Study On Internal Explosion Load And Dynamic Response Of Tank Structure Using Numerical Simulation Method

The steel storage tank structure in petrochemical industry is a typical combined thin shell container,which is often used to storage various inflammable and explosive media.In the process of filling and emptying the liquid medium in the tank,the external air enters the tank and mixed with the flammable gas produced by the liquid medium.When the concentration of the combustible gas is at the limit of the explosion limit,it is very easy to burn and explode under the condition of accidental ignition,resulting in the damage of the structure of the tank under the action of explosion overpressure and temperature rise.In this paper,the explosion accident in the internal combustion gas of the tank is studied.The mechanical problems involved are extracted and the internal explosion load and the dynamic response of the tank structure are studied by numerical simulation.The specific research work is as follows:(1)Coupled dynamic analysis of storage tanks with liquid based on TNT equivalent modelThe TNT equivalent method is used to equivalents the explosion load of the flammable gas cloud,and the fluid solid coupling model of the detonating common node in the liquid storage tank is established.The displacement coordination and the acceleration and velocity coupling between the internal detonating flow field and the storage tank structure are realized.Based on this model,the internal explosion overpressure of the storage tank structure under the conditions of different TNT equivalent and different level height is analyzed.(2)CFD simulation of explosion temperature and pressure load of flammable gas in storage tankA computational fluid dynamics(CFD)method is used to establish a numerical model for the explosion of a flammable gas in a container.By simulating a small container and comparing with the experimental results,the correctness of the numerical model is verified.On this basis,the explosion process of the flammable gas in the tank structure is simulated,and the heating and overpressure load distribution on the inner wall of the tank are obtained,and the influence of the heat transfer process on the overpressure of the explosion is discussed.(3)Study on coupling problem of flammable gas explosion in storage tankBased on the weak coupling method,the fluid solid coupling and coupling heat transfer in the combustion process of the internal flammable gas in the tank are studied.The elastoplastic dynamic response and the temperature distribution under the action of temperature rise are analyzed,and the coupling between the internal explosion flow field and the structure of the tank is further studied by the strong coupling method.The heat transfer problem is analyzed and compared with the weak coupling method.(4)Study on temperature,pressure load of internal explosion and dynamic response of tank structureBased on the three-dimensional shell conduction coupling model,the distribution of temperature and pressure inside the tank wall under different ignition positions is analyzed.Based on the three-dimensional thermal fluid solid coupling model,the dynamic response of the storage tank structure under the joint action of overpressure and heating load is studied.The Johnson-Cook model is used to describe the strain hardening and the temperature softening effect.The dynamic response and the failure position of the storage tank structure under different ignition positions are discussed.