The time-to-failure assessment of large crude oil storage tank exposed to pool fire

Abstract

In large crude oil tank farm, fire is a major primary event in domino effects according to past accidents. The quantitative risk assessment of domino fire accident is a key issue for the accident prevention of large storage tank farm. The most widely used equation for the estimation of the tank's time to failure (TTF) exposed to pool fire is not suitable for 100,000 m3 external floating roof tank. The purpose of this study is to establish simplified models for the calculation of the tank TTF with respect to heat radiation intensity, filling level and the availability of safety protections under different fire conditions. The finite element transient heat transfer modeling of 100,000 m3 external floating roof tank in the case of fire scenarios was performed. The quantitative assessment of safety protection performance in delaying the tank failure under fire conditions was performed according to the simulation results. The application of the TTF equation to case-studies of crude oil tank farm showed the importance of safety protection for the prevention and mitigation of the domino effect. The TTF model provides a basis to the risk management and emergency response in large tank farm.