Research on Case Studies of Energy-Saving Technology Applications for Vessels

Abstract

This dissertation presents three case studies of application on energy-saving technologies for sea-going vessels The first case is to calculate the potential energy savings in ship’s cooling circuits based on a container vessel A simulation model of frequency-controlled seawater (SW) pumps is proposed and has been verified by measurements The SW pumps operating at a minimum frequency of 30 Hz have a maximum energy reduction of almost 79% under both full and partial load conditions when the SW intake is below 32°C The frequency-controlled drive of the container vessel has a calculated return-on-investment period of only a few months The second case is to implement a supercapacitor-based energy storage system (SESS) on a small vessel and a method of predicting equivalent-circuit parameters for supercapacitor modules is presented The module consists of a single supercapacitor made by Maxwell BCAP3000-P270-T04 with a capacitance of 3000 F and NessCap ESHSR-1600C0-002R7A5T with a capacitance of 1600 F in series in parallel or the combination of the both The equivalent-circuit parameters are identified by charging the module from zero to the rated voltage and by measuring its terminal voltage during the internal charge redistribution over the time of 30 minutes Simulations and experiments reveal that prediction of equivalent-circuit parameters for a supercapacitor module is feasible and effective The measurement results shows the SESS installed in a vessel with wind and solar power can indeed reduce fuel consumption to achieve the purpose of energy conservation and carbon reduction Furthermore the third case is to add power factor (PF) correction capacitors on two fishing vessels to increase energy efficiency since low PF of marine electrical systems due to motor loads is often overlooked Three alternative methods for predicting alternator fuel consumption in vessels before and after adding PF correction capacitors are investigated and results of the field verification effort are presented In addition the return-on-investment period for installing PF correction capacitors on two fishing vessels is analyzed to determine the critical parameters governing the economics of PF corrections in marine electrical systems Test results show that the payback period for installing PF corrections will significantly depend on the number of alternator running hours per year and the price of fuel oils

Date of Award	2015 Apr 27
Original language	English
Supervisor	Chien-Hsing Lee (Supervisor)