De-rating of prime mover reduces fuel consumption
In today’s environment of slow steaming, a permanent engine reduction can increase remarkably the economy of existing vessels and reduce the fuel consumption under these new engine load conditions. Main engines are normally designed for a specific high speed. However, for Slow-Steaming another Power-Speed-Course is decisive. A throttling of the engines reduces the engine specific maximal continuous power (MCR) and with this, the designed maximal speed of the vessel permanently. This leads to a higher economy with lower specific fuel consumption (sfoc).
MV Cap San Nicolas (9.600 TEU) in service since May 2013
Measures for throttling include the modification of the injectors, plates between crosshead and piston rod as well as a new set-up of the turbo charger. This means, that always the engines technical data have to be changed. In addition also cylinders can be cut-off - this has to be done in connection with a new torsional vibr... [More]
Propulsion improvement adaptations achieve fuel consumption decrease, depending on ships type, of up to six percent.
To reduce fuel consumption on vessels, different propulsion improvement adaptions can be done – according to type of vessels and operating range. While pre-swirl-equipments increase the propeller force, boost nozzles the drive efficiency by an effective propeller force. Post-swirl-equipments are leading partly the torsional energy back into forward speed. Because of these pre-swirl-equipments or nozzles fuel consumption can be reduced by up to 5% and by propeller fins and rudder bowls of up to 2%.
The following adaptations can be used: pre-swirl-stator, post-swirl-fins, nozzles, propeller fins, German Leitrad and Costa-Bowl. Which adaptation leads to an efficiency increase depends on the operating profile of the vessel. To evaluate the potential as well as the interaction with the ship’s hull and also other components, an analysis by the help of computational... [More]