Impact of diesel pilot distribution on the ignition process of a dual fuel medium speed marine engine

Abstract

Recent emission legislation in the marine sector has emphasized the need to reduce nitrogen oxides (NO x) emissions as well as sulphur emissions. Certain special sea areas, regulated by the MARPOL Convention, are provided with a higher level of protection due to their oceanographical and ecological conditions.

Research on Fuel Efficiency and Emissions of Converted Diesel Engine with Conventional Fuel Injection System for Operation on Natural Gas

“…These types of engines, also known as dual-fuel engines, can provide significant improvements in efficiency and emissions [16][17][18][19][20][21][22][23][24][25]. For example, in research on a dual-fuel cargo truck engine [26] a decrease in NO x of up to six times and decrease in CO of up to 83% were observed compared to diesel only operation.…”

“…For example, in research on a dual-fuel cargo truck engine [26] a decrease in NO x of up to six times and decrease in CO of up to 83% were observed compared to diesel only operation. The MARPOL 73/79 VI annex standard Tier III norms were achieved in a Wärtsillä company average revolution 20DF ship engine when the engine operated with NG fuel feed, without using secondary emission reduction technologies (such as selective catalytic reduction technology) [24]. Compared to petroleum-based fuel, at least on a theoretical basis, the NG chemical composition contains a carbon/hydrogen ratio that is more favourable for decreasing CO 2 emissions responsible for the greenhouse effect by a quarter.…”

“…Moreover, even when there is an increase in HC emissions from using NG, the overall impact on the greenhouse effect is low, when compared to using diesel only [26]. Also, operation during low load modes results in instability, leading to a reduction in efficiency indicators, and during nominal power load operation and with a large gas fraction of 90% to 95% in the fuel balance, this may result in knocking [24,27]. To solve these problems, motor methods are generally used: adjustment of the compression ratio and combustion chamber optimisation [10,28,29], air vortex movement increase in the cylinder [28], and exhaust gas recirculation (EGR) technology [24,26], among others.…”

“…Also, operation during low load modes results in instability, leading to a reduction in efficiency indicators, and during nominal power load operation and with a large gas fraction of 90% to 95% in the fuel balance, this may result in knocking [24,27]. To solve these problems, motor methods are generally used: adjustment of the compression ratio and combustion chamber optimisation [10,28,29], air vortex movement increase in the cylinder [28], and exhaust gas recirculation (EGR) technology [24,26], among others. Research results attest to the conclusion that depending on the operating conditions, the use of NG can increase [24] as well as reduce instances of engine knocking phenomena [27].…”

Power management optimization of hybrid power systems in electric ferries

“…In addition, the fluctuation of oil prices required the incentive to investigate more technologically advanced and efficient solutions to reduce operational expenses in the transportation industry [3,4]. Therefore, the industry has collectively been exploring other opportunities for emissions control and energy savings which range from burning low emission fuels such as liquefied natural gas [1] and using dual fuel [5] to progressively electrify ships through increasing hybridization [6]. In the same context, the IMO suggested the concept of hybrid electric vessels as one of the energy efficient index to control and limit a vessel's emissions [7].…”