新型结构热电元件的多物理场耦合研究

Multiphysics Coupling Research on Thermoelectric Element with New Structure

为了改善热电元件的工作性能,提出了两种新型结构的热电元件,分别是半倾斜型和双倾斜型,倾斜角度57.99°。参考传统的垂直型热电元件,采用数值模拟的方法,通过控制电流、热端温度和冷热端温差等参量,对三种结构的热电元件进行了温度场、电场耦合分析。结果显示:双倾斜型电热元件能够实现最低的冷端温度,且随着电流的增大,不同结构冷端温度的差值先增大后减小;在小功率条件下,双倾斜型电热元件制冷量最大;双倾斜结构能够达到最高的制冷系数,但在大功率条件下制冷系数却最低;倾角为钝角处存在场强突变现象;最大电流密度均出现在不与半导体接触的铜片区域中;双倾斜结构更适用于微小型低功耗热电设备。

Two kinds of thermoelectric elements with new structures are proposed to improve the working performance of thermoelectric element. They are semi-sloping type and double-sloping type respectively. The slope angle is 57.99°. Taking the traditional vertical thermoelectric element as a reference, temperature field and electric field coupling research is carried on the three kinds of thermoelectric elements with different structures by means of numerical simulation and controlling current, hot side temperature and temperature difference between cold side and hot side. The results show that: Double-sloping type can achieve the lowest cold side temperature. The difference between cold side temperature of different structures increases first and decreases second with the increase of current. The cooling capacity of double-sloping type is the largest in the condition of small power. The double-sloping structure can achieve the highest COP, but makes the lowest COP in the condition of large power. The electric field intensity will change suddenly where the slope angle is obtuse. The maximum of current density occurs in copper region where copper does not touch with semiconductor. Double-sloping structure is more suitable for the thermoelectric equipment with small size and small power.