采用DMM计算方式的高压断路器气流场仿真分析

Simulation and analysis of flow field in high-voltage circuit breakers with DMM computing method

针对压气式SF 6灭弧室气流场的高精仿真,采用一种基于动触头侧运动(dynamic contact moving method,DMM)的计算方式,结合气流场控制方程组和湍流方程联合求解;运用域动分层法动网格更新技术,对比传统仿真求解中采用的静触头部分运动(stationary contact moving method,SMM)计算方式,研究灭弧室内部气流场特性的规律。通过静弧触头端部和压气室出口处的气流压力和密度动态分布对比分析,在触头分开全过程中,运用SMM和DMM这2种不同计算方式对冷态气流场仿真均具有可行性。仿真结果表明,在小开距情况下,采用DMM计算方式时,动、静弧触头区域有相对更强的气流压力差,喷口喉部出现明显阻塞,压气缸与喷口上游通道的气流密度更高,更贴近灭弧室开断初期内部气流场的真实状况,可准确描述断路器气流场参数的分布及变化规律。

Aiming at the high precision simulation of gas flow field of the compressed SF 6 arc-quenching chamber,a simulation based on the dynamic contact moving method(DMM)was adopted,which combined the governing equations of the airflow field and the turbulence equations to solve the problem..By using the dynamic mesh updating technique of the domain-dynamic hierarchical method,the characteristics of the flow field inside the arc extinguishing chamber were studied by comparing the stationary contact moving method(SMM)used in the traditional simulation solution..Through the comparative analysis of the dynamic distribution of air pressure and density at the end of static arc contact and outlet of compressor,it was feasible to simulate the cold air flow field by using SMM and DMM in the whole process of contact separation.The simulation results show that the dynamic and static arc contact area has relatively stronger air pressure difference when DMM is used in the case of small gap.Obvious obstruction occurrs in the throat of the nozzle.The air flow density in the upstream passage of the cylinder and nozzle is higher,which is closer to the real situation of the internal air flow field in the initial stage of interrupter interruption,and can accurately describe the distribution and variation of the air flow field parameters of circuit breaker.