Heat transfer modelling of LiquifiedNaturalGas (LNG)Tanks (Numerical estimation ofLNG volume and tank temperature)

摘要

Thispaper introduces methods on estimatingdynamicLiquified Natural Gas (LNG)volume and tank temperature on LNG vesselthroughout theladen(full)and ballast(empty)voyage by calculating the overall heat leakage of the tankusing heat transfer equationsinvolving conductiveand convective heatflowbased on parametric approach.Thisstudy considers a simplified model consisting of 4 layer tankbased on tanksused in anactualLNG vessel.The methods involveanalyzing tank structure,determining thermal resistance of bothsteadyconductive and convective heat flowsthrough sphericaltank,volume and temperature estimation formulation as function of time andperforming dataanalysis on raw data toempiricallydetermine the evaporation ratio of LNG sprays as function of LNG volume.The results producedbased on a two weekvoyageof a five tank vesselare compared with actualrawdata and the comparisons are analyzed in this paper.