高静压下两间隙气体开关结构及电场优化设计

Optimization Design of Two Gap Gas Switch Structure and Electric Field Under High Hydrostatic Pressure

为解决可控冲击波设备的两间隙气体火花开关在非常规页岩油开发中结构强度不够的问题,提出了一种适用于高静压、有限空间中的气体火花开关结构强度与电场分布同步优化的设计方法。基于有限元模拟与理论分析,评估了50 MPa外部高静压对气体火花开关结构强度的影响,针对结构强度足够的气体火花开关模型,通过高斯定理对开关内部的电场分布进行了优化分析,给出了两电极气体火花开关结构强度与电场分布同步优化的设计方案。研究结果表明:开关结构强度主要与腔室壁厚正相关,而壁厚的增加会提高开关异常放电概率,在特定的壁厚参数下,电极半径存在最佳值使得绝缘子表面电场强度最低。在保证结构强度的前提下,对现有开关电场分布进行了优化分析,优化后的开关间隙电场的不均匀度有轻微提高,而高压绝缘子内、外表面电场强度分别衰减了59.6%与31.0%。通过先增加结构强度、后优化电场分布的方法,实现了对冲击波设备的两电极气体火花开关结构强度与电场分布的同步优化。

To solve the problem of insufficient structural strength of two gap gas spark switches for controllable shock wave equipment in unconventional shale oil development,this paper proposes a design method for synchronously optimizing the structural strength and electric field distribution of gas spark switches in high static pressure and limited space.Based on finite element simulation and theoretical analysis,the impact of 50 MPa external high static pressure on the structural strength of the gas spark switch is evaluated.For a gas spark switch model with sufficient structural strength,the electric field distribution inside the switch is optimized and analyzed through Gauss’theorem,leading to a design scheme for synchronously optimizing the structural strength and electric field distribution of a two electrode gas spark switch.The research results indicate that the strength of the switch structure is primarily positively correlated with the chamber wall thickness,and the increase in wall thickness may increase the probability of abnormal discharge of the switch.Under specific wall thickness parameters,there is an optimal value for the electrode radius to make the electric field intensity on the insulator surface the lowest.On the premise of ensuring the structural strength,the existing switch electric field distribution is optimized and analyzed.The optimized switch gap exhibits a slight improvement in the uniformity of the electric field,and the electric field intensity on the inner and outer surfaces of the high-voltage insulator is respectively reduced by 59.6%and 31.0%.By first increasing the structural strength and then optimizing the electric field distribution,synchronous optimization of the structural strength and electric field distribution of the two electrode gas spark switch in shock wave equipment is achieved.