CN110699043B - An environmentally friendly mixed refrigerant - Google Patents

Abstract

The invention discloses an environment-friendly mixed refrigerant, which comprises 1-90% of a first component, 1-90% of a second component, 1-90% of a third component and 1-97% of a fourth component by mass percentage; wherein: the first component is trifluoroiodomethane, the second component is at least one of 1,1,1, 2-tetrafluoroethane and pentafluoroethane, the third component is at least one of trans-1, 3,3, 3-tetrafluoropropene, 2,3,3, 3-tetrafluoropropene and difluoromethane, and the fourth component is at least one of 1, 1-difluoroethane, monofluoroethane, propylene, propane, dimethyl ether and isobutane. The GWP value of the mixed refrigerant provided by the invention is greatly reduced relative to R404A, ODP is 0, and the environmental performance is superior to R404A.

Description

An environmentally friendly mixed refrigerant

technical field

The invention relates to a refrigeration working medium, in particular to an environment-friendly mixed refrigeration working medium.

Background technique

At present, with the global warming and the deterioration of the ecological environment in recent years, the international community has formulated a series of laws and regulations to limit the use of high global warming potential (GWP) refrigerants, and to replace high GWP refrigerants Higher requirements have been put forward, requiring new refrigerants to have zero ozone depleting potential (ODP), and the lowest possible GWP value. The Kigali Amendment to the Montreal Protocol passed in 2016 formulated a more stringent reduction plan for refrigerants with high GWP values. China, as a signatory to the contract, will achieve a target of 80% reduction in CO2 equivalents by 2045. Therefore, research and development of environmentally friendly refrigerants with low GWP value is imminent. Due to the contradiction between the environmental protection characteristics, explosion characteristics and thermodynamic properties of refrigerants, pure working fluids often cannot meet the current needs. Mixed working fluids can balance the physical properties of refrigerants. Its characteristics have attracted great attention, but a more perfect refrigerant alternative has not yet been found.

In the field of refrigeration and refrigeration, the more commonly used refrigerants are R404A and R507A, but both of them have high GWP values (GWP values are as high as 4000). Although R455A, R457A and R459B meet the requirement that the GWP value is less than 150, they are all weakly flammable (A2L) mixed refrigerants, and the filling capacity cannot exceed 1.2KG, so they can only be used in small equipment such as refrigerators and freezers. It cannot be used in ordinary cold storage, refrigerated transport vehicles, refrigerated containers and other equipment. Although R448A and R449A are non-flammable refrigerants (A1 grade) as substitutes for R404A/R507A, their GWP is also as high as 1300, and the cooling performance is lower than that of R404A.

To sum up, how to overcome the deficiencies of the existing technology and find a refrigerant with low GWP value and good thermodynamic performance has become an urgent problem to be solved.

SUMMARY OF THE INVENTION

In order to solve the defects existing in the prior art, the present invention proposes an environment-friendly mixed refrigeration working fluid, the mixed working fluid has a lower GWP value and a zero ODP value, and can obtain better thermodynamic performance parameters and good environmental performance. Can be used to replace R404A and R134a refrigerants.

The technical solution adopted by the present invention to solve the technical problems existing in the known technology is: an environment-friendly mixed refrigerant, in terms of mass percentage, comprising 1%-90% of the first component, 1%-90% of the first component The second component, 1%-90% of the third component and 1%-97% of the fourth component; wherein: the first component is trifluoroiodomethane, and the second component is 1, At least one of 1,1,2-tetrafluoroethane and pentafluoroethane, the third component is trans-1,3,3,3-tetrafluoropropene, 2,3,3,3 - at least one of tetrafluoropropene and difluoromethane, the fourth component is at least one of 1,1-difluoroethane, monofluoroethane, propylene, propane, dimethyl ether and isobutane kind.

Further, in terms of mass percentage, it comprises 50%-68% of the first component, 9%-11% of the second component, 18%-32% of the third component and 5%-10% of the first component Four components.

Further, in terms of mass percentage, it includes 50% of the first component, 11% of the second component, 29% of the third component and 10% of the fourth component.

Further, in terms of mass percentage, it includes 52% of the first component, 11% of the second component, 27% of the third component and 10% of the fourth component.

Further, in terms of mass percentage, it includes 67% of the first component, 10% of the second component, 18% of the third component and 5% of the fourth component.

Further, in terms of mass percentage, it includes 1% of the first component, 34.5% of the second component, 62% of the third component and 2.5% of the fourth component.

Further, in terms of mass percentage, it includes 5% of the first component, 35% of the second component, 56% of the third component and 4% of the fourth component.

Further, in terms of mass percentage, it includes 14% of the first component, 10% of the second component, 66% of the third component and 10% of the fourth component.

Further, in terms of mass percentage, it includes 1% of the first component, 40% of the second component, 58% of the third component and 1% of the fourth component.

Further, the second component comprises 70%-90% of 1,1,1,2-tetrafluoroethane and 10%-30% of pentafluoroethane by mass percentage.

The advantages and positive effects of the present invention are as follows: the mixed refrigeration working fluid provided by the present invention has a greatly reduced GWP value compared to R404A, ODP is 0, and the environmental performance is better than that of R404A;

The mixed refrigeration working fluid provided by the invention can reduce the flammability of the refrigerant, is a weakly flammable or non-flammable refrigerant, and has better safety performance;

The refrigeration coefficient of the mixed refrigeration working fluid provided by the invention is not lower than R404A, and has higher system performance.

Detailed ways

In order to be able to further understand the content of the invention, features and effects of the present invention, the following examples are hereby listed and described in detail as follows:

An environmentally friendly mixed refrigerant, in terms of mass percentage, comprising 1%-90% of the first component, 1%-90% of the second component, 1%-90% of the third component and 1% -97% of the fourth component; wherein: the first component is trifluoroiodomethane, and the second component is at least one of 1,1,1,2-tetrafluoroethane and pentafluoroethane One, the third component is at least one of trans-1,3,3,3-tetrafluoropropene, 2,3,3,3-tetrafluoropropene and difluoromethane, the fourth The component is at least one of 1,1-difluoroethane, monofluoroethane, propylene, propane, dimethyl ether and isobutane.

That is, if the total mass of the mixed refrigerant after mixing is X; then multiply the mass of X by 1%-90% of the first component; the mass of X multiplied by the second component of 1%-90%; The third component is X multiplied by 1%-90%; the mass is X multiplied by 1%-97% of the fourth component; these four components are physically mixed evenly in the liquid phase. The following expressions follow in this way.

The percentage of each component refers to the proportion of the mass of the component in the total mass of the mixed refrigerant.

Preferably, by mass percentage, it comprises 50%-68% of the first component, 9%-11% of the second component, 18%-32% of the third component and 5%-10% of the first component Four components.

Preferably, it comprises 50% of the first component, 11% of the second component, 29% of the third component and 10% of the fourth component in mass percent.

Preferably, in mass percent, it comprises 52% of the first component, 11% of the second component, 27% of the third component and 10% of the fourth component.

Preferably, it comprises 67% of the first component, 10% of the second component, 18% of the third component and 5% of the fourth component in mass percent.

Preferably, it comprises 1% of the first component, 34.5% of the second component, 62% of the third component and 2.5% of the fourth component in mass percent.

Preferably, in mass percent, it comprises 5% of the first component, 35% of the second component, 56% of the third component and 4% of the fourth component.

Preferably, it comprises 14% of the first component, 10% of the second component, 66% of the third component and 10% of the fourth component in mass percent.

Preferably, it comprises 1% of the first component, 40% of the second component, 58% of the third component and 1% of the fourth component in mass percent.

Preferably, the second component comprises 70%-90% of 1,1,1,2-tetrafluoroethane and 10%-30% of pentafluoroethane by mass percentage. That is, the second component includes 1,1,1,2-tetrafluoroethane and pentafluoroethane, wherein the mass of 1,1,1,2-tetrafluoroethane is 70% of the total mass of the second component -90%; the mass of pentafluoroethane is 10%-30% of the total mass of the second component.

The environment-friendly mixed refrigeration working fluid provided by the present invention is prepared by mixing trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), pentafluoroethane (R125), trans- -1,3,3,3-tetrafluoropropene (R1234zeE), 2,3,3,3-tetrafluoropropene (R1234yf), difluoromethane (R32), 1,1-difluoroethane (R152a), Monofluoroethane (R161), propylene (R1270), propane (R290), dimethyl ether (RE170) and isobutane (R600a) are divided into four groups, and one component or several components are taken out from each group; The four groups are physically mixed uniformly in the liquid phase according to the corresponding proportions. Conventional physical mixing methods can also be used to mix the components of the four groups uniformly according to the corresponding proportions.

Among them, trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a) and pentafluoroethane (R125) have flame retardancy and can be used as flame retardants for other flammable refrigerants. By adjusting the addition amount of R13I1, R134a and R125, an environmentally friendly mixed refrigerant with higher safety performance can be obtained. The basic physical parameters of each component are shown in Table 1.

Table 1: Basic physical parameters of each component

In order to make those skilled in the art better understand the application solution of the present invention, the technical solution will be clearly and completely described below with reference to the specific embodiments. The described embodiments are only some of the embodiments in the application solution of the present invention. Not all embodiments, based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art based on the application embodiments of the present invention without making creative work, shall belong to the scope of protection of this application, A number of specific examples are given below, wherein the proportioning ratio of each component is by mass, assuming that the mixed refrigerant refrigerant after mixing is 100 parts by mass, then the proportioning ratio of each component in the following embodiments , represents the mass fraction of each component when the total mass of the mixed refrigerant is 100 parts, which is equivalent to the mass percentage of each component in the total mass of the mixed refrigerant.

For example, four components, component A, component B, component C, and component D, are mixed in the mass percentage of a:b:c:d, where a+b+c+d=100, indicating the mixed mixture Assuming that the refrigerant is 100 parts by mass, the mass of component A is a part, the mass of component B is b parts, the mass of component C is c parts, and the mass of component D is d parts; equivalent to : The mass percentage of component A to the total mass of the mixed refrigerant is a%, the mass of component B to the total mass of the mixed refrigerant is b%, and the mass of component C to the total mixed refrigerant The mass percentage of the mass is c%, and the mass percentage of the mass of the component D to the total mass of the mixed refrigerant is d%. And so on.

Example 1:

Trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), trans-1,3,3,3-tetrafluoropropene (R1234zeE), 1,1-difluoroethane The four components of alkane (R152a) are uniformly mixed physically in the liquid phase according to the mass percentage of 68:9:18:5 to obtain an environmentally friendly mixed refrigerant.

That is, if the mass of the mixed refrigerant after mixing is X; then the mass is X multiplied by 68% trifluoroiodomethane (R13I1); the mass is X multiplied by 9% of 1,1,1,2-tetrafluoromethane Ethane (R134a); mass X times 18% trans-1,3,3,3-tetrafluoropropene (R1234zeE); mass X times 5% 1,1-difluoroethane (R152a ); these four components are physically mixed evenly in the liquid phase. The following expressions follow in this way.

Example 2:

Trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), trans-1,3,3,3-tetrafluoropropene (R1234zeE), monofluoroethane (R161) The four components are physically mixed uniformly in the liquid phase according to the mass percentage of 50:11:29:10 to obtain an environmentally friendly mixed refrigerant.

Example 3:

The four groups of trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), trans-1,3,3,3-tetrafluoropropene (R1234zeE) and propylene (R1270) According to the mass percentage of 52:11:27:10, the mixture is physically mixed evenly in the liquid phase to obtain an environmentally friendly mixed refrigerant.

Example 4:

Trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), trans-1,3,3,3-tetrafluoropropene (R1234zeE), propane (R290) four groups According to the mass percentage of 50:11:29:10, the mixture is physically mixed evenly in the liquid phase to obtain an environmentally friendly mixed refrigerant.

Example 5:

Trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), trans-1,3,3,3-tetrafluoropropene (R1234zeE), dimethyl ether (RE170) tetra The components are physically mixed uniformly in the liquid phase according to the mass percentage of 68:9:18:5 to obtain an environmentally friendly mixed refrigerant.

Example 6:

Trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), trans-1,3,3,3-tetrafluoropropene (R1234zeE), isobutane (R600a) four The components are physically mixed uniformly in the liquid phase according to the mass percentage of 14:8:68:10 to obtain an environmentally friendly mixed refrigerant.

Example 7:

The four components of trifluoroiodomethane (R13I1), pentafluoroethane (R125), trans-1,3,3,3-tetrafluoropropene (R1234zeE), 1,1-difluoroethane (R152a) According to the mass percentage of 51:11:32:6, the mixture is physically mixed evenly in the liquid phase state to obtain an environmentally friendly mixed refrigerant.

Example 8:

The four components of trifluoroiodomethane (R13I1), pentafluoroethane (R125), trans-1,3,3,3-tetrafluoropropene (R1234zeE), and monofluoroethane (R161) were 50:11 : 29: 10 mass percentage, the physical mixing is uniform in the liquid phase, and an environmentally friendly mixed refrigerant is obtained.

Example 9:

The four components of trifluoroiodomethane (R13I1), pentafluoroethane (R125), trans-1,3,3,3-tetrafluoropropene (R1234zeE) and propylene (R1270) were prepared according to 52:11:27: 10 mass percent, physically mixed evenly in the liquid phase, to obtain an environmentally friendly mixed refrigerant.

Example 10:

The four components of trifluoroiodomethane (R13I1), pentafluoroethane (R125), trans-1,3,3,3-tetrafluoropropene (R1234zeE) and propane (R290) were prepared according to 50:11:29: 10 mass percent, physically mixed evenly in the liquid phase, to obtain an environmentally friendly mixed refrigerant.

Example 11:

The four components of trifluoroiodomethane (R13I1), pentafluoroethane (R125), trans-1,3,3,3-tetrafluoropropene (R1234zeE) and dimethyl ether (RE170) are in a ratio of 68:9: The mass percentage of 18:5 is uniformly mixed physically in the liquid phase, and an environmentally friendly mixed refrigerant is obtained.

Example 12:

The four components of trifluoroiodomethane (R13I1), pentafluoroethane (R125), trans-1,3,3,3-tetrafluoropropene (R1234zeE) and isobutane (R600a) were 14:8: The mass percentage of 68:10 is physically mixed evenly in the liquid phase, and an environmentally friendly mixed refrigerant is obtained.

Example 13:

Trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), pentafluoroethane (R125), trans-1,3,3,3-tetrafluoropropene (R1234zeE) , 1,1-difluoroethane (R152a) four components according to the mass percentage of 67:7:3:18:5, in the liquid phase state, the physical mixing is uniform, and an environmentally friendly mixed refrigerant is obtained.

Example 14:

Trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), pentafluoroethane (R125), trans-1,3,3,3-tetrafluoropropene (R1234zeE) The four components of monofluoroethane (R161) are uniformly mixed physically in the liquid phase according to the mass percentage of 47:9:4:30:10 to obtain an environmentally friendly mixed refrigerant.

Example 15:

Trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), pentafluoroethane (R125), trans-1,3,3,3-tetrafluoropropene (R1234zeE) The four components of propylene (R1270) are uniformly mixed physically in the liquid phase according to the mass percentage of 50:9:1:30:10 to obtain an environmentally friendly mixed refrigerant.

Example 16:

Trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), pentafluoroethane (R125), trans-1,3,3,3-tetrafluoropropene (R1234zeE) , propane (R290) four components according to the mass percentage of 50:9:1:30:10, in the liquid phase state, the physical mixing is uniform, to obtain an environmentally friendly mixed refrigeration working fluid.

Example 17:

Trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), pentafluoroethane (R125), trans-1,3,3,3-tetrafluoropropene (R1234zeE) The four components of dimethyl ether (RE170) are uniformly mixed physically in the liquid phase according to the mass percentage of 66:9:2:18:5, and an environmentally friendly mixed refrigerant is obtained.

Example 18:

Trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), pentafluoroethane (R125), trans-1,3,3,3-tetrafluoropropene (R1234zeE) , isobutane (R600a) four components according to the mass percentage of 14:8:2:66:10, in the liquid phase state, the physical mixing is uniform, and an environmentally friendly mixed refrigeration working fluid is obtained.

Example 19:

Trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), 2,3,3,3-tetrafluoropropene (R1234yf), 1,1-difluoroethane (R152a) ) The four components are physically mixed uniformly in the liquid phase according to the mass percentage of 68:9:18:5 to obtain an environmentally friendly mixed refrigerant.

Example 20:

The four components of trifluoroiodomethane (R13I1), pentafluoroethane (R125), 2,3,3,3-tetrafluoropropene (R1234yf), 1,1-difluoroethane (R152a) were prepared according to 51: The mass percentage of 11:32:6 is physically mixed evenly in the liquid phase, and an environmentally friendly mixed refrigerant is obtained.

Example 21:

The trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), pentafluoroethane (R125), 2,3,3,3-tetrafluoropropene (R1234yf), 1, The four components of 1-difluoroethane (R152a) are physically mixed uniformly in the liquid phase according to the mass percentage of 67:7:3:18:5, thereby obtaining an environment-friendly mixed refrigerant.

Example 22:

The four components of trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), difluoromethane (R32), 1,1-difluoroethane (R152a) were divided into 68: The mass percentage of 9:18:5 is physically mixed evenly in the liquid phase, and an environmentally friendly mixed refrigerant is obtained.

Example 23:

The four components of trifluoroiodomethane (R13I1), pentafluoroethane (R125), difluoromethane (R32), 1,1-difluoroethane (R152a) are in a mass percentage of 51:11:32:6 , in the liquid phase state, the physical mixing is uniform, and an environmentally friendly mixed refrigerant is obtained.

Example 24:

Trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), pentafluoroethane (R125), difluoromethane (R32), 1,1-difluoroethane (R152a) ), the four components are physically mixed uniformly in the liquid phase according to the mass percentage of 67:7:3:18:5 to obtain an environmentally friendly mixed refrigerant.

Example 25:

Trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), trans-1,3,3,3-tetrafluoropropene (R1234zeE), 1,1-difluoroethane The four components of alkane (R152a) are uniformly mixed physically in the liquid phase according to the mass percentage of 90:1:1:8 to obtain an environmentally friendly mixed refrigerant.

Example 26:

Trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), trans-1,3,3,3-tetrafluoropropene (R1234zeE), 1,1-difluoroethane The four components of alkane (R152a) are uniformly mixed physically in the liquid phase according to the mass percentage of 1:1:90:8 to obtain an environmentally friendly mixed refrigerant.

Example 27:

Trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), trans-1,3,3,3-tetrafluoropropene (R1234zeE), 1,1-difluoroethane The four components of alkane (R152a) are uniformly mixed physically in the liquid phase according to the mass percentage of 1:90:1:8 to obtain an environmentally friendly mixed refrigerant.

Example 28:

Trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), trans-1,3,3,3-tetrafluoropropene (R1234zeE), 1,1-difluoroethane The four components of alkane (R152a) are uniformly mixed physically in the liquid phase according to the mass percentage of 1:1:1:97 to obtain an environmentally friendly mixed refrigerant.

Example 29:

Trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), trans-1,3,3,3-tetrafluoropropene (R1234zeE), 1,1-difluoroethane The four components of alkane (R152a) are uniformly mixed physically in the liquid phase according to the mass percentage of 1:40:58:1 to obtain an environmentally friendly mixed refrigerant.

Example 30:

Trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), trans-1,3,3,3-tetrafluoropropene (R1234zeE), 1,1-difluoroethane The four components of alkane (R152a) are physically mixed uniformly in the liquid phase according to the mass percentage of 5:35:56:4 to obtain an environment-friendly mixed refrigerant.

Example 31:

Trifluoroiodomethane (R13I1), 1,1,1,2-tetrafluoroethane (R134a), trans-1,3,3,3-tetrafluoropropene (R1234zeE), 1,1-difluoroethane The four components of alkane (R152a) are uniformly mixed physically in the liquid phase according to the mass percentage of 1:34.5:62:2.5 to obtain an environmentally friendly mixed refrigerant.

The basic parameters such as the environmental performance and temperature glide (under standard atmospheric pressure of 101.325 kPa) of the above embodiment and R404A refrigerant are recorded in Table 2.

Table 2: Basic physical parameters of mixed refrigerant and R404A

The thermal parameters (exhaust pressure and temperature) and relative system performance (the relative volume cooling capacity and relative efficiency COP of each embodiment relative to R404A) are recorded in Table 3.

Table 3: Performance comparison results of mixed refrigerant and R404A

In Table 3 above, A1* is the experimentally measured or predicted value; the safety of the mixed refrigerant satisfies the A1 level.

It can be seen from Table 2 that the GWP value of the mixed refrigerant provided by the present invention is much lower than that of R404A, and the environmental performance is better, among which the GWP of Examples 1-6, Example 19, Example 25, Example 26 and Example 28 All are less than 150, which meets the requirements of current international laws and regulations. The temperature glide of Example 1, Example 5, Example 19 and Example 26-29 are all less than 1 °C, which can reduce the temperature glide of refrigerant during system operation. adverse effects.

Under the refrigeration conditions of evaporation temperature of -23°C, condensation temperature of 43°C, superheat degree of 12°C, subcooling degree of 5°C, and comprehensive compressor efficiency of 0.8, the thermal parameters of the above embodiment and R404A (exhaust gas) Table 3 shows the comparison results of relative system performance (relative volumetric cooling capacity and relative efficiency COP of each embodiment relative to R404A).

It can be seen from Table 3 that the performance of the mixed refrigerant provided by the present invention is better than that of R404A under refrigeration conditions, and the COP is increased by 5% to 15% in different embodiments. The cooling capacity is lower than that of R404A refrigerant, but it can basically reach about 60% of R404A, and the exhaust temperature is basically the same as that of R404A. Except for Example 23, the exhaust pressure is lower than that of R404A, which can be directly used for the replacement of R404A refrigerant.

The above-mentioned embodiments are only used to illustrate the technical idea and characteristics of the present invention, and the purpose is to enable those skilled in the art to understand the content of the present invention and implement them accordingly, and the present invention cannot be limited only by the present embodiment. The patent scope, that is, all equivalent changes or modifications made to the spirit disclosed in the present invention, still fall within the patent scope of the present invention.

Claims (10)

1. An environment-friendly mixed refrigerant is characterized by comprising 1-90% of a first component, 1-90% of a second component, 1-90% of a third component and 1-8% of a fourth component by mass percentage; wherein: the first component is trifluoroiodomethane, the second component is 1,1,1, 2-tetrafluoroethane, the third component is trans-1, 3,3, 3-tetrafluoropropene, and the fourth component is 1, 1-difluoroethane.

2. The environment-friendly mixed refrigerant according to claim 1, which comprises, by mass, 5% to 90% of trifluoroiodomethane, 1% to 35% of 1,1,1, 2-tetrafluoroethane, 1% to 56% of trans-1, 3,3, 3-tetrafluoropropene, and 4% to 8% of 1, 1-difluoroethane.

3. The environment-friendly mixed refrigerant according to claim 1, which comprises, by mass, 5% to 68% of trifluoroiodomethane, 9% to 35% of 1,1,1, 2-tetrafluoroethane, 18% to 56% of trans-1, 3,3, 3-tetrafluoropropene, and 4% to 5% of 1, 1-difluoroethane.

4. An environmentally friendly mixed refrigerant according to claim 3 which comprises, in mass percent, 68% trifluoroiodomethane, 9% 1,1,1, 2-tetrafluoroethane, 18% trans-1, 3,3, 3-tetrafluoropropene and 5% 1, 1-difluoroethane.

5. An environmentally friendly mixed refrigerant according to claim 3 which comprises, in mass percent, 5% trifluoroiodomethane, 35% 1,1,1, 2-tetrafluoroethane, 56% trans-1, 3,3, 3-tetrafluoropropene and 4% 1, 1-difluoroethane.

6. The environment-friendly mixed refrigerant according to claim 1, which comprises 68-90% of trifluoroiodomethane, 1-9% of 1,1,1, 2-tetrafluoroethane, 1-18% of trans-1, 3,3, 3-tetrafluoropropene and 5-8% of 1, 1-difluoroethane by mass percentage.

7. An environment-friendly mixed refrigerant is characterized by comprising 68% of trifluoroiodomethane, 9% of 1,1,1, 2-tetrafluoroethane, 18% of trans-1, 3,3, 3-tetrafluoropropene and 5% of dimethyl ether in percentage by mass.

8. An environment-friendly mixed refrigerant is characterized by comprising 68% of trifluoroiodomethane, 9% of 1,1,1, 2-tetrafluoroethane, 18% of 2,3,3, 3-tetrafluoropropene and 5% of 1, 1-difluoroethane by mass percentage.

9. An environment-friendly mixed refrigerant is characterized by comprising 67 mass percent of trifluoroiodomethane, 7 mass percent of 1,1,1, 2-tetrafluoroethane, 3 mass percent of pentafluoroethane, 18 mass percent of trans-1, 3,3, 3-tetrafluoropropene and 5 mass percent of 1, 1-difluoroethane.

10. An environment-friendly mixed refrigerant is characterized by comprising 67 mass percent of trifluoroiodomethane, 7 mass percent of 1,1,1, 2-tetrafluoroethane, 3 mass percent of pentafluoroethane, 18 mass percent of 2,3,3, 3-tetrafluoropropene and 5 mass percent of 1, 1-difluoroethane.