Experimental study on jet fire characteristics of hydrogen-blended natural gas

Abstract

Blending hydrogen into natural gas can increase fuel reactivity and the risk of jet fires in case of pipeline leakage though it is an effective delivery method. In this work, horizontal jet fires of hydrogen-blended natural gas at various operating pressures and hydrogen content were investigated experimentally. The flame temperature, lift-off distance, and flame length were measured for the scenarios with 0%–50% hydrogen content (in volume fraction) and 200–800 Pa. Results show that with the increase of hydrogen content, the flame temperature rises while the lift-off distance and flame length decrease. The flame length is slightly affected when the hydrogen content is less than 10% and a maximum reduction in flame length is 13.7% as the blended hydrogen content increases to 50%. Further theoretical analysis suggested the dimensionless correlations of the temperature distribution along the jet axis, lift-off distance, and flame length with different hydrogen content, respectively. The research results may provide reference for the risk assessment of hydrogen-blended natural gas pipelines.