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Thunderstorms occurrence in the Czech Republic
Kovář, Jan ; Krška, Karel (referee) ; Jebáček, Ivo (advisor)
This bachelor thesis focuses on storm situations in the Czech Republic and their occurrence in the period 1961-2020. It analyses the conditions of occurrence and appearance of thunderstorms and describes the storm activity at Karlovy Vary, Prague-Ruzyně, Brno-Tuřany and Ostrava-Mošnov airports in the period between 2001-2020. Marginal mention is made of the phenomena accompanying the storm, conditions of its passage and methods of detection.
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Experimental and Numerical Assessment of the Heat Transfer Coeficients for Industrial Steam Turbine for Siemens Industrial Turbomachinery
Hladík, Petr ; Pospíšil, Jiří (referee) ; Hrabovský, Jozef (advisor)
The subject of this diploma thesis is experimental and numerical assessment of the heat transfer coefficients during condensation of water steam in simplified parts of an industrial steam turbine. This simplified part is a pipe with circular cross section, which is often used in simulations of processes inside the steam turbine. The first part of thesis describes theoretical basics of heat transfer during conduction, convection and condensation. The content of other chapters is description of methods used to determine heat transfer coefficient. These are: ex-perimental analysis performed on a measuring device and evaluated using finite element ana-lysis (FEA), computational fluid dynamics analysis (CFD) in ANSYS CFX and analytical calculations of heat transfer coefficients using mathematical models for condensation. Thesis is concluded by validation and comparison of obtained results.
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The Mpemba effect and its use in applications
Wittek, David ; Hejčík, Jiří (referee) ; Mauder, Tomáš (advisor)
Hot water appears to freeze faster than cold water. Already Aristoteles mentions this seemingly meaningless fact in his writings. However, to this day no one has been able to fully clarify this phenomenon. Work is focused on factors, which may affect the freezing process of liquids. The composition of the experimental set up will be designed to approach the conditions of the pioneer of scientific research on this issue, E. Mpemba. He has obtained the most convincing results confirming existence of the phenomenon. Based on results, it will be discussed possibilities of practical application, for example for saving time during freezing.
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Heating systems in preschools
Schäferová, Hana ; Topič, Jan (advisor)
The topic of a master thesis is solution of infant’s school heating. The thesis summarizes state of art infant’s school heating from practical and legislative point of view. The thesis contains solution of infant’s school heating created by author of thesis. In addition, the thesis contains an experiment which is focused on examination of heat output from cover radiator.
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Study efficiency of modern thermal insulation for buildings
Šot, Petr ; auditor, Karel Trojan, Brno, energetický (referee) ; Šťastník, Stanislav (advisor)
The bachelor´s thesis deals with the problem of thermoreflect insulation. The small part of thesis focuses on the energy demand of buildings and its problems. Then the greater extent is analysed problems by heat transfer of material. It includes effects arising from the individual methods of heat transfer and defines the level of expression of individual methods of heat transfer in materials. The thesis presents an overview of experimental methods for determining thermal insulating properties of insulators. Then there is shown a selection of the most widespread insulation materials used in today´s construction. It includes the division of insulators in terms of used materials and subsequent classification of the most used materials in these groups. Another part of thesis deals with the thermoreflect isolation. There are mentioned the necessary concepts for the study of thermoreflect thermal insulation, which include the emissivity surface, the coefficient of mutual radiation and translucency of the material. Then there is described the method heat transfer of thermoreflect isolation. On the next there are presented experimental methods of determining thermal insulating properties thermoreflect thermal-insulating material. The thesis also includes a practical part, which contains the measurement results on a small range of samples taken termoreflection insulators. In the end there is mentioned a brief realization of thermoreflection thermal insulation materials in buildings.
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Thermal Losses of the Biomass Boiler
Suchánková, Lenka ; Milčák, Pavel (referee) ; Kracík, Petr (advisor)
The bachelor thesis focuses on the heat loss of the solid fuel boiler, especially on the loss of heat conduction and transfer to the surroundings. In order to minimalize thermal leaks through the boiler walls, materials with good isolation capabilities must be selected when designing. In Microsoft Excel, a universal mathematical model was created to calculate the heat flux flowing through the flat wall of the boiler, from which temperatures can be obtained on the inside of the wall. The work describes the calculation method on which the model is based and its correctness is verified on an experiment based on sensing of temperature fields of wall sur-faces of equipment burning biomass by thermal camera. The model can be used for a wall with up to 9 layers of material, where the wall can be cooled (heat loss) by air and water.
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Analysis of Ceiling Heating
Carbol, Ladislav ; Plášek, Josef (referee) ; Vendlová, Lucie (advisor)
Diploma thesis deals with analysis of radiant ceiling heating in VUT dormitories. The work contains a theoretical analysis of radiant and convection heat transmission of ceiling heating. Part of this work is creation of mathematical model for evaluation of variables typical for radiant ceiling heating. Model outposts are compared with data measured on a real building.
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Design of air heating system
Nagorskyi, Bogdan ; Baláš, Marek (referee) ; Kracík, Petr (advisor)
This bachelor thesis describes potential possibilities to substitute hot-water radiators with hot-air units with controlled air supply. Introduction part of the thesis describes basic thermal comfort factors. Subsequently, their application in traditional heating systems was performed. After that the issue of conditional heating efficiency of the original heating systems with the simultaneous application of ventilation was discussed, the analysis of which was the reason for the suitability of designing a new system of warm air heating with controlled air supply. The design of the hot-air heating system was performed for the living room of a typical panel apartment unit. During designing a new installation, the emphasis was put primarily on eliminating the main drawbacks of the hot-air heating system, namely the height distribution of the temperature layers. The system was designed in accordance with hygiene standards and its components include other air treatment elements. In the economic evaluation of the project, calculations of the possible implementation of the hot-air system and comparison with similar products commonly available on the market were made.
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Verification of thermal-insulation properties of the foil materials
Šot, Petr ; TROJAN,, Karel (referee) ; Šťastník, Stanislav (advisor)
The master´s thesis deals with verification of thermal insulating property of thermoreflection foil insulations. The teoretical part of thesis focuses on the energy demand of buildings, the problems of heat transfer material, terms required for study of thermoreflection thermal insulation and experimental methods for determination of thermal insulating properties of insulators. In the next part the chapter is accompanied by an overview of the most common insulation materials which used in construction. The last part of teoretical part is devoted to the description of thermoreflect formation and analysis of the spread of thermal insulating layers of thermoreflection thermal insulation. The first part of thesis is devoted to the use of thermoreflection therm insulation in buildings. The second part of thesis is devoted to the design, assembly and calibration of the measuring device that uses a method of protected warm chamber. It is declared as a binding method of detection of the heat transfer performance of thermoreflection thermal insulation. The developed measuring device allows detection of endpoints in some direction of propagation of heat. Measurment of heat transfer coefficient devoted the third part of practical part. This part contains a description of the samples used for the measurement of the heat transfer coefficient. In the fourth chapter of the practical part are presented the results of the heat transfer coefficient measurments on selected samples of thermoreflection foil insulation. It is shown the characteristic of heat transfer coefficient of individual samples, the dependence of the heat transfer coefficient on the position of the sample in the measuring device and the recommendation of an appropriate use of sample in the works for the climatic conditions of the Czech republic. The work concludes the chapter of comparing and evaluating of all samples with practical recommendations.
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