The S-CO2 power cycle has the advantages of compact structure and high energy density, which can be used to recover the waste heat of ship exhaust, thus improving the energy efficiency of ships and ...reducing emissions. The hybrid heat exchangers with etched plates and fins can be used as the heat transfer device of S-CO2 and exhaust, its heat transfer and pressure drop characteristics have a great influence on S- CO2 power cycle performance. In this study, a CFD model of the hybrid heat exchangers was established. The effects of different exhaust inlet temperatures, inlet mass flow rates and inlet pressures on the heat transfer and the pressure drop characteristics were analyzed by Fluent. The results show that the inlet temperatures and inlet mass flow rates of exhaust have a great influence on the heat transfer characteristics of the hybrid heat exchanger. The inlet mass flow rates and inlet pressures of exhaust have a great influence on the pressure drop characteristics of the hybrid heat exchangers. In the design of the hybrid heat exchangers, the status of the exhaust need to be considered to ensure efficient operation of the heat exchangers. The study can provide guidance for the design of the hybrid heat exchangers.
The global shipping industry faces huge pressure to reduce its greenhouse (GHG) emissions due to the International Maritime Organization (IMO) has introduced strict regulations to decrease GHG ...emissions from ships. New energy sources can provide a solution for green shipping because they have the advantages of abundant, renewable and clean. This paper examines the current progress made regarding the integration of new energy sources into conventional ship power systems, including solar energy, wind energy and fuel cells. It also discusses the possibilities for using the aforementioned three new energy sources in ship power systems ranging from technical principles to subsequent applications. Furthermore, basic working theories of new energy sources, application methods, existing new energy ships and core technologies required are summarized in detail. The integration of new energy sources into traditional ship power systems has enormous potential to bring the shipping industry in line with international regulatory requirements and is set to become a key focus of ship-related researches in the immediate future.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Accurate predictive method for ship dynamic is a keynote precondition for structural design and an important consideration for strength evaluation. A wave-ship coupling model focusing on the ...estimating of ship dynamics is numerically established to solve the fluid–structure interaction. Numerical calculation based on the presented algorithm is carried out, and the dynamical response for both ship and fluid is thus investigated with MATLAB. The dynamical responses including the structural force, deformation, velocity, and energy with different ship mass and stiffness are obtained. Experiment is conducted in the towing tank to investigate the peak frequency and transient amplitude with different wave speeds. It is found that the ship dynamics is closely related to the quality and stiffness of the structure, as well as the wave velocity of the fluid. An appropriate estimating method for ship dynamics is thus proposed through series of discussion on numerical results and experimental data.
•Analyse the risks of maritime supply chains from different perspectives.•Develop an advanced risk analysis method to tackle the uncertainty in risk data.•Compare risk analysis results by using ...different methods to demonstrate the advantages of the newly proposed one.•Conduct an empirical study to provide useful insights for the identification and control of high risks.
This paper aims to develop a novel model to assess the risk factors of maritime supply chains by incorporating a fuzzy belief rule approach with Bayesian networks. The new model, compared to traditional risk analysis methods, has the capability of improving result accuracy under a high uncertainty in risk data. A real case of a world leading container shipping company is investigated, and the research results reveal that among the most significant risk factors are transportation of dangerous goods, fluctuation of fuel price, fierce competition, unattractive markets, and change of exchange rates in sequence. Such findings will provide useful insights for accident prevention.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In the face of increasingly severe energy shortage and environmental pollution, the use of new forms of energy will become an important direction for the future development of ships. A hybrid power ...system comprised of various types of energy, such as conventional fossil fuels, renewables, hydrogens, fuel cells and batteries, can ensure a continuous and reliable power source for ships by using different types of energy for various operating conditions. This has become an emerging solution for greener ships and attracted attention from both industry and academia. A state-of-the-art multi-energy hybrid power system for ships is introduced in this paper. The configuration and characteristics of series, parallel and series-parallel hybrid power systems are analyzed and compared. Challenges of multi-energy power system for large-scale ships such as reliability, control and efficiency are discussed, and possible solutions are proposed.
•Development of multi-energy hybrid power system, consisting of solar energy, energy storage, and diesel engines.•Key technologies to develop the multi-energy hybrid power system for ships.•Issues in the large-scale multi-energy ships, and suggestions to resolve these issues.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
► A practical laser device for pavement macrotexture measurement. ► Obtain three groups of macrotexture parameters. ► Seven types of pavement surface employed in system verification. ► The device can ...provide efficient, reliable, accurate and consistent measurements.
Pavement surface macrotexture greatly contributes to tire-pavement skid resistance which has a direct effect on traffic operation and safety particularly at high speeds. Therefore, efforts are needed to develop effective and practical devices to measure macrotexture profile. In this study, a practical laser device was developed, which is lightweight and portable with low cost. Following a critical review on existing devices, this paper outlines the hardware and software configurations of the proposed system. A comprehensive illustration on how the system works is presented to show a number of merits associated with the proposed device and accompanying analysis programs. Results from pilot testing experiments confirm that the proposed system provides efficient, reliable, accurate and consistent measurements for pavement surface profiles.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Due to the increasing demand for energy conservation and the reduction of emissions, renewable energy applications for ships have attracted a great deal of attention. In this paper, a 5000-vehicle ...space pure car and truck carrier (PCTC) is selected as the research object. Then, on the basis of the existing power system, a unified grid-tied/stand-alone solar system is designed with a built-in battery energy storage system. The system includes a solar energy generation unit, a battery storage system, a diesel generating set, grid-tied/stand-alone controlled inverters, a battery management system (BMS) and an energy management system. According to an analysis of the experimental data, it can be concluded that the use of solar energy hybrid power, in theory, can reduce fuel consumption by 4.02% and carbon dioxide (CO2) emissions by 8.55% a year.
•A large-scale hybrid PV/diesel ship power system is designed.•The energy saving and emission reduction effects are analyzed through an experimental test.•Ships using this PV hybrid power system can effectively reduce fuel consumption.•The PV hybrid power system design scheme can provide significant guidance for the same type of ships.
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Wind energy plays a significant role in the energy consumption reduction of the sail-assisted vessels. During the navigation process, how to select the ideal airfoil sails is crucial for the vessel ...safety and wind energy conversion efficiency. We resolve the airfoil sails selection problem by utilizing computational fluid dynamics simulation. Within the computational fluid dynamics simulation approach, with shear-stress transport k–ω turbulence model, we analyze the performance of the three typical airfoil sails including NACA23012, NACA0012, and NACA0018 in the wind field from the perspective of force condition, lift and drag coefficients, and lift–drag ratio under generous wind speeds and angles of attack. And we investigate the pressure contours of the airfoil sails. Then, we can determine the aerodynamic performance of the airfoil sails promptly and identify suitable sails for the sail-assisted vessels under the given wind field.
•Analyse the primary data to estimate the appearance frequencies of risk factors resulting in maritime accidents.•Evaluate the joint impact of human factors and other risk factors on different types ...of maritime accidents.•Develop an accident data-driven Bayesian network to realise human factor oriented maritime accident analysis.•Conduct an empirical study to provide insights for the prevention of a particular type of accidents involving human errors.
A data-driven Bayesian network (BN) is used to investigate the effect of human factors on maritime safety through maritime accident analysis. Its novelties consist of (1) manual collection and analysis of the primary data representing frequencies of risk factors directly derived from maritime accident reports, (2) incorporation of human factors into causational analysis with respect to different maritime accident types, and (3) modelling by a historical accident data-driven approach, to generate new insights on critical human factors contributing to different types of accidents. The modelling of the interdependency among the risk influencing factors is structured by Tree Augmented Network (TAN), and validated by both sensitivity analysis and past accident records. Our findings reveal that the critical risk factors for all accident types are ship age, ship operation, voyage segment, information, and vessel condition. More importantly, the findings also present the differentiation among the vital human factors against different types of accidents. Most probable explanation (MPE) is used to provide a specific scenario in which the beliefs are upheld, observing the most probable configuration. The work pioneers the analysis of various impacts of human factors on different maritime accident types. It helps provide specific recommendations for the prevention of a particular type of accidents involving human errors.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this study, stainless steel test plates with different surface roughness and textures, which are used as the heat transfer surface of a plate heat exchanger, are tested individually in calcium ...carbonate fouling experiments. The present experimental results clearly indicate a strong correlation between the surface roughness and the amount of crystallization fouling deposit. Through detailed image analysis, four stages of the formation of crystallization fouling are identified, and the impact of the surface morphology on the extent of crystallization fouling is described qualitatively.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
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