摘要
为探究生物质气与煤粉混燃对锅炉燃烧特性和污染物生成特性的影响,采用Fluent软件模拟600 MW超临界对冲锅炉内生物质气与煤粉混燃过程,研究在0、10%和20%三种不同混燃比条件下,稻壳、木屑、麦秆和稻秆混合原料气化450℃的生物质气与煤粉混燃时对锅炉燃烧特性以及污染物生成特性的影响。结果表明:加入生物质气与煤混合燃烧时,混燃比增加,利于促进锅炉的燃烧,但锅炉产生的烟气量增加,使锅炉整体燃烧温度降低;混燃比每增加10%,燃烧温度降低50℃;随着混燃比增加,锅炉内O_2含量整体下降,燃烧更加剧烈,CO迅速发生反应并完全反应,CO_2生成量上升,而SO_2和NO_x体积分数下降,20%混燃比时分别可最大降低21%和48%。模拟研究的混燃结果较为可信,混燃生物质气可显著降低锅炉污染物排放。
In order to explore the effect of co-combustion of biomass gas and pulverized coal on combustion and pollutant generation characteristics of boilers,Fluent was used to simulate co-combustion process of biomass gas and pulverized coal in a 600 MW supercritical opposed boiler.The effects of different co-combustion ratio（ 0,10% and 20%） of biomass gas gasified by mixing rice husk,sawdust,wheat straw and rice straw at 450 ℃ on boilers combustion characteristics and pollutant generation characteristics were studied.The results show that increase of co-combustion ratio is beneficial to promote the combustion characteristics of the boiler when mixedly burning biomass with coal.However,the amount of flue gas generated by the boiler will increase,resulting in a decrease in the overall combustion temperature of the boiler.When the co-combustion ratio is increased by 10%,the combustion temperature will be reduced by 50 ℃.With the increase of co-combustion ratio,the content of O2 in the boiler will decrease and the combustion will become more intense.As a result,the CO reacts rapidly and completely,resulting in an rise in the amount of CO2,while the concentration of SO2 and NOx decreases.When the co-combustion ratio is 20%,the concentration of SO2 and NOxcan be reduced by about 21% and 48%,respectively.Co-combustion results of numerical simulation is more credible,and co-combustion biomass gas can reduce pollutant emissions from boilers significantly.
作者
徐皓鹏
任少辉
邵敬爱
曾阔
杨海平
张世红
陈汉平
XU Haopeng;REN Shaohui;SHAO Jing＇ai;ZENG Kuo;YANG Haiping;ZHANG Shihong;CHEN Hanping(State Key Laboratory of Coal Combustion,Huazhong University of Science and Technology,Wuhan 430074,China;North China Power Engineering Co.,Ltd.of China Power Engineering Consulting Group,Beijing 100120,China;Shenzhen Research Institute of Huazhong University of Science and Technology,Shenzhen 518007,China)
出处
《洁净煤技术》
CAS
2018年第5期61-67,共7页
Clean Coal Technology
基金
国家自然科学基金资助项目(51476067
51506071)
深圳市知识创新计划基础研究资助项目(JCYJ20170307172032901)
关键词
生物质气
混燃
对冲锅炉
燃烧特性
污染物排放
数值模拟
biomass gas
co-combustion
opposed boiler
combustion characteristics
pollutant emission
numerical simulation
