Purpose

The purpose of this study is to determine the sealing performance of face seals by numerical analysis of thermoelastohydrodynamic characteristics of supercritical CO₂ (S-CO₂) spiral groove face seals in the supercritical regime.

Design/methodology/approach

The spiral groove face seal was used as the research object. The distribution of lubricating film pressure and temperature was analysed by solving the gas state, Reynolds and energy equations using the finite difference method. Furthermore, the influence law of sealing performance was obtained.

Findings

Close to the critical temperature of S-CO₂, face distortions produced by increasing pressure lead to divergent clearance and resulted in reduced opening force. In the state of S-CO₂, the face distortions generated by increasing seal temperature lead to convergent clearance, which enhances the opening force. In addition, near the critical temperature of S-CO₂, the opening force may be reduced by 10%, and the leakage rate of the seal sharply increases by a factor of four.

Originality/value

The thermoelastohydrodynamic characteristics of supercritical CO₂ face seals are illustrated considering the actual gas effect including compressibility, heat capacity and viscosity. Face distortions and sealing performance were calculated under different seal pressures and seal temperatures in the supercritical regime, as well as with N₂ for comparison.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2020-0169/

中文翻译：

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超临界CO2螺旋槽端面密封的热弹性流体力学特性

目的

这项研究的目的是通过对超临界状态下的超临界CO ₂（S-CO ₂）螺旋槽端面密封件的热弹流体力学特性的数值分析来确定端面密封件的密封性能。

设计/方法/方法

以螺旋槽端面密封为研究对象。利用有限差分法求解气态，雷诺和能量方程，分析了润滑膜压力和温度的分布。此外，获得了密封性能的影响规律。

发现

在接近S-CO ₂的临界温度时，由于压力增加而产生的面变形会导致间隙扩散，并导致打开力降低。在S-CO ₂的状态下，由于密封温度升高而产生的面变形导致会聚间隙，这会增大打开力。此外，在S-CO ₂的临界温度附近，打开力可能会降低10％，并且密封件的泄漏率会急剧增加四倍。

创意/价值

考虑到实际气体效应（包括可压缩性，热容量和粘度），说明了超临界CO ₂端面密封件的热弹性流体力学特性。在超临界状态下，在不同的密封压力和密封温度下，使用N ₂进行了计算，得出了表面变形和密封性能。

同行评审

本文的同行评审历史记录可在以下网址获得：https://publons.com/publon/10.1108/ILT-05-2020-0169/