气化炉激冷室下降管内气液两相热质同时传递过程数值研究

Numerical Investigation of Gas-liquid Heat and Mass Concurrent Transfer Process in Vertical Pipe in Gasifier Quenching Chamber

采用流体体积双流体模型对德士古水煤浆气化炉激冷室下降管内气液两相热质同时传递过程进行数值研究,并建立了水蒸气在气相主体中的组分传输模型。数值预测的下降管内温度分布规律与实验结果吻合较好。据此探讨了相变对下降管内液膜流动形态的影响以及流动对水蒸气分布的影响,研究结果表明,相变对液膜形态有显著影响;气体对水蒸气的携带作用使得下降管内水蒸气沿高度方向上呈大梯度分布,出口处水蒸气浓度最高,下降管内存在气体带液的现象。

A numerical simulation was conducted to investigate the gas-liquid heat and mass concurrent transfer in the vertical pipe of Texaco type coal-water slurry gasifier, using volume of fluid（VOF） multiphase flow model and the species transport model of the gas phase. The numerical prediction of the temperature distribution along the vertical pipe was in a good agreement with experiment. Based on this, both the influence of the phase transition on liquid-film flow pattern and the influence of the flow on the water vapor distribution are investigated. It is found that the liquid-film flow pattern is significantly affected by the phase transition. The liquid vapor distributes with great gradient along the vertical pipe and the liquid vapor concentration of the outlet is highest, as a result of vapor carrying effect. The liquid entrainment of the gas in the vertical pipe is also discovered.