Higher power output in thermoelectric generator integrated with phase change material and metal foams under transient boundary condition

Abstract

Phase change materials (PCMs) are useful means for energy storage and thermal management of thermoelectric generators (TEG) systems. Nevertheless, energy storage rate under transient heat loads is slow due to low thermal conductivity of PCMs. In this study, copper and nickel porous metal foams are applied in a PCM on hot side of a TEG to accelerate storage of fusion heat and power output of the TEG under transient boundary conditions. Therefore, continuous and fluctuating heat flows were imposed to the system initiating from ambient room temperature. Results of this study show that, adding the metal foams enhances heat flux through the PCM by reducing overall thermal resistance in the energy storage box. The PCM with copper foam makes higher percentage of increase of temperature in the box and higher power generation until the melting point, while the PCM with nickel provides higher storage temperature after the melting process. The metal foams improve the thermal conductance between the heat source and the TEG creating higher temperature difference across the module and making higher electrical power compared to the case with PCM-only. The corresponding power enhancement is 26.2% and 62.5% by the TEGs with the nickel and copper foams, respectively.