Fuel Cell Stack Gas Passage Layout for Wider Reactant Gas Distribution
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Solution Overview
Problem
In fuel cell stacks, the existing design limits the diffusion of reactant gas over a wider range due to partitions between oxidant gas supply ports, hindering efficient gas distribution and power generation efficiency.
Innovation Solution
The fuel cell stack incorporates a gas passage defining plate with wavy portions and varying cross-sectional flow areas in its passage portions, allowing reactant gas to flow more easily across a wider area by creating larger flow areas in certain sections and smaller pressure drops, thereby improving gas distribution performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If partitions are disposed between adjacent oxidant gas supply ports to divide them, then the oxidant gas supply ports are separated and structured, but the reactant gas does not easily flow to portions adjacent to partitions, limiting gas distribution performance
Solution Approach 1:
The gas passage defining plate incorporates wavy portions with curved surfaces instead of straight linear passages. These wavy portions create multiple flow paths that allow reactant gas to bypass partitions and reach adjacent areas more effectively, improving gas distribution while maintaining the partitioned supply port structure
Solution Approach 2:
The invention introduces varying cross-sectional flow areas in the gas passages, creating a three-dimensional flow distribution system. By adjusting the cross-sectional area along the flow direction, the patent enables better gas distribution performance without changing the basic partitioned structure of the supply ports
2Device complexity
If the gas passage portion has uniform cross-sectional area, then the structure is simple, but the reactant gas pressure drop varies and distribution performance is limited
Solution Approach 1:
The gas passage defining plate features local variations in cross-sectional flow area along the reactant gas flow path. Certain sections have larger cross-sectional areas to reduce pressure drop and improve gas distribution, while other sections maintain smaller areas. This localized optimization enhances power generation efficiency without requiring complete structural redesign
Solution Approach 2:
The invention changes the geometric parameter of the gas passage cross-sectional area along the flow direction. By creating sections with different cross-sectional areas, the patent optimizes the pressure drop characteristics and reactant gas distribution, thereby improving power generation efficiency while maintaining reasonable structural complexity
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 enhances the distribution of reactant gas across the fuel cell stack, improving power generation efficiency by ensuring reactant gas flows more evenly and efficiently through the stack, leading to improved performance.
Implementation Method 1
The connection passages of the second passage portion each have a larger cross-sectional flow area than the connection passages of the first passage portion. Thus, the reactant gas in the connection passages of the second passage portion causes a smaller pressure drop than the reactant gas in the connection 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 and wavy portions each having a wavy cross-sectional shape orthogonal to the orthogonal direction. 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 connection passages of the second passage portion each have a larger cross-sectional flow area than the connection passages of the first passage portion.