JPH03170592A - Working fluid - Google Patents

Abstract

PURPOSE:To obtain a working fluid which does not affect the ozonosphere and has an improved coefficient of performance by mixing difluoromethane, trifluoroethane, and difluoroethane. CONSTITUTION:At most 60wt.% difluoromethane is mixed with at most 80wt.% trifluoroethane and 20-65wt.% difluoroethane.

Description

[Detailed Description of the Invention] Industrial Application Fields of the Invention The present invention relates to working fluids used in heat pump devices such as air conditioners and refrigerators. as fluorocarbons (hereinafter referred to as R○○ or R○
Halogenated hydrocarbons known as R22)
Although it is widely used as a working fluid in home air conditioners, building air conditioners, and large refrigerators, the problem that the invention attempts to solve continues to change. The use and production of fluorocarbons (hereinafter referred to as specified fluorocarbons), which have a certain level of stratospheric ozone depletion ability, has already been regulated by international treaties.
Now, there is a movement to abolish production of R22.
The stratospheric ozone depletion potential 9 (hereinafter referred to as ODP) is as small as 0.05, and although it is not a specified fluorocarbon, its usage is expected to increase in the future. Nowadays, air conditioning equipment has become widespread and
It is expected that an increase in the amount of R22 used and produced will have a greater impact on the living environment of humankind. Therefore,
There is also a strong demand for the early development of a working fluid that can replace R22, which has a low ability to destroy stratospheric ozone.

The present invention was tested in view of the above-mentioned problems, and has little effect on the stratospheric ozone layer.
SUMMARY OF THE INVENTION The present invention provides an alternative working fluid for solving the above-mentioned problems.
C2H*F − ) and difluoroethane (CaH
Contains three types of fluorocarbons (4F2) Difluoromethane 0
It is characterized by a composition range of about 60% by weight, trifluoroethane 0 to about 80% by weight, difluoroethane about 20% to about 65% by weight, particularly difluoromethane O to about 50% by weight trifluoroethane 0. A composition range of about 20 to about 65% by weight of difluoroethane is desirable. Difluoromethane (ODP=0), which is a fluorocarbon that does not contain
By forming a mixture of trifluoroethane (○DP=0) and difluoroethane (○DP=O), the effect on the stratospheric ozone layer is even smaller than that of R22, and it is possible to almost eliminate it. That is. Moreover, by adopting the above-mentioned assembly range, the present invention has a vapor pressure comparable to that of R22 at a temperature of about 0 to about 50 degrees Celsius, which is the usage temperature of heat pump devices such as air conditioners and refrigerators, and can be used as a substitute for R22 in current equipment. Therefore, it is expected that ○DP in the above combinations and combination ranges will also be 0. ．．
It is a very promising working fluid as an alternative to R22.a Also, such a mixture becomes a non-azeotropic mixture, and has a temperature gradient in the condensation process and evaporation process. With this structure, a higher performance coefficient than R22 can be expected.

Additionally, in general, fluorocarbons (fluorocarbons), which have the ability to deplete stratospheric ozone, tend to have a greater global warming effect as their DP value increases.
The effect of global warming created by a certain mixture of three or more types of fluorocarbons, in which O is O, is estimated to be the same as or less than R22, and has recently become a worldwide problem. Embodiments Hereinafter, embodiments of the working fluid according to the present invention will be described with reference to the drawings.

The diagram shows difluoromethane (R32), l,1,1-1
Refluorinated ethane (R143a), 1. The equilibrium state of a working fluid α composed of a mixture of three types of fluorocarbons, 1 difluoroethane (R152a), at constant temperature and constant pressure is shown using triangular coordinates. In this triangular coordinate system, single substances are placed at each vertex of the triangle in a counterclockwise order starting from the upper vertex in descending order of boiling point, and the composition ratio (weight ratio) of each portion at a certain point on the coordinate plane is (Yo) It is expressed as the ratio of the distance between the point and each side of the triangle.

Also, at this time, the distance C between the point and the side of the triangle does not correspond to the composition ratio of the substance written at the vertex of the triangular coordinates on the side opposite the side.
This is the vapor-liquid equilibrium line of the mixture at 0 4 4 kg/cm"G, and this temperature and pressure correspond to the saturated state of R22. The upper line of the vapor-liquid equilibrium line (corresponding to R22 0°C) is the saturated vapor phase. The line below the line Vapor-liquid equilibrium line (R22, equivalent to 0°C) 1 represents the saturated liquidus line, and the area between these lines is in a vapor-liquid equilibrium state.
0℃・Pressure 18. This is the vapor-liquid equilibrium line of the mixture at 782 kg/cm2G, and this temperature and pressure also correspond to the saturated state of R22.As can be seen from the figure, 4:, R32,
R143a and R152a are each 0 to approximately 60% by weight
．． 0 to approximately 80% by weight, and a composition range of approximately 20 to approximately 65% by weight.
Further, R32, R143a and Rl52a each contain 0 to about 50% by weight. O ~ Approximately 80 weight studies Approximately 20 ~ Approximately 6
5% by weight is particularly desirable since it has a vapor pressure approximately equal to that of R22 at all operating temperatures between 0°C and 50°C.

The working fluid combinations at points A1 to F1 in the figure are shown in the table. Points A1 to C+ are vapor-liquid equilibrium lines (equivalent to R2250°C)
On the saturated vapor phase line of 2, points D1 to E1 are on the vapor-liquid equilibrium line (R
22 is on the saturated liquidus line of 2 (equivalent to 50°C), and both are on the saturated vapor line of vapor-liquid equilibrium line (R22 equivalent to 0°C) 1 and the saturated liquidus line of vapor-liquid equilibrium line (R22 equivalent to 0°C) 1. Since it is within the range between the lines, the temperature is 0°C and the pressure is 4.
At 044 kg/cm2G (corresponding to the saturated state of R22), a gas-liquid equilibrium state is reached. In addition, point F1 is on the saturated liquidus line of the vapor-liquid equilibrium line (R22, equivalent to 0°C) 1, and the saturated vapor line and vapor-liquid equilibrium line (R22, equivalent to 50°C) of the vapor-liquid equilibrium line (R22, equivalent to 50°C) 2. The plate temperature is 50℃ and the pressure is 18. At 782 kg/cm2G (corresponding to the saturated state of R22), a gas-liquid equilibrium state is reached. Therefore, the first
Actuating body with the composition shown in the table (at 0°C and 50°C)
Achieving a saturated state or a vapor-liquid equilibrium state under the saturated vapor pressure of R22 in Although it is possible to obtain the temperature and evaporation temperature, here we explain only the points on the vapor-liquid equilibrium line (R22, equivalent to 0°C) 1 or the vapor-liquid equilibrium line (R22, equivalent to 50°C) 2. Length Point inside point A+ to point F1, strap plate Temperature 0℃, pressure 4.044kg/cm2G
By performing the same operation for a working fluid that has a gas-liquid equilibrium state at a temperature of 50°C and a pressure of 18.782 kg/cm2G (both correspond to the saturated state of R22), it is possible to R22 at usage temperature
This makes it possible to obtain condensation and evaporation temperatures that are approximately equal to .

In this embodiment, the working fluid is composed of a mixture of three types of fluorocarbons.Of course, the working fluid can also be composed of a mixture of four or more types of fluorocarbons, including structural isomers. In particular, in the above-mentioned combinations and ranges, ○DP is also expected to be 0, making it a very promising working fluid as an alternative to R22. Although it is possible to expect a higher performance coefficient than R22 by constructing a Lorenz cycle in which the temperature difference between the heat source fluid and the heat source fluid is close to each other, the present invention (飄 The working fluid is a mixture of three or more types of fluorocarbons that do not contain chlorine in their molecular structure.By specifying the range of the combination, (1) the effect on the bottom ozone layer is greater than that of R22. Although it is possible to expand the range of selection of working fluids that are small and almost non-existent, (2) it has a vapor pressure similar to that of R22 at the operating temperature of the equipment, and can be used in current equipment as an alternative to R22. .

(3) Taking advantage of the temperature gradient properties of non-azeotropic mixtures, R2
This has the effect that a higher precept coefficient can be expected than 2.

[Brief explanation of the drawing]

The figure shows a structure made of a mixture of three types of fluorocarbons...
Vapor-liquid equilibrium line (R22 0℃ equivalent), 2. Vapor-liquid equilibrium line (
R22 equivalent to 50°C).

Claims (2)

[Claims] (1) A working fluid containing at least three types of fluorocarbons: 60% by weight or less of difluoromethane, 80% by weight or less of trifluoroethane, and 20 to 65% by weight of difluoroethane. (2) A working fluid characterized by containing 50% by weight or less of difluoromethane, 80% by weight or less of trifluoroethane, and 20 to 65% by weight of difluoroethane.