JP2017142052A - Freezer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent occurrence of a disproportionation reaction on a refrigerant in a freezer using the refrigerant.SOLUTION: A freezer 100 includes a heat source unit 10, a utilization unit 20A, a liquid refrigerant pipe 31 and a gas refrigerant pipe 32. The utilization unit 20A has utilization unit internal pipe lines 29a-29c. The heat source unit 10 and the utilization unit internal pipe lines 29a-29c are connected via the liquid refrigerant pipe 31 and the gas refrigerant pipe 32. The refrigerant consists mainly of HFO and HFC, and circulates in the heat source unit 10, the utilization unit 20A, the liquid refrigerant pipe 31 and the gas refrigerant pipe 32. Refrigeration oil consists mainly of an alkyl aromatic hydrocarbon and an oxygen-containing hydrocarbon. The oxygen-containing hydrocarbon contains at least one of ether and ester. The disproportionation reaction inhibitor inhibiting disproportionation reaction of the refrigerant is applied on the inner surface of at least one of the liquid refrigerant pipe 31, the gas refrigerant pipe 32 and the utilization unit internal pipe lines 29a-29c.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a refrigeration apparatus.

  In recent years, hydrofluoroolefin (HFO) is sometimes used as a refrigerant in a refrigeration apparatus, as disclosed in Patent Document 1 (Japanese Patent Laid-Open No. 2015-007257) from the viewpoint of suppressing global warming. HFO has a low global warming potential because it is easily decomposed by OH radicals in the atmosphere. Examples of HFO include 1,1,2-trifluoroethylene (HFO-1123) and 2,3,3,3-tetrafluoropropene (HFO-1234yf).

  Some refrigerants used in refrigeration devices have a low thermal stability, so that a self-decomposition reaction called a disproportionation reaction tends to occur under certain conditions. A disproportionation reaction is a chemical reaction that turns into two or more different types of substances due to causes such as two or more molecules of the same type reacting with each other.

  An example of a disproportionation reaction is the polymerization of HFO-1123 refrigerant. Since HFO-1123 is a compound represented by a molecular formula having one or more carbon-carbon unsaturated bonds, the polymerization reaction tends to proceed at high temperature and high pressure. The polymerization reaction is a reaction in which a compound having a large molecular weight (polymer compound) is generated by polymerization of a plurality of monomers. The polymer that is a compound produced by the polymerization reaction usually has a molecular weight of 10,000 or more.

  Similarly, since HFO-1234yf also has a double bond in the composition, polymerization is likely to occur depending on conditions such as high temperature.

  If a part of the refrigerant is altered due to the disproportionation reaction, the effective amount of the refrigerant circulating in the refrigerant circuit is reduced, which causes a decrease in the performance of the refrigerant circuit. Furthermore, in some cases, the product of the disproportionation reaction may be clogged in the pipeline of the refrigerant circuit, thereby hindering the circulation of the refrigerant.

  The subject of this invention is suppressing generation | occurrence | production of the disproportionation reaction of a refrigerant | coolant in the freezing apparatus using a refrigerant | coolant.

  A refrigeration apparatus according to a first aspect of the present invention includes a heat source unit, a utilization unit, a liquid refrigerant pipe and a gas refrigerant pipe, a refrigerant, and refrigeration oil. The usage unit has a usage unit internal conduit. The liquid refrigerant pipe and the gas refrigerant pipe connect the heat source unit and the utilization unit internal pipe. The refrigerant mainly contains HFO and HFC, and circulates through the heat source unit, the utilization unit, the liquid refrigerant pipe, and the gas refrigerant pipe. The refrigerating machine oil is mainly composed of an alkyl aromatic hydrocarbon and an oxygen-containing hydrocarbon. A disproportionation reaction inhibitor that suppresses the disproportionation reaction of the refrigerant is applied to at least a part of the inner surface of the liquid refrigerant pipe, the gas refrigerant pipe, and the use unit internal pipe. The oxygen-containing hydrocarbon contains at least one of ether and ester. The weight mixing ratio of HFO in the refrigerant is the first refrigerant ratio. The HFC weight mixing ratio in the refrigerant is the second refrigerant ratio. The mixing ratio of the alkyl aromatic hydrocarbon in the refrigerating machine oil is the first oil ratio. The mixing ratio of the oxygen-containing hydrocarbon in the refrigerating machine oil is the second oil ratio. When the first refrigerant ratio is greater than the second refrigerant ratio, the first oil ratio is greater than the second oil ratio, and when the first refrigerant ratio is smaller than the second refrigerant ratio, the first oil ratio is the second oil ratio. Smaller than.

  According to this configuration, the disproportionation reaction inhibitor is applied to at least a part of the inner surface of the liquid refrigerant pipe, the gas refrigerant pipe, and the use unit internal pipe. Therefore, the refrigerant circulating in the refrigerant circuit comes into contact with the disproportionation reaction inhibitor, so that the disproportionation reaction of the refrigerant hardly occurs.

  In addition, ether compounds and ester compounds that are often used as refrigerating machine oils having good compatibility with HFC refrigerants may function as initiators for the disproportionation reaction of HFO refrigerants having a carbon-carbon unsaturated bond. However, the alkyl aromatic hydrocarbon, which is one of the main components of the refrigerating machine oil, suppresses the disproportionation reaction of the HFO refrigerant while ensuring the compatibility between the HFC refrigerant and the refrigerating machine oil.

  In the refrigeration apparatus according to the second aspect of the present invention, in the refrigeration apparatus according to the first aspect, HFO is HFO1123 and HFC is R32.

  According to this configuration, by adding a predetermined amount of alkyl aromatic hydrocarbon as a main component of the refrigerating machine oil, the disproportionation reaction of HFO 1123, which is an HFO refrigerant, is ensured while ensuring compatibility with R32, which is an HFC refrigerant. Can be suppressed.

  In the refrigeration apparatus according to the third aspect of the present invention, in the refrigeration apparatus according to the first aspect or the second aspect, the first refrigerant ratio is equal to the first oil ratio, and the second refrigerant ratio is equal to the second oil ratio.

  According to this structure, the disproportionation reaction of a HFO refrigerant | coolant can be suppressed, ensuring compatibility with a HFC refrigerant | coolant by adding a predetermined amount of alkyl aromatic hydrocarbons as a main component of refrigeration oil.

  In the refrigeration apparatus according to the fourth aspect of the present invention, in the refrigeration apparatus according to any one of the first to third aspects, the first refrigerant ratio is 40% to 60%. The second refrigerant ratio is 60% to 40%. The first oil ratio is 40% to 60%. The second oil ratio is 60% to 40%.

  According to this configuration, the disproportionation reaction of the HFO refrigerant can be further suppressed while ensuring the compatibility between the HFC refrigerant and the refrigerating machine oil.

  In the refrigeration apparatus according to the fifth aspect of the present invention, in the refrigeration apparatus according to any one of the first to fourth aspects, the disproportionation reaction inhibitor is a polymerization inhibitor that suppresses the polymerization of the refrigerant.

  According to this configuration, the disproportionation reaction inhibitor suppresses the polymerization of the refrigerant. Therefore, it is possible to suppress the performance deterioration of the refrigerant circuit due to the polymerization product.

  The refrigeration apparatus according to a sixth aspect of the present invention is the refrigeration apparatus according to any one of the first to fifth aspects, wherein the disproportionation reaction inhibitor is at least one of a stabilizer, an antioxidant, and an oxygen scavenger. Contains one.

  According to this structure, the specific content of the disproportionation reaction inhibitor is designated.

  The refrigerating apparatus according to the seventh aspect of the present invention is the refrigerating apparatus according to the sixth aspect, wherein the disproportionation reaction inhibitor includes a stabilizer. The stabilizer includes at least one of an oxidation resistance improver, a heat resistance improver, and a metal deactivator. The oxidation resistance improver and the heat resistance improver are N, N′-diphenylphenylenediamine, p-octyldiphenylamine, p, p′-dioctyldiphenylamine, N-phenyl-1-naphthylamine, N-phenyl-2-naphthylamine, N- (p-dodecyl) phenyl-2-naphthylamine, di-1-naphthylamine, di-2-naphthylamine, N-alkylphenothiazine, 6- (t-butyl) phenol, 2,6-di- (t-butyl) At least one of phenol, 4-methyl-2,6-di- (t-butyl) phenol, 4,4′-methylenebis (2,6-di-t-butylphenol). Metal deactivators are imidazole, benzimidazole, 2-mercaptobenzthiazole, 2,5-dimercaptothiadiazole, salicyridin-propylenediamine, pyrazole, benzotriazole, toltriazole, 2-methylbenzimidazole, 3,5-dimethylpyrazole , Methylenebis-benzotriazole, organic acids or their esters, primary, secondary or tertiary aliphatic amines, amine salts of organic or inorganic acids, heterocyclic nitrogen-containing compounds, amines of alkyl acid phosphates Including at least one of a salt or a derivative thereof.

  According to this structure, the specific composition of the stabilizer which is a component of the disproportionation reaction inhibitor is presented.

  The refrigeration apparatus according to the eighth aspect of the present invention is the refrigeration apparatus according to the sixth aspect or the seventh aspect, wherein the disproportionation reaction inhibitor includes an antioxidant. Antioxidants include zinc dithiophosphate, organic sulfur compounds, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,2′-methylenebis ( 4-methyl-6-tert-butylphenol), phenyl-α-naphthylamine, N, N′-di-phenyl-p-phenylenediamine, N, N′-disalicylidene-1,2-diaminopropane Including one.

  According to this structure, the specific composition of the antioxidant which is a component of the disproportionation reaction inhibitor is presented.

  The refrigerating apparatus according to the ninth aspect of the present invention is the refrigerating apparatus according to any one of the sixth to eighth aspects, wherein the disproportionation reaction inhibitor includes an oxygen scavenger.

  The oxygen scavenger includes at least one of 2-ethylhexyl glycidyl ether, phenyl glycidyl ether, epoxidized cyclohexyl carbinol, di (alkylphenyl) carbodiimide, β-pinene.

  According to this configuration, a specific composition of the oxygen scavenger that is a component of the disproportionation reaction inhibitor is presented.

  According to the refrigeration apparatus according to the first to fourth aspects of the present invention, the disproportionation reaction of the refrigerant hardly occurs.

  According to the refrigeration apparatus according to the fifth aspect of the present invention, it is possible to suppress the performance deterioration of the refrigerant circuit caused by the polymerization product.

  According to the refrigeration apparatus according to the sixth to ninth aspects of the present invention, the specific content of the disproportionation reaction inhibitor is specified.

It is a schematic diagram which shows the refrigerant circuit of the freezing apparatus 100 which concerns on one Embodiment of this invention. It is a schematic diagram which shows utilization unit 20A and refrigerant | coolant communication piping 30 of the freezing apparatus 100 shown in FIG.

  Hereinafter, embodiments of a refrigeration apparatus according to the present invention will be described with reference to the drawings. In addition, the specific structure of the freezing apparatus concerning this invention is not restricted to the following embodiment, It can change suitably in the range which does not deviate from the summary of invention.

(1) Overall Configuration FIG. 1 shows a refrigeration apparatus 100 according to an embodiment of the present invention. The refrigeration apparatus 100 is an air conditioner, for example. The refrigeration apparatus 100 includes a heat source unit 10, utilization units 20A and 20B, a refrigerant communication pipe 30, and a refrigerant.

(2) Detailed configuration (2-1) Heat source unit 10
The heat source unit 10 is for generating heat or cold. The heat source unit 10 includes a compressor 11, a four-way switching valve 12, a heat source unit heat exchanger 13, a heat source unit fan 14, a heat source unit expansion valve 15, a heat source unit liquid path port 17, a heat source unit gas path port 18, and an internal heat source unit. It has the pipe lines 19a-19g.

(2-1-1) Compressor 11
The compressor 11 sucks and compresses the low-pressure gas refrigerant, converts it into a high-pressure gas refrigerant, and discharges it in the direction of the arrow.

(2-1-2) Four-way switching valve 12
The four-way switching valve 12 switches between a cold energy operation and a heat energy operation. The four-way switching valve 12 constitutes a refrigerant path indicated by a solid line during a cold-utilization operation, and constitutes a refrigerant path indicated by a broken line during a heat-utilization operation.

(2-1-3) Heat source unit heat exchanger 13
The heat source unit heat exchanger 13 performs heat exchange between the refrigerant and the air around the heat source unit 10. In the case of operation using cold heat, the heat source unit heat exchanger 13 functions as a condenser and releases the heat of the refrigerant into the air. On the other hand, in the case of operation using warm heat, the heat source unit heat exchanger 13 functions as an evaporator, and takes heat in the air into the refrigerant.

(2-1-4) Heat source unit fan 14
The heat source unit fan 14 promotes heat exchange of the heat source unit heat exchanger 13.

(2-1-5) Heat source unit expansion valve 15
The heat source unit expansion valve 15 is a valve whose opening degree can be adjusted, and functions as a refrigerant decompression device.

(2-1-6) Accumulator 16
The accumulator 16 is for accumulating liquid refrigerant that has not evaporated in the previous stage of the compressor 11 and allowing gas refrigerant to pass therethrough.

(2-1-7) Heat source unit liquid passage port 17
The heat source unit liquid passage port 17 is for connecting the liquid refrigerant pipe 31. The heat source unit liquid passage port 17 incorporates a valve for manually closing the passage through which the liquid refrigerant mainly flows when there is no plan to use the refrigeration apparatus 100 for a long period of time.

(2-1-8) Heat source unit gas path port 18
The heat source unit liquid passage port 17 is for connecting the gas refrigerant pipe 32. The heat source unit liquid passage port 17 incorporates a valve for manually closing a passage through which a gas refrigerant mainly flows when there is no plan to use the refrigeration apparatus 100 for a long period of time.

(2-1-9) Heat source unit internal pipe lines 19a to 19g
The heat source unit internal pipes 19a to 19g are a plurality of components of the heat source unit 10, that is, the compressor 11, the four-way switching valve 12, the heat source unit heat exchanger 13, and the heat source unit expansion valve 15.
The heat source unit liquid path port 17 and the heat source unit gas path port 18 are connected to each other and contribute to the exchange of refrigerant between them.

(2-2) Usage units 20A and 20B
The use units 20A and 20B are for using the heat or cold generated by the heat source unit 10 for the convenience of the user. The utilization unit 20A includes a utilization unit expansion valve 21, a utilization unit heat exchanger 22, a utilization unit fan 23, a utilization unit liquid passage port 27, a utilization unit gas passage port 28, and utilization unit internal conduits 29a to 29c. The configuration of the usage unit 20B is the same as the configuration of the usage unit 20A.

  Hereinafter, the detailed configuration of the usage unit 20A will be described, and the description of the configuration of the usage unit 20B will be omitted.

(2-2-1) Use unit expansion valve 21
The utilization unit expansion valve 21 is a valve whose opening degree can be adjusted, and functions as a gas refrigerant decompression device or a flow rate adjustment device.

(2-2-2) Utilization unit heat exchanger 22
The usage unit heat exchanger 22 performs heat exchange between the refrigerant and the air around the usage unit 20A. In the case of the cold heat utilization operation, the utilization unit heat exchanger 22 functions as an evaporator and takes heat in the air into the refrigerant. On the other hand, in the case of operation using warm heat, the utilization unit heat exchanger 22 functions as a condenser and releases the heat of the refrigerant into the air.

(2-2-3) Use unit fan 23
The usage unit fan 23 promotes heat exchange of the usage unit heat exchanger 22.

(2-2-4) Use unit liquid passage port 27
The utilization unit liquid passage port 27 is a part for connecting the liquid refrigerant pipe 31.

(2-2-5) Use unit gas passage port 28
The use unit gas path port 28 is a part for connecting the gas refrigerant pipe 32.

(2-2-6) Usage unit internal conduits 29a to 29c
The utilization unit internal conduits 29a to 29c connect a plurality of components of the utilization unit 20A, that is, the utilization unit expansion valve 21, utilization unit heat exchanger 22, utilization unit liquid passage port 27, utilization unit gas passage port 28. The conduit contributes to the exchange of refrigerant between them.

(2-3) Refrigerant communication pipe 30
The refrigerant communication pipe 30 is for connecting the heat source unit 10 and the utilization unit 20A to form a refrigerant circuit. The refrigerant communication pipe 30 has a liquid refrigerant pipe 31 and a gas refrigerant pipe 32. The liquid refrigerant pipe 31 connects the heat source unit liquid passage port 17 and the utilization unit liquid passage port 27. The gas refrigerant pipe 32 connects the heat source unit gas path port 18 and the utilization unit gas path port 28.

(2-4) Refrigerant The refrigerant circulates through the heat source unit 10, the utilization units 20A and 20B, and the refrigerant communication pipe 30. The refrigerant includes a compound represented by a molecular formula having one or more carbon-carbon unsaturated bonds. The refrigerant is, for example, HFO.

(2-5) Disproportionation reaction inhibitor 40
FIG. 2 shows the utilization unit 20 </ b> A and the refrigerant communication pipe 30 of the refrigeration apparatus 100. The disproportionation reaction inhibitor 40 is applied to at least some of the inner surfaces of the liquid refrigerant pipe 31, the gas refrigerant pipe 32, and the usage unit internal pipes 29a to 29c. The disproportionation reaction inhibitor 40 is a substance that suppresses the occurrence and progression of the disproportionation reaction. Preferably, the disproportionation reaction inhibitor 40 is a polymerization inhibitor that suppresses the polymerization of the refrigerant.

  The disproportionation reaction inhibitor 40 includes at least one of a stabilizer, an antioxidant, and an oxygen scavenger.

(2-5-1) Stabilizer The stabilizer contains at least one of an oxidation resistance improver, a heat resistance improver, and a metal deactivator.

  The oxidation resistance improver and the heat resistance improver include at least one of the substances listed below.

<Oxidation resistance improver, heat resistance improver>
N, N′-diphenylphenylenediamine, p-octyldiphenylamine, p, p′-dioctyldiphenylamine, N-phenyl-1-naphthylamine, N-phenyl-2-naphthylamine, N- (p-dodecyl) phenyl-2-naphthylamine , Di-1-naphthylamine, di-2-naphthylamine, N-alkylphenothiazine, 6- (t-butyl) phenol, 2,6-di- (t-butyl) phenol, 4-methyl-2,6-di- (T-butyl) phenol, 4,4′-methylenebis (2,6-di-t-butylphenol).

  The metal deactivator includes at least one of the substances listed below.

<Metal deactivator>
Imidazole, benzimidazole, 2-mercaptobenzthiazole, 2,5-dimercaptothiadiazole, salicyridin-propylenediamine, pyrazole, benzotriazole, toltriazole, 2-methylbenzimidazole, 3,5-dimethylpyrazole, methylenebis-benzotriazole, Organic acids or their esters, primary, secondary or tertiary aliphatic amines, amine salts of organic or inorganic acids, heterocyclic nitrogen-containing compounds, amine salts of alkyl acid phosphates or their derivatives.

(2-5-2) Antioxidant The antioxidant contains at least one of the substances listed below.

<Antioxidant>
Zinc dithiophosphate, organic sulfur compound, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, 2,2′-methylenebis (4-methyl-6) -Tert-butylphenol), phenyl-α-naphthylamine, N, N′-di-phenyl-p-phenylenediamine, N, N′-disalicylidene-1,2-diaminopropane.

(2-5-3) Oxygen absorber The oxygen absorber contains at least one of the substances listed below.

<Oxygen scavenger>
2-ethylhexyl glycidyl ether, phenyl glycidyl ether, epoxidized cyclohexyl carbinol, di (alkylphenyl) carbodiimide, β-pinene.

(3) Basic operation (3-1) Cooling operation In the cooling operation, the four-way switching valve 12 constitutes a refrigerant path indicated by a solid line in FIG. The compressor 11 discharges the high-pressure gas refrigerant in the direction of the arrow in FIG. The high-pressure gas refrigerant reaches the heat source unit heat exchanger 13 after passing through the four-way switching valve 12. The heat source unit heat exchanger 13 functions as a condenser and converts the high-pressure gas refrigerant into a high-pressure liquid refrigerant. The high-pressure liquid refrigerant is decompressed by the heat source unit expansion valve 15, the liquid refrigerant pipe 31, and the use unit expansion valve 21 to become a gas-liquid two-phase refrigerant, and reaches the use unit heat exchanger 22. The utilization unit heat exchanger 22 functions as an evaporator and absorbs heat from the surrounding air in the process of converting the gas-liquid two-phase refrigerant into a low-pressure gas refrigerant, thereby cooling the surrounding air. The low-pressure gas refrigerant passes through the gas refrigerant pipe 32 and then the four-way switching valve 12 and then is sucked into the compressor 11 through the accumulator 16.

(3-2) Thermal Operation In the thermal operation, the four-way switching valve 12 configures the refrigerant path indicated by the broken line in FIG. The compressor 11 discharges the high-pressure gas refrigerant in the direction of the arrow in FIG. The high-pressure gas refrigerant reaches the utilization unit heat exchanger 22 after passing through the four-way switching valve 12 and then the gas refrigerant pipe 32. The utilization unit heat exchanger 22 functions as a condenser and releases heat in the process of converting the high-pressure gas refrigerant into a high-pressure liquid refrigerant, thereby warming the surrounding air. The high-pressure liquid refrigerant is decompressed by the use unit expansion valve 21, the liquid refrigerant pipe 31, and the heat source unit expansion valve 15 to become a gas-liquid two-phase refrigerant, and reaches the heat source unit heat exchanger 13. The heat source unit heat exchanger 13 functions as an evaporator and converts the gas-liquid two-phase refrigerant into a low-pressure gas refrigerant. Thereafter, the low-pressure gas refrigerant passes through the four-way switching valve 12 and then is sucked into the compressor 11 through the accumulator 16.

(4) Installation Procedure When installing the refrigeration apparatus 100, the heat source unit 10 is installed outdoors, and the utilization units 20A and 20B are installed indoors. In this installation step, the heat source unit 10 is preliminarily filled with the amount of refrigerant required by the entire refrigeration apparatus 100 in a liquid state. Next, the refrigerant communication pipe 30 that connects the heat source unit 10 and the utilization units 20A and 20B is installed, whereby the refrigerant circuit of the refrigeration apparatus 100 is completed. Finally, the refrigerant sealed in the heat source unit 10 is released to the refrigerant circuit, and the refrigerant flows toward the utilization units 20A and 20B. At this time, when the disproportionation reaction inhibitor 40 is applied to the inner surface of the liquid refrigerant pipe 31 or the gas refrigerant pipe 32, the refrigerant contacts the disproportionation reaction inhibitor 40. Therefore, the disproportionation reaction of the refrigerant passing through the liquid refrigerant pipe 31 or the gas refrigerant pipe 32 is unlikely to occur. Next, the refrigerant that has reached the use unit liquid passage port 27 and the use unit gas passage port 28 penetrates into each part of the use unit 20A. At this time, when the disproportionation reaction inhibitor 40 is applied to the inner surfaces of the utilization unit internal pipes 29 a to 29 c, the refrigerant contacts the disproportionation reaction inhibitor 40. Therefore, the disproportionation reaction of the refrigerant passing through the use unit internal pipes 29a to 29c hardly occurs.

(5) Features (5-1)
The disproportionation reaction inhibitor 40 is applied to at least some of the inner surfaces of the liquid refrigerant pipe 31, the gas refrigerant pipe 32, and the usage unit internal pipes 29a to 29c. Therefore, since the refrigerant circulating in the refrigerant circuit comes into contact with the disproportionation reaction inhibitor 40, the disproportionation reaction of the refrigerant hardly occurs.

(5-2)
The disproportionation reaction inhibitor 40 may be a polymerization inhibitor that suppresses the polymerization of the refrigerant. According to this configuration, the disproportionation reaction inhibitor 40 suppresses the polymerization of the refrigerant. Therefore, it is possible to suppress the performance deterioration of the refrigerant circuit due to the polymerization product.

(5-3)
As the composition of the disproportionation reaction inhibitor 40, the present application presented various findings. That is, the disproportionation reaction inhibitor 40 may include at least one of a stabilizer, an antioxidant, and an oxygen scavenger. The stabilizer may include at least one of an oxidation resistance improver, a heat resistance improver, and a metal deactivator. In addition, each possible composition of an oxidation resistance improver, heat resistance improver, metal deactivator, antioxidant, and oxygen scavenger is listed in section (2-4) of this specification. According to these findings, the specific composition of the disproportionation reaction inhibitor 40 is presented, and its manufacture and preparation become possible.

(6) Modification (6-1) Configuration In the above-described embodiment, the refrigerant used in the refrigeration apparatus 100 includes a compound represented by a molecular formula having one or more carbon-carbon unsaturated bonds. Instead, the refrigerant may specifically be a mixed refrigerant mainly composed of HFO and HFC. Furthermore, the refrigerating machine oil used in the refrigerating apparatus 100 may be a refrigerating machine oil mainly composed of an alkyl aromatic hydrocarbon and an oxygen-containing hydrocarbon.

  HFO is a hydrofluoroolefin. HFO is a compound represented by a molecular formula having one or more carbon-carbon unsaturated bonds. HFO is, for example, 1,1,2-trifluoroethylene (HFO-1123) and 2,3,3,3-tetrafluoropropene (HFO-1234yf). HFO has a low global warming potential because it is easily decomposed by OH radicals in the atmosphere.

HFC is a hydrofluorocarbon. HFC is, for example, R134a represented by the molecular formula C ₂ H ₂ F ₄ , R32 represented by the molecular formula CH ₂ F ₂ , and R410A and R407c that are mixed refrigerants. Since HFC does not contain chlorine, the effect of destroying the ozone layer is small compared to chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC).

  An alkyl aromatic hydrocarbon is a compound in which an alkyl group is bonded to an aromatic hydrocarbon such as benzene and naphthalene. Alkyl aromatic hydrocarbons are, for example, alkylbenzenes such as toluene and ethylbenzene.

  The oxygen-containing hydrocarbon is an ester compound, an ether compound, or a mixture of an ester compound and an ether compound. Oxygen-containing hydrocarbons are, for example, polyvinyl ethers and polyol esters.

  In this refrigeration apparatus, the HFO refrigerant ratio, which is the HFO mixing ratio (weight ratio; the same applies hereinafter) in the mixed refrigerant, the HFC refrigerant ratio, which is the HFC mixing ratio in the mixed refrigerant, and the alkyl aromatic hydrocarbon mixing ratio in the refrigeration oil. The alkyl aromatic oil ratio and the oxygen-containing oil ratio, which is the mixing ratio of oxygen-containing hydrocarbons in the refrigerating machine oil, show the following tendencies.

  Specifically, when a mixed refrigerant having an HFO refrigerant ratio larger than an HFC refrigerant ratio is used, a refrigerating machine oil having an alkyl aromatic oil ratio larger than an oxygen-containing oil ratio is used. On the other hand, when a mixed refrigerant having a HFO refrigerant ratio smaller than the HFC refrigerant ratio is used, a refrigerating machine oil having an alkyl aromatic oil ratio smaller than an oxygen-containing oil ratio is used. For example, when the HFO refrigerant ratio is 70% and the HFC refrigerant ratio is 30%, the alkyl aromatic oil ratio is 80% and the oxygen-containing oil ratio is 20%. The HFO refrigerant ratio is preferably equal to the alkyl aromatic oil ratio, and the HFC refrigerant ratio is preferably equal to the oxygen-containing oil ratio. Furthermore, the HFO refrigerant ratio is 40-60%, the HFC refrigerant ratio is 60% -40%, the alkyl aromatic oil ratio is 40-60%, and the oxygen-containing oil ratio is 60% -40%. It is preferable. For example, when the HFO refrigerant ratio is 40% and the HFC refrigerant ratio is 60%, the alkyl aromatic oil ratio is preferably 40% and the oxygen-containing oil ratio is preferably 60%.

  This refrigeration apparatus uses a mixed refrigerant of HFO and HFC as a refrigerant having a small global warming potential. Since HFO such as HFO1123 has a carbon-carbon unsaturated bond, it may cause a polymerization reaction in a high-temperature atmosphere such as an internal space of a compressor. Moreover, when using R32 as HFC, it is preferable to use an ether compound and an ester compound as refrigerating machine oil with good compatibility with a refrigerant | coolant. However, ether compounds and ester compounds function as initiators for the polymerization reaction of HFO having a carbon-carbon unsaturated bond. The polymer produced by the polymerization reaction of HFO adheres to the piping or the like of the refrigeration apparatus and causes the refrigerant flow path to be clogged.

  However, as a main component of refrigerating machine oil, by adding a predetermined amount of alkyl aromatic hydrocarbon that does not function as a polymerization reaction initiator, the HFO polymerization reaction is suppressed while ensuring compatibility between HFC and refrigerating machine oil. Can do. Therefore, it is preferable that the higher the HFO refrigerant ratio, which is the mixing ratio of HFO in the mixed refrigerant, the higher the alkyl aromatic oil ratio, which is the mixing ratio of alkyl aromatic hydrocarbons in the refrigerating machine oil.

(6-2) Features (6-2-1) First Aspect of Modification A refrigeration apparatus 100 according to a first aspect of the modification includes a mixed refrigerant mainly composed of HFO and HFC, and an alkyl aromatic carbonization. Refrigerating machine oil mainly composed of hydrogen and oxygen-containing hydrocarbon is used. The oxygen-containing hydrocarbon contains at least one of ether and ester. In the mixed refrigerant, the weight mixing ratio of HFO is the first refrigerant ratio, and the weight mixing ratio of HFC is the second refrigerant ratio. In the refrigerating machine oil, the mixing ratio of the alkyl aromatic hydrocarbon is the first oil ratio, and the mixing ratio of the oxygen-containing hydrocarbon is the second oil ratio. When the first refrigerant ratio is greater than the second refrigerant ratio, the first oil ratio is greater than the second oil ratio. When the first refrigerant ratio is smaller than the second refrigerant ratio, the first oil ratio is smaller than the second oil ratio.

  According to this configuration, the refrigerating machine oil includes an alkyl aromatic hydrocarbon. Some HFO refrigerants have a carbon-carbon unsaturated bond and are easily polymerized at high temperatures such as HFO1123. On the other hand, ether compounds and ester compounds are suitable as refrigerating machine oils with good compatibility with HFC refrigerants such as R32. However, ether compounds and ester compounds tend to function as initiators for the polymerization reaction of HFO refrigerants having a carbon-carbon unsaturated bond. The polymer produced by the polymerization reaction adheres to the piping or the like of the refrigeration apparatus and causes the refrigerant flow path to be clogged. However, by adding a predetermined amount of alkyl aromatic hydrocarbon as the main component of the refrigerating machine oil, the polymerization reaction of the HFO refrigerant can be suppressed while ensuring the compatibility between the HFC refrigerant and the refrigerating machine oil. Therefore, the refrigeration apparatus according to the first aspect can suppress clogging of the polymer produced by the polymerization reaction of the refrigerant, and can provide a highly safe refrigeration apparatus.

(6-2-2) Second viewpoint of modification The refrigeration apparatus 100 according to the second aspect of the modification is the refrigeration apparatus according to the first aspect of the modification, in which the HFO is HFO1123, and the HFC is R32. Good.

  According to this configuration, by adding a predetermined amount of alkyl aromatic hydrocarbon as the main component of the refrigerating machine oil, the polymerization reaction of HFO 1123, which is the HFO refrigerant, is suppressed while ensuring compatibility with R32, which is the HFC refrigerant. Can do.

(6-2-3) Third viewpoint of modification The refrigeration apparatus 100 according to the third aspect of the modification is the refrigeration apparatus according to the first aspect or the second aspect of the modification, in which the first refrigerant ratio is the first. It is equal to the oil ratio, and the second refrigerant ratio is equal to the second oil ratio.

  According to this configuration, by adding a predetermined amount of alkyl aromatic hydrocarbon as a main component of the refrigerating machine oil, it is possible to suppress the polymerization reaction of the HFO refrigerant while ensuring compatibility with the HFC refrigerant.

(6-2-4) Fourth Viewpoint of Modification A refrigeration apparatus 100 according to a fourth aspect of the modification is the first refrigerant in the refrigeration apparatus according to any one of the first to third aspects of the modification. The ratio is 40% to 60%, the second refrigerant ratio is 60% to 40%, the first oil ratio is 40% to 60%, and the second oil ratio is 60% to 40%.

  According to this configuration, the polymerization reaction of the HFO refrigerant can be further suppressed while ensuring the compatibility between the HFC refrigerant and the refrigerating machine oil.

DESCRIPTION OF SYMBOLS 10 Heat source unit 19a-g Heat source unit internal conduit 20A, 20B Utilization unit 29a-c Utilization unit internal conduit 30 Refrigerant communication piping 31 Liquid refrigerant piping 32 Gas refrigerant piping 40 Disproportionation reaction inhibitor 100 Refrigeration equipment

Japanese Patent Laying-Open No. 2015-007257

Claims (9)

A heat source unit (10);
A usage unit (20A) having usage unit internal conduits (29a-29c);
A liquid refrigerant pipe (31) and a gas refrigerant pipe (32) connecting the heat source unit and the utilization unit internal pipe,
HFO and HFC as main components, a refrigerant circulating through the heat source unit, the utilization unit, the liquid refrigerant pipe and the gas refrigerant pipe,
A refrigerating machine oil mainly composed of an alkyl aromatic hydrocarbon and an oxygen-containing hydrocarbon;
With
A disproportionation reaction inhibitor (40) that suppresses the disproportionation reaction of the refrigerant is applied to the inner surface of at least a part of the liquid refrigerant pipe, the gas refrigerant pipe, and the use unit internal pipe. And
The oxygen-containing hydrocarbon includes at least one of an ether and an ester,
The weight mixing ratio of the HFO in the refrigerant is a first refrigerant ratio,
The weight mixing ratio of the HFC in the refrigerant is a second refrigerant ratio,
The mixing ratio of the alkyl aromatic hydrocarbon in the refrigerating machine oil is the first oil ratio,
The mixing ratio of the oxygen-containing hydrocarbon in the refrigerating machine oil is the second oil ratio,
When the first refrigerant ratio is larger than the second refrigerant ratio, the first oil ratio is larger than the second oil ratio, and when the first refrigerant ratio is smaller than the second refrigerant ratio, the first oil The refrigeration apparatus (100), wherein the ratio is smaller than the second oil ratio. The HFO is HFO1123;
The HFC is R32;
The refrigeration apparatus according to claim 1. The first refrigerant ratio is equal to the first oil ratio;
The second refrigerant ratio is equal to the second oil ratio;
The refrigeration apparatus according to claim 1 or 2. The first refrigerant ratio is 40% to 60%;
The second refrigerant ratio is 60% to 40%;
The first oil ratio is 40% to 60%;
The second oil ratio is 60% to 40%.
The refrigeration apparatus according to any one of claims 1 to 3. The disproportionation reaction inhibitor is a polymerization inhibitor that suppresses polymerization of the refrigerant.
The refrigeration apparatus according to any one of claims 1 to 4. The disproportionation inhibitor includes at least one of a stabilizer, an antioxidant, and an oxygen scavenger.
The refrigeration apparatus according to any one of claims 1 to 5. The disproportionation reaction inhibitor includes the stabilizer,
The stabilizer includes at least one of an oxidation resistance improver, a heat resistance improver, and a metal deactivator,
The oxidation resistance improver and the heat resistance improver are:
N, N′-diphenylphenylenediamine,
p-octyldiphenylamine,
p, p′-dioctyldiphenylamine,
N-phenyl-1-naphthylamine,
N-phenyl-2-naphthylamine,
N- (p-dodecyl) phenyl-2-naphthylamine,
Di-1-naphthylamine,
Di-2-naphthylamine,
N-alkylphenothiazine,
6- (t-butyl) phenol,
2,6-di- (t-butyl) phenol,
4-methyl-2,6-di- (t-butyl) phenol,
4,4′-methylenebis (2,6-di-tert-butylphenol),
Including at least one of
The metal deactivator is
Imidazole,
Benzimidazole,
2-mercaptobenzthiazole,
2,5-dimercaptothiadiazole,
Salicyridin-propylenediamine,
Pyrazole,
Benzotriazole,
Toltriazole,
2-methylbenzimidazole,
3,5-dimethylpyrazole,
Methylene bis-benzotriazole,
Organic acids or their esters,
Primary, secondary or tertiary aliphatic amines,
Amine salts of organic or inorganic acids,
Heterocyclic nitrogen-containing compounds,
Amine salts of alkyl acid phosphates or their derivatives,
Including at least one of
The refrigeration apparatus according to claim 6. The disproportionation reaction inhibitor includes the antioxidant,
The antioxidant is
Zinc dithiophosphate,
Organic sulfur compounds,
2,6-di-tert-butyl-4-methylphenol,
2,6-di-tert-butyl-4-ethylphenol,
2,2′-methylenebis (4-methyl-6-tert-butylphenol),
Phenyl-α-naphthylamine,
N, N′-di-phenyl-p-phenylenediamine,
N, N′-disalicylidene-1,2-diaminopropane,
Including at least one of
The refrigeration apparatus according to claim 6 or 7. The disproportionation inhibitor includes the oxygen scavenger,
The oxygen scavenger is
2-ethylhexyl glycidyl ether,
Phenylglycidyl ether,
Epoxidized cyclohexyl carbinol,
Di (alkylphenyl) carbodiimide,
β-pinene,
Including at least one of
The refrigeration apparatus according to any one of claims 6 to 8.

Images