Fuel Cell Water Production Control for Membrane Dryness
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Solution Overview
Problem
Fuel cell systems face degradation in power generation performance during prolonged high load operations due to increased dryness of the electrolyte membrane, leading to blocked gas diffusion pores and reduced power output.
Innovation Solution
A fuel cell system with a power generation controller that alternates between water production increasing and non-increasing controls to intermittently increase water production, reducing membrane dryness and preventing pore blockage, while maintaining effective power generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If water production is continuously increased during prolonged high load operation, then electrolyte membrane dryness is reduced, but gas diffusion pores become blocked and power generation performance degrades
Solution Approach 1:
The patent applies periodic action by alternately repeating water production increasing control and water production non-increasing control during prolonged high load operation. This periodic switching prevents continuous water accumulation that would block gas diffusion pores, while still periodically humidifying the electrolyte membrane to prevent dryness, thereby resolving the contradiction between maintaining membrane wetness and preserving power generation performance.
2Stability of the object's composition
If air supply is reduced to increase water production, then electrolyte membrane dryness is reduced, but oxygen supply for power generation is insufficient
Solution Approach 1:
The patent implements periodic switching between air supply reduction (to increase water production and humidify the membrane) and normal air supply (to ensure sufficient oxygen for power generation). This periodic action allows the system to periodically address membrane dryness without continuously compromising oxygen supply and power generation output.
3Stability of the object's composition
If operation state shifts to lower voltage level to increase water production, then electrolyte membrane dryness is reduced, but power generation efficiency decreases
Solution Approach 1:
The patent applies periodic action by alternately shifting the operation state to lower voltage level (to increase water production and humidify the membrane) and maintaining normal operation state (to preserve power generation efficiency). This periodic switching ensures the membrane receives adequate humidity without continuously operating at reduced efficiency.
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 effectively reduces electrolyte membrane dryness, prevents pore blockage, and maintains power generation performance during prolonged high load operations, enhancing the fuel cell system's efficiency and reliability.
Implementation Method 1
The power generation of the fuel cell produces water on the cathode, accompanied with the electrochemical reaction of hydrogen contained in the fuel gas, for example, hydrogen gas with oxygen contained in the oxygen-containing gas, for example, the air.
Implementation Method 2
An electrolyte membrane of the fuel cell generally has the favorable proton conductivity in an adequate wet state.
Implementation Method 3
A variety of methods have been proposed to use the produced water on the cathode for humidification of the electrolyte membrane
Data Source
AI summary
The invention aims to reduce degradation of the power generation performance of a fuel cell during a prolonged high load operation with high effectiveness. A fuel cell vehicle correlates the dryness of an electrolyte membrane to the cell temperature, while performing power generation control of a fuel cell based on a power demand for a driving motor. When the cell temperature exceeds a first temperature α that indicates the increased dryness of the electrolyte membrane, the fuel cell vehicle intermittently repeats temporary current increase control that shifts the operation state of the fuel cell to the state of an increased electric current and a decreased voltage in a time period t, in order to increase the amount of water production on a cathode.