High energy density entrainment-based catalytic micro-combustor for portable devices

The increasing demand for low-cost, high energy density heat sources has motivated the development of compact and lightweight combustion-based devices. In this work, we developed an energy-dense (approximate to 236 MW/m3) entrainment-based catalytic micro-combustor for heating portable systems. The multichannel micro-combustor (coated with Pt/Al2O3 catalyst) leverages a copper-nichrome wire to enable quick and localized ohmic pre-heating durations (2-3 mins). Furthermore, we demonstrated low ignition temperature (108-125 degrees C), which facilitates low energy consumption (-1948 J). In addition, an optimal fuel flow rate (3.09 x 10-8 m3/s) was determined via FEM simulations and experiments to enable fuel savings (high fuel conversion) while achieving high heat fluxes by analyzing the reaction kinetics and species transport behavior in the microchannels. Through independent testing, we established the micro-combustor's ability to maintain long-term autothermal combus-tion at a high saturation wall temperature (585 degrees C), which was attained at short timescales to enable fast heating/cooling cyclability. The successful cyclic heating demonstration of large thermal mass additions (at least 41 times the micro-combustor's mass), coupled with the combustor's high energy density, shows promise for device-level implementation for a range of commercial, defense, and energy conversion applications.

Automated summary

The development of a compact and lightweight entrainment-based catalytic micro-combustor with high energy density for heating portable systems is presented. The micro-combustor exhibits low ignition temperature, low energy consumption, and high heat fluxes. Long-term cyclic heating and fast heating/cooling capabilities make it promising for various applications in the commercial, defense, and energy conversion fields.