DSpace Collection:http://hdl.handle.net/11422/942024-03-24T00:27:51Z2024-03-24T00:27:51ZClean burning do gás natural e seus efeitos na redução de custos do transporte marítimoSilva, Raul Garcia dahttp://hdl.handle.net/11422/202092023-12-21T03:01:17Z2019-04-01T00:00:00ZTitle: Clean burning do gás natural e seus efeitos na redução de custos do transporte marítimo
Author(s)/Inventor(s): Silva, Raul Garcia da
Advisor: Vasconcellos, José Marcio do Amaral
Abstract: The need for seaborne transportation will increase significantly in the years to come. At the same time, the fuel oil price is increasing, stricter emission requirements are coming into force, and the public is becoming more concerned about the environmental footprint of shipping. As a result, the industry is investigating alternative fuels for shipping. Liquefied Natural Gas (LNG) is an attractive option since it reduces the emissions set by IMO, and is expected to be cheaper than fuel oil in the future because of the large world reserves of natural gas. The objective of this work is to demonstrate, through an investigation, based on aspects of maintenance and reliability of large marine engines, through the database available in the OREDA (Offshore and Onshore Reliability Data), which exists behind the requirements of the IMO, also a significant financial gain for shipowners and operators, provided by the increased availability of marine engines due to the Clean Burning of natural gas in naval propulsion systems. An economic analysis, will show the financial gain coming with the postponement of maintenance, provided by the increased availability. Natural gas, as propulsion fuel, will provide better price offers and therefore a cost reduction for the maritime freight takers.
Publisher: Universidade Federal do Rio de Janeiro
Type: Tese2019-04-01T00:00:00ZViabilidade técnico-econômica da turbina eólica offshoreOliveira, Thamires de Almeidahttp://hdl.handle.net/11422/201472023-12-21T03:01:15Z2019-10-01T00:00:00ZTitle: Viabilidade técnico-econômica da turbina eólica offshore
Author(s)/Inventor(s): Oliveira, Thamires de Almeida
Advisor: Estefen, Segen Farid
Abstract: This work develops a techno-economic analysis of a fixed bottom offshore wind turbine in the Southeast and Northeast regions of Brazilian. Initially, the environmental data of the selected locations such as wind and wave regimes and sea depth are obtained using global models. Subsequently, this data is used through the FAST software to analyze the hydrodynamic and structural behavior of the wind turbine. Afterward, economic analyses are performed to calculate the costs of the turbine, foundation, electrical infrastructure, and operation and maintenance during the wind turbine’s lyfecycle, which is assumed to be twenty years. The dissertation finally compares the energy production costs in Brazil concerning other countries that already have this type of energy to evaluate the price competitiveness.
Publisher: Universidade Federal do Rio de Janeiro
Type: Dissertação2019-10-01T00:00:00ZUm módulo analítico-numérico para cálculo de perfis verticais de velocidade em escoamentos com superfície livreAraujo, Thalles Augusto Abreuhttp://hdl.handle.net/11422/140192023-12-21T03:07:35Z2019-12-01T00:00:00ZTitle: Um módulo analítico-numérico para cálculo de perfis verticais de velocidade em escoamentos com superfície livre
Author(s)/Inventor(s): Araujo, Thalles Augusto Abreu
Advisor: Rosman, Paulo Cesar Colonna
Abstract: Analytical-numerical equations capable of simulating three-dimensional hydrodynamic flows (x, y, z, t) from horizontal two-dimensional information (x, y, t) are of great value. This work presents a set of equations capable of doing so in such a way that it calculates vertical variations on both magnitude and direction of the flow, presenting a strong potential for being used as an operational tool to monitor phenomena such as salt water intrusion, coastal erosion, and flooding. These equations are valid for natural water bodies of free surface and shallow waters, fresh or salt, as long as these bodies are vertically homogeneous (even if laterally stratified) and whose pressure is hydrostatic. A refined turbulent viscosity profile of parabolic shape is presented. It analytically satisfies both bottom and surface dynamic boundary conditions. From it, a preliminary velocity profile of logarithmic shape is deduced, valid for steady and uniform flows. Then, from this preliminary velocity profile, an adjusted velocity profile is deduced, which represents the most relevant terms of the Navier-Stokes equation for geophysical flows, including the nonlinear advective accelerations. Such adjusted velocity profile can be fully deduced from variables that do not depend on the vertical dimension (independents of z). Such profile is then put to test under two numerical modelling scenarios: (1) a straight channel with a slope (2D model) and (2) a curvilinear channel with horizontal bottom (3D model). The proposed set of equations proves to be potentially capable of successfully simulating both scenarios, having even simulated a secondary helical flow in the second scenario.
Publisher: Universidade Federal do Rio de Janeiro
Type: Dissertação2019-12-01T00:00:00ZIntegrated production modeling to assess the effect of subsea water separationWang, Yuxihttp://hdl.handle.net/11422/138002023-12-21T03:07:28Z2019-11-01T00:00:00ZTitle: Integrated production modeling to assess the effect of subsea water separation
Author(s)/Inventor(s): Wang, Yuxi
Advisor: Estefen, Segen Farid
Abstract: Conventional field development design and planning based on isolated work from the reservoir and the production engineering department can not capture the interaction between the two disciplines for long term production forecast. Particularly, in offshore development, it is imperative to integrate the two engineering domains in the qualification of a potential subsea technology because any new element added into the subsea architecture will impact the performance of the entire system. This thesis establishes models that integrate the reservoir and the subsea production system as a whole. The integrated approach is then applied to quantify the effect of a specific subsea technology: subsea water separation. In this work, four integrated production models are presented and compared. Two of them are fully implicitly integrated models while the other two are coupled simulations between a reservoir simulator and a pipeline simulator. Numerical examples show that, compared to loosely-coupled simulations, implicitly integrated models are in general favorable in terms of computation time and stability. Three case studies are presented to demonstrate the application of the two implicitly integrated models for evaluating the effect of subsea water separation on three quantitative indicators: NPV, recovery rate, and wax-free index. Results show that subsea water separation has the potential to increase NPV and recovery for a clustered well system by increasing production rates and reducing injection requirements. However, its application on individual satellite producers has limited advantages because of the negative interference among wells. What’s more, when applying subsea water separation, there will be a higher risk of wax deposition for a satellite well system than for a clustered well system
Publisher: Universidade Federal do Rio de Janeiro
Type: Tese2019-11-01T00:00:00Z