Energy savings on frequency regulation of ship's cooling circuits

To calculate potential energy savings in a ship's cooling circuits, a simulation model of frequency-controlled seawater (SW) pumps is proposed that has been verified by measurements. The pumps operating at a minimum frequency of 30 Hz have a maximum energy reduction of almost 79% under both full and part load conditions when the SWintake is below 32°C. A return-on-investment period of only a few months is calculated for the frequency-controlled drive on a container vessel.