The state of the four-stroke engine turbocharger plays a decisive role for long-term warranty of the full engine output and reliability under all operating conditions. Combustion residues developing on the nozzle ring and the blading of the turbine in heavy fuel operation are influencing the turbocharger efficiency to a large extent and, consequently, also the thermal engine load. To avoid an inadmissible increase of the thermal load, regular washing of the
turbocharger at compressor and turbine end, according to the manufacturer washing instructions, is an essential part of engine operation.
Engineer’s experience brought next turbocharger washing procedure, which is considered to be the most efficient on modern four-stroke engines:
- For diesel generator engines. Turbine washing shall be carried out at zero load with generator switch opened.
If possible, the cleaning process shall proceed before connecting the engine to the grid. To avoid corrosion, it must absolutely be ensured that after washing, the engine still continues running for approximately 10 minutes without or at low load to dry the turbine.
- For main propulsion. Washing is carried out within a load range from 0-20% at rated speed. For this purpose the pitch propeller plant must be changed to constant speed operation.
Washing water quantities and injection pressure have to be confirmed in manufacturer instruction manual to avoid damage to turbocharge blades.
Cleaning water drain should be monitored during procedure. Drain pipe blockages possible!