针对某300 MW四角切圆锅炉煤粉掺烧污泥运行情况，采用FLUENT软件，基于单混合分数和双混合分数PDF模型，对锅炉炉膛内的烟气流动、燃烧过程和污染物NO〖HT5”〗x排放进行数值模拟。结果表明：与单混合分数相比，双混合分数PDF模型能更好地模拟污泥的高挥发分和水分对燃烧的影响，出口烟气误差在4%以内，更加符合炉内实际燃烧过程;随着污泥掺混比例的增加，污泥中水分蒸发吸热造成炉膛内的整体燃烧温度下降;当污泥含水量为40%时，掺混比例在6%以内对锅炉的燃烧情况影响不大，在技术上是可行的;由于污泥的含氮量显著高于煤粉，对于含水量为40%的污泥，随着掺混比例的增加，NO〖HT5”〗x排放量增加；含水量为80%污泥掺混煤粉后，随着掺混比例的增加，NO〖HT5”〗x排放由于燃烧温度急剧降低而减少。

With a 300 MW tangentially fired boiler furnace as the research object,the numerical simulation was carried out using singlemixture/probability density function model and doublemixture/probability density function model.The flow and combustion process of combustible component and NO〖HT5〗x emission were obtained through numerical simulation using the fluent software.According to the results,compared with single mixing fraction,the simulation results of double mixing fraction/PDF model could better simulate the effect of high volatile matter and moisture of sludge on combustion.The error of outlet flue gas is less than 4%,which is more in line with the actual combustion process in the furnace.With the increase of sludge mixing ratio,the overall combustion temperature in the furnace decreases due to water evaporation and heat absorption in sludge.When the sludge moisture content is 40%,the mixing ratio within 6% has little effect on the combustion of the boiler,which is technically feasible.When the nitrogen content of sludge is significantly higher than that of pulverized coal,for the sludge with 40% water content,the NO〖HT5〗x emission increases with the increase of mixing content.When the sludge with 80% water content is mixed with pulverized coal,the NOx decreases sharply due to thedecrease of combustion temperature,as the mixing content increases.

TK224

2018年广州市科学研究计划重点项目专题(201804020082）；国家质量监督检验检疫总局科技项目（2017QK152）