JP2001329254A - Mixed refrigerant and refrigeration cycle equipment - Google Patents

Abstract

(57) [Problem] To propose a mixed refrigerant and a refrigeration cycle device with reduced GWP. SOLUTION: Difluoromethane (R32), 1,1
A three-component composition diagram of at least R32, R152a and propane (R290), isobutane (R600a) or butane (R600), which contains at least difluoroethane (R152a) and is represented by triangular coordinates; (The R32 / the hydrocarbon = 80
/ 20 (% by weight)) and (point R1)
a / point a that satisfies the above hydrocarbon = 95/5 (% by weight))
2 and the composition range of the R32 above the line A, and the R32 above the line B which satisfies (the R32 = 40 (% by weight)).
A mixed refrigerant characterized by being within a composition range enclosed by a composition range of

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a mixed refrigerant containing difluoromethane and 1,1-difluoroethane, and
The present invention relates to a refrigeration cycle device such as an air conditioner and a refrigerator using the same.

[0002]

2. Description of the Related Art Conventionally, a refrigeration cycle device such as an air conditioner or a refrigerator is connected to a compressor, if necessary, a four-way valve, a condenser, a throttle device such as a capillary tube or an expansion valve, an evaporator, an accumulator, and the like. Constitute a refrigeration cycle,
Cooling or heating is performed by circulating a cooling medium inside. As the refrigerant in these refrigeration cycle devices, chlorofluorocarbons (hereinafter referred to as ROO or ROO)
Is defined by the US ASHRAE34 standard. However, halogenated hydrocarbons derived from methane or ethane, which are referred to as “○” may be any numbers and / or alphabets, are known.

As the utilization temperature of the refrigerant in air conditioners, air conditioners and the like, the condensation temperature is generally used in the range of substantially 50 ° C., and the evaporation temperature is generally used in the range of substantially 0 ° C. Among them, R22 (chlorodifluoromethane, CHClF ₂ , boiling point- 40.8
° C) is widely used as a refrigerant. In a refrigerator or the like, the use temperature is slightly lower.
(R22 and R115: azeotropic refrigerants of chloropentafluoroethane, boiling point −45.6 ° C.) have been widely used as refrigerants. R22 is a fluorinated hydrocarbon containing chlorine (HCFC refrigerant), and R115, a component of R502, is a fluorinated chlorohydrocarbon containing no hydrogen (CFC refrigerant) and has a stratospheric ozone depleting ability. Regulations on usage and production are determined by the Protocol. In order to have almost no effect on the stratospheric ozone layer, it is necessary that the molecular structure does not contain chlorine, and another possibility is that chlorine-free fluorocarbons ( Alternative refrigerants for HFC refrigerants and alternative refrigerants for hydrocarbons containing no fluorine (HC refrigerants) have been proposed.

[0004] Chlorine-free fluorinated hydrocarbons (HFCs)
As a refrigerant, difluoromethane (CH_TwoF_Two, R3
2, boiling point -51.7 ° C), pentafluoroethane (CF
_Three-CHF_Two, R 125, boiling point -48.1 ° C), 1,1,
1-trifluoroethane (CF _Three-CH_Three, R143a,
Boiling point -47.2 ° C), 1,1,1,2-tetrafluoro
Ethane (CF_Three-CH_TwoF, R134a, boiling point -26.1
C), 1,1-difluoroethane (CHF_Two-CH_Three, R
152a, boiling point-24.0 ° C.)
It is considered as an alternative refrigerant candidate. That is, R3
2, R143a and R152a are weakly flammable as a single refrigerant
R32, R32, R32
Mixing made of non-flammable range consisting of 125, R134a, etc.
R125, R14 as refrigerants and alternative refrigerants to R502
3a, R134a, etc., mixed refrigeration in a nonflammable range
Medium has begun to be adopted. For example, 23% by weight of R3
2,25 wt% R125, 52 wt% R134a
Is a non-azeotropic mixed refrigerant that complies with the US ASHRAE34 standard.
R407C number is assigned in place of R22
50% by weight for package air conditioners and chillers as a medium
R32, 50% by weight of R125 azeotropic cooling
The medium is R410A in the US ASHRAE34 standard.
No. is assigned and room air is used as an alternative refrigerant for R22.
It has begun to be adopted by cons. Where room airco
R410A, package air conditioner and chiller
The reason why R407C is adopted in
Kon is a small-volume mass-produced product with high pressure R410A
Can also be used with ingenuity, packaged air conditioners
R with low pressure than R410A
The reason is that 407C is easier to use, etc.
You. The chiller is a non-azeotropic refrigerant such as R407C.
High efficiency by utilizing the temperature gradient of
Has become.

[0005] The disadvantage of the HFC mixed refrigerant that has been adopted here is that the global warming potential (hereinafter referred to as GWP), which indicates the effect on global warming, which is another global environmental problem, is different from the conventional HCFC refrigerant. Of R22 or more. The 1998 IPCC (Inter)
general panel on cli
According to Mate Change, the Intergovernmental Panel on Climate Change), when the GWP of carbon dioxide (CO ₂ ) is set to 1, the comparison value of the integrated horizontal axis for 100 years is as follows: GWP of R22 is 1900; The GWP of R32 is 880,
GWP of R125 is 3800, GWP of R143a is 5
The GWP of 400 and R134a is 1600, and the GWP of R152a is 190. Therefore, the GWP of R407C mixed with these is 2000, and the GWP of R410A is 2000.
Is estimated to be 2300.

[0006] Therefore, in order to further reduce the effect on global warming, the weak flammability is eliminated as a refrigeration cycle device. Can be reduced to about 1/10 by using.

However, the R32 single refrigerant is R410
There is a disadvantage that the pressure is higher than A, and it is difficult to use it for a package air conditioner even though it can be used for a room air conditioner. In addition, R152a single refrigerant is R410A, R4
The pressure is even lower than that of 07C and R22, and there is a drawback that the refrigerating capacity cannot be ensured with a room air conditioner or a package air conditioner.

[0008]

Therefore, in order to further solve the drawbacks of the pressure and the refrigerating capacity, R32 and R152 are required.
It is conceivable to use a mixed refrigerant consisting of R32 and R15 in Japanese Patent Publication No. 63-12512.
A mixed refrigerant comprising 2a is disclosed.

However, Japanese Patent Publication No. 63-12512 only discloses a combination of a mixed refrigerant consisting of R32 and R152a, but does not clarify a suitable composition range as a substitute refrigerant for R22 or R502.

Further, HFC refrigerants such as R32 and R152a have poor compatibility with synthetic oils such as paraffinic and naphthenic mineral oils and some alkylbenzene oils which have been used as conventional compressor lubricating oils. Lubricating oil discharged together with the refrigerant from the compressor may not return from the low-temperature evaporator to the compressor. As a method for solving this problem, use of a three-component mixed refrigerant obtained by slightly mixing hydrocarbons (HC refrigerant) which are chemically similar to mineral oil or some synthetic oils to a mixed refrigerant composed of R32 and R152a. Can be considered. These hydrocarbons include propane (CH ₃ —CH
₂ -CH _3, R290, boiling point -42.1 ° C.), isobutane _{((CH 3) 2 -CH-} CH 3, R600a, boiling point -11.8
° C.), butane _{(n-C 4 H 8,} R600, boiling point -0.5
° C). Here, in Japanese Patent Application Laid-Open No. 9-510249, propane (R290), isobutane (R600)
a) and butane (R600) are all R32 or R
Although it is supposed to form an azeotropic composition with 152a, the appropriate composition range of a ternary mixed refrigerant obtained by slightly mixing these hydrocarbons with a mixed refrigerant composed of R32 and R152a as an alternative refrigerant to R22 or R502 is as follows. Not revealed.

The present invention has been made in view of the above-mentioned problems, and is intended to clarify an appropriate composition range of the mixed refrigerant composed of R32 and R152a as a substitute refrigerant for R22 and R502.

Further, the present invention clarifies an appropriate composition range of a three-component mixed refrigerant obtained by mixing a small amount of hydrocarbons with a mixed refrigerant composed of R32 and R152a as a substitute refrigerant for R22 and R502.

[0013]

In order to achieve the above object, a first invention (corresponding to claim 1) comprises difluoromethane (R32) and 1,1-difluoroethane (R1).
52a) and the R in triangular coordinates.
In the three-component composition diagram of R32a and R152a and a hydrocarbon which is any of propane (R290), isobutane (R600a) or butane (R600), (R
32 / the hydrocarbon = 80/20 (% by weight) and a point a1 satisfying (the R152a / the hydrocarbon = 95/5).
(Weight%)) R above line A connecting point a2 that satisfies
32. A mixed refrigerant characterized by being within a composition range surrounded by a composition range of 32 and a composition range of R32 which is equal to or more than a line B where (R32 = 40 (% by weight)).

Further, the second invention (corresponding to claim 2)
Is the present invention characterized in that it comprises 40% by weight or more of R32 and 60% by weight or less of R152a.

Further, the third invention (corresponding to claim 3)
Is the present invention as described above, comprising 40% by weight or more of the R32, 12.5% by weight or less of the hydrocarbon, and R152a.

A fourth aspect of the present invention (corresponding to claim 4)
Is a refrigeration cycle apparatus using the mixed refrigerant according to any one of claims 1 to 3.

The mixed refrigerant of the present invention as described above not only can eliminate the influence on the stratospheric ozone layer, but also has the low GWP of R32 and R1 among HFC refrigerants.
52a, and a mixed refrigerant containing hydrocarbons having almost no GWP, the GWP of which is R407C or R4C.
This can be greatly reduced as compared with 10A.

The mixed refrigerant of the present invention comprises R22, R5
02, R407C, and R410A, it is a substitute refrigerant for R22 and R502 and a substitute refrigerant for these substitute refrigerants, R407C and R410A, and has a refrigerating capacity (cooling capacity) and a coefficient of performance. The decrease is alleviated.

Further, the mixed refrigerant containing hydrocarbons of the present invention is soluble in a conventional lubricating oil for a compressor composed of mineral oil or alkylbenzene oil which is close in chemical structure, and is a mixed refrigerant composed of only HFC refrigerant. Thus, there is no need to use ester oil or ether oil. Furthermore, compared to the mixed composition, R
Since more hydrocarbons are dissolved in the lubricating oil than the HFC refrigerant of R32a or R152a, the circulating composition of the hydrocarbons is less than the mixed composition charged. Therefore, in the composition range of the present invention, the weakly flammable Characteristics are maintained.

Further, the mixed refrigerant containing hydrocarbons of the present invention can be treated as a non-azeotropic mixed composition or an azeotropic-like mixed composition having a relatively small temperature gradient in both the condenser and the evaporator of the refrigeration cycle apparatus. .

[0021]

Embodiments of the present invention will be described below with reference to the drawings.

The mixed refrigerant according to the present invention is to limit the mixed composition to a weakly flammable range that can be eliminated as a refrigeration cycle device. Here, R32 and R152a
Are weakly flammable, so that the weakly flammable characteristics are maintained even in the R32 / R152a two-component mixed refrigerant having an arbitrary mixed composition obtained by mixing them. Therefore, a mixed refrigerant consisting of R32 and R152a is added to R29
Even in the case of a ternary mixed refrigerant containing a hydrocarbon selected from 0, R600a, and R600, it is necessary to maintain weakly flammable characteristics.

In the US ASHRAE 34 standard, the property of weak flammability is that the heat of combustion of the mixture is 19,000 kJ / k.
g. Here, the combustion heat of R32 is 9,400 kJ / kg, the combustion heat of R152a is 17,400 kJ / kg, R290, R600a, and R6.
The heat of combustion of 00 is about 50,000 kJ / kg.

In a two-component mixed refrigerant comprising R32 and a hydrocarbon, R32 is 80% by weight or more and hydrocarbons are 20% by weight.
If it is less than 10% by weight, the two-component mixed refrigerant composed of R32 and hydrocarbons almost forms an azeotropic composition. , Can maintain almost flammable characteristics.

Therefore, a two-component mixed refrigerant consisting of R32 and a hydrocarbon has an R.sub.3 having a lower heat of combustion than hydrocarbons.
In the case of using a three-component mixed refrigerant obtained by mixing 152a,
Even if gas-liquid separation occurs in the refrigeration cycle device,
In both gas and liquid phases, almost flammable characteristics can be maintained.

[0026] Further, 2 composed of R152a and hydrocarbon
In the case of the component-based mixed refrigerant, if R152a is 95% by weight or more and hydrocarbons is 5% by weight or less, the two-component type mixed refrigerant composed of R152a and hydrocarbon almost forms an azeotropic composition. Even if gas-liquid fractionation occurs in the inside, almost flammable characteristics can be maintained in both gas-liquid phases. Therefore, 2 consisting of R152a and hydrocarbon
The component-based mixed refrigerant has a lower R than the hydrocarbons in combustion heat.
Even when the refrigerant is a ternary mixed refrigerant mixed with 32, even if gas-liquid fractionation occurs in the refrigeration cycle apparatus, almost weakly flammable characteristics can be maintained in both gas-liquid phases. .

When a mixed refrigerant containing hydrocarbons is used, it is more soluble in conventional lubricating oils for compressors composed of mineral oil and alkylbenzene oil which are close in chemical structure, and is more soluble than R32 or R152a HFC refrigerants. Since many hydrocarbons dissolve in the lubricating oil, the circulation composition of the hydrocarbons is smaller than that of the mixed composition charged, so that the weakly flammable property is maintained in the composition range of the present invention. .

Therefore, if necessary, R290, R600a, R6
In order to maintain the weakly flammable characteristics in the case of a ternary mixed refrigerant containing hydrocarbons selected from any one of R. 00 and R.
And the three-component composition diagram of hydrocarbons, point a1 (R32 /
Hydrocarbon = 80/20% by weight) and point a2 (R152a /
It can be seen that the refrigerant mixture is desirably a mixed refrigerant having a composition range of R32 above the line A connecting (hydrocarbon = 95/5% by weight).

Hereinafter, in (Example 1) to (Example 4), in the three-component composition diagram of R32, R152a and hydrocarbon represented by triangular coordinates in FIG.
It is explained that a mixed refrigerant having a composition range surrounded by a composition range of R32 which is equal to or more than the line B of R32 of wt% is more desirable.

Further, when hydrocarbons are contained in FIG. 1, the intersection of the line B and the line A of 40% by weight of difluoromethane (R32) is R32 / R152a / hydrocarbon = 40 /
47.5 / 12.5 (% by weight), and 1
2.5 weight, so propane (R290),
11. When containing a hydrocarbon selected from any of isobutane (R600a) and butane (R600),
It is also understood that it is desirable that the content be 5% by weight or less.

[0031]

EXAMPLES (Example 1) In Example 1, (Table 1)
FIG. 4 shows the refrigerating performance of a two-component mixed refrigerant composed of R32 and R152a of the present invention, and also shows the characteristics when used as a refrigerant in a refrigeration cycle device. That is, the mixed composition of the two-component mixed refrigerant was changed such that the average condensing temperature was 50 ° C. and the average evaporating temperature was 0 ° C., and compared with R22. The compressor discharge temperature of R22 under this temperature condition is 71.7 ° C.
Further, under these temperature conditions, the compressor discharge temperature of R407C is 66.2 ° C., the temperature gradient of the condenser is 4.5 deg, and the temperature gradient of the evaporator is 4.0 deg. Further, the compressor discharge temperature of R410A under this temperature condition is 71.1.
° C, the condenser temperature gradient was 0.1 deg, and the evaporator temperature gradient was 0.1 deg. The composition of (Table 1) is R32 /
This is a mixture composition randomly selected with a binary mixed refrigerant of R152a. For example, R32 / R152a is 20/8
In the case of 0 (% by weight), there is a drawback that the room air conditioner or the package air conditioner cannot secure the refrigerating capacity because of the large mixture composition of R152a. The refrigeration capacity of the refrigeration cycle apparatus shown in Table 1 shows that R32 / R152a becomes 40/60 as the mixed composition of R32 increases.
(% By weight), it is almost equal to or more than R22, and the coefficient of performance is almost equal to R22. Also, R50
Compared to 2, both the refrigerating capacity and the coefficient of performance are higher. 40
In the range of R32 of not less than% by weight, the temperature gradient of the condenser or the evaporator of the refrigeration cycle apparatus is a relatively large non-azeotropic composition, but is almost the same as R407C.

Accordingly, R32 and R152a of the present invention
Is suitable as a substitute refrigerant for R22 and R502 and a substitute refrigerant for R407C which is a substitute refrigerant for R22 and R502. Also, 40/60% by weight of R3
The GWP of the 2 / R152a mixed refrigerant is 470, and R4
It can be reduced to about 1/4 compared to 07C.

[0033]

[Table 1] (Example 2) In Example 2, the refrigeration performance of the ternary mixed refrigerant composed of R32, R152a and R290 of the present invention is shown with reference to (Table 2), and the refrigerant is used as a refrigerant in a refrigeration cycle device. It shows the characteristics. That is, the mixed composition of the three-component mixed refrigerant was changed such that the average condensing temperature was 50 ° C. and the average evaporating temperature was 0 ° C., and compared with R22. The composition of (Table 2) is
It is a mixed composition randomly selected in the range of R32 of 40% by weight or more and R290 of 20% by weight or less. The refrigeration capacity of the refrigeration cycle apparatus shown in Table 2 exceeds R22 as the mixture composition of R32 increases, and the coefficient of performance is almost equal to R22. In addition, compared to R502, refrigeration capacity,
Exceeds both coefficient of performance. R32, 20 of 40% by weight or more
In the range of R290 of not more than% by weight, the temperature gradient of the condenser or evaporator of the refrigeration cycle apparatus becomes smaller than that of R407C as the mixture composition of R32 increases, and R410A
Become closer to

Accordingly, R32 and R152a of the present invention
And R290, the three-component mixed refrigerant is R22 or R5
02, and R40, these alternative refrigerants
Suitable as an alternative refrigerant to 7C and R410A.

Further, the GWP of the mixed refrigerant in the range of R32 of 40% by weight or more and R290 of 20% by weight or less is smaller than that of R32 / R152a mixed refrigerant having the same composition of R32 by R152a. Can further reduce the size. 40% by weight of R
When R290 is increased on line B of 32, the refrigerating capacity increases, the discharge temperature decreases, and the temperature gradient of the condenser or the evaporator has a maximum value.

R32 / R152a / R290 = 4
Although the composition of 0/40/20 (% by weight) has no problem from the refrigerating performance, it contains more hydrocarbons than the line A determined to maintain the property of weak flammability. This is undesirable from the viewpoint of. Therefore, 40
R32 / R152a / R290 = 40 / which is the intersection of the line B of R32 in weight% and the line A indicating the limit of flammability.
The point of 47.5 / 12.5 (% by weight) is considered to be the upper limit of the content of R290, and the three-component mixed refrigerant composed of R32, R152a, and R290 of the present invention has R32, 12 of 40% by weight or more. Particularly effective effects are obtained with R290 of not more than 0.5% by weight.

[0037]

[Table 2] (Example 3) In Example 3, referring to (Table 3), the refrigeration performance of a ternary mixed refrigerant composed of R32, R152a and R600a of the present invention is shown, and the characteristics when used as a refrigerant in a refrigeration cycle device are shown. It shows. That is, the mixed composition of the three-component mixed refrigerant was changed such that the average condensing temperature was 50 ° C. and the average evaporating temperature was 0 ° C., and compared with R22. The composition of (Table 3) is
40% by weight or more of R32, 20% by weight or less of R600a
Is a mixed composition selected at random in the range. (Table 3)
The refrigerating capacity of the refrigeration cycle apparatus exceeds R22 as the mixture composition of R32 increases, and the coefficient of performance is R22.
Is almost equivalent to

In addition, both the refrigerating capacity and the coefficient of performance are higher than those of R502. In the range of R32a of 40% by weight or more and R600a of 20% by weight or less, the temperature gradient of the condenser or evaporator of the refrigeration cycle device becomes smaller as compared with R407C as the mixture composition of R32 increases, and R410A
Become closer to

Accordingly, R32 and R152a of the present invention
And a three-component mixed refrigerant consisting of R600a are R22 and R5.
02, and R40, these alternative refrigerants
Suitable as an alternative refrigerant to 7C and R410A.

The GWP of the mixed refrigerant in the range of R32a of 40% by weight or more and R600a of 20% by weight or less is smaller than that of the R32 / R152a mixed refrigerant having the same composition of R32 by R152a. Can further reduce the size. 40% by weight
When R600a is increased on the line B of R32, the refrigerating capacity increases, the discharge temperature decreases, and the temperature gradient of the condenser or evaporator slightly increases. Here, R32 / R152a
The composition of / R600a = 40/40/20 (% by weight) has no problem from the refrigerating performance, but contains more hydrocarbons than the line A determined to maintain the weakly flammable property. It is undesirable from the viewpoint of weak flammability. Therefore, R32 / R152, which is the intersection of line B of R32 at 40% by weight and line A indicating the limit of weak flammability.
a / R600a = 40 / 47.5 / 12.5 (% by weight)
Is considered to be the upper limit of the content of R600a, and the three-component mixed refrigerant composed of R32, R152a, and R600a of the present invention has 40% by weight or more of R32 and 12.5% by weight.
Particularly effective effects can be obtained in the following R600a.

[0041]

[Table 3] (Example 4) In Example 4, the refrigeration performance of the three-component mixed refrigerant composed of R32, R152a and R600 of the present invention is shown with reference to (Table 4), and the characteristics when used as a refrigerant in a refrigeration cycle device. It shows. That is, the mixed composition of the three-component mixed refrigerant was changed such that the average condensing temperature was 50 ° C. and the average evaporating temperature was 0 ° C., and compared with R22. The composition of (Table 4) is
This is a mixed composition randomly selected in the range of R32 of 40% by weight or more and R600 of 20% by weight or less. The refrigeration capacity of the refrigeration cycle apparatus shown in Table 4 exceeds R22 as the mixed composition of R32 increases, and the coefficient of performance is almost equal to R22. In addition, compared to R502, refrigeration capacity,
Exceeds both coefficient of performance. R32, 20 of 40% by weight or more
In the range of R600 of less than% by weight, the temperature gradient of the condenser or evaporator of the refrigeration cycle apparatus is smaller than that of R407C as the mixture composition of R32 is increased, and R410A
Become closer to

Accordingly, R32 and R152a of the present invention
And R600 are three-component mixed refrigerants such as R22 and R50.
Alternative refrigerants, and R407, these alternative refrigerants
Suitable as an alternative refrigerant to C and R410A. Further, R32 of 40% by weight or more and R60 of 20% by weight or less.
The GWP of the mixed refrigerant in the range of 0 can be made smaller than the GWP of the R32 / R152a mixed refrigerant having the same weight of the mixed composition of R32 because R152a is further substituted with R600. When R600 is increased on the line B of R32 of 40% by weight, the refrigerating capacity and the discharge temperature decrease, and the temperature gradient of the condenser and the evaporator increases. here,
The composition of R32 / R152a / R600 = 40/40/20 (% by weight) has more hydrocarbons than the line A determined to maintain the weakly flammable property, although there is no problem from the refrigerating performance. This is undesirable from the viewpoint of weak flammability. Therefore, R3, which is the intersection of the line B of R32 of 40% by weight and the line A indicating the limit of weak flammability,
2 / R152a / R600 = 40 / 47.5 / 12.5
(% By weight) is considered to be the upper limit of the content of R600, and the three-component mixed refrigerant composed of R32, R152a, and R600 of the present invention has R32, 12.5% or more of 40% by weight or more.
Particularly effective effects are obtained with R600 of not more than% by weight.

[0043]

[Table 4] FIG. 2 shows the effect of the mixed medium of the present invention.
R32 / R shown in (Example 1) is added to the triangular coordinates of FIG.
152a = 20/80, 40/60, 60/40, 80
/ 20 (% by weight in each case) is referred to as Point A
While plotting as 1, A2, A3, A4,
R32 / R152a / hydrocarbon (any of R290, R600a, R600) shown in (Examples 2 to 4) =
40/50/10, 40/40/20, 60/30/1
0, 80/10/10, 90/5/5, and points satisfying (% by weight) points B1, B2, B3, and B4, respectively.
Plotted as points A2 to A4, points B1, B3, and B
4, a region surrounded by B5 and having a composition range of R32 which is equal to or more than the line A is shown. It can be seen that the present invention is effective within the regions obtained by the above embodiments.

[0044]

As is apparent from the above description, the present invention has the following effects. That is, (1) the influence on the stratospheric ozone layer due to the mixed refrigerant containing R32 and R152a having low GWP among the fluorinated hydrocarbons (HFC refrigerant) and, if necessary, the hydrocarbons (HC refrigerant). Can be eliminated, and the GWP of the mixed refrigerant can be reduced as compared with R407C and R410A. Also, the specified composition range can maintain weakly flammable properties.

(2) A decrease in refrigeration capacity (cooling capacity) and coefficient of performance is alleviated, and the refrigeration performance is almost the same as that of R22 under normal temperature conditions, and has better refrigeration performance than R502.

(3) In the case of a mixed refrigerant containing a hydrocarbon selected from any of propane, isobutane and butane, the mixed refrigerant is dissolved in a conventional lubricating oil for a compressor made of a mineral oil or an alkylbenzene oil which is close in chemical structure. There is.

[Brief description of the drawings]

FIG. 1 is a view showing a desirable composition range of a ternary mixed refrigerant of R32 / R152a / hydrocarbon according to the present invention.

FIG. 2 is a view showing a desirable composition range obtained by an example of a ternary mixed refrigerant of R32 / R152a / hydrocarbon according to the present invention.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shozo Funakura 1006 Kazuma Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. 72) Inventor Fumitoshi Nishiwaki 1006 Kazuma Kadoma, Kadoma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd.

Claims (4)

[Claims] 1. A difluoromethane (R32) comprising:
A three-component composition diagram of at least R32, R152a, and propane (R290), isobutane (R600a) or butane (R600), which contains at least difluoroethane (R152a) and is represented by triangular coordinates; (R32 / hydrocarbon = 80/2
0 (weight%)), and the point a1 satisfying the above (R152a /
A composition range of the R32 above a line A connecting the point a2 satisfying the hydrocarbon = 95/5 (% by weight);
2 = 40 (% by weight)). 2. The mixed refrigerant according to claim 1, comprising 40% by weight or more of the R32 and 60% by weight or less of the R152a. 3. The method according to claim 1, wherein said R32 is at least 40% by weight.
The mixed refrigerant according to claim 1, comprising 5% by weight or less of the hydrocarbon and the R152a. 4. A refrigeration cycle apparatus using the mixed refrigerant according to any one of claims 1 to 3.