摘要
根据旋转机械中常见的篦齿密封结构设计直通型和台阶型2组篦齿密封实验模型,实验研究篦齿密封的封严特性。通过实验和数值方法比较不同进出口压比和节流间隙下2组篦齿密封的封严特性,研究台阶篦齿与衬套轴向相对位置对封严特性的影响,探究篦齿内部沿程压力分布情况。研究结果表明:在密封长度相同的条件下,台阶齿泄漏系数比直通齿降低了约45%;台阶齿对节流间隙变化的敏感性要低于直通齿,表明台阶型篦齿性能稳定性优于直通齿;低压比时泄漏量受台阶篦齿与衬套轴向相对位置的影响很小;在文中条件下当齿尖位于衬套台阶中心位置时,篦齿密封的泄漏量最大;直通型和台阶型篦齿沿程压力系数的分布基本相同,都近似线性降低;与实验结果不同,数值计算结果表明台阶齿在齿尖处存在压力突降,而在齿腔中存在一个压力突峰。
Experimental models of straight-through and stepped labyrinth seals were designed to study the sealing performance of different typical labyrinth seals.By experimental and numerical methods, the sealing performances of straight-through and stepped labyrinth seals under different pressure ratio and sealing clearance were compared, the effects of relative axial location of stepped labyrinth seal on the leakage, as well as the pressure distribution of labyrinth seals were studied.The results show that, at the same sealing length, the leakage coefficient of stepped labyrinth seal is less than straight one by about d5%.The change of sealing clearance has smaller influence on the leakage of stepped labyrinth seal compared with the straight one, indicating that the stepped labyrinth seal has better sealing stability.The relative axial location has a little effect on the leakage under low pressure ratio. When the tooth tip is located at the middle of cover, the leakage of stepped labyrinth seat is the largest. The pressure distribution of stepped and straight-through labyrinth seals is similar,which shows a linear decrease.The numerical results show a pressure valley at the tooth tip and a pressure peak at a position of the cavity, which is different from the experimental results.
出处
《润滑与密封》
CAS
CSCD
北大核心
2017年第10期80-86,共7页
Lubrication Engineering
基金
国家自然科学基金项目(51522605)
国家重点基础研究发展计划(973计划)项目(2015CB251302)
北京市科技计划项目(D161100004616001
161100004616002)
中国科学院前沿科学重点研究项目(QYZDB-SSW-JSC023)
关键词
直通型篦齿
台阶型篦齿
泄漏系数
压力分布
封严特性
straight-through labyrinth seal
stepped labyrinth seal
leakage coefficient
pressure distribution
sealing performances
