甲烷/空气在微小型Swiss-roll燃烧器内燃烧的实验研究

Experimental Study of Methane/air Combustion in a Swiss-roll Miniature Combustor

为了解微小型Swiss-roll燃烧室的工作特点,进行了甲烷/空气预混气的燃烧实验,获得了燃烧器的可燃极限,研究了回热对燃烧器可燃极限的影响。结果表明,当甲烷流量在0.8-2.7mg/s之间时,所设计的微燃烧器能够实现CH4/空气的稳定燃烧,并确保火焰位于燃烧器的中心。存在回热时,燃烧器的富氧极限减小,从没有回热时的0.7减小到0.5。但是可燃极限并不关于ER=1对称,富燃极限大,而富氧极限小。同时,对微燃烧器进行了数值模拟,结果表明,燃烧器中心的回流区使燃烧器能够在较大的可燃极限范围内稳定工作。

To understand the operation features of a miniature Swiss-roll combustor,a methane/air premixed combustion experiment has been performed with the combustion limit of the combustor being obtained.The influence of a heat recirculation on the combustion limit of the combustor has also been studied.The test results show that when the methane flow rate is between 0.8 and 2.7 mg/s,the miniature combustor thus designed can fulfill a stable methane/air combustion and guarantee that the flame is located at the combustor center.With the heat recirculation being enforced,the oxygen enrichment limit of the combustor will be decreased from 0.7 (without heat recirculation) to 0.5.However,the combustion limit is not symmetrical to ER (stoichiometric equivalence ratio) =1.The fuel enrichment limit is small while the oxygen enrichment limit is large.At the same time,the authors have also conducted a numerical simulation of the miniature combustor.The simulation results show that the flow return zone at the combustor center enables the combustor to secure a stable operation in a relatively large range of combustion limit.