In this study

a new independent type B liquefied natural gas (LNG) mock up tank with an inner volume of 40 m3 and an insulation thickness of 400 mm was examined. After reasonable simplification

two-phase flow and phase change heat transfer of a cryogenic fluid in the mock up tank were simulated by unsteady three-dimensional computational fluid dynamics(CFD). The volume of fluid model was selected to track the vapor-liquid interface. The Lee model was used as the phase change model

and the influence of the static pressure on the phase change model was considered. The temperature distribution and the staticboil-off-gas (BOG) generation rate of the mock up tank were calculated

and the characteristics of the simulated tank under different liquid levels and partial insulation damage were discussed. The pressurization characteristics of the mock up tank with a closed vent was also studied. By comparing the simulation results with the experimental results

it was evident that the deviation between the simulation and experimental results was less than 10%. This shows that this model can effectively simulate the evaporation process of cryogenic liquids in the mock up tank

which provides an important reference for the design and improvement of the new independent type B LNG ship.