不同带粉量的三次风再燃试验与数值模拟  

Experimental study and numerical simulation on tertiary air reburning with different micronized coal content

作　　者：斯东波[1] 周昊[1] 岑可法[1] 

机构地区：[1]浙江大学能源清洁利用国家重点实验室,浙江杭州310027

出　　处：《浙江大学学报（工学版）》2010年第3期482-488,共7页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(60534030);浙江省自然科学基金资助项目(R107532);新世纪优秀人才支持计划资助项目(NCET-07-0761);全国优秀博士学位论文作者专项资金资助项目(200747)

摘　　要：在某200MW四角切圆燃烧煤粉炉上实施了三次风再燃技术,并采用现场试验和数值模拟相结合的方法,研究不同三次风带粉量工况下的炉内煤粉燃烧和NOx还原情况.研究结果表明,引入高速燃尽风喷口(OFA)射流可以强化混合,加快焦炭颗粒的燃尽,同时通过合理控制OFA喷口高度来避免炉膛上部超温;为降低飞灰含碳量,要尽量提高主燃区内煤粉的燃尽程度;若适当提高OFA喷口高度并合理控制炉内各区域的过量空气系数,在20%带粉量情况下,该三次风再燃方案可以获得50%以上的脱硝率并基本不影响锅炉正常运行.Tertiary air reburning technology was applied to a 200 MW tangentially coal-fired boiler,with using the micronized coal contained in the tertiary air as reburning fuel. In different conditions of the micronized coal content in the tertiary air,the coal combustion and NOx reduction were investigated by means of both field tests and numerical simulation. The results show that the high-velocity over fire air （OFA） injections can improve the mixing,and therefore make the char particles burn out quickly. Also the OFA nozzles should be located properly so as to avoid temperature increase in the upper furnace. In order to reduce the carbon content in fly ash,the coal burnout ratio in primary zone should be improved to a high level. The results also indicate that NOx reduction rate of more than 50% can be obtained without adverse impact on boiler performance with satisfying the following conditions：the OFA nozzles are shifted upward in a proper range,each zone in the furnace is operated at reasonable stoichiometry,and the micronized coal content in the tertiary air is increased to 20%.

关 键 词：三次风再燃 三次风带粉量 脱硝率 数值模拟 飞灰含碳量 

分 类 号：TK224[动力工程及工程热物理—动力机械及工程]