Study On Cargo Oil Insulation Process Of Polar Tanker Under Sloshing

During the transportation of cargo oil,the oil is always sloshing with the movement of the ship.The sloshing oil has an effect on the process of oil insulation.In recent years,with the extensive development of oil and gas resources of polar and the opening of polar routes,the research on the process of oil insulation of polar tankers has gradually become a concern.Compared with the normal temperature environment,the changes of oil temperature of the process of oil insulation of the polar low temperature environment are different.Therefore,it is of great significance to study the impact of the sloshing of oil and the extremely low temperature environment on the process of cargo oil insulation.And it is of great significance to formulate a reasonable scheme of cargo oil insulation of polar tankers.The main work of this paper is as follows:Firstly,based on the side tank of a very large crude carrier(VLCC),the paper has a certain fluidity oil as the research object.According to the heat transfer mechanism of the process of crude oil insulation and the characteristics of the viscosity with the oil temperature,the appropriate similarity criterion is selected.The physical scale experimental model is established according to the appropriate scale ratio,and the appropriate experimental oil is selected according to the similarity criterion.Simplify the temperature of polar and the form of ship movement reasonably and design experimental plans.Secondly,based on the change characteristics of oil temperature during the process of oil insulation under normal temperature environment,the oil temperature and the change rate of oil temperature in the vertical direction and horizontal direction of oil tanks under low temperature environment were analyzed.The change characteristics of oil temperature during the process of oil insulation under low temperature environment were obtained.Thirdly,based on the change characteristics of static oil temperature during the process of oil insulation,the oil temperature and the change rate of sloshing oil temperature in the vertical direction and horizontal direction of oil tanks were analyzed.The change characteristics of oil temperature during the process of sloshing oil insulation were obtained.Fourthly,Comparing the differences of the start time of convection stage,oil temperature and the inhomogeneity of temperature field under different working conditions.The low temperature effect and the oil sloshing effect of the insulation process of sloshingoil under low temperature environment are studied from the stage difference and the regional difference respectively.The results show that there are regional difference and stage difference during the process of sloshing oil insulation under low temperature environment.The heat transfer modes of cargo oil are heat conduction,natural convection and forced convection.The stage difference and regional difference in the process of oil insulation are both changed by the low temperature environment and the sloshing of the oil.In the low temperature environment,the heat exchange between the oil and the outside environment increases,which makes the impact on the temperature rise of oil in different regions is different,but the overall average temperature rise is reduced.The low temperature environment is not conducive to the heat preservation of the oil.The sloshing of the oil changes the flow of the oil,and generates forced convection inside which couples with heat conduction and natural convection.The sloshing of oil has different effects on the temperature rise of oil pr in different regions,which makes differences in the heat preservation effect of the oil.Compared with static oil,the heat preservation effect of sloshing oil is weakened,but the internal oil temperature is more uniform.Under the existing structure of the polar oil tanker,the sloshing of the oil is favorable for heat transfer,but not conducive to heat preservation.