利用风阻温升估算气封间隙和流量

摘要

运用CFD数值仿真方法和多种经验公式,计算了理想气体(空气)和水蒸气2种不同介质在气封转速N=0和N=3 000 r/min时的温升情况,并根据水蒸气和空气在旋转气封中不同的风阻温升特性,基于监控气封进出口温度变化得出气封实际工作间隙和泄漏流量,结果表明:在同样的转速下,空气风阻温升比水蒸气风阻温升更为明显,空气节流温降小,因此在燃气轮机等以空气为介质的旋转机械中,用风阻温升特性来估算气封实际工作间隙和泄漏流量的方法较为可行.%Windage heating of ideal air and steam passing through labyrinth seals was respectively calculated at rotating speeds N=0 and N=3 000 r/min using CFD numerical method and different empirical correlations,based on which,actual working clearance and leakage rate of related labyrinth seals could be obtained according to the temperature difference between inlet and outlet of the seals.Results show that at same rotating speeds,the windage heating of air is more obvious than that of steam,and the temperature drop induced by throttling effect is relatively small,therefore,it is feasible to evaluate actual working clearance and leakage rate of labyrinth seals with windage heating of air for rotating machineries like gas turbine,which takes air as its working medium.