Fuel Cell Stack Separator Sealing to Limit Cooling Side Flow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fuel cell stacks experience reduced cooling efficiency due to side flows of the cooling medium, which are not effectively managed by current separator designs, leading to decreased power generation efficiency.
Innovation Solution
The fuel cell stack incorporates first and second separators with protrusions and depressions that intersect at their ends, forming a tight seal to minimize side flows of the cooling medium, with protrusions on one separator fitting into the depressions of the adjacent separator, reducing gaps and enhancing the sealing effect.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the bottom walls of recess portions in separators are made to contact each other to prevent side flows, then side flow limitation is improved, but gaps may form due to concave curvature from forming methods, reducing sealing effectiveness
Solution Approach 1:
The invention introduces protrusions with specific local geometric features (distal ends, lateral sides) at critical locations where sealing is needed. These localized structural modifications create overlapping relationships between adjacent separators, ensuring reliable sealing at the interface regions without requiring perfect contact across the entire bottom wall surface.
Solution Approach 2:
Instead of relying on the bottom walls of recess portions to contact each other directly, the invention inverts the approach by adding protrusions that extend from the recess portions and overlap with adjacent separators. This inversion transforms the sealing mechanism from direct bottom-wall contact to protrusion-to-separator overlap, eliminating the gap formation problem.
2Ease of manufacture
If conventional forming methods are used to create separator passages, then manufacturing is simplified, but concave curvature in bulge central portions creates gaps that reduce cooling efficiency
Solution Approach 1:
The invention applies local geometric modifications (protrusions with distal ends and lateral sides) at specific locations where cooling medium flow needs to be controlled. These localized features create overlapping seals that prevent sideward flow without requiring changes to the overall forming method, thus maintaining ease of manufacture while improving cooling efficiency.
Solution Approach 2:
The invention accepts the concave curvature created by conventional forming methods but converts this potentially harmful feature into a beneficial one by adding protrusions that utilize the concave regions to create overlapping seal structures. The concave curvature that would normally create gaps is now part of the sealing mechanism, where the protrusions extend into these regions to form effective seals.
Data Source
AI summary
A fuel cell stack includes single cells stacked in a first direction. Each single cell includes a power generating unit, a first separator, and a second separator. The first separator and the second separator hold the power generating unit between the first separator and the second separator. The first separator of each single cell includes first protrusions. The second separator of each single cell includes second protrusions. A distal end of each second protrusion includes a depression that is located at a center in a second direction and extends in a third direction. A length of the depression in the second direction is greater than a length of the first protrusion in the second direction. A distal end of each first protrusion is located inside the depression.