scholarly journals An Approach for Predicting the Specific Fuel Consumption of Dual-Fuel Two-Stroke Marine Engines

2019 ◽  
Vol 7 (2) ◽  
pp. 20 ◽  
Author(s):  
Crístofer Marques ◽  
Jean-D. Caprace ◽  
Carlos Belchior ◽  
Alberto Martini
Keyword(s):  
Programming Languages ◽  
Fuel Consumption ◽  
Simulation Models ◽  
Specific Fuel Consumption ◽  
Dual Fuel ◽  
Marine Fuel ◽  
Proposed Model ◽  
Marine Engines ◽  
Dual Fuel Engines ◽  
Selection Of

Increasing environmental demands, alongside the planned penetration of natural gas as marine fuel, have rendered dual-fuel engines as an attractive prime mover alternative. In this context, knowing the specific fuel consumption is essential to selecting the most efficient engine. The specific fuel consumption can be approached by simulation models with varying levels of complexity that are either implemented by basic programming languages or simulated by dedicated packages. This study aims to develop a simplified model to predict the specific fuel consumption of dual-fuel two-stroke marine engines driving fixed or controllable pitch propellers. The model relies on clear trends approachable by polynomials that were revealed by normalizing specific fuel consumption. This model requires only the value of specific fuel consumption at a nominal maximum continuous rating to predict the engine consumption at any specified rating, including at partial engine load. The outcome of the study shows that the maximum deviations regarding the two simulated engines did not exceed −3.6%. In summary, the proposed model is a fast and effective tool for optimizing the selection of dual-fuel, two-stroke Diesel engines regarding fuel consumption.

scholarly journals Optimization of the Performance of Marine Diesel Engines to Minimize the Formation of SOx Emissions

2020 ◽  
Vol 19 (3) ◽  
pp. 473-484
Author(s):  
Mina Tadros ◽  
Manuel Ventura ◽  
C. Guedes Soares
Keyword(s):  
Fuel Consumption ◽  
Diesel Engines ◽  
Engine Speed ◽  
Exhaust Emissions ◽  
Polynomial Equations ◽  
Marine Fuel ◽  
Marine Engines ◽  
Marine Diesel ◽  
Marine Applications ◽  
Generate Polynomial

Abstract Optimization procedures are required to minimize the amount of fuel consumption and exhaust emissions from marine engines. This study discusses the procedures to optimize the performance of any marine engine implemented in a 0D/1D numerical model in order to achieve lower values of exhaust emissions. From that point, an extension of previous simulation researches is presented to calculate the amount of SOx emissions from two marine diesel engines along their load diagrams based on the percentage of sulfur in the marine fuel used. The variations of SOx emissions are computed in g/kW·h and in parts per million (ppm) as functions of the optimized parameters: brake specific fuel consumption and the amount of air-fuel ratio respectively. Then, a surrogate model-based response surface methodology is used to generate polynomial equations to estimate the amount of SOx emissions as functions of engine speed and load. These developed non-dimensional equations can be further used directly to assess the value of SOx emissions for different percentages of sulfur of the selected or similar engines to be used in different marine applications.

scholarly journals Multiobjective Optimisation of a Marine Dual Fuel Engine Equipped with Exhaust Gas Recirculation and Air Bypass Systems

Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5021
Author(s):  
Sokratis Stoumpos ◽  
Gerasimos Theotokatos
Keyword(s):  
Fuel Consumption ◽  
Engine Performance ◽  
Exhaust Gas Recirculation ◽  
Specific Fuel Consumption ◽  
Dual Fuel ◽  
Nox Emissions ◽  
Exhaust Gas ◽  
Brake Specific Fuel Consumption ◽  
Gas Recirculation ◽  
Optimisation Techniques

Dual fuel engines constitute a viable solution for enhancing the environmental sustainability of the shipping operations. Although these engines comply with the Tier III NOx emissions regulations when operating at the gas mode, additional measures are required to ensure such compliance at the diesel mode. Hence, this study aimed to optimise the settings of a marine four-stroke dual fuel (DF) engine equipped with exhaust gas recirculation (EGR) and air bypass (ABP) systems by employing simulation and optimisation techniques, so that the engine when operating at the diesel mode complies with the ‘Tier III’ requirements. A previous version of the engine thermodynamic model was extended to accommodate the EGR and ABP systems modelling. Subsequently, a combination of optimisation techniques including multiobjective genetic algorithms (MOGA) and design of experiments (DoE) parametric runs was employed to identify both the engine and the EGR/ABP systems settings with the objective to minimise the engine brake specific fuel consumption and reduce the NOx emissions below the Tier III limit. The derived simulation results were employed to analyse the EGR system involved interactions and their effects on the engine performance and emissions trade-offs. A sensitivity analysis was performed to reveal the interactions between considered engine settings and quantify their impact on the engine performance parameters. The derived results indicate that EGR rates up to 35% are required, so that the investigated engine with EGR and ABP systems, when operating at the diesel mode, achieves compliance with the ‘Tier III’ NOx emissions, whereas the associated engine brake specific fuel consumption penalty is up to 8.7%. This study demonstrates that the combination of EGR and ABP systems can constitute a functional solution for achieving compliance with the stringent regulatory requirements and provides a better understating of the underlined phenomena and interactions of the engine subsystems parameters variations for the investigated engine equipped with EGR and ABP systems.

scholarly journals Selected aspects of application of dual fuel marine engines

2012 ◽  
Vol 148 (1) ◽  
pp. 25-34
Author(s):  
Tomasz KNIAZIEWICZ ◽  
Leszek PIASECZNY
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Liquid Fuels ◽  
Dual Fuel ◽  
Fuel Gas ◽  
Simulation Research ◽  
Marine Engine ◽  
Marine Engines ◽  
Dual Fuel Engines ◽  
Marine Vessels

The paper presents examples of application of dual fuel marine engines based on the expertise of the largest marine engine manufacturers. The fueling systems of these engines have been presented as fueled with fuel gases in various combinations with liquid fuels. Examples of the application of dual fuel engines in vessels as well as variants of the powertrains have been shown. The results of own simulation research (Monte Carlo method) have also been presented related to the NOx emission from a variety of vessels operating in the area of the Bay of Gdansk proving that the use of engines fueled with fuel gas may indeed reduce the emission of NOx from marine vessels operating in this area.

scholarly journals INFLUENCE OF MARINE FUEL PROPERTIES ON IGNITION, INJECTION DELAY AND ENERGY EFFICIENCY

Transport ◽  
2021 ◽  
Vol 36 (4) ◽  
pp. 339-353
Author(s):  
Sergejus Lebedevas ◽  
Nadežda Lazareva ◽  
Paulius Rapalis ◽  
Vygintas Daukšys ◽  
Tomas Čepaitis
Keyword(s):  
Energy Efficiency ◽  
Fuel Consumption ◽  
High Speed ◽  
Operating Conditions ◽  
Fuel Properties ◽  
Rational Selection ◽  
Marine Fuel ◽  
Low Speed ◽  
Medium Speed ◽  
Selection Of

According to the International Council on Combustion Engines (CIMAC) and International Maritime Organization (IMO) statistics, the rational selection of Marine Bunker Fuel (MBF) properties is an effective way to improve operating conditions and energy efficiency of all types of marine Diesel Engines (DEs). The publication presents the results of studies on the influence of heavy and distillate MBF properties on the characteristics of different DE types: high-speed (Caterpillar 3512B, MTU 8V 396TB), medium-speed (SKL VDS 48/42, ChN 26.5/31) ir low-speed (MAN B&W 6S60MC). The aim of work is to form a methodological framework for assessing the influence of marine fuel properties on the energy performance of different types of ship power plants. Numerical methods show that in the case of unfavourable selection of the density and viscosity of marine fuels regulated by the standard ISO 8217:2017, the changes in specific fuel consumption be reach up to 10% low-speed, 4…7% medium-speed, and 2…3% high-speed DEs. As the density varies from light grades to 1010 kg/m3, the change in be is 3…4%. At low viscosity, as the density increases to 1030 kg/m3, the low-speed engine comparative fuel consumption increases by 5%. It is recommended not to use fuel with a density >1010 kg/m3 and a viscosity <300…400 mm2/s. Developed solutions for the rational selection of bunkered marine fuel properties for a specific DE model trough the influence of density and viscosity on fuel injection and combustion characteristics based on multiparametric diagrams of relative fuel consumption change.

Comparison of Performance of Supersonic Blading in Cascade and in Compressor Rotors

1971 ◽  
Vol 93 (1) ◽  
pp. 42-48 ◽  
Author(s):  
A. A. Mikolajczak ◽  
A. L. Morris ◽  
B. V. Johnson
Keyword(s):  
Fuel Consumption ◽  
Specific Fuel Consumption ◽  
Good Correspondence ◽  
Jet Engine ◽  
Highly Efficient ◽  
Mach Numbers ◽  
Selection Of ◽  
Meaningful Data

Reduction of engine weight and engine specific fuel consumption is a continuing goa of jet engine designers. An attractive approach is through the development of efficient, high-tip speed compressors operating with supersonic relative inlet Mach numbers. For these compressors, selection of highly efficient supersonic blading is required. Although the evaluation of new blade geometries can be obtained more conveniently from supersonic cascade tests rather than compressor, it has not yet been adequately established that good correspondence exists between cascade and compressor tests. The paper shows that such correspondence exists. In this paper performance of three airfoil shapes tested in cascade is briefly discussed and compared to the performance of similar airfoils tested in a rotor. A description of a supersonic tunnel is given and precautions necessary to obtain meaningful data are stressed. Good correspondence obtained between the cascade and rotor results is discussed.

CONTEMPORARY ASPECTS IN THE SELECTION OF TOOLS AND TECHNOLOGIES FOR DEVELOPING WEB SITES

2018 ◽  
pp. 125-131
Author(s):  
Petar Halachev ◽  
Aleksandra Todeva ◽  
Gergana Georgieva ◽  
Marina Jekova
Keyword(s):  
Programming Languages ◽  
Web Sites ◽  
Web Site ◽  
Work Process ◽  
Design And Development ◽  
Site Development ◽  
Complicated Process ◽  
The Creation ◽  
Guidelines And Recommendations ◽  
Selection Of

he report explores and analyzes the application of the most popular programming languages from different organizations: GitHub; Stackoverflow; the TIOBE's Community index. The main client technologies: HTML; CSS; JavaScript; Typescript are presented and analysed. Features are characterized and the advantages and the disadvantages of the server technologies are described: Java; PHP; Python; Ruby. The application areas for web site development technologies have been defined. The creation of a quality web site is a complex and complicated process, but by observing some guidelines and recommendations in the work process can help to select the tools and the technologies in its design and development.

Bioluminescent proteins prediction with voting strategy.

2020 ◽  
Vol 15 ◽  
Author(s):  
Shulin Zhao ◽  
Ying Ju ◽  
Xiucai Ye ◽  
Jun Zhang ◽  
Shuguang Han
Keyword(s):  
Amino Acid ◽  
Model Building ◽  
Prediction Method ◽  
Pair Composition ◽  
Proposed Model ◽  
Counting Rules ◽  
Significant Phenomenon ◽  
Voting Strategy ◽  
Improved Accuracy ◽  
Selection Of

Background: Bioluminescence is a unique and significant phenomenon in nature. Bioluminescence is important for the lifecycle of some organisms and is valuable in biomedical research, including for gene expression analysis and bioluminescence imaging technology.In recent years, researchers have identified a number of methods for predicting bioluminescent proteins (BLPs), which have increased in accuracy, but could be further improved. Method: In this paper, we propose a new bioluminescent proteins prediction method based on a voting algorithm. We used four methods of feature extraction based on the amino acid sequence. We extracted 314 dimensional features in total from amino acid composition, physicochemical properties and k-spacer amino acid pair composition. In order to obtain the highest MCC value to establish the optimal prediction model, then used a voting algorithm to build the model.To create the best performing model, we discuss the selection of base classifiers and vote counting rules. Results: Our proposed model achieved 93.4% accuracy, 93.4% sensitivity and 91.7% specificity in the test set, which was better than any other method. We also improved a previous prediction of bioluminescent proteins in three lineages using our model building method, resulting in greatly improved accuracy.

scholarly journals Investigation of Effect on Environmental Performance of Using LNG as Fuel for Engines in Seaport Tugboats

2021 ◽  
Vol 9 (2) ◽  
pp. 123
Author(s):  
Sergejus Lebedevas ◽  
Lukas Norkevičius ◽  
Peilin Zhou
Keyword(s):  
Diesel Engine ◽  
Natural Gas ◽  
Baltic Sea ◽  
Impact Assessment ◽  
Fuel Consumption ◽  
Dual Fuel ◽  
Nox Emissions ◽  
The Baltic Sea ◽  
Emission Analysis ◽  
The Baltic

Decarbonization of ship power plants and reduction of harmful emissions has become a priority in the technological development of maritime transport, including ships operating in seaports. Engines fueled by diesel without using secondary emission reduction technologies cannot meet MARPOL 73/78 Tier III regulations. The MEPC.203 (62) EEDI directive of the IMO also stipulates a standard for CO2 emissions. This study presents the results of research on ecological parameters when a CAT 3516C diesel engine is replaced by a dual-fuel (diesel-liquefied natural gas) powered Wartsila 9L20DF engine on an existing seaport tugboat. CO2, SO2 and NOx emission reductions were estimated using data from the actual engine load cycle, the fuel consumption of the KLASCO-3 tugboat, and engine-prototype experimental data. Emission analysis was performed to verify the efficiency of the dual-fuel engine in reducing CO2, SO2 and NOx emissions of seaport tugboats. The study found that replacing a diesel engine with a dual-fuel-powered engine led to a reduction in annual emissions of 10% for CO2, 91% for SO2, and 65% for NOx. Based on today’s fuel price market data an economic impact assessment was conducted based on the estimated annual fuel consumption of the existing KLASCO-3 seaport tugboat when a diesel-powered engine is replaced by a dual-fuel (diesel-natural gas)-powered engine. The study showed that a 33% fuel costs savings can be achieved each year. Based on the approved methodology, an ecological impact assessment was conducted for the entire fleet of tugboats operating in the Baltic Sea ports if the fuel type was changed from diesel to natural gas. The results of the assessment showed that replacing diesel fuel with natural gas achieved 78% environmental impact in terms of NOx emissions according to MARPOL 73/78 Tier III regulations. The research concludes that new-generation engines on the market powered by environmentally friendly fuels such as LNG can modernise a large number of existing seaport tugboats, significantly reducing their emissions in ECA regions such as the Baltic Sea.

Exergy analysis of a turboprop engine at different flight altitude and speeds using novel consideration

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ali Dinc ◽  
Yousef Gharbia
Keyword(s):  
Fuel Consumption ◽  
Thermal Efficiency ◽  
Exergy Efficiency ◽  
Specific Fuel Consumption ◽  
Flight Altitude ◽  
Fuel Flow ◽  
Turboprop Engine ◽  
Shaft Power ◽  
Two Parameters ◽  
The Relationship

Abstract In this study, exergy efficiency calculations of a turboprop engine were performed together with main performance parameters such as shaft power, specific fuel consumption, fuel flow, thermal efficiency etc., for a range of flight altitude (0–14 km) and flight speeds (0–0.6 Mach). A novel exergy efficiency formula was derived in terms of specific fuel consumption and it is shown that these two parameters are inversely proportional to each other. Moreover, a novel exergy efficiency and thermal efficiency relation was also derived. The relationship showed that these two parameters are linearly proportional to each other. Exergy efficiency of the turboprop engine was found to be in the range of 23–33%. Thermal efficiency of the turboprop engine was found to be around 25–35%. Exergy efficiency is higher at higher speeds and altitude where the specific fuel consumption is lower. Conversely, exergy efficiency of the engine is lower for lower speeds and altitude where the specific fuel consumption is higher.

scholarly journals CFD Study and Experimental Validation of a Dual Fuel Engine: Effect of Engine Speed

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4307
Author(s):  
Roberta De Robbio ◽  
Maria Cristina Cameretti ◽  
Ezio Mancaruso ◽  
Raffaele Tuccillo ◽  
Bianca Maria Vaglieco
Keyword(s):  
Natural Gas ◽  
High Performance ◽  
Engine Speed ◽  
Pollutant Emissions ◽  
Dual Fuel ◽  
Automotive Market ◽  
Light Duty ◽  
Viable Solution ◽  
Dual Fuel Engines ◽  
Gas Ratio

Dual fuel engines induce benefits in terms of pollutant emissions of PM and NOx together with carbon dioxide reduction and being powered by natural gas (mainly methane) characterized by a low C/H ratio. Therefore, using natural gas (NG) in diesel engines can be a viable solution to reevaluate this type of engine and to prevent its disappearance from the automotive market, as it is a well-established technology in both energy and transportation fields. It is characterized by high performance and reliability. Nevertheless, further improvements are needed in terms of the optimization of combustion development, a more efficient oxidation, and a more efficient exploitation of gaseous fuel energy. To this aim, in this work, a CFD numerical methodology is described to simulate the processes that characterize combustion in a light-duty diesel engine in dual fuel mode by analyzing the effects of the changes in engine speed on the interaction between fluid-dynamics and chemistry as well as when the diesel/natural gas ratio changes at constant injected diesel amount. With the aid of experimental data obtained at the engine test bench on an optically accessible research engine, models of a 3D code, i.e., KIVA-3V, were validated. The ability to view images of OH distribution inside the cylinder allowed us to better model the complex combustion phenomenon of two fuels with very different burning characteristics. The numerical results also defined the importance of this free radical that characterizes the areas with the greatest combustion activity.

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