共线式热电发电机在侧面散热情况下的性能  

PERFORMANCE OF COLLINEAR THERMOELECTRIC GENERATOR CONSIDERING THE HEAT DISSIPATION IN THE SIDE SURFACE

作　　者：王雪强 剧成健 兑关锁[1] Wang Xueqiang;Ju Chengjian;Dui Guansuo(School of Civil Engineering,Beijing Jiaotong University,Beijing 100044,China)

机构地区：[1]北京交通大学土木建筑工程学院,北京100044

出　　处：《力学学报》2019年第1期192-197,共6页Chinese Journal of Theoretical and Applied Mechanics

基　　金：国家自然科学基金资助项目(11772041)

摘　　要：热电材料是一种环境友好型功能材料,其可以实现热能与电能的相互转化,在热电发电、热电制冷中具有许多应用.传统的热电发电机为π型结构,要求热电腿的长度相等,在某些情况该结构不利于热电发电机的优化设计.热电发电机在高温工况下会引起强烈的热应力甚至应力集中,从而缩短了其工作寿命.另外,热电发电机的工作温度于环境温度,这样必然会有一部分热量散失到环境中,从而影响热电发电机的性能.针对该现象,本文建立了考虑散热的新型共线式热电发电机模型,该模型的热电腿可以独立进行优化,基于有限元方法,对考虑侧面散热的共线式热电发电机进行了仿真模拟,分析了其在狄利克雷边界条件下的热电性能和力学性能,得到了热电发电机的温度场、电势场、应力场,探究了不同强度的对流散热系数对热电发电机热电性能和力学性能的影响.结果表明,对流散热会降低热电发电机的能量转化效率,当对流换热系数达到100 W/(m^2·°C)时,效率为0.047 9,该值比绝热状态的转化效率0.066 7低28%.对流散热使热电发电机侧面热损失增加,降低了热应力.在实际应用中,应合理优化设计隔热系统,提高能量的转化效率.Thermoelectric material is an environment-friendly function material,which can convert energy between heat and electricity.And it holds extensive application potentiality in power generation and refrigeration.The traditional thermoelectric generator is a ff-type structure,which requires the length of the thermoelectric legs to be equal.In some cases,the structure is not conducive to the optimal design of the thermoelectric generator.Intense thermal stress and even stress concentration will be induced in the thermoelectric generator due to high-temperature working condition,leading to shortening its working life.In addition,since the operating temperature of the thermoelectric generator is higher than ambient temperature,part of the heat will inevitably be dissipated to the environment,which will affect the thermoelectric performance and mechanical performance of the thermoelectric generator.Therefore,the heat dissipation cannot be neglected when analyzing this kind of problem.For these phenomena,in this work,a novel collinear-type thermoelectric generator model is proposed considering the heat dissipation in the side surface.And the legs of the proposed thermoelectric model can be optimized independently.Then,based on the finite element method,performance of collinear thermoelectric generator considering the heat dissipation in the side surface is simulated.And the thermoelectric performance and mechanical performance under the Dirichlet boundary condition is analyzed.Simultaneously,the temperature field,electric potential field and stress field in the thermoelectric generator are obtained.The influence of various convective heat transfer coefficient on thermoelectric performance and mechanical performance of the thermoelectric generator is investigated.The results demonstrate that thermal convection can decrease the energy conversion effciency of the thermoelectric generator.When the convective heat transfer coeffcient reaches 100 W/(m2.°C),the effciency is 0.047 9 which is 28%lower than the conversion effcienc

关 键 词：热电发电机 对流散热 有限元方法 热电性能 力学性能 

分 类 号：TN377[电子电信—物理电子学]