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The desingn of the lighting protection for civil buildings
Šebesta, Ondřej ; Bátora, Branislav (referee) ; Toman, Petr (advisor)
This thesis focuses on the issue of lightning protection and goes along with ČSN EN 62 305 norms. First part goes into effects of lightning on objects and engineering networks in theory. Second part familiarizes external lightning protection and possibilities of its realization. The issues of internal protection against lightning and surge protection are analysed afterwards. Second half familiarizes protected family house and the risks are calculated for this house. External protection is designed and verified by protective angle and rolling sphere methods. Last part of this thesis focuses on internal surge protection and individual levels of surge protection are designed.
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Design of overvoltage arresters in high voltage switchgear depending up parameters of connected load
Němec, Ondřej ; Bernard, Michal (referee) ; Lázničková, Ilona (advisor)
The purpose of this thesis is to introduce the reader about the problems of design of surge arresters. The first part of this thesis describes problems of surge. In the next part of this thesis are described test pulses needed to test surge arresters. The next issues of this thesis are medium voltage switchgears and surge arresters ABB and their test. In the next part ot this thesis are described type of network according earthing of transformers. The other point of this thesis are aplications of surge arresters, figures and calculation for networks, generators, transformers and motors. In the conclusion of this thesis is the appreciation of whole problems about surge arresters.
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Rotating stall in a centrifugal compressor.
Guzej, Michal ; Pochylý, František (referee) ; Habán, Vladimír (advisor)
This thesis deals with a procedure for determining the complete processing of aerodynamic flow instabilities (rotating stall and surge) in a centrifugal compressor. At small flows the performance of a compressor system is limited by the surge line, which is caused by flow instabilities. Numerical solution is obtained using the method of transfer matrix. This system is simulated through several models with local resistances that represent the dissipation of pressure energy. Pulses are excitated in these models by the pressure jump placed before the centrifugal compressor. From the frequency-amplitude characteristics for the selected range of frequencies and flow the impedance characteristic of the compressor system is determined. We are looking for problematic frequencies in this characteristic that cause flow instabilities in the compressor system.
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Compressor Turbocharger Design
Domanský, David ; Škorpík, Jiří (referee) ; Fiedler, Jan (advisor)
The master's thesis deals with compressor turbochargers used for supercharging of combustion engines. The aim of the thesis is feasibility study of compressor surge limit simulation. First of all the principle and purpose of supercharged combustion engines is described and the compressors' types using for supercharging are mentioned as well. The main part of the thesis is focused on flow instabilities and their influence on compressor operating zone. There are mentioned some possibilities of operating zone extension. The practical part comprises the simplified computation of a one stage of centrifugal compressor and flow analysis by means of CFD simulation.
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