Abstract:

Based on the dry gas sealing and grooving method of laser technology, it is proposed to establish an orderly micro-shape of roughness level at the bottom of the circular arc groove dry gas seal (A-DGS) to improve the grooving efficiency and reduce the cost. Simulation based on the finite volume method was validated by comparing with other researches. After analyzing and filtering, it can be known there is little difference of seal performance between the windward micro-structure and leeward micro-structure, and then the opening force and leakage with different geometry and operation parameters of A-DGS based on the leeward-structure was studied, and the influence degree of all parameters was finally obtained and analyzed by a design of experiment based on Taguchi approach. The results show that the opening force is improved by orderly micro-structure, especially under low speed, high pressure and small groove depth conditions. Under given conditions, the influence of ratio of micro-structure depth and width on the opening force is greater than the film thickness and speed. The optimal parameters of arc groove structure are not affected by the micro-structure design. Based on Taguchi approach, the influence degree of different impact factors could be easily and accurately obtained, which is helpful for engineering design.

Key words: dry gas seal, arc groove, orderly micro-structure, Taguchi approach, opening performance

摘要：

基于激光技术的干气密封开槽方法，提出在圆弧线槽干气密封（A-DGS）槽底开设粗糙度量级的有序微造型，以提高开槽效率、降低成本。采用有限体积法对无微造型圆弧线槽干气密封进行仿真分析，通过与现有文献对比验证了仿真方法的正确性；对微造型结构进行分析和筛选，获得偏移迎风侧与偏移背风侧结构对密封性能影响基本无差，本研究基于偏移背风侧微造型结构进行深入研究；与无微造型圆弧线槽进行对比，分析了不同几何参数和工况参数下的开启力和泄漏量变化情况；最后对各参数的影响程度进行对比分析。结果表明：同工况下，具微造型圆弧线槽干气密封（MA-DGS）的开启力较A-DGS有一定提升，在低速高压及小槽深时提升效果最好；微造型深度和微造型宽间比对干气密封开启力的影响在给定情况下甚于膜厚与转速的影响；密封端面槽型结构优化参数不受槽底微造型设计的影响；基于Taguchi实验设计方法，可以便捷准确地获得不同影响因子的影响程度，帮助工程设计。

关键词: 干气密封, 圆弧线槽, 有序微造型, Taguchi设计方法, 开启性能