Abstract
A dynamic model of a 100 MW solid oxide fuel cell-gas turbine (SOFC-GT) hybrid system has been developed and subjected to perturbations in diurnal ambient temperature and pressure as well as load sheds. The dynamic system responses monitored were the fuel cell electrolyte temperature, gas turbine shaft speed, turbine inlet temperature and compressor surge. Using a control strategy that primarily focuses on holding fuel cell electrolyte temperature constant and secondarily on maintaining gas turbine shaft speed, safe operation was found to occur for expected ambient pressure variation ranges and for ambient temperature variations up to 28 K, when tested non-simultaneously. When ambient temperature and pressure were varied simultaneously, stable operation was found to occur when the two are in phase but not when the two are out of phase. The latter case leads to shaft over-speed. Compressor surge was found to be more likely when the system is subjected to a load shed initiated at minimum ambient temperature rather than at maximum ambient temperature. Fuel cell electrolyte temperature was found to be well-controlled except in the case of shaft over-speeds. Turbine inlet temperature remained in safe bounds for all cases.
Highlights
In this study a dynamic Simulink model of a 100 MW solid oxide fuel cellgas turbine (SOFC-GT) operating on coal syngas is subjected to perturbations from steady state operation and the dynamic response is observed
The goals of the study are to establish and quantify the dynamic response of the turbo-machinery in hybrid solid oxide fuel cell (SOFC)-GT power blocks designed for use in integrated gasification fuel cell system (IGFC) applications, and, to delineate failure mechanisms and the means to mitigate failure mechanisms
The model approach, developed by the National Fuel Cell Research Center (NFCRC) for these purposes, has been extensively peer-reviewed and validated using dynamic experimental data from a 220 kW SiemensWestinghouse SOFC-GT system tested at the NFCRC [15,16,17,18,19,20,21,22,23,24]
Summary
In this study a dynamic Simulink model of a 100 MW SOFC-GT operating on coal syngas is subjected to perturbations from steady state operation and the dynamic response is observed. The goals of the study are to establish and quantify the dynamic response of the turbo-machinery in hybrid SOFC-GT power blocks designed for use in IGFC applications, and, to delineate failure mechanisms and the means to mitigate failure mechanisms. The model approach, developed by the National Fuel Cell Research Center (NFCRC) for these purposes, has been extensively peer-reviewed and validated using dynamic experimental data from a 220 kW SiemensWestinghouse SOFC-GT system tested at the NFCRC [15,16,17,18,19,20,21,22,23,24]. MODEL AND OPERATING CONDITIONS has led to the concept of an integrated gasification fuel cell system (IGFC). The law of continuity is applied on a molar basis assuming a well-stirred reactor
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
