Influence of inlet-nozzle and outlet-diffuser mounted in the plate-shape reactor on PEMFC net power output and methanol steam reforming performance

A proton exchange membrane fuel cell (PEMFC) fueled from a plate-shape reactor under steam reforming of methanol is believed to be an optimistic minute power source. This numerical study explores the conversion efficacy of a plate methanol steam reformer (MSR) with an inlet-nozzle and an outlet-diffuser. Considering various convergent ratios and lengths of inlet-nozzle examines the conversion quality of MSR and evaluates PEMFC net power output changing divergent ratio (λ_d) and length of outlet-diffuser (L_d) at different wall-heated temperatures (T_wall). The divergent ratio is the reciprocal of convergent ratio. The results depict that the application of inlet-nozzle and outlet-diffuser to a plate reactor significantly enhances the methanol conversion of MSR and PEMFC net output power. Compared to the common reactor without nozzle and diffuser, the innovative reactor with the inlet-nozzle and outlet-diffuser ofλ_d = 4.0, and L_d = 7.5 mm creates the best improvement of the methanol conversion about 21.04 % and the hydrogen gain about 85.66 % at T_wall = 250 °C. Furthermore, the other novel reactor with the inlet-nozzle and outlet-diffuser ofλ_d = 4.0, and L_d = 10.0 mm generates the greatest rise of 20.39 % in PEMFC net output power at T_wall = 250 °C with the permissible CO emission.