混烧准东煤660 MW煤粉炉分离燃尽风位置优化研究

以某混烧准东煤与北塔山煤的660 MW超超临界四角切圆锅炉为研究对象，使用ANSYS FLUENT软件，模拟当准东煤与北塔山煤的混烧质量比分别为8∶2、9∶1和10∶0时，分离燃尽风喷口投用位置对炉膛出口NOx浓度和煤粉燃尽率的影响，确定分离燃尽风的最佳位置。研究表明，各混烧比下，还原区高度为4 m时，炉膛出口NOx浓度和煤粉燃尽率达到最佳值，NOx浓度分别为2270、2403、2605 mg/m3，煤粉燃尽率分别为9877%、9867%、9775%。保持还原区高度4 m不变，改变高低位燃尽风间距，当高低位燃尽风之间的距离为25 m时，炉膛出口NOx浓度和煤粉燃尽率达到最佳值，NOx浓度分别为227010、240300、260525 mg/m3，煤粉燃尽率分别为9877%、9867%、9775%。研究结果可为类似炉型混烧或全烧准东煤提供参考。

Study on optimization of position of separated burnout air in 660 MW pulverized coal boiler co-combustion with Zhundong Coal

Taking a 660 MW ultra supercritical tangentially fired boiler burning Zhundong coal and Beitashan coal as the research object，ANSYS FLUENT software was used to simulate the influence of the nozzle position of the separation burnout air on the NOx concentration and pulverized coal burnout rate at the furnace outlet when the mass ratio of Zhundong coal and Beitashan coal is 8∶2，9∶1 and 10∶0，so as to determine the optimal position of the separated over-fire air.The results showed that:when the mixed-burning mass ratio of Zhundong coal and Beitashan coal is 8∶2，9∶1 and 10∶0 respectively， and the height of reduction zone is 4 m，the NOx concentration at furnace outlet and the burnout rate of pulverized coal reach the best value，which are 2270，2403，2605 mg/m3，9877%，9867%，9775% respectively.When the distance between the high and low over-fire air is 2.5 m，the NOx emission and the coal burnout rate at the furnace outlet reach the best value，which are 227010，240300，260525 mg/m3，9877%，9867%，9775%，respectively.The results can provide a reference for the similar furnace type mixed combustion or full combustion of Zhundong coal.