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Determination of thermophysical properties of scale layer on steel at high temperatures
Ondruch, Tomáš ; Votavová, Helena (referee) ; Pohanka, Michal (advisor)
The thesis deals with thermophysical properties of scale layer on steel and their determination at high temperatures. The first part summarizes fundamental characteristics of scales, it is also devoted to principles of heat transfer with emphasis on heat conduction. The following text presents current state of research on scales’ thermophysical properties. Subsequently, the thesis aims to experimental measurement of thermophysical properties by use of laser flash method and conducted measurement is described, as well. The following chapters present a finite-element numerical model of the measurement aparatus and computation technique for determination of scales’ thermophysical properties is explained. The obtained results are compared with available data and sensitivity analysis of selected model parameters is carried out.
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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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Verification of thermal conductivity of wood materials
Kostka, Petr ; Neuberger, Pavel (advisor) ; Adamovský, Radomír (referee)
This diploma thesis deals with verifying the thermal conductivity and other thermophysical properties of different types of wood (spruce, oak, ash and maple). A special device ISOMET 2104, which is based on dynamic method of measurement, was used. Three different samples for each type of wood were used (for example, different age of trees). Values of the thermal conductivity, the thermal diffusivity and the specific heat capacity, depending on the gradually decreasing moisture of wood, were obtained. The key point of this study was finding that the values of thermophysical properties of wood materials vary significantly depending on the age, growing conditions, properties of the soil and other factors. Some of the data correspond with previously published studies but other data are in contrast to them.
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Possibilities of utilizing lightweight autoclaved silicate based materials for insulation of building structures
Novák, Jakub ; Sedlmajer, Martin (referee) ; Zach, Jiří (advisor)
This bachelor´s thesis deals with the issue of thermal insulation for building structures using autoclaved aerated concrete on silicate based with density up to 200 kg/m3. The theoretical part presents the knowledge of the thermal protection of buildings and thermal insulation materials. Thereafter are distributed insulation systems. Production of aerated concrete and its properties is described in detail. In thesis were evaluated possibilities of use this material. The materiál is proved to be suitable for the production of thermal insulating wall, insulated foundation slabs or composite external panels. In the practical part were find out the values of physical and mechanical properties of aerated concrete product. Test results showed that the product can be used as an alternative to standard insulation systems. Component of the practical part was also to compare various insulation materials on the present market. In the conclusion is performed an overall assessment that includes the overall findings and the results.
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Development of vacuum insulation in construction and their possible application
Kováriková, Růžena ; Peterková, Jitka (referee) ; Zach, Jiří (advisor)
The subject of the thesis is to conduct an extensive literature review on the topic of vacuum insulation and their use in construction. Processing includes the development of these materials from their inception to the present. The theoretical part is devoted to the composition and production of vacuum insulation, which are available on the industrial market. On the basis of researches should be conducted suggestion of possible alternative core insulators primarily on the basis of secondary raw materials, which could be after evacuating used in the manufacture of vacuum insulation used in the building.
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Development of ultra lightweight concretes
Popelková, Adéla ; Hubertová,, Michala (referee) ; Hela, Rudolf (advisor)
This bachelor thesis deals with the technology of production of ultralight concretes using direct lighten cementing compound and at the same time indirect lighten using lightweight aggregate. Further work deals with the choice of suitable raw materials for these concretes. The practical part consists of a proposal of several different recipes, experimental verification and by comparing their properties in a fresh or hardened state.
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The Effect of Sawdust on the Refractoriness of Insulation Chamotte
Smékalová, Veronika ; Kotásek, Martin (referee) ; Sokolář, Radomír (advisor)
Lightweight refractory products have their place between refractory materials. Still the most common way of lightweighting is by using burnable components. This bachelor work includes the theoretical part, which deals with raw materials for lightweight fireclay, manufactory, and also testing lightweight refractory products. The second part of this work deals with foreign research and its results in this area. The practical part examines the influence of the types of sawdust (spruce or beech) on properties of lightweight refractory materials. The work focuses mainly on heat resistance, temperature usability, thermal conductivity, and density. These properties are evaluated with consideration to the ash which is created by burning sawdust.
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Study of applicability of suitable materials for long-term storage of heat energy
Bukvová, Veronika ; Šot, František (referee) ; Šťastník, Stanislav (advisor)
This bachelor thesis deals with appropriate ways of storing thermal energy and selection of materials for a high capacity storage unit. The thesis describes technologies currently used for long-term storage of thermal energy, structural arrangement of the thermal unit, physical properties of the materials usable for construction of high-temperature storage units and the utilization of these materials. The thesis also describes the measuring procedure of the material characteristics and the method of evaluation.
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Study of thermal insulation properties of cement concrete exposed to high temperature
Nováková, Iveta ; Sitek,, Libor (referee) ; Bodnárová, Lenka (advisor)
Master`s thesis is divided in to two parts, practical and theoretical. In theoretical part are listed basic information’s about light weight concrete, special emphasis are given to characteristic and practical application of compact light weight concrete with Liapor aggregates. In this study is described influence of high temperature on concrete structure and chemical, mechanical and physical changes, which take place during exposal to high temperatures. Further is evaluated surface permeability of concrete and addition of polypropylene fibres to concretes resistive to high temperatures. The practical part deals with design, production and testing of cement based concrete with use of different aggregates (light weight aggregates Liapor, basalt). The properties and use for applications in high temperatures is also mentioned. The influence of high temperature on strength, absorption, thermal conductivity, changes of surface permeability and degradation of testing specimens due to heat loads according to normative heat curve (ISO 834). For better transparency are experimental tests divided in to five phases and the measured values are evaluated on the end of each phase. In conclusion are resumed all knowledge’s obtained by testing and evaluated the most suitable formulation. The approach for further research is also mentioned.
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