喷淋水对高温烟气激冷过程的模拟研究

Numerical Simulation of the Spray Cooling Process of High Temperature Syngas

气化炉产生的高温烟气进入激冷室后需要实现快速降温,为了研究这一复杂过程,分别采用Volume of Fluid(VOF)模型、Two-fluid model(TFM)模型和Mixture模型对激冷室下降管内小孔喷淋实验进行数值模拟。由于高温烟气与冷却水接触充分,采用Lee传质模型描述气液间的传质过程,从而对激冷室内温度测量值和预测值进行对比分析。模拟结果表明:VOF模型预测的温度分布较其他两个模型更合理,另外辐射模型的耦合对温度的预测值基本没有影响,说明在该工况下对流传热是影响激冷效果的主要因素。

High temperature syngas produced in the gasifier is always cooled efficiently in the quench chamber.In order to investigate this complex process,several multiphase models were used,such as Volume of fluid(VOF),mixture model and two-fluid model(TFM),to simulate the flow characteristics and heat and mass transfer of ambient spray cooling experiment.Due to the intensive interaction between high temperature syngas and spay cooling water,the Lee model was used to describe the mass transfer process.By comparing with predicted results and experimental data,it was shown that VOF model had good agreement,and this model can be used to study the effect of spray mass flow rate on the syngas temperature variation along the dip tube.Additionally,the absence of radiation model gave almost same results,which indicated that convection heat transfer was the main factor affecting the quench effect under this condition.