130 research outputs found

    Sustainable hybrid marine power systems for power management optimisation : a review

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    The increasing environmental concerns due to emissions from the shipping industry have accelerated the interest in developing sustainable energy sources and alternatives to traditional hydrocarbon fuel sources to reduce carbon emissions. Predominantly, a hybrid power system is used via a combination of alternative energy sources with hydrocarbon fuel due to the relatively small energy efficiency of the former as compared to the latter. For such a hybrid system to operate efficiently, the power management on the multiple power sources has to be optimised and the power requirements for different vessel types with varying loading operation profiles have to be understood. This can be achieved by using energy management systems (EMS) or power management systems (PMS) and control methods for hybrid marine power systems. This review paper focuses on the different EMSs and control strategies adopted to optimise power management as well as reduce fuel consumption and thus the carbon emission for hybrid vessel systems. This paper first presents the different commonly used hybrid propulsion systems, i.e., diesel–mechanical, diesel–electric, fully electric and other hybrid systems. Then, a comprehensive review of the different EMSs and control method strategies is carried out, followed by a comparison of the alternative energy sources to diesel power. Finally, the gaps, challenges and future works for hybrid systems are discussed

    Automated Tugboat Assisted Docking of Large Vessels

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    The main research aspect behind this project was the problem in docking the ship to the port with limited space and resources available, causing number of onsite accidents and loss of resources. The main objective is to increase safety on ports, reduce pollution and increase fuel efficiency, also reduce the docking time for the vessels, which can be achieved by developing an autonomous docking system involving automated operations of tugboats, the port, and the vessel itself using control systems with limited involvement from human. This requires the development of a predictive control path for each component involved in the process. This is a long-term goal and requires a lot of research work and prototyping. In this thesis work, some studies will be carried out from past research work related to the problems focused on this project and the solutions provided to tackle these problems. Further data will be extracted along with all the essential equations and based on it; mathematical model will be developed as well as the development of path trajectory algorithm will be carried out. Also, its feasibility will be tested using simulation-based prototyping

    Evaluation of Hybrid Battery System for Platform Support Vessels

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    Master's thesis in Offshore structural engineeringIn the last few years, the car industry has developed hybrid battery systems with lower battery price, higher capacity and improved safety. These improvements in performance have led to an increased interest to utilize the technology in marine applications. To satisfy the requirements of redundancy in critical situations vessels are required to run multiple engines at low to medium loads during most of operations in station keeping. Traditional combustion engines are designed to have the optimal level of fuel consumption and lowest emission per kilowatt hour when operating at medium to high loads. This practice therefore represents an overall loss and is unfavorable for environment and fuel consumption. This thesis investigates the effect and viability of applying a Hybrid Battery System (HBS) on a Platform Support Vessel (PSV) by using the battery to optimize the original power system. For the case study, the vessel Viking Energy has been considered. Viking Energy is the first vessel with a HBS approved as a redundant power source in critical operations. The system allows the vessel to reduce the numbers of active engines while ensuring instant available power if required. The remaining active engines are then operating closer to the optimal level, ensuring lower emission and fuel consumption per kilowatt hour. This study analyzes and quantifies the effect in fuel consumption and cost after implementing the HBS to the PSV. It also analyzes the weathers influence of the fuel consumption for the vessel with and without HBS. The study is based on a six-month sample period where the HBS was fully operative. The analysis gave an annual reduction in fuel of 13% comparing the sampling period with historical data given the same time distribution for the vessel. Normalizing both to actual distribution over a three-year operation period gives a calculated reduction of 17% due to more favorable distribution. The difference is mainly due to higher portion of Dynamic Positioning (DP) mode in the historical data. The economical evaluation concluded that the minimum threshold for overall fuel reduction to be 15% for the investment to break even in a ten-year perspective. A vessel is recommended to operate 34% or more of the time in DP or a mode providing similar level of fuel saving to meet an overall reduction of 15%

    Sustainable seabed mining: guidelines and a new concept for Atlantis II Deep

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    The feasibility of exploiting seabed resources is subject to the engineering solutions, and economic prospects. Due to rising metal prices, predicted mineral scarcities and unequal allocations of resources in the world, vast research programmes on the exploration and exploitation of seabed minerals are presented in 1970s. Very few studies have been published after the 1980s, when predictions were not fulfilled. The attention grew back in the last decade with marine mineral mining being in research and commercial focus again and the first seabed mining license for massive sulphides being granted in Papua New Guinea’s Exclusive Economic Zone.Research on seabed exploitation and seabed mining is a complex transdisciplinary field that demands for further attention and development. Since the field links engineering, economics, environmental, legal and supply chain research, it demands for research from a systems point of view. This implies the application of a holistic sustainability framework of to analyse the feasibility of engineering systems. The research at hand aims to close this gap by developing such a framework and providing a review of seabed resources. Based on this review it identifies a significant potential for massive sulphides in inactive hydrothermal vents and sediments to solve global resource scarcities. The research aims to provide background on seabed exploitation and to apply a holistic systems engineering approach to develop general guidelines for sustainable seabed mining of polymetallic sulphides and a new concept and solutions for the Atlantis II Deep deposit in the Red Sea.The research methodology will start with acquiring a broader academic and industrial view on sustainable seabed mining through an online survey and expert interviews on seabed mining. In addition, the Nautilus Minerals case is reviewed for lessons learned and identification of challenges. Thereafter, a new concept for Atlantis II Deep is developed that based on a site specific assessment.The research undertaken in this study provides a new perspective regarding sustainable seabed mining. The main contributions of this research are the development of extensive guidelines for key issues in sustainable seabed mining as well as a new concept for seabed mining involving engineering systems, environmental risk mitigation, economic feasibility, logistics and legal aspects

    Inland Waterway Operational Model & Simulation Along the Ohio River

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    The inland waterway system of the U.S. is a vital network for transporting key goods and commodities from the point of production to manufacturers and consumers. Shipping materials via the inland waterways is arguably the most economical and environmentally friendly option (compared to hauling freight by trains or railways). Despite the advantages the inland waterways enjoys over competing modes, key infrastructure – such as locks and dams, which help to control water levels on a number of rivers and make navigation possible – is declining. Limited funds have been allocated to make the necessary repairs to lock and dam facilities. Over the past 10 years Inland Waterways Trust Fund resources (which historically funded maintenance and improvement projects) has steadily declined. Locks and dams are of particular importance, because they assist in the maintenance of navigable depths on many of the major inland waterways (Ohio River, Upper Mississippi River, Tennessee River). To better understand the operation of the inland waterway system, this report examines a portion of the Ohio River (extending from Markland Locks and Dam to Lock 53). The specific focus is to determine what delays barge tows as they attempt to lock through these critical facilities. The Ohio River is a particularly important study area. In many ways it is representative of the conditions present throughout the inland waterways system. The average age of the lock and dam facilities exceed 50 years along our study segment. Most of these facilities are operating beyond their intended design life. As locks age, they increasingly demand more scheduled and unscheduled maintenance activities. Maintenance activities often require temporarily shuttering a lock chamber and diverting traffic through another onsite chamber (often of smaller capacity). All of the facilities included in the research area have two lock chambers ‐ thus, if one goes down for maintenance all vessels are diverted through the second chamber. In many cases this situation can produce extensive delays, which precludes cargo from reaching the destination in a timely manner. Recently, the aggregate number of hours that shippers and carriers lose due to delays has escalated. Although the U.S. Army Corps of Engineers – the agency responsible for the management and oversight of locks and dams – has worked to keep traffic flowing on the river, tightening budgets hamper efforts. For shippers and carriers to make informed decisions about when and where to deploy freight on the river, they require knowledge that illuminates factors that are most significant in affecting transit times. In particular this applies to certain conditions that are likely to create delays at lock and dam facilities. The purpose of this report is to 1) develop a comprehensive profile of the Ohio River that provides an overview of how it is integral to U.S. economic security 2) identify salient river characteristics or externally‐driven variables that influence the amount of water flowing through the main channel which consequently impacts vessels’ capacity to navigate 3) use this information (along with a 10‐year data set encompassing over 600,000 observations) to develop an Inland Waterways Operational Model (IWOM). The IWOM objective is to provide the U.S. Army Corps of Engineers, shippers, carriers, and other interested parties with access to8 a robust method that aids in the prediction of where and when conditions will arise on the river that have the potential to significantly impact lockage times and queue times (i.e. how long a vessel has to wait after it arrives at a facility to lock through). After qualitatively reviewing different features of the river system that affect vessel traffic, this report outlines two approaches to modeling inland waterway system behavior – a discrete event simulation (DES) model which uses proprietary software, and the IWOM. Although the DES produced robust findings that aligned with the historical data (because it relies upon proprietary software), it does not offer an ideal platform to distribute knowledge to stakeholders. Indeed, this is the major drawback of the DES given a critical objective of this project is to generate usable information for key stakeholders who are involved with inland waterway operations. Conversely, the IWOM is a preferable option given it relies on statistical analysis – in this sense, it is more of an open‐source solution. The IWOM uses linear regression to determine key variables affecting variation in lockage time. The final model accounts for over two‐thirds of the observed variation in lockage times from 2002‐2012, which is our study period. Practically, this means that the difference between predicted values and observed delay times is significantly less than how the delays vary around the composite average seen in the river system (R2 = 0.69). The IWOM confirms that variations in river conditions significantly affect vessel travel times. For example, river discharge ‐ the direction a vessel moves up or down a river ‐ meaningfully influences lockage times. The freight amount a vessel carries, which is represented by the amount of draft and newness of a vessel, influences lockage times. Larger vessels with more draft tend to wait longer and take longer to complete their lockage. The IWOM is less successful at predicting delay times. Because there is greater instability in this data only a modest amount of variation is explained by the model (R2 = 0.23). This, in turn, partly reflects in spillover from one vessel to the next that is difficult for the simulation to impose and account for therefore requiring additional logic. Once completed, the IWOM was used to parameterize a simulation model. This provided a graphical representation of vessels moving along the river. Users have the capability of adjusting the effects of different variables to anticipate how the system may react, and what changes in vessel traffic patterns emerge. This information will be of great use for stakeholders wanting to gain a better understanding of what conditions lockage times will increase or decrease, why delays emerge, and consequently how these impact traffic flows on the river. In programming a simulation model, users are able to visualize and intuit what causes vessel travel times to vary. Although the regression model accomplishes this, for many users this would prove unwieldy and difficult to grasp beyond a conceptual, abstract level. Matching up regression results with a visual counterpart lets users gain immediate and intimate knowledge of river and vessel behavior – this in turn can positively affect shipper and carrier modal choices. The report concludes with some recommendations for IWOM implementation and thoughts on future research needs. Also discussed are the implications results from the present study have for improving our ability to safely, securely, and swiftly move freight on the inland waterways network

    Desarrollo de una estrategia de respuesta a la demanda para la gestión de energía en estaciones de recarga de vehículos eléctricos en edificios de oficinas

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    The purpose of this document is to present the management strategy for charging electric vehicles in an office building. The first chapter analyzes the load capacity of an office building, as well as vehicular flow adjacent to it and the travel time to the work of users of private vehicles, factors considered within the management strategy. The second chapter focuses on electric vehicles, analyzes the current market and defines the parameters that were taken into account in the management strategy. The third chapter presents the management strategy developed and the algorithms implemented that are finally validated in the fourth chapter.El presente documento tiene como objetivo presentar la estrategia de gestión de recarga de vehículos eléctricos en un edificio de oficinas. El primer capítulo analiza la capacidad de carga de un edificio de oficinas, así como flujo vehicular adyacente al mismo y el tiempo de desplazamiento al trabajo de usuarios de vehículos particulares, factores considerados dentro de la estrategia de gestión. El segundo capítulo se centra en los vehículos eléctricos, analiza el mercado actual y define los parámetros que se tomaron encuenta en la estrategia de gestión. El capítulo tercero presenta la estrategia de gestión desarrollada y los algoritmos implementados que finalmente son validados en el cuarto capítulo.Línea de Investigación: Gestión de energíaMaestrí
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