Simulation Study on the Explosion Characteristics of Premixed Hydrogen-air Mixtures

Abstract In order to study the explosion characteristics of hydrogen in the air and the influence of concentration on the explosion characteristics of hydrogen, the fire and explosion of small-scale hydrogen cloud with different concentration are simulated. The distribution of explosion characteristic parameters, such as overpressure, temperature and velocity, as well as the change rule with time, are obtained. The explosion characteristic parameters in horizontal and vertical directions are discussed The results show that under the influence of the ground and gravity, oblate elliptical fireballs with horizontal direction larger than vertical direction are formed in the early stage of ignition development. With the continuous combustion, they develop into hemispherical fireballs with the diameter of the ground and spread around. The influence of concentration on the law of fire and explosion is studied, and the maximum overpressure under different concentration is obtained, which provides support for building the fire field model of liquid hydrogen leakage. It is also of great significance for the evaluation of explosion hazards and the design of corresponding protection system.