Analysis and Experiment on Metal Ablation Protection of the Large Floating Roof Oil Tanks Struck by Direct Lightning

Fire is a serious disaster for large floating roof oil tanks and brings great economic losses. The direct effects of lightning on oil tanks are mainly melting or burning at attachment point and could cause large temperature rise. Adopting the experiment method is an effective way to solve the complex problem of metal ablation. In this research, the aluminium alloy 3003 and steel alloy Q235B, which are widely used in oil tanks, are studied with the simulated lightning current. The simulated lightning current is generated by a multiple impulse current generator. The output waveforms are simulated first stroke, continuing current of interval stroke and long continuing current. The amplitudes of the experimental current components are 200kA, 8kA and 400A, respectively. The impacts of lightning…