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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Výroba vodíku z obnovitelného zdroje elektrické energie / Hydrogen production from renewable energy source

Lakva, Petr January 2013 (has links)
Hydrogen, as a form of storage for the excess energy from renewable sources, is a technically and economically viable option. However, the technology is not mature enough to compete with the other renewable energy possibilities. In this thesis, a study based on coupling two 330 kW wind-turbines with an NELP. 40 electrolyzer this connection should improve the utilization of wind power. In this thesis are two options of energy utilization. The energy produced by the wind-turbine is stored in the form, of hydrogen and is then delivered for consumption at variable power through a fuel cell, second option is use of produced hydrogen as alternative fuel for cars. This study is a general introduction for the wind energy system with hydrogen storage. Future studies should be more complex and detailed in order to understand and model the system with greater accuracy and to increase the possibility for the utilization of wind energy to generate hydrogen. This would enhance wind power competitiveness and sustain the continuously changing world energy demands.
42

[pt] RACIONALIZAÇÃO NO USO DE DIFERENTES FONTES DE GERAÇÃO DE ENERGIA EM GRANDES INSTALAÇÕES / [en] RATIONAL USE OF DIFFERENT SOURCES OF POWER GENERATION IN LARGE INSTALLATIONS

EDUARDO MAURO BAPTISTA BOLONHEZ 15 February 2016 (has links)
[pt] Neste trabalho, busca-se atender a demanda energética de grandes clientes através de um sistema híbrido de energias renováveis (HSRE, em inglês), com o mínimo custo e diminuindo as emissões de poluentes. O sistema é construído a partir do uso de células fotovoltaicas, células a combustível e chillers elétricos. Quatro tipos de célula a combustível são testadas e avaliadas quanto a viabilidade: PAFC (ácido fosfórico), SOFC (sólido óxido), MCFC (carbonato fundido) e PEMFC (membrana trocadora de prótons). Para o caso da última, geradores de hidrogênio são simulados para suprir a demanda. Os resultados são comparados com o caso base, de toda a demanda sendo atendida pela concessionária de energia elétrica local. Varia-se o custo de aquisição e instalação dos equipamentos, o custo de aquisição de gás natural e o custo da energia elétrica, além da variação da demanda e de simular o cliente em diferentes cidades. A demanda hipotética é calculada a partir de valores de iluminâncias segundo normas técnicas para cada sala de um laboratório em construção em Xerém, no Rio de Janeiro. A simulação indica como resultado a viabilidade econômica de abastecimento pelo sistema híbrido, com geradores do tipo PAFC, SOFC e MCFC. A alta demanda de hidrogênio, juntamente com o custo atual para geração do mesmo inviabiliza o retorno com uso de células PEMFC. / [en] In this work, we seek to meet the energy demand of large customers through a hybrid system of renewable energy (HRSE), with minimal cost and reducing emissions. The system is built from the use of photovoltaic cells, fuel cells and electric chillers. 4 fuel cell types are tested and evaluated for viability: PAFC (phosphoric acid) SOFC (solid oxide), MCFC (molten carbonate) and PEMFC (proton exchange membrane). In the case of the latter, hydrogen generators are simulated to meet demand. The results are compared with the base case, that includes all the demand being met by the local power company. The cost of purchase and installation of equipment, the cost of acquisition of natural gas and the cost of electricity, as well as the demand variation and simulate the client in different cities are analyzed under different values. The hypothetical demand is calculated from illuminance values according to technical standards for each room of a laboratory under construction in Xerém, in Rio de Janeiro. The simulation result shows the economic viability supply the hybrid system The high demand for hydrogen with the current cost for generating the same prevents the payback form PEMFC fuel cells.

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