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Conceptual design of a heat switch installation into a structure of satellite
Vrba, Martin ; Horák, Marek (referee) ; Mašek, Jakub (advisor)
Tato diplomová práce je zaměřena na sestavení přehledu konstrukcí a teplených cest kosmických lodí a kosmických vozidel, které se v současné době používají. Na základě specifických požadavků a standardů jsou vypracovány koncepční návrhy zástavby tepelného spínače do konstrukce družice. V jednotlivých kapitolách jsou popsány určité členy, které se na vedení tepla podílí a jsou důležité pro navrhované koncepty z pohledu konstrukce. Diplomová práce popisuje postupy výpočtu tepelných vodivostí a rozložení působící tíhové síly do míst uchycení pro jednotlivé koncepty. Na závěr provádí hodnocení a výběr potenciálně nejvhodnějšího návrhu.
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Design of synchronous linear motor thermal network
Čech, Jan ; Toman, Marek (referee) ; Knebl, Ladislav (advisor)
The first part of this thesis deals with the study of linear motors. The introduction of the thesis deals with the brief description of the linear motor, including its accessories. This part explains principle of linear motors, their general advantages and disadvantages. The next section contains an overview and division of the currently used linear motors. The second part deals with the theoretical description of forms of heat transfer. The third part of the thesis deals with the design of an equivalent thermal circuit model of a linear iron-core linear motor with permanent magnet. Hereafter, the proposed design will be used to calculate the temperatures of the individual motor units. The temperatures are later compared with the results obtained with finite element method.
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The influence of moisture on the thermal properties of the gloves
Janíčková, Žaneta ; Toma, Róbert (referee) ; Fišer, Jan (advisor)
This diploma thesis is focused on the assessment of the influence of moisture on the thermal properties of the gloves. The first part of the thesis deals with the research of topics related to the given issue as well as with the derivation of the computational relations needed for evaluation of experimental measurements. The main focus of the work lies on defining the hypotheses and experiments that are used to verify the influence of moisture on the thermal resistance of gloves. As for the experimental part, it describes the individual methods of moistening the gloves from which the moistening through the air humidity and the moistening by the immersion were analysed. To verify the suitability of selected moistening methods, the tested glove samples were measured on the thermal manikin both in a dry and a moistened state under the conditions defined by ČSN EN 511 and ČSN EN ISO 15831 standards. Individual states were repeatedly measured and afterwards the progresses of thermal resistance depending on time were graphically displayed. The thesis also includes analysis of measurement uncertainties as well as evaluation of measurement repeatability. From the obtained results, both the defined hypotheses and theoretical assumptions about the decrease of the thermal resistance of a textile material due to the influence of moisture were confirmed in the conclusion of the diploma thesis.
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Calibration task of experimental device for space technology testing
Lazar, Václav ; Horák, Marek (referee) ; Mašek, Jakub (advisor)
Diplomová práce se zabývá možnosti kalibrace experimentálního testovacího zařízení. Zejména se věnuje návrhu termálního matematického modelu popisujícího tepelné procesy uvnitř zařízení v průběhu měření tepelné vodivosti vzorku. První část práce je věnována seznámení se s testovacím zařízením, jeho limity a principem měření. Popisuje řešení třetí verze testovací komory, společně s nezbytnými úpravami, provedenými za účelem zajištění předepsaných simulačních podmínek. Zmiňuje také potřebu a důvody kalibrace. Druhá část je především zaměřená na návrh kalibračních vzorků a termálního modelu. Uvádí definované požadavky a konečné vlastnosti vyrobených vzorků. Matematický model prezentuje postup výpočtu zjištěných tepelných ztrát a poukazuje na možnosti jejich zpřesnění. Testování kalibračních vzorků bylo provedeno na nově zprovozněné třetí verzi testovací komory. Naměřené výsledky poslouží k ladění termálního modelu, nezbytného k dokončení kalibračního procesu, který umožní přikročení k další fázi testování v experimentální komoře.
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Study of utility properties thermal-reflective insulations in the buildings
Holeček, Dominik ; Skříček, Darek (referee) ; Šťastník, Stanislav (advisor)
The diploma thesis is partly dedicated to energetic efficiency of buildings and describes possibilities how to evaluate energetic efficiency of buildings in the Czech Republic. We also get to know with distribution of thermal insulators by material base and use in construction. There are also mentioned methods how to determine thermal insulations characteristics of heat insulations, so called heat conductivity coefficient. The last and the crucial chapter of theoretic part is dedicated to thermal-reflective insulations. There are mentioned some of the basic characteristics of insulations, material composition and heat transfer mechanism in their structure as well. Practical part describes measurement of thermal resistance of chosen samples of thermal-reflective insulations per measuring device on the principal of Hot Box method. In the next step was determined emissivity of aluminium foils which forms the surface of chosen samples of thermal-reflective insulations. In the end of thesis are defined possibilities of use thermal-reflective insulations in building structures especially in passive and low-energy buildings in climatic conditions of the Czech Republic.
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Study efficiency of modern thermal insulations for buildings
Holeček, Dominik ; Skříček, Darek (referee) ; Šťastník, Stanislav (advisor)
The bachelor thesis is partly dedicated to energetic efficiency of buildings and describes possibilities how to evaluate energetic efficiency of buildings in the Czech republic. There is also detailed description of the heat transfer in buildings. We also get to know with production and characteristics of chosen thermal insulators. There are also mentioned methods how to determine thermal insulations characteristics of heat insulations, so called heat conductivity coefficient. The last and the crucial chapter of theoretic part is dedicated to thermo-reflective insulations. There are mentioned some of the basic characteristics of insulations and its material composition as well as usage and methods of thermo-reflective insulations installation in buildings. Practical part is dedicated to description of chosen samples of thermo-reflective insulations and determination of their heat resistance though Hot Box measuring method.
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Drivers clothing thermal resistance database for iHVAC system
Hrubanová, Kristýna ; Pokorný, Jan (referee) ; Fišer, Jan (advisor)
This diploma thesis is focused on measurement of thermal properties of clothes by thermal manikin and on application of results for prediction of thermal comfort in system iHVAC. First part of thesis is dedicated to research with relation to this topic and to definitions of main computational equations necessary for experimental measurement. The choise of method for measurement based on available standards is an important part of this thesis. The main focus of thesis lies on measuring 5 combinations of clothes at different calibration temperatures and same temperature of manikin surface. Then data are examined and also the analysis of uncertaities and repeatability is maked. According to assupmtion , the independence of value of heat transfer coefficient to ambient temperature is comfirmed and calculated heat resistance of every single clothes is compared to existing wardrobe for system iHVAC. The outcome of this thesis is specificied and completed virtual wardrobe which serves to prediction of thermal comfort in car.
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Study utility properties of heat-reflective insulation for the buildings
Rauchfussová, Karolína ; TROJAN,, Karel (referee) ; Šťastník, Stanislav (advisor)
Presented work deals with the study progressive heat-reflecting foil thermal insulating materials and defines their thermal insulation properties. The work describes a transport mechanism of thermal energy in the structure of heat-reflecting materials, their physical properties, especially heat resistance, compared to the conventional thermal insulating materials available on Czech market. The main applications ways and installation methods of these materials (especially in low-energy and passive buildings) are also shown. The practical part is focused on asembling the measuring device HOT BOX in accordance with the valid standards, to determine the heat resistance of heat-reflecting materials. In next step the measurement of reflection of aluminum foils (an integral part of the structural arrangement heat-reflecting foil insulations) was performed.
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Diagnostics and proposal to eliminate thermal bridges buildings
Bravenec, David ; Janík, Zdeněk (referee) ; Kalousek, Miloš (advisor)
This thesis presents a comparison of building materials for vertical bearing structures of buildings, thermal insulation materials and mutual combination of structural materials and insulators. Furthermore, there are possibilities for solving the most common insulation thermal bridges construction. The paper evaluated the pros and cons of different combinations of building materials. Teplo and Area programs were used for the calculations.
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Operational Parameters of LED and their Modelling
Pavelka, Tomáš ; Novák,, Tomáš (referee) ; Gašparovský, Dionýz (referee) ; Baxant, Petr (advisor)
Doctoral thesis deals with parameters of LED light sources and their static and dynamic changes due to variable operational conditions. Firstly there is briefly described the history of light emitting diodes, that brought LED from unintentional observation of luminescence to light source, which is generally used through the whole area of lighting techniques. Thesis focuses on light parameters analysis, which are specific for semiconductor light sources and their mutual relations. These relations in compliance with understanding the principles of light emission in semiconductor light sources enable establishing of basic connections and effects usable for LED behaviour model. Mutual relations of LED parameters and influencing factors are verified by measurement of chosen testing samples. For deeper understanding of diode parameter influencing mechanisms there are analysed current degradation models including degradation of partial components. On the basis of these facts there is created a model of LED luminaire operating with LED parameters together with cooling system that represent the integral part of the luminaire. Impact of supply drivers is also studied, because they are necessary for LED operation. Designed model supports the area of static changes of light parameters, as well as the dynamic changes of output parameters. Presented model is verified by testing measurements at basic operational states and partially outside of the common operational limits. There are also presented the possibilities of real use of the model that involve the evaluation of designed luminaire for specific light sources, searching for optimal operational limits, optimization of luminaire heatsink or using public lighting systems for regulation of electricity grid load fluctuations.
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