介观尺度燃烧驱动温差发电的实验研究

Experimental Study on Mesoscale Combustion Powered Thermoelectric Generator

为开发高性能微型可移动电源系统,设计并实验测试了一种介观尺度燃烧驱动的温差发电机(micro/mesoscale combustion powered thermoelectric generator,MCP-TEG)。MCP-TEG采用多台阶稳燃技术、烟气逆流换热技术和错列肋柱(Pin-fin)强化传热技术,同时将燃料混合器、预热器、燃烧器、稳燃器、集热器和均热器一体化集成。实验结果发现,设计的MCP-TEG的发电功率为29.6W,高于目前国内外的报道值,对应的发电效率为2.84%。此外,论文详细研究了MCP-TEG的输入功率、化学当量比、冷端散热和保温设计对发电性能的影响。实验发现存在一个最佳的化学当量比,使得MCP-TEG的发电功率最大。对于水冷型MCP-TEG,增加冷端散热并不一定能够获得更大的净发电功率。燃烧器的外壁面保温特性对发电性能有重要的影响,对于当前的MCP-TEG,燃烧器外壁面增加一层3 mm的保温层后,发电功率和发电效率均比不保温条件下的结果增加了4.6%。

In order to develop high performance portable power sources,a mesoscale combustion powered thermoelectric generator(MCP-TEG)was designed and tested.Multistage backward flame stabilizing,flue gas reversing,and staggered pin fins for heat transfer enhancement,were designed to facilitate the integration of fuel pre-mixer,pre-heater,combustor,flame stabilizator,heat collector and heat spreader.Experimental results found that the present MCP-TEG was able to generate electric power of 29.6 W,which was larger than previous reports,and the corresponding power generation efficiency was 2.84%.The influences of combustion power,equivalent ratio,cold-end cooling condition and thermal insulation setting on the performance of MCP-TEG were comprehensively explored.An optimized equivalent ratio of0.95 was found to obtain the maximum electric power.For water cooled MCP-TEGs,enhancing the cold-end cooling is not necessarily to augment the net electric power.Furthermore,the thermal insulation setting of MCP-TEG is critical,that is,the addition of a 3 mm layer of insulation is capable of increasing the electric power and power generation efficiency by 4.6%compared to that without insulations.