WO2020194490A1

WO2020194490A1 - Outdoor unit and refrigeration cycle device equipped with same

Info

Publication number: WO2020194490A1
Application number: PCT/JP2019/012745
Authority: WO
Inventors: 真大郎小山; 洋貴佐藤; 悠介有井; 智隆石川; 亮築山
Original assignee: 三菱電機株式会社
Priority date: 2019-03-26
Filing date: 2019-03-26
Publication date: 2020-10-01
Also published as: JPWO2020194490A1; CN113614473B; EP3951288A4; CN113614473A; JP7154388B2; EP3951288A1

Abstract

An outdoor unit (2) is connected to an indoor unit (3) to form a refrigeration cycle device (1). The outdoor unit (2) is equipped with a compressor (10), a condenser (20), and a control device (100). The compressor (10) and the condenser (20) form a refrigerant circuit (5) that circulates a refrigerant together with an expansion mechanism (50) and an evaporator (60) that are included in the indoor unit (3). The control device (100) determines whether or not the refrigerant circulating in the refrigerant circuit (5) is insufficient, and when it is determined that the refrigerant is insufficient, provides notification of one from among liquid back operation, operation in which the evaporation temperature of the refrigerant is high, and leakage of the refrigerant from the refrigerant circuit as a factor of the determination that the refrigerant is insufficient.

Description

Outdoor unit and refrigeration cycle equipment equipped with it

This disclosure relates to an outdoor unit and a refrigeration cycle device including the outdoor unit.

Japanese Unexamined Patent Publication No. 2012-132639 (Patent Document 1) discloses a refrigeration cycle device. The outdoor unit of this refrigeration cycle apparatus includes a compressor, an oil separator, a condenser, a liquid receiver, a supercooled heat exchanger, and an accumulator. The indoor unit includes an expansion valve and an evaporator. In this refrigeration cycle apparatus, the suitability of the amount of refrigerant filled in the refrigerant circuit is determined based on the temperature efficiency of the supercooling heat exchanger. The temperature efficiency is a value obtained by dividing the degree of supercooling of the refrigerant at the outlet of the supercooled heat exchanger by the maximum temperature difference of the supercooled heat exchanger. According to this refrigeration cycle device, it is possible to determine the shortage of the refrigerant circulating in the refrigerant circuit.

Japanese Unexamined Patent Publication No. 2012-132739

When it is determined that there is a shortage of refrigerant circulating in the refrigerant circuit, there are various causes other than the case where the refrigerant is leaking. However, the refrigerating cycle device of Patent Document 1 has a refrigerant circulating in the refrigerant circuit. It is not possible to notify the factor determined to be insufficient. As a result, the on-site worker cannot take measures according to the factor determined to be insufficient of the refrigerant circulating in the refrigerant circuit.

The present disclosure has been made to solve such a problem, and an object of the present disclosure is to be able to determine the shortage of the refrigerant circulating in the refrigerant circuit and to notify the cause of the shortage of the refrigerant. It is to provide an outdoor unit and a refrigerating cycle apparatus equipped with the outdoor unit.

The outdoor unit of the present disclosure is an outdoor unit that is connected to an indoor unit to form a refrigeration cycle device, and includes a compressor that compresses the refrigerant and a condenser that condenses the refrigerant output from the compressor. The compressor and the condenser together with the expansion mechanism and the evaporator included in the indoor unit form a refrigerant circuit for circulating the refrigerant. The outdoor unit further determines whether or not the refrigerant circulating in the refrigerant circuit is insufficient, and when it is determined that the refrigerant is insufficient, the liquid back is a factor for determining that the refrigerant is insufficient. It is provided with a control device that notifies one of operation, operation in which the refrigerant evaporation temperature is high, and refrigerant leakage from the refrigerant circuit.

According to the outdoor unit of the present disclosure and the refrigeration cycle device including the outdoor unit, it is possible to determine the shortage of the refrigerant circulating in the refrigerant circuit and to notify the cause of the shortage of the refrigerant.

FIG. 5 is an overall configuration diagram of a refrigeration cycle device in which an outdoor unit according to the first embodiment is used. It is a figure which conceptually shows the state of the refrigerant around the heater in the normal state where the refrigerant shortage does not occur. It is a figure which shows an example of the change of the refrigerant temperature by a heater in a normal state. It is a figure which conceptually shows the state of the refrigerant around the heater when the refrigerant is insufficient. It is a figure which shows an example of the change of the refrigerant temperature by a heater when the refrigerant is insufficient. FIG. 5 is a flowchart showing an example of a processing procedure for determining a refrigerant shortage executed by a control device in the first embodiment. It is a figure which shows schematic structure of an outdoor unit. FIG. 5 is an overall configuration diagram of a refrigeration cycle device in which an outdoor unit according to the second embodiment is used. FIG. 5 is a flowchart showing an example of a processing procedure for determining a refrigerant shortage executed by the control device 100A in the second embodiment. FIG. 5 is an overall configuration diagram of a refrigeration cycle device in which an outdoor unit according to the third embodiment is used. FIG. 5 is a flowchart showing an example of a processing procedure for determining a refrigerant shortage executed by the control device 100C in the third embodiment. FIG. 5 is an overall configuration diagram of a refrigeration cycle device in which an outdoor unit according to a fourth embodiment is used. FIG. 5 is a flowchart showing an example of a processing procedure for determining a refrigerant shortage executed by the control device 100D in the fourth embodiment. FIG. 5 is an overall configuration diagram of a refrigeration cycle device in which an outdoor unit according to a fifth embodiment is used. It is a figure for demonstrating the determination process of the refrigerant shortage by the control device in Embodiment 5. FIG. 5 is a flowchart showing an example of a processing procedure for determining a refrigerant shortage executed by the control device 100B in the fifth embodiment.

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 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 in which an outdoor unit according to the first embodiment is used. 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 and an indoor unit 3. The outdoor unit 2 includes a compressor 10, a condenser 20, a fan 22, a liquid reservoir 30, a supercooling heat exchanger 40, a fan 42, a sight glass 45, and pipes 80 to 83, 85. Including. The outdoor unit 2 further includes

pipes

86 and 87, a refrigerant amount detection unit 70, a suction pressure sensor 90, a discharge pressure sensor 92, a control device 100, and a display device 150. The indoor unit 3 includes an expansion mechanism 50, an evaporator 60, a fan 62, and a pipe 84. The indoor unit 3 is connected to the outdoor unit 2 through

pipes

83 and 85.

The pipe 80 connects the discharge port of the compressor 10 and the condenser 20. The pipe 81 connects the condenser 20 and the liquid reservoir 30. The pipe 82 connects the liquid reservoir 30 and the supercooling heat exchanger 40. The pipe 83 connects the supercooling heat exchanger 40 and the expansion mechanism 50. The pipe 84 connects the expansion mechanism 50 and the evaporator 60. The pipe 85 connects the evaporator 60 and the suction port of the compressor 10. The pipe 86 connects the pipe 82 and the refrigerant amount detection unit 70. The pipe 87 connects the refrigerant amount detection unit 70 and the pipe 85.

The compressor 10 compresses the refrigerant sucked from the pipe 85 and outputs it to the pipe 80. 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 condenses the refrigerant output from the compressor 10 to the pipe 80 and outputs the refrigerant to the pipe 81. The condenser 20 is configured such that a high-temperature and high-pressure gas refrigerant output from the compressor 10 exchanges heat (heat dissipation) with the outside air. By this heat exchange, the refrigerant is condensed and changed to a liquid phase. 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 liquid reservoir 30 stores the high-pressure liquid refrigerant condensed by the condenser 20. The supercooling heat exchanger 40 is configured such that the liquid refrigerant output from the liquid reservoir 30 to the pipe 82 further exchanges heat (heat dissipation) with the outside air. The refrigerant becomes a supercooled liquid refrigerant by passing through the supercooled heat exchanger 40. The fan 42 supplies the outside air through which the refrigerant exchanges heat in the supercooling heat exchanger 40 to the supercooling heat exchanger 40. The sight glass 45 is a window for visually confirming air bubbles (flash gas) in the refrigerant flowing through the pipe 83.

The expansion mechanism 50 decompresses the refrigerant output from the supercooling heat exchanger 40 to the pipe 83 and outputs the refrigerant to the pipe 84. As the expansion mechanism 50, for example, an expansion valve can be used. When the opening degree of the expansion valve is changed in the closing direction, the refrigerant pressure on the outlet side of the expansion valve decreases, and the dryness of the refrigerant increases. When the opening degree of the expansion valve is changed in the opening direction, the refrigerant pressure on the outlet side of the expansion valve increases, and the dryness of the refrigerant decreases. As the expansion mechanism 50, a capillary tube may be used instead of the expansion valve.

The evaporator 60 evaporates the refrigerant output from the expansion mechanism 50 to the pipe 84 and outputs the refrigerant to the pipe 85. The evaporator 60 is configured such that the refrigerant decompressed by the expansion mechanism 50 exchanges heat (endothermic) with the air in the indoor unit 3. The refrigerant evaporates as it passes through the evaporator 60 to become superheated steam. The fan 62 supplies the evaporator 60 with outside air through which the refrigerant exchanges heat in the evaporator 60.

Refrigerant circulates in the compressor 10, the pipe 82, the condenser 20, the pipe 81, the liquid reservoir 30, the pipe 82, the overcooling heat exchanger 40, the pipe 83, the expansion mechanism 50, the pipe 84, the evaporator 60, and the pipe 85. The refrigerant circuit 5 to be used is formed.

The refrigerant amount detecting unit 70 is provided between the pipe 86 branching from the pipe 82 and the pipe 87 connected to the pipe 85. The pipe 86, the refrigerant amount detection unit 70, and the pipe 87 form a “bypass circuit” that returns a part of the refrigerant on the outlet side of the condenser 20 to the compressor 10 without passing through the indoor unit 3.

The refrigerant amount detection unit 70 includes a capillary tube (decompression device) 71, a heater 72, and

temperature sensors

73 and 74. The capillary tube 71 is connected between the pipe 86 and the pipe 87 to reduce the pressure of the refrigerant flowing in the bypass circuit. When the liquid refrigerant is supplied from the pipe 86, the capillary tube 71 is a gas-liquid two-phase so that the refrigerant that has passed through the capillary tube 71 is heated by the heater 72 without becoming a gas single phase. It is appropriately designed in consideration of the amount of heating. An expansion valve may be used instead of the capillary tube 71.

The heater 72 and the

temperature sensors

73 and 74 are provided in the pipe 87. The heater 72 heats the refrigerant that has passed through the capillary tube 71. The enthalpy of the refrigerant is increased by being heated by the heater 72. As described above, the heater 72 has a gas-liquid two-phase without becoming a gas single phase even when the refrigerant passing through the capillary tube 71 is heated by the heater 72, so that the heating amount is increased together with the specifications of the capillary tube 71. Set. The heater 72 may heat the refrigerant from the outside of the pipe 87, or may be installed inside the pipe 87 in order to more reliably transfer heat from the heater 72 to the refrigerant. When the refrigerating cycle device 1 is ON, the heater 72 may be always ON. Alternatively, the heater 72 may be turned on only during the refrigerant shortage determination process. Alternatively, the heater 72 may be turned on only when the compressor 10 is activated. In the first embodiment, it is assumed that the heater 72 is turned on only during the refrigerant shortage determination process.

The refrigerant amount detection unit 70 further includes a solenoid valve 79. The solenoid valve 79 is provided in the pipe 86 upstream of the capillary tube 71, and opens and closes according to an instruction from the control device 100. When the solenoid valve 79 is opened, the refrigerant flows through the capillary tube 71 and the pipe 87, and the refrigerant shortage can be detected. When the solenoid valve 79 is in the closed state, the flow of the refrigerant to the capillary tube 71 and the pipe 87 is blocked, so that the refrigerant shortage detection cannot be performed.

When the refrigeration cycle device 1 is ON, the solenoid valve 79 may be always ON. Alternatively, the solenoid valve 79 may be turned on only during the refrigerant shortage determination process. In the first embodiment, it is assumed that the solenoid valve 79 is turned on only during the refrigerant shortage determination process.

In FIG. 1, the solenoid valve 79 is provided in the pipe 86, but the solenoid valve 79 may be provided in the pipe 87 downstream of the capillary tube 71. However, if the solenoid valve 79 is arranged on the upstream side in the bypass circuit, the amount of liquid refrigerant that normally falls asleep in the bypass circuit can be reduced, so it is preferable to provide the solenoid valve 79 in the pipe 86. Further, it is more preferable that the solenoid valve 79 is provided at a position as close as possible to the branch portion where the pipe 86 is branched from the pipe 82.

The temperature sensor 73 detects the refrigerant temperature before the refrigerant is heated by the heater 72, that is, the temperature T1 of the refrigerant between the capillary tube 71 and the heater 72, and outputs the detected value to the control device 100. On the other hand, the temperature sensor 74 detects the refrigerant temperature after the refrigerant is heated by the heater 72, that is, the temperature T2 of the refrigerant downstream of the heater 72 and before joining the pipe 85, and outputs the detected value to the control device 100. To do. The

temperature sensors

73 and 74 may be installed outside the pipe 87, or may be installed inside the pipe 87 in order to more reliably detect the temperature of the refrigerant. The principle and method of determining the refrigerant shortage by the refrigerant amount detecting unit 70 will be described in detail later.

The suction pressure sensor 90 detects the suction pressure LP of the refrigerant in the pipe 85 and outputs the detected value to the control device 100. That is, the suction pressure sensor 90 detects the refrigerant pressure (low pressure side pressure) LP on the suction side of the compressor 10. The discharge pressure sensor 92 detects the discharge pressure HP of the refrigerant in the pipe 80 and outputs the detected value to the control device 100. That is, the discharge pressure sensor 92 detects the refrigerant pressure (high pressure side pressure) HP on the discharge side of the compressor 10.

The suction temperature sensor 302 is arranged around the suction port of the compressor 10. The suction temperature sensor 302 detects the suction temperature Ts of the refrigerant into the compressor 10.

The evaporation temperature sensor 303 detects the temperature of the refrigerant flowing through the evaporator 60 as the evaporation temperature Te of the refrigerant.

The control device 100 includes a CPU (Central Processing Unit) 102, a memory 104 (ROM (Read Only Memory) and a 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 display device 150 displays information such as the status of the refrigeration cycle device 1 sent from the control device 100 in order to notify the user or the operator.

<Explanation of refrigerant shortage judgment>
Hereinafter, a method for determining a refrigerant shortage using the refrigerant amount detecting unit 70 will be described. In addition, the refrigerant shortage occurs when the initial filling amount of the refrigerant in the refrigerant circuit is insufficient, or when the refrigerant leaks after the start of use.

FIG. 2 is a diagram conceptually showing the state of the refrigerant around the heater 72 in the normal state when the refrigerant shortage does not occur. In the following, when the refrigerant is not insufficient and the amount of the refrigerant is within an appropriate range, it may be simply referred to as "normal time".

With reference to FIG. 1 as well as FIG. 2, when the amount of refrigerant is appropriate and normal, the refrigerant is almost liquid-phased at the outlet of the condenser 20, and the liquid refrigerant is accumulated in the liquid reservoir 30. As a result, the liquid refrigerant flows through the pipe 86, and the refrigerant that has passed through the capillary tube 71 is in a state of having a large amount of liquid components. Then, the refrigerant that has passed through the capillary tube 71 is heated by the heater 72 to increase the dryness.

FIG. 3 is a diagram showing an example of a change in the refrigerant temperature due to the heater 72 in a normal state. In FIG. 3, the horizontal axis indicates the position of the pipe 87 in the extension direction, and P1 and P2 indicate the positions where the

temperature sensors

73 and 74 are installed, respectively. The vertical axis shows the refrigerant temperature at each position of the pipe 87. Note that FIG. 3 shows a case where the refrigerant is an azeotropic refrigerant (a refrigerant having no temperature gradient, for example, a refrigerant such as R410a).

With reference to FIG. 3, in the normal state, the refrigerant passing through the capillary tube 71 has a large amount of liquid components, so that the temperature of the refrigerant basically does not change even if the refrigerant is heated by the heater 72 (heating energy is high). It is used to change the latent heat of the refrigerant.) Therefore, the temperature T2 of the refrigerant after heating the refrigerant by the heater 72 is substantially the same as the temperature T1 of the refrigerant before heating the refrigerant by the heater 72.

Although not particularly shown, when the refrigerant is a non-azeotropic refrigerant (a refrigerant having a temperature gradient, for example, a refrigerant such as R407a, R448a, R449a, R463a), the temperature of the refrigerant rises slightly due to heating by the heater 72. (At most about 10 degrees).

FIG. 4 is a diagram conceptually showing the state of the refrigerant around the heater 72 when the refrigerant is insufficient. With reference to FIG. 4 and FIG. 1, when the refrigerant is insufficient, the refrigerant is gas-liquid two-phase at the outlet of the condenser 20, and the liquid refrigerant is not accumulated in the liquid reservoir 30, or even if it is accumulated. It is a small amount. As a result, the gas-liquid two-phase refrigerant flows through the pipe 86, and the refrigerant that has passed through the capillary tube 71 has a larger amount of gas components than in the normal state. Therefore, the refrigerant that has passed through the capillary tube 71 is heated by the heater 72 and evaporates, and the temperature (superheat degree) rises.

FIG. 5 is a diagram showing an example of a change in the refrigerant temperature due to the heater 72 when the refrigerant is insufficient. Also in FIG. 5, the horizontal axis indicates the position of the pipe 87 in the extension direction, and P1 and P2 indicate the positions where the

temperature sensors

73 and 74 are installed, respectively. The vertical axis shows the refrigerant temperature at each position of the pipe 87.

With reference to FIG. 5, when the refrigerant is insufficient, the refrigerant that has passed through the capillary tube 71 has a large amount of gas components. Therefore, when the refrigerant is heated by the heater 72, the refrigerant evaporates and the temperature of the refrigerant rises. (Superheat> 0). Therefore, the temperature T2 of the refrigerant after heating the refrigerant by the heater 72 is higher than the temperature T1 of the refrigerant before heating the refrigerant by the heater 72.

When the refrigerant is a non-co-boiling refrigerant, the temperature rise of the refrigerant by the heater 72 when the refrigerant is insufficient and the temperature rise of the refrigerant by the heater 72 when the refrigerant is normal (temperature rise based on the temperature gradient of the refrigerant) can be distinguished. The heating amount of the heater 72 is appropriately set.

In this way, the refrigerant amount detection unit 70 can determine whether or not there is a refrigerant shortage in the refrigerant circuit based on the amount of temperature rise of the refrigerant when the refrigerant is heated by the heater 72.

The control device 100 acquires the suction temperature Ts of the compressor 10 detected by the suction temperature sensor 302. The control device 100 acquires the suction pressure LP of the compressor 10 detected by the suction pressure sensor 90. The control device 100 calculates the saturation temperature ST (LP) of the suction pressure LP. The control device 100 calculates the suction superheat degree SH of the compressor 10 by subtracting the saturation temperature ST (LP) of the suction pressure LP of the compressor 10 from the suction temperature Ts of the compressor 10.

The control device 100 acquires the evaporation temperature Te of the refrigerant detected by the evaporation temperature sensor 303. The control device 100 may calculate the evaporation temperature Te of the refrigerant by converting the suction pressure LP detected by the suction pressure sensor 90 into the refrigerant saturated gas temperature.

The control device 100 determines whether or not the refrigerant circulating in the refrigerant circuit 5 is insufficient, and when it is determined that the refrigerant is insufficient, the control device 100 notifies the cause of the refrigerant shortage as follows.

The control device 100 determines the refrigerant circuit 5 when the difference (T2-T1) between the temperature T1 detected by the temperature sensor 73 of the refrigerant amount detection unit 70 and the temperature T2 detected by the temperature sensor 74 is the threshold value Th1 or more. It is determined that the refrigerant circulating inside is insufficient.

In the liquid back operation, since the refrigerant flows from the evaporator 60 to the compressor 10 in a state where the liquid refrigerant is contained, the suction superheat degree SH of the compressor 10 becomes small. During the liquid back operation, a large amount of refrigerant moves to the suction side of the compressor 10, so that the amount of refrigerant supplied to the refrigerant amount detection unit 70 decreases. As a result, it is determined that the refrigerant circulating in the refrigerant circuit 5 is insufficient. Therefore, when it is determined that the refrigerant circulating in the refrigerant circuit 5 is insufficient, the control device 100 causes the liquid back as a factor when the suction superheat degree SH of the compressor 10 is smaller than the threshold value Th2. Notify that you are driving.

When the operation with a high evaporation temperature Te is being executed, the amount of refrigerant on the low pressure side of the refrigerant circuit 5 is large, so that the amount of refrigerant supplied to the refrigerant amount detection unit 70 is reduced. As a result, it is determined that the refrigerant circulating in the refrigerant circuit 5 is insufficient. Therefore, when the control device 100 determines that the refrigerant circulating in the refrigerant circuit 5 is insufficient and the evaporation temperature Te of the refrigerant is the threshold value Th3 or more, the evaporation temperature of the refrigerant is a factor. Notify that the driving is high.

If it is determined that the refrigerant circulating in the refrigerant circuit 5 is insufficient during the operation in which the evaporation temperature of the refrigerant is low and not in the liquid back operation, the refrigerant may leak to the outside from the refrigerant circuit 5. Highly sexual. Therefore, when the control device 100 determines that the refrigerant circulating in the refrigerant circuit 5 is insufficient, the suction superheat degree SH of the compressor 10 is a threshold value Th2 or more, and the refrigerant evaporation temperature Te is a threshold. If the value is less than Th3, the refrigerant circuit 5 notifies the outside of the refrigerant as a factor.

FIG. 6 is a flowchart showing an example of a refrigerant shortage determination processing procedure executed by the control device in the first embodiment. The series of processes shown in this flowchart are repeatedly executed while the refrigeration cycle device 1 is in steady operation.

With reference to FIG. 6, in step S101, the control device 100 determines whether or not the refrigerant shortage determination control is being executed. Refrigerant shortage determination control is executed, for example, once an hour for several minutes. When the refrigerant shortage determination control is not executed (NO in step S101), the control device 100 shifts the process to the return without executing the subsequent series of processes. If it is determined that the refrigerant shortage determination control is being executed (YES in step S101), the process proceeds to step S102.

In step S102, the control device 100 turns on (opens) the solenoid valve 79 and turns on the heater 72.

In step S103, the control device 100 acquires the detected values of the temperatures T1 and T2 from the

temperature sensors

73 and 74 of the refrigerant amount detecting unit 70, respectively.

In step S104, the control device 100 determines whether or not the difference between the acquired temperature T2 and the temperature T1 (T2-T1), that is, the amount of temperature rise of the refrigerant by the heater 72 is equal to or greater than the threshold value Th1. To do. When it is determined that the amount of temperature rise of the refrigerant by the heater 72 is equal to or higher than the threshold value Th1 (S104: YES), the control device 100 determines that the refrigerant circulating in the refrigerant circuit 5 is insufficient, and processes the refrigerant. Proceeds to step S105. When it is determined that the amount of temperature rise of the refrigerant by the heater 72 is less than the threshold value Th1 (S104: NO), the control device 100 determines that the refrigerant circulating in the refrigerant circuit 5 is not insufficient, and processes the refrigerant. Proceeds to step S110.

In step S105, the control device 100 determines whether or not the suction superheat degree SH of the compressor 10 is less than the threshold value Th2. When it is determined that the suction superheat degree SH of the compressor 10 is less than the threshold value Th2 (S105: YES), the process proceeds to step S107. When it is determined that the suction superheat degree SH of the compressor 10 is equal to or higher than the threshold value Th2 (S105: NO), the process proceeds to step S106.

In step S106, the control device 100 determines whether or not the evaporation temperature Te of the refrigerant is the threshold value Th3 or more. When it is determined that the evaporation temperature Te of the refrigerant is equal to or higher than the threshold value Th3 (S106: YES), the process proceeds to step S108. When it is determined that the evaporation temperature Te of the refrigerant is less than the threshold value Th3 (S106: NO), the process proceeds to step S109.

In step S107, the control device 100 displays on the display device 150 that it is determined that the refrigerant circulating in the refrigerant circuit 5 is insufficient due to the liquid back operation.

In step S108, the control device 100 displays on the display device 150 that it is determined that the refrigerant circulating in the refrigerant circuit 5 is insufficient due to the operation in which the evaporation temperature of the refrigerant is high.

In step S109, the control device 100 displays on the display device 150 that it is determined that the refrigerant circulating in the refrigerant circuit 5 is insufficient because the refrigerant sealed in the refrigerant circuit 5 leaks to the outside.

In step S110, the control device 100 turns off (closes) the solenoid valve 79 and turns off the heater 72.

As described above, when a non-azeotropic refrigerant is used, when the refrigerant is heated by the heater 72, the temperature of the refrigerant rises even if the amount of the refrigerant is appropriate. Therefore, the threshold value Th1 in step S104 determines the type of refrigerant used and the heater 72 so that the amount of temperature rise of the refrigerant in the normal state by the heater 72 and the amount of temperature rise in the case of insufficient refrigerant can be distinguished. It is appropriately set based on the amount of heating.

As described above, in the first embodiment, it is possible to determine whether or not the refrigerant is insufficient based on the amount of temperature rise of the refrigerant by the heater 72. Therefore, the accuracy of determining the refrigerant shortage depends on the accuracy of detecting the temperature rise of the refrigerant by the heater 72. Therefore, in the outdoor unit 2 according to the first embodiment, the refrigerant amount detecting unit 70 is arranged at a position that is not easily affected by the wind that disturbs the detection of the temperature rise amount. Specifically, the refrigerant amount detection unit 70 is arranged at a location where the influence of the air flow is small as compared with the condenser 20. The wind to be affected is included, the wind that has passed through the condenser 20, the wind before passing through the condenser 20, and the natural wind. As a result, it is possible to prevent the refrigerant amount detecting unit 70 from being affected by the wind and causing an error in the above-mentioned temperature rise amount.

FIG. 7 is a diagram schematically showing the structure of the outdoor unit 2 of the refrigeration cycle device 1. With reference to FIG. 7, the inside of the outdoor unit 2 is divided into a heat exchange chamber 202 and a machine room 204 by a partition plate (wall) 206. The heat exchange chamber 202 houses a condenser 20, a liquid reservoir 30, a supercooled heat exchanger 40 (none of which is shown), and

fans

22 and 42. The condenser 20 and the supercooling heat exchanger 40 (hereinafter, may be collectively referred to as “heat exchange section”) and the

fans

22 and 42 are provided on the side surface of the housing of the outdoor unit 2, and this example. Then, the heat exchange section is provided on the back side and the

fans

22 and 42 are provided on the front side, and the exhaust heat air of the heat exchange section flows from the back side to the front side of the heat exchange chamber 202. The machine room 204 houses the compressor 10, each pipe, the suction pressure sensor 90, the discharge pressure sensor 92, and the control device 100.

In the outdoor unit 2 according to the first embodiment, the refrigerant amount detecting unit 70 is housed in the machine room 204. In the heat exchange chamber 202, a wind accompanying the operation of the

fans

22 and 42, or a natural wind is flowing while the fan is stopped. When the refrigerant amount detecting unit 70 is arranged in the heat exchange chamber 202 through which such wind flows, the refrigerant amount detecting unit 70 (particularly the temperature sensors 73 and 74) is affected by the wind, so that the temperature of the refrigerant by the heater 72 is generated. An error may occur in the measurement of the amount of rise. In this example, since the refrigerant amount detection unit 70 is housed in the machine room 204 separated from the heat exchange room 202 by the partition plate 206, it is not affected by the wind. Therefore, according to the outdoor unit 2, the amount of temperature rise of the refrigerant by the heater 72 can be measured with high accuracy.

In the above, the liquid reservoir 30 is arranged in the heat exchange chamber 202, but it may be arranged in the machine room 204.

As described above, according to the first embodiment, the refrigerant is based on the amount of temperature rise of the refrigerant that has passed through the heater 72, regardless of whether the degree of supercooling of the refrigerant is large or small or a non-azeotropic refrigerant is used. The shortage can be determined.

According to the first embodiment, it is possible to notify the operator or the user of the factor determined to be the refrigerant shortage. As a result, it is possible to take measures according to the factors determined to be insufficient refrigerant.

In the first embodiment, since the refrigerant amount detecting unit 70 is arranged in the machine room 204 which is not affected by the wind, the above-mentioned temperature rise amount has an error due to the influence of the wind on the refrigerant amount detecting unit 70. Can be avoided. As a result, according to the first embodiment, it is possible to accurately determine the shortage of the refrigerant in the refrigerant circuit 5.

Embodiment 2.
In the second embodiment, as the heat source in the refrigerant amount detection unit, a high-temperature and high-pressure refrigerant on the discharge side of the compressor 10 is used instead of the heater 72. As a result, the refrigerant amount detection unit can be configured without separately providing the heater 72.

FIG. 8 is an overall configuration diagram of a refrigeration cycle device in which the outdoor unit according to the second embodiment is used. With reference to FIG. 8, the refrigeration cycle device 1A includes an outdoor unit 2A and an indoor unit 3. The outdoor unit 2A includes a refrigerant amount detection unit 70A and a control device 100A, respectively, in place of the refrigerant amount detection unit 70 and the control device 100 in the outdoor unit 2 of the first embodiment shown in FIG.

The refrigerant amount detection unit 70A includes a heat exchange unit 78 instead of the heater 72 in the refrigerant amount detection unit 70 of the first embodiment shown in FIG. 1, and further includes temperature sensors 75 to 77. The heat exchange unit 78 is configured to exchange heat between the high-temperature and high-pressure refrigerant output from the compressor 10 and the refrigerant that has passed through the capillary tube 71. Then, the temperature sensor 73 detects the refrigerant temperature on the upstream side of the heat exchange unit 78, that is, the temperature T1 of the refrigerant between the capillary tube 71 and the heat exchange unit 78. On the other hand, the temperature sensor 74 detects the temperature of the refrigerant on the downstream side of the heat exchange unit 78, that is, the temperature T2 of the refrigerant downstream of the heat exchange unit 78 and before merging with the pipe 85.

The temperature sensor 75 detects the temperature T3 of the high-temperature and high-pressure refrigerant output from the compressor 10, and outputs the detected value to the control device 100A. The temperature sensor 76 detects the temperature T4 of the refrigerant output from the compressor 10 and passed through the heat exchange unit 78, and outputs the detected value to the control device 100A. That is, the temperature sensors 75 and 76 detect the temperatures of the refrigerants supplied from the compressor 10 to the condenser 20 before and after the passage of the heat exchange unit 78, respectively. The temperature sensor 77 detects the temperature T5 of the refrigerant sucked into the compressor 10 and outputs the detected value to the control device 100A.

The control device 100A determines whether or not there is a refrigerant shortage in the refrigerant circuit 5A based on the amount of temperature rise of the refrigerant when the refrigerant flowing through the pipe 87 is heated by the heat exchange unit 78. More specifically, the control device 100A determines that the refrigerant shortage has occurred when the temperature rise amount of the refrigerant by the heat exchange unit 78 becomes equal to or more than the threshold value.

Here, since the heating amount of the heat exchange unit 78 changes depending on the operating state of the refrigerating cycle device 1A, the temperature rise amount of the refrigerant in the pipe 87 in the heat exchange unit 78 also changes depending on the operating state of the refrigerating cycle device 1A. .. In particular, when the refrigerant is a non-azeotropic refrigerant, the temperature rises when the gas-liquid two-phase refrigerant flowing through the pipe 87 is heated in the heat exchange section 78, even if there is no refrigerant shortage, and the amount of the temperature rise Depends on the amount of heating. Even if the refrigerant is an azeotropic refrigerant, the temperature of the refrigerant may rise if the amount of heat of the heat exchange unit 78 is large.

Therefore, in the second embodiment, the heating amount of the heat exchange unit 78 is calculated, and the threshold value for determining whether or not the refrigerant is insufficient (refrigerant in the heat exchange unit 78) is calculated based on the heating amount. Threshold for the amount of temperature rise) is set. As a result, even if the heating amount of the heat exchange unit 78 changes depending on the operating state of the refrigeration cycle device 1A, the refrigerant shortage can be accurately determined.

The amount of heat of the heat exchange unit 78 can be calculated as follows, for example. The heating amount (W = J / s) of the heat exchange unit 78 is calculated by the following equation.

Heating amount = G × H… (1)
Here, G is the flow rate of the refrigerant flowing from the compressor 10 to the heat exchange unit 78, and H is the enthalpy difference of the refrigerant flowing from the compressor 10 to the heat exchange unit 78 before and after the heat exchange unit 78.

The refrigerant flow rate G (kg / hr) can be calculated by the following equation.
Refrigerant flow rate G = V × R × D… (2)
Here, V is the amount of displacement (m ³ ) of the compressor 10, that is, the amount of refrigerant sucked per rotation of the compressor 10. R is the rotation speed (1 / hr or 1 / s) of the compressor 10, and D is the density of the refrigerant (kg / m ³ ). The density D is an amount determined by the refrigerant temperature and pressure on the suction side of the compressor 10, and can be calculated from the temperature T5 detected by the temperature sensor 77 and the suction pressure LP detected by the suction pressure sensor 90. it can.

The enthalpy difference H (kJ / kg) can be calculated by the following equation.
Enthalpy difference H = H3-H4 ... (3)
Here, H3 is the enthalpy of the refrigerant supplied from the compressor 10 to the heat exchange unit 78, and H4 is the enthalpy of the refrigerant after passing through the heat exchange unit 78. The enthalpy H3 is an amount determined by the discharge pressure HP of the compressor 10 and the refrigerant temperature before passing through the heat exchange unit 78, and is detected by the discharge pressure HP detected by the discharge pressure sensor 92 and the temperature sensor 75. It can be obtained from the temperature T3. Further, the enthalpy H4 is an amount determined by the discharge pressure HP of the compressor 10 and the refrigerant temperature after passing through the heat exchange unit 78, and can be obtained from the discharge pressure HP and the temperature T4 detected by the temperature sensor 76. it can.

FIG. 9 is a flowchart showing an example of a processing procedure for determining a refrigerant shortage executed by the control device 100A in the second embodiment. The series of processes shown in this flowchart are repeatedly executed while the refrigeration cycle apparatus 1A is in steady operation.

With reference to FIG. 9, in step S201, the control device 100A determines whether or not the refrigerant shortage determination control is being executed. Refrigerant shortage determination control is executed, for example, once an hour for several minutes. When the refrigerant shortage determination control is not executed (NO in step S201), the control device 100A shifts the process to the return without executing the subsequent series of processes. If it is determined that the refrigerant shortage determination control is being executed (YES in step S201), the process proceeds to step S202.

In step S202, the control device 100A acquires the detected values of the temperatures T1 to T5 from the temperature sensors 73 to 77, respectively, acquires the rotation speed R of the compressor 10, and further acquires the rotation speed R of the compressor 10 from the suction pressure sensor 90 and the discharge pressure sensor 92, respectively. Acquire the detected values of the suction pressure LP and the discharge pressure HP.

In step S203, the control device 100A calculates the refrigerant flow rate G using the above formula (2) and calculates the enthalpy difference H using the above formula (3).

In step S204, the control device 100A calculates the heating amount (G × H) of the heat exchange unit 78 by multiplying the calculated refrigerant flow rate G by the enthalpy difference H.

In step S205, the control device 100A flows through the threshold value Th4 (flows through the pipe 87 in the heat exchange unit 78) for determining whether or not there is a refrigerant shortage based on the calculated heating amount of the heat exchange unit 78. Set the threshold value for the amount of temperature rise of the refrigerant).

The relationship between the heating amount and the threshold value Th4 is obtained in advance by pre-evaluation, simulation, etc. according to the type of the refrigerant used, and is stored in the ROM of the control device 100A. Qualitatively, the larger the heating amount, the larger the threshold Th4, and when the heating amount is the same, the threshold value of the non-azeotropic refrigerant is larger than the threshold value of the azeotropic refrigerant.

In step S206, the control device 100A has a threshold value Th4 of the difference between the temperature T2 and the temperature T1 (T2-T1) acquired in step S202, that is, the amount of temperature rise of the refrigerant flowing through the pipe 87 in the heat exchange unit 78. Determine if it is above or not. When it is determined that the amount of temperature rise of the refrigerant is the threshold value Th4 or more (S206: YES), the control device 100A determines that the refrigerant circulating in the refrigerant circuit 5 is insufficient, and the process is step S207. Proceed to. When it is determined that the amount of temperature rise of the refrigerant is less than the threshold value Th4 (S206: NO), the control device 100A determines that the refrigerant circulating in the refrigerant circuit 5 is not insufficient, and processes it as a return. Migrate.

In step S207, the control device 100A determines whether or not the suction superheat degree SH of the compressor 10 is less than the threshold value Th2. When it is determined that the suction superheat degree SH of the compressor 10 is less than the threshold value Th2 (S207: YES), the process proceeds to step S209. When it is determined that the suction superheat degree SH of the compressor 10 is equal to or higher than the threshold value Th2 (S207: NO), the process proceeds to step S208.

In step S208, the control device 100A determines whether or not the evaporation temperature Te of the refrigerant is the threshold value Th3 or more. When it is determined that the evaporation temperature Te of the refrigerant is equal to or higher than the threshold value Th3 (S1208: YES), the process proceeds to step S210. When it is determined that the evaporation temperature Te of the refrigerant is less than the threshold value Th3 (S208: NO), the process proceeds to step S211.

In step S209, the control device 100A displays on the display device 150 that it is determined that the refrigerant circulating in the refrigerant circuit 5 is insufficient due to the liquid back operation.

In step S210, the control device 100A displays on the display device 150 that it is determined that the refrigerant circulating in the refrigerant circuit 5 is insufficient due to the operation in which the evaporation temperature of the refrigerant is high.

In step S211 the control device 100A displays on the display device 150 that it is determined that the refrigerant circulating in the refrigerant circuit 5 is insufficient because the refrigerant sealed in the refrigerant circuit 5 leaks to the outside.

As described above, according to the second embodiment, as the heat source in the refrigerant amount detection unit 70A, the heat exchange unit 78 using the high temperature and high pressure refrigerant on the discharge side of the compressor 10 is provided instead of the heater 72. , The refrigerant amount detection unit can be configured without providing the heater 72.

Further, the heating amount of the heat exchange unit 78 changes depending on the operating state of the refrigerating cycle apparatus 1A. According to the second embodiment, the threshold value Th4 of the temperature rise amount of the refrigerant flowing through the pipe 87 in the heat exchange unit 78 Is set based on the heating amount of the heat exchange unit 78, so that the refrigerant shortage can be accurately determined even if the operating state of the refrigerating cycle apparatus 1A changes.

According to the second embodiment, as in the first embodiment, it is possible to notify the operator or the user of the factor determined to be the refrigerant shortage. As a result, it is possible to take measures according to the factors determined to be insufficient refrigerant.

Embodiment 3.
FIG. 10 is an overall configuration diagram of a refrigeration cycle device in which the outdoor unit according to the third embodiment is used. With reference to FIG. 10, the refrigeration cycle device 1C includes an outdoor unit 2C and an indoor unit 3. The outdoor unit 2C includes a control device 100C instead of the control device 100 of the outdoor unit 2 of the first embodiment shown in FIG. The outdoor unit 2C further includes a condensation temperature sensor 305 and a liquid refrigerant temperature sensor 304.

The condensation temperature sensor 305 is provided at the inlet of the supercooling heat exchanger 40. The condensation temperature sensor 305 detects the temperature of the refrigerant as the condensation temperature Tx.

The liquid refrigerant temperature sensor 304 is provided at the outlet of the supercooling heat exchanger 40. The liquid refrigerant temperature sensor 304 detects the temperature of the refrigerant as the liquid refrigerant temperature Ty.

The control device 100C calculates the degree of supercooling SC of the refrigerant at the outlet of the supercooling heat exchanger 40 by subtracting the liquid refrigerant temperature Ty from the condensation temperature Tx.

SC = Tx-Ty ... (4)
The control device 100C determines that the refrigerant circulating in the refrigerant circuit 5 is insufficient when the supercooling degree SC is the threshold value Th5 or less.

FIG. 11 is a flowchart showing an example of a processing procedure for determining a refrigerant shortage executed by the control device 100C in the third embodiment. The series of processes shown in this flowchart are repeatedly executed while the refrigeration cycle apparatus 1C is in steady operation.

With reference to FIG. 11, in step S301, the control device 100C determines whether or not the refrigerant shortage determination control is being executed. Refrigerant shortage determination control is executed, for example, once an hour for several minutes. When the refrigerant shortage determination control is not executed (NO in step S301), the control device 100C shifts the process to the return without executing the subsequent series of processes. If it is determined that the refrigerant shortage determination control is being executed (YES in step S301), the process proceeds to step S302.

In step S302, the control device 100C acquires the condensation temperature Tx from the condensation temperature sensor 305 and acquires the liquid refrigerant temperature Ty from the liquid refrigerant temperature sensor 304.

In step S303, the control device 100C calculates the degree of supercooling SC of the refrigerant at the outlet of the supercooling heat exchanger 40 based on the condensation temperature Tx and the liquid refrigerant temperature Ty.

In step S304, the control device 100C determines whether or not the supercooling degree SC is the threshold value Th5 or less. When it is determined that the supercooling degree SC is equal to or less than the threshold value Th5 (S304: YES), the control device 100C determines that the refrigerant circulating in the refrigerant circuit 5 is insufficient, and the process proceeds to step S305. move on. When it is determined that the supercooling degree SC exceeds the threshold value Th5 (S304: NO), the control device 100C determines that the refrigerant circulating in the refrigerant circuit 5 is not insufficient, and shifts the process to return. To do.

In step S305, the control device 100C determines whether or not the suction superheat degree SH of the compressor 10 is less than the threshold value Th2. When it is determined that the suction superheat degree SH of the compressor 10 is less than the threshold value Th2 (S305: YES), the process proceeds to step S307. When it is determined that the suction superheat degree SH of the compressor 10 is equal to or higher than the threshold value Th2 (S305: NO), the process proceeds to step S306.

In step S306, the control device 100C determines whether or not the evaporation temperature Te of the refrigerant is the threshold value Th3 or more. When it is determined that the evaporation temperature Te of the refrigerant is equal to or higher than the threshold value Th3 (S306: YES), the process proceeds to step S308. When it is determined that the evaporation temperature Te of the refrigerant is less than the threshold value Th3 (S306: NO), the process proceeds to step S309.

In step S307, the control device 100C displays on the display device 150 that it is determined that the refrigerant circulating in the refrigerant circuit 5 is insufficient due to the liquid back operation.

In step S308, the control device 100C displays on the display device 150 that it is determined that the refrigerant circulating in the refrigerant circuit 5 is insufficient due to the operation in which the evaporation temperature of the refrigerant is high.

In step S309, the control device 100C displays on the display device 150 that it is determined that the refrigerant circulating in the refrigerant circuit 5 is insufficient because the refrigerant sealed in the refrigerant circuit 5 leaks to the outside.

As described above, according to the third embodiment, it is possible to determine whether or not the refrigerant is insufficient based on the degree of supercooling SC of the refrigerant at the outlet of the supercooling heat exchanger 40.

According to the third embodiment, similarly to the first and second embodiments, the operator or the user can be notified of the factor determined to be the refrigerant shortage. As a result, it is possible to take measures according to the factors determined to be insufficient refrigerant.

Embodiment 4.
FIG. 12 is an overall configuration diagram of a refrigeration cycle device in which the outdoor unit according to the fourth embodiment is used. With reference to FIG. 12, the refrigeration cycle device 1D includes an outdoor unit 2D and an indoor unit 3. The outdoor unit 2D includes a control device 100D instead of the control device 100 of the outdoor unit 2 of the first embodiment shown in FIG. The outdoor unit 2D further includes a condensation temperature sensor 305, a liquid refrigerant temperature sensor 304, and an outside air temperature sensor 301.

The outside air temperature sensor 301 is provided around the condenser 20. The outside air temperature sensor 301 detects the outside air temperature To.

The control device 100D calculates the degree of supercooling SC of the refrigerant at the outlet of the supercooling heat exchanger 40 by subtracting the liquid refrigerant temperature Ty from the condensation temperature Tx.

The control device 100D sets the degree of refrigerant supercooling (condensation temperature Tx-liquid refrigerant temperature Ty) at the outlet of the supercooling heat exchanger 40 to the maximum temperature difference of the supercooling heat exchanger 40 (condensation temperature Tx-outside air temperature To). By dividing, the temperature efficiency ε of the supercooling heat exchanger 40 is calculated.

ε = (Tx-Ty) / (Tx-To)… (5)
When the temperature efficiency ε is the threshold value Th6 or less, the control device 100D determines that the refrigerant circulating in the refrigerant circuit 5 is insufficient.

FIG. 13 is a flowchart showing an example of a processing procedure for determining a refrigerant shortage executed by the control device 100D in the fourth embodiment. The series of processes shown in this flowchart are repeatedly executed while the refrigeration cycle apparatus 1D is in steady operation.

With reference to FIG. 13, in step S401, the control device 100D determines whether or not the refrigerant shortage determination control is being executed. Refrigerant shortage determination control is executed, for example, once an hour for several minutes. When the refrigerant shortage determination control is not executed (NO in step S401), the control device 100D shifts the process to the return without executing the subsequent series of processes. If it is determined that the refrigerant shortage determination control is being executed (YES in step S401), the process proceeds to step S402.

In step S402, the control device 100D acquires the condensation temperature Tx from the condensation temperature sensor 305, acquires the liquid refrigerant temperature Ty from the liquid refrigerant temperature sensor 304, and acquires the outside air temperature To from the outside air temperature sensor 301.

In step S403, the control device 100D calculates the temperature efficiency ε of the supercooling heat exchanger 40 based on the outside air temperature To, the condensation temperature Tx, and the liquid refrigerant temperature Ty.

In step S404, the control device 100D determines whether or not the temperature efficiency ε of the supercooling heat exchanger 40 is equal to or less than the threshold value Th6. When it is determined that the temperature efficiency ε of the supercooling heat exchanger 40 is equal to or less than the threshold value Th6 (S404: YES), the control device 100D determines that the refrigerant circulating in the refrigerant circuit 5 is insufficient. , The process proceeds to step S405. When it is determined that the temperature efficiency ε of the supercooling heat exchanger 40 exceeds the threshold value Th6 (S404: NO), the control device 100D determines that the refrigerant circulating in the refrigerant circuit 5 is not insufficient. Move the process to return.

In step S405, the control device 100D determines whether or not the suction superheat degree SH of the compressor 10 is less than the threshold value Th2. When it is determined that the suction superheat degree SH of the compressor 10 is less than the threshold value Th2 (S405: YES), the process proceeds to step S407. When it is determined that the suction superheat degree SH of the compressor 10 is equal to or higher than the threshold value Th2 (S405: NO), the process proceeds to step S406.

In step S406, the control device 100D determines whether or not the evaporation temperature Te of the refrigerant is the threshold value Th3 or more. When it is determined that the evaporation temperature Te of the refrigerant is equal to or higher than the threshold value Th3 (S406: YES), the process proceeds to step S408. When it is determined that the evaporation temperature Te of the refrigerant is less than the threshold value Th3 (S406: NO), the process proceeds to step S409.

In step S407, the control device 100D displays on the display device 150 that it is determined that the refrigerant circulating in the refrigerant circuit 5 is insufficient due to the liquid back operation.

In step S408, the control device 100D displays on the display device 150 that it is determined that the refrigerant circulating in the refrigerant circuit 5 is insufficient due to the operation in which the evaporation temperature of the refrigerant is high.

In step S409, the control device 100D displays on the display device 150 that it is determined that the refrigerant circulating in the refrigerant circuit 5 is insufficient because the refrigerant sealed in the refrigerant circuit 5 leaks to the outside.

As described above, according to the fourth embodiment, it is possible to determine whether or not the refrigerant is insufficient based on the temperature efficiency ε of the supercooling heat exchanger 0.

According to the fourth embodiment, as in the first to third embodiments, the operator or the user can be notified of the factor determined to be the refrigerant shortage. As a result, it is possible to take measures according to the factors determined to be insufficient refrigerant.

Embodiment 5.
FIG. 14 is an overall configuration diagram of a refrigeration cycle device in which the outdoor unit according to the fifth embodiment is used. With reference to FIG. 14, the refrigeration cycle device 1B includes an outdoor unit 2B and an indoor unit 3. The outdoor unit 2B includes a control device 100B instead of the control device 100 of the outdoor unit 2 of the first embodiment shown in FIG.

FIG. 15 is a diagram for explaining the refrigerant shortage determination process by the control device in the fifth embodiment. As shown in FIG. 15, the control device 100B calculates the temperature rise amount (T2-T1) of the refrigerant by the heater 72 at A second intervals (t1, t2, t3 ...). The control device 100B calculates the average value M of the temperature rises of the latest three times of the refrigerant. The control device 100B determines that the refrigerant is insufficient when the average value M becomes the threshold value Th1 or more. The control device 100B is engaged for B minutes, and when the average value M becomes less than the threshold value Th1, it is determined that the refrigerant is not insufficient.

FIG. 16 is a flowchart showing an example of a processing procedure for determining a refrigerant shortage executed by the control device 100B in the fifth embodiment. The series of processes shown in this flowchart are repeatedly executed while the refrigeration cycle apparatus 1B is in steady operation.

With reference to FIG. 16, in step S501, the control device 100B determines whether or not the refrigerant shortage determination control is being executed. Refrigerant shortage determination control is executed, for example, once an hour for several minutes. When the refrigerant shortage determination control is not executed (NO in step S501), the control device 100B shifts the process to the return without executing the subsequent series of processes. If it is determined that the refrigerant shortage determination control is being executed (YES in step S501), the process proceeds to step S102.

In step S502, the control device 100B turns on the solenoid valve 79 and turns on the heater 72.

In step S503, when A seconds have elapsed from the time when the solenoid valve 79 was turned on and the heater 72 was turned on, or the time when the detected values of the temperatures T1 and T2 were acquired last time, the process proceeds to step S504.

In step S504, the control device 100B acquires the detected values of the temperatures T1 and T2 from the

temperature sensors

73 and 74 of the refrigerant amount detecting unit 70, respectively.

In step S505, the latest three average values of the difference between the temperature T2 and the temperature T1 (T2-T1), that is, the latest three average values M of the amount of temperature rise of the refrigerant by the heater 72 are calculated.

In step S506, the control device 100B determines whether or not the average value M is the threshold value Th1 or more. When it is determined that the average value M is equal to or higher than the threshold value Th1 (S506: YES), the control device 100B determines that the refrigerant circulating in the refrigerant circuit 5 is insufficient, and the process proceeds to step S508. .. When it is determined that the average value M is less than the threshold value Th1 (S506: NO), the control device 100B determines that the refrigerant circulating in the refrigerant circuit 5 is not insufficient, and the process proceeds to step S507. ..

In step S507, when B minutes have elapsed from the time when the solenoid valve 79 is turned on and the heater 72 is turned on (S507: YES), the process proceeds to step S513. When B minutes have not elapsed from the time when the solenoid valve 79 is turned on and the heater 72 is turned on (S507: NO), the process returns to step S503.

In step S508, the control device 100B determines whether or not the suction superheat degree SH of the compressor 10 is less than the threshold value Th2. When it is determined that the suction superheat degree SH of the compressor 10 is less than the threshold value Th2 (S508: YES), the process proceeds to step S510. When it is determined that the suction superheat degree SH of the compressor 10 is equal to or higher than the threshold value Th2 (S510: NO), the process proceeds to step S511.

In step S509, the control device 100B determines whether or not the evaporation temperature Te of the refrigerant is equal to or higher than the threshold value Th3. When it is determined that the evaporation temperature Te of the refrigerant is equal to or higher than the threshold value Th3 (S109: YES), the process proceeds to step S511. When it is determined that the evaporation temperature Te of the refrigerant is less than the threshold value Th3 (S509: NO), the process proceeds to step S512.

In step S510, the control device 100B displays on the display device 150 that it is determined that the refrigerant circulating in the refrigerant circuit 5 is insufficient due to the liquid back operation.

In step S511, the control device 100B displays on the display device 150 that it is determined that the refrigerant circulating in the refrigerant circuit 5 is insufficient due to the operation in which the evaporation temperature of the refrigerant is high.

In step S512, the control device 100B displays on the display device 150 that it is determined that the refrigerant circulating in the refrigerant circuit 5 is insufficient because the refrigerant sealed in the refrigerant circuit 5 leaks to the outside.

In step S513, the control device 100B turns off (closes) the solenoid valve 79 and turns off the heater 72.

As described above, according to the fifth embodiment, when the detected temperatures T1 and T2 vary, it is possible to prevent an erroneous determination of whether or not the refrigerant is insufficient.

In the above embodiment, the control device determines the shortage of the refrigerant by using the average value of the temperature rises of the plurality of times in the first embodiment, but the present invention is not limited to this.

The control device may determine the shortage of the refrigerant by using the average value of the temperature rises of the plurality of times in the second embodiment. The control device may determine the shortage of the refrigerant by using the average value of the degree of supercooling at the outlet of the supercooling heat exchanger in the third embodiment. The control device may determine the shortage of the refrigerant by using the average value of the temperature efficiencies of the supercooled heat exchanger in the fourth embodiment.

It is also planned that each of the embodiments disclosed this time will be appropriately combined and implemented within a technically consistent range. And it should be considered that the embodiments disclosed this time are 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, 1B, 1C, 1D refrigeration cycle device, 2,2A, 2B, 2C, 2D outdoor unit, 3 indoor unit, 10 compressor, 20 condenser, 22, 42, 62 fan, 30 liquid reservoir, 40 Overcooling heat exchanger, 45 sight glass, 50 expansion valve, 60 evaporator, 70, 70A refrigerant amount detector, 71 capillary tube, 72 heater, 73-77, 301, 302, 304, 305 temperature sensor, 78 heat exchange Department, 79 electromagnetic valve, 80-87 piping, 90, 92 pressure sensor, 100, 100A, 100B, 100C, 100D control device, 102 CPU, 104 memory, 150 display device, 201 temperature sensor, 202 heat exchange room, 204 machine Room, 206 dividers, 208 boxes.

Claims

An outdoor unit that is connected to an indoor unit to form a refrigeration cycle device.
A compressor that compresses the refrigerant and
A condenser for condensing the refrigerant output from the compressor is provided.
The compressor and the condenser together with an expansion mechanism and an evaporator included in the indoor unit form a refrigerant circuit for circulating the refrigerant.
The outdoor unit further
It is determined whether or not the refrigerant circulating in the refrigerant circuit is insufficient, and when it is determined that the refrigerant is insufficient, the liquid back operation is used as a factor for determining that the refrigerant is insufficient. An outdoor unit comprising an operation in which the evaporation temperature of the refrigerant is high and a control device for notifying one of the leakage of the refrigerant from the refrigerant circuit.
When it is determined that the refrigerant is insufficient, the control device determines that the liquid back operation is the factor when the suction superheat degree of the compressor is smaller than the first threshold value. The outdoor unit according to claim 1, which is notified.
When it is determined that the refrigerant is insufficient, the control device operates with a high evaporation temperature of the refrigerant as the factor when the evaporation temperature of the refrigerant is equal to or higher than the second threshold value. The outdoor unit according to claim 1, which notifies that.
When it is determined that the refrigerant is insufficient, the control device has the suction superheat degree of the compressor equal to or higher than the first threshold value and the evaporation temperature of the refrigerant is lower than the second threshold value. In this case, the outdoor unit according to claim 1, which notifies the leakage of the refrigerant from the refrigerant circuit as the factor.
A bypass circuit configured to return a part of the refrigerant on the discharge side of the condenser to the compressor without passing through the indoor unit.
A heater configured to heat the refrigerant flowing through the bypass circuit, a preheating temperature sensor that detects the temperature of the refrigerant before being heated by the heater, and the refrigerant heated by the heater. It is equipped with a refrigerant amount detection unit including a post-heating temperature sensor that detects the temperature of the
Whether or not the refrigerant circulating in the refrigerant circuit is insufficient in the control device using the amount of temperature rise calculated from the temperature detected by the post-heating temperature sensor and the temperature detected by the preheating temperature sensor. The outdoor unit according to claim 1, wherein the outdoor unit is determined.
The outdoor unit according to claim 5, wherein the control device determines that the refrigerant circulating in the refrigerant circuit is insufficient when the temperature rise amount is equal to or higher than the third threshold value.
The fifth aspect of the present invention, wherein the control device determines that the refrigerant circulating in the refrigerant circuit is insufficient when the average value of the temperature rise amount at a plurality of times is equal to or more than a third threshold value. Outdoor unit.
The outdoor unit according to claim 5, wherein the refrigerant amount detection unit is provided at a location where the influence of airflow is small as compared with the condenser.
The outdoor unit according to claim 5, wherein the heater is a heater.
The outdoor unit according to claim 5, wherein the heater is a refrigerant pipe on the discharge side of the compressor.
A valve provided in the bypass circuit and configured to switch the flow and cutoff of the refrigerant in the bypass circuit is further provided.
The control device is
The valve is controlled to be in the open state during execution of determination control for determining whether or not the refrigerant circulating in the refrigerant circuit is insufficient.
The outdoor unit according to claim 5, wherein the valve is controlled to be closed while the determination control is not being executed.
The outdoor unit according to claim 5, further comprising a decompression device provided in the bypass circuit and configured to reduce the pressure of the refrigerant flowing in the bypass circuit.
A supercooling heat exchanger for supercooling the refrigerant flowing out of the condenser is provided.
The outdoor according to claim 1, wherein the control device determines that the refrigerant circulating in the refrigerant circuit is insufficient when the degree of supercooling in the supercooling heat exchanger is equal to or less than the fourth threshold value. Machine.
A supercooling heat exchanger for supercooling the refrigerant flowing out of the condenser is provided.
The outdoor unit according to claim 1, wherein the control device determines that the refrigerant circulating in the refrigerant circuit is insufficient when the temperature efficiency of the supercooling heat exchanger is equal to or less than the fifth threshold value. ..
The outdoor unit according to any one of claims 1 to 14, and the outdoor unit.
A refrigeration cycle device including the indoor unit connected to the outdoor unit.