分液罐内气液两相流分离效率的数值模拟及优化

Numerical simulations and optimization of separation efficiency of gas-liquid two-phase flow in flare knock-out drum

火炬系统中,分液罐通过有效分离放空气体中携带的液滴或固体杂质,减少气体中的凝液量,避免火雨现象的发生,并对火炬系统的安全运行和环境保护起到关键作用。运用FLUENT软件,进行了火炬系统卧式分液罐中液滴直径、出入口压差、工作温度、气体含液率、分液罐长径比等因素对分离效率影响的数值模拟和优化分析。研究表明,在满足设计规范要求的前提下,适当增大液滴直径,减小出入口压差,提高工作温度,降低气体含液率,增大分液罐长径比,将有利于提高分液罐的分离效率。

Knock-out drum in the flare system can avoid rain of fire because it can effectively separate droplets or solid impurities from the vent gas and reduce the amount of condensate in the gas. Therefore, knock-out drum plays a key role for the safety of the flare system and the protection of the environment. In the paper, FLUENT software was applied to simulate the effect of droplet diameter, the pressure difference between the inlet and outlet, working temperature, liquid holdup of the gas and length-diameter ratio on separation efficiency of horizontal knock-out drum. The results showed that properly increasing the droplet diameter, working temperature and length-diameter ratio of knock-out drum, decreasing the pressure difference of the inlet and outlet, liquid fraction can benifit to increase the separation efficiency of the knock-out drum.