JPH01139684A - Working medium mixture - Google Patents

Abstract

PURPOSE:To obtain the title novel mixture having excellent refrigeration and heating efficiency, usable for refrigerator, heat pump, etc., and having excellent thermal stability, by using specific hydrocarbons such as n-butane and monochlorotetrafluoroethane as essential components. CONSTITUTION:The objective mixture contains (A) at least one kind of hydrocarbons selected from n-butane, cyclobutane, n-pentane, isopentane and cyclopentanes and (B) monochlorotetrafluoroethane as essential components. In the case of necessitating the improvement in the thermal stability for the use under severe condition, the working medium is added with about 1wt.% of a stabilizer such as dimethyl phosphite.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a novel working medium mixture that can be used in refrigerators, heat pumps, etc.

[Prior Art] Air conditioning, refrigeration and refrigeration equipment (refrigeration cycle/heat pump cycle), waste heat recovery power generation (Rankine cycle), heat exchange equipment (heat pipe), etc. have been put into practical use or tested and developed. Working media used in these devices include water, hydrocarbons such as propane and butane, trichlorofluoromethane (R11), and chlorodifluoromethane (+
722) 3 fluorocarbons or ammonia are known.

[Problems to be solved by the invention] Since fluorocarbons have low toxicity, are non-flammable, and are chemically stable, and various types of fluorocarbons with different standard 7F points are easily available, evaluation research as a working medium has been conducted. It is actively carried out. The present invention provides novel fluorocarbons that have high heat recovery efficiency, particularly for freezers, refrigerators, N4!1 air conditioners, water heaters, or heat pump systems for waste heat recovery.

[Means for Solving the Problems] The present invention relates to a working medium mixture characterized in that it contains at least one kind selected from hydrocarbons having 4 to 5 carbon atoms and tetrafluoroethane as essential components. It is.

Monochlorotetrafluoroethane in the present invention includes:
l-chloro-1,2,2,2-tetrafluoroethane (
Two types of isomers are known: R124) and 1-chloro-1,1,2,2-tetrafluoroethane (R124a), but since their physical properties are similar to each other, they cannot be used alone. Often, mixtures of these may also be used.
In the following description, an example will be shown in which R124 and one selected from n-butane, cyclobutane, n-pentane, isopentane, and cyclopentane are used as essential components and are used in combination.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to FIG. 1, which shows a flow sheet of a refrigeration cycle system using the working medium mixture of the present invention (hereinafter sometimes simply referred to as 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 a compressor 1 and then led to a condenser 2, where it is cooled and condensed by a load fluid introduced through a pipe 3. On the other hand, the load fluid is reversely heated in the condenser 2 and passed through the pipe 3' for load heating. Next, the condensed working medium is transferred to the pressure reducing device i! After being depressurized by t4, it is guided to the evaporator 5, and in the evaporator 5 /i? 6
After being heated by the heat source fluid introduced from the tube 6' and discharged from the pipe 6', it is sucked into the compressor l again and the above cycle is repeated, while the hot a fluid is reversely cooled in the evaporator 5,
It is provided for cooling through a tube 6.

2 and 3 are pressure-enthalpy diagrams showing the cycles of the working medium mixture in the refrigeration cycle system shown in FIG. 1. Figure 2 shows what becomes wet when the working medium, saturated steam, is compressed adiabatically.
Figure 3 shows what is in a dry state.

The change in the working medium due to the compressor in Figure 1 is the change from 8 to 9 or from 13 to 14 in Figures 2 and 3, and the change in the working medium due to the condenser is 9→1O→11 or 14. →15→16→17, the change in the working medium due to the depressurizer corresponds to the change from 11 to 12 or from 17 to 18, and the change in the working medium due to the evaporator corresponds to the change from 12 to 8 or 18 to 13. .

The operating conditions of the refrigeration cycle system shown in FIG. 1 using the working medium mixture of the present invention are the evaporation path temperature of the working medium in the evaporator (temperature 7 or 13, hereinafter referred to as evaporation temperature) and the working medium in the condenser. Temperature of the condenser (temperature with code 9 or 15; hereinafter referred to as condensing temperature)
It was set. Tables 1 to 12 show the coefficient of performance and refrigeration capacity per unit volume of the compressor in the above refrigeration cycle system using the working medium mixture of the present invention, along with comparative examples.

As understood from the table, n-butane, cyclobutane, n
- The working medium mixture of the present invention containing at least one selected from pentane, isopentane, and cyclopentane and R124 as essential components can be greatly improved compared to the case where R124 is used alone. It can be seen that the working medium mixture having a composition of about 20 mol % is greatly improved compared to the case where R124, n-butane, cyclobutane, n-pentane, isopentane, and cyclopentane are used alone. Hydrocarbons such as n-butane, cyclobutane, n-pentane, isopentane, and cyclopentane, which are one of the acid components of the working medium mixture of the present invention, have a higher coefficient of performance than R124, but have a lower refrigerating capacity per unit volume of the compressor. It has the disadvantage of low flammability. On the other hand, although R124 has the disadvantage of a lower coefficient of performance than hydrocarbons such as n-butane, cyclobutane, n-pentane, isopentane, and cyclopentane, it has a high refrigerating capacity per unit volume of the compressor and is non-flammable. By using the working medium mixture of the present invention, each of the disadvantages can be improved and the advantages can be utilized, and it can be seen that it is extremely effective.

The working medium mixture of the present invention is particularly effective in refrigeration cycle applications for air conditioning, refrigeration and refrigeration in low to high temperature fields, or can also be used as a working medium in various other heat recovery techniques such as the Rankine cycle. 0 can also be done
The working medium mixture of the present invention has excellent thermal stability and does not require stabilizers under normal conditions of use; however, if improved thermal stability is required due to severe conditions of use, dimethyl phosphide may be used. , phosphite compounds such as diisopropyl phosphite and diphenyl phosphite, or thiophosphite compounds, phosphine sulfide compounds such as triphenoxyphosphine sulfite and trimethylphosphine sulfide, and other stabilizers such as glycidyl ethers. It may be added in a small amount of about 1 part by weight per 100 parts by weight of the medium.

Table 1 (Evaporation temperature: 0℃, Condensation temperature = 60℃, Degree of supercooling: 0℃) Table 2 (Evaporation temperature: Knee 20℃ 1 Condensation temperature = 4
0°C, degree of supercooling: 0°C) Table 3 (Evaporation temperature: 0°C, condensing temperature = 60°C, degree of supercooling 20°C) Table 4 (different optical temperature: 20°C, condensing temperature: 40°C , degree of supercooling: 0°C) Table 5 (evaporation temperature: 0°C, condensation temperature = 60°C, degree of supercooling: O
"C) Table 6 (M temperature: knee 20℃, condensation temperature: 40℃
, supercooling degree: 0℃) Table 7 (Evaporation temperature: 0℃, condensation temperature 280℃, supercooling degree: 0℃) Table 8 (Evaporation temperature 20℃)
°C, condensation temperature: 40 °C, degree of supercooling: 0 °C) Table 9 (evaporation temperature: 20 °C, condensation temperature: 60 °C, degree of supercooling: 0 °C) i7
510 Table CM temperature knee 20℃, aWl[:4G℃, m
Immediately: ooC) [Effects of the Invention] The working medium mixture of the present invention is particularly excellent in refrigeration cycle efficiency, that is, freezing and heating efficiency, and is recognized as being significantly improved compared to monochlorotetrafluoroethane.

[Brief explanation of the drawing]

Fig. 1 is a flow sheet of a refrigeration cycle for explaining one embodiment of the present invention, and Figs. 2 and 3 are pressure-enthalpy diagrams of cycles using the working medium mixture of the present invention as the working medium. This is a diagram.

Claims (1)

[Claims] 1. A working medium mixture comprising at least one member selected from n-butane, cyclobutane, n-pentane, isopentane, and cyclopentanes and monochlorotetrafluoroethane as essential components.