High Temperature Stationary Solid Oxide Fuel Cell Systems in the Renewable Future

2009 ◽  
Author(s):  
Fabian Mueller ◽  
Brian Tarroja
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Cell System ◽  
Solid Oxide ◽  
Pollutant Emissions ◽  
Oxide Fuel ◽  
Cell Systems ◽  
Load Following ◽  
And Control ◽  
Energy Conversion Devices

Solid oxide fuel cells (SOFCs) are attractive emerging energy conversion devices. Particularly, SOFC electrochemically react fuel and oxygen to generate electricity efficiently with ultra low pollutant emissions. For SOFC systems to be widely utilized in the future, SOFC will have to be effectively integrated with a wide array of energy resources and conversion devices including base-loaded nuclear and coal as well as renewables. Load following generators and/or energy storage will be required to manage intermittent renewables. Base-loaded fuel cell systems (i.e., present day SOFCs) that use potentially dispatchable fuel resources will be increasingly difficult to market. Fuel generators such as SOFCs that can load follow with ultra-low emissions will become increasingly attractive, particularly in future grid scenarios with increased renewables. Simulations results are shown in the paper that demonstrates the intermittent challenge of renewables and the potential for SOFC systems to provide load following capability. SOFCs have the potential to be very attractive load following generators which achieve high efficiencies at part load with low emissions. Research and development is needed to understand solid oxide fuel cell system and control development to minimize dynamics that can degrade the fuel cell during load following. Understanding of degradation of optimally controlled fuel cell is needed to fully understand the true potential of SOFC systems in future grids with increased intermittent renewable penetration.

Surge Prevention Techniques for a Turbocharged Solid Oxide Fuel Cell Hybrid System

2021 ◽  
Author(s):  
L. Mantelli ◽  
M. L. Ferrari ◽  
A. Traverso
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Rotational Speed ◽  
Pressure Ratio ◽  
High Energy ◽  
Cell System ◽  
Solid Oxide ◽  
Pollutant Emissions ◽  
Inlet Temperature ◽  
Oxide Fuel

Abstract Pressurized solid oxide fuel cell (SOFC) systems are one of the most promising technologies to achieve high energy conversion efficiencies and reduce pollutant emissions. The most common solution for pressurization is the integration with a micro gas turbine, a device capable of exploiting the residual energy of the exhaust gas to compress the fuel cell air intake and, at the same time, generating additional electrical power. The focus of this study is on an alternative layout, based on an automotive turbocharger, which has been more recently considered by the research community to improve cost effectiveness at small size (< 100 kW), despite reducing slightly the top achievable performance. Such turbocharged SOFC system poses two main challenges. On one side, the absence of an electrical generator does not allow the direct control of the rotational speed, which is determined by the power balance between turbine and compressor. On the other side, the presence of a large volume between compressor and turbine, due to the fuel cell stack, alters the dynamic behavior of the turbocharger during transients, increasing the risk of compressor surge. The pressure oscillations associated with such event are particularly detrimental for the system, because they could easily damage the materials of the fuel cells. The aim of this paper is to investigate different techniques to drive the operative point of the compressor far from the surge condition when needed, reducing the risks related to transients and increasing its reliability. By means of a system dynamic model, developed using the TRANSEO simulation tool by TPG, the effect of different anti-surge solutions is simulated: (i) intake air conditioning, (ii) water spray at compressor inlet, (iii) air bleed and recirculation, and (iv) installation of an ejector at the compressor intake. The pressurized fuel cell system is simulated with two different control strategies, i.e. constant fuel mass flow and constant turbine inlet temperature. Different solutions are evaluated based on surge margin behavior, both in the short and long terms, but also monitoring other relevant physical quantities of the system, such as compressor pressure ratio and turbocharger rotational speed.

Investigation of a Novel Reciprocating Compression Reformer for Use in Solid Oxide Fuel Cell Systems

2003 ◽  
Author(s):  
Anthony N. Zinn ◽  
Todd H. Gardner ◽  
David A. Berry ◽  
Robert E. James ◽  
Dushyant Shekhawat
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Cell System ◽  
Optimal Operation ◽  
Solid Oxide ◽  
Phase Reaction ◽  
Oxide Fuel ◽  
Carbon Formation ◽  
Fuel Cell System ◽  
Cell Systems

A novel reciprocating compression device has been investigated as a non-catalytic natural gas reformer for solid oxide fuel cell systems. The reciprocating compression reformer is a potential improvement over current reforming technology for select applications due to its high degree of heat integration, its homogenous gas phase reaction environment, and its ability to co-produce shaft work. Performance modeling of the system was conducted to understand component integration and operational characteristics. The reformer was modeled by utilizing GRI mech. in tandem with CHEMKIN. The fuel cell was modeled as an equilibrium reactor assuming constant fuel utilization. The effect on the reformer and the reformer – fuel cell system efficiencies and exit gas concentrations was examined over a range of relative air-to-fuel ratios, 0.2 to 1.0, and at compression ratios of 50 and 100. Results from this study indicate that the reformer – fuel cell system could approach 50% efficiency, if run at low relative air-to-fuel ratios (0.3 to 0.5). With higher air-to-fuel ratios, system efficiencies were shown to continuously decline due to a decrease in the quality of synthesis gas provided to the fuel cell (i.e. more power being produced by the reformer). Optimal operation of the system has been shown to occur at a relative air-to-fuel ratio of approximately 0.775 and to be nearly independent of the compression ratio in the reciprocating compression reformer. Higher efficiencies may be obtained at lower relative air-to-fuel ratios; however, operation below this point may lead to excessive carbon formation as determined from an equilibrium carbon formation analysis.

ChemInform Abstract: Analysis, Optimization, and Control of Solid-Oxide Fuel Cell Systems

ChemInform ◽  
2013 ◽  
Vol 44 (15) ◽  
pp. no-no
Author(s):  
Robert J. Braun ◽  
Tyrone L. Vincent ◽  
Huayang Zhu ◽  
Robert J. Kee
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Cell Systems ◽  
Optimization And Control ◽  
And Control

Modeling and control of tubular solid-oxide fuel cell systems. I: Physical models and linear model reduction

2011 ◽  
Vol 196 (1) ◽  
pp. 196-207 ◽  
Author(s):  
Andrew M. Colclasure ◽  
Borhan M. Sanandaji ◽  
Tyrone L. Vincent ◽  
Robert J. Kee
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Model Reduction ◽  
Linear Model ◽  
Solid Oxide ◽  
Physical Models ◽  
Oxide Fuel ◽  
Cell Systems ◽  
Modeling And Control ◽  
And Control
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