Energy Efficiency and Environmental Analysis of the Green-Hydrogen Fueled Slow Speed Marine Diesel Engine

Abstract

Marine diesel engines are facing challenges to cope with the emission-reduction regulations set by the international maritime organization (IMO). Hydrogen fuel is one of the alternative fuels which can be used to reduce the exhaust gas emissions from ships. The current paper investigates the effect of using diesel-hydrogen dual fuels on the environmental, energetic and exergetic performance parameters of slow speed marine diesel engine. The investigation is performed using Engineering Equation Solver (EES) software package. As a case study, slow speed diesel engine has been investigated. The results obtained revealed that the energetic and exergetic parameters are influenced by engine load and hydrogen substitution percent. The exergy efficiency is increased by 3.65%, 8.20%, 13.99%, and 21.7% for the hydrogen substitution percentages of 10%, 20%, 30%, and 40%, respectively compared with the diesel engine at full load. Environmentally, CO and CO2 emissions are reduced and NOx emissions are increased as the hydrogen energy content increases. Dual fuel engine with input hydrogen energy fractions of 10% and 20% will comply with the required NOx emission regulations set by IMO after using selective catalytic reduction (SCR) system. It will comply with the required regulations with relative percentages of 96.4% and 98.4%, respectively.