氦透平膨胀机充气式迷宫密封性能的仿真研究

Simulation researches on performance of inflated labyrinth seal of turbo-expander

探究充气式迷宫密封的密封气进气压力与泄漏量的关系,通过数值模拟对氦透平膨胀机的密封结构进行仿真计算,研究在250~700 kPa范围内密封气进气压力变化对密封泄漏量的影响。结果表明:在不接通密封气时,密封泄漏量与压比呈现出线性关系;受密封气对密封气进气口稳压槽内射流抑制作用的影响,泄漏量与密封气进气压力呈现负相关关系;受转子旋转对流体做功的影响,泄漏量为零时的密封气压力高于进口压力。

The relationship between the inlet pressure of sealing gas and the seal leakage was studied,and the sealing structure of the helium turbine expander was computed by using the numerical simulation method,the influence of inlet pressure variation on the seal leakage was researched in the range of 250 ~ 700 kPa.The calculation results show that there is a linear relationship between the leakage and the pressure ratio;the leakage is negatively correlated with the inlet pressure of the sealing gas due to the inhibition of the jet flow in the regulating groove of the sealing gas inlet by the sealing gas;the rotor rotation does work on the fluid and thus increases the total pressure of the fluid,the sealing gas pressure is greater than the inlet pressure when the seal leakage is zero.