Dispersion characteristics of hydrogen leakage: Comparing the prediction model with the experiment

A quick and accurate assessment of the hydrogen dispersion when leakage accident happens is useful for minimizing the safety risk. A simplified prediction model was proposed in this paper to predict the dispersion of hydrogen, which was validated by a series of experiments of helium (instead of hydrogen) dispersion in an environmental cabin. The impacts of the helium flow rate, air temperature, and humidity are also explored in the experiments. Results show that when helium leaks continuously upwards in an unobstructed space for a short time, a stable field of concentration will quickly form around the leakage source. The prediction model is found to accurately predict concentration at the central axis when the dimensionless height is 95 < z/d < 195. In addition, A new experimentally fitted entrainment coefficient improve the accuracy of this model, the prediction model is more accurate in predicting the concentration at the central axis. When the jet is dominated by buoyancy and momentum (10 < Fr < 268), buoyancy-dominated (Fr ≤ 10) and momentum-dominated (Fr ≥ 268), the maximum deviations between the prediction model and the experiment are 0.95%, 2.61% and 2.71%, respectively. The deviation of the non-central axis prediction model increase compared with the center line, and the maximum deviation is 17.61%. The distance to the source of leakage and the amount of leakage can be predicted through the rapid prediction model calculation of hydrogen concentration monitoring in the industry.