JPH03168289A - Working fluid - Google Patents

Abstract

PURPOSE:To provide a working fluid reduced in the affection thereof on the ozone layer of the stratosphere and employed as a substitute of dichlorodifluoromethane (R12) by containing trifluoromethane, chlorodifluoromethane and dichlorotrifluoroethane in a specific ratio. CONSTITUTION:The objective working fluid contains at least three kinds of freons comprising (A) <=80wt.% (preferably <=65wt.%) of trifluoromethane, (R23) (B) <=90wt.% (preferably <=85wt.%) of chlorodifluoromethane (R22) and (C) 10-95wt.% (preferably 15-90wt.%) of 2,2-dichloro-1,1,1-trichloroethane (R123). The working fluid is employed in freezers, heat pumps, etc.

Description

[Detailed Description of the Invention] Industrial Field of Application The present invention relates to working fluids used in refrigerators, heat pumps, etc. Halogenated hydrocarbons called ○○ or RO○○ are known, and the usage temperature ranges from 0 to 50°C at condensation and/or evaporation temperatures.
Among them, dichlorodifluoromethane (CCl*F2, R12) is widely used as a working fluid in refrigeration air conditioners, car air conditioners, large refrigerators, etc.

Problems to be solved by the invention In recent years, depletion of the stratospheric ozone layer by fluorocarbons has become a global environmental problem, and fluorocarbons (hereinafter referred to as specified fluorocarbons) have a large ability to deplete the stratospheric ozone. Regarding C, there are already no restrictions on usage and production under international treaties.Furthermore, there is a movement to abolish the use and production of specified fluorocarbons in the future.Now, R12 has an ozone depletion coefficient (trichlorofluoromethane). CCi*F
When the i-stratospheric ozone depletion potential of ) is 1, the stratospheric ozone depletion potential 9 (hereinafter referred to as ODP) is 1. It is a specified fluorocarbon of 0, and today's refrigeration and air conditioning equipment is widely used.
Reducing the amount of Rl2 used and produced will have a tremendous impact on the human living environment.Therefore, the ability to deplete the ozone in the lower atmosphere is small, and there is a strong demand for the early development of a working fluid that can replace Rl2.

The present invention was attempted in view of the above-mentioned problems, and is intended to provide a working fluid that has less influence on the stratospheric ozone layer and can be used as an alternative to R12.

Means for Solving the Problems The present invention is capable of solving the above-mentioned problems.
Contains three types of fluorocarbons (HC 1 2F3) Trifluoromethane 0-80 weight yarn Chlorodifluoromethane 0-90 weight K Dichlorotrifluoroethane l
It is characterized by a composition range of 0 to 95% by weight, and particularly preferably a composition range of 0 to 65% by weight of trifluoromethane, 0 to 85% by weight of chlorodifluoromethane, and 15 to 90% by weight of dichlorotrifluoroethane. The working fluid is trifluoromethane (○DP=O), a fluorocarbon that does not contain chlorine in its molecular structure, which has almost no ozone-depleting ability, and a molecular structure that has an extremely low ozone-depleting ability. Chlorodifluoromethane (ODP=0.05) and dichlorotrifluoroethane (ODP=0.0) are fluorocarbons containing both chlorine and hydrogen.
By forming a mixture of at least two of 2), it is possible to make the effect on the stratospheric ozone layer much smaller than that of R12. Accordingly, L. ．． This makes it possible to provide a working fluid that can be used in current equipment as an alternative to R12.
In particular, the ODP in the above combinations and ranges is 0.
01-0.04, making it an extremely promising working fluid as an alternative to Rl2.In addition, such a mixture is a non-azeotropic mixture, and has a temperature gradient in the condensation and evaporation processes, resulting in a temperature difference with the heat source fluid. A higher coefficient of performance than Rl2 can be expected by keeping the Lorentz cycle close to each other.

The present invention particularly applies to mixtures of three or more types of fluorocarbons including trifluoromethane.
Because the critical temperature is low (25.7℃) and the vapor pressure is high, it cannot be used alone in refrigerators, heat pumps, etc. whose operating temperature is 0 to 50℃. By mixing chlorodifluoromethane, which is a high fluorocarbon, with a third fluorocarbon whose vapor pressure is lower than that of R12 and whose ODP is lower, the vapor pressure of the mixture is made almost equal to that of R12, and a working fluid with a lower ODP is made. It is possible to obtain.

Examples Examples of working fluids according to the present invention will be explained with reference to the drawings. Fig. 1 shows trifluoromethane (R23), chlorodifluoromethane (R22), 2,2-dichloro-1.
1. A working fluid composed of a mixture of three types of fluorocarbons, 1-trifluoroethane (Rl23).The equilibrium state at constant temperature and constant pressure is shown using triangular coordinates. At each vertex, single substances are placed counterclockwise from the upper vertex in descending order of boiling point. Also, in this case, the distance between the point and the side of the triangle, tit, corresponds to the composition ratio of the substance marked at the vertex of the triangular coordinates on the side opposite the side. At i (t temperature 0℃・pressure 2.116kg/cm
This is the vapor-liquid equilibrium line of the mixture at G, and this temperature and pressure corresponds to the saturated state of R12.
(equivalent to 0°C) The upper line of l is the saturated vapor phase line. The vapor-liquid equilibrium line (
R120℃ equivalent) The lower line of 1 represents the saturated liquidus line.
In the area between these lines, there is a state of vapor-liquid equilibrium. 373kg
/amIG This is the vapor-liquid equilibrium line of the mixture, and this temperature and pressure also correspond to the saturated state of R12 - L If R23 is used alone, the critical temperature will be exceeded at 50 ° C. α To form such a mixture Therefore, a saturated state exists, and it can be used in refrigerators, heat pumps, etc. whose operating temperature is 0 to 50°C. As can be seen from the figure, tQ R 2 3, R22 and R123
are respectively 0~80M weight 0~90% by weight, 10~
A composition range in which R23, R22, and R123 are each 95% by weight is desirable because it has almost the same vapor pressure as R12 at a service temperature of 0 to 50°C. 0-85% by weight. 15-90
Group precept range as weight %! It is particularly desirable because it has almost the same vapor pressure as R12 at all operating temperatures between 0°C and 50°C. It is shown in Table 1. Points A1 to C1 are the vapor-liquid equilibrium line (
Points D1 to F1 are on the saturated liquid line of Rl2 (equivalent to 50°C) 2, and the vapor-liquid equilibrium line (equivalent to R120°C) are on the saturated liquid line of 2.
The temperature of the plate should be 0°C.
Pressure 2. 1 1 6 kg/cm”G (R 1
Corresponding to the saturated state of 2), the working fluid has the vapor-liquid equilibrium state and the composition shown in Table 1.
By realizing a saturated state or a vapor-liquid equilibrium state under the conditions of the saturated vapor pressure of R12 at 50°C and 50°C, and operating at the saturated vapor pressure of R12 at the same temperature at a usage temperature of 0 to 50°C, it is almost the same as Rl2. Although it is possible to obtain equal condensation and evaporation temperatures, here we will explain only the points on the vapor-liquid equilibrium line (R12, equivalent to 50°C) 2. Rope board Temperature 0℃・Pressure 2.116kg/c
m”G and temperature 50℃・pressure 1 1.37 3kg/c
By performing the same operation on a working fluid that has a vapor-liquid equilibrium state at m''G (both correspond to the saturated state of R12), the condensation temperature is almost equal to R12 at the operating temperature of 0 to 50°C It is possible to obtain the evaporation temperature as shown in Figure 2. The equilibrium state at constant temperature and constant pressure is shown using triangular coordinates. In Figure 2, 3 Lt, temperature 0°C, pressure 2.1
It is the vapor-liquid equilibrium line of the mixture at 16 kg/cm2G, and it is also the vapor-liquid equilibrium line of the mixture at 16 kg/cm2G.
In this case, ζi R23, R22 and R123a
are 0~80% by weight, 10~90% by weight, respectively.
A certain range of assembly force such that 95% by weight <. It is preferable that R23, R22 and R123a each have a vapor pressure of 0 to 65% by weight since it has almost the same vapor pressure as R12. It is particularly desirable to have a composition range of 0 to 85% by weight and 15 to 90% by weight.The composition and ODP of the working fluid at points A2 to F2 in Figure 2 are shown in Table 2. A2 to point C2 is the vapor-liquid equilibrium line (
Rl2 (equivalent to 50℃) Also on the saturated gas phase line of 4, point D
Points 2 to F2 are on the saturated liquid line of the vapor-liquid equilibrium line (R Table 2 12, equivalent to 50°C) 4, and the saturated vapor line of the vapor-liquid equilibrium line (R12, equivalent to 0°C) 3 and the vapor-liquid equilibrium line (R12 Temperature: 0℃, Pressure: 2. 1
At 16 kg/cm"G (corresponding to the saturated state of R12), there is a gas-liquid equilibrium state. Therefore, the working fluid with the composition shown in Table 2 is R12 at 0°C and 50°C.
By realizing a saturated state or a vapor-liquid equilibrium state under the condition of the saturated vapor pressure of
It is possible to obtain a condensation temperature and evaporation temperature that are almost equal to 2. Here and here & friends. The nail that explains only the points on the vapor-liquid equilibrium line (R12, 50℃ equivalent) 4. The inside of points A2 to F2. Sunawa board at temperature 0℃, pressure 2.116kg/c
m”G and temperature 50℃・pressure i 1.37 3kg/c
By performing the same operation on a working fluid having a composition that reaches a vapor-liquid equilibrium state at m''G (both correspond to the saturated state of Rl2), the condensation temperature and This makes it possible to obtain the evaporation temperature.

In the above embodiments, the working fluid is composed of a mixture of three types of fluorocarbons.Of course, it is also possible to use a mixture of four or more types of fluorocarbons, including structural isomers. In this case, the composition should be within a range such that trifluoromethane is 0 to 80% by weight, chlorodifluoride methane is O to 90% by weight, and dichlorotrifluoroethane is 10 to 95% by weight, which is approximately equivalent to R12 at a usage temperature of 0 to 50°C. Desirable because it has high vapor pressure. Furthermore, trifluoromethane 0 to 65% by weight, chlorodifluoromethane 0 to 85% by weight, dichlorotrifluoroethane 15 to 90% by weight, and approximately R12 at all operating temperatures between 0°C and 50°C. Particularly desirable as they have comparable vapor pressures (1), especially in the combinations mentioned above and ODP in a certain range of 1l from 0.01 to 0.
．． 04, making it an extremely promising working fluid as an alternative to R12.In addition, such a mixture becomes a non-azeotropic mixture, with a temperature gradient in the condensation and evaporation processes. Although a higher coefficient of performance than Rl2 can be expected by constructing a Lorentz cycle, the effect of the invention is clear from the above explanation. A mixture of three or more types of fluorocarbons, including fluorocarbons that do not contain chlorine and fluorocarbons that contain both chlorine and hydrogen in their molecular structure.By identifying the range of their composition, (1) (2) It has a vapor pressure similar to that of R12 at the operating temperature of equipment where trifluoromethane alone cannot be used. L, R1
(3) Utilizing the temperature gradient properties of non-azeotropic mixtures, R1 can be used as an alternative to R1.
Even if it has an effect such as being able to expect a higher performance coefficient than 2.

[Brief explanation of the drawing]

Figures 1 to 2 are diagrams showing the equilibrium state at a constant temperature and constant pressure using triangular coordinates of a working fluid α constituted by a mixture of three types of fluorocarbons. 1. 3... Gas-liquid equilibrium line (R12 o ℃ equivalent),
2, 4... Gas-liquid equilibrium line (R12 equivalent to 50°C).

Claims (2)

[Claims] (1) A working fluid containing at least three types of fluorocarbons: 80% by weight or less of trifluoromethane, 90% by weight or less of chlorodifluoromethane, and 10 to 95% by weight of dichlorotrifluoroethane. (2) A working fluid containing at least three types of fluorocarbons: 65% by weight or less of trifluoromethane, 85% by weight or less of chlorodifluoromethane, and 15 to 90% by weight of dichlorotrifluoroethane.