Fuel Cell Humidifier Shutdown Design for Mold Mitigation
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Solution Overview
Problem
Mold formation and accumulation in membrane-based humidifiers for proton-exchange membrane (PEM) fuel cells, particularly due to the susceptibility of non-acidic water transfer membranes to bacterial growth and contamination, which impede water transport and reduce membrane performance.
Innovation Solution
Implementing a method to create an anaerobic environment within the humidifier during shutdown by reducing oxygen concentration and promoting in situ hydrogen peroxide generation using a palladium-based catalyst, along with incorporating acidic gas transport layers to inhibit mold growth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If non-acidic water transfer membranes are used in humidifiers, then water transport efficiency is improved, but susceptibility to bacterial growth and mold formation increases
Solution Approach 1:
The patent changes the pH parameter of the gas transport layer from neutral to acidic (pH 2-4) to create an environment that inhibits bacterial growth and mold formation while maintaining water transport efficiency through the non-acidic membrane
Solution Approach 2:
The patent uses a composite structure combining a non-acidic water transfer membrane with an acidic gas transport layer, where each layer performs its specific function: the membrane transports water while the acidic layer prevents microbial growth
2Object-affected harmful factors
If oxygen is present in the humidifier during shutdown, then mold growth is promoted, but maintaining anaerobic conditions requires additional system complexity
Solution Approach 1:
The patent employs a catalyst that automatically generates hydrogen peroxide from residual hydrogen and oxygen during shutdown, creating an anaerobic environment without requiring external intervention or complex control systems
Solution Approach 2:
The patent replaces mechanical or chemical cleaning systems with a catalytic system that uses hydrogen peroxide generation to biologically inhibit mold growth, simplifying the overall system architecture
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
Prevents mold formation and accumulation by maintaining an anaerobic environment and utilizing hydrogen peroxide to decompose bacteria, thereby prolonging the life and performance of the humidifier.
Implementation Method 1
promoting in situ hydrogen peroxide generation using a palladium-based catalyst
Implementation Method 2
promoting in situ hydrogen peroxide generation using a palladium-based catalyst
Implementation Method 3
a water transfer membrane that permits water transport from a wet side to a dry side
Implementation Method 4
a water transfer membrane that permits water transport from a wet side to a dry side
Implementation Method 5
The ion exchange membrane electrolyte facilitates the migration of protons from the anode to the cathode
Implementation Method 6
incorporating acidic gas transport layers to inhibit mold growth
Data Source
AI summary
Methods and apparatus for reducing the tendency for mold formation and accumulation in membrane-based humidifiers used in PEM fuel cell systems can include reducing the oxygen concentration and/or generating hydrogen peroxide within the humidifier upon shutdown of a fuel cell system. In some embodiments, a fuel cell system comprises valves and lines located and operable to facilitate introduction of hydrogen into the humidifier upon shutdown of the system. In some embodiments, a fuel cell humidifier comprises a catalyst for promoting the generation of hydrogen peroxide from hydrogen and oxygen, and/or comprises acidic gas transport layers.