| With the constant increase of the consumption of liquefied gas, it's 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 cargo at port and during marine transportation, mainly caused by low temperature, flammable and explosive characteristics of the liquefied gas.This dissertation is the subsystem of Risk Assessment of Liquefied Gas Carrier, and its key content studies the thermal response of LPG(Liquefied petroleum Gas)tank exposed to one side fire. First, the safety of a workpiece is related to stress it bears and its temperature, so is the tank of LPG vessel. Temperature field distribution and stress field distribution of LPG vessel are calculated in order to estimate its safety status. As to the calculation of the temperature field distribution, the heat transfer model of LPG vessel under flame surroundings is set up first, then the heat transfer boundary conditions of LPG vessel are determined according to the heat transfer theory and the heat exchange boundary conditions of LPG vessel is calculated, finally the temperature field distribution of this model is calculated and analyzed by ANSYS software. With regard to stress calculation of LPG vessel, the stress of LPG vessel is caused mainly by thermal stress and mechanical stress. In order to make clear the influence of two kinds of stress to the total stress, equivalent thermal stress of LPG vessel under only temperature load and its equivalent mechanical stress under only inner wall stress are calculated and analyzed, then its equivalent total stress is calculated, analyzed and compared.Second, the failure process of LPG vessel tank usually includes two phases: the crack formation and the crack propagation. After the temperature field distribution and the stress field distribution of LPG vessel tank without cracks are calculated, the...
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