Numerical simulation study on the influence mechanism of the ratio of the shell I.D. to the busbar O.D. (Rf) on the steady state temperature rise (Trise) of GIS

In this paper, a dimensionless constant R_f (the ratio of the shell I.D. (cm) to the busbar O.D. (cm)) is defined to measure the relative size of the GIS (Gas Insulated Switchgear) shell and busbar, and this parameter has a large influence on the natural convection heat dissipation capability inside the gas chamber. A two-dimensional multi-physical field coupling computational model was established to study the influence mechanism of R_f on the steady state temperature rise inside the GIS, and the results show that: with the increase of R_f, the T_rise first decreases rapidly and then decreases slowly and finally tends to flatten out, i.e., there exists a critical value of R_f-threshold, and there is no obvious effect of increasing the size of the shell on the reduction of the steady state temperature rise inside the GIS when the value of R_f is larger than this value. In the internal filling of different insulating gases, different filling pressures, different current levels, the above law exists, only the specific value of the slight difference (2.5~3.25). In industrial design, it can be roughly considered that when the R_f>3, you can can take into account the design of structural compactness and more excellent temperature rise performance. The above research can provide a new constraint for GIS size design, thus simplifying the GIS design process.