Fuel Cell Impurity Separator for Underwater Vehicle Efficiency
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Solution Overview
Problem
Fuel cells used in enclosed environments, such as underwater vehicles, face inefficiencies due to impurities in the hydrogen fuel stream and non-reactant gases like nitrogen crossing the proton-exchange membrane, leading to reduced performance and increased storage requirements for oxygen and diluents.
Innovation Solution
A system with a fuel cell, anode, and cathode, where a separator is used to capture and recycle unused fuel and oxygen, and a method to mix air with concentrated oxygen gas is employed to maintain optimal oxygen-to-diluent concentrations, utilizing a palladium membrane or zeolite to separate impurities from the fuel stream and recycle them back to the cathode.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If fuel is recycled after passing across the anode to improve system efficiency, then overall fuel utilization improves, but impurity concentration in the fuel stream increases
Solution Approach 1:
The patent extracts and removes impurities from the recycled fuel stream using a separator positioned in the recirculation line. This allows the fuel to be continuously purified as it cycles through the system, maintaining high fuel utilization efficiency while preventing impurity accumulation that would otherwise occur with recycling.
Solution Approach 2:
The separator acts as an intermediary component in the fuel recirculation system. It mediates between the need to recycle fuel for efficiency and the need to remove impurities, by intercepting the fuel stream, removing contaminants, and returning cleaned fuel to the anode inlet.
2Volume of stationary object
If air or dilute oxygen is supplied to the cathode instead of concentrated oxygen, then storage volume requirements decrease, but non-reactant gas cross-over into the fuel stream increases
Solution Approach 1:
The separator removes non-reactant gases (such as nitrogen from air) that have crossed over from the cathode side into the fuel stream. This enables the use of air or dilute oxygen at the cathode without allowing the accumulated non-reactant gases to degrade anode performance.
Solution Approach 2:
The patent converts the potentially harmful effect of non-reactant gas cross-over into a manageable issue by using the separator to remove these gases. The separator transforms the harmful impurity accumulation into a removable contaminant, allowing the benefit of using air breathing cathodes to be realized without the detrimental effects.
3Productivity
If cathode exhaust is recycled and mixed with incoming air to maintain oxygen concentration, then oxygen utilization improves, but storage volume requirements increase
Solution Approach 1:
The separator extracts and removes excess non-reactant gases from the recycled cathode exhaust stream. This allows the system to recycle cathode exhaust for improved oxygen utilization while preventing the accumulation of diluents that would otherwise require additional storage volume.
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 approach enhances fuel cell efficiency and longevity by maintaining fuel purity, reducing corrosion, and minimizing storage volume requirements, while preventing performance degradation and extending the operational life of the fuel cell.
Implementation Method 1
utilizing a palladium membrane or zeolite to separate impurities from the fuel stream
Implementation Method 2
utilizing a palladium membrane or zeolite to separate impurities from the fuel stream
Implementation Method 3
a cathode and an anode separated by a proton-exchange membrane
Implementation Method 4
a cathode and an anode separated by a proton-exchange membrane
Implementation Method 5
a fuel source, such as hydrogen (H2), is passed across the anode. Oxygen or an oxygen containing gas is passed across the cathode. The cathode and anode interact such that electricity is generated
Data Source
AI summary
A system has a fuel cell with an anode, a membrane, and a cathode. A source of fuel passes along the anode and a source of an oxygen containing gas passes along the cathode. A downstream line captures fuel downstream of the anode and a separator separates impurities from the fuel on the downstream line, and recirculates fuel downstream of the separator for passage across the anode. A method of mixing air with an oxygen concentrated gas is also disclosed.