High coolingperformances of H‐shape heat sink for thermoelectric energy harvesting system (TEHs) at asphalt pavement

Abstract

There has been an increased recognition in road thermal energy harvesting for the past decades due to the massive waste heat from the asphalt pavement. This study aims to design a thermoelectric energy harvesting system (TEHs) that converts the waste heat from the surface of asphalt pavement into useful electrical energy. The TEHs utilizes the H-shape element in subterranean cooling in order to achieve a high-temperature difference (ΔT). In this proposed cooling element method, an aluminum plate was welded in between two 1.25 in. of diameters H-shape structures, and two cascaded thermoelectric modules (TEM), APH-127-10-25-S, were placed in between the top plate and bottom plate. The heat transfer analysis for the TEHs is performed using finite element analysis (FEA) simulation and validated with an experimental investigation. Based on simulation results, the H-shape cooling element has a 75% improvement of ΔT from a single rod cooling element design. Furthermore, using a top plate with 100 × 200 mm dimension, also given an extra 8°C of ΔT than the top plate with a 65 × 200 mm dimension, it appears that the conduction shape factor, S, may have influenced the heat distribution in the cooling element. While, in field testing, the results can corroborate with the simulation where the maximum ΔT has reached a similar ΔT of 23°C, with a maximum relative error of 0.057%. Based on the feasibility studies with an application, the TEHs has effectively fully charged 5 F supercapacitors, within 3 hours, for the use of automatic street lights, which substantiated the significance of TEHs design. The present study represents a new perspective for self-sustainable TEHs design integrated with high cooling performances of the H-shape element in subterranean cooling.