JPH07126613A - Dimethyl ether-based mixed working fluid and heat pump device using the same - Google Patents

Abstract

PURPOSE:To obtain a working fluid useful as a substitute for R134a, hardly having an undesirable effect on the ozone layer of the stratosphere. CONSTITUTION:This mixed working fluid contains 15-85wt.% of pentafluorodimethyl ether, <=85wt.% of 1,1-difluoroethane and one selected from <=75wt.% of dimethyl ether, <=75wt.% of trifluorodimethyl ether, <=65wt.% of tetrafluorodimethyl ether and <=35wt.% of difluorodimethyl ether as a fluorinated dimethyl ester composed only of two carbon atoms, one oxygen atom, one hydrogen atom and one fluorine atom. Another working fluid comprises only 15-85wt.% of pentafluorodimethyl ether and <=85wt.% of 1,1- difluoroethane.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dimethyl ether mixed working fluid and a heat pump device such as a refrigerator-freezer, a car cooler and a large-sized refrigerator.

[0002]

2. Description of the Related Art Conventionally, a heat pump device such as a refrigerator / freezer, a car cooler, and a large refrigerator has a compressor, a condenser, a throttle device such as a capillary tube and an expansion valve, and an evaporator connected in a pipe, and a working fluid inside thereof. By circulating it, a cooling action is performed. In these heat pump devices, CFCs as working fluid (hereinafter referred to as R ○○ or R ○
Halogenated hydrocarbons derived from methane or ethane, which are referred to as XX), are known to be used at a condensing temperature of about 50 ° C, an evaporating temperature of about -30 ° C in a freezer-refrigerator, a car cooler or a large freezer. In the machine, it is usually used in the range of about 0 ° C. Among them, dichlorodifluoromethane (CCl ₂ F ₂ , R12, boiling point -30 ° C) has been widely used as a working fluid in refrigerators, car coolers, large-scale refrigerators, etc., but in recent years depletion of the stratospheric ozone layer by CFCs has resulted in a global environment. Since it is a problem and has a large ozone depletion potential in the stratosphere, the Montreal International Convention has already regulated its use and production, and there is a movement to abolish its use and production in the future. In order to have almost no effect on the stratospheric ozone layer, it is required that the molecular structure does not contain chlorine, and as a possible possibility, chlorine-free fluorohydrocarbons have been proposed. and, as a substitute for R12, 1,1,1,2-tetrafluoroethane (CF ₃ -CH
₂ F, R134a, boiling point −27 ° C.) is proposed.

[0003]

[Problems to be Solved by the Invention] However, R13
4a has lower thermodynamic performance than that of R12.
From this point of view, it is not a satisfactory solution
It is the actual situation. R134a is also the ozone depletion ability in the stratosphere.
Shows almost no impact on global warming
If the global warming potential (hereinafter referred to as GWP) is relatively large
Has been done. Values reported at the 1991 UNEP Conference
According to the report, trichlorofluoromethane (CCl₃F, R1
1, the boiling point + 24 ℃) GWP is 1, chlorine
Difluoromethane (CH₂F
₂, R32, boiling point −52 ° C.) has a GWP of 0.13, pen
Tafluoroethane (CF₃-CHF₂, R125, boiling point -48
GWP of 0.84, 1,1,1-trifluoroe
Tan (CF₃-CH₃, R143a, boiling point −48 ° C.)
Is unknown, 1,1,1,2-tetrafluoroethane (CF₃-
CH ₂F, R134a, boiling point -27 ° C) GWP is 0.2
5,1,1-difluoroethane (CHF₂-CH₃, R152
a, boiling point-25 ° C.) has a GWP of 0.03.
Here, R32, R125, and R143a are more than R134a.
It has a very low boiling point and is not an alternative to R134a by itself.
I can't. R152a has a boiling point close to that of R134a, and GW
P is smaller than R134a, but it has flammability
There is.

The present invention has been tested in view of the above-mentioned problems, and has almost no effect on the stratospheric ozone layer, and there is a possibility that the effect on global warming can be reduced.
The present invention provides a working fluid alternative to 34a, and the present invention seeks to propose a mixture of chlorine-free fluorinated dimethyl ethers and 1,1-difluoroethane.

Here, dimethyl ethers are referred to as E ○○
Marked as ○, 100th place is -1 carbon atom, 10th place is hydrogen atom +
The 1st and 1st positions represent the number of fluorine atoms. The single candidate for these alternative working fluids is WLKopko, 'Beyond CFCs: Extending th
e Search for New Refrige-rants'ASHRAE's 1989 CFC
. Conf p.39-46 (1989.9) (double luer ^_Copco, human Bu Yonto Bu Shiefu CS:... Ekusutente Bu Inku Bu The search Fore New Rifurisshi Bu ^{Lantz, Asure,} vinegar Bu 1989 Sea f-theta Conference) to have been described in conjunction with the boiling point. Fluorinated dimethyl ethers composed of only 2 carbon atoms, 1 oxygen atom, hydrogen atom and fluorine atom are ethers which do not contain chlorine in the molecular structure and therefore have almost no ozone depletion ability. Particularly, ethers containing a hydrogen atom have a boiling point of -40 ° C or higher under atmospheric pressure, and therefore, are mixed with 1,1-difluoroethane to give 1,
1,1,2-tetrafluoroethane (CF ₃ -CH ₂ F, R1
34a, boiling point −27 ° C.), and a mixture having a boiling point equivalent to (1) pentafluorodimethyl ether (E125, CF
₃ -O-CHF ₂ , boiling point -35 ° C) (2) Dimethyl ether (E170, CH ₃ -O-CH ₃ , boiling point -24 ° C) (3) Trifluorodimethyl ether (E143a, CF
₃ -O-CH ₃ , boiling point -23 ° C) (4) tetrafluorodimethyl ether (E134a, CF ₃ -O-CH ₂ F, boiling point -20 ° C) (5) difluorodimethyl ether (E152a, CHF ₂
-O-CH _3, those desirably a mixture selected from any of the boiling point -5 ° C.). The GWPs of the fluorinated dimethyl ethers listed here have not yet been definitively established, but are being investigated as possible alternatives to the GWPs of fluorinated hydrocarbons. For example, Z.Zhang, RDS
aini, MJKurylo and REHuie, 'RateConstants for t
he Reactions of the Hydroxyl Radical with Several
Par-tially Fluorinated Ethers' J.Phys.Chem., Vol.9
6, p. 9301-9304 (1992) (Set Twang, R. D. Sini, M.
... Shi Bu E over Krilo Ant Bu Earl E. Hyuie, ^and late Constance Fore The notes scan Bu Of The height Bu hexyl La Defense Ikaru Uisu Bu Sehe Bu Lal path - Sharii Furuorineiteto Bu Est - stealth ^Bu, Shi Bu Yanaruofu Bu Fishi The Bu Cal chemistry), the OH radical reaction in the atmosphere, ethane-free hydrofluorocarbon Fluorinated dimethyl ether with oxygen atoms in between is larger than
Results have been reported that predict that the atmospheric life is short and GWP is small.

Prior art patents for chlorine-free fluorinated ethers include the following. First, as an American patent, USP 2,066,905 discloses trifluorodimethyl ether (E143, C ₂ H ₃ F ₃ O). In USP2,500,388, perfluoro dimethyl ether _{(E116, CF 3 -O-CF} 3, boiling point -5
9 ° C.) and the like are disclosed. USP 3,362,180
Discloses E125, E134a and the like. US
P3,394,878 discloses an azeotropic mixture of E143a and E116. USP 3,409,555
So trifluoromethyl - trifluoroethyl ether _{(CF 3 -O-CH 2 -CF} 3, boiling point + 5.6 ° C.) and dichlorofluoromethane (R21, boiling point + 9 ° C.) minimum boiling point azeotropic mixture is disclosed . In USP 3,922,228,
The highest boiling azeotrope of E125 and E170 is disclosed. In USP4,041,148, bis - mixture of difluoromethyl ether (E134, CHF ₂ -CHF _2, boiling point + 5 ° C.) and E116 is disclosed. USP
4, 139 and 607, E134 and carbon dioxide (C
A mixture of O ₂ ) is disclosed. USP 4,783
276 (JP-A-63-205386) discloses an azeotropic mixture of E170 and R12. USP 4,94
8,526 discloses an azeotrope of E125 and chlorodifluoromethane (R22, boiling point -41 ° C). USP 4,961,321 (JP-A-2-24849)
0) discloses mixtures of E134 and chlorine-free fluorohydrocarbons. USP 5,061,394
Then, E170 and chlorotetrafluoroethane (R12
4, boiling point -10 [deg.] C.), the highest boiling azeotrope is disclosed. In USP 5,182,040, E170 and 1,
1,2,2-Tetrafluoroethane (R134, boiling point-
20 ° C.) highest boiling azeotrope and the like are disclosed. U
SP 5,221,492 discloses a mixture of E170 and perfluoropropane (R218, boiling point −38 ° C.) and the like.

Japanese Patent Application for Fluorinated Ethers Not Containing Chlorine is Japanese Patent Laid-Open No. 3-93882, E116.
Is disclosed. In Japanese Patent Laid-Open No. 3-93883, E12
5 is disclosed. In Japanese Patent Laid-Open No. 4-110386, 2
Or fluorinated ethers having 3 carbon atoms are disclosed.

Foreign patents for fluorinated ethers containing no chlorine include EP134 in EP385,737A.
Is disclosed. EP443,912A (JP-A-4-
253927) discloses the highest boiling azeotrope of E170 and R134a. In WO91 / 13968, E170 and R13 are the same as EP443,912A.
The highest boiling azeotrope of 4a is disclosed. WO93
/ 04138 discloses fluorinated ethers having 3 carbon atoms. In WO93 / 14173, E1
A mixture of 43a or E134a and R134a is disclosed. In WO93 / 14174, E125 and R3
Mixtures of 2, R125 and R143a are disclosed. In WO93 / 14175, E125 and E134
Mixtures with a, E134 and R134a are disclosed.

However, the working fluids shown in these conventional patents have a boiling point greatly different from that of 1,1,1,2-tetrafluoroethane (R134a, boiling point -27 ° C.), or except the azeotropic mixture. Since the composition range is not specified, it cannot be used as it is in the current equipment using R134a.

[0010]

In order to solve the above problems, the present invention provides 1,1-difluoroethane (R152a).
Is a mixed working fluid consisting of dimethyl ethers and 2
Of fluorinated dimethyl ethers consisting of carbon atoms, oxygen atoms, hydrogen atoms and fluorine atoms. The fluorinated dimethyl ethers mixed here include at least E125,
One or more selected from 170, E143a, E134a, and E152a, and the mixed working fluid according to the present invention is composed of three kinds in total or two kinds of R152a and E125. The present invention further provides that the composition range of these mixtures is such that the vapor pressure of the mixture is approximately R134.
It is specified so as to be equivalent to a. Further, the present invention is a heat pump device using the working fluid.

[0011]

According to the present invention, the combination of the above working fluids is 1,1-difluoroethane (R152a), which has a boiling point of -40 ° C or higher under atmospheric pressure, has almost no ozone depletion ability, and has a molecular structure. By using a mixture of two or more selected from any of ethers (ODP = 0) that does not contain chlorine, it is possible to almost completely eliminate the effect on the stratospheric ozone layer, similar to R134a. It is what In particular, the ODP in the above combination and in the specified composition range is also expected to be 0, which is an extremely promising working fluid as an alternative to R134a.

The present invention also provides E125, which has a lower boiling point than R134a, and R152a, which has a higher boiling point than R134a.
And E170 and E143, which have higher boiling points than R134a
a, E134a, E152a is mixed with one or more selected, and by specifying the composition range thereof, the operating temperature of a heat pump device such as a refrigerator / freezer, a car cooler, or a large refrigerator is about -30 to about 50. It has the same vapor pressure as R134a at ℃, and can expect the same refrigerating capacity as R134a.
It is possible to provide a working fluid that can be used even in the current equipment using 12.

The mixture has a boiling point difference of 30 deg.
Since it is a mixture of 1,1-difluoroethane (R152a) and fluorinated dimethyl ethers within the range, it is expected that it will be a near-azeotropic non-azeotropic mixture. Since it has a small temperature gradient in the condensation process and the evaporation process, air etc. By constructing a Lorenz cycle in which the temperature difference with the heat source fluid is close, the coefficient of performance (C
OP) heat pump device can be configured. Particularly in a refrigerator-freezer, in order to make the frost on the evaporator uniform, it is usual to construct the evaporator long in the flow direction of the cooling air, and to cool the outlet side of the working fluid whose temperature rises during the evaporation process. A Lorenz cycle can be easily constructed by exchanging heat with the inlet side of the working air and exchanging heat with the inlet side of the working fluid, which has the lowest temperature in the evaporation process, with the outlet side of the cooling air.

Further, since such a mixture is composed only of 1,1-difluoroethane (R152a) having a lower global warming potential (GWP) than R134a and fluorinated dimethyl ethers, it is possible to reduce the influence on global warming. There is a nature. Further, E125 has low solubility in a polymer compound, excellent heat stability, and is nonflammable, and therefore R125a, E170, E143a, and E152a.
By further limiting the composition range of the fluorinated dimethyl ethers to the non-flammable range, the fluorinated dimethyl ether can be used as it is in a normal heat pump device.

[0015]

The working fluid of the present invention is a mixed working fluid composed of 1,1-difluoroethane (R152a) and dimethyl ethers, containing at least E125, and E17.
0, E143a, E134a, or E152a. Further, the composition range of these mixtures is specified so that the vapor pressure of the mixture becomes almost equal to R134a. Examples of working fluids according to the present invention will be described below with reference to vapor pressure diagrams.

FIG. 1 shows pentafluorodimethyl ether (E125, CF ₃ —O—CHF ₂ , boiling point −35 ° C.), 1,1-difluoroethane (R152a, CHF ₂ —CH ₃ , boiling point −25).
℃), dimethyl ether (E170, CH ₃ -O-CH ₃ , boiling point -24 ℃) of the working fluid consisting of a mixture of three at the constant temperature and constant pressure using triangular coordinates. is there.

In the present triangular coordinates, a single substance is arranged at each vertex of the triangle counterclockwise from the upper vertex in the ascending order of the boiling points, and the composition ratio of each component at a certain point on the coordinate plane ( The weight ratio) is represented by the ratio of the distance between the point and each side of the triangle. At this time, the distance between the point and the side of the triangle corresponds to the composition ratio of the substance described at the apex of the triangular coordinate on the side opposite to the side.

In FIG. 1, 1 is a vapor-liquid equilibrium line of the mixture at a temperature of −30 ° C. and a pressure of 0.0849 MPa, and this temperature / pressure corresponds to a saturated state of R134a at a temperature of −30 ° C. Gas-liquid equilibrium line (R134a-3
The upper line 1V of (corresponding to 0 ° C) 1 is a saturated vapor phase line, and the lower line 1L of the vapor-liquid equilibrium line (R134a-30 ° C) 1 is a saturated liquid phase line. In, the gas-liquid equilibrium state is reached. In addition, 2 is temperature 0 ℃, pressure 0.29
This is a vapor-liquid equilibrium line of the mixture at 33 MPa, and this temperature / pressure also corresponds to the saturated state of R134a at a temperature of 0 ° C. Furthermore, 3 is temperature 50 ℃, pressure 1.3173M
It is a vapor-liquid equilibrium line of the mixture at Pa, and this temperature / pressure also corresponds to the saturated state of R134a at a temperature of 50 ° C.

The composition on the saturated vapor phase line V vaporizes at a pressure higher than that of R134a at the same temperature as R134a, and R1
It liquefies at the same pressure as 34a. At the same temperature as R134a, the composition on the saturated liquidus line L is vaporized at the same pressure as R134a and liquefied at a pressure lower than R134a. The composition in the area between these two lines vaporizes at higher pressure than R134a at the same temperature as R134a,
It liquefies at a pressure lower than 4a. That is, the composition in the area between the gas-liquid equilibrium line 3 at 50 ° C. changes from the gas phase to the liquid phase at 50 ° C. at a pressure lower than that of R134a, and R1
At the same pressure as 34a, the gas phase higher than 50 ° C condenses,
Change to liquid phase below 50 ° C. Further, the composition in the area between the vapor-liquid equilibrium lines 1 or 2 at -30 ° C or 0 ° C is 0
At C, the liquid phase changes to a gas phase at a pressure higher than R134a, and at the same pressure as R134a, a liquid phase lower than -30 ° C evaporates and changes to a gas phase higher than -30 ° C.
The liquid phase below 0 ° C evaporates and changes to the gas phase above 0 ° C. That is, the composition between the gas-liquid parallel lines 1 and 3 has almost the same evaporation pressure as that of R134a at a temperature of -30 ° C and the same condensation pressure as that of R134a at a temperature of 50 ° C. Suitable for machine. Further, the composition between the gas-liquid parallel lines 2 and 3 has almost the same evaporation pressure as that of R134a at a temperature of 0 ° C. and has the same condensation pressure as that of R134a at a temperature of 50 ° C., and thus is suitable for a car cooler.

As can be seen from the figure, E125, R152
a and E170 are approximately 15 to approximately 55% by weight, respectively, 0 to
The composition range of about 85% by weight to 0 to about 75% by weight is R134a at a use temperature of about -30 to about 50 ° C.
It is desirable because it has a vapor pressure almost equal to. Furthermore, E
The composition range in which 125, R152a and E170 are approximately 20 to approximately 55% by weight, 0 to approximately 80% by weight and 0 to approximately 65% by weight, respectively, is substantially the same as that of R134a at a use temperature of approximately 0 to approximately 50 ° C. It is desirable because it has a vapor pressure of.

FIG. 2 shows pentafluorodimethyl ether (E125, CF ₃ —O—CHF ₂ , boiling point −35 ° C.), 1,1-difluoroethane (R152a, CHF ₂ —CH ₃ , boiling point −25).
° C), trifluorodimethyl ether (E143a, CF
₃ -O-CH _3, the three types constituted the working fluid by a mixture of the boiling point -23 ° C.), there is shown using a triangular coordinate equilibrium at a constant temperature and constant pressure. Also in FIG. 2, 1 is the vapor-liquid equilibrium line of the mixture at a temperature of −30 ° C. and a pressure of 0.0849 MPa, and 2 is the vapor-liquid equilibrium line of the mixture at a temperature of 0 ° C. and a pressure of 0.2933 MPa, and further 3 Is a temperature of 50 ° C and a pressure of 1.3173 MPa
3 is a vapor-liquid equilibrium line of the mixture in FIG.

In this case, E125, R152a and E143a are approximately 15 to approximately 45% by weight and 0 to approximately 8% by weight, respectively.
5% by weight, 0 to about 75% by weight composition range,
It is desirable because it has a vapor pressure almost equal to that of R134a at a use temperature of about -30 to about 50 ° C.
A composition range in which 52a and E143a are approximately 20 to approximately 45% by weight, 0 to approximately 80% by weight, and 0 to approximately 70% by weight, respectively, is desirable at a use temperature of approximately 0 to approximately 50 ° C.

FIG. 3 shows pentafluorodimethyl ether (E125, CF ₃ —O—CHF ₂ , boiling point −35 ° C.), 1,1-difluoroethane (R152a, CHF ₂ —CH ₃ , boiling point −25).
° C), tetrafluorodimethyl ether (E134a,
₃ shows the equilibrium state at constant temperature and constant pressure of a working fluid composed of a mixture of three kinds (CF ₃ —O—CH ₂ F, boiling point −20 ° C.) using triangular coordinates.

In this case, E125, R152a and E134a are approximately 15 to approximately 55% by weight and 0 to approximately 8% by weight, respectively.
The composition range of 5% by weight, 0 to about 65% by weight,
It is desirable because it has a vapor pressure almost equal to that of R134a at a use temperature of about -30 to about 50 ° C.
A composition range in which 52a and E134a are respectively approximately 20 to approximately 55% by weight, 0 to approximately 80% by weight, and 0 to approximately 60% by weight is desirable at a use temperature of approximately 0 to approximately 50 ° C.

FIG. 4 shows pentafluorodimethyl ether (E125, CF ₃ —O—CHF ₂ , boiling point −35 ° C.), 1,1-difluoroethane (R152a, CHF ₂ —CH ₃ , boiling point −25).
° C), difluorodimethyl ether (E152a, CHF ₂
-O-CH _3, the working fluid constituted by a mixture of three types of boiling -5 ° C.), there is shown using a triangular coordinate equilibrium at a constant temperature and constant pressure.

In this case, E125, R152a and E152a are approximately 15 to approximately 85% by weight and 0 to approximately 8% by weight, respectively.
The composition range of 5% by weight, 0 to about 35% by weight,
It is desirable because it has a vapor pressure almost equal to that of R134a at a use temperature of about -30 to about 50 ° C.
A composition range in which 52a and E152a are approximately 20 to approximately 85% by weight, 0 to approximately 80% by weight, and 0 to approximately 30% by weight is desirable at a use temperature of approximately 0 to approximately 50 ° C.

Taken together, these are composed of 15 to 85% by weight of pentafluorodimethyl ether, 85% by weight or less of 1,1-difluoroethane, and fluorination consisting of only 2 carbon atoms, 1 oxygen atom, hydrogen atom and fluorine atom. As the dimethyl ether, a mixed working fluid containing one kind selected from dimethyl ether 75 wt% or less, trifluorodimethyl ether 75 wt% or less, tetrafluorodimethyl ether 65 wt% or less, or difluorodimethyl ether 35 wt% or less is about −30. ~
It is desirable because it has a vapor pressure almost equal to that of R134a at a use temperature of about 50 ° C.

A more preferable composition range is 20 to 85% by weight of pentafluorodimethyl ether, 80% by weight or less of 1,1-difluoroethane, and 6% of dimethyl ether.
5% by weight or less or trifluorodimethyl ether 70
Weight% or less or tetrafluorodimethyl ether 60
A mixed working fluid containing one selected from either less than or equal to 30% by weight or less than or equal to 30% by weight of difluorodimethyl ether is desirable because it has a vapor pressure almost equal to that of R134a at a use temperature of about 0 to about 50 ° C.

Incidentally, pentafluorodimethyl ether (E125) and 1,1-difluoroethane (R152
In the case of a mixed working fluid consisting of two components of a), R13
The composition range for obtaining a vapor pressure equivalent to 4a is preferably a range on the side connecting E125 and R152a of each triangular coordinate, but even in a mixture derived from the above specified composition range, R134a is preferable. Only a slightly higher vapor pressure is considered to be practically acceptable.

That is, a two-component system consisting only of 15 to 85% by weight of pentafluorodimethyl ether (E125) and 85% by weight or less of 1,1-difluoroethane (R152a) has a low GWP of R152a and a flammability of R152a of 30% by weight. If it is less than or equal to%, it is thought that it can be almost reduced. 70 to 85% by weight of this E125 and 1 of R152a
The composition range of 5 to 30% by weight is E125, which is a composition range for achieving a vapor pressure equivalent to that of R134a.
5 to 35 wt% and R152a to 65 to 85 wt%, the composition ratio of E125 is higher, and the vapor pressure is slightly higher than that of R134a, which is considered to increase the refrigerating capacity than R134a. Therefore, pentafluorodimethyl ether (E125) and 1,1-difluoroethane (R1
A binary system consisting only of 52a) is also useful as an alternative to R134a.

Table 1 shows the ideal refrigerating performance of a two-component system consisting only of E125 and R152a. The conditions are as follows: condensing average temperature is 50 ° C., evaporation average temperature is −30 ° C., condenser outlet supercooling degree is 0 deg, evaporator outlet superheat degree is 0 deg.
Is the case. As can be seen from (Table 1), the two-component system consisting only of 15-85 wt% of pentafluorodimethyl ether (E125) and 15-85 wt% of 1,1-difluoroethane (R152a) has a condensation pressure and an evaporation pressure of R
Since it is close to 134a, it has a refrigerating capacity equal to or higher than R134a, and the coefficient of performance is also close to R134a. In addition, the temperature gradient in the condensation process and the evaporation process is extremely small, resulting in an azeotropic mixture. Further, E125, which is a composition range for obtaining a vapor pressure equivalent to that of R134a, is 15 to 35% by weight and R
The two-component system in which 152a is 65 to 85% by weight shows almost the same characteristics as R134a, and rather, both the refrigerating capacity and the coefficient of performance are improved as compared with R134a. Further, E125 is 70 to 85% by weight and R152a is 15 to 30% by weight.
Although the two-component system consisting of wt% has a vapor pressure slightly higher than that of R134a, it is found that it exhibits almost the same characteristics as R134a, and by constructing a Lorenz cycle in which the temperature difference with the heat source fluid is close, A higher coefficient of performance can be expected than in Table 1).

[0032]

[Table 1]

Further, in the above embodiments, the working fluid is composed of a mixture of 1,1-difluoroethane and two or more ethers, but the structural isomers of trifluorodimethyl ether, tetrafluorodimethyl ether and difluorodimethyl ether are isomerized. It is of course possible to form the working fluid from a mixture of four or more ethers including the body.

[0034]

As is apparent from the above description, the present invention provides pentafluorodimethyl ether (E125) 15.
~ 85 wt% and 1,1-difluoroethane (R152
a) 85% by weight or less, one kind selected from fluorinated dimethyl ethers consisting only of 2 carbon atoms, 1 oxygen atom, hydrogen atom and fluorine atom, and a working fluid containing chlorine in its molecular structure. By not making a mixture consisting only of CFCs and ethers, and by specifying the composition range,
(1) As with R134a, it is possible to expand the range of choices of working fluid that has almost no effect on the stratospheric ozone layer. (2) Use of heat pump devices such as refrigerators / coolers, car coolers, and large refrigerators It is about -3
At 0 to approximately 50 ° C., it has a vapor pressure similar to that of R134a, and can be expected to have the same refrigerating capacity as R134a.
4a can also be used in existing equipment using R12, (3) such a mixture is expected to be a near-near azeotrope non-azeotropic mixture, especially in a refrigerator / freezer,
A Lorenz cycle can be easily constructed, and R1
A coefficient of performance higher than that of 34a can be expected. (4) Since such a mixture is composed only of 1,1-difluoroethane (R152a) and fluorinated dimethyl ethers, it may be possible to reduce the influence on global warming.
(5) Pentafluorodimethyl ether (E125)
Has low solubility in polymer compounds, excellent thermal stability, and is nonflammable. Therefore, 1,1-difluoroethane (R
152a) and other fluorinated dimethyl ethers can be used as they are in ordinary heat pump devices by limiting the composition range to (5) pentafluorodimethyl ether (E125) and 1,1-difluoroethane. The binary system consisting only of (R152a) has a low GWP of R152a and is useful as a substitute for R134a.

[Brief description of drawings]

FIG. 1 is a triangular coordinate diagram showing the equilibrium state of a working fluid composed of a mixture of three kinds of ethers E125, R152a, and E170 at a constant temperature and a constant pressure.

FIG. 2 is a triangular coordinate diagram showing an equilibrium state of a working fluid composed of a mixture of three kinds of ethers E125, R152a, and E143a at a constant temperature and a constant pressure.

FIG. 3 is a triangular coordinate diagram showing the equilibrium state of a working fluid composed of a mixture of three kinds of ethers E125, R152a, and E134a at a constant temperature and a constant pressure.

FIG. 4 is a triangular coordinate diagram showing the equilibrium state of a working fluid composed of a mixture of three kinds of ethers E125, R152a, and E152a at a constant temperature and a constant pressure.

[Explanation of symbols]

 1 Gas-liquid equilibrium line (R134a-30 ° C equivalent) 2 Gas-liquid equilibrium line (R134a 0 ° C equivalent) 3 Gas-liquid equilibrium line (R134a 50 ° C equivalent) V Saturated vapor phase line L Saturated vapor phase line

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Mitsuharu Matsuo 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] 1. Pentafluorodimethyl ether 15-8
5% by weight, 85% by weight or less of 1,1-difluoroethane, 75% by weight or less of dimethyl ether or trifluorodimethyl ether, as a fluorinated dimethylether consisting only of 2 carbon atoms, 1 oxygen atom, 1 hydrogen atom and 1 fluorine atom. A dimethyl ether-based mixed working fluid comprising three components including one selected from 75% by weight or less, 65% by weight or less of tetrafluorodimethyl ether or 35% by weight or less of difluorodimethyl ether. 2. Pentafluorodimethyl ether 15-8
A dimethyl ether-based mixed working fluid comprising two components containing only 5% by weight and 85% by weight or less of 1,1-difluoroethane. 3. Pentafluorodimethyl ether 15-8
5. A fluorinated dimethyl ether consisting of 5% by weight, 85% by weight or less of 1,1-difluoroethane, and 2 carbon atoms, 1 oxygen atom, hydrogen atom and fluorine atom. A heat pump device using the dimethyl ether-based mixed working fluid. 4. Pentafluorodimethyl ether 15-8
The heat pump apparatus using a dimethyl ether-based mixed working fluid according to claim 2, which contains only 5% by weight and 85% by weight or less of 1,1-difluoroethane.