摘要
用实验与数值模拟手段研究了含氢量对氢气/甲烷混合燃料的扩散燃烧特性的影响,结果表明,在保持燃料总发热量不变的前提下,含氢量的增加并未使火焰长度发生显著变化,这是由于含氢量增加引起火焰缩短的趋势与燃料流量增加引起火焰加长的趋势共同作用的结果。所有燃料火焰的最高温度都发生在回流区内,随着含氢量的增加,火焰高温区域的轴向高度越来越大。火焰稳定性随着含氢量的提高而显著加强。OH基浓度分布的PLIF测量结果表明,随着含氢量的增加,火焰根部的边界越来越清晰,这说明根部的燃烧强度越来越剧烈。NOx排放浓度随着燃料中含氢量的增加而呈指数上升趋势,并与火焰温度的变化趋势相符合。燃料含氢量从0%增加到80%时,NOx浓度相对增加了46%,而从80%增加到100%时,NOx浓度相对增加了48%。从这个角度上说,含氢量80%的燃料也许比纯氢燃料更具有优势。
By using test and numerical simulation methods,studied was the influence of hydrogen content on the diffusion combustion characteristics of a hydrogen/methane mixture fuel. It has been found that under the precondition of keeping the total heating value unchanged,the increase in hydrogen content has not caused a remarkable change in flame length. This is the result of a joint action of the increase of the hydrogen content,which will result in a tendency to shorten the flame and the increase of the fuel flow rate,which will lead to a tendency to lengthen the flame. The highest temperature of all the fuel flames happens in the return flow zone. With an increase of the hydrogen content,the flame in the high temperature zone becomes higher and higher in the axial direction. The flame stability is notably enhanced with an increase of the hydrogen content. The results of the OH concentration distribution measured by PLIF (planar laser induced fluorescence) show that with an increase of the hydrogen content,the boundary at the root of the flame becomes more and more clear,indicating that the combustion at the root grows in intensity ever strongly. The NOx emissions concentration assumes an exponent ascending tendency and corresponds with the variation tendency of the flame temperature when the hydrogen content in the fuel is increased. When the hydrogen content of the fuel increases from 0% to 80%,the NOx concentration relatively increases by 46%. When the hydrogen content increases from 80% to 100%,the NOx concentration relatively increases by 48%. From such a standpoint,the fuel with a hydrogen content of 80% is perhaps more advantageous than pure hydrogen fuel.
出处
《热能动力工程》
CAS
CSCD
北大核心
2010年第1期102-106,共5页
Journal of Engineering for Thermal Energy and Power
基金
国家自然科学基金资助项目(50576098)
国家863计划基金资助项目(2006AA05A104)
关键词
氢气
甲烷
扩散火焰
含氢量
燃烧特性
hydrogen,methane,diffusion flame,hydrogen content,combustion characteristics