Engines can be made more efficient and fuel consumption can be reduced by using a Blending-on-Board (BOB) technique for system oil on board ships, claims Maersk Fluid Technology (MFT).
A white paper published by MFT shows how a consistent replenishment of system oil without oil losses can improve engine performance, lower maintenance intervals, and reduce a vessel’s environmental impact, all of which lead to significant cost savings.
Two-stroke marine engines are lubricated using system oil and cylinder oil. The cylinder oil is continuously consumed and scrapped out and will deteriorate over time as it is faced with challenging conditions in modern engines. System oil is used to cool and lubricate the essential parts of the engine and as a hydraulic oil to operate and control engine components and systems.
A system developed by MFT, known as SEA-Mate Blending-on-Board (BOB), blends cylinder lubricants using in-use system oil and a high Base Number (BN) cylinder oil to provide the appropriate BN cylinder oil. This system has been patented and is marketed as SEA-Mate Blending-on-Board and has been approved by MAN B&W and Wärtsilä/WinGD.
The purpose of SEA-Mate BOB is that it provides a continuous refresh of the system oil in the crank case, reversing the typical deterioration of the in-use system oil. This generates clean oil with excellent detergency. By refreshing the system oil the viscosity of fresh oil is maintained (fresh oil viscosity is thinner as it increases in thickness over time) which enhances mechanical efficiency and reduces fuel consumption.
System oil is often used for lubricating the turbocharger, an expensive and sensitive piece of equipment. Replenished system oil is less likely to age and deteriorate, contaminate and cause wear on bearings and other components. Reduced wear on engine components will generate maintenance and spare parts’ savings.
Additionally, system oil that is used for cooling the piston crowns can be subjected to contamination from a build up of carbon deposits in the cooling space of the crown where it is transferred to. This is likely to reduce the cooling effect and lead to burning and erosion of the crown. Replenished oil will reduce the chance of this happening and extend piston life.
According to MFT, the biggest saving will come from the reduction in sludge production as a result of constant replenishment of in-use system oil with fresh system oil. Ports often charge for sludge disposal and thereby eliminating sludge will cut costs. The exact savings will be based upon the individual operating profile of each vessel.
MFT estimates its BOB system will generate annual savings on a small bore two-stroke main engine of around US $20-40,000 and for a medium to large bore engine as much as $40,000 – 90,000.
According to MFT, the BOB system is available to all shipowners.
Read more on MFT’s white paper.
Images courtesy of MFT.
