Fuel Cell Anode Condensed Water Estimation for Drain Valve Control
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Solution Overview
Problem
Existing fuel cell systems inaccurately determine the amount of condensed water in the anode, leading to frequent and unintended opening/closing of the drain valve, causing stack flooding and increased exhaust gas concentration due to dynamic vehicle behavior and road slopes.
Innovation Solution
An apparatus and method to estimate the actual amount of condensed water in the anode by calculating initial water vapor, diffusion, discharge, and recirculation, eliminating the need for a water level sensor and enabling precise control of the drain valve.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a water level sensor is used to control the drain valve, then the condensed water can be discharged when reaching a full level, but the valve frequently opens/closes unintentionally due to vehicle dynamics and road slopes causing inaccurate water level detection
Solution Approach 1:
The patent replaces the mechanical water level sensor system with a computational model that calculates condensed water amount based on fuel cell operating parameters (current, temperature, humidity, flow rates). This substitution eliminates the mechanical sensing components that are susceptible to vehicle dynamics interference, providing more reliable and stable control of the drain valve.
Solution Approach 2:
The patent introduces an intermediary calculation system that uses operating parameters as mediators to indirectly determine condensed water amount. Instead of directly measuring water level with a sensor, the system uses current, temperature, humidity, and flow rate data as intermediaries to compute the condensed water amount, thereby avoiding direct exposure to vehicle dynamics interference.
2Ease of operation
If a water level sensor is installed in the water trap, then condensed water discharge can be controlled, but the system complexity and manufacturing cost increase
Solution Approach 1:
The patent extracts and removes the water level sensor component from the water trap system. By eliminating this component, the system complexity and manufacturing cost are reduced while maintaining the condensed water discharge control function through the alternative calculation-based approach.
Solution Approach 2:
The system uses its own operating parameters (current, temperature, humidity, flow rates) to self-determine the condensed water amount without requiring external sensing components. This self-service approach eliminates the need for additional sensors and reduces system complexity.
3Device complexity
If the drain valve is controlled based on sensor values only, then the control is simple, but stack flooding occurs due to mismatch between sensor reading and actual water level
Solution Approach 1:
The patent implements a feedback mechanism where the calculated condensed water amount continuously informs the drain valve control decisions. The system uses real-time operating parameters to update the condensed water amount calculation, creating a closed-loop feedback system that adapts to changing operating conditions and prevents stack flooding more reliably than simple sensor-based control.
Solution Approach 2:
The patent changes the control parameter from direct water level measurement to calculated condensed water amount based on multiple operating parameters. This parameter transformation allows the system to account for various operating conditions (current, temperature, humidity, flow rates) that affect condensed water formation, improving reliability without significantly increasing control 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
Accurate estimation of condensed water prevents malfunction during vehicle dynamics, reduces manufacturing costs, and prevents stack flooding and exhaust gas concentration increases.
Implementation Method 1
a portion thereof passes through the electrolyte membrane due to the concentration difference and is discharged to the anode
Implementation Method 2
the product water discharged from the anode is condensed and stored in a water trap included in the hydrogen supply system
Data Source
AI summary
An apparatus for estimating an amount of condensed water in an anode of a fuel cell system includes: an initial anode water vapor amount calculation unit to calculate an initial amount of water vapor in the anode of a fuel cell upon startup, an anode diffusion amount calculation unit to calculate an amount of H2O diffused from a cathode to the anode, a purge amount calculation unit to calculate an amount of water vapor discharged upon gas purging in the anode, a recirculation amount calculation unit to calculate the amount of water vapor recirculated to the anode, and a condensed water amount determination and water level estimation unit to calculate the actual amount of water vapor in the anode based on values calculated using these units and to calculate the amount of condensed water in a water trap.