Geometry optimization of exhaust ducts applied in thermoelectric cogeneration efficiency

With following world demand for electricity and increasing scarcity of natural energy resources, it is imperative to search for alternative methods for electricity production or increasing the efficiency of existing processes. The use of Seebeck modules have been shown the green output of power cogeneration using waste heat energy. Furthermore, the overall conversion efficiency of thermal energy into electric by this system is about 5%, a factor that discourages the high costs embedded. The goal of this work aims to seek increased efficiency in thermal-electrical conversion indeed by Seebeck modules (TEG), starting from a geometry optimization of hot gases exhaust duct. The duct thickness was varied lengthwise to flow and from a heuristic optimization process, good results of surface equalization temperature was found by finite element simulations. A low surface temperature gradient allows TEG working near the maximum efficiency condition, distant of mechanical failure.