JPH03168282A - 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 for dichlorodifluoromethane (R12) by containing difluoromethane, chlorodifluoromethane and dichlorofluoroethane in a specific ratio. CONSTITUTION:The objective working fluid contains at least three kinds of freons comprising (A) <=85wt.% (preferably <=75wt.%) of difluoromethane (R32), (B) <=95wt.% (preferably <=90wt.%) of chlorodifluoromethane (R22) and (C) 5-80wt.% (preferably 10-75wt.%) of 1,1-dichloro-1-fluoroethane (R141b). The working fluid is employed in freezers, heat pumps, etc.

Description

Detailed Description of the Invention Industrial Application Field of the Invention C1 Conventional technology related to working fluids used in refrigerators, heat pumps, etc. In refrigerators, heat pumps, etc., fluorocarbons (hereinafter referred to as ROO Or written as R○○○〉
Halogenated hydrocarbons called halogenated hydrocarbons are known, and are usually used at a condensation temperature and/or evaporation temperature in the range of approximately 0 to approximately 50°C.Among them, dichlorodifluoromethane (CC1*Fm, R12) is used under refrigeration. kite
Although it is widely used as a working fluid in car air conditioners and large refrigerators, the problem that the invention attempts to solve continues to change. Regarding fluorocarbons, which have a large destructive capacity (hereinafter referred to as specified fluorocarbons), international treaties have already regulated their usage and production, and there are also moves to abolish the use and production of specified fluorocarbons in the future. Now, R12 is the ozone depletion coefficient (trichlorofluoromethane (CCl*F)
When the bottom-sphere ozone-depleting ability of 0 specified fluorocarbons, and is now widely used in refrigeration and air conditioning equipment.
Reducing the amount of R12 used and produced would have a tremendous impact on the human living environment. Therefore, the 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. The present invention (above) was tried in view of the above problems, and has a small effect on the ozone layer in the stratospheric region.
It provides a working fluid that can replace R12.

Means for Solving the Problems The present invention aims to solve the above-mentioned problems.
Difluoromethane containing three types of fluorocarbons (ClaF) 0 to approximately 85% by weight Chlorodifluoromethane O to approximately 95% by weight
Weight κ is characterized by a range of approximately 5 to approximately 85% by weight of dichlorofluoroethane, particularly difluoromethane O to approximately 75% by weight, chlorodifluoromethane O to approximately 90% by weight, dichlorofluoroethane (abbreviated) 10
As mentioned above, the working fluid should be difluoromethane (○DP=0), which is a fluorocarbon that does not contain chlorine in its molecular structure and has almost no ozone-depleting ability. and a mixture of at least three types of chlorodifluoromethane (○DP=0.05) and dichlorofluoroethane (ODP=0.1), which are fluorocarbons containing both chlorine and hydrogen in their molecular structures with extremely low ozone depletion ability. By doing so, it is possible to make the influence on the stratospheric ozone layer much smaller than Rl2.The present invention also makes it possible to make the use of refrigerators, heat bombs, etc. within the above-mentioned range. It is possible to provide a working fluid that can be used in current equipment as a substitute for L 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. 02
~0. This mixture is expected to be a very promising working fluid as a replacement for 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 a Lorenz cycle, a higher performance coefficient than that of R12 can be expected. Difluoromethane (R32), chlorodifluoromethane (R22), 1. 1-dichlorol-
The working fluid Q is composed of a mixture of three types of fluorocarbons (RI4lb). The equilibrium state at a constant temperature and constant pressure is shown using triangular coordinates.
In this triangular coordinate system, a single substance is placed at each vertex of the triangle in the order of decreasing boiling point, starting from the upper vertex, in a counterclockwise order, and the composition ratio (weight ratio) of each component at a certain point on the coordinate plane is ) C It is also expressed as the ratio of the distance between the point and each side of the triangle.In this case, the distance between the point and the side of the triangle is
It corresponds to the composition ratio of the substance written at the vertex of the triangular coordinates on the side opposite to the side.In Figure 1, t i & 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 correspond to the saturated state of R12. Vapor-liquid equilibrium line (R12 equivalent to 0°C)
The upper line of 1 represents the saturated gas phase gas-liquid equilibrium line (equivalent to R120°C) The lower line of 1 represents the saturated liquidus line, and the area between these lines is the vapor-liquid equilibrium state.2 teeth
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 R14lb are respectively O to about 85 weight groups, 0 to about 95 weight κ, about 5 to about 80 weight% (R1 at a usage temperature of about 0 to about 50°C)
It is desirable because it has almost the same vapor pressure as 2 (℃ Sara!
;1, R32, R22 and R14lb are each 0~approximately 75% by weight; 0~approximately 90% by weight; 10~approximately 75% by weight
Particularly desirable is a combination and range in which L1 has almost the same vapor pressure as R12 at all operating temperatures between 0°C and 50°C. ~0.07 h
This is a very promising working fluid as a replacement for Rl2.

Table 1 shows the working fluid composition and ODP at points A1 to F1 in FIG.

':) 1st layer of wood, 1st layer, 1st table Points A1 to CI in the same figure are the vapor-liquid equilibrium line (Rl2 5
Also, points DI to F1 are on the saturated liquid line of the vapor-liquid equilibrium line (R12, equivalent to 50°C) 2, and the saturated gas phase line of the vapor-liquid equilibrium line (Rl2, equivalent to 0°C) 2. Phase line and vapor-liquid equilibrium line (R12 equivalent to 0℃) The transition temperature O
℃・Pressure 2.11 6 kg/cm"G (R 1 2
Therefore, the working fluid having the composition shown in Table 1 & above 0
Achieving a saturated state or a vapor-liquid equilibrium state under the condition of the saturated vapor pressure of R12 at 50 t at °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, Almost equal condensing temperature
If it is possible to obtain the evaporation temperature, here Ct vapor-liquid equilibrium line (R12 equivalent to 50°C) 2
Only the above points have been explained. The hole inside points A1 to Fl. Temperature 0°C, pressure 2.116 kg/
cm”G and temperature 50℃・pressure 1 1.373kg/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 R12), condensation approximately equal to that of R12 can be obtained at a usage temperature of approximately 0 to approximately 50°C. Although it is possible to obtain the temperature and evaporation temperature, in this example, the working fluid is composed of a mixture of three types of fluorocarbons. Although it is of course possible to configure the working fluid by Effects of the Invention As is clear from the above explanation, the present invention provides a working fluid with fluorocarbons that do not contain chlorine in its molecular structure. A mixture of three or more types of fluorocarbons that contain both chlorine and hydrogen in their molecular structure. By specifying the range of the combination, (1) the effect on the stratospheric ozone layer is much smaller than that of R12. Therefore, although it is possible to expand the range of working fluid selection, (2) it has a vapor pressure similar to that of R12 at the operating temperature of the equipment, and even if it can be used in current equipment as an alternative to R12 ( 3) Utilizing the temperature gradient properties of non-azeotropic mixtures, R1
Even if it has the effect 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.
120℃ equivalent), 2...vapor-liquid equilibrium line (R12 50
℃ equivalent).

Claims (2)

[Claims] (1) Difluoromethane 85% by weight or less, chlorodifluoromethane 95% by weight or less, dichlorofluoroethane 5
A working fluid containing up to 80% by weight of at least three types of fluorocarbons. (2) Difluoromethane 75% by weight or less, chlorodifluoromethane 90% by weight or less, dichlorofluoroethane 1
A working fluid containing 0 to 75% by weight of at least three types of fluorocarbons.