Biomass fast pyrolysis liquid, also known as bio-oil, is a promising renewable fuel for heat and power generation; however, implementing crude bio-oil in some current combustion systems can degrade combustion performance and emissions. In this study, optimizing fuel properties to improve combustion is considered. Various bio-oils with different fuel properties are tested in a pilot stabilized spray burner under very close flow conditions. Effects of solids, ash and water content of bio-oil as well as ethanol blending were examined. The results show the amount of solids and ash fractions of the fuel were correlated with combustion efficiency. The CO and unburned hydrocarbon emissions decreased with both water and ethanol content. Increasing the fuel’s volatile content by blending in ethanol has been shown to improve flame stability. Also, the organic fraction of particulate matter emissions was found to be a strong function of the thermogravimetric analysis residue of the fuel.

Combined Cycle power plants have recently become a serious alternative for standard coal- and oil-fired power plants because of their high thermal efficiency, environmentally friendly operation, and short time to construct. The combined cycle plant is an integration of the gas turbine and the steam turbine, combining many of the advantages of both thermodynamic cycles using a single fuel. By recovering the heat energy in the gas turbine exhaust and using it to generate steam, the combined cycle leverages the conversion of the fuel energy at a very high efficiency. The heat recovery steam generator forms the backbone of combined cycle plants, providing the link between the gas turbine and the steam turbine. The design of HRSG has historically largely been completed using thermodynamic principles related to the steam path, without much regard to the gas-side of the system. An effort has been made using resources at both UK and Vogt Power International to use computational fluid dynamics (CFD) analysis of the gas-side flow path of the HRSG as an integral tool in the design process. This thesis focuses on how CFD analysis can be used to assess the impact of the gas-side flow on the HRSG performance and identify design modifications to improve the performance. An effort is also made to explore the software capabilities to make the simulation an efficient and accurate.

No description available.

In this study, experimental investigation of solid propellant combustion instability using an end burning T-Burner setup is performed. For this purpose, a T-Burner setup is designed, analyzed, constructed and tested with all its sub components. T-Burner setup constructed is mainly composed of a base part, a control panel and the T-Burner itself. Combustion chamber, pressure stabilization mechanism, pressurization system, measurement instruments and data acquisition systems form the T-Burner. Pressure stabilization mechanism is utilized in two different alternatives, first of which is by the use of nitrogen gas and a small surge tank with a cavitating venturi. This is a brand new approach for this kind of system. The second alternative is the use of a choked nozzle for pressure stabilization. Resonance frequencies of the system with the two different pressure stabilization mechanisms are experimentally evaluated. Helmholtz frequency of the T-burner constructed is calculated and no Helmholtz instability is observed in the system. Constructed T-Burner setup is operated for a specific solid propellant. System worked successfully and pressure data are obtained. Pressure data revealed oscillatory behaviour. Decay and growth rates of pressure oscillations are used for the calculation of pressure response of the propellant tested. By the use of this T-Burner comparison of the behavior of different propellants can be performed. It can be used as a test device for measuring quantitatively the response of a burning propellant to unsteady motions.

Made available in DSpace on 2015-03-26T12:31:15Z (GMT). No. of bitstreams: 1 texto completo.pdf: 3119904 bytes, checksum: 770fb2ea44d4f089808e545fb90de602 (MD5) Previous issue date: 2010-11-05 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objective of this study was to develop and evaluate the performance of a gas heater for drying of agricultural products. A heater was coupled to a fixed bed dryer in rows for execution of the tests. The gas nozzles were sized and tested with inclinations of 25 and 45 degrees. Drying air temperature was controlled at 60 and 100°C. Combustible LPG was used to heat the drying air. Maize grain (Zea mays L.) with an initial moisture content of 12.0% w.b. was used in the experiment. To evaluate the performance of the gas heater, the thermal efficiency, flame characteristics and composition of the combustion gases were analyzed. From the results, it was possible to verify that the utilized methodology is adequate for sizing of the heater, considering the characteristics of the experimental prototype. Concentrations of carbon monoxide were measured which indicate that combustion was complete and that the heater was operated correctly. Flames formed in the gas heater demonstrated that combustion was both stable and regular. The gas heater presented a thermal efficiency comparable with values encountered in literature, and possesses the potential to provide quality heated air for grain drying with no risk of contamination. / Objetivou-se com este trabalho desenvolver e avaliar o desempenho de um gerador de gás quente para a secagem de produtos agrícolas. O gerador de gás quente foi acoplado a um secador de leito fixo em leiras para a execução dos testes. Foram dimensionados e testados dois bicos de gás com inclinações de 25 e 45 graus. A temperatura do ar de secagem foi controlada em 60 e 100 °C. O combustível GLP foi utilizado para o aquecimento complementar do ar de secagem. O milho em grãos (Zea mays L.) com teor inicial de água de aproximadamente 12,0% b.u. foi usado no experimento. Para o desempenho do gerador de gás quente analisou-se a eficiência térmica, as características da chama e a composição dos gases de combustão. Pelos resultados, verificou-se que a metodologia utilizada é adequada para o dimensionamento do gerador de gás quente, considerando-se as características do protótipo experimental. As concentrações de monóxido de carbono medidas indicaram que a combustão foi completa e que o gerador de gás quente foi operado de maneira correta. As chamas formadas no gerador de gás quente demonstraram que a combustão se desenvolveu de forma estável e regular. O gerador de gás quente teve eficiência térmica coerente com os valores encontrados na literatura. O gerador de gás quente possui potencial para disponibilizar ar aquecido com qualidade para a secagem de grãos sem risco de contaminação.

In the effort to introduce fuel cell technology in the field of decentralized and mobile power generators, a hydrocarbon reformer to syngas seems to be the way for the market uptake. In this thesis, a potential technology is developed and investigated, in order to convert commercial liquid fuel (diesel, kerosene and biodiesel) to syngas. The fundamental concept is to oxidise the fuel in a oxygen depleted environment, obtaining hydrogen and carbon monoxide as main products of the reaction. In order to extend the flammability limit of hydrocarbon/air mixtures, the rich combustion experiments have been carried out in a two-layer porous medium combustor, which stabilises a flame at the matrix interface and recirculates the enthalpy of the hot products in order to enhance the reaction rates at ultra-rich equivalence ratio. This thesis demonstrates the feasibility of the concept, by exploring characteristic parameters for a compact, reliable and cost effective device. Specifically, a range of equivalence ratios, thermal loads and porous materials have been examined. n-heptane was successfully reformed up to an equivalence ratio of 3, reaching a conversion efficiency (based on the lower heating value of H2 and CO over the fuel input) up to 75% for a packed bed of alumina beads. Thermal loads from P=2 to 12 kW at phi=2.0 demonstrated that heat losses can be reduced to 10%.Similarly, diesel, kerosene and bio-diesel were reformed to syngas in a Zirconia foam burner with conversion efficiency over 60%. The effect of different burners, thermal loads and equivalence ratios have also been assessed for these commercial fuels, leading to equivalent conclusions. A preliminary attempt to reduce the content of CO and hydrocarbons in the reformate has been also performed using commercial steam reforming and water-gas shift reaction catalysts, obtaining encouraging results. Finally, soot emission has been assessed, demonstrating particle formation for all the fuels above phi=2.0, with biodiesel showingthe lowest soot formation tendency among all the fuels tested.

Este trabalho apresenta um sistema Queimador Registrador de Baixas Vazões de Biogás que permite a queima de biogás em miniestações de tratamento de esgoto, em que o aproveitamento energético não é viável devido à baixa e inconstante vazão de biogás. Este sistema vai ao encontro das necessidades mundiais de redução na emissão dos gases do efeito estufa, em especial o gás metano, presente no biogás produzido por meio da digestão anaeróbica do esgoto sanitário, que é aproximadamente vinte e uma vezes mais impactante à atmosfera que o gás carbônico. O princípio se baseia no armazenamento do biogás em um gasômetro volumétrico, tipo telescópio, que depois de cheio libera o biogás que é queimado automaticamente, podendo o volume queimado ser quantificado para posterior obtenção de créditos de carbono. O sistema de controle é de baixo custo e pode ser absorvido por instalações de pequeno porte. Para que o módulo de controle tenha capacidade de monitorar e quantificar o volume de biogás queimado, foram utilizados: um sensor para detecção do nível do gasômetro cheio, um sensor para detecção do nível do gasômetro vazio, uma válvula para controle da entrada de gás e um centelhador semelhante ao utilizado em um fogão de cozinha para a queima do biogás. Também foi utilizado um contador que permite o sistema quantificar o número de vezes que o gasômetro foi esvaziado e contabilizar o volume de biogás queimado. / This work presents a system Burner Recorder Low Flows Biogas which allows the burning of biogas in sewage treatment small stations, in which the energy use is not feasible due to the low and unstable flow of biogas. This system meets the needs of global reduction in emissions of greenhouse gases, particularly methane, present in the biogas produced by the anaerobic digestion of sewage, which is approximately twenty-one times more damaging to the atmosphere than carbon dioxide. The principle is based on biogas storage in a volumetric gasometer, a kind of telescope, which after full releases biogas which is automatically burned, making it possible to be quantified to subsequently carbon credits attainment. It is a low cost system and can be absorbed by small installations. In order to enable the control module to monitor and quantify the volume of biogas burned, it was necessary to use a sensor for level detection of the full gasometer, a sensor for level detection the level of the empty gasometer, a valve to control the entry of gas and a spark-gap similar to that used in a kitchen stove for biogas burning. It was also utilized a counter which allows the system to quantify the number of times the gasometer was emptied and to measure the volume of biogas burning.

Low swirl burners (LSBs) have gained popularity in heating and gas power generation industries, in part due to their proven capacity for reducing the production of NOx, which in addition to reacting to form smog and acid rain, plays a central role in the formation of the tropospheric ozone layer. With lean operating conditions, LSBs are susceptible to combustion instability, which can result in flame extinction or equipment failure. Extensive work has been performed to understand the nature of LSB combustion, but scaling trends between laboratory- and industrial-sized burners have not been established. Using hydrogen addition as the primary method of flame stabilization, the current work presents results for a 2.54 cm LSB to investigate potential effects of burner outlet diameter on the nature of flame stability, with focus on flashback and lean blowout conditions. In the lean regime, the onset of instability and flame extinction have been shown to occur at similar equivalence ratios for both the 2.54 cm and a 3.81 cm LSB and depend on the resolution of equivalence ratios incremented. Investigations into flame structures are also performed. Discussion begins with a derivation for properties in a multicomponent gas mixture used to determine the Reynolds number (Re) to develop a condition for turbulent intensity similarity in differently-sized LSBs. Based on this requirement, operating conditions are chosen such that the global Reynolds number for the 2.54 cm LSB is within 2% of the Re for the 3.81 cm burner. With similarity obtained, flame structure investigations focus on flame front curvature and flame surface density (FSD). As flame structure results of the current 2.54 cm LSB work are compared to results for the 3.81 cm LSB, no apparent relationship is shown to exist between burner diameter and the distribution of flame surface density. However, burner diameter is shown to have a definite effect on the flame front curvature. In corresponding flow conditions, a decrease in burner diameter results a broader distribution of curvature and an increased average curvature, signifying that compared to the larger 3.81 cm LSB, the flame front of the smaller burner contains tighter, smaller scale wrinkling.

Titanium dioxide (TiO2) is an important semiconducting metal oxide and is expected to play an important role in future applications related to photonic crystals, energy storage, and photocatalysis. Two aspects regarding the combustion synthesis have been investigated; scale-up in laboratory synthesis and advanced nanoparticle synthesis. Concerning the scale-up issue, a novel curved wall-jet (CWJ) burner was designed for flame synthesis. This was achieved by injecting precursors of TiO2 through a central port into different flames zones that were stabilized by supplying fuel/air mixtures as an annular-inward jet over the curved wall. This provides a rapid mixing of precursors in the reaction zone with hot products. In order to increase the contact surface between the precursor and reactants as well as its residence time within the hot products, we proposed two different modifications. The CWJ burner was modified by adding a poppet valve on top of the central port to deliver the precursor tangentially into the recirculating flow upstream within the recirculation zone. Another modification was made by adopting double-slit curved wall-jet (DS-CWJ) configuration, one for the reacting mixture and the other for the precursor instead of the central port. Particle growth of titanium dioxide (TiO2) nanoparticles and their phases were investigated. Ethylene (C2H4), propane (C3H8), and methane (CH4) were used with varying equivalence ratio and Reynolds number and titanium tetraisopropoxide (TTIP) was the precursor. Flow field and flame structure were quantified using particle image velocimetry (PIV) and OH planar laser-induced fluorescence (PLIF) techniques, respectively. TiO2 nanoparticles were characterized using high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Raman Spectroscopy, and BET nitrogen adsorption for surface area analysis. The flow field quantified by PIV consisted of a wall-jet region leading to a recirculation zone, an interaction jet region, followed by a merged-jet region. The modified CWJ burner revealed appreciable mixing characteristics between the precursor and combustion gases within these regions, with a slight increase in the axial velocity due to the precursor injection. This led to more uniformity in particle size distribution of the synthesized nanoparticles with the poppet valve (first modification). The double-slit modification improved the uniformity of generated nanoparticles at a very wide range of stable experimental conditions. Images of OH fluorescence showed that flames are tightly attached to the burner tip and TTIP has no influence on these flames structures. The particle size was slightly affected by the operating conditions. The phase of TiO2 nanoparticles was mainly dependent on the equivalence ratio and fuel type, which impact flame height, heat release rate and high temperature residence time of the precursor vapor. For ethylene and methane flames, the anatase content is proportional to the equivalence ratio, whereas it is inversely proportional in the case of propane flames. The anatase content reduced by 8% as we changed Re between 8,000 and 19,000, implying that the Re has a slight effect on the anatase content. The synthesized TiO2 nanoparticles exhibited high crystallinity and the anatase phase was dominant at high equivalence ratios (φ >1.6) for C2H4, and at low equivalence ratios (φ <1.3) for the C3H8 flame. Concerning advanced nanoparticle synthesis, a multiple diffusion burner and flame spray pyrolysis (FSP) were adopted in this study to investigate the effect of doping/coating on TiO2 nanoparticles. The nanoparticles were characterized by the previously mentioned techniques in addition to thermogravimetric analysis (TGA) for carbon content, X-ray photoelectron spectroscopy (XPS) for surface chemistry, ultraviolet-visible spectroscopy (UV-vis) for light absorbance, inductively coupled plasma (ICP) for metal traces, and superconducting quantum interference device (SQUID) for magnetic properties. Results from multi diffusion burner show that doping TiO2 with vanadium changes the phase from anatase to rutile while doping and coating with carbon or SiO2 does not affect the phase. Doping with iron reduces the band gab of TiO2 particles by reducing the conduction band. FSP results show that iron doping changes the valance band of the nanoparticles and enhances their paramagnetic behavior as well as better light absorption than pure titania, which make these particles good candidates for photocatalytic applications.

My grandfather 's name is Adolf Šprincl . Over 12 years he was a professional coach hockey teams in France (with various interruptions from 1971 to 1994 ) , where he trained teams in Tours, Villard de Lans and Grenoble. The last named team is most associated with him. Les Loups de Brleurs - Wolves in the burner. My father's name is Milan Šprincl . From the age of 5 years he`s playing hockey. From the age of 18 years it played at a professional level in the Czech first league . The most important places in his life are hockey stadiums in Jihlava and Hodonin. Both stadiums stands on the site of a old cemetery in neighborhood there is a Baroque cemeterychapel. I tried to play hockey, but I failed. I continue in the family tradition of hockey and also the grandfather's work in Grenoble. Documentary film with elements of experimental manipulations and fiction passages will map to the development of French hockey and also the mystique associated with hockey . Attempts to reveal a seemingly random connections between hockey and sacred land for the rest of the dead. At the same time this film plans to close a series of films with the theme of my personal family history, to which I perceive in abstract forms. The film is shot on VHS camcoder. I shoot hockey stadiums (especially in Hodonin and Jihlava ) in which interests me as architectural monumentality of these sports , but also the context in which they are found (hockey arena on former cemeteries , etc. ) . The next part takes place in France , near Grenoble, where he focuses on the current state of French hockey (interviews with prominent personalities of French hockey - Jean Leblond / Vice President of the French hockey , Dany Grandor / former player Grenobelu - officer team, Stéphane Bailles / first hockey scout in France, Jean - Luc Dalaison / journalist Le Dauphiné and others) and link to my grandfather , who is one of the most important figures in the history of the hockey team Bruleurs Les Loups de Grenoble . Another important part is i work with historical documents ( articles in French and Czech press about his grandfather , his personal correspondence , notebooks with notes for training and game strategy , and also relics of his time in France) and a part takes place on the ice rink , where you will be using the other game lines and projections manipulated match in hockey (tells the legend of the mountain Vercors of wolves who ate people ) . Part of the film is the creation of costumes (especially hockey jerseys ) and props.