针对某电站锅炉进行了掺烧干化污泥的工程试验,重点考察了不同污泥掺烧比例下锅炉性能的变化。干化后的污泥灰份占比最高,其水份与烟煤水平接近。干化后的城市污泥、印染污泥热值在8000kJ/kg左右。掺烧污泥后,煤粉细度基本没有变化,炉膛整体温度水平降低。掺烧污泥有助于减少省煤器出口原始氮氧化物生成量,且掺烧比例越高,氮氧化物呈下降趋势。由于污泥的硫份高于一般煤种,同时挥发份较早析出消耗了主燃区氧量,掺烧污泥后水冷壁近壁区还原性气体浓度呈现恶化趋势。掺烧干化污泥后,CO未完全热损失呈现增大趋势,飞灰大渣含碳量无明显的变化规律。由于污泥热值较低,整体烟气量变大,排烟温度显著升高,干烟气热损失增大的趋势最为明显。475MW负荷下,干化污泥掺烧比例为2.5%,锅炉热效率下降0.23个百分点；630MW负荷下,干化污泥掺烧比例为6.0%,锅炉热效率下降0.22个百分点。掺烧污泥后,主再热汽温、主再热压力没有变化,再热减温水量有所上升。

The engineering test of dried sewage sludge co-combustion was carried out on a power plant boiler, and the changes of boiler performance under different sludge co-combustion ratios were investigated. The proportion of ash in dried sewage sludge was the highest, and the proportion of moisture in dried sewage sludge was close to that of bituminous coal. The calorific value of municipal sludge and dyeing sludge was about 8000 kJ/kg. After the co-combustion of fired sewage sludge, the fineness of pulverized coal did not change while the overall temperature level of the furnace decreased. The co-combustion of fired sewage sludge helped to reduce the amount of original nitrogen oxides produced at the economizer outlet, and the higher proportion of co-combustion, the greater downward trend of nitrogen oxides. Since the sulfur content of sludge is higher than that of coal types, and the earlier precipitation of volatile fraction consumes oxygen in the main combustion zone, the concentration of reducing gas in the near-wall area showed a deteriorating trend. After the co-combustion of fired sewage sludge, the incomplete heat loss of CO showed an increasing trend, while there was no obvious change in the carbon content of fly ash and residue. Due to the low calorific value of dried sewage sludge, the overall flue gas volume became larger, the exhaust gas temperature increased significantly, and the increasing trend of the heat loss of dry flue gas was the most obvious.

国家重点研发计划（2023YFB4102905）