Design Technology Research On Type-B Independent Liquefied Tank Of The Small And Medium LNG Carriers

With the rapid development of world economy, Chinese gross national product steps into a new time. Energy has became one of the constrains for every country since21st century. Considering that coal and oil as the traditional fossil energy got serious pollution and is not enough for the next few generations, natural gas comes to our national energy plan gradually as one kind of new green resource.Since the produced quantity of LNG couldn’t meet the demand in China, importing LNG from other countries has been a indispensable way. There are two ways of natural gas transportation including pipeline and marine transport. A few large LNG receiving terminals have been established along the coast and some are in the plan.The traditional membrane tank and Spherical tank are more complex and expensive and not worth operated in the small loading and low return route. A new concept-small and medium LNG ship that loaded less than10000m3has emergedin LNG carriers development history. It combines the large LNG terminal and other districts with its flexibility. As the LNG industry in China starts just in twenty years, the LNG technology of design and building are not mature enough for now, let along the small and medium LNG ship. Therefore, to study its cargo tank system design method and key technology proves to be one of the important issues for the ship building industry in China.As to the study, he design approach and research steps of my paper are the followings:(1) Introduce the development of natural gas and marine LNG business, analysis the condition in China and conclude that Small and Medium LNG Carriers are necessary in China;(2) Collect a large number of domestic and international related LNG ship status, elaborate the features of LNG ship and its cargo tank;(3) Describe the design methods in design temperature and design pressure, design load, skirts, shell materials, insulation layer by study the IGC codes;(4) Summarize the technology of independent type-B cargo tank including the materials and the skirts. Define the thickness of the tank by finite element;(5) Design a20000m3LNG tank to verify the feasibility of the design method in this paper and check it by finite element calculation method.