Analysis For Cargo Handling Pipeline Of LNG Carrier

LNG carrier is a kind of special ships using for the ocean shipping of LNG which under the condition of normal pressure and -163℃. Because of its characteristics of high-technology, high-difficulty and high value-added, the LNG carrier is deemed as has the highest requirement on design technology and building technology in all commercial ships. It is compared to the pearl in the crown of all civil ships. The LNG carrier has a high requirement because of the particularity of its cargo LNG, the LNG has a ultralow temperature, it would harm the equipments of the ship and people around it if it is leaked. The mentioned risk will be magnified when the LNG carrier loading or discharging in a port near a city. Consequently, the analysis of the cargo handling pipeline of LNG carrier is very meaningful.The cargo handling pipeline of LNG carrier is analysised in the aspect of stress and pressure drop in this thesis. In the first part of the thesis, the emphasis is the stress analysis of this pipeline system, the meaning and purpose of the stress analysis is concluded, the task and process of the stress analysis is combed. The software CAESARⅡis used in this analysis work, it is used to model the pipeline system and build the model of key functions of this system, it is used to check the level of the first stresses and the second stresses of this pipeline according to the related standard, the result indicates that the current design of the cargo handling pipeline of this LNG carrier is available. In the first part, research about the key functions of this system is also conducted and some meaningful conclusions are obtained.The pressure drop analysis of the cargo handling pipeline of LNG carrier is the emphasis in the second part of this thesis. The meaning and purpose of the pressure drop is concluded. The theory and customary analytical approaches are introduced. The software AFT Fathom is used to modeling and analysis the pressure drop, liquid velocity in pipe and operating time of pipeline system in different cargo handling modes. According to the limiting conditions of operating time and liquid velocity in pipe specified by the pipe code, the analysis result of the current design of this pipe system is checked, reasonable cargo handling modes are confirmed. In a word, in this thesis, a practicable analytical approach of the cargo handling pipeline of LNG carrier is concluded, a lot of key issues is discussed and some significant conclusions are obtained, all that could be a good foundation for the further analysis and the application of this kind of pipeline technology.