7 research outputs found

    Techno-economic investigation of alternative propulsion plants for ferries and RoRo ships

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    In this paper, the main alternative propulsion plants based on reciprocating internal combustion engines of a ferry or RoRo ship operating in routes that include Emission Control Areas (ECAs) are comparatively assessed. Specifically, a dual fuel engine propulsion plant is compared with a conventional Diesel engine plant. For both cases, the installation of a Waste Heat Recovery system, which covers a part of the ship electric energy demand, is also considered. The ship main DF engines are assumed to operate using LNG and a small amount of MDO for initiating combustion, whereas low sulphur MDO was regarded as the fuel for the case of the Diesel engine plant. The installation of selective catalytic reduction (SCR) after-treatment unit for reducing the NOx emissions for the case of Diesel engines plant is also taken into account. The propulsion plants were modelled under steady state conditions, and the simulation results were analysed in order to compare the alternative configurations. Furthermore, the energy efficiency design index (EEDI) values were calculated and the two examined propulsion system cases were compared on EEDI basis. Finally, the Life Cycle Cost for each alternative propulsion plant was calculated and used for completing an economic evaluation of the Dual fuel propulsion plant versus the conventional designs applied in ferries

    A decision support system for the development of voyage and maintenance plans for ships

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    The waterborne sector faces nowadays significant challenges due to several environmental, financial and other concerns. Such challenges may be addressed, among others, by optimising voyage plans, and diagnosing as early as possible engine failures that may lead to performance degradation. These two issues are addressed by the Decision Support System (DSS) presented herein, which focuses on the operation of merchant ships. For the development of voyage plans, a multicriteria decision problem is developed and handled with the PROMETHE method, while a multivariable control chart is used for the fault diagnosis problem. A MATLAB-based software implementation of the DSS has been developed adopting a modular architecture, while, in order to provide a generic software solution, the required input data are retrieved from dedicated web-services, following specific communication and data exchange protocols

    Design of a Mass Air Flow Sensor Employing Additive Manufacturing and Standard Airfoil Geometry

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    This work concerns the design, fabrication, and preliminary characterization of a novel sensor for determining the air intake of low and medium power internal combustion engines employed at various applications in the marine industry. The novelty of the presented sensor focuses on the fabrication process, which is based on additive manufacturing combined with PCB technology, and the design of the sensing elements housing geometry, which is derived through suitable CFD simulations and is based on standard airfoil geometry. The proposed process enables low-cost, fast fabrication, effective thermal isolation, and facile electrical interconnection to the corresponding circuitry of the sensor. For initial characterization purposes, the prototype device was integrated into a DIESEL engine testbed while a commercially available mass air flow sensor was employed as a reference; the proper functionality of the developed prototype has been validated. Key features of the proposed device are low-cost, fast on-site manufacturing of the device, robustness, and simplicity, suggesting numerous potential applications in marine engineering

    Design of a Mass Air Flow Sensor Employing Additive Manufacturing and Standard Airfoil Geometry

    No full text
    This work concerns the design, fabrication, and preliminary characterization of a novel sensor for determining the air intake of low and medium power internal combustion engines employed at various applications in the marine industry. The novelty of the presented sensor focuses on the fabrication process, which is based on additive manufacturing combined with PCB technology, and the design of the sensing elements housing geometry, which is derived through suitable CFD simulations and is based on standard airfoil geometry. The proposed process enables low-cost, fast fabrication, effective thermal isolation, and facile electrical interconnection to the corresponding circuitry of the sensor. For initial characterization purposes, the prototype device was integrated into a DIESEL engine testbed while a commercially available mass air flow sensor was employed as a reference; the proper functionality of the developed prototype has been validated. Key features of the proposed device are low-cost, fast on-site manufacturing of the device, robustness, and simplicity, suggesting numerous potential applications in marine engineering

    Techno-economical investigation of alternative propulsion concepts of ferries operating in Mediterranean sea – introduction of LNG as alternative fuel

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    Paper describing the techno-economical investigation of alternative propulsion concepts of ferries operating in the Mediterranean sea

    Accurate instantaneous engine speed recording by employing an optical measurement system-application to a typical low power industrial engine

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    The presented work concerns the development of a novel measurement system for determining the instantaneous rotational speed of an engine with high accuracy. The developed system is mainly based on a commercially available optical sensor and appropriate data acquisition / post-processing procedure. The accuracy of the system is high; speed recording with a resolution of one degree of crank angle has been succeeded when measuring the speed of a one cylinder four stroke S.I. motored engine. The deduced experimental results were compared with the corresponding theoretical ones obtained by appropriate simulations, validating the proper functionality of the developed system. Furthermore, the system was also integrated into a typical four cylinder low power industrial engine successfully. Key-features of the proposed measurement configuration are accuracy, simplicity and low-cost suggesting numerous potential applications
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