带径向管屏水冷壁辐射废锅内流场与传热的数值模拟

Numerical Simulation of Flow Field and Heat Transfer in Radiant Syngas Cooler with Radial Tube Water Wall

对低压气流床辐射废锅进行直接数值模拟,分析带径向管屏水冷壁辐射废锅内流场与传热。结果表明:管屏水冷壁增强了辐射传热与湍流,降低了回流区的气流及灰渣温度,使得射流长度变短,回流区域及回流速度变小;无管屏与有管屏的截面平均温度差随截面高度增加而逐渐增加,到达出口处其截面平均温度差达到80℃;管屏水冷壁有效提高气流降温速度和热回收效率,但使细小灰渣颗粒更易于富集在辐射废锅顶锥及管屏水冷壁周边区域。

This paper discusses the direct numerical simulation method applied to the low-pressure entrained-flow radiant syngas cooler,and analyzes the flow field and heat transfer in radiant syngas cooler with radial tube water wall. The research results show that the tube water wall enhances the radiation heat transfer and turbulence,reduces the temperature of ash and flow of recirculation zone,and shortens jet length,and decreases the recirculation zone and recirculation velocity. With the sectional height going up,the sectional mean temperature difference between the no-tube screen and tube screen increase gradually,reaching 80℃ at the exit. The tube water wall improves the airflow cooling speed and heat recovery efficiency,but it makes fine ash particles enriched more easily in the top cone of radiant syngas cooler and the surrounding area of tube water wall.