JPH1194490A - Air conditioner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable air conditioner which can use both R22 and HFC based coolant without causing any deterioration of material or refrigerating machine oil. SOLUTION: The air conditioner employs a vapor pressure compression refrigeration cycle comprising a coolant compressor 1, a condenser 3, expansion units 4, 5, an evaporator 7 and an accumulator 9 coupled sequentially wherein an HNBR rubber applicable to both R22 and HFC based coolant (R407C) is employed as a rubber material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an air conditioner using a vapor compression refrigeration cycle. Especially R22 and HFC
The present invention relates to an air conditioner corresponding to both refrigerants of a system refrigerant.

[0002]

2. Description of the Related Art HCFC-based refrigerants have been determined to be totally abolished worldwide because of the effects of depletion of the ozone layer and global warming. Therefore, instead of the refrigerant such as R22 currently used in air conditioners, the ozone layer is not destroyed.
We decided to use FC refrigerant. However, since HFC-based refrigerants have poor compatibility with refrigerant oils such as mineral oil used in refrigeration systems such as R22, ester-based or ether-based refrigerant oils are practically useful for easily dissolving refrigerants. Used. However, the former ester-based refrigerating machine oil undergoes hydrolysis in the presence of moisture,
The acid generated by the decomposition lowers the reliability of equipment constituting the refrigeration cycle, such as abrasion and corrosion. In addition, the latter ether-based refrigerating machine oil is also oxidized and degraded by moisture and air, thereby reducing reliability. It is known that the water causing the hydrolysis and the oxidative deterioration is also present in the organic material.

[0003] Therefore, as disclosed in JP-A-7-305905, as a material for suppressing the hydrolysis of ester oil of lubricating oil for HFC-based refrigerants, it was produced without reducing or containing a substance that promotes hydrolysis. CR rubber, NBR rubber,
By using EPDM rubber, hydrin rubber, or the like, it is possible to prevent deterioration of refrigerating machine oil, and prevent corrosion and wear of equipment.

[0004]

From the viewpoint of protection of the ozone layer, all products will eventually be transferred to HFC-based refrigerant-compatible air conditioners. However, since there are many product series, all products cannot be changed to HFC-based refrigerants at the same time, and mixed production of R22-compatible air conditioners and HFC-based refrigerant-compatible air conditioners is essential. Therefore, a material that can be used for R22 and the HFC-based refrigerant is required.

[0005] Further, the HFC-based refrigerant has a large polarity, and by using a highly polar oil in which oxygen is introduced into the molecular structure to ensure compatibility, the polarity contributing to the solubility of the substance is increased.
There is a great difference between R22 and HFC refrigerant. Based on this point, it is necessary to make the material compatible with both.

[0006] The rubber material used for the seal portion is swollen by the refrigerant or the refrigerating machine oil, and the refrigerant or the refrigerating machine oil enters the material, or the additive material in the material is extracted, so that the rubber material has a tensile strength or hardness. Material properties change. If the seal is not maintained and the refrigerant leaks due to the change in the material properties, the device stops or the refrigerant is released to the atmosphere, which causes global warming. Therefore, it is necessary to select an appropriate rubber material so that the seal is not maintained.

[0007] However, CR rubber, NBR produced without reducing or containing the above-mentioned conventional hydrolysis-promoting substances.
It is known that rubber, EPDM rubber, and hydrin rubber have insufficient mechanical strength and cannot maintain a seal in an environment where HFC-based refrigerant and refrigerating machine oil coexist. If the seal is not maintained and the refrigerant leaks, the equipment may stop,
Refrigerant is released into the atmosphere, causing global warming.
Therefore, the conventional materials could not be adapted to both R22 and HFC-based refrigerants.

On the other hand, refrigerating machine oil for HFC-based refrigerant generates acid when decomposed by hydrolysis or oxidative deterioration, which causes corrosion wear of sliding parts, lowering of insulation and copper plating phenomenon.
It is necessary to prevent the additive or the like extracted from the material from being swollen by the refrigerant or the refrigerating machine oil from promoting it.

An object of the present invention is to provide an air conditioner which can be used for both R22 and HFC-based refrigerants without deteriorating the material and without deteriorating the refrigerating machine oil.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. First, at least a refrigerant compression device, a condenser, an expansion device, an evaporator, and an accumulator are sequentially connected. In a refrigerant used for an air conditioner using a vapor compression refrigeration cycle, HNBR rubber is used as a rubber material that can be used for both R22 and HFC-based refrigerant (R407C).

Here, HNBR will be described. HN
BR is a method of minimizing the double bond of NBR,
Hydrogen is added. NBR is an acrylonitrile-butadiene copolymer, and the molecular structure is It is. The butadiene (—CH 2 —CH = CH—CH 2 —) double bond is opened by hydrogenation, and the reduced one is HNBR.
It is. This HNBR rubber is combined with R22 and HFC refrigerant (R
407C) and good results were obtained.

Second, R407C, R407E, and R407E are used as HFC-based refrigerants used in the air conditioner or the refrigerator.
Means are to use 410A, R404A, and R507A.

Third, an ester oil is used as the refrigerating machine oil used in the air conditioner.

Fourthly, the refrigerating machine oil used in the air conditioner is ether oil.

Fifth, HNB used in the air conditioner
The method is to reduce the moisture in R to 1000 ppm or less.

Sixth, HNB used in the air conditioner
The total amount of chlorine-based, phosphorus-based, and sulfur-based residues in R is 1% or less.

Seventh, HNB used in the air conditioner
The amount of bound acrylonitrile in R is 30% or more, and the iodine value is 30 g / 100 g or less.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a system diagram of a refrigeration cycle according to the first invention. FIG. 2 is a diagram showing a state of the organic material used for the ball valve.

First, an air conditioner of this embodiment using HNBR rubber as a rubber material that can be used for both R22 and HFC-based refrigerant (R407C) will be described with reference to FIGS. In FIG. 1, 1 is a refrigerant compression device, 2 is a four-way valve, 3 is a condenser, 4 and 6 are expansion devices, 5 and 8 are ball valves, 7 is an evaporator, and 9 is an accumulator, which are sequentially connected. Constitute a refrigeration cycle. FIG. 2 is a detailed view of the 5 and 8 ball valves. 10 is a ball valve and 11 is an O-ring. The O-ring 11 has a structure that contacts the refrigerant and the refrigerating machine oil. In particular, HF is used as a working refrigerant for a refrigeration cycle.
When a C-based refrigerant is used, since the HFC-based refrigerant does not contain chlorine, the compatibility with the conventional refrigerating machine oil mainly containing mineral oil, alkylbenzene, etc. used for R22 is remarkably reduced. Cannot be used with refrigerating machine oil. Therefore, it is necessary to use a refrigerating machine oil such as an ether oil or an ester oil which ensures compatibility with the HFC-based refrigerant due to molecular polarity. The HFC-based refrigerant and the ether oil and the ester oil have large polarities, and the polarity contributing to the solubility of the substance is significantly different between R22 and the HFC-based refrigerant. Even if the material does not deteriorate in R22, the HFC-based refrigerant results in deterioration. Therefore, in the present invention, the H22 rubber which does not deteriorate is used as the rubber material used for the O-ring 11, so that R22 and HFC
Since the refrigerating machine oil does not deteriorate even when either of the system refrigerants is used, it is possible to provide an air conditioner that does not reduce reliability such as corrosion wear of sliding parts, insulation deterioration, and copper plating phenomenon. . Next, another embodiment will be described. Factors causing hydrolysis and oxidative degradation of refrigerator oil by organic materials include water contained in the materials. Generally, rubber and polyester are 2,000 in production.
When water is contained in the refrigerating machine oil, the amount of water in the refrigeration cycle increases, and hydrolysis is likely to occur. In the invention of the present embodiment, H is manufactured by controlling the amount of water contained in the organic material used in the refrigeration cycle to 1000 ppm or less.
That is, a rubber material of NBR rubber is used. As a result, it is possible to suppress an increase in water in the refrigeration cycle generated from the material, to suppress hydrolysis and oxidative deterioration,
Deterioration of refrigerating machine oil, and corrosion and wear of equipment can be prevented. Another embodiment will be described. Another factor of hydrolysis and oxidative deterioration of refrigerator oil by organic materials is a flow agent, a flow accelerator, and an anti-aging agent that are blended to improve the material productivity or material properties. . In particular, the excipient is added with sulfur in order to improve the mechanical properties such as hardness and tensile strength by making the intermolecular bonds of the rubber material into a network structure. It reacts in the machine oil to generate sulfuric acid, and the sulfuric acid acts as a catalyst to promote hydrolysis. In addition, the flow promoting agent and the antioxidant include an organic acid or a substance that combines with a substance in a refrigeration cycle to generate an acid, and thus has an action of promoting hydrolysis. Further, as another factor of hydrolysis and oxidative deterioration of refrigerator oil by organic materials, there are acid catalysts and alkali catalyst substances used for crosslinking and plasticizing rubber materials. These catalysts also cause a phenomenon that promotes hydrolysis. Sulfur is the mainstream in the former additive, but in the present invention, a non-sulfur additive that does not use sulfur at all, for example,
Peroxides, metal oxides, quinone dioximes, chlorine compounds, poisocyanates, etc., and further, as a radiation stream that does not require a compounding agent as a stream, a stream accelerator, an amount of an antioxidant, The latter is to use those manufactured by controlling the total amount of stearic acid, sodium prophosphate, sodium hydroxide, etc., which are the acid catalyst / alkali catalyst, to 1% or less. Still another embodiment will be described. HN
BR, like general NBR, improves oil resistance as the amount of acrylonitrile increases, and heat resistance, lubricating oil additive resistance, chemical resistance, and durability as iodine value decreases (hydrogenation rate increases). Improves. Acrylonitrile content is 30
% And an iodine value of 30 [g / 100 g] or less, R22 and HFC-based refrigerant (R407C)
In both cases, a test result that the above characteristics are improved has been obtained. In this embodiment, a more reliable air conditioner can be realized by implementing one or more of the above-described inventions.

As described above, as the HFC-based refrigerant, R
407C, R407E, R410A, R404A, R5
07A can be used to form an air conditioner or a refrigerator. Further, the refrigerating machine oil used in the air conditioner may be an ester oil. Still further, the refrigerating machine oil used for the air conditioner may be ether oil. Furthermore, the water in the HNBR is reduced to 100
It may be characterized in that it is set to 0 [ppm] or less. Furthermore, a total of chlorine-based, phosphorus-based, and sulfur-based residues in the HNBR may be 1% or less. Furthermore, the amount of bound acrylonitrile in the HNBR is 30% or more, and the iodine value is 30 g
/ 100 g] or less.

[0022]

As described above, according to the present invention,
By using HNBR rubber that does not deteriorate the material, R22
And an air conditioner that can be used for both HFC-based refrigerants.

Also, by using the HNBR rubber, the refrigerating machine oil does not deteriorate, so that it is possible to provide an air conditioner which does not reduce reliability such as corrosion and abrasion of a sliding portion, insulation deterioration and copper plating phenomenon. .

[Brief description of the drawings]

FIG. 1 is a system diagram of a refrigeration cycle in a first invention of an air conditioner according to the present invention.

FIG. 2 is a diagram showing a state of an organic material used for a ball valve.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Refrigerant compression device, 2 ... Four-way valve, 3 ... Condenser, 4, 6 ...
Expansion device, 5, 8 ball valve, 7 evaporator, 9 accumulator, 10 ball valve, 11 O-ring.

Claims (1)

[Claims] 1. An air conditioner using a vapor compression refrigeration cycle in which at least a refrigerant compression device, a condenser, an expansion device, an evaporator, and an accumulator are sequentially connected, a rubber material used for each of the components is R22. An air conditioner characterized by using HNBR rubber, which can be used for both HFC and HFC-based refrigerant (R407C).