Liquid Hydrogen Tank Dome Joint for External Welding Access
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The storage of hydrogen in its gaseous state at ambient temperature and pressure requires large volumes due to its low density and volatility, necessitating complex refrigeration systems and access challenges for tank maintenance in liquid hydrogen reservoirs.
Innovation Solution
A tank design with a central portion and dome that form a protruding tab when joined, allowing for external welding and easy mounting/dismounting without reducing the tank length, enabling multiple access operations for maintenance and repair.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a convex dome is welded to each end of a shell using a butt weld, then the tank achieves hermetic sealing and structural integrity, but accessibility for welding tools and positioning tools is severely limited
Solution Approach 1:
The dome assembly is segmented into two main parts: the dome itself and a separate flange assembly. This segmentation allows the flange with positioning features to be attached to the dome, creating a modular unit that can be handled and positioned more easily during assembly while maintaining the hermetic seal through the flange-dome connection.
Solution Approach 2:
A flange assembly acts as an intermediary element between the dome and the shell. This flange includes positioning lugs that extend outward, serving as mediators that facilitate the positioning and welding operations from outside the tank, thereby improving accessibility without compromising the sealing integrity of the dome-shell joint.
2Manufacturing precision
If welding tools need to pass around the tank for butt welding operations, then proper welding can be achieved, but the tank requires excessive clearance space and complex positioning procedures
Solution Approach 1:
The flange assembly is pre-equipped with positioning lugs that protrude outward from the dome. These lugs are positioned in advance to align with corresponding features on the shell, enabling straightforward alignment and positioning before welding begins. This preliminary positioning arrangement simplifies the welding procedure and reduces the complexity of positioning operations.
3Reliability
If the tank is designed for complete sealing, then hydrogen storage integrity is maintained, but maintenance and repair operations require complex disassembly procedures
Solution Approach 1:
The connection between the dome and shell is segmented into separable components: the dome, the flange assembly with positioning lugs, and the shell. This segmentation maintains hermetic sealing during normal operation while allowing the dome and flange to be detached as a unit for maintenance purposes, thereby improving ease of repair without compromising storage integrity.
Data Source
AI summary
A tank, in particular for a liquid hydrogen reservoir, provided with at least one dome fixed by way of an outer welded joint and having a central portion provided with at least one free end including a first connecting element and at least one dome provided with an open end including a second connecting element, the dome and the central portion being able to be joined together, the first connecting element and the second connecting element being configured to form, when the central portion and the dome are joined together, a protruding tab extending toward the outside of the tank and able to be welded to a protruding end, such a protruding tab making it possible in particular to join together the tank, this being done entirely from the outside of said tank, and to easily mount and dismount the dome, in particular without accessibility issues.