Fuel Cell Separator Connecting Passage Structure Against Warpage
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Solution Overview
Problem
The existing fuel cell separators, particularly those formed by stamping, often experience residual stress and warpage due to deformation around holes and passage grooves, which can affect their structural integrity and performance.
Innovation Solution
The fuel cell separator design includes protrusions in the connecting passages that extend towards the power generating unit, enhancing the rigidity and reducing warpage, while also incorporating cooling passages between adjacent groove passages to improve cooling efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the base of the separator is stamped to form passage grooves and holes, then the separator can be manufactured with integrated flow paths, but residual stress and warpage occur due to large deformation in surrounding areas
Solution Approach 1:
The separator is divided into multiple plate-like members that are stacked together. The passage grooves and holes are formed by stacking pre-formed plates rather than stamping the entire base at once. This segmentation reduces the deformation area in each individual plate, thereby reducing residual stress and warpage while still achieving integrated flow paths through the stacked configuration.
Solution Approach 2:
The invention transitions from forming all passage grooves and holes in a single plane (2D stamping) to a three-dimensional stacked configuration. By distributing the flow path formation across multiple layers, the deformation required in each individual plate is reduced, minimizing residual stress and warpage while maintaining the integrated flow path functionality.
2Productivity
If passage grooves are deeply formed to ensure adequate reactant gas flow, then flow efficiency improves, but the separator becomes more prone to warpage and structural deformation
Solution Approach 1:
The deeply formed passage grooves are distributed across multiple stacked plate members rather than being formed in a single deep stamping operation. Each plate requires less deformation to achieve the necessary flow path depth, reducing residual stress and preventing warpage while maintaining adequate reactant gas flow efficiency through the cumulative effect of multiple layers.
3Stability of the object's composition
If the separator structure is made more rigid to prevent warpage, then structural stability improves, but manufacturing complexity increases
Solution Approach 1:
The separator is constructed from multiple simple plate-like members that are stacked and joined together. Each individual plate can be manufactured using simple stamping processes with minimal deformation, maintaining manufacturing simplicity. The stacked configuration inherently provides structural rigidity and warpage resistance through the multi-layer construction, achieving both goals without significantly increasing manufacturing complexity.
Data Source
AI summary
A separator for a fuel cell includes multiple main passages configured to face a power generating unit and allow reactant gas to flow through the main passages, a supply-side manifold hole configured to supply the reactant gas toward the main passages, a discharge-side manifold hole configured to discharge the reactant gas from the main passages, multiple supply-side connecting passages that connect the supply-side manifold hole and the main passages to each other, and multiple discharge-side connecting passages that connect the discharge-side manifold hole and the main passages to each other. At least one of the supply-side connecting passages and the discharge-side connecting passages has a protrusion that protrudes toward the power generating unit, the protrusion being partially provided in an extending direction of the connecting passage.