Development of a Standalone, Liquid Fuelled Miniature Power Generation System

Abstract

Abstract This paper aims at developing a novel mesoscale combustion-based thermoelectric power generator as an alternate to the electrochemical batteries. Most of the micro and mesoscale combustors investigated till date are based on external fuel and air supply systems, which may not be beneficial for a practical system. The proposed design is a standalone system which makes use of the heat conducted through the combustor walls, as an energy source to evaporate the liquid fuel stored in a surrounding tank and supply the vaporized fuel to the combustor. The high momentum fuel (vapor) jet is designed to entrain the ambient air in appropriate proportion so as to form a combustible mixture. The fuel/air mixture is fed to a mesoscale combustor and the flame is stabilized by facilitating hot gas recirculation regions. The hot combustion products then flow over a ceramic plate on the other side of which the hot side of a thermoelectric module (TEM) is attached, while ensuring a near uniform temperature, to generate electricity. The cold side of the TEM is maintained at relatively lower temperature and the heat is designed to be rejected using fins to the ambient. The prototype is designed to produce an electrical power output of 12 W with an overall efficiency of about 2.4% (heat load of 500 W) and endurance of 1.5 h in a single fuel refill. The paper presents detailed description of the constituent components and the CFD analysis which evaluates the performance of the system.