煤气化辐射废锅内高温气固两相流动传热传质数值研究

基于欧拉-拉格朗日方法对煤气化辐射废锅内高温气固两相流动传热传质特性进行了三维数值计算,水冷壁上的灰渣沉积过程采用熔渣沉积反弹模型描述。结果表明:灰渣沉积主要发生在辐射废锅的中下部,射流区流速和温度在距离底部5.5 m处迅速衰减,灰渣厚度和导热热阻在此处迅速增加,对流辐射复合换热系数和传热系数在此处迅速下降;随着入口温度的升高,壁面沉积厚度和导热热阻逐渐升高,对流辐射复合换热系数和传热系数由于温差的影响也逐渐升高;随着操作压力的升高,壁面沉积厚度和导热热阻逐渐下降,对流辐射复合换热系数和传热系数逐渐升高。

Numerical Study on Heat and Mass Transfer Characteristics of High Temperature Gas-solid Two-phase Flow Inradiant Syngas Cooler of Coal Gasification

Based on Euler-Lagrange method,the heat and mass transfer characteristics of high temperature gas-solid two-phase flow in the radiant syngas cooler of coal gasification radiation are numerically calculated in this paper.The slag deposition on water wall surface is described by slag deposition rebound model.The results show that the ash deposition mainly occurs in the middle and lower part of the radiant syngas cooler (RSC),the velocity and temperature of the jet zone decay rapidly at 5.5 m from the bottom,the thickness of ash and thermal-conduction resistance increase rapidly,and the compound heat transfer coefficient of convective radiation and overall heat transfer coefficient decrease rapidly here.With the increase of inlet temperature,the thickness of wall deposition and thermal-conduction resistance increase,and the compound heat transfer coefficient of convective radiation and overall heat transfer coefficient gradually increase due to the influence of temperature difference.With the increase of operating pressure,the thickness of wall deposition and thermal-conduction resistance decrease gradually,while the compound heat transfer coefficient of convective radiation and overall heat transfer coefficient increase gradually.