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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.
31

Análise de um sistema de cogeração empregando turbina a gás aplicada a uma indústria de malte

Carvalho, Marcelo Bergamini de [UNESP] 04 1900 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-04Bitstream added on 2014-06-13T20:39:47Z : No. of bitstreams: 1 carvalho_mb_me_guara.pdf: 1667182 bytes, checksum: 466e1d7987c5db03c6d55f35bb29386b (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Universidade Estadual Paulista (UNESP) / Neste trabalho analisa-se a viabilidade técnica e econômica da instalação de sistemas de cogeração, com emprego de turbinas a gás e dois diferentes tipos de trocadores de calor: um utilizando vidro e o outro convencional. Os sistemas são aplicados em uma indústria de transformação de cevada em malte, de médio porte, localizada no Vale do Paraíba. Para cada tipo de tecnologia empregada, seja por operação em paridade elétrica ou térmica, seleciona-se diferentes turbinas comercialmente disponíveis no mercado. Os resultados demonstram que existe viabilidade técnica e econômica para o emprego desta tecnologia na referida indústria. O período de amortização do capital investido é relativamente pequeno em relação à vida útil dos equipamentos empregados. PALAVRAS-CHAVES: Cogeração, Gás Natural, Conservação de Energia, Turbina a Gás. / The purpose of this work is to analyses the technical and economic feasibility to install cogeneration systems, using gas turbine associated with two different kinds of heat exchanger: the first utilize glass heat exchanger and second utilize conventional heat exchanger. These systems are being applied in medium sized barley transformation industry into malt located in Vale do Paraíba . To each kind of technology, is made a comparison in cogeneration operating in electric parity or thermal parity. Different turbines commercially available are chosen. The results show that there are technical and economic feasibility to make use of this technology in the industry in question. The pay-back period of investment is determinate as a function of annual interest rate, electricity tariff and fuel price. Key Words: Cogeneration, natural gas, energy conservation, Gas turbines.
32

Análise técnico-econômica da utilização de um gerador à gás natural em um sistema de cogeração: estudo de caso

Costa, Adriana Aparecida dos Santos [UNESP] 06 1900 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:30:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-06Bitstream added on 2014-06-13T18:59:52Z : No. of bitstreams: 1 costa_aas_me_guara.pdf: 2059273 bytes, checksum: b8ab2fd24ffac7e626369adad28e0f50 (MD5) / Neste trabalho é apresentada uma proposta de sistema de cogeração utilizando motor de combustão interna à gás natural, visando otimizar a utilização da energia primária em um estudo de caso de uma empresa produtora de chapas pré-pintadas. Este grupo moto-gerador foi adquirido para suprir a escassez de energia elétrica no ano de 2001 no Brasil, e hoje tem sua operação inviável economicamente se utilizado somente como gerador. Para isso realizou-se uma auditoria energética na empresa em questão, uma análise do mercado energético atual, da legislação vigente sobre cogeração, da viabilidade técnico-econômica da implementação do sistema proposto, das perspectivas de expansão do parque industrial da empresa e dos aspectos estratégicos no que diz respeito a diversificação na obtenção da energia elétrica. Estudou-se também as características do sistema elétrico existente e as características dos equipamentos responsáveis pela geração de energia térmica. O estudo realizado buscou propor a melhor forma de utilização do grupo moto-gerador, com o menor impacto no sistema elétrico atual e sem prejuízos para o processo de produção. Os resultados deste trabalho convergiram para um sistema de cogeração compacto que melhor se adaptou às particularidades da empresa estudada. Além da vantagem financeira que este trabalho constatou, também existem vantagens técnicas e estratégicas. Assim sendo, este trabalho proporciona o suporte técnico necessário para a tomada de decisões de como melhor aproveitar o potencial energético do equipamento adquirido pela empresa em questão e para outras empresas que apresentam um panorama semelhante. / In this work is presented a proposal of a cogeneration system using internal combustion engine using natural gas, with the objective to improve the employment of the primary energy in the case study in a manufacturer company of pre-painted metallic sheets. This moto-generation group was acquired in 2001 in order to supply the lack of providing of the electrical energy that Brazil confronted in the same year and now its utilization is not economic feasibility. An energetic audit has been carried out in the industry, an analysis of current energy market, the rules cogeneration's legislation, a technical economic feasibility of the cogeneration system proposed an analysis regarding the company's expansion plan and the flexibility for supplying energy of the other sources. This work also analysed the existent electrical system and the characteristics of the equipment responsible for the thermal energy generation. This work has focused on a better utilization of the moto-generation group with a minimum number of changes in the electrical system and without causing any disturbance damages for the manufacture's production process. The results of this work indicated that a compact cogeneration system is the best solution considering the characteristics of the enterprise studied. Besides the financial advantages verified, there are technical and strategic advantages. So, this work will give technical support for decisions about the best advantage the energetic potential of the equipment acquired by company in matter and for other companies that present a similar panorama.
33

Využití kogenerace a trigenerace pro energetické zásobování odlehlých objektů / Application of cogeneration and trigeneration for outlying buildings supplying

Fojtík, Lukáš January 2010 (has links)
This diploma work deals with the topic application of cogeneration and trigeneration for outlying buildings supplying. The first part this work containes description of technology and methods of realization. In this part there is also described absorption circulation. The second part this work targets concepts energy independedce the building, that has concrete energy consumption, including economic analysis.
34

Combined Heat and Power Systems for Commercial Buildings: Investigating Cost, Emissions, and Primary Energy Reduction Based on System Components

Smith, Amanda D 15 December 2012 (has links)
Combined heat and power (CHP) systems produce electricity and useful heat from fuel. When power is produced near a building which consumes power, transmission losses are averted, and heat which is a byproduct of power production may be useful to the building. That thermal energy can be used for hot water or space heating, among other applications. This dissertation focuses on CHP systems using natural gas, a common fuel, and systems serving commercial buildings in the United States. First, the necessary price difference between purchased electricity and purchased fuel is analyzed in terms of the efficiencies of system components by comparing CHP with a conventional separate heat and power (SHP) configuration, where power is purchased from the electrical grid and heat is provided by a gas boiler. Similarly, the relationship between CDE due to electricity purchases and due to fuel purchases is analyzed as well as the relationship between primary energy conversion factors for electricity and fuel. The primary energy conversion factor indicates the quantity of source energy necessary to produce the energy purchased at the site. Next, greenhouse gas emissions are investigated for a variety of commercial buildings using CHP or SHP. The relationship between the magnitude of the reduction in emissions and the parameters of the CHP system is explored. The cost savings and reduction in primary energy consumption are evaluated for the same buildings. Finally, a CHP system is analyzed with the addition of a thermal energy storage (TES) component, which can store excess thermal energy and deliver it later if necessary. The potential for CHP with TES to reduce cost, emissions, and primary energy consumption is investigated for a variety of buildings. A case study is developed for one building for which TES does provide additional benefits over a CHP system alone, and the requirements for a water tank TES device are examined.
35

Evaluation of Performance of Combined Heat and Power Systems with Dual Power Generation Units (D-CHP)

Knizley, Alta Alyce 14 December 2013 (has links)
In this research, a new combined heat and power (CHP) system configuration has been proposed that uses two power generation units (PGU) operating simultaneously with different operational strategies (D-CHP). The performance of the proposed D-CHP system configuration, with one PGU operated at a constant base load and the other operated following the electric load, is quantified in terms of operational cost savings, primary energy consumption (PEC) savings, and carbon dioxide emissions (CDE) savings over a reference case employing a conventional, separate heat and power system. D-CHP system performance is also compared to standard, single PGU operational strategies. The D-CHP system configuration is first examined for four different building configurations simulated using the weather of Chicago, IL. Then, the D-CHP system feasibility study is extended to examine a full-service restaurant benchmark building in nine different U.S. climate zones. Next, the D-CHP configuration is simulated under a second operational strategy, in which one PGU operates base-loaded while the other follows the thermal load, and the two D-CHP strategies are compared. Additionally, the effect of thermal storage on D-CHP system performance is examined. Finally, the D-CHP configuration is extended to a combined cooling, heating, and power configuration (D-CCHP), and the feasibility of this configuration is examined. In addition to D-CHP and D-CCHP systems performance analyses, the parameters of power-to-heat ratio; cost, emissions and primary energy consumption spark spreads; cost and emission ratios; and thermal difference are proposed and examined as performance indicators. It was determined that D-CHP and D-CCHP system strategies can be a viable alternative to traditional CHP system or combined cooling, heating, and power (CCHP) system operational strategies, in terms of operational cost, PEC, and CDE performance. Generally, the D-CHP and D-CCHP configurations are found to perform comparably to or better than traditional CHP and CCHP configurations.
36

Evaluation Of Propane Fueled Chp Systems For Small Commercial Applications

Ramsay, Justin Byron 13 December 2008 (has links)
This thesis evaluates the effects of Combined Heating and Power (CHP) systems with a Propane fueled spark ignited engine as prime mover used in a small commercial building. The system was evaluated in five different U.S. cities. The most common operating modes, thermal load following (FTL) and electric load following (FEL) were evaluated, and an optimized operating mode was developed and investigated. The optimized operating mode is a hybrid (FHL) of FEL and FTL operation. Methodology for the derivation and application of these models is presented. Also, the economic effects of Diesel and Natural Gas were investigated. The results for all five cities and all three operating modes were gathered and compared with a conventional system. Comparisons were made based on cost, primary energy consumption, and carbon dioxide emissions. It was concluded that the feasibility of CHP had great potential, but is highly dependent upon the location of the system.
37

Micro-cogeneration optimal design for service hot water thermal loads

Jones, Sophia Christina Acle 08 1900 (has links)
No description available.
38

Využití kaplných biopaliv pro energetické zásobování areálu Technická 2 / Utilizing of liquide biofuels for energy supply in the complex Technicka 2

Kopecký, Jakub January 2010 (has links)
Theme of this thesis is utilizing of liquide biofuels for energy supply in the complex Technicka 2. This work is divided into three parts. The first part dealt with the issue of liquid biofuels, both globally and within the Czech Republic. In the next part are noted technologies for heating, power and cooling of of liquid biofuels. In the third part is noted evaluation of using cogeneration unit from Seva, a.g. for komplex Technicka 2 in different types of traffic.
39

Projekt ORC cyklu / Project ORC -cycle

Černý, Jakub January 2014 (has links)
The aim of this thesis is the project for biomass cogeneration units using ORC cycle and subsequent use of thermal energy for drying wood biomass for a briquetting line. The introducing sections describe the principle of cogeneration, organic Rankine cycle (primarily the indication of potential applications and their use in practice) and the selection of the proper working fluid. The following sections provide a technical description of the selected plants for cogeneration unit, total circulation scheme and calculation of the evaporator working fluid. The last section is devoted to the economic evaluation of three variants according to the investor's task to design a better option for implementation.
40

A framework for electricity generation opportunities in the South African integrated iron and steel industry : the ArcelorMittal Newcastle case / Marais, B.

Marais, Brendan January 2011 (has links)
Electricity availability and the costs thereof in South Africa were traditionally considered an abundant and low cost commodity, but in recent years this situation has changed altogether. Industries are challenged by a strained national electricity grid and tariff increases more than four times the national inflation rate over the past two years, with further tariff increases expected in subsequent years; thus, exposing industries to significant business risks that may jeopardise the sustainability of industries. With the majority of the national electricity supply derived from coal, South Africa's push to reduce carbon emissions exerts even more pressure on industries as electricity usage is inextricably linked to its carbon footprint. In addition, South Africa's reliance on cogeneration from industries for its 2010 - 2030 electricity capacity plan further promotes industries to become more self–sufficient concerning electricity generation. In view of the above, there is a need in the South African integrated iron and steel industry for a framework that collectively addresses the governing factors pertaining to electricity generation in this industry, technical and economical quantification of available technologies and implementation of these technologies. This dissertation researches the current driving/governing and the remediating factors to become more self–sufficient in terms of electricity generation. A framework for electricity generation opportunities in the integrated iron and steel industry is developed from the literature study and the researcher's own experience. The framework embodies four building blocks into a single and all–encompassing framework, which provides the necessary governing factors that quantify the potential need to pursue electricity generation/cogeneration, the technical and economical implications and, inevitably, the implementation requirements and guidelines. Validating the framework against case studies pertaining to ArcelorMittal Newcastle realised a correlation of between 84.6% to 97.6% concerning the technical parameters. In addition, the validation process also indicated that the framework is aligned with current practices applied by ArcelorMittal South Africa. The framework will enable South African integrated iron and steel industries to expand and adapt their own procedures to be specific to their operational requirements. The implementation of the framework should be tailored to address the specific needs concerning cogeneration in industry. / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2012.

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