The aim of this work is the experimental validation of a steady-state and transient ejector model for high temperature fuel cell hybrid system applications. This is a mandatory step in performing the steady state and the transient analysis of the whole plant to avoid critical situations and to develop the control system. The anodic recirculation test rig, developed at TPG-University of Genoa, and already used in previous works to validate the ejector design models (0D and computational fluid dynamics), was modified and used to perform tests at transient conditions with the aim of ejector transient model validation. This ejector model, based on a “lumped volume” technique, has been successfully validated against experimental data at steady-state and transient conditions using air or $CO2$ at room temperature and at $150°C$ in the secondary duct inlet. Then, the ejector model was integrated with the models of the connecting pipes, and with the volume simulation tool, equipped with an outlet valve, in order to generate an anodic recirculation model. Also in this case, the theoretical results were successfully compared with the experimental data obtained with the test rig. The final part of the paper is devoted to the results obtained with square wave functions generated in the ejector primary pressure. To study the effects of possible fast pressure variations in the fuel line (ejector primary line), the test rig was equipped with a servo-controlled valve upstream of the ejector primary duct to generate different frequency pressure oscillations. The results calculated with the recirculation model at these conditions were successfully compared with the experimental data too.

1.
Agnew
,
G. D.
,
Bozzolo
,
M.
,
Moritz
,
R. R.
, and
Berenyi
,
S.
, 2005, “
The Design and Integration of the Rolls-Royce Fuel Cell Systems 1MW SOFC
,” ASME Paper No. 2005-GT-69122.
2.
Agnew
,
G. D.
,
Townsend
,
J.
,
Moritz
,
R. R.
,
Bozzolo
,
M.
,
Berenyi
,
S.
, and
Duge
,
R.
, 2004, “
Progress in the Development of a Low Cost 1MW SOFC Hybrid
,” ASME Paper No. 2004-GT-53350.
3.
2004,
Technical Meeting
,
Genoa
, May, PIP-SOFC European Project No. NNE5-2001-00791.
4.
Johannesen
,
N. H.
, 1951, “
Ejector Theory and Experiments
,” Transactions of the Danish Academy of Technical Sciences A.T.S. No. 1.
5.
Chen
,
Y. M.
, and
Sun
,
C. Y.
, 1997, “
Experimental Study of the Performance Characteristic of a Steam-Ejector Refrigeration System
,”
Exp. Therm. Fluid Sci.
0894-1777,
15
,
384
394
.
6.
Sun
,
D. W.
,
Eames
,
I. W.
, and
Aphornratana
,
S.
, 1995, “
Evaluation of a Novel Combined Ejector-Absorption Refrigeration Cycle—I: Computer Simulation
,”
Int. J. Refrig.
0140-7007,
19
, pp.
172
180
.
7.
Marini
,
M.
,
Massardo
,
A. F.
,
Satta
,
A.
, and
Geraci
,
M.
, 1992, “
Low Area Ratio Aircraft Fuel Jet-Pump Performance With and Without Cavitation
,”
ASME J. Fluids Eng.
0098-2202,
114
, pp.
626
631
.
8.
Marsano
,
F.
,
Magistri
,
L.
, and
Massardo
,
A. F.
, 2004, “
Ejector Performance Influence on a Solid Oxide Fuel Cell Anodic Recirculation System
,”
J. Power Sources
0378-7753,
129
, pp.
216
228
.
9.
Ferrari
,
M. L.
,
Traverso
,
A.
, and
Massardo
,
A. F.
, 2004, “
Transient Analysis of Solid Oxide Fuel Cell Hybrids. Part B: Anode Recirculation Model
,” ASME Paper No. 2004-GT-53716.
10.
Bernardi
,
D.
,
Bozzolo
,
M.
,
Marsano
,
F.
,
Tarnowski
,
O.
, and
Agnew
,
G.
, 2005, “
,” ASME Paper No. 2005-GT-68085.
11.
Ferrari
,
M. L.
,
Bernardi
,
D.
, and
Massardo
,
A. F.
, 2006, “
Design and Testing of Ejectors for High Temperature Fuel Cell Hybrid Systems
,”
ASME J. Fuel Cell Sci. Technol.
1550-624X,
3
, pp.
284
291
.
12.
Roberts
,
R. A.
,
Jabbari
,
F.
,
Brouwer
,
J.
,
Gemmen
,
R. S.
, and
Liese
,
E. A.
, “
Inter-Laboratory Dynamic Modelling of a Carbonate Fuel Cell for Hybrid Application
,” ASME Paper No. 2003-GT-38774.
13.
Shelton
,
M.
,
Celik
,
I.
,
Liese
,
E.
, and
Tucker
,
D.
, 2005, “
A Study in the Process Modeling of the Startup of Fuel Cell/Gas Turbine Hybrid Systems
,” ASME Paper No. 2005-GT-68466.
14.
Shelton
,
M.
,
Celik
,
I.
,
Liese
,
E.
,
Tucker
,
D.
, and
Lawson
,
L.
, 2005, “
A Transient Model of a Hybrid Fuel Cell/Gas Turbine Test Facility Using Simulink
,” ASME Paper No. 2005-GT-68467.
15.
Stiller
,
C.
,
Thorud
,
B.
, and
Bolland
,
O.
, 2005, “
Safe Dynamic Operation of a Simple SOFC/GT Hybrid System
,” ASME Paper No. 2005-GT-68481.
16.
Ferrari
,
M. L.
, 2003, “
Dynamic Model of the Anodic Side Recirculation of Solid Oxide Fuel Cells in Hybrid Systems
,” MS thesis, University of Genoa, Genoa, Italy, in Italian.
17.
Hirscenhofer
,
J. H.
,
Stauffer
,
D. B.
,
Engleman
,
R. R.
, and
Klett
,
M. G.
, 1998, “
Fuel Cell Handbook
,”
US Department of Energy
, Report No. DOE/FETC-99/1076.
18.
Ferrari
,
M. L.
,
Magistri
,
L.
,
Traverso
,
A.
, and
Massardo
,
A. F.
, 2005, “
Control System for Solid Oxide Fuel Cell Hybrid Systems
,” ASME Paper No. 2005-GT-68102.
19.
Drummond
,
C. K.
, 1991, “
Transient Flow Thrust Prediction for an Ejector Propulsion Concept
,” AIAA Paper No. 89-2906.
20.
Ferrari
,
M. L.
, 2006, “
Transient Analysis of Solid Oxide Fuel Cell Hybrid Plants and Control System Development
,” Ph.D. thesis, University of Genoa, Genoa, Italy.
21.
Traverso
,
A.
, 2005, “
TRANSEO Code for the Dynamic Simulation of Micro Gas Turbine Cycles
,” ASME Paper No. 2005-GT-68101.
22.
Traverso
,
A.
, 2004, “
TRANSEO: A New Simulation Tool for Transient Analysis of Innovative Energy Systems
,” Ph.D. thesis, University of Genoa, Genoa, Italy.
23.
2006, FELICITAS European Project No. TIP4-CT-2005-516270, First Year Report.
24.
Costabile
,
L.
, 2005, “
Experimental Analysis of Anodic and Cathodic Recirculations for Solid Oxide Fuel Cell Based Hybrid Systems
,” MS thesis, University of Genoa, Genoa, Italy, in Italian.
25.
2005, Technical Meeting,
Røskilde
, May, PIP-SOFC European Project No. NNE5-2001-00791.
26.
International Organization for Standardization
, 1993, “
Guide to the Expression of Uncertainty in Measurement
.”
27.
Marsano
,
F.
,
Magistri
,
L.
,
Bozzolo
,
M.
, and
Tarnowski
,
O.
, 2004, “
Influence of Fuel Composition on Solid Oxide Fuel Cell Hybrid System Layout and Performance
,” ASME Paper No. GT2004-53853.
28.
Traverso
,
A.
,
Ferrari
,
M. L.
,
Pascenti
,
M.
, and
Massardo
,
A. F.
, 2006, “
Physical Simulator of Start-Up for Hybrid System Cathode Side
,”
Fourth International Conference on Fuel Cell Science, Engineering and Technology
,
Irvine, CA
, Paper No. FUELCELL2006-97051.