一种温差电单偶热电转换效率的测试方法

A test method for heat to electricity conversion efficiency of thermoelectric unicouple

提出了一种温差电单偶热电转换效率的测试方法,将测定输入温差电单偶的热流量分解为测定温差电单偶的输出电功率与测定从温差电单偶流出的热流量,并用温差电热流量计测定温差电单偶冷面流出的热流量。该测试方法避免了测量输入温差电元件的热流量,因此可以不考虑温差电元件侧面对流、辐射热损失防护问题。半导体温差电材料的塞贝克系数可以是金属的几倍,因此温差电热流量计的灵敏度高,热电转换效率的测量可以获得较高精度。给出了一些温差电单偶热电转换效率的测试结果。热面温度500℃,冷面温度50℃时,碲化铅/碲化铋级联温差电单偶的最大热电转换效率测试结果为8.45%。当冷面温度固定在50℃,作者测试了一对碲化铋温差电单偶热电转换效率随热面温度变化的规律,结果显示其热电转换效率呈近似线性增长。讨论了测试误差的来源,认为测试误差主要来源于热流量计的标定误差。

The paper presented a test method for heat to electricity conversion efficiency of thermoelectric unicouple. During the test, the input thermal power of thermoelectric unicouple has been divided into the output electrical power plus output thermal power out of the unicouple. The later has been determined by a thermoelectric thermal power meter. The method avoids the difficulties to measure the input thermal power into the unicouple, so that the convection and radiation heat lose out of the unicouple side can be ignored. Because the value of Seebeck Coefficient of the semiconductor thermoelectric materials could be many times of the metals＇, the thermal power meter has high sensitivity, so that higher test precision could be gained for conversion efficiency of thermoelectric unicouple.The paper also presented some test results. The maximum conversion efficiency of PbTe/BiTe cascade unicouple is 8.45%, when the cold and hot side temperature is 50 ℃ and 500 ℃, respectively. Fixed the cold side temperature at 50 ℃, it was tested the dependence of maximum efficiency of a BiTe unicouple on hot side temperature. Test results show that the maximum conversion efficiency increases linearly. At last the paper discussed about the source of test error of the method. It indicate that the test error of the method is caused mainly by the calibration of thermal power meter.