Fuel Cell Air Compressor Control Using Pipe Pressure Loss Maps
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Solution Overview
Problem
Existing fuel cell systems face challenges in accurately controlling the flow rate of cathode gas due to varying pressure losses in intake and exhaust pipes, which depend on the specific specifications of the pipes, leading to inconsistencies in cathode gas flow rates across different products.
Innovation Solution
A fuel cell system that includes an air compressor, control device, atmospheric pressure sensor, airflow meter, and pressure sensors to create pressure loss maps for intake and exhaust pipes, allowing for precise control of the air compressor's rotation speed based on target flow rates, thereby compensating for varying pipe specifications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed value is used for pressure loss at the intake line and exhaust line, then the fuel cell system can be designed universally for different products, but the flow rate of cathode gas cannot be controlled accurately due to variations in actual pressure loss
Solution Approach 1:
The control device performs preliminary actions by creating pressure loss maps for the intake line and exhaust line before actual power generation. It operates the air compressor at multiple different airflow meter flow rates, measures the actual pressure losses, and stores this data in maps. This preliminary characterization of the specific piping configuration enables accurate flow rate control during subsequent operation, resolving the contradiction between universal design and precise control.
2Adaptability or versatility
If the specifications of the pipes are varied for different products, then the pressure loss at the intake line and exhaust line changes, but this leads to inconsistency in cathode gas flow rate control across products
Solution Approach 1:
The control device implements feedback by measuring the actual pressure loss in the intake line and exhaust line using pressure sensors and airflow meter, then using this measured data to create product-specific pressure loss maps. During operation, the control device refers to these maps to determine the appropriate air compressor rotation speed that achieves the target cathode gas flow rate, ensuring consistent and reliable control across different product configurations.
3Ease of operation
If the air compressor rotation speed is controlled based on fixed pressure loss values, then the system operation is simplified, but the cathode gas flow rate deviates from target values due to actual pressure loss variations
Solution Approach 1:
The control device changes the operational parameters by creating pressure loss maps that characterize the actual pressure loss characteristics of the specific intake line and exhaust line configuration. Instead of using fixed pressure loss values, the system refers to these empirical maps to determine the air compressor rotation speed, thereby achieving precise flow rate control while maintaining relatively simple control logic through map-based lookup.
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 system enables accurate control of cathode gas flow rates by determining intake and exhaust pipe pressure losses before power generation, ensuring consistent performance across different products such as passenger cars, trucks, and stationary power facilities.
Implementation Method 1
an atmospheric pressure sensor configured to acquire an atmospheric pressure
Implementation Method 2
an air compressor configured to compress the cathode gas flowing through the system intake unit and discharge the cathode gas to the fuel cell stack
Implementation Method 3
a pressure sensor configured to acquire an outlet pressure that is a pressure on an outlet side of the air compressor
Implementation Method 4
an airflow meter configured to acquire an airflow meter flow rate that is a flow rate of the cathode gas to be sucked into the air compressor
Implementation Method 5
a fuel cell stack configured to generate electric power using the cathode gas supplied via the system intake unit
Data Source
AI summary
A fuel cell system includes a system intake unit, a system exhaust unit, a fuel cell stack, an atmospheric pressure sensor, an air compressor, an airflow meter, a pressure sensor, and a control device, and prior to power generation, the air compressor is operated in a state in which an intake pipe and an exhaust pipe are connected, an exhaust pipe pressure loss map and an intake pipe pressure loss map are generated, and in power generation, an exhaust pipe pressure loss and an intake pipe pressure loss are determined by referring to the exhaust pipe pressure loss map and the intake pipe pressure loss map based on a target value of a stack flow rate, and the air compressor is controlled by a determined rotational speed for realizing the target value at the pressure ratio of the inlet pressure and the outlet pressure.