Numerical study on characteristics of hydrogen deflagration and detonation in the combustion tube

In severe accidents for a nuclear power plant, the zirconium-water reaction may produce a huge amount of hydrogen. The hydrogen combustion and explosion produce heavy pressure and temperature loads, which may cause equipment damage and even containment failure. Based on previous experiments on detonation in the tube, this study established numerical models of hydrogen deflagration and detonation in the tube using the FLUENT software. The process of flame acceleration and onset of detonation was accurately simulated. Calculation and experimental results show that the detonation velocity increases with the increase of stoichiometric ratio, and the peak temperature and pressure reach the maximum when stoichiometric ratio is 1.2. The detonation velocity, peak temperature and pressure are positively correlated with the initial pressure. The verified models can be used to predict hydrogen explosion phenomenon and evaluate its consequences in pressurized water reactor containment under severe accidents.