动压式环瓣浮环密封特性及摩擦磨损研究

Seal Characteristics and Friction and Wear of Dynamic Pressure Split Floating Ring

关键词:  动压槽  环瓣浮环  密封特性  开启力  摩擦磨损

Key words:  Dynamic pressure groove  Split floating ring  Sealing characteristics  Opening force  Friction and wear

摘要:

普通接触式环瓣浮环密封高速下不开启易造成磨损失效，动压式环瓣浮环一定转速下径向开启并保持无摩擦无磨损稳定运行，具有较好的应用前景。建立动压式环瓣浮环密封固体域及流场数值计算模型，计算开启阻力、开启力、泄漏率及温升，分析动压槽结构参数对密封开启的影响，讨论密封性能随槽型参数的变化趋势。基于数值分析优化参数，试验验证开槽前后密封的泄漏率及温升，讨论不同开启情况下密封的磨损特性。结果表明：优化的动压槽能明显改变主密封间隙中的压力分布，提高流体动压力，实现开启，使密封高速下稳定无摩擦运转并保持较低的泄漏率，大幅度降低摩擦温升，改善密封的摩擦磨损。动压槽最佳深度宜为3~5μm，密封具有较大的开启力；槽宽增大开启力先增大后变缓，过大的槽宽对提高开启力不明显；工作压力增加，密封开启难度增加，可通过增加槽数或提高转速实现开启；动压槽的槽深较大时，密封先迅速磨损后逐渐稳定，具有自磨损、自稳定的特点。

Abstract:

It is easy to cause wear failure if the ordinary contact split floating ring seal does not open at high speed. The dynamic pressure split floating ring seal can open radially at a certain speed and keep stable operation without friction and wear， which has a good application prospect. The numerical model of solid region and flow field of dynamic pressure split floating ring seal is established. The opening resistance， opening force， leakage rate and temperature rise are calculated. The effects of structural parameters of dynamic pressure groove on seal opening are analyzed， and the variation trend of seal performance with groove parameters is discussed. Based on numerical analysis and optimization of parameters， the leakage rate and temperature rise of the seal before and after slotting are verified by experiments， and the wear characteristics of the seal under different opening conditions are discussed. The results show that the optimized dynamic pressure groove can significantly change the pressure distribution in the main seal clearance， increase the fluid dynamic pressure， realize the opening， make the seal operate stably without friction at high speed， keep a low leakage rate， greatly reduce the friction temperature rise， and improve the friction and wear of the seal. The optimal depth of the dynamic pressure groove is 3~5μm， and the seal has a large opening force. With the increase of groove width， the opening force first increases and then slows down， and too large groove width is not obvious to improve the opening force. With the increase of working pressure， it is more difficult to open the seal， which can be realized by increasing the number of slots or increasing the speed. When the groove depth of the dynamic pressure groove is large， the seal will wear rapidly at first and then gradually stabilize， which has the characteristics of self wear and self stability.