启停阶段干气密封界面微结构的摩擦热力学研究

Study on Friction Thermodynamics of the Microstructure of Dry Gas Seal Interface During the Start⁃stop Phase

以动环端面带微米级双向螺旋槽与圆弧槽结构的干气密封为研究对象,考虑密封界面热传导建立不同微结构密封副干摩擦工况下的热力学模型,采用完全热力耦合方法进行摩擦传热分析。研究结果表明:动环端面微结构的存在,使接触面局部产生高温热点,热点区域主要集中于开槽区域周围,高温热点沿周向周期性分布,双向螺旋槽界面热点较集中;动静环接触面最高温度随转速的增大、运行时间的延长上升趋势越明显;微槽深度对界面最高温度的影响在起始阶段不明显,随着滑动过程的进行,浅槽界面最高温度逐渐高于深槽界面;相同转速、槽深情况下,圆弧槽界面温升低于双向螺旋槽界面;碳石墨静环接触面等效应力分布情况与高温热点区域具有相似性,接触面局部温差产生的热应力是导致应力集中的主要因素。

Aimed at the dry gas seal with bidirectional spiral groove and circular arc groove on the end face of moving ring,considering the heat conduction at the sealing interface,the thermodynamic models of different microstructure sealing pairs under dry friction conditions were established.The friction heat transfer analysis was carried out by the complete ther⁃mal⁃mechanical coupling method.The results show that the existence of the microstructure on the end face of the moving ring causes local high temperature hot spots on the contact surface.The hot spots are mainly concentrated around the grooved area,and the high temperature hot spots are periodically distributed along the circumferential direction.The hot spots at the interface of bidirectional spiral groove are concentrated.The maximum temperature of the contact surface of the dynamic and static ring increases more obviously with the increase of the rotating speed and the running time.The influence of microgroove depth on the maximum temperature of the interface is not obvious at the initial stage,as the sliding process progresses,the maximum temperature of shallow groove interface is gradually higher than that of deep groove interface.Under the same rotating speed and groove depth,the temperature rise of arc groove interface is lower than that of the bidi⁃rectional spiral groove interface.The equivalent stress distribution on the contact surface of carbon graphite static ring is similar to that in the hot spot area of high temperature,and the thermal stress caused by the local temperature difference on the contact surface is the main factor leading to stress concentration.