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The Intermediate Heat Exchanger for ESFR reactor primary circuit
Švihel, Miroslav ; Baláš, Marek (referee) ; Šen, Hugo (advisor)
The thesis is mainly focused on the design of the intermediate heat exchanger primary circuit of the reactor ESFR. Heat exchanger is calculated heat, hydraulic and strength and is finally processed part drawings. There are designed the basic dimensions of the tube bundle and container heat exchanger. There are included an overview of concepts and so far used types IHX at the nuclear power plants with fast reactors. There are also mentioned basic parameters of the project ESFR and evaluated the safety and operational reliability of the heat exchanger.
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Preparation and characterisation of ceramic electroactive materials for Na-ion batteries
Vaněk, Martin ; Libich, Jiří (referee) ; Čech, Ondřej (advisor)
Hlavním cílem této práce je charakterizace vzorků titanátů, jako materiálů pro sodíko-iontové (Na-ion) akumulátory. Syntéza některých vzorků je součástí této práce. Charakterizace je zaměřena na elektrochemické vlastnosti, složení a morfologii použitých materiálů. První část se zabývá lithium-iontovými (Li-ion) akumulátory. Byly vybrány, protože jsou ve vědeckých článcích dobře popsány a základní funkční princip je aplikovatelný také na Na-ion akumulátory. Materiály používáné pro katody, anody a elektrolyty následují po krátké části shrnující parametry a konstrukci Li-ion akumulátorů. Následující kapitola je zaměřena na sodíko-iontové akumulátory. Srovnání sodíku a lithia je následováno materiály používanými pro elektrody a elektrolyty (s důrazem na anodové materiály). Třetí část popisuje analytické metody použité pro charakterizaci elektrod a materiálů. Jedná se o elektrochemickou charakterizaci (cyklická voltametrie a galvanostatické cyklování s potenciálovým omezením), morfologii (rastrovací elektronová mikroskopie) a složení (X-ray difrakční spektroskopie). Poslední dvě kapitoly obsahují syntézu a charakterizaci sodného titanátu a charakterizaci dvou vzorků TiO2. Výsledky této práce jsou shrnuty v závěru.
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Investigation of intercalation of alkaline metals in electrochromic devices
Kortyš, Petr ; Špičák, Petr (referee) ; Svoboda, Vít (advisor)
This work deals with investigation of intercalation of alkaline metals in electrochromic devices by the help of the quartz crystal microbalance method. The general aim is to investigate the influence of molar mass and resistance on properties of vanadium pentoxide and tungsten trioxide electrochromic films. The main measuring method used for investigating of interacalation of sodium and lithium ions into these films is the cyclic voltammetry. Drawn graphs reveals that sodium and lithium ions shows different qualities during intercalation, particularly in participation of solvent, therefore, in the influence of molar mass and in structural changes in the films.
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XRD characterization of electrodes and electrode materials for electrochemical power sources
Klvač, Ondřej ; Chladil, Ladislav (referee) ; Čech, Ondřej (advisor)
The thesis describes available choices of methods for research of electrochemical power source electrode strcture by x-ray diffraction spectroscopy. At first there is a theoretical computation of difractogram. Then there are discussed possibilities of in-situ and ex-situ techniques as background research. Practical part of thesis compares theoretical assumptions to measurements of lithium and sodium cells, including analyze of crystallographic phases and lattice constants. As a conclusion, there are discussed possibilities of subsequent research.
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Negative electrodes for sodium ion batteries
Šátek, Dominik ; Libich, Jiří (referee) ; Máca, Josef (advisor)
This bachelor thesis deals with sodium-ion accumulators with focus on negative electrode, introduces basic terms in the field of secondary cells and describes production of accumulators. The result of this work are tested electrodes based on natural carbon and sodium metatitanate. These electrodes are then compared with each other and evaluated.
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Influence of calculation accuracy on final parameters of heat exchanger
Matyska, Stanislav ; Radil, Lukáš (referee) ; Foral, Štěpán (advisor)
The aim of this thesis is to make the design of the heat exchanger more accurate. It is assumed that the division of the tube bundle of the heat exchanger to a plurality of parts by the transferred thermal output can achieve more accurate values. The first part of this thesis is dedicated to the sorting of the heat exchangers according to different criteria, and a brief description of most of them. It describes what are their functions and what are the demands placed on them. Next, there is given a detailed description of the tubular heat exchanger, specifically the mantle one because it is fundamental for this thesis. To investigate the influence of calculation accuracy, there is selected a reference heat exchanger, which processes the study. There are described the main characteristics for the reference heat exchanger (transferred thermal output, heat transfer fluids, their temperature on inputs and outputs) and its construction (geometry of the heat exchanger, number of tubes, tube geometry). The thesis also discusses the influence of calculation accuracy of the heat exchanger at its parameters. In the next part, there is made a basic calculation of the tube bundle length and the pressure losses of the proposed heat exchanger. Here are assembled the theoretical basis for the calculation by dividing the tube bundle. Specific calculations are performed so that the tube bundle of the heat exchanger is divided into a selectable number of parts by the transferred thermal output. In each section, there is performed a calculation of the length of the specific tube bundle part. Individual lengths are added up and finally put together the entire tube bundle length. At the end of this section, there are calculated the pressure losses in the heat exchanger in a similar manner as for the calculating the total length of the tube bundle. In conclusion of this thesis there are described and clarified the results of the calculations. It examines the difference between the results of the reference and the proposed heat exchanger.
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Sodium - Carbon-dioxide Heat Exchangers for Sodium Cooled Fast Reactor NPP (SFR)
Foral, Štěpán ; Šimo, Tomáš (referee) ; Matal, Oldřich (advisor)
This master’s thesis deals with a design of Na-CO2 heat exchanger. There is a comparison of shell and tube heat exchanger with PCHE in the first part. Further the shell and tube heat exchanger with internally finned tubes was chosen as the basic conception. There was performed an optimization of construct and operations parameters for this concept. The optimization was performed on the basis of thermal and hydraulic calculations. Further there were performed calculations for ensuring of safe operation of the heat exchanger. The conclusion of the diploma thesis deals with comparison of the designed heat exchanger with similar projects.
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Heat exchangers Natrium - Carbon Dioxide
Foral, Štěpán ; Šimo, Tomáš (referee) ; Šen, Hugo (advisor)
This bachelor thesis describes design of heat exchanger for sodium cooled fast reactor of the IV. generation and compares the achieved solution with other realized projects. The first part deals with brief description of individual types of the nuclear reactors of the IV. generation and their main assets. There is an emphasis on the description of the sodium cooled fast nuclear reactor. The second part deals with complex design of a heat exchanger, when the initial concept is considered to be a heat exchanger with sodium on one side (warming medium) and carbon dioxide on the other side (heated medium). The core of this part is comparing individual concepts of the heat exchanger when variable construction materials are used. Furthermore there is accomplished range of heat, hydraulic and strength calculations of basic proportion of the options of the solution of the heat exchanger with work medium inside of pipes and outside of pipes. There are presented summary of the accomplished observation and comparing of the designed concept with realized similar projects in the conclusion.
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Sodium-ion batteries: research of carbon based negative electrode materials
Homolka, Tomáš ; Máca, Josef (referee) ; Libich, Jiří (advisor)
This work focuses on the research of hard carbon as a promising negative electrode material for sodium-ion batteries. The first part deals with electrochemical cells and their development in general. Then lithium-ion cells, their history and the materials currently used are mentioned. The next section discusses sodium-ion cells, their development so far, current issues and differences compared to lithium-ion cells, as they appear to be one of the promising post-lithium technologies with the potential for rapid commercialization. In the practical part, properties of some material samples are tested with a focus on their capacity and coulombic efficiency.
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Intermediate heat exchanger natrium - natrium
Kupčík, Petr ; Martinec, Jiří (referee) ; Šen, Hugo (advisor)
This paper deals with intermediate heat exchangers in nuclear power plants. First section of this paper is devoted to analysis and divide of construction designs of intermediate heat exchangers in commercial and experimental power plants. There is a description of thermal, hydraulic and strength calculations during projection of IHX in the second chapter. There has been made a blueprint of loop type IHX in the final chapter of this paper.
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