微型多孔介质燃烧器内非预混合成气燃烧特性研究

Study on combustion characteristics of non-premixed syngas inmicro porous medium combustor

微型燃烧器是微型热光电系统(micro-thermophotovoltaic,MTPV)的重要组成部分,其外壁温度的高低及均匀性对MTPV系统的能源转换效率有重要影响。本研究提出了一种新型微型多孔介质燃烧器,该燃烧器通过在微型燃烧器内设置多孔介质来增强热量的传递,使更多的热量实现了有效循环,从而提高了燃烧器的换热性能;应用数值模拟方法研究了微型多孔介质燃烧器内H 2-CO-CH 4非预混合成气的燃烧特性,分析了多孔介质、燃料质量流量、当量比及外部环境对燃烧器外壁温度、中心温度及火焰位置的影响。研究结果表明:与自由火焰微型燃烧器相比,微型多孔介质燃烧器具有更高的外壁温度和更低的火焰温度;在当量比为1时,微型多孔介质燃烧器具有最高的外壁温度;外壁温度与对流传热系数之间呈线性变化规律。

The micro combustor is an important part of micro-thermophotovoltaic(MTPV)system,the outer wall temperature and its uniformity of combustor have an important influence on energy conversion efficiency of MTPV system.A new type of micro porous medium combustor was proposed in this study.The heat-transfer performance is improved by setting porous medium in micro combustor,and more heat circulates effectively.The combustion characteristics of H 2-CO-CH 4 non-premixed syngas in micro porous medium combustor were studied by n umerical simulation.The effects of porous medium,fuel mass flow rate,equivalence ratio and external environment on outer wall temperature,center temperature and flame position of combustor were analyzed.The study results show that compared with free flame micro combustor,micro porous medium combustor has higher outer wall temperature and lower flame temperature.When the equivalence ratio is 1,the outer wall temperature of micro porous medium combustor reaches the peak.The relationship between the outer wall t emperature and the convection heat-transfer coefficient presents a linear change rule.