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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.
981

A systems approach to biogasplanning in Stockholm, Sweden

Österlin, Calle January 2012 (has links)
The Swedish capital Stockholm is at the forefront of biogas gas use, especially when it comesto biogas used for vehicle gas. This technology has the potential of being a fuel with veryhigh environmental performance, but in order to realize the full potential publicenvironmental management must be optimized. Environmental objectives are anenvironmental management is one tool that is used to strive for the desired development. Theaim of this study is to explain the dynamics within the biogas system in Stockholm, with aparticular emphasis on which factors that affects the amount of biogas available for vehiclegas upgrading on the market in Stockholm. The study has been conducted using modelingsessions with key stakeholders involved in the biogas system. The study concludes that theformulation of environmental objectives has a profound impact on how the variousstakeholders act, and thus how the system behaves. The trade off of how much fossil naturalgas that can be mixed into the renewable biogas based vehicle gas is at the very pinnacle ofcomplex matter. A conclusion that is of vital importance for the local planning process andwhen the experiences of Stockholm’s environmental planning are communicated out to therest of the world.
982

Automatic control of a marine loading arm for offshore LNG offloading offloading / Commande d’un bras de chargement de gaz naturel liquéfié en milieu marin

Besset, Pierre 27 April 2017 (has links)
Un bras de chargement de gaz est une structure articulée dans laquelle du méthane peut s’écouler à température cryogénique. En haute mer, ces bras sont installés sur le pont de navires-usines et se connectent à des méthaniers pour leur transférer du gaz. En raison de problèmes de sécurité et de performances, il est souhaité que le bras de chargement soit robotisé pour qu’il se connecte automatiquement. Cette thèse a pour objectif l‘automatisation de la connexion. Cette opération nécessite un pilotage de grande précision vis à vie de la taille du bras. Pour cette raison le bras est d’abord étalonné pour augmenter sa précision statique. Ensuite, des analyses modales expérimentales mettent en évidence l’importante souplesse de la structure des bras de chargement. Pour cette raison un générateur de trajectoires « douces », à jerk limité, est développé afin de piloter le bras sans le faire vibrer. Enfin, un système de compensation actif visant à compenser les mouvements relatifs des deux navires est mis en place. Cette compensation combine la génération de trajectoires douces avec une composante prédictive basée sur des réseaux de neurones. Cette dernière permet de prédire et d’anticiper les mouvements des navires sur l’océan, afin d’annuler tout retard dans la compensation. Finalement, cette thèse présente la première connexion automatique d’un bras de chargement, et démontre la validité de cette approche. / Marine loading arms are articulated structures that transfer liquefied gas between two vessels. The flanging operation of the loading arm to the receiving tanker is very sensitive. This thesis aims to robotize a loading arm so it can flange automatically. The required accuracy for the connection is very high. A calibration procedure is thus proposed to increase the accuracy of loading arms. Moreover a jerk-limited trajectory generator is developed to smoothly drive the arm without inducing oscillation. This element is important because the structures of loading arms have a very low stiffness and easily oscillate, as highlighted by modal analyses.A predictive active compensation algorithm is developed to track without delay the relative motion between the two vessels. This algorithm relies on an artificial neural network able to predict the evolution of this relative motion. Finally this thesis presents the first automatic connection of an offshore loading arm. The success of the final tests validate the feasibility the automatic connection and the validity of this approach.
983

Le gaz naturel algérien dans la sécurité énergétique de l'Union Européenne : un enjeu géopolitique / The Algerian Natural Gas in European Union’s Energy Security : a Geopolitical Challenge

Kedidir, Mansour 12 June 2015 (has links)
Au lendemain de son indépendance, l’Algérie était confrontée au problème du développement de son potentiel gazier. Pour se soustraire à l’emprise de la France sur ses hydrocarbures, elle décida de placer son gaz dans le marché américain. Cette option visait à développer l’industrie du GNL et à optimiser la rente pour pouvoir financer le développement économique du pays. Après l’échec de ce choix, l’Algérie s’est retournée vers le marché européen. Depuis, les échanges se sont intensifiés au point où l’Algérie est considérée aujourd’hui comme un partenaire énergétique stratégique de l’Union européenne. Cette situation lui donnera-t-elle la possibilité de continuer à approvisionner l’Europe en gaz ? Au regard des contraintes liées à la gestion du secteur de l’énergie, la concurrence des deux gaz russe et qatari et l’entrée prévisible en production des gisements en Mediterrannée orientale, la part du gaz algérien dans la sécurité énergétique de l’Europe constitue-t-elle un enjeu géopolitique ? La présente thèse a pour objectif de confirmer ou d’infirmer la réalité de cet enjeu. Pour cela, elle pose des questions inhérentes aux différentes politiques initiées par l’Algérie durant plus d’un demi-siècle, à sa marge de manœuvre pour se maintenir au troisième rang des fournisseurs de gaz à l’Europe, et à la dépendance de cette dernière en matière de gaz et à ses perceptions géopolitiques à l’égard de ses fournisseurs (principalement, la Russie et les pays producteurs de la rive Sud). / After the National Independence (1962), Algeria was dealing with the difficulties of developing its gas potential. In order to escape the French hegemony of its hydrocarbons resources, Algeria decided to place and invest its gas resources in the US market. This economic option was motivated by the urgent need to develop the LNG industry and to maximize incomes in order to improve the national economic development. After the failure of this economic option, Algeria got back to the European market. Since then, EU – Algeria economic relations have been intensified. Nowadays, Algeria is considered as a strategic EU partner, in the field of energy resources. Does this situation enable Algeria to supply the European economy with gas for a long time? Given the international constraints related to the management of the energy sector, competition from both Russia and Qatar and the new discovered gas reserves in Eastern Mediterranean basin, does the Algerian gas and its importance in EU energy security represent a geopolitical issue?This thesis aims to examin the pertinence of this issue. It seeks to respond to questions related to the various policies initiated by Algeria for more than half a century, to Algeria’s strategy to maintain its position as the third strategic gas supplier of Europe, and to the European energy dependence and its geopolitical perceptions towards its suppliers (especially Russia and the South side of Mediterranean basin producers).
984

Understanding the Energy Interdependence Between the EU and Russia: Case of the Baltic Sea Region

Izosimova, Svetlana January 2016 (has links)
This study is conducted with the purpose to unfold hidden sides of the EU – Russian energy cooperation and to shed a light on possible reasons for existing problems that have rarely been voiced before. This study provides an alternative view on the role of the Baltic Sea region in the overall EU – Russian energy dialogue and its current situation. In this research the historical observation of the energy interdependence regime development is examined and the crucial turning points in the energy interdependence like the EU enlargement 2004, the gas cut offs 2006 and 2009, and crises 2014 are reconsidered. The energy security policies of the EU and Russia are analyzed by adopting the realist approach and applied to the case of the Baltic Sea region. Furthermore, based on the regional complex security theory and interdependence theory, the way how interstate gas relations in the Baltic Sea region affect the EU – Russian interdependence is discussed.
985

Toky ropy a zemního plynu v Evropě: současná situace a perspektivy / Flows of oil and natural gas in Europe: current situation and perspectives

Hynoušová, Hana January 2011 (has links)
The aim of this thesis is to analyze and determine the actual flow of oil and natural gas in Europe, from the results to draw conslusions of the weight of the EU's dependence on Russian energy supplies and subsequently to determine the possibilities and prospects for further security flows of oil and natural gas to the EU. Oil and natural gas are the basic strategic raw materials of world economics, including economics of European countries. Most of the European countries does not have adequate supplies of energy raw materials. In particular, EU countries are therefore dependent on external supplies of oil and natural gas. The first chapter of the thesis is focused on oil and natural gas as major raw materials for the current energy situation in Europe. I defined the terms "oil" and "natural gas" and I analyzed the significant deposits of these materials and described their current production and consumption in Europe. In the second chapter I focused on the current flows of oil and natural gas in Europe, particularly on the European network of pipelines. On the baisis of these two chapters I specified the weight of the EU's dependence on energy supplies from Russia and identified the main problems of these supplies. In the third chapter of the thesis I dealt with the security flow of oil and natural gas to the EU and its perspectives and I gave the EU energy policy. I have analyzed selected documents of European energy policy, the EU's energy mix and I identified possible ways to reduce the EU's energy dependency. I included diversification of supply routes and the diversification of EU energy mix among these options. In conclusion, I summarized the current European energy situation, assessed European energy policy and outlined its future development.
986

Characterizing Storm Water Runoff from Natural Gas Well Sites in Denton County, Texas

Wachal, David J. 05 1900 (has links)
In order to better understand runoff characteristics from natural gas well sites in north central Texas, the City of Denton, with assistance through an EPA funded 104b3 Water Quality Cooperative Agreement, monitored storm water runoff from local natural gas well sites. Storm water runoff was found to contain high concentrations of total suspended solids (TSS). Observed TSS concentrations resulted in sediment loading rates that are similar to those observed from typical construction activities. Petroleum hydrocarbons, in contrast, were rarely detected in runoff samples. Heavy metals were detected in concentrations similar to those observed in typical urban runoff. However, the concentrations observed at the gas well sites were higher than those measured at nearby reference sites. Storm water runoff data collected from these sites were used to evaluate the effectiveness of the water erosion prediction project (WEPP) model for predicting runoff and sediment from these sites. Runoff and sediment predictions were adequate; however, rainfall simulation experiments were used to further characterize the portion of the site where drilling and extraction operations are performed, referred to as the "pad site." These experiments were used to develop specific pad site erosion parameters for the WEPP model. Finally, version 2 of the revised universal soil loss equation (RUSLE 2.0) was used to evaluate the efficiency of best management practices (BMPs) for natural gas well sites. BMP efficiency ratings, which ranged from 52 to 93%, were also evaluated in the context of site management goals and implementation cost, demonstrating a practical approach for managing soil loss and understanding the importance of selecting appropriate site-specific BMPs.
987

Výpočet tepelné bilance využití latentního tepla spalin pomocí kondenzátoru / Calculation of the heat balance of latent heat utilization of flue gases by means of a condenser

Toman, Filip January 2018 (has links)
Thesis is focused on calculation of the condenser of flue gas, which is created by burning of natural gas. In the first part is theoretical overview of equations describing film condensation and physical properties of the flue gas. The second part deals with practical thermal calculation of the specified condenser. In third part parametric study is done in which a tempature of cooling water at inlet and the coefficient of excess air are changed. The last part of the thesis is dedicated to geometric design of the flue gas condenser whose required power is 8 MW.
988

Simulátor GateCycle a jeho aplikace / GateCycle simulator and its applications

Svoboda, Adam January 2018 (has links)
Hlavná náplň tejto práce je oboznámenie so softvérom GateCycle od spoločnosti General Electric a jeho následná aplikácia na simulovanie industriálneho parného kotla produkujúceho 120 t pary za hodinu. Dizajn práce je vo forme výučbového materiálu, ktorý môže byť použitý vo výuke predmetu procesného inžinierstva zameraného na simulačné softvéry. Prvá časť práce je venovaná krátkej teórii o simulačných softvéroch a uvádza niekoľko najznámejších procesných inžinierskych simulačných programov. Druhá časť je napísaná formou GateCycle manuálu. V krátkosti predstavuje pracovné prostredie a rozhranie softvéru, demonštruje ako vytvoriť a spustiť simulačný model, zadať vstupné dáta a vytvoriť reporty. Tretia časť práce je praktická, vybraný industriálny parný kotol je prezentovaný a následne je vybudovaný jeho simulačný model. Táto časť je vytvorená vo forme príručky „krok za krokom“ vysvetľujúcej ako vytvoriť model kotla a aké dáta boli zadané do jednotlivých procesných aparátov. Kotol je simulovaný v 3 režimoch, využívajúc zemný plyn, ťažký vykurovací olej, či dechtovú vykurovaciu zmes ako palivo a je prevádzkovaný za mierne rozličných procesných podmienok. V závere sú vypočítané spotreby paliva porovnané s reálnymi prevádzkovými dátami a je vyhodnotená presnosť výpočtov softvéru GateCycle v týchto konkrétnych prípadoch.
989

Experimentální ověření kogeneračního systému na bázi plynové mikroturbíny / Experimental verification of a gas micro-turbine cogeneration system

Buřil, Lukáš January 2019 (has links)
This master’s thesis deals with problematics of natural gas microturbine integration into industrial laundry operation. This integration means utilization of waste heat for direct drying and water heating in a heat exchanger. This heated water can be used in further laundry processes, for example laundering. All the experiments were carried out on the cogeneration system that is installed in Laboratory of Energy Intensive Processes in NETME Centre at the Faculty of Mechanical Engineering of Brno University of Technology. This system consists of a natural gas microturbine Capstone C30 with nominal electric power of 30 kW, an industrial dryer Primus DX55 with a nominal capacity of 55 kg for laundry and a heat exchanger Vakading type Vakavlas with nominal power of 53 kW. All necessary theoretical and technical preparation was done in order to carry out experiments as follows: • Standard drying program • Water accumulation test • Test of performance of heat exchanger • Direct drying with the use of microturbine’s flue gases These experiments were analyzed and discussed within this thesis. The main contribution of this work is as follows: • Summary of all the knowledge in the area of direct drying • Creation of methodology of utilization of flue gases for direct drying not only in laundry industry but in related fields • Summary of requirements and ways of heat exchanger testing and determination of heat exchanger parameters • Determination of optimal working settings of installed cogeneration system • Description of weak spots in the system and suggested improvements • Basic economic analysis of operating costs During the experiments, it was found that in case of direct drying better results could be achieved in comparison with standard drying. The functionality of the whole system together with the heat exchanger was verified and thus also the possibility of integrating the turbine into the washing process was confirmed. The integration of a natural gas microturbine is both technically and economically feasible for many industrial applications.
990

Technologie pro zkapalňování plynů a jeho využití a distribuce / Technology for liquefaction gases and its use and distributing

Štěpánek, Jindřich January 2013 (has links)
This thesis deals with technologies for gas liquefaction and storage. The first section summarizes the development of liquefaction technology using expanders and throttling valves, followed by current technology. This is especially a rotary expanders. The storage technology is the above-ground storage of cryogenic tanks. The thesis includes proposals turbine wheels for liquefaction lines and included two proposals liquefaction cycles.

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