摘要
由于尾气传热性能差,尾气余热热电转换系统中常采用具有强化换热结构的尾气换热器,其中,锯齿错列肋片式是常见型式之一。但如何平衡传热性能和流动阻力实现对换热器内部结构和整体尺寸的优化,使得热电系统获得总的净输出功率最大,是值得研究的内容。但现有成果均是基于限定尺寸结构,对换热器局部尺度及热电性能进行分析,没有针对强化换热器的整体优化结构和最大净输出功率展开研究。建立基于汽车尾气余热回收的热电转换数值模型,结合场协同理论,分析锯齿错列肋片式尾气换热器内部肋片结构对热电功率的影响。此外,综合考虑传热性能与流动阻力的平衡,以热电转换最大净输出功率为优化目标,对热电模块结构进行优化,并获得热电系统的相应最优性能。研究结果表明,固定热电模块尺寸时,净输出功随肋片高度增加明显增加,但受肋宽影响较小;对热电模块尺寸进行优化时,肋高和肋宽的变化均对热电模块的最优尺寸产生较大影响,单位面积最大净输出功随肋宽增加而明显降低,但受肋高的影响较小。
Due to the poor heat transfer performance of exhaust gas,exhaust heat exchangers with enhanced heat exchange structure are often used in exhaust waste heat thermoelectric conversion systems.Among them,the offset-strip fin type is one of the common types.However,how to balance heat transfer performance and flow resistance to optimize the internal structure and overall size of the heat exchanger,so that the thermoelectric system can obtain the maximum total net output power,is worthy of research.However,the existing results are based on the analysis of the local size and thermoelectric performance of the heat exchanger based on a certain limited size structure,and there is no research on the overall optimized structure and maximum net output power of the enhanced heat exchanger.A thermoelectric conversion numerical model based on automobile exhaust heat recovery is established,combined with field synergy principle,and the influence of the internal fin structure of the offset-strip fin type exhaust heat exchanger on the thermoelectric power is analyzed.In addition,comprehensively by considering the balance of heat transfer performance and flow resistance and taking the maximum net output power of thermoelectric conversion as the optimization goal,the thermoelectric module structure is optimized,and the corresponding optimal performance of the thermoelectric system is obtained.The research results show that the net output power increases significantly with the increase of the fin height,but is less affected by the width of the fin when the size of the thermoelectric module is fixed.However,when the size of the thermoelectric module is optimized,the changes of the fin height and the fin width have great impact on the optimal size of thermoelectric module.The maximum net output power of per unit area decreases significantly with the increase of fin width,but is less affected by fin height.
作者
何为
姚光森
蔡紫涵
石颖
杨添会
王誉霖
HE Wei;YAO Guangsen;CAI Zihan;SHI Ying;YANG Tianhui;WANG Yulin(Key Laboratory of Refrigeration Technology of Tianjin,Tianjin University of Commerce,Tianjin 300134)
出处
《机械工程学报》
EI
CAS
CSCD
北大核心
2021年第6期184-191,共8页
Journal of Mechanical Engineering
基金
国家自然科学基金(51806152)
国家科技部国际合作(2017YFE0198000)资助项目。
关键词
热电转换
强化换热
锯齿错列肋片
尾气余热
thermoelectric conversion
enhanced heat transfer
offset-strip fin type
exhaust waste heat
