JPH0797585A - Refrigeration equipment - Google Patents

Abstract

(57) [Summary] [Purpose] By suppressing the generation of foreign matter in the refrigeration cycle that uses hydrofluorocarbons and ester-based oils that are compatible with this hydrofluorocarbon, it does not cause any problems to the component parts and is durable. Improves reliability and reliability. [Composition] A hydrofluorocarbon-based refrigerant and a refrigerating machine oil having compatibility with the refrigerant, and a compression mechanism for compressing the refrigerant from a low pressure to a high pressure, a condensing mechanism for cooling the high-pressure compressed refrigerant, In a refrigerating apparatus having a closed refrigeration cycle including an expansion mechanism for expanding the condensed refrigerant and an evaporation mechanism for evaporating the expanded refrigerant to a low-pressure refrigerant, a melting point of refrigerating machine oil in the refrigeration cycle is The concentration of aliphatic compounds in the range of -50 ℃ to 150 ℃ with a density of 1.2g / ml or less at 25 ℃ is 50
It is below ppm.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a refrigerating apparatus incorporated in, for example, an air conditioner, a refrigerator, etc., and more particularly to a refrigerating apparatus using a hydrofluorocarbon type refrigerant which is regarded as the most effective alternative refrigerant.

[0002]

2. Description of the Related Art The use of CFCs that lead to the destruction of the ozone layer is regulated, and there is an urgent need to develop a refrigeration system that uses a hydrofluorocarbon-based refrigerant that does not destroy the ozone layer. Refrigeration equipment is used for evaporation, compression, condensation,
It is represented by an air conditioner, a refrigerator, etc. in which a refrigeration cycle having four functions of expansion is incorporated. In the refrigeration cycle, the refrigerant circulates while repeatedly changing from liquid to gas and from gas to liquid. Further, refrigerating machine oil is an essential element in a compression mechanism that compresses a refrigerant.

A conventional refrigerant compressor in a refrigeration cycle will be described with reference to FIG. FIG. 1 shows an example of a hermetic rotary compressor. A motor mechanism 4 including a stator 2 and a rotor 3 is installed in a closed casing 1.
A compression mechanism 5 is provided below the motor mechanism 4, and the compression mechanism 5 is driven by the motor mechanism 4 via the shaft 8.
The refrigerant introduced from the supply pipe 6 via the accumulator (not shown) is compressed by the compression mechanism 5 and is once discharged into the casing 1. Then, the refrigerant is discharged from the discharge pipe 7 provided in the upper portion of the casing 1 to the refrigerator side. To supply. Refrigerating machine oil 20 is contained to lubricate the compression mechanism 5. In FIG. 1, 9 is a bearing, 10 is a cylinder, 11 is a sub-bearing, 12 is a crank, 13 is a roller, 14 is a blade, and 15 is a spring. Figure 2
Is a hermetic reciprocating refrigerant compressor, and is often used in a refrigeration system together with a hermetic rotary compressor. The compression mechanism 5 is composed of a piston 16 and a reciprocating cylinder 17, and is lubricated with refrigerating machine oil 20.

The refrigerant compressed by the refrigerant compressor circulates in the refrigeration cycle. Taking a refrigerator as an example, the refrigeration cycle will be described with reference to FIG. The refrigerant is compressed by the compressor 23, which is a compression mechanism, cooled through the pedestal pipe 24, which is a condensation mechanism, the heat radiation pipe 25, and the clean pipe 26, expanded through the capillary tube 21, which is an expansion mechanism, and is an evaporation mechanism. It evaporates in the evaporator 22 and cools the inside of the refrigerator 27. Then, it is compressed again by the compressor 23.

Conventionally, dichlorodifluoroethane (hereinafter referred to as CFC12) or monochlorodifluoromethane (hereinafter referred to as HCFC22) has been used as a refrigerant for such a closed refrigeration cycle.
Is mainly used and circulates in the refrigeration cycle. Further, as the refrigerating machine oil that is enclosed to maintain the lubricity of the compressor 23, naphthene-based or paraffin-based mineral oil that is soluble in CFC12 and HCFC22 is used.

However, recently, it has become clear that the release of CFCs such as the above-mentioned refrigerant (CFC12) leads to the destruction of the ozone layer and seriously affects the human body and biological systems. Therefore, the ozone depletion coefficient (1.0 in the case of CFC12) The use of high CFC12 etc. is gradually reduced, and it is decided not to use it in the future. Under these circumstances, CFC12 alternative refrigerants such as fluorocarbons containing no chlorine 1,1,1,2
-Tetrafluoroethane (hereinafter referred to as HFC134a) and
Hydrofluorocarbon-based refrigerants such as 1,1-difluoroethane (hereinafter referred to as HFC152a) have been developed,
Development of refrigerating machine oil suitable for this refrigerant is desired. Here, as a necessary characteristic of the refrigerating machine oil, compatibility with the refrigerant can be mentioned because of oil return in the cycle. HFC134a etc.
Since it is hardly dissolved in mineral oil, which is a conventional refrigerating machine oil, attempts have been made to use synthetic oils such as soluble polyester oils, polyether oils, and fluorine oils.

[0007]

However, synthetic oils such as polyester-based oils and hydrofluorocarbon-based refrigerants have polar groups in their respective molecular structures, so they are compared to conventional refrigerants and non-polar refrigerating machine oils. And the dissolution characteristics are completely different. FIG. 4 shows the solubility of hydrofluorocarbons and paraffin hydrocarbons, which are non-polar substances of the aliphatic compounds. According to Fig. 4, while the conventional refrigerants CFC12 and HCFC22 have relatively high solubility,
It can be seen that the solubility of HFC134a is extremely low. Further, FIG. 5 shows the solubility of refrigerating machine oil and paraffin hydrocarbons. From FIG. 5, it can be seen that the conventional refrigerating machine oil, mineral oil, has a high solubility with paraffin hydrocarbons, whereas polyester oil has a very low solubility. Therefore, if a low-solubility aliphatic compound is present in a refrigeration cycle that uses a synthetic oil such as polyester oil and a hydrofluorocarbon-based refrigerant, it will be carried as a precipitate in the refrigeration cycle together with the refrigerant and oil. .

The substance generated due to these causes (hereinafter referred to as a deposit) circulates in the cycle shown in FIG. 3 together with the compressed refrigerant, and has a very small inner diameter (for example, φ1.0 mm or less) in the capillary tube 21. There is a problem of depositing inside. This capillary tube 21
If a deposit accumulates inside, the circulation of the refrigerant is hindered, resulting in poor cooling.

For example, HFC134a and HFC as refrigerants
The results of analyzing the refrigeration cycle of the compressor 152a, in which a compressor using polyester-based oil as the refrigerating machine oil was used for a refrigerator for 4000 hours and the refrigeration cycle was analyzed, will be described. When the capillary tube in the refrigeration cycle was disassembled after the actual machine durability test, it was found that a deposit was deposited inside the copper (Cu) capillary tube in both HFC134a and HFC152a. FIG. 6 shows the analysis result of this deposit component by Fourier transform infrared spectroscopy (FT-IR), and FIG. 7 shows the analysis result by gas chromatography analysis (GC) of the sample dissolved in chloroform. In addition, Table 1 shows the analysis results by gas chromatography analysis (GC) of the refrigerant after the durability test.

[Table 1] From FT-IR analysis results shown in FIG. 6, 2950 cm ^-1 attributable to aliphatic ^{hydrocarbons, 2900cm -1, 2840cm -1, 1470cm} -1, 14
60cm ^-1, absorption of around 800cm ^-1 was observed in the deposit component.

Further, from the GC analysis result shown in FIG. 7, the presence of paraffinic hydrocarbon in the deposit component was confirmed. On the other hand, from the gas analysis results of the refrigerant shown in Table 1, HFC13
It was confirmed that the refrigerant itself was hardly decomposed in both 4a and HFC152a. From the above analysis results, it is considered that the deposit is mainly produced by the involvement of the aliphatic compound and that the aliphatic compound such as paraffin hydrocarbon is not dissolved in the refrigerant or the refrigerating machine oil.

When HFC134a, which is a refrigerant to be replaced by CFC12, etc., and synthetic oil, such as polyester series oil, are applied to the refrigeration cycle, if the same polyester series refrigerating machine oil is used, it becomes a component part. There is a problem that defects occur and the quality and durability are greatly reduced.

[0012] More recently, in addition to CFCs classified as CFCs, CFCs classified as HCFCs containing hydrogen and chlorine have also become regulations. Therefore,
As for HCFC-based refrigerants such as HCFC22, difluoromethane (hereinafter referred to as HFC32) is used as an alternative, and HFC32 / pentafluoroethane (hereinafter referred to as HFC125) is used as a mixed refrigerant.
HFC32 / HFC152a, HFC32 / HFC134a, or HFC32 / HFC134a / HFC125 are listed as candidates. All of these refrigerants are hydrofluorocarbon-based refrigerants having polarities. Therefore, it is important to stabilize the properties of synthetic oils such as polyester oils that can be used in combination with hydrofluorocarbon refrigerants.

The present invention has been made in response to such conventional circumstances, and when hydrofluorocarbon is used as a refrigerant and synthetic oil compatible with hydrofluorocarbon is used as a refrigerating machine oil in a refrigeration cycle, the system is An object of the present invention is to provide a refrigerating apparatus capable of improving durability and reliability without causing a trouble in component parts by suppressing generation of internal foreign matter.

[0014]

A refrigeration system of the present invention comprises a hydrofluorocarbon-based refrigerant and a refrigerating machine oil compatible with the refrigerant, and a compression mechanism for compressing the refrigerant from a low pressure to a high pressure, and a high pressure. In a refrigerating apparatus having a closed refrigeration cycle consisting of a condensing mechanism for cooling the compressed refrigerant, an expansion mechanism for expanding the condensed refrigerant, and an evaporation mechanism for evaporating the expanded refrigerant to a low-pressure refrigerant, For the refrigerating machine oil in this refrigeration cycle, the melting point is in the range of -50 ℃ to 150 ℃, and the density at 25 ℃ is
The concentration of the aliphatic compound, which is 1.2 g / ml or less, is 50 ppm or less.

The aliphatic compound according to the present invention is contained in various components incorporated in the refrigeration cycle. As the constituent parts, a motor part which constitutes the compression mechanism is mentioned first. When constructing a motor component, the winding is wound around the core of the stator, but winding oil such as winding lubricating oil is used to tightly wind the winding and not damage the winding during molding. This winding oil is used to increase the slipperiness between the windings when manufacturing the windings themselves. If such a winding oil contains an aliphatic compound with a melting point in the range of -50 ° C to 150 ° C and a density at 25 ° C of 1.2 g / ml or less, it will be used in the refrigeration cycle together with the motor parts. It is easy to generate deposits when brought into the. Therefore, as the winding oil, ester-based, ether-based, alkylbenzene-based synthetic oils containing no aliphatic compound as described above are preferable.

Of the refrigeration cycle parts, the refrigeration cycle pipes and the metal machine parts in the compressor are processed with cutting oil, press oil, or the like when forming into the final shape.
The processed rust preventive oil is used. Therefore, synthetic oils containing none of the above-mentioned aliphatic compounds in these oils are preferable.

Further, among the refrigeration cycle parts, the organic material parts are made of an organic material which does not contain the above-mentioned aliphatic compound as a component to be separated in the refrigerating machine oil. Therefore, when obtaining organic material parts by injection molding,
It is preferable to use a release agent or the like that does not contain any of the above aliphatic compounds.

In order to investigate the precipitation behavior of the components separated in the winding oil, the processing oil, the refrigerant of the organic material components and the polyester-based oil used in the above refrigeration cycle components, the following shielded tube test was conducted. . Prepare 9 heat-resistant glass test tubes, and put 10 g of refrigerant and 100 g of polyester oil into each test tube. Then, the winding oils A, B, C and the processing oils D, E, F are each 1 wt% with respect to the polyester oil, and the organic material parts G to L are
Add 5g individually to each test tube. Aged each test tube for 14 days in a constant temperature bath kept at 175 ℃. After aging, draw out 1 ml of polyester-based oil and put it into a separately prepared heat-resistant glass test tube with 9 ml of refrigerant and check for precipitates in the temperature range of -50 ° C to 150 ° C. The results of this shield tube test are shown in Table 2.

[Table 2] The temperature range from -50 ℃ to 150 ℃ is set because this range is the temperature range within the refrigeration cycle when the refrigeration system is operating. The winding oil A and the organic material part I were cloudy and a precipitate was observed over the entire range. Precipitates were found in the winding oil B, the processing oils D and E, and the organic material parts G and K in some temperature ranges. On the other hand, no deposits were found in the winding oil C, the processing oil F, and the organic material parts H, J, and L over the entire temperature range. An examination of the polyester-based oils in which precipitates were observed revealed that all had melting points in the range of -50 ° C to 150 ° C and exceeded 50 ppm of aliphatic compounds with a density of 1.2 g / ml or less at 25 ° C. Was included. In addition, the content of these aliphatic compounds in the polyester-based oil in which no precipitate was observed was 50 ppm or less.

The aliphatic compound has a density of 1.2 g / ml at 25 ° C.
When it exists in the refrigeration cycle without being dissolved in the refrigerant and refrigerating machine oil, the liquid density of the refrigerant is generally 0.9 to 1.2 g / ml (25 ° C) as shown in Table 3, so it is easy to use the refrigerant in the cycle. It becomes easy to generate a deposit in the capillary tube by circulating. When the density of the aliphatic compound at 25 ° C. is 0.6 or more, deposits are likely to be formed. Therefore, the density of aliphatic compounds at 25 ° C is 0.6
To 1.2 g / ml.

[0020]

[Table 3] Examples of the aliphatic compound that satisfies the above conditions include paraffinic hydrocarbon compounds having 10 to 70 carbon atoms such as normal decane and higher paraffin. The paraffinic hydrocarbon compound having 10 to 70 carbon atoms may be used alone or as a mixture. Even if such an aliphatic compound adheres to the surface of a mechanical component and / or an insulating component or is contained inside and is extracted by a refrigerant or a refrigerating machine oil, its concentration in the refrigerating machine oil is low. 50
If it is less than ppm, it becomes difficult to generate a deposit.

As the refrigerating machine oil according to the present invention, a synthetic oil compatible with the hydrofluorocarbon of the refrigerant can be used. Synthetic oils include polyester-based oils, polyether-based oils, fluorine-based oils, alkylbenzene-based oils, etc., which are inferior in hygroscopicity compared to conventional mineral oils, but improved compared to polyether-based oils. Further, a polyester-based oil, which has a lower manufacturing cost than a fluorine-based oil and is compatible with a hydrofluorocarbon-based refrigerant, is preferable.

Such a polyester oil has an ester bond formed in the molecule by the reaction of a hydroxyl group and a carboxyl group, can dissolve hydrofluorocarbons alone or in a mixture, and can slide in a refrigeration cycle. A compound that maintains lubricity between members. Among these polyester-based oils, complex ester (polyester) -based oils, which are reaction products of hindered alcohols such as neopentanediol, neopentanetriol, and pentaerythritol with monocarboxylic acids or dicarboxylic acids, are used in combination with hydrofluorocarbons. It is suitable because it has excellent compatibility and also has excellent lubricity between sliding members in the refrigeration cycle.

Further, these refrigerating machine oils contain sulfur-based, phosphorus-based, and halogen-based extreme pressure additives as required, or wear resistance improvers, antioxidants, heat resistance improvers, and corrosion inhibitors (especially copper). Metal deactivator), a hydrolysis inhibitor, an antifoaming agent and the like.

The hydrofluorocarbon according to the present invention is a compound consisting of carbon, fluorine and hydrogen, which can replace the conventional refrigerants CFC12 and HCFC22. For example, HFC134a, HFC152a, HFC32, HFC125, HFC143a
Can be illustrated. These hydrofluorocarbons can be used alone or as a mixture of two or more kinds.

[0025]

[Function] The concentration of an aliphatic compound having a melting point in the range of -50 ° C to 150 ° C and a density at 25 ° C of 1.2 g / ml or less is 50%.
When it is less than or equal to ppm, it is possible to suppress the formation of deposits in the refrigerating machine oil when the refrigerating machine is operated. Therefore, a refrigeration cycle that is highly reliable and maintains good performance can be obtained. Further, the conventional refrigeration cycle can be used without being significantly changed.

[0026]

EXAMPLES Examples of the present invention will be described below. Example 1 HFC134a was prepared as a hydrofluorocarbon refrigerant, and hindered ester which was a polyester oil was prepared as a refrigerating machine oil. Next, we prepared motor parts using 100% synthetic oil as a winding oil, constituted a refrigeration cycle, assembled a refrigerator, and ran for 5000 hours at 25 ° C. The concentration of the aliphatic compound in the refrigerating machine oil of the refrigeration cycle was 20 ppm or less.

Nitrogen gas was introduced into the capillary tube as a means for measuring the amount of deposits produced in the capillary tube during operation, and the flow rate was measured. Since the nitrogen gas flow rate decreases as the deposit generation amount increases, the deposit generation amount can be known by measuring the nitrogen gas flow rate and determining the ratio (%) to the initial value. The measurement result is shown in FIG.

Example 2 100% of refrigeration cycle piping parts and metal machinery parts inside the compressor
A polyester oil was used as a synthetic oil, and a rust preventive oil was also made of the same polyester oil to form a refrigeration cycle, and a refrigerator was assembled and operated at 25 ° C for 5000 hours. The concentration of the aliphatic compound in the refrigerating machine oil of the refrigeration cycle was 20 ppm or less.

The flow rate of nitrogen gas was measured under the same conditions as in Example 1. The measurement result is shown in FIG.

Example 3 An organic material part in a compressor was molded, a refrigerating cycle was constituted, a refrigerator was assembled, and an operation was carried out at 25 ° C. for 5000 hours. The organic material parts inside the compressor used raw materials and additives that do not contain aliphatic compounds having 10 to 70 carbon atoms. For example, an aromatic polyester film containing no additive was used as the insulating film. Also, the mold release agent used for molding is 10 to 7 carbon atoms.
For example, volatile hydrocarbon oils free of aliphatic compounds of 0 were used. The concentration of the aliphatic compound in the refrigerating machine oil of the refrigeration cycle was 20 ppm or less. The flow rate of nitrogen gas was measured under the same conditions as in Example 1. The measurement result is shown in FIG.

Comparative Example 1 HFC134a was prepared as a hydrofluorocarbon refrigerant, and hindered ester which was a polyester oil was prepared as a refrigerating machine oil. Next, prepare motor parts using paraffinic hydrocarbon oil (mixture of 20 to 50 carbon atoms) as winding oil, configure a refrigeration cycle, assemble a refrigerator, and
It was operated at 5000C for 5000 hours. The residual paraffinic hydrocarbon oil was 100 ppm with respect to the refrigerator oil. The flow rate of nitrogen gas was measured under the same conditions as in Example 1. The measurement result is shown in FIG. Comparative Example 2 Paraffin hydrocarbon oil (mixture of 20 to 50 carbon atoms) was used as the refrigeration cycle piping parts and metal machinery parts in the compressor.
The synthetic oil containing 0% by weight was used for processing, and the same anti-rust oil was also used for the refrigeration cycle to construct a refrigeration cycle, and a refrigerator was assembled and operated at 25 ° C for 5000 hours. The remaining paraffinic hydrocarbon oil is 200
It was ppm. The flow rate of nitrogen gas was measured under the same conditions as in Example 1. The measurement result is shown in FIG. Comparative Example 3 An organic material part in a compressor was molded, a refrigeration cycle was constituted, a refrigerator was assembled, and operation was performed at 25 ° C. for 5000 hours. The organic material parts inside the compressor used raw materials and additives that do not contain aliphatic compounds having 10 to 70 carbon atoms. For example, an aromatic polyester (PBT) containing no additive was used as the cluster material. On the other hand, a paraffinic hydrocarbon oil (mixture having 20 to 50 carbon atoms) was used as a release agent at the time of molding. The remaining paraffinic hydrocarbon oil in Comparative Example 3 was 250 ppm with respect to the refrigerating machine oil. The flow rate of nitrogen gas was measured under the same conditions as in Example 1. The measurement result is shown in FIG. Comparative Example 4 HFC134a was prepared as the refrigerant, and hindered ester was prepared as the refrigerator oil. Next, motor parts using paraffinic hydrocarbon oil as winding oil, refrigeration cycle piping parts, metal parts inside compressor processed using synthetic oil containing paraffinic hydrocarbon oil, and rust preventive oil The same synthetic oil was used as a cluster material using paraffin hydrocarbon oil as a mold release agent as an organic material part in the compressor (P
BT) was prepared, a refrigeration cycle was constructed, a refrigerator was assembled, and operation was performed at 25 ° C. for 5000 hours.
The residual paraffinic hydrocarbon oil (mixture having 20 to 50 carbon atoms) was 600 ppm with respect to the refrigerating machine oil.
The flow rate of nitrogen gas was measured under the same conditions as in Example 1. The measurement result is shown in FIG.

According to FIG. 8, the first to third embodiments have 50
Even after the operation for 00 hours, the nitrogen gas flow rate hardly decreased. On the other hand, Comparative Examples 1 to 4 showed a large decrease compared to Examples 1 to 3. Further, after the operation was completed, the capillary tube in the refrigeration cycle was disassembled and the state of deposit formation was investigated, but in any of Examples 1 to 3, almost no deposit formation was observed.

Further, after the operation was completed, the electric wire coating material and insulating paper of the motor constituting the compression mechanism portion, and further the refrigerating machine oil itself were examined, and Examples 1 to 3 were obtained.
Are all normal (the total acid number of the refrigerator oil is 0.01
mgKOH / g), both were found to be very good.

Example 4 HFC134a was prepared as a hydrofluorocarbon type refrigerant, and hindered ester which was a polyester type oil was prepared as a refrigerating machine oil. Next, a motor component using a mixed oil of paraffinic hydrocarbon oil and ester oil as a winding oil was prepared, a refrigeration cycle was configured, a refrigerator was assembled, and operation was performed at 25 ° C for 5000 hours. The paraffinic hydrocarbon oil was 45 ppm with respect to the refrigeration oil. As a result of measuring the flow rate of nitrogen gas under the same conditions as in Example 1, 5000
Even after the operation for a while, the flow rate of nitrogen gas hardly decreases,
Almost no deposit was observed. After the operation was completed, the electric wire coating material and insulating paper of the motor that constitutes the compression mechanism, and further the refrigerating machine oil itself were examined.
0.01 mgKOH / g), both were found to be very good.

Examples 5 to 31 Examples in which a hindered ester which is a polyester oil is used as a refrigerating machine oil and various hydrofluorocarbon type refrigerants are used as refrigerants will be described below. Refrigeration cycle using the same motor parts as in Example 1, cycle piping parts same as in Example 2, metal machine parts in the compressor and refrigeration cycle using rust preventive oil, organic material parts in the compressor as in Example 3. Each refrigeration cycle using was constructed and a refrigerator was assembled and operated at 25 ° C. for 2000 hours. The combinations are shown in Table 4. The flow rate of nitrogen gas was measured under the same conditions as in Example 1. The measurement results are shown in Table 4. According to Table 4, Examples 5 to 31 have 2000
Even after the operation for a while, the nitrogen gas flow rate did not decrease much compared to the initial value. Further, after the operation was completed, the capillary tube in the refrigeration cycle was disassembled and the state of deposit formation was investigated, but almost no deposit formation was observed.

Further, after the operation was completed, the electric wire coating material and insulating paper of the motor constituting the compression mechanism portion, and further the refrigerating machine oil itself were examined.
1 has no abnormality for all (total acid number of refrigerating machine oil is 0.0
1 mgKOH / g), both were found to be very good.

[0037]

[Table 4]

[0038]

EFFECT OF THE INVENTION A hydrofluorocarbon type refrigerant,
The refrigerating apparatus of the present invention containing a refrigerating machine oil having compatibility with this refrigerant, the components used in the refrigerating cycle, the refrigerating machine oil, the melting point is in the range of -50 ℃ ~ 150 ℃, at 25 ℃ Of aliphatic compounds with a density of 1.2 g / ml or less
Since the concentration is 50 ppm or less, it is possible to prevent foreign matter (deposit) generated in the refrigeration cycle from accumulating in the refrigeration cycle piping. In addition, the conventional refrigeration cycle using CFC12 or HCFC22 can be used without major modification. Therefore, the refrigerating apparatus of the present invention is most suitable for a refrigerator having a refrigerating cycle using hydrofluorocarbon, and can improve durability and reliability.

[Brief description of drawings]

FIG. 1 is a cutaway view of a conventional hermetic rotary refrigerant compressor.

FIG. 2 is a cutaway view of a conventional hermetic reciprocating refrigerant compressor.

FIG. 3 is a diagram showing a refrigeration cycle for a refrigerator.

FIG. 4 is a diagram showing the solubility of a refrigerant and an aliphatic compound.

FIG. 5 is a diagram showing solubility of refrigerating machine oil and an aliphatic compound.

FIG. 6 is a diagram showing an analysis result of a Fourier transform infrared spectroscopic analysis (FT-IR) of a deposit component.

FIG. 7 is a diagram showing an analysis result of a deposit component by gas chromatography analysis (GC).

FIG. 8 is a diagram showing a result of measuring a nitrogen gas flow rate in a capillary tube.

[Explanation of symbols]

1 ... Casing, 2 ... Stator, 3 ......... Rotor, 4 ... Motor mechanism, 5 ... Compression mechanism, 6 ...
Supply pipe, 7 ... Discharge pipe, 8 ... Shaft, 9 ...
Bearing, 10 ………… Cylinder, 11 ………… Sub bearing, 12 ………… Crank, 13 ………… Roller, 14 ……
… Blade, 15 ……… Spring, 16 ……… Piston, 17 ……… Reciprocating cylinder, 20 ……… Refrigerating machine oil, 21 ……… Capillary tube, 22 ……… Evaporator, 23 ……… Compressor, 24 ………… Cage pipe, 25
……… Radiation pipe, 26 ……… Clean pipe, 27…
……refrigerator.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location C10N 40:30

Claims (7)

[Claims] 1. A hydrofluorocarbon-based refrigerant,
A compression mechanism that contains a refrigerating machine oil compatible with the refrigerant, compresses the refrigerant from a low pressure to a high pressure, a condensing mechanism that cools the high pressure-compressed refrigerant, and an expansion that expands the condensed refrigerant. In a refrigerating apparatus having a closed refrigeration cycle including a mechanism and an evaporation mechanism that evaporates the expanded refrigerant into a low-pressure refrigerant, a melting point of the refrigerating machine oil in the refrigeration cycle is from -50 ° C to 150 ° C. ℃ range, the density at 25 ℃
A refrigeration system characterized in that the concentration of the aliphatic compound that is 1.2 g / ml or less is 50 ppm or less. 2. The refrigerating apparatus according to claim 1, wherein the aliphatic compound is a paraffinic hydrocarbon compound having 10 to 70 carbon atoms. 3. The refrigerating apparatus according to claim 1 or 2, wherein the component forming the refrigerating cycle is a motor component using winding oil, and the refrigerating machine oil in the refrigerating cycle is used for the refrigerating machine oil. Concentration of aliphatic compound is 5
Refrigeration equipment characterized by being below 0 ppm. 4. The refrigerating apparatus according to claim 3, wherein the winding oil is synthetic oil. 5. The refrigerating apparatus according to claim 1 or 2, wherein the parts constituting the refrigeration cycle are machine parts using processing oil and / or rust preventive oil, and the refrigeration in the refrigeration cycle is performed. A refrigeration system characterized in that the concentration of the aliphatic compound in the machine oil is 50 ppm or less. 6. The refrigerating apparatus according to claim 5, wherein the processing oil and / or the rust preventive oil is a synthetic oil. 7. The refrigerating apparatus according to claim 1, wherein the components that constitute the refrigeration cycle are mechanical components and / or insulating components, and the concentration of the aliphatic compound in the refrigeration machine oil in the refrigeration cycle. Refrigeration equipment characterized by a concentration of 50 ppm or less.