1,720,972 research outputs found
A comparison of dispersion models for the LNG dispersion at port of Koper, Slovenia
Full text linkThe challenges of ensuring green shipping and green ports force ports to adequately and safely implement engineered systems for the distribution and supply of LNG in port areas that meet the requirements of Seveso Directive. As the process of LNG bunkering is only seemingly similar to classical oil bunkering or liquid cargo, the handling of the technical and safety challenges is much more subject to investigation. In this work, the dispersion part of the consequences of LNG release, pooling, evaporation and dispersion during the future bunkering operation in the port of Koper, Slovenia, where the populated area (city) is located in close proximity. We follow the comparison of three different tools, namely the model Unified Dispersion Model (UDM) implemented by the software PHAST from DNV-GL® and two CFD (FDS - Fire Dynamics Simulator from NIST and Ansys Fluent®) in the same case scenario. Geometry, initial and boundary conditions are assumed to be the same as far as possible according to the limitations of the respective software tools. The simulation tools are first applied to a flat terrain model and later the models of CFD are compared, including the 3D geometry of the dock site in real size, with two relevant wind directions. The effects of evaporation rates on water and turbulence on CFD estimates are also given and numerically tested. The results of the applied models provide valuable information for further establishment of similar LNG leakage and dispersion models for simulation in ports or similar facilities
Ship-to-ship LNG Bunkering: Risk Assessment and Safety Zones
Full text linkIn this paper risk assessment for the ship to ship LNG bunkering is carried out by exploiting the results of the projects “SUstainability PERformance of LNG-based maritime mobility – PLUS” (SUPER-LNG PLUS) financed by Interreg-Adrion and the project “Risk management system for design and operation of installations for LNG refuelling” (TRiTON) financed by the Greek government. Ship to ship bunkering constitutes a simple method when storage tanks cannot be installed in the port areas. In brief, risk assessment is conducted in the following basic steps: a) assessment of plant damage states and their frequency of occurrence, b) assessment of consequences and c) risk integration. First, the Master Logic Diagram (MLD) technique is used to identify the initial events that create a disturbance in the installation and have the potential to lead to an LNG release during a ship to ship bunkering operation. Moreover, safety functions and systems for preventing LNG release, are identified and Event trees are developed to model the accident sequences which lead to damage states. By exploiting available failure rate data, the frequency of each damage state is estimated. In parallel, the consequences of LNG release are estimated based on the heat radiation or overpressure dose an individual receives. Finally, iso-risk contours are calculated by combining the frequencies of the various accidents with the corresponding consequences. A case study for a ship to ship bunkering in a Greek port is presented
A Comparison of Alternative Cryogenic Fuels for Regional Marine Transportation from the Perspective of Safety
Full text linkMarine industry has been forced to move towards sustainable fuels. Cryogenic gases as Liquefied Natural Gas (LNG) and ammonia (LNH3) can be the solution for fuel storage and transportation even for remote reservoir.
Besides liquefied hydrogen (LH2) seems to be a long-term solution, but several studies are addressed to this
new opportunity. To deal with intensive use of these three fuels, a detailed comparison for the technical, economic and environmental point of view is strongly needed. Nevertheless, so far, a full understanding on the complex phenomena characterizing the accidental release of LNG, LH2 and LNH3 in harbour environment has
not been assessed. In this paper, a comparison of the three fuels for the safety perspective, i.e., the hazards
and the consequences of accidental release, is shown, considering storage systems which can be possibly installed on small ships such as ferries, trailers, cabin cruiser, small cargos, and leisure
Remote risk assessment: A case study using SCOPE software
No full textA thorough risk assessment requires input from experts in both safety analyses and the system under analysis. The cost of collecting together the required expertise for a short risk assessment may mean that for some small and medium enterprises (SME), the risk assessment is not deemed worthwhile or is completed using a generic form. This is despite the possible safety and performance benefits that can be identified via a thorough risk assessment. This paper presents a case study of a risk assessment on a rare periodic inspection & maintenance procedure planned by a LPG storage and distribution company in Slovenia. The company identified the need to risk assess this procedure and determine possible safety and performance improvements, including analysis of planned human activities. The expertise for this task was available through contacts spread across Ireland, Italy and Slovenia, but the costs of all the experts gathering together at the site were prohibitive. The solution was the use of SCOPE risk assessment software over internet video conferencing. All participants could share their expertise to identify the hazards and control the risks. This paper presents the method used and explores the requirements and benefits of this approach
Risk assessment for LNG storage and bunkering at ports
No full textIn this paper the main achievements of the project entitled “Sustainable Performance of LNG-based maritime mobility” (SUPER-LNG) financed by the Adriatic Ionian Interreg framework will be outlined. The project deals with safety and security issues in ports of the Adriatic and Ionian area owing to the increasing use of LNG as marine fuel; LNG tends to replace conventional fuels by contributing to the environmental emissions reduction leading, thus, to more sustainable shipping. In the framework of the project, guidelines were developed for risk assessment and emergency planning of LNG facilities and operations at ports. To that end a training programme has been created with the aim to mainly promote safety and to transfer knowledge of the LNG fuel chain to stakeholders, such as port operators, maritime instructors, port authorities and stakeholders in planning, licensing and emergency management. The situation of LNG bunkering at ports, as well as the guidelines and the training programme developed, will be presented and discussed in the present work
Safety guidelines and a training framework for LNG storage and bunkering at ports
Full text linkThe challenges of ensuring green shipping and green ports force ports to adequately and safely implement engineered systems for the distribution and supply of LNG in port areas that meet the requirements of Seveso Directive. As the process of LNG bunkering is only seemingly similar to classical oil bunkering or liquid cargo, the handling of the technical and safety challenges is much more subject to investigation.
In this work, the dispersion part of the consequences of LNG release, pooling, evaporation and dispersion during the future bunkering operation in the port of Koper, Slovenia, where the populated area (city) is located in close proximity. We follow the comparison of three different tools, namely the model Unified Dispersion Model (UDM) implemented by the software PHAST from DNV-GL® and two CFD (FDS - Fire Dynamics Simulator from NIST and Ansys Fluent®) in the same case scenario. Geometry, initial and boundary conditions are assumed to be the same as far as possible according to the limitations of the respective software tools. The simulation tools are first applied to a flat terrain model and later the models of CFD are compared, including the 3D geometry of the dock site in real size, with two relevant wind directions. The effects of evaporation rates on water and turbulence on CFD estimates are also given and numerically tested. The results of the applied models provide valuable information for further establishment of similar LNG leakage and dispersion models for simulation in ports or similar facilities
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Risk-based optimization of operational procedures
No full textThe maturity of management systems allows drawing the conclusion that in modern industries the activities are mostly written, consolidated and verified within operational procedures. This also applies for the activities that are carried out infrequently, e.g., rare maintenance or testing activities, that being uncommon, are less known and thus characterized by an higher potential risk. In order to optimize the procedure, both from the productivity and from the safety (occupational and process) point of view, a risk assessment of the procedure has to be performed, highlighting which of the tasks within the procedure mainly contributes to the risk of the working activity. Usually the analysis of the procedures is carried on through a task analysis (as in Builes et al., 2014). In this paper the task analysis is used as a starting point for a quantitative risk assessment carried on through an integrated decision analysis (as in Leva et al., 2015). Through the integrated decision analysis, the logical-probabilistic model of the procedure is elaborated jointly with a consequences estimation obtaining a risk assessment for all the sequences of tasks from work procedure under analysis. The comparative risk analysis considered two (original and optimized) procedure alternatives. The risk assessment considered both possible equipment failures and the potential personnel errors in executing, mainly manual, testing procedure. In this paper, an application of the integrated decision analysis, through the SPACCO software tool, is shown for a cold water pressure test of the LPG storage tank in industrial installation. The risk has been assessed in terms of delays in the operations and economical impact in case of occupational and/or process accidents. Observing the variation of the risk distribution the procedure optimization has been performed and the risk reduction calculated
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