Fuel Cell Stack Passage Structure for Uniform Reactant Gas Supply
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In fuel cell stacks, the spaced-apart oxidant gas supply ports create partitions that hinder the even distribution of reactant gas across the power generation portion, limiting the efficiency of power generation.
Innovation Solution
The fuel cell stack design includes a gas passage portion with opposing and wavy portions, and a frame member with supply and discharge ports, which allows for a wider distribution of reactant gas by varying the cross-sectional flow areas of the connection passages and main passages.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If oxidant gas supply ports are spaced apart to supply reactant gas, then power generation capability is improved, but gas distribution uniformity deteriorates due to partitions between supply ports
Solution Approach 1:
The gas passage portion is divided into multiple passage regions (first passage region, second passage region, third passage region) with different cross-sectional flow areas. This segmentation allows each region to serve specific functions: the first region receives gas from supply ports, the second region (with larger area) promotes lateral diffusion to overcome partition effects, and the third region distributes gas to the power generation portion, thereby achieving both adequate power generation and uniform gas distribution.
Solution Approach 2:
Different regions of the gas passage portion are designed with different cross-sectional flow areas to create local quality variations. The second passage region has a larger cross-sectional flow area than the first and third regions, creating a localized expansion zone that enhances gas diffusion laterally across partitions while maintaining restricted flow in other regions for controlled distribution.
2Stability of the object's composition
If gas passage cross-sectional area is increased to improve gas distribution, then reactant gas diffusion range is improved, but pressure drop increases
Solution Approach 1:
The gas passage is segmented into three distinct passage regions with progressively varying cross-sectional areas. Instead of uniformly increasing the cross-sectional area throughout, the design locally expands only the second passage region while keeping the first and third regions with smaller areas, thereby limiting pressure drop while still providing sufficient diffusion space in the intermediate region.
Solution Approach 2:
The cross-sectional flow area is increased only partially and locally in the second passage region rather than excessively throughout the entire gas passage. This partial expansion provides just enough space for lateral gas diffusion to overcome partition effects without creating excessive pressure drop that would result from a uniformly large cross-sectional area.
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 gas passage portion, improving the performance of the fuel cell stack by increasing the efficiency of power generation.
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
Figure 1~2
Figure 3~4
Figure 5~6
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 through which the reactant gas is supplied to the gas passage portion and a discharge port through which the reactant gas is discharged from the gas passage portion. 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.