Miniaturization technologies for advanced energy conversion and transfer systems

Microfabrication technologies have made possible the development of meso-sc ale energy conversion and chemical processing systems with microscale featu res, Scaling effects, such as the linear increase in surface-area-to-volume ratio that affects surface processes such as convection heat transfer, ads orption, and catalytic chemical conversion processes, provide some of the m otivation for the miniaturization efforts. Other mechanical, thermal, and f luid scaling effects are presented. Fabrication and material limitations, a s well as scaling effects, must be considered in the design process and may result in miniaturized systems that are considerably different than their full-scale prototypes, System and component development efforts at Battelle Pacific Northwest National Laboratories are highlighted. A fuel atomizer f or gas turbine engines and a multicomponent fuel processor for the producti on of on-demand hydrogen are microscale components that show potential for improving current large-scale systems. Complete miniaturized systems such a s a gas turbine, a vapor-absorption heat pump, and a Joule-Thompson cryocoo ler could be used for mobile power production and cooling of electronics an d individuals. Components for miniaturized systems include microbatteries w ith multiple definable voltage levels and a high degree of integratability and a combustor/evaporator for methane combustion with low levels of harmfu l emissions.