Study On System Simulation Of Vapor Phase In Liquid Cargo Tank For Oil Tanker

Vapor behavior of crude oil during its transportation is a hotspot and difficulty in Marine Transportation of Crude Oil (MATCO), due to its importance and potential impact to oil companies, government organizations and independent tanker fleets, since they should pay much attention to its security, economy and pollution during transportation. Commonly, Survey during crude oil voyages and simulation based on computer are the solutions in international study. Based on previous outcomes, the author built physical and mathematical model aiming at vapor space, IGS and VS, and simulated the behavior of the vapor in the cargo tank system.Firstly, the object was determined and its characteristic was introduced according as our motive; In terms of methodology on modeling, physical model was formed, via some reasonable hypotheses and simplifications on object. The object was then plotted into several subsystems basing on inherent mechanism of object. At the same time, transfer of mass, heat and momentum between system and surroundings were analyzed, and the same between subsystems.Secondly, mathematical models of all subsystems were formed respectively as follows. Mass transfer theory and boundary layer theory were applied in the transfer of mass between vapor phase and liquid phase in cargo tank, a hypothesis that its behavior only took place in a thin layer was made. Whereafter, mass conversation law was applied in the evaporation of crude oil in cargo tank, a mathematical model was formed making use of the outcome up to date. Otherwise, mathematical model of the gas dynamical behavior in pipeline network was achieved by applying gas pipeline model of great difference of pressure to a unit of pipe and applying finite unit method to the whole gas pipeline network.Thirdly, on the viewpoint of system theory, the thermodynamic theory on multi-component and variable mass system was applied into vapor space of liquid cargo tank, and a nil dimension mathematical model aiming at thermodynamic of vapor/gas in vapor space was formed. By applied latent difference law into one-rank and non-linedifferential equations, the mathematical model was induced into simulation model. Selected appropriate calculation step, a typical operation on liquid cargo-loading was simulated.At last, based on the operations on liquid cargo system of crude oil tanker, "a software of dynamic simulation on vapor space of liquid cargo system for crude oil tanker" was brought to success, adopting numerical simulation and non-numerical simulation. This software should be provided with a function implementing the simulation experimentation.This paper is avail to probing into the theory of liquid cargo system in liquid cargo tanker and optimizing the operation on tanker.