Study Of LNG Leakage And Diffusion

LNG is an environmentally friendly and efficient clean energy.With the enhancement of people’s environmental awareness and the need of social development,the demand for LNG is growing rapidly around the world,which was 0.293 billion tons in year 2017.Now it is the golden age for the development of LNG industry.However,the leak of LNG can be very dangerous and cause irrevocable significant loss.Therefore,it is helpful for the determination of safe area to study the diffusion movement and concentration range and provide guidance for the emergencies.This paper conducted the study of the leakage and diffusion of LNG tank from three aspects: theoretical analysis,Fluent numerical simulation and experimental verification.Firstly analyzed the mode of tank leakage,the processes of diffusion and the factors of influencing,used plate model establishing the calculation models of leakage and diffusion,and analyzed the impacts of various factors on concentration range of methane diffusion.The results show that:The larger the mass of leakage,the longer distance of the downwind transition point,the larger the concentration area of methane’s diffusion.The greater the wind speed,the closer distance of the downwind transition point,the smaller the concentration area of methane’s diffusionThen used CFD Fluent and Tecplot to establish the model of tank’s leakage,numerical simulation and post-processing,and analyzed the impacts of wind speed,temperature,the mass of LNG leakage and timing on the range of concentration and temperature.Finally conducted leakage experiment,compared and analyzed the concentration range of methane under plate model and numerical simulation when other conditions remains the same,and the results are within the allowable error range to prove the correctness of the models and simulations.The results show that: the maximum distance is 3.5m when the concentration range is 15%,the maximum distance is 5m when the concentration range is 10%,the maximum distance is 10.8m when the concentration range is 6%,the maximum distance is 11.5m when the concentration range is 5%,the maximum distance is 12.5m when the concentration range is 4%,the maximum distance is 14 m when the concentration range is 2%.The explosion range is about from 3.5m to 11.5m.