NH_(3)/CH_(4)轴向空气分级燃烧NO生成的动力学分析  

Kinetic Analysis of NO Formation in Axial Air-staged NH_(3)/CH_(4) Combustion

作　　者：李莹 宗超[2] 朱彤[1] 秦朝葵[1] LI Ying;ZONG Chao;ZHU Tong;QIN Chaokui(School of Mechanical Engineering,Tongji University,Shanghai 201804,China;Postdoctoral Station of Engineering,Tongji University,Shanghai 201804,China)

机构地区：[1]同济大学机械与能源工程学院,上海201804 [2]同济大学机械工程博士后流动站,上海201804

出　　处：《工程热物理学报》2024年第12期3915-3924,共10页Journal of Engineering Thermophysics

基　　金：国家自然科学基金项目(No.51976140)。

摘　　要：NH_(3)/CH_(4)燃料面临的最大挑战之一是其在燃烧时会产生大量燃料型NO_(x)。轴向空气分级燃烧技术降低富氢燃料NO_(x)排放的效果已被实验初步验证,但仍缺乏对初级燃烧室最佳当量比与NO_(x)生成之间内在关联的动力学机理研究。本文以一50k W级微型燃气轮机燃烧室为研究对象,采用Chemkin-Pro分析了NH_(3)/CH_(4)轴向空气分级燃烧中初级燃烧室当量比对NO_(x)生成过程的影响及存在最佳当量比的内在动力学机理。结果表明,最佳当量比是在初级燃烧室NO的生成量与燃料燃烧完全性之间取得平衡的结果;含氨燃料燃烧过程中NO的主要前驱体在不同当量比下均为HNO,但减少当量比会使HNO反应速率显著提高;在初级燃烧室当量比高于1.21时,初级燃烧室中的燃烧副产物HCN、H_(2)和CO在二级燃烧室中的消耗会直接或间接产生O和OH自由基,从而加剧NO的产生。One of the foremost challenges faced by NH_(3)/CH_(4) mixed fuel is the substantial formation of fuel-NO,during combustion.Axial air-staged combustion has been experimentally proved effective in mitigating NO_(x)in ammonia-blended fuel.However,there is a lack of understanding of the intrinsic correlations between the optimal equivalence ratio of primary combustion chamber and final NOs formation.This study focused on a 50 kW micro gas turbine combustion chamber and employed the Chemkin-Pro code to investigate the impacts of primary equivalence ratio on NO_(x) emissions in NH_(3)/CH_(4) axial air-staged combustion,as well as the underlying kinetic mechanism behind the optimal equivalence ratio.The results indicate that the optimal equivalence ratio represents a tradeoff between NO production and fuel consumption in the primary zone.HNO emerges as the major precursor of NO during combustion of ammonia-blended fuels across the studied range of equivalence ratios,but a decrease in which significantly exacerbates the HNO reaction rate.Moreover,when the primary equivalence ratio exceeds 1.21,the consumption of combustible products such as HCN,H_(2),and CO from the primary zone produces O and OH free radicals in the secondary zone,causing rapid formation of NO.

关 键 词：轴向空气分级燃烧 NH_(3)/CH_(4)燃烧 最佳当量比 NO 

分 类 号：TK16[动力工程及工程热物理—热能工程]