WO2020066002A1

WO2020066002A1 - Refrigeration cycle device

Info

Publication number: WO2020066002A1
Application number: PCT/JP2018/036527
Authority: WO
Inventors: 亮築山; 野本　宗; 悟梁池; 智隆石川
Original assignee: 三菱電機株式会社
Priority date: 2018-09-28
Filing date: 2018-09-28
Publication date: 2020-04-02
Also published as: CN112714854A; CN112714854B; JPWO2020066002A1; JP6937934B2

Abstract

This refrigeration cycle device (1) comprises a refrigerant circuit (110), a bypass passage (111), a dryness alteration device (112), a temperature detection unit (113), and a control device (100). The refrigerant circuit (110) circulates a refrigerant in order through a compressor (10), a first heat exchanger (20), a first expansion device (50), and a second heat exchanger (60). The bypass passage (111) sends the refrigerant to an intake opening of the compressor (10) from the first heat exchanger (20) without passing through the first expansion device (50) and the second heat exchanger (60). The dryness alteration device (112) is configured so as to alter the dryness of the refrigerant flowing through the bypass passage (111). The temperature detection unit (113) is configured so as to detect an alteration in temperature before and after the dryness is altered by the dryness alteration device (112). The control device (100) controls the dryness alteration device (112). The control device (100) specifies a type for the refrigerant on the basis of the alteration in the temperature detected by the temperature detection unit (113).

Description

Refrigeration cycle device

The present invention relates to a refrigeration cycle apparatus, and more particularly to a refrigeration cycle apparatus that can use a pseudo-azeotropic mixed refrigerant and a non-azeotropic mixed refrigerant.

In recent years, in response to the trend of preventing global warming, the development of refrigeration systems for encapsulating a new refrigerant with a low global warming potential has been actively pursued.

Generally, a refrigerating apparatus is configured so that optimal control is performed on a designated refrigerant. If the type of the charged refrigerant is different, the saturated liquid temperature is also different, so the pressure in the refrigeration cycle must be changed. Therefore, it is necessary to change the control of the compressor and the like for each type of refrigerant.

International Publication WO2017 / 138008 (Patent Document 1) discloses a refrigeration apparatus that automatically identifies an arbitrary refrigerant from a plurality of types of refrigerants and performs efficient operation corresponding to the refrigerant.

International Publication WO2017 / 138058

In recent years, from the viewpoint of preventing global warming, in air conditioners, mixed refrigerants in which the GWP has been reduced by mixing other refrigerants with lower global warming potential (GWP) with a refrigerant consisting of a single component May be used. Among the mixed refrigerants, there are a pseudo-azeotropic refrigerant and a non-azeotropic refrigerant.

A pseudo-azeotropic refrigerant exhibits a constant boiling point when a plurality of components of a refrigerant are mixed at a certain ratio, has the same composition in a gas phase and a liquid phase, and exhibits a phase change as if it were a single component. . The pseudo-azeotropic refrigerant has the same temperature at the same pressure during the two-phase phase change, while the non-azeotropic refrigerant has the characteristic that the temperature changes during the phase change under the same pressure.

In International Publication WO2017 / 138008, the type of refrigerant is determined from the degree of supercooling of the refrigerant at the outlet of the liquid receiver provided downstream of the condenser.

However, in the case of a non-azeotropic refrigerant, the refrigerant composition changes depending on the operation state of the refrigeration system, and the saturated liquid temperature also changes. For this reason, depending on the composition, the temperature of the saturated liquid may be the same as that of another pseudo-azeotropic refrigerant. Therefore, the method of judging from the degree of supercooling disclosed in International Publication WO2017 / 138008 accurately uses non-azeotropic refrigerant. It is difficult to determine the mixed refrigerant.

の An object of the present invention is to provide a refrigeration cycle apparatus capable of correctly determining a non-azeotropic mixed refrigerant.

The present disclosure relates to a refrigeration cycle device. The refrigeration cycle device includes a compressor, a first heat exchanger, a first expansion device, a second heat exchanger, a compressor, a first heat exchanger, a first expansion device, and a second heat exchanger in that order. A refrigerant circuit for circulating the refrigerant, a bypass flow path for transmitting the refrigerant from the first heat exchanger to the suction port of the compressor without passing through the first expansion device and the second heat exchanger, A dryness change device configured to change the dryness, a temperature detection unit configured to detect a change in the temperature of the refrigerant before and after the dryness is changed by the dryness change device, and a dryness change device And a control device for controlling the The control device specifies the type of the refrigerant based on the temperature change detected by the temperature detection unit.

According to the refrigeration cycle device of the present disclosure, it is possible to detect a change in temperature when the dryness of the refrigerant is changed, so that the non-azeotropic refrigerant and the pseudo-azeotropic refrigerant can be correctly determined.

FIG. 2 is a diagram illustrating a configuration of a refrigeration cycle device according to Embodiment 1. FIG. 4 is a ph diagram of a refrigeration cycle apparatus when R410A is used as a refrigerant. FIG. 3 is a ph diagram of a refrigeration cycle apparatus when R463A is used as a refrigerant. It is a figure showing an example of a control value changed according to a refrigerant kind. 4 is a flowchart illustrating a main routine of control of the refrigeration cycle device according to Embodiment 1. 4 is a flowchart illustrating details of a process of a refrigerant type determination operation performed in the first embodiment. FIG. 9 is a diagram illustrating a configuration of a refrigeration cycle device according to Embodiment 2. 8 is a flowchart illustrating details of a process of a refrigerant type determination operation performed in the second embodiment. FIG. 9 is a diagram illustrating a configuration of a refrigeration cycle device according to Embodiment 3. FIG. 4 is a diagram illustrating a configuration of a first example of a receiver and a suction end of a bypass pipe. It is the figure which showed the some hole provided in the edge part of the bypass pipe of the 1st example. It is a graph which shows the relationship between dryness Q and liquid level height H1. FIG. 13 is a ph diagram of a refrigeration cycle apparatus when R410A is used as a refrigerant in the third embodiment. FIG. 13 is a ph diagram of a refrigeration cycle apparatus when R463A is used as a refrigerant in the third embodiment. 9 is a flowchart illustrating details of a refrigerant type determination operation process executed in a third embodiment. It is a figure which shows the structure of the 2nd example of the suction end part of a bypass piping. It is a figure showing the composition of the 3rd example of the suction end of a bypass pipe. It is a figure showing the composition of the 4th example of the suction end of a bypass pipe. It is a figure which shows the detail of the hole provided in the suction end part of the bypass pipe of the 4th example.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, a plurality of embodiments will be described. However, it is planned from the beginning of the application to appropriately combine the configurations described in the embodiments. In the drawings, the same or corresponding portions have the same reference characters allotted, and description thereof will not be repeated.

Embodiment 1 FIG.
The refrigeration cycle apparatus described in Embodiment 1 is configured to be able to use a non-azeotropic refrigerant and an azeotropic refrigerant or a pseudo-azeotropic refrigerant. In the case of such a refrigeration cycle device, the type of the refrigerant can be accurately detected by utilizing the characteristics of the non-azeotropic refrigerant. Hereinafter, the configuration of the refrigeration cycle device will be described.

FIG. 1 is a diagram illustrating a configuration of a refrigeration cycle device according to the first embodiment. In FIG. 1, the connection relation and arrangement of each device in the refrigeration apparatus are shown functionally, and the arrangement in a physical space is not necessarily shown.

冷凍 Referring to FIG. 1, refrigeration cycle apparatus 1 includes outdoor unit 2 and indoor unit 3. The outdoor unit 2 includes a compressor 10, a condenser 20, a first fan 22, and pipes 80 to 84. The outdoor unit 2 further includes a bypass channel 111, a dryness changing device 112, a temperature detecting unit 113, a first pressure sensor 90 and a second pressure sensor 92, and a control device 100. The bypass flow passage 111 includes a second expansion device 71, a first bypass pipe 86 on the upstream side of the second expansion device 71, and a second bypass pipe 87 on the downstream side. The second expansion device 71 is, for example, a capillary tube. The heating device 72 is, for example, an electric heater configured to heat the refrigerant flowing through the second bypass pipe 87. In the first embodiment, the drying degree changing device 112 is the heating device 72. In the first embodiment, the temperature detection unit 113 is the temperature sensor 73.

The indoor unit 3 includes a first expansion device 50, an evaporator 60, a second fan 62, and a pipe 83. The first expansion device 50 is, for example, an electronic expansion valve. The indoor unit 3 is connected to the outdoor unit 2 by

pipes

82 and 84.

The pipe 80 connects the discharge port of the compressor 10 and the condenser 20. The pipe 81 connects the condenser 20 and the branch point M1. The pipe 82 connects the branch point M1 and the first expansion device 50. The pipe 83 connects the first expansion device 50 and the evaporator 60. The pipe 84 connects the evaporator 60 and the suction port of the compressor 10. The first bypass pipe 86 connects the branch point M1 and the second expansion device 71. The second bypass pipe 87 connects the second expansion device 71 and the pipe 84.

The compressor 10 sucks the refrigerant from the pipe 84, compresses the sucked refrigerant, and discharges the compressed refrigerant 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 operating frequency or the rotation speed of the compressor 10, the circulation amount of the refrigerant is adjusted, and the capacity of the refrigeration cycle apparatus 1 can be adjusted. Various types can be used for the compressor 10, and for example, a scroll type, a rotary type, a screw type, and the like can be used.

The condenser 20 condenses the refrigerant discharged from the compressor 10 to the pipe 80. The condensed refrigerant is sent out to the pipe 81. The condenser 20 is configured such that the high-temperature and high-pressure gas refrigerant discharged from the compressor 10 performs heat exchange (radiation) with the outside air. By this heat exchange, the refrigerant is condensed and changes to a liquid phase. The first fan 22 supplies outside air to the condenser 20 where the refrigerant performs heat exchange in the condenser 20. By adjusting the rotation speed of the first fan 22, the refrigerant pressure (high-pressure side pressure) on the discharge side of the compressor 10 can be adjusted.

The first expansion device 50 reduces the pressure of the refrigerant sent from the condenser 20 to the pipe 82. The depressurized refrigerant is sent to the pipe 83. When the opening degree of the first expansion device 50 is changed in the closing direction, the refrigerant pressure on the low pressure side of the first expansion device 50 decreases and the dryness of the refrigerant increases. When the opening degree of the first expansion device 50 is changed in the opening direction, the refrigerant pressure on the low pressure side of the first expansion device 50 increases, and the dryness of the refrigerant decreases.

The evaporator 60 evaporates the refrigerant sent from the first expansion device 50 to the pipe 83. The refrigerant having passed through the evaporator 60 flows to the pipe 84. The evaporator 60 is configured such that the refrigerant decompressed by the first expansion device 50 performs heat exchange (heat absorption) with the air in the indoor unit 3. The refrigerant evaporates by passing through the evaporator 60 to become superheated steam. The second fan 62 supplies the air in which the refrigerant performs heat exchange in the evaporator 60 to the evaporator 60.

構成 As a configuration for detecting the type of refrigerant, a first bypass pipe 86, a second expansion device 71, a second bypass pipe 87, a heating device 72, and a temperature sensor 73 are provided. The first bypass pipe 86, the second expansion device 71, and the second bypass pipe 87 form a bypass flow path 111 that returns a part of the refrigerant that has passed through the condenser 20 to the compressor 10 without passing through the indoor unit 3. Constitute. The second expansion device 71 is, for example, a capillary tube. The second expansion device 71 is connected between the first bypass pipe 86 and the second bypass pipe 87 and reduces the pressure of the refrigerant flowing through the bypass flow path 111. As the refrigerant passes through the second expansion device 71, the pressure of the refrigerant decreases.

The heating device 72 changes the dryness of the refrigerant flowing through the second bypass pipe 87 under the same pressure. The temperature sensor 73 is provided downstream of the heating device 72 in the second bypass pipe 87. The temperature sensor 73 detects the temperature T1 of the refrigerant that has passed through the second expansion device 71, and outputs the detected value to the control device 100. The temperature sensor 73 may be installed outside the second bypass pipe 87, or may be installed inside the second bypass pipe 87 in order to more reliably detect the temperature of the refrigerant. The principle and method of refrigerant type detection using these will be described later in detail.

The first pressure sensor 90 detects the pressure LP of the refrigerant in the pipe 84 and outputs the detected value to the control device 100. That is, the first pressure sensor 90 detects the refrigerant pressure (low pressure side pressure) on the suction side of the compressor 10. The second pressure sensor 92 detects the pressure HP of the refrigerant in the pipe 80 and outputs the detected value to the control device 100. That is, the second pressure sensor 92 detects the refrigerant pressure (high pressure side pressure) on the discharge side of the compressor 10.

The control device 100 includes a CPU (Central Processing Unit) 102, a memory 104 (ROM (Read Only Memory) and RAM (Random Access Memory)), and an input / output buffer (not shown) for inputting and outputting various signals. It is comprised including. The CPU 102 executes a program stored in the ROM by expanding the program in the RAM or the like. 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 controls each device of the refrigeration cycle device 1 according to these programs. This control is not limited to processing by software, and processing by dedicated hardware (electronic circuit) is also possible.

The refrigeration cycle apparatus 1 is configured to be able to use two types of refrigerant as the enclosed refrigerant. One type is an azeotropic refrigerant or a pseudo-azeotropic refrigerant, for example, R410A. Another type is a non-azeotropic refrigerant, for example, R463A.

FIG. 2 is a ph diagram of the refrigeration cycle apparatus when R410A is used as the refrigerant. FIG. 3 is a ph diagram of the refrigeration cycle apparatus when R463A is used as the refrigerant. In the case of R410A, the isotherm in the two-phase state between the saturated liquid line and the saturated vapor line has no temperature gradient and is horizontal as shown in FIG. On the other hand, in the case of R410A, the isotherm in the two-phase state between the saturated liquid line and the saturated vapor line has a temperature gradient as shown in FIG. This is because in the case of R410A which is a pseudo-azeotropic refrigerant, the temperature does not change even if the degree of dryness changes in the two-phase state, but in the case of R463A which is a non-azeotropic refrigerant, the temperature increases when the degree of dryness increases in the two-phase state. Also show that it rises. Note that the dryness is 0 when the position of point B in FIGS. 2 and 3 is on the saturated liquid line, and 1 when it is on the saturated vapor line, and the position of point B between the saturated liquid line and the saturated vapor line. Depends on In FIGS. 2 and 3, when the state of the refrigerant changes rightward from B to C, the dryness increases.

In FIG. 1, the state of the refrigerant passing through the bypass flow path 111 changes from point A to point B in FIG. 2, and when heated by the heating device 72, changes while keeping the temperature constant as at point C. . When the heating device 72 is in the OFF state, the dryness at the point C in FIG. 1 is the same as the dryness at the point B. Therefore, the temperature T1 detected by the temperature sensor 73 is the temperature in the refrigerant state at the point B in FIG. It is. Thereafter, when the heating device is turned on to heat the refrigerant, the dryness of the refrigerant flowing through the second bypass pipe 87 increases, and the temperature T1 detected by the temperature sensor 73 becomes the temperature in the refrigerant state at point C in FIG.

Therefore, when the refrigeration cycle device is installed and the test operation is being performed, the control device 100 is sealed by changing the heating device 72 from the OFF state to the ON state and detecting whether or not the temperature T1 has changed. R463A can be determined whether the refrigerant is R410A.

FIG. 4 is a diagram showing an example of a control value changed according to the type of refrigerant. As the refrigerant temperature decreases, the target pressures of R410A and R463A are lower, and the target pressure of R410A is 0.01 to 0 lower than the target pressure of R463A. .02 MPaA. The target value of the pressure to be controlled is changed as shown in FIG. 4 according to the target refrigerant temperature. To achieve such a target pressure, the control device 100 controls at least one of the operating frequency of the compressor 10, the opening degree of the first expansion device 50, the rotation speed of the first fan 22, and the rotation speed of the second fan 62. Control one. The target value of the pressure needs to be switched as shown in FIG. 4 depending on whether the sealed refrigerant is R410A or R463A. The control values shown in FIG. 4 are stored in the memory 104 in advance as a map for each type of refrigerant.

(4) When the control device 100 performs the test operation and determines the type of the enclosed refrigerant, the control device 100 selects a map corresponding to the refrigerant and applies it to various controls. For example, when it is desired to operate the evaporation temperature at −10 ° C. and the refrigerant is R410A, the compressor 10 and the like are controlled with the pressure at 0.57 MPaA as a target value. When the refrigerant is R463A, the compressor 10 and the like are controlled with a pressure of 0.59 MPaA as a target value.

FIG. 5 is a flowchart illustrating a main routine of control of the refrigeration cycle device according to the first embodiment. With reference to FIGS. 1 and 5, at the start of the operation of the refrigeration cycle apparatus 1, the control device 100 first determines whether or not the type of the enclosed refrigerant is stored in the memory 104 in step S1. If the type of refrigerant is not stored in the memory 104 in step S1, the refrigerant type determination operation of step S2 is performed. On the other hand, if the type of refrigerant is already stored in memory 104, the process proceeds to step S3 without performing step S2.

When the refrigerant type determination operation is performed in step S2, the refrigerant type is stored in the memory 104. Then, in step S3, the control device 100 operates the refrigeration cycle device using the control value corresponding to the refrigerant type stored in the memory 104.

FIG. 6 is a flowchart showing details of the processing of the refrigerant type determination operation executed in step S2 in the first embodiment. First, in step S11, the control device 100 performs a test operation of the refrigeration cycle device 1. The conditions for this test operation are such that the refrigerant that has passed through the second expansion device 71 in the bypass channel 111 is in a two-phase state, regardless of whether the enclosed refrigerant is R410A or R463A.

Then, in step S12, control device 100 measures temperature T1 by temperature sensor 73 when heating device 72 is in the OFF state, and stores the measurement result in memory 104 as first temperature T1A. Thereafter, in step S13, the control device 100 changes the heating device 72, specifically, the heater from the OFF state to the ON state. Then, in step S14, control device 100 measures temperature T1 again by temperature sensor 73, and stores the measurement result in memory 104 as second temperature T1B.

Then, in step S15, control device 100 determines whether or not change amount ΔT (= T1B−T1A) of temperature T1 generated before and after heating by heating device 72 is larger than a threshold value.

In step S15, when ΔT> threshold, that is, when the temperature of the two-phase refrigerant increases due to heating, it is determined that the refrigerant sealed in step S16 is R463A, which is a non-azeotropic refrigerant, The control device 100 causes the memory 104 to store the refrigerant type. On the other hand, if ΔT ≦ the threshold value in step S15, that is, if the temperature of the two-phase refrigerant does not increase even when heated, the refrigerant sealed in step S17 is R410A, which is a pseudo-azeotropic refrigerant. Then, the control device 100 causes the memory 104 to store the refrigerant type.

In step S16 or S17, after the refrigerant type is stored in the memory 104, the process proceeds to step S18, and returns to the flowchart in FIG.

The first embodiment will be summarized again with reference to FIG. The refrigeration cycle apparatus 1 includes a compressor 10, a condenser 20, which is a first heat exchanger, a first expansion device 50, an evaporator 60, which is a second heat exchanger, a refrigerant circuit 110, and a bypass flow passage. 111, a dryness changing device 112, a temperature detecting unit 113, and a control device 100. The refrigerant circuit 110 circulates refrigerant in the order of the compressor 10, the first heat exchanger, the first expansion device 50, and the second heat exchanger. The bypass flow path 111 sends the refrigerant from the first heat exchanger to the suction port of the compressor 10 without passing through the first expansion device 50 and the second heat exchanger. The dryness changing device 112 is configured to change the dryness of the refrigerant flowing through the bypass passage 111. The temperature detector 113 is configured to detect a temperature change before and after the dryness is changed by the dryness changing device 112. The control device 100 controls the dryness changing device 112. The control device 100 specifies the type of the refrigerant based on the temperature change detected by the temperature detection unit 113.

Preferably, as shown in FIG. 1, the bypass flow path 111 includes a second expansion device 71, a first bypass pipe 86 located upstream of the second expansion device 71 in the refrigerant passage direction, and a refrigerant passage direction. And a second bypass pipe 87 located downstream of the second expansion device 71. The dryness changing device 112 includes a heating device 72 that heats the refrigerant flowing through the second bypass pipe 87. The temperature detection unit 113 includes a temperature sensor 73 that detects the temperature of the refrigerant downstream of the heating device 72 in the second bypass pipe 87. As shown in FIG. 6, the control device 100 controls the first temperature T1A detected by the temperature detection unit 113 when the heating by the heating device 72 is performed, and the temperature detection when the heating by the heating device 72 is not performed. The type of the refrigerant is specified based on the second temperature T1B detected by the unit 113.

As described above, in the refrigeration cycle apparatus 1 according to Embodiment 1, the enclosed refrigerant is determined to be “a pseudo-azeotropic refrigerant or a refrigerant based on whether or not the temperature T1 changes before and after heating by the heating device 72. It is configured to determine whether the refrigerant is a “single refrigerant” or a “non-azeotropic refrigerant”, and operate with a control value according to the refrigerant type stored in the memory 104 in advance. When the temperature change detected by temperature detecting section 113 is smaller than the threshold, control device 100 determines that the refrigerant is “pseudo-azeotropic refrigerant or single refrigerant”, and the temperature change is smaller than the threshold. When it is larger, it is determined that the refrigerant is a “non-azeotropic refrigerant”. In this way, the refrigeration cycle apparatus 1 can perform an operation suitable for the automatically charged refrigerant.

In the flowchart of FIG. 6, the temperature change of the refrigerant when the heating device 72 is changed from the OFF state to the ON state is monitored, but the temperature of the refrigerant when the heating device 72 is changed from the ON state to the OFF state is monitored. Changes may be monitored.

Embodiment 2 FIG.
In the first embodiment, attention is paid to a change in the temperature T1 measured by the temperature sensor 73 when heating is not performed by the heating device 72 and when heating is performed. In the second embodiment, when another heating is performed by the heating device 72 to add another temperature sensor, a temperature difference before and after passing through the heating device 72 is detected.

FIG. 7 is a diagram illustrating a configuration of a refrigeration cycle apparatus according to Embodiment 2. In FIG. 1, the connection relation and arrangement of each device in the refrigeration apparatus are shown functionally, and the arrangement in a physical space is not necessarily shown.

冷凍 The refrigeration cycle apparatus 1A shown in FIG. 7 includes an outdoor unit 2A and an indoor unit 3. In the outdoor unit 2A, a temperature sensor 74 and a receiver (liquid receiver) 42 are added to the outdoor unit 2 of the refrigeration cycle apparatus 1A shown in FIG. The configuration of the other units of outdoor unit 2A is the same as that of outdoor unit 2, and therefore description thereof will not be repeated.

The receiver 42 is disposed at the branch point M1 in FIG. 1 and stores the refrigerant that has passed through the condenser 20. Since the outlet to the first bypass pipe 86 is provided at the bottom of the receiver 42, the liquid refrigerant is sent to the first bypass pipe 86.

The temperature sensor 74 detects the temperature T2 when the liquid refrigerant supplied from the first bypass pipe 86 passes through the second expansion device 71 and becomes a two-phase refrigerant.

In the second embodiment as well, the control of the flowchart shown in FIG. 5 is performed, but the process of the refrigerant type determination operation performed in step S2 is slightly different.

FIG. 8 is a flowchart illustrating details of the processing of the refrigerant type determination operation performed in step S2 in the second embodiment. First, in step S21, the control device 100 performs a test operation of the refrigeration cycle device 1A. The conditions for this test operation are such that the refrigerant that has passed through the second expansion device 71 in the bypass flow passage 111 is in a two-phase state regardless of whether the refrigerant is R410A or R463A.

Then, in step S22, control device 100 turns on heating device 72. In step S23, the temperature T1 is measured by the temperature sensor 73 and the temperature T2 is measured by the temperature sensor 74.

Then, in step S24, control device 100 determines whether or not the amount of change in temperature (T1-T2) before and after heating by heating device 72 is greater than a threshold value.

If T1-T2> threshold, that is, if the temperature of the two-phase refrigerant has increased due to heating (YES in step S24), control device 100 determines that the refrigerant enclosed in step S25 is a non-azeotropic refrigerant. It is determined that there is a certain R463A, and the type of the refrigerant is stored in the memory 104. On the other hand, when T1−T2 ≦ threshold, that is, when the temperature of the two-phase refrigerant does not increase even when heated (NO in step S24), control device 100 determines whether the refrigerant sealed in step S26 is It is determined that the refrigerant is the pseudo azeotropic refrigerant R410A, and the type of the refrigerant is stored in the memory 104.

In step S25 or S26, after the refrigerant type is stored in the memory 104, the process proceeds to step S27, and returns to the flowchart of FIG.

The second embodiment will be summarized again with reference to FIG. The refrigeration cycle apparatus 1A includes a compressor 10, a condenser 20, which is a first heat exchanger, a first expansion device 50, an evaporator 60, which is a second heat exchanger, a refrigerant circuit 110, and a bypass flow path. 111, a dryness changing device 112, a temperature detecting unit 113A, and a control device 100. The refrigerant circuit 110 circulates refrigerant in the order of the compressor 10, the first heat exchanger, the first expansion device 50, and the second heat exchanger. The bypass flow path 111 sends the refrigerant from the first heat exchanger to the suction port of the compressor 10 without passing through the first expansion device 50 and the second heat exchanger. The dryness changing device 112 is configured to change the dryness of the refrigerant flowing through the bypass passage 111. The temperature detecting unit 113A is configured to detect a temperature change before and after the dryness is changed by the dryness changing device 112. The control device 100 controls the dryness changing device 112. Control device 100 specifies the type of refrigerant based on the temperature change detected by temperature detection unit 113A.

Preferably, as shown in FIG. 7, the bypass flow path 111 includes a second expansion device 71, a first bypass pipe 86 located upstream of the second expansion device 71 in the refrigerant passage direction, and a refrigerant passage direction. And a second bypass pipe 87 located downstream of the second expansion device 71. The dryness changing device 112 includes a heating device 72 that heats the refrigerant flowing through the second bypass pipe 87. Temperature detector 113A includes a temperature sensor 73 as a first temperature sensor and a temperature sensor 74 as a second temperature sensor. The first temperature sensor detects a first temperature T1 after the refrigerant flowing in the second bypass pipe 87 has been heated by the heating device 72. The second temperature sensor detects a second temperature T2 before the refrigerant flowing through the second bypass pipe 87 reaches the heating device 72. As shown in FIG. 8, the control device 100 specifies the type of the refrigerant based on the first temperature T1 and the second temperature T2.

As described above, in the refrigeration cycle apparatus 1A according to the second embodiment, whether the temperature of the two-phase refrigerant changes between the temperature T2 before the heating by the heating device 72 and the temperature T1 after the heating is determined. It is determined whether the enclosed refrigerant is a “pseudo-azeotropic refrigerant or a single refrigerant” or a “non-azeotropic refrigerant”, and the operation is performed with a control value corresponding to the refrigerant type stored in the memory 104 in advance. Configured to do so. When the temperature change detected by temperature detecting section 113 is smaller than the threshold, control device 100 determines that the refrigerant is “pseudo-azeotropic refrigerant or single refrigerant”, and the temperature change is smaller than the threshold. When it is larger, it is determined that the refrigerant is a “non-azeotropic refrigerant”. In this manner, the refrigeration cycle apparatus 1A can perform an operation suitable for the automatically charged refrigerant.

In FIG. 7, the receiver 42 is provided, but the receiver 42 may not be necessarily provided as shown in FIG. Further, a receiver 42 may be added to FIG. 1 of the first embodiment.

Embodiment 3 FIG.
FIG. 9 is a diagram illustrating a configuration of a refrigeration cycle apparatus according to Embodiment 3. This refrigeration cycle apparatus is configured to be able to use a pseudo-azeotropic refrigerant and a non-azeotropic refrigerant mixture. In FIG. 9, the connection relation and the arrangement of each device in the refrigeration apparatus are functionally shown, and the arrangement in a physical space is not necessarily shown.

を Referring to FIG. 9, refrigeration cycle apparatus 1B includes outdoor unit 2B and indoor unit 3. The outdoor unit 2 includes a compressor 10, a condenser 20, a first fan 22, a receiver 42, and pipes 80 to 84. Further, the outdoor unit 2 further includes a bypass flow path 111, a second expansion device 71, a temperature sensor 73, a first pressure sensor 90 and a second pressure sensor 92, and a control device 100. The second expansion device 71 is, for example, a capillary tube. The indoor unit 3 includes a first expansion device 50, an evaporator 60, a second fan 62, and a pipe 83. The first expansion device 50 is, for example, an electronic expansion valve. The indoor unit 3 is connected to the outdoor unit 2 through

pipes

82 and 84. In the third embodiment, the dryness changing device 112 includes the receiver 42 and the first fan 22. Further, the temperature detecting section 113 is constituted by a temperature sensor 73.

The indoor unit 3 has the same configuration as the first and second embodiments. The outdoor unit 2B has the same configuration as that of the second embodiment except for the portion where the first bypass pipe 86 is attached to the receiver 42. Therefore, detailed description of the same configuration will not be repeated.

As a configuration for detecting the refrigerant type, a first bypass pipe 86 and a second bypass pipe 87, a second expansion device 71 provided between the first bypass pipe 86 and the second bypass pipe 87, and a temperature sensor 73 are provided. Provided. The first bypass pipe 86, the second expansion device 71, and the second bypass pipe 87 form a bypass flow path 111 that returns a part of the refrigerant that has passed through the condenser 20 to the compressor 10 without passing through the indoor unit 3. Constitute. The second expansion device 71 is, for example, a capillary tube. The second expansion device 71 is connected between the first bypass pipe 86 and the second bypass pipe 87, and adjusts the flow rate of the refrigerant flowing through the bypass flow path 111. As the refrigerant passes through the second expansion device 71, the pressure of the refrigerant decreases.

The temperature sensor 73 is provided in the second bypass pipe 87. The temperature sensor 73 detects the temperature T1 of the refrigerant that has passed through the second expansion device 71, and outputs the detected value to the control device 100. The temperature sensor 73 may be installed outside the second bypass pipe 87, or may be installed inside the second bypass pipe 87 in order to more reliably detect the temperature of the refrigerant.

In the third embodiment, the second bypass pipe is used by changing the rotation speed of the first fan 22 provided in the condenser 20 to change the temperature and density of the refrigerant inside the condenser 20. Change the dryness flowing through 87.

The receiver 42 stores the high-pressure liquid refrigerant condensed by the condenser 20. When the rotation speed of the first fan 22 is increased, the amount of heat exchange with the outside air in the condenser 20 increases, so that the temperature of the refrigerant decreases. Then, since the refrigerant density inside the condenser 20 decreases, the amount of surplus refrigerant in the refrigerant circuit increases, and the liquid level of the receiver 42 increases. Conversely, when the rotation speed of the first fan 22 is reduced, the refrigerant density in the condenser 20 increases, so that the mass of the liquid refrigerant in the condenser 20 increases. Then, the amount of surplus refrigerant in the refrigerant circuit decreases, and the liquid level of the receiver 42 drops.

In the third embodiment, the change in the liquid level of the receiver 42 is used to change the dryness of the refrigerant flowing through the second bypass pipe 87. In the third embodiment, the refrigerant inlet D of the first bypass pipe 86 is configured such that when the liquid level of the receiver 42 changes, the dryness of the sucked refrigerant changes. When the dryness of the refrigerant sucked from the receiver 42 into the first bypass pipe 86 changes, the dryness of the refrigerant flowing through the second bypass pipe 87 changes accordingly.

FIG. 10 is a diagram showing a first example configuration of the receiver and the suction end of the bypass pipe. Referring to FIG. 10, gas refrigerant and liquid refrigerant are stored in receiver 42. From the pipe 81, the refrigerant condensed in the condenser 20 flows. The liquid refrigerant flows out of the pipe 82 from the bottom of the receiver 42. The end opening of the pipe 82 is provided at a position lower than the end opening of the pipe 81 so that the liquid refrigerant preferentially flows out of the receiver 42 even when the refrigerant mixed with the gas flows in from the pipe 81. ing. The first bypass pipe 86 is inserted from above the receiver 42 toward the inside. The first bypass pipe 86 has a plurality of openings on the side surface inside the receiver 42. With such a configuration, the dryness of the refrigerant sucked into the first bypass pipe 86 changes depending on the liquid level of the refrigerant in the receiver 42.

However, it is preferable that the lower end of the first bypass pipe 86 be provided at a position higher than the pipe 82. In other words, considering the height based on the bottom surface of the receiver 42, the first bypass is used to detect a change in the liquid level at a position where the liquid level H1 of the liquid refrigerant is higher than the height Hout1 of the outlet pipe. The height Hout2 of the lower end of the pipe 86 is higher than Hout1.

FIG. 11 is a diagram showing a plurality of holes provided at the end of the bypass pipe of the first example. FIG. 12 is a graph showing the relationship between the dryness Q and the liquid level H1. As the liquid level increases, the holes are closed by the liquid refrigerant, so that the gas refrigerant is less likely to be sucked, and the dryness Q decreases. Conversely, as the liquid level becomes lower, the number of holes for sucking the gas refrigerant increases, so that the dryness Q increases. The relationship between the dryness Q and the liquid level H1 as shown in FIG. 12 can be obtained in advance and made into a map.

FIG. 13 is a ph diagram of the refrigeration cycle apparatus when R410A is used as the refrigerant in the third embodiment. FIG. 14 is a ph diagram of the refrigeration cycle apparatus when R463A is used as the refrigerant in the third embodiment. In the case of R410A, the isotherm in the two-phase state between the saturated liquid line and the saturated vapor line has no temperature gradient and is horizontal as shown in FIG. On the other hand, in the case of R410A, the isotherm in the two-phase state between the saturated liquid line and the saturated vapor line has a temperature gradient as shown in FIG. This is because in the case of R410A which is a pseudo-azeotropic refrigerant, the temperature does not change even if the degree of dryness changes in the two-phase state, but in the case of R463A which is a non-azeotropic refrigerant, the temperature increases when the degree of dryness increases in the two-phase state. Also show that it rises.

状態 The state of the refrigerant passing through the second expansion device 71 in the bypass flow path 111 shown in FIG. 9 changes from point A to point B in FIGS. At this time, if the rotation speed of the first fan 22 is reduced, the refrigeration cycle changes from the cycle indicated by R1 to the cycle indicated by R2. At the same time, the temperature rises in the condenser 20 and the density of the refrigerant increases. For this reason, the refrigerant is further required in the condenser 20, so that the liquid refrigerant in the receiver 42 moves to the condenser 20, the amount of the liquid refrigerant in the receiver 42 decreases, and the liquid level of the receiver 42 decreases. Then, the dryness of the refrigerant flowing through the bypass flow passage 111 increases, and the state of the refrigerant passing through the second expansion device 71 changes from point A ′ to point B ′ in FIGS. 13 and 14. Therefore, when the rotation speed of the first fan 22 is reduced, the state of the refrigerant changes from the point B to the point B ′. However, in the case of the non-azeotropic refrigerant, the temperature T1 increases while the azeotropic refrigerant or the pseudo azeotropic refrigerant In the case of a boiling refrigerant, the temperature T1 does not change.

In the third embodiment as well, the control of the flowchart shown in FIG. 5 is performed, but the process of the refrigerant type determination operation performed in step S2 is slightly different.

FIG. 15 is a flowchart showing details of the processing of the refrigerant type determination operation executed in step S2 in the third embodiment. First, in step S31, the control device 100 performs a test operation of the refrigeration cycle device 1B. The conditions for this test operation are such that the refrigerant that has passed through the second expansion device 71 in the bypass flow passage 111 is in a two-phase state regardless of whether the refrigerant is R410A or R463A. Subsequently, in step S32, the control device 100 measures the temperature T1 with the temperature sensor 73, and stores the measurement result in the memory 104 as the first temperature T1A.

Then, in step S33, control device 100 changes the rotation speed of first fan 22 of condenser 20 from high speed (first rotation speed F1) to low speed (second rotation speed F2). Then, the temperature of the refrigerant in the condenser 20 increases, so that the refrigerant density increases and the required amount of the liquid refrigerant in the condenser 20 increases. Then, since the amount of surplus refrigerant in the receiver 42 decreases, the liquid level of the receiver 42 falls. Along with this, the dryness of the refrigerant in the bypass channel 111 increases.

Then, in step S34, control device 100 measures temperature T1 again by temperature sensor 73, and stores the measurement result in memory 104 as second temperature T1B.

Then, in step S35, control device 100 determines whether or not change amount ΔT (= T1B−T1A) of temperature T1 generated before and after changing the rotation speed of first fan 22 is larger than the threshold value. .

If ΔT> threshold in step S35, that is, if the temperature of the two-phase refrigerant has increased, it is determined that the refrigerant sealed in step S36 is R463A, and the control device 100 The type of the refrigerant is stored. On the other hand, if ΔT ≦ threshold in step S35, that is, if the temperature of the two-phase refrigerant does not change, it is determined that the refrigerant sealed in step S37 is R410A, and the control device 100 Stores the type of refrigerant.

{Circle around (5)} In step S36 or S37, after the refrigerant type is stored in the memory 104, the process proceeds to step S38, and returns to the flowchart of FIG.

Therefore, when the refrigeration cycle device is installed and the test operation is being performed, the control device 100 changes the rotation speed of the first fan 22 and detects whether or not the temperature T1 has changed. R463A can be determined whether it is R410A.

FIG. 16 is a diagram showing a configuration of a second example of the suction end of the bypass pipe. As shown in FIG. 16, a slit whose height direction is the longitudinal direction may be provided on the side surface of the end of the first bypass pipe 86.

FIG. 17 is a diagram showing a configuration of a third example of the suction end of the bypass pipe. As shown in FIG. 17, a plurality of pipes having different suction ports may be provided.

FIG. 18 is a diagram showing a configuration of a fourth example of the suction end of the bypass pipe. In the fourth example, the end of the first bypass pipe 86 is inserted into the receiver 42 from below. FIG. 19 is a diagram showing details of a hole provided at the suction end of the bypass pipe of the fourth example. In the fourth example, as in the first example, as shown in FIG. 19, a plurality of openings D1 to D5 are provided at the end of the first bypass pipe 86. The openings D1 to D5 are arranged at equal intervals L along the flow direction in which the refrigerant is sucked. The opening D1 is provided on the tip side (upper), and the opening D5 is provided on the lower side away from the tip.

In addition, as for the configuration in which the first bypass pipe 86 is inserted from below the receiver 42 as shown in the fourth example, a slit may be provided on the side surface as in the second example, or a plurality of suction holes may be provided as in the third example. Branch pipes having different mouth heights may be provided.

The third embodiment will be summarized again with reference to FIG. The refrigeration cycle apparatus 1B includes a compressor 10, a condenser 20, which is a first heat exchanger, a first expansion device 50, an evaporator 60, which is a second heat exchanger, a refrigerant circuit 110, and a bypass flow path. 111, a dryness changing device 112B, a temperature detecting unit 113, and a control device 100. The refrigerant circuit 110 circulates refrigerant in the order of the compressor 10, the first heat exchanger, the first expansion device 50, and the second heat exchanger. The bypass flow path 111 sends the refrigerant from the first heat exchanger to the suction port of the compressor 10 without passing through the first expansion device 50 and the second heat exchanger. The dryness changing device 112B is configured to change the dryness of the refrigerant flowing in the bypass flow path 111. The temperature detector 113 is configured to detect a temperature change before and after the dryness is changed by the dryness changing device 112B. The control device 100 controls the dryness changing device 112B. The control device 100 specifies the type of the refrigerant based on the temperature change detected by the temperature detection unit 113.

Preferably, as shown in FIG. 9, in the refrigerant circuit 110, the dryness changing device 112B includes a receiver 42 disposed between the condenser 20 as the first heat exchanger and the first expansion device 50; A first fan for sending air to the first heat exchanger; The bypass flow path 111 includes a second expansion device 71, a first bypass pipe 86, and a second bypass pipe 87. The first bypass pipe 86 is located upstream of the second expansion device 71 in the direction in which the refrigerant passes, and connects the receiver 42 and the second expansion device 71. The second bypass pipe 87 is located downstream of the second expansion device 71 in the refrigerant passage direction. A refrigerant inlet D is provided at an end of the first bypass pipe 86 inserted into the receiver 42. The refrigerant inlet D is configured such that when the liquid level height H1 of the receiver changes, the opening area for sucking the gaseous refrigerant changes. The temperature detector 113 detects the temperature T1 of the refrigerant flowing through the second bypass pipe 87. As illustrated in FIG. 15, the control device 100 determines whether the first fan 22 has a first temperature T1A detected by the temperature detection unit 113 when the first fan 22 is at the first rotation speed F1 or not. The type of the refrigerant is specified based on the second temperature T1B detected by the temperature detection unit 113 when the second rotation speed F2 is low.

The refrigerant inlet D is configured such that, when the liquid level of the receiver 42 changes, the opening area changes in a range from zero to a cross-sectional area of the first bypass pipe 86.

Preferably, as shown in FIGS. 10, 11, 17, 18, and 19, the end of the first bypass pipe 86 inserted into the receiver 42 has a liquid level of the receiver 42 as a refrigerant inlet D. A plurality of openings D1 to D5 provided at positions different from each other in the direction of change in height are provided.

Preferably, as shown in FIG. 16, the end of the first bypass pipe 86 inserted into the receiver 42 has, as a refrigerant inlet D, a slit S in which the direction of change in the liquid level of the receiver 42 is the longitudinal direction. Is provided.

As described above, in the refrigeration cycle apparatus 1B of the third embodiment, the refrigerant is sealed depending on whether or not the temperature T1 of the two-phase refrigerant changes before and after changing the rotation speed of the first fan 22. It is configured to determine whether the refrigerant is a “pseudo-azeotropic refrigerant or a single refrigerant” or a “non-azeotropic refrigerant”, and to operate with a control value corresponding to the refrigerant type stored in the memory 104 in advance. You. When the temperature change detected by temperature detecting section 113 is smaller than the threshold, control device 100 determines that the refrigerant is “pseudo-azeotropic refrigerant or single refrigerant”, and the temperature change is smaller than the threshold. When it is larger, it is determined that the refrigerant is a “non-azeotropic refrigerant”. In this manner, the refrigeration cycle apparatus 1B can perform an operation suitable for the automatically charged refrigerant.

実施 The embodiments disclosed this time are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description of the embodiments, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1, 1A, 1B refrigeration cycle device, 2, 2A, 2B outdoor unit, 3 indoor unit, 10 compressor, 20 condenser, 22 first fan, 62 second fan, 42 receiver, 50 first expansion device, 60 evaporation Vessel, 71 second expansion device, 72 heating device, 73, 74 temperature sensor, 80, 81, 82, 83, 84 piping, 86 first bypass piping, 87 second bypass piping, 90 first pressure sensor, 92 second Pressure sensor, 100 control device, 104 memory, 110 refrigerant circuit, 111 flow path, 112, 112B dryness change device, 113, 113A temperature detector, D refrigerant inlet, D1-D5 opening, M1 branch point, S slit.

Claims

A refrigeration cycle device,
A compressor,
A first heat exchanger;
A first inflation device;
A second heat exchanger;
A refrigerant circuit that circulates refrigerant in the order of the compressor, the first heat exchanger, the first expansion device, and the second heat exchanger;
A bypass passage for sending the refrigerant from the first heat exchanger to the suction port of the compressor without passing through the first expansion device and the second heat exchanger;
A dryness changing device configured to change the dryness of the refrigerant flowing in the bypass flow path,
A temperature detector configured to detect a change in the temperature of the refrigerant before and after the dryness is changed by the dryness changing device,
A control device for controlling the dryness changing device,
The refrigeration cycle device, wherein the control device specifies the type of the refrigerant based on the temperature change detected by the temperature detection unit.
A refrigeration cycle device,
A compressor,
A first heat exchanger;
A first inflation device;
A second heat exchanger;
A refrigerant circuit that circulates refrigerant in the order of the compressor, the first heat exchanger, the first expansion device, and the second heat exchanger;
A bypass passage for sending the refrigerant from the first heat exchanger to the suction port of the compressor without passing through the first expansion device and the second heat exchanger;
A dryness changing device configured to change the dryness of the refrigerant flowing in the bypass flow path,
A temperature detector configured to detect a change in the temperature of the refrigerant before and after the dryness is changed by the dryness changing device,
A control device for controlling the dryness changing device,
The refrigeration cycle device, wherein the control device changes a target pressure based on the temperature change detected by the temperature detection unit.
A first fan for supplying air to the first heat exchanger;
A second fan for supplying air to the second heat exchanger,
The control device changes the target pressure by changing at least one of a frequency of the compressor, an opening degree of the first expansion device, a rotation speed of the first fan, and a rotation speed of a second fan. Item 3. A refrigeration cycle apparatus according to item 2.
The bypass passage,
A second inflation device;
A first bypass pipe located upstream of the second expansion device in a direction in which the refrigerant passes;
A second bypass pipe located downstream of the second expansion device in a direction in which the refrigerant passes.
The dryness changing device,
A heating device for heating the refrigerant flowing through the second bypass pipe,
The temperature detection unit detects the temperature of the refrigerant downstream of the heating device of the second bypass pipe,
The control device is configured to control a first temperature detected by the temperature detection unit when heating by the heating device is performed, and a second temperature detected by the temperature detection unit when heating by the heating device is not performed. The refrigeration cycle apparatus according to claim 1, wherein the type of the refrigerant is specified based on the temperature.
The bypass passage,
A second inflation device;
A first bypass pipe located upstream of the second expansion device in a direction in which the refrigerant passes;
A second bypass pipe located downstream of the second expansion device in a direction in which the refrigerant passes.
The dryness changing device,
A heating device for heating the refrigerant flowing through the second bypass pipe,
The temperature detector,
A first temperature sensor;
A second temperature sensor;
The first temperature sensor detects a first temperature after the refrigerant flowing in the second bypass pipe is heated by the heating device,
The second temperature sensor detects a second temperature before the refrigerant flowing through the second bypass pipe reaches the heating device,
The refrigeration cycle device according to claim 1, wherein the control device specifies the type of the refrigerant based on the first temperature and the second temperature.
The dryness changing device,
In the refrigerant circuit, a receiver disposed between the first heat exchanger and the first expansion device,
A fan that blows air to the first heat exchanger,
The bypass passage,
A second inflation device;
A first bypass pipe that is located upstream of the second expansion device and that connects the receiver and the second expansion device in the direction in which the refrigerant passes;
A second bypass pipe located downstream of the second expansion device in a direction in which the refrigerant passes.
A refrigerant inlet is provided at an end of the first bypass pipe inserted into the receiver,
The refrigerant inlet is configured such that, when the liquid level of the receiver changes, an opening area for sucking the refrigerant in a gas state changes,
The temperature detector detects a temperature of the refrigerant flowing through the second bypass pipe,
The control device may further include: a first temperature detected by the temperature detection unit when the fan is at a first rotation speed; and a temperature detection when the fan is at a second rotation speed higher than the first rotation speed. The refrigeration cycle apparatus according to claim 1, wherein the type of the refrigerant is specified based on the second temperature detected by the unit.
The refrigeration cycle according to claim 6, wherein the refrigerant inlet is configured such that, when the liquid level of the receiver changes, the opening area changes in a range from zero to a cross-sectional area of the first bypass pipe. apparatus.
8. A plurality of openings provided at positions different from each other in a direction in which the liquid level of the receiver changes in a direction in which the liquid level of the receiver changes, the end of the first bypass pipe inserted into the receiver being provided at the end of the first bypass pipe. 9. A refrigeration cycle apparatus according to item 1.
The refrigeration according to claim 7, wherein a slit having a longitudinal direction in which the liquid level of the receiver changes in a longitudinal direction is provided as an inlet of the refrigerant at an end of the first bypass pipe inserted into the receiver. Cycle equipment.
When the temperature change detected by the temperature detection unit is smaller than a threshold value, the control device determines that the refrigerant is a pseudo-azeotropic refrigerant or a single refrigerant, and determines that the temperature change is equal to the threshold value. The refrigeration cycle apparatus according to any one of claims 1 to 9, wherein when it is larger than the refrigeration cycle, it is determined that the refrigerant is a non-azeotropic refrigerant.