摘要
利用多孔介质高热容和良好的导热特性,设计了带回热侧面辐射式SiC多孔介质燃烧辐射器,研究当量比、功率对燃烧辐射器的热负荷、燃烧稳定范围、表面温度均匀性和辐射效率的影响.研究结果表明:当量比一定时,提高燃烧功率可增大燃烧器表面温度和降低表面温度梯度;功率一定时,存在最佳当量比使得辐射器表面温度梯度最低.回热器可以提高辐射器表面温度均匀性和辐射效率;当量比与功率对多孔介质燃烧器辐射效率都有较大影响.小功率时,功率增大导致辐射效率增加明显.燃烧辐射器功率一定时,存在一个最佳当量比使得辐射效率最佳.本实验研究的燃烧辐射器无回热功率为7.0kW,当量比为0.75时辐射效率最高达34.7%;回热后最佳当量比降低到0.54,其对应的辐射效率提高到36.9%.
A SiC porous medium radiator（PMR）with heat recuperator was built and its performance was experimentally studied.The effect of equivalence ratio and combustion power on ignition,combustion characteristics and radiant efficiency were evaluated.The results indicate that increasing the combustion power can lead to higher surface temperature and lower temperature gradient at a fixed equivalence ratio,and that there is an optimal equivalence ratio at which the lowest gradient is gained at a fixed power.Assisted with heat recuperator,uniformity of surface temperature along the axial direction and radiant efficiency increase.Equivalence ratio and combustion power have significant effect on radiant efficiency.At low power,increasing power results in obvious augment in radiant efficiency.There is an optimal equivalence ratio leading to a perfect radiant efficiency for a given operating power.The setup in this paper can gain a radiant efficiency as high as 34.7%at power 7.0kW and equivalence ratio 0.75without thermal recuperation.With heat recuperation,however,the optimal equivalence ratio drops to 0.54and the corresponding radiant efficiency reaches 36.9%.
基金
中国高技术研究发展(863)计划(2007AA05Z236)资助
