Ship Engine Research Articles

Fault Analysis of Ship Machinery Using Machine Learning Techniques

Maintenance and repair of ship systems and prediction of fault probability have become an important issue for dynamic ship systems recently. Increasing the usability of systems by detecting the fault analysis is one of the current work areas. In recent years, the rapid development of information technologies and the machine learning approaches developing accordingly have made it possible to integrate machine learning techniques into ship systems. The use of machine learning in the studies has enabled this method to be tested in the areas of maintenance, repair, and fault analysis. To be able to predict the fault that may occur in the ship machinery systems and prevent the fault accordingly, can increase the lifespan of ship machinery's. In this study, the data obtained from an LM-2500 type ship engine were analyzed by regression and Artificial Neural Networks (ANN) algorithms to predict the fault of ship machinery. The results were compared for linear regression, decision tree regression, k nearest neighbours’ regression, random forest regression, bayesian ridge regression, extra tree regression, linear SVR regression and ANN algorithms. As a result of the analysis, it was revealed that the ANN method gave better results in machine fault prediction compared to the regression methods.

Safety evaluation of using ammonia as marine fuel by analysing gas dispersion in a ship engine room using CFD

ABSTRACT This paper seeks to address the question that each stakeholder in the maritime industry has about ammonia’s potential as a marine fuel, How safe is it to use ammonia as a fuel onboard vessel ? The principle aim of this paper is to quantify the exposure limits to which crew working onboard can get subjected to in a confined space onboard a vessel. It was achieved by simulating gas leaks at different locations inside an engine room of a hypothetical ammonia fuelled carrier similar to a 114,000 GWT LNG tanker using CFD. The transient nature of dispersion is analysed and compared for various scenarios. The results are promising and prove that ammonia does have a high risk due to its toxicity but a low risk in terms of flammability. Research findings also demonstrate that the gas dispersion depends on numerous factors such as position, area of leak, direction of leak, pressure and temperature of ammonia gas, obstruction due to placement of machinery and decks, ventilation, and the temperature gradient of surrounding material. The novelty of the paper lies in the problem it addresses and will contribute to the industry in a better understanding of the risk involved in operating an ammonia-fuelled vessel.

Design of a Thermoelectric Device for Power Generation through Waste Heat Recovery from Marine Internal Combustion Engines

Modern ships discharge large amounts of energy into the environment. More specifically, internal combustion engines (ICE) of commercial and passenger ships waste significant amounts of thermal energy at high temperature through their exhaust gases that are discharged to the atmosphere. A practical approach of recovering some amount of this energy is by using thermoelectric generator systems, which can convert thermal into electrical energy, given that there is a significant temperature difference. It is the aim of this work to propose a thermoelectric generator to recover energy from the exhaust gases of marine ICEs. The proposed thermoelectric generator uses the outside surface of the ICE manifold as the hot side of the thermoelectric module, while the cold side is maintained at a low temperature through a heat sink and induced water flow. The goal of this work is to design this thermoelectric generator and identify the configuration that produces the maximum electric power. The analysis and design are performed with the use of modeling and simulation, while commercial software is employed to study the 3-dimensional coupled fluid flow and heat transfer at a steady state. A sensitivity analysis is carried out to identify the parameters with the highest influence on power production. In addition to a full factorial sensitivity analysis, the more efficient Latin hypercube sampling is used. The analysis shows that significant energy of the exhaust gases can be converted into electric power with the use of an optimized heatsink, which creates the highest temperature difference between the two sides of the thermoelectric module.

Разработка системы охлаждения судовых малоразмерных дизелей, работающих при различных температурах забортной воды в условиях лаборатории

Using a cooling system in water transport is considered the most effective way to increase the energy efficiency of a vessel. Currently, closed-loop cooling systems and frequency-controlled drives of seawater electric pumps are actively used. An option of improving the energy efficiency of cooling systems with mounted seawater pumps is being studied. The hydraulic scheme of the unit with an energy-efficient ship engine cooling system is presented. To study ways to reduce mechanical losses in the drive of auxiliary mechanisms of a marine engine, the laboratory “Marine Diesels” of Astrakhan State Technical University developed a test bench for the Iveco 8041I06 engine. The engine cooling system does not have a thermostat to control the thermal state; instead of a thermostat on the engine, an electronically controlled variator is installed between the engine power take-off shaft and the VKS 1/16 pump. At a constant engine speed, the variator allows changing the pump speed, supply of sea water through the heat exchanger and regulating the thermal state of the engine. It has been found that during engine tests it is necessary to maintain the temperature of the outboard water constant. A description is given of the use of tanks with thermal insulation at the stand to reduce heat exchange with the environment. Variants of types of containers and materials for insulation are considered. To prepare water of the required temperature a chiller is connected to the cooling system at the experimental stand. The calculation of thermal insulation and comparison of the result with a real test is given. On the stands for testing diesel engines the change in the thermal state of the engine is carried out only by changing the load on the engine. On the developed stand, the thermal state can also be changed, including by controlling the seawater temperature, which expands its capabilities for modeling real processes.

Digital Twin-Driven Approach for Process Management and Traceability towards Ship Industry

The digital twin (DT) approach has risen in popularity for applications in many industrial process managements. By applying the “Shipyard 4.0” digital transformation trend, the ship industry is developing techniques able to reduce risks by improving operation process management. This study proposes a combination of a DT approach and practical experiment as part of a five-tier framework for DT-driven process management in the ship industry. This study focuses on the characteristic scenarios and crucial parameters within the ship engine system and shipping cargo container in operation procedures. DT-based models and platforms are established in this study based on the basic modeling of Maya and scene rendering of Unity 3D. To address the fusion issue of multi-source heterogeneous data in the ship operation process, a Bayesian neural network (BNN) method is introduced into DT’s virtual model layer and data support layer. By integrating an improved BNN-based algorithm into DT-based models, the collected data can be extracted and aggregated accordingly. In the ship engine room, the operating temperature is selected as a critical parameter, with the best mean percentage deviation (MPD) between DT-driven predictions and test value of 3.18%. During the shipping cargo container process, the results indicate that DT-based models have acceptable performances under different conditions, with optimal MPDs of 5.22%.

Development of condition-based maintenance strategy for fault diagnosis for ship engine systems

Shipping effectively covers a large part of cargo transportation in the world in an economical and reliable way. Thus, energy-efficient operation on ships is an essential subject to ensure both increasing of the efficiency level of the global transportation and economic savings. In this subject, an effective maintenance strategy followed in the ship's engine room is one of the powerful solutions. In this way, system reliability and operational safety increase while operational expenses decrease. A condition-based strategy is an up-to-date approach for maintenance. Within this method, decisions could be made about the system based on past information. In this study, some parameters of the large-sized container ship are collected for the development of the condition-based maintenance strategy. The dataset is analysed by the artificial neural network in order to the constitution of the engine performance model. Finally, the usability and effectiveness of the developed maintenance strategy are demonstrated with three scenarios. As a result of the exemplified scenarios, the improved maintenance strategy ensures that the fault diagnosis could be made effectively, depending on the instant condition of the examined engine and its past information. The proposed methodology could also adapt to any system or engine for any kind of ship.

A RAM extension to enhance ship planned maintenance system

ABSTRACT This study develops a knowledge-based planned maintenance system (PMS) supported by reliability, availability and maintainability (RAM) analysis. The system enables maintenance plan revisions based on the data analysis which calculates instant RAM values and predicts the future trends. The visualised data is monitored to support decisions at both the operational and management level. The proposed system is demonstrated with the periodical data of the main engine installed onboard a container ship. Particularly, the data visualization is conducted on fuel injection valves. The results illustrate that the enhanced PMS system adds value to the timely and effective planning of routine and non-routine maintenance tasks onboard ships. Considering the existing potential of PMS applications onboard ships, the RAM analysis provides reasonable contributions to ship engine room crew and technical managers. The further study focuses on developing a maintenance planning app to digitalise the process and to strengthen compliance with ISM Code Clause 10 and TMSA 4A.4 requirements.

Review on Intelligent Diagnosis Technology of Electronically Controlled Fuel Injection System of ME Diesel Engine

ME diesel engine plays an important role in realizing energy conservation and environmental protection and improving the intelligent level of ship engine room. Because of its high technical content and high added value, using intelligent diagnosis technology to ensure safe and reliable work is an important means to realize intelligent engine room. Taking the ship electronic fuel injection system as an example, this paper introduces its working principle and common faults, analyzes and summarizes the research status of intelligent diagnosis technology at home and abroad in four aspects: fault mechanism, data measurement and feature extraction, fault mode classification and residual life prediction. Then, it analyzes the problems and future development trend of intelligent diagnosis technology, and points out that developing a health management system integrating weak fault signal extraction, multi-source data analysis, quantitative judgment of fault mode, remaining life prediction and maintenance suggestions is an important development goal in the future.

Modified quantitative systems theoretic accident model and processes (STAMP) analysis: A catastrophic ship engine failure case

Despite the rapid advancement of technology and the increasing complexity of systems, conventional accident analysis techniques developed many years ago are still used in numerous sectors. On the other hand, these approaches are limited in detecting all underlying causes of accidents in complex socio-technical systems. In recent years, system theory-based novel accident analysis techniques have been proposed to address this issue. Systems-Theoretic Accident Model and Processes (STAMP) is one of these innovative analytic techniques with a strong detection capability. The method has the ability for analyzing human, organization, hardware, software, external factor components, and their interactions in a dynamic structure. However, despite the method's strong analysis capacity, it is a shortcoming that STAMP is a qualitative method. This study aims to present a hybrid quantitative methodology for complex system accidents based on a system engineering perspective to fill this gap. In this context, a real catastrophic marine diesel engine incident was analyzed to prove the applicability and effectiveness of the methodology. According to the analysis results, the main causes of the case incident were systematically determined as 80% human factor, 13% hardware & software factor, and 7% external factor.

Application and Development of Selective Catalytic Reduction Technology for Marine Low-Speed Diesel Engine: Trade-Off among High Sulfur Fuel, High Thermal Efficiency, and Low Pollution Emission

In recent years, the International Maritime Organization (IMO), Europe, and the United States and other countries have set up different emission control areas (ECA) for ship exhaust pollutants to enforce more stringent pollutant emission regulations. In order to meet the current IMO Tier III emission regulations, an after-treatment device must be installed in the exhaust system of the ship power plant to reduce the ship NOx emissions. At present, selective catalytic reduction technology (SCR) is one of the main technical routes to resolve excess NOx emissions of marine diesel engines, and is the only NOx emission reduction technology recognized by the IMO that can be used for various ship engines. Compared with the conventional low-pressure SCR system, the high-pressure SCR system can be applied to low-speed marine diesel engines that burn inferior fuels, but its working conditions are relatively harsh, and it can be susceptible to operational problems such as sulfuric acid corrosion, salt blockage, and switching delay during the actual ship tests and ship applications. Therefore, it is necessary to improve the design method and matching strategy of the high-pressure SCR system to achieve a more efficient and reliable operation. This article summarizes the technical characteristics and application problems of marine diesel engine SCR systems in detail, tracks the development trend of the catalytic reaction mechanism, engine tuning, and control strategy under high sulfur exhaust gas conditions. Results showed that low temperature is an important reason for the formation of ammonium nitrate, ammonium sulfate, and other deposits. Additionally, the formed deposits will directly affect the working performance of the SCR systems. The development of SCR technology for marine low-speed engines should be the compromise solution under the requirements of high sulfur fuel, high thermal efficiency, and low pollution emissions. Under the dual restrictions of high sulfur fuel and low exhaust temperature, the low-speed diesel engine SCR systems will inevitably sacrifice part of the engine economy to obtain higher denitrification efficiency and operational reliability.

Ambient-noise Free Generation of Clean Underwater Ship Engine Audios from Hydrophones using Generative Adversarial Networks

Generative adversarial networks (GANs) have been extensively used in image domain showing promising results in generating and learning data distributions in the absence of clean data. However, the audio domain, specially underwater acoustics are not yet fully explored in reporting the efficiency and applicability of GANs. We propose an audio GAN framework called ambient noise-free GAN (AN-GAN) to address the underwater acoustic signal denoising problem by removing the background ambient noise. The proposed AN-GAN can learn a clean audio generation with improved signal-to-noise ratio (SNR) given only the noisy samples from the underwater audio dataset. The simulated and real-time data collected from online available source ShipsEar, is used for the analysis and validation purpose. The comparative analysis shows an average percentage improvement of proposed AN-GAN with GAN-based and conventional statistical underwater denoising methods as 6.27% for UWAR-GAN, 227% for Wavelet denoising, 247% for EMD and 65% for Wiener technique.

The Mathematical Model of Marine Engine Room Equipment Based on Machine Learning

This study is aimed at reducing the occurrence of oil spill accidents in the engine room of ships and carries out risk prevention for the equipment of the port ships, thereby reducing pollution to the marine ecological environment. Firstly, the concepts and principles of cluster analysis and ship automatic identification system are expounded. Secondly, the data information collected by the ship’s automatic identification system (AIS) is combined with density-based cluster analysis. The accident area and extent at different stages of the ship’s engine room equipment are classified. Finally, cluster analysis is used to evaluate the risk of equipment of the port ship engine room. The results show that there are 43000 ship operation information points in port a, the average operating speed of ships is 9 kilometers, and the fastest operation speed is 16.9 kilometers. In addition, many ship routes in port a need to take risk prevention measures to minimize the impact between ships and reduce the risk of oil leakage in the engine room. The proposed cabin model can easily and quickly analyze the orientation information of the ship and classify all the data into different types according to the surrounding information points. AIS can realize the information transfer between ships and between ship and shore. Information such as the position, speed, and direction of the ship needs to be accurately known to ensure safety at sea. These data need to relate to some terminals and networks to form a maritime monitoring network. The ship AIS based on cluster analysis can cluster the areas where the ship’s speed and direction change significantly in the port area, effectively preventing accidents. Scientific risk prevention measures can effectively reduce the oil leakage risk of ship engine room equipment, improve the working efficiency of marine engines, and provide a strong foundation for the entire marine ecological environment protection.

Open-Loop Exhaust-Gas Cleaning System: Analysis of Effects Produced on Barcelona Port Water pH

The implementation of a 0.5% mass/mass sulphur cap in fuels used by ships has become a reality. Furthermore, regulation 14 of the MARPOL Convention–Annex VI (amended) establishes that the limit on fuel used by ships operating in a Sulphur Emission Control Area (SECA) cannot exceed 0.1% of mass/mass. To deal with these requirements while considering nature of the shipping business, which is the continuous carriage of cargo around the world, shipowners or shipping companies have few options for following this regulation. Apart from the use of a low-sulphur-content fuel is the use of an exhaust-gas cleaning system, also known as “scrubbers”, as an alternative. The use of these systems, specifically the open-loop system, entails the discharge to the sea of residual water used during the cleaning process of exhaust gases from ship engines. The objective of this paper is to study the effect produced by discharging this residual water on the acidity level (pH) of Barcelona port water. This objective was achieved through the periodical sampling and analysis of Barcelona port water in collaboration with the IDAEA (CSIC) laboratory. We analysed the evolution of the pH results obtained so far and obtained an initial picture of the pH Barcelona port water situation in real time regarding the effect of wash-water discharges from open-loop scrubbers. Furthermore, this paper describes the implementation of a system which is going to improve the operation of open-loop exhaust-gas cleaning systems.

Improved monitoring of shipping NO<sub>2</sub> with TROPOMI: decreasing NO<sub><i>x</i></sub> emissions in European seas during the COVID-19 pandemic

Abstract. TROPOMI (TROPOspheric Monitoring Instrument) measurements of tropospheric NO2 columns provide powerful information on emissions of air pollution by ships on open sea. This information is potentially useful for authorities to help determine the (non-)compliance of ships with increasingly stringent NOx emission regulations. We find that the information quality is improved further by recent upgrades in the TROPOMI cloud retrieval and an optimal data selection. We show that the superior spatial resolution of TROPOMI allows for the detection of several lanes of NO2 pollution ranging from the Aegean Sea near Greece to the Skagerrak in Scandinavia, which have not been detected with other satellite instruments before. Additionally, we demonstrate that under conditions of sun glint TROPOMI's vertical sensitivity to NO2 in the marine boundary layer increases by up to 60 %. The benefits of sun glint are most prominent under clear-sky situations when sea surface winds are low but slightly above zero (±2 m s−1). Beyond spatial resolution and sun glint, we examine for the first time the impact of the recently improved cloud algorithm on the TROPOMI NO2 retrieval quality, both over sea and over land. We find that the new FRESCO+ (Fast Retrieval Scheme for Clouds from the Oxygen A band) wide algorithm leads to 50 hPa lower cloud pressures, correcting a known high bias, and produces 1–4×1015 molec. cm−2 higher retrieved NO2 columns, thereby at least partially correcting for the previously reported low bias in the TROPOMI NO2 product. By training an artificial neural network on the four available periods with standard and FRESCO+ wide test retrievals, we develop a historic, consistent TROPOMI NO2 data set spanning the years 2019 and 2020. This improved data set shows stronger (35 %–75 %) and sharper (10 %–35 %) shipping NO2 signals compared to co-sampled measurements from OMI. We apply our improved data set to investigate the impact of the COVID-19 pandemic on ship NO2 pollution over European seas and find indications that NOx emissions from ships reduced by 10 %–20 % during the beginning of the COVID-19 pandemic in 2020. The reductions in ship NO2 pollution start in March–April 2020, in line with changes in shipping activity inferred from automatic identification system (AIS) data on ship location, speed, and engine.

Bio‐modified pyrotechnic composite materials for firefighting application

SummaryThe traditional aerosol‐forming composites are a mixture of potassium nitrate/chlorate and synthetic resins like phenol‐formaldehyde, melamine‐formaldehyde, polyurethane, and epoxy resin. Though these synthetic organic resins have excellent adhesion and mechanical properties, their high flammability and associated life‐threatening occupational hazard have limited their application. Such compositions' combustion flame may reach up to 2100°C and cause secondary fire risk in an explosive atmosphere, especially ship engine rooms and oil‐producing platforms. This study aimed to investigate the ability of natural flame‐retardant tannic acid, which is a natural phenolic compound abundant in many plants, to reduce the exothermicity of potassium nitrate/chlorate‐based pyrotechnic composite. In the present work, we newly developed a pyrotechnic composition that employed tannic acid as a reducer instead of synthetic resin. Its combustion behaviour, thermal properties, and fire extinguishing performance were comparatively evaluated against phenolic resin‐based traditional pyrotechnic composition. Though both the new and traditional pyrotechnic composition has shown similar fire extinguishing efficacy, the newly developed composition showed 57% lower combustion flame temperature, faster burn rate, and lower calorific value than the traditional composition. The physical and chemical characteristics of the discharged aerosol were characterized by a series of techniques viz; high‐resolution X‐ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and energy dispersive X‐ray analysis to understand the fire extinguishing mechanism.

Pregled ekoloških parametara brodskih dizel motora

The by-pass system of exhaust gas for the engine 6L20 Wartsila has been observed. The requirements of Annex VI MARPOL towards nitrogen oxide concentration in ship engine exhaust gases have been provided. The purpose of research was the determination of diesel 6L20 Wartsila by-pass exhaust gases optimum volume – at this the nitrogen oxide minimal concentration in exhaust gases is assured, the minimal increase (comparing with operation mode without by-pass) – specific effective fuel consumption, supporting of necessary thermal factor diapason of engine cylinders. The research was performed for the exhaust gas by-pass diapason 0…10 % with engine load diapason 0.55…0.85 % from nominal power. Upon experimental results it has been stated that the exhaust gas by-pass usage favors the ecological parameters of ships engine operation modes – by this at the range of exploitation load 0.55…0.85 % from nominal power the nitrogen oxide concentration in exhaust gas is decreased to 1.32….12.97 %. The exhaust gas by-pass impairs the combustion process and favors the increasing of specific effective fuel consumption and increasing the temperature of exhaust gases. The exhaust gas by-pass system effectiveness assessment should be performed by complex estimation of the following engine operation parameters: the nitrogen oxide concentration in exhaust gas, increasing of specific effective fuel consumption(SFOC), the exhaust gas temperature. As optimal degree of exhaust gas by-pass value when the maximum decrease of nitrogen oxide emission at minimal increase of fuel consumption and simultaneous engine thermal factor handling has to be considered.

Local energy production scenarios for emissions reduction of pollutants in small-medium ports

Environmental impact produced by ships in ports is a relevant problem, especially when they are located close to urban areas. This paper, taking Ancona (Italy) as a case study, analyzes the CO2 (and other chemical species) emissions produced by the auxiliary engines of ferry ships at berth. Three different configurations have been investigated, one grid-connected and two with local power plants. Cogenerative and photovoltaic scenarios have been considered varying the power size and the presence of a storage system. A computational model, based on maritime traffic and meteorological data over a one-year period, returns the percentages of the energy covered by the plant, the grid and the storage system. Environmental analysis shows that the grid-connected cold ironing scenario reduces the CO2 emissions by 34.5% compared to on-board diesel generators emissions. Cogeneration systems reduce CO2 emissions by 60–62%, while photovoltaic ones around 39%. All scenarios prove to be economically feasible.

Analisa Risiko Supply Chain Management dengan Metode Grey Failure Mode and Effect Analysis dan Root Cause Analysis di PT Pertamina Fuel Terminal Meulaboh

PT. Pertamina Fuel Terminal Meulaboh is a business unit of PT. Pertamina (Persero) under the function of Supply Distribution has the main task of carrying out the activities of receiving, stockpiling, and distributing fuel oil. In the distribution and operation processes carried out, 8 risks may occur. Based on the Gray FMEA method, the priority risk that occurs is the delay of the tanker which has the smallest gray relationship, which is 0.435 and the risk of the interconnection of information system support between functions which is still problematic is 0.452. Through the Root Cause Analysis method approach, the root causes of the risk of ship delays are non-routine maintenance/maintenance on ship engines, lack of training for crew members according to function, and bad weather conditions. Meanwhile, the risk of the interconnection of information systems support between functions is still problematic due to the lack of maintenance and network management. The alternative strategy for improvement that can be done by the company is to work with the BMKG to help predict the weather, improve the quality of workers according to their functions, provide adequate equipment and reliable mechanics to carry out SOPs for maintaining ship engines properly and cooperate with service management companies to assist companies in managing and maintaining networks.

Estimation of Dynamic Characteristics of Vibration Protection Systems of a New Type for Water Transport Vessels

The use of traditional means of vibration isolation of ship power plants does not always give the desired effect, which predetermines the need to search for and use fundamentally new devices to improve the efficiency of vibration isolation of a ship engine. This can be achieved by installing active-passive vibration isolators in the elastic mounts of the engine, such as electromagnetic hydraulic vibration isolators (EHVO) for auxiliary engines and other marine equipment. Despite the seeming simplicity of the design and principle of operation, the calculation of EHVO is a rather complex problem, the solution of which is associated with a number of difficulties due to the specific features of electromagnetic devices, since their calculation is associated with a large number of factors and limitations. The known functions of time obtained by solving the equations were used to calculate the dynamic parameters of the EHVO: vibration energy, periodicity, overheating of the coils and efficiency

The Impact of Alternative Fuels on Ship Engine Emissions and Aftertreatment Systems: A Review

Marine engines often use diesel as an alternative fuel to improve the economy. In recent years, waste oil, biodiesel and alcohol fuel are the most famous research directions among the alternative fuels for diesel. With the rapid development of the shipping industry, the air of coastal areas is becoming increasingly polluted. It is now necessary to reduce the emission of marine engines to meet the strict emission regulations. There are many types of alternative fuels for diesel oil and the difference of the fuel may interfere with the engine emissions; however, PM, HC, CO and other emissions will have a negative impact on SCR catalyst. This paper reviews the alternative fuels such as alcohols, waste oils, biodiesel made from vegetable oil and animal oil, and then summarizes and analyzes the influence of different alternative fuels on engine emissions and pollutant formation mechanism. In addition, this paper also summarizes the methods that can effectively reduce the emissions of marine engines; it can provide a reference for the study of diesel alternative fuel and the reduction of marine engine emissions.