JP2536560B2 - Working medium mixture - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel working medium mixture that can be used in refrigerators, heat pumps, and the like.

[Prior art] Air conditioning, refrigeration and refrigeration equipment (refrigeration cycle / heat pump cycle), waste heat recovery power generation (rankin cycle),
Heat exchange equipment (heat pipes) and the like have been commercialized or tested and developed. Working media used in these devices include water, hydrocarbons such as propane and butane, trichlorofluoromethane (R11), and chlorodifluoromethane (R2).
2) and the like, or ammonia and the like are known.

[Problems to be Solved by the Invention] CFCs are less toxic, non-flammable, chemically stable, and various CFCs with different standard boiling points are easily available. Has been done to. The present invention newly provides CFCs having a high heat recovery efficiency, in particular, a freezer, a refrigerator, a cooling / heating equipment, a hot water supply equipment or a heat pump system for the purpose of recovering waste heat.

[Means for Solving Problems] The present invention relates to a working medium mixture containing ethane (hereinafter abbreviated as R170) and tetrafluoroethane as essential components.

In the present invention, tetrafluoroethane includes 1,1,2,2
-Two types of isomers of tetrafluoroethane (R134) and 1,1,1,2-tetrafluoroethane (R134a) are known, but they are used alone because they have similar physical properties. Or a mixture of these may be used.
In the following description, an example in which R170 and R134a are mixed and used is shown.

Hereinafter, the present invention will be described in detail with reference to FIG. 1 showing a flow sheet of a refrigeration cycle system using the working medium mixture of the present invention (hereinafter, simply referred to as a working medium). In FIG. 1, 1 is a compressor, 2 is a condenser, 3 and 3'are load fluid pipes, 4 is a pressure reducing device, 5 is an evaporator, and 6 and 6'are heat source fluid pipes.

In the refrigeration cycle system shown in FIG. 1, the working medium is compressed by the compressor 1 and then guided to the condenser 2 where it is cooled and condensed by the load fluid introduced from the pipe 3. On the other hand, the load fluid is inversely heated in the condenser 2 and supplied to the load heating through the pipe 3 '. Next, the condensed working medium is decompressed by the decompression device 4, guided to the evaporator 5, heated in the evaporator 5 by the heat source fluid introduced from the pipe 6 and discharged from the pipe 6 ', and then again. The compressor 1 is sucked and the above cycle is repeated. On the other hand, the heat source fluid is inversely cooled in the evaporator 5 and is cooled by the pipe 6 '.

FIGS. 2 and 3 show the cycle of the working medium mixture in the refrigeration cycle system shown in FIG. 1 plotted on the pressure-enthalpy diagram. When saturated vapor of the working medium is adiabatically compressed, a wet state is shown in FIG. 2 and a dry state is shown in FIG.

The change of the working medium by the compressor in FIG. 1 is the change from 8 to 9 or 13 to 14 in FIGS. 2 and 3, and the change of the working medium by the condenser is 9 → 10 → 11 → or 14 → 15. →
The change of the working medium by the pressure reducing device corresponds to the change of 11 to 12 or 17 to 18, and the change of the working medium by the evaporator corresponds to the change of 12 to 8 or 18 to 13, respectively.

As the operating conditions of the refrigeration cycle system of FIG. 1 using the working medium mixture of the present invention, the evaporation end temperature of the working medium in the evaporator (the temperature of reference numeral 7 or 13; hereinafter referred to as evaporation temperature) and the working medium in the condenser are The temperature at the start of condensation (the temperature of code 9 or 15; hereinafter referred to as the condensation temperature) was set. Tables 1 to 2 show the coefficient of performance and the refrigerating capacity in the refrigeration cycle system using the working medium mixture of the present invention together with comparative examples.

As can be understood from the table, the coefficient of performance and the refrigerating capacity of the refrigeration cycle using the working medium mixture of the present invention in which the mixing molar ratio of R170 and R134a is in the range of 1:99 to 40:60 is R134a.
Is improved compared to when used alone, especially R170
It can be seen that when the working medium mixture of the present invention in which the mixing molar ratio of R134a and R134a is around 20:80 is used, it is greatly improved and is extremely effective. In addition, if the mixing ratio of R170 is too large, it is not preferable in terms of flammability.

The working medium mixture of the present invention is particularly effective when applied to a refrigeration cycle for the purpose of air conditioning, refrigeration and refrigeration in low to medium temperature and high temperature fields, but is used as a working medium for various other heat recovery technologies such as Rankine cycle. You can also do it. The working medium mixture of the present invention has excellent thermal stability and does not require a stabilizer under normal use conditions, but when it is necessary to improve heat stability due to severe use conditions, dimethyl phosphite is used. Phosphite compounds such as diisopropyl phosphite and diphenyl phosphite, or thiophosphite compounds, or phosphine sulfide compounds such as triphenylphosphine sulfide and trimethylphosphine sulfide, and other stabilizers such as glycidyl ethers as a working medium 100 It may be added in a small amount of about 1 part by weight with respect to parts by weight.

[Effects of the Invention] The working medium mixture of the present invention is particularly excellent in refrigeration cycle efficiency, that is, refrigeration and heating efficiency, and is significantly improved as compared with a single component before mixing.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flow chart of a refrigeration cycle for explaining an embodiment of the present invention, and FIGS. 2 and 3 are pressure charts of a cycle using a R170 / R134a mixed system as a working medium. -Drawing on the enthalpy diagram.

Claims (2)

(57) [Claims] 1. A working medium mixture comprising ethane and tetrafluoroethane as essential components. 2. The working medium mixture according to claim 1, wherein the mixing molar ratio of ethane and tetrafluoroethane is 1:99 to 40:60.