A FLAT-PLATE THERMOELECTRIC GENERATOR

A thermoelectric generator, or TEG, is a thermodynamic heat engine tha t passively converts heat into electricity. It is based on tile creati on of a sodium vapour pressure difference across a Na beta''-alumina s eparator as a result of a temperature difference. Tile open circuit vo ltage output is approximately 1 volt for a temperature difference of 7 00 degrees C. Current is collected on tile low pressure face of the se parator by a porous molybdenum electrode. One of the major obstacles f aced in TEG design is maximizing the current collection while minimizi ng restrictions to sodium diffusion through the electrode. A new desig n of tile ceramic separator and electrode configuration is proposed in which the separator incorporates an array of capillaries within a pla nar tile. Tile surface of these capillaries are coated with a thin por ous electrode which allows easy diffusion of sodium ions. A thick meta l electrode applied to tile planar surface conducts the electronic cur rent from tilt: capillaries to the external circuit. Tile planar confi guration favours the recycling of waste heat from heat sources with te mperatures ranging from 600 degrees C to 1000 degrees C.