Environment-friendly insulating gas as well as preparation method and application thereof

Abstract

The invention discloses environment-friendly insulating gas as well as a preparation method and application thereof, and relates to the technical field of insulation. The environment-friendly insulating gas provided by the invention comprises a component A and a component B, the component A is perfluorodimethyl sulfide, and the component B is any one of 1, 1, 1, 2-tetrafluoroethane and trans-1, 3, 3, 3-tetrafluoropropene; the component A and the component B can form an insulating gas composition similar to a single gas in macroscopic property, so that the insulating gas composition has a lower liquefaction temperature of-24 to-64 DEG C, the insulating strength is more than 0.97 times that of the existing insulating gas SF6, the GWP value is only 2-1140, and the insulating gas composition has a wide application prospect of perfectly replacing SF6.

Description

Technical Field

[0001] The present invention relates to the field of insulation technology, and in particular to an environmentally friendly insulating gas and a preparation method and application thereof. Background Art

[0002] Sulfur hexafluoride (SF6) is the most widely used insulating and arc-extinguishing medium in the power industry. However, SF6 has an extremely high global warming potential (GWP) of up to 23,900, which seriously affects the environment. Therefore, finding an environmentally friendly and high-performance SF6 alternative gas is a key issue that needs to be urgently addressed in the field of high-voltage electrical equipment.

[0003] At present, the mainstream solution for replacing sulfur hexafluoride is to use a mixture of fluorinated nitrile (PFN) and fluorinated ketone (PFK) with a buffer gas for insulation and arc extinguishing, such as heptafluoroisobutyronitrile C4-PFN ((CF3)2CFCN), perfluoropentaneketone C5-PFK (C5F 10 O), etc. These gases have high dielectric strength, and their GWP values ​​are much lower than SF6, they are non-destructive to the ozone layer and are environmentally friendly; however, due to the high boiling point of these gases, they need to be mixed with a large amount of buffer gas CO2, N2 or dry air, which limits their further application. For example, although the dielectric strength of perfluoropentanone is more than twice that of SF6 gas, and its GWP value is about 1, its liquefaction temperature at standard atmospheric pressure is about 26.5°C, and it needs to be mixed with a buffer gas with a low liquefaction temperature such as air and CO2 to avoid liquefaction during use, and the addition of buffer gas may affect the dielectric strength, heat dissipation performance and other characteristics of the gas composition. Therefore, there is still a need to find a gas that can perfectly replace sulfur hexafluoride, so that it has sufficient dielectric strength, a lower GWP value and a lower liquefaction temperature. Summary of the invention

[0004] In order to solve the shortcomings of the prior art, the present invention provides an environmentally friendly insulating gas, including component A and component B, component A is perfluoromethyl sulfide, and component B is any one of 1,1,1,2-tetrafluoroethane and trans-1,3,3,3-tetrafluoropropylene; components A and B can form an insulating gas composition with a lower liquefaction temperature and macroscopic properties similar to a single gas, and the obtained insulating gas has high insulation strength and low GWP value, and has the application prospect of perfectly replacing sulfur hexafluoride.

[0005] Another object of the present invention is to provide a method for preparing environmentally friendly insulating gas.

[0006] Another object of the present invention is to provide an application of environmentally friendly insulating gas.

[0007] The above-mentioned purpose of the present invention is achieved through the following technical solutions:

[0008] An environmentally friendly insulating gas, comprising component A and component B, wherein component A comprises perfluoromethyl sulfide; and component B is any one of 1,1,1,2-tetrafluoroethane and trans-1,3,3,3-tetrafluoropropylene;

[0009] When the component B is 1,1,1,2-tetrafluoroethane, the environmentally friendly insulating gas includes the following components calculated by mass: 24.6 to 75.5 parts of component A and 24.5 to 76.4 parts of component B;

[0010] When the component B is trans-1,3,3,3-tetrafluoropropylene, the environmentally friendly insulating gas includes the following components calculated by mass: 9.4 to 48.5 parts of component A and 51.5 to 90.6 parts of component B.

[0011] The components A and B used in the present invention are both substances with low greenhouse effect potential (GWP value): wherein, component A is perfluoromethyl sulfide, the dielectric strength is 1.7 times that of SF6, the atmospheric life is short, the toxicity is low, the GWP value is only 8, and the liquefaction temperature is -20°C; component B is at least one of 1,1,1,2-tetrafluoroethane and trans-1,3,3,3-tetrafluoropropylene, wherein, the dielectric strength of 1,1,1,2-tetrafluoroethane is 0.6 times that of SF6, it is non-toxic, the GWP value is 1360, and the liquefaction temperature is -26°C; the dielectric strength of trans-1,3,3,3-tetrafluoropropylene is 0.65 times that of SF6, it is non-toxic, the atmospheric life is also short, the GWP value is 6, and the liquefaction temperature is -19°C. It can be seen that the GWP values ​​of components A to B selected in the present invention are all much lower than the GWP value of SF6 (23900).

[0012] Since the GWP values ​​of each component are low, the insulating gas in the present invention has a low GWP value, which is beneficial to environmental protection. The environmentally friendly insulating gas obtained by mixing at least one of 1,1,1,2-tetrafluoroethane and trans-1,3,3,3-tetrafluoropropylene with perfluoromethyl sulfide is similar to the pure substance gas in macroscopic properties, and therefore has a lower liquefaction temperature. On this basis, the environmentally friendly insulating gas of the present invention also satisfies the following formula (I):

[0013] Er_ 环保绝缘气体 >Er_ 组分A ×x1+Er_ 组分B ×x2(I)

[0014] In the formula, Er_ 环保绝缘气体 is the insulation strength of environmentally friendly insulating gas relative to SF6; Er_ 组分A is the dielectric strength of gas component A relative to SF6; Er_ 组分Bis the insulation strength of gas component B relative to SF6; x1 is the mass proportion of gas component A; x2 is the mass proportion of gas component B. That is, in the environmentally friendly insulating gas provided by the present invention, there is a synergistic effect between components A and B, and the environmentally friendly insulating gas obtained by mixing the two components has a higher insulation strength than the sum of the insulation strengths of the two components. Based on excellent insulation strength, lower GWP value and lower liquefaction temperature, the environmentally friendly insulating gas provided by the present invention can fully replace sulfur hexafluoride and has a wide range of application prospects in the fields of insulation and arc extinguishing.

[0015] It should be noted that in order to ensure that the gas mixture obtained in the present invention has sufficient insulation strength, lower GWP and liquefaction temperature, the mass ratio between components A and B needs to be controlled.

[0016] Preferably, when the component B is 1,1,1,2-tetrafluoroethane, the environmentally friendly insulating gas includes the following components calculated by mass: 70.5 to 75.5 parts of component A and 24.5 to 29.5 parts of component B.

[0017] Preferably, when the component B is trans-1,3,3,3-tetrafluoropropylene, the environmentally friendly insulating gas includes the following components calculated by mass: 45.5 to 48.5 parts of component A and 51.5 to 54.5 parts of component B.

[0018] The environmentally friendly insulating gas whose mass fractions of each component satisfy the above relationship has a lower GWP value.

[0019] Preferably, the above-mentioned environmentally friendly insulating gas also includes component C, and the component C includes at least one of nitrogen, oxygen, air and carbon dioxide.

[0020] The above-mentioned component C is a diluent gas, such as nitrogen, oxygen, air or carbon dioxide, which are all low greenhouse gas, among which the GWP values ​​of nitrogen, oxygen and air are about 0, and the GWP value of carbon dioxide is 1. The purpose of adding component C is: on the one hand, it can further reduce the liquefaction temperature of the mixed gas to meet the application requirements of insulation equipment in cold northern regions; on the other hand, it can appropriately reduce the amount of insulation gas used to reduce the amount of insulation gas used, thereby reducing the maintenance cost of insulation equipment.

[0021] More preferably, when the component B is 1,1,1,2-tetrafluoroethane, the environmentally friendly insulating gas includes the following components calculated by mass:

[0022] 24.6-75.5 parts of component A, 24.5-76.4 parts of component B, 0-28 parts of component C.

[0023] More preferably, when the component B is trans-1,3,3,3-tetrafluoropropene, the environmentally friendly insulating gas includes the following components calculated by mass:

[0024] 9.4 to 48.5 parts of component A, 51.5 to 90.6 parts of component B, 0 to 28 parts of component C.

[0025] In a specific embodiment of the present invention, the insulation strength of the environmentally friendly insulating gas measured under the condition of an inter-electrode spacing of 0.1 inches is 0.97 to 1.83 times that of SF6.

[0026] In a specific embodiment of the present invention, the liquefaction temperature of the environmentally friendly insulating gas is -24 to -64°C.

[0027] In a specific embodiment of the present invention, the greenhouse effect potential of the environmentally friendly insulating gas is 2-1140.

[0028] The present invention also protects a method for preparing the above-mentioned environmentally friendly insulating gas, which comprises the following steps: mixing the components at a temperature of -30 to -50°C and vaporizing them to obtain the environmentally friendly insulating gas.

[0029] In a specific embodiment of the present invention, the vaporization is performed at 0-5°C.

[0030] The present invention also protects the application of the above-mentioned environmentally friendly insulating gas in insulation and arc extinguishing.

[0031] The environmentally friendly insulating gas provided by the present invention has a lower GWP value, liquefaction temperature and higher dielectric strength, can fully replace SF6, and has macroscopic properties similar to pure gas, so when the gas leaks, the component content of the gas remains unchanged. When maintaining electrical equipment, the gas can be directly replenished without other operations such as analysis and detection, and has broad application prospects in the fields of insulation and arc extinguishing.

[0032] Preferably, the working voltage of the environmentally friendly insulating gas in the above application is 3 to 1200 kV.

[0033] Compared with the prior art, the present invention has the following beneficial effects:

[0034] The environmentally friendly insulating gas provided by the present invention includes perfluoromethyl sulfide and at least one of 1,1,1,2-tetrafluoroethane and trans-1,3,3,3-tetrafluoropropylene. After the two components are mixed, an environmentally friendly insulating gas similar to a gaseous pure substance can be obtained. Therefore, it has a lower liquefaction temperature of -24 to -64°C, and the insulation strength is more than 0.97 times that of the existing insulating gas SF6. The GWP value is only 2 to 1140, and it has a wide application prospect of perfectly replacing SF6. DETAILED DESCRIPTION

[0035] The present invention is further described below in conjunction with specific embodiments, but the embodiments do not limit the present invention in any form. Unless otherwise specified, the raw materials and reagents used in the embodiments of the present invention are conventionally purchased raw materials and reagents.

[0036] Example 1

[0037] An environmentally friendly insulating gas comprises component A and component B, wherein component A is perfluoromethyl sulfide; component B is trans-1,3,3,3-tetrafluoropropylene; the mass fractions of component A and component B in the environmentally friendly insulating gas are 9.4 parts and 90.6 parts respectively.

[0038] The method for preparing the environmentally friendly insulating gas in this embodiment includes the following steps:

[0039] Environmentally friendly insulating gas can be obtained by mixing the components at a temperature of -40°C and completely vaporizing them at 0°C.

[0040] Example 2

[0041] An environmentally friendly insulating gas, which is different from the first embodiment only in that:

[0042] The mass fractions of component A and component B in the environmentally friendly insulating gas are 15.5 parts and 84.5 parts respectively.

[0043] The method for preparing the environmentally friendly insulating gas in this embodiment is consistent with that in Embodiment 1.

[0044] Example 3

[0045] An environmentally friendly insulating gas, which is different from the first embodiment only in that:

[0046] The mass proportions of component A and component B in the environmentally friendly insulating gas are 30 parts and 70 parts respectively.

[0047] The method for preparing the environmentally friendly insulating gas in this embodiment is consistent with that in Embodiment 1.

[0048] Example 4

[0049] An environmentally friendly insulating gas, which is different from the first embodiment only in that:

[0050] The mass fractions of component A and component B in the environmentally friendly insulating gas are 45.5 parts and 54.5 parts respectively.

[0051] The method for preparing the environmentally friendly insulating gas in this embodiment is consistent with that in Embodiment 1.

[0052] Example 5

[0053] An environmentally friendly insulating gas, which is different from the first embodiment only in that:

[0054] The mass fractions of component A and component B in the environmentally friendly insulating gas are 48.5 parts and 51.5 parts respectively.

[0055] The method for preparing the environmentally friendly insulating gas in this embodiment is consistent with that in Embodiment 1.

[0056] Example 6

[0057] An environmentally friendly insulating gas, which is different from the first embodiment only in that:

[0058] The component B is 1,1,1,2-tetrafluoroethane; the mass fractions of component A and component B in the environmentally friendly insulating gas are 24.6 parts and 76.4 parts respectively.

[0059] The method for preparing the environmentally friendly insulating gas in this embodiment is consistent with that in Embodiment 1.

[0060] Example 7

[0061] An environmentally friendly insulating gas, wherein the difference from Example 6 is only that:

[0062] The mass fractions of component A and component B in the environmentally friendly insulating gas are 55.5 parts and 44.5 parts respectively.

[0063] The method for preparing the environmentally friendly insulating gas in this embodiment is consistent with that in Embodiment 1.

[0064] Example 8

[0065] An environmentally friendly insulating gas, wherein the difference from Example 6 is only that:

[0066] The mass fractions of component A and component B in the environmentally friendly insulating gas are 63.5 parts and 36.5 parts respectively.

[0067] The method for preparing the environmentally friendly insulating gas in this embodiment is consistent with that in Embodiment 1.

[0068] Example 9

[0069] An environmentally friendly insulating gas, wherein the difference from Example 6 is only that:

[0070] The mass fractions of component A and component B in the environmentally friendly insulating gas are 70.5 parts and 29.5 parts respectively.

[0071] The method for preparing the environmentally friendly insulating gas in this embodiment is consistent with that in Embodiment 1.

[0072] Example 10

[0073] An environmentally friendly insulating gas, wherein the difference from Example 6 is only that:

[0074] The mass fractions of component A and component B in the environmentally friendly insulating gas are 75.5 parts and 24.5 parts respectively.

[0075] The method for preparing the environmentally friendly insulating gas in this embodiment is consistent with that in Embodiment 1.

[0076] Embodiment 11

[0077] An environmentally friendly insulating gas, which is different from the first embodiment only in that:

[0078] The environmentally friendly insulating gas also includes component C, which is nitrogen, and the mass fraction of component C is 28 parts.

[0079] The method for preparing the environmentally friendly insulating gas in this embodiment is consistent with that in Embodiment 1.

[0080] Example 12

[0081] An environmentally friendly insulating gas, which is different from the first embodiment only in that:

[0082] The environmentally friendly insulating gas also includes component C, which is oxygen, and the mass fraction of component C is 28 parts.

[0083] The method for preparing the environmentally friendly insulating gas in this embodiment is consistent with that in Embodiment 1.

[0084] Example 13

[0085] An environmentally friendly insulating gas, which is different from the first embodiment only in that:

[0086] The environmentally friendly insulating gas also includes component C, which is air, and the mass fraction of component C is 28 parts.

[0087] The method for preparing the environmentally friendly insulating gas in this embodiment is consistent with that in Embodiment 1.

[0088] Embodiment 14

[0089] An environmentally friendly insulating gas, which is different from the first embodiment only in that:

[0090] The environmentally friendly insulating gas also includes component C, which is carbon dioxide, and the mass fraction of component C is 28 parts.

[0091] The method for preparing the environmentally friendly insulating gas in this embodiment is consistent with that in Embodiment 1.

[0092] Embodiment 15

[0093] An environmentally friendly insulating gas, which is different from the first embodiment only in that:

[0094] The environmentally friendly insulating gas also includes component C, which is carbon dioxide, and the mass fraction of component C is 30 parts.

[0095] The method for preparing the environmentally friendly insulating gas in this embodiment is consistent with that in Embodiment 1.

[0096] Example 16

[0097] An environmentally friendly insulating gas, which is different from the first embodiment only in that:

[0098] The environmentally friendly insulating gas also includes component C, which is carbon dioxide, and the mass fraction of component C is 14 parts.

[0099] The method for preparing the environmentally friendly insulating gas in this embodiment is consistent with that in Embodiment 1.

[0100] Embodiment 17

[0101] An environmentally friendly insulating gas, which is different from Example 2 only in that:

[0102] The environmentally friendly insulating gas also includes component C, which is carbon dioxide, and the mass fraction of component C is 14 parts.

[0103] The method for preparing the environmentally friendly insulating gas in this embodiment is consistent with that in Embodiment 1.

[0104] Embodiment 18

[0105] An environmentally friendly insulating gas, which is different from the third embodiment only in that:

[0106] The environmentally friendly insulating gas also includes component C, which is carbon dioxide, and the mass fraction of component C is 14 parts.

[0107] The method for preparing the environmentally friendly insulating gas in this embodiment is consistent with that in Embodiment 1.

[0108] Embodiment 19

[0109] An environmentally friendly insulating gas, wherein the difference from Example 4 is only that:

[0110] The environmentally friendly insulating gas also includes component C, which is carbon dioxide, and the mass fraction of component C is 14 parts.

[0111] The method for preparing the environmentally friendly insulating gas in this embodiment is consistent with that in Embodiment 1.

[0112] Embodiment 20

[0113] An environmentally friendly insulating gas, wherein the difference from Example 5 is only that:

[0114] The environmentally friendly insulating gas also includes component C, which is carbon dioxide, and the mass fraction of component C is 14 parts.

[0115] The method for preparing the environmentally friendly insulating gas in this embodiment is consistent with that in Embodiment 1.

[0116] Embodiment 21

[0117] An environmentally friendly insulating gas, wherein the difference from Example 6 is only that:

[0118] The environmentally friendly insulating gas also includes component C, which is carbon dioxide, and the mass fraction of component C is 14 parts.

[0119] The method for preparing the environmentally friendly insulating gas in this embodiment is consistent with that in Embodiment 1.

[0120] Comparative Example 1

[0121] An insulating gas consisting of 100 parts by mass of air.

[0122] Comparative Example 2

[0123] An insulating gas comprising only 100 parts by mass of perfluoromethyl sulfide.

[0124] Comparative Example 3

[0125] An insulating gas comprising only 100 parts by mass of trans-1,3,3,3-tetrafluoropropene.

[0126] Comparative Example 4

[0127] An insulating gas comprising only 1,1,1,2-tetrafluoroethane in 100 parts by mass.

[0128] Comparative Example 5

[0129] An insulating gas comprising only 100 parts by mass of perfluoroisoamyl ketone.

[0130] Comparative Example 6

[0131] An insulating gas comprising only 100 parts by mass of perfluoroisobutyronitrile.

[0132] Comparative Example 7

[0133] An insulating gas, wherein the difference from the first embodiment is only that:

[0134] The mass fractions of component A and component B in the insulating gas are 15 parts and 85 parts respectively.

[0135] The method for preparing the insulating gas in this comparative example is consistent with that in Example 1.

[0136] Comparative Example 8

[0137] An insulating gas, wherein the difference from the first embodiment is only that:

[0138] The mass fractions of component A and component B in the insulating gas are 85 parts and 15 parts respectively.

[0139] The method for preparing the insulating gas in this comparative example is consistent with that in Example 1.

[0140] Comparative Example 9

[0141] An insulating gas, wherein the difference from Embodiment 6 is only in that:

[0142] The mass proportions of component A and component B in the environmentally friendly insulating gas are 5 parts and 95 parts respectively.

[0143] The method for preparing the insulating gas in this comparative example is consistent with that in Example 1.

[0144] Comparative Example 10

[0145] An insulating gas, wherein the difference from Embodiment 6 is only in that:

[0146] The mass fractions of component A and component B in the insulating gas are 55 parts and 45 parts respectively.

[0147] The method for preparing the insulating gas in this comparative example is consistent with that in Example 1.

[0148] Comparative Example 11

[0149] An insulating gas, wherein the difference from the first embodiment is only that:

[0150] Component B in the insulating gas is trifluoroiodomethane.

[0151] The method for preparing the insulating gas in this comparative example is consistent with that in Example 1.

[0152] Comparative Example 12

[0153] An insulating gas, wherein the difference from the first embodiment is only that:

[0154] Component B in the insulating gas is 3,3,3-trifluoropropane.

[0155] The method for preparing the insulating gas in this comparative example is consistent with that in Example 1.

[0156] Comparative Example 13

[0157] An insulating gas, wherein the difference from the first embodiment is only that:

[0158] Component B in the insulating gas is trans-1-chloro-3,3,3-trifluoropropene.

[0159] The method for preparing the insulating gas in this comparative example is consistent with that in Example 1.

[0160] Comparative Example 14

[0161] An insulating gas, wherein the difference from the first embodiment is only that:

[0162] Component B in the insulating gas is cis-1,3,3,3-tetrafluoropropene.

[0163] The method for preparing the insulating gas in this comparative example is consistent with that in Example 1.

[0164] Performance Testing

[0165] Dielectric strength test: Under the condition of an inter-electrode spacing of 0.1 inches, the dielectric strength of the gases in the above embodiments and comparative examples relative to SF6 gas was tested respectively.

[0166] GWP value: Taking CO2 as the reference value of 1.0 (100 years), the GWP values ​​of the gases in the examples and comparative examples were obtained by comparison.

[0167] Liquefaction temperature test: The liquefaction temperature of the gases in Examples 1 to 21 and Comparative Examples 1 to 14 was measured by observation method.

[0168] The specific test results are shown in Table 1 below:

[0169] Table 1. Various properties of insulating gas obtained in the examples and comparative examples

[0170]

[0171]

[0172] It can be seen from Table 1 above that the environmentally friendly insulating gas provided by the present invention includes perfluoromethyl sulfide and at least one of 1,1,1,2-tetrafluoroethane and trans-1,3,3,3-tetrafluoropropylene. After the two components are mixed, an environmentally friendly insulating gas similar to a pure gaseous substance can be obtained. Therefore, it has a lower liquefaction temperature of -24 to -64°C, and the insulation strength is more than 0.97 times that of the existing insulating gas SF6. The GWP value is only 2 to 1140, and it has a wide application prospect of perfectly replacing SF6.

[0173] According to the data of Examples 1 to 5 and 6 to 10, when component B in the environmentally friendly insulating gas is trans-1,3,3,3-tetrafluoropropylene, the mass fractions of components A and B in the gas are preferably 45.5 to 48.5 parts and 51.5 to 54.5 parts (Examples 4 to 5), respectively, and the obtained insulating gas has higher insulation strength and lower liquefaction temperature; when component B in the environmentally friendly insulating gas is 1,1,1,2-tetrafluoroethane, the mass fractions of components A and B in the gas are preferably 70.5 to 75.5 parts and 24.5 to 29.5 parts (Examples 9 to 10), respectively, and the obtained environmentally friendly insulating gas can also have higher insulation strength and lower liquefaction temperature, and the GWP value is also lower. However, the proportion of component A in the insulating gas should not be too high. As shown in Comparative Example 2, when the proportion of component A in the insulating gas is too high to reach 100%, the liquefaction temperature is as high as -22°C, which limits its further application.

[0174] According to the data of Examples 11 to 21, when the environmentally friendly insulating gas also includes component C (dilution gas), the liquefaction temperature of the mixed gas can be further reduced while ensuring higher insulation strength and lower GWP value.

[0175] According to the data of Comparative Example 1, it can be seen that the insulation strength is insufficient when air is used alone as the insulating gas. According to the data of Comparative Examples 3 to 4, the two components B in the present invention are used alone as insulating gases, and the insulation strength is also insufficient. According to the data of Comparative Examples 5 to 6, although the existing two SF6 substitutes, perfluoroisoamyl ketone and perfluoroisobutyronitrile, have sufficiently high insulation strength, their liquefaction temperature is too high, which limits their further application. According to Comparative Examples 7 to 10, when the ratio of components A to B in the insulating gas is not appropriate, the resulting gas cannot have a lower liquefaction temperature, higher insulation strength and lower GWP value. According to Comparative Examples 11 to 14, when component A in the insulating gas remains unchanged but component B is other compounds, it is difficult for components A and B to show obvious synergistic effects, and the overall performance is reduced.

[0176] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. An environmentally friendly insulating gas, characterized in that: The method comprises component A and component B, wherein component A comprises perfluoromethyl sulfide; and component B is any one of 1,1,1,2-tetrafluoroethane and trans-1,3,3,3-tetrafluoropropylene; When the component B is 1,1,1,2-tetrafluoroethane, the environmentally friendly insulating gas includes the following components calculated by mass: 24.6-75.5 parts of component A, 24.5-76.4 parts of component B; When the component B is trans-1,3,3,3-tetrafluoropropylene, the environmentally friendly insulating gas includes the following components calculated by mass: 9.4 to 48.5 parts of component A and 51.5 to 90.6 parts of component B.

2. The environmentally friendly insulating gas according to claim 1, characterized in that: Include at least one of the following (a) to (b): (a) When the component B is 1,1,1,2-tetrafluoroethane, the environmentally friendly insulating gas includes the following components calculated by mass: 70.5 to 75.5 parts of component A and 24.5 to 29.5 parts of component B; (b) When the component B is trans-1,3,3,3-tetrafluoropropylene, the environmentally friendly insulating gas includes the following components calculated by mass: 45.5 to 48.5 parts of component A and 51.5 to 54.5 parts of component B.

3. The environmentally friendly insulating gas according to claim 1, characterized in that: The composition further comprises a component C, wherein the component C comprises at least one of nitrogen, oxygen, air and carbon dioxide.

4. The environmentally friendly insulating gas as claimed in claim 3, characterized in that: Including at least one of the following (c) to (d): (c) When the component B is 1,1,1,2-tetrafluoroethane, the environmentally friendly insulating gas includes the following components calculated by mass: 24.6-75.5 parts of component A, 24.5-76.4 parts of component B, 0-28 parts of component C; (d) When the component B is trans-1,3,3,3-tetrafluoropropylene, the environmentally friendly insulating gas includes the following components calculated by mass: 9.4 to 48.5 parts of component A, 51.5 to 90.6 parts of component B, 0 to 28 parts of component C.

5. The environmentally friendly insulating gas as claimed in claim 4, characterized in that: The insulation strength of the environmentally friendly insulating gas measured under the condition of an inter-electrode spacing of 0.1 inches is 0.97 to 1.83 times that of SF6.

6. The environmentally friendly insulating gas according to claim 1, characterized in that: The liquefaction temperature of the environmentally friendly insulating gas is -24 to -64°C.

7. The environmentally friendly insulating gas according to claim 1, characterized in that: The greenhouse effect potential of the environmentally friendly insulating gas is 2-1140.

8. The method for preparing the environmentally friendly insulating gas according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: mixing the components at a temperature of -30 to -50°C and vaporizing them to obtain environmentally friendly insulating gas.

9. Use of the environmentally friendly insulating gas according to any one of claims 1 to 7 in insulation and arc extinguishing.

10. The use according to claim 9, characterized in that: The working voltage of the environmentally friendly insulating gas is 3 to 1200 kV.

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