JPH0461910B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Field of Application] The present invention relates to a novel working medium mixture that can be used in heat pumps and the like. [Prior technology] Research into recovering energy from heat sources in the medium and low temperature range, which is lower than that obtained by burning fuels such as heavy oil and petroleum, is progressing, and this has led to advances in ocean thermal power generation, geothermal binary power generation, waste heat recovery power generation, and solar thermal power generation. , temperature raising using heat pumps, heat exchange technology using heat pipes, etc. are being put into practical use or being tested. The working media used in these heat recovery technologies include water, hydrocarbons such as propane and butane, and trichloromonofluoromethane (R-11) and 1,2-dichlorotetrafluoroethane (R-114). Fluorocarbons, ammonia, etc. are known. [Purpose of the Invention] Fluorocarbons have low toxicity, are non-flammable, and are chemically stable, and various fluorocarbons with different boiling points are easily available, so research on their evaluation as working media has been actively conducted. There is. As a result of our search for fluorocarbons with high heat recovery efficiency, particularly for freezers, refrigerators, air conditioning equipment, hot water supply equipment, and heat pump systems for the purpose of waste heat recovery, we discovered monochlorodidifluoromethane and dichlorotrifluorocarbons. It has been found that a working medium mixture containing fluoroethane as an essential component is effective.
The present invention provides such a novel working medium mixture. [Structure of the invention] In the present invention, dichlorotrifluoroethane includes 1,1-dichloro-2,2,2-trifluoroethane (R-123), 1,2-dichloro-1,
Three isomers are known: 2,2-trifluoroethane (R-123a) and 1,1-dichloro-1,2,2-trifluoroethane (R-123b), but they have different physical properties. Due to their similarity, they may be used alone or a mixture thereof. In the following explanation, R-22
An example of using a mixture of (monochlorodifluoromethane) and R-123 is shown below. Hereinafter, the present invention will be explained in detail with reference to FIG. 1, which shows a flow sheet of a heat pump system using the working medium of the present invention. 1 in Figure 1 is a compressor, 2
1 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 heat pump 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 both loads 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 4
After being depressurized, it is led to the evaporator 5, where it is heated by the heat source fluid introduced through the tube 6 and discharged through the tube 6', and then sucked into the compressor 1 again to repeat the above cycle. . FIGS. 2 and 3 show the cycles of the working medium in the heat pump system shown in FIG. 1 on pressure-enthalpy diagrams. When saturated vapor as a working medium is adiabatically compressed, a wet state is shown in Fig. 2, and a dry state is shown in Fig. 3. Changes in the working medium due to the compressor in FIG. 1 are indicated by reference numerals 8 to 9 or 13 to 14 in FIGS.
The change in working medium due to the condenser is 9 → 10
→11→ or 14→15→16→17, the change in working medium due to the pressure reducing device is from 11 to 12 or from 17 to 18, and the change in working medium due to the evaporator is 12
This corresponds to the change from 8 to 13 or from 18 to 13, respectively. The operating conditions of the heat pump system shown in FIG. 1 using the working medium of the present invention are the end temperature of evaporation of the working medium in the evaporator (temperature 7 or 13, hereinafter referred to as evaporation temperature) and the start of condensation of the working medium in the condenser. (temperature number 9 or 15; hereinafter referred to as condensation temperature) was set. 1st
Table 2 shows the coefficient of performance, heating capacity per unit horsepower of the compressor, and circulation amount of the working medium in the heat pump system using the working medium of the present invention, together with comparative examples. As can be understood from the table, the coefficient of performance and heating capacity of a heat pump using the working medium of the present invention in which the mixing molar ratio of R-22 and R-123 is in the range of about 1:100 to 1:0.7 are R- This is an improvement over the case where each of 22 and R-123 is used alone, and it is also greatly improved compared to dichlorodifluoroethane (R-12), which is commonly used at present. The working medium mixture of the present invention is particularly effective when applied to a heat pump system using a medium-low temperature heat source, but it can also be used as a working medium for Rankin-Sikes or various other heat recovery techniques. The working medium mixture of the present invention has excellent thermal stability and does not require stabilizers under normal conditions of use; however, when it is necessary to improve thermal stability due to severe conditions of use, dimethyl phosphite can be used. , phosphite-based compounds such as diisopropyl phosphite and diphenyl phosphite, or thiophosphite-based compounds, or phosphine sulfide-based compounds such as triphenoxyphosphine sulfide and trimethylphosphine sulfide, and other stabilizers as the working medium. It may be added in a small amount of about 1 weight per 100 parts by weight.

【table】

〔Effect of the invention〕

The working medium mixture of the present invention is excellent in heat recovery efficiency, particularly in heat pump system efficiency, that is, heating and cooling efficiency, and is significantly improved compared to the single component before mixing.

[Brief explanation of drawings]

Figure 1 is a flow sheet of a heat pump for explaining one embodiment of the present invention, and Figures 2 and 3 are pressure-enthalpy diagrams of a cycle using an R-22/R-123 mixed system as the working medium. This is a diagram filled in.

Claims (1)

[Scope of Claims] 1. A working medium mixture characterized by containing monochlorodifluoromethane and dichlorotrifluoroethane as essential components. 2 The mixing molar ratio of monochlorodifluoromethane and dichlorotrifluoroethane is 1:100 to 1:
0.7.