Waste heat recovery plant for exhaust ducts using thermoelectric generators

Alternative methods for electricity production are needed in view of the scarcity of natural sources resulting from population growth and the consequent demand for energy. The inefficient use of energy requires new recovery processes in order to increase the system's gains. The use of Seebeck modules (TEG) have been shown the novel output of power recovery using waste heat energy. This work proposes a recovery plant from waste heat starting from a geometry optimization of exhaust duct. The distance between each TEG and surface was varied lengthwise to flow, creating a thermally resistive air layer, and from a heuristic optimization process, good results about equalization on surface temperature were found by finite element analysis. The thermoelectric modules used were tested in real conditions and results compared with data sheet. Finally it is exposed an electrical arrangement for a 42 TEG MPPT power plant. The novel design shows a low surface temperature gradient that allows TEG work closely to maximum efficiency condition and distant of mechanical failure.