Plastic Floating Bearing for Cryogenic Tank Thermal Expansion

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Solution Overview

Problem

Existing tank systems for transporting and storing liquid gases, such as liquefied hydrogen and liquefied natural gas, face challenges in compactness, robustness, and thermal insulation due to the need to withstand cryogenic temperatures and external influences like vibrations and temperature differences.

Innovation Solution

A tank system design that incorporates a loose bearing element and a fixed bearing element made of plastic, allowing for translational movement and expansion of the inner tank relative to the outer tank, while providing secure fixation and efficient compensation for external and internal influences.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional double- or multi-walled tank systems are used for cryogenic storage, then thermal insulation is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:
Improveheat lossVSAvoidtank system structure
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent employs a vacuum insulation layer (thin film/vacuum barrier) between the inner and outer tanks to minimize heat transfer. This vacuum barrier acts as a thermal insulator without requiring complex multi-layer wall structures, thereby reducing heat loss while maintaining system simplicity.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The patent extracts the thermal insulation function by creating a vacuum space between the inner and outer tanks. By removing matter (air) from the gap, heat conduction and convection are eliminated, providing effective thermal insulation without adding complex insulating materials or structures.

Inventive Principle:
Principle #2Taking out (Extraction)

2Stability of the object's composition

If the inner tank is rigidly fixed to the outer tank, then structural stability is improved, but adaptability to thermal expansion and external influences worsens

Engineering Contradiction:
Improvetank positioningVSAvoidthermal expansion compensation
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The patent introduces a dynamic suspension system with elastic elements (springs or elastomeric bearings) that allow the inner tank to move relative to the outer tank. This dynamic mounting accommodates thermal expansion, contraction, and external forces while maintaining stable positioning, resolving the contradiction between rigidity and adaptability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the mechanical properties of the mounting elements by using materials with specific elastic characteristics. These elements can deform elastically under thermal stress or external forces, allowing the tank system to adapt to parameter changes (temperature, pressure, vibration) while maintaining overall structural stability.

Inventive Principle:
Principle #35Parameter changes

3Strength

If bearing components are used to connect inner and outer tanks, then structural support is improved, but thermal bridge formation worsens

Engineering Contradiction:
Improvebearing load capacityVSAvoidheat transfer through bearing
Core Design Contradiction:
StrengthVSLoss of energy

Solution Approach 1:

The patent uses composite bearing elements that combine materials with different thermal and mechanical properties. For example, using materials with low thermal conductivity (such as plastics, composites, or vacuum) in the bearing structure reduces heat transfer while maintaining the necessary mechanical strength and load-bearing capacity.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent introduces an intermediary medium (vacuum or insulating material) in the bearing connection between the inner and outer tanks. This intermediary reduces thermal conduction through the bearing while still allowing mechanical support and movement, thereby minimizing heat transfer paths.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Volume of moving object

If compact tank system design is pursued, then space utilization is improved, but manufacturing simplicity and economy worsen

Engineering Contradiction:
Improvetank system volumeVSAvoidmanufacturing complexity
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The patent employs a nested configuration where the inner tank is placed within the outer tank, with the vacuum insulation layer and bearing elements integrated into the annular space between them. This nested design achieves compact volume utilization while maintaining relatively simple manufacturing processes for each component.

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent designs the outer tank to serve multiple functions: structural containment, thermal insulation barrier, and mounting structure for the suspension system. This multi-functionality reduces the number of separate components needed, simplifying manufacturing while achieving compact design.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 tank system achieves improved durability, compactness, and energy efficiency by minimizing heat transfer and accommodating thermal expansion, while maintaining cost-effectiveness and ease of manufacturing.

Implementation Method 1

The floating bearing element and/or the fixed bearing element comprise a plastic. Preferably, the floating bearing element and/or the fixed bearing element are made of the plastic.

Methodology Applied
Scientific EffectThermal insulation: Thermal Insulation

Implementation Method 2

The floating bearing is designed such that it permits a translational movement and/or an expansion of the inner tank relative to the outer tank in an axial direction.

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 3

there is usually a vacuum, especially a high vacuum, in the gap between the inner and outer tanks

Methodology Applied
Scientific EffectVacuum insulation: Vacuum

Data Source

PatentEP4524456A1Tank system
Publication Date: 2025.03.19 FRIEDRICH BOYSEN GMBH & CO KG
  • EP4524456A1 patent drawingFigure 1
  • EP4524456A1 patent drawingFigure 2
  • EP4524456A1 patent drawingFigure 3

AI summary

A tank system (10) for a transport system, in particular for a motor vehicle, for receiving a gaseous or liquid medium (12), preferably liquefied petroleum gas (LPG), comprises an inner tank (14) for receiving the medium and an outer tank (16), wherein the inner tank is supported in the outer tank by means of a floating bearing (21) with a floating bearing element and a fixed bearing (23) with a fixed bearing element, forming a gap (18). The floating bearing is designed such that it allows translational movement and/or expansion of the inner tank relative to the outer tank in an axial direction. The floating bearing element and/or the fixed bearing element consists at least partially, and in particular entirely, of plastic.