731 / 2022-03-31 19:21:14

Research on the compatibility between eco-friendly insulating medium C5F10O and sealing material EPDM

SF6 alternative gas,C5F10O/CO2 mixed gas,compatibility

C₅F₁₀O is a promising eco-friendly substitute for insulating gas SF₆ in gas insulated switchgear. Existing research has verified the application feasibility of C₅F₁₀O in terms of dielectric strength, but the compatibility of C₅F₁₀O with the sealing material ethylene-propylene-diene monomer (EPDM) still remains to be tested.In this paper, a 28-day thermal accelerated aging experiment was carried out to study the deterioration behavior of C₅F₁₀O/N₂ and EPDM under long-term coexistence conditions. The compressive modulus of EPDM and the composition changes of C₅F₁₀O/N2 mixture were then determined to evaluate their compatibility with each other.

The results showed that C₅F₁₀O was significantly decomposed after contacting with EPDM, and the decomposition products mainly included CO, CO₂, C₃F₆, C₃F₇H and C₅F₁₀O, among which C₃F₆ and C₃F₇H had the highest concentration. Moreover, in C₅F₁₀O/N₂ environment, the compressive modulus of EPDM also decreased significantly compared to that in pure N₂ environment.

Therefore, EPDM has poor compatibility with C₅F₁₀O. In the application of C₅F₁₀O as an insulation medium, special attention should be paid to the air tightness of the gas chamber, and the maintenance cycle of the sealing material of the equipment should be shortened accordingly.