Fuel Cell Air Compressor Control for Predicted Acceleration Loads
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Fuel cell systems face challenges in efficiently managing the rotation speed of air compressors used for oxidant gas supply, particularly when the requested output is low, leading to increased power consumption and potential damage due to acceleration G-forces during vehicle movement, which complicates the use of air bearings in limited vehicle spaces.
Innovation Solution
A fuel cell system with a controller that detects movement speed and predicted acceleration G-forces to adjust the rotation speed of the air compressor, ensuring it operates at appropriate speeds to prevent rotor and housing contact, thereby improving durability and fuel efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If the rotation speed of the air compressor is reduced to improve fuel efficiency when the requested output is small, then fuel efficiency is improved, but the rotor and housing may come into contact due to acceleration G-forces during vehicle movement, reducing reliability
Solution Approach 1:
The control device predicts acceleration G-forces in advance and proactively increases the rotation speed of the air compressor before the acceleration occurs. This preliminary action ensures that the rotor is already floating on the air bearing when acceleration happens, preventing contact between the rotor and housing while maintaining fuel efficiency during normal operation
Solution Approach 2:
The control device continuously monitors vehicle acceleration and uses this feedback to dynamically adjust the rotation speed of the air compressor. When acceleration is detected, the rotation speed is increased to maintain the air bearing; when acceleration is not present, the rotation speed is reduced to improve fuel efficiency
2Device complexity
If an air bearing is used in the air compressor to reduce size and improve efficiency, then device size is reduced and efficiency is improved, but the minimum rotation speed requirement increases power consumption
Solution Approach 1:
The air compressor operates with dynamic rotation speed adjustment rather than a fixed minimum speed. The rotation speed is increased only when acceleration G-forces are predicted, and reduced during normal operation, allowing the system to benefit from the compact air bearing design while minimizing power consumption
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 enhances the durability and fuel efficiency of the air compressor by dynamically adjusting its rotation speed based on movement speed and predicted acceleration, reducing the risk of damage and optimizing power usage.
Implementation Method 1
The air compressor includes a rotor, an air bearing, and a housing. The air compressor using the air bearing has a mechanism in which an air flow is generated between a rotor (rotator) and a housing by rotating the rotor to float the rotor.
Implementation Method 2
The controller includes an acceleration detector configured to predict an acceleration G to be applied to the mobile body.
Data Source
AI summary
A fuel cell system for a mobile body includes a fuel cell, an oxidant gas supply system, and a controller. The oxidant gas supply system includes an air compressor. The air compressor includes a rotor, an air bearing, and a housing. The controller includes a movement speed detector configured to measure a movement speed of the mobile body, and an acceleration detector configured to predict an acceleration to be applied to the mobile body. The controller is configured to determine whether the acceleration predicted by the acceleration detector is equal to or higher than a predetermined acceleration threshold, and control a rotation speed of the air compressor to be equal to or higher than a predetermined first rotation speed when determination is made that the acceleration predicted by the acceleration detector is equal to or higher than the acceleration threshold.