四角切圆锅炉在O_2/CO_2气氛下燃烧特性数值模拟  

Numerical study on combustion characteristics of a tangentially fired pulverized-coal boiler in O_2/CO_2 atmosphere

作　　者：姬海民 徐党旗[1] 李红智[1] 赵治平[1] 薛宁[1] 周飞[1] 聂剑平[1] JI Haimin XU Dangqi LI Hongzhi ZHAO Zhiping XUE Ning ZHOU Fei NIE Jianping(Xi＇an Thermal Power Research Institute Co. ,Ltd. ,Xi＇an 710032,China)

机构地区：[1]西安热工研究院有限公司,陕西西安710032

出　　处：《热力发电》2016年第10期54-59,共6页Thermal Power Generation

基　　金：中国华能集团公司总部科技项目(HNKJ12-H06)

摘　　要：利用Fluent软件对330 MW机组四角切圆煤粉锅炉常规燃烧和富氧燃烧进行了数值模拟研究,对比分析了不同工况下炉膛中心温度、辐射力、O_2分布、CO浓度、NO_x浓度之间的差异。结果表明:在富氧燃烧时,当O_2体积分数为21%时,炉内的燃烧温度总体要低于常规空气气氛下的燃烧温度,即辐射力低于常规空气气氛,燃烧排放的CO_2浓度远远高于常规燃烧,NO_x生成量较常规燃烧也有一定程度降低;在富氧条件下,随着φ(O_2)/φ(CO_2)增加,炉内煤粉燃烧得到强化,燃烧速度加快,中心温度提高,辐射强度增大,NO_x生成量增多,烟气中CO_2浓度就越大,越易于收集利用。The Fluent software was applied to carry out numerical simulation on combustion of a 330 MW unit tangentially pulverized coal fired boiler in air （02/N2 = 21 %/79 %） and oxygen-enriched （02/CO2 21%/79%, O2/CO2=25%/75%, O2/CO2 = 30%/70%, O2/CO2 = 35%/65%） atmosphere. The tempera- ture in the furnace center area, the radiation intensity,the concentration distribution of 02, CO, and NOx in different atmospheres were compared. The results show that,when the 02 concentration is 21% ,the fur- nace temperature during the oxygen-enriched combustion is lower than that during the air combustion, meaning the radiation intensity is weaker than that in the normal air atmosphere. The CO2 emission in O2/CO2 atmosphere is much higher than that in the conventional air combustion. The NOx formation is greatly lower than that in the air atmosphere . When the 02/CO2 ratio increases, the pulverized-coal com- bustion in the furnace gets stronger, leading to an acceleration in the Combustion speed, thus the tempera- ture in the furnace center area and the radiation intensity increases. Therefore, the NOx formation and the COz concentration grows,which makes the NOx and CO2 be easy to be captured.

关 键 词：煤粉 锅炉 四角切圆燃烧 常规燃烧 富氧燃烧 燃烧特性 污染物排放 数值模拟 

分 类 号：TK227.1[动力工程及工程热物理—动力机械及工程]