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Možnosti ochrany proti výbuchu plynných směsí
Kvasnička, Jakub
This thesis is focused on the issue of protection against explosion of gaseous mixtures. At the beginning the basic standards which the issue is based on are presented. Basic knowledge of combustion as a possible cause or consequence of explosion is described in the thesis. Possible circumstances which can affect the process of explosion are specified and thenvarious sources of initiation are described. The main and most comprehensive part of the thesis is focused on methods of explosion protection This part includes a list of possibilities of how to avoid explosions or minimalize damages. Explosion suppression devices are studied in detail, their parts are described as well as the principle of operation and possible layout of these features in technology. In the last part of the thesis some new trends in the area of explosion protection are stated.
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THERMAL DECOMPOSITION OF SOLID BIOFUELS AND ASSOCIATED FINE PARTICLE GENERATION
Sitek, Tomáš ; Ličbinský, Roman (referee) ; Svěrák, Tomáš (referee) ; Pospíšil, Jiří (advisor)
Despite otherwise indisputable advantages, biomass burning is associated with significant emissions of fine particles. The different behavior of dissimilar types of biomass during thermal decomposition can be explained to some extent by the different composition, i.e. the different content of cellulose, hemicellulose and lignin. The main aim of this work was to find the emission characteristics of these three components during heating in a thermogravimetric analyzer. The monitored parameters were the heating rate and the oxygen content in the combustion atmosphere. The output is the dependence of the sample mass and also the corresponding distributions of particles on the temperature. The results show considerable differences between the individual samples, but in general the pyrolysis of cellulose produces the highest particle emissions. Higher oxygen content in the combustion atmosphere and lower heating rates cause earlier sample decomposition and reduce particulate emissions. This is followed by an evaluation of the transferability to a sample of a real biomass based on its known composition using a simple weighted arithmetic mean. Useful information on particle sampling and electron microscope visualization, supplemented by images of particles from the pyrolysis of selected samples can also be found in this work.
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Composition of Municipal Waste
Straka, David ; Musilová, Petra (referee) ; Elbl, Patrik (advisor)
This bachelor thesis deals with the composition of municipal and mixed municipal waste. Introduction of the research part deals with the composition and properties of waste. In the next section, the waste is considered as fuel and compared with conventional solid fuels. The conculusion of the research part is devoted to the research of the waste composition from selected incinerators adn foreign countries. The compulational part of the thesis deals with the determation of energy properties of the waste.
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NOx production and elimination
Boška, Michal ; Jecha, David (referee) ; Chlápek, Petr (advisor)
Bachelor’s thesis deal with production and elimination emission of nitrogen oxides their influence for animated and inanimate nature and their characteristic. Main part of thesis is theoretic analysis of creation mechanisms in combustion suits and description most widely used method of elimination nitrogen oxides. Part of thesis deal with problems concerning of nitrogen oxides at legislation at Czech Republic.
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Degradation of Biomass Fuels during Storing
Elbl, Patrik ; Kracík, Petr (referee) ; Lisý, Martin (advisor)
This thesis aims to deal with degradation of biomass fuels during storing. The first part of thesis is dedicated to research study concerning of biomass in general. There are mentioned properties of biomass, separation, issues of combustion and storing. The second part deals with experimental determination of degradation of fuel during storing and weather conditions.
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Ignition engine emissions
Semela, Lukáš ; Píštěk, Václav (referee) ; Kaplan, Zdeněk (advisor)
This thesis deals with emissions of ignition engines. The introduction acquaints the reader with the history and lays out the reasons why it is a crucial topic to be dealt with. Furthermore, the term emission is being explained as well as the description of its chemical composition, the impact on the environment and human organism. The method of measuring is also mentioned in this thesis. Then the explanation continues with European Union’s current legislation. The whole thesis is concluded with information on the additional modification of emissions and chapter that outlines the future of automobiles regarding the environment.
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40/5000 Fine particles produced by the stove
Škvařil, Ondřej ; Baláš, Marek (referee) ; Pospíšil, Jiří (advisor)
This master thesis deals with problematics of fine particles produced during combustion in fireplace stoves. The theoretical part is focused on the analysis of the atmosphere, health consequences, solid pollutants, the formation of particles (origin), particle separation and how they are regulated by laws. Theoretical section of the thesis addresses analysis of biomass and its combustion. In the applied section are listed given methods of the particles measuring according to regulations, common errors during measurement and methods of identification of measured fine particles. Then follow specific measurements of the formed very fine particles produced by the SMPS method. Subsequently, the results of the measurement are evaluated and summarized in the conclusion.
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The Influence of Operating Parameters and Construction Parameters of the Process Burner on Stability and Combustion Processes Parameters
Skryja, Pavel ; Jegla, Zdeněk (referee) ; Odstrčil, Miloslav (referee) ; Stehlík, Petr (advisor)
The objectives of this paper focus upon composing recommendations with respect to burners design while observing aerodynamic, together with present and advanced developments in the field of flame technology principles. Specifically the aims are set at flame stability and pollutions. Important part of this paper is a novel design procedure dealing with premixed burners. Further, by exploiting the results of testing program enabled one to design burners exhibiting low level of nitrogen oxides emissions. On the basis of aerodynamic analysis of premixed burners flow path several recommendations on the geometry resulted in proposing two ejectors, which transport the combustion air. In the first ejector the fuel jet, generated by flow through a nozzle, draws the specified part of the combustion air, and then the mixture is a driving agent of the second ejector. The remaining part of combustion air flows first through the radial curved vanes, and second its tangential velocity component is augmented by axial vanes prior it enters mixing part of the second ejector. For the additional contribution to the rotating motion the inclined axial vanes built inside the nozzle of the second ejector are responsible. The resulting swirling number reaches the values up to 2.6. For the burner so arranged fire stability and low NOx emissions in the wide operating conditions can be expected. Within the frame of extensive testing program in the field of diffusion burners several modifications have been carried out such as setting of axial vanes which secure the swirling motion, changes of combustion air flows path, and modifications of secondary nozzles, these resulted in extending zone of stabilized flame and reducing the formation of NOx, e.g. NOx emissions of 70 ppm, prior the modifications, have dropped to 30 ppm (dry flue gas 3% O2). The main contribution of this paper stands in applications of development activities results in aerodynamic and flame within their implementation in the field of burners design. Further, it is the proposed design of burners which are capable of simultaneously firing products of the biomass microwave pyrolysis, namely syngas and bio-oils.
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Testing facilities for burner testing
Sobočík, Robert ; Hájek, Zdeněk (referee) ; Bělohradský, Petr (advisor)
This Bachelor’s thesis is focused on testing facilities intended for burner testing. It deals with a thorough research of accessible material including specialist technical literature and relevant websites in order to gather any available information on current burners and monitor present situation in the market, as well as to provide new information on burner testing facilities and collecting, processing and evaluating the data gained in testing process in Czech and foreign companies.
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