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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.
21

Technický audit vodojemů / Technical Audit of Water Tanks

Šlesinger, Jan January 2015 (has links)
This diploma thesis aims to design a methodology for technical audit of water tanks. The first part presents basic information on water tanks, followed by a brief summary of Czech legislation related to developing water tank renewal financing plans. The key part of the thesis is designing the structure of TEAA water tanks module, which will be included in TEA Water methodology, being developed at Institute of Municipal Water Management. The module under proposal is implemented as a MS Excel application, which is used to assess selected water tanks. The assessment results are compared to results obtained using TEA Water web application, which implements a draft of the TEAA module from October 2014, and to the results obtained using TAWAT.xls application.
22

Wireless Sensor And Actuator Nodes For A Process Control Experiment

Wälivaara, Jesper January 2018 (has links)
This report details the work which has been done to redesign an older process control lab setup, in order for it to become fully modular and wirelessly controllable.The process control lab setup of interest was the quadruple water tank process. Asa proof of concept, a single prototype tank module of the quadruple tank setup wasto be redesigned, where this new design would use entirely modular and wirelesslycontrollable sensors and actuators. The design of these wireless devices was donefrom scratch, the end result was that a set of micro-controller based devices whichcommunicate over Xbee radios were manufactured. Control of this wireless tanksystem was achieved through a custom Simulink interface, said interface was alsocreated during this project. The finalized tank prototype system worked as intendedand it fulfilled all of the relevant system requirements regarding the sensor and actuator network design. There was originally a mechanical design component in thisproject which had to be left after the initial research stages due to time constraints,which concerned the construction of a new tank system. This prototype system wasa proof of concept, which proved the feasibility of building larger scale wirelesslycontrollable process control systems, such as the quadruple water tank process.
23

Modélisation et contrôle des ballons d'eau chaude sanitaire à effet Joule : du ballon individuel au parc / Modeling and control of electric hot water tanks : from the single unit to the group

Beeker-Adda, Nathanaël 13 July 2016 (has links)
Cette thèse s'intéresse au développement de stratégies de décalage de charge pouvant être appliquées à un parc de chauffe-eau Joule (CEJ).On propose une modélisation entrée-sortie du système que constitue le CEJ. L'idée est de concevoir un modèle précis et peu coûteux numériquement, qui pourrait être intégré dans un CEJ intelligent. On présente notamment un modèle phénoménologique multi-période d'évolution du profil de température dans le CEJ ainsi qu'un modèle de la demande en eau chaude. On étudie des stratégies d'optimisation pour un parc de CEJ dont la résistance peut être pilotée par un gestionnaire central. Trois cas de figures sont étudiés. Le premier concerne un petit nombre de ballons intelligents et présente une méthode de résolution d'un problème d'optimisation en temps discret. Puis, on s'intéresse à un parc de taille moyenne. Une heuristique gardant indivisibles les périodes de chauffe (pour minimiser les aléas thermo-hydrauliques) est présentée. Enfin, un modèle de comportement d'un nombre infini de ballon est présenté sous la forme d'une équation de Fokker-Planck. / This thesis focuses on the development of advanced strategies for load shifting of large groups of electric hot water tanks (EHWT).The first part of this thesis is dedicated to representing an EHWT as an input-output system. The idea is to design a simple, tractable and relatively accurate model that can be implemented inside a low-power computing unit embedded in a smart EHWT, for practical applications of optimization strategies. It includes in particular a phenomenological multi-period model of the temperature profile in the tank and a realistic domestic hot water consumption model.The second part focuses on the design of optimal control strategies for a group of tanks. Three use-cases are studied. The first one deals with a small number of smart and controllable EHWT for which we propose a discrete-time optimal resolution method. The second use-case adresses a medium-scale group of controllable tanks and proposes a heuristic which keeps the heating period undivided to minimize thermo-hydraulic hazards. Finally, we present the modelling of the behavior of a infinite population of tanks under the form of a Fokker-Planck equation.
24

Zdroje vody a čerpací stanoviště pro požární techniku v okrese Písek. / Water resources and water pumping sites for fire equipment in Písek district.

VIKTORA, Vladimír January 2011 (has links)
In my diploma thesis I have created the updated version of water sources and pumping sites for fire equipment in the Písek district. I acquired large volumes of data by a detailed physical inspection of possible water sources in all villages in the Písek district. In my thesis I have mentioned water sources only in those villages that are classified into fire protection units, category II and III. The complete summary of all water sources and water pumping sites is on the attached CD. The data contain the name of the village, type of water source, GPS coordinates, additional information about the water source and any additional notes regarding repairs, distances from the village, etc. Photo documentation and the map section were produced for each water source. In many villages, there are hydrant networks which, in those villages where there is no water source, can have a substantial effect on fire safety. The thesis also includes the list of all hydrant networks in the Pisek district, including the owners and operators. The thesis can be used for the Operating and Information Centre of the Fire Brigade for the South Bohemian region which, for the demand for water for rescue and liquidation can send the unit directly to the water source according to the ascertained data. For some water sources, below the table in the note, there may be corrections or improvements that lead to a better use of these sources. The thesis monitors the existing status of the water and pumping sites for fire equipment in the Pisek district. I compared the acquired data with data from South Bohemian Region Regulation No.4/2003 at 2.12.2003. It results from the compared data that permanent updating and communication on the part of the municipalities with the Fire Brigade is necessary. In many places, water sources are closed and new water points originate with the possibility to pump this basic and main extinguishing agent.
25

Techno-economic analysis of power‑to‑heat‑to‑power storage for a residential building

López de Ceballos Regife, Alicia January 2021 (has links)
Despite the share of renewable energies worldwide is increasing, which can help in reducing the CO2 emissions, their unpredictability has become a problem due to the mismatch between generation and demand. Among the different alternatives to solve this problem, energy storage is a very interesting solution. Depending on the aim of the storage, there are two types: intra‑day or seasonal. The former corresponds normally to a highly efficient and high‑cost storage, such as the Li‑ion; whilst the latter is a low efficient and low‑cost storage. An example of this second type of storage is the power‑to‑heat‑to‑power storage, whose efficiency is mainly determined by the heat‑to‑power converter, and it can be increased if the waste heat produced in the converter is reused in a combined heat and power system.Given that the residential sector represents a large amount of the global energy use (both electricity and heat), this study has considered a power‑to‑heat‑to‑power storage in a fully electrified residential building with a PV installation in order to increase self‑consumption and reduce the cost. Both the heating, electricity and cooling demand are supplied by the system.As this storage technology is currently under an early stage of development, this project aims to understand the main challenges for this storage and the advantages over a very well settled technology, such as the Li-ion. In order to achieve this objective, a model has been created in Matlab. A parametric study has been conducted in which optimum sizing of the components for several scenarios have been considered, as a means to identify the most important parameters that could hinder the feasibility of the power‑to‑heat‑to‑power storage system.From the optimization it was concluded that the scenarios with a thermally driven heat pump for cooling, resulted in larger installations leading to higher cost due to the low coefficient of performance. Regarding the other scenarios which consider an electrical heat pump for cooling, this technology can surpass the Li-ion performance for heat‑to‑power efficiencies over 20 %. In these cases, the feasibility is clearly hindered by the cost per energy capacity, which must be below 5 €/kWh and could be achieved with silicon; and the cost per power capacity that must be around 300 €/kW. An example of a heat‑to‑power converter could be the TPV technology which is a solid‑state converter, whose efficiency is currently around 30 % and is expected to reduce its cost up to 300 €/kW. In smaller systems, in which the stand‑by heat losses have more impact over the system’s feasibility due to the larger surface to volume ratio, it is imperative to reduce these heat losses, as well as reduce the cost per energy and power capacities. In addition, it is remarkable that there is no significant improvement when increasing the heat‑to‑power efficiencies over certain values. To finish, as this technology increases its feasibility when implemented in large systems, further studies should be done in the industrial and tertiary sector.
26

Analýza hltnosti pojistného ventilu na napájecí vodě / The feedwater safety valve flow capacity analysis

Fialová, Michaela January 2011 (has links)
In this thesis I review the sufficient flow capacity of the safety valve against high-pressure heater thermal pressurization in high-pressure feedwater heater on nuclear power Dukovany. I present basic possible cases of thermal pressurization both a high node heater, and the extended pressure unit in case of closure all power heads to steam generators.
27

Development and Characterization of an Underwater Acoustics Laboratory Via in situ Impedance Boundary Measurements

Vongsawad, Cameron Taylor 20 December 2021 (has links)
Modeling underwater acoustic propagation comes with a variety of challenges due to the need for proper characterization of the environmental conditions. These conditions include ever changing and complex water properties as well as boundary conditions. The BYU underwater acoustics open-air tank test-bed and measurement chain were developed to study underwater acoustic propagation within a controlled environment. It was also developed to provide ways to test and validate ocean models without the high cost associated with obtaining open ocean measurements. However, tank measurements require additional characterization of boundary conditions associated with the walls of the tank which would not be present in an open ocean. The characterization of BYU's underwater acoustic tank included measuring the calibrated impulse response of the tank through frequency deconvolution of sine swept signals in order to determine the frequency dependent reverberation time through reverse Schroeder integration. The reverberation time allows for calculating the frequency dependent spatially averaged acoustic absorption coefficient of the tank enclosure boundaries. The methods used for this study, common to room acoustics, also yield insights into the Schroeder frequency limit of the tank as well as validate models used for quantifying the speed of sound in the tank. The acoustic characterization was validated alongside predicted values and also applied to a tank lined with anechoic panels in order to improve the potential for modeling the tank as a scaled open ocean environment. An initial investigation into effective tank models evaluated the idealized rigid-wall and pressure-release water-air boundary model, a finite-impedance boundary model applying the measured acoustic boundary absorption and a benchmark open ocean model known as ORCA in order to determine potential tank model candidates. This study demonstrates the efficacy of the methodology for underwater acoustic tank characterization, provides a frequency dependent acoustic boundary evaluation from 5-500 kHz, and provides an initial comparison of tank models with applied characterization.
28

Utvärdering av potential för värmeåtervinning från laborationsutrustning : Möjligheten att använda en kylvattenbassäng som termiskt säsongslager

Hammarström, Anton January 2018 (has links)
HETA utbildningar i Härnösand har ett ångkraftverk för undervisningssyfte som kyls ner med vatten från en underjordisk bassäng på cirka 329 m³. Syftet med detta examensarbete har varit att undersöka hur bassängen med spillvärmen från kraftverket kan användas som ett säsongslager i kombination med en befintlig 7,8 kW värmepump för att värma upp maskinhallen i deras laboratoriebyggnad. Ett kalkylark skapades i Microsoft Excel för att kunna genomföra beräkningarna. Då mätdata saknades skapades ett simulerat scenario baserat på temperaturstatistik och körschema för kraftverket från år 2017. Transmissionsförluster beräknades för bassängen och maskinhallen. För bassängen användes mestadels observationsdata och kännedom hos personalen, medan maskinhallens isolering i huvudsak fick uppskattas efter byggår. Resultatet blev att värmepumpen med aktuellt körschema kunde täcka cirka 45 % av maskinhallens årliga uppvärmningsbehov. Av de 276 GJ som tillfördes genom kylning av ångkraftverket under ett år beräknades endast 2,7 % kunna utnyttjas till uppvärmning av maskinhallen, på grund av för lite isolering i bassängen. De största begränsningarna för högre täckning och större nyttjande av spillvärmen bedömdes vara placeringen i tid av kraftverkets körningar, och värmepumpens effekt. Om körningarna skulle förläggas i huvudsak till november–april och värmepumpen ersättas med en på 10 kW, skulle 74 % av värmebehovet kunna täckas och över 18 % av spillvärmen utnyttjas. Andra saker som förbättrad isolering i bassängen och större vattenvolym bedömdes också kunna förbättra bassängens kapacitet som energilager. / HETA Education in Härnösand has a steam power plant for educational purposes which is cooled with water from a 329 m³ underground basin. The purpose of this thesis has been to examine how the basin with the waste heat can be used as seasonal thermal energy storage with an existing 7.8 kW heat pump in order to heat the machine room of their lab building. A spreadsheet was created in Microsoft Excel in order to carry out the calculations. As no measurement data was available, a simulated scenario was created based on temperature statistics and the operating schedule for the power plant from the year 2017. Transmission losses were calculated for the basin and the machine room. For the basin, mostly observational data and knowledge among the staff were used, while the insulation for the machine room mainly had to be estimated based on the construction year. The result was that the heat pump, with the current operating schedule, could cover around 45% of the yearly heating demand of the machine room. Of the 276 GJ that were added through cooling of the power plant during a year, according to calculations, only 2,7% could be used for heating the machine hall, due to lacking insulation in the basin. The greatest limitations for achieving a higher heating coverage and a greater usage of the waste heat were assessed to be the placement in time of the power plant runs, and the effect of the heat pump. If the runs would be placed mainly in November–April, and the heat pump replaced with a 10 kW one, around 74% of the heating demand could be covered and 18 % of the waste heat used. Other things, such as increased insulation in the basin and larger water volume were also assessed to be able to increase the capacity of the basin as heat storage.

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