JPH03168293A - Working fluid - Google Patents

Abstract

PURPOSE:To provide a working fluid having only small effects on the stratospheric ozone layer, alternative to dichlorodifluoromethane (R12), comprising a trifluorethane, chlorodifluoromethane and a dichlorofluorethane at specified proportion. CONSTITUTION:The objective working fluid comprising (A) <=90 (pref. <=85)wt.% of 1,1,1-trifluorethane (R143a), (B) <=95 (pref. <=90)wt.% of chlorodifluoromethane (R22), and (C) 5-65 (pref. 10-60)wt.% of 1,1-dichloro-1-fluorethane (R141b). The working fluid is used in refrigerating machines, 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. A halogenated hydrocarbon called R○○○ is known, and the usage temperature is 0 to 50℃ for condensation temperature and/or evaporation temperature.
In particular, dichlorofluorocarbon methane (CCleFa, Rl2) is widely used as a working fluid for refrigeration kites, car air conditioners, large refrigerators, etc., but the problem that the invention is trying to solve has recently changed. The depletion of the stratospheric ozone layer by carbon dioxide has become a global environmental issue, and international treaties have already regulated the use and production of fluorocarbons (hereinafter referred to as specified fluorocarbons), which have a large ability to deplete the stratospheric ozone. Furthermore, there is a movement to abolish the use and production of specific fluorocarbons in the future.Now, R12 is the ozone depletion coefficient (trichlorofluoromethane (CCl*F)).
When the stratospheric ozone depletion potential of the stratospheric ozone depleting potential is 1, the bottom stratum ozone depletion potential 9 (hereinafter referred to as ODP) is 1. 0 specified fluorocarbons, which is now widely used in refrigeration and air conditioning equipment.
Reductions in the amount of R12 used and produced will have an enormous impact on the human living environment. However, the present invention has been tested in view of the above-mentioned problems, and has a small effect on the stratospheric ozone layer.
Means for Solving the Problems The present invention provides an alternative working fluid for the above-mentioned problems. Dichlorofluoroethane (C2
Contains three types of fluorocarbons (HsCl IsF) Trifluoroethane 0 ~ 90 weight gourd Chlorodifluoromethane 0 ~
It is characterized by a composition range of 95% by weight dichlorofluoroethane 5 to 65% by weight, particularly trifluoroethane O to 85% by weight κ chlorodifluoromethane O to 90% by weight dichlorofluoroethane 10 to 6
A composition range of 0% by weight is desirable, and the present invention uses trifluoroethane (○DP=O), which is a fluorocarbon that does not contain chlorine in its molecular structure and has almost no ozone depletion ability, as the working fluid. Chlorodifluoromethane (ODP = 0.05) and dichlorofluoroethane (○D P = 0.1), which are fluorocarbons containing both chlorine and hydrogen in their molecular structures, have extremely low ozone depletion ability.
), it is possible to make the effect on the stratospheric ozone layer much smaller than that of R12. In particular, it is possible to provide a working fluid that can be used in current equipment as an alternative to L and R12, which has a vapor pressure similar to that of R12 at temperatures ranging from 0 to 50 °C, which is the operating temperature of machines, heat pumps, etc. The ODP in the above combinations and ranges is 0.
01~0. 07, making it an extremely promising working fluid as an alternative to R12.In addition, such a mixture is 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 cycle, an embodiment of the working fluid according to the present invention will be described with reference to the drawings. Friend 1, 1. 1-trifluoroethane (
Rl43a), oo difluoromethane (R22) 1,
1-dichloro-l-fluoroethane (Rl4 l b)
The working fluid Q is composed of a mixture of three types of fluorocarbons.The equilibrium state at constant temperature and constant pressure is shown using triangular coordinates. Single substances are arranged counterclockwise in descending order of boiling point, and the composition ratio (weight ratio) of each component at a certain point on the coordinate plane (y) Also, in this case, the distance between the point and the side of the triangle Git corresponds to the ratio of the substances written at the vertex of the triangular coordinates on the side opposite to the side.
In the figure, 1 is temperature 0℃ and pressure 2. 116kg/
This is the vapor-liquid equilibrium line of the mixture at cm'G, and this temperature and pressure correspond to the saturated state of R12.
The upper line of 1 (equivalent to 120°C) represents the saturated gas phase. The lower line of the vapor-liquid equilibrium line (equivalent to R120°C) 1 represents the saturated liquidus line. The area between these lines is in a state of vapor-liquid equilibrium. Tonanmata 2 [Top Temperature 50℃/Pressure 11. 373kg
/cm''G, and this temperature and pressure also correspond to the saturated state of R12.As can be seen from the figure, R143a, R22 and R14lb are each O ~ 90% by weight.0 ~ 95% by weight 5 R1 at a service temperature of ~50°C in a range Cyo~65% by weight
It is desirable because it has almost the same vapor pressure as 2 (1
QR143a, R22 and Rl4lb are each 0 to 8
A range of 5% by weight O to 90% by weight KID to 60% by weight (t.%) is particularly desirable because it has a vapor pressure almost equivalent to Rl2 at all operating temperatures between 0°C and 50°C. In particular, the ODP in the above-mentioned combination and set range is 0.01 to 0.07, and even though it is a very promising working fluid as an alternative to R12, the working fluid at points A1 to F1 in FIG. Table 1 and ODP are shown in Table 1. Points Al to CI are on the saturated vapor phase line of vapor liquid equilibrium line (Rl2 equivalent to 50°C) 2.
In addition, points D1 to Fl are on the saturated liquid line of the vapor-liquid equilibrium line (Rl2 equivalent to 50°C) 2, and the vapor-liquid equilibrium line (R12
saturated gas phase line and vapor-liquid equilibrium line (R120℃ equivalent)
(equivalent) The temperature is 0°C and the pressure is 2. 1 1 6 kg/c
m'G (corresponding to the saturated state of R12) is in a vapor-liquid equilibrium state. Therefore, the saturated vapor pressure of R12 at 0°C and 50°C is By realizing a saturated state or a vapor-liquid equilibrium state under the conditions and operating at a usage temperature of approximately 0 to approximately 50°C, the condensation temperature and evaporation temperature are approximately equal to those of R12 by operating at the saturated vapor pressure of R12 at the same temperature. Here, only the points on the vapor-liquid equilibrium line (R12, equivalent to 50°C) 2 are explained. The force intersection between points Al and Fl is the plate that is inside the temperature O°C and pressure 2. 1 1 6kg
/cm”G and temperature 50t-pressure 1 1.3 7 3k
By performing the same operation on a working fluid that has a gas-liquid equilibrium state at g/cm2G (both correspond to the saturated state of R12), the condensation temperature and Although it is possible to obtain the 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 construct a fluid, such a mixture becomes a non-azeotropic mixture, and in the condensation and evaporation processes, a Lorenz cycle is constructed in which the temperature difference between the blowing fluid and the heat source fluid is close to each other, with a temperature gradient. Therefore, it is possible to expect a higher performance coefficient than that of R12. By specifying the composition range of fluorocarbons, which contain both chlorine and hydrogen, we have determined that (1) the influence on the stratospheric ozone layer is much smaller than that of R12; Although it is possible to expand the range of selection, (2) L. Although it can be used as a substitute for R12 with current equipment, (3) Rl
It has the effect of being expected to have a higher performance coefficient than 2.

[Brief explanation of the drawing]

Figure 1.C top This is a diagram showing the equilibrium state of a working fluid composed of a mixture of three types of fluorocarbons using triangular coordinates at a constant temperature and constant pressure. : equivalent), 2...vapor-liquid equilibrium line (R
12 50℃ equivalent).

Claims (2)

[Claims] (1) A working fluid containing at least three types of fluorocarbons: 90% by weight or less of trifluoroethane, 95% by weight or less of chlorodifluoromethane, and 5 to 65% by weight of dichlorofluoroethane. (2) A working fluid containing at least three types of fluorocarbons: 85% by weight or less of trifluoroethane, 90% by weight or less of chlorodifluoromethane, and 10 to 60% by weight of dichlorofluoroethane.