蜂窝结构对篦齿-蜂窝密封封严性能的影响

Effect of Honeycomb Structure on Sealing Performance of Labyrinth-Honeycomb Seal

为提高压气机级间气路封严密封性能,在传统六边形蜂窝的基础上,改变其结构得到方形蜂窝和圆形蜂窝,数值研究不同间隙、压比和转速下蜂窝结构对篦齿-蜂窝密封封严性能的影响。结果表明:间隙增加时,篦齿密封、六边形蜂窝密封、方形蜂窝密封、圆形蜂窝密封4种密封方式泄漏量均线性增加,但由于蜂窝破坏了流场透气效应,故篦齿-蜂窝密封泄漏量增速最慢,其中圆形蜂窝密封封严效果最好;压比增加时,4种密封方式泄漏量均增加,但篦齿及蜂窝腔室内形成漩涡亦随压比增加而愈发强烈,耗散更多能量,故泄漏量增速逐渐变缓;转子转速增加时,流体环向速度增加,4种密封方式泄漏量均减小,而蜂窝环向切割流体形成漩涡耗散能量,故篦齿-蜂窝密封减小幅度较大。在大间隙高压比高转速的工况下,篦齿-蜂窝衬套结构封严效果更好,其中篦齿-圆形蜂窝密封最具优势。

In order to improve the sealing performance of gas sealing between compressor stages,based on the traditional hexagon honeycomb,the square honeycomb and circular honeycomb were obtained by changing its structure,the effect of the honeycomb structure on the sealing performance of the labyrinth-honeycomb seal were numerically studied,and the sealing characteristics and sealing mechanism of the four seals,the labyrinth seal,the hexagonal honeycomb seal,the square honeycomb seal and the circular honeycomb seal were comparatively analyzed in cases of different seal clearance,pressure ratio and rotation speed.The results show that the leakage of the four seals are increased at an approximately linear rate with the increase of clearance,and the increase rate of the leakage of labyrinth-honeycomb bushing seal is slower than that of labyrinth-smooth seal since the honeycomb destroys the flow field ventilation effect.Among the three labyrinth-honeycomb seals,labyrinth-circular honeycomb seal has the best sealing effect.With the increase of pressure ratio,the leakage of the four seals is increased,but the growth rate gradually becomes slower due to the formation of strong whirlpool in labyrinth and honeycomb cavity.With the increase of rotational speed,the fluid circumferential velocity is increased,the leakage of the four seals is decreased,and because the honeycomb circumferential cuts fluid and forms a whirlpool to dissipate energy,the leakage of labyrinth-honeycomb seal is decreased greatly.Under the condition of large clearance and high pressure ratio and high speed,the labyrinth-honeycomb seal has better sealing effect,among which the labyrinth circular honeycomb seal has the most advantage.