A data-driven process control topology for energy efficiency optimization of fan operation in E/R ventilation system of marine vessels

The capacity of engine room (E/R) ventilation fans installed in marine vessels is defined during design stage based on maximum air flow required by Main Engine (M/E), Diesel Generators (D/Gs) and Boilers. However, the actual vessel´s operating profile at reduced M/E power and speed does not justify the use of full capacities. In this paper, a data-driven process control topology is proposed to adjust the speed of E/R ventilation fan motors according to the variation of combustion air flow requirements in order to optimize energy efficiency during ship´s sea-going and cargo operation periods. The controller dynamics are established through parameter monitoring, regardless of the model of the controlled plant. For the tanker vessel under investigation, a case study initially defines the plant operational constraints and its power saving potential. The proposed variable frequency process control topology is then applied as a retrofit installation to the existing 18.5kW E/R fan motor starters. Onboard experimental results show significant improvement in vessel´s power balance, D/G fuel consumption and level of emission factors (CO₂, SO₂, NO_x), validating the performance of the proposed control topology, which is implemented using commercial Programmable Logic Controllers (PLCs) and Variable Speed Drive (VFD) units.