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Increasing the pressure to the limit is the common procedure which should be done regularly by adjusting the injection time of each cylinder. This is not really saving fuel as this is just the recommendation of the engine builder.
However, there are trends in the market to achieve additional fuel savings by exeeding the pmax limits up to 5 bar within the tolerance of the engine builder. This will bring additional fuel savings of up to 3%.
To support and monitor this trend all our systems are enabled to online record the shaftpower and to present the load index on the shop test or sea trial curve (called correlation chart).
On the display you can now online see how much the pressure can be increased to optimize the fuel consumption. If the limits will exceeded the system it can automatically send an alarm.
Unbalanced engines on power cause torsional vibrations which simply are a waste of energy. Or in other words, such torsional vibrations are caused when the cylinders brake against each other, which means that the engine is not perfectly balanced and this leads to a significant increase in fuel consumption.
Crucial to this issue is Det Norske Veritas guidance which states: “1% difference inperformance is 1% higher fuel consumption". However, the perfect power balance can only be detected by an online monitoring systems. It determines in real time and with high precision the exact performance differences between the cylinders in one cycle.
Fuel saving proof
This has been successfully proofed on many ships where most engines were significantly out of power balance even the newly overhauled engines.
The effectiveness of power balancing was demonstrated with the fact that the engine vibrations fell by a remarkable 35%. Onother proof was given by Siemens SIMOS IMAC 55 Energy Management showing online the specific fuel consumption reduction up to 4gr/kWh (means arround 2% fuel saving) due to hig precission power balance. Such a reduction minimizes maintenance and replacement costs, since the excess energy does not affect the clutch, bearings and piston rings.