超超临界锅炉磨煤机组合运行方式优化数值模拟  

Optimal Simulation on the Combination Mode of Mills for an Ultra-supercritical Utility Boiler

作　　者：方庆艳[1] 汪华剑[1] 陈刚[1] 周怀春[1] 

机构地区：[1]煤燃烧国家重点实验室(华中科技大学),湖北省武汉市430074

出　　处：《中国电机工程学报》2011年第5期1-6,共6页Proceedings of the CSEE

基　　金：国家自然科学基金项目(50806024;51025622);广东省重大科技专项(2008A080800029)~~

摘　　要：在不同磨煤机组合运行方式下,对一台1 000 MW超超临界前后墙旋流对冲燃烧煤粉锅炉进行了炉内流动、燃烧、传热与NOx排放特性数值模拟研究。模拟结果与试验测量值符合性较好。结果表明,不同的磨煤机组合运行方式对煤粉颗粒在炉膛内的停留时间、燃烧器区域空气分级效果、下炉膛出口烟气温度和水冷壁壁面热流分布有不同的影响。相比6台磨煤机运行,当5台磨煤机运行,停运上层燃烧器时,煤粉颗粒停留时间增加,飞灰含碳量降低,煤粉燃尽率增加;燃烧器区域空气分级效果得到强化,NOx排放量降低;下炉膛出口烟气温度降低,有利于降低大屏过热器挂渣的倾向。The characteristics of flow, combustion, heat transfer and NOx emission were numerically investigated under the different combination modes of mills for a 1 000 MW ultra-supercritical swirling opposed coal-fired utility boiler. The simulated results agree well with the measured values. The results show that the different combination modes of mills have different influence on the residence time of the pulverized-coal particles, effect of air staging in the burner region, flue gas temperature at the exit of the lower furnace and heat flux distribution on the furnace walls. Compared with the operating mode with all 6 mills in service, that with 5 mills in service and stopping the upper burners can increase the residence time of the pulverized-coal particles, resulting in the reduction of carbon content in the fly ash and the increase of pulverized-coal burnout. It can also enhance the effect of air staging in the burner region. Consequently, the NOx emission decreases. The flue gas temperature at the exit of the lower furnace can also decrease, being helpful to reducing the slagging tendency on the surfaces of the platen super-heaters.

关 键 词：煤粉 超超临界锅炉 燃烧 优化 数值模拟 

分 类 号：TK223[动力工程及工程热物理—动力机械及工程]