超临界二氧化碳气体端面密封阻塞效应研究

为了分析超临界二氧化碳气体临界状态大幅度物性参数变化和偏离理想气体的真实气体效应对干气密封性能的影响,建立螺旋槽干气密封端面微尺度三维流动模型,分别采用Fluent软件中二氧化碳的实际气体模型和理想气体模型求解密封端面流动方程。数值模拟结果表明:考虑超临界二氧化碳实际气体效应时,端面更容易发生阻塞工况;气膜间隙和转速增大,阻塞效应增强,但温度升高,阻塞效应减弱;在阻塞工况下,密封开启力和泄漏量均随着气体温度、转速增加而降低。

Study on Blocking Effect Supercritical Carbon Dioxide of Dry Gas Seal

In order to investigate the effect of the trans-critical state parameter changes and the real gas characteristics of supercritical carbon dioxide when flowing through dry gas seal face on the seal performance,a 3 D flow model for S-CO2 at microscale spiral groove of dry gas seal was developed,and solved respectively by using Real Gas Model(RGM) and Ideal Gas Model in Fluent software.The numerical simulation results show that the choked flow is more likely to occur at the exit of the seal when considering the real gas effect of supercritical carbon dioxide.The blocking effect is increased with the increase of film gap and rotating speed,but are decreased with the increase of the medium temperature.Under the choked flow condition,the opening force and the leakage are decreased with the increase of gas temperature and rotating speed.