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Thesis (Ph.D.)--University of California, Davis, 2008. / Adviser: Rajeevan Amirtharajah. Includes bibliographical references.

Thesis supervisor: Andrew Kusiak. Includes bibliographic references (p. 141-147).

Thesis (M.S.)--University of Wisconsin--Madison, 1982. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 134-137).

Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 58-62). Also available on the World Wide Web.

Resumo: No trabalho apresentado foi realizada uma análise de eficiência energética levando em conta variáveis tais como a pressão, a temperatura, o estado físico dos componentes e a atividade de cada elemento que compõe a unidade de craqueamento em refino de petróleo. Tal análise foi realizada baseando-se na Primeira e Segunda leis da Termodinâmica. Destacou-se na análise do FCC a geração e a perda de energia com os gases, levando em conta a concentração molar de cada gás na entrada e na saída do FCC. No riser foram levadas em conta as transformações ocorridas e sua cinética com o propósito de fazer uma análise de gasto de energia no processo de formação inicial dos produtos do FCC; com isso, determinaram-se as quantidades de calor que foram utilizados no processo principal de formação. Foram realizadas análises sobre os fluxos de massas no vaso separador com a abordagem de um suposto fluxo interno, que seria a diferença entre as energias adquiridas com o vapor de retificação com os fluxos de carbono arrastados e com energia vinda do riser, e o fluxo de saída também para o processo de retificação no stripper. Verificou-se a energia gerada pelo regenerador e sua distribuição, que é feita com o aquecimento do catalisador na linha de transmissão do stripper e das perdas de energia com a troca do catalisador gasto e pela massa de catalisador que entra no riser. A energia perdida durante o processo foi associada à energia perdida na integralidade e em cada unidade. Verificou-se que uma parcela do calor gerado no processo é absorvida por gases inertes necessários ou integrados a gases reagentes; além disso, observou-se a formação de novos gases e compostos químicos que geram certas quantidades de energia, e que estão e são importantes na contabilização de toda energia que é gerada. Em tal análise levou-se em conta a energia de formação dos gases e a ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: In the present study it was performed an analysis of energy efficiency taking into account variables such as pressure, temperature, physical state of the components and activities of each element that makes up a cracker in petroleum refining. The First and Second Law of Thermodynamics were used for the present analysis. It was highlighted in the analysis of the FCC the generation and loss of energy with the gases, taking into account the molar concentration of each gas at the inlet and outlet of the FCC. In the riser it was taken into account the transformations and their kinetics in order to make an analysis of energy use in the process of initial formation of the products of the FCC; with these results, it was determined the amounts of heat that were used in the main proceedings training. It was analyzed the flow of masses in the separator vessel with the approach of a supposed internal flow, which would be the difference between the energy gained steam with the rectification of carbon fluxes and dragged with energy coming from the riser, and the outflow also for the grinding process in stripper. There was the energy generated by the regenerator and its distribution, which is made by heating the catalyst in the transmission line striper and loss of energy with the exchange of spent catalyst and the mass of catalyst entering the riser. The energy lost during the process was associated with the energy that disappeared in the whole and in each unit. It was found that a portion of the heat generated is absorbed by inert gases necessary or integrated reactive gases; in addition, it was observed the formation of new gases and chemicals that generate amounts of energy, and are important in accounting for all energy that is generated. In this analysis it was taken into account the energy of formation of exhaust gases and the opportunities of products formation in the conditions ... (Complete abstract click electronic access below) / Orientador: José Antonio Perrella Balestieri / Coorientador: Rubens Alves Dias / Banca: Luiz Roberto Carrocci / Banca: Luciano Fernando dos Santos Rossi / Mestre

Made available in DSpace on 2014-06-11T19:29:53Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-07-29Bitstream added on 2014-06-13T20:00:00Z : No. of bitstreams: 1 silva_ugo_me_guara.pdf: 1310169 bytes, checksum: 03b83347690591e428c0b581f7931124 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / No trabalho apresentado foi realizada uma análise de eficiência energética levando em conta variáveis tais como a pressão, a temperatura, o estado físico dos componentes e a atividade de cada elemento que compõe a unidade de craqueamento em refino de petróleo. Tal análise foi realizada baseando-se na Primeira e Segunda leis da Termodinâmica. Destacou-se na análise do FCC a geração e a perda de energia com os gases, levando em conta a concentração molar de cada gás na entrada e na saída do FCC. No riser foram levadas em conta as transformações ocorridas e sua cinética com o propósito de fazer uma análise de gasto de energia no processo de formação inicial dos produtos do FCC; com isso, determinaram-se as quantidades de calor que foram utilizados no processo principal de formação. Foram realizadas análises sobre os fluxos de massas no vaso separador com a abordagem de um suposto fluxo interno, que seria a diferença entre as energias adquiridas com o vapor de retificação com os fluxos de carbono arrastados e com energia vinda do riser, e o fluxo de saída também para o processo de retificação no stripper. Verificou-se a energia gerada pelo regenerador e sua distribuição, que é feita com o aquecimento do catalisador na linha de transmissão do stripper e das perdas de energia com a troca do catalisador gasto e pela massa de catalisador que entra no riser. A energia perdida durante o processo foi associada à energia perdida na integralidade e em cada unidade. Verificou-se que uma parcela do calor gerado no processo é absorvida por gases inertes necessários ou integrados a gases reagentes; além disso, observou-se a formação de novos gases e compostos químicos que geram certas quantidades de energia, e que estão e são importantes na contabilização de toda energia que é gerada. Em tal análise levou-se em conta a energia de formação dos gases e a... / In the present study it was performed an analysis of energy efficiency taking into account variables such as pressure, temperature, physical state of the components and activities of each element that makes up a cracker in petroleum refining. The First and Second Law of Thermodynamics were used for the present analysis. It was highlighted in the analysis of the FCC the generation and loss of energy with the gases, taking into account the molar concentration of each gas at the inlet and outlet of the FCC. In the riser it was taken into account the transformations and their kinetics in order to make an analysis of energy use in the process of initial formation of the products of the FCC; with these results, it was determined the amounts of heat that were used in the main proceedings training. It was analyzed the flow of masses in the separator vessel with the approach of a supposed internal flow, which would be the difference between the energy gained steam with the rectification of carbon fluxes and dragged with energy coming from the riser, and the outflow also for the grinding process in stripper. There was the energy generated by the regenerator and its distribution, which is made by heating the catalyst in the transmission line striper and loss of energy with the exchange of spent catalyst and the mass of catalyst entering the riser. The energy lost during the process was associated with the energy that disappeared in the whole and in each unit. It was found that a portion of the heat generated is absorbed by inert gases necessary or integrated reactive gases; in addition, it was observed the formation of new gases and chemicals that generate amounts of energy, and are important in accounting for all energy that is generated. In this analysis it was taken into account the energy of formation of exhaust gases and the opportunities of products formation in the conditions ... (Complete abstract click electronic access below)

D.Ing. (Electrical and Electronic Engineering) / The non-linear resonant pole (NLRP) inverter is part of the family of soft switching topologies based on resonant phenomena. The sequence of commutation that occurs between the semiconductors of a conventional voltage source inverter is modified through the mechanisms of energy exchange between added passive energy storage components. The NLRP inverter, through its psuedo resonant behaviour (resonant transition), gives rise to zero voltage and zero current turn-on of the switching devices as well as soft turn-off. The switching device voltage stresses are around 1 p.u, while the current stresses are reduced to around 1.3 p.u, by feeding back a portion of the load current. The rms current flowing through the inductor and switches is greatly reduced by driving the inductor into saturation (non-linear mode of operation). The advantages of soft switching, such as high switching frequency which allows greater dynamic response and higher power densities, along with reduced EMI, are achieved with this topology. Detailed analysis at multi- and sub-cycle levels is carried out, resulting in circuit equations and the criteria for commutation success. The commutation boundaries of the inverter are defined and methods discussed on how to extend them. The modulation of the NLRP inverter and some aspects regarding its use as part of both low and high performance induction motor drives are presented.

Ocean Data Acquisition System (ODAS) buoys are deployed in many seas around the world, a subset of these are wave monitoring buoys. Most are powered by solar panels. Many of these buoys are subjected to movement from waves, and could benefit from a wave energy converter specifically designed for ODAS buoys (WECO). A particular buoy that could benefit from this technology is the TriAXYS wave buoy [1]. This thesis discusses the development of a self-contained WECO that would replace one of the buoys four on board batteries, and harvest energy from the buoy motion to charge the remaining three batteries. A major constraint on the WECO is that it can’t affect buoy motion and jeopardize wave data that is derived from the motion. Rather than follow a traditional approach to simulating the motion of the buoy / WECO system, using hydrodynamic modelling and theoretical wave profiles, existing motion data from a buoy installation was analyzed to find the loads that were applied to the buoy to cause the motion. The complete set of mass properties of the TriAXYS buoy were derived from the 3D model provided by AXYS Technologies. These mass properties were compared to the linear and rotational accelerations to find the loads that were applied at the buoy center of gravity (CG) to cause the recorded motion. An installation off the coast of Ucluelet, BC was selected for this investigation because it is subjected to open ocean swells, and data from the winter months of November to March of 2014 to 2016 is available. Winter data was used since there is more wave action to power the WECO during the winter months, and there is sufficient solar irradiation to power the buoy in summer months. Accurate buoy motion data at a 4 Hz sampling rate was available from three rotational rate gyros and three linear accelerometers installed in the buoy. Each dataset of samples represented a 20 minute window that was recorded once every hour. Five conceptual WECO designs were developed, each of which focused on the extraction of power from a different degree of freedom (DOF) of buoy motion (surge, sway, heave, roll, and iv pitch). Three designs used a sliding (linear) oscillating mass, and one was aligned with each of the surge, sway, and heave axis of the buoy. Two designs used a rotating oscillating mass, and the axis of rotation of each device was aligned with either the roll or pitch axis of the buoy. All proposed WECO configurations were modeled as articulated mass, spring, and damper systems in MATLAB using the Lagrange method. Each WECO/buoy assembly formed an articulated body. Mass properties for each configuration were derived from the 3D models. The equations of motion for the original buoy no longer applied, but the environmental forces applied to the hull would still be valid as long as the WECO didn’t alter motion significantly. The power take off (PTO) was modeled following standard convention as a viscous dashpot. The damping effect of the dashpot was included in the models using Rayleigh’s dissipation function that estimated the energy dissipated by the PTO. A subset of load datasets was selected for evaluating the maximum power potential of each WECO. Each WECO was tuned to each dataset of loads using the spring rate, and the damping coefficient was optimized to find the maximum power while avoiding end stop collisions. A second subset of data was selected to evaluate the average power that would be generated throughout the winter months for the two most promising designs. This evaluation was performed for static spring and damping coefficients, and the coefficients that resulted in the highest power output were discovered. The motion of the WECO oscillating mass with respect to the buoy was used in conjunction with the damping ratio to form an estimate of the ideal (i.e. with no mechanical or electrical losses) power generation potential of each WECO configuration during the winter months. The two leading WECO designs both had sliding (linear) oscillating masses, one was aligned with the surge axis and produced theoretical average of just over 0.5 W, the other was aligned with the heave axis and produced theoretical average of just under 0.5 W. / Graduate