Experimental investigation of the use of innovative porous heat sinks in the cooling of thermoelectric modules

This thesis experimentally investigates the use of lattice-structured heat sinks with different topologies and porosities to improve heat transfer on the hot surface of a thermoelectric cooler. Two different heat sink types were examined within the scope of this thesis: Strut-based and triply periodic minimal surface-based. Axial and diagonal topologies were considered for the strut-based and gyroid and diamond topologies were considered for the triply periodic minimal surface-based with three different porosities of 60%, 70%, and 80%. The commercial TEC1-12706 module was used as the thermoelectric cooler. In the experiments, the heat sinks were integrated into the hot surface of the module and tested under constant air velocity and variable electric current conditions. The module's performance was evaluated in terms of key thermodynamic performance parameters such as hot and cold surface temperatures, temperature difference, cooling capacity, electrical power consumption, and Coefficient of Performance (COP). The study showed that heat sink topology and porosity have a decisive effect on the performance of thermoelectric coolers. High porosity improved heat convection and low porosity improved heat conduction. Thus, the importance of optimum porosity, which balances both heat transfer mechanisms, was highlighted. Accordingly, among all samples, optimum performance in terms of cooling capacity and COP was obtained from the diagonal strut-based heat sink with 60% porosity at approximately 1.5 A. The COPs of diagonal strut-based heat sinks were determined to be 0.66-1.77 in the 0.5-2.5 A range.