CIESC Journal ›› 2020, Vol. 71 ›› Issue (5): 2202-2214.DOI: 10.11949/0438-1157.20191586

• Surface and interface engineering • Previous Articles     Next Articles

Performance analysis on diffuser self-pumping hydrodynamic and hydrostatic mechanical seal

Cheng GE(),Jianjun SUN(),Xuchen SU,Chenbo MA,Qiuping YU   

  1. College of Mechanical and Electrical Engineering, Nanjing Forestry University, Nanjing 210037, Jiangsu, China
  • Received:2019-12-26 Revised:2020-03-03 Online:2020-05-05 Published:2020-05-05
  • Contact: Jianjun SUN

扩压式自泵送流体动静压型机械密封性能分析

葛诚(),孙见君(),苏徐辰,马晨波,於秋萍   

  1. 南京林业大学机械电子工程学院,江苏 南京 210037
  • 通讯作者: 孙见君
  • 作者简介:葛诚(1994—),男,硕士研究生,gecheng18@163.com
  • 基金资助:
    国家重点研发计划项目(2018YFB2000800)

Abstract:

The opening force of the seal end face is an important index to ensure the non-contact operation of the non-contact mechanical seal. To overcome the shortcoming that the opening force of the seal face decreases with the increase of the rotating speed, a kind of diffuser self-pumping hydrodynamic and hydrostatic mechanical seal was designed based on the working principle of the diffuser of the centrifugal pump or compressor. The three-dimensional flow fields of the seal face was analyzed by Fluent, the sealing performance of the self-pumping mechanical seal was compared with ordinary self-pumping mechanical seal, and the influence of structural and operational parameters on the performance of self-pumping mechanical seal was discussed. Results show that the opening force of the face of self-pumping mechanical seal with the diffuser is more than 50% higher than that of the ordinary self-pumping mechanical seal with the same spiral groove parameters, and the opening force increases with the speed. With the increase of the width of diffuser ring, the opening force and the leakage rate increase significantly. Reducing the depth of diffuser ring can effectively improve the opening force. Even the structure size of the expansion ring is changed, the effect of the width ratio of groove to diffuser ring, groove number and helix angle on the diffuser self-pumping mechanical seal sealing performance is not affected. Consequently, through the matching of structural parameters, the better sealing performance can be obtained under certain operating conditions.

Key words: mechanical seal, interface, opening force, diffuser, CFD, numerical simulation, leakage rate

摘要:

密封端面开启力是保证非接触式机械密封非接触运行的重要指标。为克服普通自泵送流体动静压型机械密封端面开启力随转速增大而减小这一不足,基于离心式泵或压缩机的扩压器工作原理提出了一种扩压式自泵送流体动静压型机械密封。数值模拟比较了普通自泵送和扩压式自泵送流体动静压型机械密封的密封性能,探讨了密封面结构参数和工况参数对扩压式自泵送流体动静压型机械密封性能的影响规律。结果表明:扩压式自泵送流体动静压型机械密封相比同等螺旋槽参数的普通自泵送流体动静压型机械密封的密封界面开启力提升了50%以上,并随转速增大而增大;随着扩压环槽增宽,开启力和泄漏率都显著增大;减小扩压环槽深度,能有效提高开启力;扩压环槽结构尺寸的变化基本不影响槽扩宽比、槽数和螺旋角对密封性能的影响规律。在一定的工况参数下,通过结构参数匹配,扩压式自泵送流体动静压型机械密封可以获得较优的密封性能。

关键词: 机械密封, 界面, 开启力, 扩压, 计算流体力学, 数值模拟, 泄漏率

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