Fuel Cell Stack Flow Passage Structure for Wider Oxidant Diffusion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In fuel cell stacks, the existing design limits the diffusion of oxidant gas over a wider range of the power generation portion due to partitions between oxidant gas supply ports, hindering efficient gas distribution and power generation efficiency.
Innovation Solution
The fuel cell stack design includes a gas passage portion with opposing portions arranged in parallel and connection passages, where the second passage portion has a larger cross-sectional flow area than the first passage portion, allowing easier flow and distribution of reactant gas, and the third passage portion has a smaller cross-sectional area to enhance pressure drop differences, facilitating wider gas distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If partitions are disposed between adjacent oxidant gas supply ports to divide them, then the structure is simplified and manufacturing is easier, but the oxidant gas does not easily flow to portions adjacent to each partition, limiting the diffusion range
Solution Approach 1:
The gas passage portion is designed with varying cross-sectional flow areas in different regions. The first passage portion has a smaller cross-sectional area while the second passage portion has a larger cross-sectional area, creating local quality differences that guide gas flow distribution and enable wider diffusion despite the presence of partitions.
Solution Approach 2:
The invention changes the parameter of cross-sectional flow area along the gas flow path. By making the cross-sectional area of the second passage portion larger than that of the first passage portion, the gas flow is facilitated to spread more widely, thereby improving the diffusion range of oxidant gas while maintaining the partition structure.
2Productivity
If the cross-sectional flow area of main passages is increased to facilitate gas flow, then the pressure drop decreases and gas distribution improves, but the device complexity increases due to the need for varying passage dimensions
Solution Approach 1:
The gas passage portion is segmented into multiple distinct passage portions (first passage portion and second passage portion) with different cross-sectional flow areas. This segmentation allows each portion to have optimized dimensions for its specific function, achieving improved gas distribution while keeping the overall design manageable through modular segmentation.
Solution Approach 2:
Different regions of the gas passage portion are assigned different cross-sectional areas based on local flow requirements. The first passage portion has a smaller area suitable for its function, while the second passage portion has a larger area to facilitate wider gas diffusion, creating local quality optimization without requiring complete redesign of the entire passage system.
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 design improves the performance of distributing reactant gas over a wider range, enhancing the overall efficiency of gas distribution and power generation in the fuel cell stack.
Implementation Method 1
the main passages of the second passage portion each have a larger cross-sectional flow area than the main passages of the first passage portion. Thus, the reactant gas in the main passages of the second passage portion causes a smaller pressure drop than the reactant gas in the main passages of the first passage portion
Data Source
AI summary
A fuel cell stack includes stacked cells, each including a sheet-shaped power generation portion, two separators, a gas passage defining plate that includes a gas passage portion through which reactant gas flows, and a frame member that includes a supply port and a discharge port. The gas passage portion includes opposing portions extended in a flow direction of the reactant gas and arranged in parallel in an orthogonal direction. A main passage is defined between each opposing portion and the power generation portion. The gas passage portion includes a first passage portion adjacent to the supply port in the flow direction and a second passage portion adjacent to the first passage portion in the orthogonal direction. The main passages of the second passage portion each have a larger cross-sectional flow area than the main passages of the first passage portion.