JP2962676B2 - Refrigeration equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus provided with a refrigeration cycle for compressing and liquefying a refrigerant with a compressor and expanding the liquefied refrigerant, such as a refrigerator and a refrigerating apparatus.
In particular, the present invention relates to a refrigeration system using a refrigeration oil composition having a critical temperature of 40 ° C. or higher and containing no chlorine, for example, a refrigeration oil composition compatible with chlorofluorocarbon 134a.

[0002]

2. Description of the Related Art In recent years, the use of chlorofluorocarbons (chlorofluorocarbons, abbreviated as CFCs) has been subject to restrictions worldwide due to environmental pollution, in particular, ozone depletion and global warming.

[0003] Freon subject to regulation is Freon 11, Freon 12, Freon 113, Freon 114, Freon 115 and the like, all of which contain chlorine. Fluorocarbons 12 that have been used exclusively as refrigerants in equipment refrigeration systems are also subject to regulations.

Therefore, an alternative refrigerant is required. Recently, hydrogen fluoride carbon (HFC), which has low reactivity with ozone and has a short decomposition period in the atmosphere, has attracted attention as an alternative refrigerant. Is a typical refrigerant. That is, Freon 134a has an ozone depletion potential (ODP)
Is CFC12 (dichlorodifluoromethane CCl
₂ F ₂ ) is 0 when it is 1, and the global warming potential (GWP) is 0.3 or less when Freon 12 is 1. It is nonflammable and its thermophysical properties such as temperature-pressure characteristics are close to those of Freon 12. It is said that there is an advantage that it can be put to practical use without largely changing the structure of a refrigeration apparatus or a refrigerant compressor, such as a refrigerator, a dehumidifier, and an air conditioner (air conditioner), which have conventionally used Freon 12. It has been.

However, Freon 134a (1.1.1-
Tetrafluoroethane (CH ₂ FCF ₂ ) has a very unique property due to its unique chemical structure, and it is difficult to use a refrigerating machine oil such as a mineral oil or an alkylbenzene oil which has been used in a conventional refrigeration system of CFC-12. Poor compatibility, making practical use impossible. In addition, the compatibility of lubrication, friction and abrasion resistance, and the effect on electrical insulation of the sliding parts of the compression machine is a problem, and the development of a new material system for the compressor and refrigeration equipment is eagerly awaited. Have been.

Therefore, before referring to the problem of compatibility between the refrigerant and the refrigerating machine oil, a conventional refrigerant compressor and a refrigerating apparatus using a CFC-based refrigerant will be described with reference to FIGS.

FIG. 7 is a vertical sectional view of a main part of a conventional hermetic rotary compressor, FIG. 8 is a cross-sectional view for explaining the displacement of the compressor section, and FIG. 9 is a general refrigeration cycle. FIG.

In FIG. 7, reference numeral 1 designates a case relating to a closed container which also serves as an oil reservoir.

The electric motor 22 comprises a stator 19 and a rotor 20, and a rotary shaft 4A made of cast iron is fitted to the rotor 20. The rotating shaft 4A has the eccentric portion 3, and has a hollow shaft hole 17 at one end.

[0010] winding portion 19a of the stator 19, the core wire is covered with an ester imide film, electrically insulating film of polyethylene te terephthalate is mounted between the core portion and the winding portion of the stator, also the rotational axis The surface of 4A is finished by grinding.

The compressor section 23 includes a cylinder 2 made of an iron-based sintered body, a cast iron roller 7 fitted into the eccentric section 3 of the rotary shaft 4A and eccentrically rotating along the inside of the cylinder 2, and a tip end of the roller 7. A high-speed steel vane 10 that reciprocates in the groove 8 of the cylinder 2 while being in contact with the other end thereof while being pressed by the spring 9. The main bearing 5 and the sub-bearing 6 made of cast iron or an iron-based sintered body are used as main mechanism elements.

The auxiliary bearing 6 is provided with a discharge valve 27, a discharge cover 25 is attached so as to form a silencer 28, and the main bearing 5, cylinder 2 and auxiliary bearing 6 are connected by bolts 21. .

The back surface 11 of the vane 10 and the cylinder 2
Of the pump chamber 1 surrounded by the groove 8 and the main bearing 5 and the sub-bearing 6
2 are configured.

The main bearing 5 has a suction piece 14 into which a naphthene-based or alkylbenzene-based refrigerating machine oil 13A in which refrigerant Freon gas stored in the bottom of the case 1 is dissolved can be sucked into a pump chamber 12, and the sub-bearing 6 has a pumping piece. Room 12
There is a discharge port 16 through which the refrigerating machine oil 13A can be discharged to the oil feed pipe 15. The oil supply pipe 15 has a shaft hole 17 of the rotary shaft 4A.
Refrigerator oil 13 </ b> A is supplied to the shaft portion 17, and further, the oil can be supplied to the sliding portion at a key point through the branch hole 18.

The operation of the rotary compressor constructed as described above will be described with reference to FIGS. When the compressor is operated and the cast-iron rotating shaft 4A rotates, the tempered cast-iron roller 7 rotates with it, and the high-speed steel vane 10 is pressed by the spring 9, and the tip of the high-speed steel vane 10 abuts against the roller 7 while abutting on the roller 7. Alternatively, the refrigerant reciprocates in the groove 8 of the iron-based sintered body cylinder 2, compresses the refrigerant (Freon 12) flowing from the refrigerant suction port (not shown), and discharges the refrigerant through the refrigerant discharge port 24 to the discharge pipe 29. From the compressor. The winding portion 19a of the stator 19 and the electric insulating film (not shown) are immersed in refrigeration oil in which Freon is dissolved or exposed to a spraying environment by mist.

In the conventional combination of the refrigerating machine oil composed of mineral oil or alkylbenzene and Freon 12, the Freon 12 is completely compatible with the refrigerating machine oil in all usage ranges. There was no need to worry about the two-layer separation phenomenon or the various problems related to the compatibility of refrigeration oil with so-called chlorofluorocarbon 134a in which the refrigeration oil stays in the heat exchanger. However, in the case of a fluorinated hydrocarbon-based refrigerant containing no chlorine having a unique property, for example, Freon 134a, there is no practical refrigerating machine oil that easily dissolves the refrigerant, so that the compatibility between the refrigerant and the refrigerating machine oil is not sufficient. Is the biggest practical issue.

In general, in order to increase the performance of a compressor, that is, the coefficient of performance (COP) indicating the energy efficiency, it was necessary to minimize the mechanical loss of the compressor and to maximize the volumetric efficiency.

Most of the mechanical loss of the refrigerant compressor is caused by friction loss in a journal bearing or a thrust bearing in a mechanical part, stirring power of oil, and the like. Generally, it is based on the theory of fluid lubrication of a journal bearing. It has been said that the best solution is to minimize the coefficient of friction (μ) in the equation shown below.

[0019]

(Equation 1)

[0020] That is, in a refrigerant compressor operated under fluid lubrication conditions, in addition to the structural factors of the dimensions and shape, the actual viscosity of the refrigerating machine oil in a dissolved state of Freon, which is a factor governed by the operating environment, depends on the mechanical characteristics of the compressor. It shows that it is greatly related to the loss.

On the other hand, the condition for maintaining the highest volumetric efficiency is to completely seal the components that perform the compression operation in the machine room for compressing the refrigerant gas so that the refrigerant gas does not leak from the high pressure side to the low pressure side. That is. Also in this case, it is necessary to pay attention to the fact that the actual viscosity of the refrigerating machine oil in which the refrigerant is dissolved is making an important movement.

As described above, in the refrigerant compressor conventionally used for Freon 12 and the refrigeration system using the same, the actual viscosity of the refrigeration oil at the time of the melting of the refrigerant at the rated operation point under the normal operation condition is adjusted to the optimum condition. Means that it is important for the performance of the compressor.

On the other hand, refrigeration systems such as refrigerators, dehumidifiers, and air conditioners, although rare, are often operated in a high-temperature environment far exceeding normal operating conditions. As it becomes thinner, it enters into a so-called boundary lubrication area with metal contact between bearing sliding parts, the friction coefficient increases temporarily, and heat is generated,
Biting and seizure sticking phenomena occur between the bearing and the rotating shaft, which causes the reliability of the refrigerant compressor to be impaired. Therefore, it is necessary to take measures to prevent a fatal problem from occurring even under boundary lubrication conditions. In a conventional refrigerant compressor using Freon 12, chlorine in Freon 12 has effectively acted as an extreme pressure agent. In other words, when biting or seizure adhesion occurs between the bearing and the rotating shaft, the refrigerant Freon 12 dissolved in the refrigerating machine oil as the bearing lubricating oil is decomposed by the frictional heat,
The decomposition product chlorine reacts with the iron on the bearing surface to form iron chloride, which acts as a lubricant.

As described above, in a refrigerating apparatus using a high-pressure container type rotary compressor, for example, a refrigerator,
The operating conditions at an ambient temperature of 30 ° C. are as follows: the discharge pressure of the compressor is about 10 kg / cm ² abs, the oil temperature is about 100 ° C., and the actual viscosity of the oil is 1 to 4.
Alkylbenzene or mineral oil refrigeration oil that becomes cSt (56 cSt at 40 ° C., 6 cS at 100 ° C.)
t) is good in terms of the coefficient of performance indicating the energy efficiency and the reliability of the product, and most products have been used in this range.

On the other hand, a refrigerating apparatus using a low-pressure vessel type reciprocating compressor (the description of the structure and operation is omitted)
For example, in a refrigerator, operating conditions at an ambient temperature of 30 ° C. are such that a compressor suction pressure is about 1.6 kg / cm ² abs, an oil temperature is 85
° C, mineral oil based refrigerating machine oil that has an actual oil viscosity of 2 to 6 cSt (at 40 ° C, 8 to 15 cSt, at 100 ° C,
(1.8-4.2 cSt) have been used as refrigerant compressors and refrigeration systems.

Next, a basic refrigeration cycle in which a refrigerant compressor for sucking, compressing, and discharging a CFC-based refrigerant will be described with reference to FIG.

As shown in FIG. 9, the compressor 40 has a low temperature,
The low-pressure refrigerant gas is compressed, and the high-temperature, high-pressure refrigerant gas is discharged and sent to the condenser 41. The refrigerant gas sent to the condenser 41 becomes a high-temperature, high-pressure refrigerant liquid while releasing the heat into the air, and is sent to an expansion mechanism (for example, an expansion valve or a capillary tube) 42. The high-temperature, high-pressure refrigerant liquid passing through the expansion mechanism is converted into low-temperature, low-pressure wet steam by the throttle effect and sent to the evaporator 43. The refrigerant entering the evaporator 43 absorbs heat from the surroundings and evaporates, and the low-temperature and low-pressure refrigerant gas exiting the evaporator 43 is sucked into the compressor 40, and the same cycle is repeated thereafter.

Conventionally, Freon 12 has been used as this refrigerant. However, since the use of Freon 12 has been restricted as described above, Freon 13 has been
When 4a is to be used, conventional mineral oil-based or alkylbenzene-based refrigerating machine oil for CFC 12 has CFC 13
The compatibility with 4a was remarkably poor, causing many practical problems. Therefore, the development of refrigerating machine oil having excellent compatibility with Freon 134a has been actively conducted.
Various refrigeration oils have been proposed.

As typical examples, compounds having an ether bond as exemplified below are known.

For example, in Japanese Patent Application Laid-Open No. 1-259093, propylene glycol monoether can be represented by the general formula (10) as “refrigeration oil for CFC compressor”.

[0031]

Embedded image

(Where R in the formula is a group having 1 to 8 carbon atoms and n is an integer of 4 to 19). The terminal of the glycol is etherified and can be represented by the general formula (11) of a jetel type compound.

[0033]

Embedded image

(Where R ₁ and R ₂ in the formula _each have 1 to 8 carbon atoms)
Alkyl groups , n is an integer, average molecular weight 300 to 60
0) can be further represented by the general formula (12) of a monoether type compound of propylene glycol and an ethylene glycol copolymer in JP-A 1-25995.

[0035]

Embedded image

(Where R is an alkyl group having 1 to 14 carbon atoms, m and n are integers, and the ratio of m: n is 6: 4 to 1:
9 average molecular weight of 300 to 2000).

The difference between these polyalkylene glycols and conventional mineral oils or alkylbenzene oils is that by introducing an ether bond into the molecule, the affinity for Freon 134a is enhanced, the compatibility is greatly improved, and compression is achieved. Prevents lubrication of the refrigerant due to the two-layer separation phenomenon (separation of refrigerant and refrigerating machine oil without melting) at the sliding part of the machine, and oil return to the compressor caused by the stagnation phenomenon due to oil adhesion to the inner wall of the heat exchanger Improvements have been made to solve various problems relating to the reliability of the compressor and the refrigeration device, such as seizure and biting of the sliding portion of the compressor.

However, those containing a large number of ether bonds (C—O—C) in the molecule as described above have (1) a large saturated moisture absorption rate (easy to absorb moisture) and (2) a low volume resistivity ( 3) Poor oxidative stability, easy to increase total acid value. However, such a method is unsuitable for a refrigerant compressor and a refrigeration apparatus that use a hermetic motor as an electric motor.

[0039] That is, although the compatibility with the refrigerant is improved invasion the motor of the insulator, there is a problem that deteriorates the electrical insulating properties. In any of the above compounds, the terminal group of the molecule having an ether bond is end-capped with hydrogen, and this hydrogen further increases the hygroscopicity. Therefore, a proposal has been made to esterify this hydrogen to obtain a refrigerating machine oil represented by the following formula (see Japanese Patent Application Laid-Open No. 2-132178).

[0040]

Embedded image

(Where R is a hydrocarbon group, R ¹ is an alkylene group, R ² is an alkyl group, and n is an integer giving a viscosity of the compound of 10 to 300 (40 ° C.))
This compound also has a similar problem because the improvement in compatibility with the refrigerant is due to a large number of ether bonds present in the molecule, as in the case of the above.

The compound having an ether bond as described above tends to take in water due to the above problem (1), and the water itself makes the compound itself hydrolyzed and becomes unstable.

In addition, moisture freezes and clogs the capillaries of the refrigeration cycle, causing a pressure imbalance. In addition, from (2), the volume resistivity is reduced, and the voltage insulation is reduced. From (3), when the total acid value increases, the compound is hydrolyzed and becomes unstable.

[0044]

As described above, Freon 134a, which is an alternative refrigerant to the conventional Freon 12, has a unique molecular structure. And has a fatal problem that it lacks compatibility with refrigerating machine oil, which is the basis of refrigerant compressors and refrigerating devices.

Attempts have also been made to improve compatibility, but with this, new problems such as lowering of electrical insulation, problems of moisture, and problems of instability such as hydrolysis and decomposition of compounds by acids are caused. Have been. Hereinafter, each problem will be described in more detail.

If a refrigerating machine oil having poor compatibility is used forcibly, the refrigerant compressor and the refrigerating apparatus cannot be put to practical use in terms of performance and reliability as described below.

In general, when the solubility of the refrigerating machine oil in the refrigerant is low, the oil discharged from the compressor separates in the heat exchanger and the oil component remains on the wall surface, and the amount of oil returning to the compressor decreases. As a result, the oil level of the compressor decreases, causing a so-called oil rising phenomenon, and the oil supply level decreases.

In a refrigeration system in which a large amount of refrigerant is sealed, when the temperature of the compressor is exposed to a low temperature, the liquid refrigerant is unevenly distributed in the bottom of the compressor. Is supplied to the sliding surface of the rotating shaft, making it difficult to secure a lubricating oil film and causing damage to the compressor.

On the other hand, in the refrigerating apparatus, the separated refrigerating machine oil adheres to the inner wall of the low-temperature evaporator and forms a heat insulating layer, thereby significantly impairing the heat transfer performance. When the action of closing the expansion mechanism (capillary tube) or pipe pipe works, the amount of circulating refrigerant is drastically reduced, and the cooling power is reduced. As a compressor, the pressure of the suction gas decreases and the pressure of the discharge gas increases, leading to thermal degradation of the refrigerating machine oil and damage to the mechanical bearings, significantly impairing the long-term reliability of the refrigerant compressor and refrigerating device. Will be.

Accordingly, an object of the present invention is to solve these conventional problems, and to provide a conventional refrigerant containing chlorine.
It is an object of the present invention to provide a refrigerating apparatus that uses a suitable refrigerating machine oil as a lubricating oil when a part or all of the refrigerant is replaced with a chlorine-free Freon-based refrigerant represented by Freon 134a. If (1) moisture absorption, (2)
Body volume resistivity, with improve such (3) oxidative deterioration,
Under all operating conditions of the refrigeration system, CFC 134a
A refrigerating machine oil that satisfies the first goal of at least a critical melting temperature of 0 ° C. or lower for a medium-temperature refrigerating device such as a dehumidifier, based on searching for a new refrigerating machine oil composition that is compatible with And by developing a refrigerating machine oil that satisfies the second target of critical melting temperature of -30 ° C or lower for low-temperature refrigerating devices such as refrigerators, the performance, efficiency, It is an object of the present invention to provide a refrigerating apparatus having excellent reliability.

The refrigeration apparatus including a refrigerant compressor, generally under normal use conditions is operated, to increase the coefficient of performance (COP) which indicates the energy efficiency is the ratio between the input and the freezing capacity of the refrigerant compressor, From a long-term perspective, it will help prevent global warming (GWP).

As a means for improving the performance of the compressor, in order to reduce the input of the compressor, it is necessary to reduce the friction coefficient based on the theory of fluid lubrication of the coaxial bearing. To this end, the solubility of Freon 134a and the refrigerating machine oil of the present invention is measured, and the optimum value of the actual viscosity of the oil used in the compressor is set. Important to derive the highest coefficient of performance as
Becomes

Therefore , based on the above bearing theory, the performance is improved by defining the optimum viscosity range of the refrigerating machine oil for the refrigerating apparatus using the rotary compressor of the high pressure vessel type and the reciprocating type compressor of the low pressure vessel type. It is important to achieve high reliability. However, the refrigeration system is, in fact, very rarely operated in a high-temperature environment exceeding the design expectation or in an extremely severe operation such as overload operation.In this case, sufficient reliability is required. It is necessary to secure.

When the compressor using the Freon 134a is used in a so-called boundary lubrication region involving metal contact beyond the fluid lubrication region of the coaxial bearing, biting and seizure of the sliding portion of the compressor bearing may occur. , Tend to be larger than in the case of the conventional CFC 12. In the case of Freon 12, when the sliding part of the bearing makes metal contact, Freon 12 dissolved in the oil is decomposed to form a chemical film of iron chloride on the iron-based sliding friction surface. It acted as an extreme pressure action, suppressing adhesion and seizure phenomena.

On the other hand, in a compressor using chlorofluorocarbon 134a, it is difficult to supply chlorine because it is a refrigerant containing no chlorine, and it is difficult to expect the extreme pressure action as in the above-mentioned fluorocarbon 12. is there.

Therefore, even if the sliding bearing of the compressor runs out of oil using a chlorofluorocarbon-based refrigerant typified by chlorofluorocarbon 134a , the use of a refrigerating machine oil to which an extreme pressure agent is added can be achieved. It is important to ensure sufficient reliability by preventing biting and seizure of the sliding part even in the case of an extremely severe operation.

Further, in a refrigeration system having a refrigerant compressor using a chlorofluorocarbon-based refrigerant represented by chlorofluorocarbon 134a and a refrigerating machine oil composition, an electric insulating film or insulating film constituting a motor portion of the compressor is provided. An electric insulation system that can withstand long-term reliability with electric insulation materials such as coated windings
It is important to do .

Fluorocarbon 134a is characterized by having a high water absorption rate. Refrigeration oil compatible with chlorofluorocarbon 134a is also relatively hydrophilic even if considerably improved. Easy to bring. The water in the refrigerating apparatus separates from the ice in the evaporator on the low-temperature side, closes a thin pipe such as a capillary tube, and lowers the refrigerating performance. In the long term, refrigeration oil, refrigerant,
An electrical insulating material or the like causes a hydrolysis reaction, which causes negative characteristics such as generation of an acidic substance and a decrease in mechanical strength. Therefore, in a refrigeration system in which a chlorofluorocarbon-based refrigerant, such as chlorofluorocarbon 134a , and a refrigeration oil coexist, it is effective to improve the reliability of the refrigeration system by separating and adsorbing only water without absorbing the refrigerant. it is also that Do important to use a dryer filled with desiccant to work.

[0059]

The object of the present invention is to provide (1). Hydrofluorinated carbon (HFC) is the main component
A refrigerant having an ambient temperature of 40 ° C. or higher and compressing the refrigerant
A hermetic compressor, a condenser for condensing the refrigerant,
A dryer for drying the refrigerant, and an expansion for expanding the refrigerant
A mechanism, an evaporator for evaporating the refrigerant, and a viscosity of 40 ° C.
At 2 to 70 cSt, at 100 ° C. at 1 to 9 cSt
Refrigeration oil based on a certain fatty acid ester oil
The refrigerating machine oil is represented by the following general formulas (1) to (5).
At least selected from the group of fatty acid ester oils shown
(Wherein R ₂ is an alkyl having 5 to 12 carbon atoms).
Can mix two or more kinds with different carbon numbers.
And the fats represented by the following general formulas (1) to (5)
Among fatty acid ester oils, R ₂ has less than 5 carbon atoms
This is achieved by a refrigeration system consisting of refrigeration oil that does not contain carbon numbers .

[0060]

Embedded image (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ (1)

[0061]

Embedded image R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ (2)

[0062]

Embedded image C · (CH ₂ —OCOR ₂ ) ₄ (3)

[0063]

Embedded 104] _{(R 2 · COOH 2 C)} 3 · C · CH 2 · O · CH 2 · C (CH 2 · OCOR 2) 3 ... (4)

[0064]

Embedded image

[0065] (2). As described above, an ester of a fatty acid having two or more ester bonds in the molecule is indispensable as the ester oil, and one having one ester bond has poor compatibility with a refrigerant and cannot be used. Fatty acid ester oils are obtained by an ester reaction between alcohols and fatty acids. Polyhydric alcohols are desirable as alcohols, and fatty acids having 6 to 8 carbon atoms are desirable, and they may be monobasic or polybasic. . Further, ester oils include hindered ester oils and complex ester oils, and from the viewpoint of compatibility with refrigerants, ester oils having a branched structure rather than a linear structure tend to be more desirable. Examples of practical fatty acid ester oils are shown below by general formulas (1) to (5).

The general formulas (1) to (4) are examples of a hindered ester oil, and the general formula (5) is an example of a complex ester oil.

These ester oils may be used alone or in combination of two or more. Further, they may be contained as at least 50 wt% base oil, and the remainder may be supplemented with other well-known refrigerator oil. General formula,

[0068]

(R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) (Neobentyl glycol (abbreviated as NPG) ester having two ester bonds in the molecule) Example) General formula,

[0069]

Embedded image R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) (trimethylolalkyl (propane, abbreviated as TMP) -based ester having three ester bonds in the molecule) Example) General formula,

[0070]

Embedded image C. (CH ₂ —OCOR ₂ ) ₄ ... (3) (abbreviated as pentaerythritol having four ester bonds in the molecule) (PET)

[0071]

Embedded 109] _{(R 2 · C O O H} 2 C) 3 · C · CH 2 · O · CH 2 · C (CH 2 · OC OR 2) 3 ... (4) (6 months of ester bonds in the molecule Example of dipentaerythritol (abbreviated as DPET) based ester having

[0072]

Embedded image

(Example of Complex Ester Having Four or More Ester Bonds in the Molecule) In each of the above general formulas, R ₁ is H or an alkyl group having 1 to 3 carbon atoms, and R ₂ is an alkyl group having 5 to 5 carbon atoms. R 12 represents an alkyl group having 1 to ₃ carbon atoms, and n represents 0 or an integer of 1 to 5, respectively.

The general formulas (1) to (4) are esters of a polyhydric alcohol and a monocarboxylic acid. By arbitrarily selecting the kind of the alcohol and the compound of the monocarboxylic acid alone or plurally, A desired viscosity grade can be obtained.

In the complex ester represented by the general formula (5), the chemical structure of the central dibasic acid (dicarboxylic acid) is represented by succinic acid (n = 2), glitalic acid (Glut), adipine Acid (abbreviated as AZP), pimelic acid, suberic acid, azelaic acid, sebacic acid (n = 8)
To obtain high viscosity and wide critical solution temperature range by selecting various molecular chains of polyhydric alcohol and terminal monocarboxylic acid and changing the mixing ratio (molar fraction). Can be.

These hindered ester oils and complex ester oils are used alone or in combination to adjust the viscosity to obtain a base oil.

The refrigerant used in the present invention, which has a critical temperature of 40 ° C. or higher and is mainly composed of a carbon fluoride-based refrigerant containing no chlorine , is 1,1,1,2-tetrafluorofluorocarbon 134a. In addition to ethane (R134a) , there are hydrofluorocarbons and fluorocarbons as shown below .
Specific examples of hydrofluorocarbons include difluoromethane (R32), pentafluoroethane (R125), 1,1,
2,2-tetrafluoroethane (R134) , 1,1,2-trifluoro
Oroethane (R143) , 1,1,1-trifluoroethane (R14
3a), 1,1-difluoroethane (R152a) and monofluoroethane (R161).

Specific examples of the fluorocarbon include hexafluoropropane (C216) and octafluorocyclobutane (C318). Of these, especially 1,1,2,2
-Tetrafluoroethane (R134), 1,1,2-trifluoroethane (R134), 1,1,1-trifluoroethane (R143
a) Hexafluoropropane (C216) has a boiling point close to that of conventional dichlorodifluoromethane (R12),
Preferred as an alternative refrigerant.

In addition to using these hydrofluorocarbon or fluorocarbon-based refrigerants alone, it is also possible to use them as a mixture of two or more. By the way, the reason why the critical temperature of the refrigerant is set to 40 ° C. or higher is that a refrigerating device having a condenser temperature of 40 ° C. or higher is required.

The object of the present invention is as follows: (3). Hydrofluorinated carbon (HFC) is the main component
When the ambient temperature is 40 ° C or higher and the viscosity is 40 ° C
An ester oil of a fatty acid having 5-32 cSt was used as a base oil.
This is a refrigeration system that is used with refrigerating machine oil enclosed.
This refrigeration apparatus has a closed high-pressure capacity for compressing the refrigerant.
And a condenser for condensing the refrigerant.
A compressor, a dryer for drying the refrigerant, and an expander for the refrigerant.
An expansion mechanism for expanding, and an evaporator for evaporating the refrigerant.
And the refrigerating machine oil is represented by the general formulas (1) to (5).
At least selected from the group of fatty acid ester oils shown
(Wherein R ₂ is an alkyl having 5 to 12 carbon atoms).
Can mix two or more kinds with different carbon numbers.
And the fats represented by the general formulas (1) to (5)
Among the ester oils of acids, those having a carbon number of R ₂ smaller than 5
Tsu by the refrigeration apparatus comprising a refrigerating machine oil do not include those of prime numbers
Even achieved.

In this type of high-pressure container type rotary compressor, the actual oil viscosity by dissolving Freon 134a at a gas pressure of 9 to 11 kg / cm ² abs and an oil temperature of about 100 ° C. is 1.0 to 1.0.
The viscosity at 40 ° C. is 2 to 7 so that it falls within 4.0 cSt.
The refrigerating machine oil of 0 cSt, preferably 5.0 to 32 cSt according to the above (2) is sealed in advance.

On the other hand, in a refrigerating apparatus equipped with a low-pressure vessel type reciprocating compressor, (4). Hydrogenated
The main component is hydrogenated carbon (HFC) and the critical temperature is 40 ° C or higher.
With the refrigerant above, at 5-15 cSt when the viscosity is 40 ° C
Enclosed with refrigerating machine oil based on a certain fatty acid ester oil
This is a refrigeration system used in a frozen state.
Is a closed type low pressure vessel type reciprocating
Compressor, a condenser for condensing the refrigerant, and the refrigerant
Dryer for drying the refrigerant, and an expansion mechanism for expanding the refrigerant
And an evaporator for evaporating the refrigerant.
The oil is composed of the fatty acids represented by the general formulas (1) to (5).
Containing at least one member selected from the group of ester oils
(However, R ₂ is an alkyl group having 5 to 12 carbon atoms,
Different types can be mixed).
Of fatty acid ester oils represented by general formulas (1) to (5)
Among them, it includes those carbon atoms the number of carbon atoms in R ₂ is less than 5
This is achieved by a refrigeration system consisting of no refrigeration oil .

At least two ester bonds in the above molecule
The composition of the fatty acid ester oils
As described in detail in section (2).

In the low-pressure vessel type reciprocating compressor, the actual viscosity of the oil in dissolving the chlorofluorocarbon 134a at a suction gas pressure of 1.0 to 2.0 kg / cm ² abs at an oil temperature of 85 ° C. is 2.0 to 4.5 c.
5.0-1 when the viscosity is 40 ° C.
5 cSt, 2.0-4.5 cSt at 100 ° C.
The refrigerating machine oil described in the item (2) is previously enclosed.

[0085] be added to the extreme pressure agent in the refrigeration machine oil
it can. The extreme pressure agent serves as an anti-wear agent for the sliding portion, for example, an alkyl polyoxyalkylene phosphate represented by the general formulas (6) and (7), and a dialkyl phosphate represented by the general formula (8) And the like.

[0086]

Embedded image

[0087]

Embedded image

[0088]

[0089]

Embedded image

However, R _{6 is} an alkyl group having 8 to 16 carbon atoms. These phosphate esters may be added alone or in combination of two or more. The practical addition amount is 0.05 to 10 wt%.

Further, together with the above extreme pressure agent (antiwear agent),
It is also effective to add an acid scavenger, an antioxidant, an antifoaming agent and the like.

The acid scavenger is added to remove ester oil when it is present in the refrigerating machine oil, whereby the ester oil is decomposed and becomes unstable. The acid scavenger reacts with an acid such as an epoxy compound. Compounds are preferred. In particular, compounds having an epoxy group and an ether bond such as diglycidyl ether compounds such as polyalkylene glycol diglycidyl ether, monoglycidyl ether compounds such as phenylglycidyl ether, and aliphatic cyclic epoxy compounds are preferable. The reason is that the epoxy group of these compounds captures an acid, and contributes to the improvement of the compatibility between the refrigerating machine oil and the refrigerant even if the ether bond is more or less.

[0093] The above-mentioned other additives are chlorine scavengers for eliminating the influence of residues such as chlorine-based cleaning agents used when manufacturing compressors and refrigeration systems, and oxidative degradation during distribution and storage of oil. Additives for preventing foaming, additives for preventing foaming, and the like, which can be dealt with by conventional general techniques, and are not specifically regulated here.

Also, at least a part of the refrigerant is
Replaced with a chlorofluorocarbon-based refrigerant represented by 4a
For example, in a refrigeration system including a refrigerant compressor used in combination with refrigerating machine oil and the refrigerant and the (2) base oil fatty acid ester oil according to claim, as the electrical insulating film constituting an electric motor of the compressor, A crystalline plastic film having a glass transition temperature of 50 ° C. or higher, or a composite film in which a resin layer having a high gas transition temperature is coated on a film having a low glass transition temperature, has a glass transition temperature of 12
It is desirable to use an enamel-coated wire having a temperature of 0 ° C. or higher, or an enamel wire in which a layer having a low glass transition temperature is formed as a lower layer and a high layer is formed as an upper layer.

As a practical insulating film,
Polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, polyether ketone, polyethylene naphthalate, at least one kind of insulating film selected from the group of polyamide imide and polyimide is preferable, and as the enamel coating, the group of polyester imide, polyamide and polyamide imide At least one kind of insulating layer selected from

[0096] Furthermore, in fluorocarbon refrigerant containing no chlorine represented at least a part of the refrigerant on the front <br/> down 134a
In the refrigerating apparatus according to the above (1) or (3) , wherein the refrigerant is used in combination with the refrigerating machine oil based on the fatty acid ester oil described in the above (2) , a dryer is provided in a refrigerating cycle path.
Is desirable. Then , as a desiccant to be filled into the dryer, a carbon dioxide absorption container at a carbon dioxide gas partial pressure of 250 mmHg at 25 ° C. and a pore diameter of 3.3 angstrom or less,
It is to use a synthetic zeolite composed of a composite salt of silicic acid and alkali metal aluminate of not more than 1.0%.

[0097]

A hindered ester or complex ether having two or more ester bonds in the molecule and having a viscosity of 2 to 70 cSt at 40 ° C, preferably 5 to 32 cSt.
cSt, 1 to 9 cSt at 100 ° C., preferably 2 to 9 cSt
The refrigerating machine oil 6cSt is at a minimum, a compressor, a condenser, is constructed from the expansion mechanism and an evaporator, the refrigerant reduced
The refrigeration apparatus using be replaced by fluorocarbon refrigerant containing no chlorine represented partially in flon 134a with, for compatibility with the refrigerant in the whole temperature range of the parts to be used is good, the refrigerant and the refrigerating machine oil Is not present.

Therefore, (1) separation of two layers in the oil storage section in the compressor is eliminated, and oil supply to the bearing sliding section is guaranteed. (2) In the state where the CFC gas discharged from the compressor is liquefied by the condenser or in a low temperature environment of −30 ° C. or lower in the evaporator, the oil always has a low viscosity CFC 134.
Since it exists in a state of being dissolved in a and has a low viscosity as a whole, the return of oil to the compressor is improved. Therefore, since the oil level drop phenomenon of the compressor is eliminated, the supply of oil to the bearing sliding portion can be ensured, and the problem of biting and seizure can be solved.

Further, the refrigerating machine oil has a small saturated water content of less than one-tenth, which is a drawback of the conventional polyoxyalkylene glycol oil, has a large effect of improving the oxidative deterioration stability, and has a high level of electric insulating oil. Some volume low efficiency is 10 ¹³
Ωcm. Therefore, in the refrigerant compressor accommodating the motor unit in the pressure vessel and the refrigeration apparatus using the same, the chlorofluorocarbon 134a and the refrigeration oil of the present invention are not separated, and both the performance and the reliability of the compressor are excellent. Show the features. The refrigerating machine oil has an excellent compatibility even for chlorofluorocarbon refrigerant containing chlorine, such as a conventional flon 12 and flon 22, replacing a portion of the previously described flon 134a with hydrofluorocarbon refrigerants containing these conventional chlorine ,
They can be used in combination.

Next, among the refrigerating machine oils used in the refrigerating apparatus of the present invention, the oil viscosity at 40 ° C. is preferably 5 to 32 ct.
s is sealed in a high pressure vessel type rotary compressor,
Looking at the coefficient of performance of the compressor, the point where 15 cSt oil was used shows a peak, and the coefficient of performance representing the performance of the compressor is 5-1.4 cSt, which is approximately 1.4 or more.
If the combination of and alkylbenzene oil is 1, 0.95 ~
The range is 0.93, which indicates that there is no practical problem. Further, it was found that when the viscosity at 40 ° C. was 56 cSt, the refrigerating machine oil used in the present invention was superior to the polyoxypropylene glycol oil in the coefficient of performance of the compressor. This is because the ester bonds held by the oil itself are molecularly oriented mainly on the shaft of the compressor and the surface of the iron-based sliding portion of the bearing portion to improve lubricity.
Due to the property of easily dissolving in a, the effect of reducing the actual viscosity and improving the mechanical loss works together to improve the coefficient of performance of the compressor.

On the other hand, the low pressure vessel type reciprocating compressor operates at a low pressure of 1 to ² kg / cm ² abs in the vessel, so that the fluctuation range of the dissolved amount and the actual viscosity of Freon 134a is small. Therefore, characteristics due to the types of the refrigerant and the refrigerating machine oil are unlikely to appear, and the viscosity is 5 to 15 cSt at 40 ° C. and 2 at 100 ° C.
Those in the range of ４4 cSt were found to be good in reliability and performance.

Next, in the refrigerating machine oil used in the refrigerating apparatus of the present invention, primary pressure-reducing OH groups in molecules such as alkyl polyoxyalkylene phosphates and dialkyl phosphates are used as extreme pressure agents. When an appropriate amount of the second-class strong phosphate ester is blended in an amount of 0.05 to 10 wt%, an ester-bonded lubricating oil film having molecular orientation is formed on the surface of the iron-based sliding portion constituting the shaft and the bearing of the compressor. , Which can form a stronger phosphoric acid ester chemisorption film by removing, making the lubrication of the sliding part better,
Biting and seizure can be prevented.

The lubricating properties of the refrigerating machine oil used in the present invention to which the extreme pressure agent was added were examined and examined.
In the Falex test (oil seizure test) assuming that 34a was not dissolved, a significant improvement in the critical seizure surface pressure was achieved, and furthermore, 50% of Freon 134a was dissolved assuming a higher concentration of dissolution. With respect to the wear amount of the iron-based sliding member of the refrigerating machine oil, the wear amount could be reduced to 1/5 or less as compared with the non-added product. The appropriate range of the addition amount is 0.05 to 10 wt% as described above. Although the test results of the wear amount will be specifically described in the section of Examples below, they are as shown in FIG. 6, and the effect of the addition to reduce the wear amount is remarkable.

Further, additives such as an acid scavenger, an antioxidant and a foaming agent which are usually used together with the above-mentioned extreme pressure agent can be blended, and they act more effectively.

Next, at least a part of the refrigerant was changed to Freon 1
34a , regarding the electrical insulation material of the refrigerant compressor using this refrigerant and the refrigerating machine oil of the present invention together, the insulating film, which is the electrical insulation system material of the motor part, is made of crystalline plastic having a glass transition temperature of 50 ° C. or higher. Film, for example, polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, polyether ethyl ketone, polyethylene naphthalate,
Polyamideimide, polyimide, or a composite film that coats a resin layer with a high gas transition temperature on a film with a low glass transition temperature is less likely to cause deterioration in tensile strength properties and electrical insulation properties, so that there is no practical problem. It will be subdued. This is because the amount of water taken in and the amount of generated acid are very small as compared with the conventional polyoxyalkylene glycol oil, so that deterioration of the film itself due to hydrolysis hardly occurs.

Similarly, for the magnet wire used in the motor part, an enamel coating having a glass transition temperature of 120 ° C. or higher, for example, a single layer of polyesterimide, polyamide, polyamideimide, etc. An enamel coating in which a material having a high glass transition temperature is composited in the upper layer has a low degree of degradation of the film due to hydrolysis, generation of cracks, softening, swelling, a decrease in dielectric breakdown voltage, etc. as in the case of the above-described film, and has low reliability in practical use. It turned out to be useful for improvement. Some enamel coatings of magnet wire have self-lubricating properties and add internal lubricant and external lubricant for the purpose of improving electrical workability. The characteristic inherits the above-mentioned basic structure as it is.

Lastly, the operation of the dryer forming a part of the refrigeration system of the present invention will be described. As shown in FIG. 10, the dryer 45 is disposed between the condenser 41 and the expansion mechanism 42. This is because the ester compound of the refrigerating machine oil component and the CFC-based refrigerant easily bring moisture into the refrigerating apparatus . ,
Since a part of the ester compound is compressed together with the refrigerant gas in the compressor 40 to become high temperature and may be partially decomposed during a long period of use to generate water, these waters are removed.
This prevents the capillary of the refrigeration apparatus from being clogged or freezing on the evaporator to deteriorate the heat conduction.

[0108] At least a part of the refrigerant is made of Freon 134a .
Replacing, if the refrigerating machine oil used in the present invention this coolant providing a dryer in the refrigeration apparatus for <br/> coexist, the desiccant filled in the dryer, pore size 3.3 angstroms or less, 25 ° C., Synthetic zeolite comprising silicic acid and an alkali metal aluminate complex salt having a carbon dioxide gas absorption capacity at a carbon dioxide gas partial pressure of 250 mmHg of not more than 1.0% is preferable.
Examples of this type include XH-9 and XH-600 (trade names, manufactured by Union Showa Co., Ltd.), all of which have a small fluorine ion adsorption amount.

The carbon dioxide absorption capacity was 1.5%.
In the above, the fluorine ion absorption amount reaches 0.24% or more, and the adsorption characteristics and breaking strength as molecular sieves are reduced. In addition, the corroded crystal pickles cause clogging of the refrigeration cycle piping and damage to the bearing sliding portion of the compressor. From this viewpoint, the present invention in which the pore diameter is controlled by the carbon dioxide gas absorber does not have such a concern, and makes it possible to construct a highly reliable refrigeration apparatus.

[0110]

BRIEF DESCRIPTION the respective embodiments of the present invention with reference to FIG. 1 to FIG. 6 and Table 1 to Table 4. <Examples 1 to 17> These examples show one embodiment of the present invention .
The hermetic rotary compressor according to the refrigeration cycle and the refrigerant compressor uses Freon 134a as a refrigerant, and has a viscosity of 2 to 70 cSt at 40 ° C., more preferably 5 to 32 cSt at 100 ° C. as a refrigerating machine oil. Viscosity 1-9
An example in which cSt, more preferably 2 to 6 cSt, an ester oil shown in Table 1 having two or more ester groups in the molecule is used together will be analyzed. Table 1 also shows conventional refrigerator oils for comparison.

FIG. 1 shows a two-phase separation temperature diagram for explaining the compatibility between Freon 134a and refrigerating machine oil. Fron 134a and refrigerating machine oil are sealed in a high-pressure glass container, and the melting ratio and each temperature are shown. It summarizes the results of visual observation of the state of two-layer separation for each case. The horizontal axis shows the concentration of oil in Freon 134a, and the vertical axis shows the two-layer separation temperature. The first target value shown in this figure is a lower critical melting temperature required by a refrigerating apparatus having a medium evaporator temperature (0 ° C. or less) such as a dehumidifier, and a second target value. It shows the lower critical melting temperature (all specified values) required by a refrigerating apparatus such as a refrigerator having a low temperature evaporator temperature (-30 ° C. or lower).

A conventional refrigerating machine oil, for example, Nippon Sun Oil Co., Ltd.
Brand name Suniso 4GSD (naphthenic) or Z300
(Alkylbenzene type) does not dissolve, and in the case of PAG56 (polyalkylene glycol) (trade name, also manufactured by Nippon Sun Oil Co., Ltd.), the lower critical dissolution temperature (indicated by L1) is -6.
0 ° C. and the upper critical melting temperature (indicated by U1) is 35 ° C. Refrigerator containing ester oil having two or more ester groups in the molecule used in the present invention
The oil has an excellent critical dissolution temperature with a lower critical dissolution temperature (indicated by L2) of -70 ° C and an upper critical dissolution temperature (U2) of 70 ° C or more. Among them, the lower critical melting temperature is a practically important factor in the heat exchanger of the refrigerating apparatus, and the upper critical melting temperature is a practical factor in the refrigerant compressor.

That is, FIG. 10 shows a refrigeration cycle configuration diagram of the refrigeration apparatus. In the refrigeration apparatus including the refrigerant compressor 40, the condenser 41, the dryer 45, the expander 42, and the evaporator 43, When the refrigerating machine oil is operated in combination with Freon 134a, the conventional naphthenic mineral oil suniso 4GSD and the alkylbenzene oil Z300A shown in Conventional Examples 1 and 2 are used.
(Same name as manufactured by Nippon Sun Oil Co., Ltd.) states that when a large amount of refrigerant is present and the refrigerant lays down in the compressor, the refrigerant layer with a higher density becomes Since it is unevenly distributed in the upper layer, as shown in a longitudinal sectional view of a main part of the refrigerant compressor (an example of a closed type rotary compressor) in FIG. 7, oil supply to the shaft 4A, the main bearing 5, and the sub bearing 6 is performed as follows. The refrigerant layer unevenly distributed in the lower layer is sucked from the suction port 14 of the pump. Therefore, the viscosity of the refrigerant layer is smaller than that of the refrigerating machine oil, and when the oil is supplied to the bearing portion, the oil film is thin and the metal contact is likely to occur. In addition, since the temperature of the sliding friction surface instantaneously rises, the refrigerant gasifies, and the condition shifts to more severe conditions. When this phenomenon is repeated, damage occurs due to biting and seizure of the shaft and bearing,
The performance as a refrigerant compressor will be lost.

Further, the heat exchanger of the refrigerating apparatus shown in FIG.
For example, when used for the evaporator 43 used at 0 to -60 ° C,
The refrigerating machine oil discharged together with the refrigerant gas from the compressor 40 causes two-layer separation in the condenser 41, and the refrigerating machine oil adheres to the inner wall of the heat exchanger pipe, and the refrigerating machine oil stays and exchanges heat. Since the heat insulation phenomenon of the vessel occurs, the cooling performance of the refrigerating apparatus is significantly impaired, which is not practical. In this regard, the polyalkylene glycol shown in Table 1 in Conventional Example 3 is advantageous in that it does not cause two-layer separation in the condenser 41 because the lower critical dissolution temperature is −60 ° C. Since the temperature of the machine 40 is at least 80 ° C, the upper critical melting temperature is 3
5, the two-layer separation completely occurs, and when the bearing is refueled as in Conventional Examples 1 and 2, damage due to biting and seizure between the shaft and the bearing occurs. You will lose performance.

A refrigerant compressor equipped with a hermetic motor, for example, a hermetic rotary compressor shown in FIG. 7 is naturally required to have characteristics as an electric insulating oil.

FIG. 2 shows the relationship between the water absorption and the volume resistivity of the refrigerating machine oil containing the ester oil used in the present invention and the conventional mineral oil and polyalkylene glycol. Even when the water content is controlled to 500 ppm or less, the conventional polyalkylene glycol exhibits a low value of 10 ¹² Ωcm or less due to the action of an ether bond in the molecule, which is not desirable.

On the other hand, the refrigerating machine oil used in the present invention in which two or more ester groups are introduced exhibits a high insulation performance of 10 ¹³ Ωcm or more, and satisfies the standard value of “JISC2320” electrical insulating oil. It was found that it could be put to practical use. Although the conventional mineral oil has high insulation performance, it cannot be put to practical use because of its poor compatibility with Freon 134a.

Next, a refrigerating machine oil compatible with Freon 134a
The relationship between the type, chemical structure, and lower critical solution temperature of the ester oil as a component will be described in detail with reference to Table 1.

The kind of the ester oil having two or more ester groups in the molecule used as a component of the refrigerator oil means a monobasic organic acid or an ester of a polybasic organic acid and a polyhydric alcohol, and is representative. Typical ester oils include hindered ester oils represented by neobentyl glycol-based esters, trimethylolpropane (or ethane) -based esters, and pentaerythritol-based esters, and complex-based esters. The relationship between the name, viscosity and critical dissolution temperature is shown.

[0120]

[Table 1]

[0121] Note that in the sample names in Table 1 have those simplified displays the name of the chemical synthesis of ester oils, for example if the NGP / n-C ₈ of Example 1, NGP neopentyl glycol , NC ₈ is an abbreviation for a normal organic acid (linear fatty acid) having 8 carbon atoms, and represents an ester of neopentyl glycol and a normal organic acid (linear fatty acid) having 8 carbon atoms. In addition, the NGP / i-2EH of Example 3
Then, i-2EH is an abbreviation for iso-2-ethylhexyl acid, neopentyl glycol and iso-2-ethyl.
Represents an ester with hexylic acid (a fatty acid having a branched chain).

As a result, (1) neopentyl glycol esters (NPGs) are, as shown in Examples 1 to 4, an ester of dipentic alcohol neopentyl glycol and a monocarboxylic acid monobasic acid. Yes, it is characterized by having two ester groups in the molecule. These chemical structures show an important relationship with the compatibility with Freon 134a and the viscosity characteristics of oil.

That is, the monocarboxylic acid has 7 to 7 carbon atoms.
8 are good and the lower critical solution temperature is -29.
~ -70 ° C, viscosity at 40 ° C is 2.8-7.0 cSt.
Met.

The lower critical solution temperature is lower as the number of carbon atoms of the monocarboxylic acid (fatty acid) is smaller, and the iso-2-ethylhexyl (i-2E) of Example 3 having a branched chain in the molecule is used.
H) Isoheputan acid and Example 4 (I-C ₇₎ towards the acid is lower, it was found to be advantageous. Further, Example 5 is an example in which the number of carbon atoms (11) of the carboxylic acid is increased in order to increase the viscosity.
9 cSt, the lower critical solution temperature was found to be the limit at -40 ° C.

(2) Next, trimethylpropanol (TMP) esters having three ester bonds in the molecule will be described with reference to Examples 6 to 10.

An ester oil obtained by condensation of a trihydric alcohol, trimethylolpropane (TMP), and a monobasic organic acid, a monocarboxylic acid, has three ester groups in the molecule and has a carbon number of the monocarboxylic acid. For 6 to 8, the viscosity at 40C is in the range of 10.8 to 32.2 cSt, and the lower critical melting temperature is in the range of -20 to -60C. Those having a temperature of −20 ° C. or lower include those of heptanoic acid (nC ₇ ) of Example 6, octanoic acid (nC ₈ ) of Example ₈ , iso-2-ethyl hexic acid (i-2EH) of Example 9, Those below -60 ° C
Hexane (n-C ₆₎ acid of Example 7, an ester oil Isoheputan acid Example 10 (i-C _7). Here, too, the lower critical melting temperature is characterized in that it is lower as the number of carbon atoms is smaller, and is lower as the number of carbon atoms contains the branched chain (iso).

(3) The ester oil obtained by the condensation of pentaerythritol (PET) of a tetrahydric alcohol with a monocarboxylic acid has four ester groups in the molecule as shown in Examples 11 to 13; Has 6 or more carbon atoms
For 8 pieces, the viscosity at 40 ° C. is 17.5 to 52.0 cSt.
And the lower critical solution temperature is -8 to -44 ° C.
And the temperature is shifted to a higher temperature side with respect to the ester oils of the above-mentioned dihydric alcohol and trihydric alcohol. Among them, those having a lower critical dissolution temperature of −40 ° C. or lower are ester oils with hexane (nC ₆ ) acid of Actual Example 11 and iso-heptane (i-C ₇ ) acid of Example 13. . Here, too, the lower critical solution temperature is characterized in that it is lower as the number of carbon atoms is smaller, and lower as it contains a branched chain.

(4) Next, as a method for containing four ester groups in the molecule, the esterification is carried out by condensing a polyhydric alcohol and further a monocarboxylic acid, centering on a dicarboxylic acid which is a representative of dibasic organic acids. By lowering the viscosity, the lower critical dissolution temperature is lowered and the viscosity is easily increased. A complex ester thus designed is a complex ester, which will be described in Examples 14 to 17 of the present invention.

In Example 14, dicarboxylic acid glutaric acid (abbreviated as Glut), dihydric alcohol neopentyl glycol (NPG), and monocarboxylic acid hexane (C ₆ )
It is a complex ester of acid and has a viscosity of 3 at 40 ° C.
2.6 cSt, 100 ° C. was 5.9 cSt, and the critical melting temperature was −75 ° C. or less.

Example 15 shows an example in which an intermediate viscosity grade was prepared by mixing Examples 4 and 16, and also in this case, it was found that there was no significant change in the lower critical melting temperature.

In Example 16, dicarboxylic acid adipic acid (abbreviated as AZP), dihydric alcohol neopentyl glycol (NPG), and monocarboxylic acid decanoic acid (n-
Complex ester of C ₁₀ ), Example 17 shows a complex ester of dicarboxylic acid glutaric acid (Glut), dihydric alcohol neopentyl glycol (NPG), monocarboxylic acid iso-hexanoic acid (i-C ₆ ). 54.5-56.6 cSt at 40 ° C, 100 ° C
Viscosity of 7.3 to 8.6 cSt, lower critical melting temperature is -60 ° C
It turned out to be excellent.

In the complex ester, the carbon number C ₂ -C ₁₀ of the dicarboxylic acid of the dibasic organic acid and the carbon number C ₅ -C ₁₀ of the monocarboxylic acid of the monobasic acid are arbitrarily set. It is shown that when a desired molar ratio is selected and condensed with a polyhydric alcohol, one having an arbitrary viscosity can be synthesized.

By arranging these examples, esters can be represented by the following general formula. Neopentyl glycol ester:

[0134]

Embedded image (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ (1) Trimethylolpropane (or ethane) ester:

[0135]

R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ... (2) Pentaerythritol ester:

[0136]

Embedded image C · (CH ₂ —OCOR ₂ ) ₄ (3) Complex ester:

[0137]

Embedded image

More easily obtainable are dipentaerythritol esters:

[0139]

Embedded 118] _{(R 2 · C O O H} 2 C) 3 · C · CH 2 · O · CH 2 · C (CH 2 · OC OR 2) 3 ... (4) where, R _1: H or a carbon number An alkyl group having 1 to 3 R ₂ : an alkyl group having 5 to 12 carbon atoms, and a plurality of kinds having different carbon numbers can be mixed R ₃ : an alkyl group having 1 to ₃ carbon atoms n: 0 or 1 to 5 When designing an arbitrary viscosity, it was possible by selecting the types of polyhydric alcohol and carboxylic acid which is a basic organic acid.

Further, in order to obtain an intermediate viscosity, it was possible to easily adjust the viscosity by blending a low-viscosity oil and a high-viscosity oil.

As described above, in a refrigeration system using a chlorofluorocarbon-based refrigerant such as chlorofluorocarbon 134a, the first one of a hindered ester and a complex ester having two or more ester bonds in the molecule.
When the viscosity of the oil at the lower critical dissolution temperature of 0 ° C. or less, which is the target value of the oil, and the oil of the second target value, the lower critical dissolution temperature of -30 ° C. or less, is 40 ° C., 2 to 70 cS
t, more preferably 5 to 32 cSt, 1 at 100 ° C.
By selecting a compressor of 〜9 cSt, more preferably of 2 to 6 cSt, a compressor and a refrigeration apparatus having basically satisfactory performance and reliability were obtained.

These ester-based refrigerating machine oils are Freon 13
It has been confirmed that not only 4a, but also chlorine-free refrigerant gas such as Freon 152a (difluoroethane CH ₃ CHF ₂ ) has good compatibility, and it is effective for high performance and high reliability of refrigeration equipment. there were.

Further, the components of the refrigerating machine oil used in the present invention
These ester oils are flon 12 is so highly soluble in fluorocarbon refrigerant containing conventional chlorine such as Flon 22 (hydrofluorocarbon-based refrigerant chloride), even in the case of using a mixture of a portion, effective Confirmed that there is.

However, since these conventional CFC-based refrigerants containing chlorine are subject to use restrictions due to the problem of environmental destruction, they contain 50% or less of chlorine, which is representative of CFC134a.
Without coolant is 50% or more, even containing an ester oil used in the present invention at least 50% or more as a component of the refrigerating machine oil
Rukoto to be desirable.

<Embodiment 18> A rotary compressor shown in FIG.
Incorporated in a refrigeration apparatus that constitutes the figure, the compressor temperature 100 ° C. is a reliability test conditions of the refrigerator, the discharge gas pressure 9.5
Table 1 shows the relationship between the viscosity of the refrigerating machine oil stored in the compressor and the coefficient of performance (COP), which is the ratio of the refrigerating capacity of the compressor to the input, at a pressure of 〜１０10 kgf / cm ² G. The measurement was performed using oil, and the results are shown in FIG.

[0146] Figure 3 is an actual viscosity of the refrigerating machine oil accumulated in the rotary compressor on the horizontal axis, the scale coefficient of performance of the compressor (indicated by relative value) on the vertical axis, esthetic for use in the refrigerator of the present invention Alkylbenzene oil having a viscosity of 5 to 56 cSt at 40 ° C., and alkylbenzene oil (Suniso Z-300A) obtained by using polyalkylene glycol and Freon 12 of the conventional example
Represents the relationship between the actual viscosity of the refrigerating machine oil and the coefficient of performance (COP).

According to this, the conventional CFC 12 and 40 ° C.
When the coefficient of performance of Z-300A (alkylbenzene oil) having a viscosity of 56 cSt at the time of
The combination of polyalkylene glycol (PAG56) and Freon 134a in Conventional Example 3 was as low as 0.859, indicating that the energy efficiency was reduced by about 14%.

On the other hand, at 40 ° C. in Example 17 of the present invention.
At that time, the complex ester oil having a viscosity of 56.6 cSt was as good as 0.906. This is because the viscosity of the refrigerating machine oil at the time of melting the Freon 134a under the same operating conditions is as low as 4.35 cSt, so the journal bearing theory represented by the equation (9) indicating the friction coefficient described in the section of the prior art earlier. It is thought that the effect of reducing friction loss based on the above and the power of stirring oil and the heat radiation effect also move.

Next, refrigerator oil used in the refrigerator of the present invention
The viscosity of the ester oil, which is a component of
Those 2cSt of (40 ° C.), a comparison of coefficient of performance under the same conditions, those 32.6cSt (40 ℃) of Example 14, 0.926, that of 14.9cSt (40 ℃) of Example 5 Is 0.966, and 14.9 cSt of Example 10 (40
° C), which in turn improved to 0.973.
On the other hand, at 5 cSt (40 ° C.), the concentration slightly decreased to 0.953.

From these results, it can be seen that the refrigeration of the rotary compressor was
An ideal ester oil suitable as a machine oil would be an ester of 5 to 32 (precisely 5.5 to 32.6) cSt, including a range around the best value of 14.9 cSt at 40 ° C. An oil containing two or more ester bonds in the molecule as described above.

Example 19 Next, a CFC 134 was added to a low-pressure container type reciprocating compressor.
a and the refrigerating machine oil exemplified in Table 1 used in the present invention , and incorporated into a refrigerator as a refrigerating apparatus, and subjected to a high-temperature reliability test (internal pressure of the case of 1.6 kg / cm ² abs, case temperature of 85 ° C., 1 ° C.)
00V, 50 Hz).

FIG. 4 shows the results. The abscissa indicates the actually measured viscosity of the refrigerating machine oil stored in the compressor, and the ordinate indicates the coefficient of performance (COP) indicating the performance of the compressor. The viscosity of the refrigerating machine oil at 40 ° C. is shown in the example of Table 1 in 5.
The characteristics of the relationship between the actual viscosity and the coefficient of performance in the actual operation of the sample refrigerating machine oils of 5, 14.9, 22.0, 32.6 and 56.6 cSt are plotted, and are almost linearly connected.

The results show that the low-viscosity reciprocating compressor of the reciprocating type has a higher coefficient of performance as the viscosity of the refrigerating machine oil is lower. The actual viscosity is 2 to 4.2 cSt, and the viscosity of the refrigerating machine oil at 40 ° C. 5.5 to 14.9 cSt
Can be said to be superior. Note that the actual viscosity is 2 cSt.
When it becomes smaller, the roughness of the sliding parts surface of the compressor becomes
Conventional cast iron and iron-based sintered materials have a limit in finishing accuracy, tend to enter a boundary lubrication region involving metal contact, lower the coefficient of performance, and tend to have poor bearing reliability.

<Embodiment 20> Next, the lubricity of a refrigerator and a refrigerant compressor will be described.
This will be described with reference to the following examples.

As a method of evaluating the lubricity, the seizure load in the atmospheric Falex test and the CFC 134a
A high-pressure atmosphere friction test was performed to determine the seizure load in the refrigerator oil in which 0% was dissolved, and a correlation diagram of the results is shown in FIG. Note that the seizure load is obtained by applying a load from both sides to a rotating sample pin, and displaying the load at the time of seizure in pounds (lb).

Here, the refrigerating machine oil used in the refrigerating machine of the present invention is exemplified by the ester oil of trimethylolpropane (TMP) and iso-heptane (i-C ₇ ) acid of Example 10 shown in Table 1. The relationship between the kind and amount of the extreme pressure agent added to the ester oil and the lubricating properties was determined.
The material of the test piece used for the lubrication evaluation was such that the pin in the Falex test was JIS-standard SNC-21 (nickel-chrome steel), and the block was JIS-standard SU.
M41 (sulfur free-cutting steel) is a standard type. On the other hand, a high-pressure atmosphere friction test is performed on a shaft material (eutectic graphite cast iron) and a roller material (eutectic graphite cast iron) which have been used in rotary compressors. The material is evaluated by a friction test between cylinders, and is expressed by a load when a seizure phenomenon occurs.

As shown in the sample No. 1 in FIG. 5, the ester oil without the extreme pressure agent (oil of Example 10) had a Falex baking load of 700 (lb) and 9 in the atmosphere of Freon 134a.
In contrast to a low value of 0 kgf / cm ² , Sample No. 2 was composed of a dialkyl phosphate ester which is one of acidic phosphate esters having an active OH group in the molecule as an extreme pressure agent. 1% of Sakai Chemical's trade name Chiclex H-10
The addition of 1% of an ester compound of alkylene glycol and phosphoric acid (butyl polyoxypropylene phosphate) in sample No. 3 further improved the Falex baking load by 400 (lb). 1100 (lb), 9 in the atmosphere of Freon 134a
0kg / cm ² improved to confirming the effect of 180kg / cm ^2.

That is, a phosphorus compound such as an acidic phosphoric acid ester or an alkylene glycol phosphoric acid ester compound effectively acts as an extreme pressure agent, and effectively acts as an extreme pressure effect for preventing seizure regardless of the presence or absence of Freon 134a. It was proved that.

Next, in the Falex test, the load was fixed at a fixed value of 100 (lb), a test was continuously performed for a maximum of 120 minutes, and the wear amount of the pin as the iron-based test piece was measured. The results are as shown in FIG. 6. The oil of Sample No. 4 without the extreme pressure agent was worn by 25 mg, whereas the oil containing the above-mentioned phosphorus compound was the same as Sample No. 7 and Sample No. 4. As shown in No. 8, all were as small as 0.4 mg and could be reduced to 1/5 or less. The amount of the phosphorus compound added was determined according to the sample No. As shown in FIG. 5, the effect is obtained from around 0.05 wt%, and the effect is improved as the amount is increased. However, if it exceeds 10 wt%, the effect of improving lubricity reaches saturation, which is economically disadvantageous and therefore impractical.

The viscosity of the oil was determined to be 14.9 cS of the sample No. 4.
From t (40 ° C.), 56.6 cSt (40
C)), the amount of wear was also reduced.

From the above, 0.05 to 10 wt% of a phosphorus compound such as an acid phosphate, a phosphate or an alkylene glycol phosphate as an extreme pressure agent is added to the refrigerator oil used in the present invention. By adjusting the viscosity of the oil instead of adding an extreme pressure agent,
It was found that the seizure load, wear resistance, and lubricity of the iron-based sliding member can be drastically improved by increasing the viscosity. In particular, it exhibits excellent performance when a chlorofluorocarbon-based refrigerant such as chlorofluorocarbon 134a does not exist.

Example 21 Here, Tables 2 and 3 show the results of evaluating the behavior of the electrically insulating material used for the hermetic motor of the compressor in the presence of Freon 134a and the refrigerating machine oil used in the present invention. It will be described using FIG.

For the evaluation of the Freon 134a and the refrigerating machine oil, in order to eliminate the influence from the outside, the state of the property deterioration of the magnet wire (enamel coated wire) and the insulating film material was observed by a shield tube test.

(1). Insulation characteristics of magnet wire (enamel-covered wire): The magnet wire test was conducted on a shield tube test at 150 ° C for 40 days for two types of a 5% elongated product and a twisted pair test piece. An explanation will be given below using the listed results.

[0165]

[Table 2]

The CFC 134 shown in the prior art 3 in Table 1 is used.
According to the shield tube test results of the combination of polyalkylene glycol of the refrigerating machine oil and Freon 134a which are said to be compatible with the polyester wire (PEW) of sample No. 9 and the ester imide wire (EIW) of sample No. 10 in Table 2, In the case of -R), crazing (cracking) occurred in all cases with respect to the 5% elongation line, and the retention of the dielectric breakdown voltage of the twisted pair test piece was remarkably reduced to 30 to 32%.

On the other hand, a similar evaluation was made according to the present invention as shown in Table 1.
Glutaric acid (G) of Example 17 which is a refrigerating machine oil used for
lut) the results was performed by a combination of the composite ester oil and flon 134a of neopentyl glycol (TPG) and Isohekisan acid (i-C _6), polyesters showing a deterioration in the sample No.9 and 10 of the conventional example described above For the wire (glass transition temperature: Tg is described in Table 2) and the polyesterimide wire, no abnormal appearance was observed as shown in Sample No. 11 and Sample No. 12, and the holding ratio of the dielectric breakdown voltage was 9%.
It was as high as 5% or more, indicating that the degree of deterioration of the magnet wire was extremely small. The reason for this is that the refrigerating machine oil of the present invention has a small amount of water retained at an early stage, has excellent thermal stability, and is difficult to generate an acidic substance that promotes hydrolysis, and has the effect of improving. It is what has brought.

Sample No. 13 was obtained by further coating and compounding a polyamide imide layer on the ester imide wire of sample No. 12, and sample No. 14 was prepared by using polyamide imide alone (A
IW) coatings showed good properties. In this way, the magnet wire in which the layer having a high glass transition temperature is coated on the layer having a low glass transition temperature has an effect that the upper layer film effectively acts as a protective action against erosion of Freon 134a and refrigerating machine oil. It was found that it contributed to the improvement of the reliability of the machine.

(2). Insulation Characteristics of Insulating Film: Next, a shield tube test on the insulating film of the motor was performed at 130 ° C. for 40 days to evaluate the appearance and the tensile strength retention. Table 3 shows the results.

[0170]

[Table 3]

In the case of a general polyester film (trade name: Lumirror X ₁₀ manufactured by Toray Co., Ltd.) used for a hermetic motor of a compressor, in the case of the conventional polyalkylene glycol oil shown in Sample No. 15, the oligomer component was deposited in the oil. Was observed, and the retention of tensile strength was 83%.

On the other hand, Example 1 used in the present invention
In the combination of the complex ester oil of No. 7 and Freon 134a, Lumirror X ₁₂ of Sample No. 16 and Sample No. 1
PA- which is a polyamide-imide coated polyester of No. 7
61M (trade name of Hitachi Chemical Co., Ltd.), sample No. 18 polyphenylene sulfide (PPS) film, sample
No oligomer broke out in any of the No. 19 polyetheretherketone (PEEK) films, and the tensile strength retention was excellent at 89% or more. The electrical insulation of a compressor using Freon 134a was excellent. As a system,
It has been found that the reliability can be significantly improved.

That is, in an environment where Freon 134a and refrigerating machine oil having two or more ester groups in the molecule coexist, a polyester film having a glass transition temperature of 65 ° C. or more, a polyamideimide-coded polyester film, a PPS film, and a PEEK film are used. It is necessary to properly select and complete the insulation system of the hermetic motor, which has been a problem with the oil of Conventional Example 3 shown in Sample No. 15 due to the separation of oligomer components and the reduction of film strength due to the compressor and refrigeration equipment. It was found that performance problems and practical problems related to long-term reliability could be solved.

Example 22 In a refrigeration apparatus that uses a heat exchanger at 0 ° C. or lower, the management of moisture in the refrigeration apparatus is important in terms of cooling performance and guaranteeing the quality of the electrical insulating material. It is known to have an important effect, and the establishment of technology for the water removal method is an indispensable requirement on the system of the refrigeration system.

As shown in FIG.
In the refrigeration cycle configured, the Freon 134a gas discharged from the compressor 40 is condensed by heat radiation in the condenser 41 to become a liquid refrigerant, and the high-temperature, high-pressure liquid refrigerant is cooled by the next expansion mechanism 42 to a low-temperature, low-pressure liquid refrigerant. In the process of becoming wet steam and being sent to the evaporator 43, a dryer 45 is provided between the condenser 41 and the expansion mechanism 42, and is adsorbed and removed by a desiccant represented by synthetic zeolite. Used in the present invention
It is important to properly select the type of desiccant in the use environment where the refrigerant oil and Freon 134a coexist.
These suitability will be described based on the examples in Table 4.

[0176]

[Table 4]

All the drying agents tested were manufactured by Union Showa
This is a synthetic zeolite called Molecular Sieves (trade name) manufactured by K.K. is there.

Synthetic zeolite Freon 134a and the present invention
The compatibility with the refrigerating machine oil used in the above is described based on the shield tube test results listed in Table 4.

Sample No. 20 (conventional example, trade name 4ANR)
The synthetic zeolite containing a sodium salt of aluminate or silicic acid as a main component shown in G) has a fluorine ion adsorption amount of 1.0.
It was as large as 5%, and it was found that problems such as reduction in strength due to the reaction of the synthetic zeolite and powdering occurred. Also. Sample No. 21 (conventional example, trade name 4AXH-6) and Sample No. 21 mainly containing sodium and potassium salts of aluminate and silicic acid
22 (Comparative Example, trade name XH-7) has a carbon dioxide adsorption capacity of 4.5 to 1.5% and a fluorine ion adsorption amount of 0.5%.
This was reduced to 24%. However, the fluorine ion adsorption amount is still large for practical use.

Further, Sample No. consisting of synthetic zeolite mainly composed of potassium and sodium salts of aluminate and silicic acid was used.
23 (Example, trade name XH-600) and Sample No. 2
Sample No. 3 (Example, trade name XH-9) had a carbon dioxide gas adsorption capacity of 0.2%, and the fluorine ion adsorption amount was sharply reduced to 0.04%. Practical use of fluorine ion adsorption of 0.1%
The following shows that all of these samples are sufficiently usable.

The distribution of the pore size of the synthetic zeolite is
Since there is a problem in that the characteristics of the synthetic zeolite itself are deteriorated by adsorbing the molecules of the fluorocarbon 134a, in order to control the amount of adsorbed fluorine ions to 0.1% or less, the adsorbing capacity of carbon dioxide gas must be reduced to 1%. It has been confirmed that a synthetic zeolite controlled to 0.0% or less should be used.

That is, Freon 134a is used in the present invention .
The refrigeration apparatus used in coexistence refrigerating machine oil bearing 2 months or more ester bonds in the molecule to the adsorption capacity of carbon dioxide, 25 ° C., carbon dioxide partial pressure, at 250 mmHg,
Synthetic zeolite consisting of alkali salts of silicic acid and aluminate controlled to 1.0% or less, for example, Union Showa
Product name Molecular Sieves XH-600, X
It was found that practical use of H-9 as a desiccant can effectively remove only water, has little effect such as powdering due to fluorine ion adsorption and a decrease in the strength of beads, and is remarkably excellent in practical use.

When the carbon dioxide adsorption capacity is 25 ° C., carbon dioxide partial pressure and 250 mmHg, the lower limit of 1.0% or less is as follows:
It is desirable to be as small as possible. When this is 0%, F ions are not absorbed and only water is selectively absorbed, resulting in an ideal molecular sieve.

[0184]

Since the present invention is configured as described above, it has the following effects.

(1) A refrigeration cycle comprising at least a compressor, a condenser, an expansion mechanism and an evaporator, wherein the refrigeration cycle is provided with a dryer and has a critical temperature of 4.
A refrigeration apparatus using a chlorofluorocarbon-based refrigerant represented by chlorofluorocarbon 134a of 0 ° C. or higher, wherein the refrigeration oil viscosity is 40 to 70 ° C., more preferably 2 to 70, more preferably 5 to 32 c.
St, 100 ° C., 1 to 9, more preferably 2 to 6 cS
The ester oil of the present invention having two or more ester bonds in the molecule of t is used as a base oil, and a refrigerating machine oil having a lower critical dissolution temperature of 0 ° C or lower or -30 ° C or lower is a dehumidifier as a first target. In the medium temperature refrigeration system and the low temperature refrigeration system such as a refrigerator which is the second target, the refrigerating machine oil and the refrigerant are well separated without being separated into two layers in the entire temperature range of the use environment. The lubricating oil film of the shaft of the machine, the bearing portion, and the refrigerant heat transfer performance of the heat exchanger are guaranteed, and the performance and reliability of the compressor and the refrigerating device can be remarkably improved.

(2) Addition of a phosphate ester-based extreme pressure agent having a hydroxyl group in a molecule, other antiwear agents, an acid scavenger, an antioxidant, an antifoaming agent, etc. to the refrigerating machine oil. By using the agent together, the effect of improving the lubricating properties of the sliding portion of the bearing of the refrigerant compressor is improved, and the performance and reliability are improved.

[0187] (3) Bei rotary type compressor of high-pressure vessel type
In the refrigerating device obtained , when the viscosity is 40 ° C., 2 to 7
In a refrigeration apparatus equipped with a low-pressure vessel type reciprocating compressor having a pressure of preferably 5 to 32 cSt, and a viscosity of 40 ° C., more preferably 5 to 15 cSt
By using the refrigerating machine oil used in the present invention having two or more ester bonds in each molecule of St together with Freon 134a, the coefficient of performance indicating the performance of the compressor can be improved. It is possible to reduce the power consumption of the apparatus and increase the refrigeration capacity, that is, to improve the so-called performance.

(4) As a motor insulating material of a refrigerant compressor using a chlorofluorocarbon-based refrigerant represented by chlorofluorocarbon 134a, an insulation-coated winding having a glass transition temperature of 120 ° C. or more and a glass transition temperature of 70 ° C. or more By using a refrigerating machine oil based on the ester oil used in the present invention as the refrigerating machine oil, the electrical insulation performance and long-term reliability of the refrigerating apparatus can be remarkably improved.

In the refrigeration system constructed as described above, a part or all of the conventional chlorine-containing refrigerant gas (eg, Freon 12) is placed in a chlorine-free refrigerant.
Since it is used instead, the ozone depletion potential (OPP) and global warming potential (GWP), which are problems in the global environment,
Environmentally friendly refrigeration equipment that can be reduced
There are big things that contribute to the industry.

[Brief description of the drawings]

FIG. 1 is a two-layer separation temperature diagram for explaining the compatibility between Freon 134a refrigerant and refrigerating machine oil.

FIG. 2 is a characteristic diagram showing the relationship between the amount of water dissolved in various refrigerator oils and the volume resistivity.

FIG. 3 is a graph showing the relationship between the actual viscosity of a refrigerating machine oil and the coefficient of performance during rated operation of a high-pressure container type rotary compressor.

FIG. 4 is a graph showing the relationship between the actual viscosity and the coefficient of performance of a low-pressure container type reciprocating compressor during rated operation.

FIG. 5 is a characteristic showing a relationship between a Falex test having an iron-based friction sliding surface and a high-pressure atmosphere friction test of Freon 134a-dissolved oil.

FIG. 6 is a characteristic diagram showing an amount of wear by a Falex test.

FIG. 7 is a longitudinal sectional view of a main part of the hermetic rotary compressor.

FIG. 8 is a vertical sectional view of a main part of a compression machine part of the rotary compressor.

FIG. 9 is a configuration diagram of a refrigeration cycle of the refrigeration apparatus.

FIG. 10 is a configuration diagram of a refrigeration cycle of the refrigeration apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Case, 2 ... Cylinder, 3 ... Eccentric part, 4 ... Rotating shaft, 5 ... Main bearing, 6 ... Sub bearing, 7 ... Roller, 8 ... Cylinder groove, 9 ... Spring, 10 ... Vane, 13 ... Refrigeration oil , 17 ... shaft hole, 19 ... stator, 19a ... winding, 20 ... rotor, 22 ... electric motor, 23 ... compressor part, 40 ... compressor, 41 ... condenser, 42 ... expansion mechanism, 43 ... evaporator , 45 ... Dryer.

──────────────────────────────────────────────────続 き Continued on front page (72) Inventor Makoto Tanaka 800, Tomita, Ohira-cho, Shimotsuga-gun, Tochigi Prefecture Inside Tochigi Plant, Hitachi, Ltd. Hitachi Research Laboratory (72) Inventor Hiroaki Hata 800, Tomita, Ohira-cho, Ohira-machi, Shimotsuga-gun, Tochigi Prefecture Tochigi Plant, Hitachi, Ltd. (72) Inventor Takuji Nariyoshi 800, Tomita, Ohira-cho, Shimotsuga-gun, Tochigi Prefecture Inside the Tochigi Plant, Hitachi, Ltd. References JP-A-59-117447 (JP, A) JP-A-55-79642 (JP, A) 154968 (JP, U) JP-A-56-141545 (JP, U) U.S. Pat. No. 4,851,144 (US, A) International Publication 90/12849 (WO, A1) "CFCs: Time of Transaction", American Society of Heating, Refrigerator, and Air-Conditioning Engineers, Inc. p. 211-216 (1989) "Tribologist" (Japan Lubrication Society), Vol. 9, p. 621-626 (1990) Document issued by Union Showa Co., Ltd., "Development Process of Molecular Sheaves for R-134a, an Alternative to Car Air Conditioners" (March 2, 1991) Document issued by Union Showa Co., Ltd., "XH-7 And XH-9 ”(as of November 1, 1989)“ Certificate ”issued by Union Showa Co., Ltd. (as of April 28, 1994) (58) Fields surveyed (Int. Cl. ⁶ , DB Name) C10M 105/38 C09K 5/04 F25B 1/00 395 C10N 40:30

Claims (24)

(57) [Claims] (1) Hydrofluorinated carbon (HFC) as a main component
Refrigerant whose critical temperature is 40 ° C. or higher, a hermetic compressor that compresses the refrigerant, a condenser that condenses the refrigerant, a dryer that dries the refrigerant, and an expansion mechanism that expands the refrigerant, An evaporator for evaporating the refrigerant, 2 to 70 cSt when the viscosity is 40 ° C., and 1 when the viscosity is 100 ° C.
And a refrigerating machine oil having a base oil of an ester oil of a fatty acid of up to 9 cSt , wherein the refrigerating machine oil is represented by the following general formulas (1) to (5).
At least one selected from the group of fatty acid ester oils
(Where R ₂ is an alkyl group having 5 to 12 carbon atoms)
Can mix two or more kinds with different carbon numbers),
And fatty acids represented by the following general formulas (1) to (5)
Among ester oils, the number of carbon atoms of R ₂ is smaller than 5
A refrigeration system consisting of refrigeration oil not containing (1) (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) embedded image _{C · (CH 2 -OCOR 2)} 4 ... (3) embedded image _{(R 2 · COOH 2 C)} 3 · C · CH 2 · O · CH 2 · C (CH 2 · OCOR 2) ₃ … (4) 2. Hydrofluorinated carbon (HFC) as a main component
Refrigerant whose critical temperature is 40 ° C. or higher, a hermetic compressor that compresses the refrigerant, a condenser that condenses the refrigerant, a dryer that dries the refrigerant, and an expansion mechanism that expands the refrigerant, An evaporator for evaporating the refrigerant, 2 to 70 cSt when the viscosity is 40 ° C., and 1 when the viscosity is 100 ° C.
And a refrigerating machine oil having a base oil of an ester oil of a fatty acid of up to 9 cSt , wherein the refrigerating machine oil is represented by the following general formulas (1) to (3).
At least one selected from the group of fatty acid ester oils
(Where R ₂ is an alkyl group having 5 to 12 carbon atoms)
Can mix two or more kinds with different carbon numbers),
And fatty acids represented by the following general formulas (1) to (3)
Among ester oils, the number of carbon atoms of R ₂ is smaller than 5
A refrigeration system consisting of refrigeration oil not containing (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· 2) embedded image C. (CH ₂ —OCOR ₂ ) ₄ (3) wherein R _{1 is} H or an alkyl group having 1 to 3 carbon atoms 3. Hydrofluorinated carbon (HFC) as a main component
A refrigerant having a critical temperature of 40 ° C. or higher and a viscosity of 40 ° C.
Refrigerating apparatus is used in a state of enclosing the refrigerating machine oil as the base oil the ester oil of 5~32cSt der Ru fatty when
This refrigeration apparatus is a closed type high pressure vessel type rotary type pressure compressor for compressing the refrigerant.
And compressor, a condenser for condensing the refrigerant, a dryer for drying the refrigerant, and an expansion mechanism for expanding the refrigerant, and an evaporator for evaporating the refrigerant, the refrigerating machine oil is generally below Expressions (1) to (5)
At least one selected from the group of fatty acid ester oils
(Where R ₂ is an alkyl group having 5 to 12 carbon atoms)
Can mix two or more kinds with different carbon numbers),
And fatty acids represented by the following general formulas (1) to (5)
Among ester oils, the number of carbon atoms of R ₂ is smaller than 5
A refrigeration system consisting of refrigeration oil not containing (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) embedded image _{C · (CH 2 -OCOR 2)} 4 ... (3) [of 12] _{(R 2 · COOH 2 C)} 3 · C · CH 2 · O · CH 2 · C (CH 2 · OCOR 2) ₃ … (4) 4. Hydrofluorinated carbon (HFC) as a main component
A refrigerant having a critical temperature of 40 ° C. or higher and a viscosity of 40 ° C.
5 to 32 cSt fatty acid ester oil at the time of base oil
Refrigeration equipment used with sealed refrigeration oil
This refrigeration apparatus is a closed type high pressure vessel type rotary type pressure compressor for compressing the refrigerant.
And compressor, a condenser for condensing the refrigerant and a drier for drying the refrigerant, and an expansion mechanism for expanding the refrigerant, and an evaporator for evaporating the refrigerant, the refrigerating machine oil is generally below Expressions (1) to (3)
At least one selected from the group of fatty acid ester oils
(Where R ₂ is an alkyl group having 5 to 12 carbon atoms)
Can mix two or more kinds with different carbon numbers),
And fatty acids represented by the following general formulas (1) to (3)
Among ester oils, the number of carbon atoms of R ₂ is smaller than 5
A refrigeration system consisting of refrigeration oil not containing (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ · · · (2) Embedded image C. (CH ₂ —OCOR ₂ ) ₄ (3) wherein R _{1 is} H or an alkyl group having 1 to 3 carbon atoms. 5. A fluorinated carbon (HFC) as a main component.
A refrigerant having a critical temperature of 40 ° C. or higher and a viscosity of 40 ° C.
5-15 cSt fatty acid ester oil at the time of base oil
Refrigeration equipment used with sealed refrigeration oil
The refrigerating apparatus is a closed-type low-pressure vessel type reciprocating pressure compressor for compressing the refrigerant.
And compressor, a condenser for condensing the refrigerant, a dryer for drying the refrigerant, and an expansion mechanism for expanding the refrigerant, and an evaporator for evaporating the refrigerant, the refrigerating machine oil is generally below Expressions (1) to (5)
At least one selected from the group of fatty acid ester oils
(Where R ₂ is an alkyl group having 5 to 12 carbon atoms)
Can mix two or more kinds with different carbon numbers),
And fatty acids represented by the following general formulas (1) to (5)
Among ester oils, the number of carbon atoms of R ₂ is smaller than 5
A refrigeration system consisting of refrigeration oil not containing (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) embedded image _{C · (CH 2 -OCOR 2)} 4 ... (3) [of 20] _{(R 2 · COOH 2 C)} 3 · C · CH 2 · O · CH 2 · C (CH 2 · OCOR 2) ₃ … (4) 6. Hydrofluorinated carbon (HFC) as a main component
A refrigerant having a critical temperature of 40 ° C. or higher and a viscosity of 40 ° C.
5-15 cSt fatty acid ester oil at the time of base oil
Refrigeration equipment used with sealed refrigeration oil
The refrigerating apparatus is a closed-type low-pressure vessel type reciprocating pressure compressor for compressing the refrigerant.
And compressor, a condenser for condensing the refrigerant and a drier for drying the refrigerant, and an expansion mechanism for expanding the refrigerant, and an evaporator for evaporating the refrigerant, the refrigerating machine oil is generally below Expressions (1) to (3)
At least one selected from the group of fatty acid ester oils
(Where R ₂ is an alkyl group having 5 to 12 carbon atoms)
Can mix two or more kinds with different carbon numbers),
And fatty acids represented by the following general formulas (1) to (3)
Among ester oils, the number of carbon atoms of R ₂ is smaller than 5
A refrigeration system consisting of refrigeration oil not containing (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ · · · (2) Embedded image C · (CH ₂ —OCOR ₂ ) ₄ (3) wherein R _{1 is} H or an alkyl group having 1 to 3 carbon atoms. 7. Hydrofluorinated carbon (HFC) as a main component
Refrigerant whose critical temperature is 40 ° C. or higher, a hermetic compressor that compresses the refrigerant, a condenser that condenses the refrigerant, a dryer that dries the refrigerant, and an expansion mechanism that expands the refrigerant, An evaporator for evaporating the refrigerant, 2 to 70 cSt when the viscosity is 40 ° C, and 1 when the viscosity is 100 ° C.
Refrigeration using ester oil of fatty acid of ~ 9 cSt as base oil
And the refrigerating machine oil is represented by the following general formulas (1) to (5).
At least one selected from the group of fatty acid ester oils
Containing a seed and represented by the following general formulas (1) to (5)
The fatty acid ester oils used are one alcohol and several
Carbons derived from a class of fatty acids and having less than 5 carbon atoms in R ₂
Refrigeration equipment consisting of refrigeration oil not including a number . (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) embedded image _{C · (CH 2 -OCOR 2)} 4 ... (3) [of 28] _{(R 2 · COOH 2 C)} 3 · C · CH 2 · O · CH 2 · C (CH 2 · OCOR 2) ₃ … (4) 8. A fluorinated carbon (HFC) as a main component.
Refrigerant whose critical temperature is 40 ° C. or higher, a hermetic compressor that compresses the refrigerant, a condenser that condenses the refrigerant, a dryer that dries the refrigerant, and an expansion mechanism that expands the refrigerant, An evaporator for evaporating the refrigerant, 2 to 70 cSt when the viscosity is 40 ° C, and 1 when the viscosity is 100 ° C.
Refrigeration using ester oil of fatty acid of ~ 9 cSt as base oil
And the refrigerating machine oil is represented by the following general formulas (1) to (3).
At least one selected from the group of fatty acid ester oils
Containing a seed and represented by the following general formulas (1) to (3)
The fatty acid ester oils used are one alcohol and several
Carbons derived from a class of fatty acids and having less than 5 carbon atoms in R ₂
Refrigeration equipment consisting of refrigeration oil not including a number . Embedded image (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) Embedded image C · (CH ₂ —OCOR ₂ ) ₄ (3) 9. A fluorinated carbon (HFC) as a main component.
A refrigerant having a critical temperature of 40 ° C. or higher and a viscosity of 40 ° C.
5 to 32 cSt fatty acid ester oil at the time of base oil
Refrigeration equipment used with sealed refrigeration oil
This refrigeration apparatus is a closed type high pressure vessel type rotary type pressure compressor for compressing the refrigerant.
And compressor, a condenser for condensing the refrigerant, a dryer for drying the refrigerant, and an expansion mechanism for expanding the refrigerant, and an evaporator for evaporating the refrigerant, the refrigerating machine oil is generally below Expressions (1) to (5)
At least one selected from the group of fatty acid ester oils
Containing a seed and represented by the following general formulas (1) to (5)
The fatty acid ester oils used are one alcohol and several
Carbons derived from a class of fatty acids and having less than 5 carbon atoms in R ₂
Refrigeration equipment consisting of refrigeration oil not including a number . (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) embedded image _{C · (CH 2 -OCOR 2)} 4 ... (3) [of 36] _{(R 2 · COOH 2 C)} 3 · C · CH 2 · O · CH 2 · C (CH 2 · OCOR 2) ₃ … (4) 10. Main component is hydrofluorinated carbon (HFC)
Refrigerant having a critical temperature of 40 ° C. or higher and a viscosity of 40
Based on fatty acid ester oils that are 5-32 cSt at
Refrigeration equipment used in a state where oil and refrigeration oil are enclosed
The refrigeration apparatus is a closed type high pressure vessel type rotary type pressure compressor for compressing the refrigerant.
And compressor, a condenser for condensing the refrigerant and a drier for drying the refrigerant, and an expansion mechanism for expanding the refrigerant, and an evaporator for evaporating the refrigerant, the refrigerating machine oil is generally below Expressions (1) to (3)
At least one selected from the group of fatty acid ester oils
Containing a seed and represented by the following general formulas (1) to (3)
Ester oil of fatty acid is one kind of alcohol and carbon number
Obtained from several kinds of fatty acid carbon number of R ₂ is 5 to different
A refrigeration system comprising refrigeration oil that does not contain smaller carbon numbers . (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) Embedded image C. (CH ₂ —OCOR ₂ ) ₄ (3) 11. Hydrofluorinated carbon (HFC) as a main component
Refrigerant having a critical temperature of 40 ° C. or higher and a viscosity of 40
Based on fatty acid ester oils that are 5-15 cSt at
Refrigeration equipment used in a state where oil and refrigeration oil are enclosed
The refrigerating apparatus is a closed type low pressure vessel type reciprocating type pressure compressor for compressing the refrigerant.
And compressor, a condenser for condensing the refrigerant, a dryer for drying the refrigerant, and an expansion mechanism for expanding the refrigerant, and an evaporator for evaporating the refrigerant, the refrigerating machine oil is generally below Expressions (1) to (5)
At least one selected from the group of fatty acid ester oils
Containing a seed and represented by the following general formulas (1) to (5)
Ester oil of fatty acid is one kind of alcohol and carbon number
Obtained from several kinds of fatty acid carbon number of R ₂ is 5 to different
A refrigeration system comprising refrigeration oil that does not contain smaller carbon numbers . (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) embedded image _{C · (CH 2 - OC OR} 2) 4 ... (3) [of 44] _{(R 2 · COOH 2 C)} 3 · C · CH 2 · O · CH 2 · C (CH 2 · OCOR 2 ) ₃ ... (4) 12. Main component is hydrofluorinated carbon (HFC)
Refrigerant having a critical temperature of 40 ° C. or higher and a viscosity of 40
Based on fatty acid ester oils that are 5-15 cSt at
Refrigeration equipment used in a state where oil and refrigeration oil are enclosed
The refrigerating apparatus is a closed type low pressure vessel type reciprocating type pressure compressor for compressing the refrigerant.
And compressor, a condenser for condensing the refrigerant and a drier for drying the refrigerant, and an expansion mechanism for expanding the refrigerant, and an evaporator for evaporating the refrigerant, the refrigerating machine oil is generally below Expressions (1) to (3)
At least one selected from the group of fatty acid ester oils
Containing a seed and represented by the following general formulas (1) to (3)
Ester oil of fatty acid is one kind of alcohol and carbon number
Obtained from several kinds of fatty acid carbon number of R ₂ is 5 to different
A refrigeration system comprising refrigeration oil that does not contain smaller carbon numbers . (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) Embedded image C. (CH ₂ —OCOR ₂ ) ₄ (3) 13. Main component is hydrofluorinated carbon (HFC)
A refrigerant having a critical temperature of 40 ° C. or higher, a hermetic compressor for compressing the refrigerant, a condenser for condensing the refrigerant, a dryer for drying the refrigerant, and an expansion mechanism for expanding the refrigerant. , an evaporator for evaporating the refrigerant, when the viscosity is 40 ℃ 2~70cSt, when the 100 ° C. 1
Refrigeration using ester oil of fatty acid of ~ 9 cSt as base oil
And the refrigerating machine oil is represented by the following general formulas (1) to (5).
At least one selected from the group of fatty acid ester oils
(Where R ₂ is an alkyl group having 5 to 12 carbon atoms)
Can mix two or more kinds with different carbon numbers),
And fatty acids represented by the following general formulas (1) to (5)
Among ester oils, the number of carbon atoms of R ₂ is smaller than 5
Refrigerator made of refrigeration oil not containing (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) embedded image _{C · (CH 2 -OCOR 2)} 4 ... (3) [of 52] _{(R 2 · COOH 2 C)} 3 · C · CH 2 · O · CH 2 · C (CH 2 · OCOR 2) ₃ … (4) 14. A fluorinated carbon (HFC) as a main component.
A refrigerant having a critical temperature of 40 ° C. or higher, a hermetic compressor for compressing the refrigerant, a condenser for condensing the refrigerant, a dryer for drying the refrigerant, and an expansion mechanism for expanding the refrigerant. , an evaporator for evaporating the refrigerant, when the viscosity is 40 ℃ 2~70cSt, when the 100 ° C. 1
Refrigeration using ester oil of fatty acid of ~ 9 cSt as base oil
And the refrigerating machine oil is represented by the following general formulas (1) to (3).
At least one selected from the group of fatty acid ester oils
(Where R ₂ is an alkyl group having 5 to 12 carbon atoms)
Can mix two or more kinds with different carbon numbers),
And fatty acids represented by the following general formulas (1) to (3)
Among ester oils, the number of carbon atoms of R ₂ is smaller than 5
Refrigerator made of refrigeration oil not containing (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ · · · (2) Embedded image C. (CH ₂ —OCOR ₂ ) ₄ (3) wherein R _{1 is} H or an alkyl group having 1 to 3 carbon atoms 15. A fluorinated carbon (HFC) as a main component.
Refrigerant having a critical temperature of 40 ° C. or higher and a viscosity of 40
Based on fatty acid ester oils that are 5-32 cSt at
Refrigerator used in a state where oil and refrigerating machine oil are enclosed
This refrigerator is a sealed high-pressure type that compresses the refrigerant.
Comprising a rotary type compressor of the container system, a condenser for condensing the refrigerant, a dryer for drying the refrigerant, and an expansion mechanism for expanding the refrigerant, an evaporator for evaporating the refrigerant, the refrigerating machine oil Is represented by the following general formulas (1) to (5).
At least one selected from the group of fatty acid ester oils
(Where R ₂ is an alkyl group having 5 to 12 carbon atoms)
Can mix two or more kinds with different carbon numbers),
And fatty acids represented by the following general formulas (1) to (5)
Among ester oils, the number of carbon atoms of R ₂ is smaller than 5
Refrigerator made of refrigeration oil not containing (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) embedded image _{C · (CH 2 -OCOR 2)} 4 ... (3) [of 60] _{(R 2 · COOH 2 C)} 3 · C · CH 2 · O · CH 2 · C (CH 2 · OCOR 2) ₃ … (4) 16. Main component is hydrofluorinated carbon (HFC)
Refrigerant having a critical temperature of 40 ° C. or higher and a viscosity of 40
Based on fatty acid ester oils that are 5-32 cSt at
Refrigerator used in a state where oil and refrigerating machine oil are enclosed
This refrigerator is a sealed high-pressure type that compresses the refrigerant.
Comprising a rotary type compressor of the container system, a condenser for condensing the refrigerant, a dryer for drying the refrigerant, and an expansion mechanism for expanding the refrigerant, an evaporator for evaporating the refrigerant, the refrigerating machine oil Is represented by the following general formulas (1) to (3)
At least one selected from the group of fatty acid ester oils
(Where R ₂ is an alkyl group having 5 to 12 carbon atoms)
Can mix two or more kinds with different carbon numbers),
And fatty acids represented by the following general formulas (1) to (3)
Among ester oils, the number of carbon atoms of R ₂ is smaller than 5
Refrigerator made of refrigeration oil not containing (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) Embedded image C. (CH ₂ —OCOR ₂ ) ₄ (3) wherein R _{1 is} H or an alkyl group having 1 to 3 carbon atoms 17. Main component is hydrofluorinated carbon (HFC)
Refrigerant having a critical temperature of 40 ° C. or higher and a viscosity of 40
Based on fatty acid ester oils that are 5-15 cSt at
Refrigerator used in a state where oil and refrigerating machine oil are enclosed
This refrigerator is a sealed low-pressure type that compresses the refrigerant.
The refrigerating machine oil includes a container type reciprocating compressor , a condenser for condensing the refrigerant, a dryer for drying the refrigerant, an expansion mechanism for expanding the refrigerant, and an evaporator for evaporating the refrigerant. Is represented by the following general formulas (1) to (5).
At least one selected from the group of fatty acid ester oils
(Where R ₂ is an alkyl group having 5 to 12 carbon atoms)
Can mix two or more kinds with different carbon numbers),
And fatty acids represented by the following general formulas (1) to (5)
Among ester oils, the number of carbon atoms of R ₂ is smaller than 5
Refrigerator made of refrigeration oil not containing (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) [ Image Omitted] C · (CH ₂ —OCOR ₂ ) ₄ (3) (R ₂ · COOH ₂ C) ₃ · C · CH ₂ · O · CH ₂ · C (CH ₂ · OCOR ₂ ) ₃ … (4) 18. Main component is hydrofluorinated carbon (HFC)
Refrigerant having a critical temperature of 40 ° C. or higher and a viscosity of 40
Based on fatty acid ester oils that are 5-15 cSt at
Refrigerator used in a state where oil and refrigerating machine oil are enclosed
This refrigerator is a sealed low-pressure type that compresses the refrigerant.
The refrigerating machine oil includes a container type reciprocating compressor , a condenser for condensing the refrigerant, a dryer for drying the refrigerant, an expansion mechanism for expanding the refrigerant, and an evaporator for evaporating the refrigerant. Is represented by the following general formulas (1) to (3)
At least one selected from the group of fatty acid ester oils
(Where R ₂ is an alkyl group having 5 to 12 carbon atoms)
Can mix two or more kinds with different carbon numbers),
And fatty acids represented by the following general formulas (1) to (3)
Among ester oils, the number of carbon atoms of R ₂ is smaller than 5
Refrigerator made of refrigeration oil not containing (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) Embedded image C. (CH ₂ —OCOR ₂ ) ₄ (3) wherein R _{1 is} H or an alkyl group having 1 to 3 carbon atoms 19. Main component is hydrofluorinated carbon (HFC)
A refrigerant having a critical temperature of 40 ° C. or higher, a hermetic compressor for compressing the refrigerant, a condenser for condensing the refrigerant, a dryer for drying the refrigerant, and an expansion mechanism for expanding the refrigerant. , an evaporator for evaporating the refrigerant, when the viscosity is 40 ℃ 2~70cSt, when the 100 ° C. 1
Refrigeration using ester oil of fatty acid of ~ 9 cSt as base oil
And the refrigerating machine oil is represented by the following general formulas (1) to (5).
At least one selected from the group of fatty acid ester oils
Containing a seed and represented by the following general formulas (1) to (5)
The fatty acid ester oils used are one alcohol and several
Carbons derived from a class of fatty acids and having less than 5 carbon atoms in R ₂
Refrigerator made of refrigeration oil without any number. (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) embedded 75] _{C · (CH 2 -OCOR 2)} 4 ... (3) [of 76] _{(R 2 · COOH 2 C)} 3 · C · CH 2 · O · CH 2 · C (CH 2 · OCOR 2) ₃ … (4) 20. Hydrofluorinated carbon (HFC) as a main component
A refrigerant having a critical temperature of 40 ° C. or higher, a hermetic compressor for compressing the refrigerant, a condenser for condensing the refrigerant, a dryer for drying the refrigerant, and an expansion mechanism for expanding the refrigerant. , an evaporator for evaporating the refrigerant, when the viscosity is 40 ℃ 2~70cSt, when the 100 ° C. 1
Refrigeration using ester oil of fatty acid of ~ 9 cSt as base oil
And the refrigerating machine oil is represented by the following general formulas (1) to (3).
At least one selected from the group of fatty acid ester oils
Containing a seed and represented by the following general formulas (1) to (3)
The fatty acid ester oils used are one alcohol and several
Carbons derived from a class of fatty acids and having less than 5 carbon atoms in R ₂
Refrigerator made of refrigeration oil without any number. (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) Embedded image C · (CH ₂ —OCOR ₂ ) ₄ (3) 21. Hydrofluorinated carbon (HFC) as a main component
Refrigerant having a critical temperature of 40 ° C. or higher and a viscosity of 40
Based on fatty acid ester oils that are 5-32 cSt at
Refrigerator used in a state where oil and refrigerating machine oil are enclosed
This refrigerator is a sealed high-pressure type that compresses the refrigerant.
Comprising a rotary type compressor of the container system, a condenser for condensing the refrigerant, a dryer for drying the refrigerant, and an expansion mechanism for expanding the refrigerant, an evaporator for evaporating the refrigerant, the refrigerating machine oil Is represented by the following general formulas (1) to (5).
At least one selected from the group of fatty acid ester oils
Containing a seed and represented by the following general formulas (1) to (5)
Ester oil of fatty acid is one kind of alcohol and carbon number
Obtained from several kinds of fatty acid carbon number of R ₂ is 5 to different
Refrigeration consisting of refrigerating machine oil not containing lower carbon number
Warehouse. (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) embedded 83] _{C · (CH 2 -OCOR 2)} 4 ... (3) [of 84] _{(R 2 · COOH 2 C)} 3 · C · CH 2 · O · CH 2 · C (CH 2 · OCOR 2) ₃ … (4) 22. Hydrofluorinated carbon (HFC) as a main component
Refrigerant having a critical temperature of 40 ° C. or higher and a viscosity of 40
Based on fatty acid ester oils that are 5-32 cSt at
Refrigerator used in a state where oil and refrigerating machine oil are enclosed
This refrigerator is a sealed high-pressure type that compresses the refrigerant.
Comprising a rotary type compressor of the container system, a condenser for condensing the refrigerant, a dryer for drying the refrigerant, and an expansion mechanism for expanding the refrigerant, an evaporator for evaporating the refrigerant, the refrigerating machine oil Is represented by the following general formulas (1) to (3)
At least one selected from the group of fatty acid ester oils
Containing a seed and represented by the following general formulas (1) to (3)
Ester oil of fatty acid is one kind of alcohol and carbon number
Obtained from several kinds of fatty acid carbon number of R ₂ is 5 to different
Refrigeration consisting of refrigerating machine oil not containing lower carbon number
Warehouse. (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) Embedded image C · (CH ₂ —OCOR ₂ ) ₄ (3) 23. Hydrofluorinated carbon (HFC) as a main component
Refrigerant having a critical temperature of 40 ° C. or higher and a viscosity of 40
Based on fatty acid ester oils that are 5-15 cSt at
Refrigerator used in a state where oil and refrigerating machine oil are enclosed
This refrigerator is a sealed low-pressure type that compresses the refrigerant.
The refrigerating machine oil includes a container type reciprocating compressor , a condenser for condensing the refrigerant, a dryer for drying the refrigerant, an expansion mechanism for expanding the refrigerant, and an evaporator for evaporating the refrigerant. Is represented by the following general formulas (1) to (5).
At least one selected from the group of fatty acid ester oils
Containing a seed and represented by the following general formulas (1) to (5)
Ester oil of fatty acid is one kind of alcohol and carbon number
Obtained from several kinds of fatty acid carbon number of R ₂ is 5 to different
Refrigeration consisting of refrigerating machine oil not containing lower carbon number
Warehouse. Embedded image (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) embedded 91] _{C · (CH 2 -OCOR 2)} 4 ... (3) [of 92] _{(R 2 · COOH 2 C)} 3 · C · CH 2 · O · CH 2 · C (CH 2 · OCOR 2) ₃ … (4) 24. Hydrofluorinated carbon (HFC) as a main component
Refrigerant having a critical temperature of 40 ° C. or higher and a viscosity of 40
Based on fatty acid ester oils that are 5-15 cSt at
Refrigerator used in a state where oil and refrigerating machine oil are enclosed
This refrigerator is a sealed low-pressure type that compresses the refrigerant.
The refrigerating machine oil includes a container type reciprocating compressor , a condenser for condensing the refrigerant, a dryer for drying the refrigerant, an expansion mechanism for expanding the refrigerant, and an evaporator for evaporating the refrigerant. Is represented by the following general formulas (1) to (3)
At least one selected from the group of fatty acid ester oils
Containing a seed and represented by the following general formulas (1) to (3)
Ester oil of fatty acid is one kind of alcohol and carbon number
Obtained from several kinds of fatty acid carbon number of R ₂ is 5 to different
Refrigeration consisting of refrigerating machine oil not containing lower carbon number
Warehouse. (R ₁ · CH ₂ ) ₂ · C · (CH ₂ OCOR ₂ ) ₂ ··· (1) R ₁ · CH ₂ · C · (CH ₂ · OCOR ₂ ) ₃ ··· (2) Embedded image C. (CH ₂ —OCOR ₂ ) ₄ (3)