JPH03168283A - Working fluid - Google Patents

Abstract

PURPOSE:To provide a working fluid reduced in the affection thereof on the ozone layer of the stratosphere and capable of being employed as a substitute of dichlorodifluoromethane (R12) by containing difluoromethane, chlorodifluoromethane and chlorodifluoroethane in a specific ratio. CONSTITUTION:The objective working fluid contains at least three kinds of freons comprising (A) <=45wt.% (preferably <=35wt.%) of difluoromethane (R32), (B) <=75wt.% (preferably <=65wt.%) of chlorodifluoromethane (R22) and (C) 25-85wt.% (preferably 35-85wt.%) of 1-chloro-1,1-difluoroethane (R142b). The working fluid is employed in freezers, heat pumps, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Application Fields of the Invention The present invention relates to the conventional technology related to working fluids used in refrigerators, heat pumps, etc. Halogenated hydrocarbons called RO○O (also written as RO○O) are known, and their condensation and/or evaporation temperatures are approximately O~
Although difluoromethane (CCl*F, R12) is commonly used in the temperature range of about 50°C, it is widely used as a working fluid in refrigerator kites, car air conditioners, large refrigerators, etc. However, the problem that the invention aims to solve is Nakaita In recent years, depletion of the stratospheric ozone layer by fluorocarbons has become a global environmental issue, and fluorocarbons (hereinafter referred to as specified fluorocarbons), which have a large ability to deplete the stratospheric ozone, are already subject to international treaties. Furthermore, there is a movement to abolish the use and production of specified fluorocarbons in the future.Rl2 is the ozone depletion coefficient (trichlorofluoromethane (CCl 0F)). The stratospheric ozone depletion potential (hereinafter referred to as ODP) is 1. It is a specific fluorocarbon with 0 fluorocarbons, and it is now widely used in refrigeration and air conditioning equipment.
Reducing the amount of R12 used and produced will have a significant impact on the human living environment.Therefore, its ability to deplete stratospheric ozone is small, and there is a strong demand for the early development of a working fluid that can replace R12. There is.

The present invention ζ has been tried in view of the above-mentioned problems and provides a working fluid that has a small effect on the stratospheric ozone layer and can be used as an alternative to R12.

Means for Solving the Problems The present invention solves the above problems by using at least L difluoromethane (CHAF!), chlorodifluoromethane (CHCIF2), and chlorodifluoroethane (CaHs).
Chlorodifluoromethane containing three types of fluorocarbons (C I F2): 0 to approximately 45% by weight Chlorodifluoromethane O to approximately 7% by weight
It is characterized by a composition range of about 25 to about 85% by weight of chlorodifluoroethane, particularly difluoromethane of about 0 to about 35% by weight, chlorodifluoromethane of about 0 to about 65% by weight, and chlorodifluoroethane of about 35 to about 35% by weight. Although a composition range of about 85% by weight is desirable, as mentioned above, the working fluid is difluoromethane (ODP=O), a fluorocarbon that does not contain chlorine in its molecular structure and has little ozone depletion ability. , a mixture of at least three types of chlorodifluoromethane (ODP=0.05) and chlorodifluoroethane (○DP=0.06), which are fluorocarbons containing both chlorine and hydrogen in their molecular structures with extremely low ozone depletion ability. This makes it possible to make the influence on the stratospheric ozone layer much smaller than Rl2.Also, by setting the above-mentioned assembly range, the present invention can reduce the temperature at which refrigerators, heat bombs, etc. are used. It is possible to provide a working fluid that can be used in current equipment as a substitute for L and R12 and has a vapor pressure similar to that of R12 at a temperature of about 0 to about 50°C. The ODP in the range is 0. 04
~0. It is predicted that it will be a very promising working fluid as an alternative to R12.In addition, such a mixture will be a non-azeotropic mixture and will have a temperature gradient in the condensation and evaporation processes. By constructing Lorenz cycles close to each other, a higher performance coefficient than R12 can be expected.

EXAMPLES Below, examples of working fluids according to the present invention will be explained with reference to the drawings. Fig. 1 shows examples of working fluids according to the present invention. Figure 1 shows examples of working fluids according to the present invention. The equilibrium state of the working fluid Q constituted by a mixture of three types of fluorocarbons at constant temperature and constant pressure is shown using triangular coordinates. Single substances are arranged clockwise in descending order of boiling point, and the ratio of each component at a certain point on the coordinate plane (
Weight ratio) [Yo] It is also expressed as the ratio of the distance between a point and each side of a triangle.Distance between a point and a side of a triangle: Top The substance written at the vertex of the triangular coordinates on the side opposite to the side. In Figure 1, I C & temperature 0℃
・Pressure 2. This is the vapor-liquid equilibrium line of the mixture at 1 1 6 kg/cm"G, and this temperature and pressure corresponds to the saturated state of Rl2. Vapor-liquid equilibrium line (R12 equivalent to 0°C)
The upper line of 1 represents the saturated vapor phase line and the vapor-liquid equilibrium line (equivalent to R120°C). The lower line of 1 represents the saturated liquidus line. The range between these two lines is in a state of vapor-liquid equilibrium. It's your turn
Temperature 50℃・Pressure 1 1. This is the vapor-liquid equilibrium line of the mixture at 373 kg/cm"G, and this temperature and pressure are also R
As you can see from the figure, this corresponds to the saturation state of R32.
, R22 and R142b each weigh approximately 45 mm
0 to approximately 75% by weight Approximately 25 to approximately 85% by weight
It is desirable because it has almost the same vapor pressure as 2.
R32, R22, and R142b are respectively O~approximately 35% by weight, 0~approximately 65% by weight, and approximately 35~approximately 85% by weight. This is especially desirable because it has almost the same vapor pressure.
DP is 0. 04-0. Expected to be 06tt R12
Table 1 shows the working fluid combinations and ODP at points A1 to F1 in FIG.

Points A1 to C1 in the figure are the vapor-liquid equilibrium line (Rl2 5
It is on the saturated vapor phase line of 2 (equivalent to 0°C) and the saturated vapor line of vapor-liquid equilibrium line (Rl2, equivalent to 0°C) 1 and the saturated liquidus line of vapor-liquid equilibrium line (R12, equivalent to 0°C) l. The temperature must be within the range between 0°C and pressure 2. 1 1
At 6 kg/cm2G (corresponding to the saturated state of R 1 2), there is a vapor-liquid equilibrium state. Also, from point DI to point F
1 is on the saturated liquid line of the vapor-liquid equilibrium line (R12 equivalent to 50°C) 1, and the saturated liquid line of the vapor-liquid equilibrium line (R12 equivalent to 50°C) 2 and the saturated liquid line of the vapor-liquid equilibrium line (R12 equivalent to 50°C) 2 The temperature is 50℃ and the pressure II. 373kg/Cm”G (R12
(corresponding to the saturated state in Table 1) is a vapor-liquid equilibrium state. Therefore, the working fluid ζi0℃ having the composition shown in Table 1
・Achieving a saturated state or a vapor-liquid equilibrium state under the condition of the saturated vapor pressure of Rl2 at 50°C, and operating at the saturated vapor pressure of R12 at the same temperature at a usage temperature of about 0 to about 50°C. If it is possible to obtain almost equal condensation and evaporation temperatures, here is the GA vapor-liquid equilibrium line (Rl2 equivalent to 0°C) 1
Alternatively, the force intersection explained only about the points on the gas-liquid equilibrium line (R12, equivalent to 50℃) 2. The hole located inside the points A1 to F1, that is, the plate Temperature 0℃, Pressure 2.
cm”G and temperature 50℃・pressure 11.37 3 kg/
cm"G (both correspond to the saturated state of R12)" By performing the same operation on a working fluid having a composition that reaches a vapor-liquid equilibrium state, condensation approximately equal to that of R12 can be obtained at a usage temperature of approximately 0 to approximately 50°C. In this example, the working fluid is composed of a mixture of three types of fluorocarbons, and a mixture of four or more types of fluorocarbons including structural isomers. Although it is of course possible to form a working fluid, such a mixture becomes a non-azeotropic mixture and has a temperature gradient in the condensation process and evaporation process. As a result, even if a higher performance coefficient than R12 can be expected, it is clear from the above explanation that the present invention (partner) has a working fluid that does not contain chlorine in its molecular structure and a fluorocarbon that does not contain chlorine in its molecular structure. By specifying the composition range of a mixture of three or more types of fluorocarbons containing both chlorine and hydrogen, (1) Q operation to make the effect on the Fl stratospheric ozone layer much smaller than that of R12. Although it is possible to expand the range of fluid selection, (2) L has a vapor pressure similar to that of Rl2 at the operating temperature of the equipment, and can be used in current equipment as a substitute for Rl2.

(3) Taking advantage of the temperature gradient properties of non-azeotropic mixtures, R1
Even if it has an effect such that a performance coefficient higher than 2 can be expected.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the equilibrium state of a working fluid α composed of a mixture of three types of fluorocarbons at constant temperature and constant pressure using triangular coordinates.
Equivalent to 20℃>, 2... Vapor-liquid equilibrium line (R12 50
℃ equivalent).

Claims (2)

[Claims] (1) Difluoromethane 45% by weight or less, chlorodifluoromethane 75% by weight or less, chlorodifluoroethane 2
A working fluid containing 5 to 85% by weight of at least three types of fluorocarbons. (2) Difluoromethane 35% by weight or less, chlorodifluoromethane 65% by weight or less, chlorodifluoroethane 3
A working fluid containing 5 to 85% by weight of at least three types of fluorocarbons.