Semipermeable Stack Plate Structure for Stable Fuel Cell Humidification
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Solution Overview
Problem
Current humidifier systems for fuel cell systems are not cost-efficient, and there is a need for an effective solution to transfer moisture from exhaust gas to supply air while maintaining stable fluid flow and preventing bypass flow.
Innovation Solution
A stack plate device with a semipermeable layer supported by inlay parts, embedded in a circumferential frame, forms alternating flow channels for exhaust gas and supply air, allowing moisture transfer through a PFSA membrane, and includes grid-like support elements to optimize mass transfer and prevent channel collapse under differential pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a semipermeable layer is used for moisture transfer, then humidification efficiency is improved, but structural stability and prevention of bypass flow deteriorate
Solution Approach 1:
The patent employs a semipermeable membrane (thin film) that allows moisture transfer while maintaining structural integrity through proper support. The membrane is the key flexible element that enables selective permeability for humidification while the support structure prevents collapse and bypass flow.
Solution Approach 2:
The semipermeable membrane acts as an intermediary between the humid air channel and the dry air channel, enabling moisture transfer while preventing direct mixing of the two fluid streams. This mediator resolves the contradiction by allowing mass transfer while maintaining flow separation.
2Productivity
If inlay parts are added to support the semipermeable layer, then mass transfer is optimized, but device complexity increases
Solution Approach 1:
The stack plate is segmented into functional zones: frame structures for flow distribution, inlay parts for membrane support, and channel regions for fluid flow. This segmentation allows each component to be optimized for its specific function while working together as an integrated system.
Solution Approach 2:
The inlay parts serve multiple functions: they provide mechanical support for the semipermeable membrane, define channel geometries, and facilitate fluid distribution. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity.
3Productivity
If flow channels are formed by stacking multiple stack plates, then humidification performance is improved, but manufacturing cost increases
Solution Approach 1:
The humidifier is divided into modular stack plates that can be manufactured independently and then assembled. Each stack plate contains integrated flow channels and support structures, allowing for cost-effective manufacturing of individual units followed by simple stacking assembly.
Solution Approach 2:
Multiple functional elements (flow channels, support structures, and membrane mounting features) are merged into a single stack plate component. This integration reduces the total number of parts and assembly steps, thereby limiting the increase in manufacturing cost despite improved performance.
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 solution enables efficient humidification of supply air by leveraging the semipermeable membrane for moisture transfer from exhaust gas, ensuring stable fluid flow and preventing bypass, thus enhancing the performance and cost-effectiveness of the humidification process.
Implementation Method 1
a semipermeable layer completely covers the through-opening... allowing moisture transfer through a PFSA membrane
Data Source
AI summary
A stack plate of a stack plate device of a humidifier includes inlay parts extending along two opposing front or longitudinal ends of the stack plate, a semipermeable layer disposed on and being stabilized by the inlay parts, and a frame disposed on multiple portions of the semipermeable layer that are disposed on the inlay parts, the frame circumferentially enclosing a through-opening in the stack plate. A remaining portion of the semipermeable layer completely covers the through-opening. An outer circumferential section of the semipermeable layer and the inlay parts are overmolded by the frame. Opposing front ends of the frame define inflow and outflow regions, respectively, on a first side of the frame for a second fluid, and opposing longitudinal ends of the frame define inflow and outflow regions, respectively, on a second side of the frame for a first fluid.