JPS63105089A - Blended refrigerant - Google Patents

Abstract

PURPOSE:To obtain a blended refrigerant, having improved coefficient of performance as well as condenser capacity and useful for heat pump air conditioners, by blending monochlorodifluoromethane as a principal component with 1,1,1- trifluoroethane. CONSTITUTION:A blended refrigerant obtained by blending (A) mono chlorodifluoromethane as a principal component with (B) 1,1,1-trifluoroethane at 0.25-0.45mol fraction. The above-mentioned refrigerant is capable of miniatur izing and improving the efficiency of conventional air conditioners.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is applicable to a working medium for a vapor compression refrigeration cycle that cools or heats a fluid by utilizing changes in the state of substances such as pressurized liquefaction and depressurized vaporization. It relates to mixed refrigerants used, and particularly to mixed refrigerants used in heating and cooling equipment used for air conditioning.

[Conventional technology] Vapor compression refrigeration cycles are used in heating and cooling equipment, refrigerators,
It is widely applied to QL devices and put into practical use.

Various working fluids, mainly fluorocarbon-based refrigerants, have been developed and put into practical use for use in such compression refrigeration cycles.

A typical working medium is a methane-based or ethane-based halogenated hydrocarbon as a single component, and in the case of methane, R1
1, R12, R13, R14, and R22, and in the case of ethane, R113, R114, and R115 are used depending on the purpose.

Among them, R22 (monochlorodifluoromethane) is widely used as a refrigerant in heating and cooling equipment used for air conditioning.

Compared to R12 (dichlorodifluoromethane), which is commonly used in refrigerators, dehumidifiers, etc., R22 can achieve greater refrigerating capacity with the same size compressor, allowing for smaller equipment.

Another advantage is that the suction pressure is higher than atmospheric pressure even at an evaporation temperature of -40°C, and it is widely used as a refrigerant that is chemically stable and has good thermodynamic properties.

Additionally, non-azeotropic mixed refrigerants have recently been studied in an attempt to supplement the characteristics that cannot be satisfied with a single refrigerant by using a mixture of refrigerants.
A heat pump air-conditioning device has been commercialized that is designed to increase the heating capacity more than R22 by mixing 3[31 (monopromotrifluoromethane) (see Dempa Shimbun dated August 30, 1985).

The above-mentioned mixed refrigerant was developed with more emphasis on improving the heating capacity than the R22 single refrigerant, so at present it has not received much attention in terms of its coefficient of performance (1931).
(Refer to pages 29-30 of the Proceedings of the 4th Annual Japan Refrigeration Society Academic Conference).

[Problems to be Solved by the Invention] The object of the present invention is to provide R22 that is even better than R22.
It is an object of the present invention to provide a working medium for a heat pump air conditioner that has a larger heating capacity than that of 22, has a higher coefficient of performance, and can reduce the size and increase the efficiency of conventional air conditioning units.

[Means for Solving the Problems] In order to achieve the above-mentioned object of the present invention, the present inventors have studied many fluorocarbon-based refrigerants. R143a (1,1°1-trifluoroethane), which is another fluorocarbon-based refrigerant that is chemically stable and has excellent thermodynamic properties, is mixed with this, preferably at a mixing ratio of 1-trifluoroethane. The mole fraction of 1.1.1-trifluoroethane in the mixed refrigerant is 0.
It has been found that this can be achieved by a mixed refrigerant for heat pump air conditioners having a temperature of 25 to 0.45.

[Example] Next, the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited to this example unless it departs from the gist of the present invention.

FIG. 1 is an outline of a vapor compression refrigeration cycle in which the mixed refrigerant (working medium) of the present invention was tested.

(1) is a compressor for the working medium, (2) is a water-cooled 2m pipe condenser 1, (3) is a liquid receiver, (4) is an expansion valve for pressure reduction, (5)
is an evaporator, (6) is a brine tank for heat absorption source, (7) is an accumulator, and (8) and (8-) are piping for heat radiation source water.

In such a vapor compression refrigeration cycle, the working medium is compressed 1! ! After being compressed in (1), it is led to a condenser (2), where it is condensed by giving heat to the introduced heat radiation source water. In this example, the temperature of the inlet and outlet of the heat radiation source water was kept approximately constant, and the condenser capacity was determined by the product of the temperature difference in the inlet and outlet, the flow rate, and the specific heat, and a comparison was made.

The condensed working medium is stored in the liquid receiver (3) and
After the pressure is regulated by the II expansion valve, it is led to the evaporator (5),
The cycle of absorbing heat from the heat-absorbing brine tank (6), evaporating it, and sucking it into the compressor (1) again via the accumulator (7) is repeated.

The heat-absorbing brine tank has a built-in heater, and is configured to control the power input in proportion to the evaporator capacity and maintain a constant wetness in the treetops to enable comparative tests. ing.

Table 1 shows the results obtained using a vapor compression refrigeration cycle having the configuration shown in FIG.

The test conditions are R143 in the mixed refrigerant of the present invention.
When using a mixed refrigerant with a different mixing ratio in a and R22 alone, the hot water temperature at the condenser inlet and outlet and the temperature of the brine tank for the heat absorption source in the evaporator are kept almost constant, and the expansion for pressure reduction is Compressor input, condenser capacity, and coefficient of performance are compared with the valve inlet liquid refrigerant temperature and accumulator inlet refrigerant temperature being approximately equal.

Example 1 is a case where the molar fraction of R143a in the mixed refrigerant of the present invention is 0.4. .

Example 2 is a case where the mole fraction of R143a is 0.35, and Example 3 is a case where the mole fraction of R143a is 0.25. The comparative example is a case where R22 is used alone as a refrigerant.

FIG. 2 shows the condenser capacity and coefficient of performance of Examples 1 to 3 and Comparative Example using the mole fraction of R143a as a parameter.

From this figure, the mole fraction of R1438 is 0.25 to 0.4
It was found that there is a maximum value in which the coefficient of performance (COPi) is higher than that of R22 in the range of 5, and that the peak occurs when the molar fraction of R143a is 0.35.

On the other hand, the condenser performance no.j also peaks when the mole fraction of R143a is 0.35. Its capacity has increased compared to R22.

When the mole fraction of R143a is 0.35+7), the coefficient of performance improvement rate compared to R22 is 2.4%, and the condenser capacity improvement rate is 7%.
Met.

[Effect of the invention] The mixed refrigerant of the present invention, which is a mixture of R143a and R22 as a working medium for a heat pump air conditioner using a vapor compression refrigeration cycle, has a higher condenser capacity than R22, which is currently widely used. It also improves the coefficient of performance, making it possible to make heat pump air conditioners smaller and more efficient.

[Brief explanation of the drawing]

Fig. 1 is a schematic explanatory diagram of a vapor compression refrigeration cycle using the mixed refrigerant of the present invention (made by Jar body), and Fig. 2 shows the change in characteristics depending on the R143a mole fraction in the R22/R143a mixed refrigerant. It is an explanatory diagram. (1)...Compressor for working medium, (2)...Water-cooled double pipe condenser, (3)...Liquid receiver, (4)...Expansion valve for pressure reduction, (5) ... Evaporator, (6) ... Brine tank for heat absorption source, (7) ... Accumulator, (8), (8-) ... Piping for heat radiation source water. Applicant Sanyo Electric Co., Ltd. Asahi Glass Co., Ltd.

Claims (2)

[Claims] (1) A mixed refrigerant comprising monochlorodifluoromethane as a main component and 1,1,1-trifluoroethane mixed therein. (2) The mixed refrigerant according to claim 1, wherein the molar fraction of 1,1,1-trifluoroethane in the mixed refrigerant is 0.25 to 0.45.