Thermodynamic design of a power optimized irreversible thermionic generator

The operating temperatures of the electrodes in a thermionic (TI) energy generator can better be determined through thermodynamic optimization rather than through heuristic principles. Since the power output of a TI generator has high functional dependence on operating temperatures, choice of these temperatures becomes a crucial aspect in the design of any TI device. The study reported here includes the optimisation of the operating temperatures of the electrodes of a TI generator with respect to maximum power output for a given heat source and heat sink, and for given electrode materials. Parametric studies on the variation of the optimised temperatures and power output, with varying heat source temperature, and a constant heat sink temperature have been carried out. Preliminary results show that the optimised cathode and anode temperatures increase (almost linearly) with increase in heat source temperature. Power output per unit electrode area increased exponentially with heat source temperature