Hydrogen Cryotank Tangential Suspension for Resonance Mitigation
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Solution Overview
Problem
Cryotank devices face issues with damage due to resonance between the natural frequency of the inner tank and the excitation frequency of the vehicle during operation, particularly in mobile applications, due to insufficient torsional stiffness of the polar suspension, which is exacerbated by the high thermal conductivity of materials like stainless steel and the increasing wall thickness requirements for hydrogen tanks.
Innovation Solution
A cryotank device with a polar suspension using rod-shaped tangential support elements that are movable in at least one dimension normal to their extension, arranged between the inner and outer containers, and composed of flexible composite fiber materials to enhance rotational natural frequency and reduce thermal conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the wall thickness of the inner tank is increased to meet maximum permissible working pressure requirements, then the strength and pressure resistance are improved, but the mass and rotational mass moment of inertia increase, leading to resonance between the natural frequency of the inner tank and the excitation frequency of the vehicle
Solution Approach 1:
The support elements are designed to be movable at least in one dimension normal to their rod-shaped extension, allowing dynamic adaptation to vibrations and resonance conditions while maintaining structural support. This mobility enables the support elements to absorb vibrational energy and avoid rigid coupling that would amplify resonance effects.
Solution Approach 2:
The support elements are made from flexible composite fiber materials that combine high strength-to-weight ratio with low thermal conductivity. These composite materials provide the necessary mechanical strength to support the thick-walled inner tank while keeping the mass and moment of inertia lower than traditional solid metal supports, thereby reducing resonance susceptibility.
2Strength
If stainless steel materials are used for suspension elements to ensure strength, then the strength is improved, but the thermal conductivity increases, leading to higher heat transfer from the outer container to the inner container
Solution Approach 1:
Composite fiber materials are used for the support elements, combining structural strength with thermally insulating properties. These materials provide the necessary mechanical strength to support the inner tank while having inherently lower thermal conductivity compared to stainless steel, thus reducing heat transfer across the suspension elements.
Solution Approach 2:
The support elements act as thermal intermediaries with low thermal conductivity, breaking the direct thermal path between the outer and inner containers. By using materials with intermediate thermal properties (composite fibers rather than high-conductivity stainless steel), the heat flow is significantly reduced while maintaining mechanical functionality.
3Ease of manufacture
If polar suspension with central tube suspension is used to attach the inner tank to the outer vessel, then the ease of manufacture is improved, but the torsional stiffness is insufficient, leading to resonance damage during operation
Solution Approach 1:
The support elements incorporate mobility in at least one dimension normal to their rod-shaped extension, enabling dynamic response to torsional and vibrational loads. This dynamic capability compensates for the inherently low torsional stiffness of the polar suspension configuration, allowing the system to absorb rather than amplify resonance effects during vehicle operation.
Solution Approach 2:
The suspension system is segmented into multiple rod-shaped support elements distributed between the inner and outer containers, rather than relying on a single central tube. This segmentation distributes the mechanical loads and provides multiple pathways for force transmission, effectively increasing the overall torsional stiffness while maintaining manufacturing simplicity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution improves the rotational natural frequency and reduces heat transfer, mitigating resonance-related damage while maintaining structural integrity and economic feasibility.
Implementation Method 1
a vacuum space is provided between the inner container and the outer container to reduce heat transfer from the outside to the inside
Implementation Method 2
composed of flexible composite fiber materials to enhance rotational natural frequency and reduce thermal conductivity
Data Source
Figure 1
Figure 2~4
Figure 5~6
AI summary
A cryogenic tank device comprising an inner container (1) for receiving a medium, in particular hydrogen, and an outer container (2), wherein the inner container (1) and the outer container (2) have a substantially cylindrical shape, wherein a polar suspension (3) is provided between the inner container (1) and the outer container (2), wherein at least one rod-shaped tangential support element (4) is provided between the inner container (1) and the outer container (2), such that the tangential support element (4) extends substantially in the circumferential direction of the inner and outer containers (1, 2) from a connection on the inner container (1) to a connection on the outer container (2), wherein the tangential support element (4) is designed to be movable at least in one dimension normal to its rod-shaped extension.