配风方式对四角切圆煤粉锅炉燃烧特性影响数值分析  

Numerical analyses of effect of air distribution on combustion characteristics of tangentially pulverized coal-fired boiler

作　　者：李素芬[1] 刘丽萍[1] 陈贵军[1] 段联胜 

机构地区：[1]大连理工大学海洋能源利用与节能教育部重点实验室,辽宁大连116024 [2]大化集团热电厂,辽宁大连116031

出　　处：《大连理工大学学报》2010年第4期491-496,共6页Journal of Dalian University of Technology

摘　　要：借助CFD软件平台,利用Fluent对四角切圆煤粉锅炉炉内燃烧过程进行了三维稳态数值模拟,重点研究了二次风配风方式对炉内流动和燃烧过程的影响,探讨了不同配风方式下炉内流场、温度场、组分场的变化规律.结果表明:在均等配风、正宝塔配风、倒宝塔配风三种配风方式中,正宝塔配风为最佳配风方式.它不仅能保证炉内具有较好气流充满度和下二次风风速,利于煤粉与空气的混合与燃烧,减少炉渣中的可燃物含量,而且能够保证高温火焰位于燃烧区的中心位置,延长煤粉到炉膛出口的距离.研究结果对锅炉运行、设计和改造具有理论指导意义.3-D steady numerical simulation of combustion and flow fields in a tangentially pulverized coal-fired boiler was carried out by Fluent CFD Software to study the effect of secondary air distribution on flow and combustion. The change trends of flow,temperature and mixture field under three different air distribution modes,i.e. equal,positive pagoda and inverted pagoda-style air distribution modes,were probed. The results show that positive pagoda-style air distribution mode is the best one. This air distribution mode can not only ensure a better air full degree and a better lower secondary air speed,which enhances mixing and combusting between coal and air to reduce the contents of combustible substance of the slag,but also ensure that high temperature combustion flame is at the center of the area of burner,which prolongs the residence time of coal in the furnace and helps coal dust burn completely. The results obtained here can provide important theoretical guidance for boiler-operation,design and reconstruction in the future.

关 键 词：四角切圆煤粉锅炉 配风方式 燃烧特性 数值模拟 

分 类 号：TK224[动力工程及工程热物理—动力机械及工程]