Performance Of Marine Diesel Engine Research Articles

Investigation of Seasonal Effects on Two-Stroke Marine Diesel Engine Performance Parameters and Emissions

Investigation of Seasonal Effects on Two-Stroke Marine Diesel Engine Performance Parameters and Emissions

Analysis of methods of managing the environmental safety of the navigation passage of ships of maritime transport

The requirements of the MARPOL international convention on ensuring the environmental performance of marine diesel engines in relation to the emission of sulfur oxides, as well as marine fuels during navigation passages of sea transport vessels in special ecological areas, are given. The use of scrubber cleaning of exhaust gases and the use of fuel mixtures, which include biodiesel fuel, are considered as methods that meet these requirements. The research was carried out on ships of the Bulker Carrier class with deadweight of 63,246 tons during the navigation transition between the ports of Northern Europe. One of the vessels used scrubber cleaning of exhaust gases as a method of environmental safety management. The other is the use of fuel mixtures, which include biodiesel fuel. Both vessels are equipped with a 5S60ME-C8.2 MAN-Diesel&Turbo marine diesel engine as the main engine, and three 6EY18ALW Yanmar diesel engines as auxiliary engines. The ratio of sulfur oxides to carbon oxides – SO2/CO2 – was chosen as an indicator for evaluating the effectiveness of environmental safety management methods. This value was monitored and regulated by an automatic monitoring system. It was found that both methods meet the requirements of the MARPOL convention, namely, they will support the SO2/CO2 ratio in the range of 2.29–4.17 (when in special environmental control zones) and in the range of 6.46–20.83 (when in outside the zone of special environmental control). The use of environmental safety management methods increases energy costs for ensuring this process. When using exhaust gas scrubbing, additional power losses reach 237–278 kW. In the case of using a fuel mixture that includes biodiesel fuel, power losses amount to 18–20 kW. It has been experimentally confirmed that the use of a fuel mixture that includes biodiesel fuel is characterized by a lower level of environmental sustainability. At the same time, compared to the use of scrubber cleaning of exhaust gases, this method requires less energy consumption and is also characterized by simpler additional equipment. In this regard (and also taking into account that all the requirements of Annex VI MARPOL are provided), it is recommended as the main one to ensure the environmental safety of navigation passages of sea transport vessels.

A Deep Learning-Based Fault Warning Model for Exhaust Temperature Prediction and Fault Warning of Marine Diesel Engine

Marine diesel engines are essential for safe navigation. By predicting the operating conditions of diesel engines, the performance of marine diesel engines can be improved, failures can be prevented to reduce maintenance costs, and emissions can be controlled to protect the environment. To this end, this paper proposes a hybrid neural network (HNN) prediction model (CNN-BiLSTM-Attention) based on deep learning (DL) for predicting the exhaust gas temperature (EGT) of marine diesel engines. CNN is used to extract features from time-series data, BiLSTM is used to predict the time series through modeling, and Attention is used to improve the accuracy and robustness of fault prediction. Moreover, through comparison experiments with other neural network prediction models, it has been proven that the CNN-BiLSTM-Attention method is more accurate. This article also presents an approach to fault prediction by integrating the Mahalanobia distance and the mathematical model. Based on the Mahalanobia distance between the prediction result and the actual value, the function mapping method combined with the criterion is used to set the alarm value and threshold of the monitoring indicators, and the failure data set is used for experimental verification. The results indicate that the approach presented in this article can accurately realize the operating condition monitoring and fault early warning of marine diesel engines, which provides a new way of thinking for the research of fault early warning and health management of marine diesel engines.

Impact of Biofuel on the Environmental and Economic Performance of Marine Diesel Engines

The results of the research work on biofuel’s impact on the environmental and economic performance of marine diesel engines are presented. During the research, a fuel mixture was used that consisted of the diesel fuel RMA10 and FAME biofuel. The objective of the research was to determine the optimal concentration of biofuel mixed with diesel fuel. The research work was carried out on three of the same type of marine medium-speed diesel engine, 6N165LW Yanmar. One of the diesel engines only operated on diesel fuel, and the other two operated on a mixture of diesel fuel and 5–20% biofuel. During the experiment, the diesel engines operated at a load of 50–80% of the rated value. Experimentally, it was found that using biofuel improved the environmental friendliness of diesel engines: the emission of nitrogen oxides in exhaust gases was reduced by 8.7–23.4%, and the emission of carbon oxides in exhaust gases was reduced by 3.1–24%. However, when using biofuel, the economic efficiency of diesel operation decreased as the specific effective fuel consumption increased by 0.5–9.3%. The highest environmental efficiency was achieved when using a fuel mixture that included 10–15% biofuel in an 80% diesel load. In this case, the emission of nitrogen oxides was reduced by 21–23.5%, the emission of carbon oxides was reduced by 16.5–19.2%, and the magnification of the specific useful consumption of the diesel engine was 1–1.55%.

Analysis of the operation of marine diesel engines when using engine oils with different structural characteristics

The object of research is the process of lubrication of marine trunk diesel engines. The subject of research is marine diesel engine oils, which provide lubrication, cooling and separation of friction surfaces. The analysis of the operation of marine diesel engines using motor oils with different structural characteristics is carried out. The studies are carried out on Yanmar 6EY18AL diesel engines of a Multipurpose Vessel class ship with deadweight of 27540 tons. The objective of research is to determine the effect of the structural characteristics of the oil layer (contact angle and thickness) on the performance parameters of a marine diesel engine and the performance characteristics of the oil used in its circulating lubrication system. At the same time, the compression pressure, the concentration of nitrogen oxides in the exhaust gases, and the temperature of the exhaust gases after the cylinder are considered as the operating parameters of the diesel engine; as performance characteristics of the oil – its Base Number, as well as its Wear and Contaminant Elements. The studies are carried out on two diesel engines of the same type, in the circulating lubrication system of which oils with different structural characteristics were used. Structural characteristics of the oil layer were determined by ellipsometry. The operational characteristics of the diesel engine – using the Doctor diagnostic system. Oil performance – by spectrographic analysis. It has been established that an increase in the contact angles of wetting and the thickness of the oil layer improves the heat and power and environmental performance of a diesel engine. At the same time (for the period of operation of diesel engines 500–1000 hours), the decrease in compression pressure in the cylinder slows down, the temperature of gases after the cylinder decreases, and the emission of nitrogen oxides with exhaust gases decreases. In addition, the wear of diesel parts and oil oxidation are reduced. The information obtained in the course of the study on the structural characteristics of motor oils will provide the possibility of their selection and further use of those that will contribute to a better maintenance of the operational performance of marine diesel engines.

Measurement of the friction force of sliding friction pairs in low-speed marine diesel engines and comparison with numerical simulation

Low-speed marine diesel engines are widely used as propulsion power equipment on ocean-going merchant ships. There are three important sliding friction pairs in the engine: piston assembly-cylinder liner, piston rod-stuffing box, and crosshead slipper-guide. They greatly influence the mechanical efficiency and stability of the engine. However, there is no effective method to measure the friction of the three friction pairs so far, which limits the improvement of tribological performance and the reduction of fuel consumption in low-speed marine diesel engines. In the current study, an indirect measurement method is presented and the measurement of the friction force under fired conditions is realized for the first time. By comparing the experimental results of friction force with the model-based numerical results, it is found that they are in good agreement. The difference between the numerical and experimental maximum friction force is less than 5%. Both theory and experiments show that the friction force reaches the maximum after the top dead center, which is about one-tenth of the gas force. The work of this paper is expected to provide an effective tool for evaluating the tribological performance of marine diesel engines.

A Study on Anti-Shock Performance of Marine Diesel Engine Based on Multi-Body Dynamics and Elastohydrodynamic Lubrication

Diesel engine anti-shock performance is important for navy ships. The calculation method is a fast and economic way compared to underwater explosion trial in this field. Researchers of diesel engine anti-shock performance mainly use the spring damping model to simulate the main bearings of a diesel engine. The elastohydrodynamic lubrication method has been continuously used in the main bearings of diesel engines in normal working conditions. This research aims at using the elastohydrodynamic lubrication method in the main bearings of the diesel engine in external shock conditions. The main bearing elastohydrodynamic lubrication and diesel engine multi-body dynamics analysis is based on AVL EXCITE Power Unite software. The external shock is equivalent to the interference on the elastohydrodynamic lubrication calculation. Whether the elastohydrodynamic lubrication algorithm can complete the calculation under interference is the key to the study. By adopting a very small calculation step size, a high number of iterations, and increasing the stiffness of the thrust bearing, the elastohydrodynamic lubrication algorithm can be successfully completed under the external impact environment. The calculation results of the accelerations on engine block feet have a similar trend as the experiment results. Diesel engines with and without shock absorbers in external shock conditions are calculated. This calculation model can also be used for diesel engine dynamics calculations and main bearing lubrication calculations under normal working conditions.

Effect of direct water injection on combustion and emissions characteristics of marine diesel engines

In this study, the effect of direct water injection (DWI) was investigated on the performance of marine diesel engine based on the three-dimensional simulation model. The water injection quantity, temperature and timing were researched on the in-cylinder pressure and temperature, indicated power and NOx emissions. Then, the DWI strategies were compared with the exhaust gas recirculation (EGR). The results showed that the in-cylinder pressure, temperature, indicated power and NOx emissions decrease with increasing of water quantity. Reductions in NOx emissions up to 55.6% were obtained after applying DWI to the engine at the compression stroke. The water injection temperature has a little effect on the combustion and emissions of marine engine. The indicated power decreased when the water injection timing in the compression stroke. However, the indicated power increased when the water injection timing in the late combustion phase. The water injection timing in the compression stroke has more potential in reduction NOx emissions. The NOx emissions with water injection in the compression stroke decreased by 40% compared to the value with water injection in the later combustion phase. The ability of DWI and EGR were researched on the solve the trade-off between power and NOx emissions. The results showed that the DWI strategy can reduce NOx emissions at the higher indicated power compared with the results of EGR.

DEVELOPMENT OF MARINE ENGINE PERFORMANCE PREDICTION MODEL THROUGH NEURAL NETWORK APPROACH

The prediction and control of marine diesel engine performance and emission rates is not an easy task in real time. Comprehensive engine performance testing for entire operating conditions is extremely costly and time consuming. Therefore, the option of using a computer model can be used to determine those parameters. This work is concerned with the modeling of artificial neural networks in predicting the performance parameters of marine diesel engines such as torque, power, fuel consumption, efficiency and exhaust emission gases. Input data were obtained from engine tests in the laboratory operated with palm biodiesel and running at various speeds and loads. The predicted results have been validated by comparing the output values of the model with the experimental data. The results show that the prediction model using neural network gives good agreement to the experimental results which yield higher correlation coefficient of 0.98194 and lower mean square error of 0.0026809. This study proves that a trained neural network model is capable to determine the performance of marine diesel engines in the accepted range.

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

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.

Experimental study on diesel engine exhaust gas recirculation performance and optimum exhaust gas recirculation rate determination method.

In order to study the exhaust gas recirculation (EGR) performance of marine diesel engines, a venturi high-pressure EGR device was established to overcome the exhaust gas reflow problem based on a certain type of turbocharged diesel engine. The EGR performance test is accomplished and an optimal EGR decision-making optimization method based on grey correlation coefficient modified is proposed. The results show that the venturi tube EGR can basically meet the injection requirements of high-pressure exhaust gas and achieve good results. Through the venturi tube EGR, the NOX emissions reduce significantly with the maximum drop of 30.6%. The explosive pressure in cylinder reduces with the EGR rate increases and the cylinder pressure curve shows a single peak at low-speed conditions and double peaks at high-speed condition. However, the fuel consumption rate, NOX and smoke have been negatively affected. Due to small samples, the traditional evaluation method is difficult to determine the optimal EGR rate reasonably, while the proposed method can effectively solve this problem. It can weaken the shortcomings of subjective judgement and greatly improve the rationality of decision-making results.

Review on Simulation of Non-reacting Fuel Spray

Marine diesel engines (MDEs) are interested due to their ability to generate high power and fuel economy. Nowadays, researchers are seeking different methods to develop the performance of MDEs. Fuels spray behavior has key role to improve of MDEs. Therefore, in the present paper, fundamental of non-reacting and non-evaporating fuel spray simulation are reviewed. For this purpose, recent works in this context are presented and after that, microscopic and macroscopic characteristics of non-reacting spray are described. Finally, the basic formulations of Eulerian-Lagrangian multiphase and different breakup models are presented.

Performance of marine diesel engine in propulsion mode with a waste oil-based alternative fuel

Marine diesel engines are one of the most representative fossil fuels consumers on the planet. These engines are responsible for a large amount of air pollutants, including greenhouse gas emissions. This concern led to the adoption of new regulations and policies for shipping, which involved more intensive restrictions for airborne emissions. This scenario, in addition to the finite fossil fuel reserves, the fluctuating price of fossil fuel and its share of the annual costs of ships, has boosted the development of new alternative fuels for marine diesel engines from traditional ones. It is known that waste oils are one of the most abundant residues generated within the industry. This study assesses the technical suitability of an alternative fuel oil, obtained from recycled waste automotive lube oil, in comparison with traditional fuels, complying with the ISO 8217 for distillate fuel oils. The alternative fuel was tested on a full scale marine diesel engine test bench, simulating real operating conditions for marine diesel engines and electric diesel generators in steady loads. To this end, the engine was cooled with sea water and coupled to a hydraulic brake, which allowed tests to be undertaken in different engine loads and propulsion modes, such as controllable and fixed pitch propeller propulsion systems. The results demonstrated that the alternative fuel burns rapidly but with a delay at the end of combustion, which should be expected for this type of fuel. Additionally, the energy efficiency of the diesel engine is comparable to the distillate fuel commonly used by the fishing fleet; however, due to its higher heating value, the alternative fuel presents lower fuel consumption. According to the emissions, the alternative fuel exhibits lower NOx and CO2 emission levels but slightly higher CO emissions and smoke opacity levels than common fuels, with the sulphur content in the fuel below the maximum level being allowable by more stringent marine rules. Hence, waste oil-based alternative fuel oils are acceptable for use in marine diesel engines operated on-board a ship under real conditions and meet the rules applicable to marine environments for burning fuel oils.

Recirkulacija ispušnih plinova s cijeljem skrbi za okoliš tijekom rada brodskih dizelskih motora

Recirkulacija ispušnih plinova s cijeljem skrbi za okoliš tijekom rada brodskih dizelskih motora

Development of a surrogate fuel mechanism for application in two-stroke marine diesel engine

A reduced n-tetradecane-toluene mechanism was developed as a surrogate fuel for marine diesel engines. The new mechanism includes 85 species and 317 reactions. The mechanism was used in a computational fluid dynamics model to investigate the performance of marine diesel engine. The new mechanism was validated with experimental data from experiments with a shock tube, flow reactor, jet-stirred reactor and marine diesel engine. The effect of toluene content on the performance of marine diesel engines was also investigated. The results showed that the calculated ignition delay times of n-tetradecane and toluene species were consistent with the experimental data. The errors in the mole fractions of main middle species of toluene were in an acceptable range. The calculated in-cylinder pressure of the marine diesel engine was consistent with the experimental data. The calculated quantity of NOx was also close to the experimental data. The physical properties of toluene significantly affected the performance of the marine diesel engine. The n-tetradecane-toluene mechanism including 30% mass fraction toluene is most suitable as a surrogate fuel for a marine diesel engine, considering the comparisons of calculated and experimental data of power, brake specific fuel consumption, and the quantities of NOx and CO2.

Influence of Different Fuels Physical Properties for Marine Diesel Engine

The physical properties and chemical mechanisms have direct relationship with combustion. The physical properties of different alternative fuels are researched on the effect of performance of marine diesel engine in this paper. The effect of in-cylinder pressure, emission products and the main species are compared. It can provides a direction for the researchers in established the CFD model. The results show that the in-cylinder pressure and temperature have large difference for different alternative fuels. The in-cylinder pressure and temperature are lower for the heavy oil. Due to the worse combustion, the soot mass has maximum value for heavy oil. The C14H30 and O2 mass have higher value at the start of combustion for the heavy oil. It also explains the combustion process of heavy oil.

Experimental and simulation-based investigations of marine diesel engine performance against static back pressure

After-treatment technologies are adopted in automobiles and ships to meet strict emission regulations, which increase exhaust back pressure. Furthermore, underwater exhaust systems are employed on board ships to save space, and reduce noise and pollution on working decks. However, water at exhaust outlet creates a flow resistance for the exhaust gases, which adds to the back pressure. High back pressure reduces the operating limits of an engine, increases fuel consumption, and can lead to exhaust smoke. While the effects of back pressure were recognized earlier, there is a lack of experimentally validated research on the performance limits of a turbocharged, marine diesel engine against high back pressure for the entire operating window. The focus of this research is to provide a comprehensive understanding of back pressure effects on marine diesel engine performance, and to identify limits of acceptable back pressure along with methods to tackle high back pressure.In this work, a pulse turbocharged, medium speed, diesel engine was tested at different loads and engine speeds; against different values of static back pressure. Additionally, mean value model simulations could be validated and were used to compare the performance of a pulse and constant pressure turbocharged engine against high back pressures of 1meter water-column (mWC), and for two different values of valve overlap.Using the validated simulation model, the conceptual basis for the engine smoke limit as well as for thermal overloading is investigated. A methodology applying the conceptual basis to define boundaries of acceptable back pressures has been presented in this paper. A combination of pulse turbocharger systems and small valve overlap showed to significantly improve back pressure handling capabilities of engines.

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

Different combustion models and alternative fuels can be used in simulations under the same operating conditions to study their effects on marine diesel engine performance. In-cylinder pressure and temperature, emission products (NOx, HC, CO, CO2), and the distributions of equivalence ratio, temperature and emission products were simulated. The simulation model was validated with experimental data. Errors in in-cylinder pressure and emissions were in the acceptable range. Results show that the maximum in-cylinder combustion pressure calculated using the detailed chemistry solver combustion model (SAGE) is closer to the experimental data than the results of others models. There is little difference in pressures between n-heptane and n-tetradecane in the same combustion model. The integrated heat releases are almost the same for the different models. However, the n-heptane-SAGE model has a larger error than do the other models for the quantity of NOx. Comparing the errors of NOx, HC, CO and CO2, the n-heptane-CTC/shell simulation model data are closest to the experimental data. The important element reactions of the alternative fuel mechanism needs to be adjusted to ensure the emissions are consistent with experimental data. Finally, the contours of temperature, equivalence ratio and emission products are validated by comparing the results of different models.

Prediction of marine diesel engine performance by using artificial neural network model

This study deals with an artificial neural network (ANN) modelling of a marine diesel engine to predict the output torque, brake power, brake specific fuel consumption and exhaust gas temperature. The input data for network training was gathered from engine laboratory testing running at various engine speeds and loads. An ANN prediction model was developed based on a standard back-propagation Levenberg–Marquardt training algorithm. The performance of the model was validated by comparing the prediction data sets with the measured experiment data and output from the mathematical model. The results showed that the ANN model provided good agreement with the experimental data with a coefficient of determination (R2) of 0.99. The prediction error of the ANN model is lower than the mathematical model. The present study reveals that the artificial neural network approach can be used to predict the performance of a marine diesel engine with high accuracy

Experimental Evaluation of Marine Diesel Engine Performance Using Blends of Biodiesel and Diesel with High-Sulfur Concentration

O oleo diesel e um combustivel muito utilizado no Brasil e sua composicao pode apresentar teores de enxofre elevados podendo chegar ate 5.000 ppm (0,5% em massa) a depender de sua finalidade, como e o caso do combustivel utilizado em embarcacoes, o chamado diesel maritimo. Neste contexto, este trabalho teve como objetivo avaliar o desempenho (potencia, torque e consumo de combustivel) de motores do ciclo diesel abastecidos com misturas de diesel maritimo e biodiesel. Os combustiveis avaliados foram as misturas de 5% (B5); 10% (B10); 20% (B20); 40% (B40), 60% (B60) de biodiesel adicionado ao diesel maritimo e o biodiesel puro (B100). Os resultados obtidos para potencia demonstram que as misturas de biodiesel tiveram melhor desempenho na rotacao em torno de 2500 rpm. Os resultados de torque para as misturas combustiveis estiveram na faixa de 366 – 374 Nm na rotacao em torno de 1500 rpm e 370 Nm para o diesel maritimo em mesma rotacao. O diesel maritimo apresentou os melhores resultados de consumo de combustivel (20,8 kg/h a 1500 rpm). A utilizacao 5% de biodiesel adicionado ao diesel maritimo foi 7,7% mais vantajoso economicamente do que diesel maritimo puro. DOI: 10.5935/1984-6835.20160085