Simulation Study Of The Lng Ship Liquid Cargo Loading System

In recent years, with the soaring of oil price and KYOTO PROTOCOL being effective on 16th Feb 2005, liquefied natural gas becomes more and more popular as a kind of high calorific value and clean energy source. Our nation has already commenced to build LNG fleet so as to improving the security of using natural gas and reducing the supply price of LNG. In view of LNG's special damages caused by its' extra-cryogenic speciality and to assure the security of LNG transportation at sea, the process of liquid cargo handling on LNG carrier becomes more complex and dangerous than other liquid carriers .It is an urgent problem that how to improve the competence on the management of the LNG shipping company and on the technology of the crews in a short period. There is no doubt that training the crews on the simulator is one of the most effective ways. Therefore, It's imperative for the development of Liquid Cargo Handling Simulator on LNG carrier, which matches the requirements of crews training.Regarding of simulator, the Euramerican companies, such as NORCONTROL, TRANSAS and so on, have developed the relevant products, which have been applied in many countries and regions. So far, there is no liquid cargo handling simulator of LNG being developed in China, although a great deal of researches on marine simulator have been carried out, the simulators including tanker, LPG and chemistry carriers.In this paper, the mathematic models on the main components in the liquid cargo handling system, such as the cargo pump and compressor, valve and piping, liquid cargo tanker, have been provided, through analyzing the principle of liquid cargo handling system on the membrane-type LNG carrier, also, the mathematic models on the change of pressure and temperature in the tanker during the process of liquid cargo handling have been deduced. In the end, the liquid cargo handling simulator software is developed under the circumstance of VB 6.0 integration programme of the object, by applying plenty of widgets, designing graphical user interface of liquid cargo handling simulator software and realizing the software kennel, and all the steps of LNG cargo handling were simulated by the simulator.