figure 4 - Figure 5 The upper layer indicates the on / off state of the first compressor 12. Figure 4 - Figure 5 The lower layer indicates the on / off state of the second compressor 14. Figure 4 - Figure 5 The horizontal axis of the upper and lower layers represents time T, and the vertical axis represents on / off.

[0128] like Figure 4 As shown, at time T0, the air conditioning unit 1 is started. During the first period P1 from time T0 to time T1, the first drive control unit 421 only drives the first compressor 12. In addition, the first drive control unit 421 calculates the air conditioning load LD, i.e., the first air conditioning load L1, during the first period P1.

[0129] Furthermore, when the first air conditioning load L1 is lower than the first threshold TH1, the second drive control unit 422 determines to drive only the second compressor 14.

[0130] Therefore, at time T1, the drive of the first compressor 12 is stopped, and the drive of the second compressor 14 is started.

[0131] On the other hand, when the first air conditioning load L1 is above the first threshold TH1, the second drive control unit 422 determines to drive both the first compressor 12 and the second compressor 14.

[0132] Therefore, as Figure 4As shown by the dashed line, at time T1, the first compressor 12 continues to be driven. Additionally, at time T1, the second compressor 14 begins to be driven. That is, at time T1, both the first compressor 12 and the second compressor 14 are driven.

[0133] Figure 5 This is a timing diagram illustrating another example of the transition of the compressor's state in Implementation 1. Figure 5 It is a time series diagram when the inhalation temperature difference ΔTP becomes below the specified threshold ΔTHA during the first period.

[0134] like Figure 5 As shown, at time T0, the air conditioning unit 1 is started. During the first period P1 from time T0 to time T1, the first drive control unit 421 only drives the first compressor 12. In addition, the first drive control unit 421 calculates the air conditioning load LD, i.e., the first air conditioning load L1, during the first period P1.

[0135] When the intake temperature difference ΔTP falls below the predetermined threshold ΔTHA during the first period P1, the second drive control unit 422 determines to drive only the second compressor 14 at time T1.

[0136] Therefore, at time T1, the drive of the first compressor 12 is stopped, and the drive of the second compressor 14 begins. Then, during the second period P2 from time T1 to time T2, only the second compressor 14 is driven. In addition, during the second period P2, the second drive control unit 422 calculates the air conditioning load LD, i.e., the second air conditioning load L2, for the second period P2.

[0137] Furthermore, when the second air conditioning load L2 is lower than the second threshold TH2, the second drive control unit 422 determines to drive only the second compressor 14.

[0138] Therefore, at time T2, the first compressor 12 continues to be stopped, and the second compressor 14 continues to be driven. That is, at time T2, only the second compressor 14 is driven.

[0139] On the other hand, when the second air conditioning load L2 is above the second threshold TH2, the second drive control unit 422 determines to drive both the first compressor 12 and the second compressor 14.

[0140] Therefore, as Figure 5 As shown by the dashed line, at time T2, the first compressor 12 begins to be driven. Additionally, at time T2, the second compressor 14 continues to be driven. That is, at time T2, both the first compressor 12 and the second compressor 14 are driven.

[0141] For reference Figure 4 - Figure 5As explained, the second drive control unit 422 determines, based on the air conditioning load LD, whether to drive both the first compressor 12 and the second compressor 14, or only the second compressor 14. Therefore, it is possible to appropriately switch between individual operation of the second compressor 14 and concurrent operation of the first compressor 12 and the second compressor 14, depending on the air conditioning load LD.

[0142] [1-2-3. Processing of the outdoor unit control unit]

[0143] Next, refer to Figure 6 The processing of the outdoor unit control unit 40 is explained. Figure 6 This is a flowchart illustrating an example of the processing of the outdoor unit control unit 40 in Embodiment 1.

[0144] like Figure 6 As shown, firstly, in step S101, the first drive control unit 421 drives the first compressor 12 when the air conditioning device 1 is started.

[0145] In this way, when the air conditioning unit 1 is started, only the first compressor 12 is driven. Therefore, even if liquid refrigerant enters the compressor, damage to the compressor can be suppressed. This is because the second compressor 14 is more likely to be damaged when compressing liquid refrigerant compared to the first compressor 12.

[0146] Next, in step S103, the first drive control unit 421 calculates the first air conditioning load L1. The first air conditioning load L1 is the air conditioning load LD during the first period P1.

[0147] Next, in step S105, the outdoor unit control unit 40 determines whether the first period P1 has elapsed since the air conditioning device 1 was started in step S101.

[0148] If the outdoor unit control unit 40 determines that the first period P1 has not been completed (step S105; NO), the process returns to step S103. If the outdoor unit control unit 40 determines that the first period P1 has been completed (step S105; YES), the process proceeds to step S107.

[0149] Then, in step S107, the second drive control unit 422 determines whether the inhalation temperature difference ΔTP is below the predetermined threshold ΔTHA during the first period P1.

[0150] If the second drive control unit 422 determines that the inhalation temperature difference ΔTP is below the predetermined threshold ΔTHA (step S107; YES), the process proceeds to step S117. If the second drive control unit 422 determines that the inhalation temperature difference ΔTP is not below the predetermined threshold ΔTHA (step S107; NO), the process proceeds to step S109.

[0151] Then, in step S109, the second drive control unit 422 determines whether the first air conditioning load L1 is above the first threshold TH1.

[0152] If the second drive control unit 422 determines that the first air conditioning load L1 is not above the first threshold TH1 (step S109; NO), the process proceeds to step S111.

[0153] Then, in step S111, the second drive control unit 422 drives the second compressor 14.

[0154] Next, in step S113, the second drive control unit 422 stops the drive of the first compressor 12. Then, the process ends.

[0155] If the second drive control unit 422 determines that the first air conditioning load L1 is above the first threshold TH1 (step S109; YES), the process proceeds to step S115.

[0156] Then, in step S115, the second drive control unit 422 drives the second compressor 14. Then, the process ends.

[0157] If the result is YES in step S107, then in step S117, the second drive control unit 422 drives the second compressor 14.

[0158] Next, in step S119, the second drive control unit 422 stops the drive of the first compressor 12.

[0159] Next, in step S121, the second drive control unit 422 calculates the second air conditioning load L2. The second air conditioning load L2 is the air conditioning load LD during the second period P2.

[0160] Furthermore, through the processes in steps S107, S117, S119, and S121, the air conditioning device 1 achieves the following effect: Specifically, when the air conditioning load LD is low, it can suppress the indoor unit 30 from repeatedly switching on and off the temperature control (temperature control start / temperature control on / thermo-on), thus suppressing the reduction in user comfort.

[0161] Next, in step S123, the outdoor unit control unit 40 determines whether the second period P2 has elapsed since the first compressor 12 was stopped in step S119.

[0162] If the outdoor unit control unit 40 determines that the second period P2 has not passed (step S123; NO), the process returns to step S121. If the outdoor unit control unit 40 determines that the second period P2 has passed (step S123; YES), the process proceeds to step S125.

[0163] Then, in step S125, the second drive control unit 422 determines whether the second air conditioning load L2 is above the second threshold TH2.

[0164] If the second drive control unit 422 determines that the second air conditioning load L2 is not above the second threshold TH2 (step S125; NO), then the process ends. If the second drive control unit 422 determines that the second air conditioning load L2 is above the second threshold TH2 (step S125; YES), the process proceeds to step S127.

[0165] Then, in step S127, the second drive control unit 422 drives the first compressor 12. Then, the process ends.

[0166] Steps S101 to S103 correspond to an example of the "first control step".

[0167] Steps S107 to S119 correspond to an example of the "second control step".

[0168] [1-3. Effects, etc.]

[0169] As described above, the air conditioning device 1 of this embodiment connects a first compressor 12 driven by a gas engine 11 and a second compressor 14 driven by a motor 13 in parallel to circulate refrigerant for air conditioning. The device includes an outdoor unit control unit 40 that controls the driving of the first compressor 12 and the second compressor 14. The outdoor unit control unit 40 includes: a first drive control unit 421 that drives only the first compressor 12 during a first period P1 when the air conditioning device 1 is started, and calculates the air conditioning load LD, i.e., the first air conditioning load L1, during the first period P1; and a second drive control unit 422 that determines, based on the first air conditioning load L1, whether to drive both the first compressor 12 and the second compressor 14, or only the second compressor 14. The second drive control unit 422 determines to drive only the second compressor 14 when the suction temperature difference ΔTP during the first period P1 is below a predetermined threshold ΔTHA.

[0170] Therefore, based on the air conditioning load LD (i.e., the first air conditioning load L1) during the first period P1, it is determined whether to drive both the first compressor 12 and the second compressor 14, or only the second compressor 14. Thus, it is possible to appropriately switch between the individual operation of the second compressor 14 and the combined operation of the first compressor 12 and the second compressor 14.

[0171] Furthermore, when the intake temperature difference ΔTP falls below the predetermined threshold ΔTHA during the first period P1, it is determined that only the second compressor 14 will be driven. Therefore, it is possible to appropriately switch between individual operation of the second compressor 14 and concurrent operation of the first compressor 12 and the second compressor 14.

[0172] In addition, in this embodiment, when the intake temperature difference ΔTP becomes below the predetermined threshold ΔTHA in the first period P1, the second drive control unit 422 drives only the second compressor 14 in the second period P2, and calculates the air conditioning load LD, i.e., the second air conditioning load L2, in the second period P2. Based on the second air conditioning load L2, it determines whether to drive both the first compressor 12 and the second compressor 14, or only the second compressor 14.

[0173] Therefore, when the intake temperature difference ΔTP falls below the predetermined threshold ΔTHA during the first period P1, the air conditioning load LD (i.e., the second air conditioning load L2) during the second period P2 determines whether to drive both the first compressor 12 and the second compressor 14, or only the second compressor 14. Thus, it is possible to appropriately switch between the individual operation of the second compressor 14 and the combined operation of the first compressor 12 and the second compressor 14.

[0174] In addition, in this embodiment, multiple indoor units 30 are included. If the inhalation temperature difference ΔTP of at least one indoor unit 30 is below the predetermined threshold ΔTHA during the first period P1, the second drive control unit 422 determines to drive only the second compressor 14.

[0175] Therefore, when the suction temperature difference ΔTP of at least one of the multiple indoor units 30 falls below the predetermined threshold ΔTHA during the first period P1, it is determined that only the second compressor 14 will be driven. Thus, even when multiple indoor units 30 are included, it is possible to appropriately switch between individual operation of the second compressor 14 and concurrent operation of the first compressor 12 and the second compressor 14.

[0176] In addition, in this embodiment, when the first air conditioning load L1 is above the first threshold TH1, the second drive control unit 422 determines to drive both the first compressor 12 and the second compressor 14, and when the first air conditioning load L1 is below the first threshold TH1, it determines to drive only the second compressor 14.

[0177] Therefore, when the first air conditioning load L1 is above the first threshold TH1, it is determined that both the first compressor 12 and the second compressor 14 will be driven; when the first air conditioning load L1 is below the first threshold TH1, it is determined that only the second compressor 14 will be driven. Thus, by setting the first threshold TH1 to an appropriate value, it is possible to appropriately switch between the individual operation of the second compressor 14 and the combined operation of the first compressor 12 and the second compressor 14.

[0178] In addition, in this embodiment, when the second air conditioning load L2 is above the second threshold TH2, the second drive control unit 422 determines to drive both the first compressor 12 and the second compressor 14, and when the second air conditioning load L2 is below the second threshold TH2, it determines to drive only the second compressor 14.

[0179] Therefore, when the second air conditioning load L2 is above the second threshold TH2, it is determined that both the first compressor 12 and the second compressor 14 will be driven; when the second air conditioning load L2 is below the second threshold TH2, it is determined that only the second compressor 14 will be driven. Thus, by setting the second threshold TH2 to an appropriate value, it is possible to appropriately switch between the individual operation of the second compressor 14 and the combined operation of the first compressor 12 and the second compressor 14.

[0180] Furthermore, the control method of the air conditioning device 1 in this embodiment controls the air conditioning device 1, which connects a first compressor driven by a gas engine and a second compressor driven by a motor in parallel to circulate refrigerant for air conditioning. The method includes a control unit that controls the driving of the first compressor and the second compressor. The control unit performs: a first control step, in which, when the air conditioning device is started, only the first compressor is driven during a first period, and the air conditioning load during the first period, i.e., the first air conditioning load, is calculated; and a second control step, in which, based on the first air conditioning load, it is determined whether to drive both the first compressor and the second compressor, or only the second compressor, is driven. In the second control step, if the suction temperature difference ΔTP is below a predetermined threshold ΔTHA during the first period, it is determined that only the second compressor is driven.

[0181] The control method of the air conditioning device 1 in this embodiment achieves the same effect as the air conditioning device in this embodiment.

[0182] Furthermore, the outdoor unit control program 431 of the air conditioning device 1 in this embodiment is an outdoor unit control program 431 that connects the first compressor 12 driven by the gas engine 11 and the second compressor 14 driven by the motor 13 in parallel to circulate the refrigerant for air conditioning. In this program, the outdoor unit processor 42 of the outdoor unit control unit 40, which controls the drive of the first compressor 12 and the second compressor 14, functions as the first drive control unit 421 and the second drive control unit 422. When the air conditioning device 1 is started, the first drive control unit 421 drives only the first compressor 12 during the first period P1 and calculates the air conditioning load LD, i.e., the first air conditioning load L1, during the first period P1. Based on the first air conditioning load L1, the second drive control unit 422 determines whether to drive both the first compressor 12 and the second compressor 14, or only the second compressor 14. If the suction temperature difference ΔTP is below the predetermined threshold ΔTHA during the first period P1, the second drive control unit 422 determines to drive only the second compressor 14.

[0183] The outdoor unit control program 431 of the air conditioning device 1 in this embodiment achieves the same effect as the air conditioning device 1 in this embodiment.

[0184] (Other implementation methods)

[0185] Furthermore, Embodiment 1 has been described as a technical example disclosed in this application. However, the technology disclosed herein is not limited to this and can also be applied to embodiments that have been modified, substituted, added, omitted, etc. Therefore, other embodiments are described below.

[0186] In this embodiment, the "control unit" is described as the outdoor unit control unit 40, but the embodiment is not limited to this. It is sufficient for the "control unit" to control the operation of the first compressor 12 and the second compressor 14. For example, the "control unit" may also have the functions of both the outdoor unit control unit 40 and the indoor unit control unit 50. That is, the "control unit" may also control each part of the outdoor unit 10 and the indoor unit 30.

[0187] In this embodiment, the second period P2 is described as being the same length as the first period P1, but the embodiment is not limited to this. The second period P2 can be a period longer than the first period P1, or it can be a period shorter than the first period P1.

[0188] In this embodiment, the case where the specified threshold ΔTHA is "2°C" and the transition threshold ΔTHB is "1°C" is described, but the embodiment is not limited to this. For example, it is acceptable as long as the specified threshold ΔTHA is greater than the transition threshold ΔTHB.

[0189] Furthermore, in this embodiment, the case where the second threshold TH2 is the same as the first threshold TH1 is described, for example, but the embodiment is not limited to this. The second threshold TH2 can be a value larger than the first threshold TH1, or it can be a value smaller than the first threshold TH1.

[0190] The outdoor unit processor 42 and the indoor unit processor 52 can also be hardware programmed to implement corresponding functional units. That is, these processors can be constructed, for example, by ASIC (Application Specific Integrated Circuit) or FPGA (Field Programmable Gate Array).

[0191] The outdoor unit communication circuit 41 and the indoor unit communication circuit 51 can also perform wireless communication respectively. For example, standards such as Wi-Fi (registered trademark) and WiMax (registered trademark) can be used for wireless connection.

[0192] exist Figure 6 In the flowchart shown, for ease of understanding of the actions, the processing steps of the outdoor unit control unit 40 are divided into units based on the main processing content, without limiting the actions by the method of dividing the processing units or their names. It is also possible to divide the process into more step units based on the processing content. Furthermore, a single step unit can be divided to include more processes. Additionally, the order of these steps can be appropriately replaced without affecting the spirit of this disclosure.

[0193] Furthermore, the above-described embodiments are used to illustrate the technology disclosed herein, and therefore, various changes, substitutions, additions, omissions, etc., can be made within the scope of the claims or their equivalents.

[0194] (Note)

[0195] Based on the description of the above embodiments, the following technology is disclosed.

[0196] (Technology 1)

[0197] An air conditioning device connects a first compressor driven by a gas engine and a second compressor driven by a motor in parallel to circulate refrigerant for air conditioning. The device includes a control unit that controls the driving of the first compressor and the second compressor. The control unit comprises: a first drive control unit that, when starting the air conditioning device, drives only the first compressor during a first period and calculates the air conditioning load (i.e., the first air conditioning load) during the first period; and a second drive control unit that, based on the first air conditioning load, determines whether to drive both the first compressor and the second compressor or only the second compressor. The second drive control unit determines to drive only the second compressor if the suction temperature difference is below a predetermined threshold during the first period, and determines to drive only the second compressor during a second period if the suction temperature difference is below the predetermined threshold during the first period. It also calculates the air conditioning load (i.e., the second air conditioning load) during the second period and, based on the second air conditioning load, determines whether to drive both the first compressor and the second compressor or only the second compressor.

[0198] This structure determines whether to drive both the first and second compressors, or only the second compressor, based on the air conditioning load during the first period (i.e., the first air conditioning load). Therefore, it allows for appropriate switching between individual operation of the second compressor and concurrent operation of the first and second compressors.

[0199] Furthermore, if the intake temperature difference falls below a predetermined threshold during the first period, it is determined that only the second compressor will be driven. Therefore, it is possible to appropriately switch between individual operation of the second compressor and concurrent operation of the first and second compressors.

[0200] Furthermore, if the intake temperature difference falls below a predetermined threshold during the first period, the system determines whether to drive both the first and second compressors, or only the second compressor, based on the air conditioning load during the second period (i.e., the second air conditioning load). Therefore, it is possible to appropriately switch between individual operation of the second compressor and concurrent operation of the first and second compressors.

[0201] (Technology 2)

[0202] According to the air conditioning device described in Technology 1, which includes multiple indoor units, when the intake temperature difference of at least one of the multiple indoor units is below a predetermined threshold during the first period, the second drive control unit determines to drive only the second compressor.

[0203] With this structure, if the suction temperature difference of at least one of the multiple indoor units falls below a predetermined threshold during the first period, it is determined that only the second compressor will be driven. Therefore, even in the case of multiple indoor units, it is possible to appropriately switch between the individual operation of the second compressor and the concurrent operation of the first and second compressors.

[0204] (Technology 3)

[0205] According to the air conditioning device described in Artificial 1 or 2, when the first air conditioning load is above a first threshold, the second drive control unit determines to drive both the first compressor and the second compressor, and when the first air conditioning load is below the first threshold, it determines to drive only the second compressor.

[0206] This structure determines that when the first air conditioning load is above a first threshold, both the first and second compressors will be driven; when the first air conditioning load is below the first threshold, only the second compressor will be driven. Therefore, by setting the first threshold to an appropriate value, it is possible to appropriately switch between the individual operation of the second compressor and the combined operation of the first and second compressors.

[0207] (Technology 4)

[0208] According to the air conditioning device described in Technology 1, when the second air conditioning load is above the second threshold, the second drive control unit determines to drive both the first compressor and the second compressor, and when the second air conditioning load is below the second threshold, it determines to drive only the second compressor.

[0209] This structure determines that when the second air conditioning load is above the second threshold, both the first and second compressors will be driven; when the second air conditioning load is below the second threshold, only the second compressor will be driven. Therefore, by setting the second threshold to an appropriate value, it is possible to appropriately switch between the individual operation of the second compressor and the combined operation of the first and second compressors.

[0210] (Technology 5)

[0211] A control method for an air conditioning device is provided, wherein the air conditioning device connects a first compressor driven by a gas engine and a second compressor driven by a motor in parallel to circulate refrigerant for air conditioning. The method includes a control unit that controls the driving of the first compressor and the second compressor. In the control method, the control unit performs: a first control step, in which, when the air conditioning device is started, only the first compressor is driven during a first period, and the air conditioning load during the first period, i.e., a first air conditioning load, is calculated; and a second control step, based on the first air conditioning load, determining whether to drive both the first compressor and the second compressor, or only the second compressor, is driven. In the second control step, if the suction temperature difference during the first period is below a predetermined threshold, it is determined that only the second compressor is driven; if the suction temperature difference during the first period is below the predetermined threshold, only the second compressor is driven during a second period, and the air conditioning load during the second period, i.e., a second air conditioning load, is calculated. Based on the second air conditioning load, it is determined whether to drive both the first compressor and the second compressor, or only the second compressor, is driven.

[0212] According to the control method of this air conditioning device, the same effect as the air conditioning device described in Technology 1 can be achieved.

[0213] (Technology 6)

[0214] A computer program product stores a control program for an air conditioning device that connects a first compressor driven by a gas engine and a second compressor driven by a motor in parallel to circulate refrigerant for air conditioning. In the computer program product, a processor controlling the drives of the first and second compressors functions as both a first drive control unit and a second drive control unit. When the air conditioning device is started, the first drive control unit drives only the first compressor during a first period and calculates the air conditioning load (i.e., the first air conditioning load) during that first period. Based on the first air conditioning load, the second drive control unit determines whether to drive both the first and second compressors, or only the second compressor. If the suction temperature difference is below a predetermined threshold during the first period, the second drive control unit determines to drive only the second compressor. If the suction temperature difference is below the predetermined threshold during the first period, the second drive control unit drives only the second compressor during a second period and calculates the air conditioning load (i.e., the second air conditioning load) during the second period. Based on the second air conditioning load, the second drive control unit determines whether to drive both the first and second compressors, or only the second compressor.

[0215] According to the computer control program product, the same function and effect as the air conditioning device described in Technology 1 can be achieved.

[0216] Industrial availability

[0217] As described above, the air conditioning device, the control method for the air conditioning device, and the computer program product disclosed herein can be appropriately used to switch between the individual operation of the second compressor and the combined operation of the first compressor and the second compressor in an air conditioning device.

[0218] Explanation of reference numerals in the attached figures

[0219] 1. Air conditioning unit

[0220] 10 Outdoor Units

[0221] 11 Gas Engine

[0222] 12 First Compressor

[0223] 13 motors

[0224] 14 Second compressor

[0225] 30 Indoor Units

[0226] 31 Indoor heat exchanger

[0227] 34. Inhalation temperature sensor

[0228] 40. Outdoor Unit Control Department (Control Department)

[0229] 41 Outdoor unit communication circuit

[0230] 42 Outdoor unit processor (processor)

[0231] 421 First Drive Control Unit

[0232] 422 Second Drive Control Unit

[0233] 43 Outdoor unit memory

[0234] 431 Outdoor Unit Control Program (Control Program)

[0235] 50 Indoor Unit Control Section

[0236] 51 Indoor unit communication circuit

[0237] 52 Indoor unit processor

[0238] 521 Drive Control Unit

[0239] 522 Sending Department

[0240] 53 Indoor unit memory

[0241] 531 Indoor Unit Control Program

[0242] LD air conditioning load

[0243] L1 First Air Conditioning Load

[0244] L2 Second Air Conditioning Load

[0245] P1 First Period

[0246] P2 Second Period

[0247] TH1 First Threshold

[0248] TH2 second threshold

[0249] SG differential temperature signal

[0250] ΔTHA specified threshold

[0251] ΔTHB Transition Threshold

[0252] ΔTP (Inhalation Temperature Difference)

Claims

1. An air conditioning device comprising a first compressor driven by a gas engine and a second compressor driven by a motor connected in parallel to circulate refrigerant for air conditioning, characterized in that, include: A control unit that controls the drives of the first compressor and the second compressor. The control unit includes: The first drive control unit, when starting the air conditioning device, drives only the first compressor during a first period and calculates the first air conditioning load as the air conditioning load during the first period. and The second drive control unit, based on the first air conditioning load, determines whether to drive both the first compressor and the second compressor, or only the second compressor. Regarding the second drive control unit During the first period, if the intake temperature difference falls below a predetermined threshold, it is determined that only the second compressor will be driven. During the first period, if the suction temperature difference falls below a predetermined threshold, it is determined that only the second compressor will be driven during the second period, and the second air conditioning load is calculated as the air conditioning load for the second period. Based on the second air conditioning load, it is determined whether to drive both the first compressor and the second compressor, or only the second compressor.

2. The air conditioning device according to claim 1, characterized in that, Including multiple indoor units, Regarding the second drive control unit, if the suction temperature difference of at least one of the plurality of indoor units is below a predetermined threshold during the first period, it is determined that only the second compressor will be driven.

3. The air conditioning device according to claim 1 or 2, characterized in that, Regarding the second drive control unit If the first air conditioning load is above the first threshold, it is determined that both the first compressor and the second compressor will be driven. If the first air conditioning load is lower than the first threshold, it is determined that only the second compressor will be driven.

4. The air conditioning device according to claim 1, characterized in that, Regarding the second drive control unit If the second air conditioning load is above the second threshold, it is determined that both the first compressor and the second compressor will be driven. If the second air conditioner load is lower than the second threshold, it is determined that only the second compressor will be driven.

5. A control method for an air conditioning device, wherein the air conditioning device connects a first compressor driven by a gas engine and a second compressor driven by a motor in parallel to circulate refrigerant for air conditioning, the control method for the air conditioning device being characterized in that... The air conditioning device includes a control unit that controls the drives of the first compressor and the second compressor. The control unit performs: The first control step involves, when starting the air conditioning unit, driving only the first compressor during a first period and calculating the first air conditioning load as the air conditioning load during the first period; and The second control step involves determining, based on the first air conditioning load, whether to drive both the first compressor and the second compressor, or only the second compressor. In the second control step, During the first period, if the suction temperature difference falls below a predetermined threshold, it is determined that only the second compressor will be driven. During the first period, if the suction temperature difference falls below a predetermined threshold, during the second period, only the second compressor is driven and the second air conditioning load is calculated as the air conditioning load for the second period. Based on the second air conditioning load, it is determined whether to drive both the first compressor and the second compressor, or only the second compressor.

6. A computer program product storing a control program for an air conditioning device, wherein, The air conditioning device connects a first compressor driven by a gas engine and a second compressor driven by a motor in parallel, allowing refrigerant to circulate for air conditioning. The computer program product is characterized by... The processor of the control unit that controls the drives of the first compressor and the second compressor functions as both the first drive control unit and the second drive control unit. When the first drive control unit starts the air conditioning device, it drives only the first compressor during a first period and calculates the first air conditioning load as the air conditioning load during the first period. Based on the first air conditioning load, the second drive control unit determines whether to drive both the first compressor and the second compressor, or only the second compressor. Regarding the second drive control unit During the first period, if the suction temperature difference falls below a predetermined threshold, it is determined that only the second compressor will be driven. During the first period, if the suction temperature difference falls below a predetermined threshold, during the second period, only the second compressor is driven and the second air conditioning load is calculated as the air conditioning load for the second period. Based on the second air conditioning load, it is determined whether to drive both the first compressor and the second compressor, or only the second compressor.

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