JP3216416B2 - Air conditioner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioner using a fluorinated hydrocarbon refrigerant containing no chlorine as a working fluid.

[0002]

2. Description of the Related Art In the prior art, an ester oil is used as a refrigerating machine oil suitable for a fluorinated hydrocarbon-based refrigerant containing no chlorine. However, this fluorinated hydrocarbon-based refrigerant containing no chlorine and an ester oil are used. Polymers such as polyesters and polyamideimides are shown as organic materials suitable for the environment in which the above coexists. For example, Japanese Patent Application Laid-Open No. 4-183788 discloses the method.

First, a conventional air conditioner will be described with reference to FIG. 1 and Table 1. FIG. 1 is a system diagram of a refrigeration cycle, in which a compressor 1, an outdoor heat exchanger 2, an indoor heat exchanger 3, a four-way valve 4, an accumulator 5, a solenoid valve 6, an outdoor expansion valve 7, and an indoor expansion valve 8 are connected. ing.

Conventionally, the working fluid of a refrigeration cycle is HCF.
Mineral oil and the like are used for C22 and the refrigerating machine oil, and various materials are used for equipment constituting the refrigeration cycle as shown in Table 1.

[0005]

[Table 1]

Further, CR rubber, NBR rubber, hydrin rubber and the like are widely used as packings used for connecting devices. These materials have excellent refrigerant resistance and refrigerating machine oil resistance, are sufficiently compatible with conventional refrigerants and refrigerating machine oils, and have no problem in the reliability of the refrigerating cycle.

[0007]

Recently, fluorocarbon-based refrigerants containing chlorine have been known to have the effects of depletion of the ozone layer and global warming. Has been determined. Therefore, instead of refrigerants such as HCFC22 currently used in air conditioners, fluorinated hydrocarbon-based refrigerants that do not destroy the ozone layer and do not contain chlorine have become influential and become HFC32, HFC125, and HFC134.
a, HFC143a, and HFC152a may be used alone or in combination. However, chlorine-free fluorinated hydrocarbon-based refrigerants have poor compatibility with refrigeration oils such as mineral oil used in conventional refrigeration systems such as HCFC22, and have practicality that easily dissolves refrigerants. Refrigerator oil containing an ester or an ester bond is used. However, this ester oil is hydrolyzed in the presence of water, and the acid generated by the decomposition lowers the reliability of equipment constituting the refrigeration cycle, such as abrasion and corrosion. It is known that the water causing the hydrolysis exists in the organic material, and that the acid serves as a catalyst in the hydrolysis reaction of the ester oil.
Organic materials such as rubber include an acid itself that promotes the hydrolysis or a material that reacts with a substance in an ester oil to generate an acid. In the prior art, no consideration is given to the deterioration of the refrigerating machine oil due to the material in the refrigerating cycle device using the ester oil.

An object of the present invention is to solve these problems and provide a highly reliable refrigeration cycle apparatus.

[0009]

[MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
In addition, the present invention provides a working fluid,
Has ester bond as lubricating oil using hydrogenated refrigerant
Equipped with a refrigeration cycle using refrigeration oil containing a base
Compressor used for refrigeration cycle in air conditioner
10 phr or less ester plasticizer as O-ring
Using NBR rubber.

[0010]

[0011]

[0012]

[0013]

[0014]

[0015]

[0016]

[0017]

[0018]

[0019]

[0020]

[0021]

An embodiment of the present invention will be described with reference to Table 2.

[0022]

[Table 2]

In the refrigeration cycle of the present invention, a fluorinated hydrocarbon-based refrigerant containing no chlorine which causes ozone layer depletion is used alone or as a mixture of a plurality of types, for example, HFC32 / HFC125 / HFC134.
The mixed refrigerant of a is used. Refrigeration oil suitable for this mixed refrigerant is an ester or a substance containing an ester bond,
For the former, a polyol ester is used, and for the latter, a part of the molecular structure of PAG is esterified.

However, it has been found that in an environment where the mixed refrigerant and the ester oil coexist, a problem arises in compatibility of rubber materials such as CR rubber, NBR rubber and hydrin rubber shown in Table 2. In general, it is known that rubber material precipitates and swells in a refrigeration cycle having a refrigerant and a refrigerating machine oil. However, some of the substances precipitated from the rubber material hydrolyze ester bonds of the refrigerating machine oil or hydrolyze. Has the effect of accelerating the decomposition reaction.

One of the factors is a vulcanizing agent, a vulcanization accelerator and an antioxidant compounded to improve the manufacturability of the rubber material or the material properties. In particular, the vulcanizing agent adds sulfur to improve the mechanical properties such as hardness and tensile strength by making the intermolecular bonds of the rubber material into a network structure. When this sulfur precipitates in the refrigerating machine oil, it is esterified. It reacts in oil to produce sulfuric acid, which catalyzes and promotes ester hydrolysis. Further, the vulcanization accelerator and the antioxidant include an organic acid or a substance which combines with a substance in a refrigeration cycle to generate an acid, and thus has an action of promoting ester hydrolysis. The mainstream of the vulcanizing agent is sulfur, but in the present invention, non-sulfur vulcanizing agents that do not use sulfur at all, such as peroxides, metal oxides, quinone dioximes, chlorine compounds, polyisocyanates, and the like. Uses CR rubber, NBR rubber, hydrin rubber, etc. produced by using radiation vulcanization which does not require a compounding agent for vulcanization and keeping the amounts of vulcanization accelerator and antioxidant at 1 phr or less.

As a result, in the present invention, the ester hydrolysis reaction by the vulcanizing agent, vulcanization accelerator, anti-aging agent and the like in the material can be suppressed, and the deterioration of the refrigerating machine oil and the corrosion and wear of the equipment can be prevented. Can be.

Next, a second embodiment of the present invention will be described.
Another factor of ester hydrolysis of refrigerating machine oil by an organic material is an ester plasticizer that is blended to improve processability and impart flexibility to a rubber material. Ester plasticizers are mainly used for NBR, but when precipitated in refrigerating machine oil, they tend to decompose faster than ester oil and react in oil to produce fatty acids. This fatty acid acts as a catalyst for ester hydrolysis to promote the hydrolysis reaction. In the present invention, in order to suppress this phenomenon, an NBR produced by suppressing the ester plasticizer to 10 phr or less is used.
NBR / EPDM combined with ethylene propylene (EPDM) to reduce the amount of rubber or ester plasticizer
Use rubber.

As a result, in the present invention, the ester hydrolysis reaction by the ester plasticizer in the material can be suppressed, and the deterioration of the refrigerating machine oil and the corrosion and wear of the equipment can be prevented.

A third embodiment of the present invention will be described. Yet another factor in ester hydrolysis of refrigerator oil by organic materials is the moisture contained in the materials. Generally, rubber and polyester contain water of 2,000 ppm or more in production, and when this is absorbed into ester oil, the water content in the refrigeration cycle increases and hydrolysis is likely to occur. In the present invention, a rubber material such as CR rubber, NBR rubber, hydrin rubber and the like and a polyester material produced by controlling the amount of water contained in the organic material used in the refrigeration cycle to 1000 ppm or less are used.

As a result, in the present invention, it is possible to suppress the increase in water in the refrigeration cycle generated from the material and to suppress the hydrolysis, thereby deteriorating the refrigerating machine oil, corroding the equipment,
Wear can be prevented.

Next, a fourth embodiment of the present invention will be described. Still another factor in ester hydrolysis of refrigerator oil by organic materials is an acid catalyst or an alkaline catalyst substance that promotes a hydrolysis reaction in the material. These substances are used for cross-linking and plasticizing the rubber material, and are compounded at the time of manufacture, and the substances differ depending on the rubber material formulation. The NBR rubber includes, for example, stearic acid, sodium pyrophosphate, and sodium hydroxide, and the CR rubber includes, for example, sodium hydroxide and potassium sulphate. Their content is usually between 0.1 and
1 phr. In the present invention, CR rubber and NBR rubber are used.
The content of the substance that becomes an acid catalyst or an alkali catalyst is reduced to 0.
It is to use one manufactured under 1 phr or less.

As a result, in the present invention, ester hydrolysis reaction caused by a substance serving as an acid catalyst or an alkali catalyst contained in the material can be suppressed, and deterioration of refrigerating machine oil and corrosion and wear of equipment can be prevented. it can.

Further, a fifth embodiment of the present invention will be described with reference to FIG. FIG. 2 shows a state of the organic material used in the refrigerant compression device, and has a structure in which the electric motor 9, the magnet wire 10, and the O-ring 11 are in contact with the refrigerating machine oil 12. The electric insulating materials used in the motor are listed in Table 1. However, the varnish treatment is applied to the insulated wire, and in the ester oil, problems such as deterioration and dissolution of the varnish occur. In addition to reducing the properties, the substances contained in the varnish cause ester hydrolysis. In the present invention, a varnish prepared from a substance that does not cause ester hydrolysis is used. As a result, in the present invention, it is possible to prevent a decrease in the electrical insulation of the electric motor and to suppress the ester hydrolysis reaction caused by the varnish agent, thereby preventing deterioration of the refrigerating machine oil and corrosion and wear of the refrigerant compressor. . Further, by using the organic materials described in the embodiments for the O-ring and the insulating film material in the refrigerant compression device, a more reliable refrigerant compression device can be realized.

In the present invention, a highly reliable air conditioner can be realized by implementing one or more embodiments.

[0035]

According to the present invention, the present invention is applied to a refrigeration cycle.
Of refrigerating machine oil caused by the compressor O-ring
Water decomposition can be suppressed, refrigeration oil deterioration, compressor
Corrosion and wear can be prevented.

[0036]

[0037]

[0038]

[0039]

[0040]

[Brief description of the drawings]

FIG. 1 is a system diagram showing a configuration of a refrigeration cycle.

FIG. 2 is a sectional view showing a configuration of a refrigerant compression device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Compressor, 2 ... Outdoor heat exchanger, 3 ... Indoor heat exchanger, 4
... four-way valve, 5 ... accumulator, 6 ... solenoid valve, 7 ... outdoor expansion valve, 8 ... indoor expansion valve.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁷ Identification code FI F16J 15/10 F16J 15/10 C (56) References JP-A-4-91194 (JP, A) JP-A-4-331289 ( JP, A) JP-A-4-328197 (JP, A) JP-A-5-17792 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F25B 1/00 395 C08L 9 / 02 C08L 33/20 C09K 5/04 C10M 105/32 F16J 15/10

Claims (1)

(57) [Claims] 1. A chlorine-free fluorinated hydrocarbon-based refrigerant is used as a working fluid, and has an ester bond as a lubricating oil.
Empty with refrigeration cycle using refrigerating machine oil containing base
In an air conditioner, an O-ring of a compressor used in the refrigeration cycle is used.
NBR containing 10 phr or less of ester plasticizer
An air conditioner characterized by using rubber .