GAS TURBINE OPERATION AND MAINTENANCE

1. GAS TURBINE OPERATION AND MAINTENANCE P2M FTUI September 2008

2. Operating Factors Affecting Maintenance • Type and quality of fuel • Condensate, contaminants, etc • Starting Frequency • Thermal cycles • Load cycles • Thermal cycles • Environment • Abrasive and corrosive condition

3. Inspection Interval • Following table shows the operating hours at which inspection should be performed for operation on gas fuel and continuous duty Recommended Inspection Interval Note: (1) Hours mean Ëquivalent Operating Hours”reflecting the operation conditions of Gas Turbines

4. “Roll-in and Roll-out” Procedure • One (1) complete set of hot parts shall be ready for Rolling-in. The parts taken out (Roll-out) shall be reused/repaired/rejuvenated prior to the next inspection

5. Summary of GT Inspection

6. Combustor Inspection • No 1. Compressor inlet (1) • No 2. Turbine blade row 4 (1) • No 3. Flame detector and igniter (2) • No 4. Fuel nozzle (2) • No 5. Combustor basket (2) • No 6. Transition piece (2)

7. Combustion Inspection Schedule(for one (1) Gas Turbine)

8. Turbine Inspection • No 1. Compressor inlet (1) • No 2. Flame detector and igniter (2) • No 3. Fuel nozzle (2) • No 4. Combustor basket (2) • No 5. Transition piece (2) • No 6. Turbine blade (2) • No 7. Turbine vane (2) • No 8. Compressor last row and OGV’s blade and diaphragm (1)

9. Turbine Inspection Schedule(for one (1) Gas Turbine)

10. Major Overhaul Inspection • No 1. Flame detector and igniter (1) • No 2. Fuel nozzle (1) • No 3. Combustor basket (1) • No 4. Transition piece (1) • No 5. Turbine blade (1) • No 6. Turbine vane (1) • No 7. Compressor blade and diaphragm • No 8. Exhaust turbine and compressor casing • No 9. Compressor blade ring • No 10. Turbine blade ring #1, #2, #3 and #4 • Turbine journal brg and thrust brg • Rotor (2)

11. Major Overhaul Inspection Schedule(for one (1) Gas Turbine)

12. Routine Maintenance

13. Hot Parts Expected Life Time • The expected life of hot parts has been established based on design strength and the result of past operating experiences. The expected hot parts life hours with qualified repairs are as follows:

14. Definition of “EOH”Equivalent Operating Hours • To calculate hours of operation equivalent to base load continuous duty operation, when operation has been with liquid fuel and/or cyclic duty, it is necessary to segregate the actual hours of operation by duty (fired hours per start) and fuel (gas or oil). These segregated values are then used in the following equation to calculate the hours equivalent to operation at base load with gas fuel. where, H = equivalent continuous duty gas fired hours BHG = base load operating hours with gas fuel BHO = base load operating hours with distillate oil fuel PHG = peak load operating hours with gas fuel PHO = peak load operating hours with distillate oil fuel CDF = cyclic duty factor, determined from the following table

15. Cyclic Duty Factor Table

16. Hot Parts Life Evaluation • Deterioration • Creep under High Temperature • Low Cycle Fatigue • Metal Loss by Surface Oxidation & Corrosion • Life diagnosis • Load Cycles • Start / Stop Frequency • Fuel Quality • Environment • Maintenance Practice Life diagnosis procedure is decided based on each customer’s operational conditions

17. Life Evaluation Method Evaluation for Maximum Use-up • Turbine Blade • Metallurgical Analysis • γ’ phase • Creep Rupture Property • Turbine Vane • Metallurgical Analysis • Precipitated Carbide • Tensile Property

18. Life Evaluation Process for Turbine Blade

19. Life Evaluation Process for Turbine Vane

20. Life Extension Technology Reheat Technology High temp. heating of deterioratedsuperalloy Decomposition & re-solution of hypertrophiedγ’ phase and intergranular carbide Standard heat treatment the material Recovery of mechanicalproperties