Advanced Outage Compression Methods for Steam Turbines. Nicholas Marsh 13 th February 2012

Transcription

1 Advanced Outage Compression Methods for Steam Turbines Nicholas Marsh 13 th February 2012

2 Agenda Introduction Page 3 Water Jet Cleaning Page 5 Water Jet Cutting Page 10 Automated Phased Array Ultrasonic Testing Page 15 Conclusion Page 21

3 Introduction Outage Optimisation Tasks Dismantling Surface preparation Inspection Repair Re-assembly Time savings In-situ work Speed and accuracy Remote support General Solutions Modern technology Automation

4 Agenda Introduction Page 3 Water Jet Cleaning Page 5 Water Jet Cutting Page 10 Automated Phased Array Ultrasonic Testing Page 15 Conclusion Page 21

5 Example 1 Water Jet Cleaning Background Reasons for cleaning To ensure safe operation To prepare for inspection To restore swallowing capacity* To increase efficiency* * Valid for blading HP rotor requiring cleaning Conventional Sand-Blasting Time consuming Poor quality control Requires component removal Limited accessibility Risk of damage

6 Water Jet Cleaning Newly patented by Alstom, with the following features: Hard abrasive at 3-5% mix Water and abrasive pre-mixing Pressure range: bar Hose Ø: <12mm Tungsten carbide fan jet nozzle Jet velocity: 150m/s (approx) Water recirculation Continuous operation Suspension system Manual tool

7 Water Jet Cleaning Air blasting Garnet 120 mesh + Glass beads 100µm 10µm Waterjet cleaning Corundum mesh µm 10µm

8 Water Jet Cleaning Advantages Minimal material removal Surface quality, Ra= 0.8µm (sandblasting Ra= 3.2µm) Reduction in cleaning time: 20% High mobility (cleaning in situ) Short installation time Improved steam path efficiency 3.5 Surface roughness Ra [µm] Dry blasting Water Jet Cleaning with Garnet Water Jet Cleaning with Corundum Water Jet Cleaning with Zirblast 125 Water Jet Cleaning with Zirblast 63

9 Agenda Introduction Page 3 Water Jet Cleaning Page 5 Water Jet Cutting Page 10 Automated Phased Array Ultrasonic Testing Page 15 Conclusion Page 21

10 Example 2 Water Jet Cutting Background Reasons for cutting Stuck component fixings (10% of blade root pins) Conventional Drilling Imprecise Time consuming Tools not mobile Risk of damage Blade root pins Drilling damage

11 Water Jet Cutting Method Push out pins with hydraulic system Cut into stuck pins to weaken them Parts Camera 5M pixels 40mm from abrasive jet Cutting head 10 mins (approx) per pin Different sizes available Catcher Placed behind pin Detects breakthrough Different sizes available

12 Water Jet Cutting Pin cutting procedure Set up robotics next to the steam turbine Fix system with clamping mechanism Set pin position using camera tool Set parameters for piercing and cutting Pierce a hole in the centre of the pin, cutting of rivet head Cut the pattern

13 Water Jet Cutting Pin Ø range Max pin length (l) Max pin l/ø ratio Min gap (discs) mm 200mm 14 60mm Advantages Reduction in process time Greater process control Improved reliability Elimination of EHS risks High mobility for on-site Low risk of damage

14 Agenda Introduction Page 3 Water Jet Cleaning Page 5 Water Jet Cutting Page 10 Automated Phased Array Ultrasonic Testing Page 15 Conclusion Page 21

15 Example 3 Phased Array UT Testing (i) LP blade roots Background Reasons for inspection Stress corrosion and HCF High risk from large rotating parts Blade failure caused by undetected crack Manual Inspection Inconsistent Time consuming

16 Phased Array UT Inspection (i) LP blade roots Blade Fixture Phased array Ultrasonic Testing (UT) Designed for blade profile Automated traversing (some types) Scan recorded on a laptop Process validated by tests

17 Phased Array UT Inspection (i) LP blade roots Benefits Automated scanning In-situ capability Good process control High quality data Repeatability Data transmission for remote review Example test piece and results

18 Phased Array UT Inspection (ii) rotor disc heads Features: Automated, with motor drive unit Magnetic wheels Width 54mm Parallel scanning Instant data Developed for straddle roots Head calibrated for different geometries

19 Phased Array UT Inspection (ii) rotor disc heads Benefits Fast inspection (LP disc in 10 minutes) Can be done with rotor in-situ Validated, consistent process The unit between discs Data output

20 Agenda Introduction Page 3 Water Jet Cleaning Page 5 Water Jet Cutting Page 10 Automated Phased Array Ultrasonic Testing Page 15 Conclusion Page 21

21 Conclusion From manual inspection tools to robotics Full Autonomy Robotics Degree of Autonomy Full Automation Manual Manual Scanner Guided Movement Free Movement on Regular Surfaces Degree of Mobility Free Movement on Complex Surfaces

22 Conclusion - other new technologies 1. Bolt Inspection Table MPI by moveable coil Endoscopy and hardness testing Motorised turntable Range of sizes Foldable for transportation 2. Hollow Bolt Scanner UT testing In-situ inspection Stress corrosion cracks detected

23 Conclusion - other new technologies 3. Rotor Bore Scanner Ultrasonic Testing (UT) Magnetic Particle Inspection (MPI) Life assessment >50 references

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25 Title (Alstom 28) Subtitle / Main message (Alstom 26) Level 1 Level 2 Level 3 Presentation title - 01/01/ P 25