WO2021048905A1

WO2021048905A1 - Outdoor unit and refrigeration cycle device

Info

Publication number: WO2021048905A1
Application number: PCT/JP2019/035407
Authority: WO
Inventors: 智隆石川; 悠介有井; 素早坂
Original assignee: 三菱電機株式会社
Priority date: 2019-09-09
Filing date: 2019-09-09
Publication date: 2021-03-18
Also published as: FI4030122T3; EP4030122B1; EP4030122A1; ES2950759T3; CN114364934B; EP4030122A4; DK4030122T3; JPWO2021048905A1; CN114364934A; JP7199554B2

Abstract

An outdoor unit (2) is provided with: a first flow path (F1); a second flow path (F2); and a control device (100). A compressor (10) and a condenser (20) are arranged in order from a refrigerant inlet port (PI2) toward a refrigerant outlet port (PO2) on the first flow path (F1). The second flow path (F2) branches from a part between the condenser (20) and the refrigerant outlet port (PO2) on the first flow path (F1), and is configured to return a refrigerant having passed through the condenser (20) to the compressor (10). A first expansion valve (71), a liquid receiver (73), and a second expansion valve (72) are arranged on the second flow path (F2) in order from a branch point of the second flow path (F2) from the first flow path (F1) . The control device (100) controls the compressor (10), the first expansion valve (71), and the second expansion valve (72). The control device (100) provides notification regarding a shortage of the refrigerant if the duration, in which opening of the second expansion valve (72) is at an upper limit opening, exceeds a determination time.

Description

Outdoor unit and refrigeration cycle device

The present invention relates to an outdoor unit and a refrigeration cycle device.

In the refrigeration cycle equipment, excess or deficiency of the amount of refrigerant causes a decrease in the capacity of the refrigeration equipment and damage to the constituent equipment. International Publication No. 2017/199391 (Patent Document 1) discloses a refrigeration cycle device that prevents a compressor from failing by detecting a refrigerant shortage.

International Publication No. 2017/199391

A refrigeration cycle device having an injection flow path that depressurizes a part of the liquid refrigerant flowing out of the condenser, lowers the temperature, and returns it to the compressor is known. The refrigerant of the compressor can be cooled by the injection flow path. International Publication No. 2017/199391 (Patent Document 1) discloses a refrigerating apparatus having an injection flow path in addition to a general refrigerating apparatus, and detects a refrigerant shortage before the compressor fails. There is.

Generally, when the refrigerant sealed in the refrigerant circuit is insufficient due to insufficient filling amount or leakage, the efficiency of the refrigerating cycle device is lowered because the temperature of the discharged refrigerant of the compressor rises above the target temperature. Therefore, it is desirable to detect the refrigerant shortage that progresses due to the leakage of the refrigerant as soon as possible even at the stage where the compressor failure does not occur due to the refrigerant shortage.

An object of the present invention is to provide an outdoor unit and a refrigeration cycle device capable of detecting a refrigerant shortage at an early stage.

The present disclosure relates to an outdoor unit of a refrigeration cycle device configured to be connected to a load device including an inflator and an evaporator. The outdoor unit includes a refrigerant outlet port and a refrigerant inlet port for connecting to a load device, a first flow path, a compressor, a condenser, a second flow path, a first expansion valve, and a liquid receiver. , A second expansion valve and a control device are provided. The first flow path is a flow path from the refrigerant inlet port to the refrigerant outlet port, and forms a circulation flow path in which the refrigerant circulates together with the load device. The compressor and the condenser are arranged in order from the refrigerant inlet port to the refrigerant outlet port in the first flow path. The second flow path is configured to branch from the portion of the first flow path between the condenser and the refrigerant outlet port, and return the refrigerant that has passed through the condenser to the compressor. The first expansion valve, the receiver and the second expansion valve are arranged in the second flow path in order from the branch point of the second flow path from the first flow path. The control device controls the compressor, the first expansion valve, and the second expansion valve. The control device notifies that the refrigerant is insufficient when the time when the opening degree of the second expansion valve is the upper limit opening time exceeds the determination time.

According to the outdoor unit of the present disclosure and the refrigeration cycle device including the outdoor unit, when the refrigerant is insufficient due to the leakage of the refrigerant or the like, the refrigerant shortage can be detected at an early stage.

FIG. 5 is an overall configuration diagram of a refrigeration cycle device according to the first embodiment. It is a flowchart for demonstrating the control of the 1st expansion valve 71. It is a flowchart for demonstrating the control of the 2nd expansion valve 72. It is a graph which shows the relationship between the degree of progress of the refrigerant shortage at the time of the occurrence of a refrigerant leakage, and the opening degree of the expansion valve of an outdoor unit. FIG. 5 is an overall configuration diagram of a refrigeration cycle device according to the second embodiment.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Hereinafter, a plurality of embodiments will be described, but it is planned from the beginning of the application that the configurations described in the respective embodiments are appropriately combined. The same or corresponding parts in the drawings are designated by the same reference numerals, and the description thereof will not be repeated.

Embodiment 1.
FIG. 1 is an overall configuration diagram of a refrigeration cycle device according to the first embodiment. Note that FIG. 1 functionally shows the connection relationship and the arrangement configuration of each device in the refrigeration cycle apparatus, and does not necessarily show the arrangement in the physical space.

With reference to FIG. 1, the refrigeration cycle device 1 includes an outdoor unit 2, a load device 3, and

pipes

84 and 88. The outdoor unit 2 has a refrigerant outlet port PO2 and a refrigerant inlet port PI2 for connecting to the load device 3. The load device 3 has a refrigerant outlet port PO3 and a refrigerant inlet port PI3 for connecting to the outdoor unit 2. The pipe 84 connects the refrigerant outlet port PO2 of the outdoor unit 2 and the refrigerant inlet port PI3 of the load device 3. The pipe 88 connects the refrigerant outlet port PO3 of the load device 3 and the refrigerant inlet port PI2 of the outdoor unit 2.

The outdoor unit 2 of the refrigeration cycle device 1 is configured to be connected to the load device 3. The outdoor unit 2 includes a compressor 10 having a suction port G1, a discharge port G2, and an intermediate pressure port G3, a condenser 20, a fan 22, and

pipes

80, 81, 89.

The load device 3 includes an expansion valve 50, which is an expansion device, an evaporator 60, and

pipes

85, 86, and 87. The evaporator 60 is configured to exchange heat between air and a refrigerant. In the refrigeration cycle device 1, the evaporator 60 evaporates the refrigerant by endothermic heat from the air in the cooling target space. The expansion valve 50 is, for example, a temperature expansion valve that is controlled independently of the outdoor unit 2. The expansion valve 50 may be an electronic expansion valve capable of reducing the pressure of the refrigerant.

The compressor 10 compresses the refrigerant sucked from the pipe 89 and discharges it to the pipe 80. The drive frequency of the compressor 10 can be arbitrarily changed by inverter control. Further, the compressor 10 is provided with an intermediate pressure port G3, so that the refrigerant from the intermediate pressure port G3 can flow into a portion in the middle of the compression process. The compressor 10 is configured to adjust the rotation speed according to a control signal from the control device 100. By adjusting the rotation speed of the compressor 10, the circulation amount of the refrigerant is adjusted, and the capacity of the refrigeration cycle device 1 can be adjusted. Various types of compressors 10 can be adopted, and for example, scroll type, rotary type, screw type and the like can be adopted.

The condenser 20 is configured such that a high-temperature and high-pressure gas refrigerant discharged from the compressor 10 exchanges heat (heat dissipation) with the outside air. By this heat exchange, the gas refrigerant is condensed and changed to a liquid phase. The refrigerant discharged from the compressor 10 to the pipe 80 is condensed and liquefied in the condenser 20 and flows out to the pipe 81. A fan 22 for sending outside air is attached to the condenser 20 in order to improve the efficiency of heat exchange. The fan 22 supplies the condenser 20 with outside air through which the refrigerant exchanges heat in the condenser 20. By adjusting the rotation speed of the fan 22, the refrigerant pressure (high pressure side pressure) on the discharge side of the compressor 10 can be adjusted.

The outdoor unit 2 includes a first flow path F1 from the refrigerant inlet port PI2 to the refrigerant outlet port PO2 via the compressor 10 and the condenser 20. The first flow path F1 forms a circulation flow path through which the refrigerant circulates together with the flow path in which the expansion valve 50 and the evaporator 60 of the load device 3 are arranged. Hereinafter, this circulation flow path is also referred to as a "main refrigerant circuit" of the refrigeration cycle.

The outdoor unit 2 includes

pipes

91, 92, 93, 94 for flowing the refrigerant from the portion between the outlet of the condenser 20 of the circulation flow path and the refrigerant outlet port PO2 to the intermediate pressure port G3 of the compressor 10. A second flow path F2 to be formed is further provided. Hereinafter, the second flow path F2 that branches from the main refrigerant circuit and sends the refrigerant to the compressor 10 is also referred to as an “injection flow path”.

The outdoor unit 2 further includes a first expansion valve 71, a liquid receiver 73, a second expansion valve 72, and a flow rate limiting device 70, which are arranged in the second flow path F2. The liquid receiver 73 stores the liquid refrigerant. The first expansion valve 71 is arranged between the pipe 91 branched from the main refrigerant circuit and the pipe 92 connected to the inlet of the liquid receiver 73. The pipe 93 connects the gas discharge port of the receiver 73 and the pipe 94, and discharges the refrigerant gas in the receiver 73. The flow rate limiting device 70 is arranged between the pipe 93 and the pipe 94 to limit the flow rate of the refrigerant gas. As the flow rate limiting device 70, for example, a capillary tube can be used.

The pipe 91 is a pipe that branches from the main refrigerant circuit and allows the refrigerant to flow into the liquid receiver 73. The first expansion valve 71 is an electronic expansion valve capable of reducing the refrigerant in the high pressure portion of the main refrigerant circuit to an intermediate pressure. The liquid receiver 73 is a container capable of separating the gas phase and the liquid phase of the refrigerant which has been decompressed into two phases in the container, storing the refrigerant, and adjusting the circulation amount of the refrigerant in the main refrigerant circuit. The pipe 93 connected to the upper part of the receiver 73 and the pipe 94 connected to the lower part of the receiver 73 take out the refrigerant separated into the gas refrigerant and the liquid refrigerant in the receiver 73 in a separated state. It is the piping of. The second expansion valve 72 is provided in the pipe 94. The second expansion valve 72 can adjust the amount of refrigerant in the liquid receiver 73 by adjusting the amount of liquid refrigerant discharged from the pipe 94.

By providing the liquid receiver 73 in the injection flow path in this way, it becomes easy to secure the degree of supercooling in the pipe 81 which is a liquid pipe. This is because, in general, since the gas refrigerant is present in the receiver 73, the temperature of the refrigerant becomes the saturation temperature, and therefore, if the receiver 73 is arranged in the pipe 81, the degree of supercooling cannot be secured.

The outdoor unit 2 further includes

pressure sensors

110, 111, 112,

temperature sensors

120, 121, and a control device 100 that controls the compressor 10, the first expansion valve 71, and the second expansion valve 72.

The pressure sensor 110 detects the pressure PL of the suction port portion of the compressor 10 and outputs the detected value to the control device 100. The pressure sensor 111 detects the pressure PH of the discharged refrigerant of the compressor 10 and outputs the detected value to the control device 100. The pressure sensor 112 detects the pressure P1 of the refrigerant flowing out of the condenser 20, and outputs the detected value to the control device 100.

The temperature sensor 120 detects the temperature TH of the discharged refrigerant of the compressor 10 and outputs the detected value to the control device 100. The temperature sensor 121 detects the temperature T1 of the refrigerant in the pipe 81 at the outlet of the condenser 20, and outputs the detected value to the control device 100.

In the present embodiment, the second flow path F2 controls the temperature TH of the discharged refrigerant of the compressor 10 by inflowing the refrigerant whose temperature has decreased due to decompression into the compressor 10. In addition, the amount of refrigerant in the main refrigerant circuit can be adjusted by the receiver 73 installed on the second flow path F2.

The control device 100 includes a CPU (Central Processing Unit) 102, a memory 104 (ROM (Read Only Memory) and RAM (Random Access Memory)), an input / output buffer (not shown) for inputting / outputting various signals, and the like. Consists of including. The CPU 102 expands the program stored in the ROM into a RAM or the like and executes the program. The program stored in the ROM is a program in which the processing procedure of the control device 100 is described. The control device 100 executes control of each device in the outdoor unit 2 according to these programs. This control is not limited to software processing, but can also be processed by dedicated hardware (electronic circuit).

The control device 100 feedback-controls the first expansion valve 71 so that the temperature TH of the discharged refrigerant of the compressor 10 matches the target temperature.

FIG. 2 is a flowchart for explaining the control of the first expansion valve 71. When the temperature TH of the discharged refrigerant of the compressor 10 is higher than the target temperature (YES in S21), the control device 100 increases the opening degree of the first expansion valve 71 (S22). As a result, the amount of refrigerant flowing into the intermediate pressure port G3 via the receiver 73 increases, so that the temperature TH decreases.

On the other hand, when the temperature TH of the discharged refrigerant of the compressor 10 is lower than the target temperature (NO in S21 and YES in S23), the control device 100 reduces the opening degree of the first expansion valve 71 (S24). As a result, the amount of refrigerant flowing into the intermediate pressure port G3 via the receiver 73 is reduced, so that the temperature TH rises.

If the temperature TH = the target temperature (NO in S21 and NO in S23), the control device 100 maintains the opening degree of the first expansion valve 71 in the current state.

In this way, the control device 100 controls the opening degree of the first expansion valve 71 so that the temperature TH of the discharged refrigerant of the compressor 10 approaches the target temperature.

Further, in the control device 100, in order to secure the supercooling degree SC of the refrigerant at the outlet of the condenser 20 in normal operation, the second expansion valve 72 so that the temperature T1 of the refrigerant at the outlet of the condenser 20 matches the target temperature. Feedback control. At this time, in the first embodiment, the refrigerant shortage is detected at the same time.

FIG. 3 is a flowchart for explaining the control of the second expansion valve 72. The control device 100 calculates the degree of supercooling SC of the refrigerant at the outlet portion of the condenser 20 based on the temperature T1 and the pressure of the condenser 20 (approximate by PH) in steps S31 and S33. Specifically, the control device 100 calculates the supercooling degree SC by subtracting the temperature T1 from the saturation temperature of the refrigerant corresponding to the pressure PH. The conversion table for obtaining the saturation temperature of the refrigerant corresponding to each pressure is stored in the memory 104 of the control device 100 in advance. Then, the control device 100 compares the calculated supercooling degree SC with the target value. This target value is, for example, 5K (Kelvin). When the supercooling degree SC is larger than the target value (YES in S31), the control device 100 reduces the opening degree of the second expansion valve 72 (S32). As a result, the amount of liquid refrigerant discharged from the receiver 73 decreases and the amount of liquid refrigerant in the receiver 73 increases, so that the amount of refrigerant circulating in the main refrigerant circuit decreases and the temperature T1 of the refrigerant rises. As it rises, the supercooling degree SC decreases.

On the other hand, when the supercooling degree SC of the refrigerant at the outlet of the condenser 20 is smaller than the target value (NO in S31 and YES in S33), the control device 100 increases the opening degree of the second expansion valve 72 in step S34. Determine if it is fully open. Here, "fully open" means that the opening degree of the second expansion valve 72 is the upper limit value.

When the opening degree of the second expansion valve 72 is not fully opened (NO in S34), the control device 100 increases the opening degree of the second expansion valve 72 (S35). As a result, the amount of liquid refrigerant discharged from the receiver 73 increases and the amount of liquid refrigerant stored in the receiver 73 decreases, so that the amount of refrigerant circulating in the main refrigerant circuit increases, and the temperature of the refrigerant T1 Decreases, so the degree of supercooling SC increases.

On the other hand, when the opening degree of the second expansion valve 72 is fully open (YES in S34), the control device 100 determines in step S36 whether or not the state in which the second expansion valve 72 is fully open continues for the determination time. To do.

If the state in which the second expansion valve 72 is fully open does not continue for the determination time (NO in S36), the control device 100 maintains the opening degree of the second expansion valve 72 in the fully open state.

On the other hand, when the state in which the second expansion valve 72 is fully open continues for the determination time (YES in S36), in step S37, the control device 100 gives an alarm to the notification device 101 indicating that the refrigerant is insufficient. Output. The notification device 101 is, for example, a display device such as a liquid crystal display, a warning lamp, or the like, and may be a device that transmits a warning signal to an external device via a communication line.

After executing any of the processes of steps S32, S35, and S37, the control device 100 proceeds to the process in step S38. When the supercooling degree SC of the refrigerant at the outlet of the condenser 20 is the target value (NO in S31 and NO in S33), the control device 100 processes in step S38 while maintaining the current opening degree. To proceed. In these cases, the processing is once returned to the main routine, but the processing of the flowchart of FIG. 3 is repeatedly executed at regular intervals.

FIG. 4 is a graph showing the relationship between the progress of refrigerant shortage when a refrigerant leak occurs and the opening degree of the expansion valve of the outdoor unit. The degree of refrigerant shortage increases as the progress progresses from D0 to D3.

When the progress is D0 to D1, the amount of refrigerant is not insufficient yet, and there is liquid refrigerant in the receiver 73. At this stage, the temperature of the discharged refrigerant of the compressor 10 is appropriately controlled by increasing the opening degree of the second expansion valve 72 to the fully open position. However, the supercooling degree SC of the refrigerant at the outlet portion of the condenser 20 gradually decreases, and the supercooling degree SC becomes zero at the progress degree D1.

When the progress is D1 to D2, the supercooling degree SC of the refrigerant at the outlet portion of the condenser 20 is zero, but the temperature of the discharged refrigerant of the compressor 10 is still properly controlled. However, the amount of the liquid refrigerant in the receiver 73 decreases, and at the degree of progress D2, the liquid refrigerant inside the receiver 73 does not exist. At this stage, the opening degree of the second expansion valve 72 is fully opened.

At the progresses D2 to D3, the supercooling degree SC of the refrigerant at the outlet portion of the condenser 20 is zero, and the liquid refrigerant inside the receiver 73 does not exist. At this stage, the opening degree of the first expansion valve 71 is increased in order to increase the amount of refrigerant flowing into the injection flow path, but the temperature TH of the discharged refrigerant of the compressor 10 rises above the optimum state. It ends up. Then, at the degree of progress D3, the opening degree of the first expansion valve 71 is fully opened.

Looking at FIG. 4, in the process of running out of refrigerant, both the first expansion valve 71 and the second expansion valve 72 are fully opened, but the second expansion valve 72 is fully opened at an earlier stage, so that the second expansion valve 72 is fully opened. If the refrigerant shortage is determined based on the opening degree of the expansion valve 72, the refrigerant shortage can be detected at an early stage. In the present embodiment, since it is determined that the refrigerant is insufficient when the time when the opening degree of the second expansion valve 72 is fully opened reaches the determination time, it is possible to notify the user of the refrigerant shortage at an early stage. ..

Embodiment 2.
In the first embodiment, a case where a refrigerant whose supercooling degree SC can be calculated from the temperature T1 and the pressure PH, that is, a refrigerant whose pressure in the condenser is less than the critical pressure is used has been described. In recent years, the adoption of a natural refrigerant having a low global warming potential has been studied, and a refrigerant _{such as CO 2} in which the pressure in the condenser is higher than the critical pressure may be adopted. In the second embodiment, detection of a refrigerant shortage in the case of adopting such a refrigerant will be described.

FIG. 5 is an overall configuration diagram of a refrigeration cycle device according to the second embodiment. Note that FIG. 5 functionally shows the connection relationship and the arrangement configuration of each device in the refrigeration cycle apparatus, and does not necessarily show the arrangement in the physical space.

With reference to FIG. 5, the refrigeration cycle device 1A includes an outdoor unit 2A, a load device 3, and

pipes

84 and 88. Since the load device 3 and the

pipes

84 and 88 are the same as those in the first embodiment, the description will not be repeated.

In the configuration of the outdoor unit 2 shown in FIG. 1, the outdoor unit 2A includes a temperature sensor 123 instead of the pressure sensor 112, and includes a control device 100A instead of the control device 100. Since the other configurations of the outdoor unit 2A are the same as those of the outdoor unit 2, the description will not be repeated.

The temperature sensor 123 detects the outside air temperature TA, which is the ambient temperature of the outdoor unit 2A, and outputs the detected value to the control device 100A.

The control device 100A includes a CPU 102, a memory 104, an input / output buffer (not shown) for inputting / outputting various signals, and the like. The CPU 102 expands the program stored in the ROM into a RAM or the like and executes the program. The program stored in the ROM is a program in which the processing procedure of the control device 100A is described. The control device 100 executes control of each device in the outdoor unit 2 according to these programs. This control is not limited to software processing, but can also be processed by dedicated hardware (electronic circuit).

The control device 100A feedback-controls the first expansion valve 71 so that the temperature TH of the discharged refrigerant of the compressor 10 matches the target temperature. Since the control of the first expansion valve 71 is the same as the control of the first embodiment shown in FIG. 2, the description will not be repeated.

Further, in the control device 100A, in order to secure the supercooling degree SC of the refrigerant at the outlet of the condenser 20 in normal operation, the second expansion valve 72 so that the temperature T1 of the refrigerant at the outlet of the condenser 20 matches the target temperature. Feedback control. At this time, in the second embodiment, the refrigerant shortage is detected at the same time.

In this specification, for the sake of simplicity, the case of cooling a refrigerant such as _{CO 2 in a supercritical state is also referred to as a condenser 20.} Further, in the present specification, for the sake of simplicity, the amount of decrease of the refrigerant in the supercritical state from the reference temperature is also referred to as the degree of supercooling SC. In the second embodiment, the reference temperature is the temperature TA + α of the outside air measured by the temperature sensor 123, and the target value of the amount of decrease is, for example, 5K (Kelvin).

Also in the second embodiment, by setting the supercooling degree SC as the difference between the temperature TA + α and the temperature T1, the refrigerant shortage can be detected at an early stage by the processing of the flowchart shown in FIG.

When the pressure in the condenser 20 exceeds the critical pressure as in the second embodiment, if the liquid receiver 73 is provided in the intermediate pressure portion, the pressure in the high pressure portion of the main refrigerant circuit is high and the refrigerant is in a supercritical state. Even in this case, it is possible to store the liquid refrigerant having an intermediate pressure inside the receiver 73. Therefore, the design pressure of the container of the receiver 73 can be made lower than that of the high-pressure portion, and the cost can be reduced by thinning the container.

The outdoor units and refrigeration cycle devices of the first and second embodiments described above will be summarized again with reference to the drawings.

The present disclosure relates to an outdoor unit 2 of a refrigeration cycle device 1 and an outdoor unit 2A of a refrigeration cycle device 1A configured to be connected to a load device 3 including an expansion valve 50 and an evaporator 60 which are expansion devices. The outdoor unit 2 shown in FIG. 1 and the outdoor unit 2A shown in FIG. 5 include a refrigerant outlet port PO2 and a refrigerant inlet port PI2 for connecting to the load device 3, a first flow path F1, a compressor 10, and a condenser. 20, a second flow path F2, a first expansion valve 71, a liquid receiver 73, a second expansion valve 72, and a

control device

100 or 100A. The first flow path F1 is a flow path from the refrigerant inlet port PI2 to the refrigerant outlet port PO2, and forms a circulation flow path in which the refrigerant circulates together with the load device 3. The compressor 10 and the condenser 20 are arranged in order from the refrigerant inlet port PI2 toward the refrigerant outlet port PO2 in the first flow path F1. The second flow path F2 is configured to branch from the portion between the condenser 20 of the first flow path F1 and the refrigerant outlet port PO2, and return the refrigerant that has passed through the condenser 20 to the compressor 10. The first expansion valve 71, the liquid receiver 73, and the second expansion valve 72 are arranged in the second flow path F2 in order from the branch point of the second flow path F2 from the first flow path F1. The

control devices

100 and 100A are configured to control the compressor 10, the first expansion valve 71, and the second expansion valve 72. The

control devices

100 and 100A notify that the refrigerant is insufficient when the opening time of the second expansion valve 72 exceeds the determination time.

By detecting the refrigerant shortage in this way, in the configuration in which the receiver 73 is arranged in the injection flow path, the refrigerant shortage is detected at an early stage, and the capacity of the refrigeration cycle device is prevented from decreasing and the refrigerant leakage is prevented from continuing. Can be done.

Preferably, the outdoor unit 2 shown in FIG. 1 and the outdoor unit 2A shown in FIG. 5 further include a first temperature sensor 121 that detects the temperature T1 of the refrigerant outlet portion of the condenser 20 in the first flow path F1. The

control devices

100 and 100A are configured to control the opening degree of the second expansion valve 72 according to the output of the first temperature sensor 121.

More preferably, the outdoor unit 2 shown in FIG. 1 further includes a pressure sensor 111 that detects the pressure PH of the refrigerant at the refrigerant outlet portion of the condenser 20 in the first flow path F1. In the control device 100, the time when the opening degree of the second expansion valve 72 is the upper limit opening time exceeds the determination time, and the refrigerant is calculated based on the output of the first temperature sensor 121 and the output of the pressure sensor 111. When the supercooling degree SC is not the target value, it is determined that the refrigerant is insufficient.

More preferably, the refrigerant used in the configuration shown in FIG. 1 is a refrigerant used when the pressure in the condenser 20 is less than the critical pressure.

More preferably, the outdoor unit 2A shown in FIG. 5 further includes a second temperature sensor 123 that detects the temperature TA of the outside air supplied to the condenser 20. In the control device 100A, the time when the opening degree of the second expansion valve 72 is the upper limit opening time exceeds the determination time, and the difference between the detection temperature of the first temperature sensor 121 and the detection temperature of the second temperature sensor 123 is determined. If it is smaller than the value, it is judged that the refrigerant is insufficient.

More preferably, the refrigerant used in the configuration shown in FIG. 5 is carbon dioxide used when the pressure in the condenser 20 is equal to or higher than the critical pressure.

The present disclosure relates to a refrigeration cycle device including the outdoor unit described in any of the above and a load device in another aspect.

The embodiments disclosed this time should be considered to be exemplary in all respects and not restrictive. The scope of the present invention is shown by the claims rather than the description of the embodiments described above, and is intended to include all modifications within the meaning and scope equivalent to the claims.

1,1A refrigeration cycle device, 2,2A outdoor unit, 3 load device, 10 compressor, 20 condenser, 22 fan, 50 expansion valve, 60 evaporator, 70 flow limit device, 71 first expansion valve, 72 second Expansion valve, 73 refrigerant receiver, 80,81,84,85,88,89,91,92,93,94 piping, 100,100A control device, 101 notification device, 104 memory, 110,111,112 pressure sensor, 120, 121, 123 Temperature sensor, F1, F2 flow path, G1 suction port, G2 discharge port, G3 intermediate pressure port, PI2, PI3 refrigerant inlet port, PO2, PO3 refrigerant outlet port.

Claims

An outdoor unit of a refrigeration cycle device configured to be connected to a load device including an inflator and an evaporator.
Refrigerant outlet port and refrigerant inlet port for connecting to the load device,
A first flow path from the refrigerant inlet port to the refrigerant outlet port, which forms a circulation flow path through which the refrigerant circulates together with the load device.
A compressor and a condenser arranged in order from the refrigerant inlet port to the refrigerant outlet port in the first flow path.
A second flow path configured to branch from a portion of the first flow path between the condenser and the refrigerant outlet port and return the refrigerant that has passed through the condenser to the compressor.
The first expansion valve, the receiver, and the second expansion valve arranged in the second flow path in order from the branch point of the second flow path from the first flow path.
The compressor, the first expansion valve, and a control device for controlling the second expansion valve are provided.
The control device is an outdoor unit that notifies that the refrigerant is insufficient when the time when the opening degree of the second expansion valve is the upper limit opening time exceeds the determination time.
A first temperature sensor for detecting the temperature of the refrigerant at the refrigerant outlet portion of the condenser in the first flow path is further provided.
The outdoor unit according to claim 1, wherein the control device is configured to control the opening degree of the second expansion valve according to the output of the first temperature sensor.
A pressure sensor for detecting the refrigerant pressure at the refrigerant outlet portion of the condenser in the first flow path is further provided.
The control device is calculated based on the time when the opening degree of the second expansion valve is the upper limit opening time exceeds the determination time and the output of the first temperature sensor and the output of the pressure sensor. The outdoor unit according to claim 2, wherein it is determined that the refrigerant is insufficient when the degree of supercooling of the refrigerant is not the target value.
The outdoor unit according to claim 3, wherein the refrigerant is a refrigerant used when the pressure in the condenser is less than the critical pressure.
A second temperature sensor for detecting the temperature of the outside air supplied to the condenser is further provided.
In the control device, the time when the opening degree of the second expansion valve is the upper limit opening time exceeds the determination time, and the difference between the detection temperature of the first temperature sensor and the detection temperature of the second temperature sensor. The outdoor unit according to claim 2, wherein when is smaller than the determination value, it is determined that the refrigerant is insufficient.
The outdoor unit according to claim 5, wherein the refrigerant is carbon dioxide used when the pressure in the condenser is equal to or higher than the critical pressure.
A refrigeration cycle device including the outdoor unit according to any one of claims 1 to 6 and the load device.