Abstract: In order to study the gas-liquid two-phase flow phenomenon of liquid film seals under high-speed and low-temperature working conditions, a phase change model of liquid film seals was constructed based on the theory of homogeneous fluid, and two-phase flow characteristics of the fluid films and effects of operating parameters on phase change were analyzed. The results show that the divergence of the flow spaces is the main factor of the phase change of groove zones. The temperature field changes significantly due to heat absorption and heat dissipation of phase changes. With the increase in speed, the fluid dynamic pressure increases and the temperature rises, the phase change range expands and the phase change rate increases. The increase of the medium temperature weakens the fluid dynamic pressure, and the increase of vapor heat absorption and the decrease of viscosity heat dissipation are the reasons for the fluid cooling on the end surfaces. 

Key words: two-phase mechanical seal, gas-liquid two-phase flow, homogeneous fluid, thermal effect

摘要： 为研究高速、低温工况下的液膜密封气液两相流现象，基于均相流体理论，构建了液膜密封相变模型，分析了流体膜两相流动特性和工况参数对相态转变的影响。结果表明：流动空间发散是槽区相变的主要因素，相变的吸热散热导致温度场显著变化；转速升高时，流体动压增强，温度升高，相变范围扩展，相变速率增大；介质温度升高使流体动压减弱，汽化吸热量增大、黏性耗散热量减少是端面流体冷却的原因。

关键词: 两相机械密封, 气液两相流, 均相流体, 热效应