gas turbine & compressor operations & maintenance solutions “Managing Fleet Performance” Sikobe Litaba - Technical Manager, Cogsys Ltd 8th Annual Industrial & Power Gas Turbine O&M Conference 20th - 21st November 2002 London

Managing Fleet Performance who are we? capital replacement strategy emissions reporting, reliability analysis varied applications for diverse fleets performance assessment principles combined gas turbine & process compressor performance

Who are we? - Group Organisation National Grid Transco plc

Transco

£3m product investment

Advantica Technology

business unit performance monitoring software products & engineering teams for gas turbines & compressors

Cogsys Limited established 1990

ISO corrections

all performance data is ISO corrected and compared with a “fingerprint” of the engine deviations from expected performance trigger diagnostics tools to enable rapid, preventative action

Gas Turbine - baseline analysis



Actual performance points Baseline performance lines

ABC Mode

AB Mode

BC Mode

LM2500+DLE : Fuel flow (NTI) vs combuster inlet T




Change burner mode to BC to save fuel if demand is unlikely to increase




Shows a fuel issue for BC mode in this case can then drill down to determine whether mechanical or control

Gas Compressor - baseline analysis

AB Mode

BC Mode

Model Based Diagnostics - principles Actual Process Plant

Process Inputs

Discrepancies

ALERT Models






Process Outputs

Root Cause

Predicted Outputs

Rigorous Thermodynamic Modelling for Gas Turbines & Compressors Quickly eliminate spurious data (e.g. sensor errors) Determine un-measured values (e.g. hot section gas path)

Gas Turbine - Model Based Diagnostics RB211-24C gas path analysis actual process data is compared with modelled values along the gas path sensor errors are quickly eliminated by comparison with modelled values un-measured values are determined in the hot zone to support component life prediction

fault indices are produced enabling diagnosis at the component level

Gas Compressor Model Based Diagnostics

polytropic efficiency and head coefficients are modelled

deviations from the models enable possible sensor errors to be eliminated leading to rapid fault diagnosis

gas turbine driver characteristics are displayed on the compressor envelope

On Line Instrument Validation healthy discharge temp, spurious efficiency

On Line Instrument Validation healthy efficiency, spurious suction temperature

Fleet Performance Applications varied applications for diverse fleets

Onshore Pipeline Transmission (Transco UK grid)

Offshore Gas Injection (Peak Storage)

Offshore Gas Production (UK Continental Shelf)

Onshore Power Generation and CHP (France)

LTSA - Remote Monitoring (Independent Healthcare)

European Interconnector (UK- Belgium)

Acceptance Testing (Overhaul & Repair)

NGL Gas Processing

Remote Management of Fleets validated centralised data & optimised resources on-shore compression

A

B

C

off-shore compression

A

B

C

power plant

A

B

service centre

Operations control room

out-sourced maintenance / service provider

Fleet Emissions Management validated monitoring & reporting using performance data

emissions fingerprint

+

engine parameters




+

fuel flow, exhaust T mechanical condition AIT, CDP, CDT, etc..

process conditions




fuel specific gravity fuel calorific value etc..

IPPC regulatory approval fleet wide solution enabling emissions trading reduced capital investment & maintenance costs

calculated emissions

Fleet Emissions Management engine model specific validation and characterisation - SAC

Fleet Emissions Management Engine model specific validation and characterisation - DLN Typical GE LM2500+DLE Gas Turbine - NOx emission profile OCMS NOx Primary Bulk Reference Baseline - All Modes (variable bleed range 50% TFL) @ 15% O2 Ref. y = -4.76857E-01x + 2.34661E+02 y = -4.82959E-01x + 2.31191E+02

y = -2.71533E-03x 2 + 1.63574E+00x - 1.83720E+02 100

y = 5.87267E-03x 2 - 5.25563E+00x + 1.20453E+03 Full Load Rating 27.4 MW @ 470 T3SEL

EA Site Authorisation Limit

75% of Rating 20.5 MW @ 425 T3SEL

90

Push

50% of Rating 13.7 MW @ 385 T3SEL

80 NOx-PRI (AB check 1) NOx-PRI (AB check 2)

70

NOx-PRI (ABC check) NOX _P RI (m g/m ^ 3)





NOx-PRI (BC check)

60

BC

NOx-CONC (BC push)

Push

NOx-CONC (AB push 1)

50

NOx-CONC (AB push 2)

Push

NOx-CONC (ABC push)

40

Linear (NOx-PRI (AB check 1))

AB

Linear (NOx-PRI (AB check 2))

30

Poly. (NOx-PRI (ABC check))

ABC

Poly. (NOx-PRI (BC check)) 20 10 0 260

280

300

320

340

360

380

400

420

440

460

480

500

T3SEL (Deg C)

GE LM2500+DLE : NOx vs combuster inlet T




Authorisation limit burner modes BC to AB to ABC Note NOX emissions increase at end of each burner mode minimum bleed ‘push’

Fleet Reliability Management engine component life - low cycle fatigue

RR Avon Mk.1533 : Gas Generator - Low Cycle Fatigue




Implementation of OEM bulletin recommendations




Calculation of cyclic usage between stop / start cycles & over engine life




Particularly useful in variable load applications




Cost-effectively schedule component replacement particularly in hot section

Fleet Reliability Management standard station/unit alarm & trip categorisation

Fleet Capital Replacement Strategy based on Performance, Emissions, Availability & Reliability data

Fleet Capital Replacement Strategy multiple criteria decision analysis

Fleet Capital Replacement Strategy multiple criteria decision analysis

Summary OEM independent capital replacement strategy emissions reporting, reliability analysis diverse fleet and industry applications performance assessment principles combined gas turbine & process compressor performance

gas turbine & compressor operations & maintenance solutions Cogsys Limited Tel. +44 (0)161 868 4450 [email protected] www.turbo-alert.com