Research on maximum explosion overpressure in LNG storage tank areas

Abstract Maximum explosion overpressure is an important index in combustible gas explosions for safety managers and fire rescue commanders. The main factors affecting the maximum explosion overpressure in an LNG tank area were deduced by a series of reduced-scale tests. A correlation of maximum explosion overpressure in LNG tank area was developed based on the momentum conservation equation and the deduced factors in the explosion tests. The parameters in the correlation were fitted by FLACS simulations of explosions of different LNG storage tank areas. Compared with traditional methods such as the TNO Multi-Energy method and Baker-Strehlow method, this correlation is targeted to the scenario of LNG leaking from the joint of a pipeline and the tank top, which may be the most probable type of leak in LNG tank areas. The correlation was verified by five FLACS simulation cases of the LNG tank areas with tank radii of 10 m, 20 m, 30 m, 40 m and 50 m. Comparing the overpressures calculated with FLACS and the correlation, there are fewer relative deviations when the radii of tanks are larger. LNG tanks with a radius greater than 40 m have been widely developed in recent years, and the relative deviation of the correlation and FLACS greater than this size is less than 6.6%. The maximum overpressure of the test scale explosion obtained from the correlation is 326.09 Pa. It is close to 389 Pa, which is the maximum tested overpressure in this paper. This correlation can be used as a reference for LNG tank area safety managers, fire rescue commanders and researchers.

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