9Ni steel plate for inner tank wall of large liquefied natural gas storage tank, manufacturing method for 9Ni steel plate and tank wall structure

Abstract

The invention discloses a 9Ni steel plate for an inner tank wall of a large liquefied natural gas storage tank, a manufacturing method for the 9Ni steel plate and a tank wall structure. The steel plate for the inner tank wall is thick in one end and is thin in the other end in a length direction, the plate thickness of the steel plate is linearly increased or reduced within all or part of a length section, and the plate width and the plate length of the steel plate are constant; the thickness of the steel plate is gradually changed in the length direction, and a gradual-changing gradient is constant in overall length or is constant in sections; a ratio of the plate thickness Tb of the thickest end to the plate thickness Ta of the thinnest end is not greater than 2; L1, L2, and so on are different distances from the thin end part of the steel plate, and the thicknesses of the steel plate are respectively T1, T2, and so on at the corresponding distances; within the length section range of 0-L1, L1-L2, and so on, the inner plate thickness is linearly increased or reduced, and the thickness increase or reduction gradient within the length section is constant. On the premise of not affecting the capacity and the safety of the storage tank, the usage amount of the steel plate for the tank wall of the inner tank is remarkably reduced, the prefabricating processing process of the wall plate is reduced, the welding construction efficiency of the tank wall of the inner tank is improved; and moreover, the matched tank wall steel plate has the characteristics of being great in wide breadth, and trapezoidal and gradually varied in thickness.

Description

Technical field [0001] The present invention relates to the production technology of wide and thick steel plates, in particular to the 9Ni steel plate on the inner tank wall of a large LNG storage tank and its manufacturing method and tank wall structure. The steel plate has good low temperature toughness at -196°C and is suitable for energy and chemical industries with a capacity of 100,000 Large-scale liquefied natural gas storage tanks over cubic meters. Background technique [0002] Worldwide, natural gas is one of the clean energy sources, and its total demand continues to grow. Especially after the Fukushima nuclear accident in Japan, the development and utilization of nuclear energy has encountered great resistance, and natural gas as a safe and clean energy is more favored by the world's major energy-consuming countries. Correspondingly, domestic natural gas demand is also rising sharply. By 2013, my country's apparent natural gas consumption had reached 165 billion cubi...

AI Technical Summary

Problems solved by technology

[0018] ①Although the name is prestressed concrete storage tank, the real core of the above-mentioned LNG storage tank is the low temperature resistant steel inner tank. The technical difficulties and construction costs of LNG storage tank construction are mainly on the inner tank, because the inner tank is in direct contact with -165℃ LNG liquid

[0021] ②However, the plate width of 3000mm is not the ideal plate width for domestic mainstream wide and thick plate manufacturers

As one of the prefabrication processes of traditional storage tank wall panels, the crimping of wall panels not only increases the manufacturing cost of storage tanks, but also prolongs the manufacturing cycle

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