近零排放火电厂烟囱壁面冷凝水液膜分布数值模拟

Numerical simulation on water film condensed on stack inner wall of "near zero" emissions power plants

基于CFD方法,采用Eulerian Wall Film模型与Mixture模型耦合,模拟了某近零排放百万机组湿式静电除尘器出口饱和湿烟气在烟道和双内筒套筒钛板烟囱壁面冷凝水液膜的分布特征。计算得出极端气候该机组锅炉最大连续蒸发量工况下,烟囱膨胀节上部凝结水总量12.99t/h,膨胀节下部凝结水总量1.75t/h;并分析了液膜最容易被烟气二次夹带的区域为烟囱入口处的烟囱内壁、膨胀节处内壁以及近烟囱的净烟道顶部。

To design the flue duct and condensate water collector for the chimney more scientifically,on the basis of the CFD method,a model coupling Eulerian wall Film model and mixture model was applied to simulate the distribution characteristics of water film,which is from the saturated wet flue gas at outlet of the wet electrostatic precipitator,that condensing on walls of the flue duct and double-inner cylinder sleeve titanium plate stack.The calculation shows that,under the extreme weather conditions with the boiler of the maximum continuous evaporation amount,the maximum condensation amount above the expansion joint was 12.99t/h,and that below the expansion joint was 1.75t/h.Moreover,analysis shows the water film regions where liquid film would most likely be re-entrained were the inner wall at the chimney entrance,the inner wall of the expansion joint and the top of the ducts near the stack.