预热温度对微尺度燃烧影响的分析

Effects of Preheating temperature to the micro-scale combustion

针对微尺度燃烧的特点,在传热分析的基础上,建立了微型管内氢—空气预混合气的燃烧模型,针对不同的预热温度对0.2 mm微管内氢气空气预混燃烧的影响进行了研究。结果表明:对于0.2 mm微管,较高的混合气入口温度使得燃烧效率提高,火焰中心更靠近燃烧室入口。但是,由于壁面热损失,火焰中心温度增加幅度不大,燃烧室出口温度降低幅度较大。为了实现较高的微尺度燃烧室的能量转化,需要火焰有较高的出口温度,这样,就需要较合适的入口温度,而不是越高越好。

on the base of analysis of heat transfer, combustion model of hydrogen and air premixed in mi- cro-scale tube was established in consideration of characteristics of micro-scale combustion. The effects of changing parameters on combustion characteristics of hydrogen and air premixed combustion in micro-scale tube was performed with simulate methods. The results indicate： For 0.2mm micro tubes, the high mixing gas inlet temperature increases the combustion efficiency, and the flame center is closer to the combustion cham- ber inlet. However, due to the wall heat loss, the temperature of the flame center is small, and the outlet tem- perature of the combustion chamber is lower. Flame had a higher outlet temperature required in order to achieve higher micro scale combustion chamber of energy transformation. Therefore, it is necessary inlet temperature is appropriate, and not the higher the better.