Design and Off-Design Analysis of a MW Hybrid System Based on Rolls-Royce Integrated Planar Solid Oxide Fuel Cells

2007 ◽  
Vol 129 (3) ◽  
pp. 792-797 ◽  
Author(s):  
Loredana Magistri ◽  
Michele Bozzolo ◽  
Olivier Tarnowski ◽  
Gerry Agnew ◽  
Aristide F. Massardo
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Hybrid System ◽  
System Size ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Ambient Conditions ◽  
Detailed Model ◽  
Design Point ◽  
Turbine Speed

In this paper the design point definition of a pressurised hybrid system based on the Rolls-Royce Integrated Planar-Solid Oxide Fuel Cells (IP-SOFCs) is presented and discussed. The hybrid system size is about 2 MWe and the design point analysis has been carried out using two different IP-SOFC models developed by Thermochemical Power Group (TPG) at the University of Genoa: (i) a generic one, where the transport and balance equations of the mass, energy and electrical charges are solved in a lumped volume at constant temperature; (ii) a detailed model where all the equations are solved in a finite difference approach inside the single cell. The first model has been used to define the hybrid system lay out and the characteristics of the main devices of the plant such as the recuperator, the compressor, the expander, etc. The second model has been used to verify the design point defined in the previous step, taking into account that the stack internal temperature behavior are now available and must be carefully considered. Apt modifications of the preliminary design point have been suggested using the detailed IP-SOFC system to obtain a feasible solution. In the second part of the paper some off-design performance of the Hybrid System carried out using detailed SOFC model are presented and discussed. In particular the influence of ambient conditions is shown, together with the possible part load operations at fixed and variable gas turbine speed. Some considerations on the compressor surge margin modification are reported.

Design and Off-Design Analysis of a MW Hybrid System Based on Rolls-Royce Integrated Planar SOFC

2003 ◽  
Author(s):  
Loredana Magistri ◽  
Michele Bozzolo ◽  
Olivier Tarnowski ◽  
Gerry Agnew ◽  
Aristide F. Massardo
Keyword(s):  
Hybrid System ◽  
System Size ◽  
Ambient Conditions ◽  
Detailed Model ◽  
Design Point ◽  
Surge Margin ◽  
Point Analysis ◽  
Compressor Surge ◽  
Definition Of ◽  
Turbine Speed

In this paper the design point definition of a pressurised hybrid system based on the Rolls-Royce Integrated Planar-Solid Oxide Fuel Cells (IP-SOFCs) is presented and discussed. The hybrid system size is about 2 MWe and the design point analysis has been carried out using two different IP-SOFC models developed by Thermochemical Power Group (TPG) at the University of Genoa: (i) a generic one, where the transport and balance equations of the mass, energy and electrical charges are solved in a lumped volume at constant temperature; (ii) a detailed model where all the equations are solved in a finite difference approach inside the single cell. The first model has been used to define the hybrid system lay out and the characteristics of the main devices of the plant such as the recuperator, the compressor, the expander, etc. The second model has been used to verify the design point defined in the preview step, taking into account that the stack internal temperature behaviour are now available and must be carefully considered. Apt modifications of the preliminary design point have been suggested using the detailed IP-SOFC system to obtain a feasible solution. In the second part of the paper some off-design performance of the Hybrid System carried out using detailed SOFC model are presented and discussed. In particular the influence of ambient conditions is shown, together with the possible part load operations at fixed and variable gas turbine speed. Some considerations on the compressor surge margin modification are reported.

Simplified Versus Detailed Solid Oxide Fuel Cell Reactor Models and Influence on the Simulation of the Design Point Performance of Hybrid Systems

2004 ◽  
Vol 126 (3) ◽  
pp. 516-523 ◽  
Author(s):  
Loredana Magistri ◽  
Riccardo Bozzo ◽  
Paola Costamagna ◽  
Aristide F. Massardo
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Hybrid Systems ◽  
Gas Turbines ◽  
High Efficiency ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Detailed Model ◽  
Design Point ◽  
Cell Reactor ◽  
Reactor Models

High-efficiency hybrid systems (HS) based on the coupling of solid oxide fuel cells (SOFCs) and gas turbines (GT) are analyzed in this paper through the use of two different approaches: simplified and detailed SOFC models. The simplified model, already presented by the authors, is very useful for HS design and off-design analysis. The detailed model, developed by the authors and verified through the use of available experimental data, allows the complete description of the SOFC reactor’s internal behavior to be obtained. The detailed model can also be utilized for HS modeling. Both models are presented and discussed in this paper, and they are compared to each other. The results obtained for the stand-alone SOFC reactor, and the HS design point configuration are presented and carefully discussed, also taking into account the nonlinear SOFC response.

Simplified Versus Detailed SOFC Reactor Models and Influence on the Simulation of the Design Point Performance of Hybrid Systems

2002 ◽  
Author(s):  
Loredana Magistri ◽  
Riccardo Bozzo ◽  
Paola Costamagna ◽  
Aristide F. Massardo
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Hybrid Systems ◽  
Gas Turbines ◽  
High Efficiency ◽  
Solid Oxide ◽  
Simplified Model ◽  
Oxide Fuel ◽  
Detailed Model ◽  
Design Point ◽  
Reactor Models

High efficiency Hybrid Systems (HS) based on the coupling of Solid Oxide Fuel Cells (SOFCs) and Gas Turbines (GT) are analysed in this paper through the use of two different approaches: simplified and detailed SOFC models. The simplified model, already presented by the Authors1, is very useful for HS design and off-design analysis. The detailed model, developed by the Authors2 and verified through the use of available experimental data, allows the complete description of the SOFC reactor’s internal behaviour to be obtained. The detailed model can also be utilised for HS modelling. Both models are presented and discussed in this paper, and they are compared to each other. The results obtained for the stand-alone SOFC reactor, and the HS design point configuration are presented and carefully discussed, also taking into account the non linear SOFC response.

Performance Comparison of Internal and External Reforming for Hybrid SOFC-GT Applications by Using 1D Real-Time Fuel Cell Mode

2019 ◽  
Author(s):  
Hao Chen ◽  
Chen Yang ◽  
Nana Zhou ◽  
Nor Farida Harun ◽  
David Tucker
Keyword(s):  
Fuel Cells ◽  
Fuel Cell ◽  
Natural Gas ◽  
Solid Oxide Fuel Cells ◽  
Real Time ◽  
Hybrid System ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Fuel Utilization ◽  
Internal Reforming

Abstract Solid oxide fuel cells integrated with gas turbine (SOFC-GT) systems are considered among the most promising power generation units, not only because of the high efficiency, low emissions and carbon capture ability, but also the flexibility to use different kinds of fuels such as natural gas, syngas and biogas directly. In the case of natural gas, Previous researches have demonstrated that solid oxide fuel cells possess the ability to utilize natural gas directly by reforming it inside the anode because of the high operating temperature. But the major problem of internal reforming is that it increases the temperature gradient at the leading edge of fuel cell which may lead to high thermal stress and damage the cells. On the other side, external reforming requires an additional reformer outside of fuel cell, which may increase the investment costs. Also, the amount of air needed to cool the fuel cell is doubled, compared with internal reforming. A full comparison between internal reforming and external reforming of the pressurized SOFC is needed for the hybrids application. In this paper, a real time equilibrium reformer model based on minimization of Gibbs free energy was built to couple with 1D real time solid oxide fuel cell model. An internal on-anode reforming SOFC stack configuration for hybrid SOFC-GT system application was compared with external reforming configurations with 800K, 900K and 1000K reforming temperatures. The results show that internal reforming provides better performance of SOFC stack in the case of high fuel utilization. However, the external reforming showed a higher stack efficiency and smaller stack size compared with on-anode reforming when keeping a relatively lower SOFC stack fuel utilization, necessarily for high hybrid efficiency. Results indicated that external and internal reforming of fuel needs to be optimized depending on different design conditions of the entire hybrid system in terms of efficiency and investment cost. This paper shows that the hybrid system provides the opportunities for thermal integration on performance and efficiency improvement over fuel cell anode reforming.

A Matlab-Simulink Analysis of Hybrid SOFC Dynamic Behavior

2005 ◽  
Author(s):  
Umberto Desideri ◽  
Gheorghe Lazaroiu ◽  
Dario Zaninelli ◽  
Cristian Lazaroiu
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Hybrid System ◽  
Solid Oxide ◽  
Oxide Fuel ◽  
Molten Carbonate ◽  
High Hydrogen ◽  
Matlab Simulink ◽  
Fuel Flow ◽  
Molten Carbonate Fuel Cells

Fuel cells are more and more used in hybrid systems with micro-turbines for electricity and heat delivery. Two types of fuel cells are mostly used for cogeneration: solid-oxide fuel cells (SOFC) and molten carbonate fuel cells (MCFC). Solid oxide fuel cells (SOFC) are operating at high temperatures that make them well suited for cogeneration process, but influence the entire system due to their dynamic character. The hybrid system requires a pre-reforming process in order to convert the fuels, such as natural gas, in a gas with a high hydrogen content for the electrochemically oxidation with air. In this paper the dynamic model of the SOFC and of the hybrid system is developed in Matlab-Simulink environment. The comprehensive model is based on the electrochemical and thermal equations and on the temperature dynamics. The response of the SOFC and of the hybrid system to the variation of fuel flow and other parameters is investigated.

Operation and Performance Limitations for Solid Oxide Fuel Cells and Gas Turbines in a Hybrid System

2004 ◽  
Author(s):  
Miriam Kemm ◽  
Andre Hildebrandt ◽  
Mohsen Assadi
Keyword(s):  
Fuel Cells ◽  
Steady State ◽  
Solid Oxide Fuel Cells ◽  
Hybrid System ◽  
Gas Turbines ◽  
Solid Oxide ◽  
Temperature Gradients ◽  
Oxide Fuel ◽  
Single Operation ◽  
Operational Window

Temperature limitations of Solid Oxide Fuel Cells (SOFC) in transient single operation and steady-state Hybrid System (HS) operation with Gas Turbines (GT) are presented. For transient SOFC simulations, an unsteady-state SOFC model was developed by upgrading a detailed validated steady-state model. As critical SOFC single operation modes, concerning the risk of material cracking due to exceeding SOFC transient temperature gradients, heat-up and cool-down are investigated. For minimization of transient SOFC temperature gradients at start-up and shut-down, a stepwise heat-up and cool-down procedure is proposed. Concerning HS off-design and part-load operation, the impact of SOFC temperature limitations on the operational window is investigated. Results show a reduced operational window due to exceeding local SOFC temperature gradients, which can be reduced by optimal adaptation of GT to SOFC size.

Estimation of Spatial Temperature Distribution in Co-Flow Planar Solid Oxide Fuel Cells

2007 ◽  
Author(s):  
Handa Xi ◽  
Jing Sun ◽  
Jian Chen
Keyword(s):  
Fuel Cells ◽  
Steady State ◽  
Temperature Distribution ◽  
Solid Oxide Fuel Cells ◽  
Design Guidelines ◽  
Solid Oxide ◽  
Maximum Temperature ◽  
Oxide Fuel ◽  
Detailed Model ◽  
Transient Operations

Significant temperature distribution has been identified in planar Solid Oxide Fuel Cells (SOFCs) during both steady state and transient operations. In order to ensure the material stability and device protection, the maximum temperature and temperature gradient have to be closely monitored and securely maintained below certain limits. In practical implementation, however, direct measurement of the temperature distribution inside the SOFC is difficult and costly. In this paper, an observer is designed and the corresponding performance is analyzed for estimating the temperature distribution in the co-flow planar SOFC. To facilitate the observer design, we introduce a reduced-order nonlinear SOFC model that is obtained based on the high-order detailed model derived in our previous work. Using three easily accessible measurements, namely the stack voltage and the temperatures of the solid structure at the entrance and exit of the SOFC, the observer designed based on the low order model can effectively estimate the temperature profile during both steady-state and transient operations. Model-based analysis and simulation results are presented to demonstrate the performance of the estimation scheme and to provide design guidelines.

Effect of an Anode Functional Layer on Cell Performance of Anode-Supported Solid Oxide Fuel Cells by a Decalcomania Method

2013 ◽  
Vol 51 (2) ◽  
pp. 125-130 ◽  
Author(s):  
Sun-Min Park ◽  
Hae-Ran Cho ◽  
Byung-Hyun Choi ◽  
Yong-Tae An ◽  
Ja-Bin Koo ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Solid Oxide Fuel Cells ◽  
Solid Oxide ◽  
Cell Performance ◽  
Oxide Fuel ◽  
Functional Layer
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