Cleaning Turbine Blades And Nozzle Ring In Operation - ABB HT606993 Operation Manual

Operation Manual / TPL65-A32 / -A33 / -A36 + TPL69-A32 / -A33
5 Maintenance / 5.4 Cleaning turbine blades and nozzle ring in opera-
tion
5.4 Cleaning turbine blades and nozzle ring in
Wet cleaning interval
Cleaning method
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operation
The combustion of heavy fuel oil in diesel engines contaminates the tur-
bine blades and nozzle rings of turbochargers. The deposits on the tur-
bine components originate from the following combustion products:
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Soot
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Molten ash
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Cinder
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Incompletely burned fuel
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Sodium vanadyl vanadate
It is advisable to use fuels with a low ash, sulphur, sodium and vanadium
content. The fuel must also be correctly stored, prepared and handled.
We recommend using fuels with a vanadium-to-sodium mass ratio of
less than 3:1 so that the melting temperature of the sodium vanadyl
vanadate is as high as possible.
The amount of contamination increases over time, which is why regular
and correctly performed cleaning is important in order to remove the de-
posits that have formed.
Contaminated turbine components can cause a slight increase in char-
ging pressure because of narrowing of the turbine cross-section. The
contamination causes a drop in turbine efficiency, and the engine tem-
peratures downstream of the cylinder can increase. The engine perform-
ance must therefore be reduced if necessary.
The contamination of the turbine also causes rotor unbalance. Extremely
heavy contamination can lead to non-permissibly high unbalance of the
rotor.
Operating experience has shown that, in spite of regular cleaning during
operation, it is essential to carry out the overhauls during which the tur-
bine and the nozzle ring are cleaned mechanically. However, if cleaning is
carried out properly and the cleaning system is properly dimensioned,
the intervals between overhauls can be increased.
The interval between periodic cleaning is very dependent on the operat-
ing conditions. As a rule, cleaning should be carried out every 50 to 200
operating hours.
When cleaning the turbine components during operation, use wet clean-
ing. This cleaning method is tested and approved by ABB Turbocharging.
Prerequisites for wet cleaning are that the enginebuilder approves the
process and his instructions are followed.
HZTL2498_EN Rev.F December 2020