LOWESMITH, B.J. ... et al., 2009. Gas build-up in a domestic property following releases of methane/hydrogen mixtures. International Journal of Hydrogen Energy, 34 (14), pp. 5932 - 5939.
The results of large scale experiments to study gas accumulation within a ventilated enclosure representing a domestic room are presented. Gas was released vertically upwards at a pressure typical of that experienced in a domestic environment from hole sizes representative of leaks and breaks in pipes. The released gas composition was either methane or a methane/hydrogen mixture containing up to 50% hydrogen. During the experiments, gas concentrations throughout the enclosure and the external wind conditions were monitored. A mathematical model has also been developed to describe the gas release as it mixes with air and forms a layer of gas/air mixture in the upper part of the enclosure. The model accounts for both wind and buoyancy driven ventilation, which arises as a result of the formation of the gas accumulation within the enclosure. The results show the importance of buoyancy driven ventilation on the steady state gas concentrations achieved.