Damage mechanism and assessment for storage tank structures under oil and gas explosion loads

Objective As the scale for oil storage expands, the safety protection of aboveground oil storage tanks is taking increasing pressure day by day. A fire or explosion accident may easily cause domino effect accidents, leading to catastrophic consequences. To analyze the failure of aboveground oil storage tanks under oil and gas explosion loads, the dynamic response and damage assessment of oil storage tanks under dynamic load conditions were studied.

Methods By measuring and analyzing the outfield overpressure parameters of oil and gas explosion at varying volume fractions and propagation distances, the outfield dynamic load propagation parameters of oil and gas explosion under the most dangerous volume fraction (1.70%) were obtained. In combination with dimensional analysis, the dynamic load prediction model of oil and gas explosion was obtained, and the dynamic load was applied to the equal-scale aboveground oil storage tank model by simulation.

Results The outfield shock wave was observed to propagate as a spherical overpressure wave, with the maximum overpressure increment occurring during continuous oil and gas combustion. By analyzing and fitting the overpressure parameters of the outfield shock wave, the variation law of overpressure parameters with dimensionless distance was obtained, leading to the establishment of the dynamic load prediction model for oil and gas explosion and the damage criterion of aboveground oil storage tanks under dynamic load conditions. The damage criterion was then employed to evaluate the dynamic response of other oil storage tanks following an explosion of one tank in a 5 000 m³ aboveground tank farm. During domino effect explosion accidents, the maximum overpressure between successive explosions increased gradually by over 3.5%, while the explosion interval decreased continuously by more than 20%. Additionally, a“Z”shaped sequence of explosions was observed.

Conclusion Through the damage assessment and analysis for aboveground oil storage tanks under dynamic load conditions, the minimum layout distance for aboveground tank farms is fitted out, providing a scientific basis for the safe arrangement of these tanks, the prevention and control of explosion and fire accidents, and the emergency rescue and management.