Ship Diesel Research Articles

Effectiveness of application of epoxy compound without powder filler to re-pair ship propellers damaged under cavitation

Epoxy compositions are wide-spread in repairing the ship propellers blades damaged under cavitation attack. Most of the epoxy repair compositions contain the metal powders as filler. But the manufacturers of such compositions do not substantiate the expediency of using the metal powder in epoxy compositions for repairing the blades with cavitation wear spots. And the issue of the influence of metal powder filler on the cavitation wear resistance of the epoxy composition remains open. Experiments on ultrasonic magnetostrictive rig allowed drawing the conclusion, that the epoxy compositions containing the metal powder filler — Devcon Bronze Putty and Devcon Titanium Putty, and also compound K-153 doped with bronze powder — wear out without incubation period, that is the material loss takes place from the very beginning of the cavitation attack. The boundaries between the metallic particles and the epoxy matrix are the spots of the cavitation damage onset, and the composition wears out by the way of metal particles removal and subsequent destruction of the formed voids edges. Testing the compound K-153 without metal powder filler showed that refusal to add the metallic powder filler into epoxy repair compounds leads to the change in kinetics of cavitation wear of epoxy compound: there the incubation period appears on the kinetic curve of wear, during the period the quality of the surface of epoxy does not deteriorate as the removal of wear particles from the epoxy surface is absent. The application of the epoxy compositions without metal powder filler to repair the cavitation wear zones on ship propellers blades can result in essential fuel saving. It is explained by that quality of the repair composition surface does not decrease significantly; hence the propeller efficiency does not decrease. The savings might amount to 80 to 250 rubles per 1kW of ship diesel power during each interval between dock repairs.

Методика оценки технического состояния цилиндропоршневой группы судового дизеля на основе теории графов и математического анализа

Carrying out diagnostics of the ship power plant and estimation of the technical condition still remain not fully resolved issues. This is due, first of all, to a large number of active external factors, as well as to the complex process of interaction of the constituent plant elements. The cylinder-piston group of the ship diesel engine is especially sensitive to the effects of the environment. The operating conditions of this mechanism are under the influence of high temperatures and loads. The operational condition of the mating elements of the cylinder-piston group also largely depends on the physical and chemical characteristics of the working media – participants in the energy generation process. Forecasting the occurrence of both increased wear and the timing of natural aging of materials has been a task of engineering science since the advent of technology. The modern methods used in most scenarios imply the need to stop the engine, disassemble it and defect it (to determine the actual condition of the equipment and establish the amount of wear on the parts). This practice is extremely inconvenient for the prompt assessment of the technical condition under sailing conditions. Non-disassembly diagnostics is an alternative. The usage of four approaches to non-disassembly diagnostics of the marine diesel engine consists of sampling and oil analysis; vibration diagnostic control; thermographic research; and the usage of logic-oriented approaches. The method for non-disassembly diagnostics based on a logic-oriented approach to assessing the technical condition of the cylinder-piston group of a marine power plant is described, which will be equipped with the necessary mathematical and software-analytical devices. The method should allow indirectly determining the current state of the cylinder-piston group of a marine engine and predicting the development of potentially possible defects and failures.

Research on Fault Diagnosis of Ship Diesel Generator System Based on IVY-RF

Ship diesel generator systems are critical to ship navigation. However, due to the harsh marine environment, the systems are prone to failures, and traditional fault diagnosis methods are difficult to meet requirements regarding accuracy, robustness, and reliability. For this reason, this paper proposes a fault diagnosis method for a ship diesel generator system based on the IVY algorithm-optimized random forest (IVY-RF). Firstly, a model of a ship diesel generator system was constructed using MATLAB/Simulink, and the operation data under fault and normal working conditions were collected. Then, the data were preprocessed and time-domain features were extracted. Finally, the IVY-optimized random forest model was used to identify, diagnose, and classify faults. The simulation results show that the IVY-RF method could identify faulty and normal states with 100% accuracy and distinguish 12 types with 100% accuracy. Compared to seven different algorithms, the IVY-RF improved accuracy by at least 0.17% and up to 67.45% on the original dataset and by at least 1.19% and up to 49.40% in a dataset with 5% noise added. The IVY-RF-based fault diagnosis method shows excellent accuracy and robustness in complex marine environments, providing a reliable fault identification solution for ship power systems.

Features of cavitation wear of chrome electrolytic coatings

Cavitation wear is a pervasive phenomenon on water transport. The parts of ship propulsion system as well as the water-cooled surface of cylinder liners of high-speed ship diesels are subjected to cavitation attack. Bright chromium deposits are used to protect the water-cooled surface of liners. Nevertheless, the effect of cracks appearing in the electrolytic chrome coating upon depositing on the cavitation resistance of coating is still an open relevant problem. The goal of the study is to analyze the kinetics and mechanism of the destruction of the bright chrome electrolytic deposit under cavitation attack. The cavitation resistance of chrome electrolytic coatings after grinding and after polishing was studied. The chrome electrolytic coatings were obtained on the plates (90 × 30 × 7 mm in size) made of cast iron SCh21. The chrome was deposited on one side (90 × 30 mm) of the plate placed vertically by flow anodic jet chrome plating in standard electrolyte (kg/m3): chrome anhydride — 250; sulfuric acid — 2.5; trivalent chrome — no more than 5; trivalent iron ions — no more than 10. The electrolyte was prepared using distilled water of a single distillation. The parameters of depositing: electrolyte temperature is 50°C; the current density amounts to 60 A/dm2. Four samples cut from the same plate were used. The coatings on the first two samples were ground using the abrasive paper number 320. The coatings on the second pair of samples were first ground successively on the abrasive paper of different grit: 320, 500, 800, 1000, and 1200, and then polished on the cloth with GOI paste. The cavitation wear tests were carried out on a magnetostrictive vibratory rig in fresh water, the frequency and amplitude of the rig horn vibration was equal to 22 kHz and 28 μm, respectively. The spacing between the chrome-plated sample surface and the horn butt was 0.5 mm. The wear of the samples was evaluated by periodical weighing during testing. The wear of the ground samples turned to be significantly higher, than that of polished samples. The photographs of the surface after different duration of the cavitation attack show that the initial cracks formed on the coating during chrome plating are the centers of cavitation destruction. To reduce the negative impact of initial cracks on the cavitation resistance of the bright chrome electrolytic coatings deposited on the water-cooled surface of the cylinder liners of diesels it is shown expedient to include polishing in the technological process of depositing chrome coatings.

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.

Analysis Of Increasing Lubricating Oil Temperature In Ship Diesel Generators

Abstract Auxiliary aircraft is a vital part of a ship that is needed as a power plant or generator. In order to avoid more heat, lubricating oil is needed in the form of a chemical substance, in the form of a liquid given between two moving objects to reduce friction, as a protective layer separating the two surfaces in contact. This is due to the operation of the diesel generator which occurs continuously and can cause friction and erosion of the moving parts. So that friction causes changes in material structure which over time can cause heat. However, this condition makes the lubricating oil temperature increase every hour. This qualitative research uses Primary and secondary data collection methods, with observation (field survey), interviews and library research. Based on the results of the analysis, the cause of the increase in lubricating oil temperature is due to the condition of the electromotor of the seawater cooling pump through the bypass faucet not according to the desired pressure, pump bearings have wear and pump gears, then the heat absorption of the L.O Cooler shelf is not optimal due to blockages in the capillary pipes. That the increase in the temperature of the diesel generator lubricating oil above 700 C and the pressure of 2 kg/cm2 during the machinist’s duty hours 00.00-04.00 LT is caused by the diesel generator auxiliary motor having an ineffective Lo Cooler heat absorption capacity, sea water cooling pressure that is less than normal and the presence of pipe connections that leak cooling pipes

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

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

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

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

Influence of biocides on the operational properties of lubricant compositions

O organization of the production of lubricants, the creation of motor oils for various brands of locomotive, stationary, industrial, large-load self-loading ship diesels used in Republic, researched of highly effective additives and additive packages, is possible with the development of new lubricant compositions. For this purpose, investigation of multifunctional additives and additive packages in base oils according to the latest requirements has the great importance. Additives included in additive compositions in optimal concentration meet the requirements for a number of quality indicators of oils. The component added to these compositions – the biocide – may have a negative effect on the mentioned operating properties. Therefore, the main physico-chemical and operating properties of new bio-sustainable lubricants should be checked and the options recommended for application should be scientifically and practically justified. It is known, that the basic operational properties of lubricating oils are their oxidation, corrosion, corrosion and washing properties. As a result of the research conducted in the field of creating bio-sustainable additive compositions for various purpose lubricants on the basis of multifunctional additives and additive packages, it was determined that using organic compounds of different composition (α-phenyl-β-nitroethene biocide in the amount of 0.25 %) as a biocide can increase their service life possible. The specified properties of bio-sustainable oil samples created by adding biocide are determined by the relevant GOST. Our goal is to study the effect of biocide added to the oil composition.

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

Advancing sustainability in the maritime sector: energy design and optimization of large ships through information modelling and dynamic simulation

Advancing sustainability in the maritime sector: energy design and optimization of large ships through information modelling and dynamic simulation

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

A comparison of the economic value of fuel externalities from whale watching vessels: electric and diesel fueled boats in Iceland

A comparison of the economic value of fuel externalities from whale watching vessels: electric and diesel fueled boats in Iceland

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

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

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.

ВДОСКОНАЛЕННЯ ПРОЦЕСІВ МАЩЕННЯ ДИЗЕЛІВ СУДЕН МОРСЬКОГО ТА ВНУТРІШНЬОГО ВОДНОГО ТРАНСПОРТУ

Основними генераторами енергії на суднах морського та внутрішнього водного транспорту є двигуні внутрішнього згоряння (дизелі). Однієї з систем, що забезпечують їх функціонування, є система мащення. Двотактні суднові дизелі використовують дві системи мащення – лубрікаторну (за допомогою якої мастило подається на стінки циліндрової втулки) та циркуляційну (мастило в якої спрямовується до підшипників колінчатого валу). Чотиритактні (середньообертові) дизелі комплектуються лише циркуляційною системою мащення, в якої мастило потрапляє до всіх контактних вузлів дизеля, основними з яких є пари тертя поршневе кільце – втулка циліндра та вкладиш підшипника – колінчатий вал

Методы очистки нефтесодержащих вод

The article describes currently used methods of cleaning ship oil-containing waters and suggests a new method of their disposal. There are shown the specific features of the composition and properties of oil-containing waters, current requirements for the purification of oil-containing waters depending on the areas of operation of the vessel. The main reasons for oily waters emerging are given, as well as the main factors affecting the formation of oily waters on ships. A picture of a water-fuel emulsion under a microscope is illustrated. There are analyzed the methods of oil-containing water purification used on ships, their advantages and disadvantages. There is given a particular description of water purification methods: mechanical purification (straining, settling, centrifugation), physico-chemical purification (adsorption, coalescence, flotation), chemical purification (ozonation, electrochemical purification), biological purification and the method of thermal neutralization (wet burning, fire neutralization). There is presented one of the methods of mechanical wastewater treatment, namely, a scheme for primary treatment of oily waters using a grate, when the oily waters pass through numerous holes and are separated from foreign objects and large solid inclusions. Another example of mechanical wastewater treatment is the design of a clarifier with inclined plates through which the water flow passes along the plates and is divided into layers, which restrains mixing and facilitates settling oil products. A diagram of a coalescing filter (physico-chemical cleaning method) is also presented and its advantages are described. The comparative characteristics of the methods of utilization and neutralization of oily waters are given. Special attention is paid to the development and improvement of the technology of thermal neutralization of ship oil-containing waters. A method of utilization of oily waters by the heat of ship diesel exhaust gases is proposed.

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.

Carbon footprint and cost analysis of renewable hydrogen-fuelled ships

ABSTRACT The International Maritime Organization proposes several strategies to eliminate the adverse effects of ship emissions. The most important is finding alternative fuels, such as hydrogen. The current paper aims to compare diesel and renewable hydrogen-powered ships using Life Cycle Assessment (LCA) and Life Cycle Cost Assessment (LCCA). As a case study, three different ships sailing in the Red Sea area are investigated. The environmental outcomes are presented in terms of global warming potential (GWP), photochemical potential, eutrophication potential, particulate matter and acidification potential. Producing hydrogen fuel onboard ships will increase the total carbon footprint by 10%–28% higher than the currently used diesel fuels. Economically, the cost-effective target will be achieved at the cost of hydrogen production by electrolysis below 5.15$/kg.