Fuel Cell Separator Buffer With Embossed Regions
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In internal manifold fuel cells, reactant gases do not flow smoothly over the entire electrode reaction surface due to small opening areas of reactant gas inlet and outlet manifolds, necessitating buffer portions to disperse gases effectively.
Innovation Solution
The fuel cell design incorporates a reactant gas buffer portion with a first buffer region and a second buffer region, where the second buffer region has a larger depth in the stacking direction and features a plurality of embossed portions with smaller diameters or radii compared to the first buffer region, facilitating even gas flow and reducing stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the opening areas of reactant gas inlet and outlet manifolds are made small, then the device complexity is reduced, but the gas flow uniformity deteriorates
Solution Approach 1:
The buffer portion is segmented into multiple regions: a first buffer region adjacent to the manifold and a second buffer region extending toward the gas channel. This segmentation allows each region to perform specific functions - the first region for gas accumulation and the second region for uniform distribution - thereby maintaining gas flow uniformity without requiring large manifold opening areas.
Solution Approach 2:
The buffer portion extends in the stacking direction (thickness direction) of the separator, utilizing the third dimension to create a volumetric buffer region. This dimensional extension provides sufficient gas storage and distribution capacity without increasing the planar area of the manifold openings, thus resolving the contradiction between compact manifold design and uniform gas flow.
2Stability of the object's composition
If buffer portions are added to disperse reactant gases, then gas flow uniformity is improved, but the device complexity increases
Solution Approach 1:
The buffer portion is merged with the separator structure, forming an integrated component rather than a separate assembly. The buffer portion is formed as a protrusion or recess directly on the separator surface, eliminating the need for additional parts and simplifying the overall device structure while still providing the necessary gas dispersion function.
Solution Approach 2:
The separator performs multiple functions: it acts as both the structural support for the fuel cell stack and as the gas distribution medium through its integrated buffer portion. This multi-functionality eliminates the need for separate buffer components, reducing device complexity while maintaining gas flow uniformity.
3Stability of the object's composition
If the depth of buffer regions is increased to improve gas distribution, then gas flow uniformity is improved, but the stress on the separator increases
Solution Approach 1:
The buffer portion features non-uniform depth distribution, with the first buffer region having a greater depth than the second buffer region. This local quality variation optimizes gas accumulation in the region closest to the manifold while gradually transitioning to uniform distribution in the second region, improving gas flow uniformity without requiring excessive overall depth that would increase stress.
Solution Approach 2:
The buffer portion exhibits asymmetric depth configuration, with the first buffer region (adjacent to manifold) being deeper than the second buffer region (adjacent to gas channel). This asymmetric design efficiently captures and distributes gas from the manifold opening, achieving uniform gas flow with moderate overall depth and reduced separator stress.
Data Source
AI summary
A fuel cell includes a first separator including a reactant gas buffer portion which includes a first buffer region and a second buffer region. The first buffer region has a first depth in the stacking direction. First embossed portions are formed in the first buffer region. Each of the first embossed portions has a first diameter and a first radius of a corner at a distal end of each of the first embossed portions. The second buffer region has a second depth in the stacking direction larger than the first depth. Second embossed portions are formed in the second buffer region. Each of the second embossed portions has a second diameter and a second radius of a corner at a distal end of each of the second embossed portions. The second diameter is smaller than the first diameter or the second radius is smaller than the second diameter.