SF_6/N_2混合气体灭弧室中气流特性的计算分析

Analysis of Gas Flow Properties in SF_6/N_2 Mixture Interrupter

以能量平衡方程为基础,建立了分析压气式SF_6断路器灭弧室喷口气流场的数学模型,在不同比例的SF_6/N_2混合气体条件下,对上游区(压气缸)气体压力和温度以及喷口喉道内的气流量进行了数值计算,通过改变混合比、基压、喷口直径和下游扩张角等参数进行大量计算,最终达到了混合气体条件下产生及维持与纯SF_6气体接近或相同的SF_6质量流量的目的,以确保所需的灭弧能力,

Based on the energy conservation equation, a mathematical simulation program to obtain the dynamic characteristics of nozzle flow field in a puffer type SF6 circuit breaker has been developed. The pressure and temperature rise in puffer cylinder and the gas flow transient in nozzle were calculated for the SF6/N2 mixture in various values of mixing ratio. The results show that it is possible to increase the net SF6 mass flow in SF6/N2 mixture to the same level as that in pure SF6 gas and to ensure the essential interruption capability by modifying initial pressure of chamber, the value of mixing ratio and the configuration of arc chamber.