|
|
Hydrogen production from renewable energy source
Lakva, Petr ; Baláš, Marek (referee) ; Jícha, Jaroslav (advisor)
Hydrogen, as a form of storage for the excess energy from renewable sources, is a technically and economically viable option. However, the technology is not mature enough to compete with the other renewable energy possibilities. In this thesis, a study based on coupling two 330 kW wind-turbines with an NELP. 40 electrolyzer this connection should improve the utilization of wind power. In this thesis are two options of energy utilization. The energy produced by the wind-turbine is stored in the form, of hydrogen and is then delivered for consumption at variable power through a fuel cell, second option is use of produced hydrogen as alternative fuel for cars. This study is a general introduction for the wind energy system with hydrogen storage. Future studies should be more complex and detailed in order to understand and model the system with greater accuracy and to increase the possibility for the utilization of wind energy to generate hydrogen. This would enhance wind power competitiveness and sustain the continuously changing world energy demands.
|
|
| |
|
|
Low Temperature Fuel Cells H2-O2 with Anionic and Bipolar Membrane
Barath, Peter ; Sedlaříková, Marie (advisor)
The doctoral thesis deals with investigation of the catalysts and ionexchanege membranes for fuel cells H2-O2. The work contains the basic principles of chemical reactions, thermodynamic aspects and kinetic properties in PEM fuel cells.Ion-exchagers based on fluorinated polymer sulfonic acids known as NAFION are used in most cases. These compounds are very expensive. Also a strong corrosive attribute requires platinum as a catalysator. These facts make the membrane fuel cells fully non-competetive with e.g. internal combustion engine in spite of all ecological advantages of this electrical power source. The subject of doctoral thesis is research and development of compounds for the composite electrode materials base on NiOx, Ni-Pd and Raney Ni suitable as catalysts a nd alkaline or bipolar ionexchange membranes for electrochemical fuel cells.
|
|
|
Effect of compaction pressure to the electrochemical properties of the electrodes for Li-S accumulators
Jaššo, Kamil ; Tichý, Jiří (referee) ; Kazda, Tomáš (advisor)
The purpose of this diploma thesis is to describe the impact of compaction pressure on the electrochemical parameters of lithium-sulfur batteries. Theoretical part of this thesis contains briefly described terminology and general issues of batteries and their division. Every kind of battery is provided with a closer description of a specific battery type. A separate chapter is dedicated to lithium cells, mainly lithium-ion batteries. Considering various composition of lithium-ion batteries, this chapter deeply analyzes mostly used active materials of electrodes, used electrolytes and separators. Considering that the electrochemical principle of Li-S and Li-O batteries is different to Li-ion batteries, these accumulators of new generation are included in individual subhead. In the experimental part of this thesis are described methods used to measure electrochemical parameters of Li-S batteries. Next chapter contains description of preparing individual electrodes and their composition. Rest of the experimental part of my thesis is dedicated to the description of individual experiments and achieved results.
|
|
|
Measurement module based on electrochemical impedance spectroscopy intended for hydrogen fuel cell research
Přecechtěl, Vít ; Pazdera, Ivo (referee) ; Procházka, Petr (advisor)
This thesis deals with diagnostic fuel-cell parameters using electrochemical impedance spectroscopy. The document begins with brief explanation of fuel-cell operation and its basic principles. Thesis continues with description of fuel-cell voltage generation and influence of charge dual-layer on impedance. After that electrochemical impedance spectroscopy, signals used for perturbation and evaluation of impedance spectrum using Bode a Nyquist plot is described. Next part explains measurement of impedance spectrum using potentiostat in combination with lock-in amplifier or frequency response analyzer. Practical part of thesis is dedicated to electric circuit design of EIS module and software designed for automatic measurement of impedance spectrum. Last part shows results of EIS module testing.
|
|
|
Alternative energy sources
Stránský, Jaroslav ; Moskalík, Jiří (referee) ; Škvařil, Jan (advisor)
In this work, I tried to summarize the current state of world energy resources that we use to convert into electrical energy. There is solved the question of compensation running short supplies of fossil fuels and reduce discharge of greenhouse gasses. I´m looking for suitable compensation in department of alternative energy sources, among which I included the power of the Sun, water, wind, geothermal energy, using heat pumps, combustion energy, nuclear energy, fuel cells and hydrogen use. About anyone of replacing sources you learn about its history, advantages and disadvantages, the principle of function energy transform devices, and compare the potential that is available in the CR and in the world.
|
|
|
Possibilities of using hydrogen in the energy sector
Holík, Michal ; Lisá, Hana (referee) ; Baláš, Marek (advisor)
This bachelor thesis describes hydrogen energy and gives the reader an introductory look into the world of hydrogen technologies. The first part describes the production of hydrogen from fossil and renewable sources. The second part deals with the possibilities of processing and use of hydrogen in energy. The third part represents the specific application of its use.
|
|
|
Power to gas system
Urbánek, Štěpán ; Baláš, Marek (referee) ; Pospíšil, Jiří (advisor)
This bachelor thesis deals with Power to Gas system and its subcomponents. The first part of this thesis is research of the Power to Gas subcomponents. In the second part a balance model of the Power to Gas system is developed based on the traced technical parameters from the first part. The third part deals with traceable implementations of the Power to Gas system and the last part is the design of the system for home implementation.
|
|
|
Modelling of Air Supply by Compressor for Fuel Cell
Tkach, Svitlana ; Kudláček, Petr (referee) ; Novotný, Pavel (advisor)
The growing demand for freight transport and the long-term trend towards low-emission on-road trucks are driving a lot of attention towards fuel cell technology. Nowadays, computer simulations can be used to analyse complex fuel cell processes, which facilitates the time and cost of development. In this thesis, a computational model of a fuel cell system with a focus on air supply analysis is presented. An improvement in the performance characteristics of the air supply system, and therefore the fuel cell, can be achieved by using a compressor. Based on the initial design, an analysis of the influence of the compressor parameters at the design point on its power input is performed. An increase in compressor speed and isentropic efficiency at the design point led to a decrease in the required power input, while an increase in the pressure ratio at the design point led to an increase. As the result of the diploma thesis, an efficient tool for achieving optimal parameters of the fuel cell air supply system while minimizing the compressor input power is presented.
|
|
|
Thermodynamic analysis of processes in Hydrogen fuel cells.
Pavelka, Michal ; Maršík, František (advisor) ; Grmela, Miroslav (referee) ; Sciacovelli, Adriano (referee)
Non-equilibrium thermodynamics, which serves as a framework for formulating evolution equations of macroscopic and mesoscopic systems, is briefly reviewed and further developed in this work. For example, the relation between the General Equation for the Nonequilibrium Reversible- Irreversible Coupling (GENERIC) and (ir)reversibility is elucidated, and Onsager-Casimir reciprocal relations are shown to be an implication of GENERIC. Non-equilibrium thermodynamics is then applied to describe fuel cells and related devices, and theoretical conclusions are compared to experimental data. Moreover, a generalization of standard exergy analysis is developed bringing a new method for revealing a map of useful work losses in electricity producing devices. This method requires a non-equilibrium thermodynamic model, and so the general theory of non- equilibrium thermodynamics and optimization of real power generating devices stand side by side.
|
guest ::
