Abstract
In order to derive validation data for numerical code validation the REKO-3 facility at Forschungszentrum Juelich (FZJ) is used for experimental studies on recombiner behaviour under well defined steady-state conditions. One important aspect addressed in recent experiments is the influence of an oxygen depletion on the catalytic reaction. Detailed measurements of the catalyst temperature and the hydrogen concentration along the catalyst sheets have been performed for oxygen concentrations from oxygen content in air down to 1 vol.% at different flow rates. The critical oxygen concentration that marks a loss in performance of the recombiner has been determined in dependency on several influence parameters. Due to the local measurements the influence of oxygen depletion on the reaction kinetics is already detected before the integral reaction rate is affected. The numerical model REKO-DIREKT has been used for recalculation of the experiments. The code was capable to accurately calculate the influence of the oxygen concentration on the catalytic reaction by achieving good agreement with the experimental data.
