刷式汽封内部流动及泄漏特性的数值研究

摘要

The effects for the flow characteristics of brush seals due to different factors (such as the height of the back plate,radial clearance) are investigated by solving Navier-Stokes equations.The improved brush seal structures are used to analyse the internal pressure field distribution,velocity field distribution,and different types of steam seal leakage amount.The results show that with the increase of the height of the back plate,three different inlet pressure leakage rise;leakage with brush bundle thickness increased but decreased;steam leakage quantity and radial clearance is proportional.Model 5 than the other four kinds of structure of back radial pressure is low,but the brush bundle area steam flow is faster,and the leakage was significantly higher than that of other brush seal.%采用数值求解三维Navier-Stokes方程技术,研究了不同因素(如背板高度、径向间隙等)对刷式汽封内部流动特性的影响.提出了改进的刷式汽封模型,数值分析了5种刷式汽封模型压力分布、速度场及泄漏量情况.结果表明:随着背板高度的增加,3种不同进口压力下的泄漏量都随之增加;蒸汽泄漏量随着刷束厚度的增加反而降低;蒸汽泄漏量与径向间隙成正比例关系.模型5较其它4种刷式汽封模型背板径向压力低,但刷束区蒸汽流速大,泄漏量明显高于其它刷式汽封.