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Sample records for elementos combustibles destinados

  1. Research reactor fuel bundle design review by means of hydrodynamic testing; Ensayos hidrodinamicos para verificacion de diseno de un elemento combustible para reactores de investigacion

    Energy Technology Data Exchange (ETDEWEB)

    Pastorini, A; Belinco, C [Comision Nacional de Energia Atomica, San Martin (Argentina). Centro Atomico Constituyentes

    1998-12-31

    During the design steps of a fuel bundle for a nuclear reactor, some vibration tests are usually necessary to verify the prototype dynamical response characteristics and the structural integrity. To perform these tests, the known hydrodynamic loop facilities are used to evaluate the vibrational response of the bundle under the different flow conditions that may appear in the reactor. This paper describes the tests performed on a 19 plate fuel bundle prototype designed for a low power research reactor. The tests were done in order to know the dynamical characteristics of the plates and also of the whole bundle under different flow rate conditions. The paper includes a description of the test facilities and the results obtained during the dynamical characterization tests and some preliminary comments about the tests under flowing water are also presented. (author) 4 refs., 12 figs., 4 tabs. [Espanol] Durante el diseno de un elemento combustible para un reactor nuclear se requiere de la realizacion de ensayos con el objeto de verificar el comportamiento de ese diseno y permitir, de ser necesario, la introduccion de modificaciones al mismo. Para verificar las caracteristicas de respuesta dinamica e integridad estructural, se realizan ensayos de vibraciones que incluyen someter al prototipo a condiciones de circulacion del fluido similares a las que soportara durante la operacion del reactor. Estos ensayos se realizan en facilidades de ensayos conocidas como circuitos hidrodinamicos, que permiten no solo someter el prototipo al flujo de fluido, sino tambien obtener una adecuada caracterizacion de la respuesta del mismo a traves del luso de sensores de distinto tipo. En este trabajo se describen los ensayos realizados sobre un prototipo de elemento combustible de 19 placas destinado a un reactor de investigacion multiproposito de baja potencia. Los ensayos tuvieron como objetivo conocer la respuesta dinamica de las placas individuales y del elemento combustible en su

  2. Diseño y cálculo de la estructura de un prototipo destinado a participar en la competición Shell Eco-Marathon

    OpenAIRE

    Seller Robles, Antonio

    2011-01-01

    El objetivo del presente proyecto es el diseño, cálculo y estudio de los elementos necesarios para la construcción de una estructura adecuada para un prototipo de vehículo destinado a competir en la competición Shell Eco Marathon. El diseño de dicha estructura se ha llevado a cabo mediante el uso del software de diseño SolidWorks 2007 y los cálculos de distribución de tensiones en los componentes de la estructura se han realizado mediante el software de elementos finitos ANSYS. Ingeniería ...

  3. Prevention of criticality accidents. Fuel elements storage; Prevencion de accidentes de criticidad. Almacenamiento de elementos combustibles

    Energy Technology Data Exchange (ETDEWEB)

    Canavese, S I; Capadona, N M

    1991-12-31

    Before the need to store fuel elements of the plate type MTR (Materials Testing Reactors), produced with enriched uranium at 20% in U235 for research reactors, it requires the design of a deposit for this purpose, which will give intrinsic security at a great extent and no complaints regarding its construction, is required. (Author). [Espanol] Partiendo de la necesidad de almacenar elementos combustibles tipo placa MTR (Materials Testing Reactors), producidos con uranio enriquecido al 20% en U235 para reactores de investigacion, se requiere el diseno de un deposito para tal fin que brinde esencialmente un alto grado de seguridad intrinseca y que no ofrezca complicaciones en cuanto a su construccion. (Autor).

  4. Gas-flow detector for uranium contamination on finned-can surface of a reactor fuel; Detecteur a courant gazeux pour deceler la contamination en uranium des nervures des gaines de combustible nucleaire; Gazopotochnyj detektor zagryazneniya uranom rebristoj poverkhnosti obolochki reaktornykh teplovydelyayushchikh ehlementov; Detector de flujo gaseoso para medir la contaminacion de uranio en la superficie de la vaina de aletas de los elementos combustibles para reactores

    Energy Technology Data Exchange (ETDEWEB)

    Miwa, H; Shiojiri, T; Maeda, Y [Kobe Kogyo Corporation, Okubo, Akashi, Hyogo (Japan)

    1962-04-15

    alpha. Avant chaque mesure, le compteur est vide au moyen d'une pompe rotative; on y admet ensuite du gaz PR (melange de 90% d'argon et de 10% de methane). En utilisant ce nouvel appareil, les auteurs ont reussi a deceler les particules alpha emises par 1 x 10{sup -5} gramme d'uranium naturel contaminant les nervures des gaines de combustible d'unreacteur du type Calder Hall; le combustible du reacteur de recherche japonais JRR-3 sera inspecte a l'aide de ce compteur. (author) [Spanish] El detector de corriente gaseosa descrito es un contador proporcional de rejilla especialmente destinado a determinar la contaminacion del uranio en la superficie de la vaina de aletas de los elementos combustibles para reactores. Con el tipo comun de contador proporcional, compuesto solamente de catodo y colector, apenas es posible descubrir las particulas a emitidas por el uranio contaminado en superficies irregulares tales como las aletas de la envoltura de un elemento combustible, debido a la falta de uniformidad del campo electrico en 'as cercanias de la superficie. Este es el motivo que indujo a los autores a construir el contador proporcional de rejilla. Este contador consta del elemento combustible, una rejilla, unos colectores y un catodo de forma cilindrica dispuestos coaxialmente. El combustible va colocado en el centro de la rejilla y se aplica una tension negativa. El espacio entre el combustible y la rejilla actua como camara colectora de iones. La rejilla esta formada por delgados alambres de tungsteno paralelos dispuestos cilindricamente en torno del elemento combustible y conectados a masa. Los colectores son 16 alambres finos de tungsteno de construccion semejante a la de la rejilla, pero cada uno de los alambres esta electricamente aislado de los restantes. Todos los colectores estan conectados entre si a traves de resistencias de 50 k{Omega} y conectados tambien a una fuente positiva de alta tension a traves de una resistencia. El espacio entre la rejilla, los

  5. Non-Destructive Testing of Plutonium-Enriched Fuel Rods; Controles non Destructifs de Barreaux Combustibles Enrichis au Plutonium; Nedestruktivnyj-kontrol' toplivnykh sterzhnej''obogashchennykh plutoniem; Ensayo no Destructivo de Elementos Combustibles Enriquecidos en Plutonio

    Energy Technology Data Exchange (ETDEWEB)

    Libotte, P.; Inniger, H.; Leblanc, J. M. [Centre D' Etude de l' Energie Nucleaire, Societe Belge pour l' Industrie Nucleaire, S.A. (Belgonucleaire), Mol (Belgium)

    1965-09-15

    permet de connaitre la repartition longitudinale de celui-ci avec une precision superieure a {+-} 2% dans le cas d'une repartition radiale parfaite, cette derniere etant evaluee principalement par exposition sur emulsion photographique. La distribution axiale de la densite du materiau combustible est determinee avec une precision superieure a {+-} 1% par mesure de la fraction non absorbee d'un rayonnement gamma emis par une source exterieure: {sup 137}Cs ou {sup 192}Ir. Des fissures de l'ordre de 10 {mu}m peuvent etre detectees par ultrasons en utilisant la technique de reflexion des ondes. Les avantages respectifs de chaque technique non destructive sont etudies en relation avec les precisions desirees et leur eventuelle application au controle automatise de barreaux combustibles au plutonium fabriques a l'echelle industrielle. (author) [Spanish] La Societe Belge pour l'Industrie Nucleaire (BelgoNucleaire) y el Centre d'etude de l'energie nucleaire (CEN) estudian por contrato, y en cooperacion con la Comision del EURATOM, el empleo del plutonio en reactores de potencia de tipo agua a presion. En el marco de los estudios emprendidos, se han desarrollado varias tecnicas de ensayo no destructivo, con miras a evaluar la calidad de los elementos combustibles. Los ensayos no destructivos descritos en la presente memoria se emplean fundamentalmente para controlar las dimensiones y la calidad de las vainas, la integridad de las soldaduras la estanqueidad de los elementos, la densidad del material combustible y su distribucion, el enriquecimiento de plutonio y su distribucion, tanto radial como axial, en el elemento combusitible. Los metodos utilizados para estos ensayos no destructivos comprenden principalmente inspeccion por radiografia, autorradiograffa, gammagraffa y el empleo de ondas ultrasonicas. La memoria rosena los principios a que obedece cada una de las mediciones, describe en cada caso los aparatos utilizados y las tecnicas operativas aplicadas con miras a obtener

  6. LICENCIAMENTO AMBIENTAL - ELEMENTO IMPERCEPTÍVEL NA QUALIDADE DA MARCA DOS POSTOS DE REVENDAS DE COMBUSTÍVEIS - MERCADO VAREJISTA REGULADO

    Directory of Open Access Journals (Sweden)

    Cláudia Ribeiro Pereira Nunes

    2013-05-01

    Full Text Available No século XXI, a concorrência entre os postos revendedores de combustíveis – mercado varejista regulado - passou a se dar em novas bases competitivas. Dentro desse âmbito, busca-se entender se o licenciamento ambiental em suas dimensões é um dos elementos de percepção da qualidade, sendo considerado nesse ensaio como a primeira etapa de regularização de empreendimento sustentável de revenda de combustíveis no mercado regulado, ou seja, considerado como salvaguarda de conservação ambiental dos processos de abastecimento. Faz-se mister investigar se o cumprimento das exigências legais, das normas ambientais e do controle de poluentes, podem ser considerados como um diferencial competitivo no mercado regulado dos combustíveis, uma vez que a revenda de combustíveis é uma atividade potencialmente poluidora. Suscita-se, ainda, verificar se o licenciamento ambiental, salvaguarda de conservação ambiental, é ou não instrumento para consolidação de marca por ser um elemento de configuração da qualidade, na percepção dos consumidores.

  7. Carbones pobres. Utilización de combustibles pobres en la fabricación de cemento

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    Guillon, M. Henri

    1958-12-01

    Full Text Available Not availableEn el trabajo que vamos a exponer a continuación, se considerará el empleo de los combustibles pobres desde el punto de visto térmico. De este modo, por una parte se examinará el papel que desempeñan como agentes de calefacción y no como aportadores de elementos minerales a la materia prima; por otra parte, se tratará de aquellos combustibles pobres para los cuales la materia combustible es el elemento más importante en oposición a algunas materias de recuperación, desechos de minas o cenizas de hogares, por ejemplo, que contienen principalmente materias minerales y accesoriamente alguna proporción de carbono.

  8. Optimización de la aceptabilidad sensorial y global de productos elaborados con amaranto destinados a programas sociales nutricionales

    OpenAIRE

    Sosa, Miriam

    2011-01-01

    Objetivo general Analizar los factores que influyen sobre la aceptabilidad global y sensorial de alimentos elaborados en base a amaranto destinados a Programas Sociales Nutricionales (PSN). Objetivos particulares Capitulo I Investigar hábitos y preferencias alimentarias en poblaciones a las cuales son destinados los PSN. Desarrollar metodología para medir la aceptabilidad sensorial de alimentos en poblaciones que reciben PSN. Capitulo I...

  9. Development of Non-Metallic Fuel Elements for a High-Temperature Gas-Cooled Reactor; Mise au point d'elements combustibles non metalliques pour un reacteur a haute temperature, refroidi par un gaz; Razrabotka nemetallicheskikh teplovydelyashchikh ehlementov dlya vysokotemperaturnogo reaktora s gazovym okhlazhdeniem; Elementos combustibles no metalicos para un reactor de temperatura elevada refrigerado por gas

    Energy Technology Data Exchange (ETDEWEB)

    Liebmann, B.; Schafer, L.; Spener, G. [NUKEM, Nuklear-Chemie und -Metallurgie G.m.b.H., Wolfgang bei Hanau, Federal Republic of Germany (Germany)

    1963-11-15

    destinados al reactor de alta temperatura refrigerado por gas de la Brown-Boveri/Krupp Reaktorbau GmbH, se investigaron y desarrollaron dos conceptos de elemento combustible. El elemento consiste en ambos casos en una esfera de grafito de 6 cm de diametro que encierra una pastilla cilindrica de combustible de unos 20 mm de diametro y 16 mm de altura. La diferencia entre ambos conceptos estriba en el tipo de combustible y en la forma de preparar las esferas de grafito. En el primero, el combustible se prepara mezclando U{sub 3}O{sub 8} y grafito, prensando esta mezcla en pastillas y haciendo que ambos componentes reaccionen en un horno al vacio a 1800{sup o}C. La razon atomica U : C es 1:45. Como este tipo de pastilla combustible no retiene cuantitativamente los productos de fision, fue necesario impregnar la esfera de grafito para hacerla impermeable y mejorar su poder de retencion. De este modo, se lograron permeabilidades del orden de 10{sup -6}cm{sup 2}/s . Con arreglo al segundo concepto, el combustible consiste en una solucion solida de UC en ZrC recubierta de una capa de ZrC. La razon molar UC : ZrC asciende a 1 : 20. La pastilla combustible se preparo del modo siguiente: se mezclaron UO{sub 2}, ZrO{sub 2} y grafito y se prensaron en pastillas que se hicieron reaccionar para obtener los carburos, que a su vez se trituraron en un molino de bolas, para volver a prensarse a 2000{sup o}C. De este modo, se alcanzaron densidades superiores al 95% del valor teorico. La memoria describe en detalle la preparacion y algunas de las propiedades fisicas de las pastillas combustibles. Se espera que este tipo de combustible retenga suficientemente los gases de fision y permita el empleo de esferas de grafito no impregnadas. La memoria examina tambien otras ventajas de esos combustibles. [Russian] V svyazi s rabotami po sovershenstvovaniyu seplovydelyayushchikh ehlementov dlya vysokotemperaturnogo reaktora s gazovym okhlazhdeniem ''Obshchestvom stroitel'stva reaktorov Braun- Boveri

  10. Pesquisa de novos elementos Pesquisa de novos elementos

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    Gil Mário de Macedo Grassi

    1978-11-01

    Full Text Available The present study deals with the discovery of new elements synthesized by man. The introduction discusses in general the theories about nuclear transmutation, which is the method employed in these syntheses. The study shows the importance of the Periodical Table since it is through this table that one can reach a prevision of new elements and its, properties. The discoveries of the transuranic elements, together wich the data of their first preparations are also tabulated The stability of these elements is also discussed, and future speculations are showedNeste trabalho estuda-se, teoricamente, a descoberta de novos elementos sintetizados pelo homem Na introdução apresentamos um apanhado geral sobre as teorias a respeito da transmutação nuclear, que é o método utilizado nestas sínteses. Em seguida, mostramos a importância da Tabela Periódica, pois é através dela que se chega à previsão dos novos elementos e de suas propriedades. As descobertas dos transurânicos, Já realizadas com êxito, juntamente com os dados de suas primeiras preparações são tabelados. A estabilidade destes novos elementos também é discutida, e apresentadas futuras especulações.

  11. Upper nozzle welding development transfer of Angra 2/00 fuel element to F.E.C. (Fabrica de Elemento Combustivel)

    International Nuclear Information System (INIS)

    Lorenzo, R.F. di; Almeida, R.C.

    1985-01-01

    The technology development of upper nozzle welding of Angra-2 Combustible element, done at CDTN (Centro de Desenvolvimento da Tecnologia Nuclear), this technology transfer to FEC (Fabrica de Elemento Combustivel), the welders training of FEC in nozzle welding, the radiographic control of nozzle welds and the FEC personnel training in this nozzle welds radiography are presented is this report. (C.M.) [pt

  12. Influencias de las impurezas en los combustibles residuales

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    Carlos Losada

    2002-01-01

    Full Text Available A partir de considerar como campo experimental una planta generadora de electricidad que utiliza motores marinos MAN B&W L+V-28/32H, se demuestra que las impurezas formadas durante el proceso de fabricación, transportación, almacenamiento y consumo del combustible afectan la calidad de combustión y con ello los daños causados a los elementos del sistema.

  13. Assessment of End-Plug Welding of Fuel Elements; Evaluation des Soudures Terminales des Elements Combustibles; Otsenka kachestva privarki kontsevoj probki toplivnykh ehlementov; Inspeccion de la Soldadura del Tapon Terminal de los Elementos Combustibles

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Y.; Aoki, T. [Tokai Refinery, Atomic Fuel Corporation (Japan)

    1965-10-15

    faites pour des elements combustibles du reacteur JRR-3. Il s'agit d'un reacteur de recherche de 10 MW, ralenti et refroidi 3 l'eau lourde, avec des elements combustibles en uranium metallique sous gaine d'aluminium. Comme ces elements n'ont qu'une liaison mecanique entre la gaine et l'ame, il peut exister une contrainte de traction aux bouchons de la gaine sous l'effet du gonflement de l'uranium par suite de l'irradiation. Le traitement thermique provoquera une contrainte analogue dans les soudures. Une corrosion preferentielle provoquee par l'eau chaude peut se produire dans le voisinage des soudures, a cause de la difference de microstructure. Il est essentiel d'assurer l'etancheite pendant et apres l'utilisation dans le reacteur. Des specimens specialement concus ont ete utilises pour les essais d'elasticite, les essais de fluage a haute temperature, les essais thermiques et le controle de la corrosion. Plusieurs sortes de soudures ont fait l'objet d'essais non destructifs avant les controles proprement dits et ont ete verifiees quant a l'etancheite a diverses periodes entre les controles. L'etude critique des resultats obtenus peut permettre de fixer des normes d'inspection, telles que la radiographie par rayons X et l'inspection visuelle des soudures des bouchons. Le memoire donne egalement d'autres resultats pour les elements combustibles avec gaine en Magnox ou en Zircaloy. (author) [Spanish] Es muy importante establecer una correlacion entre los resultados de los ensayos y el rendimiento en los reactores en servicio, asf como perfeccionar los correspondientes metodos de ensayo no destructivo. Ahora bien, resulta algo diffcil lograr la correlacion indicada a causa de los elevados gastos que ello supone y de la intensa radiactividad. Se han efectuado varios estudios fuera del reactor simulando las condiciones que reinan en el interior de este. En el presente documento se exponen algunos datos sobre los ensayos con elementos combustibles del reactor japones de

  14. Fabrication and Testing of Prototype APM-Clad UO{sub 2} Fuel Elements; Fabrication et essai de prototypes de cartouches de combustible en bioxyde d'uranium gaine d'aluminium (APM); Izgotovlenie i ispytanie prototipa toplivnykh ehlementov na osnove UO{sub 2} s obolochkoj iz alyuminiya metodom poroshkovoj metallurgii; Elaboracion y ensayo de elementos combustibles prototipo de UO{sub 2} con revestimiento de aluminio sinterizado

    Energy Technology Data Exchange (ETDEWEB)

    Ballif, III, J. L.; Friske, W. H.; Gordon, R. B. [Atomics International, Canoga Park, California (United States)

    1963-11-15

    disposees selon un pas helicoidal de 45 ou 90{sup o}/30 cm. L'obturation des gaines des barreaux etait assuree par des bouchons en aluminium plaque argent, lies par alliage eutectique aux tubes APM. Les cartouches etaient equipees d'instruments permettant de: 1. Mesurer la temperature du fluide de refroidissement et la temperature superficielle des gaines; 2. Deceler les defectuosites des barreaux de combustible; 3. Modifier la vitesse du fluide de refroidissement (on pourrait ainsi obtenir des temperatures maximums de l'ordre de 455{sup o}C a la surface de la gaine); 4. Mesurer la vitesse du fluide de refroidissement; 5. Mesurer le degagement des produits de fission gazeux. Ces cartouches ont ete installees dans le reacteur OMRE pour atteindre un taux de combustion de l'ordre de 25000 a 30000 MWj/tU. Au 1er avril 1963 le taux atteint etait de 7700 a 12000 MWj/tU. Deux des cartouches ont ete retirees du reacteur a la suite de difficultes suscitees par leurs instruments de mesure. Les trois autres cartouches ont ete maintenues dans le reacteur. A ce jour, les resusltats de ces travaux experimentaux donnent a penser que le combustible APM-UO{sub 2} permettra d'atteindre les objectifs du programme de POPR. (author) [Spanish] En ejecucion del programa relativo al reactor de potencia prototipo de moderador organico de 50 MW(e) (POPR), se han llevado a cabo amplios trabajos de investigacion sobre productos elaborados por pulvimetalurgia de aluminio (PMA), con el fin de utilizarlos como revestimiento para el combustible de UO{sub 2}. Como parte de estos trabajos, se ha investigado la aptidud de los metodos de union eutectica, de soldadura a tope por chispas y de soldadura por compresion en frio ''Koldweld'', para realizar los cierres de los extremos del revestimiento de los elementos combustibles. Se ha estudiado la compresion vibratoria como procedimiento para rellenar de UO{sub 2} los tubos de PMA. Se han realizado ensayos fuera de reactor para reunir datos sobre la

  15. El sentido de los elementos del acto administrativo

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    Santiago Maqueda

    2010-01-01

    y promoción del bien común. La conclusión que se ofrece es que cada uno de los elementos legales del acto administrativo encuentra fundamentación filosófica en uno o varios de los elementos de la noción de "ley", y que esta es una manera idónea de justificar el sentido de cada uno de esos elementos legales.

  16. Hydraulic modelling of the CARA Fuel element; Desarrollo hidraulico del combustible CARA

    Energy Technology Data Exchange (ETDEWEB)

    Brasnarof, Daniel O; Juanico, Luis [Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Disenios Avanzados y Evaluacion Economica; Giorgi, M [Comision Nacional de Energia Atomica, General San Martin (Argentina). Dept. de Materiales; Ghiselli, Alberto M; Zampach, Ruben; Fiori, Jose M; Yedros, Pablo A [Comision Nacional de Energia Atomica, General San Martin (Argentina). Dept. de Ensayos no Destructivos

    2004-07-01

    The CARA fuel element is been developing by the National Atomic Energy Commission for both Argentinean PHWRs. In order to keep the hydraulic restriction in their fuel channels, one of CARA's goals is to keep its similarity with both present fuel elements. In this paper is presented pressure drop test performed at a low-pressure facility (Reynolds numbers between 5x10{sup 4} and 1,5x10{sup 5}) and rational base models for their spacer grid and rod assembly. Using these models, we could estimate the CARA hydraulic performance in reactor conditions that have shown to be satisfactory. (author) [Spanish] Con el objeto de validar la similitud hidraulica del elemento combustible CARA con los actuales combustibles de Atucha y Embalse, se realizaron ensayos de perdida de carga en el circuito CBP del CAC con un nuevo diseno de separador de mejor desempeno hidraulico. Se presenta aqui el analisis de los mismos, de los cuales se validaron modelos de base racional para estimar las restricciones hidraulicas de los distintos componentes estructurales (separadores, grillas y barras combustibles) en funcion del flujo refrigerante. Se estimo asi la caida de presion del CARA dentro del canal combustible Embalse en condiciones nominales de reactor, siendo la misma similar al del combustible actual de 37 barras. (autor)

  17. Non-Destructive Testing Methods Applied to Multi-Finned SAP Tubing for Nuclear-Fuel Elements; Essais Non Destructifs de Gaines a Ailettes, en Poudre d'Aluminium Frittee, pour Elements Combustibles; Nedestruktivnye metody ispytaniya rebristykh trub iz spechennogo alyuminikiog'o poroshka dlya yadernykh toplivnykh ehlementov; Metodos de Ensayo No Destructivo Aplicados a Tubos de SAP con Aletas Multiples Destinados a Elementos Combustibles

    Energy Technology Data Exchange (ETDEWEB)

    Lund, S. A. [Danish Central Welding Institution, Copenhagen (Denmark); Knudsen, P. [Danish Atomic Energy Commission, Research Establishment, Risoe (Denmark)

    1965-09-15

    Energia Atomica de Dinamarca ha emprendido el estudio de un reactor de potencia con refrigerante organico y moderador de agua pesada. Los correspondientes elementos combustibles consisten en haces de 19 barras formadas por pastillas de dioxido de uranio sinterizado, encerradas en tubos de producto de aluminio sinterizado (SAP), de 2 m de longitud, provistos de aletas helicoidales. Para obtener condiciones optimas de transmision de calor y mantener la integridad del elemento combustible durante el funcionamiento del reactor, es necesario contar con tubos de muy alta calidad. Se citan dos ejemplos que ponen de manifiesto las estrechas tolerancias dimensionales adoptadas. Para asegurar una calidad adecuada de los tubos, se establecio un control de calidad muy estricto, basado en gran medida en la aplicacion de metodos no destructivos. Se describen en esta memoria las tecnicas desarrolladas para medir el espesor de pared y los diametros, y para descubrir defectos. La compleja seccion transversal, con 24 aletas, impide aplicar metodos ultrasonicos o de comentes de Foucault para medir el espesor de la pared. Por consiguiente, se desarrollo un calibre registrador de rayos beta, cuyo funcionamiento se basa en la atenuacion sufrida por la radiacion beta proveniente de una fuente de {sup 90}Sr colocada en el interior del tubo. Para el registro continuo del espesor de la pared del tubo con seccion transversal mas simple, de 12 aletas, se utiliza un metodo ultrasonico de resonancia por inmersion. Los diametros interno y externo (entre puntos de aletas) se registran de manera continua mediante calibres neumaticos rapidos. Las fallas se detectan mediante la tecnica de eco de impulsos ultrasonicos, y examinando los tubos con corrientes de Foucault. El metodo ultrasonico permite descubrir facilmente las fisuras transversales, pero hasta ahora ha sido imposible utilizarlo para la deteccion de defectos longitudinales. Por consiguiente, ademas del ensayo ultrasonico, se aplica el examen con

  18. O exercício do estudar nos cursinhos destinados aos concursos públicos

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    Leonardo Del Puppo Luz

    2008-06-01

    Full Text Available O artigo discute o processo de produção da subjetividade contemporânea elaborado sobre o Estudar em alunos de cursinhos destinados aos concursos públicos. Procura-se discutir as tecnologias de poder, sobretudo na relação saber-poder, engendradas nestes "ambientes educacionais", já que tais construções sobre o Estudar produzem e perpetuam a manifestação de conceitos absolutos e verdadeiros de se pensar o estudo por meio de técnicas e procedimentos de funcionamentos ideais e idealizados. Busca-se problematizar este modelo homogêneo baseado no tecnicismo do estudar e nas falas sobre o verdadeiro visando colocar em análise o estereótipo do "fracasso" atrelado aos alunos vinculados a estes locais.

  19. Presencia de Fusarium graminearum en muestras de trigo destinado al consumo humano

    Directory of Open Access Journals (Sweden)

    Mauro Martinez

    Full Text Available La fusariosis es una de las enfermedades más importantes de los cereales, Fusarium graminearum es su principal agente etiológico. Este hongo posee la capacidad de producir distintos tipos y niveles de toxinas, en especial deoxinivalenol (DON. En la campaña 2012-2013 se dieron condiciones ambientales predisponentes para el desarrollo de esta enfermedad. El objetivo de este trabajo fue evaluar la presencia del hongo y el contenido de DON en 50 muestras de trigo. Los resultados demostraron la presencia de Fusarium graminearum en el 80 % de las muestras analizadas. El 24 % de las muestras presentó valores de DON ≥ 1μg/g, el 26 % varió entre 0,5 y 0,99μg/g, mientras que el 50 % restante mostró valores inferiores a 0,5μg/g. Se observó correlación entre la presencia de Fusarium graminearum y de DON. Es necesario establecer valores límites de DON en granos de trigo destinados al consumo humano.

  20. Proyecto estructural de edificio industrial de 1500m2 destinado a uso logístico, situado en el poligono L'Espartal (Jijona)

    OpenAIRE

    ESTEVE GIL, ALFONSO

    2016-01-01

    [ES] En este trabajo, el alumno realizará el proyecto estructural de una nave industrial sencilla, con tipología estructural a dos aguas, situada en un polígono industrial. Esteve Gil, A. (2016). Proyecto estructural de edificio industrial de 1500m2 destinado a uso logístico, situado en el poligono L'Espartal (Jijona). http://hdl.handle.net/10251/69514. TFGM

  1. Ultrasonic Water-Gap Measurements in MTR Fuel Elements; Mesure par Ultrasons des Espaces Intercalaires dans les Elements Combustibles des Reacteurs d'Essai de Materiaux; Izmereniya vodyanogo zazora v teplovydelyayushchikh ehlementakh dlya materialovedcheskogo reaktora s pomoshch'yu ul'trazvuka; Medicion Ultrasonica de la Capa de Agua en Elementos Combustibles para Reactores de Ensayo de Materiales

    Energy Technology Data Exchange (ETDEWEB)

    Deknock, R. [Metallurgy Department, S.C.K./C.E.N., Mol (Belgium)

    1965-10-15

    distance intercalaire fournit a un enregistreur une tension stable de sortie de 1 V. Il est facile de mesurer les variations des distances intercalaires avec une precision de 5 {mu}m. Les mesures ont ete faites pour plusieurs elements combustibles. Les resultats et la reproductibilite sont tres satisfaisants. (author) [Spanish] Los elevados flujos termicos que suelen alcanzarse en los recientes reactores de ensayo de materiales, exigen recorridos adecuados para lograr una transmisiun uniforme de calor y una disipacion segura del mismo, evitando asf la formacion de vapor en la masa. Ademas, a fin de controlar el hinchamiento y el comportamiento del combustible en el reactor, tambien debe medirse la capa de agua en experimentos realizados despues de la irradiacion, con elementos combustibles agotados. A tal efecto se ha disenado una sonda ultrasonica destinada a medir, en una longitud de 1 m el espesor de 3 mm de agua correspondiente al elemento combustible BR-2. En el caso de los experimentos posteriores a la irradiacion, es necesario trabajar con el elemento combustible sumergido en un tanque de agua, a profundidad no menor de 6 m. La sonda puede resistir una prolongada inmersion en agua, y no le afectan las dosis normales de radiacion gamma. Aunque proyectado conforme al metodo usual de reflexion de impulsos, el sistema permite separar pulsos emitidos y reflejados, usando un cristal ferro-electrico de 10 MHz, con elevada disipacion inherente de energia. Puede usarse un osciioscopio para la lectura, en cuyo caso el tiempo se representa en el eje horizontal, regulandose la velocidad de barrido de manera que sea directamente proporcional a la velocidad de propagacion de la onda, es decir, al espesor de la capa de agua. Este tipo de representacion da resultados satisfactorios cuando setrata de un numero limitado de mediciones, pero sin duda resulta mas conveniente el registro grafico. En este caso, se da a los impulsos emitidos y reflejados la forma deseada y se les inyecta

  2. The Application of Various Nondestructive Testing Methods to Fuel Elements of the Orgel Type; Application des Differentes Methodes d'Essais Non Destructifs aux Elements Combustibles du Type Orgel; Primenenie razlichnykh nedestruktivnykh metodov ispytanij k toplivnym ehlementam tipa ''orgel''; Aplicacion de Distintos Metodos de Ensayo No Destructivo a los Elementos Combustibles de Tipo Orgel

    Energy Technology Data Exchange (ETDEWEB)

    Bonnet, P.; Jansen, J. [EURATOM, C.C.R., Ispra (Italy)

    1965-09-15

    methode a un capteur montre quelles sont les limites d'utilisation de ces deux methodes. Defauts transversaux; La methode a un capteur appliquee a cette recherche fait l'objet d'une breve description. Entrainement mecanique: Le memoire fait etat d'un banc mecanique, type laboratoire, pour la recherche des criteres d'essais et d'un banc de passage des tubes, de type semi-industriel, pour l'examen en continu avec enregistrement des defauts. Les difficultes rencontrees et les moyens misenceuvrepoury remediersont evoques. c) Tests par radiographie. Cette methode fera l'objet d'un memoire special; seuls sont indiques les resultats obtenus sur tubes de force ou sur tubes de gaines. d) Test divers Les test finaux sur elements combustibles complets peuvent se resumer en deux parties. Tests d'etancheite au moyen du test a l'helium developpe par la SOGEV. Un dispositif permet d'examiner simultanement 4 ou 6 elements combustibles ou separement 2 ou 3. Tests classiques de radiographie; l'accent est mis plus particulierement sur l'etude des soudures; on donne la marge des conditions experimentales pour obtenir une bonne definition. En conclusion, les auteurs presentent un projet de chaine de controle semi-industrielle avec les differentes possibilites de traitements et essaient de degager une certaine philosophie des tests non destructifs appliques aux elements combustibles. (author) [Spanish] La memoria presenta los distintos metodos empleados para deteccion de fallas (de tipo dimensional o estructural) en vainas de elementos combustibles. Los autores describen, asimismo, los ensayos finales con elementos combustibles completos, en particular radiografia de las soldaduras y pruebas de estanqueidad. Este tema se ha tratado ya en forma parcial. El estudio de las caracteristicas dimensionales de las vainas lisas de SAP (producto de aluminio sinterizado) ha sido objeto de trabajos bastante avanzados. La memoria examina en particular los siguientes temas: 1. Medicion de diametros internos

  3. Desarrollo del método de los elementos finitos

    Directory of Open Access Journals (Sweden)

    Luís Otero Pereiro

    1997-02-01

    Full Text Available El Análisis por Elementos Finitos constituye hoy día una herramienta de cálculo para resolver problemas de ingeniería, en estructuras, elementos de máquinas, mecánica de los fluidos y transferencia de calor, entre otros. Esto ha propiciado una gran difusión de los programas de cálculo asistidos por computadora, con los cuales seafirma es posible disminuir el costo de un proyecto hasta en 50%. En el artículo se demuestra que solo mediante la comprensión de los principios en que se basa el método de los elementos finitos se podrá hacer un empleo adecuado de cualquiera de estos sistemas de cálculo. Además, se explica porqué este método no constituye un descubrimiento dentro del campo de la resistencia de los materiales y la teoría de la elasticidad, sino que sienta sus bases sobre estos aspectos.

  4. Non-Destructive Methods for Determining Burn-Up in Nuclear Fuel; Methodes Non Destructives d'Evaluation du Taux de Combustion dans le Combustible Nucleaire; Metody opredeleniya vygoraniya v yadernom toplive bez razrusheniya obraztsa; Metodos No Destructivos para Determinai el Grado de Combustion de los Elementos Combustibles Nucleares

    Energy Technology Data Exchange (ETDEWEB)

    McGonnagle, W. J. [Illinois Institute of Technology, Chicago, IL (United States)

    1966-02-15

    gamma emis par les matieres radioactives qui se forment au cours du processus de fission, en particulier le spectrometre a cristal courbe, le spectrometre Compton magnetique, le spectrometre Compton a coiencidence et le spectrometre a scintillation. Parmi les autres methodes non destructives, on peut citer l'activation de feuilles, la transmission des neutrons, l'analyse par activation, la mesure des rayonnements gamma de capture et la mesure des neutrons instantanes et differes. Le memoire etudie les principes essentiels des differents appareils et procedes ci-dessus, leur precision et leurs limitations. Le memoire presente des methodes non destructives utilisant les isotopes stables produits au cours du processus de fission. Dans les mesures au moyen de ces isotopes, le schema d'irradiation n'a qu'une importance secondaire et le temps de refroidissement ne joue aucun role. De plus, on dispose de donnees nucleaires plus precises sur les produits stables de la fission. Il semble que les plus utiles de tous les isotopes stables produits au cours du processus de fission soient ceux du zirconium, du molybdene, du ruthenium et du neodyme. Le memoire etudie l'interet de ces methodes d'analyse non destructive. (author) [Spanish] Los metodos no destructivos son de gran utilidad para medir cuantitativamente el grado de combustion. El metodo ideal seria el que no requiriese datos especiales sobre los espectros neutrtfni- cos, las irradiaciones precedentes o el tiempo de enfriamiento. Los elementos combustibles irradiados llevan en cierto modo el registro de su grado de combustion. Este registro consiste en el conjunto de los isotopos radiactivos y estables resultantes del proceso de fision. Desgraciadamente, tanto con los metodos no destructivos como con los destructivos el espectro neutronico, las irradiaciones precedentes y el tiempo de enfriamiento influyen sobre dicho registro. Analogamente, la falta de datos nucleares precisos tales como las secciones eficaces nucleares

  5. Magnox Fuel Cycles; Cycles des combustibles gaines de magnox; Toplivnye tsikly magnoks; Ciclos de combustible magnox

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, A. [United Kingdom Atomic Energy Authority, Risley, Warrington, Lancs (United Kingdom)

    1963-10-15

    esquemas de irradiacion que se producen segun los diversos programas de carga del combustible, y describe someramente los metodos de calculo utilizados en la actualidad. Compara diversos programas de carga continua o intermitente del combustible. Estudia el problema de la irradiacion eficiente de la primera carga, junto con los metodos de reabastecimiento retardado y de transposicion de los elementos combustibles. Discute las ventajas economicas y los problemas que plantea la utilizacion de uranio, no natural en reactores de flujo nivelado. Formula consideraciones de orden practico sobre la carga de combustible durante la marcha en reactores nuevos y hace referencia a la experiencia adquirida en Bradwell y en Berkeley. Describe someramente el efecto que ejercen las variaciones del costo del combustible y de su resistencia sobre los aspectos economicos del ciclo de combustible. (author) [Russian] Rassmatrivaetsya vzaim o zavisimost' mezhdu potokom izlucheniya i temperaturnym raspredeleniem i kharakteristikami oblucheniya, vyzvannaya razlichnoj praktikoj zameny topliva, opisyvayutsya sushchestvuyushchie metody rascheta. Provoditsya sravnenie razlichnykh skhem zameny topliva, vklyuchaya kak sistemu vygruzki topliva portsiyami, tak i sistemu nepreryvnoj vygruzki. Problema ehffektivnogo oblucheniya pervoj zagruzki rassmatrivaetsya vmeste so skhemami zapazdyvayushchej nachal'noj zameny topliva i ego peremeshcheniya. Rassmatrivayutsya ehkonomicheskie preimushchestva i trudnosti ispol'zovaniya neprirodnogo urana v vyrovnennykh reaktorakh. Rassmatrivaetsya prakticheskoe reshenie skhemy zameny topliva na novykh reaktorakh i delaetsya ssylka na opyt, priobretennyj v Braduehlle i Berkli. Opisyvaetsya vliyani razlichnoj stoimosti topliva i prodolzhitel'nosti kampanii za ehkonomichnost' toplivnogo tsikla. (author)

  6. Calculo de volúmenes en modelos remallados de elementos finitos

    Directory of Open Access Journals (Sweden)

    Andrés Lapuebla-Ferri

    2011-06-01

    Full Text Available El Método de los Elementos Finitos asistido por ordenador es una herramienta muy extendida en ingeniería. En ciertas aplicaciones, se precisa modificar la malla del modelo a lo largo del proceso de simulación, lo que se conoce como remallado. En estos casos, además, suele ser necesario realizar mediciones en el modelo de elementos finitos, como por ejemplo calcular el volumen de ciertas regiones del mismo. Los paquetes comerciales disponibles en la actualidad permiten satisfacer algunas de estas necesidades, aunque adolecen de ciertas limitaciones. En este trabajo se presenta una aplicación desarrollada en el código propio de MatlabQc, que permite el cálculo aproximado del volumen de una región del espacio comprendida entre una malla de elementos finitos cuadriláteros lineales y otra malla topológicamente equivalente a la anterior, esta última obtenida a través de un proceso de remallado.

  7. Determination of the Effectiveness of Control Rods in the VVER Reactor Fuel Assemblies; Determination de l'Efficacite des Barres de Reglage dans les Ensembles Combustibles du reacteur VVER; Opredelenie ehffektivnosti reguliruyushchikh sterzhnej v sborkakh reaktora VVEHR; Determinacion de la Eficacia de las Barras de Control en los Conjuntos de Elementos Combustibles del Reactor VVER

    Energy Technology Data Exchange (ETDEWEB)

    Semenov, V. N.; Lunin, G. L.; Komissarov, L. V.; Kamyshan, A. N.; Halizev, V. I.; Andrianov, G. Ja.; Voznesenskij, V. A.; Kuz' micheva, V. A.; Lebedev, V. I. [Ordena Lenina Institut Atomnoj Energii Im. I.V. Kurchatova, Moskva, SSSR (Russian Federation)

    1964-06-15

    The paper describes experiments done in homogeneous mock-ups of the fuel assemblies from the VVER Reactor (at one level of enrichment) to determine the effectiveness of absorbing systems comprising shim fuel assemblies or water cavities and of absorbing rods clad in jackets made of differing materials. The paper also gives data on some experiments that have been done in mock-ups of assemblies with differing levels of enrichment. These experiments make it possible to verify the methods used in calculation and to evaluate the prospects of using them for heterogeneous reactors. (author) [French] Le memoire decrit les experiences qui ont ete faites pour determiner l 'efficacite des absorbants contenus dans les barres de compensation, l'effet cavitaire et l 'efficacite des absorbants gaines de materiaux divers, au moyen d'assemblages homogenes de cartouches de combustible du reacteur VVER (reacteur de puissance ralenti et refroidi a l 'eau ayant le meme taux d'enrichissement. On y trouve en outre des donnees sur certaines experiences executees a l 'aide d'assemblages de cartouches de combustible taux d'enrichissement differents. Ces travaux permettent de verifier la methode de calcul et d'evaluer ses possibilites d'application aux reacteurs non homogenes. (author) [Spanish] Se describen en la memoria experimentos para determinar la eficacia de los materiales absorbentes contenidos en las barras de compensacion, el efecto de cavitacion y la eficacia de los materiales absorbentes revestidos de diversos materiales, realizados con ayuda de los conjuntos homogeneos de elementos combustibles del reactor VVER (reactor de potencia moderado y refrigerado por agua) con un solo grado de enriquecimiento. Ademas, se exponen datos sobre los experimentos efectuados con ayuda de conjuntos de grados de enriquecimientos; variados. Tales experimentos permiten verificar el metodo de calculo teorico, utilizad o y evaluar la posibilidad de aplicarlo a los reactores no homogeneos. (author

  8. El análisis por elementos finitos: una metodología muy reciente en economía

    OpenAIRE

    Escribano Ródenas, Miguel

    2006-01-01

    La técnica de análisis por elementos finitos (AEF) consiste en dividir la geometría en la que se quiere resolver una ecuación diferencial de un campo escalar o vectorial en un dominio, en pequeños elementos, teniendo en cuenta unas ecuaciones de campo en cada elemento, los elementos del entorno de vecindad y las fuentes generadoras de campo en cada elemento. Habitualmente, esta técnica es muy utilizada en el ámbito de la ingeniería debido a que muchos problemas físicos de interés se form...

  9. Um século de ópera em São Paulo

    Directory of Open Access Journals (Sweden)

    Odilon Nogueira de Matos

    1954-09-01

    Full Text Available CERQUERA (Paulo de Oliveira Castro . — Um século de ópera  em São Paulo. São Paulo, 1954, 328 págs. (Primeiro Parágrafo do Artigo Na fase da historiografia brasileira em que nos encontramos, os livros-fontes, destinados à divulgação de documentos ou de elementos informativos, assume uma importânica vital.

  10. Comprobaciones resistentes de elementos constructivos de tierra

    Directory of Open Access Journals (Sweden)

    Estrada, Enrique

    1986-11-01

    Full Text Available This work has the purpose to compare, by means of different tests on adobe bricks and masonry, the obtained resistant properties and those of other similar works carried out in countries having a wide tradition and knowledge about earth as construction material. Elements (adobe bricks and blocks have been tested to compression and bending, and masonry made of those elements to compression and diagonal compression.El presente trabajo pretende comparar, por medio de distintos ensayos sobre elementos y fábricas de mampostería de tierra, las propiedades resistentes obtenidas con las de otros trabajos similares realizados en países con dilatada tradición y conocimiento de la tierra como material de construcción. Se han ensayado elementos (adobes y bloques a compresión y flexotracción y fábricas formadas por conjuntos de los mismos a compresión y a compresión diagonal.

  11. El agua como elemento de composición en complejos residenciales sostenibles

    OpenAIRE

    Kusinska, E

    2013-01-01

    Este artículo presenta renovaciones de áreas urbanas abandonadas y degradadas con esquemas de agua. Las nuevas inversiones residenciales en este tipo de parcelas, diseñadas de acuerdo con los principios del desarrollo sostenible, coinciden de manera adecuada con el paisaje urbano existente y forman espacios de reunión atractivos destinados a los residentes relacionados con el agua. Este trabajo también describe un trabajo de diseño de los alumnos de segundo año realizada en la Cátedra de Ento...

  12. Combustion

    CERN Document Server

    Glassman, Irvin

    2008-01-01

    Combustion Engineering, a topic generally taught at the upper undergraduate and graduate level in most mechanical engineering programs, and many chemical engineering programs, is the study of rapid energy and mass transfer usually through the common physical phenomena of flame oxidation. It covers the physics and chemistry of this process and the engineering applications-from the generation of power such as the internal combustion automobile engine to the gas turbine engine. Renewed concerns about energy efficiency and fuel costs, along with continued concerns over toxic and particulate emissions have kept the interest in this vital area of engineering high and brought about new developments in both fundamental knowledge of flame and combustion physics as well as new technologies for flame and fuel control. *New chapter on new combustion concepts and technologies, including discussion on nanotechnology as related to combustion, as well as microgravity combustion, microcombustion, and catalytic combustion-all ...

  13. La formación profesional inicial universitaria y el análisis multirreferencial de dispositivos destinados a la formación profesional.

    OpenAIRE

    Souto, Marta; Mazza, Diana; Monetti, Elda

    2010-01-01

    El trabajo se propone indagar en los modos de gestión de la formación universitaria de carácter pre-profesional, en tres casos de la investigación “La formación profesional inicial universitaria y el análisis multirreferencial de dispositivos destinados a la formación profesional”, dirigido por Marta Souto. El problema de investigación es ¿cómo se piensa y resuelve la formación profesional inicial (o pre-profesional) en las carreras universitarias? ¿Qué modalidades y caracterís...

  14. Combustion

    CERN Document Server

    Glassman, Irvin

    1997-01-01

    This Third Edition of Glassman's classic text clearly defines the role of chemistry, physics, and fluid mechanics as applied to the complex topic of combustion. Glassman's insightful introductory text emphasizes underlying physical and chemical principles, and encompasses engine technology, fire safety, materials synthesis, detonation phenomena, hydrocarbon fuel oxidation mechanisms, and environmental considerations. Combustion has been rewritten to integrate the text, figures, and appendixes, detailing available combustion codes, making it not only an excellent introductory text but also an important reference source for professionals in the field. Key Features * Explains complex combustion phenomena with physical insight rather than extensive mathematics * Clarifies postulates in the text using extensive computational results in figures * Lists modern combustion programs indicating usage and availability * Relates combustion concepts to practical applications.

  15. El potencial de la madera como elemento estructural

    OpenAIRE

    Valladares Pagliotti, Enzo

    2013-01-01

    El empleo de estructuras de madera para construcciones con grandes luces y magnitud media es recogido por este artículo, que propone la combinación de elementos madera laminada y aserrada articulados por conectores metálicos.

  16. Combustion engineering

    CERN Document Server

    Ragland, Kenneth W

    2011-01-01

    Introduction to Combustion Engineering The Nature of Combustion Combustion Emissions Global Climate Change Sustainability World Energy Production Structure of the Book   Section I: Basic Concepts Fuels Gaseous Fuels Liquid Fuels Solid Fuels Problems Thermodynamics of Combustion Review of First Law Concepts Properties of Mixtures Combustion StoichiometryChemical EnergyChemical EquilibriumAdiabatic Flame TemperatureChemical Kinetics of CombustionElementary ReactionsChain ReactionsGlobal ReactionsNitric Oxide KineticsReactions at a Solid SurfaceProblemsReferences  Section II: Combustion of Gaseous and Vaporized FuelsFlamesLaminar Premixed FlamesLaminar Flame TheoryTurbulent Premixed FlamesExplosion LimitsDiffusion FlamesGas-Fired Furnaces and BoilersEnergy Balance and EfficiencyFuel SubstitutionResidential Gas BurnersIndustrial Gas BurnersUtility Gas BurnersLow Swirl Gas BurnersPremixed-Charge Engine CombustionIntroduction to the Spark Ignition EngineEngine EfficiencyOne-Zone Model of Combustion in a Piston-...

  17. Elementos decorativos en el cartel taurino

    Directory of Open Access Journals (Sweden)

    Begoña Torres

    2001-01-01

    Full Text Available El estudio de los elementos decorativos del cartel taurino (viñetas, orlas y adornos -que se abordan en este artículo por primera vez- es una fuente de información fundamental que nos aporta importantes datos sobre la relación del cartel taurino con el libro y otros impresos, los cambios en el gusto, la pervivencia de elementos ornamentales a lo largo del tiempo, la preferencia en los temas decorativos y el intercambio de adornos entre diferentes imprentas, la difusión masiva de imágenes, su relación con el texto, y las innovaciones técnicas introducidas en la imprenta durante los siglos XIX y XX.The study of decoratives elements represented in the bullfight affiche (drawings, borders and ornaments -addresses for the firts time in this anide- it's a basic source of Information, which contributes to get important facts about the relationship between a poster and other books and printed material; the changes in the style, the persistency of ornamental elements thoughout time, the preference just in decorative themes and the exchanges of ornaments among printers; the massive dissemination of images, his relation with the text and the technical innovations brought into the press during the 19th and the 20 centuries.

  18. Combustion

    CERN Document Server

    Glassman, Irvin

    1987-01-01

    Combustion, Second Edition focuses on the underlying principles of combustion and covers topics ranging from chemical thermodynamics and flame temperatures to chemical kinetics, detonation, ignition, and oxidation characteristics of fuels. Diffusion flames, flame phenomena in premixed combustible gases, and combustion of nonvolatile fuels are also discussed. This book consists of nine chapters and begins by introducing the reader to heats of reaction and formation, free energy and the equilibrium constants, and flame temperature calculations. The next chapter explores the rates of reactio

  19. Pulsating combustion - Combustion characteristics and reduction of emissions

    Energy Technology Data Exchange (ETDEWEB)

    Lindholm, Annika

    1999-11-01

    In the search for high efficiency combustion systems pulsating combustion has been identified as one of the technologies that potentially can meet the objectives of clean combustion and good fuel economy. Pulsating combustion offers low emissions of pollutants, high heat transfer and efficient combustion. Although it is an old technology, the interest in pulsating combustion has been renewed in recent years, due to its unique features. Various applications of pulsating combustion can be found, mainly as drying and heating devices, of which the latter also have had commercial success. It is, however, in the design process of a pulse combustor, difficult to predict the operating frequency, the heat release etc., due to the lack of a well founded theory of the phenomenon. Research concerning control over the combustion process is essential for developing high efficiency pulse combustors with low emissions. Natural gas fired Helmholtz type pulse combustors have been the experimental objects of this study. In order to investigate the interaction between the fluid dynamics and the chemistry in pulse combustors, laser based measuring techniques as well as other conventional measuring techniques have been used. The experimental results shows the possibilities to control the combustion characteristics of pulsating combustion. It is shown that the time scales in the large vortices created at the inlet to the combustion chamber are very important for the operation of the pulse combustor. By increasing/decreasing the time scale for the large scale mixing the timing of the heat release is changed and the operating characteristics of the pulse combustor changes. Three different means for NO{sub x} reduction in Helmholtz type pulse combustors have been investigated. These include exhaust gas recirculation, alteration of air/fuel ratio and changed inlet geometry in the combustion chamber. All used methods achieved less than 10 ppm NO{sub x} emitted (referred to stoichiometric

  20. Design of the Small Rods Forming the Fuel Element of the First Charge of the EL4 Reactor. Cladding Problems; Etude des crayons constituant l'element combustible du premier jeu d'EL4 - probleme de la gaine; Problema pokrytiya nebol'shikh steeknej, obrazushchikh toplivnyj ehlement pervoj zagruzki reaktora EL.4; Estudio de las barras que constituyen los elementos combustibles de la primera carga del reactor EL4 - el problema de las vainas

    Energy Technology Data Exchange (ETDEWEB)

    Bailly, H.; Ringot, C.; Weisz, M. [Centre d' Etudes Nucleaires de Saclay (France)

    1963-11-15

    ) [Spanish] Las vainas de los elementos combustibles de la primera carga del reactor EL-4 son de acero inoxidable. La eleccion del grado del acero y del espesor de la vaina depende de la resistencia a la corrosion y de la resistencia mecanica que se deseen. Las tensiones y las temperaturas de funcionamiento no permiten concebir una vaina que resista durante toda la vida util del elemento combustible si no se uti liza un grado de acero muy resistente y un espesor,superior a 0,5 mm. Se admite que la vaina se adhiera al combustible por fluencia: la deformacion por juego en sentido diametral puede producir una ovalizacion y un pliegue; el juego longitudinal puede dar lugar a flexiones de la vaina. Se han realizado muchos ensayos con vainas de 0,3 a 0,4 mm de espesor para estudiar el modo de deformacion en funcion de los juegos. Para estar seguros de que no se produciran ovaliza ciones con los espesores previstos, y para mantener lo mas baja posible la temperatura en el interior de la barra es preciso eliminar completamente el juego durante la fabricacion. (author) [Russian] Dlya pervoj nagruzki toplivnogo ehlementa reaktora EL.4 ispol'zuetsya pokrytie iz nerzhaveyushchej stali. Vybor splava i tolshchiny pokrytiya svyazan s korrozionnymi i mekhanicheskimi svojstvami metalla. Rabochie napryakheniya i temperatury ne dast vozmokhnosti sproektirovat' pokrytie, stojkoe v techenie vsego sroka sluzhby toplivnogo ehlementa; dlya dostikheniya takoj tseli neobkhodimo bylo by ispol'zovat' ochen' stojkoe pokrytie tolshchinoj bolee 0,5 mm. Dopuskaetsya, chto pokrytie v protsesse spekaniya soedinyaetsya s toplivom. Diametral'noe izmenenie toplivnykh ehlementov mokhet privesti k obrazovaniyu oval'noj formy i nerovnostej; prodol'noe izmenenie sistemy toplivnykh ehlementov mokhet privesti k prodol'nomu izgibu pokrytiya. Byli provedeny mnogochislennye opyty v otnoshenii tolshchiny pokrytiya v predelakh' 0,3 - 0,4 mm s tem, chtoby vyyasnit' kharakter izmeneniya toplivnykh ehlementov v zavisimosti

  1. Combustible structural composites and methods of forming combustible structural composites

    Science.gov (United States)

    Daniels, Michael A.; Heaps, Ronald J.; Steffler, Eric D.; Swank, W. David

    2013-04-02

    Combustible structural composites and methods of forming same are disclosed. In an embodiment, a combustible structural composite includes combustible material comprising a fuel metal and a metal oxide. The fuel metal is present in the combustible material at a weight ratio from 1:9 to 1:1 of the fuel metal to the metal oxide. The fuel metal and the metal oxide are capable of exothermically reacting upon application of energy at or above a threshold value to support self-sustaining combustion of the combustible material within the combustible structural composite. Structural-reinforcing fibers are present in the composite at a weight ratio from 1:20 to 10:1 of the structural-reinforcing fibers to the combustible material. Other embodiments and aspects are disclosed.

  2. Combustion Stratification for Naphtha from CI Combustion to PPC

    KAUST Repository

    Vallinayagam, R.

    2017-03-28

    This study demonstrates the combustion stratification from conventional compression ignition (CI) combustion to partially premixed combustion (PPC). Experiments are performed in an optical CI engine at a speed of 1200 rpm for diesel and naphtha (RON = 46). The motored pressure at TDC is maintained at 35 bar and fuelMEP is kept constant at 5.1 bar to account for the difference in fuel properties between naphtha and diesel. Single injection strategy is employed and the fuel is injected at a pressure of 800 bar. Photron FASTCAM SA4 that captures in-cylinder combustion at the rate of 10000 frames per second is employed. The captured high speed video is processed to study the combustion homogeneity based on an algorithm reported in previous studies. Starting from late fuel injection timings, combustion stratification is investigated by advancing the fuel injection timings. For late start of injection (SOI), a direct link between SOI and combustion phasing is noticed. At early SOI, combustion phasing depends on both intake air temperature and SOI. In order to match the combustion phasing (CA50) of diesel, the intake air temperature is increased to 90°C for naphtha. The combustion stratification from CI to PPC is also investigated for various level of dilution by displacing oxygen with nitrogen in the intake. The start of combustion (SOC) was delayed with the increase in dilution and to compensate for this, the intake air temperature is increased. The mixture homogeneity is enhanced for higher dilution due to longer ignition delay. The results show that high speed image is initially blue and then turned yellow, indicating soot formation and oxidation. The luminosity of combustion images decreases with early SOI and increased dilution. The images are processed to generate the level of stratification based on the image intensity. The level of stratification is same for diesel and naphtha at various SOI. When O concentration in the intake is decreased to 17.7% and 14

  3. Análisis de tensiones en árboles de geometría compleja bajo cargas debido al efecto giroscópico.

    Directory of Open Access Journals (Sweden)

    M. Sánchez Noa

    2005-09-01

    Full Text Available En el presente trabajo se exponen los resultados del análisis realizado en árboles de compleja geometríapertenecientes a un multiplicador planetario tipo 2KH-A destinado a emplearse en aerogeneradores deelectricidad. En el mismo, se presentan los modelos físico-matemáticos de dichos árboles para seranalizados mediante el método de los elementos finitos, considerando el estado de carga que surge alfuncionar el mecanismo y contemplando el efecto adicional de las cargas giroscópicas. Se muestran laszonas de conflicto de tensiones y se analizan propuestas de diseño que permitan, garantizando laresistencia y rigidez, realizar variaciones dimensionales y mejorar la compacidad de los elementos,disminuyendo a la vez el peso de los mismos.

  4. Elementos clave para la gestión de la creatividad

    Directory of Open Access Journals (Sweden)

    Rosa María Fuchs Ángeles

    2009-06-01

    Full Text Available Las organizaciones se encuentran en la búsqueda permanente de la innovación, y para alcanzarla deben fomentar la creatividad. El presente artículo analiza una serie de elementos que se tienen en cuenta en la gestión de la creatividad organizacional y propone un modelo con los factores indispensables que las organizaciones deberían considerar para lograrla.Los elementos que se analizan son: la cultura y el entorno organizacional, la estrategia, la estructura, la comunicación, el contacto con el cliente, los mecanismos de recursos humanos (como el reclutamiento, el entrenamiento, el diseño de puestos, la compensación, la promoción y evaluación del desempeño, la orientación en el largo plazo y, finalmente, el ciclo de vida organizacional. A partir del análisis de estos elementos, se identificaron los pilares que se consideran indispensables para la gestión de la creatividad. El modelo propuesto está conformado por 5 pilares: la alineación entre estrategia, cultura y estructura organizacionales, llamada por los autores «Santísima Trinidad», la publicidad interna, la voz del consumidor, el reconocimiento y la mirada al futuro. Posteriormente, se presenta el caso de una empresa innovadora peruana desde la perspectiva del modelo y las conclusiones del estudio.

  5. The Atterberg limits and their significance in the ceramic and brick industries

    Directory of Open Access Journals (Sweden)

    Sembenelli, P.

    1966-12-01

    Full Text Available Not availableLos límites de consistencia de Atterberg suministran los elementos para una rigurosa clasificación de las arcillas y para valorar muchas de sus propiedades. Pueden emplearse con utilidad para emprender un estudio riguroso, bien de los materiales destinados a la industria cerámica y de los ladrillos, o bien para proyectar las plantas de producción, integrando o sustituyendo algunos criterios todavía en uso.

  6. SINTERIZACIÓN CÉRAMICA POR ELEMENTOS FINITOS

    Directory of Open Access Journals (Sweden)

    Nolasco Arango

    Full Text Available Este artículo describe y establece la eficacia de utilizar el análisis de elementos finitos (discretización para predecir los cambios de forma de un plato cerámico formado mediante la tecnología de prensado isostático (Prensa Sacmi PHO-600 durante el proceso de sinterización. El modelo desarrollado se basa en el principio de conservación de la masa y no incluye las deformaciones mecánicas del material. Para su implantación se requiere: i la descripción de la malla de elementos finitos del cuerpo crudo prensado, ii la densidad del plato compactado antes y después del proceso de sinterización. Las predicciones numéricas obtenidas se comparan con los resultados reales del proceso de cocción, mediante el contraste entre los diámetros y alturas de la pieza y el coeficiente de contracción. Los resultados muestran una diferencia de0,52% en diámetro y 0,48% en altura entre el valor numérico y el valor real; y una diferencia en contracción de 3,49%. Ésta es una muy buena predicción en términos prácticos.

  7. IEA combustion agreement : a collaborative task on alternative fuels in combustion

    International Nuclear Information System (INIS)

    Larmi, M.

    2009-01-01

    The focus of the alternative fuels in combustion task of the International Energy Agency is on high efficiency engine combustion, furnace combustion, and combustion chemistry. The objectives of the task are to develop optimum combustion for dedicated fuels by fully utilizing the physical and chemical properties of synthetic and renewable fuels; a significant reduction in carbon dioxide, NOx and particulate matter emissions; determine the minimum emission levels for dedicated fuels; and meet future emission standards of engines without or with minimum after-treatment. This presentation discussed the alternative fuels task and addressed issues such as synthetic fuel properties and benefits. The anticipated future roadmap was presented along with a list of the synthetic and renewable engine fuels to be studied, such as neat oxygenates like alcohols and ethers, biogas/methane and gas combustion, fuel blends, dual fuel combustion, high cetane number diesel fuels like synthetic Fischer-Tropsch diesel fuel and hydrogenated vegetable oil, and low CN number fuels. Implementation examples were also discussed, such as fuel spray studies in optical spray bombs; combustion research in optical engines and combustion chambers; studies on reaction kinetics of combustion and emission formation; studies on fuel properties and ignition behaviour; combustion studies on research engines; combustion optimization; implementing the optimum combustion in research engines; and emission measurements. Overall milestone examples and the overall schedule of participating countries were also presented. figs.

  8. Internal combustion engine using premixed combustion of stratified charges

    Science.gov (United States)

    Marriott, Craig D [Rochester Hills, MI; Reitz, Rolf D [Madison, WI

    2003-12-30

    During a combustion cycle, a first stoichiometrically lean fuel charge is injected well prior to top dead center, preferably during the intake stroke. This first fuel charge is substantially mixed with the combustion chamber air during subsequent motion of the piston towards top dead center. A subsequent fuel charge is then injected prior to top dead center to create a stratified, locally richer mixture (but still leaner than stoichiometric) within the combustion chamber. The locally rich region within the combustion chamber has sufficient fuel density to autoignite, and its self-ignition serves to activate ignition for the lean mixture existing within the remainder of the combustion chamber. Because the mixture within the combustion chamber is overall premixed and relatively lean, NO.sub.x and soot production are significantly diminished.

  9. Combustion Stratification for Naphtha from CI Combustion to PPC

    KAUST Repository

    Vallinayagam, R.; Vedharaj, S.; An, Yanzhao; Dawood, Alaaeldin; Izadi Najafabadi, Mohammad; Somers, Bart; Johansson, Bengt

    2017-01-01

    This study demonstrates the combustion stratification from conventional compression ignition (CI) combustion to partially premixed combustion (PPC). Experiments are performed in an optical CI engine at a speed of 1200 rpm for diesel and naphtha (RON

  10. Fuel and combustion stratification study of Partially Premixed Combustion

    OpenAIRE

    Izadi Najafabadi, M.; Dam, N.; Somers, B.; Johansson, B.

    2016-01-01

    Relatively high levels of stratification is one of the main advantages of Partially Premixed Combustion (PPC) over the Homogeneous Charge Compression Ignition (HCCI) concept. Fuel stratification smoothens heat release and improves controllability of this kind of combustion. However, the lack of a clear definition of “fuel and combustion stratifications” is obvious in literature. Hence, it is difficult to compare stratification levels of different PPC strategies or other combustion concepts. T...

  11. Development of flameless combustion; Desarrollo de la combustion sin flama

    Energy Technology Data Exchange (ETDEWEB)

    Flores Sauceda, M. Leonardo; Cervantes de Gortari, Jaime Gonzalo [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)]. E-mail: 8344afc@prodigy.net.mx; jgonzalo@servidor.unam.mx

    2010-11-15

    The paper intends contribute to global warming mitigation joint effort that develops technologies to capture the CO{sub 2} produced by fossil fuels combustion and to reduce emission of other greenhouse gases like the NO{sub x}. After reviewing existing combustion bibliography is pointed out that (a) touches only partial aspects of the collective system composed by Combustion-Heat transfer process-Environment, whose interactions are our primary interest and (b) most specialists think there is not yet a clearly winning technology for CO{sub 2} capture and storage. In this paper the study of combustion is focused as integrated in the aforementioned collective system where application of flameless combustion, using oxidant preheated in heat regenerators and fluent gas recirculation into combustion chamber plus appropriated heat and mass balances, simultaneously results in energy saving and environmental impact reduction. [Spanish] El trabajo pretende contribuir al esfuerzo conjunto de mitigacion del calentamiento global que aporta tecnologias para capturar el CO{sub 2} producido por la combustion de combustibles fosiles y para disminuir la emision de otros gases invernadero como NOx. De revision bibliografica sobre combustion se concluye que (a) trata aspectos parciales del sistema compuesto por combustion-proceso de trasferencia de calor-ambiente, cuyas interacciones son nuestro principal interes (b) la mayoria de especialistas considera no hay todavia una tecnologia claramente superior a las demas para captura y almacenaje de CO{sub 2}. Se estudia la combustion como parte integrante del mencionado sistema conjunto, donde la aplicacion de combustion sin flama, empleando oxidante precalentado mediante regeneradores de calor y recirculacion de gases efluentes ademas de los balances de masa y energia adecuados, permite tener simultaneamente ahorros energeticos e impacto ambiental reducido.

  12. Measures for a quality combustion (combustion chamber exit and downstream); Mesures pour une combustion de qualite (sortie de chambre de combustion et en aval)

    Energy Technology Data Exchange (ETDEWEB)

    Epinat, G. [APAVE Lyonnaise, 69 (France)

    1996-12-31

    After a review of the different pollutants related to the various types of stationary and mobile combustion processes (stoichiometric, reducing and oxidizing combustion), measures and analyses than may be used to ensure the quality and efficiency of combustion processes are reviewed: opacimeters, UV analyzers, etc. The regulation and control equipment for combustion systems are then listed, according to the generator capacity level

  13. Los libros de texto de química destinados a estudiantes de medicina y cirugía en España (1788-1845)

    OpenAIRE

    Bertomeu Sánchez, José Ramón

    2000-01-01

    Este trabajo forma parte de en un proyecto de investigación sobre la farmacología en la sociedad española del siglo XIX, en particular, acerca del papel de las prácticas y los conocimientos químicos en la transición de la materia médica a la farmacología experimental. Dentro de ese esquema general, el objeto de este artículo es el estudio de los libros de texto destinados a los estudiantes de medicina y de cirugía durante los años finales del siglo XVIII y la primera mitad del siglo XIX. Se t...

  14. Aplicación del método de elementos naturales a problemas estructurales

    Directory of Open Access Journals (Sweden)

    Libardo Andrés González Torres

    2008-01-01

    Full Text Available El objetivo del presente artículo se enmarca en la revisión de la teoría y la implementación numérica de uno de los métodos numéricos sin malla usados para la solución de problemas de tipo estructural, el método de los elementos naturales (MEN, junto con la contrastación de los resultados obtenidos para dos problemas estructurales elástico-lineales en dos dimensiones con la solución analítica exacta y la aproximada por el método de los elementos finitos (MEF. Se describe la técnica de interpolación usada por el MEN para obtener las funciones de forma y se presen-tan las características más importantes del método en su forma estándar. Se presentan los resultados de dos simula-ciones de problemas estructurales realizadas usando un código escrito en Matlab 6.5 para la solución de ecuacio-nes diferenciales de elasticidad lineal en dominios bidimensionales. Se concluye que el método de los elementos naturales es similar al de los elementos finitos en cuanto a estabilidad y convergencia, con la ventaja de que la ma-lla es generada automáticamente y la no dependencia de la solución aproximada con la distribución de la nube de puntos que define la geometría.

  15. Combustion stratification for naphtha from CI combustion to PPC

    NARCIS (Netherlands)

    Vallinayagam, R.; Vedharaj, S.; An, Y.; Dawood, A.; Izadi Najafabadi, M.; Somers, L.M.T.; Johansson, B.H.

    2017-01-01

    This study demonstrated the change in combustion homogeneity from conventional diesel combustion via partially premixed combustion towards HCCI. Experiments are performed in an optical diesel engine at a speed of 1200 rpm with diesel fuel. Single injection strategy is employed and the fuel is

  16. Low NOx combustion technologies for high-temperature natural gas combustion

    International Nuclear Information System (INIS)

    Flamme, Michael

    1999-01-01

    Because of the high process temperature which is required for some processes like glass melting and the high temperature to which the combustion air is preheated, NOx emission are extremely high. Even at these high temperatures, NOx emissions could be reduced drastically by using advanced combustion techniques such as staged combustion or flame-less oxidation, as experimental work has shown. In the case of oxy-fuel combustion, the NOx emission are also very high if conventional burners are used. The new combustion techniques achieve similar NOx reductions. (author)

  17. Combustion instability control in the model of combustion chamber

    International Nuclear Information System (INIS)

    Akhmadullin, A N; Ahmethanov, E N; Iovleva, O V; Mitrofanov, G A

    2013-01-01

    An experimental study of the influence of external periodic perturbations on the instability of the combustion chamber in a pulsating combustion. As an external periodic disturbances were used sound waves emitted by the electrodynamics. The purpose of the study was to determine the possibility of using the method of external periodic perturbation to control the combustion instability. The study was conducted on a specially created model of the combustion chamber with a swirl burner in the frequency range from 100 to 1400 Hz. The study found that the method of external periodic perturbations may be used to control combustion instability. Depending on the frequency of the external periodic perturbation is observed as an increase and decrease in the amplitude of the oscillations in the combustion chamber. These effects are due to the mechanisms of synchronous and asynchronous action. External periodic disturbance generated in the path feeding the gaseous fuel, showing the high efficiency of the method of management in terms of energy costs. Power required to initiate periodic disturbances (50 W) is significantly smaller than the thermal capacity of the combustion chamber (100 kW)

  18. Cuentas ambientales: un plan de cuentas integrado, ¿si o no?

    OpenAIRE

    Panario Centeno, María Marta

    2011-01-01

    Se aborda el tema de las "cuentas ambientales" y el "plan de cuentas". Dicho tema es sumamente interesante, ya que las cuentas ambientales son elementos fundamentales de registro e evidencia de hechos contables, o sea, sin las cuentas nada podría ser contabilizado y expuesto contablemente; y el plan de cuentas es uno de los aspectos más importantes del sistema contable, destinado a orientar el registro de las operaciones, ofreciendo la ventaja de uniformidad de las cuentas utilizada...

  19. Informe sobre los elementos prefabricados de yeso utilizados hoy día en Francia

    Directory of Open Access Journals (Sweden)

    Courivaud, I.

    1965-03-01

    Full Text Available Not availableAunque la fabricación de losetas o placas de yeso no es una industria nueva en Francia, aproximadamente en el año 1920 cuando empiezan a aparecer en el mercado francés los primeros elementos prefabricados de yeso. Por primera vez estos elementos fabricados industrialmente tenían sus dimensiones perfectamente "calibradas y presentaban sus paramentos perfectamente lisos; no requiriendo una vez montados los tradicionales enlucidos para su acabado.

  20. Rotary combustion device

    NARCIS (Netherlands)

    2008-01-01

    Rotary combustion device (1) with rotary combustion chamber (4). Specific measures are taken to provide ignition of a combustible mixture. It is proposed that a hollow tube be provided coaxially with the axis of rotation (6), so that a small part of the mixture is guided into the combustion chamber.

  1. Combustion physics

    Science.gov (United States)

    Jones, A. R.

    1985-11-01

    Over 90% of our energy comes from combustion. By the year 2000 the figure will still be 80%, even allowing for nuclear and alternative energy sources. There are many familiar examples of combustion use, both domestic and industrial. These range from the Bunsen burner to large flares, from small combustion chambers, such as those in car engines, to industrial furnaces for steel manufacture or the generation of megawatts of electricity. There are also fires and explosions. The bountiful energy release from combustion, however, brings its problems, prominent among which are diminishing fuel resources and pollution. Combustion science is directed towards finding ways of improving efficiency and reducing pollution. One may ask, since combustion is a chemical reaction, why physics is involved: the answer is in three parts. First, chemicals cannot react unless they come together. In most flames the fuel and air are initially separate. The chemical reaction in the gas phase is very fast compared with the rate of mixing. Thus, once the fuel and air are mixed the reaction can be considered to occur instantaneously and fluid mechanics limits the rate of burning. Secondly, thermodynamics and heat transfer determine the thermal properties of the combustion products. Heat transfer also plays a role by preheating the reactants and is essential to extracting useful work. Fluid mechanics is relevant if work is to be performed directly, as in a turbine. Finally, physical methods, including electric probes, acoustics, optics, spectroscopy and pyrometry, are used to examine flames. The article is concerned mainly with how physics is used to improve the efficiency of combustion.

  2. Pedogeoquímica em perfis de alteração na região de Lavras (MG. II - elementos menores e elementos das terras raras

    Directory of Open Access Journals (Sweden)

    M. P. C. Lacerda

    2002-03-01

    Full Text Available Na região de Lavras, MG, analisou-se o comportamento geoquímico dos elementos menores (EM e elementos das terras raras (ETR ao longo da evolução pedogenética em perfis de solos com horizonteB textural, individualizados a partir de rochas de composição ácida, intermediária e básica do substrato. Nos perfis, realizaram-se análises químicas de EM e ETR, avaliando perdas e ganhos pelo balanço químico de massa. O estudo possibilitou o grupamento dos EM em duas classes: (amobilidade moderada a alta: perda da rocha fresca até o sólum; (bmobilidade moderada: enriquecimento relativo e eventualmente real no sólum. O comportamento dos ETR revelou grande mobilidade ao longo da evolução dos perfis de alteração.

  3. Elementos estruturais do pensamento crítico de enfermeiros atuantes em emergências

    OpenAIRE

    Crossetti, Maria da Graça Oliveira; Universidade Federal do Rio Grande do Sul; Bittencourt, Greicy Kelly Gouveia Dias; Universidade Federal da Paraíba/PNPD.; Lima, Ana Amelia Antunes; Universidade Federal de Ciências da Saúde de Porto Alegre UFCSPA); Goés, Martha Georgina Oliveira de; Universidade Federal do Rio Grande do Sul; Saurin, Gislaine; Universidade Federal do Rio Grande do Sul

    2014-01-01

    Objetivou-se neste estudo analisar os elementos estruturais do pensamento crítico (PC) do enfermeiro no processo de tomada de decisão clínica. Estudo exploratório, qualitativo, com 20 enfermeiros de emergências em três hospitais do sul do Brasil. A coleta de dados deu-se de abril a junho de 2009; aplicou-se um caso clínico validado, deste os enfermeiros listaram problemas de saúde, cuidados prescritos e ordenaram os elementos estruturais no PC. Na análise de conteúdo, desvelaram-se categorias...

  4. El análisis por elementos finitos: una metodología muy reciente en economía

    Directory of Open Access Journals (Sweden)

    Escribano Ródenas, Miguel

    2006-01-01

    Full Text Available La técnica de análisis por elementos finitos (AEF consiste en dividir la geometría en la que se quiere resolver una ecuación diferencial de un campo escalar o vectorial en un dominio, en pequeños elementos, teniendo en cuenta unas ecuaciones de campo en cada elemento, los elementos del entorno de vecindad y las fuentes generadoras de campo en cada elemento. Habitualmente, esta técnica es muy utilizada en el ámbito de la ingeniería debido a que muchos problemas físicos de interés se formulan mediante la resolución de una ecuación diferencial en derivadas parciales, a partir de cuya solución es posible modelar dicho problema (transmisión del calor, electromagnetismo, cálculo de estructuras, etc. Esta técnica se encuentra automatizada en las herramientas software comerciales, llamadas herramientas de análisis por elementos finitos para problemas físicos tanto de propósito general, como aplicadas a problemas físicos particulares. Sin embargo, su aplicación es aún poco conocida en economía y a veces es incluso confundida con la discretización de las ecuaciones diferenciales, técnica que es mucho más utilizada en estudios económicos. No es habitual encontrar herramientas comerciales en que se automatice esta labor para problemas económicos. Esta comunicación presenta la técnica matemática del AEF y algunas ideas para su aplicación en la resolución de problemas de tipo económico.

  5. Some Factors Affecting Combustion in an Internal-Combustion Engine

    Science.gov (United States)

    Rothrock, A M; Cohn, Mildred

    1936-01-01

    An investigation of the combustion of gasoline, safety, and diesel fuels was made in the NACA combustion apparatus under conditions of temperature that permitted ignition by spark with direct fuel injection, in spite of the compression ratio of 12.7 employed. The influence of such variables as injection advance angle, jacket temperature, engine speed, and spark position was studied. The most pronounced effect was that an increase in the injection advance angle (beyond a certain minimum value) caused a decrease in the extent and rate of combustion. In almost all cases combustion improved with increased temperature. The results show that at low air temperatures the rates of combustion vary with the volatility of the fuel, but that at high temperatures this relationship does not exist and the rates depend to a greater extent on the chemical nature of the fuel.

  6. Reduced NOX combustion method

    International Nuclear Information System (INIS)

    Delano, M.A.

    1991-01-01

    This patent describes a method for combusting fuel and oxidant to achieve reduced formation of nitrogen oxides. It comprises: It comprises: heating a combustion zone to a temperature at least equal to 1500 degrees F.; injecting into the heated combustion zone a stream of oxidant at a velocity within the range of from 200 to 1070 feet per second; injecting into the combustion zone, spaced from the oxidant stream, a fuel stream at a velocity such that the ratio of oxidant stream velocity to fuel stream velocity does not exceed 20; aspirating combustion gases into the oxidant stream and thereafter intermixing the aspirated oxidant stream and fuel stream to form a combustible mixture; combusting the combustible mixture to produce combustion gases for the aspiration; and maintaining the fuel stream substantially free from contact with oxidant prior to the intermixture with aspirated oxidant

  7. Method and device for diagnosing and controlling combustion instabilities in internal combustion engines operating in or transitioning to homogeneous charge combustion ignition mode

    Science.gov (United States)

    Wagner, Robert M [Knoxville, TN; Daw, Charles S [Knoxville, TN; Green, Johney B [Knoxville, TN; Edwards, Kevin D [Knoxville, TN

    2008-10-07

    This invention is a method of achieving stable, optimal mixtures of HCCI and SI in practical gasoline internal combustion engines comprising the steps of: characterizing the combustion process based on combustion process measurements, determining the ratio of conventional and HCCI combustion, determining the trajectory (sequence) of states for consecutive combustion processes, and determining subsequent combustion process modifications using said information to steer the engine combustion toward desired behavior.

  8. The Diesel Combustion Collaboratory: Combustion Researchers Collaborating over the Internet

    Energy Technology Data Exchange (ETDEWEB)

    C. M. Pancerella; L. A. Rahn; C. Yang

    2000-02-01

    The Diesel Combustion Collaborator (DCC) is a pilot project to develop and deploy collaborative technologies to combustion researchers distributed throughout the DOE national laboratories, academia, and industry. The result is a problem-solving environment for combustion research. Researchers collaborate over the Internet using DCC tools, which include: a distributed execution management system for running combustion models on widely distributed computers, including supercomputers; web-accessible data archiving capabilities for sharing graphical experimental or modeling data; electronic notebooks and shared workspaces for facilitating collaboration; visualization of combustion data; and video-conferencing and data-conferencing among researchers at remote sites. Security is a key aspect of the collaborative tools. In many cases, the authors have integrated these tools to allow data, including large combustion data sets, to flow seamlessly, for example, from modeling tools to data archives. In this paper the authors describe the work of a larger collaborative effort to design, implement and deploy the DCC.

  9. Control Methods Used in the Department of Metallurgy for Structure and Fuel Elements; Methodes de Controle Utilisees au Departement de Metallurgie pour les Elements de Structure et les Elements Combustibles; Metody kontrolya struktury toplivnykh ehlementov v departamente metallurgii; Metodos de Control Utilizados en el Departamento de Metalurgia para los Elementos Estructurales y Combustibles

    Energy Technology Data Exchange (ETDEWEB)

    Destribats, Marie-Therese; Allain, C.; Prot, A.; Thome, P. [Centre d' Etudes Nucleaires de Saclay (France)

    1965-09-15

    reactores indujeron a utilizar y a perfeccionar numersos metodos no destructivos destinados a inspeccionar los distintos materiales que intervienen en la construccion de esos reactores; en particular radiografia y gamma- grafia, metodos ultrasonicos y empleo de corrientes de Foucault.. A continuacion se enumeran las operaciones de control llevadas a cabo durante la construccion de reactores pertenecientes a las familias EdF (grafito-gas) y EL 4 (agua pesada), y de elementos colaminados; se hace hincapie en ciertos aspectos caracteristicos de estos metodos, algunos de los cuales son ya bien conocidos. Familia EdF: metodos ultrasonicos para medir el espesor de las paredes de tubos de uranio o aleacion de uranio ; localizacion de las cavidades en esos tubos por gammagraffa; empleo de medios ultrasonicos para control de los tratamientos termicos a que se someten los tubos; empleo de procedimientos ultrasonicos para buscar fallas (inclusiones, grietas) en las palanquillas y barras con que se elaboran las vainas de Mg-Zr; control de la estanqueidad de los elementos mediante exudacion de helio. EL4: uso de metodos ultrasonicos y corrientes de Foucault para medir espesores de pared en tubos de Zircaloy, sean de fuerza o de guia; empleo de metodos ultrasonicos para inspeccionar tubos de fuerza de Zircaloy y vainas de acero inoxidable; radiografia al vacio de vainas de Be; control de la estanqueidad de barras huecas mediante exudacion de helio. Elementos colimados: medida del espesor de vainas mediante el empleo de corrientes de Foucault pulsadas; verificacion de la posicion del alma en tubos y placas mediante radiografia, recuento gamma y aplicacion de corrientes de Foucault pulsadas; control de la homogeneidad del combustible por recuento gamma; deteccion de defectos en barras de Zr-U mediante procedimientos ultrasonicos y gammagraficos; determinacion de las zonas despegadas en placas, empleando metodos ultrasonicos, corrientes de Foucault pulsadas y medicion de resistividad. Estos

  10. Materials Control in the Fabrication of Enriched Uranium Fuels; Controle des Matieres au Cours de la Fabrication des Combustibles a Base d'Uranium Enrichi; Uchet materialov pri izgotovlenii topliva na obogashchennom urane; Control de Materiales en la Elaboracion de Combustibles de Uranio Enriquecido

    Energy Technology Data Exchange (ETDEWEB)

    Cardwell, Jr., R. G. [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1966-02-15

    cantidades de oxido - se desarrollaron y adoptaron como normas durante el diseflo y la fabricacion de los prototipos de los elementos combustibles destinados a la puesta en marcha del reactor de ensayo de materiales (MTR), del BSR de tipo piscina, del reactor movil de potencia del ejercito, del reactor de torre de blindaje, del reactor de demostracion para la Conferencia de Ginebra, del reactor de flujo elevado para la produccion de isotopos y del reactor experimental refrigerado por gas. La experiencia adquirida sirve de base a esta memoria en la que se destacan los problemas de control de materiales y su solucion durante la fabricacion de varios tipos de componentes de combustible de uranio enriquecido. Un buen sistema de control de materiales debe perseguir los objetivos basicos siguientes: a) reducir al minimo el numero de unidades de material que haya que contabilizar, b) establecer registros distintos para cada operacion importante y relacionarlos de manera que resulte facil encontrar las diferencias, c) integrar el mayor numero posible de controles en el numero minimo de registros a fin de evitar la duplicacion y d) introducir en el sistema un numero de verificaciones suficiente para garantizar su seguridad. En todos los programas de fabricacion se logro un control eficaz estableciendo un procedimiento unitario en las siguientes etapas: a) entrada de las materias primas, b) fabricacion de componentes, c) tratamiento de los componentes y d) manipulacion de la chatarra. La reunion de los registros de control en un resumen general ayudo a confirmar las existencias, a evaluar el proceso de fabricacion y a preparar los informes administrativos. El establecimiento de metodos de muestreo y el examen de los resultados pusieron de manifiesto la necesidad de un control multiple para asegurar un contenido adecuado de combustible. Cuando el contenido de combustible en aleacion revestia importancia critica se recurrio con buenos resultados al ajuste mecanico y a la medicion de la

  11. New class of combustion processes

    International Nuclear Information System (INIS)

    Merzhanov, A.G.; Borovinskaya, I.P.

    1975-01-01

    A short review is given of the results of work carried out since 1967 on studying the combustion processes caused by the interaction of chemical elements in the condensed phase and leading to the formation of refractory compounds. New phenomena and processes are described which are revealed when investigating the combustion of the systems of this class, viz solid-phase combustion, fast combustion in the condensed phase, filtering combustion, combustion in liquid nitrogen, spinning combustion, self-oscillating combustion, and repeated combustion. A new direction in employment of combustion processes is discussed, viz. a self-propagating high-temperature synthesis of refractory nitrides, carbides, borides, silicides and other compounds

  12. Experimental validation for combustion analysis of GOTHIC code in 2-dimensional combustion chamber

    International Nuclear Information System (INIS)

    Lee, J. W.; Yang, S. Y.; Park, K. C.; Jung, S. H.

    2002-01-01

    In this study, the prediction capability of GOTHIC code for hydrogen combustion phenomena was validated with the results of two-dimensional premixed hydrogen combustion experiment executed by Seoul National University. The experimental chamber has about 24 liter free volume (1x0.024x1 m 3 ) and 2-dimensional rectangular shape. The test were preformed with 10% hydrogen/air gas mixture and conducted with combination of two igniter positions (top center, top corner) and two boundary conditions (bottom full open, bottom right half open). Using the lumped parameter and mechanistic combustion model in GOTHIC code, the SNU experiments were simulated under the same conditions. The GOTHIC code prediction of the hydrogen combustion phenomena did not compare well with the experimental results. In case of lumped parameter simulation, the combustion time was predicted appropriately. But any other local information related combustion phenomena could not be obtained. In case of mechanistic combustion analysis, the physical combustion phenomena of gas mixture were not matched experimental ones. In boundary open cases, the GOTHIC predicted very long combustion time and the flame front propagation could not simulate appropriately. Though GOTHIC showed flame propagation phenomenon in adiabatic calculation, the induction time of combustion was still very long compare with experimental results. Also, it was found that the combustion model of GOTHIC code had some weak points in low concentration of hydrogen combustion simulation

  13. Una aproximación a las modalidades y elementos de las ayudas públicas anticompetitivas

    Directory of Open Access Journals (Sweden)

    Jesús Alfonso Soto Pineda

    2017-01-01

    Full Text Available La defensa de la libre competencia configura una de las herramientas más importantes en el entorno global y un elemento fundamental de la política económica, centrado en controlar las conductas capaces de restringir la competencia propiamente dicha y el acceso al mercado. Así, en entornos de gran relevancia económica, el control de ayudas públicas se ha instaurado como uno de los elementos fundamentales de esta política. Razón por la cual en el presente artículo se abordará la implementación de dicho control en entornos en los cuales aún no es una realidad. Para ello, se presentan dos criterios que determinan la legalidad o ilegalidad concurrencial de una ayuda pública, sus modalidades; y los elementos que deben converger en estos subsidios para que resulten anticompetitivos

  14. Preliminary assessment of combustion modes for internal combustion wave rotors

    Science.gov (United States)

    Nalim, M. Razi

    1995-01-01

    Combustion within the channels of a wave rotor is examined as a means of obtaining pressure gain during heat addition in a gas turbine engine. Several modes of combustion are considered and the factors that determine the applicability of three modes are evaluated in detail; premixed autoignition/detonation, premixed deflagration, and non-premixed compression ignition. The last two will require strong turbulence for completion of combustion in a reasonable time in the wave rotor. The compression/autoignition modes will require inlet temperatures in excess of 1500 R for reliable ignition with most hydrocarbon fuels; otherwise, a supplementary ignition method must be provided. Examples of combustion mode selection are presented for two core engine applications that had been previously designed with equivalent 4-port wave rotor topping cycles using external combustion.

  15. Contabilización del cuarto elemento del costo

    Directory of Open Access Journals (Sweden)

    Carlos Augusto Rincón Soto

    2008-01-01

    servicios de externalización deben ser asignados en un espacio exclusivo para ellos en la recopilación de los costos y para la contabilización, pues este no pertenece a ninguno de los tres elementos del costo* dados en los conceptos comunes en la mayoría de textos académicos de contabilidad de costos, siendo el uso de este dato importante explicitarlo en la contabilidad para análisis y toma de decisiones.

  16. Combustion modeling in internal combustion engines

    Science.gov (United States)

    Zeleznik, F. J.

    1976-01-01

    The fundamental assumptions of the Blizard and Keck combustion model for internal combustion engines are examined and a generalization of that model is derived. The most significant feature of the model is that it permits the occurrence of unburned hydrocarbons in the thermodynamic-kinetic modeling of exhaust gases. The general formulas are evaluated in two specific cases that are likely to be significant in the applications of the model.

  17. A predictive model of natural gas mixture combustion in internal combustion engines

    Directory of Open Access Journals (Sweden)

    Henry Espinoza

    2007-05-01

    Full Text Available This study shows the development of a predictive natural gas mixture combustion model for conventional com-bustion (ignition engines. The model was based on resolving two areas; one having unburned combustion mixture and another having combustion products. Energy and matter conservation equations were solved for each crankshaft turn angle for each area. Nonlinear differential equations for each phase’s energy (considering compression, combustion and expansion were solved by applying the fourth-order Runge-Kutta method. The model also enabled studying different natural gas components’ composition and evaluating combustion in the presence of dry and humid air. Validation results are shown with experimental data, demonstrating the software’s precision and accuracy in the results so produced. The results showed cylinder pressure, unburned and burned mixture temperature, burned mass fraction and combustion reaction heat for the engine being modelled using a natural gas mixture.

  18. Boiler using combustible fluid

    Science.gov (United States)

    Baumgartner, H.; Meier, J.G.

    1974-07-03

    A fluid fuel boiler is described comprising a combustion chamber, a cover on the combustion chamber having an opening for introducing a combustion-supporting gaseous fluid through said openings, means to impart rotation to the gaseous fluid about an axis of the combustion chamber, a burner for introducing a fluid fuel into the chamber mixed with the gaseous fluid for combustion thereof, the cover having a generally frustro-conical configuration diverging from the opening toward the interior of the chamber at an angle of between 15/sup 0/ and 55/sup 0/; means defining said combustion chamber having means defining a plurality of axial hot gas flow paths from a downstream portion of the combustion chamber to flow hot gases into an upstream portion of the combustion chamber, and means for diverting some of the hot gas flow along paths in a direction circumferentially of the combustion chamber, with the latter paths being immersed in the water flow path thereby to improve heat transfer and terminating in a gas outlet, the combustion chamber comprising at least one modular element, joined axially to the frustro-conical cover and coaxial therewith. The modular element comprises an inner ring and means of defining the circumferential, radial, and spiral flow paths of the hot gases.

  19. El Instituto Federal Electoral, un analisis de sus elementos democratizadores

    Directory of Open Access Journals (Sweden)

    Saenz Lopez, K.

    2004-01-01

    Full Text Available El Instituto Federal Electoral ha sido poco estudiado en lo relativo a los aspectos endógenos de su actividad, en este análisis se proponen cinco elementos que se presumen son responsables de favorecer la transición a la democracia que México ha vivido desde 1990.

  20. Welding procedures used in the fabrication of fuel elements for the DON Reactor exponential experiment; La soldadura en la fabricacion de elementos combustibles destinados a una experiencia exponencial

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Beltran, A; Jaraiz Franco, E; Rivas Diaz, M. de las

    1965-07-01

    This exponential experiment required 74 units (37 loaded with UO{sub 2} and 37 with UC) to simulate the Reactor fuel channels. Each unit was enclosed in a tube similar to the calandria ones. It contained the pressure tube, the shroud and the 19 rods cluster. Within the pressure tube, in touch with the elements, was the organic liquid. (Author)

  1. CAPTAÇÃO, RESGATES E LIQUIDEZ: IMPACTO NA RENTABILIDADE DE FUNDOS MULTIMERCADOS DESTINADOS A INVESTIDORES DE VAREJO

    Directory of Open Access Journals (Sweden)

    Flávia Vital Januzzi

    2018-03-01

    Full Text Available Com base na análise de 634 fundos multimercados brasileiros destinados a investidores de varejo no período de outubro de 2009 a dezembro de 2015, este estudo buscou avaliar o impacto do volume de captações, resgates e nível de liquidez sobre o Índice de Sharpe Ajustado trimestral desses fundos. Para viabilizar as análises empregou-se o modelo de regressão quantílica. Os resultados sinalizam que não existe relação significativa entre o nível de liquidez e o desempenho do fundo. Todavia, constatou-se que o volume de resgates afeta negativa e significativamente a performance dos fundos em determinados quantis. Os resultados obtidos vão ao encontro das evidências encontradas por Rakowski (2010 para o mercado norte-americano. No que tange à captação, evidenciou-se que com exceção dos fundos de pior desempenho, aqueles com maior captação corrente tendem a apresentar melhor desempenho atual. No entanto, a maior entrada de recursos acaba por comprometer a rentabilidade futura dos mesmos.

  2. HERCULES Advanced Combustion Concepts Test Facility: Spray/Combustion Chamber

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, K. [Eidgenoessische Technische Hochschule (ETH), Labor fuer Aerothermochemie und Verbrennungssysteme, Zuerich (Switzerland)

    2004-07-01

    This yearly report for 2004 on behalf of the Swiss Federal Office of Energy (SFOE) at the Laboratory for Aero-thermochemistry and Combustion Systems at the Federal Institute of Technology ETH in Zurich, Switzerland, presents a review of work being done within the framework of HERCULES (High Efficiency R and D on Combustion with Ultra Low Emissions for Ships) - the international R and D project concerning new technologies for ships' diesels. The work involves the use and augmentation of simulation models. These are to be validated using experimental data. The report deals with the development of an experimental set-up that will simulate combustion in large two-stroke diesel engines and allow the generation of reference data. The main element of the test apparatus is a spray / combustion chamber with extensive possibilities for optical observation under variable flow conditions. The results of first simulations confirm concepts and shall help in further work on the project. The potential offered by high-speed camera systems was tested using the institute's existing HTDZ combustion chamber. Further work to be done is reviewed.

  3. Gradual combustion - method for nitrogen oxide suppression during brown coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.P.; Verzakov, V.N.; Lobov, T.V.

    1990-10-01

    Discusses combustion of brown coal in BKZ-500-140-1 boilers and factors that influence emission of nitrogen oxides. Temperature distribution in the furnace was evaluated. Effects of burner position, burner number and burner type as well as air excess ratio on chemical reactions during brown coal combustion, formation of nitrogen oxides and their emission were comparatively evaluated. Analyses showed that by optimum arrangement of burners and selecting the optimum air excess ratio a part of nitrogen oxides formed during the initial phase of combustion was reduced to molecular nitrogen in the second phase. On the basis of evaluations the following recommendations for furnace design are made: use of straight-flow burners characterized by a reduced mixing ratio with secondary air, parallel arrangement of burners which guarantees mixing of the combustion products from the burners with stable and unstable combustion (products of incomplete coal combustion), reducing the air excess ratio to below 1.0. 5 refs.

  4. Desenvolvimento de espessante alimentar com valor nutricional agregado, destinado ao manejo da disfagia

    Directory of Open Access Journals (Sweden)

    Carlos Henrique Pagno

    2014-04-01

    Full Text Available A disfagia se caracteriza por uma disfunção no processo de deglutição, sinal prevalente de doenças degenerativas como esclerose múltipla e doença de Parkinson. Alimentos de textura modificada e bebidas espessadas são tradicionalmente utilizados no auxílio para o tratamento clínico da disfagia. Assim, este trabalho objetivou desenvolver uma formulação de espessante alimentar com valor nutricional agregado, e avaliar sua eficiência em diferentes alimentos líquidos (leite integral, sucos de maçã, uva e laranja, sob diferentes condições de tempo de preparo (10 e 120 minutos e 24 horas e temperatura ambiente (25°C e refrigerada (10°C. A formulação foi composta de concentrado proteico de soro, mix de vitaminas e minerais e goma guar como agente espessante. Os valores obtidos para a viscosidade mostraram diferença estatisticamente significativa (P<0,05 entre os tempos de espessamento, sendo que as viscosidades no tempo de 10 minutos e após 24 horas variaram, respectivamente, 58±3cP a 180±2cP na consistência de néctar; de 310±4Cp a 1084±3cP na consistência de mel e 844±14 a 2848±22cP na consistência de pudim. No entanto, a maioria das bebidas permaneceu dentro dos padrões internacionais sugeridos pela National Dysphagia Diet (NDD, para a consistência de alimentos destinados a pacientes disfágicos.

  5. Los Bienes Destinados al Uso General: Tratamiento Contable en Diferentes Administraciones Locales Europeas

    Directory of Open Access Journals (Sweden)

    María Teresa Balaguer Coll

    2001-06-01

    Full Text Available Como respuesta a la necesidad de una mayor información para la gestión, los sistemas contables públicos han sido sometidos a un proceso general de reforma, especialmente en la administración local. Estas reformas afectan, entre otros, al tratamiento contable de los activos fijos. Dada la especial naturaleza que poseen algunos de estos activos, como es el caso de los bienes destinados a uso general, este artículo tiene por objeto analizar la problemática contable que tales bienes originan, mostrando diferentes posturas académicas y las prácticas contables de las entidades locales en diferentes países europeos. En general, se aprecia una clara tendencia a la presentación de mayor información sobre el activo fijo en los estados financieros, siendo el criterio de valoración más utilizado el coste histórico. Palabras clave: bienes de uso general, contabilidad pública, entidades locales europeas. ABSTRACT In response to the need for better management information, pubic sector accounting systems have been subjected to a general reform process, especially in local government. These reforms cover, among other things, accounting for capital assets. Given the special nature of some of these assets, such as community assets, this article aims to analyse the problematic roots of accounting, examining different academic positions as well as the accounting rules and practices of local authorities in different European countries. In general, there appears to be a clear tendency to present more information on capital assets in financial statements, with historic cost being the most utilised valuation criteria.

  6. Structural analysis of fuel in a vertical drop cask system accident; Análisis estructural del combustible en un accidente de caída vertical del contenedor

    Energy Technology Data Exchange (ETDEWEB)

    Muñoz Cardador, J.; Cerracín Arranz, A.; Muñoz-Reja Ruiz, C.

    2016-07-01

    Una de las situaciones más limitantes en el análisis de integridad del combustible gastado durante el transporte, es el de los hipotéticos accidentes de caída del contenedor. El escenario que debe ser analizado en este tipo de accidentes, según especifica el título 10 de las Code Federal Regulations (10 CFR 71.73) de la NRC, es el de la caída libre del sistema combustible-contenedor desde una altura de nueve metros con el posterior impacto contra una superficie plana, rígida y horizontal en la posición más desfavorable. En concreto, en este artículo se realiza el análisis de la respuesta del combustible bajo el supuesto de caída en posición vertical del contenedor. Para este tipo de análisis, Enusa ha desarrollado y presenta en este artículo un modelo elasto-plástico de elementos finitos capaz de simular mediante un cálculo cuasiestático el comportamiento de una barra combustible irradiada durante el accidente postulado y evaluar su integridad estructural. Aproximaciones mediante un cálculo dinámico a este análisis también has sido acometidas y sus resultados podrán ser presentados en futuros artículos.

  7. Utilização do rejeito de sinter feed como agregado na produção de peças de concreto para pavimentação

    OpenAIRE

    Ayrton Vianna Costa

    2009-01-01

    O presente trabalho versa sobre os estudos e a viabilidade técnica e conveniência ecológica do aproveitamento e emprego do rejeito de sinter feed, oriundo de atividades mineradoras de ferro, como agregado na produção do concreto para a fabricação de elementos pré-fabricados destinados à pavimentação. Em virtude da restrita bibliografia a respeito do assunto, a pesquisa foi desenvolvida com base no conhecimento dos agregados tradicionais e de algumas poucas experiências práticas do uso de reje...

  8. Piso intertravado produzido com rejeito de sinter feed

    OpenAIRE

    Costa, A. V.; Gumieri, A. G.; Brandão, P. R. G.

    2014-01-01

    O presente trabalho apresenta a viabilidade técnica do aproveitamento e da conveniência ecológica do emprego do rejeito de sinter feed,oriundo de atividades mineradoras de ferro, como agregado na produção do concreto, inicialmente para a fabricação de elementos pré-fabrica dos destinados à pavimentação, com possibilidade de expansão para outras finalidades. Inicialmente, foram realizados os seguintes ensaios de caracterização dos materiais: caracterização física, química e ambiental do rejeit...

  9. Evaluación participativa: filosofía de intervención colaborativa en la Iniciativa Urban Murcia. Espíritu Santo

    OpenAIRE

    Verde Mártín, Carmen María; Martínez Gómez, Rosa

    2013-01-01

    El Ayuntamiento de Murcia está desarrollando, en el marco de la política de Cohesión de la UE, el proyecto de Iniciativa Urbana. "URBAN Espíritu Santo", destinado a la regeneración socioeconómica de una barriada desfavorecida de la periferia de la ciudad. En la zona residen unas 4000 personas -un 25% de etnia gitana-, y ha sufrido una degradación progresiva como consecuencia del bajo nivel educativo, actividad económica marginal y otras. El proyecto, adoptando la cultura como elemento innovad...

  10. Creación de un sistema de control de rotores mediante Python

    OpenAIRE

    Góngora García, Samuel

    2014-01-01

    En este proyecto final de carrera abordaremos la creación de un sistema de control de rotores destinados al seguimiento de satélites, en un principio, de órbita baja. La placa de desarrollo utilizada en este proyecto será una Raspberry Pi. Como podremos ir comprobando con la lectura de esta memoria la utilización de elementos de hardware y software libres será un pilar de este proyecto. La continua aparición de hardware para prototipado, y la gran comunidad de desarrolladore...

  11. Uncertainties in hydrogen combustion

    International Nuclear Information System (INIS)

    Stamps, D.W.; Wong, C.C.; Nelson, L.S.

    1988-01-01

    Three important areas of hydrogen combustion with uncertainties are identified: high-temperature combustion, flame acceleration and deflagration-to-detonation transition, and aerosol resuspension during hydrogen combustion. The uncertainties associated with high-temperature combustion may affect at least three different accident scenarios: the in-cavity oxidation of combustible gases produced by core-concrete interactions, the direct containment heating hydrogen problem, and the possibility of local detonations. How these uncertainties may affect the sequence of various accident scenarios is discussed and recommendations are made to reduce these uncertainties. 40 references

  12. The combustion behavior of diesel/CNG mixtures in a constant volume combustion chamber

    Science.gov (United States)

    Firmansyah; Aziz, A. R. A.; Heikal, M. R.

    2015-12-01

    The stringent emissions and needs to increase fuel efficiency makes controlled auto-ignition (CAI) based combustion an attractive alternative for the new combustion system. However, the combustion control is the main obstacles in its development. Reactivity controlled compression ignition (RCCI) that employs two fuels with significantly different in reactivity proven to be able to control the combustion. The RCCI concept applied in a constant volume chamber fuelled with direct injected diesel and compressed natural gas (CNG) was tested. The mixture composition is varied from 0 - 100% diesel/CNG at lambda 1 with main data collection are pressure profile and combustion images. The results show that diesel-CNG mixture significantly shows better combustion compared to diesel only. It is found that CNG is delaying the diesel combustion and at the same time assisting in diesel distribution inside the chamber. This combination creates a multipoint ignition of diesel throughout the chamber that generate very fast heat release rate and higher maximum pressure. Furthermore, lighter yellow color of the flame indicates lower soot production in compared with diesel combustion.

  13. Combustion characteristics and air pollutant formation during oxy-fuel co-combustion of microalgae and lignite.

    Science.gov (United States)

    Gao, Yuan; Tahmasebi, Arash; Dou, Jinxiao; Yu, Jianglong

    2016-05-01

    Oxy-fuel combustion of solid fuels is seen as one of the key technologies for carbon capture to reduce greenhouse gas emissions. The combustion characteristics of lignite coal, Chlorella vulgaris microalgae, and their blends under O2/N2 and O2/CO2 conditions were studied using a Thermogravimetric Analyzer-Mass Spectroscopy (TG-MS). During co-combustion of blends, three distinct peaks were observed and were attributed to C. vulgaris volatiles combustion, combustion of lignite, and combustion of microalgae char. Activation energy during combustion was calculated using iso-conventional method. Increasing the microalgae content in the blend resulted in an increase in activation energy for the blends combustion. The emissions of S- and N-species during blend fuel combustion were also investigated. The addition of microalgae to lignite during air combustion resulted in lower CO2, CO, and NO2 yields but enhanced NO, COS, and SO2 formation. During oxy-fuel co-combustion, the addition of microalgae to lignite enhanced the formation of gaseous species. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. A Survey of the Fuel Cycles Operated in the United Kingdom; Etude d'ensemble sur les cycles de combustible au Royaume-Uni; Obzor toplivnykh tsiklov, ispol'zuemykh v soedinennom korolevstve; Estudio de los ciclos de combustible utilizados en el Reino Unido

    Energy Technology Data Exchange (ETDEWEB)

    Allday, C. [United Kingdom Atomic Energy Authority, Risley, Warrington, Lancs (United Kingdom)

    1963-10-15

    'un combustible au plutonium et ses incidences sur le prix de revient et le cycle du combustible. Enfin, il precise la place qu'occupent les reacteurs a l'uranium naturel gaine de magnox et les reacteurs AGR dans le programme britannique d'energie d'origine nucleaire. (author) [Spanish] a) El ciclo uranio natural/Magnox. En el Reino Unido se ha adoptado el reactor de uranio natural moderado con grafito y refrigerado con gas como base del respectivo programa de energia nucleoelectrica. Se explotan desde hace siete afios los reactores de Calder Hall y Chapelcross; ahora han comenzado a funcionar los reactores de Berkeley y Bradwell, de la Central Electricity Generating Board, y hay reactores en construccion o en proyecto en otros siete emplazamientos. El combustible destinado a esos reactores se prepara y elabora en el establecimiento de Springfields de la Atomic Energy Authority y de alli se transporta al reactor para efectuar la carga. Una vez irradiado y descargado, el combustible se lleva al establecimiento de la AEA en Windscale, para separar el uranio y el plutonio de los productos de fision. El autor resena la experiencia en el Reino Unido en materia de calculo y elaboracion de elementos combustibles, explotacion de reactores, transporte de combustible irradiado y regeneracion del mismo. Alude al comportamiento del combustible en un reactor y a los programas de carga y descarga alternada, tema que se desarrolla mas' extensamente en otra memoria. b) Reactores de combustible enriquecido. En el Reino Unido se viene probando un reactor avanzado refrigerado con gas, cuyo prototipo comenzo a desarrollar potencia en 1963. El combustible se elabora con oxido de uranio enriquecido revestido de acero inoxidable y sera regenerado en una seccion especial que se agregara al establecimiento de separacion de combustible Magnox en Windscale. El uranio enriquecido para el reactor avanzado (AGR) se produce en la planta de difusion gaseosa en Capenhurst. En lugar del oxido de uranio

  15. económica. Algunos elementos de análisis para precisar los conceptos

    Directory of Open Access Journals (Sweden)

    Luis Antonio Cruz Soto

    2002-01-01

    Full Text Available El presente artículo responde a una serie de inquietudes del autor con respecto al carácter conceptual del neoliberalismo y su relación con la globalización económica. Para ello se ofrecen algunos elementos de estudio para distinguir el significado de la democracia liberal y el liberalismo económico. Posteriormente, se exponen los principales principios del liberalismo económico clásico y una breve semblanza histórica de éste, así como una enunciación de los elementos que originaron el surgimiento del neoliberalismo económico. Finalmente, se define el carácter global del neoliberalismo en el contexto de la globalización económica

  16. ANÁLISE PARAMÉTRICA DO COMPORTAMENTO DE ELEMENTOS DE MEMBRANA APLICADA A ESTRUTURAS DE CONCRETO ARMADO VIA CONFIABILIDADE ESTRUTURAL

    OpenAIRE

    G. O. Porto, Naiara; C. Pantoja, João; A. de Souza, Rafael

    2017-01-01

     Abstract. A importância do conhecimento do nível de segurança de uma estrutura é crucial para a realização de um bom projeto estrutural. Este artigo tem como objetivo fazer uma análise paramétrica em elementos de membrana de estruturas de concreto armado via confiabilidade estrutural. Para obtenção do nível de segurança do elemento de membrana o método de simulação de Monte Carlo foi utilizado. Uma variação determinística nos carregamentos aplicados sobre o elemento de membrana é feita e a c...

  17. Fuel and combustion stratification study of Partially Premixed Combustion

    NARCIS (Netherlands)

    Izadi Najafabadi, M.; Dam, N.; Somers, B.; Johansson, B.

    2016-01-01

    Relatively high levels of stratification is one of the main advantages of Partially Premixed Combustion (PPC) over the Homogeneous Charge Compression Ignition (HCCI) concept. Fuel stratification smoothens heat release and improves controllability of this kind of combustion. However, the lack of a

  18. Maximal combustion temperature estimation

    International Nuclear Information System (INIS)

    Golodova, E; Shchepakina, E

    2006-01-01

    This work is concerned with the phenomenon of delayed loss of stability and the estimation of the maximal temperature of safe combustion. Using the qualitative theory of singular perturbations and canard techniques we determine the maximal temperature on the trajectories located in the transition region between the slow combustion regime and the explosive one. This approach is used to estimate the maximal temperature of safe combustion in multi-phase combustion models

  19. Effect of Variant End of Injection Period on Combustion Process of Biodiesel Combustion

    Directory of Open Access Journals (Sweden)

    Khalid Amir

    2016-01-01

    Full Text Available Biodiesel is an alternative fuel as a replacement to the standard diesel fuel in combustion diesel engine. The biodiesel fuel has a significantly influences throughout the combustion process and exhaust emission. The purpose of this research is to investigate the combustion process behavior during the End of Injection (EOI period and operates under variant conditions using Rapid Compression Machine (RCM. Experimental of RCM is used to simulate a combustion process and combustion characteristics of diesel engine combustion. Three types of biodiesel blend which are B5, B10 and B15 were tested at several injection pressures of 80 MPa, 90 MPa and 130 MPa under different ambient temperatures, 750 K to 1100 K. The results of this study showed that the ignition delay slightly reduced with increasing the content of biodiesel blends from B5, B10 and B15 and became more shorten as the injection pressure been enhanced. As the injection pressure increased, the behavior of combustion pressure at end of injection is reduced, radically increased the NOX emission. It is noted that the process of combustion at the end of injection increased as the ambient temperature is rising. In fact, higher initial ambient temperature improved the fuel atomization and mixing process. Under the biodiesel combustion with higher ambient temperature condition, the exhaust emission of CO, O2, and HC became less but increased in NOX emission. Besides, increased in blends of biodiesel ratio are found to enhance the combustion process, resulted a decreased in HC emissions.

  20. Jet plume injection and combustion system for internal combustion engines

    Science.gov (United States)

    Oppenheim, Antoni K.; Maxson, James A.; Hensinger, David M.

    1993-01-01

    An improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been found to yield a higher maximum combustion pressure in the cylinder, as well as shortening the time period to attain such a maximum pressure.

  1. Path planning during combustion mode switch

    Science.gov (United States)

    Jiang, Li; Ravi, Nikhil

    2015-12-29

    Systems and methods are provided for transitioning between a first combustion mode and a second combustion mode in an internal combustion engine. A current operating point of the engine is identified and a target operating point for the internal combustion engine in the second combustion mode is also determined. A predefined optimized transition operating point is selected from memory. While operating in the first combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion engine to approach the selected optimized transition operating point. When the engine is operating at the selected optimized transition operating point, the combustion mode is switched from the first combustion mode to the second combustion mode. While operating in the second combustion mode, one or more engine actuator settings are adjusted to cause the operating point of the internal combustion to approach the target operating point.

  2. Combustion, detonation, shock waves. Proceedings of the Zel'dovich memorial - International conference on combustion. Volume 1

    International Nuclear Information System (INIS)

    Merzhanov, A.G.; Frolov, S.M.

    1995-01-01

    This book contains lectures by the experts in various fields of modern research in combustion, detonation and shock waves, presented at the Zel'dovich memorial - International conference on combustion dedicated to the 80-th birthday of academician Ya.B. Zel'dovich. There are eight chapters discussing the state-of-the-art in combustion kinetics, ignition and steady-state flame propagation, diffusion and heterogeneous combustion, turbulent combustion, unsteady combustion, detonation, combustion and detonation analogies, intense shock waves and extreme states of matter [ru

  3. Fuels and Combustion

    KAUST Repository

    Johansson, Bengt

    2016-08-17

    This chapter discusses the combustion processes and the link to the fuel properties that are suitable for them. It describes the basic three concepts, including spark ignition (SI) and compression ignition (CI), and homogeneous charge compression ignition (HCCI). The fuel used in a CI engine is vastly different from that in an SI engine. In an SI engine, the fuel should sustain high pressure and temperature without autoignition. Apart from the dominating SI and CI engines, it is also possible to operate with a type of combustion: autoignition. With HCCI, the fuel and air are fully premixed before combustion as in the SI engine, but combustion is started by the increased pressure and temperature during the compression stroke. Apart from the three combustion processes, there are also a few combined or intermediate concepts, such as Spark-Assisted Compression Ignition (SACI). Those concepts are discussed in terms of the requirements of fuel properties.

  4. Fuels and Combustion

    KAUST Repository

    Johansson, Bengt

    2016-01-01

    This chapter discusses the combustion processes and the link to the fuel properties that are suitable for them. It describes the basic three concepts, including spark ignition (SI) and compression ignition (CI), and homogeneous charge compression ignition (HCCI). The fuel used in a CI engine is vastly different from that in an SI engine. In an SI engine, the fuel should sustain high pressure and temperature without autoignition. Apart from the dominating SI and CI engines, it is also possible to operate with a type of combustion: autoignition. With HCCI, the fuel and air are fully premixed before combustion as in the SI engine, but combustion is started by the increased pressure and temperature during the compression stroke. Apart from the three combustion processes, there are also a few combined or intermediate concepts, such as Spark-Assisted Compression Ignition (SACI). Those concepts are discussed in terms of the requirements of fuel properties.

  5. Lump wood combustion process

    Science.gov (United States)

    Kubesa, Petr; Horák, Jiří; Branc, Michal; Krpec, Kamil; Hopan, František; Koloničný, Jan; Ochodek, Tadeáš; Drastichová, Vendula; Martiník, Lubomír; Malcho, Milan

    2014-08-01

    The article deals with the combustion process for lump wood in low-power fireplaces (units to dozens of kW). Such a combustion process is cyclical in its nature, and what combustion facility users are most interested in is the frequency, at which fuel needs to be stoked to the fireplace. The paper defines the basic terms such as burnout curve and burning rate curve, which are closely related to the stocking frequency. The fuel burning rate is directly dependent on the immediate thermal power of the fireplace. This is also related to the temperature achieved in the fireplace, magnitude of flue gas losses and the ability to generate conditions favouring the full burnout of the fuel's combustible component, which, at once ensures the minimum production of combustible pollutants. Another part of the paper describes experiments conducted in traditional fireplaces with a grate, at which well-dried lump wood was combusted.

  6. Combustion Research Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Combustion Research Laboratory facilitates the development of new combustion systems or improves the operation of existing systems to meet the Army's mission for...

  7. Combustion chemistry and formation of pollutants; Chimie de la combustion et formation des polluants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    This book of proceedings reports on 7 papers on combustion chemistry and formation of pollutants presented during the workshop organized by the `Combustion and Flames` section of the French society of thermal engineers. The chemistry of combustion is analyzed in various situations such as: turbojet engines, spark ignition engines, industrial burners, gas turbines etc... Numerical simulation is used to understand the physico-chemical processes involved in combustion, to describe the kinetics of oxidation, combustion and flame propagation, and to predict the formation of pollutants. (J.S.)

  8. Heavy metals behaviour during mono-combustion and co-combustion of sewage sludge

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, M. Helena; Abelha, Pedro; Olieveira, J.F. Santos; Gulyurtlu, Ibrahim; Cabrita, Isabel [INETI-DEECA, Lisboa (Portugal)

    2005-03-01

    This paper presents the study of the combustion of granular dry sewage sludge performed on a pilot fluidized bed system. The results of mono-combustion of sludge and co-combustion with coal were compared with those of coal combustion for ash partitioning, the formation of gaseous pollutants and heavy metals behaviour. It was found that the mineral matter of sludge was essentially retained as bottom ashes. The production of fines ashes was small during the mono-combustion due to the tendency of coal to produce fine ashes which also contained unburned char. The degree of heavy metal volatilization was found to be slightly higher during co-combustion than in mono-combustion; however, most of them were retained in ashes and their emissions were found to be below the regulated levels. Hg was completely volatilized; however, during combustion trials involving coal it was captured by cyclone ashes at temperatures below 300 deg C. During sludge mono-combustion the retention of Hg in cyclone ashes containing low LOI was not enough to decrease emissions below the regulated levels; hence, it is necessary to install dedicated flue gas treatment for Hg removal. The leachability and ecotoxicity of sludge and ashes was compared with the new regulatory limits for landfill disposal in the EU. It was found that the release of organic matter and heavy metals found in the sludge was low from granular bed ashes; hence, except for sulphate release, bed ashes were converted into inert and non-ecotoxic materials. Ashes from test with limestone and cyclone ashes seemed to be more problematic because of pH effects and contamination with steel corrosion products. The recovery and reutilization of sludge bed ashes could, therefore, be possible, as long as the release of sulphate do not interfere with the process.

  9. Twenty-fifth symposium (international) on combustion

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    Approximately two-thirds of the papers presented at this conference are contained in this volume. The other one-third appear in special issues of ''Combustion and Flame'', Vol. 99, 1994 and Vol. 100, 1995. Papers are divided into the following sections: Supersonic combustion; Detonations and explosions; Internal combustion engines; Practical aspects of combustion; Incineration and wastes; Sprays and droplet combustion; Coal and organic solids combustion; Soot and polycyclic aromatic hydrocarbons; Reaction kinetics; NO x ; Turbulent flames; Turbulent combustion; Laminar flames; Flame spread, fire and halogenated fire suppressants; Global environmental effects; Ignition; Two-phase combustion; Solid propellant combustion; Materials synthesis; Microgravity; and Experimental diagnostics. Papers have been processed separately for inclusion on the data base

  10. LES and RANS modeling of pulverized coal combustion in swirl burner for air and oxy-combustion technologies

    International Nuclear Information System (INIS)

    Warzecha, Piotr; Boguslawski, Andrzej

    2014-01-01

    Combustion of pulverized coal in oxy-combustion technology is one of the effective ways to reduce the emission of greenhouse gases into the atmosphere. The process of transition from conventional combustion in air to the oxy-combustion technology, however, requires a thorough investigations of the phenomena occurring during the combustion process, that can be greatly supported by numerical modeling. The paper presents the results of numerical simulations of pulverized coal combustion process in swirl burner using RANS (Reynolds-averaged Navier–Stokes equations) and LES (large Eddy simulation) methods for turbulent flow. Numerical simulations have been performed for the oxyfuel test facility located at the Institute of Heat and Mass Transfer at RWTH Aachen University. Detailed analysis of the flow field inside the combustion chamber for cold flow and for the flow with combustion using different numerical methods for turbulent flows have been done. Comparison of the air and oxy-coal combustion process for pulverized coal shows significant differences in temperature, especially close to the burner exit. Additionally the influence of the combustion model on the results has been shown for oxy-combustion test case. - Highlights: • Oxy-coal combustion has been modeled for test facility operating at low oxygen ratio. • Coal combustion process has been modeled with simplified combustion models. • Comparison of oxy and air combustion process of pulverized coal has been done. • RANS (Reynolds-averaged Navier–Stokes equations) and LES (large Eddy simulation) results for pulverized coal combustion process have been compared

  11. EVALUACIÓN DE LOS COSTOS DE VEHÍCULOS DE PROPULSIÓN ELÉCTRICA Y A GASOLINA

    OpenAIRE

    Gomez, Juan Pablo; Almeida, Ivo; da Silva, Roberto Bernardo; de Arruda, Fabiana S.; Brasil, Augusto C.de M.

    2016-01-01

    [ES] El inminente agotamiento de las fuentes de energía primaria, principalmente por la dependencia energética del petróleo trae como resultado la inversión en nuevos modelos de energía para la movilidad destinados a mejorar la calidad de vida de la población, buscando nuevas formas de reducir el uso de combustibles fósiles como fuente de energía. El sistema de transporte ha sufrido muchas críticas por ser responsable del consumo de gran parte de estos combustibles, por lo cual, desde hace al...

  12. Trace elements in the Prestige fuel-oil spill: Levels and influence on Laxe Ria sediments (NW Iberian Peninsula); Elementos traza en el combustible vertido por el Prestige: Niveles e impacto sobre el sedimento de la Ria de Laxe (noroeste de Espana)

    Energy Technology Data Exchange (ETDEWEB)

    Prego, R; Cobelo-Garcia, A; Santos-Echeandia, J [Instituto de Investigaciones Marinas CSIC, Vigo, (Spain); Marmolejo-Rodriguez, J [Centro Interdisciplinario de Ciencias Marinas-Instituto Politecnico Nacional, La Paz, (Mexico)

    2006-03-15

    Trace elements have been determined in sediments from the Laxe Ria (NW Iberian Peninsula) one year before and one year after the Prestige fuel-oil spill (November 2002; 42 degrees 11 minutes North, 12 degrees 02 minutes West). The elements analyzed (Cd, Cu, Mo, Ni, Se and V) were chosen because they appeared to represent a potential contaminant from the deposited oil in the sediments. Enrichment factors, based on Al-normalized background concentrations, did not indicate metal contamination in the sediments from most of the ria; however, a severe contamination by Cu, Mo, Ni and V was found in the area of Corme Inlet, where the fuel oil could have accumulated as a result of the ria's hydrodynamic pattern. [Spanish] Se cuantifico la concentracion de 19 elementos quimicos en el combustible pesado derramado al mar desde los tanques del petrolero Prestige (noviembre de 2002; 42 grados 11 minutos Norte, 12 grados 02 minutos Este). Entre ellos, se investigo la presencia de Cd, Cu, Mo, Ni, Se y V en el sedimento superficial de la Ria de Laxe (NO de Espana) en los anos anterior y posterior al vertido debido a que sus niveles son similares tanto en el fuel como en el sedimento. Los factores de enriquecimiento, obtenidos tras normalizacion de las concentraciones con el aluminio, no indican contaminacion del sedimento en la ria. No obstante, se detecto una severa contaminacion por Cu, Mo, Ni y V en la ensenada de Corme donde el vertido podria haberse acumulado como resultado de la hidrodinamica de la propia ria.

  13. High Frequency Combustion Instabilities of LOx/CH4 Spray Flames in Rocket Engine Combustion Chambers

    NARCIS (Netherlands)

    Sliphorst, M.

    2011-01-01

    Ever since the early stages of space transportation in the 1940’s, and the related liquid propellant rocket engine development, combustion instability has been a major issue. High frequency combustion instability (HFCI) is the interaction between combustion and the acoustic field in the combustion

  14. Decrease of noxious emissions in the residual fuel oil combustion; Disminucion de emisiones nocivas en la combustion de aceite combustible residual

    Energy Technology Data Exchange (ETDEWEB)

    Mandoki W, Jorge [Econergia S. de R. L. de C. V. Mexico, D. F. (Mexico)

    1994-12-31

    The residual fuel oil combustion emits noxious substances such as carbonaceous particulate, nitrogen oxides, and sulfur trioxide at unacceptable levels. Water emulsified in the fuel substantially reduces such emissions, achieving besides, in most of the cases, a net saving in the fuel consumption. The beneficial effects are shown in burning the residual fuel oil as a water emulsion, as well as the method to produce an adequate emulsion. The emulsified fuel technology offers a low cost option to reduce air pollution. The fuel oil quality has been declining during the last decades due to: 1. Increase in the production of crude heavy oils, generally with higher content of asphaltens and sulfur. 2. Less availability of vacuum distillation residues due to its conversion into greater value products. 3. More intensive conversion processes such as catalytic cracking, visbreaking, etc. that increase the asphaltenes concentration in the bottoms, causing instability problems. 4. The increase in the vanadium and other metals content as the concentration of asphaltenes increases. The use of emulsified fuel oil provides an efficient and economical method to substantially reduce the noxious emissions to the atmosphere. The emulsion contains water particles in a diameter between 2 and 20 microns, uniformly distributed in the fuel oil, generally in a proportion generally of 5 to 10%; besides, it contains a tensioactive agent to assure a stable emulsion capable of withstanding the shearing forces of the pumping and distribution systems. When the atomized oil drops get into the combustion chamber, the emulsified water flashes into high pressure steam, originating a violent secondary atomization. The effect of this secondary atomization is the rupture of the oil drops of various hundred microns, producing drops of 5 to 15 microns in diameter. Since the necessary time for combustion is an exponential function of the drop diameter, a very substantial improvement in the combustion is

  15. Combustion Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — For more than 30 years The Combustion Research Facility (CRF) has served as a national and international leader in combustion science and technology. The need for a...

  16. Method and apparatus for active control of combustion rate through modulation of heat transfer from the combustion chamber wall

    Science.gov (United States)

    Roberts, Jr., Charles E.; Chadwell, Christopher J.

    2004-09-21

    The flame propagation rate resulting from a combustion event in the combustion chamber of an internal combustion engine is controlled by modulation of the heat transfer from the combustion flame to the combustion chamber walls. In one embodiment, heat transfer from the combustion flame to the combustion chamber walls is mechanically modulated by a movable member that is inserted into, or withdrawn from, the combustion chamber thereby changing the shape of the combustion chamber and the combustion chamber wall surface area. In another embodiment, heat transfer from the combustion flame to the combustion chamber walls is modulated by cooling the surface of a portion of the combustion chamber wall that is in close proximity to the area of the combustion chamber where flame speed control is desired.

  17. Fuel Combustion Laboratory | Transportation Research | NREL

    Science.gov (United States)

    Fuel Combustion Laboratory Fuel Combustion Laboratory NREL's Fuel Combustion Laboratory focuses on designs, using both today's technology and future advanced combustion concepts. This lab supports the combustion chamber platform for fuel ignition kinetics research, was acquired to expand the lab's

  18. Sandia Combustion Research: Technical review

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-07-01

    This report contains reports from research programs conducted at the Sandia Combustion Research Facility. Research is presented under the following topics: laser based diagnostics; combustion chemistry; reacting flow; combustion in engines and commercial burners; coal combustion; and industrial processing. Individual projects were processed separately for entry onto the DOE databases.

  19. Modelo no lineal en elementos finitos para muros livianos con entramados de acero sujetos a carga lateral

    Directory of Open Access Journals (Sweden)

    Carlos Andrés Gaviria M.

    2013-01-01

    Full Text Available En este artículo se presentan los resultados de una investigación que tuvo como propósito modelar con elementos finitos el comportamiento a cargas laterales de los muros livianos compuestos de un entramado típico de acero para diferentes materiales de revestimiento. Se inició con la recopilación de información de ensayos de caracterización en los elementos del muro y las conexiones entre estos, a partir de esta información y la investigación realizada por [1] se construyó un modelo de elementos finitos que considera el comportamiento no lineal de las conexiones entre los elementos. Este modelo fue ajustado con la información de los ensayos ante carga lateral realizados en probetas a escala real para cinco configuraciones de revestimiento. En este proceso se encontraron grandes diferencias entre los parámetros del modelo ajustado y los iniciales que son atribuidas a la interacción entre los componentes del muro liviano. La validación del modelo se realizó prediciendo los resultados experimentales de una nueva configuración en la cual se combinan varios materiales, obteniendo un error del 6.9%. Este resultado indica una buena capacidad de predicción del modelo para otras posibles configuraciones de revestimiento.

  20. Elementos da representação social da AIDS agrupados em dimensões: uma técnica estrutural

    OpenAIRE

    Natividade,Jean Carlos; Camargo,Brígido Vizeu

    2012-01-01

    Este estudo demonstra a possibilidade de caracterização da estrutura da representação social da Aids através do grau de valorização simbólica de elementos. Essa técnica fornece dados intervalares sobre a importância atribuída aos elementos da representação social e possibilita o cálculo de correlações entre eles.

  1. COMBUSTION SIMULATION IN A SPARK IGNITION ENGINE CYLINDER: EFFECTS OF AIR-FUEL RATIO ON THE COMBUSTION DURATION

    Directory of Open Access Journals (Sweden)

    Nureddin Dinler

    2010-01-01

    Full Text Available Combustion is an important subject of internal combustion engine studies. To reduce the air pollution from internal combustion engines and to increase the engine performance, it is required to increase combustion efficiency. In this study, effects of air/fuel ratio were investigated numerically. An axisymmetrical internal combustion engine was modeled in order to simulate in-cylinder engine flow and combustion. Two dimensional transient continuity, momentum, turbulence, energy, and combustion equations were solved. The k-e turbulence model was employed. The fuel mass fraction transport equation was used for modeling of the combustion. For this purpose a computational fluid dynamics code was developed by using the finite volume method with FORTRAN programming code. The moving mesh was utilized to simulate the piston motion. The developed code simulates four strokes of engine continuously. In the case of laminar flow combustion, Arrhenius type combustion equations were employed. In the case of turbulent flow combustion, eddy break-up model was employed. Results were given for rich, stoichiometric, and lean mixtures in contour graphs. Contour graphs showed that lean mixture (l = 1.1 has longer combustion duration.

  2. The Evaluation of Solid Wastes Reduction with Combustion System in the Combustion Chamber

    International Nuclear Information System (INIS)

    Prayitno; Sukosrono

    2007-01-01

    The evaluation of solid wastes reduction with combustion system is used for weight reduction factor. The evaluation was done design system of combustion chamber furnace and the experiment was done by burning a certain weight of paper, cloth, plastic and rubber in the combustion chamber. The evaluation of paper wastes, the ratio of wastes (paper, cloth, plastic and rubber) against the factor of weight reduction (%) were investigated. The condition was dimension of combustion chamber furnace = 0.6 X 0.9 X 1.20 X 1 m with combustion chamber and gas chamber and reached at the wastes = 2.500 gram, oxygen pressure 0.5 Bar, wastes ratio : paper : cloth : plastic : rubber = 55 : 10 : 30 : 5, the reduction factor = 6.36 %. (author)

  3. Biofuels combustion.

    Science.gov (United States)

    Westbrook, Charles K

    2013-01-01

    This review describes major features of current research in renewable fuels derived from plants and from fatty acids. Recent and ongoing fundamental studies of biofuel molecular structure, oxidation reactions, and biofuel chemical properties are reviewed, in addition to combustion applications of biofuels in the major types of engines in which biofuels are used. Biofuels and their combustion are compared with combustion features of conventional petroleum-based fuels. Two main classes of biofuels are described, those consisting of small, primarily alcohol, fuels (particularly ethanol, n-butanol, and iso-pentanol) that are used primarily to replace or supplement gasoline and those derived from fatty acids and used primarily to replace or supplement conventional diesel fuels. Research efforts on so-called second- and third-generation biofuels are discussed briefly.

  4. Low emission internal combustion engine

    Science.gov (United States)

    Karaba, Albert M.

    1979-01-01

    A low emission, internal combustion compression ignition engine having a cylinder, a piston movable in the cylinder and a pre-combustion chamber communicating with the cylinder near the top thereof and in which low emissions of NO.sub.x are achieved by constructing the pre-combustion chamber to have a volume of between 70% and 85% of the combined pre-chamber and main combustion chamber volume when the piston is at top dead center and by variably controlling the initiation of fuel injection into the pre-combustion chamber.

  5. Alcohol combustion chemistry

    KAUST Repository

    Sarathy, Mani; Oß wald, Patrick; Hansen, Nils; Kohse-Hö inghaus, Katharina

    2014-01-01

    . While biofuel production and its use (especially ethanol and biodiesel) in internal combustion engines have been the focus of several recent reviews, a dedicated overview and summary of research on alcohol combustion chemistry is still lacking. Besides

  6. Modelado del Ensayo ILTS mediante Modelos de Elementos Finitos

    OpenAIRE

    Rus Gelo, Leyre

    2015-01-01

    La finalidad de este proyecto consiste en modelar el comportamiento que presenta una viga de material compuesto en L , sometida a flexión en cuatro puntos , siguiendo la normativa AITM1 - 0069 creada por Airbus. Con el objetivo de poderlo comparar con los ensayos experimentales y con otros modelos numéricos y analíticos. Para ello se realizan diferentes ensayos virtuales haciendo uso de la herramienta Patran - Nastran, empleando el Método de los Elementos Finitos. A partir de de los datos pr ...

  7. Diesel oil combustion in fluidized bed; Combustion de aceite diesel en lecho fluidizado

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Cazares, Mario [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1992-07-01

    The effect of the fluidized bed depth in the combustion in burning diesel oil in a fluidized bed, was analyzed. A self sustained combustion was achieved injecting the oil with an injector that utilized a principle similar to an automobile carburetor venturi. Three different depths were studied and it was found that the deeper the bed, the greater the combustion efficiency. Combustion efficiencies were attained from 82% for a 100mm bed depth, up to 96% for a 200mm bed depth. The diminution in the efficiency was mainly attributed to unburned hydrocarbons and to the carbon carried over, which was observed in the black smoke at the stack outlet. Other phenomena registered were the temperature gradient between the lower part of the bed and the upper part, caused by the fluidization velocity; additionally it was observed that the air employed for the oil injection (carbureting air) is the most important parameter to attain a complete combustion. [Espanol] Se analizo el efecto de la profundidad del lecho en la combustion al quemar aceite diesel en un lecho fluidizado experimental. Se logro combustion autosostenida inyectando el aceite con un inyector que utilizo un principio similar al venturi del carburador de automovil. Se estudiaron tres diferentes profundidades del lecho y se encontro que a mayor profundidad del lecho, mayor eficiencia de la combustion. Se lograron eficiencias de la combustion desde 82% para el lecho de 100 mm de profundidad hasta 96% para el de 200 mm. La disminucion de la eficiencia se atribuyo, principalmente, a los hidrocarburos no quemados y al carbon arrastrado, lo cual se observo en el humo negro a la salida de la chimenea. Otros fenomenos registrados fueron el gradiente de temperatura entre la parte baja del lecho y la parte superior causado por la velocidad de fluidizacion; ademas, se observo que el aire utilizado para inyectar el aceite (aire de carburacion) es el parametro mas importante para lograr una combustion completa.

  8. Transient flow combustion

    Science.gov (United States)

    Tacina, R. R.

    1984-01-01

    Non-steady combustion problems can result from engine sources such as accelerations, decelerations, nozzle adjustments, augmentor ignition, and air perturbations into and out of the compressor. Also non-steady combustion can be generated internally from combustion instability or self-induced oscillations. A premixed-prevaporized combustor would be particularly sensitive to flow transients because of its susceptability to flashback-autoignition and blowout. An experimental program, the Transient Flow Combustion Study is in progress to study the effects of air and fuel flow transients on a premixed-prevaporized combustor. Preliminary tests performed at an inlet air temperature of 600 K, a reference velocity of 30 m/s, and a pressure of 700 kPa. The airflow was reduced to 1/3 of its original value in a 40 ms ramp before flashback occurred. Ramping the airflow up has shown that blowout is more sensitive than flashback to flow transients. Blowout occurred with a 25 percent increase in airflow (at a constant fuel-air ratio) in a 20 ms ramp. Combustion resonance was found at some conditions and may be important in determining the effects of flow transients.

  9. Shale oil combustion

    International Nuclear Information System (INIS)

    Al-dabbas, M.A.

    1992-05-01

    A 'coutant' carbon steel combustion chamber cooled by water jacket was conslructed to burn diesel fuel and mixlure of shale oil and diesel fuels. During experimental work nir fuel ratio was determined, temperaturces were measured using Chromel/ Almel thermocouple, finally the gasous combustion product analysis was carricd out using gas chromatograph technique. The constructed combustion chamber was operating salisfactory for several hours of continous work. According to the measurements it was found that: the flame temperature of a mixture of diesel and shale oil fuels was greater than the flame temperature of diesel fuel. and the sulfer emissious of a mixture of diesel and shale oil fuels was higher than that of diesel fuel. Calculation indicated that the dry gas energy loss was very high and the incomplete combustion energy loss very small. (author). 23 refs., 35 figs

  10. Shale oil combustion

    Energy Technology Data Exchange (ETDEWEB)

    Al-dabbas, M A

    1992-05-01

    A `coutant` carbon steel combustion chamber cooled by water jacket was conslructed to burn diesel fuel and mixlure of shale oil and diesel fuels. During experimental work nir fuel ratio was determined, temperaturces were measured using Chromel/ Almel thermocouple, finally the gasous combustion product analysis was carricd out using gas chromatograph technique. The constructed combustion chamber was operating salisfactory for several hours of continous work. According to the measurements it was found that: the flame temperature of a mixture of diesel and shale oil fuels was greater than the flame temperature of diesel fuel. and the sulfer emissious of a mixture of diesel and shale oil fuels was higher than that of diesel fuel. Calculation indicated that the dry gas energy loss was very high and the incomplete combustion energy loss very small. (author). 23 refs., 35 figs.

  11. Evaluación del efecto de fertilización, aplicación de estiércol y absorción de elementos en el rendimiento de la secuencia papa-kiwicha, evaluado mediante la técnica del elemento faltante

    Directory of Open Access Journals (Sweden)

    Edgardo Alaluna G.

    2014-06-01

    Full Text Available El presente trabajo evalúa el efecto de la fertilización al suelo, incorporación de estiércol y fertilización foliar de los elementos N, P, K, Mg, Fe, Mn y Zn, los cuales fueron evaluados mediante la técnica del elemento faltante. El experimento se condujo en un suelo de textura tipo arena de la Costa central del Perú y se usaron como plantas indicadoras los cultivos de papa y kiwicha, este último para evaluar el efecto residual de cada uno de los tratamientos. La fertilización al suelo para cada elemento en mg kg,l fue de 200 =N, PP5 Y K20; 50 =MgO Y Fe; 25 = Mn y Zn. Se utilizó el diseño completo al azar con arreglo factorial, con tres repeticiones y conducido en macetas de 4 kg de suelo. La evaluación consistió en medir el rendimiento de materia seca total y absorción total de nutrientes analizados en los tejidos de la papa y kiwicha. Con la incorporación de 25 l/ha estiércol es posible suplir los requerimientos nutricionales de los elementos Fe, Mn y Zn para el cultivo de la papa; así mismo, mediante este procedimiento se puedo suplir parcialmente los requerimientos de K y Mg Y de manera muy limitada los de P y N. En la kiwicha el tratamiento completo mostró ligera depresión en su rendimiento comparado con las ausencias de Mg, K, Mn y P, pues estos elementos fueron favorecidos por la mineralización del estiércol adicionado al cultivo anterior. Así mismo, el efecto residual del estiércol favoreció la disponibilidad del N, P Y K, los cuales incrementaron la producción en 1025%, 42% Y 13% con relación a los tratamientos sin estiércol, y mostró efecto negativo frente a las ausencias de Mn, Fe y Zn debido a la quelación de estos con la materia orgánica. La fertilización foliar sólo mostró efecto positivo en los tratamientos con buen balance nutricional a nivel del suelo como en los casos del completo, testigo y en ausencia de elementos menores. En los tratamientos con estiércol se observó efecto positivo

  12. Investigation of the combustion kinetics and polycyclic aromatic hydrocarbon emissions from polycaprolactone combustion.

    Science.gov (United States)

    Chien, Y C; Yang, S H

    2013-01-01

    Polycaprolactone (PCL) is one of the most attractive biodegradable plastics that has been widely used in medicine and agriculture fields. Because of the large increase in biodegradable plastics usage, the production of waste biodegradable plastics will be increasing dramatically, producing a growing environmental problem. Generally, waste PCL is collected along with municipal solid wastes and then incinerated. This study investigates the combustion kinetics and emission factors of 16 US Environmental Protection Agency (EPA) priority polycyclic aromatic hydrocarbons (PAHs) in the PCL combustion. Experimentally, two reactions are involved in the PCL combustion process, possibly resulting in the emission of carbon dioxide, propanal, protonated caprolactone and very small amounts of PAH produced by incomplete combustion. The intermediate products may continuously be oxidized to form CO2. The emission factors for 16 US EPA priority PAHs are n.d. -2.95 microg/g, which are much lower than those of poly lactic acid and other plastics combustion. The conversion of PCL is 100%. Results from this work suggest that combustion is a good choice for the waste PCL disposal.

  13. Elementos de la psicopatología social de los colombianos

    Directory of Open Access Journals (Sweden)

    Ismael Roldan

    1994-01-01

    Las primeras causas de la morbi-mortalidad nacional se deben a factores como la violencia, el trauma y los accidentes, asociadas con la pérdida o menoscabo de la salud mental y el consumo de sustancias, especialmente el alcohol.  Tomando como punto de partida y desarrollo la violencia intrafamiliar, se pretende abrir la discusión sobre algunos elementos que constituyen y explican la presencia de la agresión intrafamiliar.

  14. The Multi-User Droplet Combustion Apparatus: the Development and Integration Concept for Droplet Combustion Payloads in the Fluids and Combustion Facility Combustion Integrated Rack

    Science.gov (United States)

    Myhre, C. A.

    2002-01-01

    The Multi-user Droplet Combustion Apparatus (MDCA) is a multi-user facility designed to accommodate four different droplet combustion science experiments. The MDCA will conduct experiments using the Combustion Integrated Rack (CIR) of the NASA Glenn Research Center's Fluids and Combustion Facility (FCF). The payload is planned for the International Space Station. The MDCA, in conjunction with the CIR, will allow for cost effective extended access to the microgravity environment, not possible on previous space flights. It is currently in the Engineering Model build phase with a planned flight launch with CIR in 2004. This paper provides an overview of the capabilities and development status of the MDCA. The MDCA contains the hardware and software required to conduct unique droplet combustion experiments in space. It consists of a Chamber Insert Assembly, an Avionics Package, and a multiple array of diagnostics. Its modular approach permits on-orbit changes for accommodating different fuels, fuel flow rates, soot sampling mechanisms, and varying droplet support and translation mechanisms to accommodate multiple investigations. Unique diagnostic measurement capabilities for each investigation are also provided. Additional hardware provided by the CIR facility includes the structural support, a combustion chamber, utilities for the avionics and diagnostic packages, and the fuel mixing capability for PI specific combustion chamber environments. Common diagnostics provided by the CIR will also be utilized by the MDCA. Single combustible fuel droplets of varying sizes, freely deployed or supported by a tether are planned for study using the MDCA. Such research supports how liquid-fuel-droplets ignite, spread, and extinguish under quiescent microgravity conditions. This understanding will help us develop more efficient energy production and propulsion systems on Earth and in space, deal better with combustion generated pollution, and address fire hazards associated with

  15. Euler: programa didáctico de elementos finitos

    Directory of Open Access Journals (Sweden)

    Dorian Luis Linero Segrera

    2000-07-01

    Full Text Available Este artículo muestra las características del programa Euler como herramienta para el aprendizaje del método de los elementos finitos, con énfasis en el análisis estructural. Euler puede resolver entre otros los siguientes problemas: análisis matricial estático de armaduras y pórticos planos, análisis de estabilidad, evaluación de frecuencias y modos de vibración en pórticos planos, deformaciones en vigas y en elementos sometidos a fuerza axial y otros problemas controlados por la ecuación diferencial de campo unidimensional indicada en este artículo. Además, se pueden solucionar problemas de torsión en secciones no circulares, flujo potencial, transferencia de calor y otros problemas controlados por la ecuación diferencial de campo bidimensional mostrada en este documento. También es posible resolver problemas de elasticidad bidimensional en condición plana de esfuerzos y en condición plana de deformaciones. Al operar el programa, el usuario debe escribir una de las instrucciones necesarias para obtener las cantidades de interés. Las instrucciones disponibles se clasifican así: edición de matrices, operaciones matriciales básicas, solución de sistemas de ecuaciones simultáneas, ensamblaje de matrices y vectores, numeración de grados de libertad, valores y vectores propios. Existen también instrucciones para la creación de matrices elementales como: funciones de forma, matriz gradiente, matriz de rigidez, vector de términos independientes, contribución interelemental, matriz de transformación y matriz de constantes elásticas.

  16. Elementos doi: 10.5007/1807-9288.2011v7n1p167

    Directory of Open Access Journals (Sweden)

    Francisco Carlos de Carvalho Marinho

    2011-01-01

    Full Text Available Encerrando a presente edição da revista Texto Digital, apresentamos a belíssima criação "Elementos" do prof. Dr. Chico Marinho, da Universidade Federal de Minas Gerais (UFMG. Para ter acesso ao arquivo, clique aqui.

  17. Large-eddy simulation of ethanol spray combustion using a finite-rate combustion model

    Energy Technology Data Exchange (ETDEWEB)

    Li, K.; Zhou, L.X. [Tsinghua Univ., Beijing (China). Dept. of Engineering Mechanics; Chan, C.K. [Hong Kong Polytechnic Univ. (China). Dept. of Applied Mathematics

    2013-07-01

    Large-eddy simulation of spray combustion is under its rapid development, but the combustion models are less validated by detailed experimental data. In this paper, large-eddy simulation of ethanol-air spray combustion was made using an Eulerian-Lagrangian approach, a subgrid-scale kinetic energy stress model, and a finite-rate combustion model. The simulation results are validated in detail by experiments. The LES obtained statistically averaged temperature is in agreement with the experimental results in most regions. The instantaneous LES results show the coherent structures of the shear region near the high-temperature flame zone and the fuel vapor concentration map, indicating the droplets are concentrated in this shear region. The droplet sizes are found to be in the range of 20-100{mu}m. The instantaneous temperature map shows the close interaction between the coherent structures and the combustion reaction.

  18. Impacts of Combustion Conditions and Photochemical Processing on the Light Absorption of Biomass Combustion Aerosol.

    Science.gov (United States)

    Martinsson, J; Eriksson, A C; Nielsen, I Elbæk; Malmborg, V Berg; Ahlberg, E; Andersen, C; Lindgren, R; Nyström, R; Nordin, E Z; Brune, W H; Svenningsson, B; Swietlicki, E; Boman, C; Pagels, J H

    2015-12-15

    The aim was to identify relationships between combustion conditions, particle characteristics, and optical properties of fresh and photochemically processed emissions from biomass combustion. The combustion conditions included nominal and high burn rate operation and individual combustion phases from a conventional wood stove. Low temperature pyrolysis upon fuel addition resulted in "tar-ball" type particles dominated by organic aerosol with an absorption Ångström exponent (AAE) of 2.5-2.7 and estimated Brown Carbon contributions of 50-70% to absorption at the climate relevant aethalometer-wavelength (520 nm). High temperature combustion during the intermediate (flaming) phase was dominated by soot agglomerates with AAE 1.0-1.2 and 85-100% of absorption at 520 nm attributed to Black Carbon. Intense photochemical processing of high burn rate flaming combustion emissions in an oxidation flow reactor led to strong formation of Secondary Organic Aerosol, with no or weak absorption. PM1 mass emission factors (mg/kg) of fresh emissions were about an order of magnitude higher for low temperature pyrolysis compared to high temperature combustion. However, emission factors describing the absorption cross section emitted per kg of fuel consumed (m(2)/kg) were of similar magnitude at 520 nm for the diverse combustion conditions investigated in this study. These results provide a link between biomass combustion conditions, emitted particle types, and their optical properties in fresh and processed plumes which can be of value for source apportionment and balanced mitigation of biomass combustion emissions from a climate and health perspective.

  19. Engine combustion network (Ecn) : characterization and comparison of boundary conditions for different combustion vessels

    NARCIS (Netherlands)

    Meijer, M.; Somers, L.M.T.; Johnson, J.; Naber, J.; Lee, S.Y.; Malbec, L.M.; Bruneaux, G.; Pickett, L.M.; Bardi, M.; Payri, R.; Bazyn, T.

    2012-01-01

    The Engine Combustion Network (ECN) is a worldwide group of institutions using combustion vessels and/or performing computational fluid dynamics (CFD) simulation, whose aim is to advance the state of spray and combustion knowledge at engine-relevant conditions. A key activity is the use of spray

  20. Optimization of combustion chamber geometry for stoichiometric diesel combustion using a micro genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Wook

    2010-11-15

    This paper describes the optimization of combustion chamber geometry and engine operating conditions for stoichiometric diesel combustion, targeting lower gross indicated specific fuel consumption. The KIVA code, coupled with a micro genetic algorithm population of nine for each generation was used. The optimization variables were composed of ten variables related to the combustion chamber geometry and engine operating conditions. In addition, an auto mesh generator was developed for generating various kinds of combustion chambers, such as open-crater, re-entrant, deep, and shallow types. In addition, the computational models were validated against the experimental results for a stoichiometric process in terms of the combustion pressure history and emissions. Through the preset optimization, a 35% improvement in the gross indicated that specific fuel consumption was achieved. In addition, the optimization results showed that the optimum engine operating conditions employed a premixed charge compression ignition combustion regime with early injection and a narrow spray included angle. Furthermore, a higher boost pressure was used to prevent fuel film formation. (author)

  1. La productividad y la competencia : elementos condicionantes del quehacer empresarial

    OpenAIRE

    Lilia Cañon Fl

    1993-01-01

    RESUMEN Este texto conceptualiza la competencia como un aspecto inmerso en el discurrir económico y, por supuesto, social. En este sentido, la competitividad y por extensión la productividad son elementos y condiciones primordiales para revisar y tener presentes en el tratamiento o abordaje del quehacer empresarial, mucho más cuando este ha penetrado y permeabilizado el campo de la educación, lo cual obliga a elaborar, cada vez, discursos de mayor rigurosidad intelectual.

  2. Análise documental de fotografias jornalísticas: estudo exploratório dos elementos conotativos

    Directory of Open Access Journals (Sweden)

    Raquel Juliana Prado Leite de Sousa

    2015-01-01

    Full Text Available Reflete sobre a necessidade e a possibilidade de estabelecimento de maior rigor metodológico para a análise documental do processo conotativo de fotografias, tendo como objetivo realizar um estudo exploratório dos elementos de conotação. Analisa as fotografias presentes na cobertura jornalística de pesquisa científica que realizou estudo de arqueologia forense nos restos mortais dos imperadores brasileiros publicadas nos jornais O Estado de São Paulo e Folha de São Paulo em fevereiro de 2013. Parte do levantamento inicial da presença ou ausência dos elementos trucagem, pose, objetos, estetismo, sintaxe e fotogenia apontados por Barthes (1990 como formadores da conotação em fotografias jornalísticas, para posteriormente realizar análise conceitual de uma fotografia publicada nos dois jornais. Conclui que o estabelecimento de elementos para a análise e descrição do processo conotativo de fotografias deve e pode ser aprofundado, de modo a procurar, se não substituir, minimizar uma leitura subjetiva da conotação por critérios mais uniformes.

  3. Multi-stage combustion using nitrogen-enriched air

    Science.gov (United States)

    Fischer, Larry E.; Anderson, Brian L.

    2004-09-14

    Multi-stage combustion technology combined with nitrogen-enriched air technology for controlling the combustion temperature and products to extend the maintenance and lifetime cycles of materials in contact with combustion products and to reduce pollutants while maintaining relatively high combustion and thermal cycle efficiencies. The first stage of combustion operates fuel rich where most of the heat of combustion is released by burning it with nitrogen-enriched air. Part of the energy in the combustion gases is used to perform work or to provide heat. The cooled combustion gases are reheated by additional stages of combustion until the last stage is at or near stoichiometric conditions. Additional energy is extracted from each stage to result in relatively high thermal cycle efficiency. The air is enriched with nitrogen using air separation technologies such as diffusion, permeable membrane, absorption, and cryogenics. The combustion method is applicable to many types of combustion equipment, including: boilers, burners, turbines, internal combustion engines, and many types of fuel including hydrogen and carbon-based fuels including methane and coal.

  4. DIAGNOSIS OF FAILURE OF COMBUSTION IN THE COMBUSTION CHAMBER WITH A THERMOVISION EQUIPMENT

    Directory of Open Access Journals (Sweden)

    S. V. Vorobiev

    2014-01-01

    Full Text Available The use of thermovision technology to diagnose failure of the combustion flame test tube of the main combustion chamber gas turbine engine is deal with in the article. Join the thermal radiation of the jet of combustion products and the internal elements was carried out using short-wave thermovision system AGA-782 with spectral spectral filters in several ranges from 3.2 to 5.6 microns. Thermovision is mounted on the axis of the flame tube. The output signal was recorded and processed on a computer in real time, allowing monitor the combustion process and the thermal state of the object during the experiment.

  5. High Combustion Research Facility

    Data.gov (United States)

    Federal Laboratory Consortium — At NETL's High-Pressure Combustion Research Facility in Morgantown, WV, researchers can investigate new high-pressure, high-temperature hydrogen turbine combustion...

  6. Computational Modeling of Turbulent Spray Combustion

    NARCIS (Netherlands)

    Ma, L.

    2016-01-01

    The objective of the research presented in this thesis is development and validation of predictive models or modeling approaches of liquid fuel combustion (spray combustion) in hot-diluted environments, known as flameless combustion or MILD combustion. The goal is to combine good physical insight,

  7. Space Station Freedom combustion research

    Science.gov (United States)

    Faeth, G. M.

    1992-01-01

    Extended operations in microgravity, on board spacecraft like Space Station Freedom, provide both unusual opportunities and unusual challenges for combustion science. On the one hand, eliminating the intrusion of buoyancy provides a valuable new perspective for fundamental studies of combustion phenomena. On the other hand, however, the absence of buoyancy creates new hazards of fires and explosions that must be understood to assure safe manned space activities. These considerations - and the relevance of combustion science to problems of pollutants, energy utilization, waste incineration, power and propulsion systems, and fire and explosion hazards, among others - provide strong motivation for microgravity combustion research. The intrusion of buoyancy is a greater impediment to fundamental combustion studies than to most other areas of science. Combustion intrinsically heats gases with the resulting buoyant motion at normal gravity either preventing or vastly complicating measurements. Perversely, this limitation is most evident for fundamental laboratory experiments; few practical combustion phenomena are significantly affected by buoyancy. Thus, we have never observed the most fundamental combustion phenomena - laminar premixed and diffusion flames, heterogeneous flames of particles and surfaces, low-speed turbulent flames, etc. - without substantial buoyant disturbances. This precludes rational merging of theory, where buoyancy is of little interest, and experiments, that always are contaminated by buoyancy, which is the traditional path for developing most areas of science. The current microgravity combustion program seeks to rectify this deficiency using both ground-based and space-based facilities, with experiments involving space-based facilities including: laminar premixed flames, soot processes in laminar jet diffusion flames, structure of laminar and turbulent jet diffusion flames, solid surface combustion, one-dimensional smoldering, ignition and flame

  8. Underground treatment of combustible minerals

    Energy Technology Data Exchange (ETDEWEB)

    Sarapuu, E

    1954-10-14

    A process is described for treating oil underground, consisting in introducing several electrodes spaced one from the other in a bed of combustibles underground so that they come in electric contact with this bed of combustibles remaining insulated from the ground, and applying to the electrodes a voltage sufficient to produce an electric current across the bed of combustibles, so as to heat it and create an electric connection between the electrodes on traversing the bed of combustibles.

  9. Una teoría general de análisis en el diseño de elementos de máquinas

    Directory of Open Access Journals (Sweden)

    Guillermo García P.

    1985-09-01

    Full Text Available La presentación tradicional dada al diseño de máquinas orienta en la mayoría de los casos al profesor y al estudiante hacia el estudio particular de los diferentes elementos que componen un sistema. Esta forma de trabajo es, sin lugar a dudas, un paso Importante para la obtención de información de un proyecto. Pero el proceso de análisis no se puede quedar a nivel de elementos sueltos, sino que es necesario llevarlo a que se integre al nivel de conjunto de elementos que forman una máquina. Este enfoque del problema brinda la oportunidad de desarrollar un análisis completo de comienzo a fin del sistema, retomando a su debido tiempo al elemento. En esta forma se desarrolla una amplia visión de análisis para el diseño de máquinas. La apertura de esta forma de trabajo tiene sus fundamentos en la influencia de la transmisión de carga y/o movimiento sobre el diseño de la máquina.

  10. Numerical simulation of combustion and soot under partially premixed combustion of low-octane gasoline

    KAUST Repository

    An, Yanzhao

    2017-09-23

    In-cylinder combustion visualization and engine-out soot particle emissions were investigated in an optical diesel engine fueled with low octane gasoline. Single injection strategy with an early injection timing (−30 CAD aTDC) was employed to achieve partially premixed combustion (PPC) condition. A high-speed color camera was used to record the combustion images for 150 cycles. The regulated emission of carbon dioxide, carbon monoxide, nitrogen oxides and soot mass concentration were measured experimentally. Full cycle engine simulations were performed using CONVERGE™ and the simulation results matched with the experimental results. The in-cylinder soot particle evolution was performed by coupling a reduced toluene reference fuel mechanism including the PAHs formation/oxidation reactions with particulate size mimic model. The results showed that PPC presents typical stratified combustion characteristics, which is significantly different from the conventional diesel spray-driven combustion. The in-cylinder temperature and equivalence ratio overlaid with soot-NO formation regime revealed that PPC operating condition under study mostly avoided the main sooting conditions throughout the entire combustion. The evaluation of temperature distribution showed formaldehyde could be regarded as an indicator for low temperature reactions, while hydroxyl group represents the high temperature reactions. Soot evolution happened during the combustion process, hydroxyl radicals promoted the soot oxidation.

  11. Numerical simulation of combustion and soot under partially premixed combustion of low-octane gasoline

    KAUST Repository

    An, Yanzhao; Jaasim, Mohammed; Vallinayagam, R.; Vedharaj, S.; Im, Hong G.; Johansson, Bengt.

    2017-01-01

    In-cylinder combustion visualization and engine-out soot particle emissions were investigated in an optical diesel engine fueled with low octane gasoline. Single injection strategy with an early injection timing (−30 CAD aTDC) was employed to achieve partially premixed combustion (PPC) condition. A high-speed color camera was used to record the combustion images for 150 cycles. The regulated emission of carbon dioxide, carbon monoxide, nitrogen oxides and soot mass concentration were measured experimentally. Full cycle engine simulations were performed using CONVERGE™ and the simulation results matched with the experimental results. The in-cylinder soot particle evolution was performed by coupling a reduced toluene reference fuel mechanism including the PAHs formation/oxidation reactions with particulate size mimic model. The results showed that PPC presents typical stratified combustion characteristics, which is significantly different from the conventional diesel spray-driven combustion. The in-cylinder temperature and equivalence ratio overlaid with soot-NO formation regime revealed that PPC operating condition under study mostly avoided the main sooting conditions throughout the entire combustion. The evaluation of temperature distribution showed formaldehyde could be regarded as an indicator for low temperature reactions, while hydroxyl group represents the high temperature reactions. Soot evolution happened during the combustion process, hydroxyl radicals promoted the soot oxidation.

  12. Fuels and Combustion | Transportation Research | NREL

    Science.gov (United States)

    Fuels and Combustion Fuels and Combustion This is the March 2015 issue of the Transportation and , combustion strategy, and engine design hold the potential to maximize vehicle energy efficiency and performance of low-carbon fuels in internal combustion engines with a whole-systems approach to fuel chemistry

  13. Sandia Combustion Research Program

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, S.C.; Palmer, R.E.; Montana, C.A. (eds.)

    1988-01-01

    During the late 1970s, in response to a national energy crisis, Sandia proposed to the US Department of Energy (DOE) a new, ambitious program in combustion research. Shortly thereafter, the Combustion Research Facility (CRF) was established at Sandia's Livermore location. Designated a ''user facility,'' the charter of the CRF was to develop and maintain special-purpose resources to support a nationwide initiative-involving US inventories, industry, and national laboratories--to improve our understanding and control of combustion. This report includes descriptions several research projects which have been simulated by working groups and involve the on-site participation of industry scientists. DOE's Industry Technology Fellowship program, supported through the Office of Energy Research, has been instrumental in the success of some of these joint efforts. The remainder of this report presents results of calendar year 1988, separated thematically into eleven categories. Referred journal articles appearing in print during 1988 and selected other publications are included at the end of Section 11. Our traditional'' research activities--combustion chemistry, reacting flows, diagnostics, engine and coal combustion--have been supplemented by a new effort aimed at understanding combustion-related issues in the management of toxic and hazardous materials.

  14. Ultra-low pollutant emission combustion method and apparatus

    International Nuclear Information System (INIS)

    Khinkis, M.J.

    1992-01-01

    This patent describes a method for ultra-low pollutant emission combustion of fossil fuel. It comprises: introducing into a primary combustion chamber a first fuel portion of about 1 percent to about 20 percent of a total fuel to be combusted; introducing primary combustion air into the primary combustion chamber; introducing a first portion of water into the primary combustion chamber, having a first water heat capacity equivalent to a primary combustion air heat capacity of one of a primary combustion air amount of about 10 percent to about 60 percent of the first stoichiometirc requirement for complete combustion of the first fuel portion and an excess primary combustion air amount of about 20 percent to about 150 percent of the first stoichiometric requirement for complete combustion of the first fuel portion; burning the first fuel portion with the primary combustion air in the primary combustion chamber at a temperature abut 2000 degrees F to about 2700 degrees F producing initial combustion products; passing the initial combustion products into a secondary combustion chamber; introducing into the secondary combustion chamber a second fuel portion of about 80 percent to about 99 percent of the total fuel to be combusted; introducing secondary combustion air into the secondary combustion chamber in an amount of about 105 percent to about 130 percent of a second stoichiometric requirement for complete combustion of the second fuel portion; introducing a second portion of water into the secondary combustion chamber; burning the second fuel portion and any remaining fuel in the initial combustion products; passing the final combustion products into a dilution chamber; introducing dilution air into the dilution chamber; discharging the ultra-low pollutant emission vitiated air form the dilution chamber

  15. ANALYSIS OF INTERNAL COMBUSTION ENGINE WITH A NEW CONCEPT OF POROUS MEDIUM COMBUSTION FOR THE FUTURE CLEAN ENGINE

    Directory of Open Access Journals (Sweden)

    Ashok A Dhale

    2010-01-01

    Full Text Available At present, the emissions of internal combustion engine can only be improved by catalytic treatments of the exhaust gases. Such treatments, however, result in high costs and relatively low conversion efficiency. This suggests that a new combustion technique should be developed to yield improved primary combustion processes inside the engine with drastically reduced exhaust gas emissions. To fulfill all requirements, Dr. Franz Drust has proposed a new combustion concept to perform homogenous combustion in internal combustion engines. This concept used the porous medium combustion technique and is called "PM-engine". It is shown that the PM combustion technique can be applied to internal combustion engines. Theoretical considerations are presented for internal combustion engines, indicating that an overall improvement in thermal efficiency can be achieved for the PM-engine. This is explained and general performance of the new PM-engines is demonstrated for a single cylinder, water cooled, direct injection diesel engine. Verification of experiments at primary stage is described that were carried out as a part of the present study.

  16. Alcohol combustion chemistry

    KAUST Repository

    Sarathy, Mani

    2014-10-01

    Alternative transportation fuels, preferably from renewable sources, include alcohols with up to five or even more carbon atoms. They are considered promising because they can be derived from biological matter via established and new processes. In addition, many of their physical-chemical properties are compatible with the requirements of modern engines, which make them attractive either as replacements for fossil fuels or as fuel additives. Indeed, alcohol fuels have been used since the early years of automobile production, particularly in Brazil, where ethanol has a long history of use as an automobile fuel. Recently, increasing attention has been paid to the use of non-petroleum-based fuels made from biological sources, including alcohols (predominantly ethanol), as important liquid biofuels. Today, the ethanol fuel that is offered in the market is mainly made from sugar cane or corn. Its production as a first-generation biofuel, especially in North America, has been associated with publicly discussed drawbacks, such as reduction in the food supply, need for fertilization, extensive water usage, and other ecological concerns. More environmentally friendly processes are being considered to produce alcohols from inedible plants or plant parts on wasteland. While biofuel production and its use (especially ethanol and biodiesel) in internal combustion engines have been the focus of several recent reviews, a dedicated overview and summary of research on alcohol combustion chemistry is still lacking. Besides ethanol, many linear and branched members of the alcohol family, from methanol to hexanols, have been studied, with a particular emphasis on butanols. These fuels and their combustion properties, including their ignition, flame propagation, and extinction characteristics, their pyrolysis and oxidation reactions, and their potential to produce pollutant emissions have been intensively investigated in dedicated experiments on the laboratory and the engine scale

  17. Recursos administrativos: conceptos, elementos y presupuestos. Un estudio comparativo de los regímenes peruano y uruguayo

    Directory of Open Access Journals (Sweden)

    Juan Pablo Cajarville Peluffo

    2011-12-01

    Full Text Available El artículo presenta una comparación de las principales características del recurso administrativo en el Derecho peruano y uruguayo. Teniendo como contexto la comparación de ambos marcos constitucionales y legales, se desarrolla la definición del recurso administrativo como ejercicio del derecho de petición para, posteriormente, realizar el análisis de los elementos esenciales y de los elementos no esenciales del recurso administrativo. Finalmente, el trabajo ofrece una visión cuestionadora de la regulación constitucional uruguaya y permite arribar a algunas conclusiones sobre ambos ordenamientos.

  18. Bioconcentraciones foliares de elementos minerales en Lippia alba (salvia morada)

    OpenAIRE

    Schroeder, María A; Burgos, Ángela M

    2013-01-01

    Introducción: la salvia morada es un subarbusto aromático, que crece de modo espontáneo en América Central y del Sur. Frecuentemente es cultivada en jardines como ornamental, por su intenso aroma y sus propiedades medicinales y culinarias. No se encontraron estudios sobre parámetros nutricionales en esta especie. Objetivos: determinar las bioconcentraciones foliares de elementos minerales en Lippia alba (Mill.) N. E. Br. ex Britton & P. Wilson que crece naturalmente en el bioambiente del nort...

  19. La productividad y la competencia : elementos condicionantes del quehacer empresarial

    Directory of Open Access Journals (Sweden)

    Lilia Cañon Fl

    1993-05-01

    Full Text Available RESUMEN Este texto conceptualiza la competencia como un aspecto inmerso en el discurrir económico y, por supuesto, social. En este sentido, la competitividad y por extensión la productividad son elementos y condiciones primordiales para revisar y tener presentes en el tratamiento o abordaje del quehacer empresarial, mucho más cuando este ha penetrado y permeabilizado el campo de la educación, lo cual obliga a elaborar, cada vez, discursos de mayor rigurosidad intelectual.

  20. Indoor combustion and asthma.

    Science.gov (United States)

    Belanger, Kathleen; Triche, Elizabeth W

    2008-08-01

    Indoor combustion produces both gases (eg, nitrogen dioxide, carbon monoxide) and particulate matter that may affect the development or exacerbation of asthma. Sources in the home include both heating devices (eg, fireplaces, woodstoves, kerosene heaters, flued [ie, vented] or nonflued gas heaters) and gas stoves for cooking. This article highlights the recent literature examining associations between exposure to indoor combustion and asthma development and severity. Since asthma is a chronic condition affecting both children and adults, both age groups are included in this article. Overall, there is some evidence of an association between exposure to indoor combustion and asthma, particularly asthma symptoms in children. Some sources of combustion such as coal stoves have been more consistently associated with these outcomes than other sources such as woodstoves.

  1. DETERMINATION OF REFRACTORY ELEMENTS IN USED LUBRICATING OIL AND IN FUEL OIL BY ICP OES WITH EMULSIFIED SAMPLES

    OpenAIRE

    ROSELI MARTINS DE SOUZA

    2003-01-01

    O conhecimento da concentração dos elementos traço em óleo lubrificante usado é útil para a avaliação de desgastes de componentes específicos de motores.Em óleo combustível, este monitoramento permite avaliar a qualidade do combustível e prever o potencial das emissões de metais no meio ambiente. Neste trabalho, utilizou-se a espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES) para a determinação de elementos refratários em amostras de ól...

  2. Numerical investigation of biogas flameless combustion

    International Nuclear Information System (INIS)

    Hosseini, Seyed Ehsan; Bagheri, Ghobad; Wahid, Mazlan Abdul

    2014-01-01

    Highlights: • Fuel consumption decreases from 3.24 g/s in biogas conventional combustion to 1.07 g/s in flameless mode. • The differences between reactants and products temperature intensifies irreversibility in traditional combustion. • The temperature inside the chamber is uniform in biogas flameless mode and exergy loss decreases in this technique. • Low O 2 concentration in the flameless mode confirms a complete and quick combustion process in flameless regime. - Abstract: The purpose of this investigation is to analyze combustion characteristics of biogas flameless mode based on clean technology development strategies. A three dimensional (3D) computational fluid dynamic (CFD) study has been performed to illustrate various priorities of biogas flameless combustion compared to the conventional mode. The effects of preheated temperature and wall temperature, reaction zone and pollutant formation are observed and the impacts of combustion and turbulence models on numerical results are discussed. Although preheated conventional combustion could be effective in terms of fuel consumption reduction, NO x formation increases. It has been found that biogas is not eligible to be applied in furnace heat up due to its low calorific value (LCV) and it is necessary to utilize a high calorific value fuel to preheat the furnace. The required enthalpy for biogas auto-ignition temperature is supplied by enthalpy of preheated oxidizer. In biogas flameless combustion, the mean temperature of the furnace is lower than traditional combustion throughout the chamber. Compared to the biogas flameless combustion with uniform temperature, very high and fluctuated temperatures are recorded in conventional combustion. Since high entropy generation intensifies irreversibility, exergy loss is higher in biogas conventional combustion compared to the biogas flameless regime. Entropy generation minimization in flameless mode is attributed to the uniform temperature inside the chamber

  3. Materials for High-Temperature Catalytic Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ersson, Anders

    2003-04-01

    Catalytic combustion is an environmentally friendly technique to combust fuels in e.g. gas turbines. Introducing a catalyst into the combustion chamber of a gas turbine allows combustion outside the normal flammability limits. Hence, the adiabatic flame temperature may be lowered below the threshold temperature for thermal NO{sub X} formation while maintaining a stable combustion. However, several challenges are connected to the application of catalytic combustion in gas turbines. The first part of this thesis reviews the use of catalytic combustion in gas turbines. The influence of the fuel has been studied and compared over different catalyst materials. The material section is divided into two parts. The first concerns bimetallic palladium catalysts. These catalysts showed a more stable activity compared to their pure palladium counterparts for methane combustion. This was verified both by using an annular reactor at ambient pressure and a pilot-scale reactor at elevated pressures and flows closely resembling the ones found in a gas turbine combustor. The second part concerns high-temperature materials, which may be used either as active or washcoat materials. A novel group of materials for catalysis, i.e. garnets, has been synthesised and tested in combustion of methane, a low-heating value gas and diesel fuel. The garnets showed some interesting abilities especially for combustion of low-heating value, LHV, gas. Two other materials were also studied, i.e. spinels and hexa aluminates, both showed very promising thermal stability and the substituted hexa aluminates also showed a good catalytic activity. Finally, deactivation of the catalyst materials was studied. In this part the sulphur poisoning of palladium, platinum and the above-mentioned complex metal oxides has been studied for combustion of a LHV gas. Platinum and surprisingly the garnet were least deactivated. Palladium was severely affected for methane combustion while the other washcoat materials were

  4. Large eddy simulation and combustion instabilities; Simulation des grandes echelles et instabilites de combustion

    Energy Technology Data Exchange (ETDEWEB)

    Lartigue, G.

    2004-11-15

    The new european laws on pollutants emission impose more and more constraints to motorists. This is particularly true for gas turbines manufacturers, that must design motors operating with very fuel-lean mixtures. Doing so, pollutants formation is significantly reduced but the problem of combustion stability arises. Actually, combustion regimes that have a large excess of air are naturally more sensitive to combustion instabilities. Numerical predictions of these instabilities is thus a key issue for many industrial involved in energy production. This thesis work tries to show that recent numerical tools are now able to predict these combustion instabilities. Particularly, the Large Eddy Simulation method, when implemented in a compressible CFD code, is able to take into account the main processes involved in combustion instabilities, such as acoustics and flame/vortex interaction. This work describes a new formulation of a Large Eddy Simulation numerical code that enables to take into account very precisely thermodynamics and chemistry, that are essential in combustion phenomena. A validation of this work will be presented in a complex geometry (the PRECCINSTA burner). Our numerical results will be successfully compared with experimental data gathered at DLR Stuttgart (Germany). Moreover, a detailed analysis of the acoustics in this configuration will be presented, as well as its interaction with the combustion. For this acoustics analysis, another CERFACS code has been extensively used, the Helmholtz solver AVSP. (author)

  5. Manifold methods for methane combustion

    Energy Technology Data Exchange (ETDEWEB)

    Yang, B.; Pope, S.B. [Cornell Univ., Ithaca, NY (United States)

    1995-10-01

    Great progresses have been made in combustion research, especially, the computation of laminar flames and the probability density function (PDF) method in turbulent combustion. For one-dimensional laminar flames, by considering the transport mechanism, the detailed chemical kinetic mechanism and the interactions between these two basic processes, today it is a routine matter to calculate flame velocities, extinction, ignition, temperature, and species distributions from the governing equations. Results are in good agreement with those obtained for experiments. However, for turbulent combustion, because of the complexities of turbulent flow, chemical reactions, and the interaction between them, in the foreseeable future, it is impossible to calculate the combustion flow field by directly integrating the basic governing equations. So averaging and modeling are necessary in turbulent combustion studies. Averaging, on one hand, simplifies turbulent combustion calculations, on the other hand, it introduces the infamous closure problems, especially the closure problem with chemical reaction terms. Since in PDF calculations of turbulent combustion, the averages of the chemical reaction terms can be calculated, PDF methods overcome the closure problem with the reaction terms. It has been shown that the PDF method is a most promising method to calculate turbulent combustion. PDF methods have been successfully employed to calculate laboratory turbulent flames: they can predict phenomena such as super equilibrium radical levels, and local extinction. Because of these advantages, PDF methods are becoming used increasingly in industry combustor codes.

  6. Development of a Premixed Combustion Capability for Scramjet Combustion Experiments

    Science.gov (United States)

    Rockwell, Robert D.; Goyne, Christopher P.; Rice, Brian E.; Chelliah, Harsha; McDaniel, James C.; Edwards, Jack R.; Cantu, Luca M. L.; Gallo, Emanuela C. A.; Cutler, Andrew D.; Danehy, Paul M.

    2015-01-01

    Hypersonic air-breathing engines rely on scramjet combustion processes, which involve high speed, compressible, and highly turbulent flows. The combustion environment and the turbulent flames at the heart of these engines are difficult to simulate and study in the laboratory under well controlled conditions. Typically, wind-tunnel testing is performed that more closely approximates engine testing rather than a careful investigation of the underlying physics that drives the combustion process. The experiments described in this paper, along with companion data sets being developed separately, aim to isolate the chemical kinetic effects from the fuel-air mixing process in a dual-mode scramjet combustion environment. A unique fuel injection approach is taken that produces a nearly uniform fuel-air mixture at the entrance to the combustor. This approach relies on the precombustion shock train upstream of the dual-mode scramjet combustor. A stable ethylene flame anchored on a cavity flameholder with a uniformly mixed combustor inflow has been achieved in these experiments allowing numerous companion studies involving coherent anti-Stokes Raman scattering (CARS), particle image velocimetry (PIV), and planar laser induced fluorescence (PLIF) to be performed.

  7. Mathematical Modeling in Combustion Science

    CERN Document Server

    Takeno, Tadao

    1988-01-01

    An important new area of current research in combustion science is reviewed in the contributions to this volume. The complicated phenomena of combustion, such as chemical reactions, heat and mass transfer, and gaseous flows, have so far been studied predominantly by experiment and by phenomenological approaches. But asymptotic analysis and other recent developments are rapidly changing this situation. The contributions in this volume are devoted to mathematical modeling in three areas: high Mach number combustion, complex chemistry and physics, and flame modeling in small scale turbulent flow combustion.

  8. Material reciclado como elemento constructivo de una vivienda económica sustentable en la ciudad de Hco-2014

    OpenAIRE

    Sánchez Murrugarra, Ricardo

    2015-01-01

    Este proyecto de tesis consiste en el estudio del material reciclado como elemento constructivo de vivienda económica sustentable. Estos materiales después de su uso son desechado y aunque se le de algún tratamiento son desechos altamente contaminantes por su lenta degradación. Por este motivo damos la importancia de dar un uso adecuado de los materiales reciclados es un buen comienzo. Al igual que todo material reciclado empleado en la construcción, éstos se convertirá en un elemento impo...

  9. Molten salt combustion of radioactive wastes

    International Nuclear Information System (INIS)

    Grantham, L.F.; McKenzie, D.E.; Richards, W.L.; Oldenkamp, R.D.

    1976-01-01

    The Atomics International Molten Salt Combustion Process reduces the weight and volume of combustible β-γ contaminated transuranic waste by utilizing air in a molten salt medium to combust organic materials, to trap particulates, and to react chemically with any acidic gases produced during combustion. Typically, incomplete combustion products such as hydrocarbons and carbon monoxide are below detection limits (i.e., 3 ) is directly related to the sodium chloride vapor pressure of the melt; >80% of the particulate is sodium chloride. Essentially all metal oxides (combustion ash) are retained in the melt, e.g., >99.9% of the plutonium, >99.6% of the europium, and >99.9% of the ruthenium are retained in the melt. Both bench-scale radioactive and pilot scale (50 kg/hr) nonradioactive combustion tests have been completed with essentially the same results. Design of three combustors for industrial applications are underway

  10. Experimental study of improvement on combustion control of fluidized bed combustion chamber; Ryudosho shokyakuro no nenshosei no kaizen ni tsuite

    Energy Technology Data Exchange (ETDEWEB)

    Izumiya, T.; Baba, K.; Koshida, H.; Uetani, J.; Furuta, M.

    1998-10-29

    Nippon Steel Corporation has carried out an experimental study using the Yawata waste incinerator plant in order to improve combustion control of a fluidized bed combustion chamber. For controlling the forming of dioxin, combustion control is very important in addition to conventional methods. In this paper, we report two studies about improvements on combustion control. In the first study, we verified improvement on combustion control by modifying gas flow at the freeboard. The operational results of the experiments were studied using the numerical model of the combustion chamber. The modification of gas flow at freeboard was confirmed to be effective to obtain a compact design of fluidized bed combustion chamber for municipal waste. In the second, study we improved combustion control for sewage combustion with municipal waste. In burning municipal waste and sewage, it is especially required to take combustion control into careful consideration. In this experiment, we developed a new device for supplying sewage for the appropriate controlling combustion, and verified its effectiveness to combustion control and an effective reduction of dioxin. (author)

  11. Catalytic Combustion of Gasified Waste

    Energy Technology Data Exchange (ETDEWEB)

    Kusar, Henrik

    2003-09-01

    This thesis concerns catalytic combustion for gas turbine application using a low heating-value (LHV) gas, derived from gasified waste. The main research in catalytic combustion focuses on methane as fuel, but an increasing interest is directed towards catalytic combustion of LHV fuels. This thesis shows that it is possible to catalytically combust a LHV gas and to oxidize fuel-bound nitrogen (NH{sub 3}) directly into N{sub 2} without forming NO{sub x} The first part of the thesis gives a background to the system. It defines waste, shortly describes gasification and more thoroughly catalytic combustion. The second part of the present thesis, paper I, concerns the development and testing of potential catalysts for catalytic combustion of LHV gases. The objective of this work was to investigate the possibility to use a stable metal oxide instead of noble metals as ignition catalyst and at the same time reduce the formation of NO{sub x} In paper II pilot-scale tests were carried out to prove the potential of catalytic combustion using real gasified waste and to compare with the results obtained in laboratory scale using a synthetic gas simulating gasified waste. In paper III, selective catalytic oxidation for decreasing the NO{sub x} formation from fuel-bound nitrogen was examined using two different approaches: fuel-lean and fuel-rich conditions. Finally, the last part of the thesis deals with deactivation of catalysts. The various deactivation processes which may affect high-temperature catalytic combustion are reviewed in paper IV. In paper V the poisoning effect of low amounts of sulfur was studied; various metal oxides as well as supported palladium and platinum catalysts were used as catalysts for combustion of a synthetic gas. In conclusion, with the results obtained in this thesis it would be possible to compose a working catalytic system for gas turbine application using a LHV gas.

  12. Resolución por elementos finitos de problemas de mecánica de fluidos

    OpenAIRE

    Nigro, Norberto

    1993-01-01

    Tesis (DCI)--FCEFN-UNC, 1993 Recomienda dar respuesta a algunas de las dificultades que surgen en la simulación numérica de problemas de mecánica de fluídos mediante el método de los elementos finitos

  13. Combustion means for solid fuels

    Energy Technology Data Exchange (ETDEWEB)

    Murase, D.

    1987-09-23

    A combustion device for solid fuel, suitable for coal, coke, charcoal, coal-dust briquettes etc., comprising:- a base stand with an opening therein, an imperforate heat resistant holding board locatable to close said opening; a combustion chamber standing on the base stand with the holding board forming the base of the combustion chamber; a wiper arm pivoted for horizontal wiping movement over the upper surface of the holding board; an inlet means at a lower edge of said chamber above the base stand, and/or in a surrounding wall of said chamber, whereby combustion air may enter as exhaust gases leave the combustion chamber; an exhaust pipe for the exhaust gases; generally tubular gas-flow heat-exchange ducting putting the combustion chamber and exhaust pipe into communication; and means capable of moving the holding board into and out of the opening for removal of ash or other residue. The invention can be used for a heating system in a house or in a greenhouse or for a boiler.

  14. Combustion of Waste Wood. Second phase of the collaboration project on waste wood combustion

    International Nuclear Information System (INIS)

    Andersson, Annika; Andersson, Christer; Eriksson, Jan; Hemstroem, Bengt; Jungstedt, Jenny; Kling, Aasa; Bahr, Bo von; Ekvall, Annika; Eskilsson, David; Tullin, Claes; Harnevie, Henrik; Sieurin, Jan; Keihaes, Juha; Mueller, Christian; Berg, Magnus; Wikman, Karin

    2003-08-01

    Combustion of waste wood has during the last decade increased dramatically and this has resulted in a number of Swedish plants using this fuel, e.g. Handeloe P11 (Norrkoeping) and ldbaecken P3 (Nykoeping), and yet other plants that are under construction (e.g. Nynaeshamn). The experience from these plants are that waste wood combustion results in a number of operational problems. To some extent these problems are different compared with the problems related to combustion of other biofuels but the situation is not directly comparable to waste incinerators. The problems are mainly related to slagging and fouling of heat exchanger surfaces and accelerated corrosion at relatively low temperature compared to the situation for ordinary biofuels. In some cases an increase in the emissions of specific substances can also result in difficulties to fulfil the EC-directive on waste combustion. Within previous projects the main problems related to combustion of waste wood have been identified and to some extent the cause of these problems has been clarified. One result of this reported investigation is a deeper understanding of the actual causes of these problems. However, the most important result is a number of recommendations for different measures on how to achieve disturbance-free combustion of waste wood. These recommendations actually summarises the most important possible solutions on how to achieve a disturbance-free operation and a lower maintenance cost for boilers combusting waste wood and can thereby be regarded as a short summery of the whole project: 1) Improving fuel quality by Improved sorting at the source and Sieving of the fuel -> Reducing the amount of metals and chlorine and Separation of fines and thereby reducing the amount of metals. 2) Combustion modifications by Avoiding reducing conditions at the heat exchanger surfaces -> Minimising slagging, fouling and corrosion. 3) Additives or co-combustion by Addition of sulphur with the fuel; Injection of

  15. Novel approaches in advanced combustion characterization of fuels for advanced pressurized combustion

    Energy Technology Data Exchange (ETDEWEB)

    Aho, M.; Haemaelaeinen, J. [VTT Energy (Finland); Joutsenoja, T. [Tampere Univ. of Technology (Finland)

    1996-12-01

    This project is a part of the EU Joule 2 (extension) programme. The objective of the research of Technical Research Centre of Finland (VTT) is to produce experimental results of the effects of pressure and other important parameters on the combustion of pulverized coals and their char derivates. The results can be utilized in modelling of pressurized combustion and in planning pilot-scale reactors. The coals to be studied are Polish hvb coal, French lignite (Gardanne), German anthracite (Niederberg) and German (Goettelbom) hvb coal. The samples are combusted in an electrically heated, pressurized entrained flow reactor (PEFR), where the experimental conditions are controlled with a high precision. The particle size of the fuel can vary between 100 and 300 {mu}m. The studied things are combustion rates, temperatures and sizes of burning single coal and char particles. The latter measurements are performed with a method developed by Tampere University of Technology, Finland. In some of the experiments, mass loss and elemental composition of the char residue are studied in more details as the function of time to find out the combustion mechanism. Combustion rate of pulverized (140-180 {mu}m) Gardanne lignite and Niederberg anthracite were measured and compared with the data obtained earlier with Polish hvb coal at various pressures, gas temperatures, oxygen partial pressures and partial pressures of carbon dioxide in the second working period. In addition, particle temperatures were measured with anthracite. The experimental results were treated with multivariable partial least squares (PLS) method to find regression equation between the measured things and the experimental variables. (author)

  16. Development of High Efficiency Clean Combustion Engine Designs for Spark-Ignition and Compression-Ignition Internal Combustion Engines

    Energy Technology Data Exchange (ETDEWEB)

    Marriott, Craig; Gonzalez, Manual; Russell, Durrett

    2011-06-30

    This report summarizes activities related to the revised STATEMENT OF PROJECT OBJECTIVES (SOPO) dated June 2010 for the Development of High-Efficiency Clean Combustion engine Designs for Spark-Ignition and Compression-Ignition Internal Combustion Engines (COOPERATIVE AGREEMENT NUMBER DE-FC26-05NT42415) project. In both the spark- (SI) and compression-ignition (CI) development activities covered in this program, the goal was to develop potential production-viable internal combustion engine system technologies that both reduce fuel consumption and simultaneously met exhaust emission targets. To be production-viable, engine technologies were also evaluated to determine if they would meet customer expectations of refinement in terms of noise, vibration, performance, driveability, etc. in addition to having an attractive business case and value. Prior to this activity, only proprietary theoretical / laboratory knowledge existed on the combustion technologies explored The research reported here expands and develops this knowledge to determine series-production viability. Significant SI and CI engine development occurred during this program within General Motors, LLC over more than five years. In the SI program, several engines were designed and developed that used both a relatively simple multi-lift valve train system and a Fully Flexible Valve Actuation (FFVA) system to enable a Homogeneous Charge Compression Ignition (HCCI) combustion process. Many technical challenges, which were unknown at the start of this program, were identified and systematically resolved through analysis, test and development. This report documents the challenges and solutions for each SOPO deliverable. As a result of the project activities, the production viability of the developed clean combustion technologies has been determined. At this time, HCCI combustion for SI engines is not considered production-viable for several reasons. HCCI combustion is excessively sensitive to control variables

  17. Plasma igniter for internal-combustion engines

    Science.gov (United States)

    Breshears, R. R.; Fitzgerald, D. J.

    1978-01-01

    Hot ionized gas (plasma) ignites air/fuel mixture in internal combustion engines more effectively than spark. Electromagnetic forces propel plasma into combustion zone. Combustion rate is not limited by flame-front speed.

  18. Combustion and co-combustion of biomass in a bubbling fluidized bed boiler

    NARCIS (Netherlands)

    Khan, A.A.

    2007-01-01

    This PhD dissertation concerns the study of different aspects of biomass (co)-combustion in small-scale fluidized bed boilers for heat generation. The most renowned gaseous emissions from fluidized bed combustion, namely, CO and NO, are investigated with the help of experimental and theoretical

  19. Combustion from basics to applications

    CERN Document Server

    Lackner, Maximilian; Winter, Franz

    2013-01-01

    Combustion, the process of burning, is defined as a chemical reaction between a combustible reactant (the fuel) and an oxidizing agent (such as air) in order to produce heat and in most cases light while new chemical species (e.g., flue gas components) are formed. This book covers a gap on the market by providing a concise introduction to combustion. Most of the other books currently available are targeted towards the experienced users and contain too many details and/or contain knowledge at a fairly high level. This book provides a brief and clear overview of the combustion basics, suitable f

  20. Combustion of diesel fuel from a toxicological perspective. I. Origin of incomplete combustion products.

    Science.gov (United States)

    Scheepers, P T; Bos, R P

    1992-01-01

    Since the use of diesel engines is still increasing, the contribution of their incomplete combustion products to air pollution is becoming ever more important. The presence of irritating and genotoxic substances in both the gas phase and the particulate phase constituents is considered to have significant health implications. The quantity of soot particles and the particle-associated organics emitted from the tail pipe of a diesel-powered vehicle depend primarily on the engine type and combustion conditions but also on fuel properties. The quantity of soot particles in the emissions is determined by the balance between the rate of formation and subsequent oxidation. Organics are absorbed onto carbon cores in the cylinder, in the exhaust system, in the atmosphere and even on the filter during sample collection. Diesel fuel contains polycyclic aromatic hydrocarbons (PAHs) and some alkyl derivatives. Both groups of compounds may survive the combustion process. PAHs are formed by the combustion of crankcase oil or may be resuspended from engine and/or exhaust deposits. The conversion of parent PAHs to oxygenated and nitrated PAHs in the combustion chamber or in the exhaust system is related to the vast amount of excess combustion air that is supplied to the engine and the high combustion temperature. Whether the occurrence of these derivatives is characteristic for the composition of diesel engine exhaust remains to be ascertained. After the emission of the particles, their properties may change because of atmospheric processes such as aging and resuspension. The particle-associated organics may also be subject to (photo)chemical conversions or the components may change during sampling and analysis. Measurement of emissions of incomplete combustion products as determined on a chassis dynamometer provides knowledge of the chemical composition of the particle-associated organics. This knowledge is useful as a basis for a toxicological evaluation of the health hazards of

  1. Internal combustion engine

    Science.gov (United States)

    Baker, Quentin A.; Mecredy, Henry E.; O'Neal, Glenn B.

    1991-01-01

    An improved engine is provided that more efficiently consumes difficult fuels such as coal slurries or powdered coal. The engine includes a precombustion chamber having a portion thereof formed by an ignition plug. The precombustion chamber is arranged so that when the piston is proximate the head, the precombustion chamber is sealed from the main cylinder or the main combustion chamber and when the piston is remote from the head, the precombustion chamber and main combustion chamber are in communication. The time for burning of fuel in the precombustion chamber can be regulated by the distance required to move the piston from the top dead center position to the position wherein the precombustion chamber and main combustion chamber are in communication.

  2. Combustion stratification study of partially premixed combustion using Fourier transform analysis of OH* chemiluminescence images

    KAUST Repository

    Izadi Najafabadi, Mohammad

    2017-11-06

    A relatively high level of stratification (qualitatively: lack of homogeneity) is one of the main advantages of partially premixed combustion over the homogeneous charge compression ignition concept. Stratification can smooth the heat release rate and improve the controllability of combustion. In order to compare stratification levels of different partially premixed combustion strategies or other combustion concepts, an objective and meaningful definition of “stratification level” is required. Such a definition is currently lacking; qualitative/quantitative definitions in the literature cannot properly distinguish various levels of stratification. The main purpose of this study is to objectively define combustion stratification (not to be confused with fuel stratification) based on high-speed OH* chemiluminescence imaging, which is assumed to provide spatial information regarding heat release. Stratification essentially being equivalent to spatial structure, we base our definition on two-dimensional Fourier transforms of photographs of OH* chemiluminescence. A light-duty optical diesel engine has been used to perform the OH* bandpass imaging on. Four experimental points are evaluated, with injection timings in the homogeneous regime as well as in the stratified partially premixed combustion regime. Two-dimensional Fourier transforms translate these chemiluminescence images into a range of spatial frequencies. The frequency information is used to define combustion stratification, using a novel normalization procedure. The results indicate that this new definition, based on Fourier analysis of OH* bandpass images, overcomes the drawbacks of previous definitions used in the literature and is a promising method to compare the level of combustion stratification between different experiments.

  3. Experimental research on combustion fluorine retention using calcium-based sorbents during coal combustion (II)

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Q.; Ma, X.; Liu, J.; Wu, X.; Zhou, J.; Cen, K. [Liaoning Technical University, Fuxin (China). College of Resource and Environment Engineering

    2008-12-15

    Fluoride pollution produced by coal burning can be controlled with the calcium-based sorbent combustion fluorine technique in which calcium-based sorbents are mixed with the coal or sprayed into the combustion chamber. In a fixed bed tube furnace combustion experiment using one calcium-based natural mineral, limestone and one calcium-based building material, it was shown that the calcium-based sorbent particle grain size and pore structure have a big influence on the combustion fluorine retention effect. Reducing the calcium-based sorbent particle grain size and improving the calcium sorbent structure characteristics at very high temperature to enhance the fluorine retention effect is the important approach to the fluorine retention agent development. 8 refs., 1 fig., 5 tabs.

  4. Caracterización faunística en un sistema silvopastoril destinado al ganado de engorde

    Directory of Open Access Journals (Sweden)

    J Iraola

    Full Text Available La investigación se desarrolló durante cinco años, con el objetivo de evaluar el comportamiento faunístico en un sistema silvopastoril destinado al ganado de engorde. Se aplicó un modelo lineal mixto donde se usaron como efectos fijos el año, la época y la interacción año por época, y como efecto aleatorio los cuadrantes. Se determinaron los índices ecológicos número de individuos, riqueza y diversidad. También se determinó la sobrevivencia de árboles y la producción de biomasa, y se ponderó un índice de capacidad de carga biológica. Se realizaron análisis de regresiones simples entre la biomasa, los árboles y los índices número de individuos y diversidad. Se observó diferencia (p < 0,001 en el número de individuos totales entre los dos años iniciales, mientras que el segundo no difirió del tercero y el cuarto año difirió del quinto. El indicador riqueza difirió (p < 0,001 entre los diferentes años. Asimismo, hubo diferencias (p < 0,001 en la diversidad biológica y se hallaron relaciones positivas entre el componente arbóreo, la biomasa y los índices número de individuos totales y diversidad de especies. Se concluye que el sistema silvopastoril, como modelo de cobertura, posibilitó un hábitat más amplio para el desarrollo faunístico, y mejoró la relación de los índices ecológicos debido a la presencia de los árboles y el incremento de la biomasa en el sistema.

  5. Pressurized Fluidized Bed Combustion of Sewage Sludge

    Science.gov (United States)

    Suzuki, Yoshizo; Nojima, Tomoyuki; Kakuta, Akihiko; Moritomi, Hiroshi

    A conceptual design of an energy recovering system from sewage sludge was proposed. This system consists of a pressurized fluidized bed combustor, a gas turbine, and a heat exchanger for preheating of combustion air. Thermal efficiency was estimated roughly as 10-25%. In order to know the combustion characteristics of the sewage sludge under the elevated pressure condition, combustion tests of the dry and wet sewage sludge were carried out by using laboratory scale pressurized fluidized bed combustors. Combustibility of the sewage sludge was good enough and almost complete combustion was achieved in the combustion of the actual wet sludge. CO emission and NOx emission were marvelously low especially during the combustion of wet sewage sludge regardless of high volatile and nitrogen content of the sewage sludge. However, nitrous oxide (N2O) emission was very high. Hence, almost all nitrogen oxides were emitted as the form of N2O. From these combustion tests, we judged combustion of the sewage sludge with the pressurized fluidized bed combustor is suitable, and the conceptual design of the power generation system is available.

  6. AIR EMISSIONS FROM SCRAP TIRE COMBUSTION

    Science.gov (United States)

    The report discusses air emissions from two types of scrap tire combustion: uncontrolled and controlled. Uncontrolled sources are open tire fires, which produce many unhealthful products of incomplete combustion and release them directly into the atmosphere. Controlled combustion...

  7. Thermogravimetric analysis of biowastes during combustion

    International Nuclear Information System (INIS)

    Otero, M.; Sanchez, M.E.; Gomez, X.; Moran, A.

    2010-01-01

    The combustion of sewage sludge (SS), animal manure (AM) and the organic fraction of municipal solid waste (OFMSW) was assessed and compared with that of a semianthracite coal (SC) and of a PET waste by thermogravimetric (TG) analysis. Differences were found in the TG curves obtained for the combustion of these materials accordingly to their respective proximate analysis. Non-isothermal thermogravimetric data were used to assess the kinetics of the combustion of these biowastes. The present paper reports on the application of the Vyazovkin model-free isoconversional method for the evaluation of the activation energy necessary for the combustion of these biowastes. The activation energy related to SS combustion (129.1 kJ/mol) was similar to that corresponding to AM (132.5 kJ/mol) while the OFMSW showed a higher value (159.3 kJ/mol). These values are quite higher than the one determined in the same way for the combustion of SC (49.2 kJ/mol) but lower than that for the combustion of a PET waste (165.6 kJ/mol).

  8. Straw combustion on slow-moving grates

    DEFF Research Database (Denmark)

    Kær, Søren Knudsen

    2005-01-01

    Combustion of straw in grate-based boilers is often associated with high emission levels and relatively poor fuel burnout. A numerical grate combustion model was developed to assist in improving the combustion performance of these boilers. The model is based on a one-dimensional ‘‘walking......-column’’ approach and includes the energy equations for both the fuel and the gas accounting for heat transfer between the two phases. The model gives important insight into the combustion process and provides inlet conditions for a computational fluid dynamics analysis of the freeboard. The model predictions...... indicate the existence of two distinct combustion modes. Combustion air temperature and mass flow-rate are the two parameters determining the mode. There is a significant difference in reaction rates (ignition velocity) and temperature levels between the two modes. Model predictions were compared...

  9. Oxy-fuel combustion of solid fuels

    DEFF Research Database (Denmark)

    Toftegaard, Maja Bøg; Brix, Jacob; Jensen, Peter Arendt

    2010-01-01

    Oxy-fuel combustion is suggested as one of the possible, promising technologies for capturing CO2 from power plants. The concept of oxy-fuel combustion is removal of nitrogen from the oxidizer to carry out the combustion process in oxygen and, in most concepts, recycled flue gas to lower the flame...... provide additional options for improvement of process economics are however likewise investigated. Of particular interest is the change of the combustion process induced by the exchange of carbon dioxide and water vapor for nitrogen as diluent. This paper reviews the published knowledge on the oxy......-fuel process and focuses particularly on the combustion fundamentals, i.e. flame temperatures and heat transfer, ignition and burnout, emissions, and fly ash characteristics. Knowledge is currently available regarding both an entire oxy-fuel power plant and the combustion fundamentals. However, several...

  10. FASES DE RESOLUCIÓN DE UNA SITUACIÓN-PROBLEMA UTILIZANDO ELEMENTOS DE COMPETENCIAS

    Directory of Open Access Journals (Sweden)

    Ester Ruda

    2012-01-01

    Full Text Available El objetivo de este trabajo fue analizar las fases utilizadas para resolver una situación-problema a través de elementos de competencias en el proceso de enseñanza y aprendizaje de una asignatura universitaria. Se analizan las fases a desarrollar (análisis de la situación-problema, identificación de los esquemas de actuación, selección, disposición y aplicación estratégica de los esquemas de actuación; conocimiento, dominio y transferencia de los componentes de la competencia y las evidencias de logro del dominio de los componentes de la competencia. Se aplican los conceptos a un ejemplo para una asignatura del ciclo superior de una carrera relacionada con la química y se discuten los resultados obtenidos. La resolución de una situación-problema implica que los alumnos han adquirido elementos de competencias, han sorteado distintos pasos que implican el dominio de procedimientos que aparecen en toda acción competente y han aplicado interrelacionadamente contenidos conceptuales, actitudinales y procedimentales.

  11. Combustion Velocity of Benzine-Benzol-Air Mixtures in High-Speed Internal-Combustion Engines

    Science.gov (United States)

    Schnauffer, Kurt

    1932-01-01

    The present paper describes a device whereby rapid flame movement within an internal-combustion engine cylinder may be recorded and determined. By the aid of a simple cylindrical contact and an oscillograph the rate of combustion within the cylinder of an airplane engine during its normal operation may be measured for gas intake velocities of from 30 to 35 m/s and for velocities within the cylinder of from 20 to 25 m/s. With it the influence of mixture ratios, of turbulence, of compression ratio and kind of fuel on combustion velocity may be determined. Besides the determination of the influence of the above factors on combustion velocity, the degree of turbulence may also be determined. As a unit of reference in estimating the degree of turbulence, the intake velocity of the charge is chosen.

  12. Use of combustible wastes as fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kotler, V.R.; Salamov, A.A.

    1983-01-01

    Achievements of science and technology in creating and using units for combustion of wastes with recovery of heat of the escaping gases has been systematized and generalized. Scales and outlooks are examined for the use of general, industrial and agricultural waste as fuel, composition of the waste, questions of planning and operating units for combustion of solid refuse, settling of waste water and industrial and agricultural waste. Questions are covered for preparing them for combustion use in special units with recovery of heat and at ES, aspects of environmental protection during combustion of waste, cost indicators of the employed methods of recovering the combustible waste.

  13. Limpeza de elementos municiais em balística forense

    OpenAIRE

    Neto, Ana Raquel Ferreira

    2015-01-01

    A presente dissertação tem por objetivo a implementação de novos métodos de limpeza de elementos municiais de modo a substituir os métodos usados na Especialidade Forense de Balística do Laboratório de Polícia Científica da Polícia Judiciária. Estes métodos pretendem remover os três tipos de degradação/contaminação mais comuns na prática pericial do laboratório: gesso, corrosão e sangue. Os resultados obtidos no decorrer do trabalho foram avaliados de acordo com critérios pr...

  14. Fuel location, homogeneity and amount in flat and tubular configurations; Repartition, Homogeneite et Quantite du Combustible dans les Elements a Configuration Plate ou Tubulaire; Polozhenie, gomogennost' i kolichestvo topliva v ploskikh i trubchatykh konfiguratsiyakh; Disposicion, Homogeneidad y Cantidad de Combustibles en Configuraciones Planas y Tubulares

    Energy Technology Data Exchange (ETDEWEB)

    Meester, P. de [Studiecentrum voor Kernenergie, Mol (Belgium)

    1965-10-15

    controler les caracteristiques de deformabilite et les formes finales. La mesure de l'absorption a l'aide d'une source activee donne des resultats moins satisfaisants. L'auteur discute les donnees numeriques obtenues a partir de mesures statiques et d'enregistrements continus Il faut connaitre la quantite absolue de combustible par zone pour le calcul des parametres de fonctionnement du reacteur, et par element pour la comptabilite du combustible ainsi qu'aux fins de comparaison des taux d'irradiation. Le memoire traite de la fabrication et de l'utilisation des divers etalons. Il discute le degre de precision et l'elimination des erreurs. L'auteur propose plusieurs ameliorations des operations de controle. (author) [Spanish] Los elementos combustibles para el reactor de ensayo de materiales BR-2 pueden armarse con placas tipo cuadro, o bien con tubos preparados por coextrusion. En el curso de la elaboracion y antes de cargar el reactor, es nesesario verificar o medir la disposicion, homogeneidad y cantidad absoluta de combustible. La disposicion del combustible debe conocerse para fijar la ubicacion del alma en placas y tubos, y tambien como primera evaluacion de la calidad del producto en lo que atane a las especificaciones sobre su forma geometrica. Se han efectuado inspecciones mediante radiografia a unos 80-90 keV, autorradiograffa y gammagraffa con una fuente de {sup 170}Tm. Para radiografiar los tubos de combustible, se coloco en su interior un mandril de plomo al cual se habfa fijado la pelicula de rayos X y se tomaron luego varias exposiciones desde distintos angulos. Una fuente radiactiva usada para explorar el tubo longitudinalmente, combinada con una pelicula dispuesta alrededor del tubo, permitio obtener registros de elevada resolucion. La homogeneidad del combustible debe controlarse con miras a un foncionamiento seguro del reactor, es decir, se han de evitar por una parte concentraciones excesivas de combustible que podrian producir vapor en el reactor de agua

  15. Combustion characteristics and influential factors of isooctane active-thermal atmosphere combustion assisted by two-stage reaction of n-heptane

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Xingcai; Ji, Libin; Ma, Junjun; Zhou, Xiaoxin; Huang, Zhen [Key Lab. for Power Machinery and Engineering of MOE, Shanghai Jiao Tong University, 200240 Shanghai (China)

    2011-02-15

    This paper presents an experimental study on the isooctane active-thermal atmosphere combustion (ATAC) which is assisted by two-stage reaction of n-heptane. The active-thermal atmosphere is created by low- and high-temperature reactions of n-heptane which is injected at intake port, and isooctane is directly injected into combustion chamber near the top dead center. The effects of isooctane injection timing, active-thermal atmosphere intensity, overall equivalence ratio, and premixed ratio on combustion characteristics and emissions are investigated. The experimental results reveal that, the isooctane ignition and combustion can be classified to thermal atmosphere combustion, active atmosphere combustion, and active-thermal atmosphere combustion respectively according to the extent of n-heptane oxidation as well as effects of isooctane quenching and charge cooling. n-Heptane equivalence ratio, isooctane equivalence ratio and isooctane delivery advance angle are major control parameters. In one combustion cycle, the isooctane ignited and burned after those of n-heptane, and then this combustion phenomenon can also be named as dual-fuel sequential combustion (DFSC). The ignition timing of the overall combustion event is mainly determined by n-heptane equivalence ratio and can be controlled in flexibility by simultaneously adjusting isooctane equivalence ratio. The isooctane ignition regime, overall thermal efficiency, and NO{sub x} emissions show strong sensitivity to the fuel delivery advance angle between 20 CA BTDC and 25 CA BTDC. (author)

  16. Simulation of low temperature combustion mechanism of different combustion-supporting agents in close-coupled DOC and DPF system.

    Science.gov (United States)

    Jiao, Penghao; Li, Zhijun; Li, Qiang; Zhang, Wen; He, Li; Wu, Yue

    2018-07-01

    In the coupled Diesel Oxidation Catalyst (DOC) and Diesel Particular Filter (DPF) system, soot cannot be completely removed by only using the passive regeneration. And DPF active regeneration is necessary. The research method in this paper is to spray different kinds of combustion-supporting agents to the DOC in the front of the DPF. Therefore, the low temperature combustion mechanism of different kinds of combustion-supporting agents in DOC was studied, in order to grasp the law of combustion in DOC, and the influence of follow-up emission on DPF removal of soot. During the study, CH 4 H 2 mixture and diesel (n-heptane + toluene) were used as combustion-supporting agents respectively. The simplified mechanisms of two kinds of gas mixtures used as the combustion-supporting agents in DPF have been constructed and testified in the paper. In this paper, the combustion and emission conditions of the two combustion-supporting agents were analyzed so as to meet the practical requirements of different working conditions. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  17. Strobes: An oscillatory combustion

    NARCIS (Netherlands)

    Corbel, J.M.L.; Lingen, J.N.J. van; Zevenbergen, J.F.; Gijzeman, O.L.J.; Meijerink, A.

    2012-01-01

    Strobe compositions belong to the class of solid combustions. They are mixtures of powdered ingredients. When ignited, the combustion front evolves in an oscillatory fashion, and flashes of light are produced by intermittence. They have fascinated many scientists since their discovery at the

  18. Fifteenth combustion research conference

    International Nuclear Information System (INIS)

    1993-01-01

    The BES research efforts cover chemical reaction theory, experimental dynamics and spectroscopy, thermodynamics of combustion intermediates, chemical kinetics, reaction mechanisms, combustion diagnostics, and fluid dynamics and chemically reacting flows. 98 papers and abstracts are included. Separate abstracts were prepared for the papers

  19. Herramientas de software con licencia pública general para el modelado por elementos finitos

    Directory of Open Access Journals (Sweden)

    CARLOS GALEANO

    2007-01-01

    Full Text Available En el presente artículo se presentan los resultados de una revisión realizada a varios programas con licencias GPL para el modelamiento de problemas con elementos finitos. Este estudio permitió realizar la caracterización de estos programas teniendo en cuenta criterios como el tipo de análisis permitido, la compatibilidad con programas CAD, el tipo de soporte ofrecido, la actualización de las versiones, el tipo de interfaz de usuario implementado y la curva de aprendizaje para nuevos usuarios, entre otros. Posteriormente se estudiaron tres casos diferentes, los cuales fueron modelados con elementos finitos empleando distintos programas GPL. En la parte final del documento se comparan los resultados obtenidos con software libre, los arrojados por un programa comercial (Ansys, y los modelos analíticos derivados de la solución de la ecuación diferencial que rige el fenómeno particular, obteniendo una convergencia aceptable entre todos los resultados

  20. Numerical analysis for controlling mixture heterogeneity to reduce abrupt combustion in diesel PCCI combustion

    Energy Technology Data Exchange (ETDEWEB)

    Nishiwaki, Kazuie [Ritsumeikan University (Japan); Kojima, Takafumi [Takamatsu National College of Technology (Japan)

    2010-07-01

    In the energy sector, stringent regulations have been implemented on combustion emissions in order to address health and environmental concerns and help improve air quality. A novel combustion mode, premixed charge compression ignition (PCCI), can improve the emissions performance of an engine over that of conventional diesel. The aim of this research is to develop a model to analyze the mixture formation in the PCCI combustion mode. A numerical model was developed and was applied to an engine and the results were compared to experimental results. It was found that the model results are in agreement with the experimental results. This paper presented a novel LES computer model and demonstrated that it is efficient in predicting the mixture formation in the PCCI combustion mode.

  1. Modeling and simulating combustion and generation of NOx

    International Nuclear Information System (INIS)

    Lazaroiu, Gheorghe

    2007-01-01

    This paper deals with the modeling and simulation of combustion processes and generation of NO x in a combustion chamber and boiler, with supplementary combustion in a gas turbine installation. The fuel burned in the combustion chamber was rich gas with a chemical composition more complex than natural gas. Pitcoal was used in the regenerative boiler. From the resulting combustion products, 17 compounds were retained, including nitrogen and sulphur compounds. Using the developed model, the simulation resulted in excess air for a temperature imposed at the combustion chamber exhaust. These simulations made it possible to determine the concentrations of combustion compounds with a variation in excess combustion. (author)

  2. Multi-zone modelling of PCCI combustion

    NARCIS (Netherlands)

    Egüz, U.; Somers, L.M.T.; Leermakers, C.A.J.; Goey, de L.P.H.

    2011-01-01

    Early Direct Injection Premixed Charge Compression Ignition (EDI PCCI) combustion is a promising concept for the diesel combustion. Although EDI PCCI assures very low soot and NO xemission levels, the injection is uncoupled from combustion, which narrows down the operating conditions. The main

  3. Combustor nozzle for a fuel-flexible combustion system

    Science.gov (United States)

    Haynes, Joel Meier [Niskayuna, NY; Mosbacher, David Matthew [Cohoes, NY; Janssen, Jonathan Sebastian [Troy, NY; Iyer, Venkatraman Ananthakrishnan [Mason, OH

    2011-03-22

    A combustor nozzle is provided. The combustor nozzle includes a first fuel system configured to introduce a syngas fuel into a combustion chamber to enable lean premixed combustion within the combustion chamber and a second fuel system configured to introduce the syngas fuel, or a hydrocarbon fuel, or diluents, or combinations thereof into the combustion chamber to enable diffusion combustion within the combustion chamber.

  4. Juicios valorativos: elementos y proceso de formulación en la evaluación del aprendizaje

    Directory of Open Access Journals (Sweden)

    Pasek de Pinto, Eva

    2015-05-01

    Full Text Available Este artículo es producto de una investigación cuyo objetivo consistió enanalizar los elementos de los juicios valorativos y el proceso de su formulación en la evaluación de los aprendizajes. Metodológicamente se trata de un estudio documental que se realizó en siete pasos: Formular preguntas iniciales, explorar bibliografía, enfocar teóricamente el problema, establecer el modelo de análisis, observar documentos, analizar e integrar la información y elaborar conclusiones. Como resultado se obtuvo: 1 la descripción de los tres elementos de un juicio: sujeto, cópula y predicado; 2 un proceso para formular juicios estimativos en cuatro pasos: comparar, interpretar, calificar y juzgar o valorar; 3 un proceso para formular juicios predictivos en tres pasos:buscar otras opiniones, analizar realizaciones pasadas y predecir logros futuros. Se concluye que el juicio es el momento álgido de la evaluación, pues evaluar es juzgar. En consecuencia, conocer los elementos que constituyen un juicio y el proceso para formular juicios valorativos es imprescindible para generar confianza en la elaboración de juicios correctos y adecuados para una acertada toma de decisiones, conduciendo un proceso de evaluación óptimo, pertinente, justo, cónsono con la políticas educativas establecidas

  5. Establishment of Combustion Model for Isooctane HCCI Marine Diesel Engine and Research on the Combustion Characteristic

    Directory of Open Access Journals (Sweden)

    Li Biao

    2016-01-01

    Full Text Available The homogeneous charge compression ignition (HCCI combustion mode applied in marine diesel engine is expected to be one of alternative technologies to decrease nitrogen oxide (NOX emission and improve energy utilization rate. Applying the chemical-looping combustion (CLC mechanism inside the cylinder, a numerical study on the HCCI combustion process is performed taking a marine diesel engine as application object. The characteristic feature of combustion process is displayed. On this basis, the formation and emission of NOX are analyzed and discussed. The results indicate that the HCCI combustion mode always exhibit two combustion releasing heats: low-temperature reaction and high-temperature reaction. The combustion phase is divided into low-temperature reaction zone, high-temperature reaction zone and negative temperature coefficient (NTC zone. The operating conditions of the high compression ratio, high intake air temperature, low inlet pressure and small excess air coefficient would cause the high in-cylinder pressure which often leads engine detonation. The low compression ratio, low intake air temperature and big excess air coefficient would cause the low combustor temperature which is conducive to reduce NOX emissions. These technological means and operating conditions are expected to meet the NOX emissions limits in MARPOL73/78 Convention-Annex VI Amendment.

  6. Emission and combustion characteristics of multiple stage diesel combustion; Nidan nensho ni yoru diesel kikan no nensho to haishutsubutsu tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Hashizume, T; Miyamoto, T; Tsujimura, K [New A.C.E. Institute Co. Ltd., Tokyo (Japan); Kobayashi, S; Shimizu, K [Japan Automobile Research Institute, Tsukuba (Japan)

    1997-10-01

    A new concept of multiple stage diesel combustion was studied by means of engine test, combustion observation and numerical simulation, in order to reduce NOx emissions at high load conditions. With this concept, the premixed combustion occurs under the fuel lean conditions and the diffusion combustion occurs under the high temperature conditions. As seen in the result of combustion observation, a first stage combustion occurs with no luminous flame. A second stage combustion occurs with a luminous flame after very short ignition delay period. However the luminous flame is disappeared immediately. Because cylinder temperature is high, and hence soot oxidizes immediately. 5 refs., 11 figs., 1 tab.

  7. 76 FR 16646 - Circadian, Inc., Clean Energy Combustion, Inc. (n/k/a Clean Energy Combustion Systems, Inc...

    Science.gov (United States)

    2011-03-24

    ... SECURITIES AND EXCHANGE COMMISSION [File No. 500-1] Circadian, Inc., Clean Energy Combustion, Inc. (n/k/a Clean Energy Combustion Systems, Inc.), Collectible Concepts Group, Inc., Communitronics of... is a lack of current and accurate information concerning the securities of Clean Energy Combustion...

  8. Effect of combustion characteristics on wall radiative heat flux in a 100 MWe oxy-coal combustion plant

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.; Ryu, C. [Sungkyunkwan Univ., Suwon (Korea, Republic of). School of Mechanical Engineering; Chae, T.Y. [Sungkyunkwan Univ., Suwon (Korea, Republic of). School of Mechanical Engineering; Korea Institute of Industrial Technology, Cheonan (Korea, Republic of). Energy System R and D Group; Yang, W. [Korea Institute of Industrial Technology, Cheonan (Korea, Republic of). Energy System R and D Group; Kim, Y.; Lee, S.; Seo, S. [Korea Electric Power Research Institute (KEPRI), Daejeon (Korea, Republic of). Power Generation Lab.

    2013-07-01

    Oxy-coal combustion exhibits different reaction, flow and heat transfer characteristics from air-coal combustion due to different properties of oxidizer and flue gas composition. This study investigated the wall radiative heat flux (WRHF) of air- and oxy-coal combustion in a simple hexahedral furnace and in a 100 MWe single-wall-fired boiler using computational modeling. The hexahedral furnace had similar operation conditions with the boiler, but the coal combustion was ignored by prescribing the gas properties after complete combustion at the inlet. The concentrations of O{sub 2} in the oxidizers ranging between 26 and 30% and different flue gas recirculation (FGR) methods were considered in the furnace. In the hexahedral furnace, the oxy-coal case with 28% of O{sub 2} and wet FGR had a similar value of T{sub af} with the air-coal combustion case, but its WRHF was 12% higher. The mixed FGR case with about 27% O{sub 2} in the oxidizer exhibited the WRHF similar to the air-coal case. During the actual combustion in the 100 MWe boiler using mixed FGR, the reduced volumetric flow rates in the oxy-coal cases lowered the swirl strength of the burners. This stretched the flames and moved the high temperature region farther to the downstream. Due to this reason, the case with 30% O{sub 2} in the oxidizers achieved a WRHF close to that of air-coal combustion, although its adiabatic flame temperature (T{sub af}) and WHRF predicted in the simplified hexahedral furnace was 103 K and 10% higher, respectively. Therefore, the combustion characteristics and temperature distribution significantly influences the WRHF, which should be assessed to determine the ideal operating conditions of oxy- coal combustion. The choice of the weighted sum of gray gases model (WSGGM) was not critical in the large coal-fired boiler.

  9. Infrared monitoring of combustion

    International Nuclear Information System (INIS)

    Bates, S.C.; Morrison, P.W. Jr.; Solomon, P.R.

    1991-01-01

    In this paper, the use of Fourier Transform Infrared (FT-IR) spectroscopy for combustion monitoring is described. A combination of emission, transmission, and reflection FT-IR spectroscopy yields data on the temperature and composition of the gases, surfaces and suspended particles in the combustion environment. Detection sensitivity of such trace exhaust gases as CO, CO 2 , SO 2 , NO x , and unburned hydrocarbons is at the ppm level. Tomographic reconstruction converts line-of-sight measurements into spatially resolved temperature and concentration data. Examples from various combustion processes are used to demonstrate the capabilities of the technique. Industrial measurements are described that have been performed directly in the combustion zone and in the exhaust duct of a large chemical recovery boiler. Other measurements of hot slag show how FT-IR spectroscopy can determine the temperature and optical properties of surfaces. In addition, experiments with water droplets show that transmission FT-IR data yield spectra that characterize particle size and number density

  10. Estudo sobre os elementos de uma interpretação invasiva na abordagem psicanalítica winnicottiana Estudio sobre los elementos de una interpretación invasiva en el abordaje psicoanalítico winnicottiano Study on the elements of an invasive interpretation in the Winnicott psychoanalytical approach

    Directory of Open Access Journals (Sweden)

    Conceição Aparecida Serralha

    2012-04-01

    Full Text Available Partindo dos textos freudianos, este estudo reapresenta brevemente a técnica da interpretação em psicanálise e, baseando-se na obra de Winnicott, discute os elementos de uma interpretação sentida de forma invasiva pelo analisando. São identificados, nomeados e discutidos os elementos apontados por este autor: tempo, modo, graus de confiabilidade, objetividade e conhecimento, sendo ilustrados por alguns fragmentos de sessão de casos de Winnicott e de um caso da autora. O estudo evidencia a importância da capacidade de o analista se identificar com o analisando para interpretar, recebendo e entendendo a comunicação deste sobre a adequação de todos esses elementos ao seu caso.Partiendo de los textos freudianos, este estudio reapresenta brevemente la técnica de la interpretación en psicoanálisis y, basándose en la obra de Winnicott, discute los elementos de una interpretación sentida de forma invasiva por el analizando. Son identificados, nombrados y discutidos los elementos apuntados por este autor: tiempo, modo, grados de confiabilidad, objetividad y conocimiento, siendo ilustrados por algunos fragmentos de sesión de casos de Winnicott y de un caso de lo autor. El estudio evidencia la importancia de la capacidad de el analista identificarse con el analizando para interpretar, recibiendo y entendiendo la comunicación de este sobre la adecuación de todos esos elementos a su caso.From the Freudian texts, this study reintroduces briefly the technique of interpretation in psychoanalysis and, based on the Winnicott's works, discusses the elements of an interpretation felt invasive by the patient. The elements pointed out by this author and identified, named and discussed include: time, manner, degrees of trustworthiness, objectiveness and knowledge. They are illustrated with fragments of session of Winnicott's cases and one case of the author. The study highlights the importance of the analyst's capacity of identifying him

  11. Control device for combustible gas concentration

    International Nuclear Information System (INIS)

    Osawa, Yasuo.

    1988-01-01

    Purpose: To control the concentration of combustible gases such as hydrogen evolved in a reactor container upon loss-of-coolant accidents. Constitution: Combustible gases evolved from the lower area of a drywell in which a combustible atmosphere is liable to be formed locally are taken out through a take-out pipeway to the outside of a reactor container and processed by a hydrogen-oxygen recombiner. Combustible gases in other areas of the drywell are also introduced to the lower area of the drywell and then taken-out externally for procession. Further, combustible gases in the suppression chamber are introduced by the opening of a vacuum breaking valve through a gas supply pipe to the lower area of the drywell and fluids in the drywell are stirred and diluted with fluids exhausted from the gas supply pipe. Disposition of such take-out pipeway and gas supply pipe can reduce the possibility of forming local combustible atmosphere to improve the integrity of the reactor container. (Kamimura, M.)

  12. Techniques de combustion Combustin Techniques

    Directory of Open Access Journals (Sweden)

    Perthuis E.

    2006-11-01

    Full Text Available L'efficacité d'un processus de chauffage par flamme est étroitement liée à la maîtrise des techniques de combustion. Le brûleur, organe essentiel de l'équipement de chauffe, doit d'une part assurer une combustion complète pour utiliser au mieux l'énergie potentielle du combustible et, d'autre part, provoquer dans le foyer les conditions aérodynamiques les plus propices oux transferts de chaleur. En s'appuyant sur les études expérimentales effectuées à la Fondation de Recherches Internationales sur les Flammes (FRIF, au Groupe d'Étude des Flammes de Gaz Naturel (GEFGN et à l'Institut Français du Pétrole (IFP et sur des réalisations industrielles, on présente les propriétés essentielles des flammes de diffusion aux combustibles liquides et gazeux obtenues avec ou sans mise en rotation des fluides, et leurs répercussions sur les transferts thermiques. La recherche des températures de combustion élevées conduit à envisager la marche à excès d'air réduit, le réchauffage de l'air ou son enrichissement à l'oxygène. Par quelques exemples, on évoque l'influence de ces paramètres d'exploitation sur l'économie possible en combustible. The efficiency of a flame heating process is closely linked ta the mastery of, combustion techniques. The burner, an essential element in any heating equipment, must provide complete combustion sa as to make optimum use of the potential energy in the fuel while, at the same time, creating the most suitable conditions for heat transfers in the combustion chamber. On the basis of experimental research performed by FRIF, GEFGN and IFP and of industrial achievements, this article describesthe essential properties of diffusion flames fed by liquid and gaseous fuels and produced with or without fluid swirling, and the effects of such flames on heat transfers. The search for high combustion temperatures means that consideration must be given to operating with reduced excess air, heating the air or

  13. PDF Modeling of Turbulent Combustion

    National Research Council Canada - National Science Library

    Pope, Stephen B

    2006-01-01

    .... The PDF approach to turbulent combustion has the advantages of fully representing the turbulent fluctuations of species and temperature, and of allowing realistic combustion chemistry to be implemented...

  14. Sulfur Chemistry in Combustion I

    DEFF Research Database (Denmark)

    Johnsson, Jan Erik; Glarborg, Peter

    2000-01-01

    of the sulphur compounds in fossil fuels and the possibilities to remove them will be given. Then the combustion of sulphur species and their influence on the combustion chemistry and especially on the CO oxidation and the NOx formation will be described. Finally the in-situ removal of sulphur in the combustion...... process by reaction between SO2 and calcium containing sorbents and the influence on the NOx chemistry will be treated....

  15. Elementos finitos con acciones repartidas equivalentes de cualquier orden. Aplicación a los modelos de vigas de Timoshenko y Bernoulli-Euler

    Directory of Open Access Journals (Sweden)

    Romero, J. L.

    2014-09-01

    Full Text Available In the context of the Finite Element Method, two possible alternatives dealing with the concept of equivalent distributed load are presented in the paper. The first consist in using few finite elements, by slightly increasing the order of the load, while the second applies the use of a greater number of elements leaving the load in the lowest possible order. Both situations are sampled with application to the Timoshenko and Bernoulli-Euler beam models, with different orders of load are used. These equivalent distributed loads are the result of applying Legendre orthogonal polynomial approximations, to the original load, in each element. The most noteworthy conclusion is that when the least possible number of finite elements is used (i.e., one also for considering low level of regularity load cases only equivalent distributed loads of slightly higher than minimum order (four were needed to obtain an excellent approximation when computing the deflections, rotations, bending moments and shear forces inside the elements.En este trabajo se introducen, en el contexto del Método de Elementos Finitos, dos alternativas posibles en relación con el concepto de acción repartida equivalente. La primera consiste en emplear pocos elementos, elevando el orden de dicha acción, mientras que la segunda se basa en emplear un mayor número de elementos dejando la acción en el orden más bajo posible. Se ilustran ambas situaciones mediante aplicaciones a los modelos de vigas de Timoshenko y Bernoulli-Euler, empleando estas acciones con diferentes órdenes, las cuales aproximan a la acción original, mediante polinomios ortogonales de Legendre en cada elemento. Como conclusión destacable, se indica que cuando se considera el menor número posible de elementos, es decir uno, para los casos de carga poco regular, ha bastado con utilizar acciones repartidas equivalentes de orden ligeramente superior al mínimo (orden cuatro, para obtener una excelente aproximaci

  16. In situ high-temperature gas sensors: continuous monitoring of the combustion quality of different wood combustion systems and optimization of combustion process

    Directory of Open Access Journals (Sweden)

    H. Kohler

    2018-03-01

    Full Text Available The sensing characteristics and long-term stability of different kinds of CO ∕ HC gas sensors (non-Nernstian mixed potential type during in situ operation in flue gas from different types of low-power combustion systems (wood-log- and wood-chip-fuelled were investigated. The sensors showed representative but individual sensing behaviour with respect to characteristically varying flue gas composition over the combustion process. The long-term sensor signal stability evaluated by repeated exposure to CO ∕ H2 ∕ N2 ∕ synthetic air mixtures showed no sensitivity loss after operation in the flue gas. Particularly for one of the sensors (Heraeus GmbH, this high signal stability was observed in a field test experiment even during continuous operation in the flue gas of the wood-chip firing system over 4 months. Furthermore, it was experimentally shown that the signals of these CO ∕ HC sensing elements yield important additional information about the wood combustion process. This was demonstrated by the adaptation of an advanced combustion airstream control algorithm on a wood-log-fed fireplace and by the development of a combustion quality monitoring system for wood-chip-fed central heaters.

  17. Internal and surface phenomena in metal combustion

    Science.gov (United States)

    Dreizin, Edward L.; Molodetsky, Irina E.; Law, Chung K.

    1995-01-01

    Combustion of metals has been widely studied in the past, primarily because of their high oxidation enthalpies. A general understanding of metal combustion has been developed based on the recognition of the existence of both vapor-phase and surface reactions and involvement of the reaction products in the ensuing heterogeneous combustion. However, distinct features often observed in metal particle combustion, such as brightness oscillations and jumps (spearpoints), disruptive burning, and non-symmetric flames are not currently understood. Recent metal combustion experiments using uniform high-temperature metal droplets produced by a novel micro-arc technique have indicated that oxygen dissolves in the interior of burning particles of certain metals and that the subsequent transformations of the metal-oxygen solutions into stoichiometric oxides are accompanied with sufficient heat release to cause observed brightness and temperature jumps. Similar oxygen dissolution has been observed in recent experiments on bulk iron combustion but has not been associated with such dramatic effects. This research addresses heterogeneous metal droplet combustion, specifically focusing on oxygen penetration into the burning metal droplets, and its influence on the metal combustion rate, temperature history, and disruptive burning. A unique feature of the experimental approach is the combination of the microgravity environment with a novel micro-arc Generator of Monodispersed Metal Droplets (GEMMED), ensuring repeatable formation and ignition of uniform metal droplets with controllable initial temperature and velocity. The droplet initial temperatures can be adjusted within a wide range from just above the metal melting point, which provides means to ignite droplets instantly upon entering an oxygen containing environment. Initial droplet velocity will be set equal to zero allowing one to organize metal combustion microgravity experiments in a fashion similar to usual microgravity

  18. El método de los elementos finitos para el cálculo de campos electrostáticos

    Directory of Open Access Journals (Sweden)

    Francisco Román Campos

    1982-09-01

    Full Text Available EI Método de los Elementos Finitos se plantea como uno de los sistemas numéricos más apropiados para el cálculo de Campos Electrostáticos por su aplicación al estudio de geometrías cerradas en las que sus condiciones de Frontera son conocidas. En el presente artículo se comenta el empleo del Programa NASTRAN  basado en este método y del Programa TOPONET para la generación de la Red de Elementos Finitos. Los ejemplos que aquí aparecen fueron corridos en el Centro de Cómputo de la Universidad Fridericiana de Karlsruhe. Alemania Federal.

  19. Second law comparison of oxy-fuel combustion and post-combustion carbon dioxide separation

    International Nuclear Information System (INIS)

    Simpson, Adam P.; Simon, A.J.

    2007-01-01

    To define 2nd law efficiency targets for novel separation technologies, a simplified model of a power plant with two forms of CO 2 capture was developed. In this investigation, oxy-fuel combustion and post-combustion CO 2 separation were compared on an exergetic basis. Using exergy balances and black-box models of power plant components, multiple scenarios were run to determine the impact of plant configuration and separation unit efficiency on overall plant performance. Second law efficiency values from the literature were used to set the baseline performance of various CO 2 separation configurations. Assumed advances in 2nd law efficiency were used to determine the potential for overall system performance improvement. It was found that the 2nd law efficiency of air separation must reach a critical value before the thermodynamics of oxy-fuel combustion become favorable. Changes in operating equivalence ratio significantly move the tipping-point between post-combustion and oxy-fuel strategies

  20. Investigating co-combustion characteristics of bamboo and wood.

    Science.gov (United States)

    Liang, Fang; Wang, Ruijuan; Jiang, Changle; Yang, Xiaomeng; Zhang, Tao; Hu, Wanhe; Mi, Bingbing; Liu, Zhijia

    2017-11-01

    To investigate co-combustion characteristics of bamboo and wood, moso bamboo and masson pine were torrefied and mixed with different blend ratios. The combustion process was examined by thermogravimetric analyzer (TGA). The results showed the combustion process of samples included volatile emission and oxidation combustion as well as char combustion. The main mass loss of biomass blends occurred at volatile emission and oxidation combustion stage, while that of torrefied biomass occurred at char combustion stage. With the increase of bamboo content, characteristic temperatures decreased. Compared with untreated biomass, torrefied biomass had a higher initial and burnout temperature. With the increase of heating rates, combustion process of samples shifted to higher temperatures. Compared with non-isothermal models, activation energy obtained from isothermal model was lower. The result is helpful to promote development of co-combustion of bamboo and masson pine wastes. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. New technologies reducing emissions from combustion of biofuels

    International Nuclear Information System (INIS)

    Oravainen, H.

    1997-01-01

    In reducing CO 2 emissions, bioenergy will be the most important source of renewable energy in the next few decades. In principle, combustion of biomass is friendly to the environment because CO 2 released during combustion is recycled back into natural circulation. Biofuels normally contain little nitrogen and sulphur. However, depending on the combustion technology used, emissions may be quite high. This is true of combustion of biomass fuels in small appliances like wood stoves, fireplaces, small boilers etc. When fuels having high content of volatile matter are burnt in appliances using batch type combustion, the process is rather an unsteady-state combustion. Emissions of carbon monoxide, other combustible gases and particulates are quite difficult to avoid. With continuous combustion processes this is not normally a problem. This conference paper presents some means of reducing emissions from combustion of biofuels. 5 refs., 4 figs

  2. Co-combustion of anthracite coal and wood pellets: Thermodynamic analysis, combustion efficiency, pollutant emissions and ash slagging.

    Science.gov (United States)

    Guo, Feihong; Zhong, Zhaoping

    2018-08-01

    This work presents studies on the co-combustion of anthracite coal and wood pellets in fluidized bed. Prior to the fluidized bed combustion, thermogravimetric analysis are performed to investigate the thermodynamic behavior of coal and wood pellets. The results show that the thermal decomposition of blends is divided into four stages. The co-firing of coal and wood pellets can promote the combustion reaction and reduce the emission of gaseous pollutants, such as SO 2 and NO. It is important to choose the proportion of wood pellets during co-combustion due to the low combustion efficiency caused by large pellets with poor fluidization. Wood pellets can inhibit the volatilization of trace elements, especially for Cr, Ni and V. In addition, the slagging ratio of wood pellets ash is reduced by co-firing with coal. The research on combustion of coal and wood pellets is of great significance in engineering. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Naphtha vs. dieseline – The effect of fuel properties on combustion homogeneity in transition from CI combustion towards HCCI

    KAUST Repository

    Vallinayagam, R.

    2018-03-20

    The scope of this research study pertains to compare the combustion and emission behavior between naphtha and dieseline at different combustion modes. In this study, US dieseline (50% US diesel + 50% RON 91 gasoline) and EU dieseline (45% EU diesel + 55% RON 97 gasoline) with derived cetane number (DCN) of 36 are selected for experimentation in an optical engine. Besides naphtha and dieseline, PRF60 is also tested as a surrogate fuel for naphtha. For the reported fuel with same RON = 60, the effect of physical properties on combustion homogeneity when moving from homogenized charge compression ignition (HCCI) to compression ignition (CI) combustion is studied.The combustion phasing of naphtha at an intake air temperature of 95 °C is taken as the baseline data. The engine experimental results show that higher and lower intake air temperature is required for dieseline mixtures to have same combustion phasing as that of naphtha at HCCI and CI conditions due to the difference in the physical properties. Especially at HCCI mode, due to wider distillation range of dieseline, the evaporation of the fuel is affected so that the gas phase mixture becomes too lean to auto-ignite. However, at partially premixed combustion (PPC) conditions, all test fuels required almost same intake air temperature to match up with the combustion phasing of baseline naphtha. From the rate of heat release and combustion images, it was found that naphtha and PRF60 showed improved premixed combustion when compared dieseline mixtures. The stratification analysis shows that combustion is more stratified for dieseline whereas it is premixed for naphtha and PRF60. The level of stratification linked with soot emission showed that soot concentration is higher at stratified CI combustion whereas near zero soot emissions were noted at PPC mode.

  4. Comparison of different chemical kinetic mechanisms of methane combustion in an internal combustion engine configuration

    OpenAIRE

    Ennetta Ridha; Hamdi Mohamed; Said Rachid

    2008-01-01

    Three chemical kinetic mechanisms of methane combustion were tested and compared using the internal combustion engine model of Chemkin 4.02 [1]: one-step global reaction mechanism, four-step mechanism, and the standard detailed scheme GRIMECH 3.0. This study shows good concordances, especially between the four-step and the detailed mechanisms in the prediction of temperature and main species profiles. But reduced schemes were incapables to predict pollutant emissions in an internal combustion...

  5. Mercadeo en educación: elementos para una propuesta pertinente

    OpenAIRE

    Contreras Gómez, María Consuelo del Pilar

    2013-01-01

    En la presente investigación se realizó una revisión y análisis crítico de los modelos actuales sobre mercadeo educativo y se plantea una propuesta sobre elementos diferentes que deben tenerse en cuenta para un proceso de mercadeo pertinente para el sector de la educación; dichos parámetros involucran la calidad educativa, la inclusión estudiantil, la aplicación de la ética y la dimensión humana de los estudiantes, como personas en quienes está focalizada la razón de ser de las instituciones ...

  6. Burning Questions in Gravity-Dependent Combustion Science

    Science.gov (United States)

    Urban, David; Chiaramonte, Francis P.

    2012-01-01

    Building upon a long history of spaceflight and ground based research, NASA's Combustion Science program has accumulated a significant body of accomplishments on the ISS. Historically, NASAs low-gravity combustion research program has sought: to provide a more complete understanding of the fundamental controlling processes in combustion by identifying simpler one-dimensional systems to eliminate the complex interactions between the buoyant flow and the energy feedback to the reaction zone to provide realistic simulation of the fire risk in manned spacecraft and to enable practical simulation of the gravitational environment experienced by reacting systems in future spacecraft. Over the past two decades, low-gravity combustion research has focused primarily on increasing our understanding of fundamental combustion processes (e.g. droplet combustion, soot, flame spread, smoldering, and gas-jet flames). This research program was highly successful and was aided by synergistic programs in Europe and in Japan. Overall improvements were made in our ability to model droplet combustion in spray combustors (e.g. jet engines), predict flame spread, predict soot production, and detect and prevent spacecraft fires. These results provided a unique dataset that supports both an active research discipline and also spacecraft fire safety for current and future spacecraft. These experiments have been conducted using the Combustion Integrated Rack (CIR), the Microgravity Science Glovebox and the Express Rack. In this paper, we provide an overview of the earlier space shuttle experiments, the recent ISS combustion experiments in addition to the studies planned for the future. Experiments in combustion include topics such as droplet combustion, gaseous diffusion flames, solid fuels, premixed flame studies, fire safety, and super critical oxidation processes.

  7. Experimental study of combustion and emission characteristics of ethanol fuelled port injected homogeneous charge compression ignition (HCCI) combustion engine

    Energy Technology Data Exchange (ETDEWEB)

    Maurya, Rakesh Kumar; Agarwal, Avinash Kumar [Engine Research Laboratory, Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Kanpur 208 016 (India)

    2011-04-15

    The homogeneous charge compression ignition (HCCI) is an alternative combustion concept for in reciprocating engines. The HCCI combustion engine offers significant benefits in terms of its high efficiency and ultra low emissions. In this investigation, port injection technique is used for preparing homogeneous charge. The combustion and emission characteristics of a HCCI engine fuelled with ethanol were investigated on a modified two-cylinder, four-stroke engine. The experiment is conducted with varying intake air temperature (120-150 C) and at different air-fuel ratios, for which stable HCCI combustion is achieved. In-cylinder pressure, heat release analysis and exhaust emission measurements were employed for combustion diagnostics. In this study, effect of intake air temperature on combustion parameters, thermal efficiency, combustion efficiency and emissions in HCCI combustion engine is analyzed and discussed in detail. The experimental results indicate that the air-fuel ratio and intake air temperature have significant effect on the maximum in-cylinder pressure and its position, gas exchange efficiency, thermal efficiency, combustion efficiency, maximum rate of pressure rise and the heat release rate. Results show that for all stable operation points, NO{sub x} emissions are lower than 10 ppm however HC and CO emissions are higher. (author)

  8. Catalytically enhanced combustion process

    International Nuclear Information System (INIS)

    Rodriguez, C.

    1992-01-01

    This patent describes a fuel having improved combustion efficiency. It comprises a petroleum based liquid hydrocarbon; and a combustion catalyst comprising from about 18 to about 21 weight percent naphthalene, from about 75 to about 80 weight percent toluene, and from about 2.8 to about 3.2 weight percent benzyl alcohol

  9. Análisis de pérdida de estabilidad no lineal de elementos estructurales sometidos a compresión.

    Directory of Open Access Journals (Sweden)

    J. Wellesley-Bourke Funcasta

    2007-01-01

    Full Text Available En el presente artículo se muestra el análisis de perdida de estabilidad en elementos estructurales delgados bajo compresión. Se realiza la exposición de las consideraciones del análisis lineal y no lineal de perdida de estabilidad y se ejemplifica con una estructura modelada mediante elementos finitos, estableciéndose conclusiones interesantes.Presently paper deals with stability analysis in structural elements. The considerations of lineal and non lineal analysis of stability are exposed and it is exemplified with a finite element structure model, settling down interesting conclusions.

  10. Impact of higher n-butanol addition on combustion and performance of GDI engine in stoichiometric combustion

    International Nuclear Information System (INIS)

    Chen, Zheng; Yang, Feng; Xue, Shuo; Wu, Zhenkuo; Liu, Jingping

    2015-01-01

    Highlights: • Effects of 0–50% n-butanol addition on GDI engine are experimentally studied. • Higher n-butanol fractions increase combustion pressure and fasten burning rate. • Higher n-butanol fractions increase BSFC but improve BTE. • Higher n-butanol fractions enhance combustion stability but increase knock intensity. • Higher n-butanol fractions reduce exhaust temperature and NOx emissions. - Abstract: An experimental study was carried out on a turbocharged gasoline direct injection (GDI) engine fueled by n-butanol/gasoline blends. Effects of n-butanol percents (15%, 30%, and 50%) on combustion and performance of the engine operating on stoichiometric combustion condition were discussed and also compared with pure gasoline in this paper. The results indicate that n-butanol/gasoline blends increase combustion pressure and pressure rise rate, fasten burning rate, and shorten ignition delay and combustion duration, as compared to pure gasoline. Moreover, these trends are impacted more evidently with increased n-butanol fraction in the blends. In addition, higher n-butanol percent of gasoline blends increase combustion temperature but decrease the temperature in the later stage of expansion stroke, which contributes to the control of exhaust temperature at high-load. With regards to engine performance, higher n-butanol percent in the blends results in increased brake specific fuel consumption (BSFC) and higher brake thermal efficiency (BTE). However, higher n-butanol addition helps to improve combustion stability but shows slightly higher knock possibility in high-load. In that case, the knock trend could be weakened by retarding ignition timing. Moreover, higher n-butanol addition significantly decreases NOx emissions, but it increases CO emissions obviously.

  11. Algunos elementos de la programación concurrente en C++v11

    OpenAIRE

    Mazaeda Echevarría, Rogelio; de la Fuente López, Eusebio

    2016-01-01

    A partir de la versión 11 el lenguaje C++ introduce por primera vez características de programación concurrente mediante hilos, así como elementos de exclusión mutua y sincronización entre tareas. Aquí se hace un breve repaso de las características más destacadas apoyándonos en ejemplos. Departamento de Ingeniería de Sistemas y Automática

  12. Spray combustion of Jet-A and diesel fuels in a constant volume combustion chamber

    KAUST Repository

    Jing, Wei; Roberts, William L.; Fang, Tiegang

    2015-01-01

    This work investigates the spray combustion of Jet-A fuel in an optical constant-volume combustion chamber under different ambient initial conditions. Ambient temperature was varied at 800 K, 1000 K, and 1200 K and five different ambient O2

  13. Experimental study on the influence of oxygen content in the combustion air on the combustion characteristics

    International Nuclear Information System (INIS)

    Bělohradský, Petr; Skryja, Pavel; Hudák, Igor

    2014-01-01

    This study was focused on the experimental investigation of the very promising combustion technology called as the oxygen-enhanced combustion (OEC), which uses the oxidant containing higher proportion of oxygen than in the atmospheric air, i.e. more than 21%. The work investigated and compared the characteristics of two OEC methods, namely the premix enrichment and air-oxy/fuel combustion, when the overall oxygen concentration was varied from 21% to 46%. The combustion tests were performed with the experimental two-gas-staged burner of low-NO x type at the burner thermal input of 750 kW for two combustion regimes – one-staged and two-staged combustion. The oxygen concentration in the flue gas was maintained in the neighborhood of 3% vol. (on dry basis). The aim of tests was to assess the impact of the oxidant composition, type of OEC method and fuel-staging on the characteristic combustion parameters in detail. The investigated parameters included the concentration of nitrogen oxides (NO x ) in the flue gas, flue gas temperature, heat flux to the combustion chamber wall, and lastly the stability, shape and dimensions of flame. It was observed that NO x emission is significantly lower when the air-oxy/fuel method is used compared to the premix enrichment method. Moreover, when the fuel was staged, NO x emission was below 120 mg/Nm 3 at all investigated oxygen flow rates. Increasing oxygen concentration resulted in higher heating intensity due to higher concentrations of CO 2 and H 2 O. The available heat at 46% O 2 was higher by 20% compared with that at 21% O 2 . - Highlights: • Premix-enrichment and air-oxy/fuel combustion methods were experimentally studied. • NO x increased sharply as oxygen concentration increased during PE tests. • NO x was below 120 mg/Nm 3 for all investigated oxygen flow rates in AO tests. • Radiative heat transfer was enhanced ca. 20% as O 2 concentration was increased. • OEC flames were observed stable, more luminous and

  14. Combustion modeling in waste tanks

    International Nuclear Information System (INIS)

    Mueller, C.; Unal, C.; Travis, J.R.; Forschungszentrum Karlsruhe

    1997-01-01

    This paper has two objectives. The first one is to repeat previous simulations of release and combustion of flammable gases in tank SY-101 at the Hanford reservation with the recently developed code GASFLOW-II. The GASFLOW-II results are compared with the results obtained with the HMS/TRAC code and show good agreement, especially for non-combustion cases. For combustion GASFLOW-II predicts a steeper pressure rise than HMS/TRAC. The second objective is to describe a so-called induction parameter model which was developed and implemented into GASFLOW-II and reassess previous calculations of Bureau of Mines experiments for hydrogen-air combustion. The pressure time history improves compared with the one-step model, and the time rate of pressure change is much closer to the experimental data

  15. Ignition and wave processes in combustion of solids

    CERN Document Server

    Rubtsov, Nickolai M; Alymov, Michail I

    2017-01-01

    This book focuses on the application of classical combustion theory to ignition and flame propagation in solid-solid and gas-solid systems. It presents experimental investigations in the areas of local ignition, filtration combustion, self-propagating high temperature synthesis and nanopowders protection. The authors highlight analytical formulas used in different areas of combustion in solids and propose an approach based on classical combustion theory. The book attempts to analyze the basic approaches to understanding of solid-solid and solid - gas combustion presented in contemporary literature in a unified approach based on classical combustion theory. .

  16. Effects of stepwise gas combustion on NOx generation

    International Nuclear Information System (INIS)

    Woperane Seredi, A.; Szepesi, E.

    1999-01-01

    To decrease NO x emission from gas boilers, the combustion process of gas has been modified from continuous combustion to step-wise combustion. In this process the combustion temperature, the temperature peaks in the flame, the residence time of combustion products in the high-temperature zone and the oxygen partial pressure are changed advantageously. Experiments were performed using multistage burners, and the NO x emission was recorded. It was found that the air factor of the primary combustion space has a determining effect on the NO x reduction. (R.P.)

  17. Diseño mediante elementos finitos de componentes estructurales de un cuadricóptero para impresión 3D

    OpenAIRE

    PARDO APARISI, IVÁN

    2016-01-01

    El trabajo tiene como objetivo diseñar componentes estructurales, mediante el método de elementos finitos, que serán utilizados en un dron de cuatro rotores (cuadricóptero). Una característica particular de este proyecto es que los componentes estructurales a diseñar serán fabricados mediante impresión 3D. Pardo Aparisi, I. (2016). Diseño mediante elementos finitos de componentes estructurales de un cuadricóptero para impresión 3D. http://hdl.handle.net/10251/75994. TFGM

  18. Fuel Combustion and Engine Performance | Transportation Research | NREL

    Science.gov (United States)

    Fuel Combustion and Engine Performance Fuel Combustion and Engine Performance Photo of a gasoline emissions in advanced engine technologies. Photo by Dennis Schroeder, NREL NREL's combustion research and combustion and engine research activities include: Developing experimental and simulation research platforms

  19. Specifics of phytomass combustion in small experimental device

    Science.gov (United States)

    Lenhard, Richard; Mičieta, Jozef; Jandačka, Jozef; Gavlas, Stanislav

    2015-05-01

    A wood pellet combustion carries out with high efficiency and comfort in modern pellet boilers. These facts help to increase the amount of installed pellet boilers in households. The combustion process quality depends besides the combustion conditions also on the fuel quality. The wood pellets, which don`t contain the bark and branches represent the highest quality. Because of growing pellet demand, an herbal biomass (phytomass), which is usually an agricultural by-product becomes economically attractive for pellet production. Although the phytomass has the net calorific value relatively slightly lower than the wood biomass, it is often significantly worse in view of the combustion process and an emission production. The combustion of phytomass pellets causes various difficulties in small heat sources, mainly due to a sintering of fuel residues. We want to avoid the ash sintering by a lowering of temperature in the combustion chamber below the ash sintering temperature of phytomass via the modification of a burner design. For research of the phytomass combustion process in the small boilers is constructed the experimental combustion device. There will investigate the impact of cooling intensity of the combustion chamber on the combustion process and emissions. Arising specific requirements from the measurement will be the basis for the design of the pellet burner and for the setting of operating parameters to the trouble-free phytomass combustion was guaranteed.

  20. Specifics of phytomass combustion in small experimental device

    Directory of Open Access Journals (Sweden)

    Lenhard Richard

    2015-01-01

    Full Text Available A wood pellet combustion carries out with high efficiency and comfort in modern pellet boilers. These facts help to increase the amount of installed pellet boilers in households. The combustion process quality depends besides the combustion conditions also on the fuel quality. The wood pellets, which don`t contain the bark and branches represent the highest quality. Because of growing pellet demand, an herbal biomass (phytomass, which is usually an agricultural by-product becomes economically attractive for pellet production. Although the phytomass has the net calorific value relatively slightly lower than the wood biomass, it is often significantly worse in view of the combustion process and an emission production. The combustion of phytomass pellets causes various difficulties in small heat sources, mainly due to a sintering of fuel residues. We want to avoid the ash sintering by a lowering of temperature in the combustion chamber below the ash sintering temperature of phytomass via the modification of a burner design. For research of the phytomass combustion process in the small boilers is constructed the experimental combustion device. There will investigate the impact of cooling intensity of the combustion chamber on the combustion process and emissions. Arising specific requirements from the measurement will be the basis for the design of the pellet burner and for the setting of operating parameters to the trouble-free phytomass combustion was guaranteed.

  1. Traveling-Wave Thermoacoustic Engines With Internal Combustion

    Science.gov (United States)

    Weiland, Nathan Thomas; Zinn, Ben T.; Swift, Gregory William

    2004-05-11

    Thermoacoustic devices are disclosed wherein, for some embodiments, a combustion zone provides heat to a regenerator using a mean flow of compressible fluid. In other embodiments, burning of a combustible mixture within the combustion zone is pulsed in phase with the acoustic pressure oscillations to increase acoustic power output. In an example embodiment, the combustion zone and the regenerator are thermally insulated from other components within the thermoacoustic device.

  2. el método de los elementos finitos

    Directory of Open Access Journals (Sweden)

    Yamill Campos Pérez

    2007-01-01

    Full Text Available Se realiza el estudio de las tensiones internas que se generan en los acoplamientos cuadrados de hierro fundido para molinos de caña. Además, se obtienen las expresiones matemáticas para calcular las tensiones equivalentes, teniendo en cuenta la influencia de parámetros como: diámetro exterior del acoplamiento, dimensiones del agujero cuadrado, velocidad de rotación y potencia. Para la obtención de estas expresiones se empleó el método de elementos finitos (MEF. El análisis MEF se hizo a partir del cálculo estático lineal, utilizando para el programa de computación COSMOS/M, versión 2.6. Finalmente, se realizó una estandarización de los acoplamientos con el fin de reducir la variedad de éstos.

  3. Sulfur retention by ash during coal combustion. Part I. A model of char particle combustion

    Directory of Open Access Journals (Sweden)

    BORISLAV GRUBOR

    2003-02-01

    Full Text Available A model for the combustion of porous char particles as a basis for modeling the process of sulfur retention by ash during coal combustion is developed in this paper. The model belongs to the microscopic intrinsic models and describes the dynamic behavior of a porous char particle during comustion, taking into account temporal and spatial changes of all important physical properties of the char particle and various combustion parameters. The parametric analysis of the enhanced model shows that the model represents a good basis for the development of a model for the process of sulfur retention by ash during coal combustion. The model enables the prediction of the values of all parameters necessary for the introduction of reactions between sulfur compounds and mineral components in ash, primarily calcium oxide.

  4. The effect of insulated combustion chamber surfaces on direct-injected diesel engine performance, emissions, and combustion

    Science.gov (United States)

    Dickey, Daniel W.; Vinyard, Shannon; Keribar, Rifat

    1988-01-01

    The combustion chamber of a single-cylinder, direct-injected diesel engine was insulated with ceramic coatings to determine the effect of low heat rejection (LHR) operation on engine performance, emissions, and combustion. In comparison to the baseline cooled engine, the LHR engine had lower thermal efficiency, with higher smoke, particulate, and full load carbon monoxide emissions. The unburned hydrocarbon emissions were reduced across the load range. The nitrous oxide emissions increased at some part-load conditions and were reduced slightly at full loads. The poor LHR engine performance was attributed to degraded combustion characterized by less premixed burning, lower heat release rates, and longer combustion duration compared to the baseline cooled engine.

  5. Túneles varios urbanos: diseño, instalaciones y elementos de seguridad

    OpenAIRE

    Estupiñá Cano, Sergio F.

    2002-01-01

    El objetivo fundamental de este trabajo es el realizar un estudio de los elementos de seguridad y gestión básicos que se disponen o deberían disponerse en los túneles. El estudio se centra en túneles de tipo urbano, caracterizados por presentar elevados volumenes de tráfico, y en consecuencia de usuarios. La realización de esta solución como alternativa a la carretera a cielo abierto radica en que si se proyecta correctamente se obtienen una serie de ventajas como son la posibi...

  6. Imagen y elementos no verbales en informaciones políticas televisivas

    Directory of Open Access Journals (Sweden)

    María Reyes Domínguez Lázaro

    2009-12-01

    Full Text Available Destaca la importancia de la imagen, del lenguaje y otros elementos no verbales que intervienen en la comunicación. De este modo no basta con el dominio exhaustivo de las palabras orales, sino de todas aquellas no manifiestas pero si evocadoras en la mente de los telespectadores. La sociedad del siglo XXI es la sociedad de la imagen, y como tal, debe ser considerada y tenida en cuenta en cualquier proceso comunicativo y, mucho más cuando se trata de la televisión.

  7. Los elementos, las partes y el todo Reflexión sobre el papel de la “parte” en la composición formal de la arquitectura

    Directory of Open Access Journals (Sweden)

    Juan Pablo Aschner Rosselli

    2008-05-01

    Full Text Available La arquitectura se compone de una serie de elementos y son invariablemente los mismos desde sus orígenes: puertas, ventanas, columnas, muros, escaleras, cubiertas y pisos. Si bien el número es limitado, cada elemento constituye en sí mismo un mundo de variaciones y al agruparse, puede conformar partes de una totalidad o la totalidad misma: la forma arquitectónica. Veremos como la existencia o no existencia de una escala intermedia o mediadora entre los elementos y la totalidad –la parte–, determina en modo considerable el resultado final al interior del objeto arquitectónico.

  8. Incidencia de la sociedad civil en la re-implementación del componente destinado a incentivar el uso de la bicicleta en el marco de la política pública de movilidad en Bogotá entre los años de 2009 a 2012

    OpenAIRE

    Gómez Pinzón, Juan Camilo

    2013-01-01

    El texto muestra la evolución del componente destinado a incentivar el uso de la bicicleta en el marco de la política de movilidad de Bogotá desde Mockus hasta Petro y también el papel de la sociedad civil en el proceso de la reimplementación de dicho componente en la alcaldía de Moreno y en la de Petro.

  9. Elementos de diferenciación social en el Bajo Aragón durante el Bronce final-Hierro I

    Directory of Open Access Journals (Sweden)

    Andrés Álvarez García

    2013-11-01

    Full Text Available En el presente trabajo se abordan algunos de los aspectos que más interesan a la denominada Arqueología Social, el relativo a la configuración de las sociedades. Nos proponemos, tomando como base algunos elementos arqueológicos de la zona bajoaragonesa, realizar un intento de aproximación a la realidad de los grupos humanos del Bronce Final y Primer Hierro en esta comarca. No son muchos los elementos de referencia con que contamos por el momento pero algunos de ellos, elementos metálicos, enterramientos, casas, tamaño de los poblados, etc. resultan tremendamente sugestivo como para hacer este intento de acercamiento a los modelos de sociedad de esta zona.This paper analyzes one of the main aspects of the Social Archaeology: the societies configuration. Through some archaeological items found in the Bajo Aragón (Spain we propose an approach to the human societies who lived in this area at the end of Bronze Age and the beginning of Iron Age. Although the number of available items is nowadays very limited, some of them are meaningful enough metallic items, graves, houses, village sizes, . . .- to allow us to deduce how they lived and died.

  10. Improved Economic Performance of Municipal Solid Waste Combustion Plants by Model Based Combustion Control

    NARCIS (Netherlands)

    Leskens, M.

    2013-01-01

    The combustion of municipal solid waste (MSW) is used for its inertisation, reduction of its volume and the conversion of its energy content into heat and/or electricity. Operation and control of modern large scale MSW combustion (MSWC) plants is determined by economic and environmental objectives

  11. Toxicology of Biodiesel Combustion products

    Science.gov (United States)

    1. Introduction The toxicology of combusted biodiesel is an emerging field. Much of the current knowledge about biological responses and health effects stems from studies of exposures to other fuel sources (typically petroleum diesel, gasoline, and wood) incompletely combusted. ...

  12. Producer for vegetal combustibles for internal-combustion motors

    Energy Technology Data Exchange (ETDEWEB)

    1943-12-28

    A producer is described for internal-combustion motors fed with wood or agricultural byproducts characterized by the fact that its full operation is independent of the degree of wetness of the material used.

  13. OTIMIZAÇÃO DE SEÇÕES POLIGONAIS DE ELEMENTOS LINEARES DE CONCRETO ARMADO SUJEITAS À FLEXÃO COMPOSTA

    OpenAIRE

    de Faria, Flávia Castro; da Silva, Amilton Rodrigues

    2017-01-01

    Resumo. O concreto é o material mais utilizado na confecção de elementos estruturais para a construção civil no mundo. Devido à sua baixa resistência à tração ele é reforçado com barras de aço formando o concreto armado. Elementos lineares de concreto armado são comuns em edifícios de múltiplos pavimentos, pontes, galpões industriais, entre outros. O objetivo desse trabalho é utilizar um algoritmo de otimização para definir a quantidade de aço e sua posição dentro de uma seção poligonal qualq...

  14. Uso de elementos de tierras raras contenidos en los discos duros de computadoras para optimizar la quema de combustibles fluidos

    Directory of Open Access Journals (Sweden)

    Carlos Vallejos

    2014-12-01

    Full Text Available La investigación examinó el uso de imanes de neodimio provenientes de los discos duros de computadoras en desuso, y su utilización como optimizadores de la combustión de fluidos tales como propano, butano o la mezcla de los mismos. En la validación del efecto del campo magnético sobre los fluidos en referencia se utilizaron dos cocinas nuevas y dos cocinas previamente utilizadas, con su respectiva alimentación de gas. Los ensayos se realizaron sin y con imanes de neodimio provenientes de desechos tecnológicos. Como resultado de la investigación se concluyó que tales imanes son aptos para este propósito, con un rango de optimización en la combustión del gas de entre el 13 y el 20%. Esto pudo demostrarse mediante la aplicación de principios generales de la mecánica de fluidos, del campo magnético y de la termodinámica. Los resultados contribuyen a la búsqueda de estrategias para disminuir el uso de combustibles fosiles en los hogares y otros espacios donde se utiliza gas licuado para la cocción de los alimentos, así cómo para contribuir al bienestar de la microeconomía.

  15. Investigation of bluff-body micro-flameless combustion

    International Nuclear Information System (INIS)

    Hosseini, Seyed Ehsan; Wahid, Mazlan Abdul

    2014-01-01

    Highlights: • The temperature uniformity of the micro-flameless combustion increases when a triangular bluff-body is applied. • The velocity and temperature of exhaust gases are higher in micro-flameless combustion compared to the conventional mode. • The rate of fuel–oxidizer consumption in micro-flameless mode is lower than conventional micro-combustion. - Abstract: Characteristics of lean premixed conventional micro-combustion and lean non-premixed flameless regime of methane/air are investigated in this paper by solving three-dimensional governing equations. At moderate equivalence ratio (∅ = 0.5), standard k–ε and the eddy-dissipation concept are employed to simulate temperature distribution and combustion stability of these models. The effect of bluff-body on the temperature distribution of both conventional and flameless mode is developed. The results show that in the premixed conventional micro-combustion the stability of the flame is increased when a triangular bluff-body is applied. Moreover, micro-flameless combustion is more stable when bluff-body is used. Micro-flameless mode with bluff-body and 7% O 2 concentration (when N 2 is used as diluent) illustrated better performance than other cases. The maximum temperature in premixed conventional micro-combustion and micro-flameless combustion was recorded 2200 K and 1520 K respectively. Indeed, the flue gas temperature of conventional mode and flameless combustion was 1300 K and 1500 K respectively. The fluctuation of temperature in the conventional micro-combustor wall has negative effects on the combustor and reduces the lifetime of micro-combustor. However, in the micro-flameless mode, the wall temperature is moderate and uniform. The rate of fuel–oxidizer consumption in micro-flameless mode takes longer time and the period of cylinders recharging is prolonged

  16. Numerical analysis on the combustion and emission characteristics of forced swirl combustion system for DI diesel engines

    International Nuclear Information System (INIS)

    Su, LiWang; Li, XiangRong; Zhang, Zheng; Liu, FuShui

    2014-01-01

    Highlights: • A new combustion system named FSCS for DI diesel engines was proposed. • Fuel/air mixture formation was improved for the application of FSCS. • The FSCS showed a good performance on emission characteristics. - Abstract: To optimize the fuel/air mixture formation and improve the environmental effect of direct injection (DI) diesel engines, a new forced swirl combustion system (FSCS) was proposed concerned on unique design of the geometric shape of the combustion chamber. Numerical simulation was conducted to verify the combustion and emission characteristics of the engines with FSCS. The fuel/air diffusion, in-cylinder velocity distribution, turbulent kinetic energy and in-cylinder temperature distribution were analyzed and the results shown that the FSCS can increase the area of fuel/air diffusion and improve the combustion. The diesel engine with FSCS also shown excellent performance on emission. At full load condition, the soot emission was significantly reduced for the improved fuel/air mixture formation. There are slightly difference for the soot and NO emission between the FSCS and the traditional omega combustion system at lower load for the short penetration of the fuel spray

  17. Combustion & Laser Diagnostics Research Complex (CLDRC)

    Data.gov (United States)

    Federal Laboratory Consortium — Description: The Combustion and Laser Diagnostics Research Complex (CLRDC) supports the experimental and computational study of fundamental combustion phenomena to...

  18. Elementos para uma metapsicologia da interpretação em análise

    Directory of Open Access Journals (Sweden)

    Lo Bianco Anna Carolina

    1999-01-01

    Full Text Available Examinando a base conceitual da obra freudiana sobre a interpretação-sonho (Traumdeutung, o trabalho procura caracterizar alguns elementos para uma metapsicologia da interpretação psicanalítica. Conclui que da mesma maneira que o sonho, a interpretação aponta para as vicissitudes do manejo da angústia, no sentido de facilitar as vias de expressão e mobilidade do desejo.

  19. The rheodynamics and combustion of coal-water mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Burdukov, A.P.; Popov, V.I.; Tomilov, V.G.; Fedosenko, V.D. [Russian Academy of Science, Novosibirsk (Russian Federation). Inst. of Thermophysics (Siberian Branch, Russian Academy of Science)

    2002-05-01

    Investigation methods for characteristics of movement along the tubes, combustion dynamics and gasification of separate drops were developed for the coal-water mixtures (CWM). The following parameters were determined on the basis of laser heating: thermometric, pyrometric and concentration dynamics of single-drop combustion, complete combustion times, duration of temperature phases of combustion, as well as the moment and temperature of ignition. Information on the combustion mass velocity and gasification products was also obtained using laser heating. 6 refs., 13 figs., 1 tab.

  20. Bifurcation, pattern formation and chaos in combustion

    International Nuclear Information System (INIS)

    Bayliss, A.; Matkowsky, B.J.

    1991-01-01

    In this paper problems in gaseous combustion and in gasless condensed phase combustion are studied both analytically and numerically. In gaseous combustion we consider the problem of a flame stabilized on a line source of fuel. The authors find both stationary and pulsating axisymmetric solutions as well as stationary and pulsating cellular solutions. The pulsating cellular solutions take the form of either traveling waves or standing waves. Transitions between these patterns occur as parameters related to the curvature of the flame front and the Lewis number are varied. In gasless condensed phase combustion both planar and nonplanar problems are studied. For planar condensed phase combustion we consider two models: accounts for melting and does not. Both models are shown to exhibit a transition from uniformly to pulsating propagating combustion when a parameter related to the activation energy is increased. Upon further increasing this parameter both models undergo a transition to chaos: by intermittency and by a period doubling sequence. In nonplanar condensed phase combustion the nonlinear development of a branch of standing wave solutions is studied and is shown to lead to relaxation oscillations and subsequently to a transition to quasi-periodicity

  1. Fundamentals of Turbulent and Multi-Phase Combustion

    CERN Document Server

    Kuo, Kenneth Kuan-yun

    2012-01-01

    Detailed coverage of advanced combustion topics from the author of Principles of Combustion, Second Edition Turbulence, turbulent combustion, and multiphase reacting flows have become major research topics in recent decades due to their application across diverse fields, including energy, environment, propulsion, transportation, industrial safety, and nanotechnology. Most of the knowledge accumulated from this research has never been published in book form-until now. Fundamentals of Turbulent and Multiphase Combustion presents up-to-date, integrated coverage of the fundamentals of turbulence

  2. An Assessment of Combustion Dynamics in a Low-Nox, Second-Generation Swirl-Venturi Lean Direct Injection Combustion Concept

    Science.gov (United States)

    Tacina, K. M.; Chang, C. T.; Lee, P.; Mongia, H.; Podboy, D. P.; Dam, B.

    2015-01-01

    Dynamic pressure measurements were taken during flame-tube emissions testing of three second-generation swirl-venturi lean direct injection (SV-LDI) combustor configurations. These measurements show that combustion dynamics were typically small. However, a small number of points showed high combustion dynamics, with peak-to-peak dynamic pressure fluctuations above 0.5 psi. High combustion dynamics occurred at low inlet temperatures in all three SV-LDI configurations, so combustion dynamics were explored further at low temperature conditions. A point with greater than 1.5 psi peak-to-peak dynamic pressure fluctuations was identified at an inlet temperature of 450!F, a pressure of 100 psia, an air pressure drop of 3%, and an overall equivalence ratio of 0.35. This is an off design condition: the temperature and pressure are typical of 7% power conditions, but the equivalence ratio is high. At this condition, the combustion dynamics depended strongly on the fuel staging. Combustion dynamics could be reduced significantly without changing the overall equivalence ratio by shifting the fuel distribution between stages. Shifting the fuel distribution also decreased NOx emissions.

  3. Assessment of Literature Related to Combustion Appliance Venting Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, V. H.; Less, B. D.; Singer, B. C.; Stratton, J. C.; Wray, C. P.

    2015-02-01

    In many residential building retrofit programs, air tightening to increase energy efficiency is often constrained by safety concerns with naturally vented combustion appliances. Tighter residential buildings more readily depressurize when exhaust equipment is operated, making combustion appliances more prone to backdraft or spill combustion exhaust into the living space. Several measures, such as installation guidelines, vent sizing codes, and combustion safety diagnostics, are in place with the intent to prevent backdrafting and combustion spillage, but the diagnostics conflict and the risk mitigation objective is inconsistent. This literature review summarizes the metrics and diagnostics used to assess combustion safety, documents their technical basis, and investigates their risk mitigations. It compiles information from the following: codes for combustion appliance venting and installation; standards and guidelines for combustion safety diagnostics; research evaluating combustion safety diagnostics; research investigating wind effects on building depressurization and venting; and software for simulating vent system performance.

  4. Flow and Combustion in Advanced Gas Turbine Combustors

    CERN Document Server

    Janicka, Johannes; Schäfer, Michael; Heeger, Christof

    2013-01-01

    With regard to both the environmental sustainability and operating efficiency demands, modern combustion research has to face two main objectives, the optimization of combustion efficiency and the reduction of pollutants. This book reports on the combustion research activities carried out within the Collaborative Research Center (SFB) 568 “Flow and Combustion in Future Gas Turbine Combustion Chambers” funded by the German Research Foundation (DFG). This aimed at designing a completely integrated modeling and numerical simulation of the occurring very complex, coupled and interacting physico-chemical processes, such as turbulent heat and mass transport, single or multi-phase flows phenomena, chemical reactions/combustion and radiation, able to support the development of advanced gas turbine chamber concepts.

  5. Reducing emissions from diesel combustion

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This paper contains information dealing with engine design to reduce emissions and improve or maintain fuel economy. Topics include: Observation of High Pressure Fuel Spray with Laser Light Sheet Method; Determination of Engine Cylinder Pressures from Crankshaft Speed Fluctuations; Combustion Similarity for Different Size Diesel Engines: Theoretical Prediction and Experimental Results; Prediction of Diesel Engine Particulate Emission During Transient Cycles; Characteristics and Combustibility of Particulate Matter; Dual-Fuel Diesel Engine Using Butane; Measurement of Flame Temperature Distribution in D.I. Diesel Engine with High Pressure Fuel Injection: and Combustion in a Small DI Diesel Engine at Starting

  6. Mechanisms and characteristics of silicon combustion in nitrogen

    Energy Technology Data Exchange (ETDEWEB)

    Mukasian, A.S.; Martynenko, V.M.; Merzhanov, A.G.; Borovinskaia, I.P.; Blinov, M.IU.

    1986-10-01

    An experimental study is made of the principal characteristics of combustion in the system silicon-nitrogen associated with phase transitions of the first kind (silicon melting and silicon nitride dissociation). Concepts of the combustion mechanism are developed on the basis of elementary models of combustion of the second kind and filtering combustion theory. In particular, it is shown that, in the pressure range studied (10-20 MPa), filtering does not limit the combustion process. Details of the experimental procedure and results are presented. 22 references.

  7. Review of Membrane Oxygen Enrichment for Efficient Combustion

    Science.gov (United States)

    Ariono, Danu; Kusuma Wardani, Anita

    2017-07-01

    Oxygen enrichment from air is a simple way of increasing the efficiency of combustion process, as in oxy-combustion. Oxy-combustion has become one of the most attracting combustion technologies because of its potential to address both pollutant reduction and CO2 capture. In oxy-combustion, the fuel and recycled flue gas are combusted with oxygen enriched air (OEA). By using OEA, many benefits can be obtained, such as increasing available heat, improving ignition characteristics, flue gas reduction, increasing productivity, energy efficiency, turndown ratio, and flame stability. Membrane-based gas separation for OEA production becomes an attractive technology over the conventional technology due to the some advantages, including low capital cost, low energy consumption, compact size, and modularity. A single pass through membrane usually can enrich O2 concentration in the air up to 35% and a 50% concentration can be achieved with a double pass of membrane. The use of OEA in the combustion process eliminates the presence of nitrogen in the flue gas. Hence, the flue gas is mainly composed of CO2 and condensable water that can be easily separated. This paper gives an overview of oxy-combustion with membrane technology for oxygen enrichment process. Special attention is given to OEA production and the effect of OEA to the efficiency of combustion.

  8. 14 CFR 25.833 - Combustion heating systems.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Combustion heating systems. 25.833 Section... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES Design and Construction Ventilation and Heating § 25.833 Combustion heating systems. Combustion heaters must be approved. [Amdt. 25-72, 55 FR 29783, July 20, 1990...

  9. Chemistry and radiation in oxy-fuel combustion

    DEFF Research Database (Denmark)

    Yin, Chungen; Rosendahl, Lasse; Kær, Søren Knudsen

    2011-01-01

    In order to investigate the role of combustion chemistry and radiation heat transfer in oxy-fuel combustion modeling, a computational fluid dynamics (CFD) modeling study has been performed for two different oxy-fuel furnaces. One is a lab-scale 0.8MW oxy-natural gas flame furnace whose detailed in....... Among the key issues in combustion modeling, e.g., mixing, radiation and chemistry, this paper derives useful guidelines on radiation and chemistry implementation for reliable CFD analyses of oxy-fuel combustion, particularly for industrial applications....

  10. FY 1994 annual report. Advanced combustion science utilizing microgravity

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-10-01

    Researches on combustion in microgravity were conducted to develop combustion devices for advanced combustion techniques, and thereby to cope with the requirements for diversification of energy sources and abatement of environmental pollution by exhaust gases. This project was implemented under the research cooperation agreement with US's NASA, and the Japanese experts visited NASA's test facilities. NASA's Lewis Research Center has drop test facilities, of which the 2.2-sec drop test facilities are useful for researches by Japan. The cooperative research themes for combustion in microgravity selected include interactions between fuel droplets, high-pressure combustion of binary fuel sprays, and ignition and subsequent flame propagation in microgravity. An ignition test equipment, density field measurement equipment and flame propagation test equipment were constructed in Japan to conduct the combustion tests in microgravity for, e.g., combustion and evaporation of fuel droplets, combustion characteristics of liquid fuels mixed with solid particles, combustion of coal/oil mixture droplets, and estimating flammability limits. (NEDO)

  11. Sodium nitrate combustion limit tests

    International Nuclear Information System (INIS)

    Beitel, G.A.

    1976-04-01

    Sodium nitrate is a powerful solid oxidant. Energetically, it is capable of exothermically oxidizing almost any organic material. Rate-controlling variables such as temperature, concentration of oxidant, concentration of fuel, thermal conductivity, moisture content, size, and pressure severely limit the possibility of a self-supported exothermic reaction (combustion). The tests reported in this document were conducted on one-gram samples at atmospheric pressure. Below 380 0 C, NaNO 3 was stable and did not support combustion. At moisture concentrations above 22 wt percent, exothermic reactions did not propagate in even the most energetic and reactive compositions. Fresh resin and paraffin were too volatile to enable a NaNO 2 -supported combustion process to propagate. Concentrations of NaNO 3 above 95 wt percent or below 35 wt percent did not react with enough energy release to support combustion. The influence of sample size and confining pressure, both important factors, was not investigated in this study

  12. Variable compression ratio device for internal combustion engine

    Science.gov (United States)

    Maloney, Ronald P.; Faletti, James J.

    2004-03-23

    An internal combustion engine, particularly suitable for use in a work machine, is provided with a combustion cylinder, a cylinder head at an end of the combustion cylinder and a primary piston reciprocally disposed within the combustion cylinder. The cylinder head includes a secondary cylinder and a secondary piston reciprocally disposed within the secondary cylinder. An actuator is coupled with the secondary piston for controlling the position of the secondary piston dependent upon the position of the primary piston. A communication port establishes fluid flow communication between the combustion cylinder and the secondary cylinder.

  13. Systems and methods of storing combustion waste products

    Science.gov (United States)

    Chen, Shen-En; Wang, Peng; Miao, Xiexing; Feng, Qiyan; Zhu, Qianlin

    2016-04-12

    In one aspect, methods of storing one or more combustion waste products are described herein. Combustion waste products stored by a method described herein can include solid combustion waste products such as coal ash and/or gaseous combustion products such as carbon dioxide. In some embodiments, a method of storing carbon dioxide comprises providing a carbon dioxide storage medium comprising porous concrete having a macroporous and microporous pore structure and flowing carbon dioxide captured from a combustion flue gas source into the pore structure of the porous concrete.

  14. Fuel properties to enable lifted-flame combustion

    Energy Technology Data Exchange (ETDEWEB)

    Kurtz, Eric [Ford Motor Company, Dearborn, MI (United States)

    2015-03-15

    The Fuel Properties to Enable Lifted-Flame Combustion project responded directly to solicitation DE-FOA-0000239 AOI 1A, Fuels and Lubricants for Advanced Combustion Regimes. This subtopic was intended to encompass clean and highly-efficient, liquid-fueled combustion engines to achieve extremely low engine-out nitrogen oxides (NOx) and particulate matter (PM) as a target and similar efficiency as state-of-the-art direct injection diesel engines. The intent of this project was to identify how fuel properties can be used to achieve controllable Leaner Lifted Flame Combustion (LLFC) with low NOx and PM emissions. Specifically, this project was expected to identify and test key fuel properties to enable LLFC and their compatibility with current fuel systems and to enhance combustion models to capture the effect of fuel properties on advanced combustion. Successful demonstration of LLFC may reduce the need for after treatment devices, thereby reducing costs and improving thermal efficiency. The project team consisted of key technical personnel from Ford Motor Company (FMC), the University of Wisconsin-Madison (UW), Sandia National Laboratories (SNL) and Lawrence Livermore National Laboratories (LLNL). Each partner had key roles in achieving project objectives. FMC investigated fuel properties relating to LLFC and sooting tendency. Together, FMC and UW developed and integrated 3D combustion models to capture fuel property combustion effects. FMC used these modeling results to develop a combustion system and define fuel properties to support a single-cylinder demonstration of fuel-enabled LLFC. UW investigated modeling the flame characteristics and emissions behavior of different fuels, including those with different cetane number and oxygen content. SNL led spray combustion experiments to quantify the effect of key fuel properties on combustion characteristics critical for LLFC, as well as single cylinder optical engine experiments to improve fundamental

  15. Oxy-Combustion Boiler Material Development

    Energy Technology Data Exchange (ETDEWEB)

    Gagliano, Michael; Seltzer, Andrew; Agarwal, Hans; Robertson, Archie; Wang, Lun

    2012-01-31

    Under U.S. Department of Energy Cooperative Agreement No. DE-NT0005262 Foster Wheeler North America Corp conducted a laboratory test program to determine the effect of oxy-combustion on boiler tube corrosion. In this program, CFD modeling was used to predict the gas compositions that will exist throughout and along the walls of air-fired and oxy-fired boilers operating with low to high sulfur coals. Test coupons of boiler tube materials were coated with deposits representative of those coals and exposed to the CFD predicted flue gases for up to 1000 hours. The tests were conducted in electric tube furnaces using oxy-combustion and air-fired flue gases synthesized from pressurized cylinders. Following exposure, the test coupons were evaluated to determine the total metal wastage experienced under air and oxy-combustions conditions and materials recommendations were made. Similar to air-fired operation, oxy-combustion corrosion rates were found to vary with the boiler material, test temperature, deposit composition, and gas composition. Despite this, comparison of air-fired and oxy-fired corrosion rates showed that oxy-firing rates were, for the most part, similar to, if not lower than those of air-firing; this finding applied to the seven furnace waterwall materials (wrought and weld overlay) and the ten superheater/reheater materials (wrought and weld overlay) that were tested. The results of the laboratory oxy-combustion tests, which are based on a maximum bulk flue gas SO2 level of 3200 ppmv (wet) / 4050 ppmv (dry), suggest that, from a corrosion standpoint, the materials used in conventional subcritical and supercritical, air-fired boilers should also be suitable for oxy-combustion retrofits. Although the laboratory test results are encouraging, they are only the first step of a material evaluation process and it is recommended that follow-on corrosion tests be conducted in coal-fired boilers operating under oxy-combustion to provide longer term (one to two year

  16. Oxy-Combustion Boiler Material Development

    Energy Technology Data Exchange (ETDEWEB)

    Michael Gagliano; Andrew Seltzer; Hans Agarwal; Archie Robertson; Lun Wang

    2012-01-31

    Under U.S. Department of Energy Cooperative Agreement No. DE-NT0005262 Foster Wheeler North America Corp conducted a laboratory test program to determine the effect of oxy-combustion on boiler tube corrosion. In this program, CFD modeling was used to predict the gas compositions that will exist throughout and along the walls of air-fired and oxy-fired boilers operating with low to high sulfur coals. Test coupons of boiler tube materials were coated with deposits representative of those coals and exposed to the CFD predicted flue gases for up to 1000 hours. The tests were conducted in electric tube furnaces using oxy-combustion and air-fired flue gases synthesized from pressurized cylinders. Following exposure, the test coupons were evaluated to determine the total metal wastage experienced under air and oxy-combustions conditions and materials recommendations were made. Similar to air-fired operation, oxy-combustion corrosion rates were found to vary with the boiler material, test temperature, deposit composition, and gas composition. Despite this, comparison of air-fired and oxy-fired corrosion rates showed that oxy-firing rates were, for the most part, similar to, if not lower than those of air-firing; this finding applied to the seven furnace waterwall materials (wrought and weld overlay) and the ten superheater/reheater materials (wrought and weld overlay) that were tested. The results of the laboratory oxy-combustion tests, which are based on a maximum bulk flue gas SO{sub 2} level of 3200 ppmv (wet) / 4050 ppmv (dry), suggest that, from a corrosion standpoint, the materials used in conventional subcritical and supercritical, air-fired boilers should also be suitable for oxy-combustion retrofits. Although the laboratory test results are encouraging, they are only the first step of a material evaluation process and it is recommended that follow-on corrosion tests be conducted in coal-fired boilers operating under oxy-combustion to provide longer term (one to

  17. Combustion in a High-Speed Compression-Ignition Engine

    Science.gov (United States)

    Rothrock, A M

    1933-01-01

    An investigation conducted to determine the factors which control the combustion in a high-speed compression-ignition engine is presented. Indicator cards were taken with the Farnboro indicator and analyzed according to the tangent method devised by Schweitzer. The analysis show that in a quiescent combustion chamber increasing the time lag of auto-ignition increases the maximum rate of combustion. Increasing the maximum rate of combustion increases the tendency for detonation to occur. The results show that by increasing the air temperature during injection the start of combustion can be forced to take place during injection and so prevent detonation from occurring. It is shown that the rate of fuel injection does not in itself control the rate of combustion.

  18. CFD analysis of premixed hydrogen/air combustion in an upright, rectangular shaped combustion chamber

    International Nuclear Information System (INIS)

    Gera, B.; Singh, R.K.; Vaze, K.K.

    2014-01-01

    Premixed hydrogen/air combustion in an upright, rectangular shaped combustion chamber has been performed numerically using commercial CFD code CFD-ACE+. The combustion chamber had dimensions 1 m X 0.024 m X 1 m. Simulations were carried out for 10% (v/v) hydrogen concentration for which experimental results were available. Effect of different boundary condition and ignition position on flame propagation was studied. Time dependent flame propagation in the chamber was predicted by CFD code. The computed transient flame propagation in the chamber was in good agreement with experimental results. The present work demonstrated that the available commercial CFD codes are capable of modeling hydrogen deflagration in a realistic manner. (author)

  19. Elementos de la soberanía y del tribunal penal internacional

    OpenAIRE

    Scalquette, Rodrigo Arnoni

    2007-01-01

    Com o título de Elementos da Soberania e do Tribunal Penal Internacional procuramos demonstrar a ligação e pontos conflitantes entre o poder soberano e a Corte Internacional Criminal. No capítulo I, abordamos o conceito de soberania e seu enfoque de concepção política, realizado por Jean Bodin. Vimos o Estado-Leviatã de Thomas Hobbes e a soberania inalienável e indivisível de Jean-Jacques Rousseau. A relação entre Umberto Campagnolo e seu professor, Hans Kelsen, também foi abordada, nota...

  20. Arquitectura universitária : o campus como elemento arquitectónico

    OpenAIRE

    Martins, Luis Miguel Madruga, 1984-

    2017-01-01

    Dissertação de mestrado integrado em Arquitectura, Universidade Lusíada de Lisboa, 2017. Exame público realizado em 13 de Outubro de 2017. A presente investigação tem como objectivo estudar o campus universitário como elemento arquitectónico e urbanístico de modo a compreender, tanto a sua relevância histórica e social como o seu papel urbano dentro da cidade. Nesse sentido é essencial estudar o contexto histórico e social da origem da universidade e os modelos arquitectónicos que surgi...

  1. Flex-flame burner and combustion method

    Science.gov (United States)

    Soupos, Vasilios; Zelepouga, Serguei; Rue, David M.; Abbasi, Hamid A.

    2010-08-24

    A combustion method and apparatus which produce a hybrid flame for heating metals and metal alloys, which hybrid flame has the characteristic of having an oxidant-lean portion proximate the metal or metal alloy and having an oxidant-rich portion disposed above the oxidant lean portion. This hybrid flame is produced by introducing fuel and primary combustion oxidant into the furnace chamber containing the metal or metal alloy in a substoichiometric ratio to produce a fuel-rich flame and by introducing a secondary combustion oxidant into the furnace chamber above the fuel-rich flame in a manner whereby mixing of the secondary combustion oxidant with the fuel-rich flame is delayed for a portion of the length of the flame.

  2. Combustion instability modeling and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Santoro, R.J.; Yang, V.; Santavicca, D.A. [Pennsylvania State Univ., University Park, PA (United States); Sheppard, E.J. [Tuskeggee Univ., Tuskegee, AL (United States). Dept. of Aerospace Engineering

    1995-12-31

    It is well known that the two key elements for achieving low emissions and high performance in a gas turbine combustor are to simultaneously establish (1) a lean combustion zone for maintaining low NO{sub x} emissions and (2) rapid mixing for good ignition and flame stability. However, these requirements, when coupled with the short combustor lengths used to limit the residence time for NO formation typical of advanced gas turbine combustors, can lead to problems regarding unburned hydrocarbons (UHC) and carbon monoxide (CO) emissions, as well as the occurrence of combustion instabilities. The concurrent development of suitable analytical and numerical models that are validated with experimental studies is important for achieving this objective. A major benefit of the present research will be to provide for the first time an experimentally verified model of emissions and performance of gas turbine combustors. The present study represents a coordinated effort between industry, government and academia to investigate gas turbine combustion dynamics. Specific study areas include development of advanced diagnostics, definition of controlling phenomena, advancement of analytical and numerical modeling capabilities, and assessment of the current status of our ability to apply these tools to practical gas turbine combustors. The present work involves four tasks which address, respectively, (1) the development of a fiber-optic probe for fuel-air ratio measurements, (2) the study of combustion instability using laser-based diagnostics in a high pressure, high temperature flow reactor, (3) the development of analytical and numerical modeling capabilities for describing combustion instability which will be validated against experimental data, and (4) the preparation of a literature survey and establishment of a data base on practical experience with combustion instability.

  3. Combustion characteristics of crude jatropha oil droplets using rhodium liquid as a homogeneous combustion catalyst

    Science.gov (United States)

    Nanlohy, Hendry Y.; Wardana, I. N. G.; Hamidi, N.; Yuliati, L.

    2018-01-01

    Combustion characteristics of crude jatropha oil droplet at room temperature with and without catalyst have been studied experimentally. Its combustion characteristics have been observed by igniting the oil droplet on a junction of a thermocouple, and the combustion characteristics of oil droplets are observed using a high-speed camera. The results show that the uniqueness of crude jatropha oil as alternative fuel is evidenced by the different stages of combustion caused by thermal cracking in burning droplets. The results also show that the role of the catalyst is not only an accelerator agent, but there are other unique functions and roles as a stabilizer. Moreover, the results also found that the catalyst was able to shorten the ignition timing and burnout time. This phenomenon proves that the presence of catalysts alters and weakens the structure of the triglyceride geometry so that the viscosity and flash point is reduced, the fuel absorbs heat well and flammable.

  4. A study of the current group evaporation/combustion theories

    Science.gov (United States)

    Shen, Hayley H.

    1990-01-01

    Liquid fuel combustion can be greatly enhanced by disintegrating the liquid fuel into droplets, an effect achieved by various configurations. A number of experiments carried out in the seventies showed that combustion of droplet arrays and sprays do not form individual flames. Moreover, the rate of burning in spray combustion greatly deviates from that of the single combustion rate. Such observations naturally challenge its applicability to spray combustion. A number of mathematical models were developed to evaluate 'group combustion' and the related 'group evaporation' phenomena. This study investigates the similarity and difference of these models and their applicability to spray combustion. Future work that should be carried out in this area is indicated.

  5. Final report: Prototyping a combustion corridor; FINAL

    International Nuclear Information System (INIS)

    Rutland, Christopher J.; Leach, Joshua

    2001-01-01

    The Combustion Corridor is a concept in which researchers in combustion and thermal sciences have unimpeded access to large volumes of remote computational results. This will enable remote, collaborative analysis and visualization of state-of-the-art combustion science results. The Engine Research Center (ERC) at the University of Wisconsin - Madison partnered with Lawrence Berkeley National Laboratory, Argonne National Laboratory, Sandia National Laboratory, and several other universities to build and test the first stages of a combustion corridor. The ERC served two important functions in this partnership. First, we work extensively with combustion simulations so we were able to provide real world research data sets for testing the Corridor concepts. Second, the ERC was part of an extension of the high bandwidth based DOE National Laboratory connections to universities

  6. Combustion of stratified hydrogen-air mixtures in the 10.7 m3 Combustion Test Facility cylinder

    International Nuclear Information System (INIS)

    Whitehouse, D.R.; Greig, D.R.; Koroll, G.W.

    1996-01-01

    This paper presents preliminary results from hydrogen concentration gradient combustion experiments in a 10.7 m 3 cylinder. These gradients, also referred to as stratified mixtures, were formed from dry mixtures of hydrogen and air at atmospheric temperature. Combustion pressures, burn fractions and flame speeds in concentration gradients were compared with combustion of well-mixed gases containing equivalent amounts of hydrogen. The studied variables included the quantity of hydrogen in the vessel, the steepness of the concentration gradient, the igniter location, and the initial concentration of hydrogen at the bottom of the vessel. Gradients of hydrogen and air with average concentrations of hydrogen below the downward propagation limit produced significantly greater combustion pressures when ignited at the top of the vessel than well-mixed gases with the same quantity of hydrogen. This was the result of considerably higher burn fractions in the gradients than in the well-mixed gas tests. Above the downward propagation limit, gradients of hydrogen ignited at the top of the vessel produced nearly the same combustion pressures as under well-mixed conditions; both gradients and well-mixed gases had high burn fractions. Much higher flame speeds were observed in the gradients than the well-mixed gases. Gradients and well-mixed gases containing up to 14% hydrogen ignited at the bottom of the vessel produced nearly the same combustion pressures. Above 14% hydrogen, gradients produced lower combustion pressures than well-mixed gases having the same quantity of hydrogen. This can be attributed to lower burn fractions of fuel from the gradients compared with well-mixed gases with similar quantities of hydrogen. When ignited at the bottom of the vessel, 90% of a gradient's gases remained unburned until several seconds after ignition. The remaining gases were then consumed at a very fast rate. (orig.)

  7. Juan Emar, arquitecto de la prosa. Elementos de Poética y recepción

    Directory of Open Access Journals (Sweden)

    Alejandro Canseco-Jerez

    2016-04-01

    Full Text Available El artículo expone (1 los primeros elementos para la interpretación del universo de representaciones estéticas, elementos que impidieron la difusión y la "recepción" en Chile de la obra literaria de Juan Emar; (2 aproximación de la Arqui-textura -Umbral- configuración de la transversabilidad semántica de la obra emariana; y (3 el principio de "dialogización" e intertextualidad y la noción de utopía literaria en torno al universo de Mallarmé y Borges.   The article describes (1 the primary elements for the interpretation of the universe of aesthetic representations, elements which prevented the diffusion and "reception" in Chile of Juan Emar's literary work; (2 the approximation of the archi-texture -Umbral- and the shape of the semantic transversability of the Emarian work; and (3 the beginning of "dialogation" and intertextuality and the notion of literary utopia in connection with the universe of Mallarme and Borges.

  8. Evaluación de técnicas no destructivas en elementos de concreto para puentes

    Directory of Open Access Journals (Sweden)

    Ricardo Alfredo Cruz

    2015-09-01

    Full Text Available Se evaluaron las técnicas no destructivas de Velocidad de Pulso Ultrasónico (VPU, termografía infrarroja y martillo de rebote para su aplicación en elementos de puentes de concreto y para determinar su posible aplicación in situ. El estudio se desarrolló en dos etapas: diseño y elaboración de los elementos representativos de un puente de concreto y aplicación de los ensayos no destructivos sobre estos. La técnica de VPU mostró gran capacidad para evaluar la homogeneidad y calidad de la matriz de concreto, con baja sensibilidad para identificar los daños en los refuerzos. La termografía infrarroja permitió la identificación de delaminaciones ubicadas a profundidades de hasta el 50% del espesor de la losa evaluada. Con los resultados del martillo de rebote se estimó la resistencia a la compresión del concreto de las losas, cuyas lecturas obtenidas fueron afectadas por la presencia de agregado grueso.

  9. Combustion Modeling with the G-Equation Modélisation de la combustion avec l'équation de G

    Directory of Open Access Journals (Sweden)

    Peters N.

    2006-12-01

    Full Text Available Numerical investigations concerning the turbulent flame front propagation in Gasoline Direct Injection (GDI engines were made by implementing a flamelet model in the CFD code Fire. The advantage of this combustion model is the decoupling of the chemistry from the turbulent flow. For this purpose the combustion chamber has to be divided into a burned and an unburned area, which is realized by transporting a scalar field (G-Equation. The reference value defines the present averaged flame position. The complete reaction kinetics is calculated interactively with the CFD code in a one dimensional Representative Interactive Flamelet (RIF code. This combustion model was verified by simulating a 2. 0 l-2 V gasoline engine with homogeneous combustion where a parameter study was conducted to check the flamelet model for plausibility. Finally, the potential of this combustion model was investigated by simulating a hypothetical 2. 0 1-4 V GDI engine. Une investigation numérique relative à la propagation des fronts de flammes turbulents dans les moteurs à essence à injection directe (GDI a été menée en implantant un modèle de flameletdans le code 3D Fire. L'avantage de ce modèle de combustion est de découpler la chimie de l'écoulement turbulent en divisant la chambre de combustion en deux zones : brûlée et imbrûlée, à l'aide d'une équation de transport d'un scalaire (équation de G. Une valeur de référence de ce scalaire définit la position moyenne de la flamme. Une chimie complète est calculée interactivement avec le calcul 3D à l'aide d'un code monodimensionnel RIF (Representative Interactive Flamelet. Le modèle de combustion a été validé sur la simulation d'un moteur 2 litres à 2 soupapes en combustion homogène pour vérifier la représentativité de l'approche flamelet . Puis, le potentiel du modèle de combustion a été étudié en simulant un moteur modèle 2 litres 4 soupapes GDI.

  10. Reaction and diffusion in turbulent combustion

    Energy Technology Data Exchange (ETDEWEB)

    Pope, S.B. [Mechanical and Aerospace Engineering, Ithaca, NY (United States)

    1993-12-01

    The motivation for this project is the need to obtain a better quantitative understanding of the technologically-important phenomenon of turbulent combustion. In nearly all applications in which fuel is burned-for example, fossil-fuel power plants, furnaces, gas-turbines and internal-combustion engines-the combustion takes place in a turbulent flow. Designers continually demand more quantitative information about this phenomenon-in the form of turbulent combustion models-so that they can design equipment with increased efficiency and decreased environmental impact. For some time the PI has been developing a class of turbulent combustion models known as PDF methods. These methods have the important virtue that both convection and reaction can be treated without turbulence-modelling assumptions. However, a mixing model is required to account for the effects of molecular diffusion. Currently, the available mixing models are known to have some significant defects. The major motivation of the project is to seek a better understanding of molecular diffusion in turbulent reactive flows, and hence to develop a better mixing model.

  11. Optical Tomography in Combustion

    DEFF Research Database (Denmark)

    Evseev, Vadim

    spectral measurements at several line-of-sights with a view to applications for tomographic measurements on full-scale industrial combustion systems. The system was successfully applied on industrial scale for simultaneous fast exhaust gas temperature measurements in the three optical ports of the exhaust......D project, it was also important to investigate the spectral properties of major combustion species such as carbon dioxide and carbon monoxide in the infrared range at high temperatures to provide the theoretical background for the development of the optical tomography methods. The new software....... JQSRT 113 (2012) 2222, 10.1016/j.jqsrt.2012.07.015] included in the PhD thesis as an attachment. The knowledge and experience gained in the PhD project is the first important step towards introducing the advanced optical tomography methods of combustion diagnostics developed in the project to future...

  12. High Pressure Combustion Experimental Facility(HPCEF) for Studies on Combustion in Reactive Flows

    Science.gov (United States)

    2017-12-13

    SECURITY CLASSIFICATION OF: 1. REPORT DATE (DD-MM-YYYY) 4. TITLE AND SUBTITLE 13. SUPPLEMENTARY NOTES 12. DISTRIBUTION AVAILIBILITY STATEMENT 6...Report: High Pressure Combustion Experimental Facility (HPCEF) for Studies on Combustion in Reactive Flows The views, opinions and/or findings... contained in this report are those of the author(s) and should not contrued as an official Department of the Army position, policy or decision, unless so

  13. Oxy combustion with CO{sub 2} capture

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-01-15

    An update for oxyfuel-combustion carbon capture in the power industry is provided. The report was developed by the Electric Power Research Institute (EPRI) on behalf of the Global CCS Institute. In the oxyfuel-combustion processes, the bulk nitrogen is removed from the air before combustion. The resulting combustion products will have CO2 content up to about 90 per cent (dry basis). The flue gas impurities (predominantly O2, N2, and Ar) may be removed by reducing the flue gas (at moderate pressure) to a temperature at which the CO2 condenses and the impurities do not. Oxyfuel-combustion may be employed with solid fuels such as coal, petroleum coke, and biomass, as well as liquid and gaseous fuels. Some key points raised in the oxyfuel-combustion carbon capture report are: The oxyfuel-combustion/CO2 capture power plant designs being developed and deployed for service in the next four or five years are based on individual component technologies and arrangements which have demonstrated sufficient maturity, with the greatest remaining technical challenge being integrating the systems into a complete steam-electric power plant; By its nature, an oxyfuel-coal power plant is likely to be a 'near zero' emitter of all criteria pollutants; Existing air-fired power plants might be retrofitted with an air separation unit, oxyfuel-fired burners, flue gas recycle, and a CO2 processing unit, with the large fleet of air-fired power plants in service calling for more study of this option; and, Future efficiency improvements to the oxyfuel-combustion process for power generation point toward an oxyfuel-combustion plant with near zero emissions of conventional pollutants, up to 98 per cent CO2 capture, and efficiency comparable to the best power plants currently being built.

  14. Catalytic combustion in small wood burning appliances

    Energy Technology Data Exchange (ETDEWEB)

    Oravainen, H [VTT Energy, Jyvaeskylae (Finland)

    1997-12-31

    There is over a million hand fired small heating appliances in Finland where about 5,4 million cubic meters of wood fuel is used. Combustion in such heating appliances is a batch-type process. In early stages of combustion when volatiles are burned, the formation of carbon monoxide (CO) and other combustible gases are difficult to avoid when using fuels that have high volatile matter content. Harmful emissions are formed mostly after each fuel adding but also during char burnout period. When the CO-content in flue gases is, say over 0.5 %, also other harmful emissions will be formed. Methane (CH{sub 4}) and other hydrocarbons are released and the amount of polycyclic aromatic hydrocarbons (PAH)-compounds can be remarkable. Some PAH-compounds are very carcinogenic. It has been estimated that in Finland even more than 90 % of hydrocarbon and PAH emissions are due to small scale wood combustion. Emissions from transportation is excluded from these figures. That is why wood combustion has a net effect on greenhouse gas phenomena. For example carbon monoxide emissions from small scale wood combustion are two fold compared to that of energy production in power plants. Methane emission is of the same order as emission from transportation and seven fold compared with those of energy production. Emissions from small heating appliances can be reduced by developing the combustion techniques, but also by using other means, for example catalytic converters. In certain stages of the batch combustion, temperature is not high enough, gas mixing is not good enough and residence time is too short for complete combustion. When placed to a suitable place inside a heating appliance, a catalytic converter can oxidize unburned gases in the flue gas into compounds that are not harmful to the environment. (3 refs.)

  15. Catalytic combustion in small wood burning appliances

    Energy Technology Data Exchange (ETDEWEB)

    Oravainen, H. [VTT Energy, Jyvaeskylae (Finland)

    1996-12-31

    There is over a million hand fired small heating appliances in Finland where about 5,4 million cubic meters of wood fuel is used. Combustion in such heating appliances is a batch-type process. In early stages of combustion when volatiles are burned, the formation of carbon monoxide (CO) and other combustible gases are difficult to avoid when using fuels that have high volatile matter content. Harmful emissions are formed mostly after each fuel adding but also during char burnout period. When the CO-content in flue gases is, say over 0.5 %, also other harmful emissions will be formed. Methane (CH{sub 4}) and other hydrocarbons are released and the amount of polycyclic aromatic hydrocarbons (PAH)-compounds can be remarkable. Some PAH-compounds are very carcinogenic. It has been estimated that in Finland even more than 90 % of hydrocarbon and PAH emissions are due to small scale wood combustion. Emissions from transportation is excluded from these figures. That is why wood combustion has a net effect on greenhouse gas phenomena. For example carbon monoxide emissions from small scale wood combustion are two fold compared to that of energy production in power plants. Methane emission is of the same order as emission from transportation and seven fold compared with those of energy production. Emissions from small heating appliances can be reduced by developing the combustion techniques, but also by using other means, for example catalytic converters. In certain stages of the batch combustion, temperature is not high enough, gas mixing is not good enough and residence time is too short for complete combustion. When placed to a suitable place inside a heating appliance, a catalytic converter can oxidize unburned gases in the flue gas into compounds that are not harmful to the environment. (3 refs.)

  16. A Rapid-Insertion Control-Absorber Mechanism for Use in Hollow Fuel Elements; Mecanisme d'Insertion Rapide d'Absorbants pour Utilisation dans des Elements Creux; Mekhanizm bystrogo vvoda poglotitelya dlya ispol'zovaniya v polykh toplivnykh ehlementakh; Mecanismo para la Insercion Rapida de Absorbentes en Elementos Combustibles Huecos

    Energy Technology Data Exchange (ETDEWEB)

    King, E. S.F. [Atomic Energy Research Establishment Harwell, Berks. (United Kingdom)

    1964-06-15

    reglee avec une precision de 4 x 10{sup -3}cm et on peut le retirer a des vitesses de 0,04 cm/s'et 0,01 cm/s. Le mecanisme est constitue par un moteur a vernier qui entraihe une vis sans fin et eleve ou abaisse un obturateur cylindrique adapte a la protection a sa base d'un electro-aimant qui soutient un tube absorbant. Il y a un espace important autour du tube absorbant, qui tombe en chute libre (il rencontre seulement la resistance visqueuse du ralen- tisseur/refroidisseur) jusqu'a ce qu'il soit arrete dans sa chute par une barre centrale passant a travers la vis sans fin et aboutissant a un amortisseur a ressort circulaire situe au sommet du mecanisme. Apres la chute du tube absorbant, le moteur fait descendre rapidement l'obturateur dans lequel on engage de nouveau le tube. La dimension du mecanisme est comprise dans les dimensions d'ensemble de l'element et on peut le sortir du reacteur en meme temps que l'element ou separement, au moyen de la bouteille de dechargement du combustible [Spanish] El autor describe las caracteristicas tecnicas y funcionales de un mecanismo de mando para absorbentes de control, de insercion rapida, aplicable a los elementos combustibles huecos, verticales, de los reactores de ensayo de materiales de tipo DIDO, cuyo flujo termico es de 10{sup 14} n/cm{sup 2} s. La aceleracion descendente inicial del absorbente es la debida a la gravedad y la carrera total, de 61 cm, se cumple en 0,4 s. El intervalo de disparo del iman es de 5 ms. El absorbente pesa 7 kg, tiene una superficie efectiva de 1000 cm{sup 2} de Cd y una capacidad de regulacion del 3% de la reactividad. Su posicion puede fijarse con una precision de 4 x 10{sup -3}cm y la velocidad de extraccion varia entre 0,04 cm/s y 0,01 cm/s. El mecanismo consta de un motor de avance a vernier que acciona un tornillo de guia y puede elevar o bajar un obturador blindado cilindrico de ajuste estricto que lleva un electroiman en el extremo inferior y sostiene el absorbente tubular. La luz radial

  17. Reactivity studies of rice husk combustion using TGA

    International Nuclear Information System (INIS)

    Ismail, A.F.; Shamsuddin, A.H.; Mahdi, F.M.A.

    2000-01-01

    The reactivity of rice husks combustion is systematically studied the thermogravimetric analyzer (TGA). The kinetic parameters are determined from the Arrhenius plots based on the data of weight loss over temperature at different combustion heating rates. The results of proximate analysis (the moisture, volatile matters, fixed carbon, and ash contents) are also presented in this paper. The effects of process conditions on the self-ignition phenomenon of rice husk combustion are quantified. Finally, these results and compared with results for coal combustion. This research is part of the work to determine the optimal process conditions of rice husk combustion for energy production. (Author)

  18. Large-eddy simulation of swirling pulverized-coal combustion

    Energy Technology Data Exchange (ETDEWEB)

    Hu, L.Y.; Luo, Y.H. [Shanghai Jiaotong Univ. (China). School of Mechanical Engineering; Zhou, L.X.; Xu, C.S. [Tsinghua Univ., Beijing (China). Dept. of Engineering Mechanics

    2013-07-01

    A Eulerian-Lagrangian large-eddy simulation (LES) with a Smagorinsky-Lilly sub-grid scale stress model, presumed-PDF fast chemistry and EBU gas combustion models, particle devolatilization and particle combustion models are used to study the turbulence and flame structures of swirling pulverized-coal combustion. The LES statistical results are validated by the measurement results. The instantaneous LES results show that the coherent structures for pulverized coal combustion is stronger than that for swirling gas combustion. The particles are concentrated in the periphery of the coherent structures. The flame is located at the high vorticity and high particle concentration zone.

  19. Boiler for combustion fuel in a fluidized bed

    Directory of Open Access Journals (Sweden)

    Laković Mirjana S.

    2015-01-01

    Full Text Available Fuel combustion in fluidized bed combustion is a process that is current and which every day gives more attention and there are many studies that have been closely associated with this technology. This combustion technology is widespread and constantly improving the range of benefits it provides primarily due to reduced emissions. This paper presents the boilers for combustion in a fluidized bed, whit characteristics and advantages. Also is shown the development of this type of boilers in Republic of Serbia. In this paper is explained the concept of fluidized bed combustion. Boilers for this type of combustion can be improved and thereby increase their efficiency level. More detailed characteristics are given for boilers with bubbling and circulating fluidized bed as well as their mutual comparison.

  20. Combustion of drops of Mexican fuel oils with high asphaltenes content; Combustion de gotas de combustoleos mexicanos con alto contenido de asfaltenos

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Rodriguez, Jose Francisco [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

    1998-09-01

    In this work the combustion of fuel drops with a content of 18% of asphaltenes has been studied . The results obtained for this fuel were compared with the ones obtained for another with a content of 12% asphaltenes. The drops were suspended in a platinum filament and burned in an spherical radiant furnace. The drop size varied between 600 and 800 microns. The fuel drops with 12% asphaltenes showed shorter combustion times, a smaller diameter increment of the smaller diameter during the combustion stages and also a shorter burning time of the carbonaceous residue than the fuel drops with a content of 18% asphaltenes. [Espanol] En el presente trabajo se ha estudiado la combustion de gotas de combustible con 18% de contenido de asfaltenos. Los resultados obtenidos para este combustible se compararon con los obtenidos para otro con 12% de contenido de asfaltenos. Las gotas fueron suspendidas en un filamento de platino y quemadas en un horno radiante esferico. El tamano de las gotas vario entre 600 y 800 micras. Las gotas de combustible con 12% de asfaltenos mostraron tiempos de combustion mas cortos, un incremento del diametro menor durante las etapas de combustion y un tiempo de quemado del residuo carbonoso tambien mas corto que las gotas del combustible con 18% de contenido de asfaltenos.

  1. Combustion tests with different pellet qualities

    International Nuclear Information System (INIS)

    Bachs, A.; Dahlstroem, J.E.; Persson, Henrik; Tullin, C.

    1999-05-01

    Eight different pellet qualities with the diameters 6, 8 and 10 mm, from eight different producers has been tested in three pellet burners and two pellet stoves. The objective was to investigate how different diameter affect the emissions of CO, OGC and NO x . Previous experience has indicated that the pellet diameter could have significant importance for the combustion. This was not verified in the study. It showed contradictory that the diameter has a minor effect on the combustion result. The study shows that different combustion equipment give different emission. For e g hydrocarbon emissions the difference is a factor 2.2 between the 'best' and the 'worst' equipment fired on full load. The difference increases to 2.7 with lower load. The choice of fuel has a big importance for the quality of the combustion. For hydrocarbons the emissions could in an extreme situation differ with a factor 25 between 'best' and 'worst' fuel. More normally the difference is about a factor of five. Nitrogen oxide emissions are to a major part related to the nitrogen contents in the fuel. The difference between the 'best' and 'worst' fuel is in the range of a factor two. Tests with the same fuel in different equipment gives a variation of 20-30%. The combustion result depends on both the pellet quality and the equipment and there is no fuel that is good in all equipment. The big variation in combustion results shows that there is a big indifference between fuels used for small scale heating Project report from the program: Small scale combustion of biofuels. 2 refs, 15 figs, 5 tabs

  2. Hydrogen combustion modelling in large-scale geometries

    International Nuclear Information System (INIS)

    Studer, E.; Beccantini, A.; Kudriakov, S.; Velikorodny, A.

    2014-01-01

    Hydrogen risk mitigation issues based on catalytic recombiners cannot exclude flammable clouds to be formed during the course of a severe accident in a Nuclear Power Plant. Consequences of combustion processes have to be assessed based on existing knowledge and state of the art in CFD combustion modelling. The Fukushima accidents have also revealed the need for taking into account the hydrogen explosion phenomena in risk management. Thus combustion modelling in a large-scale geometry is one of the remaining severe accident safety issues. At present day there doesn't exist a combustion model which can accurately describe a combustion process inside a geometrical configuration typical of the Nuclear Power Plant (NPP) environment. Therefore the major attention in model development has to be paid on the adoption of existing approaches or creation of the new ones capable of reliably predicting the possibility of the flame acceleration in the geometries of that type. A set of experiments performed previously in RUT facility and Heiss Dampf Reactor (HDR) facility is used as a validation database for development of three-dimensional gas dynamic model for the simulation of hydrogen-air-steam combustion in large-scale geometries. The combustion regimes include slow deflagration, fast deflagration, and detonation. Modelling is based on Reactive Discrete Equation Method (RDEM) where flame is represented as an interface separating reactants and combustion products. The transport of the progress variable is governed by different flame surface wrinkling factors. The results of numerical simulation are presented together with the comparisons, critical discussions and conclusions. (authors)

  3. Verification of Conditions for use of Combustion Products‘ Heat

    Directory of Open Access Journals (Sweden)

    Kažimírová Viera

    2015-06-01

    Full Text Available Presented contribution deals with the verification of conditions for use of combustion products‘ heat, generated by combustion of wood in a fireplace used in a household. It is necessary to know the temperature behaviour of the fireplace to determine the adequacy of the technical solution for using combustion products‘ heat. The combustion products‘ temperature at the upper part of the chimney is 80-120 °C. The dew point value was established to be below 51 °C. The average observed value of combustion product velocity is 1.6 m s-1. The volume flow rate of combustion products is 12 m3 h-1. Measured values allow for effective solution of the use of combustion products‘ heat.

  4. Separating Direct and Indirect Turbofan Engine Combustion Noise While Estimating Post-Combustion (Post-Flame) Residence Time Using the Correlation Function

    Science.gov (United States)

    Miles, Jeffrey Hilton

    2011-01-01

    A previous investigation on the presence of direct and indirect combustion noise for a full-scale turbofan engine using a far-field microphone at 130 is extended by also examining signals obtained at two additional downstream directions using far-field microphones at 110 deg and 160 deg. A generalized cross-correlation function technique is used to study the change in propagation time to the far field of the combined direct and indirect combustion noise signal as a sequence of low-pass filters are applied. The filtering procedure used produces no phase distortion. As the low-pass filter frequency is decreased, the travel time increases because the relative amount of direct combustion noise is reduced. The indirect combustion noise signal travels more slowly because in the combustor entropy fluctuations move with the flow velocity, which is slow compared to the local speed of sound. The indirect combustion noise signal travels at acoustic velocities after reaching the turbine and being converted into an acoustic signal. The direct combustion noise is always propagating at acoustic velocities. The results show that the estimated indirect combustion noise time delay values (post-combustion residence times) measured at each angle are fairly consistent with one another for a relevant range of operating conditions and demonstrate source separation of a mixture of direct and indirect combustion noise. The results may lead to a better idea about the acoustics in the combustor and may help develop and validate improved reduced-order physics-based methods for predicting turbofan engine core noise.

  5. Experimental validation for combustion analysis of GOTHIC 6.1b code in 2-dimensional premixed combustion experiments

    International Nuclear Information System (INIS)

    Lee, J. Y.; Lee, J. J.; Park, K. C.

    2003-01-01

    In this study, the prediction capability of GOTHIC code for hydrogen combustion phenomena was validated with the results of two-dimensional premixed hydrogen combustion experiment executed by Seoul National University. In the experimental results, we could confirm the propagation characteristics of hydrogen flame such as buoyancy effect, flame front shape etc.. The combustion time of the tests was about 0.1 sec.. In the GOTHIC analyses results, the GOTHIC code could predict the overall hydrogen flame propagation characteristics but the buoyancy effect and flame shape did not compare well with the experimental results. Especially, in case of the flame propagate to the dead-end, GOTHIC predicted the flame did not affected by the flow and this cause quite different results in flame propagation from experimental results. Moreover the combustion time of the analyses was about 1 sec. which is ten times longer than the experimental result. To obtain more reasonable analysis results, it is necessary that combustion model parameters in GOTHIC code apply appropriately and hydrogen flame characteristics be reflected in solving governing equations

  6. Elementos para evaluar planes de estudio en la educación superior

    Directory of Open Access Journals (Sweden)

    Leda María Roldán Santamaría

    2005-01-01

    Full Text Available Este artículo presenta los lineamientos para generar una propuesta de evaluación curricular de un plan de estudios en el ámbito de la educación universitaria. Identifica la importancia que tiene este proceso para la institución con el fin de analizar las debilidades y fortalezas, con miras a la toma de decisiones para su actualización. En la propuesta se responde el por qué y para qué se debe evaluar; los beneficios que los usuarios recibirán de esa actualización; la concreción de elementos del plan de estudios por evaluar; la definición de las variables que se aplicarán en la evaluación de los elementos externos e internos. Se proponen cuáles son los sectores sociales que deben involucrarse en dicha evaluación; se analiza el momento adecuado para realizar la evaluación y cada cuanto debe aplicarse, se establece un plan estratégico para aplicar la evaluación y se presentan las sugerencias de los usos que se le pueda dar a la información recopilada con la evaluación. Evaluar un plan de estudios permite descubrir las necesidades de cambio de los planes de estudio; el establecimiento de los lineamientos para su actualización y el tiempo en que se debe cumplir con la misma para que el plan no pierda vigencia

  7. System and method for engine combustion

    Science.gov (United States)

    Sczomak, David P.; Gallon, Robert J.; Solomon, Arun S.

    2018-03-13

    A combustion system for use with one or more cylinder bores of an internal combustion engine includes at least one cylinder head defining first and second intake ports in fluid communication with the one or more cylinder bores. A flap is adjustably connected to the at least one cylinder head. The flap includes a first flap portion cooperating with the first intake port extending from an arm and a second flap portion cooperating with the second intake port extending from the arm and disposed adjacent the first flap portion. A controller in electrical communication with an actuator monitors the condition of the engine and actuates the flap to position the first and second flap portions between first and second positions to create a first combustion condition and a second combustion condition.

  8. Techniques for Liquid Rocket Combustion Spontaneous Stability and Rough Combustion Assessments

    Science.gov (United States)

    Kenny, R. J.; Giacomoni, C.; Casiano, M. J.; Fischbach, S. R.

    2016-01-01

    This work presents techniques for liquid rocket engine combustion stability assessments with respect to spontaneous stability and rough combustion. Techniques covering empirical parameter extraction, which were established in prior works, are applied for three additional programs: the F-1 Gas Generator (F1GG) component test program, the RS-84 preburner component test program, and the Marshall Integrated Test Rig (MITR) program. Stability assessment parameters from these programs are compared against prior established spontaneous stability metrics and updates are identified. Also, a procedure for comparing measured with predicted mode shapes is presented, based on an extension of the Modal Assurance Criterion (MAC).

  9. Highly time-resolved imaging of combustion and pyrolysis product concentrations in solid fuel combustion: NO formation in a burning cigarette.

    Science.gov (United States)

    Zimmermann, Ralf; Hertz-Schünemann, Romy; Ehlert, Sven; Liu, Chuan; McAdam, Kevin; Baker, Richard; Streibel, Thorsten

    2015-02-03

    The highly dynamic, heterogeneous combustion process within a burning cigarette was investigated by a miniaturized extractive sampling probe (microprobe) coupled to photoionization mass spectrometry using soft laser single photon ionization (SPI) for online real-time detection of molecular ions of combustion and pyrolysis products. Research cigarettes smoked by a smoking machine are used as a reproducible model system for solid-state biomass combustion, which up to now is not addressable by current combustion-diagnostic tools. By combining repetitively recorded online measurement sequences from different sampling locations in an imaging approach, highly time- and space-resolved quantitative distribution maps of, e.g., nitrogen monoxide, benzene, and oxygen concentrations were obtained at a near microscopic level. The obtained quantitative distribution maps represent a time-resolved, movie-like imaging of the respective compound's formation and destruction zones in the various combustion and pyrolysis regions of a cigarette during puffing. Furthermore, spatially resolved kinetic data were ascertainable. The here demonstrated methodology can also be applied to various heterogenic combustion/pyrolysis or reaction model systems, such as fossil- or biomass-fuel pellet combustion or to a positional resolved analysis of heterogenic catalytic reactions.

  10. Environmental optimisation of waste combustion

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, Robert [AaF Energikonsult, Stockholm (Sweden); Berge, Niclas; Stroemberg, Birgitta [TPS Termiska Processer AB, Nykoeping (Sweden)

    2000-12-01

    The regulations concerning waste combustion evolve through R and D and a strive to get better and common regulations for the European countries. This study discusses if these rules of today concerning oxygen concentration, minimum temperature and residence time in the furnace and the use of stand-by burners are needed, are possible to monitor, are the optimum from an environmental point of view or could be improved. No evidence from well controlled laboratory experiments validate that 850 deg C in 6 % oxygen content in general is the best lower limit. A lower excess air level increase the temperature, which has a significant effect on the destruction of hydrocarbons, favourably increases the residence time, increases the thermal efficiency and the efficiency of the precipitators. Low oxygen content is also necessary to achieve low NO{sub x}-emissions. The conclusion is that the demands on the accuracy of the measurement devices and methods are too high, if they are to be used inside the furnace to control the combustion process. The big problem is however to find representative locations to measure temperature, oxygen content and residence time in the furnace. Another major problem is that the monitoring of the operation conditions today do not secure a good combustion. It can lead to a false security. The reason is that it is very hard to find boilers without stratifications. These stratifications (stream lines) has each a different history of residence time, mixing time, oxygen and combustible gas levels and temperature, when they reach the convection area. The combustion result is the sum of all these different histories. The hydrocarbons emission is in general not produced at a steady level. Small clouds of unburnt hydrocarbons travels along the stream lines showing up as peaks on a THC measurement device. High amplitude peaks has a tendency to contain higher ratio of heavy hydrocarbons than lower peaks. The good correlation between some easily detected

  11. Mechanisms and kinetics of granulated sewage sludge combustion.

    Science.gov (United States)

    Kijo-Kleczkowska, Agnieszka; Środa, Katarzyna; Kosowska-Golachowska, Monika; Musiał, Tomasz; Wolski, Krzysztof

    2015-12-01

    This paper investigates sewage sludge disposal methods with particular emphasis on combustion as the priority disposal method. Sewage sludge incineration is an attractive option because it minimizes odour, significantly reduces the volume of the starting material and thermally destroys organic and toxic components of the off pads. Additionally, it is possible that ashes could be used. Currently, as many as 11 plants use sewage sludge as fuel in Poland; thus, this technology must be further developed in Poland while considering the benefits of co-combustion with other fuels. This paper presents the results of experimental studies aimed at determining the mechanisms (defining the fuel combustion region by studying the effects of process parameters, including the size of the fuel sample, temperature in the combustion chamber and air velocity, on combustion) and kinetics (measurement of fuel temperature and mass changes) of fuel combustion in an air stream under different thermal conditions and flow rates. The combustion of the sludge samples during air flow between temperatures of 800 and 900°C is a kinetic-diffusion process. This process determines the sample size, temperature of its environment, and air velocity. The adopted process parameters, the time and ignition temperature of the fuel by volatiles, combustion time of the volatiles, time to reach the maximum temperature of the fuel surface, maximum temperature of the fuel surface, char combustion time, and the total process time, had significant impacts. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Effects of streamwise vortex breakdown on supersonic combustion.

    Science.gov (United States)

    Hiejima, Toshihiko

    2016-04-01

    This paper presents a numerical simulation study of the combustion structure of streamwise vortex breakdown at Mach number 2.48. Hydrogen fuel is injected into a combustor at sonic speed from the rear of a hypermixer strut that can generate streamwise vortices. The results show that the burning behavior is enhanced at the points of the shock waves that are incident on the vortex and therefore the vortex breakdown in the subsonic region occurs due to combustion. The breakdown domain in the mainstream is found to form a flame-holding region suited to combustion and to lead to a stable combustion field with detached flames. In this way, streamwise vortex breakdown has an essential role in combustion enhancement and the formation of flames that hold under supersonic inflow conditions. Finally, the combustion property defined here is shown to coincide with the produced-water mass flow. This property shows that the amount of combustion is saturated at equivalence ratios over 0.4, although there is a slight increase beyond 1.

  13. Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Ojeda, William de

    2010-07-31

    The project which extended from November 2005 to May of 2010 demonstrated the application of Low Temperature Combustion (LTC) with engine out NOx levels of 0.2 g/bhp-hr throughout the program target load of 12.6bar BMEP. The project showed that the range of loads could be extended to 16.5bar BMEP, therefore matching the reference lug line of the base 2007 MY Navistar 6.4L V8 engine. Results showed that the application of LTC provided a dramatic improvement over engine out emissions when compared to the base engine. Furthermore LTC improved thermal efficiency by over 5% from the base production engine when using the steady state 13 mode composite test as a benchmark. The key enablers included improvements in the air, fuel injection, and cooling systems made in Phases I and II. The outcome was the product of a careful integration of each component under an intelligent control system. The engine hardware provided the conditions to support LTC and the controller provided the necessary robustness for a stable combustion. Phase III provided a detailed account on the injection strategy used to meet the high load requirements. During this phase, the control strategy was implemented in a production automotive grade ECU to perform cycle-by-cycle combustion feedback on each of the engine cylinders. The control interacted on a cycle base with the injection system and with the Turbo-EGR systems according to their respective time constants. The result was a unique system that could, first, help optimize the combustion system and maintain high efficiency, and secondly, extend the steady state results to the transient mode of operation. The engine was upgraded in Phase IV with a Variable Valve Actuation system and a hybrid EGR loop. The impact of the more versatile EGR loop did not provide significant advantages, however the application of VVA proved to be an enabler to further extend the operation of LTC and gain considerable benefits in fuel economy and soot reduction. Finally

  14. Aplicación de la medida de NOx para el control de motores diesel sobrealimentados

    OpenAIRE

    Cabrera López, Pedro

    2013-01-01

    Los motores de combusti'on interna est'an inmersos en una constante evoluci'on tecnol'ogica con el ¿n de mejorar sus prestaciones y satisfacer adem'as las cada vez m'as restrictivas normas anticontaminantes. En el caso de los motores diesel esto concierne especialmente a las emisiones de NOx y part'¿culas. Los sistemas destinados a reducir estas emisiones (inyecci'on directa common-rail, sobrealimentaci'on con geometr'¿a variable, recirculaci'on de gases de escape, trampas de part'¿c...

  15. Elementos de cohesión urbana en escenarios metropolitanos: intersticios y corredores.

    OpenAIRE

    Bravo Rodríguez, Belén; Rivas Navarro, José Luis

    2012-01-01

    Póster presentado en la sesión dedicada a Ámbitos, Innovación y Calidad, en las IV Jornadas Internacionales sobre Investigación en Arquitectura y Urbanismo. El ámbito metropolitano, está constituido por fragmentos autónomos y yuxtapuestos. Es necesario evitar la fragmentación y la indeterminación del espacio colectivo generando una estructura que lo cohesione socialmente. Los intersticios y corredores son elementos estructurales pero también sensibles a los lugares pequeños o a las arqu...

  16. Piezocomposites metal-cerámica como elementos activos en acelerómetros

    OpenAIRE

    Ochoa, Pilar; Villegas, Marina; Pons Rovira, José Luis; Fernández Lozano, José Francisco; Bengochea, M. A.

    2002-01-01

    [ES] Los materiales cerámicos piezoeléctricos presentan un número importante y en continuo aumento de aplicaciones. Entre éstas su utilización como elementos activos en el diseño de acelerómetros posibilita el control de vibraciones en la industria del transporte, aerospacial, robótica e ingeniería civil entre otras. Entre los múltiples diseños como material compuesto destaca, gracias a sus elevados coeficientes de carga efectivos, el denominado tipo címbalo. En este trabajo se compr...

  17. Elementos cognitivos para el análisis ergonómico del trabajo

    OpenAIRE

    Castillo-Martínez, Juan A; Universidad del Rosario, Escuela de Medicina y Ciencias de la Salud. Grupo de Investigación Salud Cognición y Trabajo

    2007-01-01

    Esta nota de investigación presenta algunos de los elementos de base para el análisis de la actividad del trabajo desde la perspectiva de la ergonomía cognitiva. Para poder aproximarse a la relación existente entre los procesos cognitivos en el trabajo y la noción de ergonomía es necesario abordar inicialmente la definición de esta disciplina. El termino ergonomía, acuñado en 1940 por el psicólogo británico Hywel Murrell, (del Griego ergo: trabajo + nomos: ley, conocimiento)...

  18. Development of a NO/x/-free combustion system

    Science.gov (United States)

    Sadakata, M.; Furusawa, T.; Kunii, D.; Imagawa, M.; Nawada, M.

    1980-04-01

    The development of a NO(x)-free combustion-heating system realizing both pollution control and energy savings is described. An experiment was carried out by using a small model plant. The system consists of a combustion furnace and a new-type multifunctional heat exchanger. The heat exchanger is a rotary continuous type designed for soot collection and for catalytic combustion of CO and H2 as well as for preheating combustion air.

  19. Combustion and Ignition Studies of Nanocomposite Energetic Materials

    Science.gov (United States)

    2010-12-14

    Characterization of a gas burner to simulate a propellant flame and evaluate aluminum particle combustion,” M. Jackson, M. L. Pantoya and W. Gill, Combustion...of a gas burner to simulate a propellant flame and evaluate aluminum particle combustion,” M. Jackson, M. L. Pantoya and W. Gill, Combustion and...changes in parameters such as particle size. The LFA measures these properties for bulk powders, consolidated pellets or even liquid mediums and is

  20. The John Zink Hamworthy combustion handbook

    CERN Document Server

    Baukal, Charles E

    2013-01-01

    Despite the length of time it has been around, its importance, and vast amounts of research, combustion is still far from being completely understood. Issues regarding the environment, cost, and fuel consumption add further complexity, particularly in the process and power generation industries. Dedicated to advancing the art and science of industrial combustion, The John Zink Hamworthy Combustion Handbook, Second Edition: Volume 3 - Applications offers comprehensive, up-to-date coverage of equipment used in the process and power generation industries. Under the leadership of Charles E. Baukal

  1. Chaotic combustion in spark ignition engines

    International Nuclear Information System (INIS)

    Wendeker, Miroslaw; Czarnigowski, Jacek; Litak, Grzegorz; Szabelski, Kazimierz

    2003-01-01

    We analyse the combustion process in a spark ignition engine using the experimental data of an internal pressure during the combustion process and show that the system can be driven to chaotic behaviour. Our conclusion is based on the observation of unperiodicity in the time series, suitable stroboscopic maps and a complex structure of a reconstructed strange attractor. This analysis can explain that in some circumstances the level of noise in spark ignition engines increases considerably due to nonlinear dynamics of a combustion process

  2. Combustion Gases And Heat Release Analysis During Flame And Flameless Combustion Of Wood Pellets

    Directory of Open Access Journals (Sweden)

    Horváth Jozef

    2015-06-01

    Full Text Available With the growing prices of fossil fuels, alternative fuels produced of biomass come to the fore. They are made of waste materials derived from the processing of wood and wood materials. The main objective of this study was to analyse the fire-technical characteristics of wood pellets. The study analysed three dust samples acquired from wood pellets made of various types of wood biomass. Wood pellet dust is produced when manipulating with pellets. During this process a potentially hazardous situations may occur. Biomass is chemically composed mostly of hemicellulose, cellulose and lignin. During straining of the biomass by heat flux, combustion initiation occurs. Also, there was a change in the composition of material throughout combustion gases production, and the amount of heat generated by a flame or flameless combustion. Measurement of fire characteristics was conducted according to ISO 5660-1 standard using a cone calorimeter. Two samples of wood pellet dust were tested under the heat flux of 35 kW.m−2 and 50 kW.m−2. The process of combustion, the time to ignition, the carbon monoxide concentration and the amount of released heat were observed.

  3. Emission characteristics of premixed lean diesel combustion. Effects of injection nozzle and combustion chamber shape on combustion and emission characteristics; Kihaku yokongo diesel nensho no haishutsubutsu tokusei. Funmu keijo oyobi nenshoshitsu keijo ga haishutsu gas tokusei ni oyobosu eikyo

    Energy Technology Data Exchange (ETDEWEB)

    Harada, A; Sasaki, S; Miyamoto, T; Akagawa, H; Tsujimura, K

    1997-10-01

    Many articles about low NOx emission combustion are reported. A mixture formation is necessary to success low NOx emission combustion. But, there is few reports about the effect of nozzle and combustion shape on emissions which give influence on mixture. In this paper, the effects on characteristic of combustion and emissions of some land of injection nozzle and combustion chamber shape were investigated. As a result, it was cleared that the influence of combustion chamber shape on characteristic of combustion and emissions was varied by spray shape, and pintle type injection nozzle was suitable for PREDIC. 7 refs., 10 figs., 1 tab.

  4. Elementos obstaculizadores de las coordinaciones pedagógicas en liceos vulnerables de la Araucanía Chilena

    Directory of Open Access Journals (Sweden)

    Juan Beltrán-Véliz

    2015-01-01

    Full Text Available En este artículo desarrollamos el siguiente objetivo: develardescriptivamente los elementos que obstaculizan las prácticas de las coordinaciones pedagógicasen liceos situados en contextos de vulnerabilidad social en la Araucanía. Planteamos un diseñocualitativo descriptivo, orientado con base en la teoría fundamentada y el método comparativoconstante. Los resultados develan que las prácticas de las coordinaciones pedagógicas estáncentradas en aspectos administrativos. Se evidencia la ausencia de competencias y de liderazgo.Finalmente, el desarrollo evaluativo no se centra en la continuidad y permanencia del proceso.Concluimos que la ausencia de liderazgo, de competencias de los JUTP, y el rol de estos centrado enuna “conducción técnica basada en el control”, son elementos que obstaculizan las prácticas de lascoordinaciones pedagógicas.

  5. A comprehensive study of combustion products generated from pulverized peat combustion in the furnace of BKZ-210-140F steam boiler

    Science.gov (United States)

    Kuzmin, V. A.; Zagrai, I. A.

    2017-11-01

    The experimental and theoretical study of combustion products has been carried out for the conditions of pulverized peat combustion in BKZ-210-140F steam boiler. Sampling has been performed in different parts of the boiler system in order to determine the chemical composition, radiative properties and dispersity of slag and ash particles. The chemical composition of particles was determined using the method of x-ray fluorescence analysis. Shapes and sizes of the particles were determined by means of electron scanning microscopy. The histograms and the particle size distribution functions were computed. The calculation of components of the gaseous phase was based on the combustion characteristics of the original fuel. The software package of calculation of thermal radiation of combustion products from peat combustion was used to simulate emission characteristics (flux densities and emissivity factors). The dependence of emission characteristics on the temperature level and on the wavelength has been defined. On the basis of the analysis of emission characteristics the authors give some recommendations how to determine the temperature of peat combustion products in the furnace of BKZ-210-140F steam boiler. The findings can be used to measure the combustion products temperature, support temperature control in peat combustion and solve the problem of boiler furnace slagging.

  6. Numerical Studies on Controlling Gaseous Fuel Combustion by Managing the Combustion Process of Diesel Pilot Dose in a Dual-Fuel Engine

    Directory of Open Access Journals (Sweden)

    Mikulski Maciej

    2015-06-01

    Full Text Available Protection of the environment and counteracting global warming require finding alternative sources of energy. One of the methods of generating energy from environmentally friendly sources is increasing the share of gaseous fuels in the total energy balance. The use of these fuels in compression-ignition (CI engines is difficult due to their relatively high autoignition temperature. One solution for using these fuels in CI engines is operating in a dualfuel mode, where the air and gas mixture is ignited with a liquid fuel dose. In this method, a series of relatively complex chemical processes occur in the engine's combustion chamber, related to the combustion of individual fuel fractions that interact with one another. Analysis of combustion of specific fuels in this type of fuel injection to the engine is difficult due to the fact that combustion of both fuel fractions takes place simultaneously. Simulation experiments can be used to analyse the impact of diesel fuel combustion on gaseous fuel combustion. In this paper, we discuss the results of simulation tests of combustion, based on the proprietary multiphase model of a dual-fuel engine. The results obtained from the simulation allow for analysis of the combustion process of individual fuels separately, which expands the knowledge obtained from experimental tests on the engine.

  7. AKR1C1 as a Biomarker for Differentiating the Biological Effects of Combustible from Non-Combustible Tobacco Products.

    Science.gov (United States)

    Woo, Sangsoon; Gao, Hong; Henderson, David; Zacharias, Wolfgang; Liu, Gang; Tran, Quynh T; Prasad, G L

    2017-05-03

    Smoking has been established as a major risk factor for developing oral squamous cell carcinoma (OSCC), but less attention has been paid to the effects of smokeless tobacco products. Our objective is to identify potential biomarkers to distinguish the biological effects of combustible tobacco products from those of non-combustible ones using oral cell lines. Normal human gingival epithelial cells (HGEC), non-metastatic (101A) and metastatic (101B) OSCC cell lines were exposed to different tobacco product preparations (TPPs) including cigarette smoke total particulate matter (TPM), whole-smoke conditioned media (WS-CM), smokeless tobacco extract in complete artificial saliva (STE), or nicotine (NIC) alone. We performed microarray-based gene expression profiling and found 3456 probe sets from 101A, 1432 probe sets from 101B, and 2717 probe sets from HGEC to be differentially expressed. Gene Set Enrichment Analysis (GSEA) revealed xenobiotic metabolism and steroid biosynthesis were the top two pathways that were upregulated by combustible but not by non-combustible TPPs. Notably, aldo-keto reductase genes, AKR1C1 and AKR1C2 , were the core genes in the top enriched pathways and were statistically upregulated more than eight-fold by combustible TPPs. Quantitative real time polymerase chain reaction (qRT-PCR) results statistically support AKR1C1 as a potential biomarker for differentiating the biological effects of combustible from non-combustible tobacco products.

  8. Internal Heterogeneous Processes in Aluminum Combustion

    Science.gov (United States)

    Dreizin, E. L.

    1999-01-01

    This paper discusses the aluminum particle combustion mechanism which has been expanded by inclusion of gas dissolution processes and ensuing internal phase transformations. This mechanism is proposed based on recent normal and microgravity experiments with particles formed and ignited in a pulsed micro-arc. Recent experimental findings on the three stages observed in Al particle combustion in air and shows the burning particle radiation, trajectory (streak), smoke cloud shapes, and quenched particle interiors are summarized. During stage I, the radiation trace is smooth and the particle flame is spherically symmetric. The temperature measured using a three-color pyrometer is close to 3000 K. Because it exceeds the aluminum boiling point (2730 K), this temperature most likely characterizes the vapor phase flame zone rather than the aluminum surface. The dissolved oxygen content within particles quenched during stage I was below the detection sensitivity (about 1 atomic %) for Wavelength Dispersive Spectroscopy (WDS). After an increase in the radiation intensity (and simultaneous decrease in the measured color temperature from about 3000 to 2800 K) indicative of the transition to stage II combustion, the internal compositions of the quenched particles change. Both oxygen-rich (approx. 10 atomic %) and oxygen-lean (combustion behavior and the evolution of its internal composition, the change from the spherically symmetric to asymmetric flame shape occurring upon the transition from stage I to stage II combustion could not be understood based only on the fact that dissolved oxygen is detected in the particles. The connection between the two phenomena appeared even less significant because in earlier aluminum combustion studies carried in O2/Ar mixtures, flame asymmetry was not observed as opposed to experiments in air or O2/CO mixtures. It has been proposed that the presence of other gases, i.e., hydrogen, or nitrogen causes the change in the combustion regime.

  9. Science review of internal combustion engines

    International Nuclear Information System (INIS)

    Taylor, Alex M.K.P.

    2008-01-01

    Internal combustion engines used in transportation produce about 23% of the UK's carbon dioxide emission, up from 14% in 1980. The current science described in this paper suggests that there could be 6-15% improvements in internal combustion fuel efficiency in the coming decade, although filters to meet emission legislation reduce these gains. Using these engines as hybrids with electric motors produces a reduction in energy requirements in the order of 21-28%. Developments beyond the next decade are likely to be dominated by four topics: emission legislation and emission control, new fuels, improved combustion and a range of advanced concepts for energy saving. Emission control is important because current methods for limiting nitrogen oxides and particulate emissions imply extra energy consumption. Of the new fuels, non-conventional fossil-derived fuels are associated with larger greenhouse gas emissions than conventional petroleum-based fuels, while a vehicle propelled by fuel cells consuming non-renewable hydrogen does not necessarily offer an improvement in emissions over the best hybrid internal combustion engines. Improved combustion may be developed for both gasoline and diesel fuels and promises better efficiency as well as lower noxious emissions without the need for filtering. Finally, four advanced concepts are considered: new thermodynamic cycles, a Rankine bottoming cycle, electric turbo-compounding and the use of thermoelectric devices. The latter three all have the common theme of trying to extract energy from waste heat, which represents about 30% of the energy input to an internal combustion engine

  10. Fluidized bed combustion: mixing and pollutant limitation

    Energy Technology Data Exchange (ETDEWEB)

    Leckner, B. [Chalmers Univ. of Technology, Goeteborg (Sweden). Dept. of Energy Conversion

    1997-10-01

    Fluidized bed combustion (FBC) has been applied commercially during a few decades, and sufficient knowledge is gained to design boilers with sizes of up to several hundreds of megawatt thermal power (MW{sub th}). The knowledge of what goes on inside a large combustion chamber is still limited, however, and this impedes further optimization and efficient solution of problems that might occur. Despite this lack of knowledge the present survey deals with combustion chamber processes and discusses mixing and distribution of fuel and air in the combustion chamber and its importance for sulphur capture and reduction of emissions of nitrogen oxides. It is desirable to present the material in a general way and to cover the entire field of FBC. However, the scarce openly published information deals mostly with coal combustion in atmospheric circulating fluidized bed (CFB) combustors, and therefore this application will receive most attention, but reference is also made to pressurized combustion and to other fuels than coal. In this context the important work made in the LIEKKI project on the analysis of different fuels and on the influence of pressure should be especially pointed out. (orig.)

  11. Research on combustion of black-liquor drops

    International Nuclear Information System (INIS)

    Macek, A.

    1999-01-01

    Black liquor, the major by-product of the kraft process for production of pulp, is one of the most important industrial fuels. It is burned in recovery boilers in the form of large spray drops (mm), with the objective of simultaneous recovery of heat and chemicals (sodium and sulfur). Even though black-liquor combustion in boilers has been practised for over half a century, research efforts toward improvement of combustion efficiency and abatement of environmental emissions are much more recent. The present paper addresses a specific aspect of that research, namely, elucidation of processes which occur during combustion of black-liquor drops in boiler-gas streams. The paper (a) gives a brief description of the kraft process, (b) reviews the experimental and theoretical (modeling) research advances on combustion of kraft-liquor drops during the 1980s and 1990s, (c) re-examines the results of an earlier combustion study in which black-liquor drops were observed in free flight at temperatures near those in recovery boilers, and (d) recommends input for the modeling of in-flight combustion of kraft-liquor drops in recovery boilers. (author)

  12. Low emission turbulent technology for fuel combustion

    International Nuclear Information System (INIS)

    Finker, F. Z.; Kubyshkin, I. B.; Zakharov, B. Yu.; Akhmedov, D. B.; Sobchuk, Ch.

    1997-01-01

    The company 'POLITEKHENERGO' in co-operation and the Russian-Poland firm 'EnergoVIR' have performed investigations for modernization of the current existing boilers. A low emission turbulent technology has been used for the modernization of 10 industrial boilers. The reduction of NO x emissions is based on the following processes: 1) multistage combustion assured by two counter-deviated fluxes; 2) Some of the combustion facilities have an abrupt slope and a reduced air supply which leads to an intense separation of the fuel in the bottom part and a creation of a low-temperature combustion zone where the active restoration of the NO x takes part; 3) The influence of the top high-temperature zone on the NO x formation is small. Thus the 'sandwich' consisting of 'cold' and'hot' combustion layers provides a full rate combustion. This technique permits to: decrease of the NO x and CO x down to the European standard values;increase of the efficiency in 1-2%; obtain a stable coal combustion up to 97-98%; assure the large loading range (30 -100%); modernize and use the old boilers

  13. Simulation of lean premixed turbulent combustion

    International Nuclear Information System (INIS)

    Bell, J; Day, M; Almgren, A; Lijewski, M; Rendleman, C; Cheng, R; Shepherd, I

    2006-01-01

    There is considerable technological interest in developing new fuel-flexible combustion systems that can burn fuels such as hydrogen or syngas. Lean premixed systems have the potential to burn these types of fuels with high efficiency and low NOx emissions due to reduced burnt gas temperatures. Although traditional Scientific approaches based on theory and laboratory experiment have played essential roles in developing our current understanding of premixed combustion, they are unable to meet the challenges of designing fuel-flexible lean premixed combustion devices. Computation, with its ability to deal with complexity and its unlimited access to data, has the potential for addressing these challenges. Realizing this potential requires the ability to perform high fidelity simulations of turbulent lean premixed flames under realistic conditions. In this paper, we examine the specialized mathematical structure of these combustion problems and discuss simulation approaches that exploit this structure. Using these ideas we can dramatically reduce computational cost, making it possible to perform high-fidelity simulations of realistic flames. We illustrate this methodology by considering ultra-lean hydrogen flames and discuss how this type of simulation is changing the way researchers study combustion

  14. Elementos de la identidad social urbana del casco histórico de Maracaibo, desde la perspectiva de las entidades de gestión

    Directory of Open Access Journals (Sweden)

    Raymundo Alberto Portillo Ríos

    2014-01-01

    Full Text Available La identidad social urbana hace alusión a aquellos elementos culturales, geográficos y sociales que posibilitan que una región se diferencie de otra, es memoria colectiva, labor compartida por toda la sociedad. El presente estudio busca distinguir los elementos que conforman la identidad social urbana del casco histórico de Maracaibo, desde la perspectiva de las entidades de gestión; la importancia de esta investigación descriptiva y aplicada, radica en los aportes que hace el estudio de la identidad al desarrollo de la colectividad, ya que reconociéndola, las ciudades potencian sus rasgos más característicos. Por los resultados obtenidos la identidad social urbana del casco histórico de Maracaibo, se distingue por el elemento religioso, histórico y patrimonial; ya que estos aspectos refuerzan la vivencia y la experiencia de la memoria urbana, compartida y transmitida de generación en generación.

  15. Solid waste combustion for alpha waste incineration

    International Nuclear Information System (INIS)

    Orloff, D.I.

    1981-02-01

    Radioactive waste incinerator development at the Savannah River Laboratory has been augmented by fundamental combustion studies at the University of South Carolina. The objective was to measure and model pyrolysis and combustion rates of typical Savannah River Plant waste materials as a function of incinerator operating conditions. The analytical models developed in this work have been incorporated into a waste burning transient code. The code predicts maximum air requirement and heat energy release as a function of waste type, package size, combustion chamber size, and temperature. Historically, relationships have been determined by direct experiments that did not allow an engineering basis for predicting combustion rates in untested incinerators. The computed combustion rates and burning times agree with measured values in the Savannah River Laboratory pilot (1 lb/hr) and full-scale (12 lb/hr) alpha incinerators for a wide variety of typical waste materials

  16. Study of experimental validation for combustion analysis of GOTHIC code

    International Nuclear Information System (INIS)

    Lee, J. Y.; Yang, S. Y.; Park, K. C.; Jeong, S. H.

    2001-01-01

    In this study, present lumped and subdivided GOTHIC6 code analyses of the premixed hydrogen combustion experiment at the Seoul National University and comparison with the experiment results. The experimental facility has 16367 cc free volume and rectangular shape. And the test was performed with unit equivalence ratio of the hydrogen and air, and with various location of igniter position. Using the lumped and mechanistic combustion model in GOTHIC6 code, the experiments were simulated with the same conditions. In the comparison between experiment and calculated results, the GOTHIC6 prediction of the combustion response does not compare well with the experiment results. In the point of combustion time, the lumped combustion model of GOTHIC6 code does not simulate the physical phenomena of combustion appropriately. In the case of mechanistic combustion model, the combustion time is predicted well, but the induction time of calculation data is longer than the experiment data remarkably. Also, the laminar combustion model of GOTHIC6 has deficiency to simulate combustion phenomena unless control the user defined value appropriately. And the pressure is not a proper variable that characterize the three dimensional effect of combustion

  17. A comprehensive review of oil spill combustion studies

    International Nuclear Information System (INIS)

    Walavalkar, A.Y.; Kulkarni, A.K.

    1996-01-01

    The complex process of in-situ burning of oil or a water-in-oil emulsion floating on top of a water-base, such as the ocean, was discussed. The process was examined before, during and after actual combustion. In general, the success of oil spill combustion is measured in terms of the fraction of the spilled oil or emulsion that is burned away. However, the air and aquatic pollution caused by the combustion should also be considered. The physical conditions such as wind velocity, waves and the presence or absence of a containment device, such as a fire boom, could determine the continuation of the combustion process. An overview of the oil spill combustion techniques was provided. There still remains a need for fundamental studies, especially in mathematical modeling, to understand the basic mechanisms and predict the applicability of the in-situ combustion. 74 refs., 7 tabs., 3 figs

  18. Formation of fuel NOx during black-liquor combustion

    International Nuclear Information System (INIS)

    Nichols, K.M.; Lien, S.J.

    1993-01-01

    Fuel NOx and thermal NOx were measured in combustion gases from black liquors in two laboratory furnaces. Combustion at 950 C in air (8% O 2 ) produced NOx concentrations of 40-80ppm. Combustion at 950 C in synthetic air containing no nitrogen (21% 0 2 in Ar) produced the same result, demonstrating that all of the NOx produced during combustion at 950 C was fuel NOx. Formation of fuel NOx increased moderately with increasing temperature in the range of 800-1,000 C, but temperature sensitivity of fuel NOx was much less than that of thermal NOx. The results imply that the major source of NOx in recovery furnace emissions is the fuel NOx in recovery furnace formed by conversion of liquor-bound nitrogen during combustion. This is consistent with thermal NOx theory, which postulates that black-liquor combustion temperatures are too low to generate significant amounts of thermal NOx

  19. Improvement of a combustion model in MELCOR code

    International Nuclear Information System (INIS)

    Ogino, Masao; Hashimoto, Takashi

    1999-01-01

    NUPEC has been improving a hydrogen combustion model in MELCOR code for severe accident analysis. In the proposed combustion model, the flame velocity in a node was predicted using five different flame front shapes of fireball, prism, bubble, spherical jet, and plane jet. For validation of the proposed model, the results of the Battelle multi-compartment hydrogen combustion test were used. The selected test cases for the study were Hx-6, 13, 14, 20 and Ix-2 which had two, three or four compartments under homogeneous hydrogen concentration of 5 to 10 vol%. The proposed model could predict well the combustion behavior in multi-compartment containment geometry on the whole. MELCOR code, incorporating the present combustion model, can simulate combustion behavior during severe accident with acceptable computing time and some degree of accuracy. The applicability study of the improved MELCOR code to the actual reactor plants will be further continued. (author)

  20. Elementos mediadores de la felicidad y el bienestar subjetivo en hombres y mujeres

    Directory of Open Access Journals (Sweden)

    Rozzana Sánchez Aragón

    2011-12-01

    Full Text Available La felicidad se identifica como una emoción básica y como una de las principales metas humanas que acompañan al ser humano por su travesía en la vida. La presente investigación se propuso explorar las diferencias sexuales y las relaciones entre elementos mediadores de la felicidad (cultura, recursos personales, auto-monitoreo, procesos de regulación emocional y el bienestar subjetivo con la pareja, la familia, los amigos, el trabajo, el autoconcepto y las necesidades básicas. Se trabajó con una muestra no probabilística de N = 203 estudiantes universitarios de la Ciudad de México quienes en forma voluntaria respondieron a una batería de pruebas de ejecución, máxima y típica, validada previamente. Los resultados muestran la supremacía de las mujeres en las habilidades emocionales así como en la expresión emocional, mientras lo que predominó en los hombres fue el ejercicio de estrategias de control emocional. Asimismo, se encontraron mayor cantidad de relaciones y estos eran más fuertes entre los elementos mediadores de la felicidad con el bienestar subjetivo de las mujeres en su relación de pareja y autoconcepto, mientras que en los hombres se refleja en su relación con los amigos, principalmente.

  1. Key factors of combustion from kinetics to gas dynamics

    CERN Document Server

    Rubtsov, Nikolai M

    2017-01-01

    This book summarizes the main advances in the mechanisms of combustion processes. It focuses on the analysis of kinetic mechanisms of gas combustion processes and experimental investigation into the interrelation of kinetics and gas dynamics in gas combustion. The book is complimentary to the one previously published, The Modes of Gaseous Combustion.

  2. Sulfur equilibrium desulfurization of sulfur containing products of combustion

    International Nuclear Information System (INIS)

    Woodroffe, J.A.; Abichandani, J.S.

    1990-01-01

    This patent describes the method for the combustion of a carbon- and sulfur-containing fuel for substantially reducing emission of gaseous sulfur compounds formed during combustion of the fuel in a combustion zone. The zone having one or more fuel inlets and one or more oxidizer inlets, and having a combustion products outlet spaced therefrom, and having one or more inorganic sorbent inlets downstream of the fuel inlet(s) and oxidizer inlet(s) and upstream of the combustion products outlet

  3. Carbon Shale Combustion in the Fluidized Bed Reactor

    Directory of Open Access Journals (Sweden)

    Olek Małgorzata

    2014-06-01

    Full Text Available The purpose of this article is to present the possibilities of coal shale combustion in furnaces with bubbling fluidized bed. Coal shale can be autothermally combusted in the fluidized bed, despite the low calorie value and high ash content of fuel. Established concentrations of CO (500 ppm and VOC (30 mg/m3 have indicated a high conversion degree of combustible material during combustion process. Average concentrations of SO2 and NOx in the flue gas were higher than this received from the combustion of high quality hard coal, 600 ppm and 500 ppm, respectively. Optional reduction of SO2 and NOx emission may require the installation of flue gas desulphurization and de-NOx systems.

  4. Enhancement of exergy efficiency in combustion systems using flameless mode

    International Nuclear Information System (INIS)

    Hosseini, Seyed Ehsan; Wahid, Mazlan Abdul

    2014-01-01

    Highlights: • Exergy efficiency in flameless combustion mode is 13% more than conventional combustion. • The maximum exergy efficiency in flameless combustion mode is achieved when oxidizer contains 10% oxygen. • Exergy destruction of flameless combustion is maximized when CO 2 is used for dilution of oxidizer. - Abstract: An exergitic-based analysis of methane (CH 4 ) conventional and flameless combustion in a lab-scale furnace is performed to determine the rate of pollutant formation and the effective potential of a given amount of fuel in the various combustion modes. The effects of inlet air temperature on exergy efficiency and pollutant formation of conventional combustion in various equivalence ratios are analyzed. The rate of exergy destruction in different conditions of flameless combustion (various equivalence ratios, oxygen concentration in the oxidizer and the effects of diluent) are computed using three-dimensional (3D) computational fluid dynamic (CFD). Fuel consumption reduction and exergy efficiency augmentation are the main positive consequences of using preheated air temperature in conventional combustion, however pollutants especially NO x formation increases dramatically. Low and moderate temperature inside the chamber conducts the flameless combustion system to low level pollutant formation. Fuel consumption and exergy destruction reduce drastically in flameless mode in comparison with conventional combustion. Exergy efficiency of conventional and flameless mode is 75% and 88% respectively in stoichiometric combustion. When CO 2 is used for dilution of oxidizer, chemical exergy increases due to high CO 2 concentration in the combustion products and exergy efficiency reduces around 2% compared to dilution with nitrogen (N 2 ). Since the rate of irreversibilities in combustion systems is very high in combined heat and power (CHP) generation and other industries, application of flameless combustion could be effective in terms of pollutant

  5. Problemas actuales del automóvil y el futuro del mismo

    OpenAIRE

    Gómez San Martín, María Begoña

    2011-01-01

    315 p. El automóvil es un elemento indispensable en la sociedad actual a nivel mundial. Pero presenta serios problemas no resueltos al día de hoy, ocasionados principalmente por el combustible universalmente utilizado: el petróleo. Estos problemas plantean serias preocupaciones cara al futuro. En esta Tesis realizamos una investigación y una prospección sobre los posibles elementos energéticos sustitutivos del petróleo.

  6. Numerical investigation of spray combustion towards HITAC conditions

    NARCIS (Netherlands)

    Zhu, Shanglong

    2017-01-01

    The features of High Temperature Air Combustion (HiTAC), i.e. high-efficiency combustion processes creating a uniform temperature distribution with low NOX and CO emissions, lend itself ideally for the combustion of all sorts of "difficult” fuels, ranging from low-calorific gases such as

  7. Method for storing radioactive combustible waste

    Science.gov (United States)

    Godbee, H.W.; Lovelace, R.C.

    1973-10-01

    A method is described for preventing pressure buildup in sealed containers which contain radioactively contaminated combustible waste material by adding an oxide getter material to the container so as to chemically bind sorbed water and combustion product gases. (Official Gazette)

  8. Combustion and extinction of magnesium fires

    International Nuclear Information System (INIS)

    Malet, J.C.; Duverger de Cuy, G.

    1988-01-01

    The studies made in France on magnesium combustion and extinguishing means are associated at the nuclear fuel of the graphite-gas reactor. Safety studies are made for ameliorate our knowledge on: - magnesium combustion - magnesium fire propagation - magnesium fire extinguishing [fr

  9. Combustion-derived substances in deep basins of Puget Sound: Historical inputs from fossil fuel and biomass combustion

    International Nuclear Information System (INIS)

    Kuo, Li-Jung; Louchouarn, Patrick; Herbert, Bruce E.; Brandenberger, Jill M.; Wade, Terry L.; Crecelius, Eric

    2011-01-01

    Reconstructions of 250 years historical inputs of two distinct types of black carbon (soot/graphitic black carbon (GBC) and char-BC) were conducted on sediment cores from two basins of the Puget Sound, WA. Signatures of polycyclic aromatic hydrocarbons (PAHs) were also used to support the historical reconstructions of BC to this system. Down-core maxima in GBC and combustion-derived PAHs occurred in the 1940s in the cores from the Puget Sound Main Basin, whereas in Hood Canal such peak was observed in the 1970s, showing basin-specific differences in inputs of combustion byproducts. This system showed relatively higher inputs from softwood combustion than the northeastern U.S. The historical variations in char-BC concentrations were consistent with shifts in climate indices, suggesting an influence of climate oscillations on wildfire events. Environmental loading of combustion byproducts thus appears as a complex function of urbanization, fuel usage, combustion technology, environmental policies, and climate conditions. - Research highlights: → We reconstructed the historical inputs of GBC and char-BC in Puget Sound, WA, USA. → Temporal trend of GBC was linked to human activities (urbanization, fuel usage). → Temporal trend of char-BC was more likely driven by regional climate oscillations. → Historical trends of combustion byproducts show the geographical heterogeneities. - Temporal trend of GBC was directly linked to human activities, while the input of char-BC in Puget Sound was more likely driven by regional climate oscillations.

  10. Extended lattice Boltzmann scheme for droplet combustion.

    Science.gov (United States)

    Ashna, Mostafa; Rahimian, Mohammad Hassan; Fakhari, Abbas

    2017-05-01

    The available lattice Boltzmann (LB) models for combustion or phase change are focused on either single-phase flow combustion or two-phase flow with evaporation assuming a constant density for both liquid and gas phases. To pave the way towards simulation of spray combustion, we propose a two-phase LB method for modeling combustion of liquid fuel droplets. We develop an LB scheme to model phase change and combustion by taking into account the density variation in the gas phase and accounting for the chemical reaction based on the Cahn-Hilliard free-energy approach. Evaporation of liquid fuel is modeled by adding a source term, which is due to the divergence of the velocity field being nontrivial, in the continuity equation. The low-Mach-number approximation in the governing Navier-Stokes and energy equations is used to incorporate source terms due to heat release from chemical reactions, density variation, and nonluminous radiative heat loss. Additionally, the conservation equation for chemical species is formulated by including a source term due to chemical reaction. To validate the model, we consider the combustion of n-heptane and n-butanol droplets in stagnant air using overall single-step reactions. The diameter history and flame standoff ratio obtained from the proposed LB method are found to be in good agreement with available numerical and experimental data. The present LB scheme is believed to be a promising approach for modeling spray combustion.

  11. A Computational Fluid Dynamics Study of Turbulence, Radiation, and Combustion Models for Natural Gas Combustion Burner

    Directory of Open Access Journals (Sweden)

    Yik Siang Pang

    2018-01-01

    Full Text Available This paper presents a Computational Fluid Dynamics (CFD study of a natural gas combustion burner focusing on the effect of combustion, thermal radiation and turbulence models on the temperature and chemical species concentration fields. The combustion was modelled using the finite rate/eddy dissipation (FR/EDM and partially premixed flame models. Detailed chemistry kinetics CHEMKIN GRI-MECH 3.0 consisting of 325 reactions was employed to model the methane combustion. Discrete ordinates (DO and spherical harmonics (P1 model were employed to predict the thermal radiation. The gas absorption coefficient dependence on the wavelength is resolved by the weighted-sum-of-gray-gases model (WSGGM. Turbulence flow was simulated using Reynolds-averaged Navier-Stokes (RANS based models. The findings showed that a combination of partially premixed flame, P1 and standard k-ε (SKE gave the most accurate prediction with an average deviation of around 7.8% of combustion temperature and 15.5% for reactant composition (methane and oxygen. The results show the multi-step chemistry in the partially premixed model is more accurate than the two-step FR/EDM. Meanwhile, inclusion of thermal radiation has a minor effect on the heat transfer and species concentration. SKE turbulence model yielded better prediction compared to the realizable k-ε (RKE and renormalized k-ε (RNG. The CFD simulation presented in this work may serve as a useful tool to evaluate a performance of a natural gas combustor. Copyright © 2018 BCREC Group. All rights reserved Received: 26th July 2017; Revised: 9th October 2017; Accepted: 30th October 2017; Available online: 22nd January 2018; Published regularly: 2nd April 2018 How to Cite: Pang, Y.S., Law, W.P., Pung, K.Q., Gimbun, J. (2018. A Computational Fluid Dynamics Study of Turbulence, Radiation, and Combustion Models for Natural Gas Combustion Burner. Bulletin of Chemical Reaction Engineering & Catalysis, 13 (1: 155-169 (doi:10.9767/bcrec

  12. A method for determining the completeness of fuel combustion

    Energy Technology Data Exchange (ETDEWEB)

    Tavger, M.D.; Chepkin, V.M.; Gruzdev, V.N.; Talantov, A.V.

    1982-01-01

    The current of conductivity (ionization) of gaseous combustion products, which forms with feeding of electric voltage to a special probe, is proposed for determining the completeness of fuel combustion. Here, the charged particles are formed from substances which form in the intermediate stages of the combustion reaction. The volume of charged particles is proportional to the volume of the intermediate substances, whose presence attests to the incompleteness of the combustion reaction. The fullness of fuel combustion is determined from a formula which includes the stoichiometric coefficient, a gas constant, the energy of activation, the characteristics of the chemical activity of the intermediate substances, the coefficient of air excess, the temperature of the combustion products and the conductivity current.

  13. Combustion chemistry - activities in the CHEK research programme

    Energy Technology Data Exchange (ETDEWEB)

    Dam-Johansen, K.; Johnsson, J.E.; Glarborg, P.; Frandsen, F.; Jensen, A.; Oestberg, M. [Technical Univ. of Denmark, Lyngby (Denmark). Dept. of Chemical Engineering

    1997-10-01

    The combustion chemistry in the oxidation of fossil fuels and biofuels determines together with mixing and heat transfer the required size of a furnace, the emission of gaseous pollutants, and the formation of ash and deposits on surfaces. This presentation describes technologies for solid fuels combustion and gives a summary of the fuels, the pollutant chemistry and the inorganic chemistry in combustion processes. Emphasis is put on the work carried out in the CHEC (Combustion and Harmful Emission Control) Research Programme. (orig.)

  14. Issues in waste combustion

    Energy Technology Data Exchange (ETDEWEB)

    Gustavsson, Lennart; Robertson, Kerstin; Tullin, Claes [Swedish National Testing and Research Inst., Boraas (Sweden); Sundquist, Lena; Wrangensten, Lars [AaF-Energikonsult AB, Stockholm (Sweden); Blom, Elisabet [AaF-Processdesign AB, Stockholm (Sweden)

    2003-05-01

    The main purpose of this review is to provide an overview of the state-of-the-art on research and development issues related to waste combustion with relevance for Swedish conditions. The review focuses on co-combustion in grate and fluidised bed furnaces. It is primarily literature searches in relevant databases of scientific publications with to material published after 1995. As a complement, findings published in different report series, have also been included. Since the area covered by this report is very wide, we do not claim to cover the issues included completely and it has not been possitile to evaluate the referred studies in depth. Basic knowledge about combustion issues is not included since such information can be found elsewhere in the literature. Rather, this review should be viewed as an overview of research and development in the waste-to-energy area and as such we hope that it will inspire scientists and others to further work in relevant areas.

  15. 30 CFR 56.4103 - Fueling internal combustion engines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fueling internal combustion engines. 56.4103... Prevention and Control Prohibitions/precautions/housekeeping § 56.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts of...

  16. 30 CFR 57.4103 - Fueling internal combustion engines.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fueling internal combustion engines. 57.4103... Prevention and Control Prohibitions/precautions/housekeeping § 57.4103 Fueling internal combustion engines. Internal combustion engines shall be switched off before refueling if the fuel tanks are integral parts of...

  17. 30 CFR 77.1105 - Internal combustion engines; fueling.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Internal combustion engines; fueling. 77.1105 Section 77.1105 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE... COAL MINES Fire Protection § 77.1105 Internal combustion engines; fueling. Internal combustion engines...

  18. Nitrogen enriched combustion of a natural gas internal combustion engine to reduce NO.sub.x emissions

    Science.gov (United States)

    Biruduganti, Munidhar S.; Gupta, Sreenath Borra; Sekar, R. Raj; McConnell, Steven S.

    2008-11-25

    A method and system for reducing nitrous oxide emissions from an internal combustion engine. An input gas stream of natural gas includes a nitrogen gas enrichment which reduces nitrous oxide emissions. In addition ignition timing for gas combustion is advanced to improve FCE while maintaining lower nitrous oxide emissions.

  19. Interactive wood combustion for botanical tree models

    KAUST Repository

    Pirk, Sören

    2017-11-22

    We present a novel method for the combustion of botanical tree models. Tree models are represented as connected particles for the branching structure and a polygonal surface mesh for the combustion. Each particle stores biological and physical attributes that drive the kinetic behavior of a plant and the exothermic reaction of the combustion. Coupled with realistic physics for rods, the particles enable dynamic branch motions. We model material properties, such as moisture and charring behavior, and associate them with individual particles. The combustion is efficiently processed in the surface domain of the tree model on a polygonal mesh. A user can dynamically interact with the model by initiating fires and by inducing stress on branches. The flames realistically propagate through the tree model by consuming the available resources. Our method runs at interactive rates and supports multiple tree instances in parallel. We demonstrate the effectiveness of our approach through numerous examples and evaluate its plausibility against the combustion of real wood samples.

  20. Micro-combustion calorimetry employing a Calvet heat flux calorimeter

    International Nuclear Information System (INIS)

    Rojas-Aguilar, Aaron; Valdes-Ordonez, Alejandro

    2004-01-01

    Two micro-combustion bombs developed from a high pressure stainless steel vessel have been adapted to a Setaram C80 Calvet calorimeter. The constant of each micro-bomb was determined by combustions with benzoic acid NIST 39j, giving for the micro-combustion bomb in the measurement sensor k m =(1.01112±0.00054) and for the micro-combustion bomb in the reference sensor k r =(1.00646±0.00059) which means an uncertainty of less than 0.06 per cent for calibration. The experimental methodology to get results of combustion energy of organic compounds with a precision also better than 0.06 per cent is described by applying this micro-combustion device to the measurement of the enthalpy of combustion of the succinic acid, giving Δ c H compfn m (cr, T=298.15 K)=-(1492.89 ± 0.77) kJ · mol -1

  1. Flameless Combustion Workshop

    National Research Council Canada - National Science Library

    Gutmark, Ephraim

    2005-01-01

    .... "Flameless Combustion" is characterized by high stability levels with virtually no thermoacoustic instabilities, very low lean stability limits and therefore extremely low NOx production, efficient...

  2. Combustion/particle sizing experiments at the Naval Postgraduate School Combustion Research Laboratory

    Science.gov (United States)

    Powers, John; Netzer, David

    1987-01-01

    Particle behavior in combustion processes is an active research area at NPS. Currently, four research efforts are being conducted: (1) There is a long standing need to better understand the soot production and combustion processes in gas turbine combustors, both from a concern for improved engine life and to minimize exhaust particulates. Soot emissions are strongly effected by fuel composition and additives; (2) A more recent need for particle sizing/behavior measurements is in the combustor of a solid fuel ramjet which uses a metallized fuel. High speed motion pictures are being used to study rather large burning particles; (3) In solid propellant rocket motors, metals are used to improve specific impulse and/or to provide damping for combustion pressure oscillations. Particle sizing experiments are being conducted using diode arrays to measure the light intensity as a function of scattering angle; (4) Once a good quality hologram is attained, a need exists for obtaining the particle distributions from hologram in a short period of time. A Quantimet 720 Image Analyzer is being used to reconstruct images.

  3. Two phase exhaust for internal combustion engine

    Science.gov (United States)

    Vuk, Carl T [Denver, IA

    2011-11-29

    An internal combustion engine having a reciprocating multi cylinder internal combustion engine with multiple valves. At least a pair of exhaust valves are provided and each supply a separate power extraction device. The first exhaust valves connect to a power turbine used to provide additional power to the engine either mechanically or electrically. The flow path from these exhaust valves is smaller in area and volume than a second flow path which is used to deliver products of combustion to a turbocharger turbine. The timing of the exhaust valve events is controlled to produce a higher grade of energy to the power turbine and enhance the ability to extract power from the combustion process.

  4. 30 CFR 56.7807 - Flushing the combustion chamber.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Flushing the combustion chamber. 56.7807 Section 56.7807 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND... Rotary Jet Piercing Rotary Jet Piercing § 56.7807 Flushing the combustion chamber. The combustion chamber...

  5. Combustion chemistry. Activities in the CHEC research programme

    Energy Technology Data Exchange (ETDEWEB)

    Dam-Johansen, K; Johnsson, J E; Glarborg, P; Frandsen, F; Jensen, A; Oestberg, M [Technical Univ. of Denmark, Dept. of Chemical Engineering, Lyngby (Denmark)

    1996-12-01

    The combustion chemistry in the oxidation of fossil fuels and biofuels determines together with mixing and heat transfer the required size of a furnace, the emission of gaseous pollutants, and the formation of ash and deposits on surfaces. This paper describes technologies for solid fuels combustion and gives a summary of the fuels, the pollutant chemistry and the inorganic chemistry in combustion processes. Emphasis is put on the work carried out in the CHEC (Combustion and Harmful Emission Control Research Programme). (au) 173 refs.

  6. Quasi-dimensional modeling of a fast-burn combustion dual-plug spark-ignition engine with complex combustion chamber geometries

    International Nuclear Information System (INIS)

    Altın, İsmail; Bilgin, Atilla

    2015-01-01

    This study builds on a previous parametric investigation using a thermodynamic-based quasi-dimensional (QD) cycle simulation of a spark-ignition (SI) engine with dual-spark plugs. The previous work examined the effects of plug-number and location on some performance parameters considering an engine with a simple cylindrical disc-shaped combustion chamber. In order to provide QD thermodynamic models applicable to complex combustion chamber geometries, a novel approach is considered here: flame-maps, which utilizes a computer aided design (CAD) software (SolidWorks). Flame maps are produced by the CAD software, which comprise all the possible flame radiuses with an increment of one-mm between them, according to the spark plug positions, spark timing, and piston position near the top dead center. The data are tabulated and stored as matrices. Then, these tabulated data are adapted to the previously reported cycle simulation. After testing for simple disc-shaped chamber geometries, the simulation is applied to a real production automobile (Honda-Fit) engine to perform the parametric study. - Highlights: • QD model was applied in dual plug engine with complex realistic combustion chamber. • This method successfully modeled the combustion in the dual-plug Honda-Fit engine. • The same combustion chamber is tested for various spark plug(s) locations. • The centrally located single spark-plug results in the fastest combustion

  7. Combustion Research Facility | A Department of Energy Office of Science

    Science.gov (United States)

    Collaborative Research Facility Back to Sandia National Laboratory Homepage Combustion Research Search the CRF Combustion Chemistry Flame Chemistry Research.Combustion_Chemistry.Flame_Chemistry Theory and Modeling Theory and Modeling Combustion Kinetics High Pressure Chemistry Chemistry of Autoignition

  8. Elementos obstaculizadores de las coordinaciones pedagógicas en liceos vulnerables de la Araucanía Chilena

    Directory of Open Access Journals (Sweden)

    Juan Beltrán-Véliz, Chile

    2015-07-01

    Full Text Available (descriptivo: En este artículo desarrollamos el siguiente objetivo: develar descriptivamente los elementos que obstaculizan las prácticas de las coordinaciones pedagógicas en liceos situados en contextos de vulnerabilidad social en la Araucanía. Planteamos un diseño cualitativo descriptivo, orientado con base en la teoría fundamentada y el método comparativo constante. Los resultados develan que las prácticas de las coordinaciones pedagógicas están centradas en aspectos administrativos. Se evidencia la ausencia de competencias y de liderazgo. Finalmente, el desarrollo evaluativo no se centra en la continuidad y permanencia del proceso. Concluimos que la ausencia de liderazgo, de competencias de los JUTP, y el rol de estos centrado en una “conducción técnica basada en el control”, son elementos que obstaculizan las prácticas de las coordinaciones pedagógicas.

  9. De los dioses a los hombres: Un recorrido histórico del descubrimiento de los elementos químicos

    Directory of Open Access Journals (Sweden)

    Pellón González, I.

    2014-12-01

    Full Text Available To achieve the apparently simple Periodic Table of the Elements has implied tremendous efforts over thousands of years. In this paper we present a brief history of the discovery of the chemical elements from prehistory to the present day, revealing the controversies that arose on the way and claiming the important work performed by alchemists in the advancement of knowledge. This is especially important if we consider that alchemy had a period of existence of many thousands of years, while the “Chemistry”, officially established as a science in the eighteenth century, has operated as such for only a few hundred years. Even so, if we consider the progress of discovery and isolation of chemical elements throughout history, it can be observed that the number of elements identified is achieved mainly in the nineteenth and twentieth centuries, reflecting the development of instrumental techniques, that facilitated this task.Llegar hasta la aparentemente sencilla Tabla Periódica de los Elementos le ha costado a la humanidad enormes esfuerzos a lo largo de miles de años. En este trabajo se recorre la historia del descubrimiento de los elementos químicos desde la Prehistoria hasta nuestros días, reflejando las controversias que se suscitaron y reivindicando el importante trabajo que realizaron los alquimistas en el progreso de los conocimientos, ya que la alquimia tuvo un período de existencia de muchos miles de años, mientras que la “Química” oficialmente establecida como ciencia en el siglo XVIII consta de sólo unos cientos de años. Aún así, al realizar un balance de la progresión del descubrimiento y aislamiento de los elementos químicos a lo largo de la Historia se puede comprobar el elevado número de elementos identificados en los siglos XIX y XX, reflejo del perfeccionamiento de las técnicas instrumentales que facilitaron esta labor.

  10. Internal combustion engines in hybrid vehicles

    NARCIS (Netherlands)

    Mourad, S.; Weijer, C.J.T. van de; Beckman, D.E.

    1998-01-01

    In this paper the use of internal combustion engines in hybrid powertrains is investigated. The substantial difference between the use of internal combustion engines in conventional and in hybrid vehicles mean that engines for hybrid vehicles should be designed specifically for the purpose. At the

  11. Posibilidades del método de elementos finitos y partículas (PFEM) en problemas de erosión de suelos granulares

    OpenAIRE

    Rodríguez Prat, Francisco

    2013-01-01

    El fenómeno de erosión es un tema de vital importancia en el ámbito de la ingeniería civil, especialmente en ingeniería de ríos. En este trabajo se analizan las posibilidades del método de elementos finitos y partículas (PFEM) para abordar este tipo de problemas. El PFEM es una variante del método de elementos finitos clásico (FEM); se ha empezado a utilizar principalmente para modelizar el movimiento de fluidos. El programa que se ha utilizado es el Pflow, desarrollado en C...

  12. Evaluation of gas radiation models in CFD modeling of oxy-combustion

    International Nuclear Information System (INIS)

    Rajhi, M.A.; Ben-Mansour, R.; Habib, M.A.; Nemitallah, M.A.; Andersson, K.

    2014-01-01

    Highlights: • CFD modeling of a typical industrial water tube boiler is conducted. • Different combustion processes were considered including air and oxy-fuel combustion. • SGG, EWBM, Leckner, Perry and WSGG radiation models were considered in the study. • EWBM is the most accurate model and it’s considered to be the benchmark model. • Characteristics of oxy-fuel combustion are compared to those of air–fuel combustion. - Abstract: Proper determination of the radiation energy is very important for proper predictions of the combustion characteristics inside combustion devices using CFD modeling. For this purpose, different gas radiation models were developed and applied in the present work. These radiation models vary in their accuracy and complexity according to the application. In this work, a CFD model for a typical industrial water tube boiler was developed, considering three different combustion environments. The combustion environments are air–fuel combustion (21% O 2 and 79% N 2 ), oxy-fuel combustion (21% O 2 and 79% CO 2 ) and oxy-fuel combustion (27% O 2 and 73% CO 2 ). Simple grey gas (SGG), exponential wide band model (EWBM), Leckner, Perry and weighted sum of grey gases (WSGG) radiation models were examined and their influences on the combustion characteristics were evaluated. Among those radiation models, the EWBM was found to provide close results to the experimental data for the present boiler combustion application. The oxy-fuel combustion characteristics were analyzed and compared with those of air–fuel combustion

  13. Comunicaciones y nuevas tecnologías: elementos claves para enfrentar la crisis paradigmática universitaria

    Directory of Open Access Journals (Sweden)

    Douglas Romero

    2000-05-01

    Full Text Available Este trabajo tiene por finalidad estudiar la necesidad vital de la incorporación de las nuevas tecnologías de la información y la comunicación como elementos fundamentales para enfrentar con éxito los nuevos paradigmas que exige el modelo de universidad contemporánea. Para lograr este objetivo la metodología utilizada para el abordaje del objeto de estudio ha sido la de una investigación de carácter documental, que ha incluido una amplia revisión bibliográfica. Esta investigación ofrece como reflexión final que la alta gerencia universitaria solo podrá enfrentar con éxito el proceso de cambio paradigmático universitario, en la medida en que asimile que las tecnologías de la información y comunicación son elementos claves de un proceso de transformación necesario conducentes al logro de uno de los valores fundamentales de la universidad como lo es la excelencia.

  14. Characteristic of combustion of Colombian gases

    International Nuclear Information System (INIS)

    Gil B, Edison; Maya, Ruben; Andres, Amel A.

    1996-01-01

    The variety of gas locations in the country, makes that the gas that will be distributed by the net of present gas pipeline a very different composition, what bears to that these they behave in a different way during its use. In this work the main characteristics of the combustion are calculated for the Colombian gases, basically the properties of the combustion and the characteristics of the smoke, as basic information for the design and operation of the gas teams and their certification. These properties were calculated with the special help software for combustion developed by the authors

  15. Plasma assisted combustion of parafin mixture

    International Nuclear Information System (INIS)

    Nedybaliuk, O.A.; Chernyak, V.Ya.; Martysh, E.V.; Lisitchenko, T.E.; Vergun, O.Yu.; Orlovska, S.G.

    2013-01-01

    In this work the results of solid paraffin combustion with the aid of the plasma of transverse and rotational gliding arc studies are represented. The question of the additional activation of paraffin based solid fuels is examined. The mixture of n-paraffin and stearin in the solid state as the model of the solid paraffin based fuel is used. The plasma assisted combustion of this model is experimentally investigated. The voltage-current characteristics of discharge at the different regimes are measured. The population temperatures of excited rotational levels are determined. The flame temperature during the combustion of solid paraffin containing mixture is calculated

  16. Colegio Hunter. Nueva York

    Directory of Open Access Journals (Sweden)

    Breuer, Marcel

    1960-12-01

    Full Text Available En marcado contraste con las edificaciones existentes del Colegio, han sido construidos dos nuevos elementos independientes, pero enlazados entre sí, destinados, respectivamente, a biblioteca y a clases. El estilo gótico tradicional, grave y estrecho que muestran los pabellones primitivos y la línea escueta, simplista, limpia de los dos prismas nuevos, juegan una brillante y notable armonía por contraste, cuyo éxito se debe a un cuidado estudio general y a una composición esmerada, en cuanto a masas, línea y materiales se refiere. Estos últimos, con sus colores característicos; son los mismos que predominan en las fachadas del Colegio: piedra caliza, piedra natural y ladrillo tostado.

  17. Combustion of lean hydrogen-air mixtures in the connected compartments

    International Nuclear Information System (INIS)

    Fan Liu; Yoshio Yoshizawa; Akio Miyori; Kenya Kubota

    1997-01-01

    A study of combustion experiments with premixed lean hydrogen-air mixtures was conducted in a vessel consisting of two compartments connected by a diameter-variable vent. Effects of various parameters (hydrogen concentration, vent diameter and initial pressure) on mechanical loads of the combustion processes including mainly the peak pressures and the rates of pressure rise were investigated. Relation of flow and combustion was approached. Ignition-combustion processes were discussed, and the combustion types were classified into three patterns according to the pressure-time histories and the flow characteristics in main combustion compartment

  18. 2017 Laser Diagnostics in Combustion GRC/GRS

    Science.gov (United States)

    2017-10-06

    scientists and engineers . The goal of GRC was to bring together scientists and engineers with a strong interest in laser-based combustion diagnostics to...processes. The GRS, held the weekend before the GRC, was organized to bring together emerging leaders in the field at an early stage in their careers ...coupled multi-scale combustion processes. The GRC on Laser Diagnostics in Combustion was designed to bring together scientists and engineers working at

  19. Oxy-coal combustion in an entrained flow reactor: Application of specific char and volatile combustion and radiation models for oxy-firing conditions

    DEFF Research Database (Denmark)

    Álvarez, L.; Yin, Chungen; Riaza, J.

    2013-01-01

    The deployment of oxy-fuel combustion in utility boilers is one of the major options for CO2 capture. However, combustion under oxy-firing conditions differs from conventional air-firing combustion, e.g., in the aspect of radiative heat transfer, coal conversion and pollutants formation....... In this work, a numerical study on pulverised coal combustion was conducted to verify the applicability and accuracy of several sub-models refined for oxy-fuel conditions, e.g., gaseous radiative property model, gas-phase combustion mechanism and heterogeneous char reaction model. The sub-models were...... implemented in CFD (Computational Fluid Dynamics) simulations of combustion of three coals under air-firing and various oxy-firing (21-35% vol O2 in O2/CO2 mixture) conditions in an EFR (entrained flow reactor). The predicted coal burnouts and gaseous emissions were compared against experimental results...

  20. Co-combustion of waste materials using fluidized bed technology

    Energy Technology Data Exchange (ETDEWEB)

    M. Lopes; I. Gulyurtlu; P. Abelha; T. Crujeira; D. Boavida; I. Cabrita [INETI-DEECA, Lisbon (Portugal)

    2004-07-01

    There is growing interest in using renewable fuels in order to sustain the CO{sub 2} accumulation. Several waste materials can be used as coal substitutes as long as they contain significant combustible matter, as for example MSW and sewage sludge. Besides the outcome of the energetic valorization of such materials, combustion must be regarded as a pre-treatment process, contributing to the safe management of wastes. Landfilling is an expensive management option and requires a previous destruction of the organic matter present in residues, since its degradation generates greenhouse gases and produces acidic organic leachates. Fluidized bed combustion is a promising technology for the use of mixtures of coal and combustible wastes. This paper presents INETI's experience in the co-combustion of coal with this kind of residues performed in a pilot fluidized bed. Both the RDF (from MSW and sewage sludge) and sewage sludge combustion problems were addressed, relating the gaseous emissions, the behaviour of metals and the leachability of ashes and a comparison was made between co-combustion and mono-combustion in order to verify the influence of the utilization of coal. 9 refs., 1 fig., 3 tabs.

  1. Disturbing effect of free hydrogen on fuel combustion in internal combustion engines

    Science.gov (United States)

    Riedler, A

    1923-01-01

    Experiments with fuel mixtures of varying composition, have recently been conducted by the Motor Vehicle and Airplane Engine Testing Laboratories of the Royal Technical High School in Berlin and at Fort Hahneberg, as well as at numerous private engine works. The behavior of hydrogen during combustion in engines and its harmful effect under certain conditions, on the combustion in the engine cylinder are of general interest. Some of the results of these experiments are given here, in order to elucidate the main facts and explain much that is already a matter of experience with chauffeurs and pilots.

  2. Scramjet Combustion Stability Behavior Modeling, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — A recent breakthrough in combustion stability analysis (UCDS) offers the potential to predict the combustion stability of a scramjet. This capability is very...

  3. 30 CFR 57.7807 - Flushing the combustion chamber.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Flushing the combustion chamber. 57.7807... and Rotary Jet Piercing Rotary Jet Piercing-Surface Only § 57.7807 Flushing the combustion chamber. The combustion chamber of a jet drill stem which has been sitting unoperated in a drill hole shall be...

  4. COMBUSTION OF BIOMASS AND CHARCOAL MADE FROM BABASSU NUTSHELL

    Directory of Open Access Journals (Sweden)

    Thiago de Paula Protásio

    2017-03-01

    Full Text Available In recent years, studies have examined the use of lignocellulosic wastes for energy generation. However, there is a lack of information on the combustibility of the residual biomass, especially the bark and charcoal of babassu nut. In this study, thermogravimetric analysis (TGA, differential thermal analysis (DTA and differential scanning calorimetry (DSC were used to achieve the following objectives: to evaluate the combustion of the residual biomass from the babassu nut; to evaluate the combustion of charcoal produced from this biomass, considering different final carbonization temperatures; and to determine the effect of the final carbonization temperature on the thermal stability of charcoal and on its performance in combustion. Thermal analyses were performed in synthetic air. In order to evaluate the characteristics of charcoal combustion and fresh biomass, the ignition temperature (Ti, the burnout temperature (Tf, characteristic combustion index (S, ignition index (Di, time corresponding to the maximum combustion rate (tp, and ignition time (tig were considered. The combustion of the babassu nutshell occurred in three phases and it was observed that this lignocellulosic material is suitable for the direct generation of heat. The increase in the final carbonization temperature caused an increase in the ignition temperature, as well as in the burnout temperature, the ignition time and the time corresponding to the maximum combustion rate. The results indicate that the increase in the carbonization temperature causes a decrease in combustion reactivity and, consequently, the charcoals produced at lower temperatures are easier to ignite and exhibit better performance in ignition.

  5. Staged combustion with piston engine and turbine engine supercharger

    Science.gov (United States)

    Fischer, Larry E [Los Gatos, CA; Anderson, Brian L [Lodi, CA; O'Brien, Kevin C [San Ramon, CA

    2011-11-01

    A combustion engine method and system provides increased fuel efficiency and reduces polluting exhaust emissions by burning fuel in a two-stage combustion system. Fuel is combusted in a piston engine in a first stage producing piston engine exhaust gases. Fuel contained in the piston engine exhaust gases is combusted in a second stage turbine engine. Turbine engine exhaust gases are used to supercharge the piston engine.

  6. Mixing and combustion enhancement of Turbocharged Solid Propellant Ramjet

    Science.gov (United States)

    Liu, Shichang; Li, Jiang; Zhu, Gen; Wang, Wei; Liu, Yang

    2018-02-01

    Turbocharged Solid Propellant Ramjet is a new concept engine that combines the advantages of both solid rocket ramjet and Air Turbo Rocket, with a wide operation envelope and high performance. There are three streams of the air, turbine-driving gas and augment gas to mix and combust in the afterburner, and the coaxial intake mode of the afterburner is disadvantageous to the mixing and combustion. Therefore, it is necessary to carry out mixing and combustion enhancement research. In this study, the numerical model of Turbocharged Solid Propellant Ramjet three-dimensional combustion flow field is established, and the numerical simulation of the mixing and combustion enhancement scheme is conducted from the aspects of head region intake mode to injection method in afterburner. The results show that by driving the compressed air to deflect inward and the turbine-driving gas to maintain strong rotation, radial and tangential momentum exchange of the two streams can be enhanced, thereby improving the efficiency of mixing and combustion in the afterburner. The method of injecting augment gas in the transverse direction and making sure the injection location is as close as possible to the head region is beneficial to improve the combustion efficiency. The outer combustion flow field of the afterburner is an oxidizer-rich environment, while the inner is a fuel-rich environment. To improve the efficiency of mixing and combustion, it is necessary to control the injection velocity of the augment gas to keep it in the oxygen-rich zone of the outer region. The numerical simulation for different flight conditions shows that the optimal mixing and combustion enhancement scheme can obtain high combustion efficiency and have excellent applicability in a wide working range.

  7. Emulación de elementos de networking interactuando con máquinas virtuales

    OpenAIRE

    Binker, Carlos; Pére, Alejandro; Buranits, Guillermo; Zurdo, Eliseo

    2016-01-01

    En este trabajo se pretende mostrar la emulación de elementos de networking tales como switches y routers interactuando con máquinas virtuales que emplean sistemas operativos diversos como ser Windows, Mac OS X, Linux en diferentes distribuciones, etc. A tal efecto se emplea una plataforma de software libre denominada GNS3 (Graphical Simulator Network 3). Después de hacer un análisis más pormenorizado de dicha plataforma con sus programas asociados se mostrará un ejemplo de laboratorio en don...

  8. El Método de Elementos Finitos en la Valoración de Opciones

    OpenAIRE

    Sanz Herranz, Héctor

    2016-01-01

    En este trabajo se expone una introducción a los conceptos propios de la teoría de valoración de derivados financieros prestando especial atención a las opciones. Asimismo, se presenta el método de los elementos finitos para la resolución de ecuaciones en derivadas parciales justificando su uso desde el marco teórico. Finalmente, se muestran sendos algoritmos del método en algunos problemas de valoración de derivados financieros. Grado en Matemáticas

  9. A REVIEW OF MILD COMBUSTION AND OPEN FURNACE DESIGN CONSIDERATION

    Directory of Open Access Journals (Sweden)

    M.M. Noor

    2012-12-01

    Full Text Available Combustion is still very important to generate energy. Moderate or Intense Low-oxygen Dilution (MILD combustion is one of the best new technologies for clean and efficient combustion. MILD combustion has been proven to be a promising combustion technology in industrial applications with decreased energy consumption due to the uniformity of its temperature distribution. It is clean compared to traditional combustion due to producing low NOx and CO emissions. This article provides a review and discussion of recent research and developments in MILD. The issue and applications are summarized, with some suggestions presented on the upgrading and application of MILD in the future. Currently MILD combustion has been successfully applied in closed furnaces. The preheating of supply air is no longer required since the recirculation inside the enclosed furnace already self-preheats the supply air and self-dilutes the oxygen in the combustion chamber. The possibility of using open furnace MILD combustion will be reviewed. The design consideration for open furnace with exhaust gas re-circulation (EGR was discussed.

  10. Elementos de política de gestión en Henry Mintzberg

    OpenAIRE

    García-Álvarez, S. (Santiago); García-Martínez, A.N. (Alejandro Néstor); Múgica, F. (Fernando)

    2016-01-01

    El trabajo de investigación consistió en estudiar un buen número de los escritos de Henry Mintzberg y prácticamente todas sus obras relacionadas con los elementos de política de gestión: no únicamente los libros, sino numerosos artículos y textos relacionados. He leído también muchos libros y artículos de otros autores de management, como Drucker, Collins, Kotter, Pfeffer, Peters y varios más, para enriquecer el texto y contrastar posturas. He estudiado con particular interés y detenimiento l...

  11. High Gravity (g) Combustion

    Science.gov (United States)

    2006-02-01

    UNICORN (Unsteady Ignition and Combustion with Reactions) code10. Flame propagation in a tube that is 50-mm wide and 1000-mm long (similar to that...turbine engine manufacturers, estimating the primary zone space heating rate. Both combustion systems, from Company A and Company B, required a much...MBTU/atm-hr-ft3) Te m pe ra tu re R is e (K ) dP/P = 2% dP/P = 2.5% dP/P = 3% dP/P = 3.5% dP/P = 4% Company A Company B Figure 13: Heat Release Rate

  12. Publication sites productive uses of combustion ash

    Science.gov (United States)

    Publication Sites Productive Uses of Combustion Ash For more information contact: e:mail: Public waste combustion ash in landfills. The new technology brief describes recent studies where ash was used

  13. Scramjet Combustion Stability Behavior Modeling, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — A recent breakthrough in combustion stability analysis (UCDS) offers the means to accurately predict the combustion stability of a scramjet. This capability is very...

  14. Production of nanocrystalline metal powders via combustion reaction synthesis

    Science.gov (United States)

    Frye, John G.; Weil, Kenneth Scott; Lavender, Curt A.; Kim, Jin Yong

    2017-10-31

    Nanocrystalline metal powders comprising tungsten, molybdenum, rhenium and/or niobium can be synthesized using a combustion reaction. Methods for synthesizing the nanocrystalline metal powders are characterized by forming a combustion synthesis solution by dissolving in water an oxidizer, a fuel, and a base-soluble, ammonium precursor of tungsten, molybdenum, rhenium, or niobium in amounts that yield a stoichiometric burn when combusted. The combustion synthesis solution is then heated to a temperature sufficient to substantially remove water and to initiate a self-sustaining combustion reaction. The resulting powder can be subsequently reduced to metal form by heating in a reducing gas environment.

  15. Torrefaction of empty fruit bunches under biomass combustion gas atmosphere.

    Science.gov (United States)

    Uemura, Yoshimitsu; Sellappah, Varsheta; Trinh, Thanh Hoai; Hassan, Suhaimi; Tanoue, Ken-Ichiro

    2017-11-01

    Torrefaction of oil palm empty fruit bunches (EFB) under combustion gas atmosphere was conducted in a batch reactor at 473, 523 and 573K in order to investigate the effect of real combustion gas on torrefaction behavior. The solid mass yield of torrefaction in combustion gas was smaller than that of torrefaction in nitrogen. This may be attributed to the decomposition enhancement effect by oxygen and carbon dioxide in combustion gas. Under combustion gas atmosphere, the solid yield for torrefaction of EFB became smaller as the temperature increased. The representative products of combustion gas torrefaction were carbon dioxide and carbon monoxide (gas phase) and water, phenol and acetic acid (liquid phase). By comparing torrefaction in combustion gas with torrefaction in nitrogen gas, it was found that combustion gas can be utilized as torrefaction gas to save energy and inert gas. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. New combustion, environment regulations: the answers for natural gas; Nouvelles reglementations, combustion, environnement: les reponses pour le gaz naturel

    Energy Technology Data Exchange (ETDEWEB)

    Le Peltier-Marc, A. [Gaz de France (GDF), 75 - Paris (France)

    1997-12-31

    This paper reports on the point of view from Gaz de France (GdF) company concerning the potential consequences of the use of natural gas in combustion systems with respect to the new regulations about combustion and environment. Details concerning the measures relative to the limitation of pollutants in small combustion installations (2 - 20 MW) are given (chimney height, SO{sub x}, NO{sub x} and dusts content in exhaust gases). (J.S.)

  17. REPRESENTAÇÃO GRÁFICA DOS ELEMENTOS DO CLIMA: ESTUDO COMPARATIVO ENTRE MARINGÁ, PR E BOTUCATU, SP

    Directory of Open Access Journals (Sweden)

    Emerson Galvani

    2006-12-01

    Full Text Available A representação gráfica de quaisquer variáveis apresenta uma dupla finalidade: a primeira relacionada à sua variação no tempo e no espaço, e a segunda ao seu caráter didático. Os elementos do clima, como temperatura do ar e do solo, umidade relativa do ar, radiação solar global (direta e difusa, saldo de radiação (onda curta e onda longa, direção e velocidade do vento, pressão atmosférica, índice de chuvas e demais componentes derivados destes, evidenciam ao longo dos dias, dos meses e dos anos uma determinada curva característica que representa as condições de tempo e clima de determinada região. O que diferencia essa ou aquela localidade em termos climáticos é a amplitude da variação desses elementos no tempo e no espaço. Por exemplo, a curva diária dos níveis de radiação solar global em superfície em duas distintas localidades, situadas em diferentes latitudes, é idêntica, e o que as diferencia é a amplitude dos valores máximos e a energia total integrada ao longo do dia e do ano. O objetivo do presente trabalho é apresentar curvas instantâneas dos principais elementos do clima mostrando sua variação instantânea, diária e sazonal para as condições climáticas de Botucatu,SP e Maringá,PR, Brasil.

  18. LA EXPERIMENTACIÓN SONORA COMO ELEMENTO EDUCATIVO. UNA PROPUESTA PARA EL FOMENTO DE LA LECTURA

    Directory of Open Access Journals (Sweden)

    Alberto González Pérez

    2014-04-01

    Full Text Available El siguiente escrito pretende ser un primer acercamiento a la relación que puede tener el sonido y el fomento de la lectura. Mucho se ha escrito sobre el tema del fomento a la lectura, de los hábitos lectores y qué textos son considerados materiales de lectura. Sin embargo, el fracaso de diversos proyectos se debe a una concepción errónea y limitado que tenemos del término lectura, ya que comúnmente encerramos esa expresión a una interacción con los libros de texto, todo lo que no entra en ese estándar no es considerado como “material para leer”. De ahí que un primer paso sea ampliar la noción de lectura para incorporar otros elementos. Es así como nace la inquietud por pensar el sonido como un elemento que tiene la potencialidad de ampliar nuestra visión de la lectura.PALABRAS CLAVE: fomento de la lectura; experimentación sonora; elemento educativoTHE SOUND EXPERIMENTATION AS EDUCATIONAL ELEMENT. A PROPOSAL FOR THE DEVELOPMENT OF THE READING ABSTRACTThe following one written it seeks to be a first approach to the relationship that can have the sound and the development of the reading. A lot it has been written on the topic from the development to the reading, of the habits readers and what texts reading materials are considered. However, the failure of diverse projects is due since commonly to an erroneous and limited conception that we have of the term reading, we contain that expression to an interaction with the text books, all that doesn't enter in that standard is not considered as "material to read". With the result that a first step is to enlarge the reading notion to incorporate other elements. It is as well as the restlessness is born to think the sound like an element that has the potentiality of enlarging our vision of the reading.KEYWORDS: foment of the reading; sound experimentation; educational element

  19. Spray combustion of Jet-A and diesel fuels in a constant volume combustion chamber

    KAUST Repository

    Jing, Wei

    2015-01-01

    This work investigates the spray combustion of Jet-A fuel in an optical constant-volume combustion chamber under different ambient initial conditions. Ambient temperature was varied at 800 K, 1000 K, and 1200 K and five different ambient O2 concentrations were used, spanning 10-21%. These ambient conditions can be used to mimic practical diesel engine working conditions under different fuel injection timings and exhaust gas recirculation (EGR) levels. Both transient and quasi-steady state analyses were conducted. The transient analysis focused on the flame development from the beginning to the end of the combustion process, illustrating how the flame structure evolves with time. The quasi-steady state analysis concentrated on the stable flame structure and compared the flame emissions in terms of spatially integrated intensity, flame effective area, and intensity per pixel. The transient analysis was based on measurements using high-speed imaging of both OH∗ chemiluminescence and broadband natural luminosity (NL). For the quasi-steady state analysis, three flame narrow-band emissions (OH∗ at 310 nm, Band A at 430 nm and Band B at 470 nm) were captured using an ICCD camera. Based on the current Jet-A data and diesel data obtained from previous experiments, a comparison between Jet-A and diesel was made in terms of flame development during the transient state and spatially integrated intensity, flame effective area, and intensity per pixel during the quasi-steady state. For the transient results, Jet-A shares a similar flame development trend to diesel, but featuring a narrower region of NL and a wider region of OH∗ with the increase of ambient temperature and O2 concentration. The soot cloud is oxidized more quickly for Jet-A than diesel at the end of combustion, evident by comparing the area of NL, especially under high O2 concentration. The quasi-steady state results suggest that soot is oxidized effectively under high O2 concentration conditions by the

  20. Internal and Surface Phenomena in Heterogenous Metal Combustion

    Science.gov (United States)

    Dreizin, Edward L.

    1997-01-01

    The phenomenon of gas dissolution in burning metals was observed in recent metal combustion studies, but it could not be adequately explained by the traditional metal combustion models. The research reported here addresses heterogeneous metal combustion with emphasis on the processes of oxygen penetration inside burning metal and its influence on the metal combustion rate, temperature history, and disruptive burning. The unique feature of this work is the combination of the microgravity environment with a novel micro-arc generator of monodispersed metal droplets, ensuring repeatable formation and ignition of uniform metal droplets with a controllable initial temperature and velocity. Burning droplet temperature is measured in real time with a three wavelength pyrometer. In addition, particles are rapidly quenched at different combustion times, cross-sectioned, and examined using SEM-based techniques to retrieve the internal composition history of burning metal particles. When the initial velocity of a spherical particle is nearly zero, the microgravity environment makes it possible to study the flame structure, the development of flame nonsymmetry, and correlation of the flame shape with the heterogeneous combustion processes.

  1. A numerical study on the effect of various combustion bowl parameters on the performance, combustion, and emission behavior on a single cylinder diesel engine.

    Science.gov (United States)

    Balasubramanian, Dhinesh; Sokkalingam Arumugam, Sabari Rajan; Subramani, Lingesan; Joshua Stephen Chellakumar, Isaac JoshuaRamesh Lalvani; Mani, Annamalai

    2018-01-01

    A numerical study was carried out to study the effect of various combustion bowl parameters on the performance behavior, combustion characteristics, and emission magnitude on a single cylinder diesel engine. A base combustion bowl and 11 different combustion bowls were created by varying the aspect ratio, reentrancy ratio, and bore to bowl ratio. The study was carried out at engine rated speed and a full throttle performance condition, without altering the compression ratio. The results revealed that the combustion bowl parameters could have a huge impact on the performance behavior, combustion characteristics, and emission magnitude of the engine. The bowl parameters, namely throat diameter and toroidal radius, played a crucial role in determining the performance behavior of the combustion bowls. It was observed that the combustion bowl parameters, namely central pip distance, throat diameter, and bowl depth, also could have an impact on the combustion characteristics. And throat diameter and toroidal radius, central pip distance, and toroidal corner radius could have a consequent effect on the emission magnitude of the engine. Of the different combustion bowls tested, combustion bowl 4 was preferable to others owing to the superior performance of 3% of higher indicated mean effective pressure and lower fuel consumption. Interestingly, trade-off for NO x emission was higher only by 2.85% compared with the base bowl. The sensitivity analysis proved that bowl depth, bowl diameter, toroidal radius, and throat diameter played a vital role in the fuel consumption parameter and emission characteristics even at the manufacturing tolerance variations.

  2. 30 CFR 57.4104 - Combustible waste.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Combustible waste. 57.4104 Section 57.4104... Control Prohibitions/precautions/housekeeping § 57.4104 Combustible waste. (a) Waste materials, including liquids, shall not accumulate in quantities that could create a fire hazard. (b) Waste or rags containing...

  3. LIEKKI 2 - Combustion technology is environmental technology

    Energy Technology Data Exchange (ETDEWEB)

    Hupa, M. [Aabo Akademi, Turku (Finland)

    1996-12-31

    Finland has wide experience in applications of various combustion technologies and fuels and in supplying energy to industry and municipalities. Furthermore, combustion hardware and equipment are amongst our most important export products. Above all, fluidized bed boilers, recovery boilers for pulp mills and heavy diesel engines and diesel power plants have achieved excellent success in the world markets. Exports of these products alone have amounted to several billions of Finnish marks of annual sales in recent years. Within modern combustion technology, the objective is to control flue gas emissions as far as possible in the process itself, thus doing away with the need for the separate scrubbing of flue gases. To accomplish this it has been necessary to conduct a large amount of research on the details of the chemistry of combustion emissions and the flows in furnaces and engine cylinders. A host of completely new products are being developed for the combustion technology field. The LIEKKI programme has been particularly interested in so-called combined-cycle processes based on pressurized fluidized bed technology

  4. Oxy-fuel combustion with integrated pollution control

    Science.gov (United States)

    Patrick, Brian R [Chicago, IL; Ochs, Thomas Lilburn [Albany, OR; Summers, Cathy Ann [Albany, OR; Oryshchyn, Danylo B [Philomath, OR; Turner, Paul Chandler [Independence, OR

    2012-01-03

    An oxygen fueled integrated pollutant removal and combustion system includes a combustion system and an integrated pollutant removal system. The combustion system includes a furnace having at least one burner that is configured to substantially prevent the introduction of air. An oxygen supply supplies oxygen at a predetermine purity greater than 21 percent and a carbon based fuel supply supplies a carbon based fuel. Oxygen and fuel are fed into the furnace in controlled proportion to each other and combustion is controlled to produce a flame temperature in excess of 3000 degrees F. and a flue gas stream containing CO2 and other gases. The flue gas stream is substantially void of non-fuel borne nitrogen containing combustion produced gaseous compounds. The integrated pollutant removal system includes at least one direct contact heat exchanger for bringing the flue gas into intimated contact with a cooling liquid to produce a pollutant-laden liquid stream and a stripped flue gas stream and at least one compressor for receiving and compressing the stripped flue gas stream.

  5. Modeling of microgravity combustion experiments

    Science.gov (United States)

    Buckmaster, John

    1995-01-01

    This program started in February 1991, and is designed to improve our understanding of basic combustion phenomena by the modeling of various configurations undergoing experimental study by others. Results through 1992 were reported in the second workshop. Work since that time has examined the following topics: Flame-balls; Intrinsic and acoustic instabilities in multiphase mixtures; Radiation effects in premixed combustion; Smouldering, both forward and reverse, as well as two dimensional smoulder.

  6. Quantifying emissions from spontaneous combustion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-09-01

    Spontaneous combustion can be a significant problem in the coal industry, not only due to the obvious safety hazard and the potential loss of valuable assets, but also with respect to the release of gaseous pollutants, especially CO2, from uncontrolled coal fires. This report reviews methodologies for measuring emissions from spontaneous combustion and discusses methods for quantifying, estimating and accounting for the purpose of preparing emission inventories.

  7. Spray combustion of biomass-based renewable diesel fuel using multiple injection strategy in a constant volume combustion chamber

    KAUST Repository

    Jing, Wei; Wu, Zengyang; Roberts, William L.; Fang, Tiegang

    2016-01-01

    Effect of a two-injection strategy associated with a pilot injection on the spray combustion process was investigated under conventional diesel combustion conditions (1000 K and 21% O2 concentration) for a biomass-based renewable diesel fuel, i

  8. Combustion systems and power plants incorporating parallel carbon dioxide capture and sweep-based membrane separation units to remove carbon dioxide from combustion gases

    Science.gov (United States)

    Wijmans, Johannes G [Menlo Park, CA; Merkel, Timothy C [Menlo Park, CA; Baker, Richard W [Palo Alto, CA

    2011-10-11

    Disclosed herein are combustion systems and power plants that incorporate sweep-based membrane separation units to remove carbon dioxide from combustion gases. In its most basic embodiment, the invention is a combustion system that includes three discrete units: a combustion unit, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In a preferred embodiment, the invention is a power plant including a combustion unit, a power generation system, a carbon dioxide capture unit, and a sweep-based membrane separation unit. In both of these embodiments, the carbon dioxide capture unit and the sweep-based membrane separation unit are configured to be operated in parallel, by which we mean that each unit is adapted to receive exhaust gases from the combustion unit without such gases first passing through the other unit.

  9. Dynamic estimator for determining operating conditions in an internal combustion engine

    Science.gov (United States)

    Hellstrom, Erik; Stefanopoulou, Anna; Jiang, Li; Larimore, Jacob

    2016-01-05

    Methods and systems are provided for estimating engine performance information for a combustion cycle of an internal combustion engine. Estimated performance information for a previous combustion cycle is retrieved from memory. The estimated performance information includes an estimated value of at least one engine performance variable. Actuator settings applied to engine actuators are also received. The performance information for the current combustion cycle is then estimated based, at least in part, on the estimated performance information for the previous combustion cycle and the actuator settings applied during the previous combustion cycle. The estimated performance information for the current combustion cycle is then stored to the memory to be used in estimating performance information for a subsequent combustion cycle.

  10. ANALOGIAS EM LIVROS DIDÁTICOS DESTINADOS AO ENSINO SUPERIOR: QUÍMICA ORGÂNICA VERSUS FÍSICO-QUÍMICA

    Directory of Open Access Journals (Sweden)

    Josué Martins Gonçalves

    2016-12-01

    Full Text Available Os livros didáticos de Química, via de regra, fazem uso de analogias por se tratar de uma disciplina que envolve inúmeros conceitos abstratos. No entanto, há pouca pesquisa envolvendo identificação e explicação sobre as analogias utilizadas em livros didáticos direcionados ao ensino superior. Nesse sentido, o presente trabalho apresenta um estudo comparativo entre as analogias encontradas em livros de Química Orgânica e Físico-química destinados a estudantes do ensino superior. Foram identificadas 277 analogias nos livros analisados e categorizadas conforme sistemas adaptados de Thiele e Treagust (1994 e Francisco Junior (2009.Uma forma de abordagem mais adequada de utilização das analogias nesses livros foi realizada, bem como a verificação da importância do papel dos professores no uso desse recurso didático. Os resultados indicam que esses livros são ricos em analogias simples, dando ênfase às análogos estruturais no caso de livros de Química Orgânica e análogos funcionais nos de Físico-Química. As analogias simples são mais fáceis de induzirem os alunos a erros conceituais, pois mostram poucas similaridades entre os domínios comparados. É importante ressaltar que nesta pesquisa observa-se uma baixa ocorrência de analogias em que o autor do livro reconhece as limitações e/ou discute estas, repassando toda a responsabilidade ao professor e ao aluno no que se refere à explicação e percepção das analogias, respectivamente. É mister afirmar que muitas das analogias encontradas em alguns capítulos dos livros analisados, poderiam ser suprimidas sem perda significativa da compreensão dos conceitos abordados.

  11. The release of nitrogen in coal combustion and pyrolysis

    International Nuclear Information System (INIS)

    Varey, J.E.; Hindmarsh, C.J.; Thomas, K.M.

    1994-01-01

    Environmental aspects of coal utilization are a major concern. Recent advances in the development of low NO x burners and the emerging technologies of fluidized bed combustion have led to the identification of coal char nitrogen as the major contributor to the nitrogen oxides released during combustion. The temperature programmed combustion and pyrolysis of a series of coals covering a wide range of rank have been investigated. In addition, maceral concentrates have been investigated to assess the variation in the combustion behavior and the release of nitrogen in the pyrolysis and combustion of macerals. This investigation has involved the use of thermogravimetric analysis - mass spectrometry (TG-MS) with two sampling options: (1) ∼1cm from the sample and (2) at the exit of the TG. The former allows reactive species to be identified in the combustion of the coals. These temperature programmed combustion results have been compared with similar measurements carried out at the exit of the TG where the products are at equilibrium. In addition, pyrolysis studies have been carried out under similar conditions. The results show that reactive intermediate species such as HCN, (CN) 2 , COS etc. can be detected in the combustion products. The evolution of these species during combustion are compared with the pyrolysis products of the coal. The results are discussed in relation to the structure of the coals and the conversion of volatile species and char nitrogen to nitrogen oxides

  12. Tubular combustion

    CERN Document Server

    Ishizuka, Satoru

    2014-01-01

    Tubular combustors are cylindrical tubes where flame ignition and propagation occur in a spatially confined, highly controlled environment, in a nearly flat, elongated geometry. This allows for some unique advantages where extremely even heat dispersion is required over a large surface while still maintaining fuel efficiency. Tubular combustors also allow for easy flexibility in type of fuel source, allowing for quick changeover to meet various needs and changing fuel pricing. This new addition to the MP sustainable energy series will provide the most up-to-date research on tubular combustion--some of it only now coming out of private proprietary protection. Plentiful examples of current applications along with a good explanation of background theory will offer readers an invaluable guide on this promising energy technology. Highlights include: * An introduction to the theory of tubular flames * The "how to" of maintaining stability of tubular flames through continuous combustion * Examples of both small-scal...

  13. 8th International symposium on transport phenomena in combustion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-31

    The 8th International Symposium on Transport Phenomena in Combustion will be held in San Francisco, California, U.S.A., July 16-20, 1995, under the auspices of the Pacific Center of Thermal-Fluids Engineering. The purpose of the Symposium is to provide a forum for researchers and practitioners from around the world to present new developments and discuss the state of the art and future directions and priorities in the areas of transport phenomena in combustion. The Symposium is the eighth in a series; previous venues were Honolulu 1985, Tokyo 1987, Taipei 1988, Sydney 1991, Beijing 1992, Seoul 1993 and Acapulco 1994, with emphasis on various aspects of transport phenomena. The current Symposium theme is combustion. The Symposium has assembled a balanced program with topics ranging from fundamental research to contemporary applications of combustion theory. Invited keynote lecturers will provide extensive reviews of topics of great interest in combustion. Colloquia will stress recent advances and innovations in fire spread and suppression, and in low NO{sub x} burners, furnaces, boilers, internal combustion engines, and other practical combustion systems. Finally, numerous papers will contribute to the fundamental understanding of complex processes in combustion. This document contains abstracts of papers to be presented at the Symposium.

  14. 1998 annual report of advanced combustion science utilizing microgravity

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    For the purpose of stabilizing energy supply, diversifying energy supply sources and reducing the worsening of global environment caused by combustion exhaust gases, advanced combustion technology was studied and the FY 1998 results were summarized. Following the previous year, the following were conducted: international research jointly with NASA, experiments using microgravity test facilities of Japan Space Utilization Promotion Center (JSUP), evaluation studies made by universities/national research institutes/private companies, etc. In the FY 1998 joint study, a total of 52 drop experiments were carried out on 4 themes using test facilities of Japan Microgravity Center (JAMIC), and 100 experiments were conducted on one theme using test facilities of NASA. In the study using microgravity test facilities, the following were carried out: study of combustion and evaporation of fuel droplets, study of ignition/combustion of fuel droplets in the suspending state, study of combustion of spherical/cylinder state liquid fuels, study of high pressure combustion of binary fuel spray, study of interaction combustion of fuel droplets in the microgravity field, etc. (NEDO)

  15. Combustion in fluidized bed reactors; Verbrennung in Wirbelschichtreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Thome-Kozmiensky, Karl J. [vivis CONSULT GmbH, Nietwerder (Germany)

    2013-03-01

    Since the first application for the coal gasification, the fluidized bed technology has passed an impressive development. Nowadays, the fluidized bed technology is utilized at chemical processes, drying and cooling, gasification, combustion and purification of exhaust gas. In the firing technology, the fluidized technology initially has been proved in the combustion of very high ash coal and sewage sludge. Recently, the fluidized bed technology also is applied in the drying of sewage sludge, combustion of domestic waste - as in Japan and Sweden - as well as in the gasification and combustion of substitute fuels, biomass - wood pellets, wood chips, straw, cocoa shells and so forth - and residues from the paper manufacturing - such as in Germany and Austria. Under this aspect, the author of the contribution under consideration reports on the combustion of sewage sludge, substitute fuels and biomass.

  16. Combustion mode switching with a turbocharged/supercharged engine

    Science.gov (United States)

    Mond, Alan; Jiang, Li

    2015-09-22

    A method for switching between low- and high-dilution combustion modes in an internal combustion engine having an intake passage with an exhaust-driven turbocharger, a crankshaft-driven positive displacement supercharger downstream of the turbocharger and having variable boost controllable with a supercharger bypass valve, and a throttle valve downstream of the supercharger. The current combustion mode and mass air flow are determined. A switch to the target combustion mode is commanded when an operating condition falls within a range of predetermined operating conditions. A target mass air flow to achieve a target air-fuel ratio corresponding to the current operating condition and the target combustion mode is determined. The degree of opening of the supercharger bypass valve and the throttle valve are controlled to achieve the target mass air flow. The amount of residual exhaust gas is manipulated.

  17. Homogeneous Charge Compression Ignition Combustion of Dimethyl Ether

    DEFF Research Database (Denmark)

    Pedersen, Troels Dyhr

    This thesis is based on experimental and numerical studies on the use of dimethyl ether (DME) in the homogeneous charge compression ignition (HCCI) combustion process. The first paper in this thesis was published in 2007 and describes HCCI combustion of pure DME in a small diesel engine. The tests...... were designed to investigate the effect of engine speed, compression ratio and equivalence ratio on the combustion timing and the engine performance. It was found that the required compression ratio depended on the equivalence ratio used. A lower equivalence ratio requires a higher compression ratio...... before the fuel is burned completely, due to lower in-cylinder temperatures and lower reaction rates. The study provided some insight in the importance of operating at the correct compression ratio, as well as the operational limitations and emission characteristics of HCCI combustion. HCCI combustion...

  18. Modeling of large-scale oxy-fuel combustion processes

    DEFF Research Database (Denmark)

    Yin, Chungen

    2012-01-01

    Quite some studies have been conducted in order to implement oxy-fuel combustion with flue gas recycle in conventional utility boilers as an effective effort of carbon capture and storage. However, combustion under oxy-fuel conditions is significantly different from conventional air-fuel firing......, among which radiative heat transfer under oxy-fuel conditions is one of the fundamental issues. This paper demonstrates the nongray-gas effects in modeling of large-scale oxy-fuel combustion processes. Oxy-fuel combustion of natural gas in a 609MW utility boiler is numerically studied, in which...... calculation of the oxy-fuel WSGGM remarkably over-predicts the radiative heat transfer to the furnace walls and under-predicts the gas temperature at the furnace exit plane, which also result in a higher incomplete combustion in the gray calculation. Moreover, the gray and non-gray calculations of the same...

  19. Annual Report: Advanced Combustion (30 September 2012)

    Energy Technology Data Exchange (ETDEWEB)

    Hawk, Jeffrey [NETL; Richards, George

    2012-09-30

    The Advanced Combustion Project addresses fundamental issues of fire-side and steam-side corrosion and materials performance in oxy-fuel combustion environments and provides an integrated approach into understanding the environmental and mechanical behavior such that environmental degradation can be ameliorated and long-term microstructural stability, and thus, mechanical performance can lead to longer lasting components and extended power plant life. The technical tasks of this effort are Oxy-combustion Environment Characterization, Alloy Modeling and Life Prediction, and Alloy Manufacturing and Process Development.

  20. Radioactivity of combustion residues from coal-fired power stations

    International Nuclear Information System (INIS)

    Vom Berg, W.; Puch, K.H.

    1996-01-01

    Each year in Germany, about 18 mill. t of combustion residues are produced from the combustion of bituminous coal and lignite. They are utilized to a great extent in the construction industry and in mining. During the combustion of coal, the radio-nuclides remain predominantly in the ash. The radionuclide concentration in lignite ash is within the range of that in natural soil. The combustion residues of bituminous coal contain radio-nuclides of a similar order of magnitude as also can occur in natural rock. The utilization of combustion residues in construction materials makes a negligible contribution to radiation exposure through retention in buildings. (orig.) [de

  1. Modeling of Plasma Assisted Combustion

    Science.gov (United States)

    Akashi, Haruaki

    2012-10-01

    Recently, many experimental study of plasma-assisted combustion has been done. However, numerous complex reactions in combustion of hydrocarbons are preventing from theoritical study for clarifying inside the plasma-assisted combustion, and the effect of plasma-assist is still not understood. Shinohara and Sasaki [1,2] have reported that the shortening of flame length by irradiating microwave without increase of gas temperature. And they also reported that the same phenomena would occur when applying dielectric barrier discharges to the flame using simple hydrocarbon, methane. It is suggested that these phenomena may result by the electron heating. To clarify this phenomena, electron behavior under microwave and DBD was examined. For the first step of DBD plasma-assisted combustion simulation, electron Monte Carlo simulation in methane, oxygen and argon mixture gas(0.05:0.14:0.81) [2] has been done. Electron swarm parameters are sampled and electron energy distribution function (EEDF)s are also determined. In the combustion, gas temperature is higher(>1700K), so reduced electric field E/N becomes relatively high(>10V/cm/Torr). The electrons are accelerated to around 14 eV. This result agree with the optical emission from argon obtained by the experiment of reference [2]. Dissociation frequency of methane and oxygens are obtained in high. This might be one of the effect of plasma-assist. And it is suggested that the electrons should be high enough to dissociate methane, but plasma is not needed.[4pt] [1] K. Shinohara et al, J. Phys. D:Appl. Phys., 42, 182008 (1-7) (2009).[0pt] [2] K. Sasaki, 64th Annual Gaseous Electronic Conference, 56, 15 CT3.00001(2011).

  2. Combustive management of oil spills

    International Nuclear Information System (INIS)

    1992-01-01

    Extensive experiments with in situ incineration were performed on a desert site at the University of Arizona with very striking results. The largest incinerator, 6 feet in diameter with a 30 foot chimney, developed combustion temperatures of 3000, F, and attendant soot production approximately 1000 times less than that produced by conventional in situ burning. This soot production, in fact, is approximately 30 times less than current allowable EPA standards for incinerators and internal combustion engines. Furthermore, as a consequence of the high temperature combustion, the bum rate was established at a very high 3400 gallons per hour for this particular 6 foot diameter structure. The rudimentary design studies we have carried out relative to a seagoing 8 foot diameter incinerator have predicted that a continuous burn rate of 7000 gallons per hour is realistic. This structure was taken as a basis for operational design because it is compatible with C130 flyability, and will be inexpensive enough ($120,000 per copy) to be stored at those seaside depots throughout the US coast line in which the requisite ancillary equipments (booms, service tugs, etc.) are already deployed. The LOX experiments verified our expectations with respect to combustion of debris and various highly weathered or emulsified oils. We have concluded, however, that the use of liquid oxygen in actual beach clean up is not promising because the very high temperatures associated with this combustion are almost certain to produce environmentally deleterious effects on the beach surface and its immediately sublying structures. However, the use of liquid oxygen augmentation for shore based and flyable incinerators may still play an important role in handing the problem of accumulated debris

  3. Thermal Behavior of Coal Used in Rotary Kiln and Its Combustion Intensification

    Directory of Open Access Journals (Sweden)

    Qiang Zhong

    2018-04-01

    Full Text Available Pyrolysis and combustion behaviors of three coals (A, B, and C coals were investigated and their combustion kinetics were calculated by the Freeman–Carroll method to obtain quantitative insight into their combustion behaviors. Moreover, the effects of coal size, air flow, oxygen content, and heating rate on coal combustion behaviors were analyzed. Results showed that the three coals have a similar trend of pyrolysis that occurs at about 670 K and this process continuously proceeds along with their combustion. Combustion characteristics and kinetic parameters can be applied to analyze coal combustion behaviors. Three coals having combustion characteristics of suitable ignition temperature (745–761 K, DTGmax (14.20–15.72%/min, and burnout time (7.45–8.10 min were analyzed in a rotary kiln. Combustion kinetic parameters provide quantitative insights into coal combustion behavior. The suitable particle size for coal combustion in a kiln is that the content of less than 74 μm is 60% to 80%. Low activation energy and reaction order make coal, especially C coal, have a simple combustion mechanism, great reactivity, be easily ignited, and a low peak temperature in the combustion state. Oxygen-enrichment and high heating rates enhance coal combustion, increasing combustion intensity and peak value, thus shortening burnout time.

  4. Steam-moderated oxy-fuel combustion

    International Nuclear Information System (INIS)

    Seepana, Sivaji; Jayanti, Sreenivas

    2010-01-01

    The objective of the present paper is to propose a new variant of the oxy-fuel combustion for carbondioxide (CO 2 ) sequestration in which steam is used to moderate the flame temperature. In this process, pure oxygen is mixed with steam and the resulting oxidant mixture is sent to the boiler for combustion with a fossil fuel. The advantage of this method is that flue gas recirculation is avoided and the volumetric flow rates through the boiler and auxiliary components is reduced by about 39% when compared to the conventional air-fired coal combustion power plant leading to a reduction in the size of the boiler. The flue gas, after condensation of steam, consists primarily of CO 2 and can be sent directly for compression and sequestration. Flame structure analysis has been carried out using a 325-step reaction mechanism of methane-oxidant combustion to determine the concentration of oxygen required to ensure a stable flame. Thermodynamic exergy analysis has also been carried out on SMOC-operated CO 2 sequestration power plant and air-fired power plant, which shows that though the gross efficiency increases the absolute power penalty of ∼8% for CO 2 sequestration when compared to air-fired power plant.

  5. Steam-moderated oxy-fuel combustion

    Energy Technology Data Exchange (ETDEWEB)

    Seepana, Sivaji; Jayanti, Sreenivas [Department of Chemical Engineering, IIT Madras, Adyar, Chennai 600 036 (India)

    2010-10-15

    The objective of the present paper is to propose a new variant of the oxy-fuel combustion for carbondioxide (CO{sub 2}) sequestration in which steam is used to moderate the flame temperature. In this process, pure oxygen is mixed with steam and the resulting oxidant mixture is sent to the boiler for combustion with a fossil fuel. The advantage of this method is that flue gas recirculation is avoided and the volumetric flow rates through the boiler and auxiliary components is reduced by about 39% when compared to the conventional air-fired coal combustion power plant leading to a reduction in the size of the boiler. The flue gas, after condensation of steam, consists primarily of CO{sub 2} and can be sent directly for compression and sequestration. Flame structure analysis has been carried out using a 325-step reaction mechanism of methane-oxidant combustion to determine the concentration of oxygen required to ensure a stable flame. Thermodynamic exergy analysis has also been carried out on SMOC-operated CO{sub 2} sequestration power plant and air-fired power plant, which shows that though the gross efficiency increases the absolute power penalty of {proportional_to}8% for CO{sub 2} sequestration when compared to air-fired power plant. (author)

  6. Consequences of sludge composition on combustion performance derived from thermogravimetry analysis

    Energy Technology Data Exchange (ETDEWEB)

    Li, Meiyan; Xiao, Benyi; Wang, Xu; Liu, Junxin, E-mail: jxliu@rcees.ac.cn

    2015-01-15

    Highlights: • Volatiles, particularly proteins, play a key role in sludge combustion. • Sludge combustion performance varies with different sludge organic concentrations. • Carbohydrates significantly affect the combustion rate in the second stage. • Combustion performance of digested sludge is more negative compared with others. - Abstract: Wastewater treatment plants produce millions of tons of sewage sludge. Sewage sludge is recognized as a promising feedstock for power generation via combustion and can be used for energy crisis adaption. We aimed to investigate the quantitative effects of various sludge characteristics on the overall sludge combustion process performance. Different types of sewage sludge were derived from numerous wastewater treatment plants in Beijing for further thermogravimetric analysis. Thermogravimetric–differential thermogravimetric curves were used to compare the performance of the studied samples. Proximate analytical data, organic compositions, elementary composition, and calorific value of the samples were determined. The relationship between combustion performance and sludge composition was also investigated. Results showed that the performance of sludge combustion was significantly affected by the concentration of protein, which is the main component of volatiles. Carbohydrates and lipids were not correlated with combustion performance, unlike protein. Overall, combustion performance varied with different sludge organic composition. The combustion rate of carbohydrates was higher than those of protein and lipid, and carbohydrate weight loss mainly occurred during the second stage (175–300 °C). Carbohydrates have a substantial effect on the rate of system combustion during the second stage considering the specific combustion feature. Additionally, the combustion performance of digested sewage sludge is more negative than the others.

  7. Consequences of sludge composition on combustion performance derived from thermogravimetry analysis

    International Nuclear Information System (INIS)

    Li, Meiyan; Xiao, Benyi; Wang, Xu; Liu, Junxin

    2015-01-01

    Highlights: • Volatiles, particularly proteins, play a key role in sludge combustion. • Sludge combustion performance varies with different sludge organic concentrations. • Carbohydrates significantly affect the combustion rate in the second stage. • Combustion performance of digested sludge is more negative compared with others. - Abstract: Wastewater treatment plants produce millions of tons of sewage sludge. Sewage sludge is recognized as a promising feedstock for power generation via combustion and can be used for energy crisis adaption. We aimed to investigate the quantitative effects of various sludge characteristics on the overall sludge combustion process performance. Different types of sewage sludge were derived from numerous wastewater treatment plants in Beijing for further thermogravimetric analysis. Thermogravimetric–differential thermogravimetric curves were used to compare the performance of the studied samples. Proximate analytical data, organic compositions, elementary composition, and calorific value of the samples were determined. The relationship between combustion performance and sludge composition was also investigated. Results showed that the performance of sludge combustion was significantly affected by the concentration of protein, which is the main component of volatiles. Carbohydrates and lipids were not correlated with combustion performance, unlike protein. Overall, combustion performance varied with different sludge organic composition. The combustion rate of carbohydrates was higher than those of protein and lipid, and carbohydrate weight loss mainly occurred during the second stage (175–300 °C). Carbohydrates have a substantial effect on the rate of system combustion during the second stage considering the specific combustion feature. Additionally, the combustion performance of digested sewage sludge is more negative than the others

  8. A Comparison of Prominent LES Combustion Models for Nonpremixed Supersonic Combustion

    Data.gov (United States)

    National Aeronautics and Space Administration — The capability of accurately simulating supersonic combustion is a vital topic for designing and advancing hypersonic air-breathing vehicles. As a consequence, there...

  9. Characterisation of wood combustion ashes

    DEFF Research Database (Denmark)

    Maresca, Alberto

    The combustion of wood chips and wood pellets for the production of renewable energy in Denmark increased from 5.7 PJ to 16 PJ during the period 2000-2015, and further increases are expected to occur within the coming years. In 2012, about 22,300 tonnes of wood ashes were generated in Denmark....... Currently, these ashes are mainly landfilled, despite Danish legislation allowing their application onto forest and agricultural soils for fertilising and/or liming purposes. During this PhD work, 16 wood ash samples generated at ten different Danish combustion plants were collected and characterised...... for their composition and leaching properties. Despite the relatively large variations in the contents of nutrients and trace metals, the overall levels were comparable to typical ranges reported in the literature for other wood combustion ashes, as well as with regards to leaching. In general, the composition...

  10. Novel Active Combustion Control Valve

    Science.gov (United States)

    Caspermeyer, Matt

    2014-01-01

    This project presents an innovative solution for active combustion control. Relative to the state of the art, this concept provides frequency modulation (greater than 1,000 Hz) in combination with high-amplitude modulation (in excess of 30 percent flow) and can be adapted to a large range of fuel injector sizes. Existing valves often have low flow modulation strength. To achieve higher flow modulation requires excessively large valves or too much electrical power to be practical. This active combustion control valve (ACCV) has high-frequency and -amplitude modulation, consumes low electrical power, is closely coupled with the fuel injector for modulation strength, and is practical in size and weight. By mitigating combustion instabilities at higher frequencies than have been previously achieved (approximately 1,000 Hz), this new technology enables gas turbines to run at operating points that produce lower emissions and higher performance.

  11. A morte como elemento cultural mexicano em Pedro Páramo, de Juan Rulfo

    Directory of Open Access Journals (Sweden)

    Ana Paula Cantarelli

    2013-06-01

    Full Text Available Pedro Páramo (1955, de Juan Rulfo, desde sua publicação tem sido alvo de inúmeros estudos desenvolvidos por pesquisadores de diferentes áreas do conhecimento (história, sociologia, filosofia, etc.. Neste texto, buscou-se elaborar uma proposta de leitura a partir do reconhecimento da morte, símbolo nacional mexicano, como um elemento constituinte da estrutura narrativa desse romance, com a intenção de ampliar o campo de análises já delineado ao redor dessa obra.

  12. Elementos para obtener el módulo de reacción de subrasante

    OpenAIRE

    OTÁLVARO, IVÁN FERNANDO; NANCLARES, FRANCISCO JAVIER

    2009-01-01

    En la actualidad el análisis tensión deformación del conjunto estructura-geomaterial se suele abordar apartir de modelos discretos, en algunas ocasiones mediante métodos numéricos tales como los elementos finitos. Sin embargo, sigue siendo bastante común representar los geomateriales a partir de la hipótesis de Winkler, ya que ofrece una mayor simplicidad para efectos de cálculo y es posible modelar simultáneamente el suelo y la estructura de cimentación. En este documento se describen los m...

  13. Study of Combustion Characteristics of Hydrocarbon Nanofuel Droplets

    Science.gov (United States)

    2017-08-23

    NUMBER (Include area code) 23 August 2017 Briefing Charts 01 August 2017 - 31 August 2017 Study of Combustion Characteristics of Hydrocarbon...Douglas Talley N/A 1 Study of Combustion Characteristics of Hydrocarbon Nanofuel Droplets DISTRIBUTION STATEMENT A. Approved for public release...Angeles ϯAir Force Research Laboratory, Aerospace Systems Directorate, Combustion Devices Group, Edwards AFB, CA ONR/ARO/AFOSR Meeting, 23 Aug., 2017

  14. Annual Report: DOE Advanced Combustion Systems & Fuels R&D; Light-Duty Diesel Combustion

    Energy Technology Data Exchange (ETDEWEB)

    Busch, Stephen [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2017-11-01

    Despite compliance issues in previous years, automakers have demonstrated that the newest generation of diesel power trains are capable of meeting all federal and state regulations (EPA, 2016). Diesels continue to be a cost-effective, efficient, powerful propulsion source for many light- and medium-duty vehicle applications (Martec, 2016). Even modest reductions in the fuel consumption of light- and medium duty diesel vehicles in the U.S. will eliminate millions of tons of CO2 emissions per year. Continued improvement of diesel combustion systems will play an important role in reducing fleet fuel consumption, but these improvements will require an unprecedented scientific understanding of how changes in engine design and calibration affect the mixture preparation, combustion, and pollutant formation processes that take place inside the cylinder. The focus of this year’s research is to provide insight into the physical mechanisms responsible for improved thermal efficiency observed with a stepped-lip piston. Understanding how piston design can influence efficiency will help engineers develop and optimize new diesel combustion systems.

  15. 46 CFR 59.15-5 - Stayed furnaces and combustion chambers.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 2 2010-10-01 2010-10-01 false Stayed furnaces and combustion chambers. 59.15-5 Section... and combustion chambers. (a) Where the plate forming the walls of stayed furnaces or combustion... wall of a stayed furnace or combustion chamber, the defective portion of the plate shall be cut away...

  16. Investigation of combustion and thermodynamic performance of a lean burn catalytic combustion gas turbine system

    International Nuclear Information System (INIS)

    Yin Juan; Weng Yiwu

    2011-01-01

    The goals of this research were to investigate the combustion and thermodynamic performance of a lean burn catalytic combustion gas turbine. The characteristics of lean burn catalytic combustion were investigated by utilising 1D heterogeneous plug flow model which was validated by experiments. The effects of operating parameters on catalytic combustion were numerically analysed. The system models were built in ASPEN Plus and three independent design variables, i.e. compressor pressure ratio (PR), regenerator effectiveness (RE) and turbine inlet temperature (TIT) were selected to analyse the thermodynamic performance of the thermal cycle. The main results show that: simulations from 1D heterogeneous plug flow model can capture the trend of catalytic combustion and describe the behavior of the catalytic monolith in detail. Inlet temperature is the most significant parameter that impacts operation of the catalytic combustor. When TIT and RE are constant, the increase of PR results in lowering the inlet temperature of the catalytic combustor, which results in decreasing methane conversion. The peak thermal efficiency and the optimal PR at a constant TIT increase with the increase of TIT; and at the constant PR, the thermal efficiency increases with the increase of TIT. However, with lower TIT conditions, the optimal PR and the peak efficiency at a constant TIT of the LBCCGT cycle are relative low to that of the conventional cycle. When TIT and PR are constant, the decrease of RE may result in lower methane conversion. The influences of RE on the methane conversion and the thermal efficiency are more significant at higher PRs. The higher thermal efficiency for the lower RE is achieved at lower PR.

  17. 16 CFR 1209.7 - Test procedures for smoldering combustion.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Test procedures for smoldering combustion. 1209.7 Section 1209.7 Commercial Practices CONSUMER PRODUCT SAFETY COMMISSION CONSUMER PRODUCT SAFETY... for smoldering combustion. This section provides the test method for determining smoldering combustion...

  18. Combustion of biodiesel in a large-scale laboratory furnace

    International Nuclear Information System (INIS)

    Pereira, Caio; Wang, Gongliang; Costa, Mário

    2014-01-01

    Combustion tests in a large-scale laboratory furnace were carried out to assess the feasibility of using biodiesel as a fuel in industrial furnaces. For comparison purposes, petroleum-based diesel was also used as a fuel. Initially, the performance of the commercial air-assisted atomizer used in the combustion tests was scrutinized under non-reacting conditions. Subsequently, flue gas data, including PM (particulate matter), were obtained for various flame conditions to quantify the effects of the atomization quality and excess air on combustion performance. The combustion data was complemented with in-flame temperature measurements for two representative furnace operating conditions. The results reveal that (i) CO emissions from biodiesel and diesel combustion are rather similar and not affected by the atomization quality; (ii) NO x emissions increase slightly as spray quality improves for both liquid fuels, but NO x emissions from biodiesel combustion are always lower than those from diesel combustion; (iii) CO emissions decrease rapidly for both liquid fuels as the excess air level increases up to an O 2 concentration in the flue gas of 2%, beyond which they remain unchanged; (iv) NO x emissions increase with an increase in the excess air level for both liquid fuels; (v) the quality of the atomization has a significant impact on PM emissions, with the diesel combustion yielding significantly higher PM emissions than biodiesel combustion; and (vi) diesel combustion originates PM with elements such as Cr, Na, Ni and Pb, while biodiesel combustion produces PM with elements such as Ca, Mg and Fe. - Highlights: • CO emissions from biodiesel and diesel tested are similar. • NO x emissions from biodiesel tested are lower than those from diesel tested. • Diesel tested yields significantly higher PM (particulate matter) emissions than biodiesel tested. • Diesel tested originates PM with Cr, Na, Ni and Pb, while biodiesel tested produces PM with Ca, Mg and Fe

  19. Proceedings of IEA combustion 2009 : IEA 31. task leaders meeting on energy conservation and emissions reduction in combustion

    International Nuclear Information System (INIS)

    2009-01-01

    The International Energy Agency (IEA) supports research and development in energy technology. This meeting provided a forum to discuss combustion processes, which is fundamental to achieving further improvements in fuel use efficiency, reducing the production of pollutants such as nitrogen oxides, and facilitating the transition to alternative fuels. The presentations demonstrated recent studies in improving the efficiency and fuel flexibility of automotive engines; improving the performance of industrial furnaces; emissions formation and control mechanisms; and fuel injection and fuel/air mixing. The conference also highlighted studies involving hydrogen combustion, alternative fuels, particulate diagnostics, fuel sprays, gas turbines, and advanced combustion processes such as homogeneous charge compression ignition (HCCI). The sessions were entitled: HCCI fuels; sprays; nanoparticle diagnostics; alternative fuels; hydrogen internal combustion engines; turbines; energy security; and collaborative task planning. All 45 presentations from the conference have been catalogued separately for inclusion in this database. refs., tabs., figs.

  20. Cálculo automático de estruturas: análise estrutural de lajes através do método dos elementos finitos

    OpenAIRE

    Geirinhas, Nuno Alexandre Riscado Valente

    2010-01-01

    O principal objectivo deste trabalho foi o desenvolvimento de um programa de cálculo automático de lajes baseado no método dos elementos finitos. Como introdução ao tema é efectuada uma análise da evolução das estruturas ao longo dos tempos, diferenciando os vários tipos de estruturas que existem. São explicitados os conceitos fundamentais da mecânica dos sólidos, bem como os vários tipos de análises estruturais, os tipos de elementos finitos mais utilizados, bem como a classificação do...

  1. Hydrogen assisted diesel combustion

    Energy Technology Data Exchange (ETDEWEB)

    Lilik, Gregory K.; Boehman, Andre L. [The EMS Energy Institute, The Pennsylvania State University, University Park, PA 16802 (United States); Zhang, Hedan; Haworth, Daniel C. [Department of Mechanical and Nuclear Engineering, The Pennsylvania State University, University Park, PA 16802 (United States); Herreros, Jose Martin [Escuela Tecnica Superior de Ingenieros Industriales, Universidad de Castilla La-Mancha, Avda. Camilo Jose Cela s/n, 13071 Ciudad Real (Spain)

    2010-05-15

    Hydrogen assisted diesel combustion was investigated on a DDC/VM Motori 2.5L, 4-cylinder, turbocharged, common rail, direct injection light-duty diesel engine, with a focus on exhaust emissions. Hydrogen was substituted for diesel fuel on an energy basis of 0%, 2.5%, 5%, 7.5%, 10% and 15% by aspiration of hydrogen into the engine's intake air. Four speed and load conditions were investigated (1800 rpm at 25% and 75% of maximum output and 3600 rpm at 25% and 75% of maximum output). A significant retarding of injection timing by the engine's electronic control unit (ECU) was observed during the increased aspiration of hydrogen. The retarding of injection timing resulted in significant NO{sub X} emission reductions, however, the same emission reductions were achieved without aspirated hydrogen by manually retarding the injection timing. Subsequently, hydrogen assisted diesel combustion was examined, with the pilot and main injection timings locked, to study the effects caused directly by hydrogen addition. Hydrogen assisted diesel combustion resulted in a modest increase of NO{sub X} emissions and a shift in NO/NO{sub 2} ratio in which NO emissions decreased and NO{sub 2} emissions increased, with NO{sub 2} becoming the dominant NO{sub X} component in some combustion modes. Computational fluid dynamics analysis (CFD) of the hydrogen assisted diesel combustion process captured this trend and reproduced the experimentally observed trends of hydrogen's effect on the composition of NO{sub X} for some operating conditions. A model that explicitly accounts for turbulence-chemistry interactions using a transported probability density function (PDF) method was better able to reproduce the experimental trends, compared to a model that ignores the influence of turbulent fluctuations on mean chemical production rates, although the importance of the fluctuations is not as strong as has been reported in some other recent modeling studies. The CFD results confirm

  2. SELECTION OF SUSTAINABLE TECHNOLOGIES FOR COMBUSTION OF BOSNIAN COALS

    Directory of Open Access Journals (Sweden)

    Anes Kazagić

    2010-01-01

    Full Text Available This paper deals with optimization of coal combustion conditions to support selection a sustainable combustion technology and an optimal furnace and boiler design. A methodology for optimization of coal combustion conditions is proposed and demonstrated on the example of Bosnian coals. The properties of Bosnian coals vary widely from one coal basin to the next, even between coal mines within the same basin. Very high percentage of ash (particularly in Bosnian brown coal makes clear certain differences between Bosnian coal types and other world coal types, providing a strong argument for investigating specific problems related to the combustion of Bosnian coals, as well as ways to improve their combustion behaviour. In this work, options of the referent energy system (boiler with different process temperatures, corresponding to the different combustion technologies; pulverised fuel combustion (slag tap or dry bottom furnace and fluidized bed combustion, are under consideration for the coals tested. Sustainability assessment, based on calculation economic and environment indicators, in combination with common low cost planning method, is used for the optimization. The total costs in the lifetime are presented by General index of total costs, calculated on the base of agglomeration of basic economic indicators and the economic indicators derived from environmental indicators. So, proposed methodology is based on identification of those combustion technologies and combustion conditions for coals tested for which the total costs in lifetime of the system under consideration are lowest, provided that all environmental issues of the energy system is fulfilled during the lifetime. Inputs for calculation of the sustainability indicators are provided by the measurements on an experimental furnace with possibility of infinite variation of process temperature, supported by good praxis from the power plants which use the fuels tested and by thermal

  3. Assessment of Literature Related to Combustion Appliance Venting Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rapp, Vi H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Singer, Brett C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Stratton, Chris [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wray, Craig P. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2012-06-01

    In many residential building retrofit programs, air tightening to increase energy efficiency is constrained by concerns about related impacts on the safety of naturally vented combustion appliances. Tighter housing units more readily depressurize when exhaust equipment is operated, making combustion appliances more prone to backdraft or spillage. Several test methods purportedly assess the potential for depressurization-induced backdrafting and spillage, but these tests are not robustly reliable and repeatable predictors of venting performance, in part because they do not fully capture weather effects on venting performance. The purpose of this literature review is to investigate combustion safety diagnostics in existing codes, standards, and guidelines related to combustion appliances. This review summarizes existing combustion safety test methods, evaluations of these test methods, and also discusses research related to wind effects and the simulation of vent system performance. Current codes and standards related to combustion appliance installation provide little information on assessing backdrafting or spillage potential. A substantial amount of research has been conducted to assess combustion appliance backdrafting and spillage test methods, but primarily focuses on comparing short-term (stress) induced tests and monitoring results. Monitoring, typically performed over one week, indicated that combinations of environmental and house operation characteristics most conducive to combustion spillage were rare. Research, to an extent, has assessed existing combustion safety diagnostics for house depressurization, but the objectives of the diagnostics, both stress and monitoring, are not clearly defined. More research is also needed to quantify the frequency of test “failure” occurrence throughout the building stock and assess the statistical effects of weather (especially wind) on house depressurization and in turn on combustion appliance venting

  4. Global cloud condensation nuclei influenced by carbonaceous combustion aerosol

    Directory of Open Access Journals (Sweden)

    D. V. Spracklen

    2011-09-01

    Full Text Available Black carbon in carbonaceous combustion aerosol warms the climate by absorbing solar radiation, meaning reductions in black carbon emissions are often perceived as an attractive global warming mitigation option. However, carbonaceous combustion aerosol can also act as cloud condensation nuclei (CCN so they also cool the climate by increasing cloud albedo. The net radiative effect of carbonaceous combustion aerosol is uncertain because their contribution to CCN has not been evaluated on the global scale. By combining extensive observations of CCN concentrations with the GLOMAP global aerosol model, we find that the model is biased low (normalised mean bias = −77 % unless carbonaceous combustion aerosol act as CCN. We show that carbonaceous combustion aerosol accounts for more than half (52–64 % of global CCN with the range due to uncertainty in the emitted size distribution of carbonaceous combustion particles. The model predicts that wildfire and pollution (fossil fuel and biofuel carbonaceous combustion aerosol causes a global mean cloud albedo aerosol indirect effect of −0.34 W m−2, with stronger cooling if we assume smaller particle emission size. We calculate that carbonaceous combustion aerosol from pollution sources cause a global mean aerosol indirect effect of −0.23 W m−2. The small size of carbonaceous combustion particles from fossil fuel sources means that whilst pollution sources account for only one-third of the emitted mass they cause two-thirds of the cloud albedo aerosol indirect effect that is due to carbonaceous combustion aerosol. This cooling effect must be accounted for, along with other cloud effects not studied here, to ensure that black carbon emissions controls that reduce the high number concentrations of fossil fuel particles have the desired net effect on climate.

  5. Turbulent Combustion Modeling Advances, New Trends and Perspectives

    CERN Document Server

    Echekki, Tarek

    2011-01-01

    Turbulent combustion sits at the interface of two important nonlinear, multiscale phenomena: chemistry and turbulence. Its study is extremely timely in view of the need to develop new combustion technologies in order to address challenges associated with climate change, energy source uncertainty, and air pollution. Despite the fact that modeling of turbulent combustion is a subject that has been researched for a number of years, its complexity implies that key issues are still eluding, and a theoretical description that is accurate enough to make turbulent combustion models rigorous and quantitative for industrial use is still lacking. In this book, prominent experts review most of the available approaches in modeling turbulent combustion, with particular focus on the exploding increase in computational resources that has allowed the simulation of increasingly detailed phenomena. The relevant algorithms are presented, the theoretical methods are explained, and various application examples are given. The book ...

  6. Emissions from small scale biomass combustion - Research needs

    International Nuclear Information System (INIS)

    Gustavsson, L.; Karlsson, M.L.; Larfeldt, J.; Leckner, B.

    1994-01-01

    Earlier investigations have shown that small scale biomass combustion leads to unacceptable emissions in the air. The most important problem is high levels of unburnt hydrocarbons. This report analyzes which are the most important reasons to these emissions and which research efforts that are necessary to increase the knowledge about the combustion processes, thereby promoting the development of environmentally feasible equipment. The following factors are defined as most crucial to emission levels: size of combustion chamber, air excess ratio, means of combustion air supply, mixing between air and fuel, transient events, and fuel quality. It is concluded that both basic and research within the area is needed. More specific, research in the form of systematic analysis of best available technology, reactor experiments, compilation of knowledge about relevant basic combustion processes, mathematical modelling as well as development of measurement techniques are called for. 15 refs, 11 figs, 1 tab

  7. Interactive wood combustion for botanical tree models

    KAUST Repository

    Pirk, Sö ren; Jarząbek, Michał; Hadrich, Torsten; Michels, Dominik L.; Palubicki, Wojciech

    2017-01-01

    We present a novel method for the combustion of botanical tree models. Tree models are represented as connected particles for the branching structure and a polygonal surface mesh for the combustion. Each particle stores biological and physical

  8. Real-time combustion control and diagnostics sensor-pressure oscillation monitor

    Science.gov (United States)

    Chorpening, Benjamin T [Morgantown, WV; Thornton, Jimmy [Morgantown, WV; Huckaby, E David [Morgantown, WV; Richards, George A [Morgantown, WV

    2009-07-14

    An apparatus and method for monitoring and controlling the combustion process in a combustion system to determine the amplitude and/or frequencies of dynamic pressure oscillations during combustion. An electrode in communication with the combustion system senses hydrocarbon ions and/or electrons produced by the combustion process and calibration apparatus calibrates the relationship between the standard deviation of the current in the electrode and the amplitudes of the dynamic pressure oscillations by applying a substantially constant voltage between the electrode and ground resulting in a current in the electrode and by varying one or more of (1) the flow rate of the fuel, (2) the flow rate of the oxidant, (3) the equivalence ratio, (4) the acoustic tuning of the combustion system, and (5) the fuel distribution in the combustion chamber such that the amplitudes of the dynamic pressure oscillations in the combustion chamber are calculated as a function of the standard deviation of the electrode current. Thereafter, the supply of fuel and/or oxidant is varied to modify the dynamic pressure oscillations.

  9. Dry low NOx combustion system with pre-mixed direct-injection secondary fuel nozzle

    Science.gov (United States)

    Zuo, Baifang; Johnson, Thomas; Ziminsky, Willy; Khan, Abdul

    2013-12-17

    A combustion system includes a first combustion chamber and a second combustion chamber. The second combustion chamber is positioned downstream of the first combustion chamber. The combustion system also includes a pre-mixed, direct-injection secondary fuel nozzle. The pre-mixed, direct-injection secondary fuel nozzle extends through the first combustion chamber into the second combustion chamber.

  10. High temperature combustion facility: present capabilities and future prospects

    International Nuclear Information System (INIS)

    Boccio, J.L.; Ginsberg, T.; Ciccarelli, G.

    1995-01-01

    The high-temperature combustion facility constructed and operated by the Department of Advanced Technology of Brookhaven National Laboratory to support and promote research in the area of hydrogen combustion phenomena in mixtures prototypical to light-water reactor containment atmospheres under potential severe accident conditions is reported. The facility can accommodate combustion research activities encompassing the fields of detonation physics, flame acceleration, and low-speed deflagration in a wide range of combustible gas mixtures at initial temperatures up to 700 K and post-combustion pressures up to 100 atmospheres. Some preliminary test results are presented that provide further evidence that the effect of temperature is to increase the sensitivity of hydrogen-air-steam mixtures to undergo detonation [ru

  11. Experimental investigation of flash pyrolysis oil droplet combustion

    DEFF Research Database (Denmark)

    Ibrahim, Norazana; Jensen, Peter A.; Dam-Johansen, Kim

    2013-01-01

    at a temperature ranging between 1000 and 1400°C with an initial gas velocity of 1.6 m/s and oxygen concentration of 3%. The evolution of combustion of bio-oil droplets was recorded by a digital video camera. It was observed that the combustion behaviour of pyrolysis oil droplet differ from the heavy oil in terms......The aim of this work is to investigate and compare the combustion behaviour of a single droplet of pyrolysis oil derived from wheat straw and heavy fossil oil in a single droplet combustion chamber. The initial oil droplet diameters were in between 500 μm to 2500 μm. The experiments were performed...

  12. Combustion: an oil spill mitigation tool

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-11-01

    The technical feasibility of using combustion as an oil spill mitigation tool was studied. Part I of the two-part report is a practical guide oriented toward the needs of potential users, while Part II is the research or resource document from which the practical guidance was drawn. The study included theoretical evaluations of combustion of petroleum pool fires under the effects of weathering and an oil classification system related to combustion potential. The theoretical analysis of combustion is balanced by practical experience of oil burning and case history information. Decision elements are provided which can be used as a guide for technical evaluations of a particular oil spill situation. The rationale for assessing technical feasibility is given in the context of other alternatives available for response to an oil spill. A series of research and technology development concepts are included for future research. The ethics of using oil burning are discussed as issues, concerns, and tradeoffs. A detailed annotated bibliography is appended along with a capsule review of a decade of oil burning studies and other support information.

  13. CloudFlame: Cyberinfrastructure for combustion research

    KAUST Repository

    Goteng, Gokop

    2013-12-01

    Combustion experiments and chemical kinetics simulations generate huge data that is computationally and data intensive. A cloud-based cyber infrastructure known as Cloud Flame is implemented to improve the computational efficiency, scalability and availability of data for combustion research. The architecture consists of an application layer, a communication layer and distributed cloud servers running in a mix environment of Windows, Macintosh and Linux systems. The application layer runs software such as CHEMKIN modeling application. The communication layer provides secure transfer/archive of kinetic, thermodynamic, transport and gas surface data using private/public keys between clients and cloud servers. A robust XML schema based on the Process Informatics Model (Prime) combined with a workflow methodology for digitizing, verifying and uploading data from scientific graphs/tables to Prime is implemented for chemical molecular structures of compounds. The outcome of using this system by combustion researchers at King Abdullah University of Science and Technology (KAUST) Clean Combustion Research Center and its collaborating partners indicated a significant improvement in efficiency in terms of speed of chemical kinetics and accuracy in searching for the right chemical kinetic data.

  14. Combustion of Sewage Sludge as Alternative Fuel for Cement Industry

    Institute of Scientific and Technical Information of China (English)

    LI Fuzhou; ZHANG Wei

    2011-01-01

    The combustion of sewage sludge and coal was studied by thermogravimetric analysis.Both differential scanning calorimetric analysis and derivative thermogravimetric profiles showed differences between combustion of sewage sludge and coal, and non-isothermal kinetics analysis method was applied to evaluate the combustion process. Based on Coats-Redfem integral method, some reaction models were tested,the mechanism and kinetics of the combustion reaction were discussed. The results show that the combustion of sewage sludge is mainly in the Iow temperature stage, meanwhile the ignition temperature and Arrhenius activation energy are lower than that of coal. The combustion of sewage sludge has the advantage over coal in some aspects, thus sewage sludge can partly replace coal used as cement industry fuel.

  15. Diffusion Driven Combustion Waves in Porous Media

    Science.gov (United States)

    Aldushin, A. P.; Matkowsky, B. J.

    2000-01-01

    Filtration of gas containing oxidizer, to the reaction zone in a porous medium, due, e.g., to a buoyancy force or to an external pressure gradient, leads to the propagation of Filtration combustion (FC) waves. The exothermic reaction occurs between the fuel component of the solid matrix and the oxidizer. In this paper, we analyze the ability of a reaction wave to propagate in a porous medium without the aid of filtration. We find that one possible mechanism of propagation is that the wave is driven by diffusion of oxidizer from the environment. The solution of the combustion problem describing diffusion driven waves is similar to the solution of the Stefan problem describing the propagation of phase transition waves, in that the temperature on the interface between the burned and unburned regions is constant, the combustion wave is described by a similarity solution which is a function of the similarity variable x/square root of(t) and the wave velocity decays as 1/square root of(t). The difference between the two problems is that in the combustion problem the temperature is not prescribed, but rather, is determined as part of the solution. We will show that the length of samples in which such self-sustained combustion waves can occur, must exceed a critical value which strongly depends on the combustion temperature T(sub b). Smaller values of T(sub b) require longer sample lengths for diffusion driven combustion waves to exist. Because of their relatively small velocity, diffusion driven waves are considered to be relevant for the case of low heat losses, which occur for large diameter samples or in microgravity conditions, Another possible mechanism of porous medium combustion describes waves which propagate by consuming the oxidizer initially stored in the pores of the sample. This occurs for abnormally high pressure and gas density. In this case, uniformly propagating planar waves, which are kinetically controlled, can propagate, Diffusion of oxidizer decreases

  16. 40 CFR 74.16 - Application requirements for combustion sources.

    Science.gov (United States)

    2010-07-01

    ... combustion sources. 74.16 Section 74.16 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED... for combustion sources. (a) Opt-in permit application. Each complete opt-in permit application for a combustion source shall contain the following elements in a format prescribed by the Administrator: (1...

  17. Demonstration project: Oxy-fuel combustion at Callide-A plant

    Energy Technology Data Exchange (ETDEWEB)

    Makino, Keiji; Misawa, Nobuhiro; Kiga, Takashi; Spero, Chris

    2007-07-01

    Oxy-fuel combustion is expected to be one of the promising systems on CO2 recovery from pulverized-coal power plant, and enable the CO2 to be captured in a more cost-effective manner compared to other CO2 recover process. An Australia-Japan consortium was established in 2004 specifically for the purpose of conducting a feasibility study on the application of oxy-fuel combustion to an existing pulverized-coal power plant that is Callide-A power plant No.4 unit at 30MWe owned by CS Energy in Australia. One of the important components in this study has been the recent comparative testing of three Australian coals under both oxy-fuel and air combustion conditions using the IHI combustion test facilities. The tests have yielded a number of important outcomes including a good comparison of normal air with oxy-fuel combustion, significant reduction in NOx mass emission rates under oxy-fuel combustion. On the basis of the feasibility study, the project under Australia-Japan consortium is now under way for applying oxy-fuel combustion to an existing plant by way of demonstration. In this project, a demonstration plant of oxy-fuel combustion will be completed by the end of 2008. This project aims at recovering CO2 from an actual power plant for storage. (auth)

  18. Understanding Combustion Processes Through Microgravity Research

    Science.gov (United States)

    Ronney, Paul D.

    1998-01-01

    A review of research on the effects of gravity on combustion processes is presented, with an emphasis on a discussion of the ways in which reduced-gravity experiments and modeling has led to new understanding. Comparison of time scales shows that the removal of buoyancy-induced convection leads to manifestations of other transport mechanisms, notably radiative heat transfer and diffusional processes such as Lewis number effects. Examples from premixed-gas combustion, non-premixed gas-jet flames, droplet combustion, flame spread over solid and liquid fuels, and other fields are presented. Promising directions for new research are outlined, the most important of which is suggested to be radiative reabsorption effects in weakly burning flames.

  19. Combustion of environmentally altered molybdenum trioxide nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Kevin; Pantoya, Michelle L. [Mechanical Engineering Department, Texas Tech University, 2500 Broadway, Lubbock, TX 79409 (United States)

    2006-06-15

    Nanocomposite thermite mixtures are currently under development for many primer applications due to their high energy densities, high ignition sensitivity, and low release of toxins into the environment. However, variability and inconsistencies in combustion performance have not been sufficiently investigated. Environmental interactions with the reactants are thought to be a contributing factor to these variabilities. Combustion velocity experiments were conducted on aluminum (Al) and molybdenum trioxide (MoO{sub 3}) mixtures to investigate the role of environmental interactions such as light exposure and humidity. While the Al particles were maintained in an ambient, constant environment, the MoO{sub 3} particles were exposed to UV or fluorescent light, and highly humid environments. Results show that UV and fluorescent lighting over a period of days does not significantly contribute to performance deterioration. However, a humid environment severely decreases combustion performance if the oxidizer particles are not heat-treated. Heat treatment of the MoO{sub 3} greatly increases the material's ability to resist water absorption, yielding more repeatable combustion performance. This work further quantifies the role of the environment in the decrease of combustion performance of nanocomposites over time. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

  20. Fuel and Additive Characterization for HCCI Combustion

    International Nuclear Information System (INIS)

    Aceves, S M; Flowers, D; Martinez-Frias, J; Espinosa-Loza, F; Pitz, W J; Dibble, R

    2003-01-01

    This paper shows a numerical evaluation of fuels and additives for HCCl combustion. First, a long list of candidate HCCl fuels is selected. For all the fuels in the list, operating conditions (compression ratio, equivalence ratio and intake temperature) are determined that result in optimum performance under typical operation for a heavy-duty engine. Fuels are also characterized by presenting Log(p)-Log(T) maps for multiple fuels under HCCl conditions. Log(p)-Log(T) maps illustrate important processes during HCCl engine operation, including compression, low temperature heat release and ignition. Log(p)-Log(T) diagrams can be used for visualizing these processes and can be used as a tool for detailed analysis of HCCl combustion. The paper also includes a ranking of many potential additives. Experiments and analyses have indicated that small amounts (a few parts per million) of secondary fuels (additives) may considerably affect HCCl combustion and may play a significant role in controlling HCCl combustion. Additives are ranked according to their capability to advance HCCl ignition. The best additives are listed and an explanation of their effect on HCCl combustion is included

  1. Testing fireproof materials in a combustion chamber

    Directory of Open Access Journals (Sweden)

    Kulhavy Petr

    2017-01-01

    Full Text Available This article deals with a prototype concept, real experiment and numerical simulation of a combustion chamber, designed for testing fire resistance some new insulating composite materials. This concept of a device used for testing various materials, providing possibility of monitoring temperatures during controlled gas combustion. As a fuel for the combustion process propane butane mixture has been used and also several kinds of burners with various conditions of inlet air (forced, free and fuel flows were tested. The tested samples were layered sandwich materials based on various materials or foams, used as fillers in fire shutters. The temperature distribution was measured by using thermocouples. A simulation of whole concept of experimental chamber has been carried out as the non-premixed combustion process in the commercial final volume sw Pyrosim. The result was to design chamber with a construction suitable, according to the international standards, achieve the required values (temperature in time. Model of the combustion based on a stoichiometric defined mixture of gas and the tested layered samples showed good conformity with experimental results – i.e. thermal distribution inside and heat release rate that has gone through the sample.

  2. Miniaturization limitations of rotary internal combustion engines

    International Nuclear Information System (INIS)

    Wang, Wei; Zuo, Zhengxing; Liu, Jinxiang

    2016-01-01

    Highlights: • Developed a phenomenological model for rotary internal combustion engines. • Presented scaling laws for the performance of micro rotary engines. • Adiabatic walls can improve the cycle efficiency but result in higher charge leakage. • A lower compression ratio can increase the efficiency due to lower mass losses. • Presented possible minimum engine size of rotary internal combustion engines. - Abstract: With the rapid development of micro electro-mechanical devices, the demands for micro power generation systems have significantly increased in recent years. Traditional chemical batteries have energy densities much lower than hydrocarbon fuels, which makes internal-combustion-engine an attractive technological alternative to batteries. Micro rotary internal combustion engine has drawn great attractions due to its planar design, which is well-suited for fabrication in MEMS. In this paper, a phenomenological model considering heat transfer and mass leakage has been developed to investigate effects of engine speed, compression ratio, blow-by and heat transfer on the performance of micro rotary engine, which provide the guidelines for preliminary design of rotary engine. The lower possible miniaturization limits of rotary combustion engines are proposed.

  3. OxyFuel combustion of Coal and Biomass

    DEFF Research Database (Denmark)

    Toftegaard, Maja Bøg

    The power and heat producing sector is facing a continuously increasing demand to reduce its emissions of CO2. Oxyfuel combustion combined with CO2 storage is suggested as one of the possible, promising technologies which will enable the continuous use of the existing fleet of suspension-fired po......The power and heat producing sector is facing a continuously increasing demand to reduce its emissions of CO2. Oxyfuel combustion combined with CO2 storage is suggested as one of the possible, promising technologies which will enable the continuous use of the existing fleet of suspension......-fired power plants burning coal or other fuels during the period of transition to renewable energy sources. The oxyfuel combustion process introduces several changes to the power plant configuration. Most important, the main part of the flue gas is recirculated to the boiler and mixed with pure oxygen....... The oxidant thus contains little or no nitrogen and a near-pure CO2 stream can be produced by cooling the flue gas to remove water. The change to the oxidant composition compared to combustion in air will induce significant changes to the combustion process. This Ph.D. thesis presents experimental...

  4. Particulate and gaseous emissions from residential biomass combustion

    International Nuclear Information System (INIS)

    Boman, Christoffer

    2005-04-01

    Biomass is considered to be a sustainable energy source with significant potentials for replacing electricity and fossil fuels, not at least in the residential sector. However, present wood combustion is a major source of ambient concentrations of hydrocarbons (e.g. VOC and PAH) and particulate matter (PM) and exposure to these pollutants have been associated with adverse health effects. Increased focus on combustion related particulate emissions has been seen concerning the formation, characteristics and implications to human health. Upgraded biomass fuels (e.g. pellets) provide possibilities of more controlled and optimized combustion with less emission of products of incomplete combustion (PICs). For air quality and health impact assessments, regulatory standards and evaluations concerning residential biomass combustion, there is still a need for detailed emission characterization and quantification when using different fuels and combustion techniques. This thesis summarizes the results from seven different papers. The overall objective was to carefully and systematically study the emissions from residential biomass combustion with respect to: i) experimental characterization and quantification, ii) influences of fuel, appliance and operational variables and iii) aspects of ash and trace element transformations and aerosol formation. Special concern in the work was on sampling, quantification and characterization of particulate emissions using different appliances, fuels and operating procedures. An initial review of health effects showed epidemiological evidence of potential adverse effect from wood smoke exposure. A robust whole flow dilution sampling set-up for residential biomass appliances was then designed, constructed and evaluated, and subsequently used in the following emission studies. Extensive quantifications and characterizations of particulate and gases emissions were performed for residential wood and pellet appliances. Emission factor ranges for

  5. Spray combustion of Jet-A and diesel fuels in a constant volume combustion chamber

    International Nuclear Information System (INIS)

    Jing, Wei; Roberts, William L.; Fang, Tiegang

    2015-01-01

    This work investigates the spray combustion of Jet-A fuel in an optical constant-volume combustion chamber under different ambient initial conditions. Ambient temperature was varied at 800 K, 1000 K, and 1200 K and five different ambient O 2 concentrations were used, spanning 10–21%. These ambient conditions can be used to mimic practical diesel engine working conditions under different fuel injection timings and exhaust gas recirculation (EGR) levels. Both transient and quasi-steady state analyses were conducted. The transient analysis focused on the flame development from the beginning to the end of the combustion process, illustrating how the flame structure evolves with time. The quasi-steady state analysis concentrated on the stable flame structure and compared the flame emissions in terms of spatially integrated intensity, flame effective area, and intensity per pixel. The transient analysis was based on measurements using high-speed imaging of both OH ∗ chemiluminescence and broadband natural luminosity (NL). For the quasi-steady state analysis, three flame narrow-band emissions (OH ∗ at 310 nm, Band A at 430 nm and Band B at 470 nm) were captured using an ICCD camera. Based on the current Jet-A data and diesel data obtained from previous experiments, a comparison between Jet-A and diesel was made in terms of flame development during the transient state and spatially integrated intensity, flame effective area, and intensity per pixel during the quasi-steady state. For the transient results, Jet-A shares a similar flame development trend to diesel, but featuring a narrower region of NL and a wider region of OH ∗ with the increase of ambient temperature and O 2 concentration. The soot cloud is oxidized more quickly for Jet-A than diesel at the end of combustion, evident by comparing the area of NL, especially under high O 2 concentration. The quasi-steady state results suggest that soot is oxidized effectively under high O 2 concentration conditions by

  6. Distillation of combustibles at temperatures below fusion

    Energy Technology Data Exchange (ETDEWEB)

    Dalin, D

    1946-09-26

    A process is described for combustion and distillation for dry fuels, such as bituminous shales, below the temperature of fusion of the ash, for the production of heat, in which the temperature in the charge of fuel forming a vertical column is maintained beneath the temperature of fusion of the ash by a withdrawal of the heat from the combustible charge by means of a fluid absorbing this heat. This fluid being constituted, for example, by water in a suitable form, so that it can be circulated through a convenient cooling system, extending through the different parts of the charge. The fluid circulating also through the desired parts of the charge and absorbing the heat, the quantity of fluid or the surface of absorption increasing with the intensity of the combustion in the part of the combustible charge traversed by the fluid.

  7. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

    Nielsen, Malene; Nielsen, Ole-Kenneth; Plejdrup, Marlene Schmidt

    Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are SO2, NOx, NMVOC, CH4, CO, CO2, N2O, NH3, particulate matter, heavy metals, dioxins, HCB and PAH. The CO2 emission in 2008...... incineration plants. The combustion of wood in residential plants has increased considerably in recent years resulting in increased emission of PAH, particulate matter and CO. The emission of NMVOC has increased since 1990 as a result of both the increased combustion of wood in residential plants...... and the increased emission from lean-burn gas engines. The dioxin emission decreased since 1990 due to flue gas cleaning on waste incineration plants. However in recent years the emission has increased as a result of the increased combustion of wood in residential plants....

  8. Danish emission inventories for stationary combustion plants

    DEFF Research Database (Denmark)

    Nielsen, Malene; Nielsen, Ole-Kenneth; Plejdrup, Marlene Schmidt

    Emission inventories for stationary combustion plants are presented and the methodologies and assumptions used for the inventories are described. The pollutants considered are SO2, NOx, NMVOC, CH4, CO, CO2, N2O, particulate matter, heavy metals, dioxins, HCB and PAH. The CO2 emission in 2007 was 10...... incineration plants. The combustion of wood in residential plants has increased considerably in recent years resulting in increased emission of PAH, particulate matter and CO. The emission of NMVOC has increased since 1990 as a result of both the increased combustion of wood in residential plants...... and the increased emission from lean-burn gas engines. The dioxin emission decreased since 1990 due to flue gas cleaning on waste incineration plants. However in recent years the emission has increased as a result of the increased combustion of wood in residential plants....

  9. International evaluation of the programme on engine-related combustion

    Energy Technology Data Exchange (ETDEWEB)

    Arcoumanis, D [Imperial College, London (United Kingdom); Greenhalgh, D [Cranfield Univ. (United Kingdom); Magnusson, B F [Norwegian Univ. of Science and Technology, Trondheim (Norway); Peters, N [Institut fuer Technische Mechanik, RWTH Aachen (Germany)

    1996-11-01

    The 12 projects in the engine related combustion programme cover the entire range from fundamental and theoretical aspects of combustion to more applied subjects such as engine control. The common denominator in the programme clearly is the internal combustion engine, both the reciprocating as well as the gas turbine engine. Such a large coverage by a relatively small number of projects necessarily leads to an isolation of some of the projects in terms of their subject as well as the methodology that is used. On the other hand, all the research areas of interest in combustion technology are represented by at least one of the projects. These are: mathematical and numerical methods in combustion; modelling of turbulent combustion; laser diagnostics of flows with combustion; studies of engine performance and their control; semi-empirical model development for practical applications. As a conclusion, the evaluation committee believes that the programme is well balanced between fundamental and applied projects. It covers the entire range of modern methodologies that are used on the international level and thereby contributes to the application and further development of these research tools in Sweden

  10. Formation of Co2P in the combustion regime

    International Nuclear Information System (INIS)

    Muchaik, S.V.; Dubrov, A.N.; Lynchak, K.A.

    1983-01-01

    Combustion of the system Co-P produces the compounds Co 2 P, CoP and CoP 3 , the first two being producible in the combustion regime, while for synthesis of stoichiometric Co 2 P at normal argon pressure, an original mixture with a certain excess of phosphorus is required. The present experiments were performed with electrolytic cobalt powder and red phosphorus. As the Co-P mixture is diluted by the final product (Co 2 P) there is a decrease in combustion temperature and rate, unaccompanied by any of the anomalies seen with dilution by cobalt. It can be suggested that although the combustion in the Co-P system and, possibly, i-- other phosphide systems, is not gasless in its kinetic aspects the combustion mechanism is similar to that in gasless systems. It is shown that formation of the phosphide Co=3''P and specimens wyth composition Co-Co 2 P in the combustion regime occurs with participation of a lIqui] phase of eutectic composition. Combustion occurs in a self-oscillating regime. The temperature for Co 2 P formation is close to its melting point, and the process activation energy comprises 205 kJ/mole

  11. Superheated fuel injection for combustion of liquid-solid slurries

    Science.gov (United States)

    Robben, F.A.

    1984-10-19

    A method and device are claimed for obtaining, upon injection, flash evaporation of a liquid in a slurry fuel to aid in ignition and combustion. The device is particularly beneficial for use of coal-water slurry fuels in internal combustion engines such as diesel engines and gas turbines, and in external combustion devices such as boilers and furnaces. The slurry fuel is heated under pressure to near critical temperature in an injector accumulator, where the pressure is sufficiently high to prevent boiling. After injection into a combustion chamber, the water temperature will be well above boiling point at a reduced pressure in the combustion chamber, and flash boiling will preferentially take place at solid-liquid surfaces, resulting in the shattering of water droplets and the subsequent separation of the water from coal particles. This prevents the agglomeration of the coal particles during the subsequent ignition and combustion process, and reduces the energy required to evaporate the water and to heat the coal particles to ignition temperature. The overall effect will be to accelerate the ignition and combustion rates, and to reduce the size of the ash particles formed from the coal. 2 figs., 2 tabs.

  12. Experimental study on combustion and slagging characteristics of tannery sludge

    International Nuclear Information System (INIS)

    Li, Chunyu; Jiang, Xuguang; Fei, Zhenwei; Chi, Yong; Yan, Jianhua

    2010-01-01

    Incineration is the most reasonable technique for tannery sludge disposal. The combustion and gaseous products emission characteristics of tannery sludge were investigated in this study. Tendency of slagging for combustion residue was also investigated based on the composition and microscopic scanning analysis. The high content of volatile matters and ash in tannery sludge was discovered. It was shown that the thermal decomposition and combustion of tannery sludge mainly occurs in a temperature frame between 150 degree Celsius and 780 degree Celsius. Organic acid was determined as the most important gaseous pollutant at low temperature combustion. The combustion residue from a specially designed furnace was analyzed by X-ray diffractometer (XRD) and energy dispersion spectroscopy (EDS) microprobe coupled in a scanning electron micro-scope (SEM). There is large amount of Ca in the combustion residue, and CaO was the main inorganic composition in these residues. The tannery sludge studied in this paper has a strong tendency of slagging, and the fusion of the residue began at 900 degree Celsius in combustion. It was further discovered that almost all the zinc (Zn) in tannery sludge is volatilized at 900 degree Celsius. The degree of volatilization for heavy metals at 900 degree Celsius followed the order of Zn > Cd >Cu > Mn > Pb > Cr. Most of Cr in tannery sludge is enriched in the residue during combustion. The present study reveals that it is critical to control the combustion temperature for optimal combustion efficiency and minimization of pollutants emission. (author)

  13. Novel combustion concepts for sustainable energy development

    CERN Document Server

    Agarwal, Avinash K; Gupta, Ashwani K; Aggarwal, Suresh K; Kushari, Abhijit

    2014-01-01

    This book comprises research studies of novel work on combustion for sustainable energy development. It offers an insight into a few viable novel technologies for improved, efficient and sustainable utilization of combustion-based energy production using both fossil and bio fuels. Special emphasis is placed on micro-scale combustion systems that offer new challenges and opportunities. The book is divided into five sections, with chapters from 3-4 leading experts forming the core of each section. The book should prove useful to a variety of readers, including students, researchers, and professionals.

  14. Flammability characteristics of combustible gases and vapors

    Energy Technology Data Exchange (ETDEWEB)

    Zabetakis, M. G. [Bureau of Mines, Pittsburgh, PA (United States)

    1964-05-01

    This is a summary of the available limit of flammability, autoignition and burning-rate data for more than 200 combustible gases and vapors in air and other oxidants, as well as of empirical rules and graphs that can be used to predict similar data for thousands of other combustibles under a variety of environmental conditions. Spec$c data are presented on the paraffinic, unsaturated, aromatic, and alicyclic hydrocarbons, alcohols, ethers, aldehydes, ketones, and sulfur compounds, and an assortment of fuels, fuel blends, hydraulic fluids, engine oils, and miscellaneous combustible gases and vapors.

  15. 3rd International Conference on Numerical Combustion

    CERN Document Server

    Larrouturou, Bernard; Numerical Combustion

    1989-01-01

    Interest in numerical combustion is growing among applied mathematicians, physicists, chemists, engine manufacturers and many industrialists. This proceedings volume contains nine invited lectures and twenty seven contributions carefully selected by the editors. The major themes are numerical simulation of transsonic and supersonic combustion phenomena, the study of supersonic reacting mixing layers, and turbulent combustion. Emphasis is laid on hyperbolic models and on numerical simulations of hydrocarbon planes with a complete set of chemical reactions carried out in two-dimensional geometries as well as on complex reactive flow simulations.

  16. Free Energy and Internal Combustion Engine Cycles

    OpenAIRE

    Harris, William D.

    2012-01-01

    The performance of one type (Carnot) of Internal Combustion Engine (ICE) cycle is analyzed within the framework of thermodynamic free energies. ICE performance is different from that of an External Combustion Engine (ECE) which is dictated by Carnot's rule.

  17. Soot temperature and KL factor for biodiesel and diesel spray combustion in a constant volume combustion chamber

    KAUST Repository

    Zhang, Ji

    2013-07-01

    This paper presents measurements of the soot temperature and KL factor for biodiesel and diesel combustion in a constant volume chamber using a two-color technique. This technique uses a high-speed camera coupled with two narrowband filters (550. nm and 650. nm, 10. nm FWHM). After calibration, statistical analysis shows that the uncertainty of the two-color temperature is less than 5%, while it is about 50% for the KL factor. This technique is then applied to the spray combustion of biodiesel and diesel fuels under an ambient oxygen concentration of 21% and ambient temperatures of 800, 1000 and 1200. K. The heat release result shows higher energy utilization efficiency for biodiesel compared to diesel under all conditions; meanwhile, diesel shows a higher pressure increase due to its higher heating value. Biodiesel yields a lower temperature inside the flame area, a longer soot lift-off length, and a smaller soot area compared to diesel. Both the KL factor and the total soot with biodiesel are lower than with diesel throughout the entire combustion process, and this difference becomes larger as the ambient temperature decreases. Biodiesel shows approximately 50-100. K lower temperatures than diesel at the quasi-steady stage for 1000 and 1200. K ambient temperature, while diesel shows a lower temperature than biodiesel at 800. K ambient. This result may raise the question of how important the flame temperature is in explaining the higher NO. x emissions often observed during biodiesel combustion. Other factors may also play an important role in controlling NO. x emissions. Both biodiesel and diesel temperature measurements show a monotonic dependence on the ambient temperature. However, the ambient temperature appears to have a more significant effect on the soot formation and oxidation in diesel combustion, while biodiesel combustion soot characteristics shows relative insensitivity to the ambient temperature. © 2013 Elsevier Ltd.

  18. 24 CFR 3280.710 - Venting, ventilation and combustion air.

    Science.gov (United States)

    2010-04-01

    ... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Venting, ventilation and combustion... Fuel Burning Systems § 3280.710 Venting, ventilation and combustion air. (a) The venting as required by... appliance listing and the appliance manufacturer's instructions. (b) Venting and combustion air systems...

  19. Industria y competitividad regional: elementos para una estrategia en el Occidente colombiano

    Directory of Open Access Journals (Sweden)

    Jorge Lotero

    1995-07-01

    Full Text Available El objetivo principal de este estudio es presentar algunos elementos para el diseño de una estrategia de competitividad de la industria manufacturera desde la perspectiva regional. Partiendo de un breve análisis de la industria en el caso de la región del occidente colombiano, se plantea que en el marco de un nuevo modelo de desarrollo económico e industrial, le compete a los entes regionales promover acciones para elevar la competitividad de las actividades económicas. Dichas acciones deben centrarse en la generación de externalidades que incrementan la productividad total de los factores en la industria.

  20. Coal combustion waste management study

    International Nuclear Information System (INIS)

    1993-02-01

    Coal-fired generation accounted for almost 55 percent of the production of electricity in the United States in 1990. Coal combustion generates high volumes of ash and flue gas desulfurization (FGD) wastes, estimated at almost 90 million tons. The amount of ash and flue gas desulfurization wastes generated by coal-fired power plants is expected to increase as a result of future demand growth, and as more plants comply with Title IV of the 1990 Clean Air Act Amendments. Nationwide, on average, over 30 percent of coal combustion wastes is currently recycled for use in various applications; the remaining percentage is ultimately disposed in waste management units. There are a significant number of on-site and off-site waste management units that are utilized by the electric utility industry to store or dispose of coal combustion waste. Table ES-1 summarizes the number of disposal units and estimates of waste contained at these unites by disposal unit operating status (i.e, operating or retired). Further, ICF Resources estimates that up to 120 new or replacement units may need to be constructed to service existing and new coal capacity by the year 2000. The two primary types of waste management units used by the industry are landfills and surface impoundments. Utility wastes have been exempted by Congress from RCRA Subtitle C hazardous waste regulation since 1980. As a result of this exemption, coal combustion wastes are currently being regulated under Subtitle D of RCRA. As provided under Subtitle D, wastes not classified as hazardous under Subtitle C are subject to State regulation. At the same time Congress developed this exemption, also known as the ''Bevill Exclusion,'' it directed EPA to prepare a report on coal combustion wastes and make recommendations on how they should be managed

  1. Construction of combustion models for rapeseed methyl ester bio-diesel fuel for internal combustion engine applications.

    Science.gov (United States)

    Golovitchev, Valeri I; Yang, Junfeng

    2009-01-01

    Bio-diesel fuels are non-petroleum-based diesel fuels consisting of long chain alkyl esters produced by the transesterification of vegetable oils, that are intended for use (neat or blended with conventional fuels) in unmodified diesel engines. There have been few reports of studies proposing theoretical models for bio-diesel combustion simulations. In this study, we developed combustion models based on ones developed previously. We compiled the liquid fuel properties, and the existing detailed mechanism of methyl butanoate ester (MB, C(5)H(10)O(2)) oxidation was supplemented by sub-mechanisms for two proposed fuel constituent components, C(7)H(16) and C(7)H(8)O (and then, by mp2d, C(4)H(6)O(2) and propyne, C(3)H(4)) to represent the combustion model for rapeseed methyl ester described by the chemical formula, C(19)H(34)O(2) (or C(19)H(36)O(2)). The main fuel vapor thermal properties were taken as those of methyl palmitate C(19)H(36)O(2) in the NASA polynomial form of the Burcat database. The special global reaction was introduced to "crack" the main fuel into its constituent components. This general reaction included 309 species and 1472 reactions, including soot and NO(x) formation processes. The detailed combustion mechanism was validated using shock-tube ignition-delay data under diesel engine conditions. For constant volume and diesel engine (Volvo D12C) combustion modeling, this mechanism could be reduced to 88 species participating in 363 reactions.

  2. Combustion of Jordanian oil shale using circulating fluidized bed

    International Nuclear Information System (INIS)

    Hamdan, M.; Al-Azzam, S.

    1998-11-01

    this study re[resents design and manufacturing of a lab-scale circulating fluidized bed (C.F.B) to burn low grade fuel such as Jordanian oil shale. Hydrodynamic properties of C.F.B. were studied like minimum fluidization velocity, circulation flux and carryover rate. a hot run was firstly conducted by the combustion of L.P.G. to start up the combustion process. It proceeds until reaching the minimum burning temperature of oil shale particles, at which time the LPG supply was gradually reduced and oil shale feeding started. soon after reaching a self sustainable condition of oil shale particles, the LPG supply was cut off. The main combustion variables were investigated such as air to fuel ratios, temperature profiles across the bed, exhaust gas analysis and combustion efficiency. a combustion intensity of 859 kg/hr.m 2 and combustion efficiency of 96% were achieved. (authors). 19 refs., 9 tab., 18 fig

  3. Analysis of Turbulent Combustion in Simplified Stratified Charge Conditions

    Science.gov (United States)

    Moriyoshi, Yasuo; Morikawa, Hideaki; Komatsu, Eiji

    The stratified charge combustion system has been widely studied due to the significant potentials for low fuel consumption rate and low exhaust gas emissions. The fuel-air mixture formation process in a direct-injection stratified charge engine is influenced by various parameters, such as atomization, evaporation, and in-cylinder gas motion at high temperature and high pressure conditions. It is difficult to observe the in-cylinder phenomena in such conditions and also challenging to analyze the following stratified charge combustion. Therefore, the combustion phenomena in simplified stratified charge conditions aiming to analyze the fundamental stratified charge combustion are examined. That is, an experimental apparatus which can control the mixture distribution and the gas motion at ignition timing was developed, and the effects of turbulence intensity, mixture concentration distribution, and mixture composition on stratified charge combustion were examined. As a result, the effects of fuel, charge stratification, and turbulence on combustion characteristics were clarified.

  4. Introduction to Physics and Chemistry of Combustion Explosion, Flame, Detonation

    CERN Document Server

    Liberman, Michael A

    2008-01-01

    Most of the material covered in this book deals with the fundamentals of chemistry and physics of key processes and fundamental mechanisms for various combustion and combustion related phenomena in gaseous combustible mixture. It provides the reader with basic knowledge of burning processes and mechanisms of reaction wave propagation. The combustion of a gas mixture (flame, explosion, detonation) is necessarily accompanied by motion of the gas. The process of combustion is therefore not only a chemical phenomenon but also one of gas dynamics. The material selection focuses on the gas phase and

  5. Numerical simulations of turbulent jet ignition and combustion

    Science.gov (United States)

    Validi, Abdoulahad; Irannejad, Abolfazl; Jaberi, Farhad

    2013-11-01

    The ignition and combustion of a homogeneous lean hydrogen-air mixture by a turbulent jet flow of hot combustion products injected into a colder gas mixture are studied by a high fidelity numerical model. Turbulent jet ignition can be considered as an efficient method for starting and controlling the reaction in homogeneously charged combustion systems used in advanced internal combustion and gas turbine engines. In this work, we study in details the physics of turbulent jet ignition in a fundamental flow configuration. The flow and combustion are modeled with the hybrid large eddy simulation/filtered mass density function (LES/FMDF) approach, in which the filtered form the compressible Navier-Stokes equations are solved with a high-order finite difference scheme for the turbulent velocity and the FMDF transport equations are solved with a Lagrangian stochastic method to obtain the scalar (temperature and species mass fractions) field. The hydrogen oxidation is described by a detailed reaction mechanism with 37 elementary reactions and 9 species.

  6. Theoretical Adiabatic Temperature and Chemical Composition of Sodium Combustion Flame

    International Nuclear Information System (INIS)

    Okano, Yasushi; Yamaguchi, Akira

    2003-01-01

    Sodium fire safety analysis requires fundamental combustion properties, e.g., heat of combustion, flame temperature, and composition. We developed the GENESYS code for a theoretical investigation of sodium combustion flame.Our principle conclusions on sodium combustion under atmospheric air conditions are (a) the maximum theoretical flame temperature is 1950 K, and it is not affected by the presence of moisture; the uppermost limiting factor is the chemical instability of the condensed sodium-oxide products under high temperature; (b) the main combustion product is liquid Na 2 O in dry air condition and liquid Na 2 O with gaseous NaOH in moist air; and (c) the chemical equilibrium prediction of the residual gaseous reactants in the flame is indispensable for sodium combustion modeling

  7. Application of the FIRST Combustion model to Spray Combustion

    NARCIS (Netherlands)

    de Jager, B.; Kok, Jacobus B.W.

    2004-01-01

    Liquid fuel is of interest to apply to gas turbines. The large advantage is that liquids are easily storable as compared to gaseous fuels. Disadvantage is that liquid fuel has to be sprayed, vaporized and mixed with air. Combustion occurs at some stage of mixing and ignition. Depending on the

  8. The John Zink Hamworthy combustion handbook, v.1 fundamentals

    CERN Document Server

    Baukal, Charles E

    2012-01-01

    Despite the length of time it has been around, its importance, and vast amounts of research, combustion is still far from being completely understood. Environmental, cost, and fuel consumption issues add further complexity, particularly in the process and power generation industries. Dedicated to advancing the art and science of industrial combustion, The John Zink Hamworthy Combustion Handbook, Second Edition: Volume One - Fundamentals gives you a strong understanding of the basic concepts and theory. Under the leadership of Charles E. Baukal, Jr., top combustion engineers and technologists f

  9. Modeling and simulation of combustion chamber and propellant dynamics and issues in active control of combustion instabilities

    Science.gov (United States)

    Isella, Giorgio Carlo

    A method for a comprehensive approach to analysis of the dynamics of an actively controlled combustion chamber, with detailed analysis of the combustion models for the case of a solid rocket propellant, is presented here. The objective is to model the system as interconnected blocks describing the dynamics of the chamber, combustion and control. The analytical framework for the analysis of the dynamics of a combustion chamber is based on spatial averaging, as introduced by Culick. Combustion dynamics are analyzed for the case of a solid propellant. Quasi-steady theory is extended to include the dynamics of the gas-phase and also of a surface layer. The models are constructed so that they produce a combustion response function for the solid propellant that can be immediately introduced in the our analytical framework. The principal objective mechanisms responsible for the large sensitivity, observed experimentally, of propellant response to small variations. We show that velocity coupling, and not pressure coupling, has the potential to be the mechanism responsible for that high sensitivity. We also discuss the effect of particulate modeling on the global dynamics of the chamber and revisit the interpretation of the intrinsic stability limit for burning of solid propellants. Active control is also considered. Particular attention is devoted to the effect of time delay (between sensing and actuation); several methods to compensate for it are discussed, with numerical examples based on the approximate analysis produced by our framework. Experimental results are presented for the case of a Dump Combustor. The combustor exhibits an unstable burning mode, defined through the measurement of the pressure trace and shadowgraph imaging. The transition between stable and unstable modes of operation is characterized by the presence of hysteresis, also observed in other experimental works, and hence not a special characteristic of this combustor. Control is introduced in the

  10. Combustion and direct energy conversion inside a micro-combustor

    International Nuclear Information System (INIS)

    Lei, Yafeng; Chen, Wei; Lei, Jiang

    2016-01-01

    Highlights: • The flammability range of micro-combustor was broadened with heat recirculation. • The quenching diameter decreased with heat recirculation compared to without recirculation. • The surface areas to volume ratio was the most important parameter affecting the energy conversion efficiency. • The maximum conversion efficiency (3.15%) was achieved with 1 mm inner diameter. - Abstract: Electrical energy can be generated by employing a micro-thermophotovoltaic (TPV) cell which absorbs thermal radiation from combustion taking place in a micro-combustor. The stability of combustion in a micro-combustor is essential for operating a micro-power system using hydrogen and hydrocarbon fuels as energy source. To understand the mechanism of sustaining combustion within the quenching distance of fuel, this study proposed an annular micro combustion tube with recirculation of exhaust heat. To explore the feasibility of combustion in the micro annular tube, the parameters influencing the combustion namely, quenching diameter, and flammability were studied through numerical simulation. The results indicated that combustion could be realized in micro- combustor using heat recirculation. Following results were obtained from simulation. The quenching diameter reduced from 1.3 mm to 0.9 mm for heat recirculation at equivalence ratio of 1; the lean flammability was 2.5%–5% lower than that of without heat recirculation for quenching diameters between 2 mm and 5 mm. The overall energy conversion efficiency varied at different inner diameters. A maximum efficiency of 3.15% was achieved at an inner diameter of 1 mm. The studies indicated that heat recirculation is an effective strategy to maintain combustion and to improve combustion limits in micro-scale system.

  11. Pre-Combustion Carbondioxide Capture in Integrated Gasification Combined Cycles

    Directory of Open Access Journals (Sweden)

    M. Zeki YILMAZOĞLU

    2010-02-01

    Full Text Available Thermal power plants have a significant place big proportion in the production of electric energy. Thermal power plants are the systems which converts heat energy to mechanical energy and also mechanical energy to electrical energy. Heat energy is obtained from combustion process and as a result of this, some harmful emissions, like CO2, which are the reason for global warming, are released to atmosphere. The contribution of carbondioxide to global warming has been exposed by the previous researchs. Due to this fact, clean energy technologies are growing rapidly all around the world. Coal is generally used in power plants and when compared to other fossil energy sources unit electricity production cost is less than others. When reserve rate is taken into account, coal may be converted to energy in a more efficient and cleaner way. The aim for using the clean coal technologies are to eradicate the harmful emissions of coal and to store the carbondioxide, orginated from combustion, in different forms. In line with this aim, carbondioxide may be captured by either pre-combustion, by O2/CO2 recycling combustion systems or by post combustion. The integrated gasification combined cycles (IGCC are available in pre-combustion capture systems, whereas in O2/CO2 recycling combustion systems there are ultrasuper critical boiler technologies and finally flue gas washing systems by amines exists in post combustion systems. In this study, a pre-combustion CO2 capture process via oxygen blown gasifiers is compared with a conventional power plant in terms of CO2 emissions. Captured carbondioxide quantity has been presented as a result of the calculations made throughout the study.

  12. Influencia del portainjerto “Terrano” sobre la acumulación de elementos orgánicos y calidad de pimiento morrón

    Directory of Open Access Journals (Sweden)

    Maria Antonia Flores Cordova

    2018-05-01

    Full Text Available El pimiento morrón es muy susceptible a Phytophthora capsici, por lo que, el uso de portainjertos puede ayudar a reducir la incidencia de enfermedades que afectan la raíz e incrementar y mejorar la calidad del fruto y su composición química. El objetivo del presente estudio fue evaluar el efecto del portainjerto comercial “Terrano” sobre la calidad y la acumulación de elementos orgánicos en la hoja, pedúnculo y pulpa de pimiento morrón (Capsicum annuum L.. El trabajo se estableció en un sistema de malla sombra en Delicias, Chihuahua, México, durante el ciclo de producción 2012, con un diseño experimental factorial 2x2, en un diseño de bloques completos al azar, en donde el factor a fue la variedad: Fascinato y Janette, mientras que, el factor b fue el uso del portainjerto “Terrano” (con y sin injerto, dando cuatro tratamientos: Fascinato/Terrano, Fascinato/sin injertar, Janette/Terrano y Janette/sin Injertar. Se evaluó la acumulación de elementos orgánicos: nitrógeno (N, azufre (S, hidrógeno (H, carbono (C, proteínas, así como, la calidad del pimiento morrón (firmeza, color y peso. Se presentaron diferencias estadísticamente significativas por efecto del portainjerto sobre las variedades estudiadas, este incrementó la acumulación de elementos orgánicos: N, S, y proteína en hoja y pulpa de la variedad Janette, además, incrementó el peso del fruto. El uso del portainjerto “Terrano” podría ser una técnica viable para mejorar la acumulación de elementos orgánicos y calidad del pimiento morrón en las variedades Fascinato y Janette.

  13. Coal-water slurry fuel internal combustion engine and method for operating same

    Science.gov (United States)

    McMillian, Michael H.

    1992-01-01

    An internal combustion engine fueled with a coal-water slurry is described. About 90 percent of the coal-water slurry charge utilized in the power cycle of the engine is directly injected into the main combustion chamber where it is ignited by a hot stream of combustion gases discharged from a pilot combustion chamber of a size less than about 10 percent of the total clearance volume of main combustion chamber with the piston at top dead center. The stream of hot combustion gases is provided by injecting less than about 10 percent of the total coal-water slurry charge into the pilot combustion chamber and using a portion of the air from the main combustion chamber that has been heated by the walls defining the pilot combustion chamber as the ignition source for the coal-water slurry injected into the pilot combustion chamber.

  14. Naphtha vs. dieseline – The effect of fuel properties on combustion homogeneity in transition from CI combustion towards HCCI

    KAUST Repository

    Vallinayagam, R.; An, Yanzhao; S.Vedharaj; Sim, Jaeheon; Chang, Junseok; Johansson, Bengt

    2018-01-01

    The scope of this research study pertains to compare the combustion and emission behavior between naphtha and dieseline at different combustion modes. In this study, US dieseline (50% US diesel + 50% RON 91 gasoline) and EU dieseline (45% EU diesel

  15. The combustion of biomass - the impact of its types and combustion technologies on the emission of nitrogen oxide

    Directory of Open Access Journals (Sweden)

    Mladenović Milica R.

    2016-01-01

    Full Text Available Harmonization of environmental protection and the growing energy needs of modern society promote the biomass application as a replacement for fossil fuels and a viable option to mitigate the green house gas emissions. For domestic conditions this is particularly important as more than 60% of renewables belongs to biomass. Beside numerous benefits of using biomass for energy purposes, there are certain drawbacks, one of which is a possible high emission of NOx during the combustion of these fuels. The paper presents the results of the experiments with multiple biomass types (soybean straw, cornstalk, grain biomass, sunflower oil, glycerin and paper sludge, using different combustion technologies (fluidized bed and cigarette combustion, with emphasis on the emission of NOx in the exhaust gas. A presentation of the experimental installations is given, as well as an evaluation of the effects of the fuel composition, combustion regimes and technology on the NOx emissions. As the biomass combustion took place at temperatures low enough that thermal and prompt NOx can be neglected, the conclusion is the emissions of nitrogen oxides primarily depend on the biomass composition- it is increasing with the increase of the nitrogen content, and decreases with the increase of the char content which provides catalytic surface for NOx reduction by CO. [Projekat Ministarstva nauke Republike Srbije, br. TR33042: Improvement of the industrial fluidized bed facility, in scope of technology for energy efficient and environmentally feasible combustion of various waste materials in fluidized bed i br. III42011: Development and improvement of technologies for efficient use of energy of several forms of agricultural and forest biomass in an environmentally friendly manner, with the possibility of cogeneration

  16. Engine combustion control via fuel reactivity stratification

    Science.gov (United States)

    Reitz, Rolf Deneys; Hanson, Reed M; Splitter, Derek A; Kokjohn, Sage L

    2013-12-31

    A compression ignition engine uses two or more fuel charges having two or more reactivities to control the timing and duration of combustion. In a preferred implementation, a lower-reactivity fuel charge is injected or otherwise introduced into the combustion chamber, preferably sufficiently early that it becomes at least substantially homogeneously dispersed within the chamber before a subsequent injection is made. One or more subsequent injections of higher-reactivity fuel charges are then made, and these preferably distribute the higher-reactivity matter within the lower-reactivity chamber space such that combustion begins in the higher-reactivity regions, and with the lower-reactivity regions following thereafter. By appropriately choose the reactivities of the charges, their relative amounts, and their timing, combustion can be tailored to achieve optimal power output (and thus fuel efficiency), at controlled temperatures (and thus controlled NOx), and with controlled equivalence ratios (and thus controlled soot).

  17. Methane combustion over lanthanum-based perovskite mixed oxides

    Energy Technology Data Exchange (ETDEWEB)

    Arandiyan, Hamidreza [New South Wales Univ., Sydney (Australia). School of Chemical Engineering

    2015-11-01

    This book presents current research into the catalytic combustion of methane using perovskite-type oxides (ABO{sub 3}). Catalytic combustion has been developed as a method of promoting efficient combustion with minimum pollutant formation as compared to conventional catalytic combustion. Recent theoretical and experimental studies have recommended that noble metals supported on (ABO{sub 3}) with well-ordered porous networks show promising redox properties. Three-dimensionally ordered macroporous (3DOM) materials with interpenetrated and regular mesoporous systems have recently triggered enormous research activity due to their high surface areas, large pore volumes, uniform pore sizes, low cost, environmental benignity, and good chemical stability. These are all highly relevant in terms of the utilization of natural gas in light of recent catalytic innovations and technological advances. The book is of interest to all researchers active in utilization of natural gas with novel catalysts. The research covered comes from the most important industries and research centers in the field. The book serves not only as a text for researcher into catalytic combustion of methane, 3DOM perovskite mixed oxide, but also explores the field of green technologies by experts in academia and industry. This book will appeal to those interested in research on the environmental impact of combustion, materials and catalysis.

  18. Combustibility of tetraphenylborate solids

    International Nuclear Information System (INIS)

    Walker, D.D.

    1989-01-01

    Liquid slurries expected under normal in-tank processing (ITP) operations are not ignitible because of their high water content. However, deposits of dry solids from the slurries are combustible and produce dense, black smoke when burned. The dry solids burn similarly to Styrofoam and more easily than sawdust. It is the opinion of fire hazard experts that a benzene vapor deflagration could ignite the dry solids. A tetraphenylborate solids fire will rapidly plug the waste tank HEPA ventilation filters due to the nature of the smoke produced. To prevent ignition and combustion of these solids, the waste tanks have been equipped with a nitrogen inerting system

  19. Studies in combustion dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Koszykowski, M.L. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    The goal of this program is to develop a fundamental understanding and a quantitative predictive capability in combustion modeling. A large part of the understanding of the chemistry of combustion processes comes from {open_quotes}chemical kinetic modeling.{close_quotes} However, successful modeling is not an isolated activity. It necessarily involves the integration of methods and results from several diverse disciplines and activities including theoretical chemistry, elementary reaction kinetics, fluid mechanics and computational science. Recently the authors have developed and utilized new tools for parallel processing to implement the first numerical model of a turbulent diffusion flame including a {open_quotes}full{close_quotes} chemical mechanism.

  20. Study of mechanically activated coal combustion

    Directory of Open Access Journals (Sweden)

    Burdukov Anatolij P.

    2009-01-01

    Full Text Available Combustion and air gasification of mechanically activated micro-ground coals in the flux have been studied. Influence of mechanically activated methods at coals grinding on their chemical activeness at combustion and gasification has been determined. Intense mechanical activation of coals increases their chemical activeness that enables development of new highly boosted processing methods for coals with various levels of metamorphism.