Numerical study on transient supercooling performance of annular thermoelectric cooler

Abstract

Transient supercooling can effectively improve the performance of thermoelectric coolers (TECs), especially seen from the studies on flat-plate TECs. But for an annular facility, annular thermoelectric coolers (ATECs) are a better choice because their annular structures increase contact areas. For further studying it, a 3D transient model coupling temperature field and electric potential field is established to study the effects of pulse current amplitude (P), pulse width (τ), annular thermoelectric angle (θ), leg length (r) of thermoelectric element, convective heat transfer coefficient (h) and pulse current shape on the transient performance of ATEC made of variable properties materials. The results show that P and τ are still key factors for the said ATEC, let the P is constant, there is an optimal pulse width minimizing the cold end temperature. If the annular thermoelectric angle θ increases, ATEC with a cold end cross-sectional area larger than that of the hot end makes the supercooling poorer. Let the leg lengths r of the ATEC are 0.8 mm and 0.7 mm respectively, the minimum cold end temperatures (Tc,min) are 236.41 K and 246.18 K as the cross-sectional area of the cold end gets smaller but larger than that of the hot end. The larger of the h is, the better the heat will be dissipated from the hot end of the ATEC, till a certain value of h, the transient performance no longer changes significantly for no much more heat could be dissipated. As the study shown, applying different pulse current shapes leads to the acquisition of different supercooling indicators.