为探究燃煤电站协同处置市政污泥对机组现有设备系统和运行状况的影响,开展实验室掺烧试验与现场实炉掺烧试验。试验结果表明,实验室掺烧水分13%的干污泥,掺入污泥比例20%,混合燃料着火温度升高36℃,燃尽率下降1.5%;随污泥比例增加,燃料可磨性下降,结渣倾向加重。现场试验掺烧水分40%的污泥,掺烧比例10%及以下,输煤、制粉系统运行正常,锅炉结焦状况、汽水参数、风烟参数等均在正常范围内;烟气中二噁英毒性当量最高值为0.038ng/m3(11%O2,以TEQ计),HCL、HF质量浓度最高分别为2.50、0.23mg/m3,烟尘质量浓度≤10mg/m3,SO2质量浓度≤35mg/m3,NOx质量浓度≤50mg/m3,均满足国家排放标准;飞灰、大渣、石膏中的氰根离子、烷基汞、重金属、氟离子排放均满足国家标准要求。污泥掺烧比例10%及以下时,机组的输煤系统、制粉系统、燃烧系统、送引风机等辅机均能适应,不会对飞灰、大渣、石膏的品质及利用产生影响,且烟气中的NOx、SO2、烟尘、二噁英、HCl、HF等均可达标排放。进一步提高污泥掺烧比例时,仍需注意制粉系统的干燥出力与研磨出力核算,同时需监测炉膛烟温变化及管壁结渣情况、污染物排放情况,合理安全地解决污泥处置问题。

In order to explore the impact of co-disposal of municipal sludge in coal-fired power stations on the existing equipment systemand operation status of the unit, laboratory co-combustion test and on-site co-combustion test was carried out. The test results show thatwhen dry sludge with 13% water content is mixed with 20% sludge in the laboratory, the ignition temperature of the mixed fuel is increased by 36 ℃ and the burnout rate is decreased by 1.5%. With the increase of sludge proportion, the grindability of fuel decreases andthe tendency for slagging increases. In the field test, the sludge with 40% water content is mixed with 10% or less, the coal handling andpulverizing system operates normally, the boiler coking condition, steam and water parameters, air and smoke parameters are within thenormal range; The maximum toxic equivalent value of dioxin in flue gas is 0.038 ng/ m3(11% O2), the maximum values of HCL and HFare 2.50 and 0.23 mg/ m3.The mass concentration of smoke and dust is≤ 10 mg/ m3, the mass concentration of SO2 is≤ 35 mg/ m3,the mass concentration of NOx is≤ 50 mg/ m3, all of which can meet the national emission standards. The emission of cyanide ion, alkyl mercury, heavy metal and fluorine ion in fly ash, large slag and gypsum meet the requirements of national standards. The results showsthat when the sludge blending ratio is 10% or less, the auxiliary equipment of the unit such as the coal handling system, the pulverizingsystem, the combustion system, the forced draft fan and the induced draft fan can adapt, and will not affect the quality and utilization offly ash, large slag and gypsum, in addition the NOx, SO2, soot, dioxin, HCl and HF in the flue gas can be discharged up to standard.When further increasing the sludge blending ratio, it is still necessary to pay attention to the calculation of drying output and grinding output of the pulverizing system, and monitor the change of furnace flue gas temperature, slagging on the pipe wall and pollutant discharge,so as to reasonably and safely solve the sludge disposal problem.

0 引言

1 研究方法

2 混合燃料燃烧特性

   2.1 试验燃料

   2.2 磨制特性试验

   2.3 燃烧特性试验

3 现场试验

   3.1 试验燃料

   3.2 对输煤系统的影响

   3.3 对制粉系统的影响

   3.4 对锅炉效率的影响

   3.5 对汽水参数的影响

   3.6 对燃烧和结渣的影响

   3.7 对锅炉辅机运行的影响

   3.8 对飞灰、大渣、石膏的影响

   3.9 对锅炉污染物生成的影响

4 结论