7f compressor fouling

8/2/2019 7F Compressor Fouling

1/12

7F Compressor Fouling

Progress Energy - Richmond County Plant7FA.03 DLN 2.6

Presented by: Ben Meissner


2/12

Background Unit 8

7FA.03, Donaldson Inlet Conical/Cylindrical

No On-line water washes performed

Semi-annual off-line water wash (borescope)

Last inlet filter replacement Fall 2007Replacement was based on failure to meetburst test criteria (not DP)

Current Filter - Donaldson Spiderweb


3/12

Discovery

On the morning of Oct 31, 2010 (@0300) it wasnoted that Gas Turbine Unit 8 on the combined cycleblock was performing 27 MW lower than the adjacentunit (Unit 7).

Units were on base load control with IGVs open at87.

Cooling tower plume was drifting into Unit 8s inlet

CPD for Unit 8 was 22 psig lower than Unit 7

Troubleshooting was performed and Unit 8 was shutdown to perform compressor inspections


4/12

Trouble Shooting Unit 8

AFPCS (compressor inlet pressure)- 4.74 inH 2O vs. 2.34inH2O on unit 7.

AFPBD (bell mouth pressure)- 12 inH 2O lower than unit 7.

While inline Points above were forced at current values,Transducer tubing was removed and any moisture wasremoved resulted in minor change in instrument value.

Inlet filters were inspected and recorded as wet from coolingtower plume but no filters were damaged

The #2 bearing vibration showed a 0.8 in/sec increaseduring the event but returned to normal a few hours later.


5/12

MW and #2 Bearing Data


6/12

Unit 8 Compressor Efficiency Data

It was noted that there were several inletDP events prior to this event


7/12

Unit 8 Compressor Inspection

Conducted inspections of the compressor inlet and aftend.Stator blades were found to have significant build up of sludge

Aft compressor blades were covered with a white powder substance (smoldered deposits)


8/12

Unit 8 Inlet Inspection

Inlet duct (clean side) was inspected and puddles of black water were discoveredPools of water (2 deep) found behind inlet filtersIt is believed that this water carried over to the

compressor and deposited on the compressor blades(sludge)


9/12

Unit 8 Inlet Filter InspectionTwo filter sets were removed for inspection.One filter was removed and sectioned using a band saw-massamounts of dust/pollen fell out of the filter mediaThe other was sent out for flow/pressure testing No results yet.Clean side corrugated web was rusty/corroded (water is passingthough filters)Water puddle marks were found on the clean side of the filters at theseal.


10/12

Corrective Actions

No compressor blade damage was found

Performed 2 off-line water washes to cleancompressor

Inlet was cleaned and standing water wasremoved

Future project created to install clean side drains

Inlet filters were left as is for time being (waitingmaterials and window of opportunity)

Unit was put back on-line


11/12

Summary

It is believed the spike in vibration was caused by sludge falling off the compressor stator blades and impacting rotating blades

Compressor efficiency and MW output were restored and exceededUnit 7 output by 7 MW after water wash cleanings

Unit 7 was inspected soon after and was found to have somefouling as well

Gore Inlet filters Gore H12 3-layer conical/cylindrical filters will be

installed this spring

DRB Industry CF80Max drift eliminators will be installed in thehoods to knock down heavy moisture from cooling tower drift.


12/12

Thank You

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7f compressor fouling

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