Abstract:

In order to prevent the leakage accident of LNG storage tank, using PHAST software, taking the storage tank of Xiangtan Xinao Hetang storage and distribution station as the research object, this study explored the influence of different leakage aperture and different wind speed on the diffusion distance of LNG steam cloud leakage and the spray fire and explosion range caused by the leakage. The simulation results show that the steam cloud leakage diffusion distance, fire radiation influence radius and explosion overpressure influence radius are directly proportional to the size of the leakage aperture, while the steam cloud leakage diffusion distance and explosion overpressure influence radius are inversely proportional to the wind speed. In the leakage scenario with a leakage aperture of 25 mm, the critical distance of the flammable and explosive zone, the radius of the blast radiation dead zone and the overpressure radius corresponding to the explosion overpressure of 50 kPa are 10, 7 and 8 times that in the 5 mm scenario, respectively. In the leakage scenario with a leakage aperture of 100 mm, the critical distance of flammability and explosion, the radius of the dead zone of jet fire radiation, and the overpressure radius corresponding to the explosion overpressure of 50 kPa are 37, 21 and 33 times that in the scenario of 5 mm, respectively.

Key words: liquefied natural gas (LNG), tank leakage, steam cloud, diffusion distance, jet fire