Abstract: The spiral groove dry gas seal generates a certain amount of heat when running at high speed and pressure, which will lead to the thermo-elastic deformation of the sealing ring. Consequently, unstable operation and leakage increase will appear. The gas film pressure and velocity can be obtained based on the boundary condition of velocity-slip and the energy equation for the gas film is derived in this paper with the boundary condition of temperature-jump. The temperature distribution in the gas film can be solved by using the film pressure, velocity and energy equation with the numerical calculation of the software Matlab. The results show that the gas film velocity decreases first and then increases as the gas flows from the external into the interior and the velocity is smaller near the groove root, while the film temperature increases first and then decreases and the temperature is higher near the groove root. The film temperature distribution has little difference with and without considering the temperature-jump. The effect of the temperature-jump on the gas film temperature could be ignored.

Key words: dry gas seal, microscale, gas film, fluid mechanics, numerical simulation

摘要： 螺旋槽干气密封在高压、高速旋转时内部会产生一定量的热，导致密封环发生热弹变形，从而使运行不稳定和泄漏量增大。首先在速度滑移边界条件下，求出气膜压力和气膜速度；然后推导出气膜的能量微分方程，同时引入温度阶跃边界条件，进而利用气膜的压力、速度和能量方程，通过Matlab软件数值计算得到气膜的温度分布。结果表明，随着气体从外径流入内径，气膜速度的分布规律是先降低后升高，槽根部周围速度较低；随着气体从外径流入内径，气膜温度的分布规律是先升高后降低，槽根部周围温度较高；考虑温度阶跃下的温度分布与不考虑温度阶跃下的温度分布相差较小，可以不予考虑温度阶跃对干气密封气膜温度的影响。

关键词: 干气密封, 微尺度, 气膜, 流体力学, 数值模拟