Development of 72kV Class Environmentally-Benign CO₂ Gas Circuit Breaker Model

Abstract

Adopting CO 2 as an alternative gas of SF 6 in a gas circuit breaker from the environmental viewpoint, a 72 kV-31.5 kA class CO 2 gas circuit breaker (CO 2-GCB) model, which does not contain SF 6 gas at all, was designed, and produced. In the CO 2-GCB model, some effective technologies for current interruption by CO 2 gas were adopted; namely, puffer pressure enhancing techniques utilizing arc energy during a current interruption and ablation phenomena of a polymer element located in the puffer cylinder. As a result of current interruption and electric insulation tests, the CO 2-GCB model achieved practical levels of performance. Furthermore, it was found by carrying out a life cycle assessment (LCA) that the CO 2-GCB model could reduce the global warming impact by about 40% compared to the latest SF 6 gas circuit breaker in the same rating for 20 years operation including one maintenance opportunity.

Particle Composition of CO2-CF3I Mixture at Temperatures of 300-30,000 K

“…5(c), a further increase in X CF3I from 0.9 to 0.99 results in marked diminution in the number density of CO 2 and COF 2 A further increase in X CF3I to 1 leads CO and C 3 O 2 to be absent, but resulting in production of C 5 . These phenomena lead the particles C 2 F 6 , I 2 , CF 4 and C 5 to be present as the principal particles, as already found in Fig. 4, …”

“…2, the gas for X CF3I below 0.96 consists of CO 2 , CF 4 , CO, I 2 , COF 2 and C 2 F 6 . While, I 2 , CF 4 , CO and C 3 O 2 behaves as the principal particles in the concentration range from 0.96 to 0.99. A further increase in X CF3I to 1 leads the particles C 2 F 6 , I 2 , CF 4 and C 5 to be present as the principal particles.…”

“…At the present stage, the CO 2 is expected to be promising quenching gas, especially for high-voltage circuit breakers (1)- (4) . Although having global warming effect, CO 2 has very much lower global-warming-potential than SF 6 .…”

“…At a temperature of about 2,000 K, CO 2 , COF 2 , CO and I shows higher number densities than other species. A further diminution to temperatures of 300-500 K results in decline in the number densities of COF 2 and I, but leads CO 2 , CF 4 , CO and I 2 to be present at high number densities of 10 24 m −3 order or above. Secondly, the similar calculations were performed for different X CF3I .…”

Thermodynamic and Transport Properties of Ar Thermal Plasmas with Polymer Ablated Vapors and Influence of Their Inclusions on Plasma Temperature

“…For interactions of C-C, O-O and Ar-Ar, we calculated πΩ with Monchick's table (11) using exponential repulsive potential given by Abrahamson (12) . For interactions between the other same molecules such as C 2 by the hard-sphere method using the effective radii (14) . The quantities πΩ for interactions between the different neutral molecules were estimated by the empirical combining rule (15) .…”