微型钝体燃烧器中氢气燃烧的实验与模拟

Experimental and Numerical Studies of Hydrogen/Air Combustion in a Micro-Combustor With a Bluff Body

对氢气／空气在微型钝体燃烧器内的预混燃烧特性进行了实验研究和数值模拟，主要探讨了当量比和进气速度对吹熄极限、燃烧效率和排烟温度的影响，结果表明：1）微型钝体燃烧器的吹熄极限比无钝体时增大了3～5倍。2）吹熄极限随着当量比的增大而明显增大。3）随着当量比的增大，火焰锋面向上游移动，壁面平均温度升高，排烟温度也随之升高。4）随着进气速度的增大，火焰被吹向下游并被拉长，壁温分布均匀性变差，燃烧效率和排烟温度均呈现出先增大后减小的规律。

Combustion characteristics of lean hydrogen/air mixture in a planar micro-combustor with a bluff body were investigated experimentally and numericaUy. Effects of the equivalence ratio and inlet velocity on the blow-off limit, combustion efficiency and exhaust gas temperature were examined. The results show that the blow-off limit of the micro-eombustor is extended by 3-5 times as compared with that of the straight channel without a bluff body. Moreover, the blow-off limit increases with the equivalence ratio. In addition, with the increase of equivalence ratio, the flame front shifts upstream, and the average wall temperature and the exhaust gas temperature increase as well. Furthermore, with the increase of inlet velocity, the flame front is prolonged and becomes narrower, and the outer wall temperature becomes less uniform. Meanwhile, the combustion ef- ficiency and exhaust gas temperature increase first and then decrease, i.e., they vary non-monotonously.