SECTION OF NAVAL ARCHITECTURE MARINE ENGINEERING HELLENIC NAVAL

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS MODELLING AND ASSESSMENT OF COMPRESSOR FAULTS ON MARINE GAS TURBINES I. Roumeliotis 1, N. Aretakis 2, K. Mathioudakis 2, E. A. Yfantis 1 Presented by: A. Alexiou 1 Section of Naval Architecture & Marine Engineering Hellenic Naval Academy 2 Laboratory of Thermal Turbomachines National Technical University of Athens GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 1

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Modelling And Assessment Of Compressor Faults On Marine Gas Turbines ØMODELLING ASPECTS §Engine Adaptive Model §Compressor Faults Simulation and Modelling §Zooming Feature §Ship Mission Analysis Model ØCASE STUDY §Fouling §Tip Clearance Increase §Erosion ØSUMMARY & CONCLUSIONS GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 2

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Engine Adaptive and Performance Model GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 3

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Engine Adaptive and Performance Model Transformation of component performance maps (modification factors) Typical Adaptation Results GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 4

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Diagnosis ØUse of the same modification factors for engine component diagnosis f 1~W f 3~Δpb f 2~np f 4~nb f 5~W f 6~np GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 5

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Compressor Faults Modelling Higher Fidelity Compressor Model is utilized for Fault Simulation • MFs relations, derived from measurements, for different faults are not available in the literature • Scaling the map using MFs obtained at a specific rotational speed may not be suitable for other rotational speeds • The possible effect of the fault on the surge line can not be evaluated • The effect of IGVs and VSVs faults can not be evaluated • The influence of compressor specific characteristics on the fault effect, like stage loading distribution, can not be evaluated GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 6

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Adaptive Stage Stacking • Establishment of Compressor Stall Limits • Determination of the Effect of Bleeds and Variable Geometry • Derivation of Individual Stage Characteristics for specific compressor data using MFs Adaptive Stage Stacking Method Typical Adaptation Results GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 7

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Compressor Faults Modelling Modification Factors for Faults - Simulation Fault Severity Factor Distribution Factor Transformation factors: Modification factors for the most affected stage GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 8

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Compressor Faults Modelling Compressor Fouling ØFault distribution (Ni)* ØEffect of the fault at the performance characteristics of the stage that is most susceptible to fouling (MΦ, MΨ, Mη)** Mi Φref, fault/Φref Ψref, fault/Ψref ηref, fault/ηref 0. 986 0. 970 0. 966 *Tarabrin A. P. , Schurovsky V. A. , Bodrov A. I. , Stadler J-P, 1998, ASME Paper No. 98 -GT-416 **Suder, K. L. , Chima, R. V, Strazisar, A. J, Roberts, W. B, 1994, ASME Paper No. 94 -GT-339. GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 9

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Twin Shaft Engine with Higher Fidelity Compressor GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 10

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Ship Mission Analysis Model GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 11

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Modelling And Assessment Of Compressor Faults On Marine Gas Turbines ØMODELLING ASPECTS §Engine Adaptive Model §Compressor Faults Modelling and Simulation §Zooming Feature §Ship Mission Analysis Model ØCASE STUDY §Fouling §Tip Clearance Increase §Erosion ØSUMMARY & CONCLUSIONS GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 12

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Assessment and Analysis of Compressor Faults Test Case Generic naval vessel, CODOG propulsion system with 2 Gas Turbines engaged for speeds greater than 20 knots Operating profile for the test case vessel ØIt is assumed that all faults have a severity that cause a reduction of the power output by 4% when the engine operates at the maximum continuous rating, as defined by the TIT. GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 13

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Assessment and Analysis of Compressor Faults Compressor Fouling Modelling ØFault distribution (Ni)* ØEffect of the fault at the performance characteristics of the stage that is most susceptible to fouling (MΦ, MΨ, Mη)** Mi Φref, fault/Φref Ψref, fault/Ψref ηref, fault/ηref 0. 986 0. 970 0. 966 *Tarabrin A. P. , Schurovsky V. A. , Bodrov A. I. , Stadler J-P, 1998, ASME Paper No. 98 -GT-416 **Suder, K. L. , Chima, R. V, Strazisar, A. J, Roberts, W. B, 1994, ASME Paper No. 94 -GT-339. GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 14

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Assessment and Analysis of Compressor Faults Fouling Ø Fouling decreases the compressor swallowing capacity and efficiency. Ø For the fault severity considered here the surge margin reduction is rather small. GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 15

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Assessment and Analysis of Compressor Faults Fouling Ø The increase of specific fuel consumption due to fouling increases for higher power demand. Ø The fouling severity examined here results to the increase of the total consumed fuel by approximately 1%. Ø Emissions: NOx +2. 5%, CO and UHC decrease (higher TIT). GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 16

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Assessment and Analysis of Compressor Faults Compressor Tip Clearance Increase Modelling ØFault distribution (Ni)* ØEffect of the fault at the performance characteristics of the stage that is most susceptible to fouling (MΦ, MΨ, Mη)** Mi Φref, fault/Φref Ψref, fault/Φref ηref, fault/ηref 0. 965 0. 931 0. 928 *Zaita A. K. , Buley G, Karslons G. , 1997, ASME Paper No. 97 -GT-278 **Inoue M. , Kuroumaru M. , Fukuhara M. , 1985, ASME Paper No. 85 -GT-62. GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 17

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Assessment and Analysis of Compressor Faults Tip Clearance Increase Ø Tip clearance increase can be a potential problem with respect to surge margin during low power operation GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 18

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Assessment and Analysis of Compressor Faults Tip Clearance Increase Ø The increase on specific fuel consumption at part-load operation is significant. Ø The increasing impact of the fault during part-load operation results to an increase of the block fuel by 2. 4%, Ø Emissions: NOx +5. 3%, CO and UHC decrease (higher TIT). GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 19

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Assessment and Analysis of Compressor Faults Compressor Blade Erosion Modelling ØFault distribution (Ni)* ØEffect of the fault at the performance characteristics of the stage that is most susceptible to fouling (MΦ, MΨ, Mη)** Mi Φref, fault/Φref Ψref, fault/Φref ηref, fault/ηref 0. 971 0. 899 0. 967 *Tabakoff W. , Lakshminarasimha A. N. , Pasin M. , 1989, ASME Paper No. 89 -GT-182 **Reid L. , Urasek D. C. , 1973, ASME J Eng Gas Turbines Power, 95(3), pp 199 -204. GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 20

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Assessment and Analysis of Compressor Faults Blade Erosion Ø The surge margin is noticeably reduced for the whole operating envelope of the engine GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 21

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Assessment and Analysis of Compressor Faults Blade Erosion Ø The increase on specific fuel consumption is increasing with decreasing power setting. Ø The engine performance deterioration due to erosion results to an increase of the total consumed fuel by almost 1. 7%. Ø Emissions: NOx +3. 5%, CO and UHC decrease (higher TIT). GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 22

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Assessment and Analysis of Compressor Faults Fault Signatures Ø The most suitable quantities for fault detection are different if operating points of the same TIT or the same power are compared (Same TIT: W, CDP, Wf, Same Power: T 48, EGT). Ø The GG speed exhibits an interesting behavior from a diagnostic point of view. Different faults produce different fault signatures. GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 23

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Diagnostic Procedure W CDP CDT EGT Engine Level Diagnosis Measurements Compressor Fault f 1, f 2, f 5, f 6 Compressor fault Stage Level Diagnosis MΦ, ΜΨ, Μη GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 24

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Modelling And Assessment Of Compressor Faults On Marine Gas Turbines ØMODELLING ASPECTS §Engine Adaptive Model §Compressor Faults Modelling and Simulation §Zooming Feature §Ship Mission Analysis Model ØCASE STUDY §Fouling §Tip Clearance Increase §Erosion ØSUMMARY & CONCLUSIONS GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 25

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Summary & Conclusions • An engine performance model with an integrated compressor zooming capability was employed for simulating compressor faulty operation. • The engine model is coupled to a marine vessel’s mission analysis model, thus allowing the prediction of the gas turbine off design operation in connection to the vessel’s operation. • Specific Fuel Consumption effect is depending on power setting. Fouling effect is more severe at high power settings while tip clearance increase and erosion at part load operation. • Block Fuel: Fouling has the smallest impact in the range of 1%, while tip clearance increase has the largest one, in the range of 2. 4%. GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 26

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS Summary & Conclusions • Surge Margin: Fouling effect is negligible. Tip clearance increase results to significant reduction at low speeds. Erosion effect is noticeable for the whole operating envelope. • The gas generator speed exhibit a distinctly different behaviour for the three faults simulated. • The engine model can be adapted to specific compressor and engine performance data. • The engine model can be used for component fault diagnosis, as part of a prognostic procedure but also as a teaching tool. • The integrated tool can be used as part of a technoeconomic analysis procedure. GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 27

SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS GT-2012 -69740: Modelling And Assessment Of Compressor Faults On Marine Gas Turbines 28