SOFC Process Gas Mixing Chamber Using Anode Off-Gas Enthalpy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-temperature fuel cell systems, particularly large-scale SOFC systems, face challenges in reducing complexity and investment costs in plant construction, as well as requiring faster responses to transient load changes.
Innovation Solution
A method and system for preparing a process gas by integrating the mixing of steam and raw fuel with the premixing of anode off-gas at a single process stage, utilizing the enthalpy of recirculated high-temperature anode off-gas for direct evaporation of the raw fuel, thereby reducing the number of components and complexity in the plant construction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an evaporator unit, mixer unit, and premixer unit are used in series to prepare process gas and premix process gas, then the fuel cell system can achieve stable operation and proper fuel vaporization, but the system complexity and investment costs increase significantly
Solution Approach 1:
The patent combines the evaporator unit, mixer unit, and premixer unit into a single integrated mixing chamber where liquid fuel, steam, and anode off-gas are mixed and vaporized simultaneously. This eliminates the need for separate serial units while maintaining the functional requirements for fuel preparation and system stability.
Solution Approach 2:
The mixing chamber serves multiple functions simultaneously: it acts as an evaporator for fuel vaporization, a mixer for combining fuel with steam and anode off-gas, and a premixer for preparing the process gas for the fuel cell. This multi-functionality reduces the number of components needed while ensuring stable operation.
2Ease of manufacture
If multiple separate units (evaporator, mixer, premixer) are used in the process stream, then proper phase change and mixing can be achieved, but the plant construction complexity and investment costs increase
Solution Approach 1:
The patent merges the evaporator, mixer, and premixer units into a single integrated mixing chamber that performs all three functions in one location, thereby simplifying plant construction while maintaining proper phase change and mixing processes.
Solution Approach 2:
The mixing chamber utilizes the enthalpy of the incoming anode off-gas to provide the heat required for fuel vaporization, eliminating the need for separate external heating systems or complex thermal management infrastructure.
3Ease of operation
If traditional separate units are used for fuel evaporation and mixing, then thorough mixing can be achieved, but the response time to transient load changes is slower
Solution Approach 1:
By combining evaporation and mixing functions in a single chamber, the system eliminates the sequential processing delays between separate units, enabling faster response to load changes while maintaining thorough mixing through the integrated design.
Solution Approach 2:
The integrated mixing chamber allows dynamic adjustment of fuel vaporization and mixing in real-time response to load changes, as all components are co-located and can respond simultaneously to control signals without the lag inherent in serial processing through multiple separate units.
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 approach significantly reduces investment costs and complexity in plant construction, enables faster response to transient load changes, and improves thermal and overall efficiency of the fuel cell system by utilizing the enthalpy of the anode off-gas for evaporation.
Implementation Method 1
evaporating the atomized raw fuel by the enthalpy submitted in the mixing chamber by the introduced high-temperature anode off-gas
Implementation Method 2
pressurizing the supplied raw fuel that will be atomized by means of a nozzle by supplying mechanical energy, and injecting through the nozzle atomized raw fuel in the form of a spray
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to method and a high-temperature fuel cell system for preparing a process gas, amongst other steps by: introducing (pS14) steam generated by an evaporation means into a mixing chamber, injecting (pS24) through a nozzle atomized raw fuel in the form of a spray into the mixing chamber, and mixing (S40) the process gas by converging the process stream in the common mixing chamber. The invention particularly provides introducing (pS34) recirculated high-temperature anode off-gas into the same common mixing chamber; and evaporating (S42) the atomized raw fuel by the enthalpy submitted in the mixing chamber by the introduced high-temperature anode off-gas.