Nested Tunnel Bipolar Plates for Compact Fuel Cell Stacks
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Solution Overview
Problem
The existing fuel cell stacks are large in size and require significant coolant volume to maintain temperature, which is inefficient in terms of space and fluid flow capabilities for hydrogen, oxygen, and coolant.
Innovation Solution
The design incorporates nested tunnels in bipolar plates with a subgasket to reduce the overall length of the fuel cell stack while enhancing fluid flow efficiency, allowing for a compact and efficient distribution of reactants and coolant.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If traditional separate tunnel configurations are used in bipolar plates, then sufficient fluid flow channels are provided, but the overall length of the fuel cell stack increases and space efficiency decreases
Solution Approach 1:
The patent implements nested tunnels where coolant tunnels are positioned within or adjacent to reactant tunnels in the bipolar plate. This nesting arrangement allows both coolant and reactant flow channels to coexist in a compact configuration, reducing the overall length of the fuel cell stack while maintaining sufficient flow capacity for both fluids.
Solution Approach 2:
The patent transitions from traditional separate, linear tunnel arrangements to a nested, multi-dimensional configuration where tunnels are arranged in both planar and vertical dimensions. This dimensional reorganization enables more efficient space utilization and reduces the stack's overall length.
2Temperature
If larger coolant volume is circulated to maintain temperature, then effective cooling is achieved, but the system becomes less efficient in terms of fluid flow capabilities and space utilization
Solution Approach 1:
The nested tunnel configuration allows coolant channels to be positioned within or adjacent to reactant channels, enabling effective heat removal from the membrane electrode assembly without requiring large coolant volumes. The close proximity of coolant tunnels to the active area improves thermal management efficiency.
Solution Approach 2:
The patent optimizes coolant tunnel placement to be locally adjacent to regions requiring cooling, specifically positioning coolant tunnels near the membrane electrode assembly where heat generation occurs. This localized cooling approach improves temperature management effectiveness while reducing overall coolant volume requirements.
3Volume of moving object
If the fuel cell stack is made more compact, then space efficiency improves, but fluid flow capabilities for hydrogen, oxygen, and coolant may be compromised
Solution Approach 1:
The nested tunnel design maintains adequate flow cross-sections for hydrogen, oxygen, and coolant by arranging tunnels in a nested configuration rather than requiring larger separate channels. This preserves fluid flow capabilities while achieving a more compact stack overall.
Solution Approach 2:
By organizing tunnels in multiple dimensions (nested arrangements combining planar and vertical positioning), the patent maintains sufficient flow capacity for all reactants and coolant without increasing the stack's overall footprint, thus preserving productivity in a compact form.
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
This configuration decreases the overall length of each fuel cell, enabling a higher flow rate of fluids and improving the compactness of the fuel cell stack assembly while maintaining effective temperature management.
Implementation Method 1
The thermal properties of typical liquid coolants require that a relatively large volume be circulated through the system to reject sufficient waste energy in order to maintain the temperature of the stack within an acceptable range
Implementation Method 2
allowing for a compact and efficient distribution of reactants and coolant
Implementation Method 3
a thin, proton transmissive, non-electrically conductive, solid polymer electrolyte membrane
Implementation Method 4
having the anode catalyst on one face and the cathode catalyst on the opposite face
Implementation Method 5
In proton exchange membrane (PEM) type fuel cells, hydrogen is supplied to the anode of the fuel cell and oxygen is supplied as the oxidant to the cathode
Data Source
AI summary
A fuel cell stack assembly includes first and second bipolar plates, an active area membrane, and an optional subgasket. The first bipolar plate defines a first plurality of tunnels and the second bipolar plate defines a second plurality of tunnels. The second plurality of tunnels may be engaged with and nested between the first plurality of tunnels. The active area membrane may be disposed within an internal periphery of a subgasket between the first and second bipolar plates wherein the subgasket may, optionally, be positioned between the first and second plurality of tunnels.