Experiment of Hydrogen Deflagration

Abstract

Safety measures need to be taken and existing regulations should be re-examined in order to realize installing hydrogen refueling stations in towns. To obtain a basis for re-examining regulations, we have carried out experiments on hydrogen deflagration. We have observed the maximum overpressure of 1.5 kPa from the deflagration of 5.2 m3of 30% hydrogen/ 70% air mixture at the range of 10 m from the gas mixture with no obstacle in open space. The maximum overpressure did not exceed the safety limit of 9.8 kPa recomended in WE-NET safe design guideline, though the overpressure was much higher than one of 0.18 kPa from the deflagration of 9.5% town gas. However, greater overpressure and flame propagation velocity have appeared when a dense obstacle exists inside of hydrogen/air mixture. The hydrogen deflagration in confined space like a tube has also generated greater overpressure than in open space.