无焰燃烧斯特林发动机加热器仿真与优化

针对某斯特林机A型加热器改进后的B型加热器效果不理想,采用数值模拟,分析2种加热器的结构等特点,并对其进行优化设计。数值模拟结果发现,B型加热器仅增加了加热管长度和翅片面积,但总换热量不变,加热管长度增加反而导致整机死容积增加,对整机性能不利;改进B型加热器管排布置方式,并增大管径大小,能够促进其流场与烟气相匹配,增加前排换热能力;增加加热器管顶部与旋流器出口距离,有助于提高换热能力。

Simulation and optimization of flameless combustion Stirling engine heater

The effect of the improved type B Stirling engine heater is unsatisfactory compared with type A Stirling engine heater. Therefore, the structure and other characteristics of the two heaters are analyzed and the optimization is also carried out by numerical simulation. The numerical results show that the total heat exchange remains the same although the lengths of heater tube and fin area of type B heater increase. In addition, the increase of heater tube length leads to the increase of dead volume, which is unfavorable to the performance of the engine. Improving the arrangement of type B heater tube and increasing the size of tube diameter can promote the match of flue gas flow field and increase the heat transfer capacity of the front row. Increasing the distance between the top of heater tube and the outlet of cyclone is helpful to improve heat transfer capacity.