【摘要】 从调整小型燃烧器壁面热性能的角度出发,对改善其稳燃性能进行了研究,共进行了两个实验.第1个实验采用多孔介质燃烧技术,比较研究了不同导热率的壁面材料(硅与石英)对燃烧器稳燃性的影响.结果发现,尽管两种材料燃烧器有着相同的低速极限,但是高导热率的硅燃烧器比石英燃烧器有着更大的高速极限,使火焰能够稳定在多孔介质材料上而不被吹出.第2个实验探索了各向异性材料热解石墨燃烧器的性能,作为对比,对各向同性的不锈钢316常规材料燃烧器也进行了研究.由于壁面被增强的流向导热及被减弱的法向热损失,热解石墨与各向同性的不锈钢相比,稳燃极限扩大,有着更大的稳燃区间.更多还原

【Abstract】 In this study, we performed two sets of experiment to investigate conditions that would improve the flame stability of small-scale combustors by adjusting the thermal properties of walls. In the first experiment, we used porous media combustion technology to study the effects of the thermal conductivities of different wall materials(silicon and quartz) on the flame stability. We found that although two types of wall materials had the same low-velocity limit, the silicon combustor with higher thermal conductivity had a higher high-velocity limit than the quartz combustor, which stabilized the flame on porous media to prevent blow-off extinction. In the second experiment, we investigated the performance of a pyrolytic graphite combustor with respect to its thermally orthotropic properties. For comparison, we also studied the performance of the conventional isotropic material stainless steel 316. The results showed that the pyrolytic graphite combustor exhibited wider flame-stability limits than the stainless steel combustor, due to its enhanced stream-wise heat conduction and reduced span-wise heat loss.更多还原