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Technology solution for energy savings in industrial processes
Cyž, Antonín ; Miklas, Václav (referee) ; Konečná, Eva (advisor)
This bachelor thesis is a search of known technological solutions for energy saving in industrial processes. The first part contains a description of the methodology for the analysis of energy consumption in the company. The first part also solves some of the statutory obligations of an energetic area in companies. Then follows a description and possible use of individual technological devices. The theoretical part of the work evaluates and describes the possibilities to increase the energy efficiency of an industrial laundry. Finally, the economic – energy balance of a specific operation is analyzed, including the evaluation of the financial return on investment.
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Microstructure of non-equiblirium Al-Mn based solid solutions
Poková, Michaela
Heat exchangers in automotive industry are often manufactured from aluminum-based alloy AW 3003. In recent time, the aim to reduce the weight of the cars leads to thickening of the foils, which are used for manufacturing of the heat exchangers. In order to fulfill all requirements on mechanical properties of the exchanger, new materials and thermo-mechanical treatments have to be found. Modified alloy AW 3003 with addition of zirconium seems to be perspective. Zirconium forms metastable precipitates Al3Zr, which pin moving grain boundaries and shift recrystallization to higher temperatures. The most effective heat treatment, which leads to precipitation of these particles, seems to be a two-step annealing at temperatures 250 řC and 450 řC with slow heating rate. The precipitates formed were of diameter 10 nm.
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Analysis of heat losses of operated heat exchangers
Sýs, Tomáš ; Babička Fialová, Dominika (referee) ; Jegla, Zdeněk (advisor)
The proposed bachelor’s thesis deals with calculation and analysis of heat losses of operated heat exchangers used for food applications. In the first part of the thesis, general problematics of heat exchangers is introduced, including their use and breakdown by basic categories, as well as problematics of insulation, which is supplemented by a list of the most commonly used types of insulation. Another chapter is devoted both to the assignment and description of the industrial case; drawing documentation and measured input data necessary for the calculation of heat losses are also presented. The last part of the thesis introduces the used method of assessment of heat losses of the heat exchanger network, achieved results and their discussion.
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Fluidized bed boiler for burning coal and wood 150t/h
Popelka, Ondřej ; Lisý, Martin (referee) ; Skála, Zdeněk (advisor)
This thesis is focused in calculation and designing of fluid bed boiler for burning coal and wood biomass in the form of wood chips. The uniqueness of fluidized bed boiler is circulating fluidized layer and cyclone ash separator from flue gases beyond the combustion chamber.Work was divided into several parts due to different parameters of the fuel.. Stoichiometry calculations, emissions calculations, enthalpy of combustion and flue gas desulphurization calculations are performed in various parts.Further, calculating of the losses of boiler and its efficiency comparing to the calculation and design of each heat transfer surfaces was also solved so that resulting size and quantity meet the required specifications.Drawn set of this designed boiler based on calculations is included in the annex to this paper.
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Microstructure of non-equiblirium Al-Mn based solid solutions
Poková, Michaela
Heat exchangers in automotive industry are often manufactured from aluminum-based alloy AW 3003. In recent time, the aim to reduce the weight of the cars leads to thickening of the foils, which are used for manufacturing of the heat exchangers. In order to fulfill all requirements on mechanical properties of the exchanger, new materials and thermo-mechanical treatments have to be found. Modified alloy AW 3003 with addition of zirconium seems to be perspective. Zirconium forms metastable precipitates Al3Zr, which pin moving grain boundaries and shift recrystallization to higher temperatures. The most effective heat treatment, which leads to precipitation of these particles, seems to be a two-step annealing at temperatures 250 řC and 450 řC with slow heating rate. The precipitates formed were of diameter 10 nm.
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Modelling of flows in a heat exchanger
Hudeček, František ; Milčák, Pavel (referee) ; Špiláček, Michal (advisor)
This thesis considers problematics of calculating and designing heat exchangers. First way of solving the designing problem is by using mathematical formulas for heat transfer, which are based on manifold measurements. Second approach is can be considered modern as the designing of heat exchangers is realized by using computing technology and appropriate software for simulation of flow and heat transfer. These computations are realized for specified type of heat exchanger that is chosen after a brief research. The results are then post processed, commented and these two approaches are compared and evaluated.
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The efficiency of heat exchangers in the cryogenic processes
Horvát, Petr ; Krištof, Ondřej (referee) ; Svěrák, Tomáš (advisor)
Heat exchangers and their use in cooling processes are the major topic of this thesis. The theoretical part of the thesis deals with the mechanisms of heat transfer, outlining their problems at low temperature. Furthermore, the thesis describes the types of heat exchangers used in practice, then a relatively large part dealing with the problem of calculations connected with tube heat exchangers is included. Relations for both normal and cryogenic conditions are given. In the experimental part, the heat transfer on the semi-operating glass tube heat exchanger is examined by cooling the room air with 55% ethylene glycol in order to compare the heat-transfer coefficients determined from the heat balances and from the dimensionless criteria based on the relations mentioned in the theoretical part of the thesis. For a pair of coolant flows and four airflows, input and output flow temperatures, pressure and relative air humidity at the inlet were measured. At higher airflows, more than double efficiency of heat exchange was observed, at the lowest airflow the exchanged heat was up to half against the theoretical model. The reason for these deviations is probably the condensation of air humidity in the heat exchanger and the design of the heat exchanger. The flow of coolant had practically no influence on the amount of heat exchanged. As found, for the studied heat exchanger it is non-effective to operate in low airflow modes and it is unnecessary to operate at higher flow rates of the cooling medium.
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Heat recovery in Building Services
Hrabová, Kristýna ; Plášek, Josef (referee) ; Šikula, Ondřej (advisor)
This thesis deals with the optimization of sewer heat recovery. For proper design and optimization it is necessary to use three basic methods: diagnostics, heat balance calculations and modeling. In 2D software Area Calculation are simulated different types of sewer exchangers arranged in sewer pipes. Using models of software CalA and simulations will be selected optimal variant. Using software BSim, which is based on more zone numerical simulation of the energy needs of buildings in relation to indoor climate, are detected heat needs of an office building. The optimal number of sewer exchanger is designed from the identified performance heat exchangers and supplies heat for the building.
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Fluidized bed boiler for burning coal and wood 150t/h
Popelka, Ondřej ; Lisý, Martin (referee) ; Skála, Zdeněk (advisor)
This thesis is focused in calculation and designing of fluid bed boiler for burning coal and wood biomass in the form of wood chips. The uniqueness of fluidized bed boiler is circulating fluidized layer and cyclone ash separator from flue gases beyond the combustion chamber.Work was divided into several parts due to different parameters of the fuel.. Stoichiometry calculations, emissions calculations, enthalpy of combustion and flue gas desulphurization calculations are performed in various parts.Further, calculating of the losses of boiler and its efficiency comparing to the calculation and design of each heat transfer surfaces was also solved so that resulting size and quantity meet the required specifications.Drawn set of this designed boiler based on calculations is included in the annex to this paper.
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Heat transfer surfaces design and fouling of the heat exchangers from hollow plastic fibers
Bokišová, Lenka ; Dohnal, Mirko (referee) ; Raudenský, Miroslav (advisor)
This thesis studies a possibility of using hollow fibres for construction of innovative heat exchangers. The first part introduces to the field of heat exchangers and polymers as materials suitable for formation of heat transfer surfaces. Further, the potential of hollow fibres of small diameters is outlined, including the merits, limits and proposals for improving. The significant part of the work is dedicated to the review of methods of fibres fixation and separation and review of fouling and cleaning of heat exchangers. Overviews of design possibilities which prevent fibres clustering have been made. The solutions, which are prepared for experimental research at Heat Transfer and Fluid Flow Laboratory are stated, including analysis of “curly” fibres application. The next part presents calculations for models of water – water and water – air heat exchangers and discusses influence of fibre diameter, flow velocity and the other parameters on heat characteristics. The heat transfer and fluid flow formulas using for heat exchangers of a bigger order can be employed with small changes. Furthermore, the influence of hollow fibres arrangement and distances on heat transfer is discussed.
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