Integrated SOFC Combustor Assembly for Rapid Startup and Low Emissions
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Solution Overview
Problem
Conventional solid oxide fuel cells (SOFCs) face challenges with high operating temperatures, material degradation, and emissions, particularly from hydrocarbon fuels, and require bulky preheaters and heat exchangers for rapid start-up, which are heavy, large, and costly.
Innovation Solution
An integrated SOFC combustor assembly that utilizes an integrated combustion chamber to achieve rapid heating without bulky preheaters or heat exchangers, using anode off-gas combustion for temperature rise, and features a turbogenerator for high efficiency and weight reduction, enabling rapid startup and efficient thermal management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If conventional preheaters and heat exchangers are used for rapid start-up, then the SOFC can reach operational temperature quickly, but the system becomes heavy, large, and costly
Solution Approach 1:
The combustion chamber is integrated directly with the SOFC stack, merging the heating function into the fuel cell structure itself. This eliminates the need for separate preheaters and heat exchangers, achieving rapid start-up without the weight and size penalties of conventional thermal management components
Solution Approach 2:
The SOFC system uses its own combustion process to heat itself during start-up. The combustion chamber burns fuel to generate heat that directly warms the SOFC stack, eliminating the need for external heating systems and enabling the system to serve its own thermal management needs
2Loss of time
If conventional preheaters and heat exchangers are used for rapid start-up, then the SOFC can reach operational temperature quickly, but the system size and cost increase
Solution Approach 1:
The combustion chamber is integrated directly with the SOFC stack, merging the heating function into the fuel cell structure itself. This eliminates the need for separate preheaters and heat exchangers, achieving rapid start-up without the weight and size penalties of conventional thermal management components
Solution Approach 2:
The invention extracts and eliminates the unnecessary intermediate thermal management components (preheaters, heat exchangers) from the system architecture. By removing these redundant components, the system achieves rapid start-up capability with reduced complexity, size, and cost
3Use of energy by moving object
If high operating temperatures are used for efficient SOFC operation, then energy conversion efficiency increases, but material degradation accelerates
Solution Approach 1:
The system dynamically adjusts operating temperature parameters based on operational requirements. During normal operation, high temperatures maximize energy conversion efficiency. During start-up and shutdown phases, temperature profiles are controlled to prevent thermal shock and material degradation, optimizing the balance between efficiency and durability
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 SOFC combustor assembly achieves rapid startup (<30 minutes) and high power density (3.6 kW/kg) with reduced system size and weight, efficient thermal management, and low emissions, suitable for aerospace applications.
Implementation Method 1
The combustion chamber may be configured to mix compressed air with the off-gas from the one or more SOFC tubes or stacks and combust the compressed air and the off-gas into combustion products
Implementation Method 2
The plenum housing may be configured to direct the combustion products from the second end to the first end along the outer surface
Data Source
AI summary
The solid oxide fuel cell with combustor (SOFC-C) addresses the problems of fast start-up, high gravimetric power density and emission control facing SOFC in aerospace and other mobile vehicle applications by providing a highly efficient clean power generation for full or partial hybrid propulsion systems. The SOFC-C may include one or more SOFC tubes and a combustion chamber integrated within a housing. Fuel may be provided through an anode portion of the one or more SOFC tubes or stacks and be combusted upon exiting the one or more SOFC tubes or stacks. The combustion products may then be provided through a cathode portion of the one or more SOFC tubes or stacks, whereby pollutants may be reduced or removed from the combustion products by the cathode portion prior exiting the housing as exhaust. A cathode inlet temperature may be controlled by controlling the fuel flow.