Experimental studies of combustion processes of stratified and uniform hydrogen-air mixtures

Abstract

Hydrogen-air mixtures are highly flammable. The acceleration of the flame and subsequent deflagration to detonation transition (DDT) can cause enormous damage to hydrogen energy infrastructure. Since leakage of hydrogen and its subsequent stratification according to the height of a room or structure is the most likely process to cause emergencies that arise at hydrogen energy facilities, studies of combustion and detonation in stratified hydrogen-air mixtures are of particular interest. The paper presents the results of the estimated flame front velocity and maximum overpressure in experiments involving the deflagration of a hydrogen-air mixture for vertical gradients of the hydrogen volume fraction in a closed channel with an annular blockage. This horizontally oriented channel has a square section of 0.6 × 0.6 m and a length of 12 m. The average hydrogen content of the gas used in the experiments varied in the range of 9–15 vol %.