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3.11 TURBINE CLEANING SYSTEM
3.11.1 GENERAL DESCRIPTION
As a large quantity of air is passing through the gas turbine compressor section, a thin layer of
deposits will eventually build up on the surfaces after a period of time, depending on the
ambient air pollution and operating hours. This layer will over time reduce the compressor
efficiency and thereby the turbine performance.
The purpose of the cleaning system is to remove this layer and thus keep the performance of the
gas turbine at an optimal level. How often the compressor needs cleaning is a matter of
experience based on a comparison between current and rated gas turbine performance data.
Two methods for cleaning the LM2500 compressor section are available, the offline, or crank
soak cleaning method and the online cleaning method, which will extend the intervals between
offline cleaning cycles.
One common water wash module is used for all four units that contains most of the cleaning
system components. The water wash module is connected via flexible tubing to the liquid
manifold and spray nozzles located on the inlet bellmouth of the turbine that needs to be
cleaned.
As a cleaning liquid, a recommended cleaning solution is mixed with distilled or de-mineralized
water. Depending on ambient temperatures and air moisture conditions, it may be necessary to
add an antifreeze agent to the solution/water mixture. For the rinsing liquid, use distilled or de-
mineralized water, equally with antifreeze agent, if required.
The cleaning and rinsing liquids, respectively, are injected into the compressor section in three
separate cycles, as the gas generator high pressure rotor is being cranked by the electro-hydrau-
lic start system.
ACETONE, METHYL ETHYL KETONE (MEK) AND ISOPROPANOL ARE
EXTREMELY FLAMMABLE AND TOXIC TO SKIN, EYES, AND
RESPIRATORY TRACT. USE THESE ONLY IN WELL VENTILATED
AREAS AND KEEP AWAY FROM SPARKS AND OPEN FLAME. AVOID
INHALATION OF THE FUMES WHICH ARE TOXIC UPON PROLONGED
EXPOSURE OR IN HIGH CONCENTRATION.
OBSERVE ALL CLEANING AGENT MANUFACTURER WARNINGS WITH
REGARD TO THE HANDLING, STORAGE AND MIXING OF THEIR
PRODUCTS.
The use of non-isopropyl alcohols, ethylele glycol or additives containing chlorine,
sodium or potassium are not permitted since they may attack the titanium and
other metals in the gas generator.
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3.11.2 SYSTEM DESCRIPTION
The cleaning module consists of a water wash tank (item 1, figure 1 below), used for both on-
line and off-line cleaning, which contains the cleaning/rinsing liquid. The level is registered by
a level indicator (3). The reservoir is fed through a filler cap on top of the tank. Spare liquid can
be drained through a drain valve (12)
The cleaning/rinsing liquid is fed from the water wash module to the water wash system on the
turbine (wash nozzles) by means of pressurized air from the instrument air supply. Correct air
supply pressure is regulated by means of air filter regulators (8). The off-line and on-line clean-
ing methods require different air pressures. Hence, one regulator controls the pressure for the
off-line water wash air supply pressure, while the other controls the pressure for the on-line air
supply pressure.
The off-line water wash system is controlled by a hydraulically operated valve which is
mounted on the compressor package skid. The supply to the nozzles can be watched in a water
flow indicator (10). The temperature gauge (4) indicates the temperature of the cleaning/rinsing
liquid.
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Figure 1: Water wash module
1.Water wash tank 7. Air supply tank ball valves (off-line/on-line)
2. Filling valve 8. Pressure air filter regulator
3. Level glass/indicator 9. Manual on/off valve
4. Temperature gauge 10. Flow glass
5. Supply pressure indicator 11. Strainer
6. Pressure safety release valve 12. Reservoir drain valve
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3.11.3 TURBINE CLEANING
3.11.3.1 GENERAL
The chapter below outlines the principle of the offline cleaning procedure. For a detailed
description with the actual steps for the procedure please refer to Chapter 5.2 Operation
Procedures.
3.11.3.2 OFFLINE CLEANING
The offline, or crank soak turbine cleaning procedure is carried out manually while the gas
turbine is in shutdown and the exhaust temperature indicates below 93ºC. A recommended
cleaning agent may be added to the water in order to improve the cleaning capabilities.
This method requires the turbine to be driven by the starter motor while spraying the cleaning
solution into the gas generator compressor section. The cleaning solution is pumped from the
reservoir to a series of nozzles around the gas turbine inlet by means of the electrically driven
pump. The turbine is then left in stand still for a given period for the detergent to soak. Then the
turbine is motored by the starter again during the rinse period for the rinse water to remove the
detergent and dirt from the compressor. Drain the power turbine casing after each wash.
3.11.3.3 ONLINE CLEANING
The intention of online cleaning is to reduce the effect of compressor fouling on the
performance and to lengthen the time between shutdowns before a crank-soak wash is
necessary.
This cleaning procedure is carried out while the turbine is in operation and at full speed. The
liquid pumped into the compressor will evaporate in the turbine section due to the high
temperatures in the turbine.
3.11.3.4 CLEANING AGENTS
Prior to handling the cleaning agents please familiarize with the warnings given in
general information and each manufacturers warnings.
For detailed information related to cleaning detergent for the gas turbine please refer to the
General Electric CD-ROM GEK112165 with GEK105054 General Electric Operation and
Maintenance Manual Volume I, Appendix A5, “Liquid Detergent for Compressor Cleaning”.
Follow the manufacturer’s recommendation when making the solution. For information related
to cleaning procedures please refer to Chapter 5.2 of this User Manual.
3.11.3.5 CLEANING WATER
For detailed information related to cleaning solution and water for rinsing purpose please refer
to GEK105054 General Electric Operation and Maintenance Manual Volume I, Appendix A4,
“Compressor Cleaning Water Purity Specification”.
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Solution quantities, off-line:
• Detergent solution 75.7 liters (20 gallons) - 72 liters (19 gallons) of water mixed
with 3.7 liters (1 gallon) of detergent.
• Rinse water 151 liters (40 gallons).
Solution quantities, on-line:
• Rinse water 19 liters/min (5 gallons/min) for 10 minutes. Total of 190 liters (50
gallons).
D-R recommended to run the on-line wash two times during a 24 hours period.
The temperature of the solution must be between 38ºC and 60ºC during the off-line
wash.
3.11.4 RELATED REFERENCE INFORMATION
3.11.4.1 RELATED TAGS
Table 1: Related tags and documents
Tag no. Description Supplier Documentation
Turbine cleaning system - refer to P&ID 01.18070.0012-AF-010
X-T1101 Turbine water wash unit D-R -
T11-BL-900 Water wash reservoir filler Starline PDF23585 - dim. drawing
cap valve PDF16558 - datasheet
V-T1111 Water wash reservoir D-R -
T11-LG-1364 Reservoir level indicator KSR Kuebler PDF21683 - NORSOK
datasheet
PDF7126 - user manual
T11-TW-1373 Reservoir heater temperature WIKA PDF23035 - NORSOK
controller/thermo well datasheet
PDF9953 - datasheet
T11-TG-1373 Reservoir temperature gauge WIKA PDF23033 - NORSOK
datasheet
PDF12180 - operating
instructions
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Tag no. Description Supplier Documentation
T11-PG-1372 Pressure gauge indicator WIKA PDF12178 - operating
instructions
PDF21605 - NORSOK
datasheet
PDF21603 - NORSOK
datasheet
T11-PSV-1366 Safety/relief valve Anderson Greenwood/ PDF7116 - operating &
Tyco Flow Control safety instructions
PDF8641 - maintenance
instructions
PDF8112 - dim. drawing
PDF19067 - NORSOK
datasheet
PDF19059 - NORSOK
datasheet
T11-SP-13900 Regulator for instrument Bifold Fluidpower/ PDF6598 - operating &
water wash on-line Håland Instrumentering maintenance manual
PDF6599 - technical manual
T11-SP-13901 Regulator for instrument PDF12079 - techn.
water wash off-line information/dim. drawing
PDF6655 - datasheet
SIB001-1353 Water wash reservoir drain Oliver/Håland PDF13307 - tech. manual
Instrumentering AS PDF13310 - product
SIB001-1358 Off-line water wash air supply datasheet
valve PDF13311 - GA drawing
SIB001-1359 On-line water wash air supply
valve
SIB001-1365 Off-line water wash valve
T11-SP-12900 Water to engine strainer Flochem/di Douglas PDF12589 - tech. manual
Italia S.P.A. PDF7892 - user manual
PDF7891 - tech. dwg
T11-FG-1369 Water flow gauge indicator Brooks Instruments s.a.s. PDF7158 - user manual
T11-SDV-1350 Hydraulic operated valve PMC Servi/ PDF21698 - operating
T11-SDV-2350 The Water Hydraulics instructions
T11-SDV-3350 PDF7144 - dim. drawing
T11-SDV-4350 PDF7145 - GA drawing
PDF14515 - instrument
datasheet
3.11.4.2 RELATED DRAWINGS AND DOCUMENTS
Table 2: Related drawings and documents
Drawing/doc. no. Title
01.18070.0012-AF-010 Water Wash System (P&ID)
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Table 2: Related drawings and documents
Drawing/doc. no. Title
01.18070.0012-AC-007 GT Water Wash Trolley (Common) (GA)
01.18070.0012-FA-010 P&ID Component & Instrument List, Water Wash System
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