WO2021095115A1

WO2021095115A1 - Outdoor unit and refrigeration cycle device

Info

Publication number: WO2021095115A1
Application number: PCT/JP2019/044280
Authority: WO
Inventors: 亮築山
Original assignee: 三菱電機株式会社
Priority date: 2019-11-12
Filing date: 2019-11-12
Publication date: 2021-05-20
Also published as: JPWO2021095115A1; JP7150192B2

Abstract

An outdoor unit (2) comprises a first flow path (F1), a second flow path (F2), and a notification device (101). A compressor (10) and a condenser (20) are arranged in the first flow path (F1). The second flow path (F2) branches off from a plurality of branch points (BP1 to BP3) of the first flow path (F1) downstream from the condenser (20) and then merges at a confluence point (A) to return the refrigerant that has passed through the condenser (20) to the compressor (10). A first opening-closing valve (V1) is located between a first gas-liquid separation structure (711) and the confluence point (A). A second opening-closing valve (V2) is located between a second gas-liquid separation structure (712) and the confluence point (A). A flow rate adjustment device (73) and a refrigerant heating device (75) are arranged in the second flow path (F2) in order from the confluence point (A). A temperature sensor (122) detects the temperature of the refrigerant that has passed through the refrigerant heating device (75). The notification device (101) provides notification of a refrigerant shortage according to the output of the temperature sensor (122).

Description

Outdoor unit and refrigeration cycle device

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

In International Publication No. 2016/135904, the refrigerant filled in the refrigerant circuit is filled with "temperature efficiency", which is the value obtained by dividing the degree of supercooling of the refrigerant at the outlet of the supercooler by the maximum temperature difference of the supercooler. A refrigerating apparatus including a refrigerant amount determining unit for determining the amount is disclosed.

International Publication No. 2016/135904

With the method described in International Publication No. 2016/135904, it may not be possible to detect the decrease in the amount of refrigerant from the time when the amount of refrigerant begins to decrease until the state in which the shortage of refrigerant actually progresses.

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

The present disclosure relates to an outdoor unit of a refrigeration cycle device configured to be connected to a load device including an inflator and an evaporator. The outdoor unit includes a first flow path, a compressor, a condenser, a heat exchanger, a second flow path, a first gas-liquid separation structure, a first on-off valve, a second gas-liquid separation structure, and the like. It includes a second on-off valve, a flow rate adjusting device, a refrigerant heating device, a temperature sensor, and a notification device. The first flow path forms a circulation flow path through which the refrigerant circulates by being connected to the load device. The compressor and condenser are arranged in the first flow path. The second flow path branches from a plurality of branch points of the first flow path downstream of the condenser in the direction in which the refrigerant circulates, and then merges at the confluence, so that the refrigerant that has passed through the condenser is returned to the compressor. It is composed of. The first gas-liquid separation structure is provided at the first branch point among the plurality of branch points. The first on-off valve is arranged between the first gas-liquid separation structure and the confluence. The second gas-liquid separation structure is provided at the second branch point among the plurality of branch points. The second on-off valve is arranged between the second gas-liquid separation structure and the confluence. The flow rate adjusting device and the refrigerant heating device are arranged in the second flow path in order from the confluence. The temperature sensor detects the temperature of the refrigerant that has passed through the refrigerant heating device in the second flow path. The notification device notifies the refrigerant shortage according to the output of the temperature sensor.

According to the outdoor unit of the present disclosure, it is possible to selectively branch refrigerants having different dryness from a plurality of branch points to the refrigerant heating device and determine the refrigerant shortage, so that the refrigerant shortage can be detected at an early stage.

It is a figure which shows the structure of the refrigerating cycle apparatus 1 which concerns on this embodiment. It is a figure for demonstrating the state in which gas-liquid separation cannot be performed in a gas-liquid separation mechanism. It is a figure for demonstrating the state in which gas-liquid separation is possible in a gas-liquid separation mechanism. It is a Moriel diagram which shows the refrigerating cycle corresponding to the refrigerating cycle apparatus shown in FIG. It is a figure which shows the relationship between the dryness of a refrigerant after passing through a bypass flow path and a refrigerant filling rate when passing through each branch part. It is a flowchart for demonstrating control in a refrigerant shortage detection mode.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Hereinafter, modifications of the plurality of embodiments will be described, but it is planned from the beginning of the application that the embodiments and the configurations described in the respective modifications 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.

FIG. 1 is a diagram showing a configuration of a refrigeration cycle device 1 according to the present embodiment. With reference to FIG. 1, the refrigeration cycle device 1 includes an outdoor unit 2, a load device 3, and

extension pipes

84 and 88.

The outdoor unit 2 of the refrigeration cycle device 1 is configured to be connected to the load device 3 by

extension pipes

84 and 88.

The outdoor unit 2 includes a compressor 10, a condenser 20, a liquid receiver (receiver) 30, a supercooler 35, a heat exchanger 40, and pipes 80 to 83, 89. The liquid receiver 30 is arranged between the pipe 81 and the condenser 20 and is configured to store the refrigerant.

The flow path F1 from the compressor 10 to the connection port to the load device 3 through the condenser 20, the liquid receiver 30, the supercooler 35, and the heat exchanger 40 in this order circulates the refrigerant together with the load device 3. It is configured to form a flow path. Hereinafter, this circulation flow path is also referred to as a "main circuit" of the refrigeration cycle.

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

pipes

85, 86, 87. The expansion device 50 is, for example, a temperature expansion valve that is controlled independently of the outdoor unit 2.

The compressor 10 compresses the refrigerant sucked from the pipe 89 and discharges it to the pipe 80. The compressor 10 has a suction port G1, a discharge port G2, and an intermediate pressure port G3. The compressor 10 is configured to suck the refrigerant that has passed through the evaporator 60 from the suction port G1 and discharge the refrigerant from the discharge port G2 toward the condenser 20 together with the refrigerant sucked from the intermediate pressure port G3. To.

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 refrigerating capacity of the refrigerating 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 discharged from the compressor 10 to the pipe 80 and flows it to the liquid receiver 30 and the pipe 81. The condenser 20 is configured such that a high-temperature and high-pressure gas refrigerant discharged from the compressor 10 exchanges heat with the outside air. By this heat exchange, the heat-dissipated refrigerant condenses and changes into 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 on the discharge side of the compressor 10 can be adjusted.

The liquid receiver 30 is arranged between the first passage H1 of the heat exchanger 40 and the condenser 20, and is configured to store the refrigerant.

The supercooler 35 is provided to further lower the temperature of the liquid refrigerant, which is the saturation temperature in the receiver 30, and to secure the supercooling degree SC. For example, the refrigerant passing through the supercooler 35 is further cooled by a fan (not shown) or the like.

The heat exchanger 40 has a first passage H1 and a second passage H2, and is configured to exchange heat between the refrigerant flowing through the first passage H1 and the refrigerant flowing through the second passage H2.

The outdoor unit 2 further includes pipes 91 to 94 and an expansion valve 92. The pipe 91 branches from the branch point BP4 of the pipe 83. The pipe 91, the expansion valve 92, the pipe 93, the second passage H2 of the heat exchanger 40, and the pipe 94 constitute a third passage F3 for flowing the refrigerant from the branch point BP4 of the main circuit to the intermediate pressure port G3 of the compressor 10. To do. The third flow path F3 is also referred to as an "injection flow path".

The outdoor unit 2 further includes start-up pipes 711 to 713, on-off valves V1 to V3, pipes 72, a flow rate adjusting device 73, pipes 74, and a refrigerant heating device 75. As the on-off valves V1 to V3, for example, a solenoid valve can be used.

The start-up pipe 711 branches from the branch point BP1 of the pipe 81 connected to the outlet of the liquid receiver 30 of the circulation flow path, and is connected to the confluence point A of the pipe 72 via the on-off valve V1.

The start-up pipe 712 branches from the branch point BP2 of the pipe 82 connecting the refrigerant outlet of the supercooler 35 and the refrigerant inlet of the first passage H1 of the heat exchanger 40, and joins the pipe 72 via the on-off valve V2. Connected to point A.

The start-up pipe 713 branches from the branch point BP3 of the refrigerant outlet of the first passage H1 of the heat exchanger 40, and is connected to the confluence point A of the pipe 72 via the on-off valve V3.

The pipe 72 connects the merging point A where the refrigerants that have passed through the on-off valves V1 to V3 merge and one end of the flow rate adjusting device 73. The pipe 74 connects the other end of the flow rate adjusting device 73 to the pipe 89. The refrigerant heating device 75 is configured to heat the refrigerant that has passed through the flow rate adjusting device 73. As the refrigerant heating device 75, for example, an electric heater can be used.

As the flow rate adjusting device 73, for example, a capillary tube can be typically used, but any device such as an orifice in which the cross-sectional area of the flow path becomes narrow and a pressure difference occurs may be used. Further, an expansion valve may be used as the flow rate adjusting device 73. Hereinafter, the second flow path F2 that branches from the main circuit and sends the refrigerant to the compressor 10 via the flow rate adjusting device 73 is referred to as a “bypass flow path”.

When the refrigerant leaks and the refrigerant becomes insufficient due to branching by the start-up pipes 711 to 713, the two-phase refrigerant mixed with the gas refrigerant is introduced into the pipe 72.

The bypass flow path may be connected to the intermediate pressure port G3 instead of the suction port G1 of the compressor 10.

The outdoor unit 2 further includes

pressure sensors

110, 111,

temperature sensors

120, 121, 122, and a control device 100 for controlling the outdoor unit 2.

The pressure sensor 110 detects the pressure PL of the suction refrigerant of the compressor 10 and outputs the detected value to the control device 100. The pressure sensor 111 detects the pressure PH of the discharged refrigerant of the compressor 10 and outputs the detected value to the control device 100. The temperature sensor 120 detects the temperature TA of the outside air sent to the condenser 20, and outputs the detected value to the control device 100. The temperature sensor 121 detects the temperature TC of the refrigerant sent from the outlet of the condenser 20 to the liquid receiver 30, and outputs the detected value to the control device 100. The temperature sensor 122 detects the temperature T1 of the refrigerant heated by the refrigerant heating device 75 after passing through the flow rate adjusting device 73, and outputs the detected value to the control device 100.

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

As described above, in the present embodiment, the branch point BP1 at the outlet of the receiver 30 which is the high pressure portion, the branch point BP2 at the outlet of the supercooler 35, and the outlet of the first passage H1 of the heat exchanger 40. A second flow path F2 for sending the refrigerant from any of the branch points BP3 to the suction port G1 of the compressor 10 which is the low pressure portion is provided. A flow rate adjusting device 73 and a refrigerant heating device 75 are arranged in the second flow path F2.

A temperature sensor 122 for measuring the actual temperature of the refrigerant and a pressure sensor 110 for detecting the low pressure saturation temperature from the pressure are provided in a portion through which the refrigerant heated by the refrigerant heating device 75 passes.

For a two-phase refrigerant, if the pressure is measured with a pressure sensor, the corresponding temperature (saturation temperature) is determined. A conversion table showing the correspondence between the pressure and the saturation temperature is stored in the memory 104 of the control device 100 in advance. The control device 100 obtains the saturation temperature corresponding to the pressure PL from the conversion table, and calculates the difference from the temperature T1 actually measured by the temperature sensor. When the saturation temperature is T0, the superheat degree SH is SH = T1-T0.

For the low pressure saturation temperature, the pressure at point C may be measured and converted into temperature. By obtaining the difference between the actual temperature and the low-pressure saturation temperature, the presence or absence of the superheat degree SH can be determined.

In such a configuration, a gas-liquid separation mechanism is provided at each of the branch points BP1 to BP3 from the main flow path to the bypass flow path. FIG. 2 is a diagram for explaining a state in which gas-liquid separation is not possible in the gas-liquid separation mechanism. FIG. 3 is a diagram for explaining a state in which gas-liquid separation is possible in the gas-liquid separation mechanism.

With reference to FIGS. 2 and 3, the gas-liquid separation mechanism is composed of rising pipes 711 to 713 that rise from pipes 81 to 83, which are liquid pipes, in the directions opposite to gravity, respectively.

As shown in FIG. 2, when the dryness of the refrigerant flowing in the pipes 81 to 83 is small, the two-phase refrigerant in which the liquid refrigerant and the gas refrigerant are mixed flows in the start-up pipes 711 to 713 and the pipe 72. On the other hand, as shown in FIG. 3, when the dryness of the refrigerant flowing through the pipes 81 to 83 is large, the liquid refrigerant drops due to gravity in the middle of the start-up pipes 711 to 713, and any of the start-up pipes 711 to 713 is used. A single-phase gas refrigerant separated from the liquid refrigerant flows through the pipe 72 via the pipe 72.

When a two-phase refrigerant is flowing in the bypass flow path, heat is absorbed as latent heat for vaporizing the refrigerant even if it is heated by the refrigerant heating device 75. Therefore, the temperature T1 detected by the temperature sensor 122 coincides with the saturation temperature of the refrigerant. In this state, the degree of superheat of the refrigerant SH = 0.

On the other hand, when a gas-state refrigerant is flowing in the bypass flow path, when the refrigerant heating device 75 heats the refrigerant, the heat is absorbed by the refrigerant as sensible heat, so that the temperature of the refrigerant rises. Therefore, the temperature T1 detected by the temperature sensor 122 becomes higher than the saturation temperature of the refrigerant, and the degree of superheat of the refrigerant SH> 0.

FIG. 4 is a Moriel diagram showing a refrigeration cycle corresponding to the refrigeration cycle apparatus shown in FIG. In FIG. 4, the cycle when the amount of refrigerant is sufficient is shown by a solid line, and the cycle when the amount of refrigerant is insufficient is shown by a broken line.

If the refrigerant is not insufficient, the refrigerant that has passed through the condenser 20 is a liquid refrigerant. Therefore, at any of the branch points BP1, BP2, and BP3, the state of the refrigerant is a liquid refrigerant, which is the state on the left side of the point A3 in FIG.

However, when the amount of liquid refrigerant in the receiver 30 becomes low due to insufficient refrigerant, the position of the branch point moves to the right on the Moriel diagram. In FIG. 4, the paths F2 (1), F2 (2), and F2 (3) show the state change of the refrigerant flowing in the second flow path F2 when the amount of the refrigerant is reduced to a certain amount.

The path F2 (1) shows a path when the refrigerant flows from the branch point BP1 to the second flow path F2 when the on-off valve V1 is opened and the on-off valves V2 and V3 are closed. At this time, the states of points A, B, and C in FIG. 1 are shown as points A1, B1, and C1 in FIG. 4, respectively.

The path F2 (2) indicates a path when the refrigerant flows from the branch point BP2 to the second flow path F2 when the on-off valve V2 is opened and the on-off valves V1 and V3 are closed. At this time, the states of points A, B, and C in FIG. 1 are shown as points A2, B2, and C2 in FIG. 4, respectively.

Route F2 (3) indicates a route when the refrigerant flows from the branch point BP3 to the second flow path F2 when the on-off valve V3 is opened and the on-off valves V1 and V2 are closed. At this time, the states of points A, B, and C in FIG. 1 are shown as points A3, B3, and C3 in FIG. 4, respectively.

A flow rate of refrigerant corresponding to the differential pressure determined by the expansion device 50 and the evaporator 60 of the main circuit flows through the second flow path F2, which is a bypass passage. When the pressure is reduced by the flow rate adjusting device 73, the state of the refrigerant changes from points A1, A2, A3 to points B1, B2, B3, respectively. Then, when the refrigerant is heated by the refrigerant heating device 75, the state of the refrigerant changes from points B1, B2, B3 to points C1, C2, and C3, respectively.

At point A2 in FIG. 4, the state of the refrigerant is a two-phase state, and at point A3, the state of the refrigerant is a single-phase liquid state. In the path F2 (2) and the path F2 (3), a certain amount of liquid refrigerant flows through the pipe 74. Therefore, even if the point moves to the right by heating, the temperature of the refrigerant does not change at the saturation temperature because it does not exceed the saturated gas line. Therefore, at points C2 and C3, the degree of superheat SH is zero.

On the other hand, at point A1 in FIG. 4, the state of the refrigerant is a single-phase gas state. In the path F2 (1), since the liquid refrigerant hardly flows through the pipe 74, the heat given to the refrigerant from the refrigerant heating device 75 becomes sensible heat, and the temperature of the refrigerant in the gas state is higher than the saturation temperature. It gets higher. Therefore, at point C1, the degree of superheat SH is SH> 0.

When the amount of refrigerant further decreases from the state of the broken line in FIG. 4, the path F2 (2) also moves to the left, and the superheat degree SH becomes SH> 0 even at the point C2, and when the amount of refrigerant further decreases, the path F2 (3) Also moves to the left and at point C3, the superheat degree SH becomes SH> 0.

That is, by opening the on-off valves V1, V2, and V3 one by one in order and examining the degree of superheat SH in the three states, the degree of decrease in the amount of refrigerant, in other words, the degree of refrigerant shortage can be known.

FIG. 5 is a diagram showing the relationship between the dryness of the refrigerant after passing through the bypass flow path and the refrigerant filling rate when passing through each branch portion. Here, the refrigerant filling rate of 100% indicates a specified filling amount that is not excessive or deficient in design, and it is assumed that the difference from 100% is the insufficient amount. At the beginning of installation, there is a margin in the filling amount, so for example, the refrigerant filling rate may be 105%. Then, when the amount of refrigerant leaks and decreases to less than 100%, it is determined that the refrigerant is insufficient.

The degree of dryness that allows gas-liquid separation is a value determined by the design of the gas-liquid separation mechanism. The dryness of the gas-liquid separable limit is set to 0.05, and is shown by a broken line in FIG. When the refrigerant filling rate is more than 96%, the degree of superheat SH = 0 regardless of which of the on-off valves V1 to V3 is opened, and due to the limitation of this gas-liquid separation mechanism, the refrigerant shortage cannot be detected.

When the refrigerant filling rate is 96%, the degree of superheat SH> 0 when the on-off valve V1 is opened and the refrigerant flows from the branch point BP1 to the bypass flow path. Therefore, when this gas-liquid separation mechanism is used, it is possible to detect that the refrigerant is insufficient when the refrigerant filling rate is 96% or less. When the refrigerant filling rate is 96% and the on-off valve V2 or V3 is opened to allow the refrigerant to flow through the bypass flow path, the degree of superheat of the refrigerant after passing through the bypass flow path SH = 0.

When the refrigerant filling rate is 91%, the degree of superheat SH> 0 when the on-off valve V1 or V2 is opened and the refrigerant flows from the branch point BP1 or BP2 into the bypass flow path. When the refrigerant filling rate is 91%, the degree of superheat of the refrigerant SH = 0 after passing through the bypass flow path when the on-off valve V3 is opened and the refrigerant flows through the bypass flow path.

When the refrigerant filling rate is 84%, the degree of superheat SH of the refrigerant after passing through the bypass flow path is SH> 0 regardless of which of the on-off valves V1, V2, and V3 is opened. From the above, by selectively opening one on-off valve V1 to V3, the degree of refrigerant shortage in three stages can be detected.

FIG. 6 is a flowchart for explaining the control in the refrigerant shortage detection mode. The refrigerant shortage detection mode is periodically executed by a timer or the like, for example, once a day or several days.

Here, the amount of the liquid refrigerant held in the liquid receiver 30 varies depending on the operating state of the refrigeration cycle device. Originally, the amount of the refrigerant should be a sufficient amount so that the liquid remains in the liquid receiver 30 even in the operating state where the liquid amount in the liquid receiver 30 is the smallest.

The operating state in which the amount of liquid in the receiver is most reduced is the state in which the temperature TC, which is the condensation temperature, is high (the pressure in the high-pressure part is rising due to the influence of the outside air temperature, the rotation speed of the fan, etc.) is there. In this case, the density of the refrigerant in the main circuit increases and the volume decreases. Since the liquid refrigerant is discharged from the receiver 30 to the circulation circuit side by the amount of the volume reduction of the refrigerant in the main circuit, the amount of liquid in the receiver 30 is reduced.

In addition, when using multiple indoor units, if there is a stopped indoor unit, the refrigerant for that amount is stored in the receiver, so it is received when all of the multiple indoor units are in operation. The amount of liquid in the liquid container decreases.

Therefore, in order to enable detection of refrigerant shortage at an early stage, in the present embodiment, in the refrigerant shortage detection mode, the heat exchanger 40 is connected from the outlet 30 of the receiver 30 provided with the gas-liquid separation mechanism. The dryness of the portion leading to the outlet is increased as compared with the normal operation, and the refrigerant shortage detection unit provided in the bypass flow path makes it easy to detect the refrigerant shortage.

Specifically, when the refrigerant shortage detection mode is set, in step S1, the control device 100 sets the operating frequency of the compressor 10 to a predetermined fixed frequency. Further, the opening degree of the expansion valve 92 of the injection flow path is also fixed.

Further, the control device 100 changes the rotation speed of the fan 22. In the normal operation mode, the rotation speed of the fan 22 is determined so that each device works efficiently. For example, the difference between the outside air and the temperature TC is set to be 10 ° C.

On the other hand, in the refrigerant shortage detection mode, the control device 100 sets the rotation speed of the fan 22 to be equal to or lower than the minimum rotation speed that can be obtained in normal operation. For example, the rotation of the fan 22 may be stopped. As a result, the efficiency of heat exchange with the outside air in the condenser 20 is lowered, and the refrigerant is less likely to be condensed in the condenser 20. Then, the dryness of the portion provided with the gas-liquid separation mechanism increases as compared with the normal operation. That is, the ratio of gas refrigerant in the refrigerant increases as compared with the case of normal operation.

Subsequently, in step S2, the control device 100 opens the on-off valve V1 and flows the refrigerant through the bypass flow path with the on-off valves V2 and V3 closed. Subsequently, in step S3, the control device 100 determines whether or not the refrigerant is insufficient. The control device 100 detects whether or not the refrigerant is insufficient based on the presence or absence of the superheat degree SH at the outlet (point C) of the refrigerant heating device.

In steps S1 to S3 described above, the control device 100 increases the dryness of the outlet of the condenser 20 and increases the circulation amount of the refrigerant in the main circuit so that the refrigerant shortage can be detected at an early stage. The superheat degree SH of the point C is confirmed after setting the state close to the sky. By operating under stricter conditions than normal operating conditions, it becomes easier to determine the refrigerant shortage based on the degree of superheat SH.

In step S3, if there is no refrigerant shortage (NO in S3), that is, if the degree of superheat SH = 0, the control device 100 terminates the refrigerant shortage detection mode assuming that the amount of refrigerant is appropriate.

On the other hand, in step S3, when the refrigerant is insufficient (YES in S3), that is, when the degree of superheat SH> 0, the control device 100 determines that the refrigerant is insufficient, and proceeds to step S4.

In step S4, the control device 100 closes the on-off valve V1 and opens only the on-off valve V2 among the on-off valves V1 to V3. Then, in step S5, the control device 100 detects whether or not the refrigerant is insufficient based on the presence or absence of the superheat degree SH at the outlet (point C) of the refrigerant heating device. In step S5, when the refrigerant is not insufficient (NO in S5), that is, when the degree of superheat SH = 0, in step S9, the control device 100 sets the branch points BP1, BP2, which are stored in the memory 104 in advance. The amount of refrigerant is calculated with reference to a table showing the relationship between which of BP3 is selected and the amount of refrigerant filled. In this case, in the example shown in FIG. 5, it is calculated that the amount of the refrigerant filled is 91% or more and less than 96%.

On the other hand, in step S5, when the refrigerant is insufficient (YES in S3), that is, when the degree of superheat SH> 0, the control device 100 determines that the refrigerant is further insufficient, and proceeds to step S6.

In step S6, the control device 100 closes the on-off valve V2 and opens only the on-off valve V3 among the on-off valves V1 to V3. Then, in step S7, the control device 100 detects whether or not the refrigerant is insufficient based on the presence or absence of the superheat degree SH at the outlet (point C) of the refrigerant heating device. In step S7, when the refrigerant is not insufficient (NO in S7), that is, when the degree of superheat SH = 0, in step S10, the control device 100 refers to the table stored in the memory 104 in advance and the refrigerant. Calculate the amount. In this case, in the example shown in FIG. 5, it is calculated that the amount of the refrigerant filled is 84% or more and less than 91%.

On the other hand, if the refrigerant is insufficient in step S7 (YES in S7), that is, if the degree of superheat SH> 0, the control device 100 determines that the refrigerant is further insufficient, and proceeds to step S8. In step S8, the control device 100 calculates the amount of the refrigerant with reference to the table stored in the memory 104 in advance. In this case, in the example shown in FIG. 5, it is calculated that the amount of the refrigerant filled is less than 84%.

After the calculation of the amount of refrigerant is executed in any of steps S8, S9, and S10, the control device 100 sends an alarm to the notification device 101 indicating that the refrigerant is insufficient in step S11. Output. The notification device 101 is, for example, a display device such as a liquid crystal display, a warning lamp, or the like, and may be a device that transmits a warning signal to an external device via a communication line.

Based on the output result from the notification device 101, the user can consider whether to stop the refrigerating cycle device, when to repair the refrigerant leak or to fill the refrigerant shortage. The control device 100 may notify the user or the service provider of the urgency or the additional encapsulation amount based on the detected shortage amount.

After notifying the user of the amount of refrigerant using the notification device 101, the control device 100 ends the processing of the refrigerant shortage detection mode.

(Modification example)
In the above-described example, the amount of refrigerant is changed in three stages by flowing the refrigerant from three branch points having different dryness of the refrigerant to the bypass flow path, thereby changing the dryness of the refrigerant flowing toward the refrigerant heating device 75 in three stages. However, by changing the rotation speed of the fan 22 in each of steps S8, S9, and S10, the dryness of the refrigerant may be further changed to detect the amount of the refrigerant with finer accuracy.

Further, even if the rotation speed of the fan 22 is fixed and the dryness is changed by changing the operating frequency of the compressor 10 in each of steps S8, S9, and S10, the amount of refrigerant can be detected with even finer accuracy. good.

Further, the rotation speed of the fan 22 and the operating frequency of the compressor 10 are fixed, and instead, the degree of dryness is changed by changing the opening degree of the expansion valve 92 in each of steps S8, S9, and S10 to further increase the amount of refrigerant. It may be detected with fine accuracy.

Also in the above embodiment, in order to change the dryness of the refrigerant when detecting the amount of the refrigerant, either the rotation speed of the fan 22 or the operating frequency of the compressor 10 is changed to open the expansion valve 92. It may be used in combination with the change of degree.

Further, even if the supercooler 35 is not provided, the refrigerant branched from the plurality of branch points BP1 and BP2 is selected by the on-off valves V1 and V2 and flows to the second flow path F2 which is a bypass flow path. Therefore, it is possible to detect the refrigerant shortage at an early stage.

Further, even if the heat exchanger 40 is not provided, the refrigerant branched from the plurality of branch points BP1 and BP3 is selected by the on-off valves V1 and V3 and flows to the second flow path F2 which is a bypass flow path. Therefore, it is possible to detect the refrigerant shortage at an early stage.

Finally, the present embodiment will be summarized again with reference to the drawings.
As shown in FIG. 1, the present disclosure relates to an outdoor unit 2 of a refrigeration cycle device 1 configured to be connected to a load device 3 including an inflator 50 and an evaporator 60. The outdoor unit 2 includes a first flow path F1, a compressor 10, a condenser 20, a second flow rate F2, a first gas-liquid separation structure, a first on-off valve, and a second gas-liquid separation structure. , A second on-off valve, a flow rate adjusting device 73, a refrigerant heating device 75, a temperature sensor 122, and a notification device 101.

For example, the start-up pipe 711 in FIG. 1 corresponds to the "first gas-liquid separation structure". The on-off valve V1 of FIG. 1 corresponds to the "first on-off valve". The riser pipe 712 of FIG. 1 corresponds to the “second gas-liquid separation structure”. The on-off valve V2 of FIG. 1 corresponds to the "second on-off valve".

The first flow path F1 is connected to the load device 3 to form a circulation flow path through which the refrigerant circulates. The compressor 10 and the condenser 20 are arranged in the first flow path F1. The second flow path F2 branches from a plurality of branch points BP1 to BP3 of the first flow path F1 downstream of the condenser 20 in the direction in which the refrigerant circulates, and then merges at the confluence point A and passes through the condenser 20. It is configured to return the generated refrigerant to the compressor 10. The first gas-liquid separation structure is provided at the first branch point among the plurality of branch points. The first on-off valve is arranged between the first gas-liquid separation structure and the confluence point A. The second gas-liquid separation structure is provided at the second branch point among the plurality of branch points. The second on-off valve is arranged between the second gas-liquid separation structure and the confluence point A.

For example, the "first branch point" corresponds to the branch point BP1 of FIG. 1, and the "second branch point" corresponds to the branch point BP2 of FIG.

The flow rate adjusting device 73 and the refrigerant heating device 75 are arranged in the second flow path F2 in order from the confluence point A. The temperature sensor 122 detects the temperature of the refrigerant that has passed through the refrigerant heating device 75 of the second flow path F2. The notification device 101 notifies the refrigerant shortage according to the output of the temperature sensor 122.

In this way, since it is possible to select one from a plurality of branch points and flow it through the second flow path, the sensitivity for detecting the refrigerant shortage can be changed, and the refrigerant shortage can be detected at an early stage. It becomes.

In the above description, it has been described that the start-up pipe 711 corresponds to the "first gas-liquid separation mechanism" and the start-up pipe 712 corresponds to the "second gas-liquid separation structure". Two of 711 to 713 may be selected to correspond to the "first gas-liquid separation mechanism" and the "second gas-liquid separation mechanism". For example, in a configuration in which the supercooler 35 is not provided, the "first gas-liquid separation mechanism" is associated with the start-up pipe 711, the "second gas-liquid separation structure" is associated with the start-up pipe 713, and the "second opening / closing" is performed. The on-off valve V3 may be associated with the "valve". Further, for example, in a configuration in which the heat exchanger 40 is not provided, the "first gas-liquid separation mechanism" is associated with the start-up pipe 711, and the "second gas-liquid separation structure" is associated with the start-up pipe 712. The on-off valve V2 may be associated with the on-off valve.

Preferably, the outdoor unit 2 further includes a supercooler 35, a heat exchanger 40, a third gas-liquid separation structure, and a third on-off valve. The supercooler 35 and the heat exchanger 40 are arranged in order in the first flow path F1 downstream of the condenser 20. The third gas-liquid separation structure is provided at the third branch point among the plurality of branch points BP1 to BP3.

For example, the start-up pipe 713 in FIG. 1 corresponds to the "third gas-liquid separation structure". The on-off valve V3 of FIG. 1 corresponds to the "third on-off valve". The "third branch point" corresponds to the branch point BP3 of FIG.

The third on-off valve is arranged between the third gas-liquid separation structure and the confluence point A. The first branch point is arranged between the refrigerant outlet of the condenser 20 and the refrigerant inlet of the supercooler 35 in the first flow path F1. The second branch point is arranged between the refrigerant outlet of the supercooler 35 and the refrigerant inlet of the heat exchanger 40 in the first flow path F1. The third branch point is arranged downstream of the refrigerant outlet of the heat exchanger 40 in the first flow path F1.

More preferably, the outdoor unit 2 further includes a control device 100 that controls the on-off valves V1 to V3 and detects a refrigerant shortage based on the output of the temperature sensor 122.

More preferably, the outdoor unit 2 has a normal mode and a refrigerant shortage detection mode as operation modes. The outdoor unit 2 further includes a dryness increasing device that increases the dryness of the refrigerant after passing through the condenser 20. For example, a fan 22 corresponds to the “dryness increasing device”. The control device 100 controls the dryness increasing device, and is configured to increase the dryness of the refrigerant after passing through the condenser 20 in the refrigerant shortage detection mode as compared with the normal mode.

In this way, since the dryness of the refrigerant is increased in the refrigerant shortage detection mode, it is possible to detect the refrigerant shortage at an early stage.

Preferably, the first gas-liquid separation structure and the second gas-liquid separation structure are configured to branch the first flow path to the second flow path in the direction opposite to gravity at the first branch point and the second branch point, respectively. To.

By having such a gas-liquid separation structure, it is possible to facilitate the separation of the gas-phase refrigerant. As a result, the dryness of the refrigerant sent to the refrigerant heating device 75 is increased, so that it is possible to detect the refrigerant shortage at an early stage.

Although the present embodiment has been described above by exemplifying a refrigerator provided with the refrigerating cycle device 1, the refrigerating cycle device 1 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 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 Refrigeration cycle device, 2 Outdoor unit, 3 Load device, 10 Compressor, 20 Condenser, 22 Fan, 30 Recipient, 35 Supercooler, 40 Heat exchanger, 50 Expansion device, 60 Evaporator, 72,74 , 80, 81, 82, 83, 85, 86, 87, 89, 91, 93, 94 piping, 73 flow control device, 75 refrigerant heating device, 84,88 extension piping, 92 expansion valve, 100 control device, 101 notification Equipment, 104 memory, 110,111 pressure sensor, 120,121,122 temperature sensor, 711,712,713 riser pipe, BP1, BP2, BP3, BP4 branch point, F1, F2, F3 flow path, G1 suction port, G2 discharge port, G3 intermediate pressure port, H1 first passage, H2 second passage, V1, V2, V3 on-off valve.

Claims

An outdoor unit of a refrigeration cycle device configured to be connected to a load device including an inflator and an evaporator.
A first flow path that forms a circulation flow path through which the refrigerant circulates by being connected to the load device, and
A compressor and a condenser arranged in the first flow path,
In the direction in which the refrigerant circulates, after branching from a plurality of branch points of the first flow path downstream of the condenser, the refrigerant merges at the confluence, and the refrigerant that has passed through the condenser is returned to the compressor. The configured second flow path and
A first gas-liquid separation structure provided at the first branch point among the plurality of branch points,
A first on-off valve arranged between the first gas-liquid separation structure and the confluence,
A second gas-liquid separation structure provided at the second branch point of the plurality of branch points,
A second on-off valve arranged between the second gas-liquid separation structure and the confluence,
A flow rate adjusting device and a refrigerant heating device arranged in the second flow path in order from the confluence.
A temperature sensor that detects the temperature of the refrigerant that has passed through the refrigerant heating device in the second flow path, and
An outdoor unit including a notification device for notifying a refrigerant shortage according to the output of the temperature sensor.
A supercooler and a heat exchanger arranged in order downstream of the condenser in the first flow path,
A third gas-liquid separation structure provided at the third branch point among the plurality of branch points,
Further provided with a third on-off valve arranged between the third gas-liquid separation structure and the confluence.
The first branch point is arranged between the refrigerant outlet of the condenser and the refrigerant inlet of the supercooler in the first flow path.
The second branch point is arranged between the refrigerant outlet of the supercooler and the refrigerant inlet of the heat exchanger in the first flow path.
The outdoor unit according to claim 1, wherein the third branch point is arranged downstream of the refrigerant outlet of the heat exchanger in the first flow path.
The outdoor unit according to claim 2, further comprising a control device that controls the first to third on-off valves and detects a refrigerant shortage based on the output of the temperature sensor.
The outdoor unit has a normal mode and a refrigerant shortage detection mode as operation modes.
Further provided with a dryness increasing device for increasing the dryness of the refrigerant after passing through the condenser.
The control device is configured to control the dryness increasing device and increase the dryness of the refrigerant after passing through the condenser in the refrigerant shortage detection mode as compared with the normal mode. The outdoor unit according to 3.
The first gas-liquid separation structure and the second gas-liquid separation structure branch from the first flow path to the second flow path in the direction opposite to gravity at the first branch point and the second branch point, respectively. The outdoor unit according to claim 1, which is configured in 1.
A refrigeration cycle device including the outdoor unit according to any one of claims 1 to 5 and the load device.