Fuel Cell Stack Water Drainage via Dummy Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional fuel cell stacks face challenges in effectively draining condensed water, leading to rapid voltage fluctuations and MEA catalyst deterioration due to water accumulation in unit cells, and existing solutions complicate the system and increase production costs.
Innovation Solution
A water drainage structure is implemented by forming dummy cells using end anode and cathode plates without hydrogen or air inlet/outlet apertures, positioned at the end cell portion of the fuel cell stack, which includes a cathode dummy cell and an anode dummy cell with gas diffusion layers to prevent water from entering unit cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional bipolar plates with inlet/outlet apertures are used in end cell portions, then water drainage is insufficient leading to water accumulation in unit cells, but adding separate water drainage structures complicates the system and increases production costs
Solution Approach 1:
The patent combines the water drainage function with the existing bipolar plate structure by modifying the end anode plate and end cathode plate to include water outlet apertures and drainage flow passages. This integration eliminates the need for separate water drainage structures, resolving the contradiction between effective water drainage and system complexity.
Solution Approach 2:
The bipolar plates in the end cell portions are designed to serve multiple functions: electrical conduction, gas distribution, and water drainage. The drainage flow passages and water outlet apertures enable the same structural components to perform both their traditional electrochemical functions and water removal functions, avoiding additional system complexity.
2Reliability
If water drainage structures are added to prevent water accumulation, then MEA catalyst deterioration is reduced, but manufacturing complexity and production costs increase
Solution Approach 1:
The water drainage functionality is merged into the bipolar plate manufacturing process itself. The drainage flow passages are formed as integral parts of the bipolar plates during fabrication, allowing the same manufacturing techniques (such as extrusion or molding) to produce both the structural and drainage features simultaneously, thus maintaining ease of manufacture while protecting MEA catalyst durability.
3Reliability
If dummy cells are created by modifying existing bipolar plates into end anode and cathode plates, then water is effectively drained from the fuel cell stack, but the manufacturing process becomes more complex
Solution Approach 1:
The invention modifies specific parameters of the bipolar plates (such as aperture positions, flow passage configurations, and plate thickness in certain regions) to create effective water drainage while maintaining compatibility with existing bipolar plate manufacturing methods. These parameter adjustments are made within the normal manufacturing capabilities, avoiding the need for entirely new manufacturing processes.
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 configuration effectively drains condensed water, stabilizes cell voltage, and reduces the risk of MEA catalyst deterioration while simplifying the manufacturing process and reducing costs by utilizing existing bipolar plate manufacturing methods.
Implementation Method 1
The GDL functions to uniformly diffuse reactant gases and transmit generated electricity
Implementation Method 2
the MEA includes a polymer electrolyte membrane through which hydrogen ions (i.e., protons) are transported
Implementation Method 3
The hydrogen supplied to the anode is dissociated into hydrogen ions (protons, H+) and electrons (e−) by a catalyst disposed in the electrode/catalyst layer
Implementation Method 4
A fuel cell is an electricity generation system that electrochemically converts the chemical energy directly into electrical energy in a fuel cell stack
Data Source
AI summary
The present invention provides a fuel cell stack with a water drainage structure, which can effectively drain condensed water and prevent water from flowing into unit cells by combining an end anode plate (EAP) and an end cathode plate (ECP), which are formed by modifying an anode plate (AP) and cathode plate (CP) respectively. In doing so, the modified anode plate (AP) and cathode plate (CP) are converted into a dummy cell which is positioned at the end portions of the fuel cell stack.