Thermo-economic optimization of an indirectly coupled solid oxide fuel cell/gas turbine hybrid power plant

Operating points of a 300 kW solid oxide fuel cell gas turbine (SOFC-GT) power plant simulator are estimated with the use of a multiple model adaptive estimation (MMAE) algorithm. This algorithm aims to improve the flexibility of controlling the system to changing operating conditions. Through a set of empirical transfer functions (TFs) derived at two distinct operating points of a wide operating envelope, the method demonstrates the efficacy of estimating online the probability that the system behaves according to a predetermined dynamic model. By identifying which model the plant is operating under, appropriate control strategies can be switched and implemented. These strategies come into effect upon changes in critical parameters of the SOFC-GT system—most notably, the load bank (LB) disturbance and fuel cell (FC) cathode airflow parameters. The SOFC-GT simulator allows the testing of various FC models under a cyber-physical configuration that incorporates a 120 kW auxiliary power unit and balance-of-plant (Bop) components. These components exist in hardware, whereas the FC model in software. The adaptation technique is beneficial to plants having a wide range of operation, as is the case for SOFC-GT systems. The practical implementation of the adaptive methodology is presented through simulation in the matlab/simulink environment.

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Thermal modeling of a solid oxide fuel cell and micro gas turbine hybrid power system based on modified LS-SVM

International Journal of Hydrogen Energy ◽

10.1016/j.ijhydene.2010.08.022 ◽

2011 ◽

Vol 36 (1) ◽

pp. 885-892 ◽

Cited By ~ 32

Author(s):

Xiao-Juan Wu ◽

Qi Huang ◽

Xin-Jian Zhu

Keyword(s):

Fuel Cell ◽

Power System ◽

Solid Oxide Fuel Cell ◽

Gas Turbine ◽

Thermal Modeling ◽

Solid Oxide ◽

Oxide Fuel ◽

Hybrid Power System ◽

Micro Gas Turbine ◽

Hybrid Power

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System Configuration and Performance Studies of Solid Oxide Fuel Cell -Gas Turbine Hybrid Cycle

ASME/JSME 2007 Thermal Engineering Heat Transfer Summer Conference, Volume 2 ◽

10.1115/ht2007-32671 ◽

2007 ◽

Author(s):

Wei Jiang ◽

Ruxian Fang ◽

Jamil A. Khan ◽

Roger A. Dougal

Keyword(s):

Fuel Cell ◽

Power Plant ◽

Solid Oxide Fuel Cell ◽

Gas Turbine ◽

Finite Volume ◽

Hybrid System ◽

High Energy ◽

Solid Oxide ◽

Oxide Fuel ◽

Hybrid Cycle

Fuel Cell is widely regarded as a potential alternative in the electric utility due to its distinct advantages of high energy conversion efficiency, low environmental impact and flexible uses of fuel types. In this paper we demonstrate the enhancement of thermal efficiency and power density of the power plant system by incorporating a hybrid cycle of Solid Oxide Fuel Cell (SOFC) and gas turbine with appropriate configurations. In this paper, a hybrid system composed of SOFC, gas turbine, compressor and high temperature heat exchanger is developed and simulated in the Virtual Test Bed (VTB) computational environment. The one-dimensional tubular SOFC model is based on the electrochemical and thermal modeling, accounting for the voltage losses and temperature dynamics. The single cell is discretized using a finite volume method where all the governing equations are solved for each finite volume. Simulation results show that the SOFC-GT hybrid system could achieve a 70% total electrical efficiency (LHV) and an electrical power output of 853KW, around 30% of which is produced by the power turbine. Two conventional power plant systems, i.e. gas turbine recuperative cycle and pure Fuel Cell power cycle, are also simulated for the performance comparison to validate the improved performance of Fuel Cell/Gas Turbine hybrid system. Finally, the dynamic behavior of the hybrid system is presented and analyzed based on the system simulation.

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