Fuel Cell Seal Lateral Edge Flow Restriction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fuel cell seal arrangements face challenges in effectively restricting the flow of fuel cell fluids, such as hydrogen and oxygen, at the lateral edges of gas diffusion layers and membrane electrode assemblies, leading to potential mixing and leakage issues within fuel cell stacks.
Innovation Solution
A seal assembly is designed to restrict flow through the outer lateral edges of gas diffusion layers and membrane electrode assemblies, featuring a single-piece, impregnated seal configuration that is injection molded, using nonsilicone materials like EPDM or FKM rubber, and strategically spaced to facilitate even distribution and reduce flash during molding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a seal is used to restrict flow through lateral edges of gas diffusion layers and membrane electrode assemblies, then fluid leakage and mixing are prevented, but the complexity of the fuel cell assembly increases
Solution Approach 1:
The seal integrates multiple sealing functions into a single component that simultaneously seals the lateral edges of both the first and second gas diffusion layers, as well as the membrane electrode assembly. This consolidation reduces the number of separate seal components and simplifies the overall assembly process while maintaining comprehensive sealing coverage across all critical interfaces.
Solution Approach 2:
The seal is designed as a multi-functional component that performs sealing duties at multiple locations within the fuel cell assembly. It simultaneously addresses sealing requirements for the first gas diffusion layer, second gas diffusion layer, and membrane electrode assembly, thereby reducing overall system complexity through functional integration.
2Reliability
If multiple seal channels are used to ensure complete sealing coverage, then sealing reliability is improved, but manufacturing complexity and cost increase
Solution Approach 1:
The seal employs a three-dimensional impregnated configuration where molten seal material is injected and allowed to penetrate and conform to the lateral edges of the gas diffusion layers and membrane electrode assembly. This dimensional approach allows a single seal channel to achieve comprehensive sealing coverage that would otherwise require multiple separate channels, simplifying the molding process while ensuring complete sealing.
Solution Approach 2:
The seal utilizes changes in the physical state of the seal material, transitioning from solid to molten during injection molding. The molten material flows into and impregnates the lateral edge structures, then solidifies to form a compliant seal bead. This parameter change enables complete sealing coverage through a single molding operation rather than requiring multiple sealed channels.
3Reliability
If the seal material is highly compliant to conform to edge variations, then sealing effectiveness is improved, but the seal may deform under operating pressure and temperature
Solution Approach 1:
The seal material undergoes parameter changes based on operating conditions: it remains compliant and conformable at lower temperatures and pressures to accommodate edge variations, while maintaining sufficient structural integrity at elevated temperatures and pressures to resist deformation. The impregnated configuration and multi-functional design enable the seal to adapt its mechanical properties to different operational states.
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 enhances the sealing efficiency by improving the flow of molten seal material during molding, forming a more compliant seal bead that effectively blocks fluid flow, reducing leakage and mixing, and allowing for a reduced number of seal channels, thereby improving the overall performance of fuel cell stacks.
Implementation Method 1
A seal at the lateral perimeters of the GDLs and the MEA prevents reactants from mixing in the GDLs and leaking into their opposite manifolds
Implementation Method 2
The solution enhances the sealing efficiency by improving the flow of molten seal material during molding, forming a more compliant seal bead that effectively blocks fluid flow
Data Source
AI summary
An example fuel cell seal assembly includes a seal configured to restrict flow of a fuel cell fluid through at least one of an outer lateral edge of a first gas diffusion layer, an outer lateral edge of a membrane electrode assembly, and an outer lateral edge of a second gas diffusion layer. The outer lateral edge of the first gas diffusion layer is laterally spaced from the outer lateral edge of the second gas diffusion layer. An example method of sealing a fuel cell interface includes limiting flow of a fuel cell fluid using a seal configured to restrict flow through an outwardly facing edge of at least one of a first gas diffusion layer and an outwardly facing edge of a second gas diffusion layer. The outwardly facing edge of the first gas diffusion layer is spaced from the outwardly facing edge of the second gas diffusion layer.