焚烧处理是我国生活污泥主要处置方式，燃煤与污泥掺混燃烧是研究热点之一，但在小规模燃煤机组研究和应用较少，基于国内某电厂210 MW四角切圆燃煤机组，对8个工况分别开展掺烧生活污泥的现场试验。结果表明，随污泥掺烧比例增加，燃料水分、灰分和硫分含量逐渐增加，热值逐渐降低。对于固体产物，由于污泥中重金属含量高于燃煤，在掺混污泥燃烧后，飞灰、炉渣和脱硫石膏的重金属含量增加，存在二次污染风险。常规烟气污染物NOx、SO2和粉尘排放受掺烧污泥影响较小，现有烟气净化工艺可满足燃煤烟气的超低排放要求；掺烧污泥后重金属及其化合物等污染物浓度上升，最高提升了约3.6倍，满负荷工况下掺烧10%污泥时，二噁英平均质量浓度为0.021 ng/m3（以毒性当量浓度TEQ计），但仍满足相关排放要求；掺烧10%生活污泥时，炉膛平均温度仅下降15 ℃，热效率降幅低于0.5%，影响并不显著。

Incineration treatment is the main disposal method of domestic sludge in my country. Mixing combustion with coal is one of the research hotspots, but it is less researched and applied in small-scale coal-fired units. Based on the 210 MW four-corner tangential-circle coal-fired unit of a domestic power plant, field tests of mixing domestic sludge for 8 working conditions were carried out, respectively, and the monitoring data and test results were compared and analyzed. The results show that ash content and the sulfur content increase gradually with the increase of sludge blending ratio, the calorific value of the fuel decreases gradually. For solid products, since the content of heavy metals in sludge is higher than that of coal, the content of heavy metals in fly ash, slag and desulfurized gypsum increase after mixed sludge combustion, and there is a risk of secondary pollution. The emission of conventional flue gas pollutants NOx,SO2 and dust is less affected by the mixed burning of sludge, and the existing flue gas purification process can meet the ultra-low emission requirements of coal-fired flue gas.After mixed burning of sludge, the concentration of heavy metals and their compounds and other pollutants increase by about 3.6 times at most. Under full load condition, when 10% sludge is mixed burning, the average mass concentration of dioxin is 0.021 ng/m3 (calculated by toxic equivalent concentration TEQ), but it still meets the relevant emission requirements. When 10% domestic sludge is mixed, the average temperature in the furnace only decrease by 15 ℃, and the decrease in thermal efficiency is less than 0.5%, the effect is not significant.

0 引言

1 现场试验

   1.1 燃煤机组概况

   1.2 试验工况

   1.3 试验设计与方法

2 试验结果与分析

   2.1 燃料特性分析

   2.2 燃料与燃烧产物的微量成分

   2.3 烟气污染物排放

   2.4 燃烧温度及稳定性

   2.5 锅炉热效率

   2.6 受热面积灰与腐蚀

   2.7 风烟系统

3 结论