Improved Performance of a Radiative-Based Thermoelectric Power Generator with Vertical Finned Absorber: An Experimental Investigation

This paper is an extension of our previous research aimed to improve the performance of radiative-based thermoelectric power generator concept through the use of vertical finned absorber instead of horizontal one (TEG-RVFA).To this end, we used the experimental setup developed in previous study and modified it according to the objective of this paper.The TEG-RVFA is composed of a heated plate (297 mm×182 mm) and four sets of vertical finned absorbers (41 mm×55 mm) with 40×40 mm thermoelectric modules to absorb the heat emitted.At the back side, a finned aluminum heat sink 119 mm wide and 200 mm length with two DC fans was used for cooling.The electrical power supplied to the heater varied between 1000 -1400 watts and the air gap between the heated plate and the finned absorber varied between 1 to 5 cm.Data recorded included the generated voltage, current, and temperatures at various locations.Results are also compared to those published earlier with horizontal finned absorber.It was observed that the electrical current generated varied like in the case with horizontal finned absorber (TEG-RHFA); it increased with the power supplied and reducing the air gap space.However, the TEG-RVFA led to better performance.The maximum power generated and the temperature difference between the hot and cool sides of thermoelectric modules observed at 1400 Watt and 3 cm air gap space were 1.63 Watt and 73.85℃ compared to 0.78 Watt and 58.93℃ for TEG-RHFA.The maximum power generation efficiency is 7.4% with horizontal fins and 9.1% for vertical finned absorber.This improvement is due to better heat transfer due to induced air circulation between the fins reducing heat accumulation at the base of the absorber and creating higher temperature difference between the two sides of thermoelectric modules.Therefore, TEG-RVFA is recommended for use when considering application in waste heat recovery such as furnaces and chimneys.