燃气轮机燃烧室液雾自燃延迟时间预测方法

为减少一体化加力燃烧室内支板火焰稳定器高度与进口试验参数较高所导致的昂贵基础试验成本，采用经试验数据验证的数值计算方法，对不同高度的一体化模型加力燃烧室燃烧性能进行数值模拟，分析模型加力燃烧室高度变化和侧壁边界层效应对一体化加力燃烧室回流区、总压恢复系数以及燃烧效率的影响。在保持空间油雾场分布均匀与阻塞比一致的前提下，简化扇形加力燃烧室模型为矩形加力燃烧室模型，其中模型加力燃烧室高度H分别为200，150和100 mm，总长L=1 480 mm，宽B=125 mm。结果表明：模型加力燃烧室高度的降低对燃烧性能影响较小，其中回流率最大降幅为0.16%，总压恢复系数最大降幅为0.15%，燃烧效率的最大降幅为1.9%；模型加力燃烧室侧壁面边界的引入对燃烧性能影响较小，回流率、总压恢复系数最大降幅均小于1%，燃烧效率的最大降幅仅为0.7%；可以采用单支板火焰稳定装置降低高度的方法简化试验件设计。

A prediction method for spray autoignition delay time in gas turbine combustor

A phenomenon of liquid jet in cross flow in fuel lean premixed pre evaporation combustor main stage was studied. The autoignition prediction model was constructed with considering the atomization, evaporation and autoignition process of liquid jets in cross flow for RP 3 jet fuel sprays, eventually the autoignition delay time was predicted based on the time evolution of the CH in the liquid gas mixture. The model was validated by comparing to experimental results and was then utilized to analyze the influences of variables such as temperature, pressure, main stream velocity and liquid to air momentum ratio on the autoignition delay time. The results show that for liquid jet in cross flow formed by direct injection type nozzle, its fuel air mixing downstream is mainly affected by the liquid to air momentum ratio and main stream velocity, in which liquid to air momentum ratio determines total fuel air ratio, while stream velocity mainly affects the droplet sizes and the related evaporation time; the autoignition delay time decrease with the increase of pressure, liquid to air momentum ratio and main stream velocity. The autoignition delay time of spray is less affected by the negative temperature effect compared to premixed combustibles.