Fuel Cell Purge Control Preventing Hydrogen Backflow
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In fuel cell vehicles, hydrogen can flow backwards to the stack enclosure during purging and condensate discharge, leading to hydrogen leaks and potential safety issues, and existing solutions like backflow prevention members increase installation costs.
Innovation Solution
A method that sets target purge and discharge degrees for anode gas and condensate, using an air pressure control valve and backflow diagrams to adjust these parameters to prevent hydrogen backflow without requiring disassembly of the stack enclosure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a backflow prevention member is installed in the air discharge line to prevent hydrogen from flowing backwards to the stack enclosure, then safety is improved, but installation costs increase substantially
Solution Approach 1:
The patent replaces the mechanical backflow prevention member with an electronic control system that uses a controller to monitor system state and dynamically adjust the opening degree of the air pressure control valve. This substitution eliminates the need for additional mechanical components while achieving the same safety function through intelligent control algorithms that prevent hydrogen backflow by maintaining proper pressure differentials.
Solution Approach 2:
The patent changes the operational parameters of the existing air pressure control valve by dynamically adjusting its opening degree based on real-time system conditions. Instead of using a fixed mechanical barrier, the system varies the valve opening parameter to control hydrogen flow and prevent backflow, thereby achieving safety improvements without additional hardware costs.
2Reliability
If the air pressure control valve is closed to prevent hydrogen backflow during purging and condensate discharge, then safety is improved, but the ability to discharge hydrogen and condensate is reduced
Solution Approach 1:
The patent implements dynamic control of the air pressure control valve by continuously adjusting its opening degree based on real-time system conditions. The controller monitors parameters such as hydrogen concentration, pressure differentials, and flow rates, and dynamically modifies the valve opening to maintain optimal balance between preventing hydrogen backflow and enabling efficient purging and condensate discharge. This dynamic adjustment resolves the contradiction by adapting the valve position to current operational needs rather than maintaining a fixed closed state.
Solution Approach 2:
The system employs feedback control where the controller continuously monitors system state (hydrogen concentration, pressure, flow conditions) and adjusts the air pressure control valve opening degree accordingly. This closed-loop control ensures that the valve maintains an opening that prevents hydrogen backflow while simultaneously allowing efficient discharge of purged hydrogen and condensate, thereby resolving the contradiction between safety and productivity.
Data Source
AI summary
A method for controlling a fuel cell vehicle is provided. The method includes setting a target purge degree of an anode gas and a target opening degree of an air pressure control valve and determining whether a fuel cell stack is in a power generation stop state. When the fuel cell stack is in the power generation stop state, when the anode gas is purged from the anode based on the target purge degree and the target opening degree, whether hydrogen in the anode gas will flow backwards to a stack enclosure is determined. When the hydrogen flows backwards, at least one of the target purge degree and the target opening degree to a level at which the backflow of the hydrogen is prevented is modified, and the anode gas from the anode based on the modified target purge degree and the modified target opening degree is purged.