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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

Microturbine for Micro-Cogeneration Application

Murray, PAUL 27 September 2009 (has links)
A micro-cogeneration system based on an ArtesJet KJ-66 hobby microturbine may be able to provide a single family dwelling with required heat and power, increasing total efficiency due to utilization of waste heat. The feasibility of such a system was investigated. An engine model based on the similar JG-100 engine was developed, written in Microsoft Excel™ and Visual Basic™. The predicted running characteristics of the KJ-66 were simulated, and a prediction of how these characteristics would be shifted if a diffuser was attached to the engine was made. An experimental test program was carried out on the KJ-66 engine to determine if this prediction was correct, and to more accurately characterize the performance of the engine. Two diffusers were constructed to use with the testing, along with the nozzle that was supplied with the engine. Having the diffusers on the engine reduced the fuel air ratio by approximately 20% as predicted. A hypothetical micro-cogeneration system was simulated building on the earlier engine model, with modified turbomachinery maps and combustor performance based on the experimental data. An 85% effective recuperator was included in the model, as well as a recovery heat exchanger. The simulation showed an electrical output of 8.9 kW, a heat output of 30.9 kW, an electrical efficiency of 15.5%, and a total efficiency of 69.0%. While these efficiencies are low, improvements could be made by modifying the turbomachinery and by using a condensing recovery heat exchanger to give a better overall efficiency for the micro-cogeneration system. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2009-09-26 22:03:57.11
2

A Study on the Blade Strength and the Dynamic Characteristics of Microturbines

Chen, Hsuan-sheng 01 July 2005 (has links)
The high speed mini or micro-turbo electrical power system¡]MTEPS¡^has been used widely as an important spare power source in different military purposes and all kinds of emergency facilities. The interaction between the centrifugal and pressure load on turbo blades of a high speed MTEPS system is investigated in this project. The effect of temperature on the strength variation of the turbo blades will be investigated by employing the thermal-mechanical- creep coupling model provided in the MARC finite element method package. The stress distribution of the compressor, turbine, rotor and blades are calculated. The combined effect of temperature, pressure and rotation speed on the stress and deformation of compressor and turbine blades was also evaluated and compared in this project.
3

The Impact of a Microturbine Power Plant on an Off Road Range Extended Electric Vehicle

Zetts, Andrew Wyatt 31 March 2015 (has links)
The purpose of this thesis is to examine the feasibility of using a microturbine to power an off-road Series Hybrid Autonomous Vehicle (SHEV), and evaluate the benefits and drawbacks inherent in using a microturbine rather than an Internal Combustion Engine (ICE). The specific power plant requirements for a low speed hybrid vehicle that must operate extensively as an Electric Vehicle (EV) and run on JP-8 (a diesel equivalent) are unusual; few options can adequately address all of these needs. Most development of Hybrid Electric Vehicles (HEVs) has focused on gasoline ICE power plants, but Diesel ICEs are heavier, which has an adverse effect on EV range. While mechanically-linked turbine vehicles failed to have the same performance abilities of their ICE counterparts, a microturbine generator-powered SHEV can take advantage of its battery pack to avoid the issues inherent in its mechanical predecessors. A microturbine generator is mechanically decoupled from the powertrain, allowing for an incredibly power dense power plant that lightens the weight of the vehicle. This weight reduction directly correlates to an increased EV operational range, enhancing mobility, stealth, and the tactical effectiveness of the squad that the vehicle is intended to support. To determine the full impact that a microturbine might have on this specific SHEV, modeling of the vehicle was conducted to directly compare a microturbine and an ICE power plant using two drive cycles that were designed to simulate the typical operation specific to the vehicle. Drive cycle analysis revealed that the improved EV performance and design flexibility offered by the microturbine's weight justifies the selection of a microturbine over an ICE for this specific case. This decision is dependent upon several factors: a microturbine with fuel efficiency comparable to an ICE, the selection of a large battery pack, and an emphasis on EV operations. / Master of Science
4

Experimentální ověření parametrů vodní mikroturbíny / Testing of micro water turbine

Zríni, Miroslav January 2018 (has links)
The aim of the diploma thesis is to measure and subsequently to evaluate microturbine characteristics. This is a new type of turbine, which was designed in the diploma thesis and is based on the theory of waterwheels. It is designed for low heads and low flow, where conventional turbines are not suitable. Taking advantage of this low heads area will be very important in the future as the hydroenergetic potential is getting gradually exhausted. The turbine has two ways of regulation - turning blades and shifting the drawer. In the first phase, two complex measurements were performed. The next step was to process the measured data gradually in three programs. The result is the rendering of the characteristics that describe the hydraulic parameters of the turbine. The last chapter shows the design proposals for automatic regulation.
5

Caractérisation des paliers et écoulements secondaires d'une microturbine

Gauthier, Félix January 2009 (has links)
Depuis plus de 10 ans, l'étude de microsystèmes (MEMS : MicroElectroMechanical Systems) permettant la génération de puissance à petite échelle a fait l'objet d'une multitude de recherches dans le but d'offrir une meilleure alternative par rapport aux piles électrochimiques. Les premières études portant sur les microturbines à gaz ont permis de révéler le potentiel des micromachines rotatives pour l'implantation de micro centrales d'énergie sur une puce. La conception et la fabrication d'une première génération de microturbopompe ont permis d'établir les lignes directrices pour la conception d'une microturbine à cycle Rankine. Pour le bon fonctionnement d'un tel dispositif et pour en améliorer ses performances, il est important de mieux comprendre le comportement des écoulements internes influant sur le mouvement du rotor puisqu'ils ont été très peu étudiés. Le but de la présente recherche est d'effectuer une étude détaillée des composantes secondaires de la microturbopompe précédemment développée afin d'approfondir la compréhension des phénomènes en jeu lors de son opération. Dans la présente étude, des investigations expérimentales et des modèles approfondis ont été faits sur les joints d'étanchéité hydrodynamiques, le palier axial hydrostatique, le palier radial hydrostatique et l'écoulement radial secondaire. Combinée avec la modélisation de la turbine multiétage et de la pompe hydrodynamique, l'intégration simultanée de toutes les composantes a mis en évidence les interactions possibles entre les composantes. Ainsi, une nouvelle configuration d'opération a été proposée permettant d'atteindre un niveau de performance similaire aux essais antérieurs (295 kRPM), mais avec une pression d'alimentation du palier axial réduite considérablement ([environ]50%). Cette réduction de pression permet de se rapprocher davantage de l'opération avec des paliers autosuffisants qui a même été expérimentée, pour une première fois, à basse vitesse (77 kRPM). L'étude des joints d'étanchéité a démontré leur performance à haute vitesse (50 kPa à 190 kRPM) et l'importance bénéfique des effets de tension de surface. La pompe hydrodynamique a été caractérisée expérimentalement pour la première fois avec un écoulement externe, montrant que sa performance est limitée par le joint d'étanchéité. Pour la pompe avec un écoulement interne, un débit massique de 12 mg/s a été pompé à une vitesse de 180 kRPM. Une différence notable a été mesurée entre les deux types pompes implantés confirmant, pour une première fois, l'effet des forces centrifuges sur les performances de la pompe hydrodynamique. L'amélioration de la modélisation du palier axial a permis d'évaluer la position axiale du rotor en utilisant les pertes de pression et les débits massiques mesurés expérimentalement dans le palier axial. La forte rigidité angulaire du palier axial a également été mise en évidence. Finalement, les écoulements et le comportement dynamique du palier radial ont été étudiés analytiquement et expérimentalement, permettant de définir de nouveaux critères de conception afin d'éviter l'apparition d'instabilités dynamiques. L'étude plus approfondie des composantes secondaires de la microturbopompe a permis d'améliorer la compréhension des phénomènes dominants lors de son opération. Une base de compréhension supplémentaire a donc été établie pour le développement de micromachines rotatives telles que la microturbine à cycle Rankine et les microturbines à gaz.
6

Dynamique de rotor d’une turbine renversée à moyeu flexible

Landry, Céderick January 2017 (has links)
Le mémoire de maîtrise présente la dynamique de rotor d’une microturbine à gaz à configuration renversée permettant l’intégration de pales en céramique. Cette configuration permet d’utiliser des pales de turbine complètement en céramique car elles sont retenues en compression de l’extérieur par un anneau en composite qui est en rotation. Par contre, la configuration renversée nécessite une nouvelle conception de moyeu de turbine. En effet, l’anneau en composite est loin de l'axe de rotation. Par conséquent, il se dilate beaucoup dus aux efforts centrifuges ce qui entraîne un grand déplacement des pales. L’idée est donc de faire un moyeu flexible qui vient suivre le déplacement des pales pour appliquer une pression en dessous de ceux-ci, afin de les tenir en place par friction. La dynamique de rotor avec moyeu flexible est très peu documentée dans la littérature. Le projet de recherche consiste en la compréhension de la dynamique d’un moyeu flexible pour cibler les paramètres intervenant dans la vibration d’une turbine renversée. La recherche se fera via la conception d’un prototype permettant d’étudier l’effet de la flexibilité pour un concept donné. L’analyse de dynamique de rotor avec moyeu flexible est faite avec un modèle par éléments finis linéaire. Malgré le fait que des non-linéarités peuvent provenir des roulements à billes supportés par des films amortisseurs, un type de roulements couramment utilisé pour supporter des turbocompresseurs, il est démontré qu’un modèle linéarisé capte plutôt bien les tendances mesurées. Le but de ce projet est de déceler les paramètres problématiques d’un moyeu flexible et de découvrir les paramètres permettant une bonne dynamique.
7

Small-Scale Solar Central Receiver System Design and Analysis

Murray, Daniel 01 June 2012 (has links)
This thesis develops an analytical model of a small-scale solar central receiver power plant located at the California Polytechnic State University in San Luis Obispo, California at 35.28° N, 120.66° W. The model is used to analyze typical energy output at any time during the year. The power plant is designed to produce an output of 100 kW electrical power, and is supplemented by the combustion of natural gas. Methodologies for determining the proper size and layout of heliostats, optimal tower height, receiver size, and turbine engine selection are developed. In this specific design, solar shares of up to 73.2% and an annual average of 44% are possible through the use of a gas-solar hybrid microturbine engine. Larger solar shares are not possible due to the limited size of land (about 0.5 acres used for this project) which limits the number of possible heliostat installations.
8

Optimal Capacity and Location Assessment of Natural Gas Fired Distributed Generation in Residential Areas

January 2014 (has links)
abstract: With ever increasing use of natural gas to generate electricity, installed natural gas fired microturbines are found in residential areas to generate electricity locally. This research work discusses a generalized methodology for assessing optimal capacity and locations for installing natural gas fired microturbines in a distribution residential network. The overall objective is to place microturbines to minimize the system power loss occurring in the electrical distribution network; in such a way that the electric feeder does not need any up-gradation. The IEEE 123 Node Test Feeder is selected as the test bed for validating the developed methodology. Three-phase unbalanced electric power flow is run in OpenDSS through COM server, and the gas distribution network is analyzed using GASWorkS. The continual sensitivity analysis methodology is developed to select multiple DG locations and annual simulation is run to minimize annual average losses. The proposed placement of microturbines must be feasible in the gas distribution network and should not result into gas pipeline reinforcement. The corresponding gas distribution network is developed in GASWorkS software, and nodal pressures of the gas system are checked for various cases to investigate if the existing gas distribution network can accommodate the penetration of selected microturbines. The results indicate the optimal locations suitable to place microturbines and capacity that can be accommodated by the system, based on the consideration of overall minimum annual average losses as well as the guarantee of nodal pressure provided by the gas distribution network. The proposed method is generalized and can be used for any IEEE test feeder or an actual residential distribution network. / Dissertation/Thesis / M.S. Electrical Engineering 2014
9

MODELING AND SIMULATION OF A MICROTURBINE GENERATOR TO BE COUPLED WITH A MOLTEN CARBONATE FUEL CELL FOR DISTRIBUTED GENERATION

Justice, Karleine M. 28 June 2007 (has links)
No description available.
10

Micro-CHP Modeling and Simulation using Thermodynamic Cycles

Moran, Alan Mark 09 December 2006 (has links)
This thesis discusses the thermoeconomic modeling and simulation of micro-CHP systems powered by various prime movers. Micro Cooling, Heating, and Power (micro-CHP) is becoming an increasingly important energy option as the demand for electrical power as well as heating and cooling for buildings increases worldwide. Micro-CHP has the potential to increase the total energy efficiency for cooling, heating, and powering residences, offices, and other relatively small buildings by using waste thermal energy from electricity production to deliver heating and cooling. Calculation methodologies are presented for the different components of micro CHP systems using thermodynamic cycles and mass and energy balances. System performance characteristics are calculated and compared for different prime movers using various fuels. Performance characteristics that are compared include fuel consumption, monthly energy savings, and system energy efficiencies.

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