Fuel Cell Air Compressor Bypass Control for Axial Force Relief
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Solution Overview
Problem
Fuel cell air compressors face issues with high axial forces due to conventional bearing systems, leading to reduced service life and efficiency, and require precise control to operate effectively across varying conditions.
Innovation Solution
A fuel cell control system with a control flow channel and return valve that redirects high-pressure gas back to the gas inlet, converting pressure energy into kinetic energy to reduce axial forces and allowing precise control of gas flow rates through the central control unit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dynamic pressure air bearing is used to support the rotor and offset the axial load, then the air compressor can operate without oil-lubricated bearings, but the axial force still affects the service life and efficiency
Solution Approach 1:
The patent extracts the axial load from the pressure wheel by introducing a separate axial bearing (thrust bearing) to support the rotor shaft. This isolates the axial force support function from the pressure wheel, allowing the pressure wheel to focus on compression while the bearing handles the axial load, thereby extending service life and improving efficiency
Solution Approach 2:
The patent introduces a dynamic pressure air bearing as an intermediary element between the rotor shaft and the housing. This air bearing uses a film of compressed air to support the axial load, preventing direct mechanical contact and reducing friction and wear, which improves reliability and reduces the effective axial force on the pressure wheel
2Reliability
If air compressors use conventional oil-lubricated bearings, then they can support axial load effectively, but they fail to meet the cleanliness requirements of proton exchange membranes
Solution Approach 1:
The patent replaces conventional oil-lubricated mechanical bearings with a dynamic pressure air bearing system. This substitution eliminates oil contamination while maintaining axial load support capability through aerodynamic pressure, satisfying both cleanliness requirements and mechanical support needs for proton exchange membrane fuel cells
Solution Approach 2:
The patent uses pneumatic principles by introducing compressed air to create a dynamic pressure air bearing. The air film generated by the rotating rotor shaft provides both lubrication (eliminating oil) and axial load support, achieving a dual function that meets cleanliness requirements while maintaining effective force support
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
The system reduces axial forces, prolongs compressor life, improves efficiency, and enhances performance by optimizing gas flow and pressure management, effectively addressing operational demands in different conditions.
Implementation Method 1
part of the pressure energy of the gas is converted into kinetic energy, which reduces the pressure on the wheel-back side of the pressure wheel, and reduces the axial force
Data Source
AI summary
The fuel cell control system includes: a reactor; an air compressor, wherein the air compressor has a compressing cavity, the compressing cavity has a gas inlet and a gas outlet, a rotatable pressure wheel is disposed inside the compressing cavity, and the gas outlet is in communication with the reactor; a control flow channel, wherein a first end of the control flow channel is in communication with the gas-intake side of the pressure wheel, a second end of the control flow channel is in communication with the wheel-back side of the pressure wheel, and the control flow channel is provided with a return valve for regulating the flow rate of the control flow channel; and a central control unit, wherein the central control unit is communicatively connected to the return valve to control the opening degree of the return valve.