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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Transporting and Disposing of Wastewater from North Dakota Oil Producers

Yin, Qingqing January 2012 (has links)
North Dakota’s oil boom is aided by a new technology, fracking. But this technology implies large amounts of wastewater. The methods of dealing with this wastewater are now an issue. Currently, North Dakota locks it into deep injection wells in the Bakken formation. With the development of membrane technologies to treat wastewater, it may be feasible to treat the wastewater and reuse it. This study uses a mathematical programming model to minimize the total cost of dealing with wastewater using three methods - deep well injection, on-site treatment, and off-site treatment. The model results show it is cost-effective to use on-site and large capacity off-site treatment to treat the 20% of the wastewater that flows back within the first 30-60 days after a well is drilled.
2

Geochemical Determination of the Fate and Transport of Injected Fresh Wastewater to a Deep Saline Aquifer

Walsh, Virginia M 16 July 2012 (has links)
Deep well injection into non-potable saline aquifers of treated domestic wastewater has been used in Florida for decades as a safe and effective alternative to ocean outfall disposal. The objectives of this study were to determine the fate and transport of injected wastewater at two deep well injection sites in Miami Dade County, Florida, USA. Detection of ammonium in the Middle Confining units of the Floridan aquifer above the injection zone at both sites has been interpreted as evidence of upward migration of injected wastewater, posing a risk to underground sources of drinking water. Historical water quality data, including ammonia, chloride, temperature, and pH from existing monitoring wells at both sites from 1983 to 2008, major ions collected monthly from 2006 and 2008, and a synoptic sampling event for stable isotopes, tritium, and dissolved gases in 2008, were used to determine the source of ammonium in groundwater and possible migration pathways. Geochemical modeling was used to determine possible effects of injected wastewater on native water and aquifer matrix geochemistry. Injected wastewater was determined to be the source of elevated ammonium concentrations above ambient water levels, based on the results of major ion concentrations, tritium, dissolved noble gases and 15N isotopes analyses. Various possible fluid migration pathways were identified at the sites. Data for the south site suggest buoyancy-driven vertical pathways to overlying aquifers bypassing the confining units, with little mixing of injected wastewater with native water as it migrated upward. Once it is introduced into an aquifer, the injectate appeared to migrate advectively with the regional groundwater flow. Geochemical modeling indicated that CO2 -enriched injected wastewater allowed for carbonate dissolution along the vertical pathways, enhancing permeability along these flowpaths. At the north site, diffusive upward flow through the confining units or offsite vertical pathways were determined to be possible, however no evidence was detected for any on-site confining unit bypass pathway. No evidence was observed at either site of injected wastewater migration to the Upper Floridan aquifer, which is used as a municipal water supply and for aquifer storage and recovery.
3

Collection and analyses of physical data for deep injection wells in Florida

Unknown Date (has links)
Deep injection wells (DIW) in Florida are regulated by the U.S. Environmental Protection Agency (USEPA) and the state of Florida through the Underground Injection Control regulations contained within the Safe Drinking Water Act. Underground injection is defined as the injection of hazardous waste, nonhazardous waste, or municipal waste below the lowermost formation containing an underground source of drinking water within one-quarter mile of the wellbore. Municipalities in Florida have been using underground injection as an alternative to surface disposal of treated domestic wastewater for nearly 40 years. The research involved collecting data as of September, 2007 on all the Class I DIWs in the state of Florida and evaluating the differences between them. The analysis found regional differences in deep well practice and canonical correlation analyses concluded that depth below the USDW is the most significant factor to prevent upward migration of the injected fluid. / by Jie Gao. / Thesis (M.S.C.S.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.
4

Caracterização preliminar da hidrogeologia e meio ambiente no município de Monções/SP - uma contribuição à gestão dos recursos hídricos / Preliminary characterization of the hydrogeology and environment in the municipality of Monções/SP - a contribution to hydrics resources management

Luiz, Rubens Marques 18 December 2006 (has links)
Este trabalho objetivou a investigação hidrogeológica do município de Monções (cidade do noroeste paulista) onde se estimou existir um total de 61 poços tubulares profundos que exploram dois aqüíferos com porosidades distintas, o Aqüífero Adamantina (granular) e o Aqüífero Serra Geral (fraturado). Ambos são responsáveis por 100% do abastecimento do município, daí o interesse em investigá-los melhor. O aqüífero superior (sedimentar), localmente de pequena espessura, responde por aproximadamente 60% das captações existentes e apenas 20% da vazão total extraída, o que não o torna menos importante e sim mais vulnerável. No inferior, concentra-se a minoria dos poços da área e a maior parte do volume disponível. A metodologia adotada teve por base o reconhecimento geológico preliminar da área e o cadastramento de pontos considerados referências importantes dentro da proposta deste estudo, como poços tubulares profundos, contato geológico das formações presentes na área, locais de depósito e despejo de resíduos urbanos, indústria, áreas de plantio, pontos de degradação fisiográfica, cemitério, entre outros. Em seguida, realizou-se a coleta pontual das informações de interesse que consistiu no registro fotográfico digital das situações consideradas de maior relevância, levantamento de coordenadas e cotas topográficas destes pontos e, por fim, a coleta de água de poços que melhor representassem o contexto da área investigada. Para o tratamento destes dados os pontos foram inicialmente locados na Planta Topográfica de Gastão Vidigal (Instituto Brasileiro de Geografia e Estatística ? 1:50.000), uma vez que a área investigada está inserida na referida Folha, e, posteriormente, conferidos e plotados através da etapa de georreferenciamento. O levantamento realizado propiciou a elaboração de um banco de dados para o município e a confecção de mapas de contorno estrutural (topo da Formação Serra Geral) e de isoespessura (Formação Adamantina), facilitando estimativas de reservas hídricas. Possibilitou ainda uma avaliação crítica dos atuais sistemas de captação, assim como viabilizou a confecção de mapas simplificados (geológico e hidrogeológico) em escala até então não disponível (1:50.000), elaborados com o auxílio do software de georreferenciamento ArcView GIS 3.3. Complementarmente, através da investigação do comportamento químico das águas dos aqüíferos locais, foi possível uma proposta de classificação quanto às zonas produtoras. / This work aims the hydrogeologic investigation of Monções municipality (city in the NW São Paulo State - Brazil) where it has been estimated to exist an amount of 61 deep wells exploring two aquifers with different porosity, the Adamantina Aquifer (granular) and Serra Geral Aquifer (fractured). The reason of better investigation is both are responsible by 100% of the municipality water supply. The top aquifer (sedimentary) has locally a small thickness and presents around 60% of the wells on the area and provides only 20% of the total flow exploited. This situation doesn\'t make the aquifer less important but more vulnerable. On the other hand, the bottom aquifer represents the minority of the wells and most of the available flow. The methodology applied was based in preliminary geologic inspection (field work) and register of points that were considered important in this work proposal, like deep wells, formations geologic contact that occur in the study area, urbane residues deposits and launching places (realeasing places), industry, plantation field, physiographic degradation points, cemetery, among others. After that, a punctual collection information of interest was performed, including digital photographic register of the more relevant situations, survey of coordinates and topographic quote of these points and, at last, water collect from representative wells located in the area. For the treatment of these informations, the points were at first located in the Gastão Vidigal topographic map (Brazilian Institute of Geography and Statistic ? 1:50.000), as the study area is included in this chart, and, subsequently, ratified and plothed using the georreference software. The survey developed made possible the elaboration of a database to the investigated municipality and of a structural contour map (Serra Geral Formation\'s Top), as well as a map of isothickness (Adamantina Formation) making easier the estimation of groundwater reserves. Moreover, this information permitted a critical evaluation of the current collection systems as well as made possible the confection of simple maps (geology and hydrogeology), in a better scale that the available one (1:50.000) using the ArcView 3.3 software. Supplementary, through the description the chemical characteristics of waters from local aquifers, made possible a proposal for classification with regard to production areas.
5

Caracterização preliminar da hidrogeologia e meio ambiente no município de Monções/SP - uma contribuição à gestão dos recursos hídricos / Preliminary characterization of the hydrogeology and environment in the municipality of Monções/SP - a contribution to hydrics resources management

Rubens Marques Luiz 18 December 2006 (has links)
Este trabalho objetivou a investigação hidrogeológica do município de Monções (cidade do noroeste paulista) onde se estimou existir um total de 61 poços tubulares profundos que exploram dois aqüíferos com porosidades distintas, o Aqüífero Adamantina (granular) e o Aqüífero Serra Geral (fraturado). Ambos são responsáveis por 100% do abastecimento do município, daí o interesse em investigá-los melhor. O aqüífero superior (sedimentar), localmente de pequena espessura, responde por aproximadamente 60% das captações existentes e apenas 20% da vazão total extraída, o que não o torna menos importante e sim mais vulnerável. No inferior, concentra-se a minoria dos poços da área e a maior parte do volume disponível. A metodologia adotada teve por base o reconhecimento geológico preliminar da área e o cadastramento de pontos considerados referências importantes dentro da proposta deste estudo, como poços tubulares profundos, contato geológico das formações presentes na área, locais de depósito e despejo de resíduos urbanos, indústria, áreas de plantio, pontos de degradação fisiográfica, cemitério, entre outros. Em seguida, realizou-se a coleta pontual das informações de interesse que consistiu no registro fotográfico digital das situações consideradas de maior relevância, levantamento de coordenadas e cotas topográficas destes pontos e, por fim, a coleta de água de poços que melhor representassem o contexto da área investigada. Para o tratamento destes dados os pontos foram inicialmente locados na Planta Topográfica de Gastão Vidigal (Instituto Brasileiro de Geografia e Estatística ? 1:50.000), uma vez que a área investigada está inserida na referida Folha, e, posteriormente, conferidos e plotados através da etapa de georreferenciamento. O levantamento realizado propiciou a elaboração de um banco de dados para o município e a confecção de mapas de contorno estrutural (topo da Formação Serra Geral) e de isoespessura (Formação Adamantina), facilitando estimativas de reservas hídricas. Possibilitou ainda uma avaliação crítica dos atuais sistemas de captação, assim como viabilizou a confecção de mapas simplificados (geológico e hidrogeológico) em escala até então não disponível (1:50.000), elaborados com o auxílio do software de georreferenciamento ArcView GIS 3.3. Complementarmente, através da investigação do comportamento químico das águas dos aqüíferos locais, foi possível uma proposta de classificação quanto às zonas produtoras. / This work aims the hydrogeologic investigation of Monções municipality (city in the NW São Paulo State - Brazil) where it has been estimated to exist an amount of 61 deep wells exploring two aquifers with different porosity, the Adamantina Aquifer (granular) and Serra Geral Aquifer (fractured). The reason of better investigation is both are responsible by 100% of the municipality water supply. The top aquifer (sedimentary) has locally a small thickness and presents around 60% of the wells on the area and provides only 20% of the total flow exploited. This situation doesn\'t make the aquifer less important but more vulnerable. On the other hand, the bottom aquifer represents the minority of the wells and most of the available flow. The methodology applied was based in preliminary geologic inspection (field work) and register of points that were considered important in this work proposal, like deep wells, formations geologic contact that occur in the study area, urbane residues deposits and launching places (realeasing places), industry, plantation field, physiographic degradation points, cemetery, among others. After that, a punctual collection information of interest was performed, including digital photographic register of the more relevant situations, survey of coordinates and topographic quote of these points and, at last, water collect from representative wells located in the area. For the treatment of these informations, the points were at first located in the Gastão Vidigal topographic map (Brazilian Institute of Geography and Statistic ? 1:50.000), as the study area is included in this chart, and, subsequently, ratified and plothed using the georreference software. The survey developed made possible the elaboration of a database to the investigated municipality and of a structural contour map (Serra Geral Formation\'s Top), as well as a map of isothickness (Adamantina Formation) making easier the estimation of groundwater reserves. Moreover, this information permitted a critical evaluation of the current collection systems as well as made possible the confection of simple maps (geology and hydrogeology), in a better scale that the available one (1:50.000) using the ArcView 3.3 software. Supplementary, through the description the chemical characteristics of waters from local aquifers, made possible a proposal for classification with regard to production areas.
6

A precise, General, Non-Invasive and Automatic Speed Estimation Method for MCSA Steady-State Diagnosis and Efficiency Estimation of Induction Motors in the 4.0 Industry

Bonet Jara, Jorge 16 June 2023 (has links)
Tesis por compendio / [ES] Hay dos aspectos cruciales a la hora de operar motores de inducción en la industria: la estimación de su eficiencia (para minimizar el consumo de energía) y su diagnóstico (para evitar paradas intempestivas y reducir los costes de mantenimiento). Para estimar la eficiencia del motor es necesario medir tensiones y corrientes. Por ello, resulta conveniente y muy útil utilizar la misma corriente para diagnosticar también el motor (Motor Current Signature Analysis: MCSA). En este sentido, la técnica MCSA más adecuada es aquella basada en la localización de armónicos de fallo en el espectro de la corriente de línea del estator en régimen permanente, pues esta es la condición de funcionamiento de la mayoría de los motores de inducción de la industria. Por otro lado, dado que la frecuencia de estos armónicos depende de la velocidad, resulta imprescindible conocer esta magnitud con precisión, ya que esto permite localizar correctamente los armónicos de fallo, y, por tanto, reducir las posibilidades de falsos positivos/negativos. A su vez, una medida precisa de la velocidad también permite calcular con precisión la potencia mecánica, lo que se traduce en una estimación más exacta del rendimiento. Por último, para adaptarse a las necesidades de la Industria 4.0, en la que se monitoriza continuamente un gran número de motores, la velocidad también debe ser obtenida de manera no invasiva, automática y para cualquier motor de inducción. A este respecto, dado que la medición precisa de la velocidad a través de un encóder es invasiva y costosa, las técnicas de estimación de velocidad sin sensores (SSE en inglés) se convierten en la mejor opción. En la primera parte de esta tesis se realiza un análisis exhaustivo de las familias de técnicas SSE presentes en la literatura técnica. Como se demuestra en ella, aquellos métodos basados en armónicos de ranura (RSHs en inglés) y en armónicos laterales de frecuencia rotacional (RFSHs) son potencialmente los únicos que pueden satisfacer todos los requisitos mencionados anteriormente. Sin embargo, como también se demuestra en esta parte, y hasta esta tesis, siempre había existido un compromiso entre la precisión (característica de los RSHs) y la aplicabilidad general del método (característica de los RFSHs). En la segunda parte, y núcleo de esta tesis, se presenta una metodología que acaba con este compromiso, proporcionando así el primer método de estimación de velocidad preciso, general, no invasivo y automático para el diagnóstico en estado estacionario MCSA y la estimación de la eficiencia de motores de inducción que operan en un contexto de Industria 4.0. Esto se consigue desarrollando una novedosa técnica basada en RSHs que, por primera vez en la literatura técnica, elimina la necesidad de conocer/estimar el número de ranuras del rotor, lo que había impedido hasta la fecha que estos métodos fueran de aplicación general. Esta técnica proporciona además un procedimiento fiable y automático para localizar la familia de RSHs en el espectro de la corriente de línea de un motor de inducción. De igual forma y sin la ayuda de un experto, la técnica es capaz de determinar los parámetros necesarios para estimar la velocidad a partir de los RSHs, utilizando medidas tomadas en régimen estacionario. La metodología es validada utilizando motores con diferentes características y tipos de alimentaciones, empleando para ello simulaciones, pruebas de laboratorio y 105 motores industriales. Además, se muestra un caso de aplicación industrial en el que el algoritmo desarrollado se implementa en un sistema de monitorización continua mediante MCSA, lo que acaba conduciendo al descubrimiento de un nuevo fallo en motores sumergibles de pozo profundo: el desgaste de los anillos de cortocircuito. Por último, se presenta una segunda aplicación directa para este tipo de motores derivada del procedimiento de detección de RSHs: el uso de estos armónicos para diagnosticar, en fase temprana, cortocircuitos entre espiras. / [CA] Hi ha dos aspectes crucials a l'hora d'operar motors d'inducció en la indústria: l'estimació de la seua eficiència (per a minimitzar el consum d'energia) i el seu diagnòstic (per a evitar parades intempestives i reduir els costos de manteniment). Per a estimar l'eficiència del motor és necessari mesurar tensions i corrents. Per això, resulta convenient i molt útil utilitzar el mateix corrent per a diagnosticar també el motor (Motor Current Signature Analysis: MCSA). En aquest sentit, la tècnica MCSA més adequada és aquella basada en la localització d'harmònics de fallada en l'espectre del corrent de línia de l'estator en règim permanent, ja que aquesta és la condició de funcionament de la majoria dels motors d'inducció de la indústria. D'altra banda, atés que la freqüència d'aquests harmònics depén de la velocitat, resulta imprescindible conéixer aquesta magnitud amb precisió, ja que això permet localitzar correctament els harmònics de fallada i, per tant, reduir les possibilitats de falsos positius/negatius. Al seu torn, una mesura precisa de la velocitat també permet calcular amb precisió la potència mecànica, la qual cosa es tradueix en una estimació més exacta del rendiment. Finalment, per a adaptar-se a les necessitats de la Indústria 4.0, en la qual es monitora contínuament un gran nombre de motors, la velocitat també ha de ser obtinguda de manera no invasiva, automàtica i per a qualsevol motor d'inducció. En aquest sentit, atès que el mesurament precís de la velocitat a través d'un encóder és invasiva i costosa, les tècniques d'estimació de velocitat sense sensors (SSE en anglés) es converteixen en la millor opció. En la primera part d'aquesta tesi es realitza una anàlisi exhaustiva de totes les famílies de tècniques SSE presents en la literatura tècnica. Com es demostra en ella, aquells mètodes basats en harmònics de ranura (RSHs en anglès) i harmònics laterals de freqüència rotacional (RFSHs en anglés) són els més prometedors, ja que son potencialment els únics que poden satisfer tots els requisits esmentats anteriorment. No obstant això, com també es demostra en aquesta part, i fins a aquesta tesi, sempre havia existit un compromís entre la precisió (característica dels RSHs) i l'aplicabilitat general del mètode (característica dels RFSHs). En la segona part, i nucli d'aquesta tesi, es presenta una metodologia que acaba amb aquest compromís, proporcionant així el primer mètode d'estimació de velocitat precís, general, no invasiu i automàtic per al diagnòstic en estat estacionari MCSA i l'estimació de l'eficiència de motors d'inducció que operen en un context d'Indústria 4.0. Això s'aconsegueix desenvolupant una nova tècnica basada en RSHs que, per primera vegada en la literatura tècnica, elimina la necessitat de conéixer/estimar el nombre de ranures del rotor, cosa que havia impedit fins avui que aquests mètodes foren d'aplicació general. Aquesta tècnica proporciona a més un procediment fiable i automàtic per a localitzar la família de RSHs en l'espectre del corrent de línia d'un motor d'inducció. De la mateixa forma i sense l'ajuda d'un expert, la tècnica és capaç de determinar els paràmetres necessaris per a estimar la velocitat a partir dels RSHs, utilitzant mesures preses en règim estacionari. La metodologia és validada utilitzant motors amb diferents característiques i condicions d'alimentació, emprant per a això simulacions, proves de laboratori i 105 motors industrials. A més, es mostra un cas real d'aplicació industrial en el qual l'algoritme desenvolupat és implementat en un sistema de monitoratge continu mitjançant MCSA, la qual cosa acaba conduint al descobriment d'una nova fallada en motors submergibles de pou profund: el desgast dels anells de curtcircuit. Finalment, es presenta una segona aplicació directa per a aquest tipus de motors derivada del procediment de detecció de RSHs: l'ús d'aquests harmònics per a diagnosticar, en fase primerenca, curtcircuits entre espires. / [EN] There are two crucial aspects when operating induction motors in industry: efficiency estimation (to minimize energy consumption) and diagnosis (to avoid untimely outages and reduce maintenance costs). To estimate the motor's efficiency, it is necessary to measure voltages and currents. Hence, it is convenient and very useful using the same current to also diagnose the motor (Motor Current Signature Analysis: MCSA). In this regard, the most suitable MCSA technique is that based on locating fault harmonics in the spectrum of the stator line current under steady-state, as this is the operating condition of most induction motors in industry. Since the frequency of these harmonics depends on the speed, it becomes essential to be able to know this magnitude with precision, as this makes it possible to correctly locate the fault harmonics, and therefore, reduce the chances of false positives/negatives. In turn, an accurate speed information also allows to calculate the mechanical power with precision, which results in a more accurate estimation of the motor performance. Finally, to adapt to the needs of 4.0 Industry, where large numbers of motors are continuously monitored, the speed must not only be obtained very accurately, but also non-invasively, automatically (without the need for an expert) and for any induction motor. In this regard, since precise speed measurement through a shaft sensor is invasive and expensive, Sensorless Speed Estimation (SSE) techniques become the best option. The first part of this thesis conducts a thorough analysis of all the families of SSE techniques present in the technical literature. As demonstrated therein, those techniques based on Slotting and Rotational Frequency Sideband Harmonics are the most promising, as they can potentially meet all the aforementioned requirements. However, as also proved in this part, and up to this thesis, there had always been a trade-off between accuracy, characteristic of Rotor Slot Harmonics (RSHs), and general applicability, characteristic of Rotational Frequency Sideband Harmonics (RFSHs). The second part, and core of this thesis, presents a methodology that ends with this trade-off between accuracy and general applicability, thus providing the first precise, general, noninvasive and automatic speed estimation method for MCSA steady-state diagnosis and efficiency estimation of induction motors that operate in a 4.0 Industry context. This is achieved by developing a novel RSH-based technique that, for the first time in technical literature, eliminates the need to know/estimate the number of rotor slots, which had so far prevented these techniques to be generally applicable. This technique also provides a reliable and automatic procedure to, from among the high number of significant harmonics present in the spectrum of the line current of an induction motor, locate the RSHs family. Also automatically and without the help of an expert, the technique is able to determine the parameters needed to estimate speed from RSHs, using only measurements taken during the motor normal operation at steady-state. The methodology is validated using motors with different characteristics and supply conditions, by simulations, lab tests and with 105 industrial motors. Furthermore, a real industrial case of application is shown as well, where the speed estimation algorithm is implemented in a continuous motor condition monitoring system via MCSA, which eventually leads to the discovery of a new fault in deep-well submersible motors: the wear of end-rings. Finally, a second direct application derived from the reliable and automatic procedure to detect RSHs is presented: the use of these harmonics to diagnose early-stage inter-turn faults in induction motors of deep-well submersible pumps. / Bonet Jara, J. (2023). A precise, General, Non-Invasive and Automatic Speed Estimation Method for MCSA Steady-State Diagnosis and Efficiency Estimation of Induction Motors in the 4.0 Industry [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/194269 / Compendio

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