Recursos de colección

Archivo Digital UPM (114.084 recursos)

This is an institutional repository providing access to the research output of the institution. Primarily contains thesis.

Materia = Energías Renovables

Mostrando recursos 1 - 18 de 18

  1. SolarPaces 2013: Innovations on direct steam generation in linear fresnel collectors

    Coco Enriquez, Luis; Muñoz Antón, Javier; Martínez-Val Peñalosa, José María
    Direct Steam Generation (DSG) in Linear Fresnel (LF) solar collectors is being consolidated as a feasible technology for Concentrating Solar Power (CSP) plants. The competitiveness of this technology relies on the following main features: water as heat transfer fluid (HTF) in Solar Field (SF), obtaining high superheated steam temperatures and pressures at turbine inlet (500ºC and 90 bar), no heat tracing required to avoid HTF freezing, no HTF degradation, no environmental impacts, any heat exchanger between SF and Balance Of Plant (BOP), and low cost installation and maintenance. Regarding to LF solar collectors, were recently developed as an alternative to...

  2. Sewage sludge gasification. Dolomite performance under different operating conditions

    Andrés Almeida, Juan Manuel de; Roche, Elena; Narros Sierra, Adolfo; Rodríguez Hurtado, María Encarnación
    Gasification is a technology that can replace traditional management alternatives used up to date to deal with this waste (landfilling, composting and incineration) and which fulfils the social, environmental and legislative requirements. The main products of sewage sludge gasification are permanent gases (useful to generate energy or to be used as raw material in chemical synthesis processes), liquids (tars) and char. One of the main problems to be solved in gasification is tar production. Tars are organic impurities which can condense at relatively high temperatures making impossible to use the produced gases for most applications. This work deals with the...

  3. Energía renovable a partir de los lodos de depuradoras urbanas

    Roche, Elena; Andrés Almeida, Juan Manuel de; Narros Sierra, Adolfo; Rodríguez Hurtado, María Encarnación
    El lodo de depuradora es el residuo líquido o semilíquido procedente de las Estaciones Depuradoras de Aguas Residuales (EDARs) del que puede obtenerse una energía renovable empleando la tecnología de la gasificación. Esta tecnología consiste en la oxidación parcial del sustrato carbonoso del lodo a altas temperaturas bajo condiciones subestequiométricas de aire, oxígeno u otros agentes gasificantes. Los productos obtenidos mediante gasificación son: un gas de síntesis (SYNGAS, con composición variable de H2, CO) un residuo carbonizado (char) y una fracción líquida de compuestos orgánicos de distinto peso molecular denominados alquitranes. El gas de síntesis tiene aplicaciones como son la...

  4. Dry cooling with night cool storage to enhance solar power plants performance in extreme conditions areas

    Muñoz Antón, Javier; Martínez-Val Peñalosa, José María; Abbas Cámara, Rubén; Abánades Velasco, Alberto
    Solar thermal power plants are usually installed in locations with high yearly average solar radiation, often deserts. In such conditions, cooling water required for thermodynamic cycles is rarely available. Moreover, when solar radiation is high, ambient temperature is very high as well; this leads to excessive condensation temperature, especially when air-condensers are used, and decreases the plant efficiency. However, temperature variation in deserts is often very high, which drives to relatively low temperatures during the night. This fact can be exploited with the use of a closed cooling system, so that the coolant (water) is chilled during the night and...

  5. Steady-state thermal analysis of an innovative receiver for linear Fresnel reflectors

    Abbas Cámara, Rubén; Muñoz Antón, Javier; Martínez-Val Peñalosa, José María
    The study of the performance of an innovative receiver for linear Fresnel reflectors is carried out in this paper, and the results are analyzed with a physics perspective of the process. The receiver consists of a bundle of tubes parallel to the mirror arrays, resulting on a smaller cross section for the same receiver width as the number of tubes increases, due to the diminution of their diameter. This implies higher heat carrier fluid speeds, and thus, a more effective heat transfer process, although it conveys higher pumping power as well. Mass flow is optimized for different tubes diameters, different...

  6. Selective ablation with UV lasers of a-Si:H thin film solar cells in direct scribing configuration

    Lauzurica Santiago, Sara; García-Ballesteros Ramírez, Juan José; Colina Brito, Mónica; Sanchez Aniorte, Maria Isabel; Molpeceres Álvarez, Carlos Luis
    Monolithical series connection of silicon thin-film solar cells modules performed by laser scribing plays a very important role in the entire production of these devices. In the current laser process interconnection the two last steps are developed for a configuration of modules where the glass is essential as transparent substrate. In addition, the change of wavelength in the employed laser sources is sometimes enforced due to the nature of the different materials of the multilayer structure which make up the device. The aim of this work is to characterize the laser patterning involved in the monolithic interconnection process in a...

  7. Use of alternative fuels obtained from renowable sources in Brayton cycles

    Escudero Olano, Marcos; Jiménez Alvaro, Ángel; López Paniagua, Ignacio; Rodríguez Martín, Javier
    Analysis and simulation of the behaviour of gas turbines for power generation using different nonconventional fuels obtained from different renewable sources are presented. Three biomass-tobiofuel processes are considered: anaerobic digestion of biomass (biogas), biomass gasification (synthesis gas) and alcoholic fermentation of biomass and dehydration (bioethanol), each of them with two different biomass substrates (energy crops and municipal solid waste) as input. The gas turbine behaviour in a Brayton cycle is simulated both in an isolated operation and in combined cycle. The differences in gas turbine performance when fired with the considered biofuels compared to natural gas are studied from different...

  8. Propuesta de desarrollo para la República Serbia: aplicabilidad de metodologías de sostenibilidad y eficiencia energética.

    Prlainovic, Milica
    Hasta hoy, el hombre ha sido capaz de alcanzar logros inesperados en términos de descubrimientos científicos; se ha desarrollado y ha avanzado de forma constante, al igual que sus investigaciones. Por otro lado, todo esto ha provocado varias consecuencias negativas que van unidas al desarrollo tecnológico. El hombre comenzó a utilizar la energía y los recursos naturales de manera muy egoísta, sin pensar, y sólo en los últimos años ha comenzado a considerar cuáles son los aspectos negativos de sus propios avances. Empezó a preguntarse hasta cuando la naturaleza va a tolerar el agotamiento de los recursos sin cargo. Es evidente...

  9. Influence of laser wavelength on Laser-Fired contacts for crystalline silicon solar cells

    Sanchez Aniorte, Maria Isabel; Muñoz Martín, David; Morales Furió, Miguel; Ortega, Pablo; Martín, Isidro; Colina Brito, Mónica; Alcubilla, R.; Molpeceres Álvarez, Carlos Luis
    In the Laser-Fired Contact (LFC) process, a laser beam fires a metallic layer through a dielectric passivating layer into the silicon wafer to form an electrical contact with the silicon bulk [1]. This laser technique is an interesting alternative for the fabrication of both laboratory and industrial scale high efficiency passivated emitter and rear cell (PERC). One of the principal characteristics of this promising technique is the capability to reduce the recombination losses at the rear surface in crystalline silicon solar cells. Therefore, it is crucial to optimize LFC because this process is one of the most promising concepts to...

  10. Use of alternative fuels obtained from renewable sources in brayton cycles

    Escudero Olano, Marcos; Jiménez Alvaro, Ángel; López Paniagua, Ignacio; Rodríguez Martín, Javier
    Analysis and simulation of the behaviour of gas turbines for power generation using different nonconventional fuels obtained from different renewable sources are presented. Three biomass-tobiofuel processes are considered: anaerobic digestion of biomass (biogas), biomass gasification (synthesis gas) and alcoholic fermentation of biomass and dehydration (bioethanol), each of them with two different biomass substrates (energy crops and municipal solid waste) as input. The gas turbine behaviour in a Brayton cycle is simulated both in an isolated operation and in combined cycle. The differences in gas turbine performance when fired with the considered biofuels compared to natural gas are studied from different...

  11. Métodos para la estimación de la temperatura estática de la formación en yacimientos de petróleo y geotérmicos

    Rodríguez Martín, Javier; López Paniagua, Ignacio; Jiménez Alvaro, Ángel; Nieto Carlier, Rafael; González Fernández, M. Celina
    Las empresas explotadoras de yacimientos de petróleo y geotérmicos diseñan y construyen sus instalaciones optimizándolas según dos características especialmente representativas: su temperatura y su presión. Por ello, tener información precisa sobre ambos aspectos lo antes posible puede permitir ahorros importantes en las inversiones en infraestructuras y también acortar los plazos de comienzo de explotación; ambos, aspectos esenciales en la rentabilidad del yacimiento. La temperatura estática de una formación es la temperatura existente antes del inicio de las tareas de perforación del yacimiento. Las operaciones de perforación tienen como objetivo perforar, evaluar y terminar un pozo para que produzca de una...

  12. Air-steam gasification of sewage sludge in a bubbling bed reactor: Effect of alumina as a primary catalyst

    Andrés Almeida, Juan Manuel de; Narros Sierra, Adolfo; Rodríguez Hurtado, María Encarnación
    Numerous references can be found in scientific literature regarding biomass gasification. However, there are few works related to sludge gasification. A study of sewage sludge gasification process in a bubbling fluidised bed gasifier on a laboratory scale is here reported. The aim was to find the optimum conditions for reducing the production of tars and gain more information on the influx of different operating variables in the products resulting from the gasification of this waste. The variables studied were the equivalence ratio (ER), the steam-biomass ratio (SB) and temperature. Specifically, the ER was varied from 0.2 to 0.4, the SB...

  13. Behaviour of dolomite, olivine and alumina as primary catalysts in air-steam gasification of sewage sludge

    Andrés Almeida, Juan Manuel de; Narros Sierra, Adolfo; Rodríguez Hurtado, María Encarnación
    Sewage sludge gasification assays were performed in an atmospheric fluidised bed reactor using air and air–steam mixtures as the gasifying agents. Dolomite, olivine and alumina are three well known tar removal catalysts used in biomass gasification processing. However, little information is available regarding their performance in sewage sludge gasification. The aim of the current study was to learn about the influence of these three catalysts in the product distribution and tar production during sewage sludge gasification. To this end, a set of assays was performed in which the temperature (750–850 °C), the in-bed catalyst content (0, 10 and 15 wt.%)...

  14. Laser-fired contact optimization in c-Si solar cells

    Ortega, P.; Orpella, A.; Martin, I.; Lopez, G.; Voz, C.; Sanchez Aniorte, Maria Isabel; Molpeceres Álvarez, Carlos Luis; Alcubilla, R.
    In this work we study the optimization of laser-fired contact (LFC) processing parameters, namely laser power and number of pulses, based on the electrical resistance measurement of an aluminum single LFC point. LFC process has been made through four passivation layers that are typically used in c-Si and mc-Si solar cell fabrication: thermally grown silicon oxide (SiO2), deposited phosphorus-doped amorphous silicon carbide (a-SiCx/H(n)), aluminum oxide (Al2O3) and silicon nitride (SiNx/H) films. Values for the LFC resistance normalized by the laser spot area in the range of 0.65–3 mΩ cm2 have been obtained

  15. Diseño y construcción de un banco de ensayos para la caracterización de inversores fotolvoltaicos autónomos en la Universidad Nacional de Ingeniería (Perú)

    Garrido Velasco, Zaida
    La electrificación rural fotovoltaica es cada vez más una necesidad vital para el completo abastecimiento eléctrico en Perú. La gran extensión del país y su diversidad hacen imposible el acceso de la red eléctrica a muchas zonas. Por este motivo se están realizando proyectos, normas y si están promoviendo acciones de cooperación internacional que permitan asegurar la calidad eléctrica, reforzar el sistema eléctrico y promover el uso sostenible de energía. Uno de los componentes de los sistemas fotovoltaicos es el inversor. Su función es la de transformar corriente continua (DC) en corriente alterna (AC). El uso de este componente se...

  16. Planificación Rural Sostenible en el Distrito de Coixtlahuaca, Oaxaca, México

    Serra Varela, María Jesús
    El presente proyecto responde a una serie de problemas y carencias presentes en el distrito de Coixtlahuaca, Oaxaca, México. Esta zona, caracterizada por altos índices de marginalidad y pobreza, tiene una economía basada en la agricultura y la ganadería de subsistencia. La necesidad a la que se ven sometidas las familias para sobrevivir, ha provocado una gran presión sobre los recursos naturales, causando la deforestación masiva y pérdidas paulatinas de productividad en los cultivos. Esto ha tenido repercusiones aún mayores, ya que la pérdida de propiedades del suelo, ha dado lugar a un descenso en el recargo de acuíferos y...

  17. Optimization of interferometric photonic cells for biochemical sensing based on advanced high sensitivity optical techniques

    Casquel del Campo, Rafael; Holgado Bolaños, Miguel; Molpeceres Álvarez, Carlos Luis; Morales Furió, Miguel; Ocaña Moreno, José Luis
    The integration between micro-nano fluidics and optics is a new emerging research field, with promising high impact applications in the area of optical biosensing devices. This is the case of tunable Mach-Zehnder interferometers, photonic crystals and ring resonators, which have been demonstrated recently. Recent investigations1 have demonstrated that by combination of the simultaneous used of Ellipsometry, Reflectometry and Spectrometry based technologies broadly used in semiconductor industry at sub-micron spot-size level and advanced photonic structures, a relevant improvement can be achieved at the level of performance of the current state of the art for label-free biosensing and nano-fluidics metrology. The variation...

  18. Avances en la fabricación de células y módulos fotovoltaicos de silicio en capa fina mediante láser

    Fernández Robledo, Susana; Lauzurica Santiago, Sara; García-Ballesteros Ramírez, Juan José; Molpeceres Álvarez, Carlos Luis; Guadaño Ayuso, Gonzalo; Allen-Perkins, F.; Ocaña Moreno, José Luis
    El láser es un instrumento omnipresente en la fabricación de módulos fotovoltaicos. Los láser estándar para la interconexión monolítica de dispositivos de lámina delgada de a-Si son láser de estado sólido bombeados por diodo (DPSS) emitiendo en longitudes IR (λ=1064 nm) y en VIS (λ=532 nm). En este trabajo mostramos estudios de ablación de algunos materiales fotovoltaicos (óxidos conductores transparentes (OCT) y a-Si) con láser emitiendo en UV en el régimen de nanosegundos (ns). La afección térmica resultante en la ablación es menor, y por tanto se reduciría el riesgo de cortocircuitos en la interconexión monolítica, convirtiendo a las fuentes...

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