过量空气系数对微细腔内氢气预混燃烧效率的影响

针对微型涡轮气体发动机燃烧效率和停留期等问题，设计了一套微细环型腔燃烧实验装置．进行了氢气与空气预混燃烧特性实验，测试并获得了微细环型腔内燃烧效率和着火浓度极限，分析了燃气浓度比对燃烧状况的影响．结果表明，在微细型腔内进行可燃气体与空气的预混燃烧具有可行性，但由于微细通道管壁表面散热损失相对增大，火焰传播速度减小，过量空气燃烧效率较低．实验发现，在微细燃烧装置中，富燃料燃烧时燃烧效率相对较低．在相同系数下，燃烧效率先是随氢气量的增大而增大，而后随之下降．在相同的供氢量条件下，燃烧效率随过量空气系数的增大先是增大，而后则随之减小．

Influence of Hydrogen-Air Ratio on Combustion Efficiency for Microcombustor

An experimental apparatus for gas combustion in annular microchamber was set up. The experimental research was carried out on the burning stability of premixed hydrogen-air gas. The influences of hydrogen-air ratio on the combustion efficiency in annular microchamber were examined for different conditions. The experimental results show that it is feasible for premixed Hydrogen-air gas combustion in annular microchamber, but the combustion efficiency decreases evidently due to the increase of dissipation heat loss from the micro-combustor wall and its short residence time in microchamber. The excess air ratio for stable burning ranges between 1 and 4. The wall temperature and combustion efficiency increases with the excess air ratio first, and then decreases with it.