Abstract:

The relief rate of liquefied hydrocarbon spherical tanks for mixed components under external fire scenarios depends not only on the heat absorbed, but also on the relief time. Using static calculation methods to calculate the relief rate, the results tend to be conservative. In this research, a dynamic safety relief model of liquefied hydrocarbon spherical tank groups was constructed to calculate the safety relief load of liquefied hydrocarbon spherical tank groups under external fire scenarios. DYNSIM, a dynamic simulation software, was used to simulate the impact of external fire on the relief of liquefied hydrocarbon spherical tanks and tank groups with different compositions and volumes. The simulation results show that during the relief, the relief rate, relief temperature and molecular weight of relief medium vary with the relief time. Compared to static calculation methods, dynamic simulation considers the time factor, and the calculation results are more aligned with the actual relief conditions. Using dynamic simulation methods to calculate the relief parameters of spherical tank groups can reasonably optimize the relief network, providing guidance for the design of safety valves and flare systems.

Key words: liquefied hydrocarbon, spherical tank, fire, safety relief, dynamic simulation