摘要
利用温差发电技术进行发动机废热回收的研究日益受到关注。为此,以热源温度250℃、热沉温度30℃为工况,考虑半导体热电材料（碲化铋）物理参数随温度的变化,数值研究了热电元件长度和截面积、导热基底厚度这3个结构参数对温差发电模块发电性能的影响。针对1维模型精度低和灵活性差的特点,建立了3维热电耦合物理模型。数值模拟结果表明：对于峰值输出功率而言,热电元件长度存在最优值,在该研究条件下,最优值在0.075～0.125 mm范围内,与理论分析结果近似,能量转化效率则随热电元件长度的增加而减小;输出功率随热电元件截面积的增大而减小,面积比功率和能量转化效率则缓慢下降;导热基底越厚,输出功率和能量转化效率均越减小。并且建立了简易实验测试装置,通过测试商用热电器件验证了物理模型的准确性。研究结果能为温差发电模块构型设计提供参考。
Applying thermoelectric power generation in waste heat recovery from internal combustion engine has aroused increasing scientific activities. We numerically investigated the influences of geometry, including the length and cross section area of thermoelement and the substrate thickness, on the performance of thermoelectric module. Taking some parameters of semiconductor（BiTe） varying with temperature into consideration, we investigated heat source of 250 ℃and heat sink of 30 ℃. Moreover, since one-dimensional models are defected for their lower flexibility and inferior precision, we established a three-dimensional thermoelectric model for the calculation. The results show that, under the chosen conditions, there is an optimal thermoelement length between 0.075～0.125 mm for the peak output powers, which agrees with theoretical analysis. Longer thermoelement length leads to lower energy efficiency; while cross section area gets larger, output power increases but energy efficiency decreases slowly; the thicker a substrate is, the lower output power and energy efficiency are. The physical model is validated through tests using a commercial thermoelectric module. This investigation provides references for designing thermoelectric modules＇ geometry.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2014年第5期1599-1604,共6页
High Voltage Engineering
基金
激光推进及其应用国家重点实验室基础研究项目(编号略)~~
关键词
碲化铋
温差发电模块
热电元件
热电耦合方程
输出功率
能量转化效率
bismuth telluride
thermoelectric module
thermoelement
thermoelectric physical model
output power
energy efficiency
