Browse Topic: Marine engines

Items (294)
Maritime transportation plays a vital role in the economy and is one of the most energy-efficient modes of transportation. However, it is a growing source of greenhouse gas emissions. A potential solution to lower carbon emissions from maritime transport is to use renewable fuels in marine engines. Hydrogen or methanol can serve as the primary energy source in internal combustion (IC) engines. However, their high autoignition temperatures require an external ignition source to start combustion in compression ignition (CI) engines. The Dual Fuel (DF) approach offers an effective method for incorporating these fuels. To accurately simulate dual fuel combustion, certain parameters need to be carefully addressed. One crucial parameter to investigate is estimating the flame entrainment area, as it directly affects the mass burning rate. In this work, a novel geometric approach is developed to estimate the evolution of the flame entrainment area. This model is integrated into a multi-zone
Parsa, SomayehDaenens, ArthurVerschaeren, RoelDierickx, JeroenVerhelst, Sebastian
This paper explores the potential of leveraging methanol's knock-resistant properties to facilitate both dual fuel (DF) and spark ignition (SI) operation in retrofitted heavy-duty (HD), high-speed marine engines. The study involves retrofitting an original 6-cylinder 7.15L CI diesel engine with port fuel injection (PFI) of methanol to enable DF operation. Later, the diesel injectors were replaced with six spark plugs allowing SI operation. Notably, efforts were made to minimize adaptations to the existing diesel engine, maintaining the compression ratio (CR) at 17.6:1 and retaining the same turbocharging pressure. This research aims to assess the feasibility of retrofitting conventional HD diesel engines (high CR, large bore) for dual-fuel and SI operation on methanol, with a focus on optimizing engine performance, while preserving key characteristics for HD applications, e.g. high torque and high power density. The high CR required spark retarding to prevent knock at higher loads in
Dejaegere, QuintenBallerini, AlbertoDemiddeleer, SheldonVanderbeken, ThomasBracke, KwintenGyselinck, BenD'Errico, GianlucaVerhelst, Sebastian
With the adoption of the IMO Greenhouse Gas Emission Reduction Strategy Revision, the international shipping industry is facing huge pressure to reduce greenhouse gas emissions, and the conversion of ship power from traditional fossil fuels to low-carbon and zero-carbon fuels is the fundamental solution, and ammonia fuel, as a zero-carbon fuel, is an important direction for the development of ship power in the future. Based on a marine low-speed diesel engine with a bore of 520 mm, computational fluid dynamics (CFD) numerical simulation was carried out to study the effects of different diesel energy fractions, ammonia injection pressure, ammonia injection timing and ammonia diesel injection interval on the combustion and emission characteristics of the engine under the dual-fuel combustion mode of high-pressure dual direct injection. The calculation results show that under the condition of the current engine, 5% of diesel energy can reduce carbon emissions by 92.8% under the premise of
Yang, JinchengLiu, LongGui, Yong
Nowadays, the energy transition is at the most critical moment. In order to achieve the emission reduction target of ships, a form of boosting piston inside methanol fuel injector has been carried out. The physical property fluctuations and phase change of methanol under high pressure have been considered in the design phase. 1D-3D coupling method is used to comprehensively evaluate the performace of the injector. To this end, an Amesim simulation model is established to systematically study and analyze the injection characteristics. The injection performance of the injector under four typical loads are calculated, which is evaluated from the perspectives of injection quantity, injection duration, valve response, and leakage of boost components. In the nozzle block, the cavitation intensity of methanol is stronger than that of diesel. To reduce the possibility of cavitation erosion, as a consequence, a CFD model is established to optimize the structure of nozzle components. By adding
Yang, LiWen, LimingZhang, HanwenLu, GangaoDong, Weijie
This study presents a method for identifying the reliability state of diesel engines by utilizing artificial neural networks (ANNs). The Sulzer 6AL20/24 marine diesel engine was selected as the test subject for this research. Vibration signals were collected during tests conducted on a laboratory test stand under normal operating conditions and during simulations of six different engine faults. Next, the recorded signals were analyzed and transformed into labeled samples for supervised learning. In this phase, the time histories of the vibration signals were divided into segments and augmented, with several key features calculated for each segment. Highly correlated signals were excluded from further analysis based on the Pearson correlation coefficient. The processed samples were then used to train and fine-tune the ANN. The trained ANN was subsequently used to identify the engine’s reliability state and classify the present fault type. To evaluate the effectiveness of the proposed
Pająk, MichałKluczyk, MarcinMuślewski, ŁukaszLisjak, Dragutin
The purpose of this SAE Recommended Practice is to provide guides toward standard conditions for operating marine engine throttles (gasoline or diesel) where push-pull cable control is applicable. For control cable information see SAE J917.
Marine Technical Steering Committee
Ammonia-fired reciprocating engines have emerged as a promising technology in the maritime and power generation sector at medium-to-large scale (1–80 MW). The use of “on-the-fly” partial ammonia decomposition to produce a relatively small amount of hydrogen that can be used as combustion promoter, replacing fossil fuels in this function, enables this technology to provide carbon-free propulsion and power generation. In this context, it is envisioned that a hydrogen-fired prechamber ignition strategy offers significant advantages by accelerating the ammonia ignition and complete combustion process, increasing its reliability and robustness while still aiming to achieve low NO x , N2O, and NH3 emissions. This study exploits an OpenFOAM-based Large Eddy Simulation (LES) numerical modeling framework to investigate the ignition and combustion behavior of an ammonia main charge ignited by a hydrogen-fired prechamber. First, a conventional port-injection premixed configuration for the ammonia
Indlekofer, ThomasHaugen, Nils ErlandFørde, Olav ØyvindGruber, Andrea
This study explores the feasibility of using a sustainable lignin-based fuel, consisting of 44 % lignin, 50 % ethanol, and 6 % water, in conventional compression ignition (CI) marine engines. Through experimental evaluations on a modified small-bore CI engine, we identified the primary challenges associated with lignin-based fuel, including engine startup and shutdown issues due to solvent evaporation and lignin solidification inside the fuel system, and deposit formation on cylinder walls leading to piston ring seizure. To address these issues, we developed a fuel switching system transitioning from lignin-based fuel to cleaning fuel with 85 vol% of acetone, 10 vol% of water and 5 vol% of ignition improving additive, effectively preventing system clogs. Additionally, optimizing injection parameters, adopting a constant pressure delivery valve, and fine-tuning injection timing mitigated lignin deposit formation related to incomplete combustion or spray tip penetration to the cylinder
Terauchi, MotokiSimonsen, TorMortensen, SimonSchramm, JesperIvarsson, Anders
This SAE Recommended Practice specifies graphic symbols for operator controls, gauges, tell-tales, indicators, instructions, and warning against risks in small craft and for engines and other equipment intended to be used in small craft.
Marine Technical Steering Committee
Using ammonia as a carbon-free fuel is a promising way to reduce greenhouse gas emissions in the maritime sector. Due to the challenging fuel properties, like high autoignition temperature, high latent heat of vaporization, and low laminar flame speeds, a dual-fuel combustion process is the most promising way to use ammonia as a fuel in medium-speed engines. Currently, many experimental investigations regarding premixed and diffusive combustion are carried out. A numerical approach has been employed to simulate the complex dual-fuel combustion process to better understand the influences on the diffusive combustion of ammonia ignited by a diesel pilot. The simulation results are validated based on optical investigations conducted in a rapid compression–expansion machine (RCEM). The present work compares a tabulated chemistry simulation approach to complex chemistry-based simulations. The investigations evaluate the accuracy of both modeling approaches and point out the limitations and
Krnac, DominikManickam, BhuvaneswaranHoland, PeterPathak, UtkarshScharl, ValentinSattelmayer, Thomas
Internal combustion engines are becoming ever more efficient as mankind seeks to mitigate the effects of climate change while still maintaining the benefits that a mechanized society has brought to the global economy. As peak values, mass production spark-ignition engines can now achieve approximately 40% brake thermal efficiency and heavy-duty truck compression-ignition engines can approach 50%. While commendable, the unfortunate truth is that the remainder gets emitted as waste heat and is sent to the atmosphere to no useful purpose. Clearly, if one could recover some of this waste heat for beneficial use then this is likely to become important as new means of mitigating fossil CO2 emissions are demanded. A previous study by the authors has identified that the closed Joule cycle (or complications of it beginning to approximate the closed Ericsson cycle) could reasonably be developed to provide a practical means of recovering exhaust heat when applied to a large ship engine. In that
Turner, JamesKenkoh, Kesty YongGubba, SreenivasaVorraro, Giovanni
Present work investigates the relationship between the combustion parameters of a well-known ECN heavy-duty nozzle called Spray D and marine-size nozzles. The study is carried out in OpenFOAM software within the framework of RANS turbulence modelling, using a flamelet based tabulation technique known as FGM to model the combustion. The large nozzles are tested in a constant volume chamber representative of marine engines, for which a CFD setup is validated against inert data in literature. The reacting results have been validated first with experimental data, initializing the domain with a highly reactive environment (23% oxygen) and engine-like swirl. Then, a less reactive initial condition was set up in the domain (15% oxygen) without swirl, to achieve a Spray D-like environment. The main goal is to study the variation of the combustion parameters Ignition Delay Time (IDT) and Lift-Off Length (LOL) as function of nozzle diameter, leading to a mathematical correlation to estimate the
Di Matteo, AndreaSomers, Bart
Methanol is a suitable alternative fuel to relieve the problem of energy shortage and decrease the emission of greenhouse gases. The effect of direct-injection timing of methanol and diesel on the combustion characteristics of a marine diesel engine with bore of 210 mm was simulated with a 3-dimentional computational fluid dynamic (CFD) software AVL-FIRE. The combustion model was set-up and validated by the experimental data from the marine diesel engine. Results show that there are two peaks on the heat release rate (HRR) curves with the normal diesel-methanol combustion process. The first HRR peak is caused by the combustion of diesel. The second HRR peak is resulted from the hybrid combustion process of diesel and methanol. The injection timing of diesel influences the peak pressure rise rate (PPRR) and ignition timing. The indicated mean effective pressure (IMEP), the maximum in-cylinder pressure and combustion duration are influenced by the direct-injection timing of methanol
Li, XiaoYan, PingLi, Hong-MeiZheng, LiangShen, GangHu, Yu-ChenHan, Dan
Ammonia is a widely used and known chemical. Today it is seen as a carbon free solution to fuel thermal engines especially in applications where other solutions would not be realistic. For marine applications, electrical or fuel cells solutions for example would not allow spans long enough to sustain big cargo ships ranges. Engine manufacturer such as MAN, Wartsila or Win-GD have already announced the development of marine engine running on ammonia. But while ammonia is a non-CO2 emitting fuel, it has some caveats such as being gaseous in standard conditions and hard to ignite. As it is now, ammonia is usually used in compression ignition engines with the help of highly reactive carbonated pilot fuels. Many forms of dual-fuel combustion are conceivable, although all the simple ones use a carbon-based fuel and quite often originated from fossil oil. The addition of High Reactivity Fuel to Ammonia is an interesting combustion mode that can be used to calibrate different fuel parameters
Samson, RichardMorin, Anne-GaëlleFoucher, Fabrice
A phenomenological model for high-pressure direct injection natural gas-diesel dual-fuel marine engine was developed, which includes natural gas mixing process using Musculus discrete control volume transient diesel jet model, combustion process using quasi-steady model and Woschini heat transfer model, NO generation using Zeldovich mechanism. Effects of natural gas injection pressure and the start of injection timing on the mixing and combustion process were investigated. The results indicated that increasing the injection pressure with fixed injection mass, the NO emission decreased. While the start of injection timing was before TDC, retarding the injection start timing will increase NO generation.
Xiong, QianLiang, DezhiWang, LujiangShi, XinruLiu, LongMa, Xiuzhen
Ammonia, as a carbon-free fuel, is a promising alternative fuel source for decarbonization of the shipping industry. Nevertheless, the poor flammability and low flame speed restrict its potential application as marine engine fuel. In order to explore the ammonia application feasibility and methods in marine engines, the effects of two combustion promoters, including n-heptane and hydrogen, on improving the ammonia combustion characteristics were compared and discussed theoretically in this study, in terms of flammable intake boundary conditions and laminar flame speed under engine operating conditions. A new detailed reaction mechanism of ammonia/n-heptane dual fuel was developed and validated to characterize the combustion of ammonia and diesel. The results demonstrate that the flammability of ammonia is more sensitive to intake temperature as compared to equivalence ratio and intake pressure. The introduction of n-heptane or hydrogen has been observed to have a noteworthy impact on
Liu, LongWu, YueWang, YangWu, JieWang, Xiqing
Heavy heat load is one of the bottlenecks restricting the highly intensive marine engine development. Reducing wall heat loss contributes to this target. The wall heat transfer is mainly influenced by flame-wall interaction (FWI). In this paper, a wall temperature distribution measurement system is developed based on the Laser-Induced Phosphorescence (LIP). The effects of the coating thickness and the laser fluence on LIP are studied to clarify the accuracy of wall temperature measurement based on LIP and the one-dimensional wall temperature distribution. In addition, a conjugate heat transfer model of FWI was established based on CONVERGE to simulate the FWI and the accompanying heat transfer process. The simulation is compared with the experimental wall temperature results and demonstrates the effectiveness of the conjugate heat transfer model. The influence of the initial velocity, the impinging distance and the wall roughness on the wall heat transfer are studied. The effective way
Xuefeng, XUERun, CHENTie, LIXinyi, ZHOUJiale, CAOXin, TANG
Due to the incoming phase out of fossil fuels from the market in order to reduce the carbon footprint of the automotive sector, hydrogen-fueled engines are candidate mid-term solution. Thanks to its properties, hydrogen promotes flames that poorly suffer from the quenching effects toward the engine walls. Thus, emphasis must be posed on the heat-up of the oil layer that wets the cylinder liner in hydrogen-fueled engines. It is known that motor oils are complex mixtures of a number of mainly heavy hydrocarbons (HCs); however, their composition is not known a priori. Simulation tools that can support the early development steps of those engines must be provided with oil composition and properties at operation-like conditions. The authors propose a statistical inference-based optimization approach for identifying oil surrogate multicomponent mixtures. The algorithm is implemented in Python and relies on the Bayesian optimization technique. As a benchmark, the surrogate for the SAE5W30
De Renzis, EdoardoMariani, ValerioBianchi, Gian MarcoCazzoli, GiulioFalfari, Stefania
The upcoming regulations to achieve zero-emission passenger transport present challenges for designing new ferry powertrains. The proposed work investigates the feasibility of using a Proton Exchange Membrane Fuel Cell (PEMFC) power system to power a long-haul ferry. The paper describes the zero-order cell model as well as the method for estimating cell degradation. The stack modeling, heat balance equations, and auxiliary modeling are also presented. The proposed model enables the simulation of the fuel cell under different operating conditions and includes the use of air or oxygen as an oxidizer. A thermal management strategy for the overall PEMFC system is also proposed. The model was calibrated on the characteristic curves of the PEMFC Ballard FCvelocity™ HD6 (150 kW) and validated by reproducing experimental results. Then, a real load profile of a ferry, as well as the proposed powertrain is considered as case study. The presented results are related to a single daily mission and
Saponaro, GianmarcoStefanizzi, MicheleFranchini, EmanueleTorresi, MarcoCamporeale, Sergio
The transport of goods and people by sea, today, must meet the need to reduce the consumption of fuel oil. In addition, it has to ensure operational reliability and vessel availability, to reduce maintenance costs and comply with emission legislation. To this end, it is necessary to apply a marine engine combustion control system already widely used in engines for land transport. This will allow the ship's engines to operate reliably and in compliance with the best performance for which it was designed. The combustion control could also ensure a more balanced operation of the cylinders and reduce the torsional vibrations of the entire engine, as well as the management of the engine according to the adopted fuel: diesel, dual fuel, methanol, ammonia. Generally, the control of combustion in engines is carried out through the use of pressure sensors that face directly into the combustion chamber. These are expensive systems and are affected by the severe operating conditions of the marine
Mancaruso, EzioDe Simio, LuigiIannaccone, SabatoMarchitto, LucaVaglieco, Bianca MariaMilano, LucaCameretti, Maria Cristina
With a view to reducing the environmental impact of fossil fuels, advanced lignin-based biofuels could provide a valuable contribute, since lignin is the most abundant biopolymer on earth after cellulose. However, its thermophysical properties would hamper its use as a pure fuel. In this work we investigated the combustion behavior of sprays of a liquid lignin-methanol blend and evaluated its potential as a low-carbon marine fuel for large two-stroke engines. To this end, an experimental campaign was conducted in an optically accessible combustion chamber whose main dimensions correspond to those of a single cylinder for large two-stroke engines. The chamber is provided with optical accesses for optical diagnostics of the combustion process. The combustion of the mixture was ignited using a diesel pilot jet as the ignition source. Two marine injectors are mounted in the chamber, namely “main” and “pilot” injectors. The tests were performed in environmental conditions around 40 bar and
Lazzaro, MaurizioSementa, PaoloCatapano, FrancescoTornatore, CinziaIannuzzi, StefanoBoot, MichaelKouris, Panos
The use of renewable fuels such as hydrogen and methanol in marine engines is a promising way to reduce greenhouse gas emissions from maritime transport. Hydrogen and methanol can be used as the main fuel in dual-fuel engines. However, the co-combustion of hydrogen-diesel and methanol-diesel needs to be carefully studied. In the present work, the ignition delay (ID) and laminar burning velocity (LBV) for pilot-ignited dual fuel engine operation with hydrogen or methanol are studied. A constant volume batch reactor numerical setup is used in the open source Cantera code to calculate the effect of the premixed fuel on the ID of the pilot fuel. Also, Cantera is used to simulate a freely-propagating, adiabatic, 1-D flame to estimate the laminar flame speed of either hydrogen or methanol and how it is affected by the presence of pilot fuel. First, suitable chemical kinetic schemes are selected based on experimental data collected from the literature. Then ID and LBV are estimated for
Parsa, SomayehVerhelst, Sebastian
In the upcoming decade sustainable powertrain technologies will seek for market entrance in the transport sector. One promising solution is the utilization of dual-fuel engines using renewable methanol ignited by a pilot diesel fuel. This approach allows the displacement of a significant portion of fossil diesel, thereby reducing greenhouse gas emissions. Additionally, this technology is, next to newbuilds, suited for retrofitting existing engines, while maintaining high efficiencies and lowering engine-out emissions. Various researchers have experimentally tested the effects of replacing diesel by methanol and have reported different boundaries for substituting diesel by methanol, including misfire, partial burn, knock and pre-ignition. However, little research has been conducted to explore ways to extend these substitution limits. Therefore, this study aims to investigate the effects of intake conditions, such as intake air temperature and pressure, and exhaust gas recirculation (EGR
Dierickx, JeroenDejaegere, QuintenVan Gijzeghem, AndreasDevos, StanDe Cock, BertenVerhelst, Sebastian
This paper describes a recommended practice and procedure for the correlation of test cells that are used for the performance testing of APU (auxiliary power unit) engines. Test cell correlation is performed to determine the effect of any given test cell enclosure and equipment on the performance of an engine relative to the baseline performance of that engine. The baseline performance is generally determined at the original equipment manufacturer (OEM) designated test facility. Although no original equipment manufacturer (OEM) documents are actually referenced, the experience and knowledge of several OEMs contributed to the development of this document. Each engine Manufacturer has their own practices relating to correlation and they will be used by those OEMs for the purpose of establishing certified test facilities.
EG-1E Gas Turbine Test Facilities and Equipment
This paper describes a recommended practice and procedure for the correlation of test cells that are used for the performance testing of turboprop and turboshaft engines. This Aerospace Recommended Practice (ARP) shall apply to both dynamometer and propeller based testing. Test cell correlation is performed to determine the effect of any given test cell enclosure and equipment on the performance of an engine relative to the baseline performance of that engine. Although no original equipment manufacturer (OEM) documents are actually referenced, the experience and knowledge of several OEMs contributed to the development of this document. Each engine manufacturer has their own practices relating to correlation and they will be used by those OEMS for the purpose of establishing certified test facilities.
EG-1E Gas Turbine Test Facilities and Equipment
This SAE Aerospace Recommended Practice (ARP) describes a recommended practice and procedure for the correlation of test cells that are used for the performance testing of turbofan and turbojet engines. Test cell correlation is performed to determine the effect of any given test cell enclosure and equipment on the performance of an engine relative to the baseline performance of that engine. When baseline testing is performed in an indoor test cell, the baseline performance data are adjusted to open air conditions. Although no original equipment manufacturer (OEM) documents are actually referenced, the experience and knowledge of several OEM’s contributed to the development of this document. Each engine Manufacturer has their own practices relating to correlation and they will be used by those OEMs for the purpose of establishing certified test facilities.
EG-1E Gas Turbine Test Facilities and Equipment
The thermal and mechanical loads of the engine rise dramatically with the increase in engine power density, which places higher demands on the design of the piston. In this paper, the design development of a steel piston for a marine diesel engine belonging to 190 series heavy-duty diesel engines was studied. The design methods including material selection and structural design were used to finished the preliminary design. In the meanwhile, the design philosophies of the aluminum alloy piston and composite piston for the 190 series diesel engines were used for reference in the design process. The designed steel piston was tested in the engine durability bench test and simulated for reliability. The results showed that the failure of the steel piston occurred at the same position in both the test and the simulation. The cause of cracking in the steel piston was analyzed, and the insufficient strength of the local structure led to high-cycle fatigue failure. Based on the failure
Liu, YipengJing, GuoxiZhang, LongfeiHan, MengyuZhang, WeibinLiu, HaiZhang, Zhongwei
In marine or stationary engines, consistent engine performance must be guaranteed for long-haul operations. A dual-fuel combustion strategy was used to reduce the emissions of particulates and nitrogen oxides in marine engines. However, in this case, the combustion stability was highly affected by environmental factors. To ensure consistent engine performance, the in-cylinder pressure measured by piezoelectric pressure sensors is generally measured to analyze combustion characteristics. However, the vulnerability to thermal drift and breakage of sensors leads to additional maintenance costs. Therefore, an indirect measurement via a reconstruction model of the in-cylinder pressure from engine block vibrations was developed. The in-cylinder pressure variation is directly related to the block vibration; however, numerous noise sources exist (such as, valve impact, piston slap, and air flowage). A deep neural network (DNN) model is among the most feasible ways to reconstruct the in
Kim, GyeonggonPark, ChansooKim, WooyeongJeon, JeeyeonJeon, MiyeonBae, ChoongsikKim, Wooyeong
This SAE Recommended Practice covers all electrical devices suitable for use in marine engine compartments and fuel tank spaces.
Marine Technical Steering Committee
Obtaining and analyzing indicator diagrams are mandatory procedures stipulated by the technical operating rules for most types of marine engines. For this purpose a whole arsenal of mechanical and electronic indicating devices of periodic or continuous action is created. Information on the results of engine indications in bench tests are usually provided by the manufacturer in the form of bitmaps. This complicates the process of using them as reference diagrams necessary for comparison with real diagrams obtained during operation using electronic diagnostic systems. Changes in approaches to logistics operations in maritime transport have imposed a number of limitations, narrowing the use of indicator methods. The tendency to reduce the commercial speed of ships makes it impossible to take indicator diagrams on the specified modes of operation. As a result, the effectiveness of using indicator diagrams for assessing the current technical condition is drastically reduced. In this regard
Belousov, EvgenMarchenko, AndriiRybalchenko, MykolaTuluchenko, GalinaGritsuk, IgorSavchuk, VolodymyrVolodarets, Mykyta
Optical combustion phenomena investigation is a common tool for passenger car and automotive engines. Large-bore engines for stationary and mobile applications, on the other hand, have a lower optical examination density. This is mainly due to the technically more complex design of the optical accesses that have to provide a larger field of view and withstand high mechanical and thermal loads. Nevertheless, an optical investigation of in-cylinder phenomena in large-bore engines is essential to optimize efficient and environmentally friendly combustion processes using new sustainable e-fuels. To realize a simple optical access with maximum observability of the combustion chamber, a fisheye optic for the direct integration into internal combustion engines was developed and used for in-cylinder Mie-scattering investigations of diesel and Oxymethylene Ether (OME3-5) pilot fuel spray of natural gas dual-fuel combustion processes in a MAN 35/44DF single-cylinder research engine. As this
Karmann, Stephan BernhardWeber, StefanStürzl, WolfgangPrager, MaximilianJaensch, MalteWachtmeister, Georg
This paper experimentally investigates the effects of water-diesel emulsion properties on marine diesel engine performance and exhaust emissions. The study was conducted in a six-cylinder, in-line, four-stroke, direct-injection 3D6 marine diesel engine that runs on water-diesel emulsion and pure diesel fuel according to the propeller characteristic. The results show that the chemical energy of the gas mixture in the cylinders of an engine using the water-diesel emulsion of 15% water content was 0.875 times that of diesel fuel. The emulsion consumption must be increased by 1.14 times to compensate for the loss of chemical energy, and the excess air coefficient is more significant by 1.225 times. A part of the heat released from the reactions is spent on water evaporation during emulsion combustion, which reduces the exhaust gas temperature and NOx by more than 35%. On average, the smoke number is higher by 2% in low-speed modes, while it is less than 3% in other operating modes. The
Hiep, Nguyen HaQuan, Nguyen Quoc
The world of shipping is at a turning point. Alongside methanol, ammonia and other PtL (Power to Liquid) fuels, liquefied natural gas (LNG) offers one way of achieving climate-friendly ship operation. Although currently still derived from fossil sources, LNG combines the properties of already having a well-established land-based infrastructure, of enabling a 100 % climate-neutral supply via electrolysis and methanization, and of its ability for any high proportion of climate-neutral LNG to be used as a drop-in fuel during the transformation process in the next decades; proven by the first bunkering of the container vessel “ElbBlue” with 20 tons of SNG (Synthetic Natural Gas) in 2021 [1]. Up to now, LNG fueled marine engines have predominantly been operated in fixed operation areas. Therefore, they can bunker stable gas qualities at specific ports and can be optimized for a specific gas quality. This has mostly been done by means of adapted engine control maps and hardware adjustments
Schleef, KarstenHenke, BjörnCepelak, SebastianGlauner, ManuelDinwoodie, JulesTheile, MartinBuchholz, Bert
With low-temperature combustion engine research reaching an applicable level, physics-based control-oriented models regain attention. For reactivity controlled combustion concepts, chemical kinetics-based multizone models have been proven to reproduce the governing physics for performance-oriented simulations. They offer accuracy levels similar to high-fidelity computational fluid dynamics (CFD) models but with a fraction of their computational effort. Nevertheless, state-of-the-art reactivity controlled compression ignition (RCCI) simulations with multizone model toolchains still face challenges related to predictivity and calculation speed. This study introduces a new multizone modelling framework that addresses these challenges. It includes a C++ code, deeply integrated with open-source, thermo-kinetic libraries, and coupled to an industry standard 1-D modelling framework. Incorporating a predictive turbulence mixing model, it aims to eliminate dependence on CFD-based initialisation
Vasudev, AneeshCafari, AlbertoAxelsson, MartinMikulski, MaciejHyvonen, Jari
Leonardo DRS Inc. Arlington, VA 571-447-4624
This SAE Standard establishes the procedure for determining the operator duty cycle sound pressure level Lodc to which operators of powered recreational craft up to 24 m in length are exposed during typical operation as determined by marine engine duty cycle studies. This document describes the instrumentation, the required calibration procedures, the test site, the specifications for “standard craft”, the craft operating conditions, microphone positioning, test procedure, engine speeds for each of the Duty Cycle modes and the formula and table for calculating the Duty Cycle operator ear sound pressure level. This document is subject to change to keep pace with technical advances as well as other international standards and practices. Changes in this Revision: The sound pressure level measurements performed while applying this document are based on the Five-Mode Marine Engine Duty Cycle instead of a single engine speed. A calculation is required to obtain the Duty Cycle operator ear
Marine Technical Steering Committee
The greatest frictional contributor in an internal combustion engine is the contact between the piston ring pack and cylinder liner. Therefore, an improved lubrication regime has the potential to raise engine efficiency while lowering emissions, aiding to meet environmental regulations. Previous ultrasonic measurements of the oil film thickness (OFT) between piston rings and the cylinder liner in a marine engine have been subject to several unexpected trends. This article refines the measurement to identify and remove these factors, the trends were found to have arisen due to the detection of ultrasonic reflections from the piston ring outside of the expected alignment zone. The extent of these undesired reflections is thought to be due to the liner thickness providing a relatively large distance for spreading of the ultrasonic wavefront. The hitherto used Frequency Index method (index of the fast Fourier transform (FFT) at the transducer central frequency) has been compared to the
Rooke, JackLi, XiangweiDwyer-Joyce, Robert S.
To improve the combustion and emission characteristics of the large-bore marine engines, the spray is usually designed as an inter-spray impingement to promote the fuel-air mixing process, which implies frequent droplet collisions. Properly describing the collision dynamics of liquid droplets has been of interest in the field of spray modeling for marine engine applications. In this context, this work attempts to develop an accurate and efficient methodology for modeling impinging sprays under engine-like conditions. Experimental validations in terms of spray penetration and morphology are initially carried out at different operating conditions considering the parametric variations of ambient temperature and pressure, where the measurements are performed on a large-scale constant volume chamber with two symmetrical injectors. The existing models, including O’Rourke and Nordin’s collision models, are also applied and the obtained results are compared to further assess the accuracy and
Zhou, QiyanLucchini, TommasoD'Errico, GianlucaParedi, DavideXia, JinLu, Xingcai
The article contains the results of operational investigations of deposit formation on external and internal surfaces of injector nozzles of the marine self-ignition engines during their operational use. The aim of this article is to introduce an image analysis method for global assessment of the quantity and quality of injector nozzle deposits in piston internal combustion engines. The components of medium-speed marine engines fueled with distillation and residual fuels were investigated. Digital images of new and used injector nozzles without deposits and with random deposits formed after natural operation on marine ships, respectively, were taken. Macro and microscopy images of external surfaces were taken in a shadowless tent and were illuminated with low-temperature lamps. The characteristic surfaces of the injector nozzles were virtually separated from the white background. The amount and quality of the resulting deposits on individual injector nozzles was determined by means of
Monieta, Jan
The article presents results of tests performed with the use of a ship engine of the type Sulzer 6AL20/24. The goal of the tests was to create and verify an identification procedure for the analyzed object’s reliability states to be used without interfering with the object operation processes. The proposed method is based on an analysis of vibrations and noise generated during the engine operation, which are considered to be the most significant diagnostic signals. The signals of the engine vibrations and noise recorded during the engine operation on a laboratory test stand have been analyzed in the time domain. A number of the recorded signal characteristics are calculated. The characteristics are statistically analyzed in order to choose those which can provide the basis for the identification of reliability states. Next, based on the spaces of ability and inability, states are formulated. The spaces are used for the identification of ability states and selected inability states
Pająk, MichałMuślewski, ŁukaszKluczyk, MarcinKolar, DavorLandowski, BogdanKałaczyński, Tomasz
The widespread application and increasingly stringent emission regulations call for more attention to optimize combustion process and emissions of marine diesel engine. This study conducts a numerical study to investigate the individual effect and their interaction of three post injection duration (3°CA, 5°CA and 7°CA), four spray included angles (145°, 150°, 155° and 160°) and four swirl ratios (0.5, 0.85, 1.2 and 1.6) in a marine diesel engine with main-post injection. These three parameters all exert impact on in-cylinder combustion performance and emissions by affecting fuel-air mixing quality. Results show that decreasing post injection duration from 7°CA to 3°CA shortens the combustion duration and decreases soot emission by 13.2%, while that induces a slight increase in NOx emissions by 1.0%. Spray included angle changes the spray targeting position within the combustion chamber. Wider spray included angle raises the peak value of in-cylinder pressure by 1%, decreases indicated
Zhao, ChangpuKong, ShiruBian, Zhishang
This SAE Standard covers dimensions, performance parameters, and nomenclature of a push-pull control cable used in outboard, inboard, and sterndrive marine throttle and shift applications.
Marine Technical Steering Committee
In this work, the possibility to perform a cold-flow simulation as a way to improve the accuracy of the starting conditions for a combustion simulation is examined. Specifically, a dual-fuel marine engine running on methanol/diesel and natural gas/diesel fueling conditions is investigated. Dual-fuel engines can provide a short-term solution to cope with the more stringent emission legislations in the maritime sector. Both natural gas and methanol appear to be interesting alternative fuels that can be used as main fuel in these dual-fuel engines. Nevertheless, it is observed that combustion problems occur at part load using these alternative fuels. Therefore, different methods to increase the combustion efficiency at part load are investigated. Numerical simulations prove to be very suitable hereto, as they are an efficient way to study the effect of different parameters on the combustion characteristics. These simulations often describe the engine with a limited engine geometry
Decan, GillesDe Buyzerie, BertLucchini, TommasoD'Errico, GianlucaVerhelst, Sebastian
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