High Temperature Fuel Cell System with Dynamic Anode Flow Control
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Solution Overview
Problem
Large solid oxide fuel cell systems face challenges in efficiently operating at non-nominal conditions due to variations in fuel composition and quality, particularly with gases having different methane percentages, leading to decreased efficiency and mechanical compatibility issues.
Innovation Solution
A high temperature fuel cell system that determines gas composition using oxygen and carbon ratios to control anode recirculation, auxiliary water feed, and gas feed, allowing for dynamic adjustment of power output to maintain optimal electricity production conditions without requiring parallel fuel cell devices for different gases.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the fuel cell system operates at non-nominal conditions with varying fuel composition, then fuel flexibility is improved, but system efficiency decreases
Solution Approach 1:
The patent implements dynamic control of anode flow characteristics by adjusting the ratio of process gas recirculation to auxiliary water feed based on real-time fuel composition analysis. This dynamic adjustment allows the system to adapt to varying fuel types (natural gas, biogas, landfill gas) while maintaining optimal operating conditions and efficiency across different fuel compositions.
Solution Approach 2:
The system monitors fuel composition parameters (O/C ratio) and adjusts operational parameters including anode gas flow rate, auxiliary water feed rate, and recirculation ratio accordingly. These parameter changes enable the system to maintain high efficiency when operating with different fuel types by optimizing the anode flow characteristics for each specific fuel composition.
2Stability of the object's composition
If the fuel cell system is designed for nominal operation point, then system stability is improved, but adaptability to different fuels decreases
Solution Approach 1:
The patent employs a feedback control system that continuously monitors fuel composition at the anode inlet and adjusts the anode flow characteristics in response. The system measures the O/C ratio of the incoming fuel gas and dynamically modifies the recirculation ratio and auxiliary water feed to maintain stable operating conditions regardless of fuel type variations, thereby achieving both stability and adaptability.
Solution Approach 2:
The control system is designed to handle multiple fuel types (natural gas, biogas, landfill gas) through a single unified system configuration. By using composition-based control that automatically adapts to different fuel types, the system achieves dual-fuel capability without requiring separate systems or complex manual reconfiguration, maintaining stability across diverse fuel inputs.
3Use of energy by moving object
If heat exchangers are sized for nominal operation point, then heat exchange efficiency is improved, but temperature stabilization speed decreases
Solution Approach 1:
The system dynamically adjusts the anode flow rate and auxiliary water feed in response to fuel composition changes, which enables faster temperature stabilization without compromising heat exchange efficiency. The dynamic control compensates for the thermal inertia of large system components by actively managing the gas flow characteristics, allowing the system to reach stable operating temperature more quickly when transitioning between different fuel types or load conditions.
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
Enables efficient operation with minimal system configuration changes, maintaining high efficiency and preventing coking even with significant variations in fuel composition, such as from natural gas to bio gas, by dynamically controlling anode flow characteristics and water feed based on gas composition.
Implementation Method 1
means for determining gas composition at the anode sides by obtaining at least amounts of oxygen (O) and carbon (C) for providing as composition information at least the relationship between the amounts of oxygen and carbon (O/C relationship) in said gas
Implementation Method 2
means for performing controlled gas recirculation at anode sides by using said composition information as control information
Implementation Method 3
means for performing controlled auxiliary water feed to the fuel cell system by using said composition information as control information
Implementation Method 4
means for controlling the rated power of the fuel cell system by controlling anode flow characteristics between said controlled gas recirculation at anode sides and said controlled auxiliary water feed
Implementation Method 5
the fuel cell system comprising at least one heat exchanger for arranging wanted temperature conditions in the fuel cell system
Data Source
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AI summary
The focus of the invention is a method for producing electricity in high temperature fuel cell system, in which method gas is circulated at anode sides (100) of the fuel cells. A gas composition at anode sides (100) is determined for providing a composition information, wanted temperature conditions are arranged for producing electricity with fuel cells. In the method rated power of the fuel cell system is controlled by performing controlled auxiliary water feed to the fuel cell system by utilizing said composition information by changing said water feed, when a need arises, by performing controlled gas recirculation at anode sides (100) by utilizing said composition information by changing said gas recirculation, when a need arises, and by performing controlled gas feed in to the fuel cell system by utilizing said composition information by changing said gas feed, when a need arises, to change the rated power of the fuel cell system to keep electricity production conditions substantially optimal for the gas used as fuel in the high temperature fuel cell system.