Research Of The Design Theory And Method On Large LNG Cryogenic Storage Tank

Recently, with many countryies’natural gas consumption growing rapidly, the natural gas consumption in the global share of energy consumption structure gradually increased. With the domestic natural gas provens growing, the government is also increasing emphasis on the development of natural gas and its cryogenic storage equipment’design and construction. As storage, transport liquefied natural gas plant, LNG storage tanks are low pressure vessels. Compared with pipeline transportation and storage in the form of compressed natural gas, storage of liquefied natural gas has Small size, storage and transportation convenience, safety advantages. The large steel storage tank is small footprint, low investment and easy operation and management and so on. Therefore it is widely used in the international area, the current technology is mastered by Europe, America and Japan. So if we master the design of key technologies, we can save a lot of cost and do not controlled by others.This article research mainly through the analysis of the current situation on the development of the domestic and international tank design, analysis of design theory, and compare the existing related standards of the design method. Based on the analysis and research materials selection, under the condition of the request of material selections, we select domestic9%Ni steel. Through the analysis of the disadvantages of domestic and foreign design criteria, we choose reliable design method to design the important part of tanks and check.This paper is mainly determined by the theory of minimum area of storage tank, to determine the overall structure. According to the standard EN14620, we determine wall thickness, storage tank bottom plate thickness and bottom edge design and row board. We calculate the middle strengthen circle about welding intervals and the specific requirements. The design results check intensity, mainly hydrostatic test, air pressure test and earthquake-resistant calculation. Finally, according to the API650to design openings, the design is easy to daily maintenance and operation.In the end, this design is discussed the economy evaluation, the design technology of large-scale LNG tanks from economics or safety nationalization are showing strong superiority and feasibility. We believe that the domestic large-scale LNG tanks on design technology development will soon formed our own design criteria.