LNG (liquefied natural gas) liquid dome fragment same-mould manufacturing and staged folding method

Abstract

The invention discloses an LNG (liquefied natural gas) liquid dome fragment same-mould manufacturing and staged folding method which includes the steps: first, manufacturing a liquid dome fragment (except for an inner stainless steel deck) and a deck panel by the same mould by taking a trunk deck as a base plane to manufacture reverse state fragments (the liquid dome fragment and the adjacent deck panel); second, positive folding: combining the reverse state fragments, then turning the reverse state fragments onto the inner deck and performing positive folding by the same mould by taking the inner deck as a base plane; third, staged erection: lifting away the liquid dome fragment from the deck panel and performing subsequent folding after data are measured in the third step and the deck panel enters dock, transferring the separated liquid dome fragment to a staged site and performing assembly-welding and fitting-out operation with the inner stainless steel deck to form a complete liquid dome fragment. Folding precision of a main portion of the liquid dome fragment and an internal structure of the deck panel is ensured, and deviation of the internal structure in the docking process is decreased.

Description

technical field [0001] The invention belongs to the field of shipbuilding, and in particular relates to a method for manufacturing LNG liquid dome segments in one body and closing them in stages. Background technique [0002] The LNG ship has high requirements on the flatness of the inner wall due to the installation of the insulating box in the cargo hold. The liquid dome segment is located on the top deck of the cargo hold and is the top entrance to the liquid cargo pump tower. There is a hole through the pump tower on the inner deck. For the key section of the final hoisting of the cargo hold, the installation of the insulation box in the large cabin and the hoisting of the pump tower have been completed during the hoisting. The nearly 30-meter-high pump tower in the cabin can pass through the opening on the inner deck smoothly, and the vertical deviation of the pump tower is required to be less than 15mm, so the manufacturing accuracy of this segment is very high. [00...

AI Technical Summary

Problems solved by technology

[0003] At present, the traditional segmental manufacturing method is to use a single segment to manufacture independently in one go. Due to the differences in the welding methods of various segments, the welding deformation produced is also different, resulting in the segment being hoisted and closed in the dock. The deviation of large joints is relatively large, and rework such as on-site cutting and trimming is common. A large number of rework not only endangers the safety of the insulation box, but also causes deviations in the verticality of the pump tower installation, which affects the finishing of the subsequent enclosure system. The work development cycle has caused a serious impact, so the current traditional manufacturing process method is difficult to meet the accuracy requirements of the liquid dome segment

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