Western navies are now subject to greater scrutiny on their green credentials due to their government ownership and the conspicuous use of fuel for their duties. The ability to reduce the fuel consumption is now foremost consideration both for the benefit of increased operating range and endurance in theatre, but also for the reduced emissions of greenhouse gases.
The adoption of more energy efficient warships cannot be allowed to lead to any reduction in naval warfighting capability and so the energy saving technologies (EST) have to be chosen, adopted, and implemented so there is a win-win outcome.
Cruise liners have recently adopted the use of absorption chillers plant (ACP) to reuse engine waste heat to generate chilled water for air conditioning and other duties. ACP potentially offer a much-reduced electrical load on warship DG sets and therefore a lower fuel consumption.
Frigate power & propulsion topologies can vary with ship operating duties and the speed-time operating profile. However, increasingly there are trends towards diesel-electric with Energy Storage System (ESS) so that peak demands from mission systems can be accommodated. However, there is normally a need to have two prime movers running at any one time to cover for a single failure. The potential benefit of the ESS to allow Single Generator Operation (SGO) and reduce engine maintenance hours and fuel consumption is studied for the electric propulsion options. This aspect, and the introduction of novel propulsion motor topologies, are examined to identify their impact on savings to the annual fuel consumption (AFC).
The study identifies that three of the most promising EST for frigates are active anti-fouling technologies, hull air lubrication systems and Hull Vane resistance reduction. New DC network-based power systems with advanced electric motors allow for reductions in the losses associated with power electronics and allow for fixed pitch propellers to be used which are more easily designed for shock withstand performance.
Keywords: Energy Saving Technologies, Frigate Power & Propulsion
