Optimum Design And Study Of Large-Scale Lng Tank

LNG tank is an important facility in the process of LNG storage and transportation. Large-scale LNG tank has characteristics of large volume, massive quality, complex structure, high security requirements and large investment. But the practical engineering examples are less in our country. Inner tank material selection, the design standard and the structure optimization of a large scale LNG tank are studied in the thesis. The large-scale LNG tanks present situation of our country and foreign, LNG tanks’shape and materials choice, structure form and insulation material are introduced. Based on the design codes related to large scale tank including BSEN14620, API620/650, JIS B8501, the different volume tank as the research object discuss the thickness calculation method of tank wall and the bottom rowing board form of tank. By analyzing the calculation results show that BSEN14620is the most economical design code, and JISB8501is safest design code. Our country can develop the design code suited for our requirements according to this standards.By calculating and analyzing each heat leak of LNG tank, tank roof heat leak is the main heat leak. The structural stress of internal tank is analyzed by ANSYS software, analytical results show that stress concentration phenomenon is discovered in a large angle welded seam and different lap siding joints, maximum stress of tank is increased with the volume and change point calculation method can effectively improve tank stress level. Due to current domestic no large-scale LNG storage tank design code, the introduction technology from abroad and self-construction of large LNG storage tank is less, so the research has some engineering significance and reference value for large-scale LNG tank design and research of our country.