文档介绍：国内图书分类号: : :杨学海导师:朱群益李争起教授申请学位:工学硕士学科、专业:热能工程所在单位:能源科学与工程学院答辩日期:2009年7月授予学位单位:哈尔滨工业大学Classified Index: .: for the Degree of Master in Engineering NUMERICAL SIMULATION OF BUSTION CHARACTERISTICS IN A DOWN-FIRED BOILER WITH SWIRL BURNER Candidate:Yang XuehaiSupervisor:Prof. Zhu Qunyi Li ZhengqiAcademic Degree Applied for:Master of EngineeringSpecialty:Thermal EngineeringAffiliation: School of Energy Sci. & of Defence:July, 2009Degree-Conferring-Institution:Harbin Institute of Technology哈尔滨工业大学工学硕士学位论文- - I摘要由于国民经济的快速发展,国家对电力需求迅速增长,而且从我国动力用煤结构而言,燃用贫煤、无烟煤等劣质煤电站容量剧增。W型火焰锅炉采用了长火焰行程、分级配风、煤粉分段燃烧等技术手段,W型火焰燃烧技术非常适用于燃用无烟煤、贫煤等劣质煤的大型电站锅炉。从1984年引进该技术到现在,我国已投运的W型火焰电站锅炉有50多台,积累了不少关于W型火焰锅炉的运行经验,但国内对该锅炉的深入研究还不够,而对利用旋流燃烧器的W型火焰锅炉的研究则更少。针对某电厂300MWe燃用无烟煤W型火焰锅炉,利用流体力学模拟计算软件Fluent对锅炉炉内单相、气固两相三维流动,传热和气固两相湍流燃烧进行了全面的数值模拟,计算了在锅炉100%设计负荷下,变化二次风和分级风风量比、变化燃烧器内外二次风叶片角度时W型火焰煤粉锅炉炉内流场分布、温度场分布及烟气成分浓度分布等,并进一步分析了污染物生成的规律,计算了NOx在W型火焰煤粉锅炉内的分布情况,结合热态满负荷工业试验数据,分析了该型锅炉炉内的燃烧特性。通过设计参数下工业试验结果和燃烧过程数值模拟计算结果的对比分析,证明所选用模拟计算方法和模型的正确性。数值模拟计算结果显示,二次风和分级风风量比增大,可调叶片角度越小时射流下冲深度大,煤粉在炉膛内行程长,停留时间长,有利于提高锅炉燃尽率。综合考虑燃尽效果、炉膛结渣风险、NOx排放、灰斗与喉口安全等因素,:1时炉膛内燃烧较好,内二次风叶片角度适当增大,外二次风叶片角度适当减小为宜。通过数值模拟计算可以很好地预测炉膛内的燃烧状况,和实验结果对照使结论更具说服力,对于该型锅炉的设计及运行具有一定的指导意义。关键词旋流燃烧器;W型火焰锅炉;数值模拟;叶片角度;二次风量哈尔滨工业大学工学硕士学位论文- - IIAbstract With the rapid development of the national economy of China, the society demands of more electricity and the capacity of lean coal-fired and anthracite-fired power plants according to the power coal configuration increases quickly. The down-fired boilers could apply to large-scale low-grade coal fired (such as lean coal and anthracite) power plants with characteristics of long flame, air zoning and pulverized coal bustion. Although more than fifty down-fired boilers have been on operation since the year of 1984 when the technology was imported and abundant operational experience have been accumulated, the research of