Failure Mechanism Analysis Of Oil Tanks Under Thermal Stress

With the construction of large oil tank farm, the risks of oil tank begin to occur. Withmany segments of oil storage, transport, refinery operation and use management in petroleumchemical industry, many cases of fire explosion in oil tank frequency happened. Among thesereasons for the accident，one should be emphasized that oil tanks are attacked by exterior ifres.Oil has the features of toxicity, combustibility and explosibility, so tanks are prone to fire andexplosion‘Under high temperature and static ifeld, temperature of tank shell will rise robustly,which causes a substantial decline of tank shell strength and causes the bursting of tank shell,so the ifre and poisoning accidents will happen and cause serious environmental pollution, lifeand property loss. The numerical research on thermal-mechanical response and failuremechanism of oil tanks subjected to fire environment, has certain theoretical value andpractical signiifcance. In the paper, the research is carired out as follows:(1)The numerical study on mechanical response at normal temperatures and pressures.The finite element software ANSYS is used for modeling, meshing, loading and solving. Themechanical properties are analyzed at normal temperature.(2)The numerical study on mechanical response of oil tank in fire environment.According to thermal-structure coupling analysis and elastic-plastic theory, thethcrma1-structural static module is veirifed, the finite element stress analysis of oil tank isimplemented in different temperature-pressure fields coupling condition and the strength of oiltank is obtained within300seconds.(3)The preliminary study on oil tank failure mechanism in the fire environment, andfailure prediction and prevention. According to failure mechanism，the theoretical predictionmethod of failure time and bursting pressure of the oil tank is put forward in an accidental fireenvironment. First the failure mechanism is analyzed, then, the failure criteria are presented.Finally，based on the failure mechanism of the oil tank, the accidental ifre safetycountermeasures of oil tank are suggested.