Numerical Simulation Of Gas Explosion And Explosion Venting Process In Linked Vessels

Vessels handling flammable gas or liquid are often interconnected through pipelines; such linked vessel configuration is quite common in chemical industrial installations. An accidental explosion in one vessel of the system will be transmitted through the linking pipeline into the other; the explosion propagating between linked vessels is characterized by much higher values of peak pressures and rates of pressure rise in the secondary vessel as compared to the explosion in an isolated vessel of the same size. Therefore, the research of gas explosion and explosion venting and their influencing factors in linked vessels will be of great significance to explosion prevention.The gas explosion and explosion venting in linked vessels are simulated by realizable k-ε turbulence model and eddy dissipation turbulent combustion model of fluent software, and conservation equations are established based on chemical reaction dynamics and fluid mechanics. The results of numerical simulation are consistent with the experimental data, which properly illustrate the effectiveness of the mathematical model.Simulation of gas explosion and explosion venting in linked vessels under different conditions are carried out to analyze the flow distribution. The results show that gas turbulence combustion is more intense and overpressure becomes higher in linked vessels with the increase of pipe length, the overall axial velocity of linked vessels increases greatly after the flame arrives into the second vessel, when gas is burning out, the axial velocity of linked vessels declines slowly and overpressure is smaller with the increase of pipe length. Compared with small vessel centre ignition, when ignition happens in the large vessel, the peak pressure in linked vessels is higher; whether the ignition occurs in the large vessel or the small vessel, the pressure rise in the second vessel will be faster than in the ignition vessel. When reduced explosion overpressure is small, the pressure in linked vessels tend to rise, non-equilibrium explosion is easy to happen, airflow velocity near explosion vent becomes higher after explosion venting just happens, the pressure outside the vessels will increase rapidly to a peak pressure then decline more slowly; with the same reduced explosion overpressure, the pressure in the small vessel increases more rapidly than in the large vessel, and non-equilibrium explosion is prone to happen in the small vessel. When venting area is small, the pressure in linked vessels tends to rise, non-equilibrium explosion is easy to happen, with the increase of venting area, and more flammable gas will be released to outside and flame deformation is more obvious outside.This study could provide some reference for explosion prevention and explosion venting technology development of linked vessels.