Fuel Cell Hydrogen Supply Control via Stop Time Prediction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing fuel cell systems perform excessive hydrogen purging when starting, leading to increased hydrogen exhaustion, pressure, and hydrogen concentration issues in exhaust gases, which complicates regulatory compliance and system performance.
Innovation Solution
A hydrogen supply method that measures the stop time period and determines the state of residual gases in the fuel cell system, adjusting hydrogen supply to maintain optimal internal pressure and concentration in the anode, minimizing purging and hydrogen loss by selectively supplying hydrogen based on the stop time, reaction, cross-over, and condensation periods.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If hydrogen purging operation is performed when the fuel cell system is started, then the concentration of hydrogen in the anode is maintained, but the supply pressure of hydrogen increases and the amount of hydrogen exhausted to the outside increases
Solution Approach 1:
The control unit predicts the concentration of hydrogen in the anode based on the stop time period before the fuel cell system is started. This preliminary assessment allows the system to determine whether purging is actually needed, avoiding unnecessary purging operations that would waste hydrogen while ensuring proper concentration control when required.
Solution Approach 2:
The system uses feedback from the stop time period measurement to adjust the purging operation. By continuously monitoring how long the system has been stopped and using this information to predict hydrogen concentration, the control unit can make informed decisions about whether to purge, thereby reducing unnecessary hydrogen exhaustion while maintaining safety.
2Quantity of substance
If excessive hydrogen purging operation is performed when the fuel cell system is started, then the concentration of hydrogen in the anode is maintained, but the supply pressure of hydrogen increases
Solution Approach 1:
The control unit predicts the hydrogen concentration based on the stop time period before starting the fuel cell system. This preliminary assessment prevents excessive purging operations by determining in advance whether purging is necessary, thereby avoiding unnecessary pressure increases in the hydrogen supply system.
Solution Approach 2:
Instead of performing a fixed excessive purging operation, the system applies partial purging only when necessary based on the predicted hydrogen concentration. This selective approach maintains hydrogen concentration when needed while avoiding unnecessary purging that would increase supply pressure.
3Quantity of substance
If hydrogen purging operation is performed without considering the stop time period, then the concentration of hydrogen in the anode is maintained, but the frequency of purging operation increases
Solution Approach 1:
The control unit performs a preliminary prediction of hydrogen concentration based on the stop time period before initiating any purging operation. This advance assessment allows the system to skip purging when the predicted concentration is already sufficient, thereby reducing the frequency of purging operations while maintaining proper hydrogen concentration.
Solution Approach 2:
The system uses feedback from the stop time period to intelligently control purging frequency. By continuously monitoring the stop duration and using it to predict whether purging is needed, the system adapts its purging frequency to actual conditions rather than operating on a fixed schedule.
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 method reduces the frequency and amount of hydrogen purged, minimizes hydrogen exhaustion and pressure, and optimizes hydrogen concentration in exhaust gases, enhancing fuel cell system performance and regulatory compliance.
Implementation Method 1
a reaction time period consumed to complete a reaction of residual hydrogen and residual oxygen residing in a fuel cell stack since the fuel system is stopped
Implementation Method 2
nitrogen and other gases included in the air passing through the cathode are crossed over through the polymer electrolyte membrane and introduced into the anode through the polymer electrolyte membrane
Data Source
AI summary
A hydrogen supply method for a fuel cell system, for supplying hydrogen according to a state of the fuel cell system when the fuel cell system is started, includes steps of (a) measuring a stop time period which elapses until the fuel cell system is started after the fuel cell system is stopped, (b) determining whether a reaction time period consumed to complete a reaction of residual hydrogen and residual oxygen residing in a fuel cell stack since the fuel system is stopped is not more than the stop time period, and (c) when it is determined in the step (b) that the stop time period is less than the reaction time period, closing a purge valve that is able to discharge gases accommodated in an anode from the anode and supplying at the same time hydrogen to the anode such that an internal pressure of the anode becomes a predetermined first target pressure.