JPH07126678A - Dimethyl ethereal mixed working fluid and heat pump device using the same - Google Patents

Abstract

PURPOSE:To obtain a working fluid, capable of providing a substitute for a fluorocarbon R134a and hardly affecting the ozonosphere of the stratosphere. CONSTITUTION:This mixed working fluid contains 5-60wt.% difluoromethane and two selected from any of <=95wt.% dimethyl ether, <=95wt.% trifluorodimethyl ether, <=95wt.% tetrafluorodimethyl ether and <=85wt.% difluorodimethyl ether as fluorinated dimethyl ethers composed of only two carbon atoms, one oxygen atom, hydrogen atoms and fluorine atoms or 5-60wt.% difluoromethane and only one selected from either of <=95wt.% tetrafluorodimethyl ether and <=85wt.% difluorodimethyl ether.

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 an alternative working fluid to 34a, and the present invention proposes a mixture of chlorine-free fluorinated dimethyl ethers and difluoromethane.

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 Bu Yonto Shiefu CS Ekusutente Bu Bu Inku The service -.. Chi Fore New Rifurisshi Bu ^{Lantz, Asure,} vinegar Bu
1989 See CFC Conference.) With 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. In particular, ethers containing a hydrogen atom have a boiling point of −40 ° C. or higher under atmospheric pressure, and thus are mixed with difluoromethane to give 1,1,1,2.
A mixture having a boiling point equivalent to that of tetrafluoroethane (CF ₃ —CH ₂ F, R134a, boiling point −27 ° C.), (1) pentafluorodimethyl ether (E125, CF ₃ —O
-CHF ₂ , boiling point -35 ° C) (2) Dimethyl ether (E170, CH ₃ -O-CH ₃ , boiling point -2)
4 ° 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 ℃) (5) difluoro dimethyl 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. J. Kurilo and R. E. Huyer ^, Late Constants Fore Reactions Off-Off High-Heavy Lateral Wise - stealth ^Bu, the sheet Bu Yanaruofu Bu Fishi Bu Cal chemistry), the OH radical reaction in the atmosphere, it is largely fluoride ether having an oxygen atom between than ethane-free hydrofluorocarbon,
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-mentioned problems, the present invention is a mixed working fluid composed of difluoromethane (R32) and dimethyl ethers, which comprises 2 carbon atoms, 1 oxygen atom, hydrogen atom and fluorine. It includes two or more selected from fluorinated dimethyl ethers consisting only of atoms. The fluorinated dimethyl ethers mixed here are E170, E143a, E134a, E15.
Two or more kinds selected from any of 2a, and the mixed working fluid according to the present invention is composed of three kinds or two kinds in total. The present invention further provides that the composition range of these mixtures is such that the vapor pressure of the mixture is approximately R134a.
It is specified to be equivalent to. Further, the present invention is a heat pump device using the working fluid.

[0011]

According to the present invention, the working fluid is mixed with difluoromethane (R32) at -25 at atmospheric pressure by the above combination.
It has a boiling point of ℃ or above and has almost no ozone depletion potential,
Ethers that do not contain chlorine in the molecular structure (ODP = 0)
By using a mixture of two or more selected from the above, it is possible to almost completely eliminate the effect on the stratospheric ozone layer, similar to R134a. 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 R32, which has a lower boiling point than R134a, and E170, E, which has a higher boiling point than R134a.
By mixing two or more selected from any one of 143a, E134a, and E152a and specifying the composition range thereof, the usage temperature of a heat pump device such as a refrigerator-freezer, a car cooler, and a large refrigerator is about -30. ~
At 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.
This makes it possible to provide a working fluid that can be used even in the current equipment using R12 as an alternative to a.

The mixture has a boiling point difference of 50 deg.
Since it is a mixture of difluoromethane (R32) and fluorinated dimethyl ethers within the range, it is expected to be a near-azeotropic non-azeotropic mixture, and since it has a small temperature gradient in the condensation process and the evaporation process, a heat source fluid such as air By configuring a Lorentz cycle in which the temperature difference between and is close to each other, a heat pump device having a coefficient of performance (COP) higher than that of R134a can be configured. Especially in a refrigerator-freezer, in order to make the frost on the evaporator uniform,
It is usual to construct an evaporator long in the flow direction of cooling air, and the outlet side of the working fluid whose temperature rises during the evaporation process exchanges heat with the inlet side of the cooling air so that the operation becomes the lowest in the evaporation process. A Lorenz cycle can be easily constructed by exchanging heat between the inlet side of the fluid and the outlet side of the cooling air.

Further, since such a mixture is composed only of difluoromethane (R32), which has a smaller global warming potential (GWP) than R134a, and fluorinated dimethyl ethers, it is possible that the effect on global warming can be reduced. . R32, E170, E143a, E152
By further limiting the composition range of the fluorinated dimethyl ethers of a to the non-flammable range, it can be used as it is in a normal heat pump device.

[0015]

EXAMPLE A working fluid of the present invention is difluoromethane (R
32) and dimethyl ethers, which is a mixed working fluid containing two or more selected from E170, E143a, E134a, and 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 difluoromethane (R32, CH ₂ F
₂ , boiling point -52 ° C), dimethyl ether (E170, CH ₃
-O-CH ₃ , boiling point -24 ° C), equilibrium of working fluid composed of trifluorodimethyl ether (E143a, CF ₃ -O-CH ₃ , boiling point -23 ° C) at constant temperature and constant pressure The state is shown using triangular coordinates.

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 has the same condensation pressure as that of R134a at a temperature of 50 ° C. Therefore, it is suitable for a refrigerator-freezer. is there.
The composition between the gas-liquid parallel lines 2 and 3 has a temperature of 0.
Has almost the same evaporation pressure as R134a at ℃,
Since it has almost the same condensing pressure as R134a at a temperature of 50 ° C., it is suitable for car coolers and large refrigerators.

As can be seen from the figure, R32, E170 and E143a are approximately 5 to approximately 25% by weight and 0 to approximately 9% by weight, respectively.
The composition range of 5% by weight and 0 to approximately 95% by weight is
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. Furthermore, R3
2, E170 and E143a have compositional ranges such that they are approximately 5 to approximately 25% by weight, 0 to approximately 90% by weight, and 0 to approximately 95% by weight, respectively, at a use temperature of approximately 0 to approximately 50 ° C.
It is desirable because it has a vapor pressure almost equal to that of 34a.

FIG. 2 shows difluoromethane (R32, CH ₂ F
₂ , boiling point -52 ° C), dimethyl ether (E170, CH ₃
-O-CH ₃ , boiling point -24 ° C), tetrafluorodimethyl ether (E134a, CF ₃ -O-CH ₂ F, boiling point -20 ° C) working fluid at a constant temperature and a constant pressure The equilibrium state is shown using triangular coordinates. Also in FIG. 2, 1 indicates a temperature of −30 ° C. and a pressure of 0.
8 is a gas-liquid equilibrium line of the mixture at 0849 MPa, 2 is a gas-liquid equilibrium line of the mixture at a temperature of 0 ° C. and a pressure of 0.2933 MPa, and 3 is a gas-liquid equilibrium line of the mixture at a temperature of 50 ° C. and a pressure of 1.3173 MPa. It is a balance line.

In this case, R32, E170 and E1
34a is approximately 5 to approximately 25% by weight, 0 to approximately 95% by weight, and 0 to approximately 95% by weight, respectively.
It is desirable because it has a vapor pressure almost equal to that of R134a at a use temperature of 0 to about 50 ° C.
A composition range such that the weight percent is 0 to approximately 95 weight percent is desirable at a utilization temperature of approximately 0 to approximately 50 ° C.

FIG. 3 shows difluoromethane (R32, CH ₂ F
₂ , boiling point -52 ° C), dimethyl ether (E170, CH ₃
-O-CH ₃ , boiling point -24 ° C), equilibrium state of working fluid composed of a mixture of three kinds of difluorodimethyl ether (E152a, CHF ₂ -O-CH ₃ , boiling point -5 ° C) at constant temperature and constant pressure Is shown using triangular coordinates.

In this case, R32, E170 and E1
52a is approximately 5 to approximately 60% by weight, 0 to approximately 95% by weight, and 0 to approximately 85% by weight, respectively.
Since it has a vapor pressure almost equal to that of R134a at a use temperature of 0 to about 50 ° C., it is desirable that R32, E170 and E152a are each about 10 to about 55% by weight and 0 to about 9% by weight.
The composition range of 0% by weight, 0 to about 80% by weight,
It is desirable at a use temperature of about 0 to about 50 ° C.

FIG. 4 shows difluoromethane (R32, CH ₂ F
₂ , boiling point −52 ° C.), trifluorodimethyl ether (E143a, CF ₃ —O—CH ₃ , boiling point −23 ° C.), tetrafluorodimethyl ether (E134a, CF ₃ —O—CH ₂ F, boiling point −20 ° C.) 3 shows the equilibrium state of the working fluid composed of the mixture of 1) at a constant temperature and a constant pressure by using triangular coordinates. Also in FIG. 4, 1 is a vapor-liquid equilibrium line of the mixture at a temperature of −30 ° C. and a pressure of 0.0849 MPa, and 2 is a temperature of 0 ° C. and a pressure of 0.293.
Is a vapor-liquid equilibrium line of the mixture at 3 MPa, and further 3
Is a vapor-liquid equilibrium line of the mixture at a temperature of 50 ° C. and a pressure of 1.3173 MPa.

In this case, R32, E143a and E
The composition ranges in which 134a is approximately 5 to approximately 15% by weight, 0 to approximately 95% by weight, and 0 to approximately 95% by weight are approximately −
It is desirable because it has almost the same vapor pressure as that of R134a at a use temperature of 30 to about 50 ° C., and the same composition range is also desirable at a use temperature of about 0 to about 50 ° C.

FIG. 5 shows difluoromethane (R32, CH ₂ F
_2, boiling point -52 ° C.), trifluoroacetic ether _{(E143a, CF 3 -O-CH} 3, boiling point -23 ° C.), difluoro dimethyl ether _{(E152a, CHF 2 -O-CH} 3, boiling point -
A working fluid composed of a mixture of three
The equilibrium state at constant temperature and constant pressure is shown using triangular coordinates.

In this case, R32, E143a and E
152a is approximately 5 to approximately 60% by weight, 0 to approximately 95% by weight, and 0 to approximately 85% by weight, respectively.
It is desirable because it has a vapor pressure almost equal to that of R134a at a use temperature of 30 to about 50 ° C., R32, E143a
And E152a are preferably in a composition range such that they are approximately 5 to approximately 55% by weight, 0 to approximately 95% by weight, and 0 to approximately 80% by weight, respectively, at a use temperature of approximately 0 to approximately 50 ° C.

FIG. 6 shows difluoromethane (R32, CH ₂ F
_2, boiling point -52 ° C.), tetrafluoro ether _{(E134a, CF 3 -O-CH} 2 F, boiling point -20 ° C.), difluoro dimethyl ether _{(E152a, CHF 2 -O-CH} 3, boiling point -
A working fluid composed of a mixture of three
The equilibrium state at constant temperature and constant pressure is shown using triangular coordinates. Also in FIG. 6, 1 is temperature −30.
It is a vapor-liquid equilibrium line of the mixture at ℃ · pressure 0.0849MPa, and 2 is temperature 0 ℃ · pressure 0.2933MP
The vapor-liquid equilibrium line of the mixture in a, and 3 is the vapor-liquid equilibrium line of the mixture at a temperature of 50 ° C. and a pressure of 1.3173 MPa.

In this case, R32, E134a and E
152a is approximately 5 to approximately 60% by weight, 0 to approximately 95% by weight, and 0 to approximately 85% by weight, respectively.
It is desirable because it has a vapor pressure almost the same as that of R134a at a use temperature of 30 to about 50 ° C.
And E152a are preferably in a composition range such that they are approximately 5 to approximately 55% by weight, 0 to approximately 95% by weight, and 0 to approximately 80% by weight, respectively, at a use temperature of approximately 0 to approximately 50 ° C.

When these are put together, difluoromethane 5
As a fluorinated dimethyl ether consisting of ˜60% by weight, 2 carbon atoms, 1 oxygen atom, hydrogen atom and fluorine atom, 95% by weight or less of dimethyl ether or 95% by weight or less of trifluorodimethyl ether or 95% by weight of terrafluorodimethyl ether % Or less than 85% by weight of difluorodimethyl ether, a mixed working fluid containing two or more selected from 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 5 to 55% by weight of difluoromethane and 90% by weight of dimethyl ether.
A mixed working fluid containing two or more selected from the following or 95% by weight or less of trifluorodimethyl ether or 95% by weight or less of terafluorodimethylether or 80% by weight or less of difluorodimethyl ether is used at a temperature of about 0 to about 50 ° C. R134a at temperature
It is desirable because it has a vapor pressure almost equal to.

In the case of a mixed working fluid consisting of two components of difluoromethane (R32) and each dimethyl ether, the composition range for obtaining a vapor pressure equivalent to that of R134a is R32 of each triangular coordinate and each dimethyl ether. The range on the side connecting the classes is preferable, but it is considered that even a mixture derived from the above specified composition range has a vapor pressure slightly higher than that of R134a, which is not a practical problem.

For example, difluoromethane (R32) 5
60% by weight and terra fluorodimethyl ether (E13
4a) A two-component system consisting only of 95% by weight or less is R32
It is considered that if the GWP is low and the flammability of R32 is 30 wt% or less, it can be almost reduced. This R32 is 5-3
The composition range such that 0 wt% and E134a are 70 to 95 wt% is 5 to 15 wt% for R32 and 8 for E134a, which is a composition range for obtaining a vapor pressure equivalent to that of R134a.
Compared to 5 to 95% by weight, the composition ratio of R32 is high,
It shows a vapor pressure slightly higher than that of 34a, and is considered to have a higher refrigerating capacity than R134a. Therefore, a binary system consisting only of difluoromethane (R32) and terrafluorodimethyl ether (E134a) is also useful as an alternative to R134a.

Table 1 shows the ideal refrigerating performance of a two-component system consisting only of R32 and E134a. The conditions are the case where the condensation average temperature is 50 ° C., the evaporation average temperature is −30 ° C., the condenser outlet supercooling degree is 0 deg, and the evaporator outlet superheat degree is 0 deg. As can be seen from (Table 1), the two-component system consisting of 5 to 60% by weight of difluoromethane (R32) and 40 to 95% by weight of telorafluorodimethyl ether (E134a) has a condensing pressure and a condensation pressure as R32 increases. The evaporation pressure is also higher than that of R134a, and thus the refrigerating capacity is significantly larger than that of R134a, but the coefficient of performance is close to that of R134a. In addition, the temperature gradient in the condensation process and the evaporation process is 10 deg or less, and a near azeotropic mixture is formed. Further, R32, which is a composition range for obtaining a vapor pressure equivalent to that of R134a, is 5 to 15% by weight and E13.
The two-component system in which 4a is 85 to 95% by weight exhibits almost the same characteristics as R134a, but rather has a higher refrigerating capacity and a coefficient of performance than R134a. The above-mentioned two-component system in which R32 is 5 to 30% by weight and E134a is 70 to 95% by weight, the composition ratio of R32 increases,
Although it shows a slightly higher vapor pressure than R134a, the coefficient of performance is higher than that of 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).

[0036]

[Table 1]

Similarly, difluoromethane (R32) 5
60% by weight and difluorodimethyl ether (E152
a) A two-component system consisting only of 85% by weight or less is considered flammable, but the GWP of R32 is low and E152
GWP of R152a which is the corresponding ethane-based CFC of a
It is expected that the GWP of E152a will also be low in view of the low value. Therefore, a binary system consisting only of difluoromethane (R32) and difluorodimethyl ether (E152a) is also useful as an alternative to R134a.

Table 2 shows the ideal refrigerating performance of a two-component system consisting only of R32 and E152a. The conditions are the case where the condensation average temperature is 50 ° C., the evaporation average temperature is −30 ° C., the condenser outlet supercooling degree is 0 deg, and the evaporator outlet superheat degree is 0 deg. As can be seen from Table 2, the two-component system consisting only of 15 to 60% by weight of difluoromethane (R32) and 40 to 85% by weight of difluorodimethyl ether (E152a) has a condensing pressure and an evaporating pressure as the composition ratio of R32 increases. It is higher than R134a, and thus the refrigerating capacity is also remarkably larger than R134a, but the coefficient of performance is higher than R134a. Further, the temperature gradient in the condensation process and the evaporation process is a combination that has the largest difference in boiling point in the present invention, so that it becomes a non-azeotropic mixture. By utilizing this temperature gradient in reverse, a Lorenz cycle in which the temperature difference between the heat source fluid and the heat source fluid is close to one another can be obtained (Table 2).
You can expect a higher coefficient of performance.

[0039]

[Table 2]

Further, in the above embodiments, the working fluid is composed of a mixture of difluoromethane and two kinds of ethers. However, the working fluid is composed of tetrafluorodimethyl ether, tetrafluorodimethyl ether and difluorodimethyl ether structural isomers. It is of course possible to constitute the working fluid by a mixture of at least one ether.

[0041]

As is apparent from the above description, the present invention comprises difluoromethane (R32) of 5 to 60% by weight and 2
CFCs and ethers containing two or more selected from fluorinated dimethyl ethers consisting of only carbon atoms, one oxygen atom, one hydrogen atom and one fluorine atom, and a working fluid containing no chlorine in the molecular structure. It is possible to expand the range of selection of the working fluid in which (1) the effect on the stratospheric ozone layer is almost the same as that of R134a, by making the mixture consisting of only one and specifying its composition range. (2) At the operating temperature of a heat pump device such as a refrigerator-freezer, a car cooler, and a large-scale refrigerator, which is approximately −30 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 that of R134a. R as an alternative to R134a
It can also be used with the current equipment using 12. (3) It is expected that such a mixture will be an almost azeotropic non-azeotropic mixture, and especially in a refrigerator / freezer, a Lorenz cycle can be easily constituted, and a higher coefficient of performance can be expected than that of R134a. (4) Since such a mixture is composed only of difluoromethane (R32) and fluorinated dimethyl ethers, it is possible that the influence on global warming can be reduced. (5) By limiting the composition range of difluoromethane (R32) and other fluorinated dimethyl ethers to a non-flammable range, the composition can be used as it is in a normal heat pump device. (6) The two-component system consisting of difluoromethane (R32) and terrafluorodimethylether (E134a) or the two-component system consisting of difluoromethane (R32) and difluorodimethylether (E152a) is GW
It is expected to have a low P and is useful as an alternative to R134a. And so on.

[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 R32, E170, and E143a at a constant temperature and a constant pressure.

FIG. 2 is a triangular coordinate diagram showing the equilibrium state of a working fluid composed of a mixture of three kinds of ethers R32, E170, and E134a at a constant temperature and a constant pressure.

FIG. 3 is a triangular coordinate diagram showing an equilibrium state of a working fluid composed of a mixture of three kinds of ethers R32, E170, and E152a at a constant temperature and a constant pressure.

FIG. 4 is a triangular coordinate diagram showing an equilibrium state of a working fluid composed of a mixture of three kinds of ethers R32, E143a, and E134a at a constant temperature and a constant pressure.

FIG. 5 is a triangular coordinate diagram showing the equilibrium state of a working fluid composed of a mixture of three kinds of ethers R32, E143a, and E152a at a constant temperature and a constant pressure.

FIG. 6 is a triangular coordinate diagram showing the equilibrium state of a working fluid composed of a mixture of three kinds of ethers R32, E134a, 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 the front page (51) Int.Cl. ⁶ Identification number Internal reference number in the agency FI Technical indication location C10M 105: 52 105: 54) C10N 40:30 (72) Inventor Mitsuharu Matsuo 1006 Kadoma, Kadoma, Osaka Prefecture Matsushita Denki Sangyo Co., Ltd.

Claims (4)

[Claims] 1. As a fluorinated dimethyl ether consisting of 5 to 60% by weight of difluoromethane, 2 carbon atoms, 1 oxygen atom, 1 hydrogen atom and 1 fluorine atom, dimethyl ether 95% by weight or less or trifluorodimethyl ether 95% by weight. % Or less or terra fluorodimethyl ether 95% by weight or less or difluorodimethyl ether 8
A dimethyl ether-based mixed working fluid comprising three components containing two kinds selected from 5% by weight or less. 2. A dimethyl ether system comprising 5 to 60% by weight of difluoromethane and two components containing only one kind selected from 95% by weight or less of telorafluorodimethyl ether and 85% by weight or less of difluorodimethylether. Mixed working fluid. 3. A fluorinated dimethyl ether consisting of 5 to 60% by weight of difluoromethane and 2 carbon atoms, 1 oxygen atom, hydrogen atom and fluorine atom. A heat pump device that uses a dimethyl ether-based working fluid. 4. The dimethyl ether-based mixed working fluid according to claim 2, which contains 5 to 60% by weight of difluoromethane and only one kind selected from 95% by weight or less of telorafluorodimethyl ether and 85% by weight or less of difluorodimethylether. The heat pump device used.