JP7309063B2 - refrigeration cycle equipment - Google Patents

Description

The present disclosure relates to a refrigeration cycle apparatus using at least one compressor.

Generally, a compressor is used as power for a heat source side unit in a refrigeration cycle apparatus. In some cases, the compressor has a predetermined replacement timing based on the cumulative operating time and the number of starts and stops (starts and stops) as parameters. It is recommended to overhaul or replace the compressor with a new one when it is time to replace the compressor.

In some refrigeration cycle apparatuses, a control device of a heat source side unit provided with a compressor is connected for communication with a load side unit provided with an evaporator. In such a refrigeration cycle apparatus, the control device of the heat source side unit obtains from the load side unit information on the temperature in the room or warehouse where the load side unit is installed (hereinafter also referred to as "load temperature"), and obtains the information. The drive frequency of the compressor can be controlled according to the information of the load temperature obtained.

In some cases, the heat source side unit of the refrigeration cycle apparatus is provided with a plurality of compressors. For example, in Japanese Patent No. 3082755 (Patent Document 1), in a refrigeration cycle apparatus having a plurality of compressors, based on the accumulated operating time of each compressor, so that the accumulated operating time of each compressor is equal. , a technique for rotating the compressors to be started is described.

Japanese Patent No. 3082755

When the control device of the heat source side unit is not connected for communication with the load side unit, generally, the control device of the heat source side unit controls the pressure of the low-pressure refrigerant sucked into the compressor (hereinafter referred to as "compressor suction pressure" or The compressor is controlled based on the difference between the detected suction pressure and a preset target pressure. In this case, since the control device of the heat source side unit cannot control the drive frequency of the compressor according to the load temperature, the refrigerant is cut off by an electric valve for the purpose of preventing overcooling in the load side unit. be. When the suction pressure of the compressor drops due to the refrigerant cutoff by the load side unit, the compressor of the heat source side unit may stop. After stopping the compressor, the compressor is restarted when a specified time has elapsed or when the suction pressure is restored. If such stop and start of the compressor are repeated frequently, there is concern that the life of the compressor will be shortened.

In addition, in a refrigeration cycle apparatus having a plurality of compressors, as disclosed in Japanese Patent No. 3082755 (Patent Document 1), the compressors to be started so that the cumulative operation time of each compressor is equal. is known. However, in rotation control that uses only the cumulative operating time as a parameter, the cumulative operating time of each compressor is equalized. If the operation near the threshold pressure for starting and stopping the compressor continues, some compressors may fall into a state of repeating starting and stopping. Therefore, there is a concern that the number of start-stops of some compressors will increase and the life of those compressors will be shortened if only the parameter of the cumulative operating time is used.

The present disclosure has been made to solve the above-described problems, and an object of the present disclosure is to enable a control device that controls a compressor to appropriately determine the number of start and stop times of the compressor without using load temperature information. is to be able to be reduced to

A refrigeration cycle device according to the present disclosure is a refrigeration cycle device in which refrigerant circulates through a circulation flow path connecting at least one compressor, condenser, pressure reducing device, and evaporator. This refrigeration cycle device includes a pressure sensor that detects a suction pressure, which is the pressure of refrigerant sucked into at least one compressor, and at least one compressor based on the result of comparing the suction pressure detected by the pressure sensor with a threshold pressure. and a controller for starting and stopping the two compressors. The control device includes a storage unit that stores the operation history of the refrigeration cycle device, and a calculation unit that adjusts the threshold pressure based on the operation history of the refrigeration cycle device.

Advantageous Effects of Invention According to the present disclosure, the number of times the compressor is started and stopped can be appropriately reduced even if the control device that controls the compressor does not use information about the load temperature.

1 is a schematic diagram (part 1) showing an example of a configuration of a refrigeration cycle apparatus; FIG. 4 is a flow chart showing an example of a processing procedure of compressor start/stop control performed by a calculation unit of a control device; 4 is a flow chart showing an example of a processing procedure performed when a calculation unit of a control device adjusts a threshold pressure; FIG. 2 is a schematic diagram (part 2) showing an example of the configuration of a refrigeration cycle apparatus; 4 is a flowchart illustrating an example of a rotation control processing procedure performed by a calculation unit of a control device;

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. A plurality of embodiments will be described below, but appropriate combinations of the configurations described in the respective embodiments have been planned since the filing of the application. The same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.

Embodiment 1.
(Configuration of refrigeration cycle device)
FIG. 1 is a schematic diagram showing an example of the configuration of a refrigeration cycle apparatus 100 according to Embodiment 1. As shown in FIG. The refrigeration cycle apparatus 100 includes a heat source side unit (first unit) 1 and a load side unit (second unit) 2 . The heat source side unit 1 and the load side unit 2 are connected by refrigerant pipes 10c and 10d. As a result, a main circuit (circulation flow path) is formed in which the refrigerant circulates through the compressor 11 and condenser 12 in the heat source side unit 1 and the decompression device 21 and evaporator 22 in the load side unit 2 .

Although one load-side unit 2 is provided in the example shown in FIG. . Further, when a plurality of load side units 2 are provided, the capacities of the plurality of load side units 2 may be the same or different.

The heat source side unit 1 includes a compressor unit 1 a , a condenser unit 1 b and a control device 3 . The compressor unit 1a and the condenser unit 1b are connected by refrigerant pipes 10a and 10b.

The compressor unit 1 a has a compressor 11 , a receiver 13 , a supercooling heat exchanger 14 and a flow control device 15 . The condenser unit 1b has a condenser 12 and a fan 12a.

The compressor 11 sucks a low-temperature, low-pressure refrigerant and compresses the sucked-in refrigerant to a high-temperature, high-pressure state. The compressor 11 is a scroll compressor, and an injection port 11a is provided in an intermediate pressure portion of the compression chamber. A bypass pipe 16 of the injection circuit 4 is connected to the injection port 11a. The injection circuit 4 is branched from the outlet side portion of the subcooling heat exchanger 14 in the main circuit (the portion between the condenser 12 and the pressure reducing device 21 in the main circuit) and connected to the injection port 11a of the compressor 11. be done.

In addition, although one compressor 11 is provided in the example shown in FIG. You may

As the compressor 11, for example, an inverter compressor is used that can control the capacity, which is the amount of refrigerant delivered per unit time, by changing the drive frequency. In this case, the heat source side unit 1 is equipped with a compressor inverter board (not shown) for changing the drive frequency, and the start/stop and drive frequency of the compressor 11 are controlled by the controller 3 .

The condenser 12 is connected to the discharge side of the compressor 11 via a refrigerant pipe 10a. The condenser 12 is configured to exchange heat between the refrigerant flowing through the main circuit and a fluid (such as water and air, refrigerant or brine) to condense the refrigerant.

Fan 12 a is configured to blow air to condenser 12 . The rotation speed of the fan 12a is controlled by the control device 3. FIG.

Receiver 13 is connected to the outlet side of condenser 12 via refrigerant pipe 10b. The receiver 13 temporarily stores the refrigerant that has flowed out of the condenser 12 and separates the refrigerant into liquid refrigerant and gas refrigerant.

The supercooling heat exchanger 14 is connected to the outlet side of the condenser 12 via the refrigerant pipe 10b and the receiver 13 . The subcooling heat exchanger 14 exchanges heat between the refrigerant that flows out of the condenser 12 and flows through the main circuit and the refrigerant that branches off from the main circuit and flows through the injection circuit 4, thereby causing the refrigerant to flow out of the condenser 12. to supercool the refrigerant flowing through the main circuit. Note that the subcooling heat exchanger 14 may not be included in the configuration of the refrigerant circuit.

The flow rate adjusting device 15 adjusts the flow rate of the refrigerant branched from the outlet side of the supercooling heat exchanger 14 to the injection circuit 4 under the control of the control device 3 . An electronic expansion valve, for example, is used as the flow control device 15 .

The heat source side unit 1 further includes a suction pressure sensor 41 . The suction pressure sensor 41 is provided on the suction side of the compressor 11 , detects the pressure (suction pressure) of refrigerant sucked into the compressor 11 , and transmits the detection result to the control device 3 .

The load side unit 2 is connected to the compressor unit 1a of the heat source side unit 1 by refrigerant pipes 10c and 10d. The load side unit 2 has a decompression device 21 and an evaporator 22 .

The decompression device 21 decompresses and expands the refrigerant subcooled by the subcooling heat exchanger 14 and adjusts the flow rate of the refrigerant. As the pressure reducing device 21, for example, an electronic expansion valve or a thermal expansion valve is used. The evaporator 22 absorbs heat and evaporates the refrigerant decompressed and expanded by the decompression device 21 by exchanging heat between the refrigerant flowing through the main circuit and the fluid (water, air, refrigerant, brine, etc.). . As the evaporator 22, for example, a fin-and-tube heat exchanger having heat transfer tubes and a large number of fins is used.

The control device 3 includes a storage unit 3a, a calculation unit 3b, an input/output buffer (not shown) for inputting/outputting various signals, and the like.

The storage unit 3a stores a program in which processing procedures of the control device 3 are described, an operation history of the refrigeration cycle device 100, and the like.

Based on the suction pressure detected by the suction pressure sensor 41 and the information stored in the storage unit 3a, the calculation unit 3b controls each device in the heat source side unit 1 (compressor 11, fan 12a, flow rate adjustment device 15 ). Further, the calculation unit 3b records information indicating the operating state of the refrigeration cycle device 100 in the storage unit 3a. A record of the operating state of the refrigerating cycle device 100 is stored in the storage unit 3a as an operating history of the refrigerating cycle device 100 . These controls are not limited to processing by software, and can be processed by dedicated hardware (electronic circuits). Note that the computing section 3b may control the decompression device 21 in the load side unit 2 in addition to each device in the heat source side unit 1 .

The types of refrigerants circulating in the refrigeration cycle device 100 are, for example, single refrigerants such as R22 and R134a, pseudo-azeotropic refrigerant mixtures such as R410A and R404A, or non-azeotropic refrigerant mixtures such as R407C. You may In addition, refrigerants that contain double bonds in the chemical formula and have a relatively small global warming potential (for example, CF3 and CF=CH2) or mixtures thereof, or natural substances such as carbon dioxide and propane A refrigerant may be used.

When the refrigerating cycle device 100 starts operating, the compressor 11 is driven first. The high-temperature and high-pressure gas refrigerant compressed by the compressor 11 is discharged from the compressor 11 and flows into the condenser 12 . In the condenser 12, the gas refrigerant that has flowed in is condensed by exchanging heat with a fluid such as air or water to become a low-temperature, high-pressure liquid refrigerant. The refrigerant flowing out of the condenser 12 and flowing through the main circuit exchanges heat with the refrigerant flowing through the injection circuit 4 branched from the main circuit in the subcooling heat exchanger 14 . Refrigerant flowing through the injection circuit 4 flows into the injection port 11 a of the compressor 11 . The amount of refrigerant that flows from the injection circuit 4 into the injection port 11 a of the compressor 11 is controlled by the flow control device 15 .

(Start/stop of compressor 11)
Start/stop of the compressor 11 is controlled based on the result of comparison between the suction pressure detected by the suction pressure sensor 41 and a threshold pressure (a start pressure Pon and a stop pressure Pcut which will be described later). The threshold pressure is set by the calculation section 3b of the control device 3 and stored in the storage section 3a of the control device 3. FIG.

FIG. 2 is a flow chart showing an example of the processing procedure of the start/stop control of the compressor 11 performed by the calculation unit 3b of the control device 3. As shown in FIG. This flowchart is repeatedly executed each time a predetermined condition is established (for example, at regular intervals).

The calculation unit 3b determines whether the compressor 11 is in operation (step S10). When the compressor 11 is in operation (YES in step S10), the calculation unit 3b determines whether the suction pressure detected by the suction pressure sensor 41 is less than the stop pressure Pcut (step S12). If the suction pressure is not less than the stop pressure Pcut (NO in step S12), the calculation unit 3b shifts the process to return while keeping the compressor 11 in the operating state. On the other hand, when the suction pressure is less than the stop pressure Pcut (YES in step S12), the calculation unit 3b stops the operation of the compressor 11 (step S14). After that, the calculation unit 3b shifts the processing to return.

When the compressor 11 is stopped (NO in step S10), the calculation unit 3b determines whether or not the suction pressure detected by the suction pressure sensor 41 exceeds the starting pressure Pon (step S16). If the suction pressure does not exceed the starting pressure Pon (NO in step S16), the calculation unit 3b shifts the process to return while keeping the compressor 11 in a stopped state. On the other hand, if the suction pressure exceeds the activation pressure Pon (YES in step S16), the calculation unit 3b activates the compressor 11 (step S18). After that, the calculation unit 3b shifts the processing to return.

In this way, the calculation unit 3b of the control device 3 determines the compressor pressure based on the result of comparing the suction pressure detected by the suction pressure sensor 41 and the threshold pressure (starting pressure Pon and stopping pressure Pcut, which will be described later). 11 start/stop (start and stop).

(Reduction of the number of times the compressor 11 starts and stops)
Based on the operation history of the refrigeration cycle apparatus 100 stored in the storage unit 3a, the calculation unit 3b adjusts the threshold pressure (starting pressure Pon and stop pressure Pcut) to start and stop the compressor 11. Reduce the number of times.

FIG. 3 is a flow chart showing an example of a processing procedure performed when the calculation unit 3b of the control device 3 adjusts the threshold pressures (the starting pressure Pon and the stopping pressure Pcut). This flowchart is repeatedly executed each time a predetermined condition is established (for example, at regular intervals).

The calculation unit 3b estimates the behavior of the load-side unit 2 from the operation history of the refrigeration cycle device 100 stored in the storage unit 3a (step S20). For example, the calculation unit 3b stores the operating state of the refrigeration cycle apparatus 100 stored in the storage unit 3a, the operating state before the most recent fixed time period (for example, 24 hours) and the operating state within the most recent fixed time period. The behavior of the load side unit 2 is estimated by comparing with .

Next, the calculation unit 3b adjusts the threshold pressures (the starting pressure Pon and the stopping pressure Pcut) from the behavior of the load side unit 2 estimated in step S20 (step S22). In this step S22, both the start pressure Pon and the stop pressure Pcut may be adjusted, or either one of them may be adjusted.

For example, it is assumed that a defrost operation is performed using a heater (not shown) or the like in order to remove frost on the evaporator 22 of the load side unit 2 . Defrost operation is generally performed periodically in the load side unit 2 . In view of this point, in step S<b>20 , based on the operation history of the refrigeration cycle device 100 , the calculation unit 3 b estimates whether or not the load side unit 2 is in the defrost operation as the behavior. Then, in step S22, when it is estimated that the load side unit 2 is in defrost operation, the calculation section 3b temporarily reduces the stop pressure Pcut. This makes it difficult to stop the compressor 11 while the compressor 11 is in operation. Furthermore, even if the suction pressure of the compressor 11 rises due to slow leaks from the stop valves of the heat source side unit 1 and the load side unit 2 after the compressor 11 stops, the suction pressure when the compressor 11 stops is Since the time required for the suction pressure to rise to the starting pressure Pon can be delayed by the amount that is low, the compressor 11 can be made difficult to start. As a result, the number of times the compressor 11 is started and stopped can be appropriately reduced.

As described above, the refrigeration cycle apparatus 100 according to the present embodiment includes the suction pressure sensor 41 that detects the suction pressure, which is the pressure of the refrigerant sucked into the compressor 11, and the suction pressure detected by the suction pressure sensor 41. A controller 3 for starting and stopping the compressor 11 based on the result of comparison with the threshold pressure (starting pressure Pon and stop pressure Pcut). The control device 3 includes a storage unit 3a that stores the operation history of the refrigeration cycle device 100, and a calculation unit 3b that adjusts the threshold pressure (starting pressure Pon and stop pressure Pcut) based on the operation history of the refrigeration cycle device. .

According to the refrigeration cycle apparatus 100 according to the present embodiment, the threshold pressure (starting pressure Pon and stop pressure Pcut) used for start/stop control of the compressor 11 is determined from the operation history (past operating state) of the refrigeration cycle apparatus 100. By adjusting , the number of times the compressor is started and stopped can be suppressed. Therefore, the number of times the compressor 11 is started and stopped can be appropriately reduced without using the temperature information of the load side unit 2 .

Further, according to the refrigeration cycle apparatus 100 according to the present embodiment, the threshold pressure is adjusted without using the temperature information of the load side unit 2 as described above. Therefore, in particular, as in the present embodiment, the evaporator 22 is provided in a separate load-side unit 2 (second unit) different from the heat source-side unit 1 (first unit). Even if the control device 3 does not acquire the load temperature information from the load side unit 2 through communication, the number of times the compressor 11 is started and stopped can be appropriately reduced.

In the above-described embodiment, an example of adjusting the threshold pressure based on the behavior of the load side unit 2 estimated by the controller 3 of the heat source side unit 1 has been described. is not limited to For example, the threshold pressure may be adjusted by contact input using a relay or the like. Also, the threshold pressure may be adjusted based on the behavior information of the load unit 2 (information different from the load temperature) acquired through communication with the load unit 2 .

Embodiment 2.
FIG. 4 is a schematic diagram showing an example of the configuration of a refrigeration cycle apparatus 100A according to Embodiment 2. As shown in FIG. A refrigerating cycle apparatus 100A includes a heat source side unit 1A and a load side unit 2 . The heat source side unit 1A includes a compressor unit 1Aa, a condenser unit 1b and a control device 3. The compressor unit 1Aa is obtained by changing the compressor 11 of the compressor unit 1a according to the first embodiment described above to a first compressor 11A and a second compressor 11B. Other structures of the refrigerating cycle device 100A are the same as those of the refrigerating cycle device 100 according to the first embodiment described above.

The first compressor 11A and the second compressor 11B are connected in parallel with each other as shown in FIG. Thus, two compressors may be provided. Note that the number of compressors is not limited to two. For example, three or more compressors may be connected in parallel depending on the load of the load-side unit 2 .

In the refrigeration cycle apparatus 100A including two first compressors 11A and second compressors 11B that are connected in parallel, the controller 3 controls the power generation so that the integrated operating times of the compressors 11A and 11B are equal. Rotating the compressors to be stopped (the control shown in FIG. 2) is effective in extending the life of the compressors. However, if rotation is performed using only the cumulative operating time as a parameter, the cumulative operating time of each of the compressors 11A and 11B can be equalized. A recurring condition can occur where one compressor reaches the end of its life earlier than the other.

Therefore, the calculation unit 3b of the control device 3 according to the second embodiment implements rotation control incorporating the cumulative operating time and the number of start/stop times of the compressors 11A and 11B.

FIG. 5 is a flowchart showing an example of a rotation control processing procedure performed by the calculation unit 3b of the control device 3 according to the second embodiment. This flowchart is repeatedly executed each time a predetermined condition is established (for example, at regular intervals).

The calculation unit 3b determines whether or not the accumulated operating time TA of the first compressor 11A is less than a first reference time (=TB+X) obtained by adding the margin time X to the accumulated operating time TB of the second compressor 11B. (step S30). Here, the integrated operating time TA of the first compressor 11A and the integrated operating time TB of the second compressor 11B are measured by, for example, the calculation unit 3b and stored in the storage unit 3a. Also, the margin time X can be set in advance.

First, the case where it is determined in step S30 that the cumulative operation time TA of the first compressor 11A is less than the first reference time (=TB+X) (YES in step S30) will be described. In this case, the calculation unit 3b determines whether or not the number NA of starting and stopping of the first compressor 11A is less than a first reference number of times (=NB+Y) obtained by adding the number of times Y of starting and stopping of the second compressor 11B to the number of times NB of starting and stopping the second compressor 11B. (step S40). Here, the start/stop count NA of the first compressor 11A and the start/stop count NB of the second compressor 11B are measured by, for example, the calculation unit 3b and stored in the storage unit 3a. Also, the margin number Y can be set in advance.

If the number NA of starting and stopping of the first compressor 11A is not less than the first reference number (=NB+Y) (NO in step S40), the calculation unit 3b determines that the number of times ΔNB of starting and stopping the second compressor 11B within a certain time is It is determined whether or not the reference number of times Z is exceeded (step S42).

If the number of times NA of starting and stopping the first compressor 11A is less than the first reference number of times (=NB+Y) (YES in step S40), or the number of times ΔNB of starting and stopping the second compressor 11B within a certain time is the reference number Z (YES in step S42), the calculation unit 3b sets the first compressor 11A as the compressor to be subjected to start/stop control (the control shown in FIG. 2 described above) (step S44).

On the other hand, if the number of start/stop times ΔNB of the second compressor 11B within the predetermined time does not exceed the reference number of times Z (NO in step S42), the calculation unit 3b selects the compressor to be controlled for start/stop as the second compressor. 11B (step S54).

Next, the case where it is not determined in step S30 that the cumulative operation time TA of the first compressor 11A is less than the first reference time (=TB+X) (NO in step S30) will be described. In this case, the calculation unit 3b determines whether or not the number of times NB of starting and stopping the second compressor 11B is less than a second reference number of times (=NA+Y) obtained by adding the number of times Y of starting and stopping of the first compressor 11A to the number of times NA of starting and stopping the first compressor 11A. (step S50).

When the number of times NB of starting and stopping of the second compressor 11B is not less than the second reference number of times (=NA+Y) (NO in step S50), the calculation unit 3b determines that the number of times ΔNA of starting and stopping the first compressor 11A within a certain time is It is determined whether or not the reference number of times Z is exceeded (step S52).

If the number of times NB of starting and stopping of the second compressor 11B is less than the second reference number of times (=NA+Y) (YES in step S50), or the number of times of starting and stopping ΔNA of the first compressor 11A within a certain period of time (YES in step S52), the calculation unit 3b sets the second compressor 11B as the compressor to be started/stopped (step S54).

On the other hand, when the number of start/stop times ΔNA of the first compressor 11A within the predetermined time is less than the reference number of times Z (NO in step S52), the calculation unit 3b selects the compressor to be controlled as the first compressor. 11A (step S44).

Through the rotation control as described above, it is possible to equalize the lives of the first compressor 11A and the second compressor 11B. For example, when the cumulative operation time TA of the first compressor 11A is shorter than the first reference time (=TB+X) and the number of times NA of starting and stopping the first compressor 11A is less than the first reference number of times (=NB+Y) , the target of start/stop control is set to the first compressor 11A. On the other hand, even if the cumulative operating time TA of the first compressor 11A is shorter than the first reference time (=TB+X), the number of starts and stops NA of the first compressor 11A is the first reference number of times (=NB+Y ), the target of the start/stop control is set to the second compressor 11B on the condition that the number of start/stop times ΔNB within a certain time of the second compressor 11B does not exceed the reference number of times Z. .

Further, when the cumulative operation time TA of the first compressor 11A is longer than the first reference time (=TB+X) and the number of start/stop times NB of the second compressor 11B is less than the second reference number of times (=NA+Y) , the target of start/stop control is set to the second compressor 11B. On the other hand, even if the cumulative operating time TA of the first compressor 11A is longer than the first reference time (=TB+X), the number of start/stop times NB of the second compressor 11B is the second reference number of times (=NA+Y). , the target of the start/stop control is set to the first compressor 11A on the condition that the number of times ΔNA of starting and stopping the first compressor 11A within a certain period of time does not exceed the reference number of times Z.

Thus, in the present embodiment, rotation control is performed based on the cumulative operating time and the number of start/stop times of each of the first compressor 11A and the second compressor 11B. Therefore, compared to the case where rotation control is performed using only the cumulative operating time as a parameter, the lives of the first compressor 11A and the second compressor 11B can be appropriately equalized.

Note that the processing procedure shown in FIG. 5 is merely an example, and the procedure is not limited to the procedure shown in FIG. For example, in FIG. 5, the number of starts and stops is determined after determining the cumulative operating time of the compressor, but the cumulative operating time may be determined after determining the number of times of starting and stopping. The priority of the integrated operating time and the number of starts and stops can be appropriately set according to the structure of the compressor.

In addition, the life of the compressor also affects the number of times the liquid is backed up and the operating frequency. The number of times of liquid backing leads to damage to the compression mechanism due to liquid compression. If the operating frequency is high, the refrigerating machine oil that lubricates the sliding parts of the compressor is taken out of the compressor, leading to damage due to poor lubrication. Therefore, the number of liquid backs and the operating frequency can also be used as parameters for determining whether to perform rotation control.

It should be considered that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present disclosure is indicated by the scope of claims rather than the above description, and is intended to include all changes within the meaning and scope of equivalence to the scope of claims.

1, 1A heat source side unit 1a, 1Aa compressor unit 1b condenser unit 2 load side unit 3 control device 3a storage unit 3b operation unit 4 injection circuit 10a, 10b, 10c, 10d refrigerant pipe, 11 Compressor 11A First Compressor 11B Second Compressor 11a Injection Port 12 Condenser 12a Fan 13 Receiver 14 Subcooling Heat Exchanger 15 Flow Adjusting Device 16 Bypass Pipe 21 Decompression Device 22 evaporator, 41 suction pressure sensor, 100, 100A refrigeration cycle device.

Claims (3)

A refrigeration cycle device in which refrigerant circulates through a circulation flow path connecting at least one compressor, a condenser, a pressure reducing device, and an evaporator,
a pressure sensor that detects a suction pressure, which is the pressure of refrigerant sucked into the at least one compressor;
a controller that starts and stops the at least one compressor based on a result of comparing the suction pressure detected by the pressure sensor with a threshold pressure;
The control device is
a storage unit that stores an operation history of the refrigeration cycle device;
A computing unit that adjusts the threshold pressure based on the operation history of the refrigeration cycle device ,
said at least one compressor, said condenser, said pressure sensor and said controller are provided in a first unit;
The decompression device and the evaporator are provided in a second unit different from the first unit,
The calculation unit estimates the behavior of the second unit based on the operation history of the refrigeration cycle device, adjusts the threshold pressure based on the estimation result,
The calculation unit estimates whether or not the defrost operation is being performed as the behavior of the second unit, and reduces the threshold pressure when it is estimated that the second unit is in the defrost operation. cycle equipment. an injection circuit that branches from a portion of the circulation flow path between the condenser and the decompression device and causes part of the refrigerant that has flowed out of the condenser to flow into the at least one compressor;
2. The apparatus according to claim 1 , further comprising a supercooling heat exchanger that supercools the refrigerant that has flowed out of the condenser by exchanging heat between the refrigerant that has flowed out of the condenser and the refrigerant that flows through the injection circuit. refrigeration cycle equipment. said at least one compressor comprises a plurality of compressors connected in parallel with each other;
2. The computing unit selects a compressor to be controlled by the control device from among the plurality of compressors based on the cumulative operating time and the number of starts and stops of each of the plurality of compressors. 3. The refrigeration cycle device according to 2 .

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