A novel mechanism for thermal management at the cold side of a pulsed two-stage thermoelectric micro-cooler with different PCM heat sink shapes

A new mechanism for thermal management at the cold side of a pulsed two-stage thermoelectric micro-cooler (Two-stage mu TEC) is presented. The Two-stage mu TEC operates under different electric current values at each stage and uses a phase change material (PCM) in different heat sink shapes for temperature control in the cold junction. A geometric factor gamma is defined for designing an optimal heat sink based on reducing the cross-sectional area of the second stage thermoelements. The aim is to save the amount of PCM used and keep the cold side temperature (Tc) constant for as long as possible. This thermoelectric device is proposed to treat skin diseases and is suitable for use in cryomassage. A one-dimensional numerical model is considered in the system's heat transfer, and cooling by natural convection on the hot side is considered. PCM is used as a cooling substance because it can absorb large amounts of latent heat at a nearly constant temperature. The influence of the electric current pulse and the gamma geometric relationship on the micro-cooler are analyzed to determine the optimum operating values that allow a constant temperature of 243 K to be reached in the cold junction. The temperature of the cold side is kept constant by using different electric currents in each stage for the geometric factor gamma = 4 during delta t(pulse )= 95.7s. On the other hand, the optimization of the heat sink, the geometric factor (c) 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).