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Study of electrolyte influence on diaphragm discharge stability and efficiency
Němcová, Lucie ; Krčma, František (referee) ; Kozáková, Zdenka (advisor)
This thesis is focused on so-called diaphragm discharge, which is one kind of electric discharges in liquid, which belongs among so-called AOP´s techniques, still more used for water cleaning in the present. One of effectiveness and stability indicators of diaphragm discharge is generation of hydrogen peroxide. In theoretical part, detail principle description of electric discharge in liquid is situated. Further, properties of electrolyte are introduced and general spectrophotometric method of obtained sample determination is described. In experimental part, a full procedure of experiment is introduced. Next part containing results and discussions introduces particular results of individual measurements and their reasons. Final chapter is the end, which forms total summary and evaluation of all results. By the application of all chosen electrolytes in solution at diaphragm discharge formation of hydrogen peroxide has appeared. Inorganic and organic electrolytes were used. As inorganic electrolytes following salts were selected – solutions of halogenides, next sodium nitrate as a representative of nitrates, potassium dihydrogenphosphate as a representative of phosphates, etc. Representative of organic electrolytes was citric acid. The value of initial conductivity of electrolytes had the main influence on hydrogen peroxide formation. Electrolytes potassium dihydrogenphosphate and sodium sulphate the great influence on effectiveness and stability of the diaphragm discharge. Their rate constants reached maximum value by the application of solution with initial conductivity of approximately 400 mikrosiemens, particularly 0.0492 mmol/l.min and 0.048 mmol/l.min. On the contrary, low values of rate constant were achieved in electrolyte ammonium chloride at around the same initial conductivity – 0.0269 mmol/l.min. During experiments stainless steel and platinum electrodes were used. It was found that kind of electrode material hadn’t influence on generation of hydrogen peroxide. Hydrogen peroxide was formed only in the cathode space.
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Simulation of steady-state and dynamic behavior of low-temperature fuel cell
Smugala, Ondrej ; Radil, Lukáš (referee) ; Ptáček, Michal (advisor)
This bachelor´s thesis is concerned with mathematic modelling of low temperature proton exchange membrane fuel cell (PEMFC). First part of the thesis is focused on explaining the principle of production of electricity by this type of source. The main advantages and disadvantages of this technology are presented there. A division of fuel cells according to the stack temperature and the kind of used electrolyte is also made in this part. Typical technical information is mentioned for every type of fuel cell. The rest of thesis is concerned with the PEMFC. Firstly there is a description of construction of fuel cell and a presentation of applications in the industry. The second part of work includes a mathematical description of steady and dynamic behavior of fuel cell which is based on relations among fundamental parameters and quantities. The other part contains all results of simulation which was made on a model created in Matlab Simulink. Comparison of the results of real measurement with the results of simulation which was performed on a modified model is provided in the last part of thesis.
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Low temperature fuel cell for ultra-light-plane
Hladiš, Lukáš ; Brázdil, Marian (referee) ; Pospíšil, Jiří (advisor)
This thesis deals with the concept of propulsion for ultralight plane with using fuel cells technology. Here are described the individual kinds of fuel cells and possible fuel. Furthermore it is listed the calculation of low-temperature fuel cell H2 - O2 with polymeric membrane (PEM). The thesis includes also a part with the design drawings of the proposed solutions.
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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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Gel polymer electrolytes with nanoparticles
Szotkowski, Radek ; Sedlaříková, Marie (referee) ; Jahn, Michal (advisor)
This master‘s thesis concerns gel polymer electrolytes formed on a methyl methacrylate base with selected types of nanoparticles. In the thesis are also analyzed the methods for measuring electrochemical properties. The practical portion deals with sample preparations of gel polymer electrolytes with different contents of alkaline salt in a solvent, creating gels with different nanoparticle content and comparing gel polymer electrolytes polymerized with heat and UV radiation. The thesis deals with the evaluation of these samples from the viewpoint of electrical conductivity and potential windows as well as thermal analysis of selected samples.
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The influence of electrolyte additives to lead-acid batteries properties
Dohnal, Martin ; Zimáková, Jana (referee) ; Bača, Petr (advisor)
This day is a lead battery is most prevalent in the automotive industry. Which is a source of energy when starting the car. In recent times the battery is used not only for startups, but also when driving in city traffic. This behavior can know the concept of a hybrid car. Which is used an electric motor which as a result reduce emissions standing cars in cities. The electric motor is powered by lead-acid battery and a rapid discharging and reducing battery life. To extend the life developed additives to the electrolyte. In the thesis, these additives investigated. If they really have a positive effect on the battery.
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