Combustion of Hydrogen at High Concentrations. Including the Effect of Obstacles

Abstract

Combustion of hydrogen-steam-air mixtures has been studied in a 2.3 m diameter sphere at 100°C and near atmospheric pressure. The ranges of concentrations Investigated were 10 to 42 percent hydrogen and 0 to 30 percent steam by volume. Over these ranges, combustion proceeded until one of the reactants was completely consumed. Measured peak combustion pressures were 10 to 20 percent below the calculated adiabatic values. The effect of fan-generated turbulence was less pronounced at high hydrogen concentrations than at low concentrations. The effect of obstacles was investigated by placing gratings in the sphere. Although gratings increased the extent of combustion and the peak pressure at low hydrogen concentrations,their effect was less at high concentrations. In general, the gratings acted as heat sinks, reducing, in some cases the peak pressure, as well as the rate of pressure rise. These observations are preliminary and further studies are required for confirmation.