JPH03170590A - 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 pentafluoroethane, tetrafluoroethane, and difluoroethane. CONSTITUTION:55-85wt.% pentafluoroethane is mixed with at most 45wt.% tetrafluoroethane and at most 30wt.% difluoroethane.

Description

[Detailed Description of the Invention] Industrial Application Fields of the Invention Conventional technology related to working fluids used in heat pump devices such as air conditioners and refrigerators Conventional technology related 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, it is still a problem that the invention attempts to solve.In recent years, the depletion of the stratospheric ozone layer by fluorocarbons has become a global environmental problem. The use and production of fluorocarbons (hereinafter referred to as specified fluorocarbons), which have a large ability to deplete the stratospheric ozone, has already been regulated by international treaties, and the use and production of specified fluorocarbons will be abolished in the future. Now, R22 has an ozone depletion coefficient (stratospheric ozone depletion potential 9 when the stratospheric ozone depletion potential of trichlorofluoromethane (CClsF) is 1, hereinafter written as ○DP) of 0. 05, and although it is not a specified fluorocarbon, its usage is expected to increase in the future.
Although it is expected that the impact on human living environment will increase as the usage and production of There is also a strong need for the early development of alternative working fluids.

The present invention was attempted in view of the above-mentioned problems, and is intended to provide a working fluid that has little effect on the stratospheric ozone layer and can be used as an alternative to U%R22.

Means for Solving the Problems The present invention solves the above-mentioned problems.
) Contains three types of fluorocarbons Pentafluoroethane (abbreviation 5)
5 to about 85% by weight Tetrafluoroethane 0 to about 45% by weight Difluoroethane 0 to about 30% by weight, especially pentafluoroethane about 55 to about 80% by weight Tetrafluoroethane Ethane O ~ approx. 45% by weight Difluoroethane 0 ~ approx. 30% by weight
It is desirable that the composition range is as follows.

Effect of the present invention (by the above-mentioned combination), the working fluid can be converted into L＼ which has almost no ozone depleting ability, and pentafluoroethane (ODP=o
), by forming a mixture of tetrafluoroethane (ODP-0) and difluoroethane (ODP=0),
Although the influence on the stratospheric ozone layer is even smaller than that of R22 and can be almost eliminated, the present invention also has the above-mentioned range, so that it can be used in heat pump devices such as air conditioners and refrigerators. Approximately 0, which is the usage temperature
It has a vapor pressure similar to that of R22 at ~50°C.
This makes it possible to provide a working fluid that can be used in current equipment as an alternative to R22. Therefore, it is expected that the ODP in the above combination and range of combinations is also 0. R
This is a very promising working fluid as an alternative to No. 22. In addition, such a mixture becomes a non-azeotropic mixture, and by configuring a Lorenz cycle with a temperature gradient in the condensation process and evaporation process, with the temperature difference from the heat source fluid being close to each other, a higher performance coefficient than R22 can be expected. It is something.

In addition, in general, fluorocarbons ζ have the ability to destroy stratospheric ozone.As the value of ○DP increases, the effect of global warming tends to increase.The working fluid according to the present invention has ○DP.
It is estimated that the effect of global warming caused by a mixture of three or more types of fluorocarbons, in which O is O, is the same as that of R22, or that it is not R22.Global warming has recently become a worldwide problem. Examples of the working fluid according to the present invention will be explained with reference to the drawings. ,1,
1, l, 2-tetrafluoroethane (R
l 34a), 1. 1-difluoroethane (R
1 5 2 Working fluid α composed of a mixture of three types of fluorocarbons in a) The equilibrium state at constant temperature and constant pressure is shown using triangular coordinates. In this triangular coordinate, at each vertex of the triangle is the upper side Single substances are arranged counterclockwise from the apex in descending order of boiling point.
Combination ratio (weight ratio) of each segment at a certain point on the coordinate plane
(It is expressed as the ratio of the distance between the point and each side of the triangle. Also, in this case, the distance between the point and the side of the triangle (as well as the ratio of the distance between the point and the side of the triangle) The ratio corresponds to the 1ζ table in Figure 1. Temperature 0℃, pressure 4.0
This is the vapor-liquid equilibrium line of the mixture at 44 kg/cm"G, and this temperature and pressure correspond to the saturated state of R22. The line above the vapor-liquid equilibrium line (equivalent to R22 0°C) is the saturated gas phase. Vapor-liquid equilibrium The line below line (R22, equivalent to 0℃) 1 represents the saturated liquidus line, and the area between these lines is in a state of vapor-liquid equilibrium. This is the vapor-liquid equilibrium line of the mixture at /cm2G, and this temperature and pressure also correspond to the saturated state of R22.
and Rl 52a are each about 55 to about 85% by weight 0 to
Approximately 45% by weight. L1 is desirable because it has a vapor pressure almost equal to that of R22 at a usage temperature of about 0 to about 50° C.
5, R134a and Rl52a are each about 55 to about 8
0% by weight. O to approximately 45% by weight (0 to approximately 30% 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 composition of the working fluid at points A1 to F1 in Fig. 1 is shown in Table 1. Points A1 to C1 are on the saturated vapor phase line of the vapor-liquid equilibrium line (R22, equivalent to 50°C) 2. Points D1 to Points F1 is the vapor-liquid equilibrium line (R22 equivalent to 50℃)2
It is on the saturated liquidus line of , and is in the range sandwiched by the saturated vapor line of vapor-liquid equilibrium line (R220℃ equivalent) 1 and the saturated liquidus line of vapor-liquid equilibrium line (R22 0℃ equivalent) 1. Therefore, the temperature is 0℃ and the pressure is 4.044 kg/cm2G (
Therefore, the working fluid having the composition shown in Table 1 is saturated under the condition of the saturated vapor pressure of R22 at 0°C and 50°C. By realizing the state or vapor-liquid equilibrium state and operating at the saturated vapor pressure of R22 at the operating temperature of approximately 0 to approximately 50 degrees Celsius, it becomes possible to obtain condensation and evaporation temperatures approximately equal to those of R22. It is something.

Here, only the points on the vapor-liquid equilibrium line (R22 equivalent to 50°C) 2 are explained. Points inside points A1 to F1, that is, the plate Temperature 0°C, pressure 4.044 kg/
cm2G and temperature 50℃・pressure 1 8.7 8 2 k
g/cm2G (both correspond to the saturated state of R22)
By performing the same operation on a working fluid that has a gas-liquid equilibrium state in be.

Figure 2 (Yo R125, 1, l, 2. 2
-tetrafluoroethane (R134), R152a (
7) Working fluid Q composed of a mixture of three types of fluorocarbons The equilibrium state at constant temperature and constant pressure is shown using triangular coordinates. In this triangular coordinate (
The standard boiling point of R152a at atmospheric pressure is lower than that of R134.
, R134, and R152a are arranged in this order. In Figure 2, 3(yo) Temperature 0℃・Pressure 4.04
is the vapor-liquid equilibrium line of the mixture at 4 kg/cm2G,
Also 4 j & temperature 50℃/pressure 18. 782kg/
This is the vapor-liquid equilibrium line of the mixture at cm''G.
The assembly range force is approximately 30% by weight<. R125, R13 is desirable because it has almost the same vapor pressure as R22.
4 and R152a each in an amount of about 70 to about 80% by weight.
Particularly desirable is a range of force that is 0 to approximately 30% by weight.Table 2 shows the working fluid requirements at points A2 to F2 in FIG. Point A2 to point C2
is on the vapor-liquid equilibrium line (equivalent to R22 50°C) 4. Point D2 to point F2 are on the vapor-liquid equilibrium line (R22 50°C)
It is on the saturated liquidus line of 4 (equivalent) and is on the vapor-liquid equilibrium line (R
22 0℃ equivalent) 3 saturated gas phase line and vapor liquid equilibrium line (R2
2. Temperature: 0°C, Pressure: 4. 04 4 kg
/cm"G (corresponding to the saturated state of R 2 2) is a gas-liquid equilibrium state. Therefore, the working fluid GEL having the composition shown in Table 2 is
By realizing a saturated state or a vapor-liquid equilibrium state under the condition of saturated vapor pressure of R22, and operating at the saturated vapor pressure of R22 at the same temperature at a usage temperature of approximately 0 to approximately 50°C,
It is possible to obtain a condensation temperature and evaporation temperature that are almost equal to R22.The force t explained only at the point on the vapor-liquid equilibrium line (R22, equivalent to 50℃) 4.The force t from point A2 to point F2 The forest inside Sunawa Cane Temperature 0℃・Pressure 4.0 4 4
kg/cm2G and temperature 50℃/pressure 1 8.7 8
2 kg/cm"G (both correspond to the saturated state of R22)
At a usage temperature of 0℃, the condensation temperature is almost equal to R22.
In the above embodiments, the working fluid is a mixture of three types of fluorocarbons, which makes it possible to obtain the evaporation temperature. Of course, it is also possible to control the fluid; in this case, about 55 to about 85% by weight of pentafluoroethane and about 4 to about 4% by weight of tetrafluoroethane
The composition range in which the concentration of difluoroethane O to approximately 30% by weight is R at a usage temperature of approximately 0 to approximately 50°C.
Pentafluoroethane is desirable because it has a vapor pressure almost equivalent to that of 22 (t).
Tetrafluoroethane O to approximately 45% by weight κ difluoroethane O to approximately 30% by weight (at 0℃)
It is particularly desirable because it has a vapor pressure almost equivalent to that of R22 at all operating temperatures between
It is a very promising working fluid as an alternative to R22, and most of these mixtures become non-azeotropic mixtures, forming a Lorenz cycle in which the temperature difference between the heat source fluid and the heat source fluid, which has a temperature gradient in the condensation process and the evaporation process, is made close to each other. By doing so, a higher performance coefficient than R22 can be expected.

Effects of the Invention As is clear from the above explanation, the present invention ζ has the following advantages: By making the working fluid a mixture of three or more types of fluorocarbons that do not contain chlorine in their molecular structure, and specifying the range of the composition, 1) Although it is possible to expand the range of selection of working fluids that have an even smaller effect on the stratospheric ozone layer than R22, and almost no effect, (2) Steam that has the same level of influence as R22 at the operating temperature of the equipment. Although it can be used with current equipment as an alternative to L R22 with a high pressure, (3) R2
Even if it has the effect that a performance coefficient higher than 2 can be expected.

[Brief explanation of the drawing]

Figures 1 and 2 show a working fluid α composed of a mixture of three types of fluorocarbons, constant temperature and constant pressure, 1, 3, vapor-liquid equilibrium line (R2, equivalent to 20°C), 2, 4, vapor-liquid equilibrium line. (Equivalent to R2250°C).

Claims (2)

[Claims] (1) A working fluid containing at least three types of fluorocarbons: 55 to 85% by weight of pentafluoroethane, 45% by weight or less of tetrafluoroethane, and 30% by weight or less of difluoroethane. (2) A working fluid characterized by containing 55 to 80% by weight of pentafluoroethane, 45% by weight or less of tetrafluoroethane, and 30% by weight or less of difluoroethane.