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Storage systems for renewable energy
Švácha, Filip ; Kracík, Petr (referee) ; Poláčik, Ján (advisor)
The aim of the thesis is to describe the current possibilities of storing electricity from renewable sources focusing on hydrogen technologies. In the first three parts, the question of energy sto-rage from renewable sources, the current energy storage options and the actual energy storage in hydrogen are discussed in the form of research. The last part is practical and its aim is to compare the current possibilities in designing a system that stores energy in hydrogen. Subsequently, the most favorable option is chosen and compared to other energy storage methods.
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Nonconventional Utilisation of Wind Energy
Zajíc, Josef ; Turek, Vojtěch (referee) ; Jícha, Jaroslav (advisor)
The thesis considers utilization of the wind energy as source of energy for the production of hydrogen. In the first part, there is described the types of wind engine specialized especially on screw wind engines and their construction. After that follows the description of dilemmas usage of electric energy addicted in time and with it connected problems with accumulation elektricity by the help of various methods. The final part of the thesis is than addicted to statistic evaluation of wind conditions, description and suggestion of the equipment hydrogen management.
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Diagnostics of electric discharges in liquids
Vašíček, Michal ; Mazánková, Věra (referee) ; Kozáková, Zdenka (advisor)
The main scope of this thesis is to measure electrical characteristics of a DC discharge in an electrolyte solution in order to evaluate individual discharge parameters (voltage, current, emitted light and sound). As a result of these parameters, a comparison between a diaphragm and capillary configuration has been realized using static and dynamic characteristics. Next part of this thesis is finding mutual differences and to set an approximate transition of individual configurations. For the study of the pin-hole discharge a polycarbonate reactor with total volume of 110 ml was used. It was divided by a changeable polyacetal insulating wall. The Shapal ceramic discs (thickness of 0.3–1.5 mm and diameter of the central pin-hole of 0.3 mm) were mounted in the centre of the insulating wall. This wall divided the reactor into two approximately equal spaces with one stainless steel electrode in each part. A DC high voltage source providing constant power supply up to 500 W was applied on the electrodes. The water solution of NaCl with initial conductivity of 570 S/cm was used as electrolyte. Time resolved electrical characteristics were recorded by a four channel oscilloscope Tektronix TDS 2024B. Measured parameters were as follows: voltage (by a HV probe Tektronix P6015A), current at ballast resistor of 5.13 , sound detected by a piezzo-microphone mounted under the reactor, and light emitted by the discharge was detected by an optical fiber in vicinity of the orifice. Measuring and processing of time resolved electrical characteristics present an accurate description of behavior of the diaphragm and capillary configuration. Voltage differences during the phase of bubble formation as well as around the breakdown point were discussed. This thesis contains a description of bubble cavitation and sets transition ratio between the diaphragm and capillary configuration approximately to l/d= 3 (where l is thickness of the wall and d is diameter of the pin-hole).
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Polarographic analysis of water
Klečka, Tomáš ; Rozman, Jiří (referee) ; Čížek, Martin (advisor)
This bachelor's project creates the necessary theoretical foundation of polarography and voltametry in the first part, which is needed to successful measurement using these technics. In the second part there is realized measurement with anodic stripping voltametry and accomplished evaluation in MATLAB. Finally there is example of procedure for laboratory task with polarograph.
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Diaphragm discharge in organic dye solutions with focus on electrolytic decomposition
Davidová, Jaroslava ; Brablec, Antonín (referee) ; Kozáková, Zdenka (advisor)
This Diploma thesis is focused on physical and chemical effects which contribute to the decomposition of organic dyes by diaphragm discharge generated in water solutions. Due to the application of DC high voltage source in continuous regime, there is an effect of electrolysis contributing to the dye decomposition by diaphragm discharge. The aim of this work was to find out when the electrolysis is running (or when is the moment of discharge breakdown) and which factors influence the breakdown. The other goal was decomposition of selected textile and food organic dyes by electrolysis itself. In the theoretical part, theory about creation of electrical discharges in aqueous solutions is noted and various types of underwater discharges are described. Background researches about underwater electrical discharges used in the world are mentioned as well as the use of diaphragm discharges and various ways how to remove organic dyes from wastewater. Finally, theories of electrolysis, UV-VIS spectroscopy and basis of other analytical methods useful for detection of organic molecules are described. Experimental part is oriented to experiment procedure which was carried out in a reactor with separated electrode areas. Separation was made by dielectric diaphragm with a pinhole in the centre. Its initial diameter was 0.4 mm. Used chemicals and course of experiments are described in this part, too. First, the breakdown moment in the reactor was investigated (i. e. determination, when only electrolysis was operating) by formation of hydrogen peroxide and measurement of dynamic (time resolved) electrical characteristics. Next, decomposition of selected dyes by electrolysis was carried out. As the decomposition was related to decolorization of the solution, UV-VIS spectroscopy in the range of 350–700 nm was used for determination of dye concentration. Next part focused on results presents various factors which had an effect on breakdown of diaphragm discharge. These factors are kind of used electrolyte, initial conductivity of solution, kind of dye, temperature of solution and type of reactor (or solution volume). From the result, the most important factor is initial solution conductivity. After the determination of the breakdown moment, the electrolysis of organic dyes was performed. The applied current was 10 mA, initial conductivity was 500 µS/cm and used electrolyte was NaCl. Moreover comparison of dye decomposition in dependence on the different applied power was realized. From this comparison one can assume, there is no significant contribution of electrolysis (the efficiency is approximately 15 %) to the diaphragm discharge in aqueous solution.
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Switched power source for electroplating
Janků, Roman ; Minárik, Vladimír (referee) ; Červinka, Dalibor (advisor)
The thesis deals with the switching source for electroplating. The theoretical principles of galvanizing, the optimal technological process and a list of most commonly used metals are described. There is also a list of well-known producers, and a description of their resources for electroplating, which have the same output parameters. In the second part of the work there is an introduction of the already-completed school source 2000A/20V, major technical imperfections is solved there. There is also proposition of technical layout made in 3D AutoCAD. Finally, there is an economic analysis of the production costs of the source and a research in suitable suppliers of components and materials. The thesis contains an estimate of the selling and total price compared with competition.
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"Power-to-Gas" Energy Storage Technology
Gálíček, Radomír ; Špiláček, Michal (referee) ; Poláčik, Ján (advisor)
Climate change is becoming a severe global issue which demands innovative technical solutions. If, in the context of reduction of gaseous carbon emissions, the share of renewable energy resources continued to rise, the need for energy storage would emerge. That could mean a shift towards hydrogen focused technologies. This bachelor’s thesis focuses on Power to gas processes and summarizes means of hydrogen production, storage and transportation. All the mentioned aspects are reviewed from technological and economical point of view. Conventional methods of hydrogen production from fossil fuels are the most common, but usage of electrolysis or biological methods may prove as competitive options in near future. Furthermore, the usage of fuel cells in the field of small-scale cogeneration units is recently going through a phase of dynamic development. The practical part of this thesis focuses on designing a seasonal Power to gas unit for a semi-detached house which is powered exclusively by renewable resources. From numerous variants the best one was chosen and compared to a conventional energy storage using lithium batteries. It is shown that even thou the electrochemical cells are more flexible variant they couldn’t match Power to gas technology in the term of seasonal energy storage.
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Electrodes for electrolyser
Kaňa, Ondřej ; Knotek, Tomáš (referee) ; Sedlaříková, Marie (advisor)
In my diploma work i focus on the production hydrogen by electrolysis of water using by electrolyzer. Especially, i concentrate on preparation electrodes for laboratory electrolyzer. I work on principles of increasing electrodes area, increasing functional surface of electrodes, by Nickel – Zinc coatings. By electroplating or chemical plating we spread microlayer of Nickel-Zinc onto electrodes made of steel plate. Then, in alkali - hydrate oxide, we will corrode Zinc components off the alloy and this is how we create pore surface of electrode. From macroscopic view, electrode has same geometrics propositions, however from microscopics view, the electrode has bigger surface area. The hydrogen production increases with unchanget sizes of electrolyzer.
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Progress in technology of mold milling with coated profile tools
Doležel, Ondřej ; Bumbálek, Bohumil (referee) ; Píška, Miroslav (advisor)
This diploma thesis is involved in possible development of different types of milling molds coated with modern plows. The first part is devoted to an analysis of contemporary trends in forms production technology. The analysis includes the different types of machines and tools for making various kinds of molds and dies. Another part deals with design of dies for sheet metal shears. The thesis continues by design of the production procedure after heat treatment and finishing die by miling. For milling of die are designed miling tools, the NC program and the possible development of manufacturing the die using a new machining center and the possibility of production optimization. The penultimate point of the thesis is technical and economical evaluation of the direction of development and comparison of positives and negatoves of each method. At the final evaluation is all summed up.
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Plastic plating
Čermák, Jan ; Kubíček, Jaroslav (referee) ; Žák, Ladislav (advisor)
The perspective of the production of plastic parts has helped to spread the metallization of these parts on a large scale. Whether a coating is functional or just decorative. This bachelor thesis presents a comprehensive study, analysis, evaluation and comparison of the possibilities of creating metal coatings on plastic materials. The thesis deals with galvanic, chemical, vacuum and special methods of plating. For all the mentioned methods of plating, the technological procedure, equipment for plating, evaluation of individual methods and analysis of the use of plated plastic parts are given.
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