Exergy Analysis of a Solid-Oxide Fuel Cell, Gas Turbine, Steam Turbine Triple-Cycle Power Plant

2012 ◽  
Author(s):  
Rebecca Z. Pass ◽  
Chris F. Edwards
Keyword(s):  
Fuel Cell ◽  
Power Systems ◽  
Solid Oxide Fuel Cell ◽  
Gas Turbine ◽  
Exergy Analysis ◽  
Combined Cycle ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Starting Point ◽  
Natural Gas Combined Cycle

In an effort to make higher efficiency power systems, several joint fuel cell / combustion-based cycles have been proposed and modeled. Mitsubishi Heavy Industries has recently built such a system with a solid-oxide fuel cell gas turbine plant, and is now working on a variant that includes a bottoming steam cycle. They report their double and triple cycles have LHV efficiencies greater than 52% and 70%, respectively. In order to provide insight into the thermodynamics behind such efficiencies, this study attempts to reverse engineer the Mitsubishi Heavy Industries system from publicly available data. The information learned provides the starting point for a computer model of the triple cycle. An exergy analysis is used to compare the triple cycle to its constituent sub-cycles, in particular the natural gas combined cycle. This analysis provides insights into the benefits of integrating the fuel cell and gas turbine architectures in a manner that improves the overall system performance to previously unseen efficiencies.

Simulation and exergy analysis of a hybrid Solid Oxide Fuel Cell (SOFC)–Gas Turbine System

Energy ◽  
2006 ◽  
Vol 31 (15) ◽  
pp. 3278-3299 ◽  
Author(s):  
F. Calise ◽  
M. Dentice d’Accadia ◽  
A. Palombo ◽  
L. Vanoli
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Gas Turbine ◽  
Exergy Analysis ◽  
Solid Oxide ◽  
Oxide Fuel

scholarly journals Exergy Analysis of an Intermediate Temperature Solid Oxide Fuel Cell-Gas Turbine Hybrid System Fed with Ethanol

Energies ◽  
2012 ◽  
Vol 5 (11) ◽  
pp. 4268-4287 ◽  
Author(s):  
Anastassios Stamatis ◽  
Christina Vinni ◽  
Diamantis Bakalis ◽  
Fotini Tzorbatzoglou ◽  
Panagiotis Tsiakaras
Keyword(s):  
Fuel Cell ◽  
Solid Oxide Fuel Cell ◽  
Gas Turbine ◽  
Hybrid System ◽  
Exergy Analysis ◽  
Solid Oxide ◽  
Intermediate Temperature ◽  
Oxide Fuel

Designing Solid Oxide Fuel Cell Gas Turbine Hybrid Systems Using Exergy Analysis

2006 ◽  
Author(s):  
K. J. Bosch ◽  
N. Woudstra ◽  
K. V. van der Nat
Keyword(s):  
Fuel Cell ◽  
Natural Gas ◽  
Solid Oxide Fuel Cell ◽  
Gas Turbine ◽  
Hybrid Systems ◽  
Exergy Analysis ◽  
Operating Conditions ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Exergy Losses

In conventional gas turbine systems combustion results in high exergy losses (∼30%) of fuel exergy input. Replacing the combustor with a high temperature fuel cell, like the Solid Oxide Fuel Cell (SOFC), will significantly reduce these exergy losses. As the SOFC electrochemically converts the natural gas, exergy losses are far lower (∼10%) compared to combustion. Natural gas entering a SOFC system has to be reformed first to hydrogen and carbon monoxide by steam reforming. Here it is chosen to use the heat generated by the fuel cell to drive the endothermic reforming reactions: internal reforming. The SOFC-GT system has the advantage that both fuel cell and gas turbine technology contribute to power production. In earlier work [1] several fuel cell system configurations with PEMFC, MCFC or SOFC, were analyzed studying the exergy flows. Here is focused on the SOFC-GT configuration, to get a detailed understanding of the exergy flows and losses through all individual components. Several configurations, combining the SOFC with the GT are possible. The selected operating conditions should prevent carbon deposition. Systems studies are performed to get more insight in the exergy losses in these combined systems. Exergy analysis facilitates the search for the high efficient SOFC-GT hybrid systems. Using exergy analysis, several useful configurations are found. Exergy losses are minimized by varying pressure ratio and turbine inlet temperature. Sensitivity studies, of equivalent cell resistance and fuel cell temperature, show that total system exergy efficiencies of more than 80% are conceivable, without using a bottoming cycle.

scholarly journals Tubular Solid Oxide Fuel Cell/Gas Turbine Hybrid Cycle Power Systems — Status

2000 ◽  
Author(s):  
Stephen E. Veyo ◽  
Larry A. Shockling ◽  
Jeffrey T. Dederer ◽  
James E. Gillett ◽  
Wayne L. Lundberg
Keyword(s):  
Fuel Cell ◽  
Power Systems ◽  
Solid Oxide Fuel Cell ◽  
Gas Turbine ◽  
Solid Oxide ◽  
Turbine Engines ◽  
Oxide Fuel ◽  
Power Cycle ◽  
Physical Attributes ◽  
Gas Fuel

The solid oxide fuel cell (SOFC) is a simple electrochemical device that operates at 1000°C, and is capable of converting the chemical energy in natural gas fuel to AC electric power at approximately 45% efficiency (net AC/LHV) when operating in a system at atmospheric pressure. Since the SOFC exhaust gas has a temperature of approximately 850°C, the SOFC generator can be synergistically integrated with a gas turbine (GT) engine-generator by supplanting the turbine combustor and pressurizing the SOFC, thereby enabling the generation of electricity at efficiencies approaching 60% or more. Conceptual design studies have been performed for SOFC/GT power systems employing a number of the small recuperated gas turbine engines that are now entering the marketplace. The first hardware embodiment of a pressurized SOFC/GT power system has been built for Southern California Edison and is scheduled for factory acceptance tests beginning in Fall, 1999 at the Siemens Westinghouse facilities in Pittsburgh, Pennsylvania. The hybrid power cycle, the physical attributes of the hybrid systems, and their performance are presented and discussed.

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