Hybrid Power Generation Device with SOFC and Turbine
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Solution Overview
Problem
Solid oxide fuel cells have limited electrical efficiency due to significant heat dissipation, with existing solutions like organic Rankine cycles and gas turbines either offering limited improvements or being costly and complex to implement.
Innovation Solution
A hybrid power generation device incorporating a solid oxide fuel cell, a catalytic burner, an expansion turbine, and a compressor to enhance heat dissipation and convert mechanical energy into electrical energy, with heat exchangers and a pre-reformer to optimize gas yield and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If solid oxide fuel cell operates to generate electrical energy, then electrical power is produced, but significant heat dissipation occurs reducing electrical efficiency below 50%
Solution Approach 1:
The patent converts the harmful heat dissipation from the fuel cell into useful thermal energy by directing exhaust gases through a heat exchanger to preheat combustion air and fuel gases. This thermodynamic approach recovers waste heat that would otherwise be lost, improving overall system efficiency while maintaining electrical power generation.
Solution Approach 2:
The patent merges the fuel cell electrical generation system with a catalytic combustion system in a hybrid configuration. The exhaust from the fuel cell is combined with combustion products in a common exhaust stream, allowing thermal energy from both sources to be utilized together, thereby converting previously wasted thermal energy into useful heat for preheating purposes.
2Loss of energy
If organic Rankine cycle is implemented to utilize heat dissipation, then some electrical current is generated, but efficiency improvement remains limited
Solution Approach 1:
Instead of using a complex Rankine cycle, the patent directly converts waste heat into useful preheating energy through a heat exchanger that warms combustion air and fuel gases. This simpler approach achieves practical efficiency improvements by eliminating the need for additional working fluids and complex phase change machinery.
Solution Approach 2:
The patent replaces the mechanical complexity of a Rankine cycle system with a direct thermal exchange system. Rather than using turbines, condensers, and evaporators, the invention uses a straightforward heat exchanger to transfer thermal energy from exhaust gases to incoming combustion gases, achieving the same heat utilization goal with much simpler equipment.
3Power
If gas turbine principle is used by replacing combustion chamber with fuel cell, then electrical power is generated, but pressure withstanding requirement makes implementation complex and costly
Solution Approach 1:
The patent segments the power generation function from the pressure withstanding function. The fuel cell operates at atmospheric pressure in a separate, simple structure, while a catalytic burner handles the combustion process. This separation allows the fuel cell to avoid complex pressure containment requirements while still contributing to electrical power generation through the hybrid system.
Solution Approach 2:
The patent combines atmospheric pressure fuel cell operation with catalytic combustion in a hybrid system. By merging these two processes and using a common exhaust system, the invention achieves electrical power generation without requiring the fuel cell to withstand high pressures, thereby simplifying the overall device structure and reducing costs.
4Stress or pressure
If compressor is added to compress main gas stream to pressure greater than 1 bar, then gas is released into atmosphere at higher pressure, but additional mechanical energy consumption is required
Solution Approach 1:
The patent merges the compression function with the expansion turbine function by coupling them on a common shaft. The turbine expands hot exhaust gases to generate mechanical work, which directly drives the compressor to pressurize the incoming gas stream. This integration allows the system to achieve pressurized discharge while recovering energy from the exhaust stream to offset the compression energy requirement.
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 hybrid device effectively enhances heat dissipation and electrical efficiency, reducing the need for external energy sources and lowering operational costs while maintaining environmental standards.
Implementation Method 1
Solid oxide fuel cells (SOFCs)... in which water is the only reaction product... the anode and cathode are the site of electrochemical reactions... dioxygen injected at the cathode is reduced to O2- ions, which migrate through the electrolyte to the anode. Simultaneously, dihydrogen undergoes an oxidation reaction at the anode... The O2- and H+ ions combine near the anode to form water, while the electrons exchanged during these redox reactions generate an electric current.
Implementation Method 2
a catalytic burner connected to an outlet of the anode, and arranged to form a main gas stream from the combustion of the unburned gases of the anodic gas stream
Implementation Method 3
an expansion turbine intended to produce mechanical energy during an expansion of the main gas stream
Implementation Method 4
a compressor intended, by consumption of the mechanical energy produced by the expansion turbine, to compress to a pressure Pf, advantageously greater than 1 bar, the main gas stream expanded by the expansion turbine
Implementation Method 5
a first heat exchanger arranged to heat the combustible gas before its injection at the anode by heat exchange with the anodic gas flow
Data Source
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AI summary
The invention relates to a hybrid device comprising: - a solid oxide fuel cell (210) which includes an anode (211) at which a combustible gas is injected at a temperature T1, and discharged by said cell in the form of an anodic gas stream at a temperature T2 greater than T1; - a burner (270) connected to an outlet of the anode (211), and arranged to form a main gas stream from the combustion of the unburned gases of the anodic gas stream; - an expansion turbine (280) intended to produce mechanical energy during an expansion of the main gas stream; - a compressor (290) intended, by consumption of the mechanical energy produced by the expansion turbine (280), to compress to a pressure Pf, advantageously greater than 1 bar, the main gas stream expanded by the expansion turbine (280).