CIESC Journal ›› 2017, Vol. 68 ›› Issue (5): 2016-2026.DOI: 10.11949/j.issn.0438-1157.20161561

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Hydrodynamic performance of liquid film seals in circumferential beveled-step spiral grooves

LI Zhentao1, HUANG Baipeng1,2, HAO Muming1, SUN Xinhui1, WANG Yunlei1, YANG Wenjing1   

  1. 1 Institute of Sealing Technology, China University of Petroleum, Qingdao 266580, Shandong, China;
    2 CNPC Dushanzi Petrochemical Company, Kelamayi 833699, Xinjiang, China
  • Received:2016-11-04 Revised:2017-01-19 Online:2017-05-05 Published:2017-05-05
  • Supported by:

    supported by the National Natural Science Foundation of China (51375497) and the Shandong Special Projects of Independent Innovation and Achievement Transformation (2014ZZCX10102-4).

周向斜面台阶螺旋槽液膜密封流体动压性能

李振涛1, 黄佰朋1,2, 郝木明1, 孙鑫晖1, 王赟磊1, 杨文静1   

  1. 1 中国石油大学(华东)密封技术研究所, 山东 青岛 266580;
    2 中国石油独山子石化公司, 新疆 克拉玛依 833699
  • 通讯作者: 郝木明
  • 基金资助:

    国家自然科学基金项目(51375497);山东省自主创新及成果转化专项项目(2014ZZCX10102-4)。

Abstract:

To reduce liquid film pressure loss in liquid flow divergent zone between sealing surfaces and to improve sealing performance, structure of circumferential beveled-step was introduced into rectangular section spiral groove and corresponding physical model was established. Based on the JFO cavitation model, effects of bevel angle ratio on liquid film pressure distribution, cavitation occurrence, and liquid film hydrodynamic performance were studied at different groove depths. When bevel angle ratio was below 1/30, liquid film pressures of downstream and upstream pumping liquid film seals along circumferential and spiral line direction were enhanced rapidly but cavitation area ratio was dropped sharply, which was more significant for upstream pumping seals. With the increase of bevel angle ratio, leading edge pressure at liquid film rupture showed an increasing trend and trailing edge pressure at liquid film reformation showed opposite trend, but cavitation area ratio increased first and decreased later. The increase of groove depth contributed to the increase of liquid film pressure and the decrease of cavitation area ratio. When groove depth ranged from 8 to 12 μm and bevel angle ratio ranged from 0.1 to 0.3, the load-carrying capacities of both liquid film seals reached to peak values with about 13.5% maximum amplification for the former and about 28% for the latter, whereas increase of friction torque was smaller with about 4.6% maximum amplification. The leakage change along with the increase of bevel angle ratio was similar to the load-carrying capacity.

Key words: spiral groove liquid film seals, circumferential beveled-step, hydrodynamic performance, liquid film pressure, cavitation area ratio

摘要:

为降低密封面间液体流动发散区液膜压力损失及提高密封性能,在矩形截面螺旋槽中引入周向斜面台阶结构并建立物理模型。基于JFO空化边界,探讨了不同槽深时,斜面转角比对液膜压力、降低空穴发生及流体动压性能的影响。结果表明:当斜面转角比小于1/30时,下游泵送或上游泵送液膜密封的周向膜压或螺旋线方向膜压均得到迅速提升而空化面积比迅速降低,尤其是上游泵送密封;随斜面转角比增大,空化面积比先增大后减小,空穴区中液膜开始破裂位置前缘压力呈增加趋势,而液膜重生成位置后缘压力反之。槽深的增加有助于提升液膜压力和降低空化面积比,当槽深为8~12 μm,在斜面转角比为0.1~0.3时,两类型液膜密封承载能力均可达到最大值,前者最大增幅约13.5%,后者约28%;摩擦扭矩最大增幅约4.6%,增幅较小;泄漏量随斜面转角比的变化规律与承载能力相似。

关键词: 螺旋槽液膜密封, 周向斜面台阶, 流体动压性能, 液膜压力, 空化面积比

CLC Number: