Multiple Transition Flow Field for Fuel Cell Reactant Delivery
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Interdigitated flow fields in fuel cells achieve efficient reactant delivery but result in high pressure drops, consuming parasitic power and requiring higher pressurization, which is inefficient, especially in mobile applications where overall efficiency and cost of electricity generation are critical.
Innovation Solution
The implementation of a multiple transition flow field design where reactants transition between the flow field plate and the gas diffusion layer multiple times, increasing reactant delivery frequency and pressure drop, thereby enhancing reactant availability and product water removal without increasing flow field plate or channel sizes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If interdigitated flow fields are used to achieve efficient reactant delivery, then reactant availability is improved, but pressure drop increases causing parasitic power consumption
Solution Approach 1:
The flow field plate is segmented into multiple flow field chambers separated by ribs, creating multiple transition zones where reactant alternates between flowing through channels and diffusing into the gas diffusion layer. This segmentation allows reactant to be delivered multiple times along the flow path, improving availability without requiring excessive pressurization
Solution Approach 2:
The reactant flow exhibits periodic action by alternating between channel flow and diffusion into the gas diffusion layer at multiple transition zones. This periodic transition pattern enhances reactant delivery frequency and uniformity across the electrode surface while maintaining more efficient pressure utilization compared to continuous high-pressure interdigitated flow
2Quantity of substance
If higher pressurization is applied to overcome pressure drop, then reactant delivery is improved, but overall efficiency decreases
Solution Approach 1:
The multiple transition flow field maintains continuous useful action by ensuring reactant continuously transitions between channel flow and diffusion into the gas diffusion layer across multiple zones. This continuous multi-zone delivery ensures thorough reactant utilization throughout the flow path without requiring excessive pressure increases, thereby maintaining overall system efficiency
3Quantity of substance
If flow field plate size is increased to improve reactant distribution, then reactant availability is improved, but device complexity and cost increase
Solution Approach 1:
The invention adds the dimension of multiple transitions along the flow path by creating alternating channel and chamber zones separated by ribs. This dimensional approach to reactant delivery—where reactant repeatedly transitions between confined channel flow and diffuse chamber flow—achieves improved distribution uniformity without increasing the overall plate size or channel dimensions, thereby avoiding increased device 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 improves reactant delivery and water removal efficiency, achieving more uniform flow and higher reactant utilization, reducing the risk of membrane dry-out and enhancing overall fuel cell performance, particularly in applications requiring high reactant distribution and water management.
Implementation Method 1
the reactants diffusing through the gas diffusion layers to be evenly distributed on the anode or cathode catalyst layers
Implementation Method 2
a flow transition extending between the first reactant channel and the second reactant channel for directing flow of the reactant between the first reactant channel, the flow field chambers and the second reactant channel
Data Source
AI summary
A fuel cell includes a membrane electrode assembly having an anode side and a cathode side, a first gas diffusion layer adjacent the cathode side of the membrane electrode assembly, and a first flow field plate contacting the first gas diffusion layer. The first flow field plate includes a reactant inlet, a reactant outlet, and a plurality of flow field chambers separated from one another by at least one rib. The reactant inlet is separated from the plurality of flow field chambers by at least one rib and the reactant outlet is separated from the plurality of flow field chambers by at least one rib. The ribs are configured to force a reactant flowing from the reactant inlet to the reactant outlet to enter the first gas diffusion layer at least twice.