温差对CaMnO_3和Ca_3Co_4O_9热电器件输出功率的影响

Effect of Temperature Difference on the Power Output of CaMnO_3 and Ca_3Co_4O_9 Thermoelectric Generators

在低温端散热条件不变的情况下,在较宽的测试温度范围内分别测试了CaMnO3(n-type)和Ca3Co4O9(p-type)单臂热电器件的输出功率,实验结果显示其最大输出功率与温差的平方有较好的线性关系。通过进一步的分析表明,其比例系数正比于Seebeck系数的加权平均值(加权函数为温度梯度函数)的平方与电阻率的平均值之比,是热导率、电导率和Seebeck系数等热电材料性能参数的综合表现,能够方便地测量,可在较宽的温度范围内近似地表征热电材料或器件的性能。

The power output of CaMnO3 and Ca3Co4O9 thermoelectric generators（TEG） was measured from room temperature to 600℃,their maximum power was directly proportional to the square of temperature difference across the TEGs.The proportionality constant was also proportional to the ratio between the square of weighted mean for Seebeck coefficient（with the temperature gradient as weighting function） and the average electrical resistivity.The ratio combined the performance parameters of thermoelectric materials such as Seebeck coefficient,electrical conductivity and thermal conductivity,can be measured approximately and easily,and can be used to characterize the performances of TEGs.