Bipolar Separator Wet Seal Pockets for Fuel Cells
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Solution Overview
Problem
The existing bipolar separator assembly for molten carbonate fuel cells requires costly and difficult welding around the entire perimeter to attach wet seal pockets to the plate member, and manual manipulation of corrugated current collectors is necessary, making automation challenging.
Innovation Solution
The bipolar separator assembly features wet seal pockets formed separately from the plate member, which are releasably positioned and secured using pressure within the fuel cell stack, eliminating the need for perimeter welding and allowing for automated assembly and reduced manual handling of current collectors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If welding is used to attach wet seal pockets to the plate member, then the sealing reliability is improved, but the manufacturing cost and complexity increase
Solution Approach 1:
The patent replaces the welding process (thermal/mechanical system) with a mechanical attachment system using tabs and slots. The wet seal pockets are attached to the plate member through mechanical insertion of tabs into slots followed by staking, eliminating the need for welding equipment and processes while maintaining attachment reliability.
Solution Approach 2:
The patent utilizes the fuel cell stack operating pressure (hydraulic principle) to enhance the sealing function. The pressure differential across the membrane seal ensures that the seal remains pressed against the sealing surface, improving sealing reliability without requiring additional mechanical fastening elements.
2Reliability
If welding is used to attach wet seal pockets to the plate member, then the sealing reliability is improved, but the manufacturing cost increases
Solution Approach 1:
The patent replaces the welding process (thermal/mechanical system) with a mechanical attachment system using tabs and slots. The wet seal pockets are attached to the plate member through mechanical insertion of tabs into slots followed by staking, eliminating the need for welding equipment and processes while maintaining attachment reliability.
3Manufacturing precision
If manual manipulation of corrugated current collectors is performed, then proper positioning is achieved, but automation becomes difficult
Solution Approach 1:
The patent incorporates pre-formed tabs on the wet seal pockets that are designed to automatically align with and insert into corresponding slots on the plate member. This preliminary preparation of alignment features enables automated machines to position and attach components without manual manipulation, while still achieving precise positioning through the tab-slot-stake mechanism.
Data Source
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AI summary
A bipolar separator assembly for use with a fuel cell comprising: a plate member having opposing first and second surfaces compatible with fuel gas and oxidant gas, respectively, the plate member having first and second opposing end segments and third and fourth opposing end segments which are transverse to the first and second opposing end segments; first and second pocket members situated adjacent the first and second end segments and extending outward of the first surface, the first and second pocket members being adapted to enclose opposing ends of an anode current collector, and third and fourth pocket members situated adjacent the third and fourth end segments and extending outward of the second surface, the third and fourth pocket members being adapted to enclose opposing ends of a cathode current collector, wherein at least a portion of each of the first, second, third and fourth pocket members is formed separately from the plate member and is releasably positioned relative to the plate member.