高压火花隙开关中气体冷却的数值模拟

 高温气体的冷却对火花隙开关的重复运行具有重要的影响。利用流体方程、热传导方程和理想气体状态方程构建的方程组，对火花隙开关中高温气体冷却的过程进行了数值模拟。分析了气体导热系数、粘性系数、对流及气体压强等要素对气体冷却速度的影响，得到了气体冷却的基本规律：火花隙开关内气体的冷却以传导为主；若不采用其他手段，气体在十几ms内冷却较困难；对流的作用经数十ms后才显著；气体的粘性系数对气体冷却的影响可以忽略。可以通过选用导热系数高的气体，优化电极结构或采用吹气方法提高气体冷却速度的办法。

Simulation of gas temperature decay in spark gap switch

Gas temperature decay is the primary factor which restricts the repetitive operation of spark switch.The gas temperature decay in gas spark switch after operation is simulated based on fluent equation,thermal conductivity equation and general gas law.The simulated results indicate some rules of the gas temperature decay in spark gap switch:(1) the heat loss of the gas is mainly caused by thermal conduction;(2) the hot gas an hardly cooldown in several tens of milliseconds;(3) the influence of convection are notable after a few tens of milliseconds;(4) the influence of the viscosity coefficient of gas on the temperature decay could be ignored.Finally the methods for accelerating gas decay are discussed and presented.