Abstract: In order to study the hazards of open hydrogen explosion, a three-dimensional numerical model of open hydrogen-air explosion was established based on Fluent fluid dynamics calculation software. On this basis, cubic premixed hydrogen-air explosion with side lengths of 0.5, 1.0, 2.0 m and 3.0 m was simulated and analyzed, and the numerical simulation results were compared with the explosion intensity grades of TNO multi-energy method and BST method. The results show that the flame propagation distance is about 2 times of the initial hydrogen radius. The dimensionless distance of the location of the maximum explosion pressure is approximately linear with the initial radius of the gas cloud. The choice of explosion intensity grade of TNO multi-energy method and BST method should increase with the increase of initial size of gas cloud.

Key words: hydrogen explosion; open space; gas cloud size; maximum overpressure;flame propagation;TNO multi-energy method; BST method