Power generation mechanics of a multi-stage thermoelectric generator with metal-organic framework coating

Abstract

Thermoelectric power generators (TEGs) have the potential for replacing batteries for electrical circuits with small power consumption. However, one of the bottlenecks that hold back TEGs is their low thermal to electrical energy conversion efficiency. Passive thermal management of TEGs and stacking multiple TEGs on top of each other can increase their conversion efficiency and maximum power output. In this thesis, we study multi-stage TEGs with Metal-Organic Framework (MOF) coating layer as a passive thermal management to increase the power output of TEGs and develop mathematical models and COMSOL simulation model to understand and decouple the other complex physics. To develop the mathematical model, thermoelectrical effects, adsorption and desorption in porous materials, heat and mass transfer in porous materials and thermophysical and transport properties of humid air are studied. The developed mathematical models later used in the development of a multi-physics simulation in COMSOL. The numerical results obtained from the developed COMSOL model showed that with desorption and thermal radiation, TEGs with MOF coating generated electrical energy that is three times of the electrical energy that is produced by TEGs with no MOF coating. Moreover, with only radiative cooling, the generated energy was double of the generated energy from TEGs without MOF coating.