Ship Diesel Engine Research Articles

Dual nanoparticles effect on the frictional and vibrational dissipation behaviors of polymer‐based water‐lubricated bearing materials

AbstractMarine water‐lubricated bearings have the advantages of environmental friendliness and long replacement cycle. However, when under the complex lubrication circumstance, the frictional and vibrational behaviors of water‐lubricated bearing always dissipate the mechanical energy output from the ship's diesel engine. Aiming at this problem and combining with previous research findings, in this paper, ceramic balls with similar mechanical properties to ship's main shaft were selected as the friction counterpart to simulate the operating conditions of marine water‐lubricated bearing. Meanwhile, dual nanoparticles of tungsten disulfide (WS2) and titanium dioxide (TiO2) were used to modify ultra‐high molecular weight polyethylene (UHMWPE) bearing material. The tribological and vibrational properties of the prepared composites were carefully investigated. The results showed that compared to pure UHMWPE, with the synergistic effect of 0.75 wt% WS2 and 0.9 wt% TiO2, the frictional and vibrational behaviors of the composites were reduced by 43.3% and 42.7%. Mechanical testing and microscopic characterization revealed the enhancement mechanism of these nanoparticles on UHMWPE. This study proposed a design strategy on marine water‐lubricated bearings for engineering application.

Effect of fuel injection pressure on biodiesel blended combustion of Inland River diesel engine

Abstract Compared with ordinary diesel, biodiesel has greater viscosity, density, and flash point, especially under medium and low load, which is easy to cause poor atomization and inadequate combustion. In this paper, an in-line six-cylinder inland river ship diesel engine was used as a model to conduct simulation tests under 50% load of propulsion characteristics to explore the effects of different fuel injection pressures on oil-gas mixing, combustion, and emission of fuel blended with a small percentage of biodiesel. The results show that the increase of fuel injection pressure can enhance the average turbulence intensity in the cylinder as well as increase the relative flow velocity between oil and gas, which is beneficial to the mixture combustion. High fuel injection pressure will promote flame propagation, increasing the maximum burst pressure and the average temperature in the cylinder. Compared to the fuel injection pressure of 24 MPa, NOx emission increases by 5.5% and 15.6% respectively at 27 MPa and 30 MPa, and decreases by 10% and 25% respectively by SOOT.

Ammonia coverage ratio control of a novel two-cell SCR-DeNOX system configuration based on IA-ISMC

To respond the China’s “14th Five-Year Plan” on the control of nitrogen oxides (NOX) emission, urea-based selective catalytic reduction (SCR) system has been widely applied to reduce the NOX emission from the diesel engine. NO2 is no longer a factor to be ignored while refining the SCR-DeNOX system model because of the ship diesel engine's long-term low temperature and oxygen-rich condition, which provides abundant conditions for the creation of NO2. Therefore, a refined eight-state two-cell SCR-DeNOX model is established in this paper. Meanwhile, the trade-off between NOX emission and tailpipe ammonia (NH3) slip is one of the major challenges which SCR-DeNOX system is facing. While meeting NOX emission standards, the requirement of limiting NH3 slip to prevent secondary pollution is becoming increasingly urgent, which needs a better structure or controller. Therefore, a two-cell SCR-DeNOX system with a by-pass valve in front of the NH3 injection is designed, integral sliding mode control based on inversion algorithm (IA_ISMC) is proposed for each cell. Based on the FTP-75 test cycle, there are three points of view are presented. Firstly, compared with the traditional six-state model, simulation results from the refined eight-state SCR-DeNOX model are closer to the experimental data. Secondly, the introduction of the by-pass structure has a mild impact on the NOX conversion efficiency, but can largely limit the NH3 slip. Finally, the controller based on IA_ISMC effectively improves the tracking performance of NH3 coverage ratio and reduces the cost of NH3 injection. To sum up, the refined two-cell SCR-DeNOX system with a by-pass valve based on IA_ISMC can enhance SCR performance and lower costs.

Bi-AAE: A binary adversarial autoencoder deep neural network model for anomaly detection in system-levels marine diesel engines

Marine diesel engines typically use multivariate time series for health condition monitoring, the anomaly detection of which is fundamental and critical for an entity's operation and management. However, detecting anomalies in multivariate time series remains a grand challenge due to the complex behavior of marine machinery. Therefore, this research proposes a binary adversarial autoencoder model to overcome this issue. The framework is built upon the principles of reconstruction models by fusing Generative Adversarial Networks and Adversarial Autoencoder approaches to analyze the degree of anomaly in multivariate time series. Additionally, it identifies anomalies through a threshold obtained by a statistical distribution-based and unsupervised setting method. To emphasize the model's performance, multivariate condition parameters from actual ship diesel engines are utilized for validation. Two membership functions are recognized as the model metrics to characterize its best performance, evidenced by scores of 0.937 for F1 scores and 0.910 for precision. The proposed strategy can be applied to different types of monitoring systems in the ship's engine room to realize system-level operation and maintenance.

Identification and detection of high NO x emitting inland ships using multi-source shore-based monitoring data

In urban areas situated along busy waterways like the Yangtze River, the diesel engines of inland navigation ships emerge as significant contributors to air pollution. Among these vessels, certain high-emission ships exhibit considerably higher levels of nitrogen oxides (NOx) emissions compared to others. To effectively identify such ships, this study employed a cost-effective ship emission monitoring sensor platform, comprising high-precision gas sensors, automatic identification system receiver, and sensitive meteorological sensors, along the Yangtze River in Wuhan City. By combining multi-source shore-based monitoring data, we identified ship emission signals and proposed a high-emission ship detection method using inverse modeling. Using this method, we successfully detected inland high-emission ships based on two months of monitoring data. Furthermore, the relationship between different ship types, sizes, speeds, and ship NO x emission rates were investigated. The results of this study are beneficial for strengthening the regulation of high-emission vessels in inland waterways, thereby reducing the adverse impact of ship emissions on the environment and climate. It also encourages the inland shipping industry to adopt more environmentally friendly technologies and fuels, as advocated by the International Maritime Organization.

Characteristics of Particulate Matter Emissions for Low-Sulfur Heavy Oil Used in Low-Speed Two-Stroke Diesel Engines of Ocean-Going Ships

Characteristics of Particulate Matter Emissions for Low-Sulfur Heavy Oil Used in Low-Speed Two-Stroke Diesel Engines of Ocean-Going Ships

Use of iron in oil concentration sensor for continuous monitoring of marine diesel engine technical condition

The article examines the features of the general problem of reliability, accuracy and durability of machines, mechanisms and devices, namely, the issue of friction, lubricating action, wear of the surfaces of parts and working bodies, which exist among themselves in very complex correlational dependencies. An approach to increasing the reliability of a ship's diesel engine is proposed, which requires the development of effective calculation methods and models for predicting the durability and wear resistance of materials of parts in friction nodes at the limit of lubrication in a wide range of changes in operating conditions and taking into account the variable modes of operation of a ship's diesel engine. The article considers the general approach and specific features of the construction of the components of the diagnostic system of the ship's internal combustion engine. Based on the selected volume of tasks solved by the diagnostic system, the sequence of functioning of its elements is determined. The implementation of this algorithm can have a significant effect in the complex use of diagnostic information together with statistical information stored individually for each mechanism, when managing its technical condition. On the basis of the proposed diagnostic model, it is possible to recognize the technical condition of marine diesel engines based on tribomonitoring data, detecting changes in friction conditions and an increase in the rate of wear of parts of the cylinder-piston group. This will enable the initiation of preventive corrective actions aimed at ensuring the reliable and safe operation of marine engines

Ship Diesel Engine Fault Diagnosis Using Data Science and Machine Learning

One of the most important elements of the reliability structure of a motor vessel is its power subsystem, with the most crucial component being the engine. An engine failure excludes the ship from operation or significantly limits its operation. Therefore, accurate fault diagnosis should be a crucial issue for modern maintenance strategies. In mechanical engineering, the vibration and acoustic signals recorded during the operation of the device are the most meaningful data used to identify the reliability state. In this paper, a novel system-oriented method of reliability state identification is proposed. The method consists of the analysis of the vibration and noise signals collected on each of the engine cylinders using supervised machine learning. The main novelty of this method is data augmentation application and SVM classifier implementation. Due to these aspects, the method becomes robust in the case of poor-quality data or a limited and incomplete learning dataset. The quality of the proposed identification method was evaluated by addressing a new industrial issue (Sulzer 6AL20/24 marine engine reliability state identification). During the tests, the efficiency of the method was analyzed in the case of a complete learning data set (all types of inability states were presented in the learning data set) and an incomplete learning data set (in the testing data set, there were new types of inability states). As a result, in both cases, a very high (100%) identification accuracy of the reliability state and the type of inability state was obtained. This is a significant increase in accuracy (4.6% for the complete and 22% for the incomplete learning data set) in comparison to the efficiency of the same method without the use of machine learning and data science.

Features of low-temperature corrosion protection of cylinder sleeves of ship low-speed engines

The article examines the specifics of solving one of the problems of low-speed marine engines, during which low-temperature corrosion of cylinder liners occurs during operation at minimum and partial load modes. An overview of the cooling systems of ship's main engines was conducted and possible prospects for improving the cooling systems of ship's diesel engines were considered. Attention is paid to the causes and methods of combating low-temperature corrosion of ship's main engines. The methods of regulating the cooling system of marine diesel engines were considered, and it was determined that the modern concept of regulation in the cooling system should include both automatic regulation of operational parameters due to the installation of frequency-regulated cooling system pumps, and regulation of the water-chemical parameters of the cooling system. Methods of regulating the operating parameters of the pumps in the cooling system of the ship's main engine were also considered, which use the principle of frequency regulation of centrifugal pumps to ensure the modes of operation with the highest efficiency. Thus, frequency regulation is an energy-efficient way of regulating centrifugal pumps with variable coolant flows in ship engine cooling systems and one of the ways to maintain an optimal temperature state. The possibility of modernizing the cooling system of cylinders of low-speed engines according to the principle of the LDCL system to reduce the impact and occurrence of low-temperature corrosion was considered

Shipboard compressor system risk analysis by using rule-based fuzzy FMEA for preventing major marine accidents

Considering the shipboard machinery, the compressed air system directly powers the ship's diesel engines' starting and routine operations. Additionally, pressurized air is distributed throughout the ship, enabling the operation of various systems. However, a compressor failure could result in the entire compressed air system collapsing, which might also result in the ship losing its maneuverability. When a ship loses its ability to maneuver, various devastating risks can arise, including grounding, collision, contact, explosion, and fire. On the other hand, compressor system risk assessment is not a widely researched subject in the field of maritime. To fill this gap, this study provides a comprehensive risk assessment of the shipboard compressor system by utilizing the rule-based fuzzy Failure Mode and Effects Analysis (FMEA) method. 33 failure modes with their causes and consequences were determined with their expert-assigned O–S-D scores. In addition, 125 If-Then rules in the fuzzy logic system were created specifically for this study. Finally, the failure modes of the shipboard compressor system were prioritized. According to the results, the most critical failure modes are identified as FM18-Broken piston rings with a 6.43 fuzzy RPN score, FM08-Piston liner wear with 6.29, and FM11-Knocking compressor operation with a 5.59. The results of this study will contribute to the maritime sector by analyzing the risks of compressor systems and introduce them to safety specialists, ship crew, shipping companies, port authorities, inspection officers, etc.

Real-Time Investigation of Primary Ship Engine Emissions by Vacuum Resonance-Enhanced Multiphoton Ionization High-Resolution Orbitrap Mass Spectrometry.

The comprehensive chemical description of air pollution is a prerequisite for understanding atmospheric transformation processes and effects on climate and environmental health. In this study, a prototype vacuum photoionization Orbitrap mass spectrometer was evaluated for field-suitability by an online on-site investigation of emissions from a ship diesel engine. Despite remote measurements in a challenging environment, the mass spectrometric performance could fully be exploited. Due to the high resolution and mass accuracy in combination with resonance-enhanced multiphoton ionization, the aromatic hydrocarbon profile could selectively and sensitively be analyzed. Limitations from commonly deployed time-of-flight platforms could be overcome, allowing to unraveling the oxygen- and sulfur-containing compounds. Scan-by-scan evaluation of the online data revealed no shift in exact m/z, assignment statistics with root mean square error (RMSE) below 0.2 ppm, continuous high-resolution capabilities, and good isotopic profile matches. Emissions from three different feed fuels were investigated, namely, diesel, heavy fuel oil (HFO), and very low sulfur fuel oil (VLSFO). Regulations mainly concern the fuel sulfur content, and thus, exhaust gas treatment or new emerging fuels, such as the cycle-oil-based VLSFO, can legally be applied. Unfortunately, despite lower CHS-class emissions, a substantial amount of PAHs is emitted by the VLSFO with higher aromaticity compared to the HFO. Hence, legislative measures might need to take further chemical criteria into account.

ENSURING THE ENVIRONMENTAL FRIENDLINESS OF MARINE DIESEL ENGINES OF SPECIALIZED SHIPS

Marine diesel engines (as the main component of a marine power plant) are sources of environmental pollution with exhaust gases, which include toxic components: carbon dioxide CO, hydrocarbons CnHm, soot C, sulfur oxides SOX, nitrogen oxides NOX [1-3]. Nitrogen oxides NOX occupy the first place among harmful emissions in almost all operating modes of diesel engines, regardless of their type, size and design features. Emission of nitrogen oxides with exhaust gases marine diesel engines is regulated by the requirements of Annex VI MARPOL. In accordance with the Tier-I, Tier-II, Tier-III standards (which apply to diesel engines of ships built after 2000, 2011 and 2016), the maximum amount of NOX in exhaust gases should not exceed the values determined by special expressions

Visualization and analysis of a Re-entrained particle with an electrostatic precipitator using PIV method

With the increasing demand for electric power and economic growth, the amount of gas emitted from power plants by power generation and diesel engines of ships and automobiles is increasing. In particular, exhaust gas contains black carbon, which is one of the pollutants that significantly influence global warming and must therefore be suppressed. It is considered that an electrostatic precipitator (ESP), which is an air purification device that uses plasma technology, can solve the problem. ESP is a mechanism that generates ion wind and electric charge by electric discharge, charges the passing particulate matter, and collects it on the ground (GND) electrode. During the dust collection process, particles charged with the discharge of ESP come into contact with the collecting electrode, and the particles lose the charge, thereby becoming neutral. With time, some of the collected particles detach from the GND electrode owing to the influence of electrostatic induction and the primary fluid. These particles are called re-entrained particles (RPs), and the phenomenon is called re-entrainment; this decreases the collecting efficiency of the ESP. The RP was successfully visualized and confirmed in this study using the particle image velocimetry (PIV) method with dry ESP, and it is beneficial for the problems that ESP may encounter during the development and application process. As a result, the movement velocity of particles and the re-entrained number of particles per second were increased by increasing the applied voltage of the plate electrode. Furthermore, the discharge current of the back needle electrode, the distance between the high voltage electrode, and the number of collected particles on the GND electrode significantly affected the re-entrained number of particles per second.

Identification of Typical Fault States of Marine Diesel Engines Based on Optimized BP Neural Network

Ship diesel engine is the core equipment of the ship, and its working condition is directly related to the safety and reliability of ship navigation. Once the ship diesel engine fails, it may cause different degrees of sea damage accidents, bringing economic losses and even endangering the life safety of crew members. The fault diagnosis can monitor the state of diesel engine during the operation of the ship and capture the fault signal to ensure that the fault can be found and eliminated in time. Therefore, the fault diagnosis research of ship diesel engine is an important research direction at present. This paper verifies that BP neural network has disadvantages such as inability to escape from local optimal solution and long convergence time, and the BP neural network optimized by genetic algorithm is based on intelligent fault state recognition. The optimized BP neural network has significantly improved in the fitting performance and classification performance. The research results have certain reference value and provide a basis for the research of intelligent fault diagnosis of marine diesel engines.

ОСОБЛИВОСТІ РОБОТИ ЛУБРИКАТОРНИХ СИСТЕМ СУДНОВИХ ДОВГОХОДОВИХ ДВИГУНІВ

The publication is devoted the decision of an actual problem increase efficiency operation of ship diesel engines by perfection processes greasing of cylinders. The outcomes bench and service tests of existing systems of lubrication of barrels of ship long-stroke diesel engines аre submitted. The main lacks of process of motion of oil in a system are established, and the characteristics of this process are determined. Keywords: ship diesel engine, greasing system, greasing channel, greasing process, cylinder, piston, a piston ring.

A literature survey on exergy analyses of marine diesel engine and power systems

The oil crisis in the world has led countries to seek an alternative fuel that can replace fossil fuels. In addition, the fact that global warming, which is one of the most important problems for the world, has reached significant levels, has led to an increase in studies on greenhouse gas emissions and the efficient use of energy. Every effort to increase efficiency contributes to both environmental and economic improvements. Considering this situation, the study was compiled by examining the studies on energy and exergy analysis related to diesel engines and marine diesel power systems in the literature. As a result of the study, it has been seen that the use of different fuel types contributes significantly to the decrease in environmental emissions as well as the increase in efficiency in diesel engines. In addition, it is thought that there are few studies in the literature on ship diesel engines, and with the increase in the studies to be done on this subject, there may be important references to both companies engaged in maritime transport and studies that will conduct research on this subject.

ESTABLISHMENT OF NOx MEASUREMENT AND CERTIFICATION SYSTEM FOR SMALL SHIPS

Measurement of NOx emissions from small ship diesel engines is technically quite complex and at most times it is very difficult or impossible to perform on board. Hence, there is need to build and model an applicable measurement and certification system compliant with NOx measurement rules of NOx Technical Code. The system needs to perform efficiently, economically and also need to have adequate elasticity for ships that cannot meet NOx criteria in order to fulfil the requirements of the Code. The aim of this study is the formation of a technical and legislative infrastructure about safe and efficient measurement and certification of NOx emissions of main and auxiliary engine in the Merchant ships, in accordance with Regulation 13 and NOx Technical Code related to the control of nitrogen oxides (NOx) and which takes place in Annex VI appendix about prevention of air pollution caused by ships in MARPOL 73/78 Convention.

Simplified calculation of friction mean effective pressure for fast simulation of fuel consumption

An environmentally friendly and economical ship operation can be accomplished through many different methods. Most of these approaches focus on technological solutions, e.g. internal engine measures in order to make the engine more eco-friendly, by changing engine control parameters for a better connection between propulsion system and ship, by usage of different fuels or fuel supplements or installation of exhaust gas-treatment systems. For many ships, it is neither efficient nor economically viable to replace or improve existing power generation or propulsion systems in order to improve efficiency or reduce emissions. Some of the internal measures used to reduce NOx-emissions like exhaust gas recirculation even lead to a higher fuel consumption. The vessel itself is still controlled by a crew and they should be kept in the loop to improve efficiency. Therefore optimal operational procedures for handling ships and specifically the outcome of engine manoeuvres is a substantial source for eco-friendly ship operations. The German research project MEmBran (Modelling Emissions and Fuel Consumption during Ship Manoeuvres) addresses especially the basis for optimising ship engine manoeuvres. It focusses on very detailed simulation of the processes of currently existing ship diesel engines, especially in a first step 4-stroke engines in order to implement models in wider comprehensive ship handling simulation software. As part of an existing planning and prediction software that can be used on board, it enables the watch keeping nautical officer and the shipping company to forecast and compare the fuel consumption of the ship for each manoeuvre. In order to reach this goal it is necessary to use fast calculating and stable methods that can be used to forecast the power output of the engine and the fuel consumption. This paper discusses an approach to calculate friction mean effective pressure.

ВПЛИВ ГАЗУ НА РУХ МАСТИЛА ПО ДЗЕРКАЛУ ЦИЛІНДРА

The publication is devoted the decision of an actual problem increase efficiency operation of ship diesel engines by perfection processes greasing of cylinders. It is interesting to consider the simultaneous movement of the liquid film of oil and gas flow in the case when the latter is turbulent. Estimating the speed distribution in this case is quite a time consuming task. Therefore, only its first stage is considered here, which consists in obtaining an asymptotic solution for large values of x. The prospect of practical application of two-phase gas-liquid film motion is quite attractive, especially in the case of the same direction, when the stabilizing effect is manifested. A quantitative description of such motion is considered exhaustive if the components of the velocity vector, the oil pressure, and the film thickness are determined. These characteristics are obtained by solving the basic equations of the mechanics of continuous media, including the equations of momentum transfer, continuity and macroscopic balance. Keywords: ship diesel engine, greasing system, greasing channel, greasing process, cylinder, piston, a piston ring.

Design and implementation of dynamic teaching model of diesel engine based on 3D printing technology

In view of the shortage of models of practical installation and teaching AIDS in the teaching and training of traditional naval ship diesel engines, the 3D printing technology is integrated with the educational concept of this course, and a multi-functional diesel engine teaching AIDS model suitable for classroom teaching is designed and manufactured, and its design method and process are expounded. A set of models of diesel engine teaching AIDS are designed and manufactured by using this method and applied in classroom teaching. The teaching effect is good, the learners’ enthusiasm is stimulated, and the teaching and training quality is improved.