Abstract
The global demand for clean fuels is increasing in order to meet the requirements of the International Maritime Organization (IMO) of 0.5% global Sulphur cap and Tier III emission limits. Natural gas has begun to be popularized on liquefied natural gas (LNG) ships because of its low cost and environment friendly. In large-bore marine engines, ignition with pilot fuel in the prechamber is a good way to reduce combustion variability and extend the lean-burn limit. However, the occurrence of knock limits the increase in power. Therefore, this paper investigates the effect of pilot fuel injection conditions on performance and knocking of a marine 2-stroke low-pressure dual-fuel (LP-DF) engine. The engine simulations were performed under different pilot fuel parameters. The results showed that the average in-cylinder temperature, the average in-cylinder pressure, and the NOx emissions gradually decreased with the delay of the pilot injection timing. Furthermore, the combustion situation gradually deteriorated as the pilot injection duration increased. A shorter pilot injection duration was beneficial to reduce NOx pollutant emissions. Moreover, the number of pilot injector orifices affected the ignition of pilot fuel and the flame propagation speed inside the combustion chamber.
Highlights
In recent years, marine engine emission regulations have become increasingly strict [1,2].On 1 January 2020, a 0.5% global Sulphur cap for marine fuels was implemented by the InternationalMaritime Organization (IMO) [3]
Emission standard and the 0.5% global Sulphur cap, many marine diesel engine manufactures are looking for engines with lower emissions and higher combustion efficiency [4]
In a marine 2-stroke lean-burn dual-fuel engine, the occurrence of knock limits the increase in power [27]
Summary
Marine engine emission regulations have become increasingly strict [1,2].On 1 January 2020, a 0.5% global Sulphur cap for marine fuels was implemented by the InternationalMaritime Organization (IMO) [3]. Marine engine emission regulations have become increasingly strict [1,2]. On 1 January 2020, a 0.5% global Sulphur cap for marine fuels was implemented by the International. In order to meet the IMO requirements of the Tier III emission standard and the 0.5% global Sulphur cap, many marine diesel engine manufactures are looking for engines with lower emissions and higher combustion efficiency [4]. Natural gas (NG) has gradually become a promising engine fuel solution in order to meet these needs [5]. Compared with the high cost of low Sulphur fuel oil (LSFO), exhaust gas recirculation (EGR), and selective catalytic reduction (SCR), natural gas engines have good development prospects because of its low cost [6]. The main component of natural gas is methane (CH4 ), which has the advantages of low heat value, good explosion resistance, abundant reserves, and good emission performance [7,8]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
