Thermal-electric and stress analysis of thermoelectric coolers under continuous pulse input current

Abstract

Thermoelectric cooling is an attractive technology to achieve active thermal management of electronic devices, integrated circuits and micro-motor mechanism. Time-varying and excessive thermal stress may cause failure in thermoelectric coolers (TECs). Nevertheless, thermal–mechanical response of such devices to the electrical input is not thoroughly analyzed yet. In this paper, a three-dimensional numerical model of TEC is established by finite element method, and effects of structural parameters on its cooling performance and mechanical reliability are discussed. Steady-state experiments are conducted to verify the correctness and rationality of the numerical model. The results show that, under optimal current conditions, the minimum temperature of the cold end of the TEC can be obtained by optimal height and width of thermoelectric legs. Moreover, optimal structural parameters of the TEC providing better cooling performance and reliability are presented; so that, the cold end temperature and von Mises equivalent stress of the optimized TEC could reduce 8.3 K and 22.6% respectively. The cooling performance and mechanical reliability of the TEC are further studied under continuous pulse currents. Influences of the pulse period, amplitude and form of the pulse currents on performances of the TEC are discussed. The results show that, increasing the pulse current form parameter reduces the stress level in the TEC. For the optimized TEC, pulse amplitude of 4 is optimal values to obtain minimum temperature on the cold end. The results of this study are expected to provide useful guideline for design and practical applications of TECs under transient cooling currents.