With regards to the overhaul of the PG9171E #2 gas turbine genset of Suzhou Blue Sky Power Plant., carried by  Nanguang Power Equipment Installation (Nanjing) Co. Ltd., It took only 31 days from Sep. 22, 2008 the initiation to Oct. 22, 2008 when the unit could be put for power generation, which set a record of the shortest time for overhauling the same type of unit.

 

Since Suzhou Blue Sky is our old customer, we attached much importance to overhauling the gas turbine unit Before overhaul, we had started careful preparation by mobilizing a work team with strong technical competence and complete work types. During the construction, our company leaders visited the scene to encourage the site personnel for many times, largely activating site personnel¡¯s enthusiasm. Meanwhile, different levels of leaders and related technicians from Suzhou Blue Sky provided with support and assistance. With their assistance appropriate, responsible, diligent and swift, we saved time for the overhaul, ensuring successful completion of the overhaul project.

 

Work scope of #2 gas turbine mainly as follows:

 

1.       Overhauling combustion system including fuel nozzles, combustion liner, crossfire tube, and transition pieces;

2.       Inspecting and cleaning inlet system;

3.       Cleaning and inspecting compressor IGV, measuring clearance, and testing startup motor of adjustable guide vanes;

4.       Inspecting compressor by uncovering casing, improving fixing method by adopting adjustable gasket, and detecting rotor and stationary blades;

5.       Treating air leakage between No. 2 bearing oil return tube and fixed flange on casing;

6.       Lifting turbine rotor out of casing, and detecting rotors at the 1^st, 2^nd and 3^rd stages;

7.       Replacing nozzles at 1^st stage in turbine; inspecting nozzles in 2^nd and 3^rd stages;

8.       Inspecting shrouds at turbine 1^st, 2^nd and 3^rd stages;

9.       Inspecting warm keeping state and cracks inside of exhaust chamber, and welding cracks; inspecting cracks, erosion and deformation etc. outside of exhaust chamber and exhaust diffuser, and welding cracks;

10.   Inspecting surface abrasion, scoring, galling, etc.; measuring clearance between bearing parts; replacing #2 and #3 bearing shells;

11.   Inspecting oil seals forward and backward bearings #1, #2 and #3, measuring clearances, and replacing oil seals forward and backward bearings #2 and #3;

12.   Laser alignment of bearing seats;

13.   Alignment of turbine bearing system;

14.   Application of high temp silver powder coating on bodies of turbine compressor casing and turbine casing, as well as on surface of exhaust diaphragm;

15.   Inspecting accessory gear box, coupling, etc.;

16.   Overhauling starting motor and cranking motor;

17.   Disassembly inspection on pressure ratio valves, control valves, and 20 VG solenoid valves in natural gas cabinet;

18.   Maintenance of parts in forward filtration skid for natural gas;

19.   Disassembly inspection on motors and pumps in lube oil system, hydraulic oil system, jacking oil system, cooling water system, cooling sealing air system, etc.;

20.   Inspection and maintenance of CO2 fire fighting system;

21.   Inspecting and cleaning air cooling system in generator;

22.   Inspecting generator forward and backward bearings, and fluorescent detection of the bearing shells.

 

As required by the owner that the overhaul be completed before the date of grid connection for power generation regulated by the local provincial authorities, and furthermore, on the basis of original overhaul plan, the laser alignment was added, the overhaul project was becoming more difficult but had to be finished in shorter time. However, in order to meet the owner¡¯s demands, the site team of our company, with the daring spirits, often worked overtime but under assurance of construction safety and quality the priority. Through our mutual endeavor, eventually we finished the overhaul project before schedule.

 

Translated by Wang Yifei Checked by Donald hwang