Research on parameter search of the worst operating condition for explosion overpressure in utility tunnels based on genetic algorithm

Abstract

In this paper, the 2D numerical simulation model for the gas pipe tank of utility tunnels is established. Aiming at optimising the maximum overpressure produced by explosion in the gas pipe tank, in restricted conditions of vent position, pre-mixed gas concentration in the tank and ignition position, a method of parameter optimisation of the worst operating condition for explosion overpressure in the gas pipe tank of utility tunnels is proposed by combining computational fluid mechanics and genetic algorithm. The results show that genetic algorithm is feasible in searching the worst operating condition for explosion overpressure in the gas pipe tank of utility tunnels and can improve the searching efficiency significantly. Methane-air pre-mixed gas under the two conditions being both pre- and post-optimised can form deflagration phenomenon. The deflagration wave is the direct factor of the overpressure formed at the boundary of the model. Both the pressure and temperature imposed by the deflagration wave acting on the model boundaries have an evident increase compared with those before optimisation. The maximum overpressure is increased by 15% and the maximum temperature is increased by 7%.