Cleaning Turbine Blades And Nozzle Ring In Operation - ABB HT564896 Operation Manual

5.4
5.4
NOTICE
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Maintenance
Cleaning turbine blades and nozzle ring
in operation
Cleaning turbine blades and nozzle ring in
operation
The combustion of heavy fuel oil in diesel engines contaminates the
turbine blades and nozzle rings of turbochargers. The deposits on the
turbine components originate from the following combustion products:
 Soot
 Molten ash
 Cinder
 Incompletely burned fuel
 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
deposits that have formed.
Contaminated turbine components can cause a slight increase in charging
pressure because of narrowing of the turbine cross-section. The
contamination causes a drop in turbine efficiency, and the engine
temperatures downstream of the cylinder can increase. The engine
performance 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
turbine 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.
Operation Manual / TPL76-C
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5.4 Page 61