In order to achieve the emission reduction target of ‘carbon peak in 2030 and carbon neutral by 2060’

as well as promote the green development of the power industry

it has become a research hotspot to develop environmently friendly insulating gas to reduce the use of SF

6

. The environmentally friendly insulating gas C

4

F

7

N has been widely concerned with its excellent insulation and environmental performance. In the paper

a two-dimensional axisymmetric nozzle arc model is built based on the MHD equation

and the arc temperature characteristics of the four gas mediums C

4

F

7

N/CO

2

and C

4

F

7

N/N

2

SF

6

and CO

2

are compared through numerical calculations before and after current zero crossing. The reasons for the difference in arc extinguishing performance of the four media are analyzed. Research shows that

compared with CO

2

gas

the radial temperature distribution of C

4

F

7

N binary mixed gas arc and the cooling rate of arc core temperature are closer to SF

6

gas

and the arc extinguishing performance is between SF

6

and CO

2

. The accumulation of energy in the arc radiation absorption zone results in the difference in arc extinguishing performance between C

4

F

7

N binary mixture and SF

6

gas. Considering the heat transfer capacity of the gas and the heat dissipation speed of the arc

the C

4

F

7

N binary gas mixture has a higher potential for substitution.