Stacked Membrane Fuel Cell Humidifier With Integrated Flow Spacing
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Solution Overview
Problem
Existing fuel cell humidifiers face challenges in being durable and cost-effective, particularly in maintaining efficient moisture exchange while withstanding high temperatures and pressure differentials, and ensuring reliable sealing without membrane dehydration.
Innovation Solution
A membrane-based humidifier design featuring a stack of unit cells with water vapor permeable membranes bonded to separators, utilizing ridges for spacing and alignment, and a sealing mechanism to maintain separation and efficient moisture transfer between flows.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If flat-sheet membrane humidifiers are used to achieve even flow distribution and lower pressure losses, then productivity and energy efficiency are improved, but device complexity increases due to additional flow-field plates and sealing surfaces
Solution Approach 1:
The patent combines the separator and flow-field plate functions into a single integrated component. The separator includes integrated flow channels that distribute reactant streams without requiring separate flow-field plates, thereby reducing the number of sealing surfaces while maintaining even flow distribution across the membrane active area.
Solution Approach 2:
The separator performs multiple functions simultaneously: it separates the anode and cathode compartments, distributes reactant flows through integrated channels, provides structural support, and creates sealing surfaces. This multi-functionality eliminates the need for separate flow-field plates and reduces overall device complexity.
2Area of stationary object
If hollow-fiber membrane humidifiers are used to increase membrane packing density, then membrane surface area is improved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent uses a stack of multiple planar membrane units, each contributing to the total membrane surface area. This segmented approach allows for easier manufacturing and assembly compared to hollow-fiber bundles, while still achieving high membrane packing density through the stacked configuration.
3Use of energy by moving object
If flat-sheet humidifiers are used to reduce pressure losses, then use of energy is improved, but device complexity increases due to additional components
Solution Approach 1:
The separator integrates flow distribution channels directly into its structure, eliminating the need for separate flow-field plates. This merging of functions maintains the low pressure loss characteristics of flat-sheet designs while reducing the number of components and assembly steps.
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
The design achieves efficient moisture exchange with reduced pressure drop and enhanced durability, allowing for reliable operation across varying temperatures and pressures, while minimizing membrane dehydration risks.
Implementation Method 1
a water vapor permeable membrane separates a first (drier) stream of fluid being delivered to a fuel cell from a second (more humid) stream that is humid (i.e. contains water vapor)... there is net transport of water from the second stream into the first stream through the water vapor permeable membrane
Data Source
AI summary
Example embodiments provide fuel cell humidifiers. An example humidifier comprises a stack of unit cells. Each of the unit cells may comprise a separator having a perimeter frame and first and second major faces, a first membrane sheet bonded to the perimeter frame on the first major face of the separator and a second membrane sheet bonded to the perimeter frame on the second major face of the separator. The perimeter frame and the first and second membrane sheets may define a cavity in an interior of the perimeter frame. Opposed frame ends of the perimeter frame may be apertured to allow a first flow to flow through the cavity in a first direction. The separator may include first and second ridges that extend across first and second frame ends. In the stack of unit cells the first and second ridges may space the unit cells apart from one another by contact with the separators of adjacent unit cells to provide passages extending through the stack of unit cells in a second direction transverse to the first direction. In some embodiments, the unit cells can all be stacked in the same orientation.