为了预测温差发电(thermoelectric generator,TEG)系统的动态特性,基于COMSOL Multiphy-sics建立了用于求解温差发电系统温度场分布的瞬态计算流体力学(computational fluid dynamics,CFD)模型和用于研究温差发电模块瞬态响应特性的分析模型,提出了混合瞬态CFD-分析模型,并经过瞬态试验验证.结果表明:由于热惯性的影响,TEG系统的转化效率会出现一个瞬时的较高值;相较于尾气温度和质量流量的瞬态波动,热电半导体的热端温度和冷端温度会存在时滞;在美国环保局的高速公路燃油经济性测试(highway fuel economy test,HWFET)模式循环工况下,瞬态模型求解得到整个温差发电系统的平均输出功率、平均转化效率分别为35.63 W和3.40%,瞬态模型的输出电压平均误差为6.41%;该模型能够以较高的精度及较短的计算时间预测温差发电系统在瞬态热源激励下的瞬态响应特性.
Abstract
To predict the dynamic characteristics of the thermoelectric generator (TEG) system, a transient computational fluid dynamics (CFD) model for solving the temperature field distribution of TEG system and an analysis model for investigating the transient response characteristics of TEG modules were established based on COMSOL Multiphysics. A hybrid transient CFD-analysis model was proposed and validated through transient experiments. The results show that due to the thermal inertia effect, the conversion efficiency of TEG system exhibits momentary peak value. Compared to the transient fluctuations of exhaust gas temperature and mass flow rate, there is time lag in the hot and cold side temperatures of the thermoelectric semiconductor. Under the highway fuel economy test (HWFET) cycle conditions defined by the U.S. Environmental Protection Agency, by the transient model, the average output power and the average conversion efficiency of the entire TEG system are solved with 35.63 W and 3.40%, respectively. The average error of the transient model′s output voltage is 6.41%. By the proposed model, the transient response characteristics of the TEG system under transient thermal source excitation can be predicted with high accuracy and short computation time.
关键词
温差发电系统 /
尾气余热回收 /
混合瞬态CFD-分析模型 /
瞬态响应特性 /
热惯性
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Key words
thermoelectric generator system /
exhaust waste heat recovery /
hybrid transient CFD-analysis model /
transient response characteristics /
thermal inertia
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参考文献
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脚注
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基金
国家自然科学基金资助项目(51977100)
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