摘要
氢气作为绿色、高效的清洁能源,富氢燃料燃烧对降低碳排放具有重要意义,但掺氢影响火焰稳定性、形态及污染物排放。以天然气掺氢燃烧技术为背景,设计非预混钝体同轴燃烧器产生回流区以稳定火焰,基于GRI-Mech 3.0燃烧反应机理,采用数值模拟分析贫燃料条件下掺氢比对甲烷燃烧的速度场、温度场、火焰形态、燃烧反应区及出口污染物排放的影响规律。结果表明:当量比及燃料体积流量一定时,随着掺氢比的增加,燃烧腔室平均流速降低,钝体下游的回流区涡结构缩小,燃烧反应区前置,火焰结构更为紧凑;燃烧室平均温度和温度均匀性随掺氢比增加而增加,相较纯甲烷燃烧分别提升了1.82%—16.22%和0.59%—1.73%;出口NO摩尔分数升高,但出口CO_(2)摩尔分数逐渐减小,且变化幅度均逐渐增加。掺氢比为20%时,CO_(2)减排6%,高掺氢比下降碳效果显著,但氮氧化物排放成倍增加。因此,研究不同掺氢比下富氢燃料燃烧特性,为天然气掺氢燃烧技术推荐合适掺氢比及非预混稳焰燃烧器的设计提供重要依据。
Hydrogen as a green and efficient clean energy source,holds significant importance in reducing carbon emissions.However,blending hydrogen can affect flame stability,morphology and pollutant emissions.Focusing on natural gas-hydrogen blending combustion technology,a non-premixed bluff body coaxial burner was designed to create a recirculation zone for flame stabilization.Based on the GRI-Mech 3.0 combustion reaction mechanism,computational fluid dynamics analysis was employed to investigate the effects of hydrogen blending ratio on the velocity and temperature fields,flame morphology,combustion reaction zone and pollutant emissions of methane-hydrogen blending combustion under lean fuel conditions.The results indicate that with a fixed equivalence ratio and hydrogen-enriched fuel volumetric flow rate,as the hydrogen blending ratio increases,the average flow velocity in the combustion chamber decreases,the recirculation zone vorteXstructure downstream of the bluff body becomes smaller,the combustion reaction zone is shifted forward,and the flame structure becomes more compact.The average temperature and temperature uniformity indeXincrease with an increasing hydrogen blending ratio,rising 1.82%-16.22%and 0.59%-1.73%respectively compared to pure methane combustion.Simultaneously,the outlet NO molar fraction increases,while the outlet CO_(2) molar fraction gradually decreases,and both changes exhibit an increasing trend.At a hydrogen blending ratio of 20%,CO_(2) emissions are reduced by 6%.However,under high blending ratios,although the carbon reduction effect is significant,nitrogen oxide emissions increase exponentially.Therefore,studying the combustion characteristics of hydrogen-enriched fuels at different blending ratios provides important insights for recommending appropriate hydrogen blending ratios and designing non-premixed stable flame burners for natural gas-hydrogen blending combustion technology.
作者
陈石义
徐育斌
刘乔迈
肖娟
王斯民
廖勇
CHEN Shiyi;XU Yubin;LIU Qiaomai;XIAO Juan;WANG Simin;LIAO Yong(Zhejiang Energy Gas Co.,Ltd.,Hangzhou 310012,Zhejiang Province,China;School of Chemical Engineering and Technology,Xi′an Jiaotong University,Xi′an 710049,Shaanxi Province,China;CPECC Southwest Company,Chengdu 610041,Sichuan Province,China)
出处
《化学工程》
CAS
CSCD
北大核心
2024年第12期76-81,共6页
Chemical Engineering(China)
基金
天然气管道掺氢、输送、分离应用技术研究及浙能先导示范项目(ZNKJ-2021-108)。
关键词
甲烷
掺氢燃烧
钝体
数值模拟
污染物
碳减排
methane
hydrogen-blended combustion
bluff body
numerical simulation
pollution
carbon emission reduction
