Thermoelastohydrodynamic characteristics of supercritical CO₂ spiral groove face seals

Abstract

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/

Citation

Zhu, D. and Bai, S. (2021), "Thermoelastohydrodynamic characteristics of supercritical CO₂ spiral groove face seals", Industrial Lubrication and Tribology, Vol. 73 No. 1, pp. 153-162. https://doi.org/10.1108/ILT-05-2020-0169