CIESC Journal ›› 2019, Vol. 70 ›› Issue (7): 2645-2659.DOI: 10.11949/j.issn.0438-1157.20190183

• Surface and interface engineering • Previous Articles     Next Articles

Analysis on real effect of supercritical carbon dioxide dry gas seal at high speed

Wei SHEN(),Xudong PENG(),Jinbo JIANG,Jiyun LI   

  1. Engineering Research Center of Process Equipment and Its Remanufacturing of Ministry of Education, Zhejiang University of Technology, Hangzhou 310014, Zhejiang, China
  • Received:2019-03-04 Revised:2019-04-07 Online:2019-07-05 Published:2019-07-05
  • Contact: Xudong PENG

高速超临界二氧化碳干气密封实际效应影响分析

沈伟(),彭旭东(),江锦波,李纪云   

  1. 浙江工业大学过程装备及其再制造教育部工程研究中心,浙江 杭州 310014
  • 通讯作者: 彭旭东
  • 作者简介:沈伟(1993—),男,硕士研究生,<email>m15757174235@163.com</email>
  • 基金资助:
    航天先进制造技术研究联合基金项目(U1737202)

Abstract:

The special properties of the supercritical carbon dioxide medium make the various practical effects in the high-speed supercritical carbon dioxide dry gas seal prominent, and ignoring these actual effects may bring large errors to the dry gas seal steady state performance solution. Taking spiral groove dry gas seal as the research object, the governing equation of film pressure considering inertia term and real flow state was derived. The film pressure distribution was obtained using finite difference method. The film stiffness and leakage rate of high-speed supercritical CO2 dry gas seal based on the real modified model and classical simplified model were compared and analyzed. The effects of real gas effect, inertia effect and turbulent effect on film stiffness and leakage rate under different pressure and velocity conditions were analyzed. The independent and interactive effects of three effects on steady-state performance were revealed. Under the given conditions, the results show that the leakage rate calculated by the classical simplified model is smaller at low speed, and both film stiffness and leakage rate calculated by the classical simplified model are smaller at high speed. Under super-high speed condition, real gas effect significantly increases film stiffness and leakage rate of the gas film, while turbulent effect increases the stiffness of the gas film and reduces the leakage rate. Inertia effect slightly influences film stiffness and leakage rate. There is a strong interaction between real gas effect and turbulent effect on steady performance.

Key words: supercritical carbon dioxide, dry gas seal, real effect, interaction, turbulent effect

摘要:

超临界二氧化碳介质物性的特殊性使得高速超临界二氧化碳干气密封中的多种实际效应突显,忽略这些实际效应可能会给干气密封稳态性能求解带来较大误差。以螺旋槽干气密封为研究对象,推导了考虑惯性项和实际流态的膜压控制方程,采用有限差分法求得膜压分布,对比分析了基于实际修正模型与经典简化模型的高速超临界二氧化碳干气密封气膜刚度和泄漏率,分析了不同介质压力和速度条件下实际气体效应、惯性效应和湍流效应对气膜刚度和泄漏率的影响规律,揭示了三种效应对稳态性能的单独影响及交互影响机理。结果表明:在本文给定条件下,经典简化模型在速度较小时求得的泄漏率偏小,而在超高速时求得的气膜刚度和泄漏率都偏小;在超高速条件下,实际气体效应使气膜刚度和泄漏率都显著增大,湍流效应使气膜刚度增大,而使泄漏率减小,惯性效应对气膜刚度和泄漏率影响很弱;实际气体效应与湍流效应对稳态性能影响之间具有很强的交互影响关系。

关键词: 超临界二氧化碳, 干气密封, 实际效应, 交互影响, 湍流效应

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