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

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 2 Modelling And Assessment Of Compressor Faults On Marine Gas Turbines  MODELLING ASPECTS  Engine Adaptive Model  Compressor Adaptive Model  Compressor Faults Simulation and Modelling  Zooming Feature  Ship Mission Analysis Model  CASE STUDY  Fouling  Tip Clearance Increase  Erosion  SUMMARY & CONCLUSIONS

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

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

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 5 Diagnosis  Use of the same modification factors for engine component diagnosis f 1 ~W f 2 ~n p f 3 ~Δp b f 4 ~n b f 5 ~W f 6 ~n p

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 6 Compressor Faults Modelling 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 Higher Fidelity Compressor Model is utilized for Fault Simulation

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 7 Adaptive Stage Stacking Adaptive Stage Stacking Method Typical Adaptation Results 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

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

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 9  Fault distribution (N i )*  Effect of the fault at the performance characteristics of the stage that is most susceptible to fouling (M Φ,M Ψ, M η )** Compressor Fouling Compressor Faults Modelling Φ ref,fault /Φ ref Ψ ref,fault /Ψ ref η ref,fault /η ref MiMi *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 : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 10 Twin Shaft Engine with Higher Fidelity Compressor

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

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 12 Modelling And Assessment Of Compressor Faults On Marine Gas Turbines  MODELLING ASPECTS  Engine Adaptive Model  Compressor Adaptive Model  Compressor Faults Modelling and Simulation  Zooming Feature  Ship Mission Analysis Model  CASE STUDY  Fouling  Tip Clearance Increase  Erosion  SUMMARY & CONCLUSIONS

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 13 Assessment and Analysis of Compressor Faults Test Case Operating profile for the test case vessel Generic naval vessel, CODOG propulsion system with 2 Gas Turbines engaged for speeds greater than 20 knots  It 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 : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 14  Fault distribution (N i )*  Effect of the fault at the performance characteristics of the stage that is most susceptible to fouling (M Φ,M Ψ, M η )** Compressor Fouling Modelling Assessment and Analysis of Compressor Faults Φ ref,fault /Φ ref Ψ ref,fault /Ψ ref η ref,fault /η ref MiMi *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 : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 15 Fouling  Fouling decreases the compressor swallowing capacity and efficiency.  For the fault severity considered here the surge margin reduction is rather small. Assessment and Analysis of Compressor Faults

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 16 Fouling  The increase of specific fuel consumption due to fouling increases for higher power demand.  The fouling severity examined here results to the increase of the total consumed fuel by approximately 1%.  Emissions: NOx +2.5%, CO and UHC decrease (higher TIT). Assessment and Analysis of Compressor Faults

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 17  Fault distribution (N i )*  Effect of the fault at the performance characteristics of the stage that is most susceptible to fouling (M Φ,M Ψ, M η )** *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. Compressor Tip Clearance Increase Modelling Φ ref,fault /Φ ref Ψ ref,fault /Φ ref η ref,fault /η ref MiMi Assessment and Analysis of Compressor Faults

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

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 19 Tip Clearance Increase  The increase on specific fuel consumption at part-load operation is significant.  The increasing impact of the fault during part-load operation results to an increase of the block fuel by 2.4%,  Emissions: NOx +5.3%, CO and UHC decrease (higher TIT). Assessment and Analysis of Compressor Faults

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 20  Fault distribution (N i )*  Effect of the fault at the performance characteristics of the stage that is most susceptible to fouling (M Φ,M Ψ, M η )** *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 Compressor Blade Erosion Modelling Φ ref,fault /Φ ref Ψ ref,fault /Φ ref η ref,fault /η ref MiMi Assessment and Analysis of Compressor Faults

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

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 22 Blade Erosion  The increase on specific fuel consumption is increasing with decreasing power setting.  The engine performance deterioration due to erosion results to an increase of the total consumed fuel by almost 1.7%.  Emissions: NOx +3.5%, CO and UHC decrease (higher TIT). Assessment and Analysis of Compressor Faults

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 23 Fault Signatures  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: T48, EGT).  The GG speed exhibits an interesting behavior from a diagnostic point of view. Different faults produce different fault signatures. Assessment and Analysis of Compressor Faults

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY Engine Level Diagnosis f1,f2,f5,f6 24 Diagnostic Procedure Measurements W CDP CDT EGT Compressor fault Stage Level Diagnosis M Φ, Μ Ψ, Μ η Compressor Fault

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 25 Modelling And Assessment Of Compressor Faults On Marine Gas Turbines  MODELLING ASPECTS  Engine Adaptive Model  Compressor Adaptive Model  Compressor Faults Modelling and Simulation  Zooming Feature  Ship Mission Analysis Model  CASE STUDY  Fouling  Tip Clearance Increase  Erosion  SUMMARY & CONCLUSIONS

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 26 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%. Summary & Conclusions

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 27 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. Summary & Conclusions

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

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 29

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 30 Emissions Prediction NOx (Lefebvre correlation) CO, UHC (Rizk & Mognia correlations) P 3 : combustor inlet pressure, V c : combustor volume, T st : flame temperature for stoichiometric combustion, W: inlet air flow, T pz : primary zone temperature, (ΔP 3 /P 3 ): dimensionless pressure drop, F: air fraction at primary zone, t res :residence time in the combustor chamber, t ev : fuel evaporation time.

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 31 Model adaptation to multiple point performance data.

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 32

GT : Modelling And Assessment Of Compressor Faults On Marine Gas Turbines LABORATORY OF THERMAL TURBOMACHINES NATIONAL TECHNICAL UNIVERSITY OF ATHENS SECTION OF NAVAL ARCHITECTURE & MARINE ENGINEERING HELLENIC NAVAL ACADEMY 33