JP2005221231A - Refrigerating device and deterioration determination method of refrigerating machine oil - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating device capable of determining the deterioration degree of a refrigerating machine oil with a simple constitution, and keeping long-period reliability. <P>SOLUTION: This device is equipped with an oil deterioration determination device 31 disposed between a four-way selector valve 2 and a gas shut-off valve 24. Since a gas coolant including much refrigerating machine oil is discharged from a compressor 1 at the heating operation time, the deterioration degree of the oil can be determined easily. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a refrigeration apparatus and a method for determining deterioration of refrigeration oil.

  In a heat pump type refrigeration system using a refrigerant, an HCFC refrigerant having a large ozone depletion coefficient has been subject to Freon regulation, and therefore, an HFC refrigerant having an ozone depletion coefficient of zero is used as an alternative refrigerant. . In this refrigeration system using an HFC refrigerant, mutual solubility between the refrigeration oil and the HFC refrigerant is one of the important characteristics, and therefore synthetic oils such as ether oil and ester oil are used as the refrigeration oil (for example, Patent Documents). 1).

However, since the synthetic oil has a strong polarity and thus easily dissolves residual impurities other than refrigeration oil and refrigerant, clogging or initial failure due to sludge after the refrigerant evaporates occurs in the decompression mechanism constituted by the electric expansion valve. Thus, there is a problem that the refrigeration cycle is abnormal and reliability is lowered.
JP-A-8-110101

  Accordingly, an object of the present invention is to provide a refrigerating apparatus and a method for determining deterioration of refrigerating machine oil that can determine the degree of deterioration of refrigerating machine oil with a simple configuration, prevent clogging of the decompression mechanism, and maintain long-term reliability. There is to do.

  In order to achieve the above object, the refrigeration apparatus of the present invention is disposed between the discharge side of the compressor and the gas shut-off valve or between the four-way switching valve and the gas shut-off valve to reduce the degree of deterioration of the refrigeration oil. An oil deterioration judging device is provided for judging the degree of deterioration of the refrigerating machine oil based on at least one of oil color, moisture content, degree of oxidation or air content.

  According to the refrigeration apparatus having the above configuration, the oil deterioration determination device is attached between the discharge side of the compressor and the gas shut-off valve or between the four-way switching valve and the gas shut-off valve (gas side pipe during heating operation). Thus, since the gas refrigerant containing a large amount of refrigeration oil is discharged from the compressor to the gas side pipe, the degree of oil deterioration can be easily determined. Therefore, the degree of deterioration of the refrigerating machine oil can be determined with a simple configuration, and the clogging of the decompression mechanism is prevented by replacing the working medium (refrigerant including refrigerating machine oil) as necessary based on the determination result. Can keep long-term reliability.

  The refrigerating apparatus according to the present invention is disposed in the gas side connecting pipe, and the degree of deterioration of the refrigerating machine oil is determined based on at least one of the color, moisture content, degree of oxidation, or air content of the refrigerating machine oil. An oil deterioration determination device for determining the degree of deterioration is provided.

  According to the refrigeration apparatus of the above embodiment, in the split type having the outdoor unit and the indoor unit, the oil deterioration determination device is attached to the gas side communication pipe during heating operation among the connection pipes connecting the outdoor unit and the indoor unit. Thus, since the gas refrigerant containing a large amount of refrigeration oil is discharged from the compressor to the gas side communication pipe, the degree of oil deterioration can be easily determined. Therefore, the degree of deterioration of the refrigerating machine oil can be determined with a simple configuration, and long-term reliability can be maintained by replacing the working medium (refrigerant including refrigerating machine oil) as necessary based on the determination result. In addition, the present invention can be applied with a simple configuration without changing the design of the outdoor and indoor units, and in existing air conditioners, the communication pipe can be replaced with a communication pipe with an oil deterioration determination device. The invention can be easily applied.

  Moreover, the refrigeration apparatus of one embodiment is characterized by using an HFC-based refrigerant.

  According to the refrigerating apparatus of the above embodiment, synthetic oils such as ether oils and ester oils used as refrigerating machine oils having mutual solubility with HFC refrigerants are strong in polarity, so that it is easy to dissolve residual impurities other than refrigerating machine oils and refrigerants. The pressure reducing mechanism composed of an electric expansion valve is prone to clogging or initial failure due to sludge, etc., but the degree of deterioration of the refrigerating machine oil is discovered early using the above oil deterioration judgment device, before a malfunction occurs Measures such as replacement of refrigerant containing refrigeration oil can be performed.

  Further, the refrigeration apparatus of one embodiment is characterized in that R32 refrigerant or a mixed refrigerant containing at least 70% by weight of R32 is used.

  According to the refrigeration apparatus of the above embodiment, synthetic oils such as ether oils and ester oils used as refrigerating machine oils having mutual solubility with R32 refrigerant or a mixed refrigerant containing at least 70% by weight of R32 are strong in polarity. It is easy to dissolve residual impurities other than refrigerating machine oil and refrigerant, and the decompression mechanism composed of an electric expansion valve is likely to be clogged with sludge etc. and initial failure. It can be discovered early and measures such as replacement of refrigerant including refrigeration oil can be performed before a failure occurs.

  Moreover, the refrigeration apparatus of one embodiment is characterized in that, in any one of the above refrigeration apparatuses, a simple determination unit is provided in the oil deterioration determination apparatus.

  According to the refrigeration apparatus of the above embodiment, for example, a chemical substance that changes color in response to moisture is applied to the oil degradation determination apparatus, and the color of the chemical substance is compared to determine the degree of moisture content. By providing the simple determination unit, it is possible to easily determine the degree of oil degradation.

  Further, the deterioration judgment method for refrigerating machine oil according to the present invention is a method for determining the degree of deterioration of refrigerating machine oil between the discharge side of the compressor and the gas shut-off valve or between the four-way switching valve and the gas shut-off valve, An oil deterioration determination device for determining based on at least one of the moisture content, the degree of oxidation, or the air content is provided, and deterioration of the refrigerating machine oil is determined.

  According to the method for judging deterioration of refrigeration oil having the above configuration, oil deterioration is judged between the discharge side of the compressor and the gas shut-off valve or between the four-way switching valve and the gas shut-off valve (gas side pipe during heating operation). By attaching the apparatus, gas refrigerant containing a large amount of refrigeration oil is discharged from the compressor into the gas side pipe, so that the degree of oil deterioration can be easily determined. Therefore, the degree of deterioration of the refrigerating machine oil can be determined with a simple configuration, and the clogging of the decompression mechanism is prevented by replacing the working medium (refrigerant including refrigerating machine oil) as necessary based on the determination result. Can keep long-term reliability.

  The deterioration determination method for refrigerating machine oil according to the present invention is an oil deterioration determination device for determining the degree of deterioration of refrigerating machine oil based on at least one of the color, moisture content, degree of oxidation or air content of the oil. Is provided in the gas side communication pipe to determine the deterioration of the refrigerating machine oil.

  According to the method for determining deterioration of refrigerating machine oil according to the above embodiment, in the split type having an outdoor unit and an indoor unit, an oil deterioration determination device is provided for the gas side connection pipe during heating operation among the connection pipes connecting the outdoor unit and the indoor unit. Since a gas refrigerant containing a large amount of refrigerating machine oil is discharged from the compressor to the gas side connecting pipe, it becomes possible to easily determine the degree of oil deterioration. Therefore, the degree of deterioration of the refrigerating machine oil can be determined with a simple configuration, and long-term reliability can be maintained by replacing the working medium (refrigerant including refrigerating machine oil) as necessary based on the determination result. In addition, the present invention can be applied with a simple configuration without changing the design of the outdoor and indoor units, and in existing air conditioners, the communication pipe can be replaced with a communication pipe with an oil deterioration determination device. The invention can be easily applied.

  In addition, the method for determining deterioration of refrigerating machine oil according to one embodiment is characterized in that an HFC-based refrigerant is used.

  According to the method for judging deterioration of refrigerating machine oil according to the above embodiment, since synthetic oils such as ether oil and ester oil used as refrigerating machine oil having mutual solubility with HFC refrigerant are strong in polarity, residual oil other than refrigerating machine oil and refrigerant remains. It is easy to dissolve impurities, and the pressure reducing mechanism composed of an electric expansion valve is likely to be clogged with sludge, etc., or to cause initial failure. Before the occurrence, it is possible to take measures such as replacing the refrigerant containing the refrigeration oil.

  In addition, the method for determining deterioration of refrigerating machine oil according to an embodiment is characterized in that R32 refrigerant or a mixed refrigerant containing at least 70% by weight of R32 is used.

  According to the method for judging deterioration of refrigerating machine oil of the above embodiment, synthetic oil such as ether oil and ester oil used as refrigerating machine oil having mutual solubility with R32 refrigerant or a mixed refrigerant containing at least 70% by weight of R32, Due to its strong polarity, it is easy to dissolve residual impurities other than refrigeration oil and refrigerant. It is possible to detect the degree of deterioration at an early stage, and to take measures such as replacement of a refrigerant containing refrigeration oil before a failure occurs.

  As is clear from the above, the refrigeration apparatus of the present invention is disposed between the discharge side of the compressor and the gas shut-off valve or between the four-way switching valve and the gas shut-off valve to reduce the degree of deterioration of the refrigeration oil. An oil deterioration judging device is provided for judging the degree of deterioration of the refrigerating machine oil based on at least one of oil color, moisture content, degree of oxidation or air content.

  Therefore, according to the refrigeration apparatus having the above configuration, between the discharge side of the compressor provided with the oil deterioration determination device and the gas shut-off valve (or between the four-way switching valve and the gas shut-off valve), the refrigeration oil Since the gas refrigerant containing a large amount of gas is discharged from the compressor, the degree of deterioration of the refrigeration oil can be determined with a simple configuration, and the working medium (refrigerant including refrigeration oil) can be replaced as necessary based on the determination result. Therefore, long-term reliability can be maintained.

  The refrigerating apparatus according to the present invention is disposed in the gas side connecting pipe, and the degree of deterioration of the refrigerating machine oil is determined based on at least one of the color, moisture content, degree of oxidation, or air content of the refrigerating machine oil. An oil deterioration determination device for determining the degree of deterioration is provided.

  Therefore, according to the refrigeration apparatus configured as described above, the gas side connection pipe during heating operation among the connection pipes connecting the outdoor unit and the indoor unit, and the gas side connection pipe provided with the oil deterioration determination device is Since the gas refrigerant containing a large amount of refrigerating machine oil is discharged from the compressor, the degree of deterioration of the refrigerating machine oil can be determined with a simple configuration, and the working medium (refrigerant including refrigerating machine oil) can be selected as necessary based on the determination result. Long-term reliability can be maintained by replacement. In addition, the present invention can be applied with a simple configuration without changing the design of the outdoor and indoor units, and in existing air conditioners, the communication pipe can be replaced with a communication pipe with an oil deterioration determination device. The invention can be easily applied.

  Also, according to the refrigeration apparatus of one embodiment, even if the decompression mechanism uses an HFC-based refrigerant that is likely to be clogged with sludge, etc., the degree of deterioration of the refrigeration oil can be detected early using the above oil deterioration determination device, causing a problem. Before the occurrence of this, it is possible to take measures such as replacing the refrigerant containing the refrigerator oil.

  In addition, the refrigeration apparatus of one embodiment uses the oil deterioration determination device to determine the degree of deterioration of refrigeration oil even when an R32 refrigerant or a mixed refrigerant containing at least 70 wt% or more of R32 is used in which the decompression mechanism is easily clogged with sludge or the like. Can be detected at an early stage, and measures such as replacement of the refrigerant containing the refrigerating machine oil can be performed before the trouble occurs.

  Moreover, the refrigeration apparatus of one embodiment can easily determine the degree of oil deterioration because any one of the refrigeration apparatuses includes a simple determination unit in the oil deterioration determination apparatus.

  Further, the deterioration judgment method for refrigerating machine oil according to the present invention is a method for determining the degree of deterioration of refrigerating machine oil between the discharge side of the compressor and the gas shut-off valve or between the four-way switching valve and the gas shut-off valve, An oil deterioration determination device for determining based on at least one of the moisture content, the degree of oxidation, or the air content is provided to determine the deterioration of the refrigerating machine oil.

  Therefore, according to the refrigeration oil deterioration determination method having the above-described configuration, between the discharge side of the compressor provided with the oil deterioration determination device and the gas shutoff valve (or between the four-way switching valve and the gas shutoff valve). Then, since the gas refrigerant containing a large amount of refrigerating machine oil is discharged from the compressor, the degree of deterioration of the refrigerating machine oil can be determined with a simple configuration, and the working medium (refrigerant including refrigerating machine oil) can be determined as necessary based on the determination result. Replacing can maintain long-term reliability.

  The deterioration determination method for refrigerating machine oil according to the present invention is an oil deterioration determination device for determining the degree of deterioration of refrigerating machine oil based on at least one of the color, moisture content, degree of oxidation or air content of the oil. Is provided in the gas side communication pipe to judge the deterioration of the refrigerating machine oil.

  Therefore, according to the refrigeration oil deterioration determination method having the above-described configuration, the gas-side connection pipe during heating operation of the outdoor unit and the connection pipe connecting the indoor units, the gas having the oil deterioration determination device disposed therein. In the side connection pipe, gas refrigerant containing a large amount of refrigeration oil is discharged from the compressor, so the degree of deterioration of the refrigeration oil can be judged with a simple configuration, and the working medium (refrigeration oil can be removed as needed) based on the judgment result. Long-term reliability can be maintained by exchanging the refrigerant. In addition, the present invention can be applied with a simple configuration without changing the design of the outdoor and indoor units, and in existing air conditioners, the communication pipe can be replaced with a communication pipe with an oil deterioration determination device. The invention can be easily applied.

  In addition, according to the method for determining deterioration of refrigerating machine oil according to an embodiment, even when an HFC refrigerant whose decompression mechanism is easily clogged with sludge or the like is used, the degree of deterioration of refrigerating machine oil can be detected early using the oil deterioration determining apparatus. Thus, measures such as replacement of the refrigerant containing the refrigerating machine oil can be performed before the trouble occurs.

  In addition, the method for determining deterioration of refrigerating machine oil according to one embodiment uses refrigerating machine oil using the above oil deterioration determining apparatus, even if the decompression mechanism uses R32 refrigerant that is easily clogged with sludge or the like, or a mixed refrigerant that contains at least 70% by weight of R32. It is possible to detect the degree of deterioration at an early stage and take measures such as replacing the refrigerant containing the refrigeration oil before the trouble occurs.

  Hereinafter, the refrigeration apparatus and the method for determining deterioration of refrigeration oil according to the present invention will be described in detail with reference to the illustrated embodiments.

(First embodiment)
FIG. 1 is a circuit diagram showing a schematic configuration of a heat pump type air conditioner as a refrigeration apparatus according to a first embodiment of the present invention. 1 is a compressor, 2 is one end connected to the discharge side of the compressor 1. The four-way switching valve 3 is an outdoor heat exchanger having one end connected to the other end of the four-way switching valve 2, and 4 is an electric expansion valve having one end connected to the other end of the outdoor heat exchanger 3. Is an indoor heat exchanger having one end connected to the other end of the electric expansion valve 4, and 6 is connected to the other end of the indoor heat exchanger 5 via a four-way switching valve 2, and the other end is a compressor. 1 is an accumulator connected to the suction side of 1.

  The air conditioner includes a temperature sensor 11 that detects a discharge pipe temperature of the compressor 1, a temperature sensor 12 that detects a refrigerant temperature of the outdoor heat exchanger 3, a temperature sensor 13 that detects an outdoor air temperature, From the temperature sensor 14 that detects the refrigerant temperature of the heat exchanger 5, the temperature sensor 15 that detects the indoor temperature, the temperature sensor 16 that detects the refrigerant temperature on the suction side of the compressor 1, and the temperature sensors 11 to 16. And a control device 7 for controlling the compressor 1, the electric expansion valve 4 and the like. In addition, a closing valve 21 is disposed between the electric expansion valve 4 and the indoor heat exchanger 5, and a closing valve 24 is disposed between the indoor heat exchanger 5 and the four-way switching valve 2. . An oil deterioration determining device 31 is disposed between the four-way switching valve 2 and the closing valve 24 that is on the gas side during heating operation.

  The compressor 1, the four-way switching valve 2, the outdoor heat exchanger 3, the electric expansion valve 4, the accumulator 6, the control device 7, the closing valve 21, the closing valve 24, the temperature sensors 11 to 13, the temperature sensor 16 and the outdoor fan ( The outdoor unit 10 is configured by an unillustrated), and the indoor unit 20 is configured by an indoor heat exchanger 5, a temperature sensor 14, a temperature sensor 15, and an indoor fan (not illustrated).

  As shown in FIG. 1, the oil deterioration judging device 31 is a sight glass in which a window glass 31b is provided on a container main body 31a having pipes connected to both ends, and the degree of oil deterioration is determined from the window glass 31b to the container main body 31a. The inside is judged visually, and a blackened resinous composition or polymer such as sludge adhering to the inside of the window glass 31b is judged visually.

  4A to 4D show determination tables provided in the oil deterioration determination device 31. FIG.

  In FIG. 4A, the degree of oil deterioration is determined by comparing the color of the oil adhering to the inside of the window glass 31b with the color of the determination table 51. For example, it is shown that the oil becomes worse as the color of the oil attached to the inside of the window glass 31b changes from brown to black.

  FIG. 4B shows that a chemical substance (cobalt or the like) whose color changes according to the moisture content is applied to a position that can be seen through the window glass 31b in the container body 31a. The degree of water content is determined by comparing the color with the color in the determination table 52. For example, the moisture content increases as the color of the chemical substance changes from yellow to green, indicating that the oil is getting worse.

  In FIG. 4C, a pigment such as a pH indicator whose color changes depending on the degree of oil oxidation is applied to a position visible through the window glass 31b in the container main body 31a, and is determined as the color of the applied pigment. The degree of oil deterioration is determined by comparing the colors in Table 53. For example, the degree of oxidation increases as the color of the pigment changes from blue to red, indicating that the oil is getting worse.

  Further, FIG. 4D shows that a chemical substance whose color changes depending on the air content is applied to a position that can be seen through the window glass 31b in the container body 31a, and the applied chemical substance. And the color of the determination table 54 are compared to determine the degree of air inclusion. For example, it shows that the air content increases as the color of the chemical substance changes.

  The determination tables 51 to 54 shown in FIGS. 4A to 4D are pasted in the vicinity of both ends of the container main body 40 as shown in FIG. FIG. 5 shows a window glass 45 and a simple determination unit 46 (applied chemical substance, fixed magnet, etc.) that can be seen through the window glass 45.

  In the air conditioner having the above configuration, by attaching the oil deterioration determination device 31 to the gas side pipe during heating operation, gas refrigerant containing a large amount of refrigeration oil is discharged to the gas side pipe, so the degree of oil deterioration can be easily determined. It becomes possible to do.

  In this way, the degree of deterioration of refrigeration oil can be determined with a simple configuration, and long-term reliability can be maintained by replacing the working medium (refrigerant including refrigeration oil) as necessary based on the determination result. Can do.

  Further, by providing the determination tables 51 to 54 in the vicinity of the container main body 31a, the degree of deterioration of the oil can be easily determined on the spot.

(Second Embodiment)
FIG. 2 is a circuit diagram showing a schematic configuration of a heat pump type air conditioner as a refrigeration apparatus according to a second embodiment of the present invention, and has the same configuration as the air conditioner of the first embodiment except for an oil deterioration judging device. The same components are denoted by the same reference numerals and description thereof is omitted. In this air conditioner, as shown in FIG. 2, an oil deterioration determination device 32 is disposed in a communication pipe 23 that is on the gas side during heating operation.

  FIG. 3 shows a connecting pipe provided with the oil deterioration judging device. The other end of the pipe 41 connected to one end of the oil deterioration judging device 40 is connected to the outdoor unit and the indoor unit by a flare joint. The other end of the pipe 43 whose one end is connected to the other end of the oil deterioration determination device 40 may be connected to the outdoor unit and the indoor unit by a high-pressure joint (sedge lock, double lock, etc.). Good.

  In the case of the second embodiment, similarly to the first embodiment, the degree of deterioration of the refrigerating machine oil can be determined with a simple configuration, and the working medium (refrigerant including the refrigerating machine oil) can be added as necessary based on the determination result. Long-term reliability can be maintained by replacement. In addition, the present invention can be applied with a simple configuration without changing the design of the outdoor unit and the indoor unit, and in the existing air conditioner, the communication pipe is replaced with a communication pipe with an oil deterioration determination device. The invention can be easily applied.

In the first and second embodiments, R32 refrigerant or a mixed refrigerant containing at least 70% by weight of R32 is used as the HFC refrigerant. Note that a mixed refrigerant of R32 refrigerant and CO _2, R32 refrigerant may be a 70% by weight or more and 90% by weight of the mixed refrigerant with respect to CO _2, a by mixed refrigerant of R32 refrigerant and R22 refrigerant Thus, the R32 refrigerant may be a mixed refrigerant in which the R32 refrigerant is 70% by weight or more and 90% by weight or less.

  In the first and second embodiments, the air conditioner as a refrigeration apparatus including the oil deterioration determination device 31 has been described. However, a wear powder determination device may be provided separately from the oil deterioration determination device. This wear powder judgment device embeds a magnet in a position visible through the window glass 31b in the container body 31a (shown in FIG. 1), and the color of the wear powder adhering to the magnet and the judgment table 55 (FIG. 4). Compare the color of (shown in (E)) to determine the degree of inclusion of wear powder. For example, the greater the amount of wear powder adhering, the darker the color and the greater the amount of wear powder. In this case, it is possible to determine the degree of the amount of wear powder contained in the refrigerant by the amount of the wear powder adhering to the magnet, and the degree of the wear powder in the refrigerant circuit can be determined with a simple configuration. By replacing the working medium (refrigerant containing refrigeration oil) as necessary based on the result, it is possible to prevent clogging of the decompression mechanism and maintain long-term reliability. Further, by providing the determination table 55 in the vicinity of the container body 31a, the degree of deterioration of the refrigerant can be easily determined on the spot.

  Further, a refrigerant oxidation determination device may be provided separately from the oil deterioration determination device and the wear powder determination device. This refrigerant oxidation determination device applies a dye such as a pH indicator whose color changes depending on the degree of oxidation of the refrigerant to a position that can be seen through the window glass 31b in the container main body 31a (shown in FIG. 1). And the color of the judgment table (similar to FIG. 4C) are compared to judge the degree of oxidation of the refrigerant. In this case, the amount of harmful substances such as hydrofluoric acid, which is a decomposition product of HFC refrigerant, and phosgene, which is the decomposition product of HCFC refrigerant, can be determined, and the working medium is replaced as necessary based on the determination result. , It can prevent deterioration of each part due to harmful substances and maintain long-term reliability. Further, by providing a judgment table in the vicinity of the container body 31a, the degree of deterioration of the refrigerant can be easily judged on the spot.

FIG. 1 is a circuit diagram of a refrigerating apparatus according to a first embodiment of the present invention. FIG. 2 is a circuit diagram of a refrigeration apparatus according to a second embodiment of the present invention. FIG. 3 is a schematic view of an oil deterioration determination device arranged in the communication pipe of the refrigeration apparatus. FIG. 4 is a diagram showing a judgment table for the simple judgment unit. FIG. 5 is a diagram showing the pasting position of the judgment table.

Explanation of symbols

1 ... compressor, 2 ... four-way switching valve,
3 ... outdoor heat exchanger, 4 ... electric expansion valve,
5 ... Outdoor heat exchanger, 6 ... Accumulator,
7 ... Control device, 10 ... Outdoor unit,
20 ... indoor unit, 21, 24 ... shut-off valve,
22, 23 ... communication piping, 31, 32 ... oil deterioration judging device.

Claims (9)

  Between the discharge side of the compressor (1) and the gas shut-off valve (24) or between the four-way switching valve (2) and the gas shut-off valve (24), the degree of deterioration of the refrigerating machine oil is determined. A refrigeration apparatus comprising an oil deterioration determination device (31) for determining based on at least one of color, moisture content, degree of oxidation, or air content.   An oil deterioration judgment device (23) disposed in the gas side communication pipe (23) for judging the degree of deterioration of the refrigeration oil based on at least one of oil color, moisture content, degree of oxidation or air content. 31) A refrigeration apparatus comprising the above. The refrigeration apparatus according to claim 1 or 2,
A refrigeration apparatus using an HFC refrigerant. The refrigeration apparatus according to claim 1 or 2,
A refrigerating apparatus using an R32 refrigerant or a mixed refrigerant containing at least 70% by weight of R32. The refrigeration apparatus according to any one of claims 1 to 4,
A refrigeration apparatus comprising a simple determination unit in the oil deterioration determination apparatus (31, 32).   Between the discharge side of the compressor (1) and the gas shut-off valve (24) or between the four-way switching valve (2) and the gas shut-off valve (24), the degree of deterioration of the refrigeration oil is determined by the color of the oil and the moisture. A method for judging deterioration of a refrigerating machine oil, comprising a device for judging oil deterioration (31) for judging based on at least one of a content rate, a degree of oxidation or an air content rate, and judging a deterioration of refrigerating machine oil .   An oil deterioration judgment device (31) for judging the degree of deterioration of refrigeration oil based on at least one of oil color, moisture content, degree of oxidation or air content is provided in the gas side connecting pipe (23). And determining the deterioration of the refrigerating machine oil. In the method for judging deterioration of refrigerating machine oil according to claim 6 or 7,
A method for judging deterioration of refrigerating machine oil, characterized by using an HFC refrigerant. In the method for judging deterioration of refrigerating machine oil according to claim 6 or 7,
A method for judging deterioration of refrigerating machine oil, wherein R32 refrigerant or a mixed refrigerant containing at least 70% by weight of R32 is used.

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