Operation cost analysis of UV-based ballast water treatment system used on a bulk carrier ship

Abstract

Fuel consumption is one of the biggest expense items in the operation of ships. Fuel consumption takes place via the main engine for propulsion of the ship and diesel generators for all other auxiliary engines. According to IMO rules, when a new machine system needs to be integrated into the ship, it is required to have low fuel consumption in terms of energy efficiency and emissions. The same is true for ballast treatment. Ballast water treatment systems (BWTS) are available in many different types of marine markets. Ship operators want to choose BWTS that will consume minimum fuel and operate at maximum efficiency. Therefore, in this study, fuel consumption under both IMO and USGC conditions, and hence the operational cost, is calculated if the UV-based BWTS system is integrated into a bulk carrier ship. While making this calculation, different generator loads and the use of different fuels (VLSFO, MGO and IFO380) used on the ships were taken into account. As a result, the highest cost is $9773 when the most expensive fuel, MGO, is used and operation is performed with a single ballast pump. In USCG mode, the minimum cost is $6382 and the maximum cost is $18929 under the same conditions. It is seen that if the fuel price increases to 1.4 $/kg, the cost of using BWTS in IMO mode can increase to $11392, and if it drops to 0.3 $/kg, the cost of using BWTS in IMO mode can decrease to $1826. It is seen that the highest cost can go up to $22066 and the lowest cost can go down to $3983, with the change of fuel prices in the use of BWTS in USCG mode. With the resulting formulation, with the power consumption of the BWTS and the diesel generator shop trail test fuel consumption values, researchers or shipping companies can repeat the calculations for all kinds of different fuels and different amounts of UV-chambers for variable ballast operations with different ballast tank capacities. Consequently, it is thought that this study is useful in determining the additional operational cost of UV-based BWTSs.