Effect of different combustion models and alternative fuels on two-stroke marine diesel engine performance

Recently, the stringent international regulations on ship energy efficiency and NOx emissions from ocean-going ships make energy conservation and emission reduction be the theme of the shipping industry. Due to its fuel economy and reliability, most large commercial vessels are propelled by a low-speed two-stroke marine diesel engine, which consumes most of the fuel in the ship. In the present work, a zero-dimensional model is developed, which considers the blow-by, exhaust gas bypass, gas exchange, turbocharger, and heat transfer. Meanwhile, the model is improved by considering the heating effect of the blow-by gas on the intake gas. The proposed model is applied to a MAN B&W low-speed two-stroke marine diesel engine and validated with the engine shop test data. The simulation results are in good agreement with the experimental results. The accuracy of the model is greatly improved after considering the heating effect of blow-by gas. The model accuracy of most parameters has been improved from within 5% to within 2%, by considering the heating effect of blow-by gas. Finally, the influence of blow-by area change on engine performance is analyzed with considering and without considering the heating effect of blow-by.

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Experimental Investigations of Marine Diesel Engine Performance Against Dynamic Back Pressure at Varying Sea-States due to Underwater Exhaust Systems

ASME 2019 Internal Combustion Engine Division Fall Technical Conference ◽

10.1115/icef2019-7216 ◽

2019 ◽

Author(s):

Harsh D. Sapra ◽

Jaswinder Singh ◽

Chris Dijkstra ◽

Peter De Vos ◽

Klaas Visser

Keyword(s):

Diesel Engine ◽

Thermal Loading ◽

Geographical Location ◽

Engine Performance ◽

Back Pressure ◽

Experimental Investigations ◽

Pressure Waves ◽

Marine Diesel Engine ◽

Marine Diesel ◽

Exhaust Systems

Abstract Underwater exhaust systems are employed on board ships to allow zero direct emissions to the atmosphere with the possibility of drag reduction via exhaust gas lubrication. However, underwater expulsion of exhaust gases imparts high and dynamic back pressure, which can fluctuate in amplitude and time period as a ship operates in varying sea-states depending on its geographical location and weather conditions. Therefore, this research aims to experimentally investigate the performance of a marine diesel engine against varying amplitudes and time periods of dynamic back pressure at different sea-states due to underwater exhaust systems. In this study, a turbocharged, marine diesel engine was tested at different loads along the propeller curve against dynamic back pressure waves produced by controlling an electronic butterfly valve placed in the exhaust line after the turbine outlet. Engine performance was investigated against single and multiple back pressure waves of varying amplitudes and wave periods based on real sea-state conditions and wave data. We found that the adverse effects of dynamic back pressure on engine performance were less severe than those found against static back pressure. Governor control and turbocharger dynamics play an important role in keeping the fuel penalty and thermal loading low against dynamic back pressure. Therefore, a marine engine may be able to handle much higher levels of dynamic back pressures when operating with underwater exhaust systems in higher sea-states.

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

International Journal of Multidisciplinary and Current Research ◽

10.14741/ijmcr/v.6.6.10 ◽

2018 ◽

Vol 6 (6) ◽

Author(s):

Nader R. Ammar

Keyword(s):

Diesel Engine ◽

Alternative Fuels ◽

Catalytic Reduction ◽

Energy Content ◽

Hydrogen Energy ◽

Marine Diesel Engine ◽

Slow Speed ◽

Marine Diesel ◽

Hydrogen Substitution ◽

Scr System

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.

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Model tests of a marine diesel engine powered by a fuel-alcohol mixture

Combustion Engines ◽

10.19206/ce-143486 ◽

2021 ◽

Author(s):

Marcin Zacharewicz ◽

Tomasz Kniaziewicz

Keyword(s):

Mathematical Model ◽

Diesel Engine ◽

Alternative Fuels ◽

Fossil Fuels ◽

Diesel Oil ◽

Marine Diesel Engine ◽

Engine Model ◽

Marine Engines ◽

Marine Diesel ◽

The Mathematical Model

The paper presents the results of model and empirical tests conducted for a marine diesel engine fueled by a blend of n-butanol and diesel oil. The research were aimed at assessing the usefulness of the proprietary diesel engine model in conducting research on marine engines powered by alternative fuels to fossil fuels. The authors defined the measures of adequacy. On their basis, they assessed the adequacy of the mathematical model used. The analysis of the results of the conducted research showed that the developed mathematical model is sufficiently adequate. Therefore, both the mathematical model and the computer program based on it will be used in further work on supplying marine engines with mixtures of diesel oil and biocomponents.

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Prediction of marine diesel engine performance under fault conditions

Applied Thermal Engineering ◽

10.1016/s1359-4311(00)00006-5 ◽

2000 ◽

Vol 20 (18) ◽

pp. 1753-1783 ◽

Cited By ~ 48

Author(s):

Dimitrios T Hountalas

Keyword(s):

Diesel Engine ◽

Engine Performance ◽

Marine Diesel Engine ◽

Marine Diesel

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Impact of Compressor Surge on Performance and Emissions of a Marine Diesel Engine

Journal of Turbomachinery ◽

10.1115/1.4033186 ◽

2016 ◽

Vol 138 (10) ◽

Cited By ~ 6

Author(s):

Nikolaos-Alexandros Vrettakos

Keyword(s):

Steady State ◽

Diesel Engine ◽

Engine Performance ◽

Marine Diesel Engine ◽

Performance Parameters ◽

Test Bed ◽

Engine Operation ◽

Compressor Surge ◽

Marine Diesel ◽

The Impact

The operation during compressor surge of a medium speed marine diesel engine was examined on a test bed. The compressor of the engine's turbocharger was forced to operate beyond the surge line, by injecting compressed air at the engine intake manifold, downstream of the compressor during steady-state engine operation. While the compressor was surging, detailed measurements of turbocharger and engine performance parameters were conducted. The measurements included the use of constant temperature anemometry for the accurate measurement of air velocity fluctuations at the compressor inlet during the surge cycles. Measurements also covered engine performance parameters such as in-cylinder pressure and the impact of compressor surge on the composition of the exhaust gas emitted from the engine. The measurements describe in detail the response of a marine diesel engine to variations caused by compressor surge. The results show that both turbocharger and engine performance are affected by compressor surge and fast Fourier transform (FFT) analysis proved that they oscillate at the same main frequency. Also, prolonged steady-state operation of the engine with this form of compressor surge led to a non-negligible increase of NOx emissions.

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