贴壁风对二次风箱流动特性影响数值模拟  

Influence of closing-to-wall air on flow characteristics of a boiler's secondaryair-box: numerical simulation

作　　者：章洪涛[1] 关键 刘瑞媚 胡卿 杨卫娟[1] 王智化[1] 裘立春 

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 [2]浙江浙能技术研究院有限公司,浙江杭州310003

出　　处：《热力发电》2017年第4期77-80,98,共5页Thermal Power Generation

基　　金：国家重点基础研究发展计划项目(973计划)(2012CB214906)~~

摘　　要：运用数值模拟方法,以某电厂300 MW机组前后墙对冲燃烧锅炉二次风箱为研究对象,研究了贴壁风改造对锅炉二次风箱内流动特性及流量分配特性的影响。结果表明:贴壁风改造前,两侧燃烧器的流量低于中间燃烧器的流量,改造后,两侧燃烧器的流量高于中间燃烧器的流量,并且流量分配的均匀性也得以提高,相应的出口截面速度规律相同;各负荷下的贴壁风率较为恒定,均约为6.57%;常用负荷下增加4%二次风风量后,燃烧器流量与无贴壁风工况差异在3%之内,仍能保证炉内燃烧稳定性。Taking the secondary-air-box of a 300 MW unit boiler with front and rear wall opposed firing as the example, numerical simulation method was employed to investigate the effects of closing-to-wall air on air distribution and flow characteristics inside the secondary-air-box. The results show that, the flow rates of the side burners were lower than that of the middle ones before the transformation. Once the closing-to-wall air jet was added, the flow rates of the side burners increased and became higher than that of the middle ones, and the uniformity of the air distribution turned better. The flue gas velocity at the burner exit section changed in the same rule. The closing-to-wall air rate was stable at about 6.57% in each case. Under rated load condition, the deviation of the burner flow rate was within 3% when adding 4% secondary air rate, which could still ensure the furnace stability.

关 键 词：燃煤锅炉 对冲燃烧 贴壁风 二次风箱 燃烧器 流量分配 流动特性 

分 类 号：TK223[动力工程及工程热物理—动力机械及工程]