SOEC/SOFC Coupling Flange Assembly for High-Temperature Gas Sealing

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Solution Overview

Problem

Current coupling solutions for high-temperature solid oxide electrolysis (SOEC) and fuel cell (SOFC) stacks face challenges in achieving reliable electrical insulation, good contact, gas distribution, and high-temperature sealing, leading to inefficiencies and complexity in assembly and disassembly, particularly in maintaining the 'Plug & Play' character.

Innovation Solution

A high-temperature sealed coupling system using a clamping system with upper and lower clamping plates, clamping rods, and a coupling flange with internal conduits and screws, along with a flexible metal seal, allows for secure gas passage and easy assembly/disassembly, ensuring efficient gas distribution and thermal expansion matching.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional coupling solutions are used for high-temperature solid oxide stacks, then assembly and disassembly can be performed, but reliable electrical insulation and high-temperature sealing are difficult to achieve, leading to gas leaks and thermal damage

Engineering Contradiction:
Improvesealing reliabilityVSAvoidcoupling system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The coupling system is divided into separate functional components: a sealing element (flexible metal gasket) for gas-tight sealing, electrical insulation elements for electrical isolation, and a clamping mechanism for mechanical assembly. This segmentation allows each component to be optimized for its specific function while maintaining overall system reliability at high temperatures.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The coupling system employs composite material strategies by combining flexible metal sealing elements with rigid structural components and electrical insulation materials. The flexible metal gasket (typically graphite or metal alloy) provides both sealing and thermal stability, while separate insulation elements prevent electrical short circuits between stack terminals and the coupling structure.

Inventive Principle:
Principle #40Composite materials

2Productivity

If conventional coupling solutions are used, then connection can be established, but good contact and gas distribution are not achieved, leading to inefficiencies

Engineering Contradiction:
Improveoperational efficiencyVSAvoidgas distribution efficiency
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The coupling flange incorporates localized gas distribution channels and flow control features that ensure uniform gas flow across the stack surface. The sealing element is designed with specific geometric features that promote even contact pressure and consistent gas sealing across the entire coupling interface, preventing localized leakage paths and ensuring efficient gas utilization.

Inventive Principle:
Principle #3Local quality

3Reliability

If the coupling system is designed for high-temperature sealing, then sealing reliability improves, but assembly and disassembly become complex, losing the 'Plug & Play' character

Engineering Contradiction:
Improvehigh-temperature sealingVSAvoidassembly ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The sealing function is extracted into a separate, replaceable flexible metal gasket that can be independently installed and removed. This allows the main coupling structure to remain simple and reusable, while the sealing element can be easily replaced without complex disassembly procedures, maintaining the Plug & Play capability even under high-temperature conditions.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The flexible metal gasket design incorporates self-aligning and self-seating features that guide proper installation without requiring complex alignment procedures. The elastic properties of the flexible material allow it to automatically conform to the coupling surface irregularities, ensuring reliable sealing through simple bolt-down assembly rather than complex multi-step procedures.

Inventive Principle:
Principle #25Self-service

4Stability of the object's composition

If a rigid coupling structure is used, then structural stability is maintained, but thermal expansion mismatches cause damage at high temperatures

Engineering Contradiction:
Improvestructural stabilityVSAvoidthermal expansion damage
Core Design Contradiction:
Stability of the object's compositionVSObject-affected harmful factors

Solution Approach 1:

The flexible metal gasket serves as a compliant sealing element that can accommodate differential thermal expansion between the stack and coupling structure. While the overall coupling structure maintains rigidity for structural stability, the flexible sealing component absorbs thermal stresses through elastic deformation, preventing damage from thermal expansion mismatches while maintaining gas-tight sealing.

Inventive Principle:
Principle #30Flexible shells and thin films

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 provides a reliable, efficient, and reusable high-temperature sealed coupling system that maintains stack integrity and facilitates easy relocation of the SOEC/SOFC stack, enhancing operational efficiency and reducing the risk of gas leaks and thermal damage.

Implementation Method 1

a flexible metal seal, positioned against said at least one of the upper and lower clamping plates and against a first end face, opposite a second end face, of the coupling flange

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

a clamping system for the SOEC/SOFC type solid oxide stack, comprising an upper clamping plate and a lower clamping plate, between which the SOEC/SOFC type solid oxide stack is clamped

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Implementation Method 3

the coupling flange comprising an internal through-duct to allow the passage of a gas inlet and/or outlet tube

Methodology Applied
Scientific EffectFluid flow through conduits:

Data Source

PatentEP4092163B1Assembly of a stack with solid oxides such as sofc/soec and a system for high temperature sealed coupling with coupling flange
Publication Date: 2024.02.14 COMMISSARIAT A LENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES
  • EP4092163B1 patent drawingFigure 1~2
  • EP4092163B1 patent drawingFigure 3~4
  • EP4092163B1 patent drawingFigure 5~6

AI summary

The main object of the invention is an assembly (80) comprising a SOEC/SOFC type solid oxide stack and a stack clamping system. This assembly (80) further comprises a high-temperature sealed coupling system (90), comprising a coupling flange (110) allowing the passage of a gas inlet and/or outlet tube (103), at least one clamping screw, provided with a clamping head (115a), and a sealing gasket, positioned against at least one of the upper (45) and lower (46) clamping plates and against the coupling flange (110).