ZT值温度依存性对温差发电器热电性能的影响

Temperature dependency of ZT value on thermoelectric generator performances

中文关键词: 优值系数  变物性  温差发电器  热电性能

英文关键词: figure of merit  variable physical properties  thermoelectric generator  thermoelectric performance

中文摘要:

      为了评估热电材料ZT值温度依存性对热电发电器性能的影响,基于HZ-20商用热电材料的热物性参数,分别采用定物性与变物性的计算方法,对温差发电器在具有不同热源温度下的工作性能进行理论研究。研究结果表明,当采用定物性方法计算时(即不考虑ZT值温度依存性),输出功率及相应转换效率的计算值,都较采用变物性计算时存在一定的偏差。当半导体热端温度低于定物性计算时采用的定性温度值时,偏差很小,但随着半导体热端温度的继续增加,偏差则越来越大,高热端温度下计算得到的计算偏差达30%左右。因此,热电材料ZT值温度依存性对温差发电器热电性能的影响不容忽视。

英文摘要:

      To assess the influence of temperature dependency of thermoelectric figure of merit (ZT) value on the thermoelectric properties, HZ-20 type thermoelectric module was taken as an example for analysis and calculation. The working performance of thermoelectric generator with different heat-side temperatures were studied theoretically by considering constant and variable physical properties. It is shown that when the constant physical properties are used, there is a certain deviation on the calculated output power and conversion efficiency in comparison with the ones using variable physical properties. When the hot-side temperature of semiconductor is lower than 503K, the deviation is very small. However, with an increasing hot-side temperature the deviation can grow by 30% in high hot-side temperature of thermoelectric generator. It can be concluded that the influence of temperature dependency for ZT value on thermoelectric properties cannot be ignored.