Study On Failure Risk Assessment Of C Type Spherical Cargo Tank Of Liquefied Gas Carrier

With the constant increase of the consumption of liquefied gas, liquefied gas transportation volume is increasing by a large margin and the corresponding accidents are constantly rising too. The carriers of liquefied gas have a lot of hidden risks of accident while they load and unload the goods at ports and during marine transportation, mainly caused by liquefied gas low temperature, flammable and explosive characteristics.The fire accidents frequently happen on ships at sea. Once the liquefied cargo tank of the liquefied gas ship explodes under the influence of fire, the consequence would be very serious. Analyzing and studying the failure mechanism of cargo tank of liquefied gas carrier under the non-normal heat source has direct guidance functions for ensuring the safety of liquefied gas carrier.This dissertation is the subsystem of Risk Assessment of Liquefied Gas Carrier, and its key content studies how to assess the failure risk of liquefied gas tank under non-normal heat source accident. The dissertation mainly carried out on discussion and research from several following aspects: According to the failure theory at first, studied and analyzed failure reason and mechanism of cargo tank of liquefied gas carrier, explored failure process and its models happening in failure accident;analyzed the stress of liquefied gas tank bulkhead under high-temperature environment by finite element principle, separately computed thermal stress and mechanical stress to clarify these two kinds of stresses influence to total stress, then calculated total stress and acquired the change rules of mechanical stress, thermal stress and total stress;The author also analyzed the fatigue and corrosion mechanism of liquefied gas tank in operation, and probed the fatigue and corrosion impact to liquefied gas tank in detail;Finally, used the computer technology to exploit the failure risk assessment software of cargo tank of liquefied gas carrier and strengthened the practicability of the research results;offered a systematic failure risk assessment method of cargo tank of liquefied gas carrier and provided strong auxiliary support for accident emergencedecision-making in order to reduce casualties and property loss to the greatest extent and lighten the pollution of the environment.