Design and construction of a height caliper of labyrinths seals of high power steam turbines; Diseno y construccion de un calibrador de alturas para sellos laberintos de turbinas de vapor de alta potencia

Energy Technology Data Exchange (ETDEWEB)

Quinonez Osuna, Jose R. [Instituto Tecnologico de Mazatlan, Mazatlan, Sinaloa (Mexico); Mazur Czerwiec, Zdzislaw [instituto de Investigaciones Electicas, Cuernavaca, Morelos (Mexico); Valdez Valdez, Omar [Instituto Tecnologico de Mazatlan, Mazatlan, Sinaloa (Mexico)

2007-11-15

This article presents the development of a new instrument that allows calibrating with exactness the labyrinths seals height of the radial type, normally used in steam turbines and many other turbo-machines. The calibration process derived from the application of the designed instrument is distinguished from the existing one in the fact of considering a perpendicularity reference that allows high exactness in the measurement of height differences (0,008 mm), which is performed at the moment of adjusting the steam seals each time that its sheets are substituted for new ones. Such characteristic, allows therefore, higher efficiency conditions, stability and trustworthiness in the unit operation, once maintenance of this kind has been applied to it. The lack of monitoring and periodic maintenance of the gaps between seals and rotor constitutes the main cause of efficiency loss in power plant turbines installed in Mexico, generating wastes of up to 4% of its capacity, which represents 15 MW in high power units. [Spanish] El articulo representa el desarrollo de un nuevo instrumento que permite calibrar con exactitud las alturas de los sellos laberinticos de tipo radial, ordinariamente empleados en turbinas de vapor y en muchas otras turbo-maquinas. El proceso de calibracion derivado de la aplicacion del instrumento disenado se distingue del existente, en el hecho de considerar una referencia de perpendicularidad que permite alta precision en la medicion de diferencias de altura (0.008 mm.), lo cual es realizado en el momento de ajustar los sellos de vapor cada vez que sus laminas son sustituidas por nuevas. Dicha caracteristica, procura por ende condiciones mayores de eficiencia, estabilidad y confiabilidad en la operacion de la unidad, una vez que le ha sido brindado un mantenimiento de esta naturaleza. La falta de monitoreo y mantenimiento periodico de los claros entre sellos y rotor, constituye la principal causa de perdida de eficiencia en las turbinas de las

Diseño y construcción de una turbina Pelton para generación eléctrica, capacidad 2 kW

OpenAIRE

Bustamante Cabrera, Edwin José; Arias Reyes, Cristian Paúl

2008-01-01

Las turbinas Pelton, se conocen como turbinas de presión por ser ésta constante en la zona del rodete, de chorro libre, de impulsión, o de admisión parcial por ser atacada por el agua sólo una parte de la periferia del rodete. Así mismo entran en la clasificación de turbinas tangenciales y turbinas de acción.

Cálculo de la transmisión paralela helicoidal de la caja multiplicadora de una turbina eólica

Directory of Open Access Journals (Sweden)

César Alberto Chagoyén-Méndez

2014-01-01

Full Text Available La caja multiplicadora de una turbina eólica es el componente de mayor complejidad mecánica y es la responsable de la mayoría de la pérdida de tiempo operacional de la turbina y del incremento de los costos. La misma no alcanza una vida proyectada de 20 años. Todos los estudios hasta el momento indican que estas fallas surgen desde el proceso de diseño. Este trabajo tuvo como objetivo demostrar algunas de las insuficiencias de las normas actuales de diseño de las cajas multiplicadoras de las turbinas eólicas, a través de la realización de una comparación de los resultados del cálculo de la transmisión paralela helicoidal de una turbina eólica de 2,5 MW, realizados por tres vías: con las normas ISO 6336:2006 Método B y AGMA 2101-D04 ( Metric Edition y mediante simulación numérica. De este análisis resulta que no existen problemas de resistencia ni de rigidez en ambas transmisiones, sin embargo la diferencia entre estos tres métodos de cálculo es considerable.

Análise termodinâmica de um ciclo de potência com célula a combustível sofc e turbina a vapor - DOI: 10.4025/actascitechnol.v28i1.1287

Directory of Open Access Journals (Sweden)

Alexandre Sordi

2006-03-01

Full Text Available O objetivo deste artigo foi realizar a análise termodinâmica de um sistema híbrido, SOFC / ST (célula a combustível tipo SOFC e turbina a vapor ST. O combustível considerado para a análise foi o gás metano (biogás produzido por meio da digestão anaeróbica de resíduos orgânicos. A metodologia utilizada foi o balanço de energia do sistema SOFC / ST, considerando a reforma interna do metano na célula a combustível, de forma a obter a sua eficiência elétrica. O resultado foi comparado a um ciclo combinado convencional de turbina a gás e turbina a vapor (GT / ST para potências entre 10 MW e 30 MW. A eficiência do sistema híbrido SOFC / ST variou de 61% a 66% em relação ao poder calorífico do metano; e a eficiência do ciclo combinado GT / ST variou de 41% a 55% para o mesmo intervalo de potência. Para geração distribuída a célula a combustível SOFC é a tecnologia mais eficiente.

Detección de cavitación en turbina Francis

OpenAIRE

Pedro Ayuso, Jorge-Mauro de

2004-01-01

En el presente proyecto se pretenden aplicar y validar diversas técnicas de detección de cavitación, prestando especial atención a los fenómenos de cavitación erosiva, pues son estos los que mayor impacto pueden tener –en términos de reducción de la vida útil- sobre las turbinas hidráulicas. Tras una introducción teórica sobre el fenómeno de la cavitación en turbinas hidráulicas, se hace un breve recorrido por el estado del arte. A continuación, se presentan una serie de med...

Investigación y Desarrollo Experimental de una Turbina de Flujo Horizontal para el aprovechamiento de las corrientes de Río y su Conversión en Energía Térmica

OpenAIRE

Rivera, Zara Mariela

2013-01-01

Las corrientes de río son un recurso que se encuentra disponible a lo largo del territorio del País y cuyo potencial aún no ha sido aprovechado para la generación de energía con pequeñas turbinas. En este proyecto se presenta una turbina de eje horizontal para transformar la energía cinética de las corrientes de río en energía térmica o eléctrica, y suministrarlas a sectores rurales que carecen de este tipo de abastecimiento. Después de realizar el análisis de algunos ríos en función de los p...

Automatic diagnosis of steam turbines in line; Diagnostico automatico de turbinas de vapor en linea

Energy Technology Data Exchange (ETDEWEB)

Pensado Vassallo, Enlai

2008-05-15

o confiabilidad. De esta manera, siendo la energia nuclear la unica alternativa viable para sustituir la quema de combustibles fosiles en plantas termoelectricas, con antecedentes como el accidente de Three Mile Island en 1979 o el desastre de Chernobil en 1986, han llevado a no despreciar los riesgos relacionados. Lo cual complica su manejo y en consecuencia ha limitado la proliferacion de mas centrales nucleares. Bajo esta realidad, la problematica se concentra en dos tares: aumentar el rendimiento de las plantas termoelectricas y reducir la emision de contaminantes, tanto gases como liquidos. Por todo esto, y en cumplimiento con los valores expresados en la mision y vision del Instituto de Investigaciones Electrica (IIE), se ha seleccionado desarrollar una herramienta de apoyo para el estudio del estado de equipos rotativos remotos. Para ello, tomando como base la experiencia del IIE en el diagnostico de turbinas de vapor, se ha desarrollado una plataforma capaz de determinar la presencia de fallas a traves del modelado de la turbina y sus elementos, se representa el comportamiento esperado y, mediante la transformacion de las senales recolectadas del sistema, se calcula el comportamiento real del equipo. Con ambos resultados se procede a aplicar una tecnica de diagnostico que permita detectar las desviaciones e inferir los desperfectos existentes. Buscando mejorar la certeza y calidad de los resultados del analisis, como complemento, se ejecuta revision de las reglas de diagnostico, con base en el registro historico de diagnosis realizada y empleando un algoritmo genetico para la inclusion de reglas nuevas, las cuales se evaluan como candidatas para la mejora del producto. Este documento representa los esfuerzos de mas de un ano en el area de diagnostico, en busca de la adecuada arquitectura para una infraestructura de diagnostico remoto que permita la deteccion de fallas en centrales con turbina de vapor. El principal reto de crear esta infraestructura es la

Re-diseño de la línea de ejes de turbinas Francis de salto elevado para la mejora de su competitividad

OpenAIRE

GARCÍA MÓNACO, ALEJANDRO

2015-01-01

El objetivo de este proyecto es mejorar la línea de ejes de las turbinas Francis de eje horizontal. En especial, se ha trabajado con aquellas máquinas diseñadas para funcionar con saltos de agua elevados. El proyecto surge del conocimiento de importantes ventajas económicas de las turbinas horizontales frente a las verticales y de la voluntad por parte de ALSTOM HYDRO de mejorar los rendimientos de las primeras para hacerlas más competitivas. Los capítulos 3 y 4 son introductorios a la pro...

Rehabilitation and extension of the useful operating life of a high pressure casing of the 75 MW steam turbine of the thermoelectric power plant President Juarez in Rosarito, B.C.; Rehabilitacion y extension de vida util de una carcasa de alta presion de la turbina de vapor de 75 MW de la central termoelectrica Presidente Juarez en Rosarito, B.C.

Energy Technology Data Exchange (ETDEWEB)

Mazur C, Zdzislaw; Hernandez R, Alejandro; Luna R, Alberto [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Fernandez, Rafael; Nieblas, Enrique [Comision Federal de Electricidad, Rosarito, Baja California (Mexico)

2004-07-01

The effective operation of the steam turbines is important to the world industries, but as all machinery, it is necessary to constantly examine and give maintenance to this equipment with the purpose of producing better results. Yet, many steam turbines arrive at an operation period of 30 or 40 years, over their original design capacity. A factor like this, only augments the probabilities of future problems with the casings, such as: thermal fatigue fissures, deformation of the horizontal union and erosion problems in the low pressure housings. The deformation of the casing can affect its capacity to maintain aligned the stationary parts of the turbine, as a consequence, damages can appear in the fixed and rotary components by interference or friction. Also, the water induction can deform the casing to such a degree that, the alignment of the stationary parts is altered until it causes contact and friction between stationary and rotary parts. However, depending on the type and degree of the casing deformation, different methods of rehabilitation can be applied. The core goal is to recover the planarity of the union of the flanges, re-machining the plane of the flange of the upper and lower casing or, alternatively, to carry out a scraping by hand. [Spanish] El funcionamiento eficaz de las turbinas de vapor es importante para las industrias del mundo, pero como toda maquinaria, es necesario examinar y dar mantenimiento constantemente a este equipo con la finalidad de producir mejores resultados. Con todo, muchas turbinas de vapor llegan a un periodo de operacion de 30 o 40 anos, por encima de su capacidad de diseno original. Un factor como este, solo eleva las probabilidades de futuros problemas con las carcasas, tales como: fisuras por fatiga termica, deformacion de la union horizontal y problemas de erosion en las carcasas de baja presion. La deformacion de la carcasa puede afectar su capacidad para mantener alineadas las partes estacionarias de la turbina, como

Code for the steam tables for pure water in visual basic 6.0.; Un codigo para las tablas de vapor para agua pura en visual basic 6.0

Energy Technology Data Exchange (ETDEWEB)

Verma, Mahendra P. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2002-07-01

The thermodynamic data of the water are of extreme importance in all of the branches of science and technology; the facilitate the understanding of the natural Earth processes. Nevertheless, for the electrical industry the water plays a very important role during the generation of electrical energy process. Different heat sources such as coal, oil, natural gas, nuclear fuel or the geothermal heat boil the water that forms the steam used to move the turbines. Consequently, the steam tables (the thermodynamic water data) are vital to model thermal and mass transference and physical-chemical processes during the generation of electrical energy. [Spanish] Los datos termodinamicos del agua son de suma importancia en todas las ramas de la ciencia y tecnologia, ellos facilitan el entendimiento de los procesos naturales de la Tierra. Sin embargo, para la industria electrica el agua juega un papel muy importante durante el proceso de generacion de energia electrica. Diferentes fuentes de calor tales como carbon, aceite, gas natural, combustible nuclear o el calor geotermico calientan el agua que forma el vapor utilizado para mover las turbinas. Luego entonces, las tablas de vapor (los datos termodinamicos de agua) son vitales para modelar transferencia termica y de masa y procesos fisico-quimico durante la generacion energia electrica.

Estudio termodinámico de una planta de ciclo combinado con turbina de gas y pre-diseño del HRSG

OpenAIRE

Martín Díaz, Carlos Daniel

2015-01-01

Dentro del gran alcance que se puede dar a los estudios de plantas de ciclos combinados, el presente estudio se centra en analizar un ciclo combinado convencional con turbina de gas, y en condiciones de diseño. En concreto, se trata de realizar un análisis termodinámico de un ciclo combinado en configuración monoeje 1x1 con recalentamiento y tres niveles de presión, con turbina de gas refrigerada por sistema vapor-aire y posteriormente un análisis de transferencia de calor en los intercamb...

Analysis of the malfunctioning and failure of a 15 MW hydraulic turbine; Analisis de malfuncionamiento y de falla de una turbina hidraulica de 15 MW

Energy Technology Data Exchange (ETDEWEB)

Garcia Illescas, R.; Perez Rodriguez, N. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2007-11-15

A case history is presented of the rehabilitation process of three hydraulic turbines with a capacity of 15 MW each one. Such units are used for electric power generation, mainly to supply part of the center zone of the Mexican Republic. The turbo-generator units had been practically destroyed by catastrophic floods and only part of the equipment was recovered and reconditioned for its operation. One of the three turbines presented serious functioning problems preventing its reliable operation that was evidenced by excessive mechanical vibrations and heating in the bearing zone. This paper presents the diagnosis of the possible causes of failure and the corrective measures taken. Serious rotor misalignment problems were observed respect to its bearings and the turbine scroll. Additionally, during the inspection of the turbine runner and of the bearing it was observed that important friction have existed, which incremented the vibrations. It is shown that such rubbings are not the cause of the problem but only a manifestation of the same. Finally some of the conclusions and their solution are presented. [Spanish] Se presenta un caso historico del proceso de rehabilitacion de tres turbinas hidraulicas con capacidad de 15 MW cada una. Dichas unidades son empleadas en la generacion electrica, principalmente para abastecer parte de la zona centro de la republica mexicana. Las unidades turbogeneradores habian sido practicamente destruidas por inundaciones catastroficas y solo parte del equipo fue rescatado y rehabilitado para su operacion. Una de las tres turbinas presento graves problemas de funcionamiento, impidiendo su operacion confiable, lo cual se manifestaba mediante vibraciones mecanicas excesivas y calentamiento en zona de chumaceras. En este articulo se presenta el diagnostico de las posibles causas de falla y las acciones correctivas tomandas. Se observan problemas fuertes de desalineamiento del rotor respecto a sus chumaceras y al caracol de la turbina

Analysis of the fault and malfunctioning of a 15 MW hydraulic turbine; Analisis de la falla y malfuncionamiento de una turbina hidraulica de 15 MW

Energy Technology Data Exchange (ETDEWEB)

Garcia I, Rafael; Perez R, Norberto [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2007-07-01

An historical case of the rehabilitation process of three hydraulic turbines with capacity of 15 MW each is presented. These units are used for the electrical generation, mainly to supply part of the central zone of the Mexican Republic. The turbo-generator units had been practically destroyed by catastrophic floods and only part of the equipment was rescued and rehabilitated for its operation. One of the three turbines presented serious operational problems, preventing its reliable operation evidenced by the excessive mechanical vibrations and heating of the bearing zone. This article presents the diagnosis of the possible causes of fault and the remedial actions taken. Strong misalignment problems of the runner with respect to its bearings and to the scroll case of the turbine are observed. In addition, during the inspection of the turbine runner and of the bearings it is observed that important frictions have existed, which increased the vibrations. It is shown that these frictions are not the cause of the problem but only one manifestation of the same. Finally some conclusions of the problem and their solution are presented. [Spanish] Se presenta un caso historico del proceso de rehabilitacion de tres turbinas hidraulicas con capacidad de 15 MW cada una. Dichas unidades son empleadas en la generacion electrica, principalmente para abastecer parte de la zona centro de la Republica Mexicana. Las unidades turbogeneradores habian sido practicamente destruidas por inundaciones catastroficas y solo parte del equipo fue rescatado y rehabilitado para su operacion. Una de las tres turbinas presento graves problemas de funcionamiento, impidiendo su operacion confiable, lo cual se manifestaba mediante vibraciones mecanicas excesivas y calentamiento en zona de chumaceras. En este articulo se presenta el diagnostico de las posibles causas de falla y las acciones correctivas tomadas. Se observan problemas fuertes de desalineamiento del rotor respecto a sus chumaceras y al

Diseño constructal de álabes de turbina de gas refrigerados mediante conductos elipticos

OpenAIRE

Bosc, Cristian

2017-01-01

Las turbinas de gas (en adelante TG), son máquinas térmicas utilizadas para transformar la energía liberada en la combustión de un hidrocarburo, en potencia o trabajo. La parte crítica en el diseño de una TG, recae en las secciones expuestas a condiciones extremas. La temperatura de entrada al rotor (RIT, por sus siglas en inglés, “rotor inlet temperature”) es la variable crítica que limita la eficiencia y la durabilidad. La eficiencia está limitada por la máxima temperatura que pueden soport...

Combined cycle simulator with gas turbine and steam turbine with one vaporization stage; Simulador de ciclo combinado con turbina de gas y de vapor con un nivel de vaporizacion

Energy Technology Data Exchange (ETDEWEB)

Del Valle Cardenas, B.; Lugo Leyte, R. [Universidad Autonoma Metropolitana, Depto de Ingenieria de Procesos e Hidraulica, Mexico, D. F. (Mexico); Toledo Velazquez, Miguel; Tolentino Eslava, G. [Seccion de Estudios de Posgrado e Investigacion, Laboratorio de Ingenieria Termica e Hidraulica Aplicada, ESIME-IPN-COFFA, Mexico, D. F. (Mexico)

1998-12-31

This paper shows the thermal analysis of a combined cycle with gas and steam turbines with one vaporization stage. The analysis is performed through a computer program, which allows the simulation of cycles with different operational conditions, obtaining this way a series of results that permits to know the way these cycles behave in effecting temperature and pressure changes; besides of being an excellent tool in thermodynamics for the user. The simulators were performed in Borland C++ and Builder C++ Versions 4.5 and 2.0 respectively, creating in this way a friendly ambient for the user. This tool offers the opportunity to all its users the ability to simulate combined cycles in a fast and easy way in order to obtain a wider understanding of its thermodynamic behavior. [Espanol] En el presente trabajo se muestra el analisis termico de un ciclo combinado con turbinas de gas y de vapor con un nivel de vaporizacion. El analisis se realiza a traves de un programa de computo, el cual permite simular los ciclos con diferentes condiciones de operacion, obteniendo con esto una serie de resultados que permiten conocer la forma en que trabajan estos ciclos al realizar cambios en temperaturas y presiones; ademas de que es una excelente herramienta para el usuario en termodinamica. Los simuladores fueron realizados en Borland C++ y Builder C++ Versiones 4.5 y 2.0 respectivamente, creandose asi un ambiente amigable para el usuario. Esta herramienta brinda la oportunidad a todos los usuarios de poder simular ciclos combinados de una manera rapida y sencilla con el fin de obtener una comprension mas amplia de su comportamiento termodinamico.

Combined cycle simulator with gas turbine and steam turbine with one vaporization stage; Simulador de ciclo combinado con turbina de gas y de vapor con un nivel de vaporizacion

Energy Technology Data Exchange (ETDEWEB)

Del Valle Cardenas, B; Lugo Leyte, R [Universidad Autonoma Metropolitana, Depto de Ingenieria de Procesos e Hidraulica, Mexico, D. F. (Mexico); Toledo Velazquez, Miguel; Tolentino Eslava, G [Seccion de Estudios de Posgrado e Investigacion, Laboratorio de Ingenieria Termica e Hidraulica Aplicada, ESIME-IPN-COFFA, Mexico, D. F. (Mexico)

1999-12-31

This paper shows the thermal analysis of a combined cycle with gas and steam turbines with one vaporization stage. The analysis is performed through a computer program, which allows the simulation of cycles with different operational conditions, obtaining this way a series of results that permits to know the way these cycles behave in effecting temperature and pressure changes; besides of being an excellent tool in thermodynamics for the user. The simulators were performed in Borland C++ and Builder C++ Versions 4.5 and 2.0 respectively, creating in this way a friendly ambient for the user. This tool offers the opportunity to all its users the ability to simulate combined cycles in a fast and easy way in order to obtain a wider understanding of its thermodynamic behavior. [Espanol] En el presente trabajo se muestra el analisis termico de un ciclo combinado con turbinas de gas y de vapor con un nivel de vaporizacion. El analisis se realiza a traves de un programa de computo, el cual permite simular los ciclos con diferentes condiciones de operacion, obteniendo con esto una serie de resultados que permiten conocer la forma en que trabajan estos ciclos al realizar cambios en temperaturas y presiones; ademas de que es una excelente herramienta para el usuario en termodinamica. Los simuladores fueron realizados en Borland C++ y Builder C++ Versiones 4.5 y 2.0 respectivamente, creandose asi un ambiente amigable para el usuario. Esta herramienta brinda la oportunidad a todos los usuarios de poder simular ciclos combinados de una manera rapida y sencilla con el fin de obtener una comprension mas amplia de su comportamiento termodinamico.

The decrease of the energy performance for the soiling of the air filters in gas turbines; Disminucion de la eficiencia energetica por ensuciamiento de filtros de aire en turbinas de gas

Energy Technology Data Exchange (ETDEWEB)

Romero Paredes, H.; Ambriz, J. J.; Vargas, M.; Godinez, M.; Gomez, F.; Valdez, L.; Pantoja, G. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Mexico D. F. (Mexico)

1995-12-31

The object of this paper is to study the effect in the turbine output of a gas turbine of the conditions of the compressor air inlet in going through a series of filters. The algorithm for the calculation of the energy losses due to the variation of the pressure drop caused by the filters according to their cleanliness condition. In the first part the series of variables that affect the gas turbines performance are exemplified, afterwards the characteristics of the air flow into a turbine are presented as well as their effects on the system. Later on, the results obtained of the system simulation are presented and compared with a real case. From the results it can be determined, that depending on the system and on the environment conditions the efficiency drop might be up to 3%, in accordance with the filters cleanliness. The maintenance periods strongly depend on the air quality variations at the filter house inlet in the zone where the power plant is located. [Espanol] El presente trabajo tiene por objetivo estudiar el efecto en la potencia generada en una turbina de gas de las condiciones de entrada del aire al compresor de una turbina de gas al pasar por un conjunto de filtros. Se presenta el algoritmo para la determinacion de las perdidas energeticas debidas a la variacion de la caida de presion generada por los filtros de acuerdo con su estado de limpieza. En la primera parte se ejemplifica el conjunto de variables que influyen en la eficiencia de las turbinas de gas, posteriormente se mencionan las caracteristicas de flujo de aire hacia una turbina y se muestran los efectos sobre el sistema. A continuacion se presentan los resultados obtenidos de la simulacion del sistema y se comparan con un caso real. De los resultados se puede apreciar que, dependiendo del sistema y de las condiciones ambientales el decremento en la eficiencia puede ser hasta del 3% en funcion del nivel de limpieza de los filtros. Los periodos de mantenimiento dependen fuertemente de las

The decrease of the energy performance for the soiling of the air filters in gas turbines; Disminucion de la eficiencia energetica por ensuciamiento de filtros de aire en turbinas de gas

Energy Technology Data Exchange (ETDEWEB)

Romero Paredes, H; Ambriz, J J; Vargas, M; Godinez, M; Gomez, F; Valdez, L; Pantoja, G [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Mexico D. F. (Mexico)

1996-12-31

The object of this paper is to study the effect in the turbine output of a gas turbine of the conditions of the compressor air inlet in going through a series of filters. The algorithm for the calculation of the energy losses due to the variation of the pressure drop caused by the filters according to their cleanliness condition. In the first part the series of variables that affect the gas turbines performance are exemplified, afterwards the characteristics of the air flow into a turbine are presented as well as their effects on the system. Later on, the results obtained of the system simulation are presented and compared with a real case. From the results it can be determined, that depending on the system and on the environment conditions the efficiency drop might be up to 3%, in accordance with the filters cleanliness. The maintenance periods strongly depend on the air quality variations at the filter house inlet in the zone where the power plant is located. [Espanol] El presente trabajo tiene por objetivo estudiar el efecto en la potencia generada en una turbina de gas de las condiciones de entrada del aire al compresor de una turbina de gas al pasar por un conjunto de filtros. Se presenta el algoritmo para la determinacion de las perdidas energeticas debidas a la variacion de la caida de presion generada por los filtros de acuerdo con su estado de limpieza. En la primera parte se ejemplifica el conjunto de variables que influyen en la eficiencia de las turbinas de gas, posteriormente se mencionan las caracteristicas de flujo de aire hacia una turbina y se muestran los efectos sobre el sistema. A continuacion se presentan los resultados obtenidos de la simulacion del sistema y se comparan con un caso real. De los resultados se puede apreciar que, dependiendo del sistema y de las condiciones ambientales el decremento en la eficiencia puede ser hasta del 3% en funcion del nivel de limpieza de los filtros. Los periodos de mantenimiento dependen fuertemente de las

The aggressiveness of the geothermal steam controlled; La agresividad del vapor geotermico controlada

Energy Technology Data Exchange (ETDEWEB)

Mercado, Sergio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1990-12-31

The first two units of Cerro Prieto have generated electric energy since 1973; in 1988 completed 15 years of continuous operation, without corrosion problems in the turbines in spite of the utilization of geothermal steam. The experience and the good results obtained during the first years of operation of these two units of 37.5 MW each, were of great help for the Cerro Prieto extension, having as of this date an installed capacity of 620 MW. [Espanol] Las dos primeras unidades de Cerro Prieto han generado energia electrica desde 1973; cumplieron 15 anos de operacion continua en 1988, sin problemas de corrosion en las turbinas a pesar del uso de vapor geotermico. La experiencia y los buenos resultados obtenidos durante los primeros anos de operacion de estas dos unidades de 37.5 MW cada una fueron de gran apoyo para la aplicacion de Cerro Prieto, teniendose a la fecha 620 MW de capacidad instalada.

The aggressiveness of the geothermal steam controlled; La agresividad del vapor geotermico controlada

Energy Technology Data Exchange (ETDEWEB)

Mercado, Sergio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1989-12-31

The first two units of Cerro Prieto have generated electric energy since 1973; in 1988 completed 15 years of continuous operation, without corrosion problems in the turbines in spite of the utilization of geothermal steam. The experience and the good results obtained during the first years of operation of these two units of 37.5 MW each, were of great help for the Cerro Prieto extension, having as of this date an installed capacity of 620 MW. [Espanol] Las dos primeras unidades de Cerro Prieto han generado energia electrica desde 1973; cumplieron 15 anos de operacion continua en 1988, sin problemas de corrosion en las turbinas a pesar del uso de vapor geotermico. La experiencia y los buenos resultados obtenidos durante los primeros anos de operacion de estas dos unidades de 37.5 MW cada una fueron de gran apoyo para la aplicacion de Cerro Prieto, teniendose a la fecha 620 MW de capacidad instalada.

Metalurgia de alabes móviles con banda integrada de turbinas de gas y su influencia sobre el comportamiento de los alabes

Directory of Open Access Journals (Sweden)

Mazur, Z.

1999-02-01

Full Text Available The influence of the microstructure of the gas turbine blades with integral shroud on the blades performance is presented. The analysis of the solidification process of the gas turbine blades during conventionally casting process (equiaxed grains with all elements which has influence on the mode of its solidification and variation of the microstructure is carried out. Also, the evaluation of the failure of the gas turbine blade is presented. A detailed analysis of the blade tip shroud microstructure (presence of the equiaxed and columnar grains and its influence on the failure initiation and propagation is carried out. Finally, conclusions and some necessary improvements of the blades casting process to prevent blades failures are presented.

Se presenta la influencia de la microestructura en el comportamiento de los alabes móviles con banda integrada de turbinas de gas bajo condiciones reales de trabajo. Para el proceso de vaciado convencional (granos equiaxiales de los alabes de turbinas de gas se lleva a cabo el análisis del proceso de solidificación presentando todos los elementos que influyen al modo de solidificación de un alabe y en la variación de la microestructura resultante. Se hace la evaluación de la falla de un alabe con la banda integrada de turbina de gas presentando el mecanismo de la falla y la influencia de la microestructura de la banda del alabe al inicio y propagación de la falla. Finalmente, se presentan las conclusiones determinando los elementos principales de la microestructura que influyen en el comportamiento de los alabes y las medidas preventivas para adecuar la microestructura a las condiciones de trabajo de los alabes.

Análise termodinâmica de um ciclo de potência com célula a combustível sofc e turbina a vapor = Thermodynamic analysis of a power cycle such as SOFC fuel cell and steam turbine

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Alexandre Sordi

2006-01-01

Full Text Available O objetivo deste artigo foi realizar a análise termodinâmica de um sistema híbrido, SOFC / ST (célula a combustível tipo SOFC e turbina a vapor ST. O combustível considerado para a análise foi o gás metano (biogás produzido por meio da digestão anaeróbica de resíduos orgânicos. A metodologia utilizada foi o balanço de energia dosistema SOFC / ST, considerando a reforma interna do metano na célula a combustível, de forma a obter a sua eficiência elétrica. O resultado foi comparado a um ciclo combinado convencional de turbina a gás e turbina a vapor (GT / ST para potências entre 10 MW e 30MW. A eficiência do sistema híbrido SOFC / ST variou de 61% a 66% em relação ao poder calorífico do metano; e a eficiência do ciclo combinado GT / ST variou de 41% a 55% para o mesmo intervalo de potência. Para geração distribuída a célula a combustível SOFC é atecnologia mais eficiente.The objective of this article was to analyze the thermodynamic of ahybrid system, SOFC / ST (SOFC fuel cell and ST steam turbine. The fuel for the analysis was the gas methane (biogas produced through the anaerobic digestion of the organic residues. The utilized methodology was the energy balance of the system SOFC / ST,considering the internal reforming of methane in the fuel cell, in a way to obtain its electric effectiveness. The result was compared to a conventional combined cycle of gas turbine and steam turbine (GT / ST for powers between 10 MW and 30 MW. The efficiency of the hybrid system SOFC / ST varied from 61 to 66% in relation to the lower heating value of methane; and the efficiency of the combined cycle GT / ST varied from 41 to 55% within the same power interval. For distributed generation, the SOFC fuel cell is the most efficienttechnology.

Criterios para la determinación del número de cucharas en una turbina Pelton

OpenAIRE

Octavio Jaramillo Valencia; José Fernando Baquero Herrera

2011-01-01

Los criterios descritos en el presente artículo se aplican en los programas de computador del proyecto de grado "Comportamiento Hidráulico de Cucharas Pelton", calificado con la distinción de meritorio, en el cual a partir de la altura neta, el caudal y la velocidad angular, se determina la geometria de las cucharas. Forma parte del programa de investigación que la Facultad de Ingeniería está llevando a cabo con el propósito de desarrollar turbinas Pelton de baja potencia con la financiación ...

TRAZADO DE CURVAS DE POTENCIA DE UNA TURBINA EÓLICA DE EJE VERTICAL CON GEOMETRÍA VARIABLE

OpenAIRE

Mario F. Bergoglio; Carlos G. Medaglia; Javier A. Carletto; Víctor Rodrigo

2017-01-01

En este trabajo se describe el diseño y las primeras pruebas de una turbina eólica de eje vertical con geometría va riable, diseñado y construido íntegramente en la Facultad de Ingeniería y Ciencias Agropecuarias de la Universidad Nacional de San Luis - Argentina. Los ensayos de laboratorio, tendientes a conocer el comportamiento integral y determinar los valores de potencia que puede entregar el dispositivo se realizaron en un túnel de viento somet...

Classification of the operating conditions of a Kaplan turbine according to its impact in the structural integrity of the runner; Clasificacion de las condiciones de operacion de una turbina Kaplan de acuerdo a su impacto en la integridad estructural del rodete

Energy Technology Data Exchange (ETDEWEB)

Palacios, Luis M; Bautista, Eder A; Espitia, J Ernesto [Instituto Tecnologico de Pachuca, Pachuca, Hidalgo (Mexico); Mazur C, Zdzislaw [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2007-11-15

Each one of the operating conditions of the turbine according to the impact they have in the structural integrity of the runner is evaluated. By means of CFD (Computational Fluid Dynamics) analysis the pressure that the working fluid exerts on the blade for the turbine operating conditions is obtained. The oscillating disturbances induced by the flow, the angular velocity of the runner and the cavitation effect have been considered. The value of maximum stress for each one of the operating conditions is related to its respective values of cavitation. With this information those operating conditions that induce the greater values of stress and represent greater wears away in the runner are determined. This way, it is possible to avoid the more severe operating conditions and if this is not possible, lineaments of redesign are established to obtain more favorable operating conditions for the runner. [Spanish] Se evaluan y clasifican cada una de las condiciones de operacion de la turbina de acuerdo al impacto que tienen en la integridad estructural del rodete. Mediante analisis de CFD (Computacional Fluid Dynamics) se obtiene la presion que el fluido de trabajo ejerce sobre el alabe para las condiciones de operacion de la turbina. Se han considerado las perturbaciones oscilatorias inducidas por el flujo, la velocidad angular del rodete y el efecto de la cavitacion. Se relacionan los valores de esfuerzo maximo para cada una de las condiciones de operacion con sus respectivos valores de cavitacion. Con esta informacion se determinan aquellas condiciones de operacion que inducen los mayores valores de esfuerzo y representan mayor desgaste en el rodete. De esta manera, es posible evitar las condiciones de operacion mas severas, y si esto no es posible, se establecen lineamientos de rediseno para obtener condiciones de operacion mas favorables para el rodete.

Recubrimientos contra la corrosión a alta temperatura para componentes de turbinas de gas

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Agüero, A.

2007-10-01

Full Text Available Hot section gas turbine components are made of superalloys, developed to withstand high temperatures in conditions in which mechanical stresses are high and that require high surface stability. However, during the 50s it became evident that compositions resulting in high mechanical strength for these materials were not compatible with those offering optimal protection from the working environments. The idea of employing protective coatings over materials with high mechanical strength resulted therefore from this situation. Presently, both aeronautic and power generation turbines operate at temperatures within the 900-1400 °C, thanks to these coatings, indispensable for their correct operation. In this work, the principal degradation mechanisms in these operating conditions and the different type of coatings presently employed by the industrial sector are described, beginning by the oldest Ni or Co aluminides, following with the addition of other metals such as Pt, Cr, etc. to the former coatings in order to increase their useful life, continuing with the overlay MCrAlY coatings and finishing with the thermal barrier coating systems. Moreover, the corresponding deposition techniques industrially employed to deposit these coatings are described, and finally, an insight of the latest research lines currently being developed is also included.

Los componentes de las zonas calientes de las turbinas de gas están hechos de superaleaciones desarrolladas para soportar altas temperaturas, en condiciones en que las tensiones mecánicas son relativamente altas y en las que se requiere una alta estabilidad superficial. Sin embargo, durante la década de 1950-60, se hizo evidente que las composiciones que aumentaban la resistencia mecánica de estos materiales y aquellas que ofrecían una óptima protección contra ambientes agresivos no eran compatibles. Esto, condujo a la idea de emplear recubrimientos protectores sobre materiales con alta

Effect on the performance with the washing of the gas turbines Ruston TB5000 with a system of washing out of line in high contamination conditions; Efecto en el rendimiento con el lavado de las turbinas de gas Ruston TB5000 con un sistema de lavado fuera de linea en condiciones de alta contaminacion

Energy Technology Data Exchange (ETDEWEB)

Diaz Diaz, Carlos Rodolfo; Aboites Davila, Fernando [CIATEQ, A.C., Queretaro (Mexico); Rocha Orozco, Moises [PEMEX Refinacion, Mexico, D.F. (Mexico)

2007-11-15

This paper shows the effects on the gas turbine performance with a washing system out of line, based on liquid detergent and water for the case of 2 Ruston TB5000 gas turbines located in conditions of high contamination in the atmosphere such as ashes, high humidity and temperature. The investigation was realized making periodical measurements of the main parameters of the turbo-pump during 1 year of operation with load conditions without stopping of about 125 mbpd (million of barrels per day) of gas LP. This article suggests how the low performance of the turbines in a hostile atmosphere can be improved and which could be the limitations of the washing systems based on liquid detergents. The data of the washing sessions were collected during a year and studied under statistical methods creating performance curves and comparing them with curves of other machines being washed with other washing systems. [Spanish] Este trabajo muestra los efectos en el rendimiento de la turbina de gas con un sistema de lavado fuera de linea, basado en detergente liquido y agua para el caso de 2 turbinas de gas Ruston TB5000 localizados en condiciones de alta contaminacion en el ambiente como cenizas, alta humedad y temperatura. La investigacion fue realizada haciendo mediciones periodicas de los parametros principales de turbo bomba durante 1 ano de operacion con condiciones de carga sin parar de alrededor de 125 mbpd (millones de barriles por dia) de gas LP. Este articulo sugiere como se puede mejorar el bajo desempeno de las turbinas en un ambiente hostil y cuales podrian ser las limitaciones de los sistemas de lavado basados en detergentes liquidos. Los datos de las sesiones de lavado fueron recolectados durante un ano y estudiados bajo metodos estadisticos creando curvas de rendimiento y comparandolas con curvas de otras maquinas siendo lavadas con otros sistemas de lavado.

Criterios para la determinación del número de cucharas en una turbina Pelton

Directory of Open Access Journals (Sweden)

Octavio Jaramillo Valencia

1985-05-01

Full Text Available Los criterios descritos en el presente artículo se aplican en los programas de computador del proyecto de grado "Comportamiento Hidráulico de Cucharas Pelton", calificado con la distinción de meritorio, en el cual a partir de la altura neta, el caudal y la velocidad angular, se determina la geometria de las cucharas. Forma parte del programa de investigación que la Facultad de Ingeniería está llevando a cabo con el propósito de desarrollar turbinas Pelton de baja potencia con la financiación de Colciencias y bajo la dirección del Ingeniero Alvaro Rey Romero.

Diseño y fabricación de un prototipo a pequeña escala de una turbina de aire, para el aprovechamiento de la energía marina, a bajo coste mediante técnicas de prototipado rápido

OpenAIRE

Salueña Berna, Javier; Ortiz Marzo, José Antonio; Raso Bautista, A.

2009-01-01

Existen diferentes procedimientos para aprovechar la energía de las olas [1]. El procedimiento que cuenta con mayor rendimiento y menor coste de mantenimiento es el de Columna Oscilante de Agua (OWC). El sistema consiste en la generación del movimiento de una turbina con el aire generado por el vaivén de la olas, con el problema añadido de que el flujo de aire es bidireccional. Actualmente la única turbina que puede girar en un solo sentido independientemente del sentido del flujo de aire es ...

Alternative analysis to increase the power in combined-cycle power plants; Analisis de alternativas para el incremento de potencia en plantas termoelectricas de Ciclo Combinado

Energy Technology Data Exchange (ETDEWEB)

Pacheco Cruz, Hector; Arriola Medellin, Alejandro M. [Gerencia de Procesos Termicos, Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: hpacheco@iie.org.mx; aarriola@iie.org.mx

2010-11-15

The electricity industry traditionally had two thermodynamic cycles for power generation: conventional steam turbine (Rankine cycle) used to supply a base load during the day, and gas turbines (Brayton cycle), for its speed response, normally used to cover peak loads. However, to provide variable peak loads, the gas turbine, as a volumetric machine is affected by the change in air density by changing the combustion temperature. This paper shows the scheme of integration of both systems, that it's known as combined cycle and the different options that would have these power plants, to maintain or increase their power in variable ambient conditions. It analyzes different options, such as: 1. Supplementary fire in the stove. 2. Air cooling intake in the gas turbine (evaporation system or mechanical system). 3. Steam injection in the combustion chamber. [Spanish] La industria electrica tradicionalmente a contado con dos ciclos termodinamicos para generacion electrica: las turbinas convencionales de vapor (ciclo de Rankine) se utilizan para suministrar una carga base durante el dia, y las turbinas de gas (ciclo de Brayton), por su rapidez de respuesta, se utilizan normalmente para cubrir las cargas pico. Sin embargo, para suministrar las cargas variables pico, la turbina a gas, por ser una maquina volumetrica, se ve afectada por el cambio de la densidad del aire de combustion al cambiar la temperatura ambiente. En este trabajo se muestra el esquema de integracion de ambos sistemas, en lo que se conoce como ciclo combinado y las diferentes opciones que tendrian estas plantas de generacion electrica para mantener o incrementar su potencia en condiciones ambiente variable. Para ello se analizan diferentes opciones, tales como: 1.- Combustion suplementaria en el recuperador de calor. 2.- Enfriamiento del aire de admision a la turbina de gas (mediante un sistema de evaporacion o mediante un sistema mecanico). 3.- Inyeccion de vapor a la camara de combustion. Palabras

Criteria for the provision and assembly of the rotor blades of a 300 MW low pressure steam turbine for electrical generation; Criterios para el suministro y ensambles de la alabes de rotor de turbina de vapor de 300 MW baja presion para generacion electrica

Energy Technology Data Exchange (ETDEWEB)

Bertin, Galo; Felix, Jorge A; Quijano, Octavio [Especialistas en Turbopartes, S.A. de C.V., Queretaro, Queretaro (Mexico)

2007-11-15

This paper presents some of the main criteria to consider from the inspection, disassembling and assembly of blades with different root types of a turbine rotor of steam turbines for power generation, having as an aim to count on a reliable rotor, fulfilling with the equipment original design and norms and international standards. [Spanish] Este trabajo presenta algunos de los criterios principales a considerar desde la inspeccion, desmontaje y montaje de alabes de diferentes tipos de raiz de un rotor de turbinas de vapor de generacion electrica, teniendo como finalidad contar con un rotor confiable, cumpliendo con el diseno original del equipo y con normas y estandares internacionales.

Conventional and intelligent generalized supervisory control for combined cycle generating power stations.; Control supervisiorio generalizado convencional e inteligente para centrales de generacion de ciclo combinado

Energy Technology Data Exchange (ETDEWEB)

Martinez M, Miguel A; Sanchez P, Marino [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Gonzalez Rubio S, Jose L [Cento Nacional de Investigacion y Desarrollo Tecnologico (Cenidet), Cuernavaca, Morelos (Mexico)

2005-07-01

Under the expectations of expansion of electric power generation in Mexico, this work exposes the development of a conventional and intelligent generalized supervisory control (CSG) for a combined cycle generation power plant. This one allows to obtain the optimal operation of the power plant through the automatic starting of the generating units and to obtain the maximum possible amount of electrical power in automatic and safe form. For the development of the CSG a control loop by temperature was implemented for the gas turbine system and a control loop by strangled pressure for the gas turbine and a control loop by strangled pressure for the steam turbine. The design of these supervisory systems was made with base in the critical limits on the involved variables of the process: blading average temperature, for the gas turbine (GT) and strangled pressure for the steam turbine (ST) [Spanish] Bajo estas expectativas de expansion de generacion de energia en Mexico, este trabajo expone el desarrollo de un control supervisorio generalizado (CSG) para una central generacion de ciclo combinado. Este permite lograr la operacion optima de la planta a traves del arranque automatico de las unidades generadoras y obtener la maxima cantidad posible de potencia electrica en forma automatica y segura. Para el desarrollo del CSG se implanto un lazo de control por temperatura para el sistema de turbina de gas y un lazo de control por presion estrangulada para la turbina de gas y un lazo de control por presion estrangulada para la turbina de vapor. El diseno de estos sistemas supervisorio se realizo con base en los limites criticos de las variables del proceso involucradas: temperatura promedio de empaletado para la turbina de gas (TG) y presion estrangulada para la turbina de vapor (TV)

ANÁLISE DOS PARÂMETROS DE FUNCIONAMENTO E SIMULAÇÃO COMPUTACIONAL EM UM PROTÓTIPO DE TURBINA OPERANDO A AR COMPRIMIDO

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Wesley Saldanha Nogueira Oliveira

2016-12-01

Full Text Available RESUMO. Este trabalho apresenta os resultados iniciais da comparação de alguns parâmetros de funcionamento do protótipo de uma turbina de ação simples, operando com ar comprimido como fluido de trabalho, realizados na unidade do SENAI de Barra do Piraí/RJ. O protótipo foi desenvolvido integralmente no Centro Universitário Geraldo Di Biase - UGB - Campus de Barra do Piraí/RJ, que inicialmente teve como o fluido de trabalho o vapor d’água, que nos testes inicias se mostrou ineficiente. A simulação computacional do sistema foi feita através do software SolidWorks na Universidade Federal Fluminense - UFF - Campus de Volta Redonda/RJ, o que permitiu determinar a faixa de trabalho que apresentou maior eficiência nos resultados experimentais do sistema por meio da relação entre pressão de operação, velocidade angular transmitida pelo fluido ao eixo da turbina e a potência da mesma. Os valores nas simulações em velocidade tangencial na região rotacional apresentaram-se convergentes aos valores experimentais medidos no protótipo.

Vapor recovery system in the gasolines commercialization; Sistema de recuperacion de vapores en la comercializacion de las gasolinas

Energy Technology Data Exchange (ETDEWEB)

Casas Barba, R.; Molina Gallegos, J.R. [Instituto Mexicano del Petroleo (IMP), Mexico, D. F. (Mexico)

1995-12-31

In the last years the studies performed with respect to the environmental pollution show that the ozone is one of the most problematic contaminants in the Metropolitan Zone of Mexico City (MZMC) and that the hydrocarbons are the main forerunners of it. The main source of hydrocarbon vapor emissions originates from the handling and distribution operations. In this paper a description is made of the involved stages in the commercialization of gasolines in the MZMC and a description is also made of the systems employed to control the emissions in the three stages of the fuels storage and distribution cycle and explains the degree the hydrocarbon emissions to the atmosphere will be reduced, once the recovery systems are installed in all of the involved stages. [Espanol] En los ultimos anos los estudios realizados con respecto a contaminacion ambiental reflejan que el ozono es uno de los contaminantes mas problematicos de la zona metropolitana de la ciudad de Mexico (ZMCM), y los hidrocarburos son los principales precursores de este. La principal fuente de emision de vapores de hidrocarburos proviene de las operaciones de manejo y distribucion de combustibles. En este articulo se hace una descripcion de las etapas involucradas en la comercializacion de las gasolinas en la ZMCM, se describen tambien los sistemas utilizados para controlar las emisiones en las tres etapas del ciclo de almacenamiento y distribucion de combustibles y se explica en que grado se reduciran las emisiones de hidrocarburos a la atmosfera, una vez que se instalen los sistemas de recuperacion en todas las etapas involucradas.

Vapor recovery system in the gasolines commercialization; Sistema de recuperacion de vapores en la comercializacion de las gasolinas

Energy Technology Data Exchange (ETDEWEB)

Casas Barba, R; Molina Gallegos, J R [Instituto Mexicano del Petroleo (IMP), Mexico, D. F. (Mexico)

1996-12-31

In the last years the studies performed with respect to the environmental pollution show that the ozone is one of the most problematic contaminants in the Metropolitan Zone of Mexico City (MZMC) and that the hydrocarbons are the main forerunners of it. The main source of hydrocarbon vapor emissions originates from the handling and distribution operations. In this paper a description is made of the involved stages in the commercialization of gasolines in the MZMC and a description is also made of the systems employed to control the emissions in the three stages of the fuels storage and distribution cycle and explains the degree the hydrocarbon emissions to the atmosphere will be reduced, once the recovery systems are installed in all of the involved stages. [Espanol] En los ultimos anos los estudios realizados con respecto a contaminacion ambiental reflejan que el ozono es uno de los contaminantes mas problematicos de la zona metropolitana de la ciudad de Mexico (ZMCM), y los hidrocarburos son los principales precursores de este. La principal fuente de emision de vapores de hidrocarburos proviene de las operaciones de manejo y distribucion de combustibles. En este articulo se hace una descripcion de las etapas involucradas en la comercializacion de las gasolinas en la ZMCM, se describen tambien los sistemas utilizados para controlar las emisiones en las tres etapas del ciclo de almacenamiento y distribucion de combustibles y se explica en que grado se reduciran las emisiones de hidrocarburos a la atmosfera, una vez que se instalen los sistemas de recuperacion en todas las etapas involucradas.

Integration of a thermal stresses supervisory system and useful life of steam turbine rotors; Integracion de un sistema supervisorio de esfuerzos termicos y vida util de rotores de turbinas de vapor

Energy Technology Data Exchange (ETDEWEB)

Carnero, Antonio; Serrano, Luis E. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Nebradt, G. Jesus; Leyva, M. Luis [Comision Federal de Electricidad, Mexico, D.F. (Mexico)

2007-11-15

lado, la mayor eficiencia de centrales de ciclo combinado con respecto a centrales convencionales se refleja en un mayor costo de produccion de la energia electrica, lo que ha obligado a que unidades convencionales de generacion disenadas para operar con carga base, ahora sean utilizadas como unidades de carga variable para satisfacer la demanda durante las horas de mayor demanda. Lo anterior, repercute en una mayor frecuencia de operaciones de paros y arranques en calientes de turbinas, por lo que el dano por fatiga se incrementara al cambiar su regimen de operacion. En Mexico existen turbinas que llevan 15 o 20 anos en operacion y que no cuenta con un supervisor de esfuerzos termicos, por lo que al cambiar su operacion de carga base a carga variable es imprescindible instalar un supervisor de esfuerzos termicos del rotor, con el fin de limitar o reducir los esfuerzos termicos y con ello reducir el dano por fatiga para extender asi su vida util esencial. El articulo trata sobre la integracion de un sistema supervisor de esfuerzos termicos, que a partir de los parametros de operacion de la turbina, se determina el gradiente de temperaturas en la zona de sellos de laberinto entre el paso de control y el primer paso de la seccion del alta presion del rotor, se calculan los esfuerzos termicos y mecanicos y la fatiga, determinando el consumo de vida util por cada ciclo de operacion (paro y arranque).

Fundaciones para turbinas eólicas costa afuera Foundations for offshore wind turbines

Directory of Open Access Journals (Sweden)

Felipe Alberto Villalobos Jara

2009-01-01

Full Text Available Este artículo describe el comienzo y la evolución de la hoy en día creciente mundialmente industria de la energía eólica costa afuera. Como un caso particular, se describe la actual política de energías renovables en el Reino Unido. Se explican las características de las cargas ambientales existentes costa afuera, tipos de suelos del fondo marino y las fundaciones que se utilizan comúnmente. El tipo de estructura y régimen de carga establecen nuevas condiciones desde el punto de vista de la Ingeniería Civil. Se presentan las cámaras a succión como una fundación alternativa para turbinas de viento costa afuera. Las cámaras a succión son actualmente una alternativa aceptada en vez de usar pilotes en aplicaciones para la industria del petróleo y el gas. Sin embargo, este no es el caso todavía en aplicaciones para aerogeneradores costa afuera.This paper describes the beginning and evolution of the now worldwide growing offshore wind energy industry. In particular, the current renewable energy policy in the UK is described. The characteristics of the environmental loads offshore, type of seabed soils and foundations commonly adopted are explained. The type of structure and loading regime establish new conditions from a Civil Engineering point of view. Suction caissons are introduced as an alternative foundation for offshore wind turbines. Suction caissons are currently an accepted alternative to pile foundations in applications for the oil and gas industry. However, this is not yet the case in applications for offshore wind turbines.

Contribución a la caracterización experimental y al modelado de turbinas de geometría variable en grupos de sobrealimentación.

OpenAIRE

Cervelló Romero, Carmen

2008-01-01

La incorporación generalizada de los sistemas de sobrealimentación a los motores diesel de automoción está haciendo imprescindible desarrollar un nivel de investigación capaz de profundizar en los factores que influyen en el funcionamiento y rendimiento de los turbogrupos acoplados a los motores de combustión interna alternativos.En esta tesis se presentan dos herramientas que van a permitir progresar en el estudio de los turbogrupos y en especial en las turbinas de geometría variable. En pri...

Rotor optimization of a Francis type hydraulic turbine through the computer flow analysis (CFD); Optimizacion del rodete de una turbina hidraulica tipo Francis a traves del analisis computacional del flujo (CFD)

Energy Technology Data Exchange (ETDEWEB)

Rosado Tamariz, Erick

2007-06-15

basicas para el analisis de flujo y el proceso de optimizacion en las turbinas, los cuales consisten en: modelado de flujo a traves de toda la turbina (conjunto), o bien el modelado de cada componente por separado, obteniendo resultados satisfactorios por ambas metodologias. En la mayoria de los casos implementando el metodo de volumen finito (MVF), con consideraciones de flujo no viscoso, con la implementacion de los modelos de dos ecuaciones para la solucion de las ecuaciones que rigen el flujo turbulento. Asi mismo, se utilizan tecnicas de optimizacion que se basan en la parametrizacion geometrica, el planteamiento de una funcion objetivo y en la disminucion del fenomeno de cavitacion. En el presente trabajo se presenta la optimizacion de un rodete de una turbina hidraulica tipo Francis modelo, considerando tres condiciones de carga (75%, 85% y 100%) a traves de la dinamica de fluidos computacionales (CFD) como parte de un analisis hidraulico para la modernizacion de una unidad de generacion de potencia. Se realiza la optimizacion del rodete de una turbina tipo Francis, mediante un analisis previo de CFD mediante el MVF, considerando los efectos viscosos del fluido y el modelo de turbulencia Sparlat-Allmaras; modelando el distribuidor y el rodete por separado. Posteriormente se realiza la generacion de un modelo parametrico del rodete y se configura la simulacion para la generacion de la base de datos. Finalmente se plantea una funcion objetivo para con ello obtener la geometria optima de los alabes del rodete. Los resultados se presentan en forma grafica donde se muestra la distribucion de presiones del rodete original y el rodete optimizado; de igual forma, se comparan las formas geometricas y los resultados globales de desempeno (potencia y rendimiento) de ambos rodetes.

Detection of the high vibration origin in the body of an electrical generator driven by steam turbine applying diagnostic techniques; Deteccion del origen de alta vibracion en el cuerpo de un generador electrico accionado por turbinas de vapor aplicando tecnicas de diagnostico

Energy Technology Data Exchange (ETDEWEB)

Martinez Bravo, Fernando (Mexico)

2007-11-15

One of the problems that electric generators present is the high vibration due to causes that can go from simple mechanical unbalance, misalignment, mechanical relaxation, resonance or some other interaction that can influence in the system. In this document is presented the vibration analysis of an electric generator with a capacity of 350 MW, driven by a steam turbine composed of three stages (high pressure, intermediate pressure and low pressure) connected to the electric generator through a rigid connection. [Spanish] Uno de los problemas que se presentan en los generadores electricos es la alta vibracion debida a causas que pueden ir desde un simple desbalance mecanico, desalineamiento, aflojamiento mecanico, resonancia o alguna otra interaccion que pueda influir en el sistema. Se presenta en este documento el analisis de vibracion de un generador electrico con una capacidad de 350 MW, impulsado por una turbina de vapor compuesta de tres etapas (alta presion, presion intermedia y baja presion) acopladas al generador electrico a traves de un acoplamiento rigido.

Application of monitoring techniques of operational parameters for the implementation of preventive and predictive maintenance programs to gas turbines; Aplicacion de tecnicas de monitoreo de parametros operacionales para la implantacion de programas de mantenimiento predictivo y preventivo en turbinas de gas

Energy Technology Data Exchange (ETDEWEB)

Gutierrez Villareal, Julio Cesar

1998-12-31

components. These techniques are: hardness testing, liquid penetrant inspection, magnetic particle inspections and metallographic examination. Chapter five describes the boroscopy inspection and its applications for a rotor analysis and gas turbine blades. Chapter six shows the results obtained and give recommendations for the vibration analysis that were carried out at a gas turbine facility. [Espanol] Esta tesis se realiza con la finalidad de implantar un programa de mantenimiento preventivo y predictivo, mediante tecnicas de monitoreo de parametros que permita sistematizar, documentar y administrar las actividades del mantenimiento. La metodologia de mantenimiento aqui descrita, se aplica a las turbinas de gas de la Terminal Maritima Dos Bocas Tabasco, Mexico. El mantenimiento preventivo se basa en la revision periodica de los equipos, mediante listas de inspeccion, donde la idea es detectar problemas que provoquen posibles fallas y realizar la reparacion o ajusted necesarios para evitarlo. Sin embargo enfrenta a la posibilidad de que el equipo este en perfecto estado y al estar en revision, tenga retrasos y problemas de arranque posteriores. El mantenimiento predictivo se basa en tecnicas que permiten la deteccion e identificacion de fallas incipientes en los equipos. Las tecnicas recomendadas en esta tesis son: Analisis de vibraciones; Evaluacion no destructivas e Inspeccion boroscopica. La estructura de la tesis consta de los capitulos siguientes: El capitulo uno describe la importancia de los programas y estrategias del mantenimiento, sus ventajas y desventajas al aplicarlas en las plantas de proceso continuo. Se plantean los procedimientos para el diseno de un programa de mantenimiento. El capitulo dos presenta la manera de planear los recursos y materiales de mantenimiento, las tecnicas de inspecciones aplicados a la turbina de gas, y finalmente se disenan listas de verificacion de inspecciones como herramienta del mantenimiento preventivo. Los capitulos siguientes

Estudo de um sistema de concentração integrado numa pequena turbina eólica de eixo vertical

OpenAIRE

Santos, António José Alves da Silva

2014-01-01

Tese de mestrado integrado em Engenharia da Energia e do Ambiente, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2014 Este trabalho pretende estudar um novo conceito de aproveitamento energético, através de um sistema de concentração eólico adaptado para turbinas de eixo vertical (VAWT). O sistema permite aumentar a velocidade do vento à entrada do rotor da turbina e assim a potência disponível. O aproveitamento energético de fonte eólica ainda não é comum no ...

Stress analysis in the last stage blade of a geothermal turbine under different excitation conditions; Analisis de esfuerzos en el alabe de la ultima etapa de turbina geotermica bajo diferentes condiciones de excitacion

Energy Technology Data Exchange (ETDEWEB)

Jimenez Alcazar, Rony Ediberto

2009-11-15

The blades of the steam turbines operate below severe conditions of pressure, temperature and steam flow, and at high rotary speeds too. These excitements generate states of stress, which depending on its magnitude and time of application; they can threaten the structural reliability of these mechanical components. In this work a stress analysis is realized in a blade L-0 of a geothermal turbine of low pressure, by means of the finite element method, by the aim to determine the states of static stress caused by the combined action of the centrifugal force and pressure of system flow, and dynamic stresses caused by the harmonic fluctuation in the steam flow. The analysis is realized under two superficial conditions in the blade: without presence of superficial damage and with presence of erosion in the bottom part of the trailing edge. The combined action of these conditions of stress is evaluated by means of an analysis of fatigue. This allows knowing the influence of the stress calculated, on the useful life of the blade. [Spanish] Los alabes de turbinas de vapor operan bajo condiciones severas de presion, temperatura y flujo de vapor, asi como a altas velocidades rotativas. Estas excitaciones generan estados de esfuerzos, que dependiendo de su magnitud y tiempo de aplicacion, pueden amenazar la confiabilidad estructural de estos componentes mecanicos. En este trabajo se realiza un analisis de esfuerzos en un alabe L-0 de una turbina geotermica de baja presion, mediante el metodo de elemento finito, con el objetivo de determinar los estados de esfuerzos estaticos causados por la accion combinada de la carga por fuerza centrifuga y presion de flujo de vapor, y esfuerzos dinamicos causados por la fluctuacion armonica en el flujo de vapor. El analisis se realiza bajo dos condiciones superficiales en el alabe: sin presencia de dano superficial y con presencia de erosion en la parte inferior del borde de salida. La accion combinada de estos estados de esfuerzos se

Análisis de la influencia del ingreso del proyecto ciclo combinado 318 MW dentro de la matriz eléctrica del Ecuador

OpenAIRE

Cárdenas Dávila, Carlos Alexis

2014-01-01

Actualmente el sistema eléctrico ecuatoriano para cubrir la demanda nacional ha utilizado principalmente generación hidroeléctrica y termoeléctrica, ésta última con la operación de unidades con turbinas a vapor y a gas, al ser las más económicas por el tipo de combustible que utilizan. Ambas tecnologías son utilizadas para generar por separado energía eléctrica. Existe la posibilidad de ser explotadas de manera más eficiente, utilizando el calor contenido en los gases de escape de las turb...

Numerical simulation by CFD of the behavior of the Inter stage 1 flow in stable state of a gas turbine Frame 7; Simulacion numerica por CFD del comportamiento del flujo en la inter etapa 1 en estado estable de una turbina de gas frame 7

Energy Technology Data Exchange (ETDEWEB)

Hernandez R, Alejandro; Lopez H, Juan Arturo R; Mazur Czerwiec, Zdizslaw; Cordero G, Jesus [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2006-07-01

This technical article presents an analysis including the three-dimensional modeling of the flow channel in the nozzle and the movable blade in order to discover the velocity distribution, temperatures and pressures of the main hot gas flow produced in the inter-stage 1. The aim is to establish key evaluation criteria leading to an opportune repair and therefore smaller operation expenses. Thus, the application of a commercial software of CFD is described to model the channel of the first stage in the gas turbine Frame 7, the geometric architecture is shown in the web of the gas turbine, as well as the border conditions used in the results assessment. [Spanish] Este articulo tecnico presenta un analisis que incluye la modelacion tridimensional del canal de flujo en la tobera y el alabe movil para conocer las distribuciones de las velocidades, temperaturas y presiones del flujo principal de gases calientes que se desarrollan en la inter-etapa 1. El fin es establecer criterios clave de evaluacion que conduzcan a una oportuna reparacion y por ende menores gastos de operacion. Asi, se describe la aplicacion de un software comercial de CFD para modelar el canal de flujo de la primera etapa de una turbina de gas Frame 7, se muestra la arquitectura geometrica y el mallado de la turbina de gas, asi como las condiciones de frontera usadas y la validacion de resultados.

Mitigación de la cavitación de extremo de alabe mediante la implementación de inyección de aire en un modelo a escala reducida de turbina Kaplan

OpenAIRE

Rivetti, Arturo; Angulo, Mauricio Abel; Lucino, Cecilia Verónica; Liscia, Sergio Oscar

2015-01-01

Las Turbinas Kaplan que operan en condiciones de alta carga pueden estar sometidas a vibraciones excesivas, ruido y cavitación. En estos casos puede presentarse erosión por cavitación sobre el anillo de descarga asociada al desarrollo de cavitación de extremo de alabe. Este fenómeno involucra características de diseño tales como sobreapertura de los alabes del distribuidor; perfil de los alabes del rodete; el incremento del huelgo debido a la apertura del alabe; la altura neta de aspiración; ...

Calculation of the temperature distribution and thermal stresses in a gas turbine nozzle cooled by air film; Calculo de la distribucion de temperaturas y esfuerzos termicos en una tobera de turbina de gas enfriada por pelicula de aire

Energy Technology Data Exchange (ETDEWEB)

Hernandez R, Alejandro; Garcia I, Rafael; Mazur C, Zdislaw [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2004-07-01

The analysis begins with the generation of a computational geometric model of the gas turbine nozzle using reverse engineering techniques. For the obtaining of the original geometry of the blade, a measurement machine by coordinates and computerized numerical control was used. Next, the computational model is converted into a three-dimensional mesh. In advance, a study of boundary conditions was made of the nozzle material as well as of the turbine operating conditions during non-operating cycles, start-ups and shut-downs. On the other hand, with the boundary conditions imposed to the model, the distributions of the temperature and pressures on the aerofoil profile of the nozzle blade were calculated. These results had to be manipulated to be exported to a finite element software (ANSYS); at this point, another nozzle model was elaborated to be able to import the temperature distribution. With the temperatures correctly imported, the simulations for the calculation of the thermal stresses were made in the nozzle. [Spanish] El analisis inicia con la generacion de un modelo geometrico computacional de la tobera de la turbina de gas utilizando tecnicas de ingenieria inversa. Para la obtencion de la geometria original del alabe, se utilizo una maquina de medicion por coordenadas y control numerico computarizado. A continuacion, el modelo computacional es convertido en una malla tridimensional. Con antelacion, se realizo un estudio de las condiciones de frontera, tanto del material de la tobera como de las condiciones de operacion de la turbina, durante ciclos de paro, arranque y disparo. Por otra parte, con las condiciones de frontera impuestas al modelo, se calcularon las distribuciones de las temperaturas y presiones sobre el perfil aerodinamico de la paleta de la tobera. Estos resultados tuvieron que ser manipulados para ser exportados a un software de elemento finito (ANSYS); en este punto, se elaboro otro modelo de la tobera para poder importar la distribucion de

Protitlaková parní turbina

OpenAIRE

Kubiš, Zdeněk

2013-01-01

Tématem diplomové práce je návrh jednotělesové parní turbiny o výkonu 60 MW pro dvoustupňový ohřev topné vody. Turbina je určena pro kogenerační cyklus, má čtyři neregulované odběry a výstup dolů do topného ohříváku. Nejprve je proveden tepelný výpočet turbiny pro provoz se 100 % páry. Dále je vypracován detailní návrh průtočného kanálu spolu s pevnostním výpočtem lopatek a rozváděcích kol. V závěru práce jsou porovnány požadované provozy a uvedena příslušná bilanční schémata. Součástí práce ...

Conditioned food aversion to control outbreaks of intoxication by Ipomoea carnea and Turbina cordata in goats

Science.gov (United States)

Conditioned food aversion is used to train livestock to avoid the ingestion of toxic plants. This technique was used to control Turbina cordata poisoning in goats in one farm, and to control Ipomoea carnea subsp. istulosa poisoning in another farm. The goats were penned at night and the next mornin...

Evaluación exergética de propuestas de disminución de consumo de vapor en usinas azucareras Exergetic evaluation of proposals for steam consumption reduction in sugar factories

Directory of Open Access Journals (Sweden)

Dora Paz

2005-12-01

Full Text Available Se realizó un modelado exergético, basado en la 2° ley de la Termodinámica, para la evaluación de las operaciones térmicas de Calentamiento-Evaporación-Cristalización (CEC en un ingenio de Tucumán. Una vez resueltos los balances de masa y energía de sistemas CEC, se determinaron los balances de exergía, evaluando las pérdidas de exergía y la eficiencia exergética. Se emplearon ecuaciones y gráficos existentes en la bibliografía para evaluar las propiedades termodinámicas de los flujos intervinientes. Se simularon y compararon con el caso base (zafra 2000, dos propuestas tendientes a disminuir las pérdidas de exergía, considerando: aumento de efectos de evaporación, mayor aprovechamiento de vapores vegetales, aumento en la concentración de melado, empleo de vapor vegetal para la cristalización y reemplazo de turbinas de vapor ineficientes por motores oleohidráulicos y eléctricos. Los resultados mostraron que las menores eficiencias exergéticas se producen en condensadores barométricos de cristalización y evaporación, y en cristalización. La reducción de irreversibilidades en las propuestas analizadas permitiría eliminar el combustible adicional necesario para operar calderas bagaceras antiguas.Exergetic modelling, based on exergetic analysis (2nd law of Thermodynamics, was applied in assessing Heating-Evaporation-Crystallization (H-E-C thermal operations in a cane sugar mill in Tucumán (Argentina. After solving mass and energy balances in H-E-C systems, exergy balance was determined. Exergy losses and exergetic efficiency were calculated. Equations and graphics found in bibliographic sources were used to calculate thermodynamic properties of intervening flows. Two alternatives for reducing exergy losses were simulated and compared with base case (2000 season. These alternatives aimed at the following goals: more evaporation effects, better use of juice vapours, increase in syrup concentration, and replacement of

Estimación del Error en un Medidor de Turbina con Insuficientes Tramos Rectos Estimación del Error en un Medidor de Turbina con Insuficientes Tramos Rectos

Directory of Open Access Journals (Sweden)

Francisco Martínez González

2012-02-01

Full Text Available In agricultural pumping plants flowmeters are frequently installed with insufficient straight sections of pipe both upstream and downstream from the meter, in order to meet the established installation specifications. It has been found that flowmeter manufacturers do not know the error rate in flow measurements under these no optimal conditions. In 1998, Hanson found that a propeller flowmeter had an error of 3,5 % when it was installed in a position a distance of two pipe diameters downstream from an elbow. This project investigated the performance of a turbine flowmeter under no optimal upstream and downstream conditions (conditions not considered by Hanson. Experiments were carried out in the Hydraulic Laboratory of the University of Guanajuato. Measurements were made in different flowmeter positions considering different flow rates. Results from this project showed that the flowmeter does not have a large error, even if it is installed in an incorrect position. However, lowest error rate is obtained when it was installed in the position recommended by the manufacturer. En pozos agrícolas, frecuentemente se presenta el caso de trenes de descarga con insuficientes tramos rectos para cumplir las especificaciones de instalación de medidores de flujo. Los fabricantes no conocen la variación del error de medición en que se incurre si los medidores se colocan bajo condiciones de insuficientes tramos rectos. Hanson (1998 encontró que un medidor de propela presenta un error de 3,5 % si se coloca con dos diámetros aguas abajo de un codo de 90o. Para conocer el desempeño de un medidor de turbina con poco tramo recto, tanto aguas arriba como aguas abajo (condiciones no consideradas por Hanson se realizaron pruebas en el Laboratorio de Hidráulica de la Universidad de Guanajuato. Se compararon las lecturas del medidor contra las de un tanque volumétrico, colocando el medidor en diferentes posiciones y con varios gastos. Los resultados indican que

Diffuse control of gas turbines in power stations of combined cycle; Contral difuso de turbinas de gas en centrales de ciclo combinado

Energy Technology Data Exchange (ETDEWEB)

Sanchez P, Marino; Garduno R, Raul; De Lara J, Salvadror; Castelo C, Luis [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2001-07-01

In this article the application of the technology of the fuzzy logic to the control of gas turbines is presented in order to evaluate it in one of the most difficult processes and with stricter control requirements that exist in the electrical generation industry. For being important for the generation electrical sector, given their use in Comision Federal de Electricidad (CFE), the first selected prototype was the gas turbines model W501 of Westinghouse, installed in the of combined cycle power stations of Dos Bocas, Veracruz, Gomez Palacio, Durango and Tula, Hidalgo, Mexico. The second selected prototype was the one of the turbo gas units type 5001 (that applies to the GE 5001 models and Westinghouse of series 191 and 251). Based on the analysis of the performance of the system of conventional control previously made, the controllers of speed and generation of electrical power were selected to be replaced by diffuse controllers. [Spanish] En este articulo se presenta la aplicacion de la tecnologia de la logica difusa al control de turbinas de gas con el proposito de evaluarla en uno de los procesos mas dificiles y con requerimientos mas estrictos de control que existen en la industria de generacion electrica. Por ser importantes para el sector electrico de generacion, dada su utilizacion en Comision Federal de Electricidad (CFE), el primer prototipo seleccionado fueron las turbinas de gas modelo W501 de Westinghouse, instaladas en la central de ciclo combinado de Dos Bocas, Veracruz, Gomez Palacio, Durango y Tula, Hidalgo, Mexico. El segundo prototipo seleccionado fue el de unidades turbogas tipo 5001 (que aplica a los modelos GE 5001 y Westinghouse de la serie 191 y 251). Basados en el analisis del desempeno del sistema de control convencional realizado previamente, los controladores de velocidad y de generacion de potencia electrica fueron seleccionados para ser sustituidos por controladores difusos.

Borosonic inspection and remaining useful operational life estimation of steam turbine rotors; Inspeccion borosonica y estimacion de vida remanente de rotores de turbinas de vapor

Energy Technology Data Exchange (ETDEWEB)

Carnero P, Jose A; Dorantes G, Oscar; Munoz Q, Rodolfo; Serrano R, Luis E. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2004-07-01

The turbo-generators used in the electric power generation frequently go through transitory operations (start ups, shut downs or power changes). Such actions cause that certain critical components of the turbines, such as rotors and casings, are put under cycles of repetitive stresses, which consume its useful life. The frequency whereupon these transitory thermal cycles happen result in the presence of high thermo-mechanical stresses that produce fatigue (damage) in the rotor material. With time, at the increase of the material fatigue, fissures form that can inclusively lead to severe, catastrophic faults. The borosonic inspection consists in introducing and positioning an automatic probe in the central drill of the rotor, this allows the non-destructive inspection with longitudinal ultrasonic beam, ultrasonic cross-sectional and ultrasonic superficial. This way, it is possible to detect and locate geometric discontinuities (superficial and volumetric), in at least 100 mm of depth from the drill surface in its entire periphery and throughout the rotor length. [Spanish] Los turbogeneradores empleados en la generacion de energia electrica con frecuencia realizan operaciones transitorias (arranques, paros o cambios de potencia). Acciones tales, provocan que ciertos componentes criticos de las turbinas, como los rotores y carcasas, sean sometidos a ciclos de esfuerzos repetitivos, lo que consume su vida util. La frecuencia con que ocurren estos ciclos termicos transitorios da como resultado la presencia de altos esfuerzos termomecanicos que producen una fatiga (dano) en el material del rotor. Con el tiempo, al incrementarse la fatiga del material, se forman fisuras que pueden conducir a fallas severas, catastroficas inclusive. La inspeccion borosonica consiste en introducir y posicionar una sonda automatica en el barreno central del rotor, ello permite la inspeccion no destructiva con haz ultrasonico longitudinal, haz ultrasonico transversal y haz ultrasonico

Desarrollo de un simulador de turbinas de gas fuera de diseño

OpenAIRE

Saiz Boned, Mercedes

2016-01-01

Este Trabajo Fin de Grado está englobado dentro de un conjunto de proyectos relacionados con la simulación y el estudio teórico de los ciclos de Turbina de Gas. Estos proyectos están siendo desarrollados dentro de la Unidad Docente de Motores Térmicos, perteneciente al Departamento de Ingeniería Energética de la Escuela Superior de Ingenieros Industriales de Madrid. Manuel Valdés del Fresno, tutor de este proyecto, ha sido la persona que ha guiado y seguido el desarrollo del proyecto desde...

Development and implementation of an interface control-process and of additional models in the simulator of combined cycle units; Desarrollo e implantacion de una interfaz control-proceso y de modelos adicionales en el simulador de unidades de ciclo combinado

Energy Technology Data Exchange (ETDEWEB)

Martinez R, Rogelio E; Ramirez G, Miguel; Melgar G, Jose L; Codero C, Juan C; Romero J, Guillermo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2001-07-01

In this article are described the design and implementation of an interface control-process and the formulation of the process models for the simulation of the vibration amplitudes of the steam and gas turbines and of the monitoring system of gas discharges, which comprise a simulator of total reach of combined cycle units. These three systems had to be developed and implemented in the simulator of combined cycle units, that the Instituto de Investigaciones Electricas (IIE) developed for the Comision Federal de Electricidad (CFE), with the purpose of solving different problematic caused by the use of a platform of commercial software for the construction of simulators. The problematic presented by the platform of software is briefly described, as well as the solutions contributed with respect to the interconnection of signals control-process, and to the lack of models of the mechanical part of the steam and gas turbines, and of the monitoring system of polluting emissions. [Spanish] En este articulo se describen el diseno e implantacion de una interfaz control-proceso y la formulacion de los modelos de proceso para la simulacion de las amplitudes de vibracion de las turbinas de gas y de vapor y del sistema de monitoreo de emisiones de gases, los cuales forman parte de un simulador de alcance total de unidades de ciclo combinado. Estos tres sistemas tuvieron que ser desarrollados e implementados en el simulador de unidades de ciclo combinado, que el Instituto de Investigaciones electricas (IIE) desarrollo para la Comision Federal de Electricidad (CFE), con el fin de resolver diferentes problematicas ocasionadas por la utilizacion de una plataforma de software comercial para la construccion de simuladores. Se describen brevemente las problematicas presentadas por la plataforma de software, asi como las soluciones aportadas en lo relativo a la interconexion de senales control-proceso, y a la falta de modelos de la parte mecanica de las turbinas de gas y de vapor, y

Estudio de corrosión bajo tensión en los aceros inoxidables 17-4PH y 17-7PH en presencia de NaCl y NaOH (20 % a 90 °C

Directory of Open Access Journals (Sweden)

Gaona-Tiburcio, Citlalli

2000-04-01

Full Text Available One of the problems that affects to the electric industry is the not programmed stoppages in the power plants, due to the failure of any main component: boiler, turbine and generator. In the turbine, the combined action of a corrosive agent (humid polluted vapor and a mechanical effort generally will result in Stress Corrosion Cracking (SCC. In this work the SCC susceptibility of the precipitation hardening stainless steels 17-4PH and 17- 7PH, thoroughly used in steam turbine blades of power stations is analyzed. The specimens were tested in the presence of NaCl and NaOH (20 % to 90 °C and different pH. The CERT test (Constant Extension Rate Test was used, at 10^-6 s^-1 supplementing it with electrochemical noise; the aim was to identify the conditions of maximum susceptibility and the performance of the studied materials. The fractographic analysis revealed ductile and brittle fracture. Intergranular crackings, characteristic of the anodic dissolution mechanism of the material was observed. Nevertheless, the main mechanism responsible the failure was hydrogen embrittlement.

Uno de los problemas que afecta a la industria eléctrica es el de los paros no programados en las plantas generadoras de electricidad, debidos al fallo de algún componente principal: caldera, turbina y generador. En la turbina, la acción combinada de un agente corrosivo (vapor húmedo contaminado y un esfuerzo mecánico, generalmente provocará corrosión bajo tensión (CBT. En este trabajo se analiza la susceptibilidad a la CBT de los aceros inoxidables, endurecibles por precipitación, 17-4PH y 17-7PH, ampliamente usados en alabes de turbina de vapor de centrales termoeléctricas. Las muestras se ensayaron en presencia de NaCl y NaOH (20 % a 90 °C, y distintos valores de pH. Se empleó el ensayo CERT (Constant Extensión Rate Test, a velocidades de 10^-6 s^-1, complementándolo con ruido electroquímico, buscando

Speed control and generation of electric power of a gas turbine by means of fuzzy-logic; Control de velocidad y de generacion de potencia electrica de una turbina de gas mediante logica difusa

Energy Technology Data Exchange (ETDEWEB)

Bahamaca Fernandez, Luis Jonathan

2000-08-01

) en una estrategia de control automatico. Los controladores difusos fueron validados mediante el desarrollo de pruebas funcionales en una estructura de simulacion de un modelo matematico no lineal para turbina de gas, ambos en lenguaje de programacion C. Estas pruebas de simulacion realizadas para la evaluacion de una buena regulacion y seguimiento de la velocidad/carga dieron resultados satisfactorios, es decir, los controladores difusos minimizaron los efectos producidos por las perturbaciones programadas del sistema (originadas por las acciones del control) y presentaron un mejor seguimiento a la referencia. Por ello, el sistema de control difuso propuesto presenta un mejor desempeno en comparacion al sistema de control convencional.

Thermal analysis of the heat recuperator of a combined cycle thermoelectric central; Analisis termico del recuperador de calor de una central termoelectrica de ciclo combinado

Energy Technology Data Exchange (ETDEWEB)

Romero Paredes, Hernando; Sanchez, I; Lazcano, L C; Ambriz, Juan Jose; Alvarez, M [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D. F. (Mexico); Gonzalez, O [Comision Federal de Electricidad, Tula (Mexico)

1997-12-31

The thermoelectric centrals of the combined cycle type (Brayton Cycle and Rankine Cycle) present a series of opportunities to increase the efficiency of the combined cycle or of the generated power. This paper shows the methodology for the performance of energy balances in a heat recuperator (H. R.), typically employed in the combined cycle stations operating in Mexico, for the assessment of the energy harnessing in the different sections conforming a H. R. The effect of the installation of evaporative coolers and/or an absorption cooling system at the gas turbine compressor intake on the steam generation in the heat recuperator, is evaluated. This extra generation of steam is quantified for its potential use in the same absorption refrigeration system. From the assessment, it follows up that the steam generation in the H.R. is inversely proportional to the ambient temperature and that, although the increased amount of steam generated can not be harnessed in total by the steam turbine, the remaining fraction is good enough to cover the heat demand for the operation of the refrigeration system. [Espanol] Las centrales termoelectricas del tipo ciclo combinado (ciclo Brayton y ciclo Rankine) presentan un conjunto de oportunidades para incrementar la eficiencia del ciclo combinado o bien la potencia generada. En el presente trabajo se expone la metodologia para realizar los balances de energia en un recuperador de calor (R.C.) tipicamente utilizado en las Centrales de Ciclo Combinado (CCC) que operan en Mexico, para evaluar el aprovechamiento de la energia en las diferentes secciones que conforman un R.C. Se evalua el efecto que tiene la instalacion de enfriadores evaporativos y/o un sistema de enfriamiento por absorcion en la succion del compresor de la turbina de gas sobre la generacion de vapor en el recuperador de calor. Se cuantifica esta generacion extra de vapor para su posible utilizacion en el mismo sistema de refrigeracion por absorcion. De la evaluacion se

Thermal analysis of the heat recuperator of a combined cycle thermoelectric central; Analisis termico del recuperador de calor de una central termoelectrica de ciclo combinado

Energy Technology Data Exchange (ETDEWEB)

Romero Paredes, Hernando; Sanchez, I.; Lazcano, L. C.; Ambriz, Juan Jose; Alvarez, M. [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D. F. (Mexico); Gonzalez, O. [Comision Federal de Electricidad, Tula (Mexico)

1996-12-31

The thermoelectric centrals of the combined cycle type (Brayton Cycle and Rankine Cycle) present a series of opportunities to increase the efficiency of the combined cycle or of the generated power. This paper shows the methodology for the performance of energy balances in a heat recuperator (H. R.), typically employed in the combined cycle stations operating in Mexico, for the assessment of the energy harnessing in the different sections conforming a H. R. The effect of the installation of evaporative coolers and/or an absorption cooling system at the gas turbine compressor intake on the steam generation in the heat recuperator, is evaluated. This extra generation of steam is quantified for its potential use in the same absorption refrigeration system. From the assessment, it follows up that the steam generation in the H.R. is inversely proportional to the ambient temperature and that, although the increased amount of steam generated can not be harnessed in total by the steam turbine, the remaining fraction is good enough to cover the heat demand for the operation of the refrigeration system. [Espanol] Las centrales termoelectricas del tipo ciclo combinado (ciclo Brayton y ciclo Rankine) presentan un conjunto de oportunidades para incrementar la eficiencia del ciclo combinado o bien la potencia generada. En el presente trabajo se expone la metodologia para realizar los balances de energia en un recuperador de calor (R.C.) tipicamente utilizado en las Centrales de Ciclo Combinado (CCC) que operan en Mexico, para evaluar el aprovechamiento de la energia en las diferentes secciones que conforman un R.C. Se evalua el efecto que tiene la instalacion de enfriadores evaporativos y/o un sistema de enfriamiento por absorcion en la succion del compresor de la turbina de gas sobre la generacion de vapor en el recuperador de calor. Se cuantifica esta generacion extra de vapor para su posible utilizacion en el mismo sistema de refrigeracion por absorcion. De la evaluacion se

Curvas de entrada - salida y características de regulación de velocidad de las centrales termoeléctricas de gas - diesel mediante pruebas de campo del sistema eléctrico interconectado de potencia (SEIP) de Petroproducción

OpenAIRE

Cabrera Pazmiño, Waldo José; Morales Pazmiño, Mario Iván; Játiva Ibarra, Jesús

2012-01-01

En el presente trabajo se presentan las curvas de entrada–salida de las unidades de generación térmica con turbinas a gas del Sistema Eléctrico Interconectado de Petroproducción (SEIP). Dentro de estas curvas se encuentran: curva de costos de generación, curva de energía térmica, curva de costo incremental, curva de consumo específico y curva de eficiencia. Se presentan los resultados de las características de regulación de velocidad, como son: rapidez controlada de subida y...

Control de Matriz de Turbinas Eólicas de Eje Vertical, Mediante Fuzzy Logic.

OpenAIRE

Javier Ordóñez Riba

2014-01-01

En este TFM se pretende mejorar la extracción de energía eléctrica a partir de energía eólica, utilizando una matriz de 18 turbinas de eje vertical, posicionadas de forma, que afecten lo menos posible a la máxima transformación de energía eólica a energía eléctrica. Se pretende obtener los conocimientos necesarios en los datos eólicos, para poder decidir sobre el movimiento de la matriz, en la búsqueda de una mayor producción energética. La matriz estará dispuesta en nueve grup...

Optimización del mantenimiento preventivo utilizando las técnicas de diagnóstico integral. Fundamento teóricopráctico; Optimization of the Preventive Maintenance Using the Technique of Integral Diagnosis. Base Theoretical-Practical

Directory of Open Access Journals (Sweden)

Pedro L Hernández Domínguez

2011-02-01

Full Text Available Se expone un método para la optimización del mantenimiento preventivo planificado (MPP a partir de laintroducción del mantenimiento basado en la condición (MBC en las turbinas y generadores de vapor de unacentral termoeléctrica cubana, utilizando las técnicas de diagnóstico integral. Se presenta el estado del arte deldesarrollo del mantenimiento y se caracteriza este en las centrales termoeléctricas cubanas; además, se realizaun estudio estadístico de las fallas y se presentan varios casos de estudio con la finalidad que el lector puedacomprender la necesidad de implantación de esta técnica, cuyos únicos costos son la organización de los datosde fallas y la colaboración del personal técnico ligado a las mismas. In this present paper the author exposed a method for the optimization of the planned preventive maintenance(PPM starting from the introduction of the condition based maintenance (CBM in the steam turbines and generatorsin a cuban thermoelectric power station, using the techniques of Integral Diagnosis. In the same one thestate of the art of the development of the maintenance is presented and the last one is characterized in the cubanthermoelectric power station, it is also carried out a statistical study of the failures and several cases of study arepresented with the purpose that the reader can understand the necessity of installation of this technique whoseonly costs belong the organization of the data of failures and the collaboration from the bound technical personnelto the same ones.

Enhancement of C/C-LAS joint using aligned carbon nanotubes prepared by injection chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Zhao, Feng-Ling; Fu, Qian-Gang, E-mail: fuqiangang@nwpu.edu.cn; Feng, Lei; Shen, Qing-Liang

2016-01-05

Carbon nanotubes (CNTs) enhanced carbon/carbon-lithium aluminum silicate (C/C-LAS) joint was prepared by a three-step technique of pack cementation, injection chemical vapor deposition (ICVD) and hot-pressing. A layer of aligned CNTs was grown on the surface of SiC coated C/C composites by ICVD method, and the joint was obtained by hot-pressing with magnesium aluminum silicate (MAS) as the interlayer. SEM observation reveals that the introduced CNTs result in the formation of a dense and crack-free CNT/MAS nanocomposite interface between SiC and MAS. Compared with the joints without CNTs, the average shear strength of the joints reinforced by CNTs was improved by 48% accompanied by an obvious change in failure mode from brittle fracture without CNTs to plastic fracture with CNTs. The pulling-out and bridging of CNTs on the fracture surfaces had a positive effect on the strength enhancement of the C/C-LAS joint.

Supervisory system for real time monitoring of transient thermal stresses in turbines rotors; Sistema supervisorio para el monitoreo en tiempo real de esfuerzos termicos transitorios en rotores de turbinas

Energy Technology Data Exchange (ETDEWEB)

Urquiza Beltran, Gustavo; Rios Miranda, Edmundo; Venegas Guzman, Ricardo; Alvarez Garcia, Gabriela [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1991-12-31

This article presents a supervisory system that, as its main functions, assists the operator on base of the thermal stresses, monitoring in real time the high pressure (HP) and intermediate pressure rotors (IP) of a steam turbine during the start, shut down and/or sudden load changes. The system is based on a thermal model uni-dimensional integrated to the SIMPER (Information System for the Predictive Maintenance of Rotating Equipment), tested in a 300 MW unit of Comision Federal de Electricidad (CFE). [Espanol] En este articulo se presenta un sistema supervisorio que, como funciones principales, asiste al operador con base en el monitoreo de esfuerzos termicos en tiempo real en los rotores de presion alta (PA) y presion intermedia (PI) de una turbina de vapor durante un arranque, paro y/o variaciones bruscas de carga. El sistema esta basado en un modelo termico unidimensional integrado al SIMPER (sistema informatico para el mantenimiento predictivo de equipo rotatorio), experimentado en una unidad de 300 MW de la Comision Federal de Electricidad (CFE).

Supervisory system for real time monitoring of transient thermal stresses in turbines rotors; Sistema supervisorio para el monitoreo en tiempo real de esfuerzos termicos transitorios en rotores de turbinas

Energy Technology Data Exchange (ETDEWEB)

Urquiza Beltran, Gustavo; Rios Miranda, Edmundo; Venegas Guzman, Ricardo; Alvarez Garcia, Gabriela [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1992-12-31

This article presents a supervisory system that, as its main functions, assists the operator on base of the thermal stresses, monitoring in real time the high pressure (HP) and intermediate pressure rotors (IP) of a steam turbine during the start, shut down and/or sudden load changes. The system is based on a thermal model uni-dimensional integrated to the SIMPER (Information System for the Predictive Maintenance of Rotating Equipment), tested in a 300 MW unit of Comision Federal de Electricidad (CFE). [Espanol] En este articulo se presenta un sistema supervisorio que, como funciones principales, asiste al operador con base en el monitoreo de esfuerzos termicos en tiempo real en los rotores de presion alta (PA) y presion intermedia (PI) de una turbina de vapor durante un arranque, paro y/o variaciones bruscas de carga. El sistema esta basado en un modelo termico unidimensional integrado al SIMPER (sistema informatico para el mantenimiento predictivo de equipo rotatorio), experimentado en una unidad de 300 MW de la Comision Federal de Electricidad (CFE).

10 conference and Latin American turbomachinery exhibition; 10 congreso y exposicion latinoamericana de turbomaquinaria

Energy Technology Data Exchange (ETDEWEB)

NONE

2007-11-15

This conference was done to promote the exchange of experiences among specialists, users, manufactures and research institutions in the field of the turbomachinery. To spread the last researches and developments focus to the design and maintenance of steam, gas and hydraulic turbines, axial compressors and centrifugal pumps, fans, electric motors, auxiliary equipment and cogeneration. [Spanish] Este congreso se realizo con el fin de promover el intercambio de experiencias entre especialistas, usuarios, fabricantes e institutos de investigacion en el campo de la turbomaquinaria. Divulgar las ultimas investigaciones y desarrollos enfocados al diseno y mantenimiento de turbinas de vapor, de gas e hidraulicas, compresores axiales y centrifugos, bombas, ventiladores, motores electricos, equipos auxiliares y cogeneracion.

Considerations over the effects caused by a heat recovery system for exhaust gases, adapted to gas turbines originally designed for the operation in a simple cycle; Consideraciones sobre los efectos causados por un sistema de recuperacion de calor de gases de escape, adaptado a turbinas de gas disenadas originalmente para operar bajo un ciclo simple

Energy Technology Data Exchange (ETDEWEB)

Cuesta Escobar, Cesar A [Instituto Mexicano del Petroleo, Mexico, D. F. (Mexico)

1994-12-31

This article sets out the considerations on what a heat recovery system from exhaust gases, to already installed and in operation gas turbines, and that were not originally designed to operate with this system, can cause. The potential effects are set forth on the control systems, on the combustion chambers, and in the gas turbine blades, utilized for natural gas pumping or power generation in land installations or in offshore platforms in trying to adapt to them a regenerative cycle or a heating system. Observed effects, fundamentally in the flame stability loop, flow velocity, thermal intensity coefficient, air/fuel relationships and mass flow. Also are presented the consequences that primary production system would suffer, mainly due to the natural gas pumping reduction, the space availability, the fuel consumption, and the maximum amount of heat susceptible to be recovered, comparing the requirements of this in the system. [Espanol] En este articulo se plantean las consideraciones sobre lo que puede provocar un sistema de recuperacion de calor de gases de escape adaptado a turbinas de gas ya instaladas, operando y que no fueron disenadas originalmente para operar con este sistema. Se plantean los probables efectos en los sistemas de control, en las camaras de combustion y en los empaletados de las turbinas de gas usadas para bombeo de gas natural o generacion electrica en instalaciones de tierra o plataformas marinas, al tratar de adaptarseles un ciclo regenerativo o un sistema para calentamiento. Efectos observados, fundamentalmente, en el LOOP de estabilidad de flama, velocidad del flujo, coeficiente de intensidad termica, relaciones aire-combustible y flujo masico. Tambien se presentan las consecuencias que sufriria el sistema primario de produccion debido, principalmente, a la reduccion del bombeo de gas natural, a la disponibilidad de espacio, al consumo de combustible y a la cantidad maxima de calor susceptible de recuperarse, comparada con los

Estimation of consumption of the useful life in the nozzles of a gas turbine by the phenomenon of thermal fatigue; Estimacion de consumo de vida util en las toberas de una turbina de gas por el fenomeno de fatiga termica

Energy Technology Data Exchange (ETDEWEB)

Perez Hernandez, Efrain [Centro Nacional de Investigacion y Desarrollo Tecnologico (Cenidet), Cuernavaca, Morelos (Mexico); Mazur C, Zdzislaw; Garcia Illescas, R. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2007-11-15

damage. [Spanish] La estimacion de vida util en los componentes calientes de las turbinas de gas como toberas y alabes es importante ya que sufren de cambios criticos de temperatura los cuales producen fatiga termomecanica durante los arranques, paros y cambios de fatiga para estimacion de vida util en las toberas de turbina de gas fabricados de aleacion base cobalto FSX-414 en las cuales se han desarrollado grietas durante la operacion. La inspeccion visual y metalografia de la tobera revelo muchas grietas por fatiga termomecanica en la superficie del alabe ademas de deterioracion de la aleacion. En los limites de grano se encontro una pelicula continua de carburos y tambien aumento de fraccion de carburos dentro de los granos. Esta densa y continua red de carburos reduce la ductilidad y aumenta la fragilidad, junto con la reduccion de energia de impacto (Charpy), facilita la iniciacion y propagacion de grietas. La iniciacion y propagacion de grieta en la aleacion fue debido a un mecanismo de fatiga termica y termofluencia que fue facilitado por fragilidad del material debido al deterioro previamente mencionado y a significativos niveles de esfuerzos termomecanicos. En el presente articulo se presentan los resultados de analisis de esfuerzos termicos a partir de los resultados de temperatura obtenidas de estudios previos de un analisis de transferencia de calor y flujo de fluidos mediante el programa Star-CD basado en volumen finito. Se muestra la metodologia empleada y las distribuciones de esfuerzos, los cuales se emplearon para el analisis de fatiga para la estimacion de vida util. Para eso se utilizo un modelo de elementos finitos en el programa NISA, asi como el programa de analisis de fatiga nCode. Para el conteo de ciclo de utilizo el metodo de Rainflow y se compararon los modelos de vida por fatiga de Manson-Coffin, Basquin, Morrow y Smih-Watson-Topper. La variacion de las propiedades mecanicas con la temperatura de la superaleacion empleada en esos componentes

Efecto de las condiciones de secado sobre el endurecimiento de los granos de caraota (Phaseolus vulgaris pretratados con vapor

Directory of Open Access Journals (Sweden)

María Virginia Mujica

2017-12-01

Full Text Available El endurecimiento de los granos de caraota (Phaseolus vulgaris generado por el almacenamiento en condiciones de alta temperatura y humedad relativa representa una limitante importante para su consumo. El objetivo del presente trabajo fue evaluar el efecto de un tratamiento con vapor y luego secado a los granos de P. vulgaris recién cosechados en la prevención de su endurecimiento. Inicialmente, se construyeron las curvas de secado a 40; 47,5 y 55 ºC. Seguidamente, los granos se trataron con vapor por 8 min 20 s y se sometieron a un proceso de secado, bajo un diseño central compuesto cuyos factores fueron la temperatura del aire (40 y 55 ºC y el tiempo de secado (4 y 8 h. La muestra secada de cada tratamiento se dividió en 3 lotes, el primero se analizó de inmediato y los otros se almacenaron por 5 semanas bajo 2 condiciones distintas 5 ºC/34 % HR y 37 ºC/75 % HR. Las determinaciones realizadas fueron humedad, capacidad de imbibición, tiempo de cocción y actividad de la peroxidasa soluble. El tiempo de secado fue de 6,5; 5 y 2,5 h a 40; 47,5 y 55 ºC, respectivamente, para alcanzar una humedad de 13 % (b.s.. El coeficiente de difusión resultó igual a 3,40x10-9; 3,52x10-9 y 3,87x10-9 m2/s, a 40, 47,5 y 55 ºC, respectivamente. El valor de la energía de activación fue de 7,33 kJ/mol. La aplicación de vapor y posterior secado de los granos no previno su endurecimiento, y este no dependió de la actividad de la peroxidasa soluble. Por lo que se puede inferir que los compuestos fenólicos y la enzima peroxidasa no son los únicos implicados en el mecanismo de endurecimiento de los granos de P. vulgaris.

THERMAL BARRIER COATINGS FOR GAS TURBINE APPLICATIONS: FAILURE MECHANISMS AND KEY MICROSTRUCTURAL FEATURES

Directory of Open Access Journals (Sweden)

JULIAN D. OSORIO

2012-01-01

Full Text Available Los avances en nuevos materiales para los dispositivos de generación de energía, como las turbinas a gas, han permitido incrementar su eficiencia y durabilidad para suplir la creciente demanda energética. Las altas eficiencias en las turbinas a gas como consecuencia de mayores temperaturas de operación, han sido posibles a través del desarrollo de recubrimientos de barrera térmica. Éstos son sistemas multicapas que proveen aislamiento térmico y protección contra la corrosión y erosión a alta temperatura. En este trabajo, se describe los procesos de aplicación de barreras térmicas, su microestructura y sus principales mecanismos de falla. Dos sistemas de barrera térmica son caracterizados y las nuevas tendencias de estos sistemas son resumidas.

Optimización del sistema de control de las pequeñas centrales hidroeléctricas (primera parte: Factores que dificultan la regulación

Directory of Open Access Journals (Sweden)

Luis Jerónimo García Faure

2011-02-01

Full Text Available En ocasiones se aborda el problema de la regulación de la velocidad de las turbinas mediante el gasto deagua como un hecho especializado de determinada rama de la ingeniería, y se trata de aplicar a las microy minicentrales las mismas soluciones que para la regulación de otros procesos industriales en loscuales el comportamiento dinámico de los sistemas externos ejerce poca influencia sobre el sistema decontrol utilizado.  In some occasions the problem of the regulation of the speed of hydraulic turbines is approached bymeans of the flow of water as a specialized problem of certain branch of the engineering, and it is appliedto micro hydropower and mini hydropower the same solutions that are applied to the regulation of otherindustrial processes in which the dynamic behavior of the external systems exerts little influence on thecontrol system employed.

Performance optimization methodology in a Francis turbine vacuum cleaner based on the modification of the boundary conditions; Metodologia de optimizacion del rendimiento en un aspirador de turbina Francis en base a la modificacion de las condiciones de frontera

Energy Technology Data Exchange (ETDEWEB)

Galvan Gonzalez, S.; Rubio Maya, C.; Mendoza Covarrubias, C. [Universidad Michoacana de San Nicolas Hidalgo, Morelia, Michoacan (Mexico)]. E-mail: srgalvan@umich.mx; crmaya@umich.mx; cmendoza@umich.mx; Pacheco Ibarra, J.; Martinez Patino, J. [Universidad de Guanajuato, Salamanca, Guanajuato (Mexico)

2010-11-15

This paper focus on establishing an optimization methodology for maximizing the draft tube performance as a function of the inlet velocity profile. The overall work is defined by four steps: the inlet velocity profile parametrization, the numerical optimization set-up, the numerical computational fluid dynamics (CFD) draft tube model and the objective function definition. However as the inlet velocity profile is a new challenge, each step of the parametrization must be properly validated. In the first step, a suitable parametrization with an appropriate number of variables is chosen to approximate an experimental draft tube inlet velocity profile. The second step considers the reduction of the actual numerical model to develop the CFD calculations. In the third step, the optimization algorithm set-up is specified. Finally, the objective function is evaluated. As each step is properly validated, it is considered this proved methodology will help to find an inlet velocity profile shape which will be able to suppress or mitigate the undesirable draft tube flow characteristics. [Spanish] Este documento se enfoca en establecer una metodologia de optimizacion para maximizar el rendimiento del tubo de aspiracion en funcion de las condiciones de frontera del aspirador. El metodo es definido en cuatro etapas: la parametrizacion del perfil de velocidades, la evaluacion del algoritmo de optimizacion, la valoracion de la funcion objetivo y la validacion del modelo numerico. La parametrizacion se realiza con un numero de variables apropiado para aproximar el perfil de velocidades experimental. El segundo paso considera establecer los parametros del algoritmo de optimizacion, la funcion objetivo es obtenida mediante un estudio de sensibilidad y el modelo numerico es validado y reducido en la cantidad de elementos para adecuarlo al proceso de optimizacion. Se considera que esta metodologia ayudara a encontrar un perfil de velocidad de entrada el cual reduzca las perdidas de

The use of laser diodes for control of uranium vaporization rates

International Nuclear Information System (INIS)

Hagans, K.; Galkowski, J.

1993-09-01

Within the Atomic Vapor Laser Isotope Separation (AVLIS) program we have successfully used the laser absorption spectroscopy technique (LAS) to diagnose process physics performance and control vaporization rate. In the LAS technique, a narrow line-width laser is tuned to an absorption line of the species to be measured. The laser light that is propagated through the sample is and, from this data, the density of the species can be calculated. These laser systems have exclusively consisted of expensive, cumbersome, and difficult to maintain argon-ion-pumped ring dye lasers. While the wavelength flexibility of dye lasers is very useful in a laboratory environment, these laser systems are not well suited for the industrial process control system under development for an AVLIS plant. Diode-lasers offer lower system costs, reduced man power requirements, reduced space requirements, higher system availability, and improved operator safety. We report the. successful deployment and test of a prototype laser diode based uranium vapor rate control system. Diode-laser generated LAS data was used to control the uranium vaporization rate in a hands-off mode for greater than 50 hours. With one minor adjustment the system successfully controlled the vaporization rate for greater than 147 hours. We report excellent agreement with ring dye laser diagnostics and uranium weigh-back measurements

La tecnología del vapor aplicada en las Minas de Almadén. Desde su origen hasta el Consejo de Administración

OpenAIRE

Calderón Herrera, David

2017-01-01

La desaparición de un gran número de elementos importantes del patrimonio industrial está siendo compensada en los últimos años con el incremento de la labor investigadora tradicional combinada con el uso de las técnicas de reconstrucción virtual, lo que le ha dado un nuevo impulso a la recuperación y puesta en valor de éste patrimonio acercándolo con ello a la sociedad. En este trabajo de investigación se estudia la etapa de instalación de la tecnología del vapor en las minas de Almadén (Ciu...

Cooling system at the compressors air inlet of the gas turbines from the Tula`s combined cycle central; Sistema de enfriamiento en la succion del compresor de las turbinas de gas de la central de ciclo combinado de Tula

Energy Technology Data Exchange (ETDEWEB)

Gonzalez F, Oscar [Comision Federal de Electricidad, Tula (Mexico); Romero Paredes, Hernando; Vargas, Martin; Gomez, Jose Francisco [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D. F. (Mexico)

1996-12-31

It has been formerly evaluated that it is possible to enhance notably the electric power generation in gas turbine power plants by cooling the air at the compressor inlet. It has been pointed out that provided a source of waste heat is available it can be very attractive the use of absorption refrigeration systems. In this paper the technical and the economical benefits of bringing the air inlet temperature down 8 Celsius degrees of the four gas turbines of the Combined Cycle Central of Tula, in the State of Hidalgo (combined cycle central-Tula) are evaluated. The results show that it is possible to achieve an efficiency enhancement of at least 1%, and that in very warm days up to 48 additional Megawatts can be generated, or about 10% of the installed capacity. The final economic result is very encouraging and an annual economical benefit in the order of 50 million pesos can be obtained and the refrigeration units can be amortized in approximately one year. [Espanol] Se ha evaluado anteriormente que es posible mejorar notablemente la capacidad de generacion electrica en plantas que utilizan turbinas de gas, mediante el enfriamiento del aire de succion del compresor. Se ha senalado que en la medida en que se encuentre disponible una fuente termica de desecho puede ser muy atractivo el uso de sistemas de refrigeracion por absorcion. En el presente trabajo se evaluan los beneficios tecnicos y economicos que puede tener el llevar el aire de succion hasta una temperatura de 8 grados Celsius, de las cuatro unidades de gas de la Central de Ciclo Combinado de Tula, Hidalgo (CCC-Tula). Los resultados muestran que es posible alcanzar un aumento en la eficiencia de al menos 1% y que se pueden generar, en dias muy calurosos, hasta 48 MW extras, equivalente al 10% de la capacidad instalada. El resultado economico final es muy alentador y puede llegar a tenerse un beneficio economico del orden de los 50 millones de pesos anuales y las unidades de refrigeracion podran pagarse en

Cooling system at the compressors air inlet of the gas turbines from the Tula`s combined cycle central; Sistema de enfriamiento en la succion del compresor de las turbinas de gas de la central de ciclo combinado de Tula

Energy Technology Data Exchange (ETDEWEB)

Gonzalez F, Oscar [Comision Federal de Electricidad, Tula (Mexico); Romero Paredes, Hernando; Vargas, Martin; Gomez, Jose Francisco [Universidad Autonoma Metropolitana-Iztapalapa, Mexico, D. F. (Mexico)

1997-12-31

It has been formerly evaluated that it is possible to enhance notably the electric power generation in gas turbine power plants by cooling the air at the compressor inlet. It has been pointed out that provided a source of waste heat is available it can be very attractive the use of absorption refrigeration systems. In this paper the technical and the economical benefits of bringing the air inlet temperature down 8 Celsius degrees of the four gas turbines of the Combined Cycle Central of Tula, in the State of Hidalgo (combined cycle central-Tula) are evaluated. The results show that it is possible to achieve an efficiency enhancement of at least 1%, and that in very warm days up to 48 additional Megawatts can be generated, or about 10% of the installed capacity. The final economic result is very encouraging and an annual economical benefit in the order of 50 million pesos can be obtained and the refrigeration units can be amortized in approximately one year. [Espanol] Se ha evaluado anteriormente que es posible mejorar notablemente la capacidad de generacion electrica en plantas que utilizan turbinas de gas, mediante el enfriamiento del aire de succion del compresor. Se ha senalado que en la medida en que se encuentre disponible una fuente termica de desecho puede ser muy atractivo el uso de sistemas de refrigeracion por absorcion. En el presente trabajo se evaluan los beneficios tecnicos y economicos que puede tener el llevar el aire de succion hasta una temperatura de 8 grados Celsius, de las cuatro unidades de gas de la Central de Ciclo Combinado de Tula, Hidalgo (CCC-Tula). Los resultados muestran que es posible alcanzar un aumento en la eficiencia de al menos 1% y que se pueden generar, en dias muy calurosos, hasta 48 MW extras, equivalente al 10% de la capacidad instalada. El resultado economico final es muy alentador y puede llegar a tenerse un beneficio economico del orden de los 50 millones de pesos anuales y las unidades de refrigeracion podran pagarse en

Analysis of the consumption of useful life by thermal fatigue in the gas turbine nozzles during the operation at continuous load and transients; Analisis de consumo de vida por fatiga termica en las toberas de turbina de gas durante operacion con carga continua y transitorios

Energy Technology Data Exchange (ETDEWEB)

Perez Hernandez, Efrain Betuel

2007-08-15

The gas turbines operate at extremely high temperatures, with high thermal and mechanical stresses, causing that the life of the involved components diminishes. In the present thesis the temperature distribution on the nozzle obtained in other investigation as a result of heat transfer and fluid flow analysis applying CDF code Star-CD was used. Next, the program NISA was used to perform the analysis of thermal stresses by means of finite element method. Finally, the results of stress analysis were introduced to the program nCode to accomplish the nozzle remaining useful life assessment due to thermal fatigue in critical location on the nozzle by means of the CLF module (Critical Location Fatigue). The full methodology used to determine the nozzle operational conditions, load history, material properties and the fatigue model used to determine the number of cycles to failure of the nozzle during constant load and transients operation is presented. [Spanish] Las turbinas de gas operan a temperaturas extremadamente altas, a elevados esfuerzos termicos y mecanicos, ocasionando que la vida de los componentes involucrados se reduzca. En la presente tesis se presentan los resultados realizados por otras investigaciones de temperaturas obtenidas a partir de un analisis de transferencia de calor y flujo de fluidos de la tobera mediante el programa Star-CD basado en volumenes finitos. Posteriormente, se utilizo el programa NISA para realizar el analisis de esfuerzos mediante elementos finitos. Finalmente, se llevaron los resultados al programa nCode para realizar la estimacion de vida util por fatiga termica en un punto critico de la tobera mediante el modulo CLF (Critical Location Fatigue). Se muestra la metodologia empleada para determinar las condiciones de operacion, historial de carga, propiedades del material y el modelo de dano por fatiga para determinar el numero de ciclo para falla de la tobera durante operacion con carga continua y transitorios.

Soldadura por fricción lineal de las aleaciones de titanio: caracterización de una soldadura longitudinal mediante ensayos a tracción

OpenAIRE

Grand, Arnaud

2006-01-01

Doble titulació La unión entre los álabes y el disco de una turbina de avión está en plena evolución por la aplicación del proceso de soldadura por fricción lineal (LFW) a las aleaciones de titanio. Ello permite conseguir una pieza única llamada blisk (blade + disk). Hasta ahora, la unión álabe / disco se hacía por un ensamblaje mecánico, pero estos sufren un fenómeno de fatiga por fretting en el punto de anclaje. A parte de evitar ese fenómeno, la soldadura por fricción lin...

Feasibility. Technical and financial concepts to determine the feasibility of a self-supplying project; Factibilidad. Conceptos tecnicos y financieros para determinar la factibilidad de un proyecto de autoabastecimiento

Energy Technology Data Exchange (ETDEWEB)

Vargas A, Enrique [IGSA S.A. de C.V. (Mexico)

2005-07-01

The co-generation is the transformation of an energy source to two or more forms. This document deals with the co-generation equipment: gas turbines, steam turbines and reciprocating motors. It also provides a comparison between turbines and motors altogether with an analysis determining how the savings in the co-generation are obtained -an analysis dealing with thermal balance, the advantage of the radiation, the heat of the oil, the heat of the coolant, the exhaust heat and the production cost of 1 kwh. [Spanish] La cogeneracion es la transformacion de una fuente de energia a dos o mas formas. En este documento se analizan los equipos de cogeneracion: turbinas de gas, turbinas de vapor y motores reciprocantes, de la comparacion entre turbinas y motores, de como se logran los ahorros en la cogeneracion, del balance termico, el aprovechamiento de la radiacion, del calor del aceite, del calor del refrigerante, del calor del escape y del costo en la produccion de 1 kwh.

Changes in steam production due to the reservoir conditions in Cerro Prieto, Baja California; Cambios en la produccion de vapor debido a las condiciones del yacimiento en Cerro Prieto, Baja California

Energy Technology Data Exchange (ETDEWEB)

Morales Cardenas, Ramon; Rodriguez Rodriguez, Marco H. [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Residencia General de Cerro Prieto, Mexicali, B.C. (Mexico)]. E-mail: marco.rodriguez01@gfe.gob.mx

2011-07-15

In more than 35 years of exploitation, thermodynamic conditions have changed in the Cerro Prieto geothermal reservoir. The effects are analyzed of the changes to the reservoir and their consequences to steam production in different field zones. For steam production, the most important features of reservoir fluids are enthalpies and pressures. The evolution of these features is presented in an enthalpy-pressure diagram. Here it can be seen that some reservoir zones have almost reached abandonment conditions. [Spanish] En mas de 35 anos de explotacion el yacimiento geotermico de Cerro Prieto ha experimentado cambios en sus condiciones termodinamicas. En este trabajo se analiza el efecto de esos cambios del yacimiento y su repercusion en la produccion de vapor para las diferentes zonas en las que se ha dividido el campo. Las propiedades mas importantes del fluido en el yacimiento para la produccion de vapor son su entalpia y su presion, por lo que se presenta la evolucion de esas propiedades en un diagrama de presion-entalpia, en el que se observa que hay zonas del yacimiento que estan proximas a alcanzar condiciones de abandono.

Custo de bombas centrífugas funcionando como turbinas em microcentrais hidrelétricas Cost of pumps as hydraulic turbines for micro-scale hydropower

Directory of Open Access Journals (Sweden)

Carlos R. Balarim

2004-04-01

Full Text Available A implantação de microcentrais hidrelétricas é uma das alternativas para suprir com energia comunidades pequenas e isoladas, situadas normalmente na área rural. O aproveitamento de potenciais hidráulicos de pequeno porte é uma alternativa cada vez mais viável devido não só à falta de recursos financeiros para os grandes empreendimentos, mas também pelo imenso potencial de geração em centrais de pequeno porte, que pouco tem sido aproveitado. O objetivo deste trabalho foi de apresentar uma metodologia simples de engenharia para estimar o custo das Bombas Funcionando como Turbinas (BFTs utilizadas em microcentrais hidrelétricas, que possam ser usadas em estudos preliminares de novos aproveitamentos hidrelétricos, sem uma investigação detalhada dos lugares onde se pretende implantar. Os custos foram obtidos consultando-se diretamente os fabricantes de equipamentos e o mercado da praça de Ponta Grossa - PR. Os resultados mostraram que, para as microcentrais hidrelétricas, sempre que os custos constituírem o aspecto dominante, e para potências até 50 kW, a opção por Bombas Funcionando como Turbinas (BFTs deve ser considerada em lugar das turbinas hidráulicas.The implantation of micro hydroelectric power stations is one of the alternatives to supply energy to small and isolated communities, normally located in rural areas. The use of small load hydraulic potential is an alternative more feasible nowadays, not only because it lacks financial resources for big undertakings, but also, due to the small hydro power station hydraulic generation potential, which just a very small part has been taken advantage of. The objective of this study was to show a simple engineering methodology in order to estimate the electro-mechanic (generating set equipment costs used in micro hydroelectric power plants, which can be applied on preliminary studies about new hydroelectric power stations to be built, without detailed investigation about the

Incorporation of a wind generator model into a dynamic power flow analysis; Incorporacion de un modelo de generador eolico al analisis de flujos dinamicos de potencia

Energy Technology Data Exchange (ETDEWEB)

Angeles Camacho, C.; Banuelos Ruedas, F. [Instituto de Ingenieria, Universidad Nacional Autonoma de Mexico (Mexico)]. E-mail: cangelesc@iingen.unam.mx; fbanuelosr@iingen.unam.mx

2011-07-15

Wind energy is nowadays one of the most cost-effective and practical options for electric generation from renewable resources. However, increased penetration of wind generation causes the power networks to be more depend on, and vulnerable to, the varying wind speed. Modeling is a tool which can provide valuable information about the interaction between wind farms and the power network to which they are connected. This paper develops a realistic characterization of a wind generator. The wind generator model is incorporated into an algorithm to investigate its contribution to the stability of the power network in the time domain. The tool obtained is termed dynamic power flow. The wind generator model takes on account the wind speed and the reactive power consumption by induction generators. Dynamic power flow analysis is carried-out using real wind data at 10-minute time intervals collected for one meteorological station. The generation injected at one point into the network provides active power locally and is found to reduce global power losses. However, the power supplied is time-varying and causes fluctuations in voltage magnitude and power flows in transmission lines. [Spanish] La energia eolica es hoy en dia una de las opciones mas efectivas y practicas para la generacion de electricidad a partir de energias renovables. Sin embargo, el incremento de la penetracion de energia eolica provoca que los sistemas de potencia se vuelvan mas dependientes y vulnerables a las variaciones de la velocidad del viento. El modelado es una herramienta que provee informacion valiosa de la interaccion dinamica entre las turbinas eolicas y las redes de potencia a las que se conectan. El presente articulo desarrolla una caracterizacion realista de un modelo de la turbina eolica. El modelo de la turbina eolica se incorpora a un algoritmo para el analisis de su contribucion a la estabilidad de una red electrica en el dominio del tiempo. La herramienta obtenida se conoce como flujos

Analysis of conjugated heat transfer, in transient state of the first stage of a gas turbine; Analisis de transferencia de calor conjugada, en estado transitorio, de la primera etapa de una turbina de gas

Energy Technology Data Exchange (ETDEWEB)

Campos Amezcua, Alfonso; Mazur C, Zdzislaw [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Gallegos Munoz, Armando [Facultad de Ingenieria Mecanica, Electrica y Electronica (FIMEE), Universidad de Guanajuato, Guanajuato (Mexico)

2007-11-15

This article presents an analysis of conjugated heat transfer in the first stage of movable blades during the starting of a gas turbine, covering a period of 1,012 seconds. The developed computer model is in 3D and uses as initial and border conditions typical starting curves for stack gases, the cooling air and the angular velocity of the blades. As a result of the numerical predictions, the temperature distributions in stack gases, the trowel of the blade and the cooling air are included, doing emphasis in the results obtained in the solid (body of the blade), since these are used for thermo-mechanical stress analysis and later estimation of the blade residual life. [Spanish] Este articulo presenta un analisis de transferencia de calor conjugada en la primera etapa de alabes moviles, durante el arranque de una turbina de gas, cubriendo un periodo de 1.012 segundos. El modelo computacional desarrollado es en tres dimensiones y utiliza como condiciones iniciales y de frontera curvas de arranque tipicas para los gases de combustion, el aire de enfriamiento y la velocidad angular de los alabes. Como resultado de las predicciones numericas, se incluyen las distribuciones de temperatura en los gases de combustion, la paleta del alabe y el aire de enfriamiento, haciendo enfasis en los resultados obtenidos en el solido (cuerpo del alabe), ya que estos se utilizan para analisis de esfuerzos termomecanicos y posterior estimacion de vida residual del alabe.

Modelo Dinámico de un Recuperador de Gases -Sales Fundidas para una Planta Termosolar Híbrida de Energías Renovables

Directory of Open Access Journals (Sweden)

Javier Bonilla

2017-01-01

Full Text Available Resumen: En este artículo se presenta un modelo dinámico para un recuperador de gases - sales fundidas incluido en una planta de demostración de una tecnología de hibridación de plantas termosolares con otras fuentes de energías renovables. Tanto el demostrador como el modelo se han desarrollado en el ámbito del proyecto HYSOL. Este trabajo describe brevemente dicho proyecto, su tecnología, demostrador y principalmente el modelo dinámico del recuperador, cuyo estado estacionario ha sido comparado con los cálculos de diseño. El artículo se completa con simulaciones dinámicas donde se estudia la convergencia del modelo, la contribución de los distintos procesos físicos a la transferencia de calor y el impacto de las condiciones ambientales a las pérdidas térmicas. Abstract: In this paper, a dynamic model of a molten salt -gas heat recovery system of a demonstrator for a hybrid renewable solar thermal power plant, developed in the scope of the HYSOL project, is presented. This work describes briefly the HYSOL project, its technology, the demonstrator and mainly the developed heat recovery system dynamic model; its steady state has been compared to the expected results from plant design calculations. This paper is completed with dynamic simulations where, the model convergence is studied, the contribution of the different heat transfer processes is analyzed, and the impact of the environment conditions to thermal losses is evaluated. Palabras clave: Almacenamiento térmico, Energía solar de concentración, Turbina de vapor, Turbina de gas, Modelica, Keywords: Thermal storage, Concentrating solar power, Steam turbine, Gas turbine, Modelica

Viabilidade de utilização de micro-turbinas eólicas para produção de energia elétrica

OpenAIRE

Oliva, João Miguel Ferreira

2016-01-01

A utilização de combustíveis fósseis para colmatar as necessidades energéticas tem vindo a aumentar continuamente as emissões de Dióxido de Carbono e outros gases de efeito estufa (GEE) que contribuem, também, para o aquecimento global. Uma das formas de minimizar estes efeitos negativos é com a utilização de energias renováveis, como a energia proveniente do sol, vento, ondas e biomassa. A energia do vento é utilizada para a produção de energia elétrica através de turbinas eólicas, estas pod...

State of the art of technologies thermosolar to concentration; Estado del arte de las tecnologias termosolares a concentracion

Energy Technology Data Exchange (ETDEWEB)

Ramos Berume, Carlos; Huacuz Villamar, Jorge M; Medrano Vaca, M. Consolacion [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

2000-07-01

focal (tubo metalico receptor). Por el interior de este tubo circula un fluido de trabajo (aceite termico) a temperaturas de hasta 390 grados Celsius, el cual es enviado a intercambiadores de calor para producir vapor sobrecalentado para operar una turbina y generar la energia electrica y Plato Parabolico (PP), contiene una estructura formada por segmentos de espejos que conforman un paraboloide donde en su punto focal (receptor/maquina termica) incide en la radiacion reflejada y se produce energia electrica. En este documento se presenta el estado del arte de las Tecnologias Termosolares a Concentracion (YYC) que permiten identificar sus desarrollos y problematica actual. Ademas, se incluye una descripcion de las perspectivas de mercado, costos de las TTC y las perspectivas tecnologicas.

Comparison of molecular models of carbon monoxide for calculation of vapor-liquid equilibrium

Directory of Open Access Journals (Sweden)

Bibian Alonso Hoyos-Madrigal

2015-01-01

Full Text Available Existen varios modelos moleculares para el monóxido de carbono desarrollados a partir de diferentes mediciones experimentales. El objetivo de este trabajo es comparar los resultados que varios de estos modelos producen en el cálculo del equilibrio líquido-vapor en busca de recomendar qué modelo debe ser usado de acuerdo la propiedad y la fase que se desea calcular. Los modelos seleccionados corresponden a cuatro modelos no polares, con uno o dos sitios Lennard-Jones, y cuatro modelos polares, con dipolos o cargas parciales para representar la polaridad del monóxido de carbono. Simulaciones Monte Carlo en la versión Gibbs canónica (NVT-GEMC se emplearon para determinar las densidades de las fases en equilibrio, la presión de vapor y la entalpia de vaporización entre 80 y 130 K con cada uno de los modelos seleccionados. Se encontró que los modelos más complejos SVH, ANC y PGB, son los que mejor describen la densidad del líquido saturado (alrededor de 7% de desviación promedio, pero estos modelos generan desviaciones mayores al 40% para las propiedades del vapor y al 20% para la entalpia de vaporización. Por otro lado, el modelo no- polar BLF generó las menores desviaciones para la presión de saturación y la densidad del vapor (6.8 y 21.5%, respectivamente. Este modelo, al igual que el modelo HCB, produce desviaciones aceptables para la densidad del líquido y la entalpia de vaporización (entre 10 y 12%. Los modelos no polares BLF y HCB, que no requieren el cálculo de las interacciones de largo alcance, se pueden considerar como los modelos moleculares que presentan un balance satisfactorio entre desviaciones en los resultados y complejidad de cálculo.

Diseño y construcción de una turbina de gas para generación de baja potencia (TGBP con ciclo regenerativo a partir de un turbocargador

Directory of Open Access Journals (Sweden)

Cesar Eduardo Mondragón Cediel

2010-01-01

Full Text Available La ciudad de Cantagallo (Bolívar en Colombia requiere 21kW de energía eléctrica para suplir las necesidades de su población ya que no tiene acceso a la red de interconexión eléctrica como muchas otras ciudades del país. La aplicación de la generación distribuida a partir de turbinas de gas de baja potencia (TGBP para suplir estas necesidades es viable en Colombia, además las TGBP a partir de turbocargadores automotrices suplen completamente los requerimientos de la generación distribuida aislada y de soporte de la red de distribución en plantas, fábricas y edificios; por lo tanto se realiza el dise.o detallado y construcción de una TGBP que genera 30kW, cuyas características específicas y técnicas le permiten ser aplicable como sistema de Generación Distribuida en Colombia a partir de un turbocargador automotriz empleando el ciclo termodinámico regenerativo para disminuir  el consumo espec.fico de combustible (SFC y por lo tanto aumentar la eficiencia del ciclo, con sus respectivos sistemas de inyección de combustible, ignición, lubricación y de adquisición de datos. Se realiza una metodolog.a de dise.o de: TGBP con ciclo regenerativo, de c.maras de combusti.n tubulares y de intercambiadores de calor (recuperadores empleando fuentes bibliográficas especializadas en el desarrollo de motores a reacción a nivel mundial así como software FEA, CFD y tecnologías de fabricación asequibles y encontradas en Colombia.

Adsorción física de gases y vapores por carbones

OpenAIRE

Martín-Martínez, José Miguel

1990-01-01

El establecimiento de las características texturales de carbones es esencial para su utilización en procesos industriales. La evaluación de la textura porosa de carbones se suele realizar mediante adsorción de gases y vapores. Por esta razón, en este libro se pretende plantear las principales estrategias más generalmente empleadas para cualificar la superficie y porosidad de carbones.

Mobile vapor recovery and vapor scavenging unit

International Nuclear Information System (INIS)

Stokes, C.A.; Steppe, D.E.

1991-01-01

This patent describes a mobile anti- pollution apparatus, for the recovery of hydrocarbon emissions. It comprises a mobile platform upon which is mounted a vapor recovery unit for recovering vapors including light hydrocarbons, the vapor recovery unit having an inlet and an outlet end, the inlet end adapted for coupling to an external source of hydrocarbon vapor emissions to recover a portion of the vapors including light hydrocarbons emitted therefrom, and the outlet end adapted for connection to a means for conveying unrecovered vapors to a vapor scavenging unit, the vapor scavenging unit comprising an internal combustion engine adapted for utilizing light hydrocarbon in the unrecovered vapors exiting from the vapor recovery unit as supplemental fuel

Fatigue lifespan of a mobile blade gas turbine with ceramic coating; Vida util por fatiga de un alabe movil de turbina de gas con recubrimiento ceramico

Energy Technology Data Exchange (ETDEWEB)

Garcia Illescas, Rafael; Z. Mazur Czerwiec, Zdzislaw; Islas Mungarro, Ricardo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: rgi@iie.org.mx; mazur@iie.org.mx; rick_iie@terra.com.mx

2010-11-15

Fatigue analysis of a gas turbine moving blade made of IN738LC was carried out in order to evaluate useful life time. The life estimation was done from a previous 3D linear finite element analysis where thermal and mechanical stress calculation at high temperatures was done during steady and transient state i.e. normal start ups and shutdowns. Several load histories with different stresses and strains in the blade were used for different cooling conditions including a thermal barrier coating in comparison with to simple blade without such coating. The important effect of high temperatures on the blade material and stress calculations is shown. The analysis is focused on two different critical zones in the blade: the leading edge at the middle of the height and a cooling channel surface, where high stresses were found in numerical analysis as well as in reality. Finally, the benefit of the presence of a thermal barrier coating in the blade life is shown. [Spanish] Se realizo el analisis de fatiga de un alabe movil de turbina de gas fabricado de IN738LC a fin de evaluar su vida util. La estimacion de vida fue realizada a partir de simulaciones lineales de esfuerzos termomecanicos por elemento finito en 3D a altas temperaturas y durante el arranque y paro normal. Se utilizaron diversos historiales de carga, esfuerzos y deformaciones del alabe para diferentes configuraciones de enfriamiento incluyendo el recubrimiento ceramico tipo barrera termica en comparacion con los resultados sin incluir dicho recubrimiento. Se presenta el efecto importante de las temperaturas elevadas en las propiedades de fatiga del material del alabe y en sus esfuerzos. El analisis se centra en dos puntos de interes identificados como criticos: borde de entrada y un canal de enfriamiento, en donde esfuerzos elevados fueron encontrados tanto numericamente como en la realidad. Finalmente se muestra el beneficio del recubrimiento tipo barrera termica en la vida del alabe.

Oxidación en vapor de agua del acero inoxidable aisi 317 a 700 y 750ºc

OpenAIRE

MARULANDA AREVALO, JOSE LUDDEY; REMOLINA MILLAN, ADULJAY; BARON, JAIRO ALBERO

2013-01-01

Se realizó la oxidación del acero inoxidable austenítico AISI SAE 317, a temperaturas de 700 y 750ºC, en un ambiente con 100% vapor de agua, para evaluar su comportamiento a la corrosión. Se realizaron curvas de ganancia de masa y las películas de óxidos se analizaron por medio de Microscopia Electrónica de Barrido (SEM) y difracción de rayos X (DRX), para observar cómo se forman las capas de óxidos y discutir el posible mecanismo de oxidación en vapor de agua. Se encontró que el mecanismo de...

OXIDACIÓN EN VAPOR DE AGUA DEL ACERO INOXIDABLE AISI 317 A 700 Y 750ºC

OpenAIRE

José Luddey Marulanda Arevalo; Aduljay Remolina Millan; Jairo Alberto Barón

2013-01-01

Se realizó la oxidación del acero inoxidable austenítico AISI SAE 317, a temperaturas de 700 y 750ºC, en un ambiente con 100% vapor de agua, para evaluar su comportamiento a la corrosión. Se realizaron curvas de ganancia de masa y las películas de óxidos se analizaron por medio de Microscopia Electrónica de Barrido (SEM) y difracción de rayos X (DRX), para observar cómo se forman las capas de óxidos y discutir el posible mecanismo de oxidación en vapor de agua. Se encontró que el mecanismo de...

Vapor pressures and enthalpies of vaporization of azides

International Nuclear Information System (INIS)

Verevkin, Sergey P.; Emel'yanenko, Vladimir N.; Algarra, Manuel; Manuel Lopez-Romero, J.; Aguiar, Fabio; Enrique Rodriguez-Borges, J.; Esteves da Silva, Joaquim C.G.

2011-01-01

Highlights: → We prepared and measured vapor pressures and vaporization enthalpies of 7 azides. → We examined consistency of new and available in the literature data. → Data for geminal azides and azido-alkanes selected for thermochemical calculations. - Abstract: Vapor pressures of some azides have been determined by the transpiration method. The molar enthalpies of vaporization Δ l g H m of these compounds were derived from the temperature dependencies of vapor pressures. The measured data sets were successfully checked for internal consistency by comparison with vaporization enthalpies of similarly structured compounds.

Methodology for energy diagnosis in distribution steam lines; Metodologia para diagnostico de energia en lineas de distribucion de vapor

Energy Technology Data Exchange (ETDEWEB)

Almanza, M; Ambriz, J J; Romero P, H [Universidad Autonoma Metropolitana Iztapalapa, Mexico, D. F. (Mexico)

1993-12-31

This paper shows a methodology that results of great advantage in the development of the energy analysis of an industrial facility that utilizes steam as a mean of energy transport and where the steam operated equipment is physically located in a remote place, away from the generation site. Mention is made here of the equipment characteristics that can be used for such purpose, the most important parameters to identify in a rapid and efficient way the faults presented in the steam distribution system in the industrial plants and the formats that contribute to keep the corresponding records for efficiently maintain in operation the steam pipeline net in conjunction with the involved accessories. [Espanol] En el presenta trabajo se muestra una metodologia que resulta de gran utilidad en el desarrollo del analisis energetico de una planta industrial, en la cual se emplee el vapor como medio de transporte de la energia y en donde el equipo que utiliza el vapor se encuentre fisicamente en un lugar apartado de la zona de generacion. Aqui se mencionan las caracteristicas del equipo que se puede utilizar para dicho diagnostico, los parametros de mayor importancia para identificar en forma rapida y eficiente las fallas que se presentan en el sistema de distribucion de vapor en las plantas industriales y los formatos que contribuyen a llevar los registros correspondientes para mantener operando eficientemente la red de vapor, en conjunto con los accesorios que en ella se involucran.

Methodology for energy diagnosis in distribution steam lines; Metodologia para diagnostico de energia en lineas de distribucion de vapor

Energy Technology Data Exchange (ETDEWEB)

Almanza, M.; Ambriz, J. J.; Romero P, H. [Universidad Autonoma Metropolitana Iztapalapa, Mexico, D. F. (Mexico)

1992-12-31

This paper shows a methodology that results of great advantage in the development of the energy analysis of an industrial facility that utilizes steam as a mean of energy transport and where the steam operated equipment is physically located in a remote place, away from the generation site. Mention is made here of the equipment characteristics that can be used for such purpose, the most important parameters to identify in a rapid and efficient way the faults presented in the steam distribution system in the industrial plants and the formats that contribute to keep the corresponding records for efficiently maintain in operation the steam pipeline net in conjunction with the involved accessories. [Espanol] En el presenta trabajo se muestra una metodologia que resulta de gran utilidad en el desarrollo del analisis energetico de una planta industrial, en la cual se emplee el vapor como medio de transporte de la energia y en donde el equipo que utiliza el vapor se encuentre fisicamente en un lugar apartado de la zona de generacion. Aqui se mencionan las caracteristicas del equipo que se puede utilizar para dicho diagnostico, los parametros de mayor importancia para identificar en forma rapida y eficiente las fallas que se presentan en el sistema de distribucion de vapor en las plantas industriales y los formatos que contribuyen a llevar los registros correspondientes para mantener operando eficientemente la red de vapor, en conjunto con los accesorios que en ella se involucran.

Fault diagnosis in the steam turbo-generator of a Combined Cycle Power Plant; Diagnostico de fallas en el turbogenerador a vapor de una central de generacion de ciclo combinado

Energy Technology Data Exchange (ETDEWEB)

Flores Abad, Angel

2006-12-15

sensores y actuadores. En la actualidad este tipo de centrales tiende a dominar el mercado de generacion electrica por medio de combustibles fosiles, debido a que son las mas eficientes, rentables, de operacion flexible y con menor impacto ambiental. En la CGCC, la turbina de vapor (TV) es una componente fundamental, ya que representa la ganancia del proceso en el sentido de que permite la generacion de energia electrica adicional al aprovechar los gases de escape de la turbina de gas. En caso de que la TV falle, la eficiencia global del proceso se reduce hasta en un 40%. Por lo anterior, en este trabajo se desarrollo un sistema de diagnostico de fallas basado en modelos, de acuerdo a la metodologia FDI (Fault Detection and Isolation) de la teoria de control, con capacidad para detectar y localizar fallas en los sensores y actuadores del turbogenerador a vapor de una CGCC. El enfoque que se utilizo emplea la redundancia analitica con el objetivo de optimizar la redundancia fisica, de manera que sea posible disminuir el costo y espacio extra que implica el utilizar dispositivos repetidos. El diseno del sistema se llevo a cabo usando el analisis estructural AE) que es una herramienta basada en la teoria de grafos y ciencias de la computacion. El AE permitio realizar: analisis de monitoreabilidad, detectabilidad y aislabilidad del proceso; y proporciono la secuencia de computo de las variables no monitoreadas (desconocidas) para obtener las relaciones de redundancia analitica. Para validar el sistema de diagnostico de fallas de la TV, se programaron los algoritmos de deteccion y localizacion de fallas en LabWindows, CVI y se integraron al simulador de la CGCC. Ademas para facilitar al usuario la visualizacion de la presencia de una falla se desarrollo una interfase grafica que indica el elemento con comportamientos anormales, ya sea sensor o actuador.

Rediseño y construcción de un sistema de filtro de agua automático y estudio para la disminución de la velocidad del agua en el canal

OpenAIRE

Cueva Jiménez, Jason Satalin

2012-01-01

El presente documento trata sobre el rediseño de un filtro de agua automático cuya finalidad es liberar de material flotante al agua que ingresa desde el Río Monjas en Bocatoma y que fluye por el canal de conducción hacia las turbinas Pelton de la planta generadora de energía de la central hidroeléctrica de Vindobona. La mayoría de material flotante que circula hacia el filtro es liviano ya que permanecen en la superficie, además las partículas más pesadas son separadas del agua en las pis...

Flow measurement in a 170-MW hydraulic turbine using the Gibson method; Medicion del flujo de una turbina hidraulica de 170 MW utilizando el metodo Gibson

Energy Technology Data Exchange (ETDEWEB)

Urquiza, Gustavo [Universidad Autonoma del Estado de Morelos (Mexico); Adamkowski, Adam [The Szewalski Institute of Fluid-Flow Machinery (Poland); Kubiak, Janusz; Sierra, Fernando [Universidad Autonoma del Estado de Morelos (Mexico); Janicki, Waldemar [The Szewalski Institute of Fluid-Flow Machinery (Poland); Fernandez, J. Manuel [Comision Federal de Electricidad (Mexico)

2007-07-15

-tiempo o de Gibson. Este metodo esta basado en el fenomeno del golpe de ariete y es aplicado al caso de una tuberia de presion de tuberia hidraulica. La version del metodo usado en el presente trabajo consiste en la medicion, durante el rechazo total de carga, del historial de tiempo y del cambio de presion en una seccion de la tuberia de presion y relaciona este cambio de presion con el nivel del embalse de la central hidroelectrica. El flujo volumetrico se determina mediante la integracion del incremento de la diferencia de presion medida con respecto al tiempo. La medicion del flujo fue posible gracias a la poca influencia de la entrada del flujo a la tuberia de presion, de 300 m longitud, evitando asi introducir un error considerable en la medicion. Se aplicaron y adoptaron para la medicion los criterios de la norma IEC-41-1991 y experiencias previas. Se utilizo un sistema de adquisicion de datos rapido y eficiente, el cual incluye una tarjeta de 16 bit. El flujo fue calculado usando un programa de computo desarrollado y probado en varios casos anteriores. Los resultados obtenidos con el metodo Gibson fueron utilizados para la calibracion de un sistema de medicion en linea basado en el metodo relativo de Winter-Kennedy. Este ultimo se usa comunmente para el monitoreo continuo del flujo de turbinas hidraulicas, siempre y cuando la calibracion en sitio haya sido realizada usando los resultados de las mediciones de un metodo absoluto. Una vez medido el flujo y la potencia de salida, se calculo la eficiencia para diferentes condiciones de operacion. Se discuten y presentan los resultados obtenidos en una curva, la cual muestra las mejores condiciones de operacion basadas en la mayor eficiencia. Los detalles de la instrumentacion, su instalacion y otros resultados obtenidos se discuten tambien en el presente articulo.

Pressure fluctuations on the bed of surge tank at the H.P. Zimapan, Hgo., with different arrangements studied on hydraulic model, with the lowest operation conditions; Fluctuaciones de presion en la base del pozo de oscilacion del P.H. Zimapan Hgo., con diferentes arreglos estudiados en modelo hidraulico ante las condiciones minimas de operacion

Energy Technology Data Exchange (ETDEWEB)

Marengo Mogollon, H. [Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico (Mexico)]. E-mail: humberto.marengo@cfe.gob.mx; Ochoa Alvarez, F.J.; Cortes Cortes, C. [Comision Federal de Electricidad (Mexico)]. E-mail: federico.ochoa@cfe.gob.mx; carlos.cortes01@cfe.gob.mx

2009-10-15

In this paper, the pressure fluctuations of the surge tank in the Zimapan Hydroelectric Project are compared in a hydraulic model. The shaft is located lateral, over the conduction tunnel and in the simple form (permitting the tunnel entering the shaft); with and without orifice plates taking into account the demand and supply condition of energy with the minimum level of water of the conduction. It was determined the hydraulic efficiency and it was found that it was the best constructive option. [Spanish] En este articulo se comparan las fluctuaciones de presion en el pozo de oscilacion del P.H. Zimapan, Hgo., Mexico las cuales fueron estudiadas en modelo hidraulico al considerar dicho pozo ubicado en diferentes posiciones; lateralmente y sobre el eje de la conduccion; pozo simple y con tuberia de conexion; con y sin placa de orificio, para maniobras de rechazo y demanda de carga de las turbinas de generacion con el nivel del agua correspondiente al NAMINO. Se determino la eficiencia hidraulica comparandola con las otras opciones encontrandose que la mejor opcion para el funcionamiento hidraulico es el pozo lateral, que ademas permite optimizar el procedimiento constructivo.

Carbón activado de semillas de tomate para adsorción de vapores de amoniaco, benceno y gasolina//Activated coal of tomato seeds for adsorption of vapors of ammonia, benzene and gasoline

Directory of Open Access Journals (Sweden)

Francisco Márquez-Montesino

2013-05-01

Full Text Available El objetivo fue comprobar las posibilidades de adsorción de amoniaco, benceno y gasolina en carbones activados, de semillas de tomate. Se realizó un análisis inmediato a la biomasa. Se concluyó que la adsorción de vapores de amoniaco, está relacionada con la adsorción física y con la presencia de gruposfuncionales de carácter ácido en la superficie activa de los carbones, que forman enlaces débiles con las moléculas de amoniaco. Se realizaron experimentos de adsorción de benceno y gasolina, que no tienen grupos funcionales como el amoniaco, siendo menos adsorbidos, confirmándose una adsorción preferentemente química. La temperatura de activación, la relación de impregnación (RI y laconcentración de la disolución ácida, no tuvieron una influencia significativa en la capacidad de adsorción de benceno, pero sí en la adsorción de amoniaco y vapores de gasolina, de gran aplicación para la eliminación de los vapores de escape en los motores de vehículos.Palabras claves: carbón, activación, adsorción, vapores, amoníaco._______________________________________________________________________________AbstractThe objective was to prove the adsorption possibilities of ammonia, benzene and vapors of gasoline in activated coals with phosphoric acid, of tomato seed. An immediate analysis to the biomass was carried out. It was concluded that the vapors adsorption of ammonia, is related with the physical adsorption andthe presence of functional groups of acid character in the active surface of the coal that form weak connections with the molecules of ammonia. Experiments of adsorption of benzene and gasoline were carried out, these substances haven't functional groups as the ammonia, so they were less adsorbed, and it was confirmed a chemical adsorption preferably. The activation temperature, the relationship of impregnation (RI and the concentration of the acid dissolution haven't a significant influence in the capacity of

Estudio del comportamiento en caliente del Inconel 718

OpenAIRE

Thomas, Amandine

2005-01-01

Las aleaciones Inconel son superaleaciones base níquel-cromo, que cubren un amplio espectro de composiciones y de propiedades. Son superaleaciones que tienen buenas propiedades de resistencia mecánica y a la corrosión que se mantienen a temperaturas altas. Las aplicaciones de estas aleaciones son muy amplias: recipientes para tratamiento térmico, turbinas, aviación, plantas nucleares generadoras de energía, etc... El Inconel 718 en particular es una aleación endurecible por precipitación, ...

3D analysis of Navier-Stokes in steady state of the behavior of the flow in the Inter stage 1 of a gas turbine Frame 7; Analisis de navier-stokes tridimensional en estado estable del comportamiento del flujo en la inter etapa 1 de una turbina de gas frame 7

Energy Technology Data Exchange (ETDEWEB)

Henandez Rosete, Alejandro; Mazur C, Zdzislaw [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2007-11-15

The results of the simulation by CFD (Computacional Fluid Dynamics) realized to the first stage of a gas turbine GE Frame 7 are presented. The analysis includes the 3D modeling of the flow channel in the nozzle and the movable blade to know the velocities distributions, temperatures and pressures of the main hot gas flow that are developed in the Inter stage. The results are influenced by the imposed border conditions in the properties of the main flow, the rotation of the movable blade, as well as the simulation of cooling air injection in the nozzle. The present study focuses in the validation of the model of the meshes of the ensemble nozzle-blade, for later realize an analysis of conjugated heat transfer in a model with ceramic lining type heat barrier (THB) in the movable blade. The analysis is realized in a CFD commercial code oriented to turbo-machinery using the equations of unstable flows 3D of Navier Stokes. [Spanish] Se presentan los resultados de la simulacion por CFD (Computacional Fluid Dynamics) realizada a la primera etapa de una turbina de gas GE Frame 7. El analisis incluye la modelacion tridimensional del canal de flujo en la tobera y el alabe movil para conocer las distribuciones de las velocidades, temperaturas y presiones del flujo principal de gases calientes que se desarrollan en la inter etapa. Los resultados son influenciados por las condiciones de frontera impuestos en las propiedades del flujo principal, la rotacion del alabe movil, asi como la simulacion de inyeccion de aire de enfriamiento en la tobera. El presente estudio se enfoca en la validacion del modelo de la malla del conjunto tobera-alabe, para posteriormente realizar un analisis de transferencia de calor conjugada en un modelo con recubrimiento ceramico tipo barrera termica (TBC) en el alabe movil. El analisis es realizado en un codigo de CFD comercial orientado a turbomaquinaria utilizando las ecuaciones de flujos inestables 3D de Navier Stokes.

Las obras de acondicionamiento del Salto del Mont-Cenis

Directory of Open Access Journals (Sweden)

Vié, Georges

1969-06-01

Full Text Available The new dam at Mont Cenis has increased to water volume in the reservoir from 32 to 320 million m3 and provides a potential energy of 650.000 million Mp x m. This article describes the work involved in the construction of this project. Among other features, the water has been led to the reservoir along a network of varying cross-section, and of 28 km total length. The pressure conduit has been designed for a flow rate of 51 m3/s, its diameter varying between 4 and 5 m. The new power stations at Villarodin are fed by a pipe 3.6 km in length and 3 m in diameter. This conduit runs along a trench and is isolated from the ground, because of the gypsum and anhydrites contained in the soil. Its weight is 10.000 Mp, which is a European record. The power station comprises to vertical Pelton turbines of 195 MVA each, and a yearly output of 485 kWh.La capacidad de la nueva presa del Mont-Cenis ha aumentado con estas obras desde 32 hasta 320 millones de m3, permitiendo el abastecimiento de una energía potencial de 650.000 millones de Mp x m. En el artículo se describen las obras y operaciones necesarias para ello; entre otras, que las aguas captadas han sido llevadas al embalse por una red de galerías de sección variable de 28 km de longitud; y que la conducción forzada, de 18 km de longitud, fue dimensionada para un caudal de 51 m3/s, con un diámetro comprendido entre 4 y 5 metros. Las nuevas centrales de Villarodin están alimentadas por una desviación de 3,6 km de longitud y 3 m de diámetro. Este conducto, colocado en un foso inclinado para aislarlo del ter reno, en esa zona de yesos y anhidritas, principalmente, tiene un peso de 10.000 Mp, lo que constituye un récord europeo. La Central comprende dos grupos verticales de turbinas Pelton de 195 MVA cada uno, con una productividad de 485 millones de kWh.

Análisis de la redundancia en la generación de vapor con parámetros inferiores en un monobloque de 64 MW // Analysis of redundancy in the steam generation with inferior parameters in an unit of 64 MW.

Directory of Open Access Journals (Sweden)

A. Paneque Matos

2000-10-01

Full Text Available La necesidad del país de mantener la generación eléctrica a fin de evitar los cortes de servicio planificados e imprevistos,debido a la difícil situación económica actual, obliga a buscar soluciones que al menos sirvan de paliativo temporal a estadesagradable situación. En una central termoeléctrica ubicada en el perímetro de la ciudad, se presentó la situación de queproducto de un accidente, un bloque quedó sin turbogenerador, estando su generador de vapor en magníficas condicionesde explotación; y que otro bloque presentaba muchas salidas forzosas fuera de servicio producto de una insuficientereparación de su generador de vapor. La carencia de fondos para acometer una efectiva reparación, hizo pensar en elanálisis de la posibilidad de utilizar la caldera de una unidad para alimentar el turbogenerador de la otra. En el presentetrabajo se muestran los cálculos correspondientes para determinar aproximadamente el comportamiento de la turbina en lasnuevas condiciones impuestas, se realizó un análisis de fiabilidad del sistema propuesto y se utilizó la simulación comoherramienta para modelar el proceso.Palabras claves: centrales termoeléctricas, fiabilidad, eficiencia, turbina de gas, caldera._______________________________________________________________________Abstract:The necessity of Cuba to maintain the electric generation in order to avoid the interruption of service in planned oraccidental way, due to the difficult current economic situation, forces to solutions that at least serve for temporary palliativeto this unpleasant situation. In a thermoelectric power station located in the perimeter of the city, a situation was presenteddue to an accident, a block with fail in the turbogenerator and the steam generator in good conditions of exploitation; andthat another block, the No.7, presented many mandatory out of service product of an insufficient repair of its generator.This situation lead to analyze the possibility of

CÁLCULO DE LOS ÍNDICES DE CONSUMO DE VAPOR EN LA PLANTA DE LLENADO, LIOFILIZACIÓN Y ENVASE Y OTROS SERVICIOS DEL CENTRO NACIONAL DE BIOPREPARADOS

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Marta Domingo Montané

2011-02-01

Full Text Available El progresivo encarecimiento de los productos y servicios energéticos se ha convertido en una preocupaciónprioritaria para toda industria, es por ello que en esta política nacional de ahorro y conservaciónde portadores energéticos se realiza este trabajo en la Planta de Llenado, Liofilización y Envasey en las áreas de Lavandería y Cocina- Comedor, pertenecientes al Centro Nacional deBiopreparados, con el objetivo de determinar los índices de consumo de vapor en los procesosproductivos. Se realizaron varias corridas con el fin de obtener los consumos de vapor directamentede la práctica o de cálculos, a partir de balances de energía y correlaciones de transferencia de calor.Se calcula también el consumo de vapor dado por las pérdidas al medio ambiente en las tuberías quelo transportan a los puntos de consumo. Se obtuvieron los índices de consumo en cada área de vapor,de combustible y económicos correspondientes. Se recomienda al Centro utilizar los índices deconsumo calculados para la comprobación de la eficiencia energética de las áreas estudiadas.  The progressive rise in the price of the products and energy services have become a high-priorityconcern for all industry, it is for it that in this national politics of saving and energy portersconservation is carried out this work, in the Plant of having Filled, Liofilization and packing;and in the areas of Laundry and Kitchen - dining room, belonging to the Centro Nacional deBiopreparados with the objective of determining the indexes of consumption of vapor in theproductive processes. They were carried out several experiments, with the purpose of obtainingthe consumptions of vapor directly of the practice or of calculations, starting from energy balancesand correlations of heat transfer . The consumption of vapor given by the losses to theenvironment in the pipes, that transports it to the consumption points is also calculated. Theconsumption indexes were obtained in each

EFECTOS DE LOS GASES PRODUCTO DE LA COMBUSTIÓN EN LOS GENERADORES DE VAPOR

Directory of Open Access Journals (Sweden)

Manuel Plá Duporté

2011-02-01

Full Text Available En el trabajo se presentan recopilados, los efectos de ensuciamiento y corrosión que provocan en ungenerador de vapor acuotubular los gases productos de la combustión de combustibles líquidos,explicándose los mecanismos mediante los cuales ocurren tanto en las zonas de alta temperaturacomo en las de baja temperatura  This paper presents gathering of the dirty and corrosion effects of flue gas from liquid fuels, also it’sexplained the process by means of which happen in high and low temperature surfaces in steam watergenerator

Vapor pressure and enthalpy of vaporization of aliphatic propanediamines

International Nuclear Information System (INIS)

Verevkin, Sergey P.; Chernyak, Yury

2012-01-01

Highlights: ► We measured vapor pressure of four aliphatic 1,3-diamines. ► Vaporization enthalpies at 298 K were derived. ► We examined consistency of new and available data in the literature. ► A group-contribution method for prediction was developed. - Abstract: Vapor pressures of four aliphatic propanediamines including N-methyl-1,3-propanediamine (MPDA), N,N-dimethyl-1,3-propanediamine (DMPDA), N,N-diethyl-1,3-propanediamine (DEPDA) and N,N,N′,N′-tetramethyl-1,3-propanediamine (4MPDA) were measured using the transpiration method. The vapor pressures developed in this work and reported in the literature were used to derive molar enthalpy of vaporization values at the reference temperature 298.15 K. An internal consistency check of the enthalpy of vaporization was performed for the aliphatic propanediamines studied in this work. A group-contribution method was developed for the validation and prediction vaporization enthalpies of amines and diamines.

Oxidación en vapor de agua a 700 ºC y 750 ºC del acero inoxidable AISI 317 recubierto con aluminio por CVD-FBR.

Directory of Open Access Journals (Sweden)

Jose L. Marulanda

2014-01-01

Full Text Available Se realizó la oxidación del acero inoxidable austenítico AISI 317 recubierto con aluminio por deposición química de vapor en lecho fluidizado, a temperaturas de 700 °C y 750ºC, en un ambiente con 100% vapor de agua, para evaluar su comportamiento. Se realizaron curvas de ganancia de masa y las películas de óxidos se analizaron por medio de SEM y difracción de rayos X, para observar la morfología de los óxidos. Se realizó la simulación termodinámica del proceso de oxidación en vapor de agua de los substratos para conocer las posibles fases sólidas y gaseosas que se podrían formar, en presencia de una ambiente con 100% vapor de agua y una atmosfera de presión. La forma de ataque a 750 ºC es similar a 700 ºC, aunque la velocidad de oxidación es mayor, ya que la difusión de los elementos de aleación y las reacciones de oxidación son más rápidas. Los recubrimientos de aluminio tienen una buena resistencia a la oxidación en vapor de agua, ya que forman una capa superficial de Al 2 O 3 , que es compacta y adherente, la cual protege al substrato del ataque corrosivo.

Vapor pressure and enthalpy of vaporization of linear aliphatic alkanediamines

International Nuclear Information System (INIS)

Pozdeev, Vasiliy A.; Verevkin, Sergey P.

2011-01-01

Highlights: → We measured vapor pressure of diamines H 2 N-(CH 2 ) n -NH 2 with n = 3 to 12. → Vaporization enthalpies at 298 K were derived. → We examined consistency of new and available in the literature data. → Enthalpies of vaporization show linear dependence on numbers n. → Enthalpies of vaporization correlate linearly with Kovat's indices. - Abstract: Vapor pressures and the molar enthalpies of vaporization of the linear aliphatic alkanediamines H 2 N-(CH 2 ) n -NH 2 with n = (3 to 12) have been determined using the transpiration method. A linear correlation of enthalpies of vaporization (at T = 298.15 K) of the alkanediamines with the number n and with the Kovat's indices has been found, proving the internal consistency of the measured data.

Automatic system of tests for control equipment in combined cycle power stations; Sistema automatico de pruebas para equipos de control en centrales de ciclo combinado

Energy Technology Data Exchange (ETDEWEB)

Martinez M, Miguel A; Flores L, Zenon; Delgadillo V, Miguel A; Gutierrez A, Ruben [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2001-07-01

a cabo en el equipo del Sistema de Adquisicion y control (SAC) y en la computadora personal (PC) que lo conforman, al igual que la metodologia utilizada para el desarrollo de las pruebas. La PC constituye la Interfaz Hombre-Maquina (IHM) y en el equipo SAC se realiza la simulacion (mediante la ejecucion de ecuaciones algebraico-diferenciales) de los procesos en los equipos compresor, camara de combustion, turbina de gas, recuperadores de calor, turbinas de vapor y condensador que integran una CTCC. Las ecuaciones que se utilizan tienen base en la termodinamica, dinamica de fluidos y transferencia de calor, se apegan al proceso real con un margen de error que se estima en 10%. Por ultimo, se describen las tendencias del PROBADOR y las ventajas tecnicas y economicas que ha proporcionado para el mejoramiento en el desempeno de los sistemas de control, ante distintas situaciones, sin necesidad de disponer del proceso real.

VAPOR PRESSURES AND HEATS OF VAPORIZATION OF PRIMARY COAL TARS

Energy Technology Data Exchange (ETDEWEB)

Eric M. Suuberg; Vahur Oja

1997-07-01

This project had as its main focus the determination of vapor pressures of coal pyrolysis tars. It involved performing measurements of these vapor pressures and from them, developing vapor pressure correlations suitable for use in advanced pyrolysis models (those models which explicitly account for mass transport limitations). This report is divided into five main chapters. Each chapter is a relatively stand-alone section. Chapter A reviews the general nature of coal tars and gives a summary of existing vapor pressure correlations for coal tars and model compounds. Chapter B summarizes the main experimental approaches for coal tar preparation and characterization which have been used throughout the project. Chapter C is concerned with the selection of the model compounds for coal pyrolysis tars and reviews the data available to us on the vapor pressures of high boiling point aromatic compounds. This chapter also deals with the question of identifying factors that govern the vapor pressures of coal tar model materials and their mixtures. Chapter D covers the vapor pressures and heats of vaporization of primary cellulose tars. Chapter E discusses the results of the main focus of this study. In summary, this work provides improved understanding of the volatility of coal and cellulose pyrolysis tars. It has resulted in new experimentally verified vapor pressure correlations for use in pyrolysis models. Further research on this topic should aim at developing general vapor pressure correlations for all coal tars, based on their molecular weight together with certain specific chemical characteristics i.e. hydroxyl group content.

Temperature control of a steam generator by means of an hybrid system PID-RLC; Control de las temperaturas de un generador de vapor mediante un sistema hibrido PID-RLC

Energy Technology Data Exchange (ETDEWEB)

Palomares Gonzalez, Daniel; Garcia Mendoza, Raul [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1991-12-31

A description is made of the design and evaluation of an hybrid control system, formed by a quadratic gaussian linear regulator (QLR) and proportional integral derivative (PID) type regulators. This scheme is used to control the reheater and secondary superheater steam temperatures of a steam generator model with a maximum capacity of 2,150,000 pounds per hour. Once applied to the model of a 300 MW steam power plant, this system showed better results than the traditional schemes and inclusively better than some modern control schemes. This fact characterizes it as a high potential system to be applied to steam power plants. [Espanol] Se describe el diseno y la evaluacion de un sistema de control hibrido, formado por un regulador lineal cuadratico gaussiano (RLC) y reguladores tipo proporcional integral derivativo (PID). Este esquema se utiliza para controlar las temperaturas de vapor del recalentador y sobrecalentador secundario del modelo de un generador de vapor con capacidad maxima de 2,150,000 libras por hora. Una vez aplicado al modelo de una unidad termoelectrica de 300 MW, este sistema produjo mejores resultados que los esquemas tradicionales e incluso mejores que algunos esquemas de control moderno. Esto lo caracteriza como un sistema con un alto potencial para aplicarse a unidades termoelectricas.

Temperature control of a steam generator by means of an hybrid system PID-RLC; Control de las temperaturas de un generador de vapor mediante un sistema hibrido PID-RLC

Energy Technology Data Exchange (ETDEWEB)

Palomares Gonzalez, Daniel; Garcia Mendoza, Raul [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1990-12-31

A description is made of the design and evaluation of an hybrid control system, formed by a quadratic gaussian linear regulator (QLR) and proportional integral derivative (PID) type regulators. This scheme is used to control the reheater and secondary superheater steam temperatures of a steam generator model with a maximum capacity of 2,150,000 pounds per hour. Once applied to the model of a 300 MW steam power plant, this system showed better results than the traditional schemes and inclusively better than some modern control schemes. This fact characterizes it as a high potential system to be applied to steam power plants. [Espanol] Se describe el diseno y la evaluacion de un sistema de control hibrido, formado por un regulador lineal cuadratico gaussiano (RLC) y reguladores tipo proporcional integral derivativo (PID). Este esquema se utiliza para controlar las temperaturas de vapor del recalentador y sobrecalentador secundario del modelo de un generador de vapor con capacidad maxima de 2,150,000 libras por hora. Una vez aplicado al modelo de una unidad termoelectrica de 300 MW, este sistema produjo mejores resultados que los esquemas tradicionales e incluso mejores que algunos esquemas de control moderno. Esto lo caracteriza como un sistema con un alto potencial para aplicarse a unidades termoelectricas.

Enthalpy of Vaporization and Vapor Pressures: An Inexpensive Apparatus

Science.gov (United States)

Battino, Rubin; Dolson, David A.; Hall, Michael A.; Letcher, Trevor M.

2007-01-01

A simple and inexpensive method to determine the enthalpy of vaporization of liquids by measuring vapor pressure as a function of temperature is described. The vapor pressures measured with the stopcock cell were higher than the literature values and those measured with the sidearm rubber septum cell were both higher and lower than literature…

Solución Matricial de Modelos para Cálculo de Equilibrio Líquido-Vapor Matrix Solution of Models to Calculate Liquid-Vapor Equilibrium

OpenAIRE

José F Orejel-Pajarito; Raúl González-García

2008-01-01

El objetivo de este artículo es demostrar la viabilidad de utilizar modelos termodinámicos de coeficientes de actividad (Wilson, NRTL, UNIQUAC) programados con matrices, en lugar de estar programados con ciclos. Se determina la relación de equilibrio líquido-vapor de las mezclas Metanol-Etanol-Benceno y Acetona-Cloroformo-Metanol representados en mapas de curvas de residuo y en mapas de líneas de destilación. Para obtener resultados más confiables y conclusiones objetivas, el estudio fue apoy...

Evolución del vapor de agua en la atmósfera mar del sureste español

Directory of Open Access Journals (Sweden)

J. Quereda Sala

2004-01-01

Full Text Available Uno de los mayores retos actuales de la climatología mediterránea es la detección de alguna señal de alerta ante el aumento térmico y disminución de las precipitaciones previstas en la mayor parte de los modelos teóricos de Cambio Climático. El objetivo de nuestro trabajo concierne a un proceso básico escasamente tratado hasta ahora y que bien podría constituir un verdadero talón de Aquiles en la hipótesis sobre el Cambio Climático. Si la elevación regional de las temperaturas es un proceso real, la evaporación en las aguas superficiales del Mediterráneo ha de haber aumentado simultáneamente. ¿Dónde está ese vapor? Una cuestión ciertamente no menor por cuanto ese vapor es el principal gas de efecto invernadero y cuya retroacción sería la responsable de la mayor parte de los aumentos térmicos, tanto de los actuales como de los futuros previstos por los modelos teóricos

Vapor pressures and vaporization enthalpy of codlemone by correlation gas chromatography

International Nuclear Information System (INIS)

Schultz, Shannon M.; Harris, Harold H.; Chickos, James S.

2015-01-01

Highlights: • The vaporization enthalpy of codlemone has been evaluated. • The vapor pressure of codlemone has been evaluated from T = (298.15 to T b ) K. • Vapor pressures for the 1-alkanols standards are available from T = (298.15 to 500) K. - Abstract: The vapor pressure and vaporization enthalpy of codlemone (trans, trans 8,10-dodecadien-1-ol), the female sex hormone of the codling moth is evaluated by correlation gas chromatography using a series of saturated primary alcohols as standards. A vaporization enthalpy of (92.3 ± 2.6) kJ · mol −1 and a vapor pressure, p/Pa = (0.083 ± 0.012) were evaluated at T = 298.15 K. An equation for the evaluation of vapor pressure from ambient temperature to boiling has been derived by correlation for codlemone. The calculated boiling temperature of T B = 389 K at p = 267 Pa is within the temperature range reported in the literature. A normal boiling temperature of T B = (549.1 ± 0.1) K is also estimated by extrapolation

Evaluación energética de los generadores de vapor F1-2 y BH-109 de una refinería Cubana de petróleo.

Directory of Open Access Journals (Sweden)

Anliet Valles Cruz

2014-03-01

Full Text Available La refinería cubana produce muchos productos para el mercado cubano como los combustibles, aceites, asfaltos y Jet-A1. Los sistemas auxiliares como vapor, aire comprimido y agua se utilizan para la obtención de los productos derivados del petróleo. La generación de vapor es uno de los sistemas auxiliares más importantes dentro de la refinería. La caldera de vapor garantiza que el vapor tenga las condiciones de operación de acuerdo con las normas internacionales. En este trabajo, se realizó la evaluación energética de F1-2 y BH-109 de calderas que utilizan los balances de energía y de masas convencionales. Se obtuvo una eficiencia energética de 61,89 y 77,31 por ciento para F1-2 y BH-109, respectivamente. Las principales pérdidas se debieron al calor sensible de los gases de combustión y a la combustión no química. Para reducir estas pérdidas, mejorar el rendimiento de la caldera y disminuir la temperatura de los gases de salida, se recomienda montar el sistema de control de exceso de aire y volver a examinar o cambiar el sistema de inyección de aire.

Petroleum Vapor Intrusion

Science.gov (United States)

One type of vapor intrusion is PVI, in which vapors from petroleum hydrocarbons such as gasoline, diesel, or jet fuel enter a building. Intrusion of contaminant vapors into indoor spaces is of concern.

Power quality in electrical networks with aeolian penetration. Case: The Turiguanó wind farm

OpenAIRE

Sierra Gil, Eduardo; Coello Igarza, Daisnel; Pérez Lorenzo, Adonis

2013-01-01

En este trabajo se describe la problemática de la generación eólica con respecto a la calidad de la energía producida, ya que incorpora inversores que distorsionan la onda fundamental de tensión y corriente, como una de las características de la generación eólica que emplea turbinas de velocidad variable, junto con las exportaciones e importaciones de potencia reactiva y la consecuente disminución del factor de potencia; para este propósito se analiza un caso práctico, a partir de mediciones ...

Curvas de arranque de unidades de 100 MW // Starting Graphs of generating units of 100 MW.

Directory of Open Access Journals (Sweden)

J. L. Rodríguez Olivera

2000-03-01

Full Text Available Se exponen las principales consideraciones para los arranques de las unidades de 100 MW en función del estado térmico yse establecen modelos de comportamiento de los principales parámetros a partir de cualquier estado térmico inicial. Paraello se parte de los métodos establecidos en las instrucciones de explotación vigentes y de las curvas de arranques delfabricante. Los modelos de variación de los parámetros fundamentales permiten obtener las curvas de arranque de estasunidades para cualquier estado térmico inicial, lo que reporta una disminución en los tiempos de puesta en servicio, ahorrode combustible en los arranques, el control y evaluación de los arranques y una mayor seguridad durante la explotación delas unidades. Se presenta un software para la obtención de estos gráficos y toda la información de los arranques.Palabras claves: Gráficos de arranque, unidades térmicas, turbinas de vapor.____________________________________________________________________________AbstractThe principal considerations for the starting of the 100 MW units are exposed in function of thermal state and behavior modelsare established of principal parameters from any thermal initial state are established.The work is based on the performance instructions of stablished methods and starting graphs supply by the manufacturer. Thevariation models of fundamental parameters allow us to obtain the base curves of these units for any thermal initial state. Alsoallow: a diminution in the set times of put on line, saving fuel, evaluation and control of the starting stage and a great securityduring the service of these generating units. A software that allowed to obtain all the starting information and the suitablegraphs is exposed.Key words: Starting graphs, thermal generating units, steam turbine, power plants.

Energy saving in the sugar cane agroindustry; Ahorro de energia en la agroindustria azucarera canera

Energy Technology Data Exchange (ETDEWEB)

Zedillo Ponce de Leon, Luis [Grupo de paises Latinoamericanos y del Caribe exportadores de azucar (Mexico)

1996-07-01

The traditional sugar mill is inefficient from the energy point of view. Most of the sugar mills were designed to use all the available bagasse, due to the risk of spontaneous ignition and environmental pollution. Consequently, the steam generators, the turbines and other components were designed to work with low efficiencies. Each ton of sugar produced generates a power potential equivalent to four to six oil barrels (bagasse and residues). That is to say, a sugar mill is capable of producing 500 ton/day of sugar, equivalent to an oil well of 2000 to 3000 barrels/day and one thermoelectric power plant of 15,000 kW. Under this context an analysis is made of the sugar mills in Latin America and the Caribbean as one of the ways of increasing their efficiency and obtain great energy savings. As far as steam generation the appropriate use of energy is dictated by the boilers' efficiency. [Spanish] El ingenio azucarero tradicional es ineficiente desde el punto de vista energetico. La mayoria de los ingenios azucareros se disenaron para usar todo el bagazo disponible, debido al riesgo de ignicion espontanea y contaminacion. En consecuencia, los generadores de vapor, las turbinas y demas componentes fueron disenados para trabajar con bajas eficiencias. Cada tonelada de azucar producida genera una potencialidad energetica equivalente de cuatro a seis barriles de petroleo (bagazo y residuos). Es decir, un ingenio capaz de producir 500 ton/dia de azucar equivalente a un pozo de petroleo de 2000 a 3000 barriles/dia y una termoelectrica de 15000 kW. Bajo este contexto se hace un analisis del ingenio azucarero en Latinoamerica y el Caribe como una de las vias para incrementar su eficiencia y lograr grandes ahorros en la energia. En cuanto a generacion de vapor se refiere, el buen uso de la energia viene expresado por la eficiencia de las calderas.

Aprovechamiento de la energía eólica mediante turbinas savonius para bombeo de agua en el poblado de San Jerónimo, Región Junín (2011 - 2013)

OpenAIRE

Tacza Casallo, Óscar Teodoro

2014-01-01

La investigación se realizó en el poblado de San Jerónimo, Región Junín, en la cual el diseño propuesto permite el aprovechamiento de la energía eólica para transformarla en energía mecánica mediante turbinas Savonius. El diseño propuesto permite el bombeo del agua de 2 709,6 litros por hora, que es utilizado para solucionar el problema de la escasez del agua y así poder obtener hasta dos cosechas por año. Para el diseño del sistema se determinó la localización de la zona, en la rivera del ri...

Modelo matemático para el diseño aerodinámico de los álabes de una turbina eólica de eje horizontal (TEEH; Mathematical Model for Blades Aerodynamic Design of a Horizontal Axis Wind Turbine (HAWT

Directory of Open Access Journals (Sweden)

Julio José Chirinos García

2015-12-01

Full Text Available El objetivo de esta investigación es elaborar un modelo matemático para el diseño aerodinámico de las palas de una turbina eólica de eje horizontal en forma rápida y confiable que facilite a construcción y comportamiento bajo diferentes condiciones. Este resultado se obtuvo por el método inductivo y deductivo partiendo de las teorías aerodinámicas de Glauert y otros introduciéndole modificaciones. Igualmente el desarrollo del modelo fue programado en una hoja de cálculo que permitió calcular el radio R del rotor, la distribución de la cuerda c(r y la variación del ángulo de torsiónӨ(r de forma automática. El desarrollo del modelo está estructurado de acuerdo a las siguientes etapas: identificación y definición, conceptualización, formulación e implementación y finalmente la validación del modelo. La validación del modelo fue hecha comparando la geometría de la pala y la potencia generada por el rotor con una familia de palas defabricantes europeos.The research purpose is elaborate a mathematical model for blade aerodynamic designing of horizontal axis wind turbine in fast and reliable way to facilitate the construction and performance evaluation under different operational conditions. To reach the theoretical and empirical approach it was used induction and deduction method starting from aerodynamic theories of Glauert and other researchers, in which necessary modifications were introduced. Also, the development of the model was programmed in aspreadsheet which allows to calcula table de radio R, the distribution of chord c (r, and the variation of twist angle or pitch Ө (r in automatic way. The development of the model was structured according to the following stages: identification and definition, conceptualization, formulationandimplementation and finally the validation of the model. The model validation was made comparing the blade geometry and generated power by the rotor with a blade family of European

Digital control for turbogas units; Control digital para unidades turbogas

Energy Technology Data Exchange (ETDEWEB)

Garcia Beltran, Carlos Daniel

1997-02-01

implementation and testing of several schemes of diffuse control: P, PD, PI and diffuse PID, of which the last one was selected for having a better answer. The results obtained in the simulations of the algebraic PI and of the diffuse PID, established that the second one improved the follow up indexes and reduced the starting period and the fuel consumption. [Espanol] La presente tesis trata sobre la rehabilitacion del sistema de control para las turbinas de gas W501 de la Central de Ciclo Combinado de Gomez Palacio, de Durango, Mexico. La primera parte del desarrollo trata sobre un proceso de reingenieria de software aplicado al sistema de control digital de las turbinas de gas de la central de ciclo combinado de Comez Palacio. Este proceso fue desarrollado utilizando conceptos de varias ramas de la ingenieria: a) involucro los conocimientos de la ingenieria de software, utilizando metodos formales para el analisis del sistema original y el rediseno del nuevo sistema: b) se utilizo la ingenieria de control en el analisis de diversas estrategias de control y automatizacion utilizados para el control de turbinas de gas, con el objetivo de verificar el tipo de instrucciones y rutinas presentes dentro del software. El producto final de esta etapa es un sistema programatico modularizado, basado en diseno estructurado, que es funcionalmente un espejo del sistema original. El sistema obtenido esta conformado por cinco modulos principales los cuales se basan en un modelo propuesto originalmente para control por lotes (batch) :i) Interfaz Hombre Maquina, ii) Control Regulatorio, iii) Protecciones, iv) Secuencias logicas y v) Supervision. La segunda etapa de desarrollo fue la mejora del control de velocidad de la turbina. Cuando se controla una unidad turbogas, debe tomarse en cuenta varias etapas de operacion tales como el arranque, el control en estado estable y el apagado. El comportamiento real de la turbina durante el arranque, y principalmente el gran numero de retrocesos

Modelo matemático para el diseño aerodinámico de los álabes de una turbina eólica de eje horizontal (TEEH Mathematical Model for Blades Aerodynami c Design of a Horizontal Axis Wind Turbine (HAWT

Directory of Open Access Journals (Sweden)

Julio José–Chirinos García

2016-02-01

Full Text Available El objetivo de esta investigación es elaborar un modelo matemát ico para el diseño aerodinámico de las palas de una turbina eólica de eje horizontal en forma rápida y confiable qu e facilite a construcción y comportamiento bajo diferentes condiciones. Este resultado se obtuvo por el método inductivo y deductivo partiendo de las teorías aerodinámicas de Glauert y otros introduciéndole modificaciones. Igualmente el d esarrollo del modelo fue programado en una hoja de cálculo que permitió calcular el radio R del rotor, la distribu ción de la cuerda c(r y la variación del ángulo de torsión Ө(r de forma automática. El desarrollo del modelo está estructura do de acuerdo a las siguientes etapas: identificación y definición, conceptualización, formulación e implementación y finalmente la validación del modelo. La validación del modelo fue hecha comparando la geometría de la pala y la potenc ia generada por el rotor con una familia de palas de fabricantes europeos. The research purpose is elaborate a mathematical model fo r blade aerodynamic designing of horizontal axis wind turbine in fast and reliable way to facilitate the construc tion and performance evaluation under different operational conditions. To reach the theoretical and empirical approa ch it was used induction and deduction method starting from aerodynamic theories of Glauert and other researchers, in which necessary modifications were introduced. Also, the development of the model was programmed in aspreadsheet which allows to calc ula table de radio R, the distribution of chord c (r, and the variation of twist angle or pitch Ө (r in automatic way. The development of the model was structured according to the following stages: identification and definition, conceptualization, formulation andimplementation and finally the validation of the m odel. The model validation was made comparing the blade geometry and generated power by the rotor with a blade family of

Point of net vapor generation and vapor void fraction in subcooled boiling

International Nuclear Information System (INIS)

Saha, P.; Zuber, N.

1974-01-01

An analysis is presented directed at predicting the point of net vapor generation and vapor void fraction in subcooled boiling. It is shown that the point of net vapor generation depends upon local conditions--thermal and fluid dynamic. Thus, at low mass flow rates the net vapor generation is determined by thermal conditions, whereas at high mass flow rates the phenomenon is hydrodynamically controlled. Simple criteria are derived which can be used to predict these local conditions for net vapor generation. These criteria are used to determine the vapor void fraction is subcooled boiling. Comparison between the results predicted by this analysis and experimental data presently available shows good agreement for wide range of operating conditions, fluids and geometries. (U.S.)

The vapor pressure and enthalpy of vaporization of M-xylene

International Nuclear Information System (INIS)

Rothenberg, S.J.; Seiler, F.A.; Bechtold, W.E.; Eidson, A.F.

1988-01-01

We measured the vapor pressure of m-xylene over the temperature range 273 to 293 deg K with a single-sided capacitance manometer. The enthalpy of vaporization was 42.2 ± 0.1 (SE) kj/ g·mol. Combining our own data with previously published data, we recommend using the values 42.0, 40.6, and 39.1 (± 0.1) (SE) kjg·mol for the enthalpy of vaporization of m-xylene at 300, 340, and 380 deg. K, respectively, and a value for the change in heat capacity on vaporization (ΔCpdeg.) of 35 ± 3 (SE) J/g·mol·K over the temperature range studied. (author)

Oxidación cíclica de un acero refractario AISI 310 a alta temperatura en atmósferas con contenidos de oxígeno variables

Directory of Open Access Journals (Sweden)

Higuera-Hidalgo, V.

2005-06-01

Full Text Available High temperature oxidation tests of an AISI 310 stainless steel was performed in two different environments: in an standard atmosphere (21 % oxygen at 704, 800, 884 and 1,000 °C and in the typical environment of a gas turbine and vapor generator of a combined-cycle electric generation unit (10 % oxygen at 800 and 1,000 °C. The oxidation kinetics was determined by means of the measurement of the weight gain per unit surface of the specimen and also determining the thickness of the oxide layer. Comparable results have been obtained using both methodologies and the effect of the oxygen content along with the other experimental differences were determined observing the oxidation kinetics in both environments. The cyclic oxidation of AISI 310 deteriorates at temperatures higher than 1,000 °C.

Se ha llevado a cabo un estudio experimental sobre la oxidación a altas temperaturas de un acero inoxidable refractario AISI 310, en dos ambientes diferentes: en una atmósfera convencional (21 % de O₂, a 704, 800, 884 y 1.000 °C y en un ambiente simulativo de una turbina de gas y del generador de vapor de uña central eléctrica de ciclo combinado (10-11 % de O₂, a 800 y 1.000 °C. La cinética de la oxidación del material se ha determinado a partir, tanto de la ganancia de peso por unidad de superficie experimentada por las probetas objeto de ensayo como por la determinación de los espesores de las capas de óxido formados. Se han obtenido resultados comparables con ambas metodologías y se ha puesto de manifiesto el efecto del contenido de oxígeno y de las demás diferencias experimentales a partir de la comparación de las cinéticas de oxidación del acero en los dos medios oxidantes analizados. La oxidación del acero AISI 310 en situaciones térmicas cíclicas empieza ya a ser importante a partir de una temperatura de 1.000 °C.

Las aguas termominerales de Tabio

Directory of Open Access Journals (Sweden)

Antonio María Barriga Villalba

1933-01-01

Full Text Available La pintoresca población de Tabio, situada en el vallecito que forman dos repliegues de la gran cordillera montañosa que rodea la sabana de Bogotá, es un pueblecito apacible, famoso desde tiempo inmemorial por las aguas termales que brotan en la falda de los cerros situados al occidente, a unos mil metros de la iglesia de la población, en terrenos de propiedad del doctor Pompilio Martínez. Fue fundada Tabio en el año 1761 (*. Se halla a 4°50'50" de latitud norte y 0° 04'00" de longitud del meridiano de Bogotá. Clima seco en la mayor parte del año, temperatura media 14°.5 C. Presión atmosférica 560 mm.; altura sobre el nivel del mar 2.650 metros; temperatura de. ebullición del agua 91°.62 C.; humedad en vapor de agua, por metro cúbico, en los días secos 127,5 gramos por metro cúbico; en los días húmedos, 251,8 gramos por metro cúbico. En el sitio de las fuentes la humedad relativa media es de 38.38 por 100 y la temperatura de la atmósfera varía de 10° C. hasta 23°C.; en los días de sol, hacia las doce del día, la temperatura de la atmósfera cerca de las fuentes es de 20°-22°C.

Evaluación de la generación de vapor de la fábrica de refrescos 23 de Agosto, en Camagüey

Directory of Open Access Journals (Sweden)

Amaury Pérez-Sánchez

2017-05-01

Full Text Available El presente trabajo se llevó a cabo en la fábrica de refrescos 23 de Agosto, con el fin de evaluar la eficiencia energética del generador de vapor, determinar las pérdidas de calor en las tuberías de vapor que se encuentran sin aislamiento, determinar el impacto medioambiental que producen los gases de combustión generados, evaluar el sistema de tratamiento del agua con que se alimenta la caldera (suavizador de agua, así como efectuar un análisis técnico-económico de dos variantes de mejoras, consistentes en 1 precalentamiento del agua con que se alimenta la caldera hasta los 90 C, y 2 aislamiento de las tuberías de vapor con el aislante lana mineral. El empleo del aislante lana mineral redujo las pérdidas de calor en las tuberías en un 90 %, aproximadamente. La eficiencia energética del generador de vapor fue de 86.64 %. Se requiere invertir $ 523.66 pesos cubanos (PC para adquirir e instalar las cantidades necesarias del aislante lana mineral, que se recuperará al cabo de 122 días. El suavizador opera de forma eficiente y los gases contaminantes alcanzan la máxima concentración a los 87.285 m, estando por encima del valor establecido en las normas cubanas. La aplicación de las dos variantes de mejora propuestas trajo consigo un ahorro total anual de PC 9931.92 por el combustible dejado de consumir en el generador de vapor. Se emplearon programas y herramientas computacionales tales como el Contamín, y hojas de cálculo Excel para el procesamiento de los datos adquiridos. (Abstract. The present work was carried out in the Factory of Sodas 23 de Agosto, with the aim to evaluate the thermal efficiency of the boiler, determine the heat losses in uninsulated steam pipes; determine the environmental impact of flue gases generated; evaluate the boiler’s feedwater treatment system (water softener,as well as to make a techno-economic analysis of two improvement alternatives, consistent in: 1 Pre-heating of the feeding water to

The vapor pressure and enthalpy of vaporization of M-xylene

Energy Technology Data Exchange (ETDEWEB)

Rothenberg, S J; Seiler, F A; Bechtold, W E; Eidson, A F

1988-12-01

We measured the vapor pressure of m-xylene over the temperature range 273 to 293 deg K with a single-sided capacitance manometer. The enthalpy of vaporization was 42.2 {+-} 0.1 (SE) kj/ g{center_dot}mol. Combining our own data with previously published data, we recommend using the values 42.0, 40.6, and 39.1 ({+-} 0.1) (SE) kjg{center_dot}mol for the enthalpy of vaporization of m-xylene at 300, 340, and 380 deg. K, respectively, and a value for the change in heat capacity on vaporization ({delta}Cpdeg.) of 35 {+-} 3 (SE) J/g{center_dot}mol{center_dot}K over the temperature range studied. (author)

Idicadores intrínsicamente seguros para las explosiones en la industria de procesos

Directory of Open Access Journals (Sweden)

Ernesto Salzano

2013-04-01

Full Text Available Los parámetros de seguridad de las sustancias inflamables, medidos por procedimientos estandarizados que, generalmente, se han adoptado para la definición de los índices de seguridad inherente, incluso si las explosiones de gas industrial, de vapor o de polvo, son motivo de preocupación. Sin embargo, es bien conocido que la naturaleza de los accidentes con explosiones son más complejos en la vida real, que los observados en el laboratorio, bajo un ambiente controlado. Por otro lado, puede haber consecuencias mucho más severas, cuando se tienen equipos de diseño o dinámica de fluidos especiales. Este trabajo propone nuevos indicadores de seguridad inherentes a las explosiones basadas en los avances recientes en la seguridad de la combustión y en las metodologías para el análisis de consecuencias.

Aluminum coating by fluidized bed chemical vapor deposition on austenitic stainless steels AISI 304 and AISI 316

Directory of Open Access Journals (Sweden)

Jose Luddey Marulanda-Arevalo

2015-01-01

Full Text Available Los revestimientos de aluminio f ueron depositados sobre aceros inoxidables AISI 304 y AISI 316 en el rango de temperatura de 5 60 a 600 °C por deposición química de vapor en lecho fluidizado(CVD – FBR. Se utilizó un lecho que consistía en 10 % de aluminio en polvo y 90 % de lecho inerte (alúmina, el cual fue fluidizado con Ar y como ga ses activadores se utilizó una mezcla de ácido clorhídrico con hidrógeno (HCl/H 2 . En el recubrimiento si n tratamiento térmico están las siguiente s especies: Al 13 Fe 4 , Fe 2 Al 5 , FeAl 2 y Al 5 FeNi, las cuales están presentes para ambos aceros. Además, el tratamiento térmico provoca la difusa de alu minio hacia el sustrato y la difusa de hierro del sustrato haci a la superficie del recubrimiento, haciendo la trans formación de los compuestos ant eriores a FeAl, Fe 2 Al 5 , FeAl 2 , Al 0.99 Fe 0.99 Ni 0.02 , AlNi y el Fe 2 AlCr. Se realizó la simulación termodinámica con el s oftware Thermo Calc para obt ener información de la posible composición y la cantidad de mat erial depositado, para condiciones seleccionadas. Las muestras recubi ertas y sin recubrir, se expus ieron a 750 ºC en una atmósfera d onde el vapor agua se transporta a las muestras usando un flujo de N 2 de 40 ml/min, más 100 % vapor de agua (H 2 O. Los dos sustratos sin revestir se comportaron de manera diferente, ya que el acero AISI 304 soportó bien el a taque y ganó poco peso (0.49 mg/cm 2 , en comparación con el acero AISI 316 que perdió mucho peso (25.4 mg/cm 2 . Los aceros recubiertos ganaron poco de peso durante las mil horas de exposición (0.26 mg/cm 2 y soportaron muy bien el ataque corrosivo en c omparación con sustratos sin r ecubrimiento.

Technological tendencies for the development and implementation of fault tolerant active controls in combined cycle power plants; Tendencias tecnologicas para el desarrollo e implantacion de controles activos tolerantes a fallas en centrales de ciclo combinado

Energy Technology Data Exchange (ETDEWEB)

Sanchez P, Marino; Verde R, Cristina [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2006-07-01

This document proposes a methodology that reunites support tools for the operator of a Combined Cycle Generating Power Station allowing him to identify and to classify gas turbine faults, it also reunites some tools for the generation of action advices in the decision making on the operation maneuvers necessary to counteract the effects caused by faults. We are talking about a system implemented in a power station with the reconfiguration of processes and fault arrangement capacities. For this purpose, the line of exhibition delimits first the existing knowledge on automatic control and operations supervision systems in a CCPP and immediately emphasizes the cracks of the system to let pass to the fault tolerant active control system that will detect faults of the gas and steam turbo-generators of a Combined Cycle Generating Power Plant. [Spanish] El presente documento propone una metodologia que reuna herramientas de ayuda al operador de una Central Generadora de Electricidad de Ciclo Combinado para permitirle la identificacion y clasificacion de fallas en las turbinas de gas, asi como herramientas para la generacion de consejos de accion en la toma de decisiones sobre las maniobras de operacion necesarias para contrarrestar los efectos provocados por fallas. Se trata principalmente de un sistema implantado en una central con las capacidades de re-configuracion de procesos y acomodo de fallas. Para esto, la linea de exposicion delimita primero el conocimiento existente sobre sistemas automaticos de control y supervision de operacion en una CGCC y resalta enseguida las grietas del sistema para darle paso al sistema de control activo tolerante a fallas que detectara fallas de los turbogeneradores de gas y vapor de una Central Generadora de Electricidad de Ciclo Combinado.

Enthalpy of vaporization and vapor pressure of whiskey lactone and menthalactone by correlation gas chromatography

International Nuclear Information System (INIS)

Simmons, Daniel; Chickos, James

2017-01-01

Highlights: • The vapor pressure and vaporization enthalpies of cis and trans-whiskey lactone have been evaluated. • Enthalpies of vaporization and vapor pressures of (+)-isomintlactone and (−)-mintlactone were also evaluated. • The sublimation enthalpy and corresponding vapor pressure of (+) -isomintlactone at T = 298.15 K is estimated. - Abstract: Enthalpies of vaporization at T = 298.15 K of cis and trans-whiskey lactone have been evaluated by correlation gas chromatography to be (68.4 ± 1.7) kJ·mol −1 and (67.5 ± 1.7) kJ·mol −1 , respectively. The enthalpies of vaporization of isomintlactone and mintlactone also evaluated by correlation gas chromatography have been found to have vaporization enthalpies of (74.2 ± 1.8) kJ·mol −1 and (73.2 ± 1.8) kJ·mol −1 respectively. The vapor pressures for cis and trans-whiskey lactone at T = 298.15 K have been evaluated as (1.5 ± 0.09) Pa and (2.0 ± 0.1) Pa using vapor pressures of a series of lactones as standards. Vapor pressures for isomintlactone and mintlactone were evaluated as (0.26 ± 0.012) Pa and (0.33 ± 0.02) Pa, respectively. Fusion and sublimation enthalpies for (+)-isomintlactone as well as the vapor pressure of the solid have been estimated.

Experiences of marijuana-vaporizer users.

Science.gov (United States)

Malouff, John M; Rooke, Sally E; Copeland, Jan

2014-01-01

Using a marijuana vaporizer may have potential harm-reduction advantages on smoking marijuana, in that the user does not inhale smoke. Little research has been published on use of vaporizers. In the first study of individuals using a vaporizer on their own initiative, 96 adults anonymously answered questions about their experiences with a vaporizer and their use of marijuana with tobacco. Users identified 4 advantages to using a vaporizer over smoking marijuana: perceived health benefits, better taste, no smoke smell, and more effect from the same amount of marijuana. Users identified 2 disadvantages: inconvenience of setup and cleaning and the time it takes to get the device operating for each use. Only 2 individuals combined tobacco in the vaporizer mix, whereas 15 combined tobacco with marijuana when they smoked marijuana. Almost all participants intended to continue using a vaporizer. Vaporizers seem to have appeal to marijuana users, who perceive them as having harm-reduction and other benefits. Vaporizers are worthy of experimental research evaluating health-related effects of using them.

Oxidación en vapor de agua a 700 ºC y 750 ºC del acero inoxidable AISI 317 recubierto con aluminio por CVD-FBR.

OpenAIRE

Jose L. Marulanda; Saul I. Castañeda; Aduljay Remolina

2014-01-01

Se realizó la oxidación del acero inoxidable austenítico AISI 317 recubierto con aluminio por deposición química de vapor en lecho fluidizado, a temperaturas de 700 °C y 750ºC, en un ambiente con 100% vapor de agua, para evaluar su comportamiento. Se realizaron curvas de ganancia de masa y las películas de óxidos se analizaron por medio de SEM y difracción de rayos X, para observar la morfología de los óxidos. Se realizó la simulación termodinámica del proceso de oxidación en vapor de agua de...

Waste Tank Vapor Project: Tank vapor database development

International Nuclear Information System (INIS)

Seesing, P.R.; Birn, M.B.; Manke, K.L.

1994-09-01

The objective of the Tank Vapor Database (TVD) Development task in FY 1994 was to create a database to store, retrieve, and analyze data collected from the vapor phase of Hanford waste tanks. The data needed to be accessible over the Hanford Local Area Network to users at both Westinghouse Hanford Company (WHC) and Pacific Northwest Laboratory (PNL). The data were restricted to results published in cleared reports from the laboratories analyzing vapor samples. Emphasis was placed on ease of access and flexibility of data formatting and reporting mechanisms. Because of time and budget constraints, a Rapid Application Development strategy was adopted by the database development team. An extensive data modeling exercise was conducted to determine the scope of information contained in the database. a A SUN Sparcstation 1000 was procured as the database file server. A multi-user relational database management system, Sybase reg-sign, was chosen to provide the basic data storage and retrieval capabilities. Two packages were chosen for the user interface to the database: DataPrism reg-sign and Business Objects trademark. A prototype database was constructed to provide the Waste Tank Vapor Project's Toxicology task with summarized and detailed information presented at Vapor Conference 4 by WHC, PNL, Oak Ridge National Laboratory, and Oregon Graduate Institute. The prototype was used to develop a list of reported compounds, and the range of values for compounds reported by the analytical laboratories using different sample containers and analysis methodologies. The prototype allowed a panel of toxicology experts to identify carcinogens and compounds whose concentrations were within the reach of regulatory limits. The database and user documentation was made available for general access in September 1994

The vapor pressures of explosives

Energy Technology Data Exchange (ETDEWEB)

Ewing, Robert G.; Waltman, Melanie J.; Atkinson, David A.; Grate, Jay W.; Hotchkiss, Peter

2013-01-05

The vapor pressures of many explosive compounds are extremely low and thus determining accurate values proves difficult. Many researchers, using a variety of methods, have measured and reported the vapor pressures of explosives compounds at single temperatures, or as a function of temperature using vapor pressure equations. There are large variations in reported vapor pressures for many of these compounds, and some errors exist within individual papers. This article provides a review of explosive vapor pressures and describes the methods used to determine them. We have compiled primary vapor pressure relationships traceable to the original citations and include the temperature ranges for which they have been determined. Corrected values are reported as needed and described in the text. In addition, after critically examining the available data, we calculate and tabulate vapor pressures at 25 °C.

Building blocks for ionic liquids: Vapor pressures and vaporization enthalpies of 1-(n-alkyl)-imidazoles

International Nuclear Information System (INIS)

Emel'yanenko, Vladimir N.; Portnova, Svetlana V.; Verevkin, Sergey P.; Skrzypczak, Andrzej; Schubert, Thomas

2011-01-01

Highlights: → We measured vapor pressures of the 1-(n-alkyl)-imidazoles by transpiration method. → Variations on the alkyl chain length n were C 3 , C 5 -C 7 , and C 9 -C 10 . → Enthalpies of vaporization were derived from (p, T) dependencies. → Enthalpies of vaporization at 298.15 K were linear dependent on the chain length. - Abstract: Vapor pressures of the linear 1-(n-alkyl)-imidazoles with the alkyl chain C 3 , C 5 -C 7 , and C 9 -C 10 have been measured by the transpiration method. The molar enthalpies of vaporization Δ l g H m of these compounds were derived from the temperature dependencies of vapor pressures. A linear correlation of enthalpies of vaporization Δ l g H m (298.15 K) of the 1-(n-alkyl)-imidazoles with the chain length has been found.

Vapor pressure and enthalpy of vaporization of oil of catnip by correlation gas chromatography

International Nuclear Information System (INIS)

Simmons, Daniel; Gobble, Chase; Chickos, James

2016-01-01

Highlights: • Vaporization enthalpies of the nepetalactones from oil of catnip have been evaluated. • Vapor pressures from T = (298.15 to 350) K have been evaluated. • Oil of catnip has a vapor pressure similar to DEET at T = 298.15 K. - Abstract: The vaporization enthalpy and vapor pressure of the two nepetalactones found in Nepeta cataria have been evaluated by correlation gas chromatography. Vaporization enthalpies at T = 298.15 K of {(68.0 ± 1.9) and (69.4 ± 1.9)} kJ ⋅ mol"−"1 have been derived for the minor diastereomer, (4aS,7S,7aS)-nepetalactone, and major one, (4aS,7S,7aR)-nepetalactone, respectively. Vapor pressures also at T = 298.15 K of p = (1.2 ± 0.04) Pa and (0.91 ± 0.03) Pa have been evaluated for the minor and the major stereoisomer. In addition to being of interest because of the remarkable effect it has on various felids, oil of catnip is also quite effective in repelling mosquitoes, comparable to diethyl-m-toluamide (DEET). The vapor pressures evaluated in this work suggest that the two stereoisomers have similar volatility to DEET at ambient temperatures.

Energy saving in agricultural pumping equipment; Ahorro de energia en equipos de bombeo agricola

Energy Technology Data Exchange (ETDEWEB)

Acosta Torres, R Aracely [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1994-12-31

This paper analyses the current state of the pumping equipment for agricultural irrigation in Mexico. Because of being of the vertical centrifugal turbine type pumps, the most commonly utilized for this service, the study has been focussed into this equipment, obtaining efficiency and consumption scenarios, as well as the potential energy saving existing in this sector. [Espanol] En el presente articulo se analiza el estado actual de los equipos de bombeo para riego agricola en Mexico, al ser las bombas centrifugas verticales tipo turbina, las mas comunmente utilizadas para este servicio, el estudio ha sido enfocado a estos equipos, obteniendose los escenarios de eficiencias y consumos, asi como, el potencial de ahorro energetico existente en este sector.

Analysis methodology for economic technical feasibility studies in offshore electrical generation systems; Metodologia de analisis para estudios de factibilidad tecnica economica en sistemas de generacion electrica costa fuera

Energy Technology Data Exchange (ETDEWEB)

Fiscal Escalante, Raul [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2007-07-01

An analysis methodology followed in the development of technique-economic feasibility studies of systems of electrical generation in offshore electrical installations is presented, including the obtaining of the curves of the turbine and generator performance, the technical considerations for the formulation of the operation scenes and the calculations of the economic evaluation of a real scenario. [Spanish] Se muestra una metodologia de analisis seguida en el desarrollo de estudios de factibilidad tecnica-economica de sistemas de generacion electrica en instalaciones electricas costa fuera, incluyendo la obtencion de las curvas de comportamiento de la turbina y el generador, las consideraciones tecnicas para la formulacion de los escenarios de operacion y los calculos de la evaluacion economica de un escenario real.

Energy saving in agricultural pumping equipment; Ahorro de energia en equipos de bombeo agricola

Energy Technology Data Exchange (ETDEWEB)

Acosta Torres, R. Aracely [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1993-12-31

This paper analyses the current state of the pumping equipment for agricultural irrigation in Mexico. Because of being of the vertical centrifugal turbine type pumps, the most commonly utilized for this service, the study has been focussed into this equipment, obtaining efficiency and consumption scenarios, as well as the potential energy saving existing in this sector. [Espanol] En el presente articulo se analiza el estado actual de los equipos de bombeo para riego agricola en Mexico, al ser las bombas centrifugas verticales tipo turbina, las mas comunmente utilizadas para este servicio, el estudio ha sido enfocado a estos equipos, obteniendose los escenarios de eficiencias y consumos, asi como, el potencial de ahorro energetico existente en este sector.

Vapor pressures and vaporization enthalpy of (−) α-bisabolol and (dl) menthol by correlation gas chromatography

International Nuclear Information System (INIS)

Keating, Leasa; Harris, Harold H.; Chickos, James S.

2017-01-01

Highlights: • The vaporization enthalpy and vapor pressure of (−) α-bisabolol and (dl)-menthol have been measured as a function of temperature. • Vapor pressures, vaporization enthalpies and boiling temperatures have been compared to available literature data. • Vapor pressures of (l)-menthol are compared to (dl)-menthol. - Abstract: The vapor pressures and vaporization enthalpies of (−) α-bisabolol and (dl)-menthol, two GRAS chemicals (generally recognized as safe) are evaluated by correlation gas chromatography using a series of saturated primary alcohols as standards. Vaporization enthalpies of (96.6 ± 2.4) and (74.2 ± 2.8) kJ mol −1 and vapor pressures of p/Pa = (0.020 ± 0.003) and (4.5 ± 0.44) were evaluated at T = 298.15 K for (−) α-bisabolol and (dl)-menthol, respectively, and compared to literature values. The vapor pressures of both compounds from T = (298.15 to 500) K have been derived from correlations using vapor pressures of a series of 1-alkanols and corresponding gas chromatographic retention times at 10 K intervals. The results were fit to a second order polynomial. Calculated normal boiling temperatures of T B = (574.8 and 492.7) K are calculated for (−) α-bisabolol and (dl)-menthol, respectively. A normal boiling temperature of T B = (485.2, and 489.7) K has previously been reported for (dl)-menthol. Vapor pressures for both (l)-menthol and (dl)-menthol from a previous study and (dl)-menthol from this study are compared with literature values.

Nonlinear analysis of thermal stresses of a of first stage nozzle of a gas turbine at full load from the results of an analysis of conjugated heat transference; Analisis no lineal de esfuerzos termicos de una tobera de primera etapa de turbina de gas a plena carga a partir de resultados de un analisis de transferencia de calor conjugado

Energy Technology Data Exchange (ETDEWEB)

Perez Hernandez, Efrain [Centro Nacional de Investigacion y Desarrollo Tecnologico (Cenidet), Cuernavaca, Morelos (Mexico); Mazur C, Zdzislaw; Garcia Illescas, R; Hernandez Rossette, Alejandro [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2007-11-15

The gas turbines operate at extremely high temperatures, at high thermal and mechanical stresses, causing that the useful life of the involved components be reduced. In the present article the results realized by previous investigations of temperatures obtained from analysis of heat transfer and flow of fluids of the nozzle by means of the Star-CD program based on finite volumes is presented. Later, the NISA program of finite elements was used to realize the analysis of thermal stresses considering the material plasticity. The methodology employed to determine the material properties variable with the temperature of the super-alloy FSX-414 and the plasticity model used in the structural analysis in the finite element program. The result will be later used in the fatigue analysis for the useful life assessment. [Spanish] Las turbinas de gas operan a temperatura extremadamente altas, a elevados esfuerzos termicos y mecanicos, ocasionando que la vida de los componentes involucrados se reduzca. En el presente articulo se presentan los resultados realizados por previas investigaciones de temperaturas obtenidas a partir de analisis de transferencia de calor y flujo de fluidos de la tobera mediante el programa Star-CD basado en volumenes finitos. Posteriormente, se utilizo el programa NISA de elementos finitos para realizar el analisis de esfuerzos termicos considerando plasticidad del material. Se muestra la metodologia empleada para determinar las propiedades del material variables con la temperatura de la superaleacion FSX-414 y el modelo de plasticidad utilizado en el analisis estructural en el programa de elemento finito. Los resultados seran empleados posteriormente en el analisis de fatiga para la estimacion de vida util.

Melting temperature, vapor density, and vapor pressure of molybdenum pentafluoride

Energy Technology Data Exchange (ETDEWEB)

Krause, Jr, R F; Douglas, T B [National Bureau of Standards, Washington, D.C. (USA). Inst. for Materials Research

1977-12-01

A sample of MoF/sub 5/ was prepared by reaction of MoF/sub 6/(g) and Mo(c). Melting curves of temperature against time established the melting temperature at zero impurity to be 318.85 K, the enthalpy of fusion to be 6.1 kJ mol/sup -1/ (+ - 5 per cent), and the cryoscopic impurity of the sample to be 0.15 mole per cent. In the presence of MoF/sub 6/(g) which was added to suppress disproportionation, the vapor density of MoF/sub 5/ over the liquid was measured by the transpiration method at 343, 363, and 383 K, the total MoF/sub 5/ that evaporated being determined by permanganate titration. The total vapor pressure of MoF/sub 5/ oligomers over the liquid was measured by a simple static method at 373 and 392 K, while melting temperatures were taken alternately to monitor possible contamination of the sample. Although the vapor pressures were adjusted for disproportionation, solution of MoF/sub 6/ in MoF/sub 5/ (1), and wall adsorption of MoF/sub 6/ their percentage uncertainty is probably several times that of the vapor densities. A combination of the two properties indicates the average extent of association of the saturated vapor to be near 2, which is the value for the dimer species (MoF/sub 5/)/sub 2/.

R-22 vapor explosions

International Nuclear Information System (INIS)

Anderson, R.P.; Armstrong, D.R.

1977-01-01

Previous experimental and theoretical studies of R-22 vapor explosions are reviewed. Results from two experimental investigations of vapor explosions in a medium scale R-22/water system are reported. Measurements following the drop of an unrestrained mass of R-22 into a water tank demonstrated the existence of two types of interaction behavior. Release of a constrained mass of R-22 beneath the surface of a water tank improved the visual resolution of the system thus allowing identification of two interaction mechansims: at low water temperatures, R-22/water contact would produce immediate violent boiling; at high water temperatures a vapor film formed around its R-22 as it was released, explosions were generated by a surface wave which initiated at a single location and propagated along the vapor film as a shock wave. A new vapor explosion model is proposed, it suggests explosions are the result of a sequence of three independent steps: an initial mixing phase, a trigger and growth phase, and a mature phase where a propagating shock wave accelerates the two liquids into a collapsing vapor layer causing a high velocity impact which finely fragments and intermixes the two liquids

Degradación de materiales cerámicos en atmósferas de combustión. Dos casos prácticos: quemadores y turbinas de gas

Directory of Open Access Journals (Sweden)

García, Eugenio

2008-12-01

Full Text Available The use of ceramic materials in energy applications with the aim of power saving through the use of high working temperatures is widely extended due to their better behaviour in those working conditions compared to than metallic materials. However, the combustion environments developed in specific applications can lead to the degradation of such materials. In this work, two ceramic materials employed in these applications are studied; a cordierite material, used as gas radiant burner for its possible application in domestic combustion boilers, and an Y₂O₃ stabilized ZrO₂ coating, used as thermal barrier coating on metallic components of a gas turbine for power generation. The microstructure and phase evolution in both materials after ageing under working conditions allows identifying the main degradation mechanism responsible of the degradation.

El buen comportamiento de los materiales cerámicos en ambientes corrosivos y a altas temperaturas los sitúa, preferentemente, en todos aquellos procesos industriales que buscan el ahorro energético, en particular los procesos de combustión de gases o de derivados del petróleo. Sin embargo, las atmósferas de combustión que se producen en ciertas aplicaciones producen la degradación de estos materiales. En este trabajo se estudian dos ejemplos de materiales cerámicos empleados en este tipo de aplicaciones; un material de cordierita, empleado como quemador de gas radiante para su posible aplicación en calderas de combustión domésticas y un recubrimiento de ZrO₂ estabilizado con Y₂O₃, empleado como barrera térmica en componentes de una turbina de gas para la producción de energía eléctrica. El estudio de la microestructura, la composición química y de fases cristalinas de ambos materiales después de su degradación en uso permite determinar cuales son los mecanismos que han tenido lugar y qué elementos de la atm

Piezoelectric trace vapor calibrator

International Nuclear Information System (INIS)

Verkouteren, R. Michael; Gillen, Greg; Taylor, David W.

2006-01-01

The design and performance of a vapor generator for calibration and testing of trace chemical sensors are described. The device utilizes piezoelectric ink-jet nozzles to dispense and vaporize precisely known amounts of analyte solutions as monodisperse droplets onto a hot ceramic surface, where the generated vapors are mixed with air before exiting the device. Injected droplets are monitored by microscope with strobed illumination, and the reproducibility of droplet volumes is optimized by adjustment of piezoelectric wave form parameters. Complete vaporization of the droplets occurs only across a 10 deg. C window within the transition boiling regime of the solvent, and the minimum and maximum rates of trace analyte that may be injected and evaporated are determined by thermodynamic principles and empirical observations of droplet formation and stability. By varying solution concentrations, droplet injection rates, air flow, and the number of active nozzles, the system is designed to deliver--on demand--continuous vapor concentrations across more than six orders of magnitude (nominally 290 fg/l to 1.05 μg/l). Vapor pulses containing femtogram to microgram quantities of analyte may also be generated. Calibrated ranges of three explosive vapors at ng/l levels were generated by the device and directly measured by ion mobility spectrometry (IMS). These data demonstrate expected linear trends within the limited working range of the IMS detector and also exhibit subtle nonlinear behavior from the IMS measurement process

Renewable energy resources of the marine environment and its control requirements

OpenAIRE

García Moreno, Emilio; Correcher Salvador, Antonio; Quiles Cucarella, Eduardo; Morant Anglada, Francisco José

2016-01-01

[ES] En este artículo se presentan una serie de dispositivos generadores de energía renovable procedente del entorno marino, que en los últimos años han despertado creciente interés. En especial se describen los tipos principales de Generadores Eólicos Flotantes, las Turbinas de Corriente Marina y diversos dispositivos basados en Energía Undimotriz. Se destacan los principales requerimientos a considerar bajo el punto de vista de la ingeniería de control, considerando los objetivos d...

Fuel vapor pressure (FVAPRS)

International Nuclear Information System (INIS)

Mason, R.E.

1979-04-01

A subcode (FVAPRS) is described which calculates fuel vapor pressure. This subcode was developed as part of the fuel rod behavior modeling task performed at EG and G Idaho, Inc. The fuel vapor pressure subcode (FVAPRS), is presented and a discussion of literature data, steady state and transient fuel vapor pressure equations and estimates of the standard error of estimate to be expected with the FVAPRS subcode are included

Uso de la generación de vapores en la determinación de metales traza por técnicas atómicas

OpenAIRE

Villanueva Alonso, Julia

2012-01-01

La generación de vapor es una técnica de introducción de muestra que ha sido empleada para incrementar la sensibilidad en la determinación de los elementos que forman hidruros usando diferentes técnicas espectroscópicas como AAS. (Espectroscopía de Absorción Atómica), AFS (Espectroscopía de Fluorescencia Atómica) o ICPOES (Espectroscopía de Emisión Óptica con fuente de Plasma de Acoplamiento Inductivo). En las últimas décadas la aplicación de la generación de vapor se ha amp...

Vapor generation methods for explosives detection research

Energy Technology Data Exchange (ETDEWEB)

Grate, Jay W.; Ewing, Robert G.; Atkinson, David A.

2012-12-01

The generation of calibrated vapor samples of explosives compounds remains a challenge due to the low vapor pressures of the explosives, adsorption of explosives on container and tubing walls, and the requirement to manage (typically) multiple temperature zones as the vapor is generated, diluted, and delivered. Methods that have been described to generate vapors can be classified as continuous or pulsed flow vapor generators. Vapor sources for continuous flow generators are typically explosives compounds supported on a solid support, or compounds contained in a permeation or diffusion device. Sources are held at elevated isothermal temperatures. Similar sources can be used for pulsed vapor generators; however, pulsed systems may also use injection of solutions onto heated surfaces with generation of both solvent and explosives vapors, transient peaks from a gas chromatograph, or vapors generated by s programmed thermal desorption. This article reviews vapor generator approaches with emphasis on the method of generating the vapors and on practical aspects of vapor dilution and handling. In addition, a gas chromatographic system with two ovens that is configurable with up to four heating ropes is proposed that could serve as a single integrated platform for explosives vapor generation and device testing. Issues related to standards, calibration, and safety are also discussed.

The vaporization enthalpy and vapor pressure of S (+)-methamphetamine at T = 298.15 K by correlation gas chromatography

International Nuclear Information System (INIS)

Thornton, Melissa; Gobble, Chase; Chickos, James

2014-01-01

Highlights: • The vaporization enthalpy of (d)-methamphetamine was measured. • The vapor pressure of (d)-methamphetamine as a function of temperature was evaluated. • The vapor pressure of 4-benzylpiperidine as a function of temperature was evaluated. - Abstract: The vaporization enthalpy and vapor pressure of S (+)-methamphetamine is evaluated by correlation-gas chromatography. A vaporization enthalpy of (58.7 ± 4.3) kJ · mol −1 and a vapor pressure, p = (38 ± 9) Pa has been obtained using a variety of secondary aliphatic amines as standards. In addition, equations describing the vapor pressure temperature dependence are provided for standards and S (+)-methamphetamine covering the temperature range from T = 298.15 K to the boiling temperature. Boiling temperatures are reproduced within an interval of 8 K or less

Observation and particle simulation of vaporized W, Mo, and Be in PISCES-B plasma for vapor-shielding studies

Directory of Open Access Journals (Sweden)

K. Ibano

2017-08-01

Full Text Available Interactions of Tungsten (W, Molybdenum (Mo, and Beryllium (Be vapors with a steady-state plasma were studied by the PISCES-B liner plasma experiments as well as Particle-In-Cell (PIC simulations for the understanding of vapor-shielding phenomena. Effective cooling of the plasma by laser-generated Be vapor was observed in PISCES-B. On the other hand, no apparent cooling was observed for W and Mo vapors. The PIC simulation explains these experimental observations of the difference between low-Z and high-Z vapors. Decrease of electron temperature due to the vapor ejection was observed in case of a simulation of the Be vapor. As for the W vapor, it was found that the plasma cooling is localized only near the wall at a higher electron density plasma (∼1019m−3. On the other hand, the appreciable plasma cooling can be observed in a lower density plasma (∼1018m−3 for the W vapor.

Intelligent control system for the temperature regulation in a gas turbine of a combined cycle fossil fuel power plant; Sistema de control inteligente para regular la temperatura en la turbina de gas de una central termoelectrica de ciclo combinado

Energy Technology Data Exchange (ETDEWEB)

Espindola Vasquez, Agustin

2004-11-15

logic theory and its performance was evaluated using a non- linear mathematical model that emulates the CTCC behavior. The fuzzy supervision system is integrated by three main modules: Supervision of blades temperature during the starting stage of the UTG; Supervision of blades temperature runback during the power generation stage of the UTG, and Control by Temperature during power generation stage of the UTG. The temperature fuzzy supervisor is implemented in a nonlinear mathematical model that simulates a CTCC. The obtained and analyzed results in the different sceneries of the simulation tests show that the temperature fuzzy supervision system displays a better performance than the obtained with the scheme of conventional supervision. [Spanish] En las Unidades Turbogas (UTG) de una Central Termoelectrica de Ciclo Combinado (CTCC), una de las variables criticas tanto desde el punto de vista operativo como desde el punto de vista de seguridad, es la temperatura de los alabes de la turbina. El mejor desempeno de la unidad turbogas desde el punto de vista de generacion electrica se obtiene cuando es posible lograr la mayor eficiencia termica. Desde el punto de vista de seguridad se busca mantener la temperatura de los alabes en el limite impuesto por el fabricante, garantizando con esto la integridad de las partes internas de la UTG al evitar que esfuerzos termicos considerables decrementen su vida util. Para mantener la temperatura de alabes dentro del limite establecido, el sistema de control de la UTG cuenta con un sistema de supervision de temperatura de alabes, que modifica la referencia de los controladores PI de velocidad o de potencia generada, mismos que regulan la valvula de flujo de combustible a la camara de combustion de la UTG. Este sistema de supervision esta basado en condiciones logicas para generar su salida. En las plantas de proceso cuya operacion es compleja y su comportamiento dinamico es no lineal, las estrategias de control de lazo simple no

Passive vapor extraction feasibility study

International Nuclear Information System (INIS)

Rohay, V.J.

1994-01-01

Demonstration of a passive vapor extraction remediation system is planned for sites in the 200 West Area used in the past for the disposal of waste liquids containing carbon tetrachloride. The passive vapor extraction units will consist of a 4-in.-diameter pipe, a check valve, a canister filled with granular activated carbon, and a wind turbine. The check valve will prevent inflow of air that otherwise would dilute the soil gas and make its subsequent extraction less efficient. The granular activated carbon is used to adsorb the carbon tetrachloride from the air. The wind turbine enhances extraction rates on windy days. Passive vapor extraction units will be designed and operated to meet all applicable or relevant and appropriate requirements. Based on a cost analysis, passive vapor extraction was found to be a cost-effective method for remediation of soils containing lower concentrations of volatile contaminants. Passive vapor extraction used on wells that average 10-stdft 3 /min air flow rates was found to be more cost effective than active vapor extraction for concentrations below 500 parts per million by volume (ppm) of carbon tetrachloride. For wells that average 5-stdft 3 /min air flow rates, passive vapor extraction is more cost effective below 100 ppm

A heated vapor cell unit for dichroic atomic vapor laser lock in atomic rubidium.

Science.gov (United States)

McCarron, Daniel J; Hughes, Ifan G; Tierney, Patrick; Cornish, Simon L

2007-09-01

The design and performance of a compact heated vapor cell unit for realizing a dichroic atomic vapor laser lock (DAVLL) for the D(2) transitions in atomic rubidium is described. A 5 cm long vapor cell is placed in a double-solenoid arrangement to produce the required magnetic field; the heat from the solenoid is used to increase the vapor pressure and correspondingly the DAVLL signal. We have characterized experimentally the dependence of important features of the DAVLL signal on magnetic field and cell temperature. For the weaker transitions both the amplitude and gradient of the signal are increased by an order of magnitude.

A heated vapor cell unit for dichroic atomic vapor laser lock in atomic rubidium

International Nuclear Information System (INIS)

McCarron, Daniel J.; Hughes, Ifan G.; Tierney, Patrick; Cornish, Simon L.

2007-01-01

The design and performance of a compact heated vapor cell unit for realizing a dichroic atomic vapor laser lock (DAVLL) for the D 2 transitions in atomic rubidium is described. A 5 cm long vapor cell is placed in a double-solenoid arrangement to produce the required magnetic field; the heat from the solenoid is used to increase the vapor pressure and correspondingly the DAVLL signal. We have characterized experimentally the dependence of important features of the DAVLL signal on magnetic field and cell temperature. For the weaker transitions both the amplitude and gradient of the signal are increased by an order of magnitude

Aceros sinterizados tratados al vapor para la fabricación de componentes de amortiguadores bitubo

Directory of Open Access Journals (Sweden)

Cambronero, L. E. G.

2000-06-01

Full Text Available In this work, properties of three sintered and steam treated alloyed irons were analysed. These materials were Fe+2Cu, Fe+0.6C+0.5Cu, and Fe+0.45P+2.5Cu, which were obtained by powder mixing. Once pressed and sintered, samples were steam treated (surface treatment which is characteristic of sintered irons. Density, hardness and tensile strength were obtained on sintered and steam treated samples, within their microstructure analysis. Also, a tribological study was carried out since some parts of shock absorbers are working under friction.

En este trabajo se analizan las propiedades de tres hierros aleados sintetizados y tratados al vapor. Los materiales seleccionados son el Fe+2Cu, Fe+0.6C+0.5Cu, y Fe+0.45P+2.5Cu, obtenidos por mezcla elemental de polvos. Una vez compactados y sintetizados, se sometieron a un tratamiento de recubrimiento característico de los hierros, como es el tratamiento al vapor. En los materiales sintetizados y tratados al vapor, se determinaron su densidad, dureza y resistencia a tracción, junto con su análisis microestructural. Así mismo dado que algunos de los componentes de los amortiguadores bitubo están sometidos a esfuerzos de fricción, se analizaron el comportamiento tribologíco de los materiales obtenidos tanto en estado sintetizado como tratados al vapor.

MEDICIÓN DEL EQUILIBRIO LIQUIDO-VAPOR DEL SISTEMA METANOL-ACETATO DE METILO A 580 mmHg

Directory of Open Access Journals (Sweden)

Carlos Ariel Cardona

2008-03-01

Full Text Available En este trabajo se midió experimentalmente el equilibrio líquido-vapor para el sistema binario metanol–acetato de Metilo a 580 mmHg. Las mediciones experimentales fueron realizadas utilizando un equipo con recirculación tipo Cottrell. Los datos obtenidos fueron comparados con los resultados adquiridos de la simulación del equilibrio líquido-vapor del sistema bajo estudio. En la simulación se empleó el modelo de actividad NRTL para representar la no idealidad de la fase líquida (con parámetros encontrados en la literatura, y la ecuación de estado de Hayden O´Connel para la no idealidad de la fase vapor. De igual manera, se correlacionaron los datos para encontrar nuevos parámetros del modelo de actividad en NRTL. Además, a partir de datos experimentales medidos a 760 mmHg encontrados en la literatura para el sistema estudiado, se verificó la Ley de Vresky, la cual permite, sin necesidad de cálculos rigurosos, predecir la dirección de desplazamiento de un azeótropo binario cunado se varía la presión del sistema.

High temperature vapors science and technology

CERN Document Server

Hastie, John

2012-01-01

High Temperature Vapors: Science and Technology focuses on the relationship of the basic science of high-temperature vapors to some areas of discernible practical importance in modern science and technology. The major high-temperature problem areas selected for discussion include chemical vapor transport and deposition; the vapor phase aspects of corrosion, combustion, and energy systems; and extraterrestrial high-temperature species. This book is comprised of seven chapters and begins with an introduction to the nature of the high-temperature vapor state, the scope and literature of high-temp

Copper-vapor-catalyzed chemical vapor deposition of graphene on dielectric substrates

Science.gov (United States)

Yang, Chao; Wu, Tianru; Wang, Haomin; Zhang, Xuefu; Shi, Zhiyuan; Xie, Xiaoming

2017-07-01

Direct synthesis of high-quality graphene on dielectric substrates is important for its application in electronics. In this work, we report the process of copper-vapor-catalyzed chemical vapor deposition of high-quality and large graphene domains on various dielectric substrates. The copper vapor plays a vital role on the growth of transfer-free graphene. Both single-crystal domains that are much larger than previous reports and high-coverage graphene films can be obtained by adjusting the growth duration. The quality of the obtained graphene was verified to be comparable with that of graphene grown on Cu foil. The progress reported in this work will aid the development of the application of transfer-free graphene in the future.

Estimated vapor pressure for WTP process streams

Energy Technology Data Exchange (ETDEWEB)

Pike, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Poirier, M. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

2015-01-01

Design assumptions during the vacuum refill phase of the Pulsed Jet Mixers (PJMs) in the Hanford Waste Treatment and Immobilization Plant (WTP) equate the vapor pressure of all process streams to that of water when calculating the temperature at which the vacuum refill is reduced or eliminated. WTP design authority asked the authors to assess this assumption by performing calculations on proposed feed slurries to calculate the vapor pressure as a function of temperature. The vapor pressure was estimated for each WTP waste group. The vapor pressure suppression caused by dissolved solids is much greater than the increase caused by organic components such that the vapor pressure for all of the waste group compositions is less than that of pure water. The vapor pressure for each group at 145°F ranges from 81% to 98% of the vapor pressure of water. If desired, the PJM could be operated at higher temperatures for waste groups with high dissolved solids that suppress vapor pressure. The SO4 group with the highest vapor pressure suppression could be operated up to 153°F before reaching the same vapor pressure of water at 145°F. However, most groups would reach equivalent vapor pressure at 147 to 148°F. If any of these waste streams are diluted, the vapor pressure can exceed the vapor pressure of water at mass dilution ratios greater than 10, but the overall effect is less than 0.5%.

Calibración y validación de un modelo en computador para simular el golpe de ariete en redes cerradas.

OpenAIRE

Velásquez Hidalgo, Carlos Férnando; Toro Botero, Francisco Mauricio

2006-01-01

El golpe de ariete, como fenómeno transitorio, ha sido un tema de estudio de la hidráulica, por sus efectos destructores en sistemas de alta presión como los conductos abastecedores de turbinas en centrales hidroeléctricas. Aunque el tema esté muy estudiado y analizado para conductos simples, comienza a aflorar la inquietud de simular este fenómeno en redes cerradas, las cuales están propensas a experimentar el golpe de ariete. Se presenta un modelo computacional para simular el Golpe de Arie...

A numerical investigation of vapor intrusion--the dynamic response of contaminant vapors to rainfall events.

Science.gov (United States)

Shen, Rui; Pennell, Kelly G; Suuberg, Eric M

2012-10-15

The U.S. government and various agencies have published guidelines for field investigation of vapor intrusion, most of which suggest soil gas sampling as an integral part of the investigation. Contaminant soil gas data are often relatively more stable than indoor air vapor concentration measurements, but meteorological conditions might influence soil gas values. Although a few field and numerical studies have considered some temporal effects on soil gas vapor transport, a full explanation of the contaminant vapor concentration response to rainfall events is not available. This manuscript seeks to demonstrate the effects on soil vapor transport during and after different rainfall events, by applying a coupled numerical model of fluid flow and vapor transport. Both a single rainfall event and seasonal rainfall events were modeled. For the single rainfall event models, the vapor response process could be divided into three steps: namely, infiltration, water redistribution, and establishment of a water lens atop the groundwater source. In the infiltration step, rainfall intensity was found to determine the speed of the wetting front and wash-out effect on the vapor. The passage of the wetting front led to an increase of the vapor concentration in both the infiltration and water redistribution steps and this effect is noted at soil probes located 1m below the ground surface. When the mixing of groundwater with infiltrated water was not allowed, a clean water lens accumulated above the groundwater source and led to a capping effect which can reduce diffusion rates of contaminant from the source. Seasonal rainfall with short time intervals involved superposition of the individual rainfall events. This modeling results indicated that for relatively deeper soil that the infiltration wetting front could not flood, the effects were damped out in less than a month after rain; while in the long term (years), possible formation of a water lens played a larger role in determining

Vapor Pressure Data Analysis and Statistics

Science.gov (United States)

2016-12-01

near 8, 2000, and 200, respectively. The A (or a) value is directly related to vapor pressure and will be greater for high vapor pressure materials...1, (10) where n is the number of data points, Yi is the natural logarithm of the i th experimental vapor pressure value, and Xi is the...VAPOR PRESSURE DATA ANALYSIS AND STATISTICS ECBC-TR-1422 Ann Brozena RESEARCH AND TECHNOLOGY DIRECTORATE

Eficiencia y disimetría: El caso bioético de la máquina de vapor y de la idea de Carnot

Directory of Open Access Journals (Sweden)

Ingeborg Carvajal Freese

2012-01-01

Full Text Available Sin lugar a dudas, la máquina de vapor representa un prototipo de aquellas iniciativas tecnológicas que parecían destinadas a cumplir el sueño de progreso, poder y control ilimitados. Sadi Carnot visualizó en la energía de vapor el motor universal e intuyó que de ahí en adelante el mundo irrevocablemente se fracturaría en dos: por un lado permanecerían, estáticos y atrasados, los pueblos primitivos productores de calor; por el otro, avanzarían de manera acelerada los hombres civilizados poseedores de la nueva máquina generadora de trabajo. Aún hoy, cuando el mito tecnológico del progreso ilimitado se ha roto, las brechas sociales siguen indefectiblemente vinculadas a los inventos que se traducen en una redistribución de la energía. Corresponde a la Bioética hacer visibles los ámbitos que se afectan cuando la eficiencia técnica se transmuta en valor y las disimetrías concomitantes se difunden y se amplifican por doquier.

Back work ratio of Brayton cycle; La relacion de trabajo de retroceso de un ciclo Brayton

Energy Technology Data Exchange (ETDEWEB)

Malaver de la Fuente, M. [Universidad Maritima del Caribe (Venezuela)]. E-mail: mmf_umc@hotmail.com

2010-07-15

This paper analyzes the existing relation between temperatures, back work ratio and net work of Brayton cycle, a cycle that describes gas turbine engines performance. The application of computational software helps to show the influence of back work ratio or coupling ratio, compressor and turbine inlet temperatures in an ideal thermodynamical cycle. The results lead to deduce that the maximum value reached in back work ratio will depend on the ranges of maximum and minimal temperatures of Brayton cycle. [Spanish] En este articulo se estudia la relacion que existe entre las temperaturas, la relacion de trabajo de retroceso y el trabajo neto en el ciclo Brayton, que es el ciclo ideal que describe el comportamiento de los motores de turbina de gas. La aplicacion de programas computarizados ayuda a mostrar la influencia de la relacion de trabajo de retroceso o relacion de acoplamiento, la temperatura de entrada al compresor y la temperatura de entrada a la turbina en este ciclo termodinamico ideal. Los resultados obtenidos permiten deducir que el valor maximo que alcanza la relacion de trabajo de retroceso dependera de los limites de temperatura maxima y minima impuestos en el ciclo Brayton.

The use of absorption refrigeration systems in combined cycle power plants; Empleo de sistemas de refrigeracion por absorcion en plantas de ciclo combinado

Energy Technology Data Exchange (ETDEWEB)

Romero Paredes, H.; Ambriz, J.J.; Vargas, M.; Godinez, M.; Gomez, F.; Valdez, L.; Pantoja, G. [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Departamento de Ingenieria de Procesos e Hidraulica, Mexico D. F. (Mexico)

1995-12-31

Day after day the electric power generation tends to be done in the most efficient way in order to diminish the generation costs and the rate of environmental pollution per KWh generated. This paper discusses the application of absorption refrigeration systems for the cooling of the air entering the compressor of a gas turbine in a combined cycle, in order to increase the mass air flow and with it the turbine output. The flows with remanent energy content that are not used in a combined cycle can be used for the operation of the absorption refrigeration system. This way, the required thermal energy for the cooling system is free. With this system it is possible to raise the gas turbine generation output from 5% to 25%. [Espanol] La generacion electrica dia con dia pretende realizarse de la manera mas eficiente posible con el objeto de disminuir los costos de generacion y la tasa de contaminacion ambiental por Kwh generado. En el presente trabajo se introduce la aplicacion de sistemas de refrigeracion por absorcion para el enfriamiento del aire de entrada al compresor de la turbina de gas de un ciclo combinado, con el objeto de aumentar el flujo masico del aire y con ello la potencia de salida de la turbina. Las corrientes con contenido remanente de energia termica que no se usan en una planta de ciclo combinado pueden servir para operar el sistema de refrigeracion por absorcion. De esta manera, la energia termica requerida para el sistema de enfriamiento es gratuita. Con este sistema es posible incrementar la potencia de generacion de la turbina de gas de 5 a 25%.

The use of absorption refrigeration systems in combined cycle power plants; Empleo de sistemas de refrigeracion por absorcion en plantas de ciclo combinado

Energy Technology Data Exchange (ETDEWEB)

Romero Paredes, H; Ambriz, J J; Vargas, M; Godinez, M; Gomez, F; Valdez, L; Pantoja, G [Universidad Autonoma Metropolitana, Unidad Iztapalapa, Departamento de Ingenieria de Procesos e Hidraulica, Mexico D. F. (Mexico)

1996-12-31

Day after day the electric power generation tends to be done in the most efficient way in order to diminish the generation costs and the rate of environmental pollution per KWh generated. This paper discusses the application of absorption refrigeration systems for the cooling of the air entering the compressor of a gas turbine in a combined cycle, in order to increase the mass air flow and with it the turbine output. The flows with remanent energy content that are not used in a combined cycle can be used for the operation of the absorption refrigeration system. This way, the required thermal energy for the cooling system is free. With this system it is possible to raise the gas turbine generation output from 5% to 25%. [Espanol] La generacion electrica dia con dia pretende realizarse de la manera mas eficiente posible con el objeto de disminuir los costos de generacion y la tasa de contaminacion ambiental por Kwh generado. En el presente trabajo se introduce la aplicacion de sistemas de refrigeracion por absorcion para el enfriamiento del aire de entrada al compresor de la turbina de gas de un ciclo combinado, con el objeto de aumentar el flujo masico del aire y con ello la potencia de salida de la turbina. Las corrientes con contenido remanente de energia termica que no se usan en una planta de ciclo combinado pueden servir para operar el sistema de refrigeracion por absorcion. De esta manera, la energia termica requerida para el sistema de enfriamiento es gratuita. Con este sistema es posible incrementar la potencia de generacion de la turbina de gas de 5 a 25%.

A Simple Experiment for Determining Vapor Pressure and Enthalpy of Vaporization of Water.

Science.gov (United States)

Levinson, Gerald S.

1982-01-01

Laboratory procedures, calculations, and sample results are described for a freshman chemistry experiment in which the Clausius-Clapeyron equation is introduced as a means of describing the variation of vapor pressure with temperature and for determining enthalpy of vaporization. (Author/SK)

Evaluation of a process for the removal of gases contained in geothermal steam through condensation and re-evaporation; Evaluacion de un proceso de remocion de gases contenidos en el vapor geotermico, por medio de la condensacion y de revaporacion

Energy Technology Data Exchange (ETDEWEB)

Angulo C, Raul; Lam Rea, Luis; Garmino, Hector; Jimenez, Humberto [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1986-12-31

The Cerro Prieto I Geothermal Field, developed and operated by the Comision Federal de Electricidad (CFE), has currently an installed electric power generation capacity of 180 MW and is at a very advanced stage in the development of Cerro Prieto II and III, which will allow to raise the generation capacity to 620 MW. During the exploitation of a geothermal field, in producing steam with the purpose of generating electricity, brines and waste gases are obtained. The hydrogen sulfide exhaust to the environment implies pollution problems, for this reason processes have been developed for the oxidation of these gases downstream the turbogenerator either in the flow of separated gases in the steam condensation or in the condensate produced. The Instituto de Investigaciones Electricas (IIE) has collaborated with CFE in the evaluation of the environmental impact of this gas and in the development of the processes for its abatement. [Espanol] El campo geotermico de Cerro Prieto I, desarrollado y operado por la Comision Federal de Electricidad (CFE), actualmente tiene una capacidad instalada de generacion de energia electrica de 180 MW, y se encuentra en etapa muy avanzada, el desarrollo de Cerro Prieto II y III, lo que permitira incrementar la capacidad de generacion a 620 MW. Durante la explotacion de un campo geotermico, al producir vapor con el proposito de generar electricidad, se obtienen salmueras y gases de desecho. La descarga de acido sulfhidrico a la atmosfera implica problemas de contaminacion, por esta razon se han desarrollado procesos para la oxidacion de este gas aguas abajo de la turbina generadora, ya sea en la corriente de gases que se separan en la condensacion del vapor o en el condensado producido. El Instituto de Investigaciones Electricas (IIE) ha colaborado con la CFE en la evaluacion del impacto ambiental de este gas y en el desarrollo de sus procesos de abatimiento.

Evaluation of a process for the removal of gases contained in geothermal steam through condensation and re-evaporation; Evaluacion de un proceso de remocion de gases contenidos en el vapor geotermico, por medio de la condensacion y de revaporacion

Energy Technology Data Exchange (ETDEWEB)

Angulo C, Raul; Lam Rea, Luis; Garmino, Hector; Jimenez, Humberto [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1985-12-31

The Cerro Prieto I Geothermal Field, developed and operated by the Comision Federal de Electricidad (CFE), has currently an installed electric power generation capacity of 180 MW and is at a very advanced stage in the development of Cerro Prieto II and III, which will allow to raise the generation capacity to 620 MW. During the exploitation of a geothermal field, in producing steam with the purpose of generating electricity, brines and waste gases are obtained. The hydrogen sulfide exhaust to the environment implies pollution problems, for this reason processes have been developed for the oxidation of these gases downstream the turbogenerator either in the flow of separated gases in the steam condensation or in the condensate produced. The Instituto de Investigaciones Electricas (IIE) has collaborated with CFE in the evaluation of the environmental impact of this gas and in the development of the processes for its abatement. [Espanol] El campo geotermico de Cerro Prieto I, desarrollado y operado por la Comision Federal de Electricidad (CFE), actualmente tiene una capacidad instalada de generacion de energia electrica de 180 MW, y se encuentra en etapa muy avanzada, el desarrollo de Cerro Prieto II y III, lo que permitira incrementar la capacidad de generacion a 620 MW. Durante la explotacion de un campo geotermico, al producir vapor con el proposito de generar electricidad, se obtienen salmueras y gases de desecho. La descarga de acido sulfhidrico a la atmosfera implica problemas de contaminacion, por esta razon se han desarrollado procesos para la oxidacion de este gas aguas abajo de la turbina generadora, ya sea en la corriente de gases que se separan en la condensacion del vapor o en el condensado producido. El Instituto de Investigaciones Electricas (IIE) ha colaborado con la CFE en la evaluacion del impacto ambiental de este gas y en el desarrollo de sus procesos de abatimiento.

Steam regulation for 5 MW back-pressure units when a failure occurs in the Los Humeros, Pue., field, Mexico; Regulacion del vapor en caso de falla a unidades a contrapresion de 5 MW en el campo de Los Humeros, Pue., Mexico

Energy Technology Data Exchange (ETDEWEB)

Rosales Lopez, Cesar [Comision Federal de Electricidad, Puebla (Mexico)]. E-mail: cesar.rosales@cfe.gob.mx

2006-07-15

Four out of the seven back-pressure power units of 5 MW operating in the Los Humeros geothermal field, State of Puebla, Mexico, are fed by one steam pipe gathering the steam produced by nine wells. When a failure occurred in any of the units and the excedence valve had to be open to deviate the steam, a decrease in the steam flow for the remaining units was noted, along with lower electrical generation. The cause for that is analyzed and explained in this paper by comparing the interconnected steam supply system to an electric circuit. A way to maintain a uniform and continuous supply of steam in the Los Humeros field has been found. It was implemented several months ago and the problem has not reoccurred. [Spanish] Cuatro de las siete unidades de 5 MW a contrapresion que operan en el campo geotermico de Los Humeros, Puebla, son alimentadas por un solo vaporducto que reune el vapor de nueve pozos productores. Cuando ocurria una falla en alguna de estas unidades y se abria por completo la valvula de excedencia para desviar el vapor, se observaba una reduccion en el flujo de vapor que llegaba a las otras tres unidades, lo que a su vez ocasionaba que la generacion de electricidad se redujera notoriamente. En este trabajo se analiza y explica la causa de ello, mediante la comparacion de este sistema interconectado de suministro de vapor con un circuito electrico, y se explica la solucion que se encontro e implemento en el campo de Los Humeros para regular el suministro continuo y uniforme de vapor, con resultados satisfactorios a varios meses de su implementacion en las cuatro unidades interconectadas.

Improvements to vapor generators

International Nuclear Information System (INIS)

Keller, Arthur; Monroe, Neil.

1976-01-01

A supporting system is proposed for vapor generators of the 'supported' type. Said supporting system is intended to compensate the disparities of thermal expansion due to the differences in the vertical dimensions of the tubes in the walls of the combustion chamber and their collectors compared to that of the balloon tanks and the connecting tube clusters of vaporization, the first one being longer than the second ones. Said system makes it possible to build said combustion chamber higher than the balloon tanks and the tube clusters of vaporization. The capacity of steam production is thus enhanced [fr

Averiguação do potencial de vento em ambiente edificado para aproveitamentos

OpenAIRE

Magalhães, Nuno Filipe da Costa

2011-01-01

O objectivo deste projecto consiste em analisar o potencial eólico em ambiente edificado urbano, considerando a utilização de turbinas eólicas de eixo vertical para produção de energia nesse contexto. Pretende-se com este documento demonstrar que, embora os estudos sobre as turbinas de eixo vertical sejam ainda reduzidos quando comparados aos das de eixo horizontal, tal não implica que as mesmas não tenham características que, em determinados cenários, sejam superiores às turbinas de eixo hor...

DSMC simulations of vapor transport toward development of the lithium vapor box divertor concept

Science.gov (United States)

Jagoe, Christopher; Schwartz, Jacob; Goldston, Robert

2016-10-01

The lithium vapor divertor box concept attempts to achieve volumetric dissipation of the high heat efflux from a fusion power system. The vapor extracts the heat of the incoming plasma by ionization and radiation, while remaining localized in the vapor box due to differential pumping based on rapid condensation. Preliminary calculations with lithium vapor at densities appropriate for an NSTX-U-scale machine give Knudsen numbers between 0.01 and 1, outside both the range of continuum fluid dynamics and of collisionless Monte Carlo. The direct-simulation Monte Carlo (DSMC) method, however, can simulate rarefied gas flows in this regime. Using the solver contained in the OpenFOAM package, pressure-driven flows of water vapor will be analyzed. The use of water vapor in the relevant range of Knudsen number allows for a flexible similarity experiment to verify the reliability of the code before moving to tests with lithium. The simulation geometry consists of chains of boxes on a temperature gradient, connected by slots with widths that are a representative fraction of the dimensions of the box. We expect choked flow, sonic shocks, and order-of-magnitude pressure and density drops from box to box, but this expectation will be tested in the simulation and then experiment. This work is supported by the Princeton Environmental Institute.

Thermogravimetric measurements of liquid vapor pressure

International Nuclear Information System (INIS)

Rong Yunhong; Gregson, Christopher M.; Parker, Alan

2012-01-01

Highlights: ► Rapid determination of vapor pressure by TGA. ► Demonstration of limitations of currently available approaches in literature. ► New model for vapor pressure assessment of small size samples in TGA. ► New model accounts for vapor diffusion and sample geometry and measures vapor pressure normally within 10%. - Abstract: A method was developed using thermo-gravimetric analysis (TGA) to determine the vapor pressure of volatile liquids. This is achieved by measuring the rate of evaporation (mass loss) of a pure liquid contained within a cylindrical pan. The influence of factors like sample geometry and vapor diffusion on evaporation rate are discussed. The measurement can be performed across a wide range of temperature yielding reasonable results up to 10 kPa. This approach may be useful as a rapid and automatable method for measuring the volatility of flavor and fragrance raw materials.

Petroleum Vapor - Field Technical

Science.gov (United States)

The screening approach being developed by EPA OUST to evaluate petroleum vapor intrusion (PVI) requires information that has not be routinely collected in the past at vapor intrusion sites. What is the best way to collect this data? What are the relevant data quality issues and ...

A Numerical Investigation of Vapor Intrusion — the Dynamic Response of Contaminant Vapors to Rainfall Events

Science.gov (United States)

Shen, Rui; Pennell, Kelly G.; Suuberg, Eric M.

2013-01-01

The U.S. government and various agencies have published guidelines for field investigation of vapor intrusion, most of which suggest soil gas sampling as an integral part of the investigation. Contaminant soil gas data are often relatively more stable than indoor air vapor concentration measurements, but meteorological conditions might influence soil gas values. Although a few field and numerical studies have considered some temporal effects on soil gas vapor transport, a full explanation of the contaminant vapor concentration response to rainfall events is not available. This manuscript seeks to demonstrate the effects on soil vapor transport during and after different rainfall events, by applying a coupled numerical model of fluid flow and vapor transport. Both a single rainfall event and seasonal rainfall events were modeled. For the single rainfall event models, the vapor response process could be divided into three steps: namely, infiltration, water redistribution, and establishment of a water lens atop the groundwater source. In the infiltration step, rainfall intensity was found to determine the speed of the wetting front and wash-out effect on the vapor. The passage of the wetting front led to an increase of the vapor concentration in both the infiltration and water redistribution steps and this effect is noted at soil probes located 1 m below the ground surface. When the mixing of groundwater with infiltrated water was not allowed, a clean water lens accumulated above the groundwater source and led to a capping effect which can reduce diffusion rates of contaminant from the source. Seasonal rainfall with short time intervals involved superposition of the individual rainfall events. This modeling results indicated that for relatively deeper soil that the infiltration wetting front could not flood, the effects were damped out in less than a month after rain; while in the long term (years), possible formation of a water lens played a larger role in

Nuevos diseños de sistemas de control híbrido, genético-adaptativo, para la regulación de la eficiencia del bloque termoenergético de las empresas del níquel.

Directory of Open Access Journals (Sweden)

Antonio Muñoz

2006-10-01

Full Text Available El artículo muestra los resultados de la investigación del sistema de avanzado híbrido (genéticoadaptativo para la generación de vapor, a través de lazos de regulación para la reducción de la dispersión de las variables del régimen operacional del proceso, con la aplicación de nuevas estrategias de control óptimo con algoritmos genéticos del gasto de energía, sobre la desviación del régimen de trabajo de las calderas; todo lo cual contribuye a la reducción de las pérdidas de energía para generar vapor, permitiendo implementar sistemas control híbridos, resultantes de la integración de sistemas de control genético-adaptativos.

The lithium vapor box divertor

International Nuclear Information System (INIS)

Goldston, R J; Schwartz, J; Myers, R

2016-01-01

It has long been recognized that volumetric dissipation of the plasma heat flux from a fusion power system is preferable to its localized impingement on a material surface. Volumetric dissipation mitigates both the anticipated very high heat flux and intense particle-induced damage due to sputtering. Recent projections to a tokamak demonstration power plant suggest an immense upstream parallel heat flux, of order 20 GW m −2 , implying that fully detached operation may be a requirement for the success of fusion power. Building on pioneering work on the use of lithium by Nagayama et al and by Ono et al as well as earlier work on the gas box divertor by Watkins and Rebut, we present here a concept for a lithium vapor box divertor, in which lithium vapor extracts momentum and energy from a fusion-power-plant divertor plasma, using fully volumetric processes. At the high powers and pressures that are projected this requires a high density of lithium vapor, which must be isolated from the main plasma in order to avoid lithium build-up on the chamber walls or in the plasma. Isolation is achieved through a powerful multi-box differential pumping scheme available only for condensable vapors. The preliminary box-wise calculations are encouraging, but much more work is required to demonstrate the practical viability of this scheme, taking into account at least 2D plasma and vapor flows within and between the vapor boxes and out of the vapor boxes to the main plasma. (paper)

Vapor pressures and enthalpies of vaporization of a series of the linear aliphatic aldehydes

Czech Academy of Sciences Publication Activity Database

Verevkin, S. P.; Krasnykh, E. L.; Vasiltsova, T. V.; Koutek, Bohumír; Doubský, Jan; Heintz, A.

2003-01-01

Roč. 206, - (2003), s. 331-339 ISSN 0378-3812 Institutional research plan: CEZ:AV0Z4055905 Keywords : aldehydes * vapor pressure * enthalpy of vaporization Subject RIV: CC - Organic Chemistry Impact factor: 1.165, year: 2003

Vapor pressures and enthalpies of vaporization of a series of γ and δ-lactones by correlation gas chromatography

International Nuclear Information System (INIS)

Kozlovskiy, Mikhail; Gobble, Chase; Chickos, James

2014-01-01

Highlights: • The vaporization enthalpies of γ-octanolactone, γ- and δ-undecanolactone and γ and δ-dodecanolactone are reported. • Equations for predicting the vapor pressures over the temperature range T = (298.15 to 350) K are provided. • Vaporization enthalpies are compared to predicted values. - Abstract: The vaporization enthalpies of γ-octanolactone, γ- and δ-undecanolactone and γ and δ-dodecanolactone used commercially as flavor ingredients are reported as are their vapor pressures over the temperature range T = (298.15 to 350) K. Vaporization enthalpies at T = 298.15 K of: (66.0 ± 3.9), (79.4 ± 4.4), (80.1 ± 4.5), (83.9 ± 4.6), and (84.61 ± 4.7) kJ · mol −1 and vapor pressures also at T = 298.15 K of: (2.8 ± 0.9), (0.12 ± 0.05), (0.09 ± 0.04), (0.04 ± 0.02), and (0.03 ± 0.02) Pa, respectively, have been evaluated by correlation gas chromatography experiments. The vaporization enthalpies of the lactones studied are reproduced within ±0.5 kJ · mol −1 using a group additivity scheme reported previously for γ- and δ-lactones. The vaporization enthalpies of the γ- and δ-lactones are compared to a similar series of ω-lactones

A study on vapor explosions

International Nuclear Information System (INIS)

Takagi, N.; Shoji, M.

1979-01-01

An experimental study was carried out for vapor explosions of molten tin falling in water. For various initial metal temperatures and subcooling of water, transient pressure of the explosions, relative frequency of the explosions and the position where the explosions occur were measured in detail. The influence of ambient pressure was also investigated. From the results, it was concluded that the vapor explosion is closely related to the collapse of a vapor film around the molten metal. (author)

Physical model for vaporization

OpenAIRE

Garai, Jozsef

2006-01-01

Based on two assumptions, the surface layer is flexible, and the internal energy of the latent heat of vaporization is completely utilized by the atoms for overcoming on the surface resistance of the liquid, the enthalpy of vaporization was calculated for 45 elements. The theoretical values were tested against experiments with positive result.

Las ondas en las universidades o las universidades en las ondas

Directory of Open Access Journals (Sweden)

Verónica Marín Díaz

2014-01-01

Full Text Available En las aulas y pasillos de las universidades vuelven a sonar las ondas hercianas que raen una variedad de programas a la anodina vida de la comunidad universitaria, inmersa en la implantación de títulos de Grado, nuevos programas de doctorado, legislación universitaria variable y un largo etcétera que afecta al devenir de la vida en el ámbito de la educación superior.

Calidad de la energía en redes eléctricas con penetración eólica. Caso: Parque Eólico de Turiguanó: Power quality in electrical networks with aeolian penetration. Case: The Turiguanó wind farm

Directory of Open Access Journals (Sweden)

Daisnel Coello Igarza

2013-06-01

Full Text Available En este trabajo se describe la problemática de la generación eólica con respecto a la calidad de la energía producida, ya que incorpora inversores que distorsionan la onda fundamental de tensión y corriente, como una de las características de la generación eólica que emplea turbinas de velocidad variable, junto con las exportaciones e importaciones de potencia reactiva y la consecuente disminución del factor de potencia; para este propósito se analiza un caso práctico, a partir de mediciones reales de potencias reactivas, factor de potencia y armónicos, realizadas en el Parque Eólico Demostrativo de Turiguanó, además de otras mediciones acumuladas en los registros de la “Documentación de explotación del parque”, exponiendo una metodología para determinar, con las mediciones realizadas, los valores de potencias reactivas, factores de potencia y armónicos para cada valor de grado de carga del parque eólico y operación de las turbinas.In this work the problem of the aeolian generation is described regarding to the quality of the produced energy because the inverters, that distort the fundamental wave of tension and current, has been incorporate like one of the characteristics of the aeolian generation that use turbines of variable speed, together with the exports and imports of reactive power and the consequent decrease of the power factor; for this purpose takes a practical example, with real measures of reactive powers, power factor and harmonics, carried out in the Demonstrative Wind Farm of Turiguanó and others accumulated measures from the records of the technical documentation of the wind farm, exposing a methodology to determine, with the realized measures, the values of reactive powers, power factor and harmonics for each value of load degree of the wind farm and operation of the turbines.

Calidad de la energía en redes eléctricas con penetración eólica. Caso: Parque Eólico de Turiguanó; Power quality in electrical networks with aeolian penetration. Case: The Turiguanó wind farm

Directory of Open Access Journals (Sweden)

Eduardo Sierra Gil

2013-06-01

Full Text Available En este trabajo se describe la problemática de la generación eólica con respecto a la calidad de la energía producida, ya que incorpora inversores que distorsionan la onda fundamental de tensión y corriente, como una de las características de la generación eólica que emplea turbinas de velocidad variable, junto con las exportaciones e importaciones de potencia reactiva y la consecuente disminución del factor de potencia; para este propósito se analiza un caso práctico, a partir de mediciones reales de potencias reactivas, factor de potencia y armónicos, realizadas en el Parque Eólico Demostrativo de Turiguanó, además de otras mediciones acumuladas en los registros de la “Documentación de explotación del parque”, exponiendo una metodología para determinar, con las mediciones realizadas, los valores de potencias reactivas, factores de potencia y armónicos para cada valor de grado de carga del parque eólico y operación de las turbinas.  In this work the problem of the aeolian generation is described regarding to the quality of the produced energy because the inverters, that distort the fundamental wave of tension and current, has been incorporate like one of the characteristics of the aeolian generation that use turbines of variable speed, together with the exports and imports of reactive power and the consequent decrease of the power factor; for this purpose takes a practical example, with real measures of reactive powers, power factor and harmonics, carried out in the Demonstrative Wind Farm of Turiguanó and others accumulated measures from the records of the technical documentation of the wind farm, exposing a methodology to determine, with the realized measures, the values of reactive powers, power factor and harmonics for each value of load degree of the wind farm and operation of the turbines.

Vaporization of irradiated droplets

International Nuclear Information System (INIS)

Armstrong, R.L.; O'Rourke, P.J.; Zardecki, A.

1986-01-01

The vaporization of a spherically symmetric liquid droplet subject to a high-intensity laser flux is investigated on the basis of a hydrodynamic description of the system composed of the vapor and ambient gas. In the limit of the convective vaporization, the boundary conditions at the fluid--gas interface are formulated by using the notion of a Knudsen layer in which translational equilibrium is established. This leads to approximate jump conditions at the interface. For homogeneous energy deposition, the hydrodynamic equations are solved numerically with the aid of the CON1D computer code (''CON1D: A computer program for calculating spherically symmetric droplet combustion,'' Los Alamos National Laboratory Report No. LA-10269-MS, December, 1984), based on the implict continuous--fluid Eulerian (ICE) [J. Comput. Phys. 8, 197 (1971)] and arbitrary Lagrangian--Eulerian (ALE) [J. Comput. Phys. 14, 1227 (1974)] numerical mehtods. The solutions exhibit the existence of two shock waves propagating in opposite directions with respect to the contact discontinuity surface that separates the ambient gas and vapor

Non-equilibrium phenomena near vapor-liquid interfaces

CERN Document Server

Kryukov, Alexei; Puzina, Yulia

2013-01-01

This book presents information on the development of a non-equilibrium approach to the study of heat and mass transfer problems using vapor-liquid interfaces, and demonstrates its application to a broad range of problems. In the process, the following peculiarities become apparent: 1. At vapor condensation on the interface from gas-vapor mixture, non-condensable components can lock up the interface surface and condensation stops completely. 2. At the evolution of vapor film on the heater in superfluid helium (He-II), the boiling mass flux density from the vapor-liquid interface is effectively zero at the macroscopic scale. 3. In problems concerning the motion of He-II bridges inside capillaries filled by vapor, in the presence of axial heat flux the He-II bridge cannot move from the heater as would a traditional liquid, but in the opposite direction instead. Thus the heater attracts the superfluid helium bridge. 4. The shape of liquid-vapor interface at film boiling on the axis-symmetric heaters immersed in l...

Effect of impact angle on vaporization

Science.gov (United States)

Schultz, Peter H.

1996-09-01

Impacts into easily vaporized targets such as dry ice and carbonates generate a rapidly expanding vapor cloud. Laboratory experiments performed in a tenuous atmosphere allow deriving the internal energy of this cloud through well-established and tested theoretical descriptions. A second set of experiments under near-vacuum conditions provides a second measure of energy as the internal energy converts to kinetic energy of expansion. The resulting data allow deriving the vaporized mass as a function of impact angle and velocity. Although peak shock pressures decrease with decreasing impact angle (referenced to horizontal), the amount of impact-generated vapor is found to increase and is derived from the upper surface. Moreover, the temperature of the vapor cloud appears to decrease with decreasing angle. These unexpected results are proposed to reflect the increasing roles of shear heating and downrange hypervelocity ricochet impacts created during oblique impacts. The shallow provenance, low temperature, and trajectory of such vapor have implications for larger-scale events, including enhancement of atmospheric and biospheric stress by oblique terrestrial impacts and impact recycling of the early atmosphere of Mars.

A Citizen's Guide to Vapor Intrusion Mitigation

Science.gov (United States)

This guide describes how vapor intrusion is the movement of chemical vapors from contaminated soil and groundwater into nearby buildings.Vapors primarily enter through openings in the building foundation or basement walls.

Condensation of vapor bubble in subcooled pool

Science.gov (United States)

Horiuchi, K.; Koiwa, Y.; Kaneko, T.; Ueno, I.

2017-02-01

We focus on condensation process of vapor bubble exposed to a pooled liquid of subcooled conditions. Two different geometries are employed in the present research; one is the evaporation on the heated surface, that is, subcooled pool boiling, and the other the injection of vapor into the subcooled pool. The test fluid is water, and all series of the experiments are conducted under the atmospheric pressure condition. The degree of subcooling is ranged from 10 to 40 K. Through the boiling experiment, unique phenomenon known as microbubble emission boiling (MEB) is introduced; this phenomenon realizes heat flux about 10 times higher than the critical heat flux. Condensation of the vapor bubble is the key phenomenon to supply ambient cold liquid to the heated surface. In order to understand the condensing process in the MEB, we prepare vapor in the vapor generator instead of the evaporation on the heated surface, and inject the vapor to expose the vapor bubble to the subcooled liquid. Special attention is paid to the dynamics of the vapor bubble detected by the high-speed video camera, and on the enhancement of the heat transfer due to the variation of interface area driven by the condensation.

Collapsing criteria for vapor film around solid spheres as a fundamental stage leading to vapor explosion

Energy Technology Data Exchange (ETDEWEB)

Freud, Roy [Nuclear Research Center - Negev, Beer-Sheva (Israel)], E-mail: freud@bgu.ac.il; Harari, Ronen [Nuclear Research Center - Negev, Beer-Sheva (Israel); Sher, Eran [Pearlstone Center for Aeronautical Studies, Department of Mechanical Engineering, Ben-Gurion University, Beer-Sheva (Israel)

2009-04-15

Following a partial fuel-melting accident, a Fuel-Coolant Interaction (FCI) can result with the fragmentation of the melt into tiny droplets. A vapor film is then formed between the melt fragments and the coolant, while preventing a contact between them. Triggering, propagation and expansion typically follow the premixing stage. In the triggering stage, vapor film collapse around one or several of the fragments occurs. This collapse can be the result of fragments cooling, a sort of mechanical force, or by any other means. When the vapor film collapses and the coolant re-establishes contact with the dry surface of the hot melt, it may lead to a very rapid and rather violent boiling. In the propagation stage the shock wave front leads to stripping of the films surrounding adjacent droplets which enhance the fragmentation and the process escalates. During this process a large quantity of liquid vaporizes and its expansion can result in destructive mechanical damage to the surrounding structures. This multiphase thermal detonation in which high pressure shock wave is formed is regarded as 'vapor explosion'. The film boiling and its possible collapse is a fundamental stage leading to vapor explosion. If the interaction of the melt and the coolant does not result in a film boiling, no explosion occurs. Many studies have been devoted to determine the minimum temperature and heat flux that is required to maintain a film boiling. The present experimental study examines the minimum temperature that is required to maintain a film boiling around metal spheres immersed into a liquid (subcooled distilled water) reservoir. In order to simulate fuel fragments that are small in dimension and has mirror-like surface, small spheres coated with anti-oxidation layer were used. The heat flux from the spheres was calculated from the sphere's temperature profiles and the sphere's properties. The vapor film collapse was associated with a sharp rise of the heat flux

Collapsing criteria for vapor film around solid spheres as a fundamental stage leading to vapor explosion

International Nuclear Information System (INIS)

Freud, Roy; Harari, Ronen; Sher, Eran

2009-01-01

Following a partial fuel-melting accident, a Fuel-Coolant Interaction (FCI) can result with the fragmentation of the melt into tiny droplets. A vapor film is then formed between the melt fragments and the coolant, while preventing a contact between them. Triggering, propagation and expansion typically follow the premixing stage. In the triggering stage, vapor film collapse around one or several of the fragments occurs. This collapse can be the result of fragments cooling, a sort of mechanical force, or by any other means. When the vapor film collapses and the coolant re-establishes contact with the dry surface of the hot melt, it may lead to a very rapid and rather violent boiling. In the propagation stage the shock wave front leads to stripping of the films surrounding adjacent droplets which enhance the fragmentation and the process escalates. During this process a large quantity of liquid vaporizes and its expansion can result in destructive mechanical damage to the surrounding structures. This multiphase thermal detonation in which high pressure shock wave is formed is regarded as 'vapor explosion'. The film boiling and its possible collapse is a fundamental stage leading to vapor explosion. If the interaction of the melt and the coolant does not result in a film boiling, no explosion occurs. Many studies have been devoted to determine the minimum temperature and heat flux that is required to maintain a film boiling. The present experimental study examines the minimum temperature that is required to maintain a film boiling around metal spheres immersed into a liquid (subcooled distilled water) reservoir. In order to simulate fuel fragments that are small in dimension and has mirror-like surface, small spheres coated with anti-oxidation layer were used. The heat flux from the spheres was calculated from the sphere's temperature profiles and the sphere's properties. The vapor film collapse was associated with a sharp rise of the heat flux during the cooling

Vapor deposition of tantalum and tantalum compounds

International Nuclear Information System (INIS)

Trkula, M.

1996-01-01

Tantalum, and many of its compounds, can be deposited as coatings with techniques ranging from pure, thermal chemical vapor deposition to pure physical vapor deposition. This review concentrates on chemical vapor deposition techniques. The paper takes a historical approach. The authors review classical, metal halide-based techniques and current techniques for tantalum chemical vapor deposition. The advantages and limitations of the techniques will be compared. The need for new lower temperature processes and hence new precursor chemicals will be examined and explained. In the last section, they add some speculation as to possible new, low-temperature precursors for tantalum chemical vapor deposition

Evidence of a sewer vapor transport pathway at the USEPA vapor intrusion research duplex

Science.gov (United States)

The role of sewer lines as preferential pathways for vapor intrusion is poorly understood. Although the importance of sewer lines for volatile organic compound (VOC) transport has been documented at a small number of sites with vapor intrusion, sewer lines are not routinely sampl...

Knudsen cell vaporization of rare earth nitrides: enthalpy of vaporization of HoN098

International Nuclear Information System (INIS)

Brown, R.C.; Clark, N.J.

1975-01-01

The enthalpy of vaporization of HoN 0 . 98 was measured by the weight-loss Knudsen cell technique using Motzfeldt-Whitman extrapolations to zero orifice area. A third-law enthalpy of vaporization of HoN 0 . 98 of 155.9 +- 5 kcal mole -1 was obtained compared to a second-law value of 162.0 +- 5 kcal mole -1 . Similar measurements on the nitrides of samarium, erbium, and ytterbium gave third-law enthalpies of vaporization of 126.8 +-- 5 kcal mole -1 ; 159.6 +- 5 kcal mole -1 , and 121.0 +- 5 kcal mole -1 , respectively. 7 tables

Improvements in the exploitation of hydraulic resources for the energy sustainable development; Mejoras en el aprovechamiento de recursos hidraulicos al desarrollo sustentable energetico

Energy Technology Data Exchange (ETDEWEB)

Kubiak S, Janusz; Urquiza B, Gustavo [Universidad Autonoma del Estado de Morelos(UAEM), Cuernavaca, Morelos (Mexico)

2006-11-15

to modify runners. This series of actions will allow the optimization of the hydraulic resources, which improve the negative effects on the environment. [Spanish] La energia hidraulica representa una alternativa a gran escala para la generacion de combustibles fosiles, contribuyendo solo en muy pequenas cantidades de emisiones de gases de invernadero y otros contaminantes atmosfericos. Sin embargo, para desarrollar el potencial hidroelectrico remanente se deben realizar cambios con miras al medio ambiente y al desarrollo social que tiendan al incremento del aprovechamiento de recursos hidraulicos. Sin embargo, en el contexto de la reestructuracion del sector electrico, el mercado favorece opciones mas contaminantes (menor costo). Parte de este articulo, esta basado sobre datos de la Agencia Internacional de Energia sobre Hidraulica, y se propone una serie de acciones para conocer y desarrollar el potencial hidraulico remanente en una via sustentable considerando generacion distribuida, centrales pequenas y centrales grandes. En la primera parte, se presentan las ventajas de la aplicacion de pequenas turbinas hidraulicas instaladas en las proximidades del usuario. Esto es, la ventaja de la generacion distribuida reside en que no es necesario construir lineas de transmision. En la segunda parte, se presentan las ventajas al instalar pequenas centrales en lugares geograficos de dificil acceso. El tamano de estas centrales puede variar de 100 kW a 5 MW dependiendo de la disponibilidad de los recursos hidraulicos con costos muy accesibles a un usuario individual o a una comunidad pequena. Ademas, esto mejorara el abastamiento del agua. En la tercera parte, se presentan resultados de mediciones de flujo y calculos de eficiencia en unidades de diferentes tamanos, entre 37.5 y 320MW. Los objetivos de estas mediciones y calculos fueron: Elaborar las caracteristicas de la turbina (eficiencia vs. Potencia); Medicion y cuantificacion de fugas en la turbina; Proporcionar

Vapor pressures and vapor compositions in equilibrium with hypostoichiometric plutonium dioxide at high temperatures

International Nuclear Information System (INIS)

Green, D.W.; Fink, J.K.; Leibowitz, L.

1982-01-01

Vapor pressures and vapor compositions have been calculated for 1500 less than or equal to T less than or equal to 4000 0 K. Thermodynamic functions for the condensed phase and for each of the gaseous species were combined with an oxygen-potential model extended into the liquid region to obtain the partial pressures of O 2 , O, Pu, PuO and PuO 2 . The calculated oxygen pressures increase very rapidly as stoichiometry is approached. At least part of this increase is a consequence of the exclusion of Pu 6 + from the oxygen-potential model. No reliable method was found to estimate the importance of this ion. As a result of large oxygen potentials at high temperatures, extremely high total pressures that produced unreasonably high vapor densities were calculated. The highest temperature was therefore limited to 400 K, and the range of oxygen-to-metal ratios was limited to 1.994 to 1.70. These calculations show that vapor in equilibrium with hypostoichiometric plutonium dioxide is poorly approximated as PuO 2 for most of the temperture and composition range of interest. The vapor is much more oxygen-rich than the condensed phase. Implications for the (U,Pu)O/sub 2-x/ system are discussed

Vapor pressure measured with inflatable plastic bag

Science.gov (United States)

1965-01-01

Deflated plastic bag in a vacuum chamber measures initial low vapor pressures of materials. The bag captures the test sample vapors and visual observation of the vapor-inflated bag under increasing external pressures yields pertinent data.

Temperature dependences of saturated vapor pressure and the enthalpy of vaporization of n-pentyl esters of dicarboxylic acids

Science.gov (United States)

Portnova, S. V.; Krasnykh, E. L.; Levanova, S. V.

2016-05-01

The saturated vapor pressures and enthalpies of vaporization of n-pentyl esters of linear C2-C6 dicarboxylic acids are determined by the transpiration method in the temperature range of 309.2-361.2 K. The dependences of enthalpies of vaporization on the number of carbon atoms in the molecule and on the retention indices have been determined. The predictive capabilities of the existing calculation schemes for estimation of enthalpy of vaporization of the studied compounds have been analyzed.

Hidrodinámica bidimensional del canal de descarga de la central hidroeléctrica de Caruachi: correlación modelo matemático 2DH-Prototipo

OpenAIRE

Toscano Díaz, M.A.; Montilla Castro, G.A.

2007-01-01

La Central Hidroeléctrica de Caruachi está localizada en la zona Sur-Oriental de Venezuela en el Estado Bolívar sobre las aguas del río Caroní. Está equipada por 12 turbinas tipo Kaplan con 2196 MW de potencia instalada y un Aliviadero con una capacidad de 30000 m3/s. En este trabajo se presenta una correlación Modelo Matemático – Prototipo, cuyo objetivo es determinar la hidrodinámica del flujo del Canal de Descarga de Caruachi mediante el modelo matemático bidimensional SMS-FESWMS-2DH. El m...

Diseño de un aerogenerador tipo H-Darrieus y estudio de la influencia del ángulo de pitch, mediante mecánica de fluidos computacional

OpenAIRE

Río Sánchez, Saúl del

2017-01-01

Este trabajo es un estudio de diseño, mediante CFD, de un aerogenerador de eje vertical de tipo H-Darrieus de tres álabes. Se ha realizado el diseño general, viendo la sensibilidad a la malla y comparando los resultados con otros de la bibliografía, se han representado las curvas características y el patrón de flujo para conocer el comportamiento de la turbina. Aparte del diseño, también se ha realizado un análisis de cómo afectan los cambios realizados en la configuración d...

Energía Minihidráulica

OpenAIRE

Mancebo Piqueras, José Antonio; Adrada Guerra, Teodoro; Martinez, Carmen

2013-01-01

La energía basada en turbinas hidráulicas de reducida potencia es, a menudo, un ejemplo- modelo dentro del campo de las energías renovables desde su aparición a finales del S. XIX, aunque los ingenios precursores surgen mucho antes. Entre los testimonios más antiguos destacan la saqia o rueda persa y la rueda hidráulica romana que había sido previamente implementada en Extremo Oriente, y que después llega a Europa a través de Egipto. Más tarde, durante la Edad Media y el Renacimiento, se gene...

Vapor-droplet flow equations

International Nuclear Information System (INIS)

Crowe, C.T.

1975-01-01

General features of a vapor-droplet flow are discussed and the equations expressing the conservation of mass, momentum, and energy for the vapor, liquid, and mixture using the control volume approach are derived. The phenomenological laws describing the exchange of mass, momentum, and energy between phases are also reviewed. The results have application to development of water-dominated geothermal resources

EL SELLAJE, UN PROBLEMA COMPLEJO EN LAS INSTALACIONES INDUSTRIALES Y DE SERVICIOS

Directory of Open Access Journals (Sweden)

Enoc Duliep Lescaille

2011-03-01

Full Text Available El escape de líquidos, aire comprimido, vapor u otros fluidos en las instalaciones industriales o de servicios representanpérdidas cuantiosas. Estas fugas ocurren fundamentalmente en los puntos donde el eje de la máquina atraviesa el cuerpode ésta, en los vástagos de las válvulas y en las uniones. En el presente trabajo se dan criterios para la selección de losdiferentes materiales utilizados en el sellaje de estos puntos y su adecuado montaje, todo lo cual influirá en alargar lavida útil de éstas, disminuir estas pérdidas y los costos por concepto de mantenimiento.  The fluid leakage as compressed air; steam or others in the industrial facilities or services represent considerablelosses. These leakages fundamentally happen in the points where the axis of the machine crosses its body, in the stemof the valves and in the unions. Presently paper approaches are given for the selection of the different materials usedin the sealing of these points and their appropriate assembly, all that which will influence in lengthening the usefullife of these, to diminish these losses and the maintenance costs.

What Good is Raman Water Vapor Lidar?

Science.gov (United States)

Whitman, David

2011-01-01

Raman lidar has been used to quantify water vapor in the atmosphere for various scientific studies including mesoscale meteorology and satellite validation. Now the international networks of NDACC and GRUAN have interest in using Raman water vapor lidar for detecting trends in atmospheric water vapor concentrations. What are the data needs for addressing these very different measurement challenges. We will review briefly the scientific needs for water vapor accuracy for each of these three applications and attempt to translate that into performance specifications for Raman lidar in an effort to address the question in the title of "What good is Raman water vapor Iidar."

Comportamiento hidrotermal de las arcillas saponiticas de la Cuenca de Madrid

Directory of Open Access Journals (Sweden)

Cuevas Rodríguez, J.

1993-08-01

Full Text Available The hydrothermal behavior of sedimentary saponitic clays from Madrid Basin has been investigated to assess their potential use as a buffer material in high level radioactive waste repositories. This paper deals with a rewiew of several aspects that has been studied: the adsorption and irreversible fixation of K+, the alteration in absence of potasium and the effects of heat and steam on textural properties of the smectitic clay. Experiments have covered temperatures up to 175 ºC with an excess of liquid water except on the last subject. Chemical and XRD analyses of final clay products and solutions indicates minor alteration of the saponite in the hydrothermal experiments either in the presence or absence of potasium. No illitization or chloritization processes seems to affect the smectite. Sepiolite was found to be largely dissolved at 175 ºC, a process that inhibited recrystallization or formation of illite observed when illite was present in significant amounts in starting materials. Accessory minerals (illite and sepiolite accompayning as traces the saponitic material underwent and intense degradation at 175 ºC in absence of potasium. On the other hand, clay steamed at 200 ºC showed significant textural changes forming highly stable silt size aggregates which hindered the swelling abilities of the saponitic material, a fact that was previously observed in montmorillonites.El comportamiento hidrotermal de las arcillas saponíticas de origen sedimentario de la Cuenca de Madrid ha sido investigado en función de su uso potencial como barrera geoquímica en el almacenamiento de residuos radiactivos de alta actividad. Este artículo es una revisión de los aspectos estudiados hasta el momento: la adsorción y fijación irreversible de K+, la alteración en ausencia de potasio y los efectos del vapor de agua a elevada temperatura en las características texturales de la arcilla. Los experimentos se han realizado a temperaturas de hasta

Ion vapor deposition and its application

International Nuclear Information System (INIS)

Bollinger, H.; Schulze, D.; Wilberg, R.

1981-01-01

Proceeding from the fundamentals of ion vapor deposition the characteristic properties of ion-plated coatings are briefly discussed. Examples are presented of successful applications of ion-plated coatings such as coatings with special electrical and dielectric properties, coatings for corrosion prevention, and coatings for improving the surface properties. It is concluded that ion vapor deposition is an advantageous procedure in addition to vapor deposition. (author)

A Lithium Vapor Box Divertor Similarity Experiment

Science.gov (United States)

Cohen, Robert A.; Emdee, Eric D.; Goldston, Robert J.; Jaworski, Michael A.; Schwartz, Jacob A.

2017-10-01

A lithium vapor box divertor offers an alternate means of managing the extreme power density of divertor plasmas by leveraging gaseous lithium to volumetrically extract power. The vapor box divertor is a baffled slot with liquid lithium coated walls held at temperatures which increase toward the divertor floor. The resulting vapor pressure differential drives gaseous lithium from hotter chambers into cooler ones, where the lithium condenses and returns. A similarity experiment was devised to investigate the advantages offered by a vapor box divertor design. We discuss the design, construction, and early findings of the vapor box divertor experiment including vapor can construction, power transfer calculations, joint integrity tests, and thermocouple data logging. Heat redistribution of an incident plasma-based heat flux from a typical linear plasma device is also presented. This work supported by DOE Contract No. DE-AC02-09CH11466 and The Princeton Environmental Institute.

Experimental analysis of the vibration on the draft tube of a Francis hydraulic turbine during operation at different power levels

Directory of Open Access Journals (Sweden)

Fernando Casanova García

2010-01-01

Full Text Available En el tubo de aspiración de una turbina hidráulica de 95 MW operando a carga parcial se presentan fuertes vibraciones. Debido a la inestabilidad hidráulica dentro del tubo se presentan fallas frecuentes en elementos estructurales de la planta, principalmente cuando la máquina opera a carga parcial. En este trabajo se midieron las presiones dentro del tubo de aspiración y los esfuerzos en la pared externa del tubo de aspiración a varios niveles de potencia para identificar la potencia donde las condiciones son críticas para la estructura. También, se realizaron mediciones a carga parcial con inyección de aire sobre los alabes fijos y con alivio de presión en el caracol. Se encontró que la inyección de aire reduce efectivamente las vibraciones mientras que el alivio de presión en el caracol no produce ningún efecto útil.

Hanford soil partitioning and vapor extraction study

International Nuclear Information System (INIS)

Yonge, D.; Hossain, A.; Cameron, R.; Ford, H.; Storey, C.

1996-07-01

This report describes the testing and results of laboratory experiments conducted to assist the carbon tetrachloride soil vapor extraction project operating in the 200 West Area of the Hanford Site in Richland, Washington. Vapor-phase adsorption and desorption testing was performed using carbon tetrachloride and Hanford Site soils to estimate vapor-soil partitioning and reasonably achievable carbon tetrachloride soil concentrations during active vapor extractions efforts at the 200 West Area. (CCl 4 is used in Pu recovery from aqueous streams.)

Vapor trap for liquid metal

Energy Technology Data Exchange (ETDEWEB)

Watanabe, T

1968-05-22

In a pipe system which transfers liquid metal, inert gas (cover gas) is packed above the surface of the liquid metal to prevent oxidization of the liquid. If the metal vapor is contained in such cover gas, the circulating system of the cover gas is blocked due to condensation of liquid metal inside the system. The present invention relates to an improvement in vapor trap to remove the metal vapor from the cover gas. The trap consists of a cylindrical outer body, an inlet nozzle which is deeply inserted inside the outer body and has a number of holes to inject the cove gas into the body, metal mesh or steel wool which covers the exterior of the nozzle and on which the condensation of the metal gas takes place, and a heater wire hich is wound around the nozzle to prevent condensation of the metal vapor at the inner peripheral side of the mesh.

Flow prediction and heat transfer in a cooling square duch of a gas turbine blade using CFD; Predicciones de flujo y transferencia de calor en un conductor de alabe enfriado de turbina de gas utilizando CFD

Energy Technology Data Exchange (ETDEWEB)

Urquiza B, Gustavo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Sierra E, Fernando [Universidad Nacional Autonoma de Mexico, Mexico D.F. (Mexico); Kubiak S, Janusz; Campos A, Rafael [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2003-10-15

A numerical investigation has been conducted to study the turbulent flow and the heat transfer in a blade turbine coolant passage involving a 180 degrees turn. The study provides a comparison test for two turbulence models. The numerical solution was conducted employing two models for turbulence, the renormalization Group Theory (RNG) and the Reynolds Stress Model (RSM), using a refined grid to model with detail the recirculating flow. Computations are performed with a commercial finite volume code which solves three dimensional, incompressible, Navier-Stokes and Energy equations. At the passage turn, significant secondary flows are present, formed by a pair of symmetrical vortices. Results have been compared against published experimental data for Re = 53 000. Very good agreement is achieved for the prediction of the local static pressure distribution along the passage. A strong effect of rotation has been observed mainly in the flow field as described in detail in the paper. [Spanish] En este trabajo se presenta una investigacion numerica para estudiar el flujo turbulento y la transferencia de calor en un conducto de enfriamiento de un alabes de turbina de gas con giro de 180 grados. El estudio proporciona una comparacion de resultados para dos modelos de turbulencia. La solucion numerica emplea dos modelos de turbulencia: el modelo de esfuerzos de Reynolds (RSM) y el modelo de la teoria del grupo de renormalizacion (RNG), utilizando una malla refinada para modelar con detalle el flujo de recirculacion. Los calculos fueron realizados con un codigo comercial de volumenes finitos el cual resuelve las ecuaciones tridimensionales de Navier-Stoke y de energia para flujo incompresible. En la seccion de giro del conductor, aparecen flujos secundarios significativos, formados por un par de celulas simetricas. Los resultados han sido comparados contra datos experimentales de la literatura para Re = 53 000. se obtuvo un buen acuerdo para la prediccion de la distribucion de

Recubrimientos protectores para componentes de turbinas de aviación y de generación de energía depositados por proyección por plasma

Directory of Open Access Journals (Sweden)

Agüero Bruna, A.

2000-08-01

Full Text Available Coatings produced by aluminium diffusion, called aluminide are employed to increase the oxidation and corrosion resistance, increasing the life of Ni and Co base superalloys components at temperatures comprised between 900 and 1050ºC. Consequently these coatings are frequently employed in aeronautic and power generation turbines as well as in the chemical industry. Aluminides are industrially produced by pack cementation or CVD and recently it has been demonstrated that its resistance significantly increases when Cr is added (chrome-aluminides. During this work, a feasibility study has been carried out in order to determine if plasma spray can be employed for depositing this type of coatings on turbine blades. Therefore, aluminium and aluminium/chromium layers were deposited on Ni base IN100 superalloy specimens that were subsequently subjected to a diffusion heat treatment under Ar flow. Characterisation and analysis of the coatings were carried out by metallography , SEM and EDS. Cyclic oxidation tests were carried out at 1050º C while molten sulphate hot corrosion was performed at 900º C. The results of this preliminary study are promising and indicate that plasma spray can be developed as an industrial process for production of aluminide and chrome-aluminide coatings.

Los recubrimientos producidos por difusión de aluminio, llamados aluminuros, se emplean para aumentar la resistencia a la oxidación y a la corrosión, incrementando la vida de componentes fabricados con superaleaciones de níquel y cobalto a temperaturas comprendidas entre 900 y 1050º C. Por ello se emplean muy frecuentemente en turbinas aeronaúticas y de producción de energía y en la industria química. Los aluminuros se obtienen industrialmente mediante cementación o CVD y recientemente se ha demostrado que su resistencia aumenta significativamente cuando se añade cromo (cromoaluminuros. Durante el presente trabajo, se ha realizado un estudio de viabilidad

Mechanics of gas-vapor bubbles

NARCIS (Netherlands)

Hao, Yue; Zhang, Yuhang; Prosperetti, Andrea

2017-01-01

Most bubbles contain a mixture of vapor and incondensible gases. While the limit cases of pure vapor and pure gas bubbles are well studied, much less is known about the more realistic case of a mixture. The bubble contents continuously change due to the combined effects of evaporation and

Vapor pressures and thermophysical properties of selected hexenols and recommended vapor pressure for hexan-1-ol

Czech Academy of Sciences Publication Activity Database

Štejfa, V.; Fulem, Michal; Růžička, K.; Matějka, P.

2015-01-01

Roč. 402, Sep (2015), 18-29 ISSN 0378-3812 Institutional support: RVO:68378271 Keywords : alcohols * vapor pressure * heat capacity * ideal - gas thermodynamic properties * vaporization enthalpy Subject RIV: BJ - Thermodynamics Impact factor: 1.846, year: 2015

Técnica de monitorado continuo (on – line para la evaluación del estado técnico de los turbogrupos de 64 y 100 MW. // Technique of continuous monitored (on - line for the evaluation of the technical state in steam turbine units of 64 and 100 MW.

Directory of Open Access Journals (Sweden)

F. de la Torre. Silva

2001-04-01

Full Text Available En este trabajo se presenta el resultado del estudio de factibilidad realizado a los turbogrupos de 64 y 100 MW de dosCentrales Termoeléctricas, sobre el empleo de técnicas de monitorado continuo “on line” para la evaluación del estadotécnico de estos turbogrupos.Palabras claves: Turbinas de vapor,vibraciones, monitorado continuo “on line”, diagnóstico.______________________________________________________________________Abstract:In this work an study of feasibility is presented. This study is carried out in steam turbine units of 64 and 100 MW, and show the use ofcontinuous monitored technique (on line for the evaluation of the technical state of these turbine units.Key Words: Steam turbines, vibrations, continuous monitoring on line, turbines supervision, Diagnosis,technical state evaluation.

Water vapor profiling using microwave radiometry

Science.gov (United States)

Wang, J. R.; Wilheit, T. T.

1988-01-01

Water vapor is one of the most important constituents in the Earth's atmosphere. Its spatial and temporal variations affect a wide spectrum of meteorological phenomena ranging from the formation of clouds to the development of severe storms. The passive microwave technique offers an excellent means for water vapor measurements. It can provide both day and night coverage under most cloud conditions. Two water vapor absorption features, at 22 and 183 GHz, were explored in the past years. The line strengths of these features differ by nearly two orders of magnitude. As a consequence, the techniques and the final products of water vapor measurements are also quite different. The research effort in the past few years was to improve and extend the retrieval algorithm to the measurements of water vapor profiles under cloudy conditions. In addition, the retrieval of total precipitable water using 183 GHz measurements, but in a manner analogous to the use of 22 GHz measurements, to increase measurement sensitivity for atmospheres of very low moisture content was also explored.

Distribution of tropical tropospheric water vapor

Science.gov (United States)

Sun, De-Zheng; Lindzen, Richard S.

1993-01-01

Utilizing a conceptual model for tropical convection and observational data for water vapor, the maintenance of the vertical distribution of the tropical tropospheric water vapor is discussed. While deep convection induces large-scale subsidence that constrains the turbulent downgradient mixing to within the convective boundary layer and effectively dries the troposphere through downward advection, it also pumps hydrometeors into the upper troposphere, whose subsequent evaporation appears to be the major source of moisture for the large-scale subsiding motion. The development of upper-level clouds and precipitation from these clouds may also act to dry the outflow, thus explaining the low relative humidity near the tropopause. A one-dimensional model is developed to simulate the mean vertical structure of water vapor in the tropical troposphere. It is also shown that the horizontal variation of water vapor in the tropical troposphere above the trade-wind boundary layer can be explained by the variation of a moisture source that is proportional to the amount of upper-level clouds. Implications for the nature of water vapor feedback in global warming are discussed.

GeoSteamNet: A computer code to simulate geothermal steam flow in a pipeline network; GeoSteamNet: Programa de computo para simular el flujo de vapor geotermico de una red de vaporductos

Energy Technology Data Exchange (ETDEWEB)

Verma P., Mahendra; Aragon A., Alfonso [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: mahendra@iie.org.mx; Ruiz L., Alejando; Mendoza C., Alfredo [Comision Federal de Electricidad, Campo Geotermico Los Azufres, Campamento Agua Fria, Michoacan (Mexico)

2011-07-15

transporte del flujo de vapor en una red de vaporductos de un campo geotermico. El movimiento del fluido se rige por los siguientes principios basicos: la conservacion de la masa, el principio de movimiento lineal (segunda ley de Newton o las ecuaciones de Navier Stokes) y la primera y segunda leyes de la termodinamica. La segunda ley de la termodinamica permite definir la direccion de un proceso espontaneo, que esta indirectamente validado en el algoritmo, debido a que el vapor fluye de alta a baja presion y el calor fluye de alta a baja temperatura. Las ecuaciones no lineales se resuelven con el metodo de Newton-Raphson. Utilizando el componente ActiveX OrificeMeter, se realizo el balance de masa para el flujo de vapor en las unidades de generacion U-15 y U-16 del campo geotermico de Los Azufres, Mich., en febrero de 2009. La U-15 fue alimentada por los pozos productores AZ-04, Z-28, Z-30, AZ-65D, y AZ-66, mientras que los pozos AZ-28A, AZ-45, Z-56, Z-67 y AZ- 69D estaban conectados a la U-16. La diferencia entre la cantidad de vapor recibida en las unidades y producida por los pozos respectivos esta dentro de {+-}4%, lo cual es aceptable para fines practicos para el suministro de vapor, tomando en cuenta las incertidumbres en varios parametros tales como la presion, la temperatura, la fluctuacion de la presion en el cabezal del pozo, entre otros. Los resultados de la simulacion de una red hipotetica de vaporductos de un sistema geotermico con dos pozos productores y una planta de generacion de energia electrica ilustran la funcionalidad de GeoSteamNet, mostrando varios puntos importantes a destacar. Para una geometria especifica de las redes de vaporductos solo hay una cierta cantidad de masa (vapor) que puede ser transportado a una presion dada de los pozos y de la planta generadora. La construccion y modificacion de una red de vaporductos son muy costosas y la produccion de pozos geotermicos responde a los factores de su naturaleza, por lo tanto, hay necesidad de

HANFORD CHEMICAL VAPORS WORKER CONCERNS and EXPOSURE EVALUATION

International Nuclear Information System (INIS)

ANDERSON, T.J.

2006-01-01

Chemical vapor emissions from underground hazardous waste storage tanks on the Hanford site in eastern Washington State are a potential concern because workers enter the tank farms on a regular basis for waste retrievals, equipment maintenance, and surveillance. Tank farm contractors are in the process of retrieving all remaining waste from aging single-shell tanks, some of which date to World War II, and transferring it to newer double-shell tanks. During the waste retrieval process, tank farm workers are potentially exposed to fugitive chemical vapors that can escape from tank headspaces and other emission points. The tanks are known to hold more than 1,500 different species of chemicals, in addition to radionuclides. Exposure assessments have fully characterized the hazards from chemical vapors in half of the tank farms. Extensive sampling and analysis has been done to characterize the chemical properties of hazardous waste and to evaluate potential health hazards of vapors at the ground surface, where workers perform maintenance and waste transfer activities. Worker concerns. risk communication, and exposure assessment are discussed, including evaluation of the potential hazards of complex mixtures of chemical vapors. Concentrations of vapors above occupational exposure limits-(OEL) were detected only at exhaust stacks and passive breather filter outlets. Beyond five feet from the sources, vapors disperse rapidly. No vapors have been measured above 50% of their OELs more than five feet from the source. Vapor controls are focused on limited hazard zones around sources. Further evaluations of vapors include analysis of routes of exposure and thorough analysis of nuisance odors

Vapor and gas sampling of single-shell tank 241-B-102 using the in situ vapor sampling system

International Nuclear Information System (INIS)

Lockrem, L.L.

1997-01-01

The Vapor Issue Resolution Program tasked the Vapor Team (the team) to collect representative headspace samples from Hanford Site single-shell tank (SST) 241-B-102. This document presents sampling data resulting from the April 18, 1996 sampling of SST 241-B-102. Analytical results will be presented in a separate report issued by Pacific Northwest National Laboratory (PNNL), which supplied and analyzed the sampling media. The team, consisting of Sampling and Mobile Laboratories (SML) and Special Analytical Studies (SAS) personnel, used the vapor sampling system (VSS) to collect representative samples of the air, gases, and vapors from the headspace of SST 241-B-102 with sorbent traps and SUMMA canisters

Estudio de microestructura y composición de la oxidación en vapor a 700 y 750oC de los aceros austeníticos AISI 304, 316 y 317

Directory of Open Access Journals (Sweden)

José Luddey Marulanda

2013-01-01

Full Text Available Se ha investigado la oxidación de los aceros inoxidables austeníticos AISI SAE: 304, 316 y 317; a temperaturas de 700 y 750oC, en una atmósfera próxima al 100% de vapor de agua, y de 10 a 1000h de exposición. La finalidad es comprobar la calidad de los aceros austeníticos y estudiar la morfología, composición y estructura de la fases de las capas formadas en la cascarilla del óxido de las muestras por Microscopía Electrónica de Barrido (SEM, Análisis de Rayos X por Dispersión de Energía (EDAX y Difracción de Rayos X (XRD, respectivamente. Así como también, se ha realizado a diferentes tiempos un estudio sistemático de termogravimetría de las muestras oxidadas, donde se ha observado que el acero AISI 304 presentó la menor ganancia de masa y el acero AISI 316 fue el de mayor de masa respecto a los tres aceros del trabajo. Adicionalmente fue realizado un estudio teórico de simulación termodinámica de oxidación en vapor de los tres aceros, en las mismas condiciones experimentales y mediante el programa Thermo-calc. En estos aceros oxidados se han comprobado la presencia de estructuras de fases de óxidos como: Fe2O3, espinelas protectoras Fe3O4 y Cr2NiO4, y óxidos mixtos de tipo (CrxFey2O3, (Fe,Cr,Mn3O4 y Ni6MnO8. Finalmente, se discute un posible mecanismo de la formación de las capas de óxidos de las muestras ensayadas.

Analyses on Water Vapor Resource in Chengdu City

Science.gov (United States)

Liu, B.; Xiao, T.; Wang, C.; Chen, D.

2017-12-01

Chengdu is located in the Sichuan basin, and it is the most famous inland city in China. With suitable temperatures and rainfall, Chengdu is the most livable cities in China. With the development of urban economy and society, the population has now risen to 16 million, and it will up to 22 million in 2030. This will cause the city water resources demand, and the carrying capacity of water resources become more and more serious. In order to improve the contradiction between urban waterlogging and water shortage, sponge city planning was proposed by Chengdu government, and this is of great practical significance for promoting the healthy development of the city. Base on the reanalysis data from NCEP during 2007-2016, the characters of Water Vapor Resources was analyzed, and the main contents of this research are summarized as follows: The water vapor resource in Chengdu plain is more than that in Southeast China and less in Northwest China. The annual average water vapor resource is approximately 160 mm -320 mm, and the water vapor resource in summer can reach 3 times in winter. But the annual average precipitation in Chengdu is about 800 mm -1200 mm and it is far greater than the water vapor resource, this is because of the transport of water vapor. Using the formula of water vapor flux, the water vapor in Chengdu is comes from the west and the south, and the value is around 50kg/(ms). Base on the calculation of boundary vapor budget, the water vapor transport under 500hPa accounted for 97% of the total. Consider the water vapor transport, transformation and urban humidification effect, the Water Vapor Resource in Chengdu is 2500mm, and it can be used by artificial precipitation enhancement. Therefore, coordinated development of weather modification and sponge city construction, the shortage of water resources in Chengdu plain can be solved. Key words: Chengdu; Sponge city; Water vapor resource; Precipitation; Artificial precipitation enhancement Acknowledgements

A technique to depress desflurane vapor pressure.

Science.gov (United States)

Brosnan, Robert J; Pypendop, Bruno H

2006-09-01

To determine whether the vapor pressure of desflurane could be decreased by using a solvent to reduce the anesthetic molar fraction in a solution (Raoult's Law). We hypothesized that such an anesthetic mixture could produce anesthesia using a nonprecision vaporizer instead of an agent-specific, electronically controlled, temperature and pressure compensated vaporizer currently required for desflurane administration. One healthy adult female dog. Propylene glycol was used as a solvent for desflurane, and the physical characteristics of this mixture were evaluated at various molar concentrations and temperatures. Using a circle system with a breathing bag attached at the patient end and a mechanical ventilator to simulate respiration, an in-circuit, nonprecision vaporizer containing 40% desflurane and 60% propylene glycol achieved an 11.5% +/- 1.0% circuit desflurane concentration with a 5.2 +/- 0.4 (0 = off, 10 = maximum) vaporizer setting. This experiment was repeated with a dog attached to the breathing circuit under spontaneous ventilation with a fresh gas flow of 0.5 L minute(-1). Anesthesia was maintained for over 2 hours at a mean vaporizer setting of 6.2 +/- 0.4, yielding mean inspired and end-tidal desflurane concentrations of 8.7% +/- 0.5% and 7.9% +/- 0.7%, respectively. Rather than alter physical properties of vaporizers to suit a particular anesthetic agent, this study demonstrates that it is also possible to alter physical properties of anesthetic agents to suit a particular vaporizer. However, propylene glycol may not prove an ideal solvent for desflurane because of its instability in solution and substantial-positive deviation from Raoult's Law.

Perspective: Highly stable vapor-deposited glasses

Science.gov (United States)

Ediger, M. D.

2017-12-01

This article describes recent progress in understanding highly stable glasses prepared by physical vapor deposition and provides perspective on further research directions for the field. For a given molecule, vapor-deposited glasses can have higher density and lower enthalpy than any glass that can be prepared by the more traditional route of cooling a liquid, and such glasses also exhibit greatly enhanced kinetic stability. Because vapor-deposited glasses can approach the bottom of the amorphous part of the potential energy landscape, they provide insights into the properties expected for the "ideal glass." Connections between vapor-deposited glasses, liquid-cooled glasses, and deeply supercooled liquids are explored. The generality of stable glass formation for organic molecules is discussed along with the prospects for stable glasses of other types of materials.

Bionanomaterials and Bioinspired Nanostructures for Selective Vapor Sensing

Science.gov (United States)

2013-04-03

agricultural crops. To meet the requirements for these and other demanding applications, new sensing approaches with improved sensor selectivity are required...of these vapors with key side- chain amino acids. DNT-binding peptide receptors were further conjugated to an oligo(ethylene glycol) hydrogel for vapor...coefficient for DNT over TNT vapor. Vapor-phase binding performance was attributed to the ability of the oligo(ethylene glycol) hydrogel to maintain the

Vapor and gas sampling of single-shell tank 241-U-104 using the in situ vapor sampling system

International Nuclear Information System (INIS)

Lockrem, L.L.

1997-01-01

The Vapor Issue.Resolution Program tasked the Vapor Team (VT) to collect representative headspace samples from Hanford Site single-shell tank (SST) 241-U-104. This document presents In Situ Vapor Sampling System (ISVS) data resulting from the July 16, 1996 sampling of SST 241-U-104. Analytical results will be presented in separate reports issued by the Pacific Northwest National Laboratory (PNNL) which supplied and analyzed the sample media

Vapor and gas sampling of single-shell tank 241-S-103 using the in situ vapor sampling system

International Nuclear Information System (INIS)

Lockrem, L.L.

1997-01-01

The Vapor Issue Resolution Program tasked the Vapor Team (VT) to collect representative headspace samples from Hanford Site single-shell tank (SST) 241-S-103. This document presents In Situ Vapor Sampling System (ISVS) data resulting from the June 12, 1996 sampling of SST 241-S-103. Analytical results will be presented in separate reports issued by the Pacific Northwest National Laboratory (PNNL) which supplied and analyzed the sample media

Vapor and gas sampling of single-shell tank 241-S-106 using the in situ vapor sampling system

International Nuclear Information System (INIS)

Lockrem, L.L.

1997-01-01

The Vapor Issue Resolution Program tasked the Vapor Team (VT) to collect representative headspace samples from Hanford Site single-shell tank (SST) 241-S-106. This document presents In Situ vapor Sampling System (ISVS) data resulting from the June 13, 1996 sampling of SST 241-S-106. Analytical results will be presented in separate reports issued by the Pacific Northwest National Laboratory (PNNL) which'supplied and analyzed the sample media

Cumulus convection and the terrestrial water-vapor distribution

Science.gov (United States)

Donner, Leo J.

1988-01-01

Cumulus convection plays a significant role in determining the structure of the terrestrial water vapor field. Cumulus convection acts directly on the moisture field by condensing and precipitating water vapor and by redistributing water vapor through cumulus induced eddy circulations. The mechanisms by which cumulus convection influences the terrestrial water vapor distribution is outlined. Calculations using a theory due to Kuo is used to illustrate the mechanisms by which cumulus convection works. Understanding of these processes greatly aids the ability of researchers to interpret the seasonal and spatial distribution of atmospheric water vapor by providing information on the nature of sources and sinks and the global circulation.

Vapor pumps and gas-driven machines

International Nuclear Information System (INIS)

Guillet, R.

1991-01-01

The vapor pump, patented in 1979 by Gaz de France, is an additional mass and heat exchanger which uses the combustion air of fuel-burning machines as an additional cold source. This cold source is preheated and, above all, humidified before reaching the burner, by means of the residual sensible and latent heat in the combustion products of the fuel-burning process. This final exchanger thus makes it possible, in many cases, to recover all the gross calorific value of natural gas, even when the combustion products leave the process at a wet temperature greater than 60 0 C, the maximum dew point of the products of normal combustion. Another significant advantage of the vapor pump being worth highlighting is the selective recycling of water vapor by the vapor pump which reduces the adiabatic combustion temperature and the oxygen concentration in the combustion air, two factors which lead to considerable reductions in nitrogen oxides formation, hence limiting atmospheric pollution. Alongside a wide range of configurations which make advantageous use of the vapor pump in association with gas-driven machines and processes, including gas turbines, a number of boiler plant installations are also presented [fr

Thermodynamics and Kinetics of Silicate Vaporization

Science.gov (United States)

Jacobson, Nathan S.; Costa, Gustavo C. C.

2015-01-01

Silicates are a common class of materials that are often exposed to high temperatures. The behavior of these materials needs to be understood for applications as high temperature coatings in material science as well as the constituents of lava for geological considerations. The vaporization behavior of these materials is an important aspect of their high temperature behavior and it also provides fundamental thermodynamic data. The application of Knudsen effusion mass spectrometry (KEMS) to silicates is discussed. There are several special considerations for silicates. The first is selection of an appropriate cell material, which is either nearly inert or has well-understood interactions with the silicate. The second consideration is proper measurement of the low vapor pressures. This can be circumvented by using a reducing agent to boost the vapor pressure without changing the solid composition or by working at very high temperatures. The third consideration deals with kinetic barriers to vaporization. The measurement of these barriers, as encompassed in a vaporization coefficient, is discussed. Current measured data of rare earth silicates for high temperature coating applications are discussed. In addition, data on magnesium-iron-silicates (olivine) are presented and discussed.

Modeling UTLS water vapor: Transport/Chemistry interactions

International Nuclear Information System (INIS)

Gulstad, Line

2005-01-01

This thesis was initially meant to be a study on the impact on chemistry and climate from UTLS water vapor. However, the complexity of the UTLS water vapor and its recent changes turned out to be a challenge by it self. In the light of this, the overall motivation for the thesis became to study the processes controlling UTLS water vapor and its changes. Water vapor is the most important greenhouse gas, involved in important climate feedback loops. Thus, a good understanding of the chemical and dynamical behavior of water vapor in the atmosphere is crucial for understanding the climate changes in the last century. Additionally, parts of the work was motivated by the development of a coupled climate chemistry model based on the CAM3 model coupled with the Chemical Transport Model Oslo CTM2. The future work will be concentrated on the UTLS water vapor impact on chemistry and climate. We are currently studying long term trends in UTLS water vapor, focusing on identification of the different processes involved in the determination of such trends. The study is based on natural as well as anthropogenic climate forcings. The ongoing work on the development of a coupled climate chemistry model will continue within our group, in collaboration with Prof. Wei-Chyung Wang at the State University of New York, Albany. Valuable contacts with observational groups are established during the work on this thesis. These collaborations will be continued focusing on continuous model validation, as well as identification of trends and new features in UTLS water vapor, and other tracers in this region. (Author)

Calculating the enthalpy of vaporization for ionic liquid clusters.

Science.gov (United States)

Kelkar, Manish S; Maginn, Edward J

2007-08-16

Classical atomistic simulations are used to compute the enthalpy of vaporization of a series of ionic liquids composed of 1-alkyl-3-methylimidazolium cations paired with the bis(trifluoromethylsulfonyl)imide anion. The calculations show that the enthalpy of vaporization is lowest for neutral ion pairs. The enthalpy of vaporization increases by about 40 kJ/mol with the addition of each ion pair to the vaporizing cluster. Non-neutral clusters have much higher vaporization enthalpies than their neutral counterparts and thus are not expected to make up a significant fraction of volatile species. The enthalpy of vaporization increases slightly as the cation alkyl chain length increases and as temperature decreases. The calculated vaporization enthalpies are consistent with two sets of recent experimental measurements as well as with previous atomistic simulations.

Prediction of vapor pressure and heats of vaporization of edible oil/fat compounds by group contribution

DEFF Research Database (Denmark)

Ceriani, Roberta; Gani, Rafiqul; Liu, Y.A.

2013-01-01

In the present work, a group contribution method is proposed for the estimation of vapor pressures and heats of vaporization of organic liquids found in edible fat/oil and biofuel industries as a function of temperature. The regression of group contribution parameters was based on an extensive...

Comparative study of the vapor analytes of trinitrotoluene (TNT)

Science.gov (United States)

Edge, Cindy C.; Gibb, Julie; Dugan, Regina E.

1998-12-01

Trinitrotoluene (TNT) is a high explosive used in most antipersonnel and antitank landmines. The Institute for Biological Detection Systems (IBDS) has developed a quantitative vapor delivery system, termed olfactometer, for conducting canine olfactory research. The research is conducted utilizing dynamic conditions, therefore, it is imperative to evaluate the headspace of TNT to ensure consistency with the dynamic generation of vapor. This study quantified the vapor headspace of military- grade TNT utilizing two different vapor generated methodologies, static and dynamic, reflecting differences between field and laboratory environments. Static vapor collection, which closely mimics conditions found during field detection, is defined as vapor collected in an open-air environment at ambient temperature. Dynamic vapor collection incorporates trapping of gases from a high flow vapor generation cell used during olfactometer operation. Analysis of samples collected by the two methodologies was performed by gas chromatography/mass spectrometry and the results provided information with regard to the constituents detected. However, constituent concentration did vary between the sampling methods. This study provides essential information regarding the vapor constituents associated with the TNT sampled using different sampling methods. These differences may be important in determining the detection signature dogs use to recognize TNT.

Análisis comparativo del mantenimiento para locomotoras diesel y de vapor // Comparative analysis of the Maintenance for Diesel and Steam Locomotives.

Directory of Open Access Journals (Sweden)

C. M. Rodríguez Gil

2000-03-01

Full Text Available El mundo globalizado no afecta por igual a todos los países del orbe. En las circunstancias actuales que tiene el ferrocarrilde la primera industria de la República de Cuba: ausencia de piezas de repuesto y limitaciones de recursos de combustible,surge la necesidad de estudiar nuevas fuentes motrices o potenciar la utilización de locomotoras a vapor, introducidas en elpaís desde 1837.La decisión de incrementar la participación de las locomotoras a vapor depende de múltiples factores quedeben ser analizados individualmente e integrados posteriormente en un análisis sistémico. Dentro de estos factores seencuentra, jugando un papel fundamental, el mantenimiento técnico y sus costos. El trabajo tiene como objetivo central elestudio comparativo de los costos por mantenimiento entre parques similares de locomotoras con tracción diesel y devapor. Este estudio forma parte de un proyecto nacional conocido como “Prometeo” encaminado a estudiar la factibilidadde la utilización masiva de las locomotoras a vapor en la industria azucarera. Para realizar el estudio se trabajó en varioscomplejos agro-industriales durante tres zafras azucareras, permitiendo llegar a recomendaciones.Palabras claves: Mantenimiento, locomotoras, costos._____________________________________________________________________________AbstractThe globalized world doesn't affect equally to all the countries. In the current circumstances the railroad of the first industry ofCuba, that is: lack of spare parts limitations of fuel, arises the necessity of the study of new motion sources or to analyze the useof steam locomotives, introduced in the country since 1837.The decision of increasing the participation of these machinesdepends on multiple factors that should be analyzed individually and later integrated in a systemic analysis. The technicalmaintenance and their costs are playing a main paper The work have as objective a comparative study of costs for maintenancebetween

Las creencias y las concepciones. Perspectivas complementarias

Directory of Open Access Journals (Sweden)

Fuensanta HERNÁNDEZ PINA

2011-01-01

Full Text Available Las creencias y las concepciones sobre la enseñanza y el aprendizaje que los profesores sostienen como docentes es una línea de investigación que está suponiendo un avance en el conocimiento sobre factores relevantes para la mejor de la educación. Desde hace más de dos décadas han sido numerosos los investigadores que han venido proporcionando resultados de investigación en torno a las creencias y las concepciones de la enseñanza y el aprendizaje lo que ha supuesto establecer nuevas e interesantes interpretaciones en dicha relación. En el trabajo que presentamos se abordan algunas de las aportaciones sobre dichas creencias y sobre las concepciones de la enseñanza y el aprendizaje.

Estimating enthalpy of vaporization from vapor pressure using Trouton's rule.

Science.gov (United States)

MacLeod, Matthew; Scheringer, Martin; Hungerbühler, Konrad

2007-04-15

The enthalpy of vaporization of liquids and subcooled liquids at 298 K (delta H(VAP)) is an important parameter in environmental fate assessments that consider spatial and temporal variability in environmental conditions. It has been shown that delta H(VAP)P for non-hydrogen-bonding substances can be estimated from vapor pressure at 298 K (P(L)) using an empirically derived linear relationship. Here, we demonstrate that the relationship between delta H(VAP)and PL is consistent with Trouton's rule and the ClausiusClapeyron equation under the assumption that delta H(VAP) is linearly dependent on temperature between 298 K and the boiling point temperature. Our interpretation based on Trouton's rule substantiates the empirical relationship between delta H(VAP) degree and P(L) degrees for non-hydrogen-bonding chemicals with subcooled liquid vapor pressures ranging over 15 orders of magnitude. We apply the relationship between delta H(VAP) degrees and P(L) degrees to evaluate data reported in literature reviews for several important classes of semivolatile environmental contaminants, including polycyclic aromatic hydrocarbons, chlorobenzenes, polychlorinated biphenyls and polychlorinated dibenzo-dioxins and -furans and illustrate the temperature dependence of results from a multimedia model presented as a partitioning map. The uncertainty associated with estimating delta H(VAP)degrees from P(L) degrees using this relationship is acceptable for most environmental fate modeling of non-hydrogen-bonding semivolatile organic chemicals.

Recommended Vapor Pressure of Solid Naphthalen

Czech Academy of Sciences Publication Activity Database

Růžička, K.; Fulem, Michal; Růžička, V.

2005-01-01

Roč. 50, - (2005), s. 1956-1970 ISSN 0021-9568 Institutional research plan: CEZ:AV0Z10100521 Keywords : solid naphthalene * vapor pressure * enthalpy of vaporization * enthalpy of fusion Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 1.610, year: 2005

SOIL VAPOR EXTRACTION TECHNOLOGY: REFERENCE HANDBOOK

Science.gov (United States)

Soil vapor extraction (SVE) systems are being used in Increasing numbers because of the many advantages these systems hold over other soil treatment technologies. SVE systems appear to be simple in design and operation, yet the fundamentals governing subsurface vapor transport ar...

Hydrodynamic forces on heave plates for offshore systems oscillating close to the seabed or the free surface

OpenAIRE

Garrido Mendoza, Carlos Ariel

2015-01-01

La energía eólica marina es uno de los recursos energéticos con mayor proyección pudiendo contribuir a reducir el consumo de combustibles fósiles y a cubrir la demanda de energía en todo el mundo. El concepto de aerogenerador marino está basado en estructuras fijas como jackets o en plataformas flotantes, ya sea una semisumergible o una TLP. Se espera que la energía eólica offshore juegue un papel importante en el perfil de producción energética de los próximos años; por tanto, las turbinas e...

Mapa de Potencial Eólico de la provincia Holguín

Directory of Open Access Journals (Sweden)

Jorge Proenza Velázquez

2007-01-01

Full Text Available En este trabajo, se aplican el modelo de microescala WasP 8.2 y el sistema de información geográfica ArcView 3.0 para obtener el mapa de d ensidad de potencia media anual del flujo de energía a 50 m de altura de la provincia Holguín, donde se representan las principales zonas geográficas del territorio con potenciales eólicos óptimos para la utilización del viento en la producción de energía eléctrica mediante la instalación de turbinas eólicas o aerogeneradores.

Bionanomaterials and Bioinspired Nanostructures for Selective Vapor Sensing

Science.gov (United States)

Potyrailo, Radislav; Naik, Rajesh R.

2013-07-01

At present, monitoring of air at the workplace, in urban environments, and on battlefields; exhaled air from medical patients; air in packaged food containers; and so forth can be accomplished with different types of analytical instruments. Vapor sensors have their niche in these measurements when an unobtrusive, low-power, and cost-sensitive technical solution is required. Unfortunately, existing vapor sensors often degrade their vapor-quantitation accuracy in the presence of high levels of interferences and cannot quantitate several components in complex gas mixtures. Thus, new sensing approaches with improved sensor selectivity are required. This technological task can be accomplished by the careful design of sensing materials with new performance properties and by coupling these materials with the suitable physical transducers. This review is focused on the assessment of the capabilities of bionanomaterials and bioinspired nanostructures for selective vapor sensing. We demonstrate that these sensing materials can operate with diverse transducers based on electrical, mechanical, and optical readout principles and can provide vapor-response selectivity previously unattainable by using other sensing materials. This ability for selective vapor sensing provides opportunities to significantly impact the major directions in development and application scenarios of vapor sensors.

¿Quién habla de las mujeres en las noticias donde ellas son las protagonistas?

Directory of Open Access Journals (Sweden)

Ana Tamarit

2011-01-01

Full Text Available Este artículo presenta un análisis de las fuentes que los periodistas utilizan en las informaciones donde las mujeres son protagonistas de las noticias. La investigación -cuantitativa y cualitativa- se ha realizado en los periódicos de ámbito nacional y local de Castilla y León. Con los resultados obtenidos observamos cómo en los periódicos las noticias que hablan de las mujeres en la mayoría de las ocasiones no se firman. Comprobamos cuáles son las fuentes más utilizadas para la elaboración de esas noticias y las diferentes formas de citar a la fuente cuando se trata de un hombre o de una mujer.

Decreased respiratory symptoms in cannabis users who vaporize

Directory of Open Access Journals (Sweden)

Barnwell Sara

2007-04-01

Full Text Available Abstract Cannabis smoking can create respiratory problems. Vaporizers heat cannabis to release active cannabinoids, but remain cool enough to avoid the smoke and toxins associated with combustion. Vaporized cannabis should create fewer respiratory symptoms than smoked cannabis. We examined self-reported respiratory symptoms in participants who ranged in cigarette and cannabis use. Data from a large Internet sample revealed that the use of a vaporizer predicted fewer respiratory symptoms even when age, sex, cigarette smoking, and amount of cannabis used were taken into account. Age, sex, cigarettes, and amount of cannabis also had significant effects. The number of cigarettes smoked and amount of cannabis used interacted to create worse respiratory problems. A significant interaction revealed that the impact of a vaporizer was larger as the amount of cannabis used increased. These data suggest that the safety of cannabis can increase with the use of a vaporizer. Regular users of joints, blunts, pipes, and water pipes might decrease respiratory symptoms by switching to a vaporizer

A Local Propagation for Vapor Explosions

International Nuclear Information System (INIS)

Ochiai, M.; Bankoff, S.G.

1976-01-01

Explosive boiling, defined as energy transfer leading to formation of vapor rapidly enough to produce large shock waves, has been widely studied in a number of contexts. Depending upon the nature and temperatures of the liquids and mode of contacting, large-scale mixing and explosive vaporization may occur, or alternatively, only relatively non-energetic, film-type boiling may exist. The key difference is whether a mechanism is operative for increasing the liquid-liquid interfacial area in a time scale consistent with the formation of a detonation wave. Small drops of a cold volatile liquid were dropped onto a free surface of a hot, non-volatile liquid. The critical Weber number for coalescence is obtained from the envelope of the film boiling region. Markedly different behavior for the two hot liquids is observed. A 'splash' theory for local propagation of vapor explosions in spontaneously nucleating liquid-liquid systems is now formulated. After a random contact is made, explosive growth and coalescence of the vapor bubbles occurs as soon as the surrounding pressure is relieved, resulting in a high-pressure vapor layer at the liquid-liquid contact area. This amounts to an impact pressure applied to the free surface, with a resulting velocity distribution obtained from potential flow theory. The peak pressure predictions are. consistent with data for Freon-oil mixing, but further evaluation will await additional experimental data. Nevertheless, the current inference is that a UO 2 -Na vapor explosion in a reactor environment cannot be visualized. In conclusion: The propagation model presented here differs in some details from that of Henry and Fauske, although both are consistent with some peak pressure data obtained by Henry, et al. Clearly, additional experimental information is needed for further evaluation of these theories. Nevertheless, it should be emphasized that even at this time a number of important observations concerning the requirements for a vapor

Optical Sensor for Diverse Organic Vapors at ppm Concentration Ranges

Directory of Open Access Journals (Sweden)

Dora M. Paolucci

2011-03-01

Full Text Available A broadly responsive optical organic vapor sensor is described that responds to low concentrations of organic vapors without significant interference from water vapor. Responses to several classes of organic vapors are highlighted, and trends within classes are presented. The relationship between molecular properties (vapor pressure, boiling point, polarizability, and refractive index and sensor response are discussed.

40 CFR 52.787 - Gasoline transfer vapor control.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Gasoline transfer vapor control. 52.787... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS Indiana § 52.787 Gasoline transfer vapor control. (a) Gasoline means any petroleum distillate having a Reid vapor pressure of 4 pounds or greater...

Las telenovelas juveniles mexicanas y las adolescentas obesas

Directory of Open Access Journals (Sweden)

Tania Meza

2006-01-01

Full Text Available Esta investigación analiza la opresión por cuerpo (obesidad a la que las mujeres son sometidas dentro del sistema patriarcal durante la adolescencia, específicamente a través de la representación televisiva que de las jóvenes gordas se hace en la telenovela juvenil mexicana. Los enormes niveles de audiencia que poseen las telenovelas en nuestro país hace indispensable, para los estudios de género desde las ciencias dela comunicación, estudiar el papel de las mujeres en dichas teleseries. En este análisis se pretende mostrar la triple marginación a la que son sometidas las adolescentes obesas en las telenovelas juveniles mexicanas: por ser mujeres, por ser jóvenes y por ser gordas.

Las redes sociales presentes en las bibliotecas

Directory of Open Access Journals (Sweden)

Magda Cecilia Sandí S.

2012-01-01

Full Text Available El presente artículo pretende evidenciar la importancia del uso de las redes sociales en las bibliotecas como una herramienta y un canal de comunicación entre el bibliotecólogo y la comunidad de usuarios. Las redes sociales son una nueva forma de comunicarnos entre las y los usuarios del Internet, su uso es irrestricto y cada vez aumenta la comunidad de usuarios de estas herramientas en la red.

Las redes sociales presentes en las bibliotecas

Directory of Open Access Journals (Sweden)

Magda Cecilia Sandí Sandí

2012-07-01

Full Text Available El presente artículo pretende evidenciar la importancia del uso de las redes sociales en las bibliotecas como una herramienta y un canal de comunicación entre el bibliotecólogo y la comunidad de usuarios. Las redes sociales son una nueva forma de comunicarnos entre las y los usuarios del Internet, su uso es irrestricto y cada vez aumenta la comunidad de usuarios de estas herramientas en la red.

Las redes sociales presentes en las bibliotecas

OpenAIRE

Magda Cecilia Sandí S.

2012-01-01

El presente artículo pretende evidenciar la importancia del uso de las redes sociales en las bibliotecas como una herramienta y un canal de comunicación entre el bibliotecólogo y la comunidad de usuarios. Las redes sociales son una nueva forma de comunicarnos entre las y los usuarios del Internet, su uso es irrestricto y cada vez aumenta la comunidad de usuarios de estas herramientas en la red.

Estimating evaporative vapor generation from automobiles based on parking activities

International Nuclear Information System (INIS)

Dong, Xinyi; Tschantz, Michael; Fu, Joshua S.

2015-01-01

A new approach is proposed to quantify the evaporative vapor generation based on real parking activity data. As compared to the existing methods, two improvements are applied in this new approach to reduce the uncertainties: First, evaporative vapor generation from diurnal parking events is usually calculated based on estimated average parking duration for the whole fleet, while in this study, vapor generation rate is calculated based on parking activities distribution. Second, rather than using the daily temperature gradient, this study uses hourly temperature observations to derive the hourly incremental vapor generation rates. The parking distribution and hourly incremental vapor generation rates are then adopted with Wade–Reddy's equation to estimate the weighted average evaporative generation. We find that hourly incremental rates can better describe the temporal variations of vapor generation, and the weighted vapor generation rate is 5–8% less than calculation without considering parking activity. - Highlights: • We applied real parking distribution data to estimate evaporative vapor generation. • We applied real hourly temperature data to estimate hourly incremental vapor generation rate. • Evaporative emission for Florence is estimated based on parking distribution and hourly rate. - A new approach is proposed to quantify the weighted evaporative vapor generation based on parking distribution with an hourly incremental vapor generation rate

Chemical processes of coal for use in power plants. Part 1: Approximate analysis and associated indexes of pulverized coal; Procesos quimicos del carbon para su uso en centrales termoelectricas. Parte 1: Analisis aproximado e indices asociados del carbon pulverizado

Energy Technology Data Exchange (ETDEWEB)

Altamirano-Bedolla, J. A.; Manzanares-Papayanopoulos, E.; Herrera-Velarde, J. R. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: emp@iie.org.mx

2010-11-15

The usage of hydrocarbons, such as natural gas, oil products and coal, will be the main source of energy to the mankind for next generations. Therefore, the actual research and technological developments point out to employ with high efficiency those fuels. The main interests are to release most of the energy as possible and to guide the combustion reactions. It is well known that during the combustion process of coal, the chemical energy is converted to thermal energy, which it allows the steam production, and therefore to produce energy through an electric generator. The main interest of the work presented here is to study the behavior of the coal combustion processes in function of the approximate analysis and some associate indices of that analysis, to point out the optimization of the coal usage as main fuel in electrical power generation plants. [Spanish] El uso de hidrocarburos como son el gas natural, los derivados del petroleo y el carbon mineral, continuara siendo en las proximas decadas la principal fuente de energia de la humanidad. Por consiguiente, la investigacion cientifica y los desarrollos tecnologicos actualmente se enfocan en emplear de manera mas eficiente dichos combustibles, satisfaciendo entre otros factores, dos intereses principales: liberar la mayor cantidad de energia, reduciendo al minimo el material combustible no quemado, y direccionar las reacciones del proceso de combustion para minimizar la cantidad de productos no deseados resultantes de la reaccion. A traves de los procesos quimicos de combustion del carbon, se transforma la energia quimica a energia termica, lo que permite la produccion de vapor para a su vez impulsar una turbina la cual esta acoplada a un generador electrico. El objetivo del presente trabajo es el estudio del comportamiento de los procesos quimicos que se llevan a cabo durante las reacciones de combus-tion del carbon en funcion del analisis aproximado y de los indices asociados resultantes de dicho analisis; lo

Remedial actions to improve the availability in steam generators; Acciones correctivas para mejorar la disponibilidad en generadores de vapor

Energy Technology Data Exchange (ETDEWEB)

Torres Toledano, J. Gerardo; Porras Loaiza, G. Lizbeth; Sanchez Hernandez, Laura E.; Salinas B, Victor M.; Nebart G, Jesus [Instituto de Investigaciones Electricas, Temixco, Morelos (Mexico)

2001-07-01

was demonstrated that the lack of power of the unit is not due to the combustion air deficiency. The metallographic study of the fault of the RU tube is mentioned, where a graph of the estimated life span at different rates of wear by corrosion and metal temperature for a tube of SA-213-TPH metal is presented. The details of the interconnections at the reheater are shown and a table of comparison of proposed temperatures at the RH outlet is present. A table of main causes of power decrease is attached. [Spanish] En este articulo se presentan los resultados del analisis de fallas recurrentes de cuatro Unidades Generadoras de Centrales Termoelectricas (UGT) de la Comision Federal de Electricidad (CFE). En tres de los cuatro casos, los estudios se enfocaron a identificar y corregir las causas raiz de fallas recurrentes en tubos de generadores de vapor, las unidades analizadas son: U-2 del Complejo Termoelectrico Pdte. Adolfo Lopez Mateos (CTPALM) de Tuxpan, Veracruz; U-3 de la Central Termoelectrica (CT) de Salamanca, y U-1 y 2 de la CT Felipe Carrillo Puerto de Valladolid, Yucatan. En el otro caso se analizo la insuficiencia de aire de combustion como una de las causas de decremento de potencia de la unidad 1 de la CT Gral. Manuel Alvarez Moreno de Manzanillo, Colima. Los generadores de vapor de la unidad 2 del CTPALM y la unidad 3 de la CT de Salamanca presentaron fallas en el banco del recalentador (RH). En este caso las recomendaciones se enfocaron al mejoramiento en las condiciones operativas para atenuar las fallas por corrosion en alta temperatura. A diferencia del CTPALM, en el caso de la U-3 de Salamanca se concluyo que es necesario el rediseno del RH; para ello se propuso permutar trayectorias de tubos calientes con los frios para uniformizar la temperatura de vapor a la salida del RH. Para evaluar los problemas que se han presentado en el generador de vapor de las unidades 1 y 2 de la CT Felipe Carrillo Puerto de Valladolid, Yucatan se analizaron las fallas de

40 CFR 52.255 - Gasoline transfer vapor control.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 3 2010-07-01 2010-07-01 false Gasoline transfer vapor control. 52.255... (CONTINUED) APPROVAL AND PROMULGATION OF IMPLEMENTATION PLANS California § 52.255 Gasoline transfer vapor control. (a) “Gasoline” means any petroleum distillate having a Reid vapor pressure of 4 pounds or greater...

33 CFR 154.826 - Vapor compressors and blowers.

Science.gov (United States)

2010-07-01

...) Excessive shaft bearing temperature. (d) If a centrifugal compressor, fan, or lobe blower handles vapor in... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Vapor compressors and blowers....826 Vapor compressors and blowers. (a) Each inlet and outlet to a compressor or blower which handles...

Effect of granosan vapors on mitosis

Energy Technology Data Exchange (ETDEWEB)

Lishenko, N P; Lishenko, I D

1974-01-01

Experiments were performed to determine the effects of granosan on the germination of vetch seeds. Vetch seeds were stored from 4-6 days in ethyl mercuric chloride vapors. Results indicated that the vapors caused a sharp decrease in germination and caused chromosomal aberrations during the anaphase.

Evaluación y adecuación de un tanque con agitador y chaqueta de vapor de 0,9 mc3 para la pasteurización de 880 kg. de pulpa de fruta

OpenAIRE

Espol; Palacios Ponce, Arturo Sócrates

2015-01-01

El presente trabajo tiene como finalidad instalar y adecuar un tanque con agitación y chaqueta de vapor para la pasteurización de 800kg por parada de pulpa de fruta con calidad y precio competitivo. Se evaluaron las condiciones operacionales del equipo y se validará la operatividad del mismo en condiciones ideales, posteriormente se determinarán los parámetros de proceso de tiempo y temperatura a través de corridas experimentales in situ. Los valores obtenidos en las pruebas experimentales se...

Molecular dynamics study of the vaporization of an ionic drop

Science.gov (United States)

Galamba, N.

2010-09-01

The melting of a microcrystal in vacuum and subsequent vaporization of a drop of NaCl were studied through molecular dynamics simulations with the Born-Mayer-Huggins-Tosi-Fumi rigid-ion effective potential. The vaporization was studied for a single isochor at increasing temperatures until the drop completely vaporized, and gaseous NaCl formed. Examination of the vapor composition shows that the vapor of the ionic drop and gaseous NaCl are composed of neutral species, the most abundant of which, ranging from simple NaCl monomers (ion pairs) to nonlinear polymers, (NanCln)n=2-4. The enthalpies of sublimation, vaporization, and dissociation of the different vapor species are found to be in reasonable agreement with available experimental data. The decrease of the enthalpy of vaporization of the vapor species, with the radius of the drop decrease, accounts for a larger fraction of trimers and tetramers than that inferred from experiments. Further, the rhombic dimer is significantly more abundant than its linear isomer although the latter increases with the temperature. The present results suggest that both trimers and linear dimers may be important to explain the vapor pressure of molten NaCl at temperatures above 1500 K.

21 CFR 888.4220 - Cement monomer vapor evacuator.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Cement monomer vapor evacuator. 888.4220 Section... (CONTINUED) MEDICAL DEVICES ORTHOPEDIC DEVICES Surgical Devices § 888.4220 Cement monomer vapor evacuator. (a) Identification. A cement monomer vapor evacuator is a device intended for use during surgery to contain or remove...

Prediction of the vapor pressure and vaporization enthalpy of 1-n-alkyl-3-methylimidazolium-bis-(trifluoromethanesulfonyl) amide ionic liquids.

Science.gov (United States)

Diedenhofen, Michael; Klamt, Andreas; Marsh, Kenneth; Schäfer, Ansgar

2007-09-07

The vapor pressures and vaporization enthalpies of a series of 1-n-alkyl-3-methylimidazolium-bis-(trifluoromethanesulfonyl) amide ionic liquids have been predicted with two different approaches using the COSMO-RS method and quantum chemical gas phase calculations. While the calculated enthalpies are in good agreement with the experimental data, COSMO-RS seems to underestimate the vapor pressures by roughly 0.5-4 log units dependent on the IL and approach used.

40 CFR 796.1950 - Vapor pressure.

Science.gov (United States)

2010-07-01

... (CONTINUED) CHEMICAL FATE TESTING GUIDELINES Physical and Chemical Properties § 796.1950 Vapor pressure. (a.... In addition, chemicals that are likely to be gases at ambient temperatures and which have low water... gases until the measured vapor pressure is constant, a process called “degassing.” Impurities more...

Nuevo equipo de proceso de destilación fraccionada en continuo por arrastre con vapor de aceites esenciales del jugo de limón mexicano

Directory of Open Access Journals (Sweden)

Francisco J. Padilla M.

2007-01-01

Full Text Available En este trabajo se presenta un nuevo equipo llamado Destilador-Fraccionador Horizontal, para realizar el procesos de destilación fraccionada en continuo por arrastre de vapor de aceites esenciales obtenidos a partir del jugo de limón mexicano (Citrus aurantifolia. La capacidad de fraccionación del nuevo equipo es analizada con soluciones modelo y soluciones reales de jugo de limón. Se emplean diseños experimentales y métodos estadísticos para investigar el desempeño del equipo y para validar su capacidad de fraccionar. Mediante la determinación de la relación S/F (gramos de vapor necesario para extraer 1 g de aceite destilado en la fase vapor, se determina que el nuevo equipo requiere una menor cantidad de energía para lograr la separación de los aceites esenciales. Eficiencias de extracción de aceites esenciales superiores al 90% son alcanzadas empleando las soluciones reales de jugo de limón.

Performance of horizontal versus vertical vapor extraction wells

International Nuclear Information System (INIS)

Birdsell, K.H.; Roseberg, N.D.; Edlund, K.M.

1994-06-01

Vapor extraction wells used for site remediation of volatile organic chemicals in the vadose zone are typically vertical wells. Over the past few years, there has been an increased interest in horizontal wells for environmental remediation. Despite the interest and potential benefits of horizontal wells, there has been little study of the relative performance of horizontal and vertical vapor extraction wells. This study uses numerical simulations to investigate the relative performance of horizontal versus vertical vapor extraction wells under a variety of conditions. The most significant conclusion that can be drawn from this study is that in a homogeneous medium, a single, horizontal vapor extraction well outperforms a single, vertical vapor extraction well (with surface capping) only for long, linear plumes. Guidelines are presented regarding the use of horizontal wells

Dynamics of trivalent rare earth molecular vapor lasers

International Nuclear Information System (INIS)

Krupke, W.F.

1976-01-01

Radiative transition probabilities in neodymium bearing vapors are reviewed and calculations are extended to visible laser transitions in terbium bearing vapor. Nonradiative relaxation processes in the pure and complexed halides are treated in greater detail. While precise, quantitative relaxation probabilities cannot be calculated on the basis of information presently available, plausibility arguments can be established which indicate the order of magnitude of relevant nonradiative decay probabilities. Reference to solid and liquid state nonradiative relaxation data for rare earth ions is reviewed to support the plausibility arguments for the vapor state. Having established the likelihood of high fluorescence yields in the vapor phase, various methods of laser pumping are discussed: optical pumping via parity allowed 4f-5d transitions; optical pumping via charge transfer bands of the vapor complex; and direct electron beam pumping

Control of sodium vapor transport in annuli

International Nuclear Information System (INIS)

Meadows, G.E.; Bohringer, A.P.

1983-11-01

The method used to control sodium vapor transport in the annuli of various components at the Fast Flux Test Facility (FFTF) is a downward purge of the annuli with high purity argon. The purge rates for the FFTF were selected by calculating the gas velocity required to overcome thermal convection transport in the annuli. To evaluate the effectiveness of the gas purge, laboratory apparatus was fabricated which simulated selected annuli in the FFTF In-Vessel Handling Machine (IVHM) and the Instrument Tree (IT) annuli. Tests were conducted at temperatures similar to FFTF conditions. Gas purge rates ranged from zero to 130% of FFTF flow rates. Test results show the effectiveness of a high purity gas purge in decreasing the accumulation of sodium vapor deposits in an annulus. The presence of water vapor and oxygen in the purge gas increased the sodium deposition rate by a factor of three over other tests usig high purity argon. The presence of a vapor control collar used in the IT annulus was shown to be beneficial for controlling vapor transport into the upper region of the annulus

Vapor pressure and thermodynamics of beryllium carbide

International Nuclear Information System (INIS)

Rinehart, G.H.; Behrens, R.G.

1980-01-01

The vapor pressure of beryllium carbide has been measured over the temperature range 1388 to 1763 K using Knudsen-effusion mass spectrometry. Vaporization occurs incongruently according to the reaction Be 2 C(s) = 2Be(g) + C(s). The equilibrium vapor pressure above the mixture of Be 2 C and C over the experimental temperature range is (R/J K -1 mol -1 )ln(p/Pa) = -(3.610 +- 0.009) x 10 5 (K/T) + (221.43 +- 1.06). The third-law enthalpy change for the above reaction obtained from the present vapor pressures is ΔH 0 (298.15 K) = (740.5 +- 0.1) kJ mol -1 . The corresponding second-law result is ΔH 0 (298.15 K) = (732.0 +- 1.8) kJ mol -1 . The enthalpy of formation for Be 2 C(s) calculated from the present third-law vaporization enthalpy and the enthalpy of formation of Be(g) is ΔH 0 sub(f)(298.15 K) = -(92.5 +- 15.7) kJ mol -1 . (author)

Ciclo combinado Diesel-Vapor como repotenciación de una central termoeléctrica: caso de estudio; Combined Cycle Diesel-Steam as Power Plant Repowering: study case

Directory of Open Access Journals (Sweden)

Alberto Eduardo Calvo González

2015-04-01

Full Text Available La necesidad imperiosa de cubrir el déficit de generación eléctrica ampliando el potencial de generación con motores diesel a fuel oíl, cuya instalación requiere de muy poco tiempo, es una solución adecuada. La idea de aprovechar los nodos del sistema electro energético, como son las subestaciones y las centrales eléctricas, para instalar los grupos electrógenos es una solución apropiada. Pero en el caso de una central termoeléctrica, al montar estas instalaciones de forma independiente, no se aprovechan las posibilidades que la combinación de procesos ofrece como la disminución del consumo de combustible, y de la contaminación ambiental por unidad de energía producida. El presente trabajo explora la posibilidad de instalar plantas eléctricas diesel a fuel oil como ciclo combinado diesel-vapor. Se demuestra la conveniencia de instalar plantas eléctricas diesel a fuel oil como ciclo combinado diesel-vapor, aprovechando la sinergia que se logra por la combinación de los procesos térmicos.  The pressing need of covering generation deficit to satisfy the demand in the shorter possible time, by enlarging the generation potential with fuel oil fueled diesel motors, it’s an appropriate solution. The idea of taking advantage of electric grid existent nodes facilities to place the generating electricity diesel motors is a non-unwise solution. But in the case of the node of steam power station place these motors in an independent way, don't take advantage of the possibilities that the processes combination offers, as the combined cycle diesel vapor for example. The work presented herein explored and showed the possibility of installing the electric diesel plants as a repowering the existing steam power plant by combined cycle diesel-steam taking advantage of the synergy achieved by thermal processes combination.

Ciclo combinado Diesel-Vapor como repotenciación de una central termoeléctrica: caso de estudio; Combined Cycle Diesel-Steam as Power Plant Repowering: study case

Directory of Open Access Journals (Sweden)

Alberto Eduardo Calvo González

2014-06-01

Full Text Available La necesidad imperiosa de cubrir el déficit de generación eléctrica ampliando el potencial de generación con motores diesel a fuel oíl, cuya instalación requiere de muy poco tiempo, es una solución adecuada. La idea de aprovechar los nodos del sistema electro energético, como son las subestaciones y las centrales eléctricas, para instalar los grupos electrógenos es una solución apropiada. Pero en el caso de una central termoeléctrica, al montar estas instalaciones de forma independiente, no se aprovechan las posibilidades que la combinación de procesos ofrece como la disminución del consumo de combustible, y de la contaminación ambiental por unidad de energía producida. El presente trabajo explora la posibilidad de instalar plantas eléctricas diesel a fuel oil como ciclo combinado diesel-vapor. Se demuestra la conveniencia de instalar plantas eléctricas diesel a fuel oil como ciclo combinado diesel-vapor, aprovechando la sinergia que se logra por la combinación de los procesos térmicos. The pressing need of covering generation deficit to satisfy the demand in the shorter possible time, by enlarging the generation potential with fuel oil fueled diesel motors, it’s an appropriate solution. The idea of taking advantage of electric grid existent nodes facilities to place the generating electricity diesel motors is a non-unwise solution. But in the case of the node of steam power station place these motors in an independent way, don't take advantage of the possibilities that the processes combination offers, as the combined cycle diesel vapor for example. The work presented herein explored and showed the possibility of installing the electric diesel plants as a repowering the existing steam power plant by combined cycle diesel-steam taking advantage of the synergy achieved by thermal processes combination.

Vapor-transport of tungsten and its geologic application

Energy Technology Data Exchange (ETDEWEB)

Shibue, Y [Hyogo Univ. of Teacher Education, Hyogo (Japan)

1988-11-10

The volatility of tungsten in a hydrous system at elevated temperatures and pressures was examined, and a tentative model for the enrichment of tungsten in hydrothermal solutions for the deposits related to granitic activities was proposed. To produce vapor-saturated solution, 17 or 15ml of 20wt% NaCl solution was introduced into an autoclave. Ca(OH){sub 2} for tungsten and H{sub 2}WO{sub 4} for base metals were used as vapor-captures, and run products were identified by X-ray powder diffractometry. The results suggested that the ratio of tungsten to base metals was higher in a vapor phase than in a liquid phase, and more enrichment of tungsten in the vapor phase occurred at higher temperature and pressure under the coexistence of the vapor and liquid phase. The tentative model emphasizing the vapor-transport of tungsten could explain the presence of tungsten deposits without large mineralization of base metals. Geological schematic model for the generation of the hydrothermal solution enriched in tungsten compared with base metals was illustrated based on above mentioned results. 21 refs., 3 figs.

Effect of vapor-phase oxygen on chemical vapor deposition growth of graphene

Science.gov (United States)

Terasawa, Tomo-o.; Saiki, Koichiro

2015-03-01

To obtain a large-area single-crystal graphene, chemical vapor deposition (CVD) growth on Cu is considered the most promising. Recently, the surface oxygen on Cu has been found to suppress the nucleation of graphene. However, the effect of oxygen in the vapor phase was not elucidated sufficiently. Here, we investigate the effect of O2 partial pressure (PO2) on the CVD growth of graphene using radiation-mode optical microscopy. The nucleation density of graphene decreases monotonically with PO2, while its growth rate reaches a maximum at a certain pressure. Our results indicate that PO2 is an important parameter to optimize in the CVD growth of graphene.

Growth of GaN layers using Ga2O vapor obtained from Ga and H2O vapor

International Nuclear Information System (INIS)

Sumi, Tomoaki; Taniyama, Yuuki; Takatsu, Hiroaki; Juta, Masami; Kitamoto, Akira; Imade, Mamoru; Yoshimura, Masashi; Mori, Yusuke; Isemura, Masashi

2015-01-01

In this study, we performed growth of GaN layers using Ga 2 O vapor synthesized from Ga and H 2 O vapor. In this process, we employed H 2 O vapor instead of HCl gas in hydride vapor phase epitaxy (HVPE) to synthesize Ga source gas. In the synthesis reaction of Ga 2 O, a Ga 2 O 3 whisker formed and covered Ga, which impeded the synthesis reaction of Ga 2 O. The formation of the Ga 2 O 3 whisker was suppressed in H 2 ambient at high temperatures. Then, we adopted this process to supply a group III precursor and obtained an epitaxial layer. X-ray diffraction (XRD) measurement revealed that the epitaxial layer was single-crystalline GaN. Growth rate increased linearly with Ga 2 O partial pressure and reached 104 µm/h. (author)

The separation of hydrocarbons from waste vapor streams

International Nuclear Information System (INIS)

Behling, R.D.; Ohlrogge, K.; Peinemann, K.V.; Kyburz, E.

1989-01-01

Hydrocarbon vapors generated from industrial processes dispersed into air are contributing factors for the creation of photochemical smog. The separation of hydrocarbon vapor by means of membranes is in case of some applications a technically simple and economic process. A membrane vapor separation process with a following treatment of the retentate by catalytic incineration is introduced in this paper

Separation of aromatics by vapor permeation through solvent swollen membrane

Energy Technology Data Exchange (ETDEWEB)

Ito, A.; Adachi, K.; Feng, Y. [Niigata University, Niigata (Japan)

1995-12-20

A vapor permeation process for aromatics separation from a hydrocarbon mixture was studied by means of the simultaneous permeation of dimethylsulfoxide vapor as an agent for membrane swelling and preferential permeation of aromatics. The separation performance of the process was demonstrated by a polyvinylalcohol membrane for mixed vapors of benzene/cyclohexane, xylene/octane and a model gasoline. The aromatic vapors preferentially permeated from these mixed vapor feeds. The separation factor was over 10. The separation mechanism of the process mainly depends on the relative salability of the vapors between aromatics and other hydrocarbons in dimethylsulfoxide. 14 refs., 9 figs., 1 tab.

Molecular dynamics study of the vaporization of an ionic drop.

Science.gov (United States)

Galamba, N

2010-09-28

The melting of a microcrystal in vacuum and subsequent vaporization of a drop of NaCl were studied through molecular dynamics simulations with the Born-Mayer-Huggins-Tosi-Fumi rigid-ion effective potential. The vaporization was studied for a single isochor at increasing temperatures until the drop completely vaporized, and gaseous NaCl formed. Examination of the vapor composition shows that the vapor of the ionic drop and gaseous NaCl are composed of neutral species, the most abundant of which, ranging from simple NaCl monomers (ion pairs) to nonlinear polymers, (Na(n)Cl(n))(n=2-4). The enthalpies of sublimation, vaporization, and dissociation of the different vapor species are found to be in reasonable agreement with available experimental data. The decrease of the enthalpy of vaporization of the vapor species, with the radius of the drop decrease, accounts for a larger fraction of trimers and tetramers than that inferred from experiments. Further, the rhombic dimer is significantly more abundant than its linear isomer although the latter increases with the temperature. The present results suggest that both trimers and linear dimers may be important to explain the vapor pressure of molten NaCl at temperatures above 1500 K.

Vapor condensation device

International Nuclear Information System (INIS)

Sakurai, Manabu; Hirayama, Fumio; Kurosawa, Setsumi; Yoshikawa, Jun; Hosaka, Seiichi.

1992-01-01

The present invention enables to separate and remove 14 C as CO 3 - ions without condensation in a vapor condensation can of a nuclear facility. That is, the vapor condensation device of the nuclear facility comprises (1) a spray pipe for spraying an acidic aqueous solution to the evaporation surface of an evaporation section, (2) a spray pump for sending the acidic aqueous solution to the spray pipe, (3) a tank for storing the acidic aqueous solution, (4) a pH sensor for detecting pH of the evaporation section, (5) a pH control section for controlling the spray pump, depending on the result of the detection of the pH sensor. With such a constitution, the pH of liquid wastes on the vaporization surface is controlled to 7 by spraying an aqueous solution of dilute sulfuric acid to the evaporation surface, thereby enabling to increase the transfer rate of 14 C to condensates to 60 to 70%. If 14 C is separated and removed as a CO 2 gas from the evaporation surface, the pH of the liquid wastes returns to the alkaline range of 9 to 10 and the liquid wastes are returned to a heating section. The amount of spraying the aqueous solution of dilute sulfuric acid can be controlled till the pH is reduced to 5. (I.S.)

Headspace gas and vapor characterization summary for the 43 vapor program suspect tanks

International Nuclear Information System (INIS)

Huckaby, J.L.; Bratzel, D.R.

1995-01-01

During the time period between February 1994 and September 1995, Westinghouse Hanford Company (WHC) sampled the waste tank headspace of 43 single-shell tanks for a variety of gaseous and/or volatile and semi-volatile compounds. This report summarizes the results of analyses of those sampling activities with respect to both the Priority 1 Safety Issues and relative to the detection in the headspace of significant concentrations of target analytes relating to worker breathing space consideration as recommended by the Pacific Northwest Laboratory (PNL) Toxicology Review Panel. The information contained in the data tables was abstracted from the vapor sampling and analysis tank characterization reports. Selected results are tabulated and summarized. Sampling equipment and methods, as well as sample analyses, are briefly described. Vapor sampling of passively ventilated single-shell tanks (tanks C-105, C-106, and SX-106 were sampled and are actively ventilated) has served to highlight or confirm tank headspace conditions associated with both priority 1 safety issues and supports source term analysis associated with protecting worker health and safety from noxious vapors

Fuel conditioning facility electrorefiner cadmium vapor trap operation

International Nuclear Information System (INIS)

Vaden, D. E.

1998-01-01

Processing sodium-bonded spent nuclear fuel at the Fuel Conditioning Facility at Argonne National Laboratory-West involves an electrometallurgical process employing a molten LiCl-KCl salt covering a pool of molten cadmium. Previous research has shown that the cadmium dissolves in the salt as a gas, diffuses through the salt layer and vaporizes at the salt surface. This cadmium vapor condenses on cool surfaces, causing equipment operation and handling problems. Using a cadmium vapor trap to condense the cadmium vapors and reflux them back to the electrorefiner has mitigated equipment problems and improved electrorefiner operations

Indirect heating of natural gas using vapor chambers; Aquecimento indireto de gas natural com uso de camaras de vapor

Energy Technology Data Exchange (ETDEWEB)

Milanez, Fernando H; Mantellil, Marcia H.B.; Borges, Thomaz P.F. [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Mecanica; Landa, Henrique G. de [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas

2005-07-01

Operation safety and reliability are major guidelines in the design of city-gate units. Conventional natural gas heaters operate by a indirect mechanism, where liquid water is used to transfer heat by natural convection between the combustion chamber and the natural gas coil. In this work, the concept of vapor chamber is evaluated as an indirect gas heater. In a vapor chamber, liquid water is in contact with the heat source, and vaporizes. The vapor condenses in contact with the heat sink. A reduced scale model was built and tested in order to compare these two heating concepts where the combustion chamber was replaced by electrical cartridge heaters. This engineering model can operate either as a conventional heater or as a vapor chamber. The comparison between the concepts was done by inducing a controlled power to the cartridges and by measuring the resulting temperature distributions. In the novel design, the heat exchanger efficiency increases, and the thermal inertia decreases, compared to the conventional system. The new sealed concept of the chamber prevents water evaporation losses. (author)

Gas turbine modular helium reactor in cogeneration; Turbina de gas reactor modular con helio en cogeneracion

Energy Technology Data Exchange (ETDEWEB)

Leon de los Santos, G. [UNAM, Facultad de Ingenieria, Division de Ingenieria Electrica, Departamento de Sistemas Energeticos, Ciudad Universitaria, 04510 Mexico, D. F. (Mexico)], e-mail: tesgleon@gmail.com

2009-10-15

This work carries out the thermal evaluation from the conversion of nuclear energy to electric power and process heat, through to implement an outline gas turbine modular helium reactor in cogeneration. Modeling and simulating with software Thermo flex of Thermo flow the performance parameters, based on a nuclear power plant constituted by an helium cooled reactor and helium gas turbine with three compression stages, two of inter cooling and one regeneration stage; more four heat recovery process, generating two pressure levels of overheat vapor, a pressure level of saturated vapor and one of hot water, with energetic characteristics to be able to give supply to a very wide gamma of industrial processes. Obtaining a relationship heat electricity of 0.52 and efficiency of net cogeneration of 54.28%, 70.2 MW net electric, 36.6 MW net thermal with 35% of condensed return to 30 C; for a supplied power by reactor of 196.7 MW; and with conditions in advanced gas turbine of 850 C and 7.06 Mpa, assembly in a shaft, inter cooling and heat recovery in cogeneration. (Author)

Water Vapor Remote Sensing Techniques: Radiometry and Solar Spectrometry

Science.gov (United States)

Somieski, A.; Buerki, B.; Cocard, M.; Geiger, A.; Kahle, H.-G.

The high variability of atmospheric water vapor content plays an important role in space geodesy, climatology and meteorology. Water vapor has a strong influence on transatmospheric satellite signals, the Earth's climate and thus the weather forecasting. Several remote sensing techniques have been developed for the determination of inte- grated precipitable water vapor (IPWV). The Geodesy and Geodynamics Lab (GGL) utilizes the methods of Water Vapor Radiometry and Solar Spectrometry to quantify the amount of tropospheric water vapor and its temporal variations. The Water Vapor Radiometer (WVR) measures the radiation intensity of the atmosphere in a frequency band ranging from 20 to 32 GHz. The Solar Atmospheric MOnitoring Spectrome- ter (SAMOS) of GGL is designed for high-resolution measurements of water vapor absorption lines using solar radiation. In the framework of the ESCOMPTE (ExpÊrience sur Site pour COntraindre les Mod- Éles de Pollution atmosphÊrique et de Transport d'Emissions) field campaign these instruments have been operated near Marseille in 2001. They have aquired a long time series of integrated precipitable water vapor content (IPWV). The accuracy of IPWV measured by WVR and SAMOS is 1 kg/m2. Furthermore meteorological data from radiosondes were used to calculate the IPWV in order to provide comparisons with the results of WVR and SAMOS. The methods of Water Vapor Radiometry and So- lar Spectrometry will be discussed and first preliminary results retrieved from WVR, SAMOS and radiosondes during the ESCOMPTE field campaign will be presented.

Mass spectrometric study of Nd2S3 vaporization

International Nuclear Information System (INIS)

Fenochka, B.V.

1987-01-01

The authors conduct a mass-spectrometric study of neodymium(III) sulfide vaporization. The chemical composition of the samples was stoichiometric and the samples were vaporized from tantalum effusion cells. When the vapor over Nd 2 S 3 is ionized by electrons the mass spectra shows monovalent cations of Nd, S, NdS, and NdO. The enthalpy of vaporization if Nd atoms from Nd 2 S 3 at average experimental temperatures and the standard enthalpy of reaction is shown. Also presented is the enthalpy of vaporization of NdS molecules from Nd 2 S 3 at average experimental temperatures and the standard enthalpy of reaction

The vapor pressure and vaporization enthalpy of R-(+)-menthofuran, a hepatotoxin metabolically derived from the abortifacient terpene, (R)-(+)-pulegone by correlation gas chromatography

International Nuclear Information System (INIS)

Gobble, Chase; Chickos, James S.

2016-01-01

Highlights: • The vaporization enthalpy and vapor pressure of R-(+) menthofuran is evaluated. • The normal boiling temperature is predicted and compared to experimental and predicted values. • A vapor pressure equation as a function of temperature for menthofuran is evaluated. - Abstract: The vapor pressure as a function of temperature and its vaporization enthalpy at T = 298.15 K of R-(+)-menthofuran, a substance metabolically derived from R-(+)-pulegone that is both a flavoring agent at low concentrations and a hepatotoxin at larger ones, is evaluated by correlation-gas chromatography. A vapor pressure p/Pa = (36 ± 12) has been evaluated at T = 298.15 K, and a normal boiling temperature of T_b/K = 482.4 K is predicted. A boiling temperature of T_b/K = 374.3 compares with the literature value of T_b/K = 371.2 at reduced pressure, p/kPa = 2.93. The vaporization enthalpy of (56.5 ± 3.0) kJ·mol"−"1 compares to an estimated value of (57.8 ± 2.9) kJ·mol"−"1.

Auxiliary Electrodes for Chromium Vapor Sensors

Energy Technology Data Exchange (ETDEWEB)

Fergus, Jeffrey; Shahzad, Moaiz; Britt, Tommy

2018-05-15

Measurement of chromia-containing vapors in solid oxide fuel cell systems is useful for monitoring and addressing cell degradation caused by oxidation of the chomia scale formed on alloys for interconnects and balance-of-plant components. One approach to measuring chromium is to use a solid electrolyte with an auxiliary electrode that relates the partial pressure of the chromium containing species to the mobile species in the electrolyte. One example is YCrO3 which can equilibrate with the chromium containing vapor and yttrium in yttria stabilized zirconia to establish an oxygen activity. Another is Na2CrO4 which can equilibrate with the chromium-containing vapor to establish a sodium activity.

Vapor generation rate model for dispersed drop flow

International Nuclear Information System (INIS)

Unal, C.; Tuzla, K.; Cokmez-Tuzla, A.F.; Chen, J.C.

1991-01-01

A comparison of predictions of existing nonequilibrium post-CHF heat transfer models with the recently obtained rod bundle data has been performed. The models used the experimental conditions and wall temperatures to predict the heat flux and vapor temperatures at the location of interest. No existing model was able to reasonably predict the vapor superheat and the wall heat flux simultaneously. Most of the models, except Chen-Sundaram-Ozkaynak, failed to predict the wall heat flux, while all of the models could not predict the vapor superheat data or trends. A recently developed two-region heat transfer model, the Webb-Chen two-region model, did not give a reasonable prediction of the vapor generation rate in the far field of the CHF point. A new correlation was formulated to predict the vapor generation rate in convective dispersed droplet flow in terms of thermal-hydraulic parameters and thermodynamic properties. A comparison of predictions of the two-region heat transfer model, with the use of a presently developed correlation, with all the existing post-CHF data, including single-tube and rod bundle, showed significant improvements in predicting the vapor superheat and tube wall heat flux trends. (orig.)

Tritium-gas/water-vapor monitor. Tests and evaluation

International Nuclear Information System (INIS)

Jalbert, R.A.

1982-07-01

A tritium gas/water-vapor monitor was designed and built by the Health Physics Group at the Los Alamos National Laboratory. In its prototype configuration, the monitor took the shape of two separate instruments: a (total) tritium monitor and a water-vapor monitor. Both instruments were tested and evaluated. The tests of the (total) tritium monitor, basically an improved version of the standard flow-through ion-chamber instrument, are briefly reported here and more completely elsewhere. The tests of the water-vapor monitor indicated that the novel approach used to condense water vapor for scintillation counting has a number of serious drawbacks and that further development of the instrument is unwarranted

Influence of soil properties on vapor-phase sorption of trichloroethylene

International Nuclear Information System (INIS)

Bekele, Dawit N.; Naidu, Ravi; Chadalavada, Sreenivasulu

2016-01-01

Highlights: • Vapor intrusion is a major exposure pathway for volatile hydrocarbons. • Certainty in transport processes enhances vapor intrusion model precision. • Detailed understanding of vadose zone vapor transport processes save resources. • Vapor sorption near-steady-state conditions at sites may take months or years. • Type of clay fractions equitably affects sorption of trichloroethylene vapor. - Abstract: Current practices in health risk assessment from vapor intrusion (VI) using mathematical models are based on assumptions that the subsurface sorption equilibrium is attained. The time required for sorption to reach near-steady-state conditions at sites may take months or years to achieve. This study investigated the vapor phase attenuation of trichloroethylene (TCE) in five soils varying widely in clay and organic matter content using repacked columns. The primary indicators of TCE sorption were vapor retardation rate (R_t), the time required for the TCE vapor to pass through the soil column, and specific volume of retention (V_R), and total volume of TCE retained in soil. Results show TCE vapor retardation is mainly due to the rapid partitioning of the compound to SOM. However, the specific volume of retention of clayey soils with secondary mineral particles was higher. Linear regression analyses of the SOM and clay fraction with V_R show that a unit increase in clay fraction results in higher sorption of TCE (V_R) than the SOM. However, partitioning of TCE vapor was not consistent with the samples' surface areas but was mainly a function of the type of secondary minerals present in soils.

Influence of soil properties on vapor-phase sorption of trichloroethylene

Energy Technology Data Exchange (ETDEWEB)

Bekele, Dawit N. [Global Center for Environmental Remediation, University of Newcastle, Callaghan, NSW 2308 (Australia); CRC for Contamination Assessment & Remediation of the Environment, Building X (Environmental Sciences Building), University of South Australia, Mawson Lakes, SA 5095 (Australia); Naidu, Ravi, E-mail: Ravi.Naidu@newcastle.edu.au [Global Center for Environmental Remediation, University of Newcastle, Callaghan, NSW 2308 (Australia); CRC for Contamination Assessment & Remediation of the Environment, Building X (Environmental Sciences Building), University of South Australia, Mawson Lakes, SA 5095 (Australia); Chadalavada, Sreenivasulu [Global Center for Environmental Remediation, University of Newcastle, Callaghan, NSW 2308 (Australia); CRC for Contamination Assessment & Remediation of the Environment, Building X (Environmental Sciences Building), University of South Australia, Mawson Lakes, SA 5095 (Australia)

2016-04-05

Highlights: • Vapor intrusion is a major exposure pathway for volatile hydrocarbons. • Certainty in transport processes enhances vapor intrusion model precision. • Detailed understanding of vadose zone vapor transport processes save resources. • Vapor sorption near-steady-state conditions at sites may take months or years. • Type of clay fractions equitably affects sorption of trichloroethylene vapor. - Abstract: Current practices in health risk assessment from vapor intrusion (VI) using mathematical models are based on assumptions that the subsurface sorption equilibrium is attained. The time required for sorption to reach near-steady-state conditions at sites may take months or years to achieve. This study investigated the vapor phase attenuation of trichloroethylene (TCE) in five soils varying widely in clay and organic matter content using repacked columns. The primary indicators of TCE sorption were vapor retardation rate (R{sub t}), the time required for the TCE vapor to pass through the soil column, and specific volume of retention (V{sub R}), and total volume of TCE retained in soil. Results show TCE vapor retardation is mainly due to the rapid partitioning of the compound to SOM. However, the specific volume of retention of clayey soils with secondary mineral particles was higher. Linear regression analyses of the SOM and clay fraction with V{sub R} show that a unit increase in clay fraction results in higher sorption of TCE (V{sub R}) than the SOM. However, partitioning of TCE vapor was not consistent with the samples' surface areas but was mainly a function of the type of secondary minerals present in soils.

Uptake of mercury vapor by wheat. An assimilation model

International Nuclear Information System (INIS)

Browne, C.L.; Fang, S.C.

1978-01-01

Using a whole-plant chamber and 203 Hg-labeled mercury, a quantitative study was made of the effect of environmental parameters on the uptake, by wheat (Triticum aestivum), of metallic mercury vapor, an atmospheric pollutant. Factors were examined in relation to their influence on components of the gas-assimilation model, U(Hg) = (C/sub A' -- C/sub L')/(r/sub L.Hg/ + r/sub M.Hg/) where U(Hg) is the rate of mercury uptake per unit leaf surface, C/sub A'/ is the ambient mercury vapor concentration, C/sub L'/ is the mercury concentration at immobilization sites within the plant (assumed to be zero), r/sub L.Hg/ is the total leaf resistance to mercury vapor exchange, and r/sub M.Hg/ is a residual term to account for unexplained physical and biochemical resistances to mercury vapor uptake. Essentially all mercury vapor uptake was confined to the leaves. r/sub L.Hg/ was particularly influenced by illumination (0 to 12.8 klux), but unaffected by ambient temperature (17 to 33 0 C) and mercury vapor concentration (0 to 40 μg m -3 ). The principal limitation to mercury vapor uptake was r/sub M.Hg/, which was linearly related to leaf temperature, but unaffected by mercury vapor concentration and illumination, except for apparent high values in darkness. Knowing C/sub A'/ and estimating r/sub L.Hg/ and r/sub M.Hg/ from experimental data, mercury vapor uptake by wheat in light was accurately predicted for several durations of exposure using the above model

Volatilization of multicomponent mixtures in soil vapor extraction applications

International Nuclear Information System (INIS)

Bass, D.H.

1995-01-01

In soil vapor extraction (SVE) applications involving multicomponent mixtures, prediction of mass removal by volatilization as a function remediation extent is required to estimate remediation time and to size offgas treatment equipment. SVE is a commonly used remediation technology which volatilizes and enhances aerobic biodegradation of contamination adsorbed to vadose zone soils. SVE is often applied at sites contaminated with petroleum products, which are usually mixtures of many different compounds with vapor pressures spanning several orders of magnitude. The most volatile components are removed first, so the vapor pressure of the remaining contaminant continually decreases over the course of the remediation. A method for assessing how vapor pressure, and hence the rate of volatilization, of a multicomponent mixture changes over the course of a vapor extraction remedy has been developed. Each component is listed, alone, with its mass fraction in the mixture, in decreasing order of pure component vapor pressure (where component analyses are unavailable, model compounds can be used), For most petroleum distillates, the vapor pressure for each component plotted against the cumulative mass fraction of the component in the mixture on semilog coordinates will produce a straight line with a high correlation coefficient. This regression can be integrated to produce an expression for vapor pressure of the overall mixture as a function of extent or remediation

Vapor Pressures of Several Commercially Used Alkanolamines

NARCIS (Netherlands)

Klepacova, Katarina; Huttenhuis, Patrick J. G.; Derks, Peter W. J.; Versteeg, Geert F.; Klepáčová, Katarína

For the design of acid gas treating processes, vapor-liquid equilibrium (VLE) data must be available of the solvents to be applied. In this study the vapor pressures of seven frequently industrially used alkanolamines (diethanolamine, N-methylethanolamine, N,N-dimethylethanolamine,

Recommended vapor pressures for thiophene, sulfolane, and dimethyl sulfoxide

Czech Academy of Sciences Publication Activity Database

Fulem, Michal; Růžička, K.; Růžička, M.

2011-01-01

Roč. 303, č. 2 (2011), s. 205-216 ISSN 0378-3812 Institutional research plan: CEZ:AV0Z10100521 Keywords : thiophene sulfolane * dimethyl sulfoxide * vapor pressure * heat capacity * vaporization enthalpy * recommended vapor pressure equation Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 2.139, year: 2011

Las multitudes y las revoluciones de nuestro tiempo

Directory of Open Access Journals (Sweden)

John Harold Biervliet

2015-08-01

Full Text Available Este artículo examina el motivo de las multitudes y las revoluciones de nuestro tiempo. Primeramente, se discuten las diferencias entre los conceptos de multitud y masa. Así, podemos considerar las revoluciones como acontecimientos de cambios sociales, económicos y políticos, provenientes de las clases baja y media de la sociedad. El meollo de este artículo refiere a la dignidad humana articulada a la contracción de los Estados de bienestar. Los ciudadanos están reflejando un desencanto hacia la clase política y una frustración con respecto al empeoramiento de las condiciones económicas y sociales. Podemos observar los casos de indignados en Grecia, España y Portugal pero también en los países árabes. De esta misma manera, las revoluciones de las multitudes siguen avanzando por medio de las demostraciones públicas y protestas sobre los espacios geográficos. Finalmente, las dinámicas de cambio a través de las revoluciones árabes son una cuestión compleja debido al círculo vicioso entre la tendencia autoritaria y la islámica. This article examines the reason of multitudes and revolutions in our time. First of all, it discusses the difference between the concept of multitude and mass. Consequently, revolutions can be considered as social, economic, and political events of changes, which come from the low and middle classes of the society. This article refers to the human dignity articulated with the contraction of Welfare states. Citizens are reflecting disenchantment towards the political class and frustration regarding the deterioration of social and economic conditions. We can observe angry people in Greece, Spain, and Portugal but also in Arabian countries. In this same way, revolutions of multitudes continue by means of public demonstrations and protests on geographical spaces. Finally, the dynamics of change through Arabian Revolutions are a complex matter due to the vicious circle between the authoritarian or Islamic

An evaluation of vapor extraction of vadose zone contamination

International Nuclear Information System (INIS)

Crotwell, A.T.; Waehner, M.J.; MacInnis, J.M.; Travis, C.C.; Lyon, B.F.

1992-05-01

An in-depth analysis of vapor extraction for remediation of soils contaminated with volatile organic compounds (VOCS) was conducted at 13 sites. The effectiveness of vapor extraction systems (VES) was evaluated on the basis of soil concentrations of VOCs and soil-gas concentrations of VOC's. The range of effectiveness was found to be 64%--99% effective in removing organic contaminants from soil. At nine of the 13 sites studied in this report, vapor extraction was found to be effective in reducing VOC cooncentrations by at least 90%. At the remaining four sites studied, vapor extraction was found to reduce VOC concentrations by less than 90%. Vapor extraction is ongoing at two of these sites. At a third, the ineffectiveness of the vapor extraction is attributed to the presence of ''hot spots'' of contamination. At the fourth site, where performance was found to be relatively poor, the presence of geological tar deposits at the site is thought to be a major factor in the ineffectiveness

Risk assessment of metal vapor arcing

Science.gov (United States)

Hill, Monika C. (Inventor); Leidecker, Henning W. (Inventor)

2009-01-01

A method for assessing metal vapor arcing risk for a component is provided. The method comprises acquiring a current variable value associated with an operation of the component; comparing the current variable value with a threshold value for the variable; evaluating compared variable data to determine the metal vapor arcing risk in the component; and generating a risk assessment status for the component.

Virtual test bench as a complement to study thermal area: application in vapor compression systems

Directory of Open Access Journals (Sweden)

Juan Manuel Belman-Flores

2015-01-01

Full Text Available Este artículo describe un simulador educativo desarrollado en el software Engineering Equation Solver para representar el comportamiento de un sistema de compresión de vapor. La aplicación está enfocada con propósitos educativos, particularmente para que estudiantes de ingeniería adquieran habilidades en el manejo de instalaciones de refrigeración. Mediante el uso de este simulador, los estudiantes tendrán la capacidad de analizar fácilmente la infl uencia que tienen parámetros medidos experimentalmente (como la velocidad de rotación del compresor, el fl ujo volumétrico y la temperatura de fl uidos secundarios sobre la efi ciencia energética del sistema y sus componentes principales. El banco virtual consta de una pantalla principal que muestra un esquema general del sistema de compresión de vapor con parámetros de entrada y de salida. Desde la pantalla principal, el desempeño de los componentes principales puede ser analizado. Finalmente, este banco de pruebas virtual ha sido probado por estudiantes de ingeniería, concluyendo que el simulador es una herramienta de apoyo que permite mejorar el aprendizaje de las diferentes áreas del conocimiento.

Analysis of organic vapors with laser induced breakdown spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Nozari, Hadi; Tavassoli, Seyed Hassan [Laser and Plasma Research Institute, Shahid Beheshti University, G. C, 1983963113 Evin, Tehran (Iran, Islamic Republic of); Rezaei, Fatemeh, E-mail: fatemehrezaei@kntu.ac.ir [Department of Physics, K. N. Toosi University of Technology, 15875-4416 Shariati, Tehran (Iran, Islamic Republic of)

2015-09-15

In this paper, laser induced breakdown spectroscopy (LIBS) is utilized in the study of acetone, ethanol, methanol, cyclohexane, and nonane vapors. Carbon, hydrogen, oxygen, and nitrogen atomic emission spectra have been recorded following laser-induced breakdown of the organic vapors that are mixed with air inside a quartz chamber at atmospheric pressure. The plasma is generated with focused, Q-switched Nd:YAG radiation at the wavelength of 1064 nm. The effects of ignition and vapor pressure are discussed in view of the appearance of the emission spectra. The recorded spectra are proportional to the vapor pressure in air. The hydrogen and oxygen contributions diminish gradually with consecutive laser-plasma events without gas flow. The results show that LIBS can be used to characterize organic vapor.

Analysis of organic vapors with laser induced breakdown spectroscopy

International Nuclear Information System (INIS)

Nozari, Hadi; Tavassoli, Seyed Hassan; Rezaei, Fatemeh

2015-01-01

In this paper, laser induced breakdown spectroscopy (LIBS) is utilized in the study of acetone, ethanol, methanol, cyclohexane, and nonane vapors. Carbon, hydrogen, oxygen, and nitrogen atomic emission spectra have been recorded following laser-induced breakdown of the organic vapors that are mixed with air inside a quartz chamber at atmospheric pressure. The plasma is generated with focused, Q-switched Nd:YAG radiation at the wavelength of 1064 nm. The effects of ignition and vapor pressure are discussed in view of the appearance of the emission spectra. The recorded spectra are proportional to the vapor pressure in air. The hydrogen and oxygen contributions diminish gradually with consecutive laser-plasma events without gas flow. The results show that LIBS can be used to characterize organic vapor

Analysis of the transient compressible vapor flow in heat pipes

Science.gov (United States)

Jang, J. H.; Faghri, A.; Chang, W. S.

1989-01-01

The transient compressible one-dimensional vapor flow dynamics in a heat pipe is modeled. The numerical results are obtained by using the implicit non-iterative Beam-Warming finite difference method. The model is tested for simulated heat pipe vapor flow and actual vapor flow in cylindrical heat pipes. A good comparison of the present transient results for the simulated heat pipe vapor flow with the previous results of a two-dimensional numerical model is achieved and the steady state results are in agreement with the existing experimental data. The transient behavior of the vapor flow under subsonic, sonic, and supersonic speeds and high mass flow rates are successfully predicted. The one-dimensional model also describes the vapor flow dynamics in cylindrical heat pipes at high temperatures.

Analysis of the transient compressible vapor flow in heat pipe

International Nuclear Information System (INIS)

Jang, J.H.; Faghri, A.; Chang, W.S.

1989-07-01

The transient compressible one-dimensional vapor flow dynamics in a heat pipe is modeled. The numerical results are obtained by using the implicit non-iterative Beam-Warming finite difference method. The model is tested for simulated heat pipe vapor flow and actual vapor flow in cylindrical heat pipes. A good comparison of the present transient results for the simulated heat pipe vapor flow with the previous results of a two-dimensional numerical model is achieved and the steady state results are in agreement with the existing experimental data. The transient behavior of the vapor flow under subsonic, sonic, and supersonic speeds and high mass flow rates are successfully predicted. The one-dimensional model also describes the vapor flow dynamics in cylindrical heat pipes at high temperatures

Headspace vapor characterization of Hanford Waste Tank SX-102: Results from samples collected on July 19, 1995. Tank Vapor Characterization Project

International Nuclear Information System (INIS)

McVeety, B.D.; Evans, J.C.; Clauss, T.W.; Pool, K.H.

1996-05-01

This report describes the results of vapor samples taken from the headspace of waste storage tank 241-SX-102 (Tank SX-102) at the Hanford Site in Washington State. Pacific Northwest National Laboratory (PNNL) contracted with Westinghouse Hanford Company (WHC) to provide sampling devices and analyze samples for inorganic and organic analytes collected from the tank headspace and ambient air near the tank. The analytical work was performed under the PNNL Vapor Analytical Laboratory (VAL) by the Tank Vapor Characterization Project. Work performed was based on a sample and analysis plan (SAP) prepared by WHC. The SAP provided job-specific instructions for samples, analyses, and reporting. The SAP for this sample job was open-quotes Vapor Sampling and Analysis Planclose quotes, and the sample job was designated S5046. Samples were collected by WHC on July 19, 1995, using the vapor sampling system (VSS), a truck-based sampling method using a heated probe inserted into the tank headspace

Headspace vapor characterization of Hanford Waste Tank AX-103: Results from samples collected on June 21, 1995. Tank Vapor Characterization Project

International Nuclear Information System (INIS)

Ligotke, M.W.; Pool, K.H.; Clauss, T.W.

1996-05-01

This report describes the results of vapor samples taken from the headspace of waste storage tank 241-AX-103 (Tank AX-103) at the Hanford Site in Washington State. Pacific Northwest National Laboratory (PNNL) contracted with Westinghouse Hanford Company (WHC) to provide sampling devices and analyze samples for inorganic and organic analytes collected from the tank headspace and ambient air near the tank. The analytical work was performed by the PNNL Vapor Analytical Laboratory (VAL) by the Tank Vapor Characterization Project. Work performed was based on a sample and analysis plan (SAP) prepared by WHC. The SAP provided job-specific instructions for samples, analyses, and reporting. The SAP for this sample job was open-quotes Vapor Sampling and Analysis Planclose quotes, and the sample job was designated S5029. Samples were collected by WHC on June 21, 1995, using the Vapor Sampling System (VSS), a truck-based sampling method using a heated probe inserted into the tank headspace

Headspace vapor characterization of Hanford Waste Tank AX-101: Results from samples collected on June 15, 1995. Tank Vapor Characterization Project

International Nuclear Information System (INIS)

Pool, K.H.; Clauss, T.W.; Evans, J.C.; McVeety, B.D.

1996-05-01

This report describes the results of vapor samples taken from the headspace of waste storage tank 241-AX-101 (Tank AX-101) at the Hanford Site in Washington State. Pacific Northwest National Laboratory (PNNL) contracted with Westinghouse Hanford Company (WHC) to provide sampling devices and analyze samples for inorganic and organic analytes collected from the tank headspace and ambient air near the tank. The analytical work was performed by the PNNL Vapor Analytical Laboratory (VAL) under the Tank Vapor Characterization Project. Work performed was based on a sample and analysis plan (SAP) prepared by WHC. The SAP provided job-specific instructions for samples, analyses, and reporting. The SAP for this sample job was open-quotes Vapor Sampling and Analysis Planclose quotes, and the sample job was designated S5028. Samples were collected by WHC on June 15, 1995, using the Vapor Sampling System (VSS), a truck-based sampling method using a heated probe inserted into the tank headspace

Las versiones homericas Las versiones homericas

Directory of Open Access Journals (Sweden)

Jorge Luis Borges

2008-04-01

Full Text Available Ningún problema tan consustancial con las letras con su modesto misterio como el que propone una traducción. Un olvido animal por la vanidad, el tenor de confesar procesos mentales que adivinamos peligrosamente comunes, el conato de mantener intacta y central una reserve incalculable de sombre, velan las tales escrituras directas. La traducciOn, en cambio, parece destinada a ilustrar la discusión estitica. El modelo propuesto a su imitaciOn es un texto visible, no un labirint° inestimable de proyectos preteritos o la acatada tentaciOn momentanea de una facilidad. Bertrand Russell define un objeto extern( como un sistema circular, irradiante, de impresiones posibles; lo mismo puede aseverarse de un texto, dadas las repercusiones incalculables de lo verbal. Un parcial y precioso documento de las vicisitudes que sufre queda en sus traducciones.

46 CFR 182.480 - Flammable vapor detection systems.

Science.gov (United States)

2010-10-01

... 100 GROSS TONS) MACHINERY INSTALLATION Specific Machinery Requirements § 182.480 Flammable vapor... permit calibration in a vapor free atmosphere. (g) Electrical connections, wiring, and components for a...

External fuel vaporization study, phase 2

Science.gov (United States)

Szetela, E. J.; Chiappetta, L.

1981-01-01

An analytical study was conducted to evaluate the effect of variations in fuel properties on the design of an external fuel vaporizaton system. The fuel properties that were considered included thermal stability, critical temperature, enthalpy a critical conditions, volatility, and viscosity. The design parameters that were evaluated included vaporizer weight and the impact on engine requirement such as maintenance, transient response, performance, and altitude relight. The baseline fuel properties were those of Jet A. The variation in thermal stability was taken as the thermal stability variation for Experimental Referee Broad Specification (ERBS) fuel. The results of the analysis indicate that a change in thermal stability equivalent to that of ERBS would increase the vaporization system weight by 20 percent, decrease oprating time between cleaning by 40 percent and make altitude relight more difficult. An increase in fuel critical temperature of 39 K would require a 40 percent increase in vaporization system weight. The assumed increase in enthalpy and volatility would also increase vaporizer weight by 40 percent and make altitude relight extremely difficult. The variation in fuel viscosity would have a negligible effect on the design parameters.

The liquid to vapor phase transition in excited nuclei

Energy Technology Data Exchange (ETDEWEB)

Elliott, J.B.; Moretto, L.G.; Phair, L.; Wozniak, G.J.; Beaulieu, L.; Breuer, H.; Korteling, R.G.; Kwiatkowski, K.; Lefort, T.; Pienkowski, L.; Ruangma, A.; Viola, V.E.; Yennello, S.J.

2001-05-08

For many years it has been speculated that excited nuclei would undergo a liquid to vapor phase transition. For even longer, it has been known that clusterization in a vapor carries direct information on the liquid-vapor equilibrium according to Fisher's droplet model. Now the thermal component of the 8 GeV/c pion + 197 Au multifragmentation data of the ISiS Collaboration is shown to follow the scaling predicted by Fisher's model, thus providing the strongest evidence yet of the liquid to vapor phase transition.

Demand management in steam generation?; Administracion de la demanda en la generacion de vapor?

Energy Technology Data Exchange (ETDEWEB)

Plauchu L., A.; Plauchu A., J. A. [Ingenieros consultores (Mexico)

1997-12-31

Energy management has acquired capital importance in all the branches of the industrial activity and services either private o public and it has been, from years behind, more familiar the technology for the demand control in the electric power distribution systems, with excellent results in the energy conservation and economy. The rate of consumption for the different forms of energy shows the prevalence of the thermal energy in a variety of end uses. Not much or almost nothing has been said of the term Demand Management or Control in Steam Generation although 12% of the total energy supply is used for this purpose. Steam demand management and control can avoid unnecessary investments that bring along the increment of operational and maintenance problems and it is for sure that it will always give raise to a more rational and economical utilization of the real capacity of steam generation. A real case is commented. [Espanol] La administracion de la energia ha cobrado importancia capital en todos los giros de actividad industrial y de servicios, privados y publicos y es de varios anos atras cada vez mas familiar la tecnologia en el control de demanda en los sistemas de distribucion de energia electrica, con magnificos resultados en el ahorro, energetico y economico. La relacion de consumos para las diferentes formas de energia muestra el predominio de la energia termica en una variedad de usos finales. Poco o nada oimos del termino Administracion o Control de Demanda en la Generacion de Vapor aun cuando el 12% de la oferta total de energia tiene como destino esta aplicacion. La administracion y control de la demanda de vapor puede evitar inversiones innecesarias e incremento de problemas de operacion y mantenimiento y con seguridad reportaran siempre una utilizacion mas racional y economica de la capacidad real de generacion de vapor, se comenta un caso real.

Demand management in steam generation?; Administracion de la demanda en la generacion de vapor?

Energy Technology Data Exchange (ETDEWEB)

Plauchu L, A; Plauchu A, J A [Ingenieros consultores (Mexico)

1998-12-31

Energy management has acquired capital importance in all the branches of the industrial activity and services either private o public and it has been, from years behind, more familiar the technology for the demand control in the electric power distribution systems, with excellent results in the energy conservation and economy. The rate of consumption for the different forms of energy shows the prevalence of the thermal energy in a variety of end uses. Not much or almost nothing has been said of the term Demand Management or Control in Steam Generation although 12% of the total energy supply is used for this purpose. Steam demand management and control can avoid unnecessary investments that bring along the increment of operational and maintenance problems and it is for sure that it will always give raise to a more rational and economical utilization of the real capacity of steam generation. A real case is commented. [Espanol] La administracion de la energia ha cobrado importancia capital en todos los giros de actividad industrial y de servicios, privados y publicos y es de varios anos atras cada vez mas familiar la tecnologia en el control de demanda en los sistemas de distribucion de energia electrica, con magnificos resultados en el ahorro, energetico y economico. La relacion de consumos para las diferentes formas de energia muestra el predominio de la energia termica en una variedad de usos finales. Poco o nada oimos del termino Administracion o Control de Demanda en la Generacion de Vapor aun cuando el 12% de la oferta total de energia tiene como destino esta aplicacion. La administracion y control de la demanda de vapor puede evitar inversiones innecesarias e incremento de problemas de operacion y mantenimiento y con seguridad reportaran siempre una utilizacion mas racional y economica de la capacidad real de generacion de vapor, se comenta un caso real.

ASME power test code ptc 4.1 for steam generators; Codigo de pruebas de potencia ASME ptc 4.1 para generadores de vapor

Energy Technology Data Exchange (ETDEWEB)

Plauchu Alcantara, Jorge Alberto [Plauchu Consultores, Morelia, Michoacan (Mexico)

2001-07-01

lo anterior al dedicar a este uso de la energia proyectos importantes, algunos de ellos con apoyo de la USAID. La medicion del aprovechamiento energetico o de la eficiencia de generadores de vapor (o calderas) se realiza aplicando algun procedimiento convenido por las partes y el de mayor aceptacion y conocimiento en Mexico e internacionalmente es el Codigo de Pruebas de Potencia ASME PTC 4.1 para Generadores de Vapor. El proposito y formalidad en la determinacion de eficiencia y capacidad de generacion de vapor, comportamiento, regimen termico base o cumplimiento de garantias, cambia radicalmente las exigencias de apego estricto al PTC 4.1 Esta definicion determinara la importancia del metodo de prueba seleccionado, las desviaciones y excepciones convenidas, la influencia de la precision y los errores de medicion, la consideracion de equipo auxiliar, etc. Una interpretacion o aplicacion incorrecta de Codigo de Pruebas ha conducido y conducira a resultados y decisiones no confiables.

Vapor-fed bio-hybrid fuel cell.

Science.gov (United States)

Benyamin, Marcus S; Jahnke, Justin P; Mackie, David M

2017-01-01

Concentration and purification of ethanol and other biofuels from fermentations are energy-intensive processes, with amplified costs at smaller scales. To circumvent the need for these processes, and to potentially reduce transportation costs as well, we have previously investigated bio-hybrid fuel cells (FCs), in which a fermentation and FC are closely coupled. However, long-term operation requires strictly preventing the fermentation and FC from harming each other. We introduce here the concept of the vapor-fed bio-hybrid FC as a means of continuously extracting power from ongoing fermentations at ambient conditions. By bubbling a carrier gas (N 2 ) through a yeast fermentation and then through a direct ethanol FC, we protect the FC anode from the catalyst poisons in the fermentation (which are non-volatile), and also protect the yeast from harmful FC products (notably acetic acid) and from build-up of ethanol. Since vapor-fed direct ethanol FCs at ambient conditions have never been systematically characterized (in contrast to vapor-fed direct methanol FCs), we first assess the effects on output power and conversion efficiency of ethanol concentration, vapor flow rate, and FC voltage. The results fit a continuous stirred-tank reactor model. Over a wide range of ethanol partial pressures (2-8 mmHg), power densities are comparable to those for liquid-fed direct ethanol FCs at the same temperature, with power densities >2 mW/cm 2 obtained. We then demonstrate the continuous operation of a vapor-fed bio-hybrid FC with fermentation for 5 months, with no indication of performance degradation due to poisoning (of either the FC or the fermentation). It is further shown that the system is stable, recovering quickly from disturbances or from interruptions in maintenance. The vapor-fed bio-hybrid FC enables extraction of power from dilute bio-ethanol streams without costly concentration and purification steps. The concept should be scalable to both large and small

Vaporization of Samarium trichloride studied by thermogravimetry

International Nuclear Information System (INIS)

Esquivel, Marcelo R.; Pasquevich, Daniel M.

2003-01-01

In the present work, the vaporization reaction of SmCl 3 (l) obtained from the 'in situ' reaction of Sm 2 O 3 (s) and Cl 2 (g)-C(s) was studied by thermogravimetry under controlled atmosphere. The effects of both the temperature between 825 C degrees and 950 C degrees and the total flow gas on the vaporization rate of the following reaction: SmCl 3 (l) = SmCl 3 (g) were analyzed. The vaporization rate of the process was found to be independent of then total gas flow rate and highly dependent on the temperature. E ap calculation led to a value of 240 ± 10 kJ.mol -1 . A comparison between this value and that of the molar enthalpy of vaporization allow to the conclusion that the reaction occur in conditions near to equilibrium. The SmCl 3 identity was determined by X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS). (author)

General well function for soil vapor extraction

Science.gov (United States)

Perina, Tomas

2014-04-01

This paper develops a well function applicable to extraction of groundwater or soil vapor from a well under the most common field test conditions. The general well function (Perina and Lee, 2006) [12] is adapted to soil vapor extraction and constant head boundary at the top. For groundwater flow, the general well function now applies to an extraction well of finite diameter with uniform drawdown along the screen, finite-thickness skin, and partially penetrating an unconfined, confined, and leaky aquifer, or an aquifer underneath a reservoir. With a change of arguments, the model applies to soil vapor extraction from a vadose zone with no cover or with leaky cover at the ground surface. The extraction well can operate in specified drawdown (pressure for soil vapor) or specified flowrate mode. Frictional well loss is computed as flow-only dependent component of the drawdown inside the extraction well. In general case, the calculated flow distribution is not proportional to screen length for a multiscreen well.

Solvent vapor annealing of an insoluble molecular semiconductor

KAUST Repository

Amassian, Aram

2010-01-01

Solvent vapor annealing has been proposed as a low-cost, highly versatile, and room-temperature alternative to thermal annealing of organic semiconductors and devices. In this article, we investigate the solvent vapor annealing process of a model insoluble molecular semiconductor thin film - pentacene on SiO 2 exposed to acetone vapor - using a combination of optical reflectance and two-dimensional grazing incidence X-ray diffraction measurements performed in situ, during processing. These measurements provide valuable and new insight into the solvent vapor annealing process; they demonstrate that solvent molecules interact mainly with the surface of the film to induce a solid-solid transition without noticeable swelling, dissolving or melting of the molecular material. © 2010 The Royal Society of Chemistry.

Vaporization of comet nuclei: Light curves and life times

Energy Technology Data Exchange (ETDEWEB)

Cowan, J J [Harvard Univ., Cambridge, MA (USA). Center for Astrophysics; A' Hearn, M F [Maryland Univ., College Park (USA)

1979-10-01

The authors have examined the effects of vaporization from the nucleus of a comet and show that a latitude dependence of vaporization can, in some cases, explain asymmetries in commetary light curves. They also find that a non-uniform distribution of solar radiation over a comet can considerably shorten the vaporization lifetime compared to the results normally obtained by assuming that the nuclear surface is isothermal. Independent of any latitude effects, comets with CO/sub 2/-dominated nuclei and with periherlion distances less than 0.5 AU have vaporization lifetimes less than or comparable to their dynamical ejection times. This may explain the observed deficit of comets with small perihelion distances. Similarly comets with CO/sub 2/-dominated nuclei and perihelia near Jupiter's orbit have vaporization lifetimes that are shorter than the time for capture into short-period orbits. They suggest, therefore, that at least some new comets are composed in large part of CO/sub 2/, while only H/sub 2/O-dominated comets, with lower vaporization rates, can survive to be captured into short-period orbits.

46 CFR 39.40-1 - General requirements for vapor balancing-TB/ALL.

Science.gov (United States)

2010-10-01

... Section 39.40-1 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY TANK VESSELS VAPOR CONTROL SYSTEMS... to control vapor emissions during a lightering or topping-off operation which does not use vapor... compressor or blower to assist vapor transfer without approval from the Commandant (CG-522). (d) Vapor...

Monitoring tropospheric water vapor changes using radiosonde data

International Nuclear Information System (INIS)

Elliott, W.P.; Smith, M.E.; Angell, J.K.

1990-01-01

Significant increases in the water vapor content of the troposphere are expected to accompany temperature increases due to rising concentrations of the greenhouse gases. Thus it is important to follow changes in water vapor over time. There are a number of difficulties in developing a homogeneous data set, however, because of changes in radiosonde instrumentation and reporting practices. The authors report here on preliminary attempts to establish indices of water vapor which can be monitored. The precipitable water between the surface and 500 mb is the first candidate. They describe their method for calculating this quantity from radiosonde data for a network very similar to the network Angell uses for detecting temperature trends. Preliminary results suggest that the noise level is low enough to detect trends in water vapor at the individual stations. While a slight increase in global water vapor is hinted at in the data, and the data suggest there may have been a net transfer of water from the Southern Hemisphere to the Northern Hemisphere, these conclusions are tentative. The authors also discuss the future course of this investigation

Secondhand Exposure to Vapors From Electronic Cigarettes

Science.gov (United States)

Czogala, Jan; Fidelus, Bartlomiej; Zielinska-Danch, Wioleta; Travers, Mark J.; Sobczak, Andrzej

2014-01-01

Introduction: Electronic cigarettes (e-cigarettes) are designed to generate inhalable nicotine aerosol (vapor). When an e-cigarette user takes a puff, the nicotine solution is heated and the vapor is taken into lungs. Although no sidestream vapor is generated between puffs, some of the mainstream vapor is exhaled by e-cigarette user. The aim of this study was to evaluate the secondhand exposure to nicotine and other tobacco-related toxicants from e-cigarettes. Materials and Methods: We measured selected airborne markers of secondhand exposure: nicotine, aerosol particles (PM2.5), carbon monoxide, and volatile organic compounds (VOCs) in an exposure chamber. We generated e-cigarette vapor from 3 various brands of e-cigarette using a smoking machine and controlled exposure conditions. We also compared secondhand exposure with e-cigarette vapor and tobacco smoke generated by 5 dual users. Results: The study showed that e-cigarettes are a source of secondhand exposure to nicotine but not to combustion toxicants. The air concentrations of nicotine emitted by various brands of e-cigarettes ranged from 0.82 to 6.23 µg/m3. The average concentration of nicotine resulting from smoking tobacco cigarettes was 10 times higher than from e-cigarettes (31.60±6.91 vs. 3.32±2.49 µg/m3, respectively; p = .0081). Conclusions: Using an e-cigarette in indoor environments may involuntarily expose nonusers to nicotine but not to toxic tobacco-specific combustion products. More research is needed to evaluate health consequences of secondhand exposure to nicotine, especially among vulnerable populations, including children, pregnant women, and people with cardiovascular conditions. PMID:24336346

Does mercury vapor exposure increase urinary selenium excretion

Energy Technology Data Exchange (ETDEWEB)

Hongo, T; Suzuki, T; Himeno, S; Watanabe, C; Satoh, H; Shimada, Y

1985-01-01

It has been reported that an increase of urinary selenium excretion may occur as a result of mercury vapor exposure. However, experimental data regarding the interaction between mercury vapor and selenium have yielded ambiguous results about the retention and elimination of selenium due to mercury vapor exposure and the decrease of selenium excretion due to mercury in the form of mercuric mercury (Hg/sup 2 +/). In this study, the authors measured urinary mercury and selenium in workers with or without exposure to mercury vapor to determine whether or not urinary selenium excretion was increased as a result of mercury vapor exposure. Urine samples were collected from 141 workers, 71 men and 70 women, whose extent of exposure to mercury vapor varied according to their job sites. Workers were divided into five groups according to their urinary mercury levels. The mercury level in group I was less than 2.8 nmol/mmol creatinine which means that this group was mostly free from mercury exposure. The average age was almost identical among the groups. For both sexes, group V (with the highest urinary mercury level) had the lowest urinary selenium level, but one-way variance analysis (ANOVA) did not reveal any significant variations of urinary selenium with urinary mercury levels; however, a weak but significant negative correlation between mercury and selenium was found in men.

Diseño de rotor para un aerogenerador de bajas velocidades

Directory of Open Access Journals (Sweden)

Hugo A. Arevalo

2009-01-01

Full Text Available En los ultimos afios ha existido un creciente interes en el disefio y el estudio de turbinas eólicas de baja velocidad debido a la mayor cantidad de lugares donde este potencial eólico esta presente. Usando elementos de Ia teoría de momentum del alabe (BEM y la teoría de la circulación, este articulo describe un metodo basado en el analisis del cambio de circulación y momentum a traves de cada estación del alabe, permitiendo calculos mas precisos y optimizando así el rendimiento del rotor en turbinas eólicas de eje horizontal, baja velocidad de viento y paso fijo. La comparaci6n de los resultados obtenidos con datos provenientes de turbinas eólicas reales muestra una alta similitud.

Water-vapor pressure control in a volume

Science.gov (United States)

Scialdone, J. J.

1978-01-01

The variation with time of the partial pressure of water in a volume that has openings to the outside environment and includes vapor sources was evaluated as a function of the purging flow and its vapor content. Experimental tests to estimate the diffusion of ambient humidity through openings and to validate calculated results were included. The purging flows required to produce and maintain a certain humidity in shipping containers, storage rooms, and clean rooms can be estimated with the relationship developed here. These purging flows are necessary to prevent the contamination, degradation, and other effects of water vapor on the systems inside these volumes.

Water vapor retrieval over many surface types

Energy Technology Data Exchange (ETDEWEB)

Borel, C.C.; Clodius, W.C.; Johnson, J.

1996-04-01

In this paper we present a study of of the water vapor retrieval for many natural surface types which would be valuable for multi-spectral instruments using the existing Continuum Interpolated Band Ratio (CIBR) for the 940 nm water vapor absorption feature. An atmospheric code (6S) and 562 spectra were used to compute the top of the atmosphere radiance near the 940 nm water vapor absorption feature in steps of 2.5 nm as a function of precipitable water (PW). We derive a novel technique called ``Atmospheric Pre-corrected Differential Absorption`` (APDA) and show that APDA performs better than the CIBR over many surface types.

Review of enhanced vapor diffusion in porous media

International Nuclear Information System (INIS)

Webb, S.W.; Ho, C.K.

1998-01-01

Vapor diffusion in porous media in the presence of its own liquid has often been treated similar to gas diffusion. The gas diffusion rate in porous media is much lower than in free space due to the presence of the porous medium and any liquid present. However, enhanced vapor diffusion has also been postulated such that the diffusion rate may approach free-space values. Existing data and models for enhanced vapor diffusion, including those in TOUGH2, are reviewed in this paper

Microscale interfacial behavior at vapor film collapse on high-temperature particle surface

International Nuclear Information System (INIS)

Abe, Yutaka; Tochio, Daisuke

2009-01-01

It has been pointed out that vapor film on a premixed high-temperature droplet surface should be collapsed to trigger vapor explosion. Thus, it is important to clarify the micromechanism of vapor film collapse behavior for the occurrence of vapor explosion. In the present study, microscale vapor-liquid interface behavior upon vapor film collapse caused by an external pressure pulse is experimentally observed and qualitatively analyzed. In the analytical investigation, interfacial temperature and interface movement were estimated with heat conduction analysis and visual data processing technique. Results show that condensation can possibly occur at the vapor-liquid interface when the pressure pulse arrived. That is, this result indicates that the vapor film collapse behavior is dominated not by fluid motion but by phase change. (author)

Headspace vapor characterization of Hanford Waste Tank 241-T-110: Results from samples collected on August 31, 1995. Tank Vapor Characterization Project

International Nuclear Information System (INIS)

McVeety, B.D.; Thomas, B.L.; Evans, J.C.

1996-05-01

This report describes the results of vapor samples taken from the headspace of waste storage tank 241-T-110 (Tank T-110) at the Hanford Site in Washington State. Pacific Northwest National Laboratory (PNNL) contracted with Westinghouse Hanford Company (WHC) to provide sampling devices and analyze samples for inorganic and organic analytes collected from the tank headspace and ambient air near the tank. The analytical work was performed by the PNNL Vapor Analytical Laboratory (VAL) by the Tank Vapor Characterization Project. Work performed was based on a sample and analysis plan (SAP) prepared by WHC. The SAP provided job-specific instructions for samples, analyses, and reporting. The SAP for this sample job was open-quotes Vapor Sampling and Analysis Planclose quotes, and the sample job was designated S5056. Samples were collected by WHC on August 31, 1995, using the Vapor Sampling System (VSS), a truck-based sampling method using a heated probe inserted into the tank headspace

Headspace vapor characterization of Hanford Waste Tank 241-TX-111: Results from samples collected on October 12, 1995. Tank Vapor Characterization Project

International Nuclear Information System (INIS)

Pool, K.H.; Clauss, T.W.; Evans, J.C.

1996-06-01

This report describes the results of vapor samples taken from the headspace of waste storage tank 241-TX-111 (Tank TX-111) at the Hanford Site in Washington State. Pacific Northwest National Laboratory (PNNL) contracted with Westinghouse Hanford Company (WHC) to provide sampling devices and analyze samples for inorganic and organic analytes collected from the tank headspace and ambient air near the tank. The analytical work was performed by the PNNL Vapor Analytical Laboratory (VAL) by the Tank Vapor Characterization Project. Work performed was based on a sample and analysis plan (SAP) prepared by WHC. The SAP provided job-specific instructions for samples, analyses, and reporting. The SAP for this sample job was open-quotes Vapor Sampling and Analysis Planclose quotes, and the sample job was designated S5069. Samples were collected by WHC on October 12, 1995, using the Vapor Sampling System (VSS), a truck-based sampling method using a heated probe inserted into the tank headspace

Headspace vapor characterization of Hanford Waste Tank 241-SX-109: Results from samples collected on August 1, 1995. Tank Vapor Characterization Project

International Nuclear Information System (INIS)

Pool, K.H.; Clauss, T.W.; Evans, J.C.

1996-05-01

This report describes the results of vapor samples taken from the headspace of waste storage tank 241-SX-109 (Tank SX-109) at the Hanford Site in Washington State. Pacific Northwest National Laboratory (PNNL) contracted with Westinghouse Hanford Company (WHC) to provide sampling devices and analyze samples for inorganic and organic analytes collected from the tank headspace and ambient air near the tank. The analytical work was performed by the PNNL Vapor Analytical Laboratory (VAL) by the Tank Vapor Characterization Project. Work performed was based on a sample and analysis plan (SAP) prepared by WHC. The SAP provided job-specific instructions for samples, analyses, and reporting. The SAP for this sample job was open-quotes Vapor Sampling and Analysis Planclose quotes, and the sample job was designated S5048. Samples were collected by WHC on August 1, 1995, using the Vapor Sampling System (VSS), a truck-based sampling method using a heated probe inserted into the tank headspace

Headspace vapor characterization of Hanford Waste Tank 241-SX-104: Results from samples collected on July 25, 1995. Tank Vapor Characterization Project

International Nuclear Information System (INIS)

Thomas, B.L.; Clauss, T.W.; Evans, J.C.

1996-05-01

This report describes the results of vapor samples taken from the headspace of waste storage tank 241-SX-104 (Tank SX-104) at the Hanford Site in Washington State. Pacific Northwest National Laboratory (PNNL) contracted with Westinghouse Hanford Company (WHC) to provide sampling devices and analyze samples for inorganic and organic analytes collected from the tank headspace and ambient air near the tank. The analytical work was performed by the PNNL Vapor Analytical Laboratory (VAL) by the Tank Vapor Characterization Project. Work performed was based on a sample and analysis plan (SAP) prepared by WHC. The SAP provided job-specific instructions for samples, analyses, and reporting. The SAP for this sample job was open-quotes Vapor Sampling and Analysis Planclose quotes, and the sample job was designated S5049. Samples were collected by WHC on July 25, 1995, using the Vapor Sampling System (VSS), a truck-based sampling method using a heated probe inserted into the tank headspace

Headspace vapor characterization of Hanford Waste Tank 241-S-112: Results from samples collected on July 11, 1995. Tank Vapor Characterization Project

International Nuclear Information System (INIS)

Clauss, T.W.; Pool, K.H.; Evans, J.C.

1996-05-01

This report describes the results of vapor samples taken from the headspace of waste storage Tank 241-S-112 (Tank S-112) at the Hanford. Pacific Northwest National Laboratory (PNNL) is contracted with Westinghouse Hanford Company (WHC) to provide sampling devices and analyze samples for inorganic and organic analytes collected from the tank headspace and ambient air near the tank. The analytical work was performed by the PNNL Vapor Analytical Laboratory (VAL) by the Tank Vapor Characterization Project. Work performed was based on a sample and analysis plan (SAP) prepared by WHC. The SAP provided job-specific instructions for samples, analyses, and reporting. The SAP for this sample job was open-quotes Vapor Sampling and Analysis Planclose quotes, and the sample job was designated S5044. Samples were collected by WHC on July 11, 1995, using the Vapor Sampling System (VSS), a truck-based sampling method using a heated probe inserted into the tank headspace

Headspace vapor characterization of Hanford Waste Tank 241-SX-105: Results from samples collected on July 26, 1995. Tank Vapor Characterization Project

International Nuclear Information System (INIS)

Pool, K.H.; Clauss, T.W.; Evans, J.C.

1996-05-01

This report describes the results of vapor samples taken from the headspace of waste storage tank 241-SX-105 (Tank SX-105) at the Hanford Site in Washington State. Pacific Northwest National Laboratory (PNNL) contracted with Westinghouse Hanford Company (WHC) to provide sampling devices and analyze samples for inorganic and organic analytes collected from the tank headspace and ambient air near the tank. The analytical work was performed by the PNNL Vapor Analytical Laboratory (VAL) by the Tank Vapor Characterization Project. Work performed was based on a sample and analysis plan (SAP) prepared by WHC. The SAP provided job-specific instructions for samples, analyses, and reporting. The SAP for this sample job was open-quotes Vapor Sampling and Analysis Planclose quotes, and the sample job was designated S5047. Samples were collected by WHC on July 26, 1995, using the Vapor Sampling System (VSS), a truck-based sampling method using a heated probe inserted into the tank headspace

Las lenguas en las sociedades del conocimiento

Directory of Open Access Journals (Sweden)

Álvarez, J. Francisco

2008-12-01

Full Text Available Languages become a strategic resource for information and knowledge societies. By expressing and sharing knowledge by means of languages, every culture generates deposits of knowledge, which can be transferred and exchanged among different epistemic communities. The contemporary technologies of information and communication have changed the structure of knowledge flows. Globalization of knowledge poses a great challenge to every language, including the Spanish one. In order to survive in the digital world, they should develop technolanguages. The lemma “Thinking in Spanish” implies a new model of governance for the Ibero-American knowledge communities.En las sociedades de la información y el conocimiento las lenguas se convierten en un recurso estratégico. Al expresar y compartir conocimiento por medio de los idiomas, las culturas generan yacimientos de conocimiento, que pueden ser transferidos e intercambiados entre comunidades epistémicas diferentes. Las actuales tecnologías de la información y la comunicación han cambiado la estructura de los flujos de conocimiento. La globalización del conocimiento plantea un gran desafío a todas las lenguas, incluyendo la española. Para sobrevivir en el mundo digital, los lenguajes han de convertirse en tecnolenguajes. El lema “Pensar en español” aporta un nuevo modelo de gobernanza para las comunidades iberoamericanas del conocimiento.

Comparison of vapor sampling system (VSS) and in situ vapor sampling (ISVS) methods on Tanks C-107, BY-108, and S-102. Revision 1

International Nuclear Information System (INIS)

Huckaby, J.L.; Edwards, J.A.; Evans, J.C.

1996-08-01

This report discusses comparison tests for two methods of collecting vapor samples from the Hanford Site high-level radioactive waste tank headspaces. The two sampling methods compared are the truck-mounted vapor sampling system (VSS) and the cart-mounted in-situ vapor sampling (ISVS). Three tanks were sampled by both the VSS and ISVS methods from the same access risers within the same 8-hour period. These tanks have diverse headspace compositions and they represent the highest known level of several key vapor analytes

Las TIC como fuente de ventaja competitiva en las PYMES

Directory of Open Access Journals (Sweden)

Álvaro Fernando Moncada Niño

2013-06-01

Full Text Available Desde su aparición, las Tecnologías de la Información y las Comunicaciones (TIC se han convertido en un recurso fundamental de las empresas para competir en la mayoría de las industrias, generalizando el planteamiento de que son fuente de ventaja competitiva. Pero realmente, ¿cuándo las TIC son fuente potencial de ventaja competitiva para las pymes? ¿Bajo qué condiciones se logra que contribuyan a generar valor y mejorar su posición competitiva? ¿Qué características deben cumplir para alcanzar y sustentar la Ventaja Competitiva? Este documento basado en la Teoría de los Recursos y Capacidades (TRC responde estas preguntas y presenta al análisis de recurso Valioso, Raro, Inimitable y Organización (VRIO como herramienta para la determinación del potencial y valor que las TIC pueden alcanzar en las pymes y cómo pueden contribuir a que la empresa alcance ventajas competitivas sostenibles, en complemento de sus recursos y capacidades organizacionales.

Las TIC como fuente de ventaja competitiva en las PYMES

Directory of Open Access Journals (Sweden)

Álvaro Fernando Moncada Niño

2013-07-01

Full Text Available Desde su aparición, las Tecnologías de la Información y las Comunicaciones (TIC se han convertido en un recurso fundamental de las empresas para competir en la mayoría de las industrias, generalizando el planteamiento de que son fuente de ventaja competitiva. Pero realmente, ¿cuándo las TIC son fuente potencial de ventaja competitiva para las pymes? ¿Bajo qué condiciones se logra que contribuyan a generar valor y mejorar su posición competitiva? ¿Qué características deben cumplir para alcanzar y sustentar la Ventaja Competitiva? Este documento basado en la Teoría de los Recursos y Capacidades (TRC responde estas preguntas y presenta al análisis de recurso Valioso, Raro, Inimitable y Organización (VRIO como herramienta para la determinación del potencial y valor que las TIC pueden alcanzar en las pymes y cómo pueden contribuir a que la empresa alcance ventajas competitivas sostenibles, en complemento de sus recursos y capacidades organizacionales.

Metal Vapor Arcing Risk Assessment Tool

Science.gov (United States)

Hill, Monika C.; Leidecker, Henning W.

2010-01-01

The Tin Whisker Metal Vapor Arcing Risk Assessment Tool has been designed to evaluate the risk of metal vapor arcing and to help facilitate a decision toward a researched risk disposition. Users can evaluate a system without having to open up the hardware. This process allows for investigating components at risk rather than spending time and money analyzing every component. The tool points to a risk level and provides direction for appropriate action and documentation.

Relaciones amorosas de pareja en las trayectorias vitales de las mujeres encarceladas

OpenAIRE

De Miguel Calvo, Estibaliz

2012-01-01

[ES]La tesis doctoral analiza las experiencias amorosas de pareja de mujeres encarceladas, con el doble objetivo de visibilizar a las mujeres presas en el ámbito de las ciencias sociales y de introducir las especificidades de las mujeres encarceladas en los debates sociológicos y feministas acerca del amor. Las escasas aproximaciones al amor entre las mujeres presas han tendido a explicar sus relaciones de pareja desde el concepto de “depende...

Pretreated Butterfly Wings for Tuning the Selective Vapor Sensing.

Science.gov (United States)

Piszter, Gábor; Kertész, Krisztián; Bálint, Zsolt; Biró, László Péter

2016-09-07

Photonic nanoarchitectures occurring in the scales of Blue butterflies are responsible for their vivid blue wing coloration. These nanoarchitectures are quasi-ordered nanocomposites which are constituted from a chitin matrix with embedded air holes. Therefore, they can act as chemically selective sensors due to their color changes when mixing volatile vapors in the surrounding atmosphere which condensate into the nanoarchitecture through capillary condensation. Using a home-built vapor-mixing setup, the spectral changes caused by the different air + vapor mixtures were efficiently characterized. It was found that the spectral shift is vapor-specific and proportional with the vapor concentration. We showed that the conformal modification of the scale surface by atomic layer deposition and by ethanol pretreatment can significantly alter the optical response and chemical selectivity, which points the way to the efficient production of sensor arrays based on the knowledge obtained through the investigation of modified butterfly wings.

Excessively High Vapor Pressure of Al-based Amorphous Alloys

Directory of Open Access Journals (Sweden)

Jae Im Jeong

2015-10-01

Full Text Available Aluminum-based amorphous alloys exhibited an abnormally high vapor pressure at their approximate glass transition temperatures. The vapor pressure was confirmed by the formation of Al nanocrystallites from condensation, which was attributed to weight loss of the amorphous alloys. The amount of weight loss varied with the amorphous alloy compositions and was inversely proportional to their glass-forming ability. The vapor pressure of the amorphous alloys around 573 K was close to the vapor pressure of crystalline Al near its melting temperature, 873 K. Our results strongly suggest the possibility of fabricating nanocrystallites or thin films by evaporation at low temperatures.

Vapor characterization of Tank 241-C-103

International Nuclear Information System (INIS)

Huckaby, J.L.; Story, M.S.

1994-06-01

The Westinghouse Hanford Company Tank Vapor Issue Resolution Program has developed, in cooperation with Northwest Instrument Systems, Inc., Oak Ridge National Laboratory, Oregon Graduate Institute of Science and Technology, Pacific Northwest Laboratory, and Sandia National Laboratory, the equipment and expertise to characterize gases and vapors in the high-level radioactive waste storage tanks at the Hanford Site in south central Washington State. This capability has been demonstrated by the characterization of the tank 241-C-103 headspace. This tank headspace is the first, and for many reasons is expected to be the most problematic, that will be characterized (Osborne 1992). Results from the most recent and comprehensive sampling event, sample job 7B, are presented for the purpose of providing scientific bases for resolution of vapor issues associated with tank 241-C-103. This report is based on the work of Clauss et al. 1994, Jenkins et al. 1994, Ligotke et al. 1994, Mahon et al. 1994, and Rasmussen and Einfeld 1994. No attempt has been made in this report to evaluate the implications of the data presented, such as the potential impact of headspace gases and vapors to tank farm workers health. That and other issues will be addressed elsewhere. Key to the resolution of worker health issues is the quantitation of compounds of toxicological concern. The Toxicology Review Panel, a panel of Pacific Northwest Laboratory experts in various areas, of toxicology, has chosen 19 previously identified compounds as being of potential toxicological concern. During sample job 7B, the sampling and analytical methodology was validated for this preliminary list of compounds of toxicological concern. Validation was performed according to guidance provided by the Tank Vapor Conference Committee, a group of analytical chemists from academic institutions and national laboratories assembled and commissioned by the Tank Vapor Issue Resolution Program

Vapor characterization of Tank 241-C-103

Energy Technology Data Exchange (ETDEWEB)

Huckaby, J.L. [Westinghouse Hanford Co., Richland, WA (United States); Story, M.S. [Northwest Instrument Systems, Inc. Richland, WA (United States)

1994-06-01

The Westinghouse Hanford Company Tank Vapor Issue Resolution Program has developed, in cooperation with Northwest Instrument Systems, Inc., Oak Ridge National Laboratory, Oregon Graduate Institute of Science and Technology, Pacific Northwest Laboratory, and Sandia National Laboratory, the equipment and expertise to characterize gases and vapors in the high-level radioactive waste storage tanks at the Hanford Site in south central Washington State. This capability has been demonstrated by the characterization of the tank 241-C-103 headspace. This tank headspace is the first, and for many reasons is expected to be the most problematic, that will be characterized (Osborne 1992). Results from the most recent and comprehensive sampling event, sample job 7B, are presented for the purpose of providing scientific bases for resolution of vapor issues associated with tank 241-C-103. This report is based on the work of Clauss et al. 1994, Jenkins et al. 1994, Ligotke et al. 1994, Mahon et al. 1994, and Rasmussen and Einfeld 1994. No attempt has been made in this report to evaluate the implications of the data presented, such as the potential impact of headspace gases and vapors to tank farm workers health. That and other issues will be addressed elsewhere. Key to the resolution of worker health issues is the quantitation of compounds of toxicological concern. The Toxicology Review Panel, a panel of Pacific Northwest Laboratory experts in various areas, of toxicology, has chosen 19 previously identified compounds as being of potential toxicological concern. During sample job 7B, the sampling and analytical methodology was validated for this preliminary list of compounds of toxicological concern. Validation was performed according to guidance provided by the Tank Vapor Conference Committee, a group of analytical chemists from academic institutions and national laboratories assembled and commissioned by the Tank Vapor Issue Resolution Program.

Muonium formation and the 'missing fraction' in vapors

International Nuclear Information System (INIS)

Fleming, D.G.; Arseneau, D.J.; Garner, D.M.; Senba, M.; Mikula, R.J.

1983-06-01

The vapor phase fractional polarizations of positive muons thermalizing as the muonium atom (Psub(M)) and in diamagnetic environments (Psub(D)) has been measured in H 2 O, CH 3 OH, C 6 H 14 , C 6 H 12 , CCl 4 , CHCl 3 , CH 2 Cl 2 and TMS, in order to compare with the corresponding fractions measured in the condensed phases. There is a marked contrast in every case, with the vapor phase results being largely understandable in terms of a charge exchange/hot atom model. Unlike the situation in the corresponding liquids, there is no permanent lost fraction in the vapor phase in the limit of even moderately high pressures (approximately 1 atm); at lower pressures, depolarization is due to hyperfine mixing and is believed to be well understood. For vapor phase CH 3 OH, C 6 H 14 , C 6 H 12 , and TMS the relative fractions are found to be pressure dependent, suggesting the importance of termolecular hot atom (or ion) reactions in the slowing-down process. For vapor phase H 2 O and the chloromethanes, the relative fractions are pressure independent. For CCl 4 , Psub(M) = Psub(D) approximately 0.5 in the vapor phase vs. Psub(D) = 1.0 in the liquid phase; fast thermal reactions of Mu likely contribute significantly to this difference in the liquid phase. For H 2 O, Psub(M) approximately 0.9 and Psub(D) approximately 0.1 in the vapor phase vs. Psub(D) approximately 0.6 and Psub(M) approximately 0.2 in the liquid phase. Water appears to be the one unequivocal case where the basic charge exchange/hot atom model is inappropriate in the condensed phase, suggesting, therefore, that radiation-induced 'spur' effects play a major role

Similarities and differences in vapor explosion criteria

International Nuclear Information System (INIS)

Cronenberg, A.W.

1978-01-01

An overview of recent ideas pertaining to vapor explosion criteria indicates that in general sense, a consensus of opinion is emerging on the conditions applicable to explosive vaporization. Experimental and theoretical work has lead a number of investigators to the formulation of such conditions which are quite similar in many respects, although the quantitative details of the model formulation of such conditions are somewhat different. All model concepts are consistent in that an initial period of stable film boiling, separating molten fuel from coolant, is considered necessary (at least for large-scale interactions and efficient intermixing), with subsequent breakdown of film boiling due to pressure and/or thermal effects, followed by intimate fuel-coolant contact and a rapid vaporization process which is sufficient to cause shock pressurization. Although differences arise as to the conditions for and the energetics associated with film boiling destabilization and the mode and energetics of fragmentation and intermixing. However, the principal area of difference seems to be the question of what constitutes the requisite condition(s) for rapid vapor production to cause shock pressurization

A heated vapor cell unit for DAVLL in atomic rubidium

OpenAIRE

McCarron, Daniel J.; Hughes, Ifan G.; Tierney, Patrick; Cornish, Simon L.

2007-01-01

The design and performance of a compact heated vapor cell unit for realizing a dichroic atomic vapor laser lock (DAVLL) for the D2 transitions in atomic rubidium is described. A 5 cm-long vapor cell is placed in a double-solenoid arrangement to produce the required magnetic field; the heat from the solenoid is used to increase the vapor pressure and correspondingly the DAVLL signal. We have characterized experimentally the dependence of important features of the DAVLL signal on magnetic field...

Vapor pressures and thermophysical properties of selected monoterpenoids

Czech Academy of Sciences Publication Activity Database

Štejfa, V.; Dergal, F.; Mokbel, I.; Fulem, Michal; Jose, J.; Růžička, K.

2015-01-01

Roč. 406, Nov (2015), 124-133 ISSN 0378-3812 Institutional support: RVO:68378271 Keywords : monoterpenoids * vapor pressure * heat capacity * ideal - gas thermodynamic properties * vaporization and sublimation enthalpy Subject RIV: BJ - Thermodynamics Impact factor: 1.846, year: 2015

Water vapor estimation using digital terrestrial broadcasting waves

Science.gov (United States)

Kawamura, S.; Ohta, H.; Hanado, H.; Yamamoto, M. K.; Shiga, N.; Kido, K.; Yasuda, S.; Goto, T.; Ichikawa, R.; Amagai, J.; Imamura, K.; Fujieda, M.; Iwai, H.; Sugitani, S.; Iguchi, T.

2017-03-01

A method of estimating water vapor (propagation delay due to water vapor) using digital terrestrial broadcasting waves is proposed. Our target is to improve the accuracy of numerical weather forecast for severe weather phenomena such as localized heavy rainstorms in urban areas through data assimilation. In this method, we estimate water vapor near a ground surface from the propagation delay of digital terrestrial broadcasting waves. A real-time delay measurement system with a software-defined radio technique is developed and tested. The data obtained using digital terrestrial broadcasting waves show good agreement with those obtained by ground-based meteorological observation. The main features of this observation are, no need for transmitters (receiving only), applicable wherever digital terrestrial broadcasting is available and its high time resolution. This study shows a possibility to estimate water vapor using digital terrestrial broadcasting waves. In the future, we will investigate the impact of these data toward numerical weather forecast through data assimilation. Developing a system that monitors water vapor near the ground surface with time and space resolutions of 30 s and several kilometers would improve the accuracy of the numerical weather forecast of localized severe weather phenomena.

Numerical modeling of a vaporizing multicomponent droplet

Science.gov (United States)

Megaridis, C. M.; Sirignano, W. A.

The fundamental processes governing the energy, mass, and momentum exchange between the liquid and gas phases of vaporizing, multicomponent liquid droplets have been investigated. The axisymmetric configuration under consideration consists of an isolated multicomponent droplet vaporizing in a convective environment. The model considers different volatilities of the liquid components, variable liquid properties due to variation of the species concentrations, and non-Fickian multicomponent gaseous diffusion. The bicomponent droplet model was employed to examine the commonly used assumptions of unity Lewis number in the liquid phase and Fickian gaseous diffusion. It is found that the droplet drag coefficients, the vaporization rates, and the related transfer numbers are not influenced by the above assumptions in a significant way.

Software for the design of acoustical steam silencers of the reaction-absorption type; Software para el diseno de silenciadores acusticos de vapor del tipo reaccion-absorcion

Energy Technology Data Exchange (ETDEWEB)

Buendia Dominguez, Eduardo H; Alvarez Chavez, Jose M [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1990-12-31

This paper describes the computer program named SILRA, that determines the outline dimensions of an acoustic steam silencer of the reaction-absorption type. These silencers are employed in the geothermoelectric power plants to lower the high levels of pressure and sound caused by the steam discharge to the surrounding atmosphere. The program has the capacity of predicting the noise level generated by the discharge without silencer depending on the emitting source. On SIRLA was successfully coupled the theory described in specialized literature with optimization techniques and experiences acquired in former designs. SIRLA is a powerful tool that allows the designer to optimize the equipment as well as the design time. [Espanol] En este trabajo se describe el programa de computo SILRA, que determina las dimensiones generales de un silenciador acustico de vapor tipo reaccion-absorcion, estos silenciadores se emplean en las centrales geotermoelectricas para abatir los altos niveles de presion de sonido provocados por la descarga del vapor a la atmosfera. El programa tiene la capacidad de predecir el nivel de ruido que genera la descarga sin silenciador, dependiendo de la fuente emisora. En SILRA se acoplaron con exito la teoria descrita en la literatura especializada con tecnicas de optimacion y experiencias adquiridas en disenos anteriores. SILRA es una poderosa herramienta que permite al disenador optimar tanto el equipo como el tiempo de diseno.

Software for the design of acoustical steam silencers of the reaction-absorption type; Software para el diseno de silenciadores acusticos de vapor del tipo reaccion-absorcion

Energy Technology Data Exchange (ETDEWEB)

Buendia Dominguez, Eduardo H.; Alvarez Chavez, Jose M. [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1989-12-31

This paper describes the computer program named SILRA, that determines the outline dimensions of an acoustic steam silencer of the reaction-absorption type. These silencers are employed in the geothermoelectric power plants to lower the high levels of pressure and sound caused by the steam discharge to the surrounding atmosphere. The program has the capacity of predicting the noise level generated by the discharge without silencer depending on the emitting source. On SIRLA was successfully coupled the theory described in specialized literature with optimization techniques and experiences acquired in former designs. SIRLA is a powerful tool that allows the designer to optimize the equipment as well as the design time. [Espanol] En este trabajo se describe el programa de computo SILRA, que determina las dimensiones generales de un silenciador acustico de vapor tipo reaccion-absorcion, estos silenciadores se emplean en las centrales geotermoelectricas para abatir los altos niveles de presion de sonido provocados por la descarga del vapor a la atmosfera. El programa tiene la capacidad de predecir el nivel de ruido que genera la descarga sin silenciador, dependiendo de la fuente emisora. En SILRA se acoplaron con exito la teoria descrita en la literatura especializada con tecnicas de optimacion y experiencias adquiridas en disenos anteriores. SILRA es una poderosa herramienta que permite al disenador optimar tanto el equipo como el tiempo de diseno.

Vaporization of tungsten-metal in steam at high temperatures

International Nuclear Information System (INIS)

Greene, G.A.; Finfrock, C.C.

2000-01-01

The vaporization of tungsten from the APT spallation target dominates the radiological source term for unmitigated target overheating accidents. Chemical reactions of tungsten with steam which persist to tungsten temperatures as low as 800 C result in the formation of a hydrated tungsten-oxide which has a high vapor pressure and is readily convected in a flowing atmosphere. This low-temperature vaporization reaction essentially removes the oxide film that forms on the tungsten-metal surface as soon as it forms, leaving behind a fresh metallic surface for continued oxidation and vaporization. Experiments were conducted to measure the oxidative vaporization rates of tungsten in steam as part of the effort to quantify the MT radiological source term for severe target accidents. Tests were conducted with tungsten rods (1/8 inch diameter, six inches long) heated to temperatures from approximately 700 C to 1350 C in flowing steam which was superheated to 140 C. A total of 19 experiments was conducted. Fifteen tests were conducted by RF induction heating of single tungsten rods held vertical in a quartz glass retort. Four tests were conducted in a vertically-mounted tube furnace for the low temperature range of the test series. The aerosol which was generated and transported downstream from the tungsten rods was collected by passing the discharged steam through a condenser. This procedure insured total collection of the steam along with the aerosol from the vaporization of the rods. The results of these experiments revealed a threshold temperature for tungsten vaporization in steam. For the two tests at the lowest temperatures which were tested, approximately 700 C, the tungsten rods were observed to oxidize without vaporization. The remainder of the tests was conducted over the temperature range of 800 C to 1350 C. In these tests, the rods were found to have lost weight due to vaporization of the tungsten and the missing weight was collected in the downstream condensate

Using in situ bioventing to minimize soil vapor extraction costs

International Nuclear Information System (INIS)

Downey, D.C.; Frishmuth, R.A.; Archabal, S.R.; Pluhar, C.J.; Blystone, P.G.; Miller, R.N.

1995-01-01

Gasoline-contaminated soils may be difficult to remediate with bioventing because high concentrations of gasoline vapors become mobile when air is injected into the soil. Because outward vapor migration is often unacceptable on small commercial sites, soil vapor extraction (SVE) or innovative bioventing techniques are required to control vapors and to increase soil gas oxygen levels to stimulate hydrocarbon biodegradation. Combinations of SVE, off-gas treatment, and bioventing have been used to reduce the costs normally associated with remediation of gasoline-contaminated sites. At Site 1, low rates of pulsed air injection were used to provide oxygen while minimizing vapor migration. At Site 2, a period of high-rate SVE and off-gas treatment was followed by long-term air injection. Site 3 used an innovative approach that combined regenerative resin for ex situ vapor treatment with in situ bioventing to reduce the overall cost of site remediation. At each of these Air Force sites, bioventing provided cost savings when compared to more traditional SVE methods

Shock wave of vapor-liquid two-phase flow

Institute of Scientific and Technical Information of China (English)

Liangju ZHAO; Fei WANG; Hong GAO; Jingwen TANG; Yuexiang YUAN

2008-01-01

The shock wave of vapor-liquid two-phase flow in a pressure-gain steam injector is studied by build-ing a mathematic model and making calculations. The results show that after the shock, the vapor is nearly com-pletely condensed. The upstream Mach number and the volume ratio of vapor have a great effect on the shock. The pressure and Mach number of two-phase shock con-form to the shock of ideal gas. The analysis of available energy shows that the shock is an irreversible process with entropy increase.

Water vapor movement in freezing aggregate base materials.

Science.gov (United States)

2014-06-01

The objectives of this research were to 1) measure the extent to which water vapor movement results in : water accumulation in freezing base materials; 2) evaluate the effect of soil stabilization on water vapor movement : in freezing base materials;...

Some empirical rules concerning the vapor pressure curve revisited

International Nuclear Information System (INIS)

Velasco, S.; White, J.A.

2014-01-01

Highlights: • A Claussius–Claperyron equation is obtained in the Pitzer corresponding states scheme. • Some well-known empirical rules for the vapor pressure are rewritten in terms of the Pitzer acentric factor. • The Guggenheim point follows the corresponding state scheme better than the normal boiling point. • The Ambrose–Walton vapor pressure equation yields excellent agreement with NIST data in all considered cases. -- Abstract: A form for the Clausius–Clapeyron vapor-pressure equation is obtained in the Pitzer corresponding states scheme. This equation allows one to rewrite the well-known Trouton, Guldberg, van Laar and Guggenheim rules in terms of the acentric factor ω. The original forms of these empirical rules are recovered for some particular values of ω. The proposed rules are checked by analyzing National Institute of Standards and Technology (NIST) data on the liquid-vapor coexistence curve for 105 fluids. These rules have been also analyzed by using the well-known Ambrose–Walton (AW) vapor pressure equation

Pretreated Butterfly Wings for Tuning the Selective Vapor Sensing

Directory of Open Access Journals (Sweden)

Gábor Piszter

2016-09-01

Full Text Available Photonic nanoarchitectures occurring in the scales of Blue butterflies are responsible for their vivid blue wing coloration. These nanoarchitectures are quasi-ordered nanocomposites which are constituted from a chitin matrix with embedded air holes. Therefore, they can act as chemically selective sensors due to their color changes when mixing volatile vapors in the surrounding atmosphere which condensate into the nanoarchitecture through capillary condensation. Using a home-built vapor-mixing setup, the spectral changes caused by the different air + vapor mixtures were efficiently characterized. It was found that the spectral shift is vapor-specific and proportional with the vapor concentration. We showed that the conformal modification of the scale surface by atomic layer deposition and by ethanol pretreatment can significantly alter the optical response and chemical selectivity, which points the way to the efficient production of sensor arrays based on the knowledge obtained through the investigation of modified butterfly wings.

Recommended vapor pressure and thermophysical data for ferrocene

Czech Academy of Sciences Publication Activity Database

Fulem, Michal; Růžička, K.; Červinka, C.; Rocha, M.A.A.; Santos, L.M.N.B.F.; Berg, R.F.

2013-01-01

Roč. 57, FEB (2013), 530-540 ISSN 0021-9614 Institutional support: RVO:68378271 Keywords : ferrocene * vapor pressure * heat capacity * ideal gas thermodynamic properties * sublimation enthalpy * recommended vapor pressure equation Subject RIV: BJ - Thermodynamics Impact factor: 2.423, year: 2013

Analysis of the transient compressible vapor flow in heat pipe

Science.gov (United States)

Jang, Jong Hoon; Faghri, Amir; Chang, Won Soon

1989-01-01

The transient compressible one-dimensional vapor flow dynamics in a heat pipe is modeled. The numerical results are obtained by using the implicit non-iterative Beam-Warming finite difference method. The model is tested for simulated heat pipe vapor flow and actual flow in cylindrical heat pipes. A good comparison of the present transient results for the simulated heat pipe vapor flow with the previous results of a two-dimensional numerical model is achieved and the steady state results are in agreement with the existing experimental data. The transient behavior of the vapor flow under subsonic, sonic, and supersonic speeds and high mass flow rates are successfully predicted. The one-dimensional model also describes the vapor flow dynamics in cylindrical heat pipes at high temperatures.

Vapor and gas sampling of single-shell tank 241-BX-110 using the in situ vapor sampling system

International Nuclear Information System (INIS)

Lockrem, L.L.

1997-01-01

The Vapor Issue Resolution Program tasked the Vapor Team (the team) to collect representative headspace samples from Hanford Site single-shell tank (SST) 241-BX-110. This document presents sampling data resulting from the April 30, 1996 sampling of SST 241-BX-110. Analytical results will be presented in a separate report issued by Pacific Northwest National Laboratory (PNNL), which supplied and analyzed the sampling media

PWFA plasma source - interferometric diagnostics for Li vapor density measurements

International Nuclear Information System (INIS)

Sivakumaran, V.; Mohandas, K.K.; Singh, Sneha; Ravi Kumar, A.V.

2015-01-01

A prototype (40 cm long) plasma source based on Li heat pipe oven has been developed for the Plasma Wakefield Acceleration (PWFA) experiments at IPR (IPR), Gujarat as a part of the ongoing Accelerator Programme. Li vapor in the oven is produced by heating solid Li in helium buffer gas. A uniform column of Li plasma is generated by UV photo ionization (193 nm) of the Li vapor in the heat pipe oven. In these experiments, an accurate measurement of Li vapor density is important as it has got a direct consequence on the plasma electron density. In the present experiment, the vapor density is measured optically by using Hook method (spectrally resolved white light interferometry). The hook like structure formed near the vicinity of the Li 670.8 nm resonance line was recorded with a white light Mach Zehnder interferometer crossed with an imaging spectrograph to estimate the Li vapor density. The vapor density measurements have been carried out as a function of external oven temperature and the He buffer gas pressure. This technique has the advantage of being insensitive to line broadening and line shape, and its high dynamic range even with optically thick absorption line. Here, we present the line integrated Lithium vapor density measurement using Hook method and also compare the same with other optical diagnostic techniques (White light absorption and UV absorption) for Li vapor density measurements. (author)

El estado actual de las vacunas contra las drogas

Directory of Open Access Journals (Sweden)

Maura Epifanía Matus Ortega

2017-12-01

Full Text Available Introducción: por lo común, la adicción a las drogas se trata con psicoterapia y farmacología que evita la unión de las sustancias psicoactivas a receptores específicos en el cerebro. El resultado de estos tratamientos no ha sido del todo satisfactorio, por lo que el desarrollo de terapias más eficaces representa un reto constante para tratar las adicciones. Una alternativa a la farmacología antiadictiva es la vacunación activa dirigida contra las sustancias de abuso. Objetivo: esta revisión reúne la información disponible sobre los fundamentos y avances científicos en la generación de una terapia inmunológica, que coadyuve al tratamiento de la adicción a sustancias como la heroína-morfina, la cocaína, la nicotina y la anfetamina. Método: se consideraron los reportes científicos disponibles en PubMed –de 2005 a abril de 2017–, sobre los fundamentos, la metodología empleada, los estudios preclínicos y clínicos, y los resultados obtenidos en dichas investigaciones para generar vacunas contra las drogas. Resultados: las vacunas lograron mitigar los efectos producidos por las sustancias en los estudios preclínicos en modelos de estudio en animales; sin embargo, con pacientes humanos los resultados no han sido del todo satisfactorios. Discusión y conclusiones: a pesar de los esfuerzos realizados por diferentes grupos de investigación y compañías farmacéuticas para generar vacunas terapéuticas contra el uso de diferentes drogas, ninguna ha alcanzado la fase III de estudios clínicos. En la actualidad, se continúa con los esfuerzos para lograr que las vacunas contra las adicciones alcancen su máxima eficiencia y eficacia, y contribuyan al tratamiento de la adicción a las drogas.

Lab-scale tests on ISV vapor transport phenomena

International Nuclear Information System (INIS)

Farnsworth, R.K.; Gardner, B.M.

1996-01-01

In situ vitrification (ISV) is a promising technology for remediating buried waste sites and contaminated soil sites. However, concerns exist that low soil permeabilities may limit vapor transport away from the advancing melt front and cause a melt expulsion that breaches ISV containment. As a result, two ISV lab tests were conducted at the Idaho National Engineering Laboratory (INEL) using INEL soil (permeability: 10 -6 cm/s) and a low permeability (10 -10 cm/s) clay material. The clay test also had a ceramic tube inserted vertically through the center of the area being melted to provide one-dimensional data on vapor transport. Results confirm that low soil permeabilities can limit vapor transport away from the advancing ISV melt front. In addition, peak pressures inside the ceramic tube were significantly greater than those outside the tube, indicating the importance of horizontal vapor transport around the advancing ISV melt front

Improvement of Oil-Vapor Treatment Facility for Wolsong Unit 3,4

International Nuclear Information System (INIS)

Kim, Jeong Guk; Kwon, S. W.; Lee, H. S.

2009-11-01

With the purpose to minimize an oil-vapor discharge to the atmosphere and to be an environmentally friendly nuclear power plant by an improvement of mist eliminator for turbine lubricant system at Wolsong Nuclear Power Plant Unit 3,4, this project - project name : Improvement of Oil-vapor Treatment Facility for Wolsong Unit 3,4 - was conducted for six months (from Apr. 15, 2009 to Oct. 14, 2009). This Project contains Oil-vapor Source and Environmental Regulation, Analysis on the Present Oil-vapor Treatment Facility, Improvement of Oil-vapor Treatment Facility, Test Facility Design, Fabrication, Installation, Test Operation, Evaluation of the Facility

Comparison of sensor characteristics of three real-time monitors for organic vapors.

Science.gov (United States)

Hori, Hajime; Ishimatsu, Sumiyo; Fueta, Yukiko; Hinoue, Mitsuo; Ishidao, Toru

2015-01-01

Sensor characteristics and performance of three real-time monitors for volatile organic compounds (VOC monitor) equipped with a photo ionization detector (PID), a sensor using the interference enhanced reflection (IER) method and a semiconductor gas sensor were investigated for 52 organic solvent vapors designated as class 1 and class 2 of organic solvents by the Ordinance of Organic Solvent Poisoning Prevention in Japan. Test vapors were prepared by injecting each liquid solvent into a 50 l Tedlar® bag and perfectly vaporizing it. The vapor concentration was from one-tenth to twice the administrative control level for all solvents. The vapor concentration was measured with the monitors and a gas chromatograph equipped with a flame ionization detector simultaneously, and the values were compared. The monitor with the PID sensor could measure many organic vapors, but it could not detect some vapors with high ionization potential. The IER sensor could also detect many vapors, but a linear response was not obtained for some vapors. A semiconductor sensor could detect methanol that could not be detected by PID and IER sensors. Working environment measurement of organic vapors by real-time monitors may be possible, but sensor characteristics and their limitations should be known.

Toxicity of vapor phase petroleum contaminants to microbial degrader communities

International Nuclear Information System (INIS)

Long, S.C.; Davey, C.A.

1994-01-01

Petroleum products constitute the largest quantity of synthetic organic chemical products produced in the US. They are comprised of mostly hydrocarbon constituents from many different chemical classes including alkenes, cycloalkanes, aromatic compounds, and polyaromatic hydrocarbons. Many petroleum constituents are classified as volatile organic compounds or VOCs. Petroleum products also constitute a major portion of environmental pollution. One emerging technology, with promise for applications to VOCs in subsurface soil environments, is bioventing coupled with soil vapor extraction. These technologies involve volatilization of contaminants into the soil gas phase by injection and withdrawal of air. This air movement causes enhancement of the aerobic microbial degradation of the mobilized vapors by the indigenous populations. This study investigated the effects of exposure of mixed, subsurface microbial communities to vapor phase petroleum constituents or vapors of petroleum mixtures. Soil slurries were prepared and plated onto mineral salts agar plates and exposed to vapor phase contaminants at equilibrium with pure product. Representative n-alkane, branched alkane, cycloalkane, and aromatic compounds were tested as well as petroleum product mixtures. Vapor exposure altered the numbers and morphologies of the colonies enumerated when compared to controls. However, even at high, equilibrium vapor concentrations, microbial degrader populations were not completely inhibited

Gas Separation Using Organic-Vapor-Resistent Membranes In Conjunctin With Organic-Vapor-Selective Membranes

Science.gov (United States)

Baker, Richard W.; Pinnau, Ingo; He, Zhenjie; Da Costa, Andre R.; Daniels, Ramin; Amo, Karl D.; Wijmans, Johannes G.

2003-06-03

A process for treating a gas mixture containing at least an organic compound gas or vapor and a second gas, such as natural gas, refinery off-gas or air. The process uses two sequential membrane separation steps, one using membrane selective for the organic compound over the second gas, the other selective for the second gas over the organic vapor. The second-gas-selective membranes use a selective layer made from a polymer having repeating units of a fluorinated polymer, and demonstrate good resistance to plasticization by the organic components in the gas mixture under treatment, and good recovery after exposure to liquid aromatic hydrocarbons. The membrane steps can be combined in either order.

Las momias de las pirámides

Directory of Open Access Journals (Sweden)

José Miguel Parra

2011-01-01

Full Text Available El público general cree, como si fuera un dogma religioso, que las pirámides egipcias no fueron las tumbas de los faraones de los Reino Antiguo y Medio porque en ninguna de las cámaras funerarias se ha encontrado nunca una momia. Este estudio compila todos los datos relevantes al respecto y describe brevemente todos los restos humanos encontrados dentro de las pirámides, demostrando la falta de base de esa extendida creencia.As a religious dogma the general public believe that the Egyptian pyramids were not the tombs for the Old and Middle Kingdom pharaohs, because never was a mummy found inside the burial chamber of any of them. This study just compile all the relevant data on the subject and describe briefly all the human remains found in the pyramids, showing the nonsense of the general belief.

Microstructure of vapor deposited coatings on curved substrates

Energy Technology Data Exchange (ETDEWEB)

Rodgers, Theron M.; Zhao, Hengbei; Wadley, Haydn N. G., E-mail: haydn@virginia.edu [Department of Materials Science and Engineering, University of Virginia, 395 McCormick Rd., P.O. Box 400745, Charlottesville, Virginia 22904 (United States)

2015-09-15

Thermal barrier coating systems consisting of a metallic bond coat and ceramic over layer are widely used to extend the life of gas turbine engine components. They are applied using either high-vacuum physical vapor deposition techniques in which vapor atoms rarely experience scattering collisions during propagation to a substrate, or by gas jet assisted (low-vacuum) vapor deposition techniques that utilize scattering from streamlines to enable non-line-of-sight deposition. Both approaches require substrate motion to coat a substrate of complex shape. Here, direct simulation Monte Carlo and kinetic Monte Carlo simulation methods are combined to simulate the deposition of a nickel coating over the concave and convex surfaces of a model airfoil, and the simulation results are compared with those from experimental depositions. The simulation method successfully predicted variations in coating thickness, columnar growth angle, and porosity during both stationary and substrate rotated deposition. It was then used to investigate a wide range of vapor deposition conditions spanning high-vacuum physical vapor deposition to low-vacuum gas jet assisted vapor deposition. The average coating thickness was found to increase initially with gas pressure reaching a maximum at a chamber pressure of 8–10 Pa, but the best coating thickness uniformity was achieved under high vacuum deposition conditions. However, high vacuum conditions increased the variation in the coatings pore volume fraction over the surface of the airfoil. The simulation approach was combined with an optimization algorithm and used to investigate novel deposition concepts to tailor the local coating thickness.

Microstructure of vapor deposited coatings on curved substrates

International Nuclear Information System (INIS)

Rodgers, Theron M.; Zhao, Hengbei; Wadley, Haydn N. G.

2015-01-01

Thermal barrier coating systems consisting of a metallic bond coat and ceramic over layer are widely used to extend the life of gas turbine engine components. They are applied using either high-vacuum physical vapor deposition techniques in which vapor atoms rarely experience scattering collisions during propagation to a substrate, or by gas jet assisted (low-vacuum) vapor deposition techniques that utilize scattering from streamlines to enable non-line-of-sight deposition. Both approaches require substrate motion to coat a substrate of complex shape. Here, direct simulation Monte Carlo and kinetic Monte Carlo simulation methods are combined to simulate the deposition of a nickel coating over the concave and convex surfaces of a model airfoil, and the simulation results are compared with those from experimental depositions. The simulation method successfully predicted variations in coating thickness, columnar growth angle, and porosity during both stationary and substrate rotated deposition. It was then used to investigate a wide range of vapor deposition conditions spanning high-vacuum physical vapor deposition to low-vacuum gas jet assisted vapor deposition. The average coating thickness was found to increase initially with gas pressure reaching a maximum at a chamber pressure of 8–10 Pa, but the best coating thickness uniformity was achieved under high vacuum deposition conditions. However, high vacuum conditions increased the variation in the coatings pore volume fraction over the surface of the airfoil. The simulation approach was combined with an optimization algorithm and used to investigate novel deposition concepts to tailor the local coating thickness

Vacuum distillation/vapor filtration water recovery

Science.gov (United States)

Honegger, R. J.; Neveril, R. B.; Remus, G. A.

1974-01-01

The development and evaluation of a vacuum distillation/vapor filtration (VD/VF) water recovery system are considered. As a functional model, the system converts urine and condensates waste water from six men to potable water on a steady-state basis. The system is designed for 180-day operating durations and for function on the ground, on zero-g aircraft, and in orbit. Preparatory tasks are summarized for conducting low gravity tests of a vacuum distillation/vapor filtration system for recovering water from urine.

Las mejores prácticas de las organizaciones y los profesionales

Directory of Open Access Journals (Sweden)

Robert L. SCHALOCK

2015-03-01

Full Text Available Este artículo se centra en las prácticas basadas en la evidencia y, sobre esta base, hacemos una invitación a que busquemos entre todos cuáles son las mejores prácticas, quién es el profesional más adecuado y qué significa ser una organización eficaz y eficiente. Tanto los profesionales como las organizaciones ofrecen servicios y apoyos que contribuyen a mejorar el bienestar y el crecimiento personal de los usuarios. En el contexto de la discusión sobre las prácticas profesionales y de las organizaciones, indicaré que las mejores prácticas profesionales empiezan con el respeto hacia las personas, el cumplimiento de los estándares y las normas éticas y deontológicas, y la utilización de las prácticas basadas en la evidencia y de la evaluación del efecto y de los resultados conseguidos. Indicaré, asimismo, que las mejores prácticas de la organización empiezan con el compromiso de ser una entidad basada en valores y, a la vez, de ser eficaz y eficiente en la prestación de los servicios y apoyos. Este compromiso de la organización se refleja en el uso de las mejores prácticas, que consisten en la utilización de equipos de alto rendimiento, en el paradigma de los apoyos, en la evaluación de los resultados obtenidos y en la mejora continua de la calidad.Como se observa en la Figura 1, examinaremos cada uno de los componentes de las mejores prácticas profesionales y de las organizaciones. Además, indicaré que, a través de su acción recíproca, las mejores prácticas de los profesionales y de las organizaciones generan un entorno cultural que tiene un efecto directo, no solo en la mejora de los servicios y apoyos que la organización ofrece a los usuarios, sino también en el bienestar y crecimiento personal del personal de la organización, lo cual, a su vez, redunda en un aumento de su eficacia y eficiencia.

Optimum design of vaporizer fin with liquefied natural gas by numerical analysis

International Nuclear Information System (INIS)

Jeong, Hyo Min; Chung, Han Shik; Lee, Sang Chul; Kong, Tae Woo; Yi, Chung Seub

2006-01-01

Generally, the temperature drop under 0 .deg. C on vaporizer surface creates frozen dews. This problem seems to increase as the time progress and humidity rises. In addition, the frozen dews create frost deposition. Consequently, heat transfer on vaporizer decreases because frost deposition causes adiabatic condition. Therefore, it is very important to solve this problem. This paper aims to study of the optimum design of used vaporizer at local LNG station. In this paper, experimental results were compared with numerical results. Geometries of numerical and experimental vaporizers were identical. Studied parameters of vaporizer are angle between two fins (Φ) and fin thickness (TH F ). Numerical analysis results were presented through the correlations between the ice layer thickness (TH ICE ) on the vaporizer surface to the temperature distribution of inside vaporizer (T IN ), fin thickness (TH F ), and angle between two fins (Φ). Numerical result shows good agreement with experimental outcome. Finally, the correlations for optimum design of vaporizer are proposed on this paper

Thermal plasma chemical vapor deposition

International Nuclear Information System (INIS)

Heberlein, J.; Pfender, E.

1993-01-01

Thermal plasmas, with temperatures up to and even exceeding 10 4 K, are capable of producing high density vapor phase precursors for the deposition of relatively thick films. Although this technology is still in its infancy, it will fill the void between the relatively slow deposition processes such as physical vapor deposition and the high rate thermal spray deposition processes. In this chapter, the present state-of-the-art of this field is reviewed with emphasis on the various types of reactors proposed for this emerging technology. Only applications which attracted particular attention, namely diamond and high T c superconducting film deposition, are discussed in greater detail. (orig.)

System of aid for the starting of the steam generator of a thermoelectric unit; Sistema de ayuda para el arranque del generador de vapor de una unidad termoelectrica

Energy Technology Data Exchange (ETDEWEB)

Quintero R, Agustin; Suarez C, Dionisio A; Aquino E, Juan C; Diaz H, Carlos A; Cruz T, Jorge A; Sanchez L, Jose A [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2002-07-01

This article presents the development of an on line aid system, whose objective is to aid the operator of a thermoelectric unit, providing the information that is required to carry out the heating and pressurization of the steam generator in the shortest possible time. The former takes place respecting the operation limits determined by the manufacturer and the conditions of security established to carry out the maneuvers of operation of the equipment. The system incorporates a scheme of predictive control, based on a neuronal model that estimates the optimal position of two final elements of control to fulfill with the curves of reference for the temperature and pressure of the main steam. The system is based on an architecture client-server and uses technology Web for the access of the information through a navigator of the Internet. [Spanish] Este articulo presenta el desarrollo de un sistema de ayuda en linea, cuyo objetivo es asistir al operador de una unidad termoelectrica, proporcionando la informacion que requiere para llevar a cabo el calentamiento y presurizacion del generador de vapor en el menor tiempo posible. Lo anterior se efectua respetando los limites de operacion determinados por el fabricante y las condiciones de seguridad establecidas para efectuar las maniobras de operacion de los equipos. El sistema incorpora un esquema de control predictivo, basado en un modelo neuronal, que estima la posicion optima de dos elementos finales de control para cumplir con las curvas de referencia para la temperatura y presion del vapor principal. El sistema esta basado en una arquitectura cliente-servidor y utiliza tecnologia Web para el acceso a la informacion a traves de un navegador del Internet.

Intelligent support system online for the operation of fossil fuel units; Sistema inteligente de ayuda en linea para la operacion de unidades termoelectricas

Energy Technology Data Exchange (ETDEWEB)

Quintero R, Agustin; Suarez C, Dionisio A; Sanchez L, Jose Alfredo [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2006-07-01

The purpose of this publication is to present a support system online for the operation (SAO) of fossil fuel units, having as objective to support the operator of fossil fuel units when handling guidelines and essential information to carry out the starting and shutdown in a safe and efficient way, reducing the consumption of the useful life of the steam generator and the turbine, as well as the operational cost. Here are presented the intelligent systems for the support of the operation and are described the main characteristics in the dominion of application for the support system, its architecture and functionality, as well as the results obtained in the system assessment performed with the aid of total reach simulator of a fossil fuel unit and a pilot unit. [Spanish] Es motivo de esta publicacion, la presentacion de un sistema de ayuda en linea para la operacion (SAO) de unidades termoelectricas que tiene como objetivo asistir al operador de una unidad termoelectrica con guias de manejo e informacion esencial para llevar a cabo el arranque o paro en forma segura y eficiente, reducir el consumo de vida util del generador de vapor y la turbina, asi como el costo de operacion. Aqui se presentan los sistemas inteligentes de ayuda a la operacion y se describen las caracteristicas principales del dominio de aplicacion para el sistema de ayuda, su arquitectura y funcionalidad, asi como los resultados obtenidos de la evaluacion del sistema realizada con la ayuda de un simulador de alcance total de una unidad termoelectrica y una unidad piloto.

A FGGE water vapor wind data set

Science.gov (United States)

Stewart, Tod R.; Hayden, Christopher M.

1985-01-01

It has been recognized for some time that water vapor structure visible in infrared imagery offers a potential for obtaining motion vectors when several images are considered in sequence (Fischer et al., 1981). A study evaluating water vapor winds obtained from the VISSR atmospheric sounder (Stewart et al., 1985) has confirmed the viability of the approach. More recently, 20 data sets have been produced from METEOSAT water vapor imagery for the FGGE period of 10-25 November 1979. Where possible, two data sets were prepared for each day at 0000 and 1200 GMT and compared with rawinsondes over Europe, Africa, and aircraft observations over the oceans. Procedures for obtaining winds were, in general, similar to the earlier study. Motions were detected both by a single pixel tracking and a cross correlation method by using three images individually separated by one hour. A height assignment was determined by matching the measured brightness temperature to the temperature structure represented by the FGGE-IIIB analyses. Results show that the METEOSAT water vapor winds provide uniform horizontal coverage of mid-level flow over the globe with good accuracy.

Uranium/water vapor reactions in gaseous atmospheres

International Nuclear Information System (INIS)

Jackson, R.L.; Condon, J.B.; Steckel, L.M.

1977-07-01

Experiments have been performed to determine the effect of varying humidities, gaseous atmospheres, and temperatures on the uranium/water vapor reaction. A balance, which allowed continuous in-system weighings, was used to determine the rates of the uranium/water vapor reactions at water vapor pressures of 383, 1586, and 2853 Pa and at temperatures of 80, 100, and 150 0 C in atmospheres of hydrogen, argon, or argon/oxygen mixtures. Based on rate data, the reactions were characterized as hydriding or nonhydriding. Hydriding reactions were found to be preferred in moist hydrogen systems at the higher temperatures and the lower humidities. The presence of hydrogen in hydriding systems was found to initially inhibit the reaction, but causes an acceleration of the rate in the final stages. In general, reaction rates of hydriding systems approached the hydriding rates calculated and observed in dry hydrogen. Hydriding and nonhydriding reaction rates showed a positive correlation to temperature and water vapor pressure. Final reaction rates in moist argon/oxygen mixtures of 1.93, 4.57, and 9.08 mole percent oxygen were greater than the rates observed in moist hydrogen or argon. Final reaction rates were negatively correlated to the oxygen concentration

Multicomponent droplet vaporization in a convecting environment

International Nuclear Information System (INIS)

Megaridis, C.M.; Sirignano, W.A.

1990-01-01

In this paper a parametric study of the fundamental exchange processes for energy, mass and momentum between the liquid and gas phases of multicomponent liquid vaporizing droplets is presented. The model, which examines an isolated, vaporizing, multicomponent droplet in an axisymmetric, convecting environment, considers the different volatilities of the liquid components, the alteration of the liquid-phase properties due to the spatial/temporal variations of the species concentrations and also the effects of multicomponent diffusion. In addition, the model accounts for variable thermophysical properties, surface blowing and droplet surface regression due to vaporization, transient droplet heating with internal liquid circulation, and finally droplet deceleration with respect to the free flow due to drag. The numerical calculation employs finite-difference techniques and an iterative solution procedure that provides time-varying spatially-resolved data for both phases. The effects of initial droplet composition, ambient temperature, initial Reynolds number (based on droplet diameter), and volatility differential between the two liquid components are investigated for a liquid droplet consisting of two components with very different volatilities. It is found that mixtures with higher concentration of the less volatile substance actually vaporize faster on account of intrinsically higher liquid heating rates

Gasoline Reid Vapor Pressure

Science.gov (United States)

EPA regulates the vapor pressure of gasoline sold at retail stations during the summer ozone season to reduce evaporative emissions from gasoline that contribute to ground-level ozone and diminish the effects of ozone-related health problems.

Indagando en la relevancia de Internet en el acceso, uso y deseos de las TIC por parte de las mujeres en las TIC

Directory of Open Access Journals (Sweden)

Núria VERGÉS BOSCH

2011-07-01

Full Text Available A partir de los años 90 las teorías feministas de la tecnología experimentan un optimismo renovado con la aparición de las TIC y el desarrollo de la tercera ola feminista. Sin embargo, la investigación en género y tecnología se ha centrado en estudiar la exclusión de las mujeres de las TIC e, inversamente, las experiencias de las mujeres y sus estrategias para incluirse en las TIC han recibido menos atención. Motivadas por nuestras experiencias tecnoactivistas y la observación de una remarcable presencia de mujeres en ellas, con Donestech, iniciamos un proyecto de investigación sobre los accesos, usos y deseos de las mujeres en las TIC. A través de una investigación ciberfeminista recogimos, analizamos y visibilizamos las experiencias y opiniones de las mujeres en las TIC. Nuestros resultados sugieren que las trayectorias de inclusión y acceso de las mujeres en las TIC son diversas, así como heterogéneos son los usos que hacen de ellas, destacando el rol jugado por Internet en todo ello. Además mostramos que las mujeres en las TIC son curiosas y entusiastas, que quieren empoderarse y compartir el conocimiento. Finalmente, les disgusta y desconfían de las relaciones de poder existentes en los mundos tecnológicos, manteniendo una actitud crítica y creativa hacia las TIC.

Water vapor and Gas Transport through Polymeric Membranes

NARCIS (Netherlands)

Metz, S.J.

2003-01-01

Water vapor transport through polymeric materials plays an important role in a large number of applications such as: food packaging, breathable clothing, roofing membranes, diapers, and the removal of water vapor from gas streams (e.g. dehydration of natural gas or the drying of compressed air).

Vaporization of fault water during seismic slip

Science.gov (United States)

Chen, Jianye; Niemeijer, André R.; Fokker, Peter A.

2017-06-01

Laboratory and numerical studies, as well as field observations, indicate that phase transitions of pore water might be an important process in large earthquakes. We present a model of the thermo-hydro-chemo-mechanical processes, including a two-phase mixture model to incorporate the phase transitions of pore water, occurring during fast slip (i.e., a natural earthquake) in order to investigate the effects of vaporization on the coseismic slip. Using parameters from typical natural faults, our modeling shows that vaporization can indeed occur at the shallow depths of an earthquake, irrespective of the wide variability of the parameters involved (sliding velocity, friction coefficient, gouge permeability and porosity, and shear-induced dilatancy). Due to the fast kinetics, water vaporization can cause a rapid slip weakening even when the hydrological conditions of the fault zone are not favorable for thermal pressurization, e.g., when permeability is high. At the same time, the latent heat associated with the phase transition causes the temperature rise in the slip zone to be buffered. Our parametric analyses reveal that the amount of frictional work is the principal factor controlling the onset and activity of vaporization and that it can easily be achieved in earthquakes. Our study shows that coseismic pore fluid vaporization might have played important roles at shallow depths of large earthquakes by enhancing slip weakening and buffering the temperature rise. The combined effects may provide an alternative explanation for the fact that low-temperature anomalies were measured in the slip zones at shallow depths of large earthquakes.

Technical and environmental aspects of combined cycle power stations with integrated gasification (CCGI); Aspectos tecnicos y medioambientales de las centrales de ciclo combinado con gasificacion integrada (CCGI)

Energy Technology Data Exchange (ETDEWEB)

Beltran Mora, Hector Alejandro; Urias Romero, Francisco [Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

2004-06-15

liquido a estado gaseoso mediante una oxidacion parcial y el gas obtenido de este proceso se llama gas de sintesis (syngas, por sus siglas en ingles) que es utilizado en Centrales de Ciclo Combinado como sustituto del gas natural. Se muestran tambien los demas componentes de este tipo de centrales como la unidad separadora de aire y se detallan algunas de las modificaciones que se deben de hacer para adaptar una turbina de gas para que utilice syngas y las consideraciones de su integracion con la unidad separadora de aire para optimizar la operacion de la planta. Se muestra una comparacion de valores de eficiencia de las centrales CCGI con las carboeletricas convencionales y con las centrales de ciclo combinado que utilizan gas natural. Finalmente se analizan las emisiones de contaminates de SO{sub 2}, NO{sub x} y CO{sub 2}. Se estudia la posibilidad de utilizar combustibles como coque de petroleo y residuos de vacio que se producen en la refineria de Cadereyta para la posible construccion de una central CCGI en Mexico.

Drag Reduction by Leidenfrost Vapor Layers

KAUST Repository

Vakarelski, Ivan Uriev

2011-05-23

We demonstrate and quantify a highly effective drag reduction technique that exploits the Leidenfrost effect to create a continuous and robust lubricating vapor layer on the surface of a heated solid sphere moving in a liquid. Using high-speed video, we show that such vapor layers can reduce the hydrodynamic drag by over 85%. These results appear to approach the ultimate limit of drag reduction possible by different methods based on gas-layer lubrication and can stimulate the development of related energy saving technologies.

Performance assessment of the In-Well Vapor-Stripping System

Energy Technology Data Exchange (ETDEWEB)

Gilmore, T.J.; White, M.D.; Spane, F.A. Jr. [and others

1996-10-01

In-well vapor stripping is a remediation technology designed to preferentially extract volatile organic compounds dissolved in groundwater by converting them to a vapor phase and then treating the vapor. This vapor-stripping system is distinctly different from the more traditional in situ air-sparging concept. In situ sparging takes place in the aquifer formation; in-well vapor stripping takes place within the well casing. The system was field demonstrated at Edwards Air Force Base, California; the first-time demonstration of this technology in the United States. Installation and testing of the system were completed in late 1995, and the demonstration was operated nearly continuously for 6 months (191 days) between January 16 and July 25, 1996. Postdemonstration hydrochemical sampling continued until September 1996. The demonstration was conducted by collaborating researchers from Pacific Northwest National Laboratory (a) and Stanford University as part of an interim cleanup action at the base. Edwards Air Force Base and its environmental subcontractor, Earth Technology Corporation, as well as EG&G Environmental, holders of the commercial rights to the technology, were also significant contributors to the demonstration.

Measurement and analysis of transient vaporization in oxide fuel materials

International Nuclear Information System (INIS)

Gorham-Bergeron, E.; Benson, D.A.

1978-01-01

A series of experiments is described in which samples are heated to produce high vapor pressure states in times of 10 -6 to 10 -3 seconds. Experimental measurements of vapor pressures over fresh UO 2 from the pulsed electron beam and pulsed reactor heating tests are presented and compared with other high temperature data. The interpretation of the vapor pressures measured in the tests is discussed in detail. Effects of original sample stoichiometry, chemical interactions with the container and non-equilibrium evaporation due to induced temperature gradients are discussed. Special attention is given to dynamic behavior in rapid heating and vaporization of the oxide due to chemical nonequilibrium. Finally, similar projected reactor experiments on irradiated fuel are described and vapor pressure predictions made using available equilibrium models. A discussion of information accessible from such future tests and its importance is presented

Ammonia IR Absorbance Measurements with an Equilibrium Vapor Cell

National Research Council Canada - National Science Library

Field, Paul

2004-01-01

Infrared (IR) absorbance spectra were acquired for 18 ammonia vapor pressures. The vapor pressures were generated with 15 gravimetrically prepared aqueous solutions and three commercial aqueous solutions using a dynamic method I.E...

Razones por las que los alumnos universitarios no utilizan las redes sociales

Directory of Open Access Journals (Sweden)

Zeynep Turan

2013-08-01

Full Text Available Aunque las redes sociales (los SRS, especialmente Facebook se han popularizado entre la juventud, hay algunos alumnos universitarios que no desean participar en ellas. Esta investigación explora las razones subyacentes por las cuales los alumnos universitarios no utilizan las redes sociales. El grupo experimental (n=20 estuvo formado por alumnos de licenciatura de entre 18 y 25 años, seleccionados mediante muestreo intencional. Se recogieron los datos en dos grandes universidades estatales de Turquía. Facebook fue seleccionado para contextualizar esta investigación, por ser una de las redes sociales más populares. Los métodos de investigación cualitativa se emplearon en la recogida y análisis de los datos. Entre las razones principales por las que no utilizan las redes sociales se encuentran su percepción como una pérdida de tiempo, o una herramienta innecesaria; las posibilidades de poder conllevar una adicción; violar las normas de privacidad, compartir información excesiva; e invocar la preocupación parental. Adicionalmente, los resultados indicaron que la mayoría de los alumnos no confió en sus amistades virtuales y que no les gustaba compartir fotografías ni opiniones políticas en línea. El haber identificado las actitudes hacia los SRS de los alumnos nousuarios nos ayudará a entender mejor las percepciones y experiencias individuales relacionadas con estos servicios sociales.

Solid vapor pressure for five heavy PAHs via the Knudsen effusion method

International Nuclear Information System (INIS)

Fu Jinxia; Suuberg, Eric M.

2011-01-01

Highlights: → We report on vapor pressures and enthalpies of fusion and sublimation of five heavy PAHs. → Solid vapor pressures were measured using Knudsen effusion method. → Solid vapor pressures for benzo[b]fluoranthene, and indeno[1,2,3-cd]pyrene have not been published in the open literature. → Reported subcooled liquid state vapor pressures may or may not lend themselves to correction to sublimation vapor pressure. → Subcooled liquid state vapor pressures might sometimes actually be closer to actual solid state sublimation vapor pressures. - Abstract: Polycyclic aromatic hydrocarbons (PAHs) are compounds resulting from incomplete combustion and many fuel processing operations, and they are commonly found as subsurface environmental contaminants at sites of former manufactured gas plants. Knowledge of their vapor pressures is the key to predict their fate and transport in the environment. The present study involves five heavy PAHs, i.e. benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[ghi]perylene, indeno[1,2,3-cd]pyrene, and dibenz[a,h]anthracene, which are all as priority pollutants classified by the US EPA. The vapor pressures of these heavy PAHs were measured by using Knudsen effusion method over the temperature range of (364 to 454) K. The corresponding values of the enthalpy of sublimation were calculated from the Clausius-Clapeyron equation. The enthalpy of fusion for the five PAHs was also measured by using differential scanning calorimetry and used to convert earlier published sub-cooled liquid vapor pressure data to solid vapor pressure in order to compare with the present results. These adjusted values do not agree with the present measured actual solid vapor pressure values for these PAHs, but there is good agreement between present results and other earlier published sublimation data.

La intangibilidad de las acciones privadas de las personas

Directory of Open Access Journals (Sweden)

Mauricio Maldonado Muñoz

2014-03-01

Full Text Available En este artículo pretendemos acercarnos a una garantía que —siguiendo cierta doctrina— hemos llamado: intangibilidad de las acciones privadas de las personas. Desde una visión que busca ser omnicomprensiva, se analizan las fuentes de las que mana la privacidad y, posteriormente, su contenido y alcances. Sobre todo, se analiza el problema de los límites de la injerencia y regulación estatal, partiendo de una posición que niega las visiones comunitaristas. En general, se trata de conceptualizar a la garantía planteada desde el punto de vista de la libertad, el derecho y las virtudes humanas, los derechos de terceros y la moral pública; concretando su vinculación con otros derechos relacionados con la privacidad. La idea central del presente trabajo consiste en demostrar la transversalidad de la garantía señalada, implicando —en ese proceso— cuestiones trascendentes para la filosofía del derecho, la teoría del derecho y, por supuesto, para el estudio del derecho de los derechos humanos.  

Review of literature on the asymmetric collapse of vapor bubbles

International Nuclear Information System (INIS)

Fremd, R.; Froehlich, G.

1977-06-01

This report contains a review of literature on the asymmetric collape of vapor bubbles by cavitation with special consideration to vapor explosions. Two numerical models, which describe the collapse of cavities in the neighbourhood of a solid surface, are presented. Moreover experimental results for this case are provided. Propositions to apply the numerical models to vapor explosions are made. (orig.) [de

Apparatus to measure vapor pressure, differential vapor pressure, liquid molar volume, and compressibility of liquids and solutions to the critical point. Vapor pressures, molar volumes, and compressibilities of protiobenzene and deuteriobenzene at elevated temperatures

International Nuclear Information System (INIS)

Kooner, Z.S.; Van Hook, W.A.

1986-01-01

An apparatus designed to measure vapor pressure differences between two similar liquids, such as isotopic isomers, or between a solution and its reference solvent at temperatures and pressures extending to the critical point is described. Vapor-phase volume is minimized and pressure is transmitted to the transducer through the liquid, thereby avoiding several experimental difficulties. Liquid can be injected into the heated part of the system by volumetrically calibrated screw injectors, thus permitting measurements of liquid molar volume, compressibility, and expansivity. The addition of a high-pressure circulating pump and injection valve allows the apparatus to be employed as a continuous dilution differential vapor pressure apparatus for determining partial molar free energies of solution. In the second part of the paper data on the vapor pressure, molar volume, compressibility, and expansivity and their isotope effects for C 6 H 6 and C 6 D 6 from room temperature to near the critical temperature are reported

Importance Profiles for Water Vapor

Science.gov (United States)

Mapes, Brian; Chandra, Arunchandra S.; Kuang, Zhiming; Zuidema, Paquita

2017-11-01

Motivated by the scientific desire to align observations with quantities of physical interest, we survey how scalar importance functions depend on vertically resolved water vapor. Definitions of importance begin from familiar examples of water mass I m and TOA clear-sky outgoing longwave flux I OLR, in order to establish notation and illustrate graphically how the sensitivity profile or "kernel" depends on whether specific humidity S, relative humidity R, or ln( R) are used as measures of vapor. Then, new results on the sensitivity of convective activity I con to vapor (with implied knock-on effects such as weather prediction skill) are presented. In radiative-convective equilibrium, organized (line-like) convection is much more sensitive to moisture than scattered isotropic convection, but it exists in a drier mean state. The lesson for natural convection may be that organized convection is less susceptible to dryness and can survive and propagate into regions unfavorable for disorganized convection. This counterintuitive interpretive conclusion, with respect to the narrow numerical result behind it, highlights the importance of clarity about what is held constant at what values in sensitivity or susceptibility kernels. Finally, the sensitivities of observable radiance signals I sig for passive remote sensing are considered. While the accuracy of R in the lower free troposphere is crucial for the physical importance scalars, this layer is unfortunately the most difficult to isolate with passive remote sensing: In high emissivity channels, water vapor signals come from too high in the atmosphere (for satellites) or too low (for surface radiometers), while low emissivity channels have poor altitude discrimination and (in the case of satellites) are contaminated by surface emissions. For these reasons, active ranging (LiDAR) is the preferred observing strategy.

The tracking of interfaces in an electron-beam vaporizer

International Nuclear Information System (INIS)

Westerberg, K.W.; McClelland, M.A.; Finlayson, B.A.

1993-03-01

A numerical analysis is made of the material and energy flow in an electron beam vaporizer. In this system the energy from an electron beam heats metal confined in a water-cooled crucible. Metal is vaporized from a liquid pool circulating in a shell of its own solid. A modified Galerkin finite element method is used to calculate the flow and temperature fields along with the interface locations. The mesh is parameterized with spines which stretch and pivot as the phase boundaries move. The discretized equations are arranged in an ''arrow'' matrix and solved using the Newton-Raphson method. Results are given for an experimental aluminum vaporizer. The effects of buoyancy and capillary driven flow are included along with the surface contributions of vapor thrust, latent heat, thermal radiation, and crucible contact resistance

Investigation of odd-order nonlinear susceptibilities in atomic vapors

Energy Technology Data Exchange (ETDEWEB)

Yan, Yaqi [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi’an Jiaotong University, Xi’an 710049 (China); Shaanxi Key Laboratory of Information Photonic Technique, Xi’an Jiaotong University, Xi’an 710049 (China); Teaching and Research Section of Maths and Physics, Guangzhou Commanding Academy of Chinese People’s Armed Police Force, Guangzhou, 510440 (China); Wu, Zhenkun; Si, Jinhai; Yan, Lihe; Zhang, Yiqi; Yuan, Chenzhi; Sun, Jia [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi’an Jiaotong University, Xi’an 710049 (China); Shaanxi Key Laboratory of Information Photonic Technique, Xi’an Jiaotong University, Xi’an 710049 (China); Zhang, Yanpeng, E-mail: ypzhang@mail.xjtu.edu.cn [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi’an Jiaotong University, Xi’an 710049 (China); Shaanxi Key Laboratory of Information Photonic Technique, Xi’an Jiaotong University, Xi’an 710049 (China)

2013-06-15

We theoretically deduce the macroscopic symmetry constraints for arbitrary odd-order nonlinear susceptibilities in homogeneous media including atomic vapors for the first time. After theoretically calculating the expressions using a semiclassical method, we demonstrate that the expressions for third- and fifth-order nonlinear susceptibilities for undressed and dressed four- and six-wave mixing (FWM and SWM) in atomic vapors satisfy the macroscopic symmetry constraints. We experimentally demonstrate consistence between the macroscopic symmetry constraints and the semiclassical expressions for atomic vapors by observing polarization control of FWM and SWM processes. The experimental results are in reasonable agreement with our theoretical calculations. -- Highlights: •The macroscopic symmetry constraints are deduced for homogeneous media including atomic vapors. •We demonstrate that odd-order nonlinear susceptibilities satisfy the constraints. •We experimentally demonstrate the deduction in part.

Vaporization and diffusion studies on the stability of doped lanthanum gallates

Energy Technology Data Exchange (ETDEWEB)

Stanislowski, M.; Singheiser, L.; Hilpert, K. [Research Center Juelich, Institute for Materials and Processes in Energy Systems, IWV-2, 52425 Juelich (Germany); Peck, D.H.; Woo, S.K. [Korea Institute of Energy Research, 71-2 Jang-Dong, Yuseong, 305-343 Daejeon (Korea); Schulz, O.; Martin, M. [RWTH Aachen University, Institute of Physical Chemistry, Landoltweg 2, 52056 Aachen (Germany)

2006-07-15

Vaporization and diffusion determine the stability of doped lanthanum gallates under SOFC operating conditions. Systematic vaporization studies of Ga and other elements were carried out using the vapor transpiration method. It was shown that the Ga vaporization is controlled by diffusion from the bulk to the surface. Diffusion coefficients D{sub Ga} and vaporization coefficients {alpha}{sub Ga} were determined by fitting the measured vaporization data to a vaporization model. Secondary phases formed as a result of the vaporization were detected. The influence of different doping levels of Sr, Mg and Fe on the Ga vaporization was elucidated. Moreover, cation self-diffusion of {sup 139}La, {sup 84}Sr and {sup 25}Mg as well as cation impurity diffusion of {sup 144}Nd, {sup 89}Y and {sup 56}Fe in polycrystalline samples of doped lanthanum gallate were directly determined for the composition La{sub 0.9}Sr{sub 0.1}Ga{sub 0.9}Mg{sub 0.1}O{sub 2.9} as an example, from diffusion profiles determined by SIMS. It was found that diffusion occurs by means of bulk and grain boundaries. The bulk diffusion coefficients are similar for all cations with activation energies which are strongly dependent on temperature. The results are explained by a frozen-in defect structure at low temperatures in the ABO{sub 3} perovskite lattice and by proposing a defect cluster containing cation vacancies in the A and B sublattices, as well as oxygen vacancies. (Abstract Copyright [2006], Wiley Periodicals, Inc.)

Waste Tank Vapor Characterization Project: Annual status report for FY 1995

International Nuclear Information System (INIS)

Ligotke, M.W.; Fruchter, J.S.; Huckaby, J.L.; Birn, M.B.; McVeety, B.D.; Evans, J.C. Jr.; Pool, K.H.; Silvers, K.L.; Goheen, S.C.

1995-11-01

This report compiles information collected during the Fiscal Year 1995 pertaining to the waste tank vapor characterization project. Information covers the following topics: project management; organic sampling and analysis; inorganic sampling and analysis; waste tank vapor data reports; and the waste tanks vapor database

Computational Fluid Dynamics Model for Saltstone Vault 4 Vapor Space

International Nuclear Information System (INIS)

Lee, Si Young

2005-01-01

Computational fluid dynamics (CFD) methods have been used to estimate the flow patterns for vapor space inside the Saltstone Vault No.4 under different operating scenarios. The purpose of this work is to examine the gas motions inside the vapor space under the current vault configurations. A CFD model took three-dimensional transient momentum-energy coupled approach for the vapor space domain of the vault. The modeling calculations were based on prototypic vault geometry and expected normal operating conditions as defined by Waste Solidification Engineering. The modeling analysis was focused on the air flow patterns near the ventilated corner zones of the vapor space inside the Saltstone vault. The turbulence behavior and natural convection mechanism used in the present model were benchmarked against the literature information and theoretical results. The verified model was applied to the Saltstone vault geometry for the transient assessment of the air flow patterns inside the vapor space of the vault region using the boundary conditions as provided by the customer. The present model considered two cases for the estimations of the flow patterns within the vapor space. One is the reference baseline case. The other is for the negative temperature gradient between the roof inner and top grout surface temperatures intended for the potential bounding condition. The flow patterns of the vapor space calculated by the CFD model demonstrate that the ambient air comes into the vapor space of the vault through the lower-end ventilation hole, and it gets heated up by the Benard-cell type circulation before leaving the vault via the higher-end ventilation hole. The calculated results are consistent with the literature information

Application of CFD to the design of the runner of a propeller turbine for small hydroelectric power plants

Directory of Open Access Journals (Sweden)

Edwin Lenin Chica Arrieta

2013-01-01

Full Text Available En este artículo se presenta un procedimiento para el diseño del rodete de una turbina hidráulica tipo hélice de acuerdo con las condiciones específicas del potencial del agua del sitio de operación basado en un análisis teórico y técnico. Para este fin, las principales características del rodete se determinan y datos tales como la cabeza de succión, el caudal nominal, y las fuerzas que se producen son establecidos durante el diseño. Para la verificación del diseño se utilizan herramientas modernas de ingeniería tales como la dinámica de fluidos computacional (CFD para predecir el flujo y el método de elementos finitos (CAE para el chequeo de la integridad estructural. El rodete diseñado puede ser una opción viable para la generación de energía eléctrica en zonas no interconectadas (ZNI del sistema interconectado nacional de electricidad en los países en desarrollo y se puede fabricar localmente.

Measurement and analysis of transient vaporization in oxide fuel materials

International Nuclear Information System (INIS)

Benson, D.A.; Bergeron, E.G.

1979-01-01

This paper describes a series of experiments in which samples are heated to produce high vapor pressure states in times of 10 -6 to 10 -3 seconds. Experimental measurements of vapor pressures over fresh UO 2 from the pulsed electron beam and pulsed reactor heating tests are presented and compared with other high temperature data. The interpretation of the vapor pressure measured in the tests is discussed in detail. Effects of original sample stoichiometry, chemical interactions with the container and non-equilibrium evaporation due to induced temperature gradients are discussed. Special attention is given to dynamic behavior in rapid heating and vaporization of the oxide due to chemical non-equilibrium. Finally, similar projected reactor experiments on irradiated fuel are described and vapor pressure predictions made using available equilibrium models. A discussion of information accessible from such future tests and its importance is presented. (orig.) [de

Failure problems in superheater spacers of steam generators; Problematica de fallas en espaciadores de sobrecalentadores de generadores de vapor

Energy Technology Data Exchange (ETDEWEB)

Chacon Nava, Jose G; Martinez Villafane, Alberto [Instituto de Investigaciones Electricas, Cuernavaca (Mexico); Fuentes Samaniego, Raul [Universidad Autonoma de Nuevo Leon (Mexico); Mojica Calderon, Cecilio [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1988-12-31

In this article the general aspects of the steam generator superheater fixed spacers failures are analyzed, emphasis is made on the influence several aspects such as the operation of the unit have, the appropriate execution of welds and the selection of binding materials. Likewise several recommendations are made to bring the failures to a minimum. [Espanol] En este articulo se analizan aspectos generales de fallas en espaciadores fijos de sobrecalentadores de generadores de vapor, y se hace hincapie en la influencia que tienen diversos aspectos tales como la operacion de la unidad, la adecuada ejecucion de soldaduras y la seleccion del material de aporte. Asimismo, se proponen algunas recomendaciones para reducir al minimo las fallas.

Interfacial Dynamics of Condensing Vapor Bubbles in an Ultrasonic Acoustic Field

Science.gov (United States)

Boziuk, Thomas; Smith, Marc; Glezer, Ari

2016-11-01

Enhancement of vapor condensation in quiescent subcooled liquid using ultrasonic actuation is investigated experimentally. The vapor bubbles are formed by direct injection from a pressurized steam reservoir through nozzles of varying characteristic diameters, and are advected within an acoustic field of programmable intensity. While kHz-range acoustic actuation typically couples to capillary instability of the vapor-liquid interface, ultrasonic (MHz-range) actuation leads to the formation of a liquid spout that penetrates into the vapor bubble and significantly increases its surface area and therefore condensation rate. Focusing of the ultrasonic beam along the spout leads to ejection of small-scale droplets from that are propelled towards the vapor liquid interface and result in localized acceleration of the condensation. High-speed video of Schlieren images is used to investigate the effects of the ultrasonic actuation on the thermal boundary layer on the liquid side of the vapor-liquid interface and its effect on the condensation rate, and the liquid motion during condensation is investigated using high-magnification PIV measurements. High-speed image processing is used to assess the effect of the actuation on the dynamics and temporal variation in characteristic scale (and condensation rate) of the vapor bubbles.

Water vapor permeabilities through polymers: diffusivities from experiments and simulations

International Nuclear Information System (INIS)

Seethamraju, Sindhu; Ramamurthy, Praveen Chandrashekarapura; Madras, Giridhar

2014-01-01

This study experimentally determines water vapor permeabilities, which are subsequently correlated with the diffusivities obtained from simulations. Molecular dynamics (MD) simulations were used for determining the diffusion of water vapor in various polymeric systems such as polyethylene, polypropylene, poly (vinyl alcohol), poly (vinyl acetate), poly (vinyl butyral), poly (vinylidene chloride), poly (vinyl chloride) and poly (methyl methacrylate). Cavity ring down spectroscopy (CRDS) based methodology has been used to determine the water vapor transmission rates. These values were then used to calculate the diffusion coefficients for water vapor through these polymers. A comparative analysis is provided for diffusivities calculated from CRDS and MD based results by correlating the free volumes. (paper)

Las relaciones de Podemos con las organizaciones sociales

Directory of Open Access Journals (Sweden)

Ignacio Mariñas

2015-09-01

Full Text Available El 15M fue el principio del proceso de cambio en España y tiene una trascendencia en el mundo porque, por primera vez desde 1989, un movimiento contestatario al sistema alcanza una repercusión mundial. En consecuencia, todos partidos políticos en España atienden las demandas de este movimiento, bien para impulsar cambios en sus programas que atiendan a sus demandas o para intentar asumir su representación política como hace Podemos. En esta exposición se considera la tradición política de este país y el surgir del 15M, para comentar, después, las críticas a Podemos como heredero del 15M, y terminar con el análisis de su relación con las organizaciones sociales. La exposición se organiza en cinco tiempos que en su conjunto dan una visión poliédrica del problema. El objetivo es tratar de contradecir el escepticismo del Quijote sobre la posibilidad de comprender las razones y las dinámicas de los cambios sociales.

Design and physical features of inductive coaxial copper vapor lasers

Energy Technology Data Exchange (ETDEWEB)

Batenin, V. M. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation); Kazaryan, M. A. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Karpukhin, V. T. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation); Lyabin, N. A. [Istok Research and Production Corporation (Russian Federation); Malikov, M. M., E-mail: mmalikov@oivtran.ru [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

2016-11-15

A physical model of a copper vapor laser pumped by a pulse-periodic inductive (electrodeless) discharge is considered. The feasibility of efficient laser pumping by an inductive discharge and reaching high output parameters comparable to those of conventional copper vapor lasers pumped by a longitudinal electrode discharge is demonstrated. The design and physical features of an inductive copper vapor laser with an annular working volume are discussed.

Las ideologias, las ciencias naturales y sus implicaciones en la educacion cientifica

Science.gov (United States)

Lozada Roldan, Sandra

Este estudio ausculto las concepciones epistemologicas de los docentes de ciencia del nivel secundario con relacion a las ideologias y las ciencias naturales. Tambien examino las posiciones de los docentes ante asuntos publicos relacionados a la ciencia. Para propositos de este estudio se diseno y se valido el cuestionario con el cual se obtuvieron los resultados. La investigacion es de tipo cuantitativa y se utilizo como diseno la encuesta. El cuestionario se administro en varias actividades de desarrollo profesional para maestros de ciencia. Un total de 78 maestros del nivel secundario respondieron el cuestionario. Para analizar los datos obtenidos se utilizaron estadisticas descriptivas como la distribucion de frecuencia y el porciento. Ademas se establecieron codigos y categorias para describir las posiciones de los maestros ante asuntos publicos relacionados a la ciencia. Los analisis demostraron que entre los docentes participantes de este estudio prevalecen ciertas concepciones epistemologicas adecuadas acerca de las ciencias naturales, a la luz de la literatura consultada. Entre estas concepciones se destacan las siguientes: a) la filosofia materialista de las ciencias naturales, b) la naturaleza tentativa y constructivista del conocimiento cientifico, c) el uso de una metodologia que garantiza cierto grado de objetividad y con el que se justifican y validan los enunciados cientificos y d) la funcion instrumental del conocimiento cientifico. Sin embargo, entre los docentes participantes de este estudio prevalecen ciertas concepciones epistemologicas erroneas acerca de las ciencias naturales, a la luz de la literatura consultada. Entre estas concepciones se destacan las siguientes: a) tendencia inductivista en el que las teorias cientificas comienzan con observaciones que establecen generalizaciones, b) secuencia jerarquica de la metodologia cientifica. Ademas, entre los docentes participantes de este estudio prevalecen concepciones epistemologicas adecuadas

Analysis of physicochemical properties of Mexican gasoline and diesel reformulated with ethanol; Analisis de las propiedades fisicoquimicas de gasolina y diesel mexicanos reformulados con etanol

Energy Technology Data Exchange (ETDEWEB)

Castillo-Hernandez, Patricia; Mendoza-Dominguez, Alberto; Caballero-Mata, Porfirio [Tecnologico de Monterrey, Campus Monterrey, Nuevo Leon (Mexico)]. E-mails: pcastillohdz@gmail.com; mendoza.alberto@itesm.mx; pcaballe@itesm.mx

2012-07-15

High energy prices, environmental issues and increasing importation of fossil fuels has provoked, in some countries, a reorientation of resources towards the development of biofuels that can partially substitute the consumption of fossil fuels. Ethanol is one of the biofuels more commonly used in the world; in the United States, Brazil and Australia gasoline blends that reach up to 85% Ethanol are commercialized. This work presents the results of a physicochemical characterization of commercial Mexican gasoline (Magna and Premium) and diesel blends with 10% vol. and 15% vol. anhydrous Ethanol. The analytical testing included: Research Octane Number, Motor Octane Number, Cetane Number, Reid Vapor Pressure, Distillation Curve and Heating Value. The stability of the blends was also evaluated. The theoretical emissions of CO{sub 2} were calculated based on the results of the physicochemical characterization. The ethanol-gasoline blends increased their Octane Number with respect to the commercial gasoline, while conserving an appropriate Distillation Index. The Cetane Number of the ethanol-diesel blends showed a substantial decrease, while the heating value of gasoline and diesel blends was negatively affected by the addition of ethanol. Nevertheless, taking into account the credits by the use of a renewable fuel, the use of the reformulated gasoline blends would imply a maximum theoretical reduction of 7.5% in CO{sub 2} emissions whereas in the case of ethanol-diesel blends it would represent a 9.2% decrease. [Spanish] Los altos precios de los energeticos, la problematica ambiental y las importaciones de combustibles continuamente a la alza, han ocasionado que algunos paises redirijan sus esfuerzos al desarrollo de biocombustibles con la finalidad de sustituir parcialmente a los combustibles fosiles. El Etanol es uno de los biocombustibles mas usados; Estados Unidos, Brasil y Australia comercializan gasolina con Etanol con una concentracion de hasta 85% en volumen. El

Los efectos de las armas en la vida de las mujeres

OpenAIRE

2005-01-01

Se calcula que en la actualidad hay en el mundo casi 650 millones de armas pequeñas. Casi el 60 por ciento de ellas están en manos de ciudadanos particulares, en su mayoría hombres. Y la gran mayoría de quienes fabrican, venden, poseen y usan, debida o indebidamente, las armas pequeñas son hombres. ¿Qué significa esto para las mujeres y niñas del mundo? Este informe estudia los efectos que las armas de fuego tienen para las mujeres en el hogar, en las comunidades y también durante un conflict...

Covering sources of toxic vapors with foam

International Nuclear Information System (INIS)

Aue, W. P.; Guidetti, F.

2009-01-01

In a case of chemical terrorism, first responders might well be confronted with a liquid source of toxic vapor which keeps spreading out its hazardous contents. With foam as an efficient and simple means, such a source could be covered up in seconds and the spread of vapors mitigated drastically. Once covered, the source could then wait for a longer time to be removed carefully and professionally by a decontamination team. In order to find foams useful for covering up toxic vapor sources, a large set of measurements has been performed in order to answer the following questions: - Which foams could be used for this purpose? - How thick should the foam cover be? - For how long would such a foam cover be effective? - Could the practical application of foam cause a spread of the toxic chemical? The toxic vapors sources included GB, GD and HD. Among the foams were 10 fire fighter foams (e.g. AFFF, protein) and the aqueous decontamination foam CASCAD. Small scale experiments showed that CASCAD is best suited for covering a toxic source; a 10 cm layer of it covers and decontaminates GB. The large scale experiments confirmed that any fire fighter foam is a suitable cover for a longer or shorter period.(author)

Tank vapor characterization project - headspace vapor characterization of Hanford Waste Tank 241-C-107: Second comparison study results from samples collected on 3/26/96

International Nuclear Information System (INIS)

Evans, J.C.; Pool, K.H.; Thomas, B.L.

1997-01-01

This report describes the analytical results of vapor samples taken from the headspace of waste storage tank 241-C-107 (Tank C-107) at the Hanford Site in Washington State. The results described in this report is the second in a series comparing vapor sampling of the tank headspace using the Vapor Sampling System (VSS) and In Situ Vapor Sampling (ISVS) system without high efficiency particulate air (HEPA) prefiltration. The results include air concentrations of water (H 2 O) and ammonia (NH 3 ), permanent gases, total non-methane organic compounds (TO-12), and individual organic analytes collected in SUMMA trademark canisters and on triple sorbent traps (TSTs). Samples were collected by Westinghouse Hanford Company (WHC) and analyzed by Pacific Northwest National Laboratory (PNNL). Analyses were performed by the Vapor Analytical Laboratory (VAL) at PNNL. Analyte concentrations were based on analytical results and, where appropriate, sample volume measurements provided by WHC

Tank vapor characterization project. Headspace vapor characterization of Hanford waste tank 241-BY-108: Second comparison study results from samples collected on 3/28/96

International Nuclear Information System (INIS)

Thomas, B.L.; Pool, K.H.; Evans, J.C.

1997-01-01

This report describes the analytical results of vapor samples taken from the headspace of waste storage tank 241-BY-108 (Tank BY-108) at the Hanford Site in Washington State. The results described in this report is the second in a series comparing vapor sampling of the tank headspace using the Vapor Sampling System (VSS) and In Situ Vapor Sampling (ISVS) system without high efficiency particulate air (HEPA) prefiltration. The results include air concentrations of water (H 2 O) and ammonia (NH 3 ), permanent gases, total non-methane organic compounds (TO-12), and individual organic analytes collected in SUMMA trademark canisters and on triple sorbent traps (TSTs). Samples were collected by Westinghouse Hanford Company (WHC) and analyzed by Pacific Northwest National Laboratory (PNNL). Analyses were performed by the Vapor Analytical Laboratory (VAL) at PNNL. Analyte concentrations were based on analytical results and, where appropriate, sample volume measurements provided by WHC

Gobierno de las TI en las universidades españolas

OpenAIRE

Fernández Martínez, Antonio; Llorens Largo, Faraón

2009-01-01

Comunicación presentada en el IV International Congress: "Evolving from IT Service Management to IT Governance", May 19, 2009, Móstoles, Madrid. El gobierno de las Tecnologías de la Información (TI) va a proporcionar a las universidades la capacidad de obtener el máximo valor de sus inversiones TI. Sin embargo en el Sistema Universitario Español (SUE) el uso de sistemas de gobierno de las TI esta muy poco extendido y apenas es incipiente. La Conferencia de Rectores de las Universidades Esp...

Vapor pressures and enthalpies of vaporization of a series of 1- and 2-halogenated naphthalenes

International Nuclear Information System (INIS)

Verevkin, Sergey P.

2003-01-01

Molar enthalpies of vaporization, Δ l g H m 0 , of 1-methyl-naphthalene, 1-chloro-napthalene, 2-chloro-naphthalene, 1-bromo-naphthalene, 2-bromo-naphthalene, and 1-iodo-naphthalene, as well as molar enthalpies of sublimation, Δ s g H m 0 , of 2-chloro-naphthalene and 2-bromo-naphthalene have been obtained from the temperature dependence of the vapor pressure determined with the transpiration method. These values and the correlation gas-chromatography method, based on the Kovat's index, have been used to determine Δ l g H m 0 and Δ s g H m 0 of 2-iodo-naphthalene. Results obtained in this work have been compared with those from the literature and found consistent

Apparatus of vaporizing and condensing liquid radioactive wastes and its operation method

International Nuclear Information System (INIS)

Irie, Hiromitsu; Tajima, Fumio.

1975-01-01

Object: To prevent corrosion of material for a vapor-condenser and a vapor heater and to prevent radioactive contamination of heated vapor. Structure: Liquid waste is fed from a liquid feeding tank to a vapor-condenser to vaporize and condense the waste. Uncondensed liquid waste, which is not in a level of a given density, is temporally stored in a batch tank through a switching valve and a pipe. Prior to successive feeding from the liquid feeding tank, the uncondensed liquid waste within the batch tank is returned by a return pump to the condenser, after which a new liquid is fed from the liquid feeding tank for re-vaporization and condensation in the vapor-condenser. Then, similar operation is repeated until the uncondensed liquid waste assumes a given density, and when the uncondensed liquid waste reaches a given density, the condensed liquid waste is discharged into the storage tank through the switching valve. (Ohara, T.)

Eddy transport of water vapor in the Martian atmosphere

Science.gov (United States)

Murphy, J. R.; Haberle, Robert M.

1993-01-01

Viking orbiter measurements of the Martian atmosphere suggest that the residual north polar water-ice cap is the primary source of atmospheric water vapor, which appears at successively lower northern latitudes as the summer season progresses. Zonally symmetric studies of water vapor transport indicate that the zonal mean meridional circulation is incapable of transporting from north polar regions to low latitudes the quantity of water vapor observed. This result has been interpreted as implying the presence of nonpolar sources of water. Another possibility is the ability of atmospheric wave motions, which are not accounted for in a zonally symmetric framework, to efficiently accomplish the transport from a north polar source to the entirety of the Northern Hemisphere. The ability or inability of the full range of atmospheric motions to accomplish this transport has important implications regarding the questions of water sources and sinks on Mars: if the full spectrum of atmospheric motions proves to be incapable of accomplishing the transport, it strengthens arguments in favor of additional water sources. Preliminary results from a three dimensional atmospheric dynamical/water vapor transport numerical model are presented. The model accounts for the physics of a subliming water-ice cap, but does not yet incorporate recondensation of this sublimed water. Transport of vapor away from this water-ice cap in this three dimensional framework is compared with previously obtained zonally symmetric (two dimensional) results to quantify effects of water vapor transport by atmospheric eddies.

Effects of molten material temperatures and coolant temperatures on vapor explosion

Institute of Scientific and Technical Information of China (English)

LI Tianshu; YANG Yanhua; YUAN Minghao; HU Zhihua

2007-01-01

An observable experiment facility for low-temperature molten materials to be dropped into water was set up in this study to investigate the mechanism of the vapor explosion. The effect of the fuel and coolant interaction(FCI) on the vapor explosion during the severe accidents of a fission nuclear reactor has been studied. The experiment results showed that the molten material temperature has an important effect on the vapor explosion behavior and pressure. The increase of the coolant temperature would decrease the pressure of the vapor explosion.

Atmospheric water vapor: Distribution and Empirical estimation in the atmosphere of Thailand

Science.gov (United States)

Phokate, S.

2017-09-01

Atmospheric water vapor is a crucial component of the Earth’s atmosphere, which is shown by precipitable water vapor. It is calculated from the upper air data. In Thailand, the data were collected from four measuring stations located in Chiang Mai, Ubon Ratchathani, Bangkok, and Songkhla during the years 1998-2013. The precipitable water vapor obtained from this investigation were used to define an empirical model associated with the vapor pressure, which is a surface data at the same stations. The result shows that the relationship has a relatively high level of reliability. The precipitable water vapor obtained from the upper air data is nearly equal to the value from the model. The model was used to calculate the precipitable water vapor from the surface data 85 stations across the country. The result shows that seasonal change of the precipitable water vapor was low in the dry season (November-April) and high in the rainy season (May-October). In addition, precipitable water vapor varies along the latitudes of the stations. The high value obtains for low latitudes, but it is low for high latitudes.

Combined rankine and vapor compression cycles

Science.gov (United States)

Radcliff, Thomas D.; Biederman, Bruce P.; Brasz, Joost J.

2005-04-19

An organic rankine cycle system is combined with a vapor compression cycle system with the turbine generator of the organic rankine cycle generating the power necessary to operate the motor of the refrigerant compressor. The vapor compression cycle is applied with its evaporator cooling the inlet air into a gas turbine, and the organic rankine cycle is applied to receive heat from a gas turbine exhaust to heat its boiler within one embodiment, a common condenser is used for the organic rankine cycle and the vapor compression cycle, with a common refrigerant, R-245a being circulated within both systems. In another embodiment, the turbine driven generator has a common shaft connected to the compressor to thereby eliminate the need for a separate motor to drive the compressor. In another embodiment, an organic rankine cycle system is applied to an internal combustion engine to cool the fluids thereof, and the turbo charged air is cooled first by the organic rankine cycle system and then by an air conditioner prior to passing into the intake of the engine.

Physical Vapor Deposition of Thin Films

Science.gov (United States)

Mahan, John E.

2000-01-01

A unified treatment of the theories, data, and technologies underlying physical vapor deposition methods With electronic, optical, and magnetic coating technologies increasingly dominating manufacturing in the high-tech industries, there is a growing need for expertise in physical vapor deposition of thin films. This important new work provides researchers and engineers in this field with the information they need to tackle thin film processes in the real world. Presenting a cohesive, thoroughly developed treatment of both fundamental and applied topics, Physical Vapor Deposition of Thin Films incorporates many critical results from across the literature as it imparts a working knowledge of a variety of present-day techniques. Numerous worked examples, extensive references, and more than 100 illustrations and photographs accompany coverage of: * Thermal evaporation, sputtering, and pulsed laser deposition techniques * Key theories and phenomena, including the kinetic theory of gases, adsorption and condensation, high-vacuum pumping dynamics, and sputtering discharges * Trends in sputter yield data and a new simplified collisional model of sputter yield for pure element targets * Quantitative models for film deposition rate, thickness profiles, and thermalization of the sputtered beam

Las Sinapsis

OpenAIRE

Jorge Eduardo Duque Parra; Genaro Morales Parra; Carlos Alberto Duque Parra

1997-01-01

Introducción

El estudio del sistema nervioso considera entre múltiples conexiones, aquéllas de carácter bioquímico que se median a través de sustancias elaboradas por las neuronas y que reciben la denominación de neurotransmisores’, dichas sustancias se vierten en las zonas de resquicio neuromuscular, neuroneuronal o neuroglandular, para modificar las condiciones de membrana y permitir la continuidad de los p...

Measurement of vapor behavior in tight-lattice bundles by neutron radiography

International Nuclear Information System (INIS)

Kureta, Masatoshi; Akimoto, Hajime

2004-01-01

Three-dimensional and instantaneous void fractions in tight-lattice 7-rod and 14-rod bundles were measured by neutron radiography in order to make clear the flow behavior and to verify the advanced fine-mesh numerical analysis codes for the R and D of the Reduced-Moderation Water Reactors (RMWR). Time-averaged 3D void fraction distribution is evaluated with the spatial resolution of 0.1 - 0.2 mm using neutron tomography, and consecutive change of vapor behavior is observed quantitatively with time step of 1 ms using high-frame-rate neutron radiography (HFR-NR). In this paper, void fraction distribution and vapor behavior of flow boiling of water in tight-lattice rod bundles are focused on and discussed based on the obtained results. 'High void fraction spot', 'void drift phenomenon', and 'vapor chimney' were observed under atmospheric pressure conditions. Here, 'high void fraction spot' indicates that high void fraction regions are appeared between adjacent rods, narrow space, at/near point of net vapor generation region. 'Void drift' and 'vapor chimney' represent that high void fraction region moves to wide triangular space and is formed a vapor flow channel so-called 'vapor chimney'. It was confirmed from the time-averaged 3D data that void fraction in the center is higher than that in the periphery. On the other hand, it was found from the HFR-NR experiments that big vapor bubbles and/or cluster flow upward intermittently not only in the center but in the periphery of the channel and, therefore, point of net vapor generation is scattered statistically in wide region. (author)

Conocimiento de las vías de transmisión de las zoonosis y de las especies afectadas entre los trabajadores rurales

Directory of Open Access Journals (Sweden)

Ana I Molineri

Full Text Available El objetivo de este trabajo fue evaluar el grado de conocimiento que tienen los trabajadores rurales sobre las zoonosis a las que se encuentran expuestos en su trabajo y su asociación con factores socio-demográficos. Se efectuó un estudio observacional transversal basado en la realización de encuestas (N = 110, n = 94, utilizando un cuestionario estructurado. El análisis incluyó c², t de Student y correlación de Pearson y de Spearman. Las zoonosis más conocidas fueron la triquinosis, la rabia y la sarna. En el caso de la brucelosis, la tuberculosis y el carbunco, fueron muy conocidas las especies que las transmiten, pero no así las formas de transmisión. Las enfermedades menos conocidas en ambos sentidos fueron la toxocariasis y la hidatidosis, seguidas por la leptospirosis y la toxoplasmosis. Para todas las zoonosis estudiadas se encontró correlación significativa (p < 0,001 entre el conocimiento de las especies transmisoras y de las vías de transmisión. Aquellos encuestados de sexo masculino, propietarios y residentes de zonas urbanas, casados y de mayor edad y antigüedad fueron quienes presentaron más conocimientos sobre las zoonosis, en general. El conocimiento que tienen los trabajadores rurales acerca de las zoonosis es insuficiente. Sería importante que los veterinarios, en conjunto con las aseguradoras de riesgos del trabajo, difundan la información adecuada entre las personas en riesgo que desarrollan sus tareas en este ámbito.

Improved waste water vapor compression distillation technology. [for Spacelab

Science.gov (United States)

Johnson, K. L.; Nuccio, P. P.; Reveley, W. F.

1977-01-01

The vapor compression distillation process is a method of recovering potable water from crewman urine in a manned spacecraft or space station. A description is presented of the research and development approach to the solution of the various problems encountered with previous vapor compression distillation units. The design solutions considered are incorporated in the preliminary design of a vapor compression distillation subsystem. The new design concepts are available for integration in the next generation of support systems and, particularly, the regenerative life support evaluation intended for project Spacelab.

Numerical simulation of superheated vapor bubble rising in stagnant liquid

Science.gov (United States)

Samkhaniani, N.; Ansari, M. R.

2017-09-01

In present study, the rising of superheated vapor bubble in saturated liquid is simulated using volume of fluid method in OpenFOAM cfd package. The surface tension between vapor-liquid phases is considered using continuous surface force method. In order to reduce spurious current near interface, Lafaurie smoothing filter is applied to improve curvature calculation. Phase change is considered using Tanasawa mass transfer model. The variation of saturation temperature in vapor bubble with local pressure is considered with simplified Clausius-Clapeyron relation. The couple velocity-pressure equation is solved using PISO algorithm. The numerical model is validated with: (1) isothermal bubble rising and (2) one-dimensional horizontal film condensation. Then, the shape and life time history of single superheated vapor bubble are investigated. The present numerical study shows vapor bubble in saturated liquid undergoes boiling and condensation. It indicates bubble life time is nearly linear proportional with bubble size and superheat temperature.

Las mujeres y los puestos para expatriados en las multinacionales latinoamericanas

Directory of Open Access Journals (Sweden)

Edgar E. Chaves Solano

2009-07-01

Full Text Available Una de los aspectos más importantes del mercado laboral mundial en la última mitad del siglo XX ha sido la tasa de participación cada vez mayor de las mujeres en puestos gerenciales. Sin embargo, es evidente, de acuerdo a la investigación existente, que las mujeres no progresan en los puestos de dirección internacional en las mismas tasas que sus homólogos masculinos. Investigaciones anteriores ha estimado que sólo el 3 % de los administradores expatriados son mujeres. Se argumenta que las mujeres en puestos de dirección internacional tienen que superar las barreras abiertas y encubiertas en sus organizaciones antes de ser tomadas en cuenta para asignaciones internacionales. Los estudios mencionados se refieren a los países desarrollados. En el caso de las corporaciones latinoamericanas no se han encontrado estudios teóricos ni empíricos que arrojen luz sobre el tema de la mujer expatriada. El objetivo del presente trabajo es obtener razones y mitos sobre la asignación de las mujeres como expatriadas en los países desarrollados para, en un posterior estudio determinar si esas razones son validas o no con las mujeres expatriadas de las corporaciones de América Latina y que estos resultados ayuden a tomar mejores decisiones a los gerentes cuando tengan que llenar un puesto en el exterior

27 CFR 19.821 - Production of vinegar by the vaporizing process.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Production of vinegar by the vaporizing process. 19.821 Section 19.821 Alcohol, Tobacco Products and Firearms ALCOHOL AND... Vinegar by the Vaporizing Process Scope of Subpart § 19.821 Production of vinegar by the vaporizing...

Chemically assisted release of transition metals in graphite vaporizers for atomic spectrometry

International Nuclear Information System (INIS)

Katskov, Dmitri; Darangwa, Nicholas; Grotti, Marco

2006-01-01

The processes associated with the vaporization of microgram samples and modifiers in a graphite tube ET AAS were investigated by the example of transition metals. The vapor absorption spectra and vaporization behavior of μg-amounts Cd, Zn, Cu, Ag, Au, Ni, Co, Fe, Mn and Cr were studied using the UV spectrometer with CCD detector, coupled with a continuum radiation source. The pyrocoated, Ta or W lined tubes, with Ar or He as internal gases, and filter furnace were employed in the comparative experiments. It was found that the kinetics of atomic vapor release changed depending on the specific metal-substrate-gas combination; fast vaporization at the beginning was followed by slower 'tailing.' The absorption continuum, overlapped by black body radiation at longer wavelengths, accompanied the fast vaporization mode for all metals, except Cd and Zn. The highest intensity of the continuum was observed in the pyrocoated tube with Ar. For Cu and Ag the molecular bands overlapped the absorption continuum; the continuum and bands were suppressed in the filter furnace. It is concluded that the exothermal interaction of sample vapor with the material of the tube causes the energy evolution in the gas phase. The emitted heat is dispersed near the tube wall in the protective gas and partially transferred back to the surface of the sample, thus facilitating the vaporization. The increased vapor flow causes over-saturation and gas-phase condensation in the absorption volume at some distance from the wall, where the gas temperature is not affected by the reaction. The condensation is accompanied by the release of phase transition energy via black body radiation and atomic emission. The particles of condensate and molecular clusters cause the scattering of light and molecular absorption; slow decomposition of the products of the sample vapor-substrate reaction produces the 'tailing' of atomic absorption signal. The interaction of graphite with metal vapor or oxygen, formed in the

Vapor liquid fraction determination

International Nuclear Information System (INIS)

1980-01-01

This invention describes a method of measuring liquid and vapor fractions in a non-homogeneous fluid flowing through an elongate conduit, such as may be required with boiling water, non-boiling turbulent flows, fluidized bed experiments, water-gas mixing analysis, and nuclear plant cooling. (UK)

Removal of hydrogen sulfide as ammonium sulfate from hydropyrolysis product vapors

Energy Technology Data Exchange (ETDEWEB)

Marker, Terry L.; Felix, Larry G.; Linck, Martin B.; Roberts, Michael J.

2017-03-14

A system and method for processing biomass into hydrocarbon fuels that includes processing a biomass in a hydropyrolysis reactor resulting in hydrocarbon fuels and a process vapor stream and cooling the process vapor stream to a condensation temperature resulting in an aqueous stream. The aqueous stream is sent to a catalytic reactor where it is oxidized to obtain a product stream containing ammonia and ammonium sulfate. A resulting cooled product vapor stream includes non-condensable process vapors comprising H.sub.2, CH.sub.4, CO, CO.sub.2, ammonia and hydrogen sulfide.

Removal of hydrogen sulfide as ammonium sulfate from hydropyrolysis product vapors

Science.gov (United States)

Marker, Terry L; Felix, Larry G; Linck, Martin B; Roberts, Michael J

2014-10-14

A system and method for processing biomass into hydrocarbon fuels that includes processing a biomass in a hydropyrolysis reactor resulting in hydrocarbon fuels and a process vapor stream and cooling the process vapor stream to a condensation temperature resulting in an aqueous stream. The aqueous stream is sent to a catalytic reactor where it is oxidized to obtain a product stream containing ammonia and ammonium sulfate. A resulting cooled product vapor stream includes non-condensable process vapors comprising H.sub.2, CH.sub.4, CO, CO.sub.2, ammonia and hydrogen sulfide.

Development of halide copper vapor laser (the characteristics of using Cul)