WO2022018803A1

WO2022018803A1 - Cold heat source unit and refrigeration cycle device

Info

Publication number: WO2022018803A1
Application number: PCT/JP2020/028128
Authority: WO
Inventors: 智隆石川; 宗野本
Original assignee: 三菱電機株式会社
Priority date: 2020-07-20
Filing date: 2020-07-20
Publication date: 2022-01-27
Also published as: JP7337278B2; JPWO2022018803A1

Abstract

A cold heat source unit (5) can be connected to a load device (3) equipped with an expansion valve (50) and an evaporator (60), and constitutes a refrigerant circuit (4) that is configured so as to circulate a refrigerant. The cold heat source unit (5) comprises at least one compressor (11), a condenser (20), and a control device (6) that controls the refrigerant circuit (4). The at least one compressor (11) comprises a high-pressure shell compressor (11). The control device (6) stops the compressor (11) when the compressor (11) is in operation and the pressure on the inlet port (111) side of the compressor (11) is negative.

Description

Cold heat source unit and refrigeration cycle equipment

This disclosure relates to a cold heat source unit and a refrigeration cycle device.

Conventionally, it is known that a high-pressure shell type compressor is used for the refrigerant circuit as a compressor for compressing the refrigerant in the cold heat source unit and the refrigerating cycle device constituting the refrigerant circuit configured to circulate the refrigerant. Has been done. The high-pressure shell type compressor is configured so that an inflow pipe for inflowing the refrigerant into the closed container is connected to the compression portion. In the high-pressure shell type compressor, the refrigerant flowing through the inflow pipe is compressed by the compression unit and discharged into the closed container. Then, the compressed high-temperature and high-pressure gas refrigerant that fills the closed container is discharged from the closed container. In such a high-pressure shell type compressor, it is possible to separate the refrigerating machine oil, which plays a role of lubricating action, sealing action, rust prevention action, etc., in the closed container.

Japanese Patent Application Laid-Open No. 2003-279176 (Patent Document 1) discloses an air conditioner including a high-pressure shell type compressor.

Japanese Unexamined Patent Publication No. 2003-279176

If a high-pressure shell type compressor is used in the refrigerant circuit as in the air conditioner disclosed in Japanese Patent Application Laid-Open No. 2003-279176, the amount of refrigerating machine oil brought into the refrigerant circuit can be reduced as much as possible. However, when the compressor is operated (hereinafter, also simply referred to as "negative pressure operation") in a negative pressure state where the pressure on the suction port side of the compressor is lower than the atmospheric pressure (for example, 1013.25 hPa). If there is a leak in the compressor circuit, there is a risk that air from the outside will enter the compressor circuit. Then, the air mixed in the refrigerant circuit comes into contact with the refrigerating machine oil accumulated in the high-pressure shell type compressor, and further becomes a high-temperature and high-pressure state in the compressor, which may cause a problem in the compressor and thus in the refrigerant circuit.

The present disclosure has been made to solve the above-mentioned problems, and even when the operating state of the compressor is a negative pressure operation, it is possible to avoid a problem in the compressor and thus in the refrigerant circuit. It is an object of the present invention to provide a cold heat source unit and a refrigeration cycle device.

The cold heat source unit according to the present disclosure can be connected to a load device including an expansion valve and an evaporator, and constitutes a refrigerant circuit configured to circulate the refrigerant. The cold heat source unit includes at least one compressor, a condenser, and a control device for controlling the refrigerant circuit. At least one compressor comprises a high pressure shell type first compressor. The control device stops the first compressor when the first compressor is in operation and the pressure on the suction port side of the first compressor is negative.

According to the present disclosure, even when the operating state of the compressor is negative pressure operation, it is possible to avoid a problem in the compressor and thus in the refrigerant circuit.

It is a figure which shows the structure of the refrigerating cycle apparatus which concerns on Embodiment 1. FIG. It is a figure which shows the structure of the high pressure shell type compressor. It is a figure which shows the structure of the low pressure shell type compressor. It is a ph diagram for comparing a refrigerating cycle when air is not mixed in a refrigerant circuit, and a refrigerating cycle when air is mixed in a refrigerant circuit. It is a flowchart for demonstrating control of a refrigerant circuit by a control device. It is a figure which shows the structure of the refrigerating cycle apparatus which concerns on Embodiment 2.

Hereinafter, embodiments of the present disclosure 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 to appropriately combine the configurations described in the respective embodiments. 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 a diagram showing a configuration of a refrigeration cycle device 1 according to a first embodiment. Note that FIG. 1 functionally shows the connection relationship and the arrangement configuration of each device in the refrigeration cycle device 1, and does not necessarily show the arrangement in the physical space.

With reference to FIG. 1, the refrigeration cycle device 1 includes a refrigerant circuit 4, a control device 6, and an alarm device 7. The cold heat source unit 5 includes a refrigerant circuit 4, a control device 6, and an alarm device 7. The refrigerant circuit 4 is configured such that the cold heat source device 2 and the load device 3 are connected by each of the extension pipe 83 and the extension pipe 87.

The cold heat source device 2 has a refrigerant inlet port 201 which is an inlet of the refrigerant to the cold heat source device 2 and a refrigerant outlet port 202 which is an outlet of the refrigerant from the cold heat source device 2. The load device 3 has a refrigerant inlet port 301 which is an inlet of the refrigerant to the load device 3 and a refrigerant outlet port 302 which is an outlet of the refrigerant from the load device 3.

The extension pipe 83 connects the refrigerant outlet port 202 of the cold heat source device 2 and the refrigerant inlet port 301 of the load device 3. The extension pipe 87 connects the refrigerant outlet port 302 of the load device 3 and the refrigerant inlet port 201 of the cold heat source device 2. As described above, the cold heat source unit 5 is configured to be connectable to the load device 3 via the extension pipe 83 and the extension pipe 87.

The load device 3 includes an expansion valve 50, an evaporator 60, a pipe 84, a pipe 85, and a pipe 86. The pipe 84 connects the refrigerant inlet port 301 and the expansion valve 50. The pipe 85 connects the expansion valve 50 and the evaporator 60. The pipe 86 connects the evaporator 60 and the refrigerant outlet port 302.

The expansion valve 50 lowers the pressure of the high-temperature and high-pressure liquid refrigerant that has flowed in from the pipe 84, and causes the low-temperature and low-pressure liquid refrigerant to flow out to the evaporator 60 through the pipe 85. The expansion valve 50 is, for example, a temperature expansion valve that is controlled independently of the cold heat source unit 5. The expansion valve 50 may be an electronic expansion valve capable of reducing the pressure of the refrigerant.

The evaporator 60 is configured to exchange heat between the low-temperature low-pressure liquid refrigerant flowing from the expansion valve 50 and the air. The evaporator 60 evaporates a low-temperature low-pressure liquid refrigerant by endothermic heat from the air in the cooling target space. By this heat exchange, the low-temperature low-pressure liquid refrigerant is condensed and changed into a low-temperature low-pressure gas refrigerant. The low-temperature low-pressure gas refrigerant obtained by the evaporator 60 flows out to the pipe 86.

The cold heat source unit 5 is not particularly limited, but is generally referred to as an outdoor unit or an outdoor unit because it is often arranged outdoors or outdoors. The cold heat source device 2 of the cold heat source unit 5 includes a plurality of

compressors

11 and 12, a condenser 20, a pipe 82, a pipe 88, and a pipe 93.

The condenser 20 has a refrigerant inlet port 221 which is an inlet of the refrigerant to the condenser 20 and a refrigerant outlet port 222 which is an outlet of the refrigerant from the condenser 20. The compressor 11 has a suction port 111 for sucking the refrigerant and a discharge port 112 for discharging the refrigerant. The compressor 12 has a suction port 121 for sucking the refrigerant and a discharge port 122 for discharging the refrigerant.

The pipe 82 connects the refrigerant outlet port 222 of the condenser 20 and the refrigerant outlet port 202 of the cold heat source device 2.

The pipe 88 branches into an inflow pipe 89 for inflowing the refrigerant into the compressor 11 and an inflow pipe 90 for inflowing the refrigerant into the compressor 12. The inflow pipe 89 is connected to the suction port 111 of the compressor 11. The inflow pipe 90 is connected to the suction port 121 of the compressor 12. The pipe 88 and the inflow pipe 89 connect the refrigerant inlet port 201 of the cold heat source device 2 and the suction port 111 of the compressor 11. The pipe 88 and the inflow pipe 90 connect the refrigerant inlet port 201 of the cold heat source device 2 and the suction port 121 of the compressor 12.

The pipe 93 branches into an outflow pipe 91 in which the refrigerant flows out from the compressor 11 and an outflow pipe 92 in which the refrigerant flows out from the compressor 12. The outflow pipe 91 is connected to the discharge port 112 of the compressor 11. The outflow pipe 92 is connected to the discharge port 122 of the compressor 12. The pipe 93 and the outflow pipe 91 connect the discharge port 112 of the compressor 11 and the refrigerant inlet port 221 of the condenser 20. The pipe 93 and the outflow pipe 92 connect the discharge port 122 of the compressor 12 and the refrigerant inlet port 221 of the condenser 20.

As described above, in the cold heat source unit 5, the compressor 11 and the compressor 12 are connected in parallel to the pipe 88 and the pipe 93. The control device 6 can control the route through which the refrigerant passes by selectively operating or stopping the compressor 11 and the compressor 12. Specifically, when only the compressor 11 is operated, the control device 6 causes the refrigerant flowing from the refrigerant inlet port 201 to flow into the compressor 11 via the pipe 88 and the inflow pipe 89, and the compressor 11 causes the refrigerant to flow into the compressor 11. The refrigerant can be compressed. When only the compressor 12 is operated, the control device 6 causes the refrigerant flowing from the refrigerant inlet port 201 to flow into the compressor 12 through the pipe 88 and the inflow pipe 90, and the refrigerant is compressed by the compressor 12. Can be done. Further, when both the compressor 11 and the compressor 12 are operated, the control device 6 causes the refrigerant flowing from the refrigerant inlet port 201 to flow into the compressor 11 through the pipe 88 and the inflow pipe 89, and causes the compressor to flow. While the refrigerant is compressed by 11, the refrigerant can be made to flow into the compressor 12 through the pipe 88 and the inflow pipe 90, and the refrigerant can be compressed by the compressor 12.

The compressor 11 is a high-pressure shell type compressor. FIG. 2 is a diagram showing a configuration of a high-pressure shell type compressor 11. With reference to FIG. 2, the compressor 11 has a closed container 151 and a compression unit 154 provided in the closed container 151. The compression unit 154 is directly connected to the inflow pipe 89. The compression unit 154 compresses the low-temperature and low-pressure gas refrigerant that has flowed in through the inflow pipe 89, and discharges the high-temperature and high-pressure gas refrigerant obtained by the compression from the discharge port 155 into the closed container 151. The high-temperature and high-pressure gas refrigerant that fills the closed container 151 flows out to the pipe 93 connected to the condenser 20 via the outflow pipe 91. As described above, in the compressor 11, the inside of the closed container 151 is filled with the high-temperature and high-pressure gas refrigerant.

The compressor 11 is configured to operate and stop, and further adjust the rotation speed during operation according to the control signal from the control device 6. The control device 6 can adjust the circulation amount of the refrigerant by adjusting the rotation speed of the compressor 11, and as a result, the refrigerating capacity of the refrigerating cycle device 1 can be adjusted. Various types of compressors 11 can be adopted, and for example, scroll type, rotary type, screw type and the like can be adopted.

The compressor 12 is a low pressure shell type compressor. FIG. 3 is a diagram showing the configuration of the low pressure shell type compressor 12. With reference to FIG. 3, the compressor 12 has a closed container 161 and a compression unit 164 provided in the closed container 161. The compression unit 164 is directly connected to the outflow pipe 92. The low-temperature low-pressure gas refrigerant that has flowed in through the inflow pipe 90 fills the closed container 161. The low-temperature low-pressure gas refrigerant that fills the closed container 161 is sucked into the compression unit 164 via the suction port 165. The compression unit 164 compresses the refrigerant sucked through the suction port 165, and the high-temperature and high-pressure gas refrigerant obtained by the compression flows out to the pipe 93 connected to the condenser 20 via the outflow pipe 92. .. As described above, in the compressor 12, the inside of the closed container 161 is filled with the low-temperature low-pressure gas refrigerant.

The compressor 12 is configured to operate and stop, and further adjust the rotation speed during operation according to the control signal from the control device 6. The control device 6 can adjust the circulation amount of the refrigerant by adjusting the rotation speed of the compressor 12, and as a result, can adjust the refrigerating capacity of the refrigerating cycle device 1. Various types of compressors 12 can be adopted, and for example, scroll type, rotary type, screw type and the like can be adopted.

During operation, the high-pressure shell type compressor 11 can separate the gas refrigerant and the refrigerating machine oil, and the gas refrigerant flows out to the pipe 93 through the outflow pipe 91, while the refrigerating machine oil is a closed container. It collects at the bottom of 151. As a result, if the refrigeration cycle is performed using the high-pressure shell type compressor 11, the amount of refrigerating machine oil carried out into the refrigerant circuit 2 can be reduced as much as possible.

On the other hand, it is known that it is more difficult for the low-pressure shell type compressor 12 to separate the gas refrigerant and the refrigerating machine oil during operation than the high-pressure shell type compressor 11. Therefore, when the refrigerating cycle is performed using the compressor 12, the amount of refrigerating machine oil carried out into the refrigerant circuit 2 increases as compared with the case where the refrigerating cycle is performed using the compressor 11. The amount of refrigerating machine oil accumulated in the compressor 12 is reduced. If the amount of refrigerating machine oil accumulated in the compressor 12 is reduced, lubrication failure of the compressor 12 may occur. Therefore, if anything, it is preferable to operate the high-pressure shell type compressor 11 as the refrigerating cycle device 1.

With reference to FIG. 1 again, the condenser 20 condenses the high-temperature and high-pressure gas refrigerant discharged from at least one of the compressor 11 and the compressor 12 and causes the gas refrigerant to flow out to the pipe 82. The condenser 20 is configured to exchange heat between the discharged high-temperature and high-pressure gas refrigerant and the outside air. The high-temperature and high-pressure gas refrigerant radiated by this heat exchange is condensed and changed into a high-temperature and high-pressure liquid refrigerant. A fan 22 for sending outside air is attached to the condenser 20 in order to increase the efficiency of heat exchange. The fan 22 supplies the outside air to the condenser 20 for the refrigerant to exchange heat in the condenser 20.

The cold heat source unit 5 further includes a pressure sensor 211, a temperature sensor 311 and a temperature sensor 312.

The pressure sensor 211 is provided on the suction port 111 side of the compressor 11 (the suction port 121 side of the compressor 12). The pressure sensor 211 measures the pressure PL on the suction port 111 side of the compressor 11 (the suction port 121 side of the compressor 12), and outputs the measured value to the control device 6.

The temperature sensor 311 is provided on the refrigerant outlet port 222 side of the condenser 20. The temperature sensor 311 measures the temperature T1 of the refrigerant flowing out of the condenser 20, and outputs the measured value to the control device 6. The temperature sensor 312 is provided around the cold heat source device 2 (for example, around the condenser 20). The temperature sensor 312 measures the temperature T2 of the outside air around the cold heat source device 2, and outputs the measured value to the control device 6.

The control device 6 includes a CPU (Central Processing Unit) 61, a storage medium memory 62 (ROM (Read Only Memory) and RAM (Random Access Memory)), and an input / output buffer (FIG.) for inputting / outputting various signals. (Not shown) etc. are included. The CPU 61 expands the program stored in the ROM into a RAM or the like and executes the program. The program stored in the ROM includes a control program in which the processing procedure of the control device 6 is described. The control device 6 executes control of each part in the refrigerant circuit 4 according to these control programs. This control is not limited to software processing, but can also be processed by dedicated hardware (electronic circuit).

The alarm device 7 issues an alarm according to the control signal from the control device 6 to notify the outside that there is a possibility that a malfunction may occur in the refrigerant circuit 4. The alarm by the alarm device 7 may be performed by displaying an alarm image on a display (not shown), by outputting an alarm sound from a speaker (not shown), or turning on an alarm lamp (not shown). It may be done by blinking.

In the refrigerating cycle apparatus 1 having the above-described configuration, the refrigerating machine oil carried out into the refrigerant circuit 2 is reduced as much as possible by operating the refrigerating cycle apparatus 1 using the high-pressure shell type compressor 11. Can be done. However, when the compressor is operated (negative pressure operation) in a negative pressure state where the refrigerant pressure on the suction port 111 side of the compressor 11 is lower than the atmospheric pressure (for example, 1013.25 hPa), the refrigerant circuit 4 is used. If there is a leak, air from the outside may enter the refrigerant circuit 4. Then, the air mixed in the refrigerant circuit 4 comes into contact with the refrigerating machine oil accumulated in the closed container 151 of the compressor 11, and further becomes a high temperature and high pressure state in the closed container 151, which causes a problem in the compressor 11 and thus in the refrigerant circuit 4. There is a risk.

Therefore, the control device 6 is configured to stop the compressor 11 when the compressor 11 is in operation and the pressure on the suction port 111 side of the compressor 11 is a negative pressure.

With reference to FIG. 4, the refrigerating cycle when air is not mixed in the refrigerant circuit 4 and the refrigerating cycle when air is mixed in the refrigerant circuit 4 are compared. FIG. 4 is a ph diagram for comparing a refrigerating cycle when air is not mixed in the refrigerant circuit 4 and a refrigerating cycle when air is mixed in the refrigerant circuit 4.

In FIG. 4, the vertical axis represents the absolute pressure p, the horizontal axis represents the specific enthalpy h, and the refrigeration cycle when air is not mixed in the refrigerant circuit 4 is represented by the reference numeral C1, and air is mixed in the refrigerant circuit 4. The refrigeration cycle at that time is represented by the reference numeral C2. Further, the isotherm of the refrigerant having a temperature corresponding to the outside air temperature is represented by T. Note that FIG. 4 shows a ph diagram when only the compressor 11 is in operation for the sake of simplicity.

For the refrigeration cycle C1, the change in the graph from point A1 to point A2 indicates the change in the state of the refrigerant in the compressor 11. The change in the graph from point A2 to point A3 indicates the change in the state of the refrigerant in the condenser 20. The change in the graph from point A3 to point A4 indicates a change in the state of the refrigerant in the expansion valve 50. The change in the graph from point A4 to point A1 indicates the change in the state of the refrigerant in the evaporator 60.

For the refrigeration cycle C2, the change in the graph from point B1 to point B2 indicates the change in the state of the refrigerant in the compressor 11. The change in the graph from point B2 to point B3 indicates a change in the state of the refrigerant in the condenser 20. The change in the graph from point B3 to point B4 indicates a change in the state of the refrigerant in the expansion valve 50. The change in the graph from point B4 to point B1 indicates a change in the state of the refrigerant in the evaporator 60.

Comparing the refrigeration cycle C1 and the refrigeration cycle C2, the following results can be obtained. The pressure after compression of the refrigerant in the refrigeration cycle C2 (pressure between B2 and B3) is higher than the pressure after compression of the refrigerant in the refrigeration cycle C1 (pressure between A2 and A3). Further, the difference α2 between the refrigerant temperature during condensation and the outside air temperature in the refrigeration cycle C2 is larger than the difference α1 between the refrigerant temperature during condensation and the outside air temperature in the refrigeration cycle C1. When air is mixed in the refrigerant circuit 4, heat transfer in the condenser 20 is hindered and the condensation temperature rises, and these are mixed in with respect to the condensation pressure corresponding to the rise in the condensation temperature. It is considered that the partial pressure of air is applied.

Further, due to the increase in the condensation temperature and the condensation pressure, the supercooling degree β2 of the refrigerant in the refrigerant outlet portion of the condenser 20 in the refrigeration cycle C2 is the supercooling of the refrigerant in the refrigerant outlet portion of the condenser 20 in the refrigeration cycle C1. Greater than degree β1. Further, the difference γ2 between the refrigerant temperature and the outside air temperature of the refrigerant outlet portion of the condenser 20 in the refrigeration cycle C2 is smaller than the difference γ1 between the refrigerant temperature and the outside air temperature of the refrigerant outlet portion of the condenser 20 in the refrigeration cycle C1. ..

As described above, comparing the refrigerating cycle C1 when air is not mixed in the refrigerant circuit 4 and the refrigerating cycle C2 when air is mixed in the refrigerant circuit 4, when air is mixed, it is found that the refrigerating cycle C1 is mixed. It can be seen that the difference between the refrigerant temperature and the outside air temperature at the refrigerant outlet portion of the condenser 20 is smaller than when air is not mixed.

Therefore, the control device 6 is configured to determine whether or not air is mixed in the refrigerant circuit 4 based on the difference between the refrigerant temperature and the outside air temperature at the refrigerant outlet portion of the condenser 20.

Specifically, the control device 6 specifies the temperature T1 of the refrigerant at the refrigerant outlet portion of the condenser 20 based on the measured value of the temperature sensor 311. The control device 6 specifies the temperature T2 of the outside air based on the measured value of the temperature sensor 312. The control device 6 determines that air is mixed in the refrigerant circuit 4 when the difference between the refrigerant temperature T1 and the outside air temperature T2 is the first value or less (for example, 2K or less).

FIG. 5 is a flowchart for explaining the control of the refrigerant circuit 4 by the control device 6. The control device 6 executes the processing of the flowchart shown in FIG. 5 by executing the control program stored in the memory 62. The processing of this flowchart is called and executed from the main control routine of the refrigerating cycle apparatus 1 at regular time intervals. In FIG. 5, the high pressure shell type compressor 11 is shown by the first compressor, and the low pressure shell type compressor 12 is shown by the second compressor. In the figure, "S" is used as an abbreviation for "STEP".

The control device 6 determines whether or not the compressor 11 is in operation (S1). When the compressor 11 is in operation (YES in S1), the control device 6 determines whether or not the pressure on the suction port 111 side of the compressor 11 is a negative pressure (S2).

When the pressure on the suction port 111 side of the compressor 11 is negative (YES in S2), the control device 6 stops the compressor 11 by outputting a control signal to the compressor 11 (S3). At this time, when the low-pressure shell type compressor 12 is in operation, the control device 6 continues the operation of the compressor 12. On the other hand, when the compressor 12 is not in operation, the control device 6 outputs a control signal to the compressor 12 to operate the compressor 12.

The control device 6 returns control to the main control routine when the pressure on the suction port 111 side of the compressor 11 is not negative (NO in S2) or after the processing of S3.

When the compressor 11 is not in operation (NO in S1), the control device 6 determines whether or not the pressure on the suction port 111 side of the compressor 11 is a negative pressure (S4). When the pressure on the suction port 111 side of the compressor 11 is negative (YES in S4), the control device 6 determines whether or not air is mixed in the refrigerant circuit 4 (S5). Specifically, in the control device 6, the difference between the refrigerant temperature T1 specified based on the measured value of the temperature sensor 311 and the outside air temperature T2 specified based on the measured value of the temperature sensor 312 is the first value or less (for example, 2K). The following) is determined.

When the difference between the refrigerant temperature T1 and the outside air temperature T2 is equal to or less than the first value (for example, 2K or less), the control device 6 determines that air is mixed in the refrigerant circuit 4 (YES in S5) and gives an alarm. By outputting a control signal to the device 7, an alarm is generated from the alarm device 7 (S7).

On the other hand, when the difference between the refrigerant temperature T1 and the outside air temperature T2 is less than the first value (for example, less than 2K), the control device 6 determines that air is not mixed in the refrigerant circuit 4 (NO in S5). , By outputting the control signal to the compressor 11, the compressor 11 is operated (S6).

The control device 6 returns control to the main control routine when the pressure on the suction port 111 side of the compressor 11 is not negative (NO in S4) or after the processing of S6 and S7.

It should be noted that the control device 6 is predetermined in the processing of S6 so that when the compressor 11 is operated in S6, the compressor 11 is not stopped again in the processing of S3 in the flowchart shown in FIG. 5 executed at regular time intervals. The compressor 11 may be continuously operated for a specified period (for example, 1 hour).

As described above, the control device 6 is a refrigerant circuit by stopping the compressor 11 when the high-pressure shell type compressor 11 is in operation and the operating state of the compressor 11 is negative pressure operation. It is possible to avoid a problem in the compressor 11 and thus in the refrigerant circuit 4 due to the high temperature and high pressure state of the air mixed in the compressor 11 in the compressor 11.

The control device 6 controls to issue an alarm when the high-pressure shell type compressor 11 is not in operation, the operating state of the compressor 11 is negative pressure operation, and air is mixed in the refrigerant circuit 4. By doing so, it is possible to notify the outside that there is a possibility that a malfunction may occur in the refrigerant circuit 4 due to the inclusion of air in the refrigerant circuit 4.

The control device 6 operates the compressor 11 again when the high-pressure shell type compressor 11 is not in operation, the operating state of the compressor 11 is negative pressure operation, and air is not mixed in the refrigerant circuit. By doing so, the compressor 11 can be operated again after confirming that air is not mixed in the refrigerant circuit 4, and as a result, the refrigeration cycle using the compressor 11 can be performed again.

The control device 6 stops the compressor 11 when the high-pressure shell type compressor 11 and the low-pressure shell type compressor 12 are in operation and the operating state of the compressor 11 is negative pressure operation. By continuing the operation of the compressor 12, it is possible to avoid a problem in the compressor 11 and thus in the refrigerant circuit 4, while continuing the refrigeration cycle using the compressor 12 to melt the cooled material to be cooled. Can be prevented.

The control device 6 is a compressor when the high-pressure shell type compressor 11 is operating while the low-pressure shell type compressor 12 is not operating and the operating state of the compressor 11 is negative pressure operation. By operating the compressor 12 while stopping the 11th, it is possible to avoid a problem in the compressor 11 and thus the refrigerant circuit 4, while executing a refrigeration cycle using the compressor 12 instead of the compressor 11. It is possible to prevent the cooling material from melting.

The control device 6 is a refrigerant circuit based on the difference between the refrigerant temperature T1 of the refrigerant outlet portion of the condenser 20 specified based on the measured value of the temperature sensor 311 and the outside air temperature T2 specified based on the measured value of the temperature sensor 312. It can be determined whether or not air is mixed in 4.

Embodiment 2.
FIG. 6 is a diagram showing the configuration of the refrigeration cycle device 100 according to the second embodiment. Note that FIG. 6 functionally shows the connection relationship and the arrangement configuration of each device in the refrigeration cycle device 100, and does not necessarily show the arrangement in the physical space.

With reference to FIG. 6, in the refrigeration cycle device 100 according to the second embodiment, the cold heat source device 200 of the cold heat source unit 500 further includes a liquid receiver (receiver) 30, a pipe 81, and a pressure sensor 212. .. Since the other configurations included in the cold heat source unit 500 are the same as the configurations included in the cold heat source unit 5 shown in FIG. 1, the description thereof will not be repeated.

The liquid receiver 30 is provided on the refrigerant outlet port 222 side of the condenser 20, and stores the liquid refrigerant flowing out from the refrigerant outlet port 222 of the condenser 20. The liquid receiver 30 is connected to the refrigerant outlet port 222 of the condenser 20 via the pipe 81, and is connected to the refrigerant outlet port 202 of the cold heat source device 200 via the pipe 82.

The pressure sensor 212 is commonly provided on the discharge side of the compressor 11 and the discharge side of the compressor 12. The pressure sensor 212 measures the pressure PH on the discharge side of the compressor 11 and the discharge side of the compressor 12, and outputs the measured values to the control device 6.

When air is not mixed in the refrigerant circuit 400, the degree of supercooling is almost 0 degree because the liquid refrigerant flowing out from the condenser 20 and the gas refrigerant coexist in the liquid receiver 30. On the other hand, when air is mixed in the refrigerant circuit 400, air is accumulated in the receiver 30 instead of the gas refrigerant, so that even if the receiver 30 is cooled, condensation does not occur and supercooling occurs. That is, when comparing the case where air is not mixed in the refrigerant circuit 400 and the time when air is mixed in the refrigerant circuit 400, when air is mixed, it is better than when air is not mixed. It can be seen that the degree of supercooling increases.

Therefore, the control device 6 according to the second embodiment has the measured value (refrigerant temperature T1) of the temperature sensor 311 provided on the refrigerant outlet port 222 side of the condenser 20 in the process of S5 in the flowchart shown in FIG. , The degree of overcooling of the refrigerant is calculated based on the measured value (pressure PH) of the pressure sensor 212, and it is determined whether or not air is mixed in the refrigerant circuit 4 based on the calculated degree of overcooling. Has been done.

Specifically, the control device 6 specifies the temperature T1 of the refrigerant at the refrigerant outlet portion of the condenser 20 based on the measured value of the temperature sensor 311. The control device 6 specifies the pressure PH on the discharge side of the compressor 11 based on the measured value of the pressure sensor 212, and calculates the saturation temperature of the refrigerant corresponding to the specified pressure PH. The control device 6 calculates the degree of supercooling by subtracting the temperature T1 of the refrigerant at the refrigerant outlet portion of the condenser 20 from the calculated saturation temperature of the refrigerant. The control device 6 determines that air is mixed in the refrigerant circuit 4 when the calculated supercooling degree is the second value or more (for example, 2K or more).

As described above, in the refrigerating cycle device 100 according to the second embodiment, the control device 6 has the refrigerant temperature T1 of the refrigerant outlet portion of the condenser 20 specified based on the measured value of the temperature sensor 311 and the measured value of the pressure sensor 212. The degree of supercooling is calculated based on the pressure PH on the discharge side of the compressor 11 specified based on the above, and it is possible to determine whether or not air is mixed in the refrigerant circuit 4 based on the calculated degree of supercooling. can.

The cold heat source unit 5 according to the first embodiment and the cold heat source unit 500 according to the second embodiment both include one high-pressure shell type compressor 11 and one low-pressure shell type compressor 12. However, the number of

compressors

11 and 12 is not limited to this. Each of the cold heat source unit 5 and the cold heat source unit 500 may be provided with at least one compressor 11, and may be provided with two or more compressors 11.

Each of the cold heat source unit 5 and the cold heat source unit 500 does not necessarily have to be provided with the compressor 12, but when at least one compressor 12 is provided, it is preferable to provide the same number or more of the compressors 11 as the compressor 12. According to such a configuration, the refrigerating cycle apparatus can perform the refrigerating cycle without reducing the amount of refrigerating machine oil brought into the refrigerant circuit as much as possible.

When a plurality of compressors 11 are provided, the control device 6 may stop the operation of all or a part of the plurality of compressors 11 in the process of S3 in the flowchart shown in FIG.

(summary)
The present disclosure relates to a cold heat source unit 5 which is connectable to a load device 3 including an expansion valve 50 and an evaporator 60 and constitutes a refrigerant circuit 4 configured to circulate a refrigerant. The cold heat source unit 5 includes at least one

compressors

11 and 12, a condenser 20, and a control device 6 for controlling the refrigerant circuit 4. At least one

compressor

11 and 12 includes a high pressure shell type compressor 11. The control device 6 stops the compressor 11 when the compressor 11 is in operation and the pressure on the suction port 111 side of the compressor 11 is negative.

By providing such a configuration, the cold heat source unit 5 prevents the air mixed in the refrigerant circuit 4 from being in a high temperature and high pressure state in the compressor 11 and causing a problem in the compressor 11 and thus in the refrigerant circuit 4. be able to.

Preferably, the control device 6 issues an alarm when the compressor 11 is not in operation, the pressure on the suction port 111 side of the compressor 11 is negative, and air is mixed in the refrigerant circuit 4. Take control.

By providing such a configuration, the cold heat source unit 5 can notify the outside that there is a possibility that a malfunction may occur in the refrigerant circuit 4 due to air being mixed in the refrigerant circuit 4.

Preferably, the controller 6 controls the compressor 11 when the compressor 11 is not in operation, the pressure on the suction port 111 side of the compressor 11 is negative, and air is not mixed in the refrigerant circuit 4. To drive.

By providing such a configuration, the cold heat source unit 5 can operate the compressor 11 again after confirming that air is not mixed in the refrigerant circuit 4, and as a result, the compressor 11 is used. The refrigeration cycle that was used can be repeated.

Preferably, the cold heat source unit 5 shown in FIG. 1 includes a temperature sensor 311 for measuring the temperature of the refrigerant at the refrigerant outlet portion of the condenser 20, and a temperature sensor 312 for measuring the temperature of the outside air supplied to the condenser 20. Further prepare. When the difference between the measured value of the temperature sensor 311 and the measured value of the temperature sensor 312 is equal to or less than the first value (for example, 2K or less), the control device 6 determines that air is mixed in the refrigerant circuit 4. ..

By providing such a configuration, the cold heat source unit 5 uses the temperature sensor 311 provided at the refrigerant outlet portion of the condenser 20 and the temperature sensor 312 for measuring the temperature of the outside air to provide air to the refrigerant circuit 4. It is possible to judge whether or not the mixture is mixed.

Preferably, the cold heat source unit 500 shown in FIG. 6 is provided at the refrigerant outlet portion of the condenser 20, and is a temperature sensor that measures the temperature of the refrigerant at the liquid receiver 30 that stores the refrigerant and the refrigerant outlet portion of the condenser 20. 311 and a pressure sensor 212 for measuring the pressure of the refrigerant at the refrigerant inlet portion of the condenser 20 are further provided. When the degree of overcooling of the refrigerant calculated based on the measured value of the temperature sensor 311 and the measured value of the pressure sensor 212 is the second value or more (for example, 2K or more), the control device 6 puts air in the refrigerant circuit 4. Is judged to be mixed.

By providing such a configuration, the cold heat source unit 500 can determine whether or not air is mixed in the refrigerant circuit 4 based on the degree of supercooling.

Preferably, at least one

compressor

11 or 12 further includes a low pressure shell type compressor 12 connected in parallel with the compressor 11. When the compressor 11 and the compressor 12 are in operation and the pressure on the suction port 111 side of the compressor 11 is negative, the control device 6 stops the compressor 11 while operating the compressor 12. To continue.

By providing such a configuration, the cold heat source unit 5 can prevent the compressor 11 and thus the refrigerant circuit 4 from malfunctioning, while allowing the refrigeration cycle using the compressor 12 to continue, so that the cooling material can be cooled. Can be prevented from dissolving.

Preferably, at least one

compressor

11 or 12 further includes a low pressure shell type compressor 12 connected in parallel with the compressor 11. The control device 6 stops the compressor 11 when the compressor 11 is operating while the compressor 12 is not operating and the pressure on the suction port 111 side of the compressor 11 is negative. The compressor 12 is operated with.

By providing such a configuration, the cooling heat source unit 5 avoids a malfunction in the compressor 11 and thus the refrigerant circuit 4, while causing the refrigeration cycle using the compressor 12 instead of the compressor 11 to be executed. It is possible to prevent the melting of the cooling material.

Preferably, at least one

compressor

11 and 12 includes the same number of compressors 11 as the compressor 12.

By providing such a configuration, the cold heat source unit 5 can perform a refrigerating cycle without reducing the amount of refrigerating machine oil brought out into the refrigerant circuit 4 as much as possible.

The present disclosure relates to a refrigerating cycle device 1 including a cold heat source unit 5 and a load device 3 and a refrigerating cycle device 100 including a cold heat source unit 500 and a load device 3 in other aspects.

Although the present embodiment has been described above by exemplifying a refrigerator equipped with the refrigerating cycle devices 1,100, the refrigerating cycle devices 1,100 may be used as an air conditioner or the like.

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

1,100 refrigeration cycle device, 2,200 cold heat source device, 3 load device, 4,400 refrigerant circuit, 5,500 cold heat source unit, 6 control device, 7 alarm device, 11, 12 compressor, 20 condenser, 22 Fan, 30 receiver, 50 expansion valve, 60 evaporator, 62 memory, 81,82,84,85,86,88,93 piping, 83,87 extension piping, 89,90 inflow pipe, 91,92 outflow pipe , 111,121,165 Inhalation port, 112,122,155 Discharge port, 151,161 Sealed container, 154,164 Compressor, 2011,221,301 Refrigerant inlet port, 202,222,302 Refrigerant outlet port, 211,212 Pressure sensor, 311,312 temperature sensor.

Claims

A cold heat source unit that can be connected to a load device including an expansion valve and an evaporator and constitutes a refrigerant circuit configured to circulate the refrigerant.
With at least one compressor,
Condensator and
A control device for controlling the refrigerant circuit is provided.
The at least one compressor comprises a high pressure shell type first compressor.
The control device is a cold heat source unit that stops the first compressor when the first compressor is in operation and the pressure on the suction port side of the first compressor is negative.
The control device issues an alarm when the first compressor is not in operation, the pressure on the suction port side of the first compressor is negative, and air is mixed in the refrigerant circuit. The cold heat source unit according to claim 1, which controls the generation.
The control device is described when the first compressor is not in operation, the pressure on the suction port side of the first compressor is negative, and air is not mixed in the refrigerant circuit. 1 The cold heat source unit according to claim 1, which operates a compressor.
A first temperature sensor that measures the temperature of the refrigerant at the refrigerant outlet portion of the condenser, and
Further equipped with a second temperature sensor for measuring the temperature of the outside air supplied to the condenser.
The controller determines that air is mixed in the refrigerant circuit when the difference between the measured value of the first temperature sensor and the measured value of the second temperature sensor is equal to or less than the first value. The cold heat source unit according to claim 2 or claim 3.
A liquid receiver provided at the refrigerant outlet portion of the condenser and storing the refrigerant, and
A first temperature sensor that measures the temperature of the refrigerant at the refrigerant outlet portion of the condenser, and
Further provided with a pressure sensor for measuring the pressure of the refrigerant at the refrigerant inlet portion of the condenser.
In the control device, when the degree of overcooling of the refrigerant calculated based on the measured value of the first temperature sensor and the measured value of the pressure sensor is the second value or more, air is mixed in the refrigerant circuit. The cooling heat source unit according to claim 2 or 3, which is determined to be present.
The at least one compressor further comprises a low pressure shell type second compressor connected in parallel with the first compressor.
The control device stops the first compressor when the first compressor and the second compressor are in operation and the pressure on the suction port side of the first compressor is negative. The cold heat source unit according to claim 1, wherein the operation of the second compressor is continued while the operation is performed.
The at least one compressor further comprises a low pressure shell type second compressor connected in parallel with the first compressor.
The control device is described when the first compressor is in operation while the second compressor is not in operation and the pressure on the suction port side of the first compressor is negative. The cold heat source unit according to claim 1, wherein the second compressor is operated while the first compressor is stopped.
The cold heat source unit according to claim 6 or 7, wherein the at least one compressor includes the same number or more of the first compressors as the second compressor.
A refrigeration cycle device including the cold heat source unit according to any one of claims 1 to 8 and the load device.