Teses em Engenharia de Recursos Naturais da Amazônia (Doutorado) - PRODERNA/ITEC

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/4045

O Doutorado Acadêmico inicou-se em 2006 e pertence ao Programa de Pós-Graduação em Engenharia de Recursos Naturais da Amazônia (PRODERNA) do Instituto de Tecnologia da UFPA (ITEC) da Universidade Federal do Pará (UFPA).

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Agora exibindo 1 - 3 de 3

Acesso aberto (Open Access)
Uma abordagem matemática aplicada ao projeto de turbinas hidrocinéticas e eólicas com difusor utilizando a teoria do elemento de pá
(Universidade Federal do Pará, 2019-04-30) VAZ, Déborah Aline Tavares Dias do Rio; VAZ, Jerson Rogério Pinheiro; http://lattes.cnpq.br/1623983294183975
It is known surrounding a turbine with diffuser may significantly increase its power. This effect has attained considerable attention as it shows theoretically the possibility of achieving a power coefficient about 2 times greater than an ordinary turbine. However, the effect of the diffuser efficiency has not been implemented into blade element momentum yet, as well as the use of minimum pressure coefficient criterion to avoid cavitation during the optimization of the hydrokinetic chord along the blade. Hence, this work presents a novel approach to design diffuser-augmented hydro turbines considering the diffuser efficiency. Based on the blade element momentum, new expressions for the axial induction factor and thrust are obtained. In addition, both efficiency and load generated on a diffuser are considered to the extension of existing formulation to determine power coefficient in cases where diffuser losses are taken into account through efficiency (ηd) and area ratio (β). To assess the proposed model, a comparative evaluation of two different diffusers (flanged conical diffuser and flanged lens diffuser) is performed. Numerical and theoretical results are compared for a shrouded turbine equipped with 83% efficiency diffuser. The relative difference observed for the maximum power coefficient between the proposed model and an actuator disk model with diffuser is about 5.3%. For the hydro turbine with flanged conical diffuser, the mass flow rate is about 20% higher than for a bare turbine, while for the turbine with flanged lens diffuser the increase is only 2.4%. Also, for the flanged conical diffuser the power is increased by 53%. Furthermore, it is observed that the proposed blade element momentum with diffuser achieved good agreement with the numerical model, providing improved results compared to other models available in the literature. The optimization model of hydrokinetic chord shows relevant results in relation to the prevention of cavitation.
Acesso aberto (Open Access)
Avaliação de potencial hidrocinético à jusante de centrais hidrelétricas
(Universidade Federal do Pará, 2017-12) HOLANDA, Patrícia da Silva; MESQUITA, André Luiz Amarante; http://lattes.cnpq.br/1331279630816662; SECRETAN, Yves; BLANCO, Claudio José Cavalcante; http://lattes.cnpq.br/8319326553139808
The maximization of the performance of hydropower projects by taking advantage of the remaining energy downstream of dams via the installation of hydrokinetic turbines is feasible. In this context, two case studies of the hydroelectric power plants are presented, one of large Tucuruí in the Tocatins river, Amazonia, and another of medium size Bariri in the Tietê river, in the Southeast of Brazil.In central hydrokinetic projects, the design of the rotor diameter and velocity of the water are fundamental and depend on the depth and velocity of the river, respectively. Thus, the Saint-Venant model has been applied to these areas of studies. The calibration of the model was performed by linear regression of the measured and simulated flow rates for both, resulting in a correlation of 0.99. Validation was performed for a point on the Tocantins river using velocities measured with an acoustic Doppler current profiler (ADCP). The measured velocities are comparable to the velocities simulated by the model. Thus, a power curve was generated for the measured flow rates and the simulated velocities for the point at which the velocities were validated, thus obtaining a correlation of 0.96. This same curve was used for estimates of velocity, calculation of the energy density, and defining a design velocity for Tucuruí HPP equal to 2.35 m/s and Bariri 2.25 m/s. After the design was velocity defined, 10 points were selected Tucuruí and 1 point Bariri for the location of hydrokinetic turbines. The velocities of these points were determined with the same method used for the validation of the velocities. The points were selected based on the channel downstream of the reservoir and at the end of the Bariri dissipation basin, with the largest depth and velocity, which are characteristics favorable for greater power generation. Considering the rivers depth and available manufacturing technology, the rotor diameter was defined for the large study in 10 m and for the medium 2.1 m. After the design velocity was defined, the rotor design was implemented using the blade element method (BEM Blade Element Momentum), allowing for the definition of an installed power curve of the turbine as a function of the river velocity. In terms of generated energy, the 10 turbines can generate 2.04 GWh/year. These numbers demonstrate the potential for utilizing the remaining energy of hydroelectric plants.
Acesso aberto (Open Access)
Desenvolvimento de sistema computacional para avaliação de lodo de esgoto sanitário como biomassa na geração de energia
(Universidade Federal do Pará, 2012-06) SANTOS, Yvelyne Bianca Iunes; PEREIRA, José Almir Rodrigues; http://lattes.cnpq.br/9918600634569244
Development of a computational system to assess sewage sludge sanitary as biomass to generate energy in combustion processes, taking into account Brazilian technical and environmental norms. Classes were created and implemented in the system to assess sewage sludge as energy potential and considered limits established in the norms NBR 10004/04, NBR 10004/87 and CONAMA Resolution nº 316/2002 for adverse environmental impacts, damages or risks to public health , identifying the feasibility of use of this residual as biomass to generate energy in combustion processes. The system was developed using a Model-View-Controller (MVC) software considered an architectural pattern, with method represented by logical rules, whose input data were the results from laboratory determination of sewage sludge samples, test processing and logical sequence of rules, and reports to enable the user to make a decision. To validate the system it was used results from technical work on the use of sewage sludge as biomass to generate energy in experimental scale, observing that the limits adopted in the system were appropriate as parameters to evaluate the energy potential of the sampled sludge, its toxicity and air pollution; that the explanatory and alert messages have been clearly sent; that the logical sequence of rules had been progressively implemented; and that the values obtained in the system had been compatible with the validation works. Finally, it was concluded that the system developed may be used to expedite decision-making, mainly, in waste treatment plant with large quantities of sludge.

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