烟叶烘烤系统多燃料预混燃烧的污染物排放特性  

Pollutant emission characteristics of tobacco curing system in multi-fuel premixed combustion

作　　者：吴正余 华永明[1] 段伦博[1] Wu Zhengyu;Hua Yongming;Duan Lunbo(School of Energy and Environment, Southeast University, Nanjing 210096, China)

机构地区：[1]东南大学能源与环境学院,南京210096

出　　处：《东南大学学报（自然科学版）》2022年第3期446-454,共9页Journal of Southeast University：Natural Science Edition

基　　金：国家重点研发计划资助项目(2019YFE0100100-08).

摘　　要：为深入掌握多燃料预混燃烧的排放特性以及应对能源短缺问题,设计了一种多燃料预混燃烧的烟叶烘烤系统,并采用计算流体动力学(CFD)方法对燃烧中污染物排放进行了研究.采用拓展的甲烷三步反应机制和涡耗散概念(EDC)模型来保证CFD的准确性,采用温度和组分波动的概率密度函数(PDF)研究了湍流条件下NO_(x)的排放特性,分析了燃料比例和燃烧温度对CO和NO_(x)排放的影响.结果表明:随燃料中H2含量的增加,燃烧温度上升,高温区停留了大量的热力型NO_(x),出口NO_(x)的排放增加;燃料中CO的含量增加,N2O-中间体生成速率会随之增加,出口NO_(x)的排放增加.多燃料预混燃烧中,热力型NO和快速型NO占NO总排放量的95.2%;当氢气在燃料中体积分数为5%~10%时,增加氢气的含量可以降低CO的排放.For an in-depth grasp of the emission characteristics of multi-fuel premixed combustion and deal with the energy shortage,a tobacco curing system in the multi-fuel premixed combustion was designed.Combustion pollutant emissions were studied by a computational fluid dynamics(CFD)method.The extended methane three-step reaction mechanism and the eddy dissipation conceptual(EDC)model were used to ensure the accuracy of CFD,and the probability density function(PDF)of temperature and composition fluctuations was used to study the NO_(x) emission characteristics under turbulent flow conditions.The effects of the fuel ratio and the combustion temperature on CO and NO_(x) emissions were analyzed.The results show that with the increase of H2 content in the fuel,the combustion temperature rises,a large amount of thermal NO_(x) remain in the high temperature area,and the NO_(x) emission at the outlet increases.As the CO content in the fuel increases,the N2O-intermediate generation rate increases and the NO_(x) emission at the outlet increases.In multi-fuel premixed combustion,thermal NO and fast NO account for 95.2%of NO emissions;when the volume fraction of hydrogen in the fuel is between 5%and 10%,increasing the content of hydrogen can reduce CO emissions.

关 键 词：数值模拟 烟叶烘烤系统 排放特性 NO_(x) 

分 类 号：TK16[动力工程及工程热物理—热能工程]