The effect of cathode airflow variation on the dynamics of a fuel cell gas turbine hybrid system was evaluated using a cyber-physical emulator. The coupling between cathode airflow and other parameters, such as turbine speed or pressure, was analyzed comparing the results at fixed and variable speed. In particular, attention was focused on fuel cell temperatures and gradients: cathode airflow, which is generally employed for thermal management of the stack, was varied by manipulating a cold-air bypass. A significant difference was observed in the two cases in terms of turbine inlet, exhaust gas, cathode inlet, and average cell temperatures. When the turbine speed was held constant, a change in cathode airflow resulted in a strong variation in cathode inlet temperature, while average cell temperature was not significantly affected. The opposite behavior was observed at variable speed. The system dynamics were analyzed in detail in order to explain this difference. Open-loop response was analyzed in this work for its essential role in system identification. However, a significant difference was observed between fixed and variable speed cases, because of the high coupling between turbine speed and cathode airflow. These results can give a helpful insight of system dynamics and control requirements. Cold-air valve bypass position also showed a strong effect on surge margin and pressure dynamics in both cases.

References

References
1.
Mueller
,
F.
,
Gaynord
,
R.
,
Auld
,
A. E.
,
Brouwer
,
J.
,
Jabbari
,
F.
, and
Samuelsen
,
S.
,
2008
, “
Synergistic Integration of a Gas Turbine and Solid Oxide Fuel Cell for Improved Transient Capability
,”
J. Power Sources
,
176
(
1
), pp.
229
239
.
2.
Veyo
,
S. E.
,
Shockling
,
L. A.
,
Dederer
,
J. T.
,
Gillet
,
J. E.
, and
Lundberg
,
W. L.
,
2002
, “
Tubular Solid Oxide Fuel Cell/Gas Turbine Hybrid Cycle Power Systems: Status
,”
ASME J. Eng. Gas Turbines Power
,
124
(
4
), pp.
845
849
.
3.
Rao
,
A. D.
, and
Samuelsen
,
G. S.
,
2002
, “
Analysis Strategies for Tubular Solid Oxide Fuel Cell Based Hybrid Systems
,”
ASME J. Eng. Gas Turbines Power
,
124
(
3
), pp.
503
509
.
4.
Tucker
,
D.
,
Liese
,
E.
, and
Gemmen
,
R.
,
2009
, “
Determination of the Operating Envelope for a Direct Fired Fuel Cell Turbine Hybrid Using Hardware Based Simulation
,”
ICEPAG
2009 International Colloquium on Environmentally Preferred Advanced Power Generation
, Newport Beach, CA, Feb. 10–12, Paper No. ICEPAG2009-1021.
5.
Tucker
,
D.
,
Abreu-Sepulveda
,
M.
, and
Harun
,
N. F.
,
2014
, “
SOFC Lifetime Assessment in Gas Turbine Hybrid Power Systems
,”
ASME J. Fuel Cell Sci. Technol.
,
11
(
5
), p.
051008
.
6.
Liese
,
E. A.
,
Gemmen
,
R. S.
,
Jabbari
,
F.
, and
Brouwer
,
J.
,
1999
, “
Technical Development Issues and Dynamic Modeling of Gas Turbine and Fuel Cell Hybrid System
,”
ASME
Paper No. 99-GT-360.
7.
Ferrari
,
M. L.
,
Pascenti
,
M.
,
Bertone
,
R.
, and
Magistri
,
L.
,
2009
, “
Hybrid Simulation Facility Based on Commercial 100 kW Micro Gas Turbine
,”
ASME J. Fuel Cell Sci. Technol.
,
6
(
3
), p.
031008
.
8.
Hohloch
,
M.
,
Widenhorn
,
A.
,
Lebküchner
,
D.
,
Panne
,
T.
, and
Aigner
,
M.
,
2008
, “
Micro Gas Turbine Test Rig for Hybrid Power Plant Application
,”
ASME
Paper No. GT2008-50443.
9.
Tucker
,
D.
,
Shelton
,
M.
, and
Manivannan
,
A.
,
2009
, “
The Role of Solid Oxide Fuel Cells in Advanced Hybrid Power Systems of the Future
,”
Interface
,
18
(
3
), pp.
45
48
.
10.
Tucker
,
D.
,
Smith
,
T. P.
, and
Lawson
,
L.
,
2006
, “
Characterization of Bypass Control Methods in a Coal-Based Fuel Cell Turbine Hybrid
,”
ICEPAG 2006 International Colloquium on Environmentally Preferred Advanced Power Generation
, Paper No. 2006-24008.
11.
Pezzini
,
P.
,
Celestine
,
S.
, and
Tucker
,
D.
,
2015
, “
Control Impacts of Cold-Air Bypass on Pressurized Fuel Cell Turbine Hybrids
,”
ASME J. Fuel Cell Sci. Technol.
,
12
(
1
), p.
011006
.
12.
Pezzini
,
P.
,
Banta
,
L.
,
Traverso
,
A.
, and
Tucker
,
D.
,
2014
, “
Decentralized Control Strategy for Fuel Cell Turbine Hybrid Systems
,”
ISA Power Industry Division Symposium
, Paper No. ISA-PWID2014-52.
13.
Zhou
,
N.
,
Yang
,
C.
, and
Tucker
,
D.
,
2015
, “
Evaluation of Cathode Air Flow Transients in a SOFC/GT Hybrid System Using Hardware in the Loop Simulation
,”
ASME J. Fuel Cell Sci. Technol.
,
12
(
1
), p.
011003
.
14.
Zhou
,
N.
,
Yang
,
C.
, and
Tucker
,
D.
,
2015
, “
Evaluation of Compressor Bleed Air Transients in a Fuel Cell Gas Turbine Hybrid System Using Hardware Simulation
,”
ASME
Paper No. GT2015-43596.
15.
Inui
,
Y.
,
Ito
,
N.
,
Nakajima
,
T.
, and
Urata
,
A.
,
2006
, “
Analytical Investigation on Cell Temperature Control Method of Planar Solid Oxide Fuel Cell
,”
Energy Convers. Manage.
,
47
(15–16), pp.
2319
1328
.
16.
Traverso
,
A.
,
Magistri
,
L.
, and
Massardo
,
A. F.
,
2010
, “
Turbomachinery for Air Management and Energy Recovery in Fuel Cell Gas Turbine Hybrid Systems
,”
Energy
,
35
(
2
), pp.
764
777
.
17.
Zhou
,
N.
,
Yang
,
C.
,
Tucker
,
D.
,
Pezzini
,
P.
, and
Traverso
,
A.
,
2014
, “
Transfer Function Development for Control of Cathode Airflow Transients in Fuel Cell Gas Turbine Hybrid Systems
,”
Int. J. Hydrogen Energy
,
40
(
4
), pp.
1967
1979
.
18.
Zaccaria
,
V.
,
Tucker
,
D.
, and
Traverso
,
A.
,
2016
, “
Transfer Function Development for SOFC/GT Hybrid Systems Control Using Cold Air Bypass
,”
Appl. Energy
,
165
, pp.
695
706
.
19.
Barelli
,
L.
,
Bidini
,
G.
, and
Ottaviano
,
A.
,
2013
, “
Part Load Operation of a SOFC/GT Hybrid System: Dynamic Analysis
,”
Appl. Energy
,
110
, pp.
173
189
.
20.
Bakalis
,
D. P.
, and
Stamatis
,
A. G.
,
2013
, “
Incorporating Available Micro Gas Turbines and Fuel Cell: Matching Considerations and Performance Evaluation
,”
Appl. Energy
,
103
, pp.
607
617
.
21.
Magistri
,
L.
,
Bozzolo
,
M.
,
Tarnowski
,
O.
,
Agnew
,
G.
, and
Massardo
,
A. F.
,
2007
, “
Design and Off-Design Analysis of a MW Hybrid System Based on Rolls-Royce Integrated Planar Solid Oxide Fuel Cells
,”
ASME J. Eng. Gas Turbines Power
,
129
(
3
), pp.
792
797
.
22.
Komatsu
,
Y.
,
Kimijima
,
S.
, and
Szmyd
,
J. S.
,
2010
, “
Performance Analysis for the Part-Load Operation of a Solid Oxide Fuel Cell–Micro Gas Turbine Hybrid System
,”
Energy
,
35
(
2
), pp.
982
988
.
23.
Yang
,
W. J.
,
Park
,
S. K.
,
Kim
,
T. S.
,
Kim
,
J. H.
,
Sohn
,
J. L.
, and
Ro
,
S. T.
,
2006
, “
Design Performance Analysis of Pressurized Solid Oxide Fuel Cell/Gas Turbine Hybrid Systems Considering Temperature Constraints
,”
J. Power Sources
,
160
(
1
), pp.
462
473
.
24.
Jiang
,
W.
,
Fang
,
R.
,
Khan
,
J.
, and
Dougal
,
R.
,
2010
, “
Control Strategies for Start-Up and Part-Load Operation of Solid Oxide Fuel Cell/Gas Turbine Hybrid System
,”
ASME J. Fuel Cell Sci. Technol.
,
7
(
1
), p.
011016
.
25.
Ferrari
,
M. L.
, and
Massardo
,
A. F.
,
2013
, “
Cathode-Anode Side Interaction in SOFC Hybrid Systems
,”
Appl. Energy
,
105
, pp.
369
379
.
26.
Pezzini
,
P.
,
Tucker
,
D.
, and
Traverso
,
A.
,
2013
, “
Avoiding Compressor Stall and Surge During Emergency Shutdown in Hybrid Turbine Systems
,”
ASME J. Eng. Gas Turbines Power
,
135
(
10
), p. 102602.
27.
Al-Masri
,
A.
,
Peksen
,
M.
,
Blum
,
L.
, and
Stolten
,
D.
,
2014
, “
A 3D CFD Model for Predicting the Temperature Distribution in a Full Scale APU SOFC Short Stack Under Transient Operating Conditions
,”
Appl. Energy
,
135
, pp.
539
547
.
28.
Aguiar
,
P.
,
Adjiman
,
C. S.
, and
Brandon
,
N. P.
,
2005
, “
Anode-Supported Intermediate Temperature Direct Internal Reforming Solid Oxide Fuel Cell: II—Model-Based Dynamic Performance and Control
,”
J. Power Sources
,
147
(1–2), pp.
136
147
.
29.
Nakajo
,
A.
,
Stiller
,
C.
,
Härkegård
,
G.
, and
Bolland
,
O.
,
2006
, “
Modeling of Thermal Stresses and Probability of Survival of Tubular SOFC
,”
J. Power Sources
,
158
(
1
), pp.
287
294
.
30.
Nakajo
,
A.
,
Mueller
,
F.
,
Brouwer
,
J.
,
Van Herle
,
J.
, and
Favrat
,
D.
,
2012
, “
Progressive Activation of Degradation Processes in Solid Oxide Fuel Cells Stacks: Part I—Lifetime Extension by Optimisation of the Operating Conditions
,”
J. Power Sources
,
216
, pp.
449
463
.
31.
Larosa
,
L.
,
Traverso
,
A.
,
Ferrari
,
M.
, and
Zaccaria
,
V.
,
2015
, “
Pressurized SOFC Hybrid Systems: Control System Study and Experimental Verification
,”
ASME J. Eng. Gas Turbines Power
,
137
(3), p.
031602
.
32.
Fardadi
,
M.
,
Mueller
,
F.
, and
Jabbari
,
F.
,
2010
, “
Feedback Control of Solid Oxide Fuel Cell Spatial Temperature Variation
,”
J. Power Sources
,
195
(
13
), pp.
4222
4233
.
33.
Stiller
,
C.
,
Thorud
,
B.
,
Bolland
,
O.
,
Kandepu
,
R.
, and
Imsland
,
L.
,
2006
, “
Control Strategy for a Solid Oxide Fuel Cell and Gas Turbine Hybrid System
,”
J. Power Sources
,
158
(
1
), pp.
303
315
.
34.
Roberts
,
R. A.
,
Brouwer
,
J.
, and
Samuelsen
,
G. S.
,
2010
, “
Fuel Cell/Gas Turbine Hybrid System Control for Daily Load Profile and Ambient Condition Variation
,”
ASME J. Eng. Gas Turbines Power
,
132
(1), p. 012302.
35.
Ferrari
,
M. L.
,
2015
, “
Advanced Control Approach for Hybrid Systems Based on Solid Oxide Fuel Cells
,”
Appl. Energy
,
145
, pp.
364
373
.
36.
Mueller
,
F.
,
Jabbari
,
F.
, and
Brouwer
,
J.
,
2009
, “
On the Intrinsic Transient Capability and Limitations of Solid Oxide Fuel Cell Systems
,”
J. Power Sources
,
187
(
2
), pp.
452
460
.
37.
Roberts
,
R.
,
Brouwer
,
J.
,
Jabbari
,
F.
,
Junker
,
T.
, and
Ghezel-Ayagh
,
H.
,
2006
, “
Control Design of an Atmospheric Solid Oxide Fuel Cell/Gas Turbine Hybrid System: Variable Versus Fixed Speed Gas Turbine Operation
,”
J. Power Sources
,
161
(
1
), pp.
484
491
.
38.
Traverso
,
A.
,
Massardo
,
A.
,
Roberts
,
R. A.
,
Brouwer
,
J.
, and
Samuelsen
,
S.
,
2007
, “
Gas Turbine Assessment for Air Management of Pressurized SOFC/GT Hybrid Systems
,”
ASME J. Fuel Cell Sci. Technol.
,
4
(
4
), pp.
373
383
.
39.
Traverso
,
A.
,
Tucker
,
D.
, and
Haynes
,
C.
,
2012
, “
Preliminary Experimental Results of Integrated Gasification Fuel Cell Operation Using Hardware Simulation
,”
ASME J. Eng. Gas Turbines Power
,
134
(
7
), p.
071701
.
40.
Hughes
,
D.
,
Wepfer
,
W. J.
,
Davies
,
K.
,
Ford
,
J. C.
,
Haynes
,
C.
, and
Tucker
,
D.
,
2011
, “
A Real-Time Spatial SOFC Model for Hardware-Based Simulation of Hybrid Systems
,”
ASME
Paper No. FuelCell2011-54591.
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