Research On The Impact Of The LNG Ship Explosion In The Lower Reaches Of The Yangtze River Based On Fluent Software

In recent years,the relevant departments of the state have intensively issued a series of policies to support the development of natural gas,and have successively built LNG filling stations along the coast and the Yangtze River,to enhance the proportion of clean energy in China’s waterway transportation,create LNG sea access to the river,and promote the green development of the Yangtze River shipping.With the development of the inland shipping industry,there are a large number of hydraulic structures such as bridges and wharves across the Yangtze River mainline,with a large distribution density.The traffic flow of ships is increasing year by year.The trend of diversification and large-scale ships is obvious.Because LNG has the characteristics of low temperature and easy diffusion,when the volume content of LNG in the air is between 5% and 15%,an explosion accident will occur in case of an open fire.Due to the dangerous cargo and large carrying capacity of LNG ships,there is a great potential risk.Once the LNG ship leaks or explodes in the Yangtze River channel,it may lead to channel obstruction,damage of LNG ships and hydraulic structures and other consequences,causing huge losses to human life and property.Therefore,before allowing LNG ships to enter the Yangtze River,it is necessary to take precautions,correctly understand the physical and chemical characteristics of LNG,and reasonably predict the impact of LNG ship leakage and explosion.By consulting the relevant literature and research results,at present,the research on the influence scope of LNG ship leakage and explosion is less in the Yangtze River trunk line.The research mainly focuses on the LNG storage tanks and LNG power ships inland and coastal waters.The method of tank leakage test or TNT equivalent calculation is used to study the influence scope of LNG leakage and explosion,but the test data has some errors,and the calculation is complex The quantity is large.In recent years,with the development of computer technology and its application in the shipping industry,the technology of using finite element software to simulate the impact of the LNG explosion is becoming more and more mature.This paper introduces the physical and chemical characteristics of LNG,analyzes the factors that affect the leakage and explosion of LNG ship,combines with the navigation conditions of the lower Yangtze River channel,and uses the hydrodynamic turbulence standard model.Based on the double equation model,Fluent software are used to simulate the diffusion range of steam cloud and the propagation characteristics of shock wave after an explosion of 40000m3 LNG ship.According to the simulation analysis results,the leakage and diffusion range of 40000m3 LNG ships under limited operation conditions and the explosion influence range under the influence of different wind speeds and different distance obstacles are given,and the preventive measures are analyzed through examples,which can provide a reference for the competent authorities to formulate relevant navigation safety guarantee measures and management regulations for LNG ships entering the Yangtze River in the lower reaches of the Yangtze River,It plays a positive role in ensuring the navigation and operation safety of ships in the lower reaches of the Yangtze River and promoting the development of green shipping.