JPH0436378A - Refrigerant - Google Patents

Abstract

PURPOSE:To obtain a refrigerant which scarcely affects the ozonosphere by mixing 1,1,2,2-tetrafluoroethane, 1,1,2-trifluoroethane, and 1-chloro-1,1- difluoroethane. CONSTITUTION:At least 75mol of 1,1,2,2-tetrafluoroethane (A) is mixed with 1,1,2-trifluoroethane (B) and 1-20mol of 1-chloro-1,1difluoroethane (C) so as to provide a molar ratio of component A to the total of components B and C of (99 to 4) : (1 to 96) to give a refrigerant comprising 100mol of this mixture.

Description

[Detailed description of the invention] Industrial applications The present invention relates to refrigerants.

BACKGROUND ART Conventionally, as working fluids or refrigerants, chlorofluorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons, azeotropic compositions thereof, and compositions in the vicinity thereof have been known.

Among these, R-
11 (trichlorofluoromethane), R-12 (dichlorodifluoromethane), R-114 (1,2-dichloro-1,1,2,2-tetrafluoroethane), R-2
2 (chlorodifluoroethane) etc. are mainly used.

However, in recent years, when chlorofluorocarbons are released into the atmosphere, they rise to the stratosphere without being decomposed because they have an extremely long lifespan before they decompose. destroy the layers,
As a result, it has been pointed out that this has a serious negative impact on the earth's ecosystem, including humans. Therefore, the use and production of these chlorofluorocarbons, which have a high possibility of depleting the stratospheric ozone layer, has been restricted by international agreements. The above-mentioned chlorofluorocarbons subject to restrictions include R, which is commonly used as mentioned above.
-11, R-12, R-114, etc. Restrictions on the use and production of these refrigerants, whose demand is increasing every year with the spread of refrigeration and air-conditioning equipment, have a large impact on the current social structure as a whole, including the living environment. Therefore, there is an urgent need to develop a new refrigerant that has no or very low risk of causing ozone depletion problems.

Means for Solving the Problems The present inventor has developed a practical product that is chemically stable when applied to refrigeration and air conditioning equipment, has a high coefficient of performance, can use mineral oil as a lubricant, and has little reaction with materials. In order to find a refrigerant that does not have the following drawbacks, and of course, when released into the atmosphere, it has little or no effect on the ozone layer in the stratosphere, and also has no significant effect on global warming. Various research efforts have been made to obtain new refrigerants. As a result, 1,1,2,2-tetrafluoroethane, 1,1,2-trifluoroethane and 1-chloro-
It has been found that a mixture consisting of 1,1-difluoroethane fulfills the requirements for that purpose.

That is, the present invention has the following features: 1, 1, 2. It concerns a refrigerant consisting of a mixture of 2-tetrafluoroethane, 1,1,2-trifluoroethane and 1-chloro-1,1-difluoroethane.

The main physical properties of 1,1,2,2-tetrafluoroethane (hereinafter referred to as R-134) used in the present invention are as follows.

Boiling point -19.8°C Critical temperature 119°C Molecular weight 102.32 Flammability None The main physical properties of 1,1,2-trifluoroethane (hereinafter referred to as R-143) are as follows.

Boiling point 5℃ Critical temperature 158℃ Molecular weight 84.041 Flammability Yes 1-chloro-1,1-difluoroethane (hereinafter referred to as R-14)
The main physical properties of 2b) are as follows.

Boiling point -9.7℃ Critical temperature 137.1℃ Molecular weight 100.50 Flammability Yes The above three types of substances have the following advantages and disadvantages when used alone as a refrigerant. . The present invention eliminates or alleviates the disadvantages of these three substances and utilizes their respective advantages by mixing these three substances in a specific ratio.

(a) R-134 has the great advantage of being nonflammable and has a coefficient of performance of R-134 when applied to a refrigeration cycle.
It has the characteristic that it is better than A. However, on the other hand, it has the disadvantage that it is not directly compatible with certain synthetic oils (eg, polyglycol oil).

The ozone depletion potential is 0, which is preferable, but the impact on global warming is not much different from R-22.

(b) R-143 is weakly flammable and has poor compatibility with mineral oil, and R-134, R-14
There is also a drawback that the refrigerating capacity per unit piston displacement is much smaller than that of 2b and the like. however,
Since the value of saturated vapor pressure with respect to temperature is small, it has the advantage that the pressure does not become too high in air conditioners used in high temperature environments. Further, it has an ozone depletion coefficient of 0, which is preferable, but on the other hand, its influence on global warming is considerably greater than that of R-22.

(c) R-142b is weakly flammable, and compared to the above two, the refrigerating capacity per unit piston displacement is smaller than R-134 (but larger than R-143). The value of the coefficient is also larger than R-134, but smaller than R-143.The ozone depletion coefficient is 0.
Although R-06 is not very large, its impact on global warming is greater than R-22, so it can be said to be somewhat problematic. However, since R-142b has good compatibility with mineral oil, it is a great advantage that the return of oil in the refrigeration cycle can be improved by adding a small amount of R-142b.

It is desirable for the refrigerant of the present invention to satisfy the following two requirements.

(a) The blending ratio of R-142b in 100 moles of the ternary mixture of R-134, R-143 and R-142b is
Must be in the range of 1 to 20 moles. If the blending ratio of R-142b is less than 1 mole, the function achieved by using mineral oil as a lubricating oil becomes insufficient due to the addition of R-142b, resulting in a decrease in refrigeration capacity and coefficient of performance,
This is not preferable because it may cause seizure of the bearing. on the other hand,
When the amount of R-142b becomes excessive, the amount of CQ ions increases, which increases the negative effect on the stratospheric ozone layer. Therefore, the upper limit of the blending ratio of R-142b is 20 moles in 100 moles of the ternary mixture.

(b) R-134 which is non-flammable and R-14 which is flammable
3 and R-142b (hereinafter referred to as R-143 and R-142b)
The mixture with
96 (hereinafter, this mixture will be referred to as the composition of the present invention). Within this composition range, the composition of the present invention exhibits nonflammability to slightly flammability. In order to make the composition of the present invention nonflammable, it is desirable that the proportion of R-134 in 100 moles of the composition be 75 moles or more. The proportion of R-134 in 100 moles of the ternary mixture is less than 4 moles and R-142
If the proportion of b is less than 20 moles, the vapor pressure of the mixture is too low, and the pressure on the low pressure side of the refrigeration cycle is always below atmospheric pressure, which may cause air to enter somewhere in the refrigerant system. If such spots are present, the flammable gas mixture in the system will mix with air, creating a risk of explosion. −
On the other hand, when R-134 exceeds 99 mol, R-14
The effect of adding 2b eliminates the advantage of being able to use mineral oil as a lubricating oil and causes the disadvantages mentioned above, which is not preferable.

In addition, in the above, for ease of explanation, R-
Although the mixture of R-143 and R-142b was referred to as a primary mixture, when preparing the composition of the present invention, there is no need to prepare a secondary mixture in advance, and the three components can be mixed simultaneously or in any order. can.

A stabilizer can be used in combination with the refrigerant of the present invention, if necessary. That is, when a high degree of stability is required under harsh usage conditions, epoxides such as propylene oxide, 1,2-butylene oxide, and glycidol; phosphors such as dimethyl phosphite, diisopropylphosphite, and diphenyl phosphite are phytes; thiophosphites such as trilauryl trithiophosphite; phosphine sulfides such as triphenoxyphosphine sulfide and trimethylphosphine sulfide; boron such as boric acid, triethylborate, triphenylborate, phenylboronic acid, and diphenylboronic acid Compounds; Phenols such as 2,6-di-tert-butyl para-cresol; Nitroalkanes such as nitromethane and nitroethane; Acrylic acid esters such as methyl acrylate and ethyl acrylate; Other dioxane,
Stabilizers such as tert-butanol, pentaerythritol, and barisopropenyltoluene can be added in an amount of about 0.01 to 5% of the weight of the working fluid.

Further, other compounds may be mixed with the mixture of the present invention within a range that does not impair the purpose or effect of the present invention. Examples of such compounds include ethers such as dimethyl ethyl and pentafluorodimethyl ether; amines such as perfluoroethylamine, and LPG.

Effects of the Invention The mixed refrigerant according to the present invention has each component that is easily decomposed and contains only a small amount of chlorine atoms that affect the ozone layer, so there is almost no risk of harmful effects on humanity due to the destruction of the ozone layer. Who?

Furthermore, as is clear from Table 1 below, the refrigerant according to the present invention has performance equivalent to or better than R-114, which is currently used as a refrigerant for cab coolers, in terms of cooling capacity and coefficient of performance. It is also well-balanced in terms of performance such as discharge gas temperature.

Further, since the refrigerant according to the present invention has low solubility in high molecular compounds, it can be used as is without changing the materials in existing refrigerators.

Furthermore, the refrigerant of the present invention has excellent thermal stability and is nonflammable or slightly flammable, so it can be used as is in ordinary refrigerators.

Still further, the refrigerant according to the invention is R-
142b, the compatibility with mineral oil is improved.

EXAMPLES Examples will be shown below to further clarify the features of the present invention.

Examples 1 to 4 and Comparative Examples 1 to 4 R-134 and R-143 in the proportions (mol%) shown in Table 1
In a 1-horsepower refrigerator that uses a mixed refrigerant consisting of
℃, the condensing temperature is 50℃, the superheating temperature is 5℃,
The operation was carried out with the degree of supercooling of the condenser set to 0°C. In addition,
Mineral oil was used as the lubricating oil for the compressor.

In addition, for comparison, R-114 alone and R-134 and R
The refrigerator was operated under the same conditions using a two-component mixed refrigerant consisting of -152a and -152a.

Table 2 shows (I) coefficient of performance and (II) refrigeration capacity [kcal/hr] obtained when each refrigerant was used.

Table 1 R-134-a'! ■(R-1434R-142b)
R-114 flammability (1+1 (20+4 (40+10 (76+20) Non-flammable, non-combustible, combustible (2+0 (2400) (50+0 (96+0 (0+0) Non-flammable, non-flammable, 100 Non-flammable Table 2 Coefficient of performance Refrigeration capacity Notes [kcal/hr] Implementation Example 1 4.41 2570 2 4.51 2270 3 4.57 1990 4 4.50 1610 Comparative example 1 4.41 1400 (*)2
4.51 1230 (*)3 4.5
7 1080 (*) 4 4.28
860 (*) 5 4.38 620 Note (*): When using the mixtures of Comparative Examples 1 to 4, if operation continues for a long time, the amount of oil in the oil reservoir of the compressor will decrease over time. This eventually causes seizure of the bearings, etc.

From the results shown in Table 2, it is clear that when the refrigerant according to the present invention is used, mineral oil can be used as a lubricating oil and stable and excellent properties are exhibited.

(that's all)

Claims (1)

[Claims] [1] 1,1,2,2-tetrafluoroethane, 1,1
, 2-trifluoroethane and 1-chloro-1,1-
A refrigerant consisting of a mixture of difluoroethane.