Flame Quenching Limits of Hydrogen Leaks

Abstract

This study examines flame quenching limits of hydrogen leaks in compression fittings and tube burners. Experimental work is presented. Measurements included ignition limits for leaking compression fittings on tubes of 3.16-12.66 mm in diameter and the ignition and quenching limits of tube burners with diameters of 0.15 - 0.56 mm. Minimum ignition flow rates of 0.028 mg/s for hydrogen, 0.378 mg/s for methane, and 0.336 mg/s for propane were found in the compression fitting experiments. The upstream pressure does not play a role in the ignition flowrate limit. The minimum quenching limits of hydrogen found in tube burners were 2.1 and 3.85 μg/s in oxygen and air, respectively. These correspond to heat release rates of 0.252 and 0.463 W, respectively, the former being the weakest observed flame ever.