|
|
Contribution to the construction of cost and energy efficient family houses
Čech, Josef ; Mohelníková, Jitka (referee) ; Gašparik,, Jozef (referee) ; MBA, Pavel Slováček, (referee) ; Hrazdil, Václav (advisor)
Dissertation focuses on the verification of construction family houses made of concrete shell block with internal thermal insulation system. The construction technology is transferred to the Czech Republic from France. The work focuses on building envelope. The suitability of implementation is assessed on the basis of verification selected thermal technical requirements placed on building envelope. Requirements are specified by legislation in force in the ČR. The verification was performed by using software simulations and measurements on realized buildings. Critical areas of construction technology were identified on the basis software simulations and measurements on site. It was suggested solution, in which critical areas comply the thermal technical requirements. The building envelope was checked also using the thermography imaging on site. Continuous measurement of interior temperature was used to evaluate thermal comfort in the room. In the completed buildings was tested airtightness of the building envelope, which revealed other critical areas of the building envelope. Critical areas are necessary to solve with sufficient care. The economic cost of implementing each variants of exterior walls made of concrete shell block with internal thermal insulation were compared with the economic costs of implementing external walls made of burnt clay hollow blocks and made of burnt clay hollow blocks with external thermal insulation system ETICS. Subsequently, the economic return was calculated for individual variants of external walls made of concrete shell blocks with internal thermal insulation. From the environmental viewpoint was made comparison of production greenhouse gas CO2 and SO2 (cause acid rains) during the life cycle of the individual variations of exterior walls made of concrete shell blocks with system of internal thermal insulation, exterior walls made of burnt clay hollow blocks and burnt clay hollow blocks with external thermal insulation syst
|
|
|
Thermal properties of the window frame and the connection joints
Hejný, Lukáš ; Hraška,, Jozef (referee) ; Doc.Ing. Miloslav Bagoňa, Ph.D (referee) ; Štěpánek, Ladislav (referee) ; Kalousek, Miloš (advisor)
This thesis deals with the solution problem of fitting a window in the wall, especially for passive houses. It provides options to optimize the window connection joints, improve the thermal transmittance of the window frame, thereby reducing the total heat loss through the window. In the first part of the thesis is a research literature on the windows and heat technical and physical mechanisms. Are described equations and physical processes taking place in the windows and related building structures. This section describes the basic points in history, technical description of windows, etc. and present ways of assembly Installation the window and the influence of the thermal properties of the heat loss. The next part deals with the description of the work and the results obtained in the course of doctoral study. Describes the main objectives of the dissertation thesis, calculations and simulations of temperature fields and the results of the calculated values. Furthermore are described and analyzed measurement data and compared with the calculated values. At the end dissertation thesis are given opportunities to improve the current solution regarding the heat transfer coefficient of the frame, the optimal way of installation fillers windows in the perimeter wall and improve the thermal properties of the connecting joint.
|
|
|
The Effect of the Bypass Factor on Design and Geometry of the Evaporator for the Cooling Unit
Vytasil, Michal ; Rubinová, Olga (referee) ; Rubina, Aleš (advisor)
Diploma thesis focuses on effect of the bypass factor on design and geometry of the evaporator for the cooling unit of data centre. Effect of the bypass factor on individual design parameters is solved in detail. All dependendecies are captured by using graphs in which s placed a cement on that parameter. In part C, mathematical and physical solutions are demonstrated calculations and processes leading to the design of the exchanger. In the end, evaluation of the calculations is done and there is also showed possible improvements for the practise.
|
|
|
Thermal properties of automotive light sources - Halogen sources
Hlubinka, David ; Hájek, Vítězslav (referee) ; Janda, Marcel (advisor)
The aim of master´s thesis is to get acquainted with the design and materials used in selected automotive light source – tungsten halogen lamp. Further, the thesis focused on the theory and appropriate selection of the thermal measurement method on a real sample. Subsequently, a model of the light source and its simulation in the ANSYS – Maxwell 3D and Mechanical programs are created. Finally, the results of the thermal simulation and the non-contact measurement of the tungsten halogen lamp are evaluated
|
|
|
Ranque - Hilsh vortex tube
Bábor, Lukáš ; Brázdil, Marian (referee) ; Šnajdárek, Ladislav (advisor)
Ranque-Hilsh vortex tube is a device that converts high pressure gas flow into two low pressure flows with higher and lower temperature, than a temperature of the inlet flow. Technically, it is a device of very simple construction, which is characterised by low initial costs, high endurance, durability and low maintenance. Its main disadvantage is low coefficient of performance, compared to conventional heat pumps at room temperature. In the first section of this paper, examples of applications where utilization of Ranque-Hilsh vortex tube is advantageous are given. Afterwards, several theoretical concepts of refrigeration cycles utilizing vortex tube to lower energy consumption are described. The final section of this thesis introduces new geometry of inlet nozzles for improving coefficient of performance of vortex tube. This geometry is then compared to straight tangential nozzles of circular cross-section. During the measurements, surface temperature of the vortex tube with respect to its length is monitored.
|
|
|
Development of Inverse Tasks Solved by Using the Optimizing Procedures and Large Number of Parallel Threads
Ondroušková, Jana ; Skarolek, Antonín (referee) ; Brestovič, Tomáš (referee) ; Horský, Jaroslav (advisor)
In metallurgy it is important to know a cooling efficiency of a product as well as cooling efficiency of working rolls to maximize the quality of the product and to achieve the long life of working rolls. It is possible to examine this cooling efficiency by heat transfer coefficients and surface temperatures. The surface temperature is hardly measured during the cooling. It is better to compute it together with heat transfer coefficient by inverse heat conduction problem. The computation is not easy and it uses estimated values which are verified by direct heat conduction problem. The time-consuming of this task can be several days or weeks, depends on the complexity of the model. Thus there are tendencies to shorten the computational time. This doctoral thesis considers the possible way of the computing time shortening of inverse heat conduction problem, which is the parallelization of this task and its transfer to a graphic card. It has greater computing power than the central processing unit (CPU). One computer can have more compute devices. That is why the computing time on different types of devices is compared in this thesis. Next this thesis deals with obtaining of surface temperatures for the computation by infrared line scanner and using of inverse heat conduction problem for the computing of the surface temperature and heat transfer coefficient during passing of a test sample under cooling section and cooling by high pressure nozzles.
|
|
|
Energy use of the facade
Salajka, Radek ; Rubinová, Olga (referee) ; Rubina, Aleš (advisor)
The main motive of this master's thesis is expanding awareness of ventilated facades and their use and comparison with external thermal insulation composite system (ETICS). I mention this in theoretical research. As an expansion to theory and a key theme of this thesis is a description of individual physical events present on the facade and in it's ventilated gap based on data output from measurement. The data gathering was made by a group of professionals who have done an on-point facade measurement on a real ventilated facade throughout a year - more detail in text. I personally have been a part of a research team and I describe my work and research in detail in the third part of this master's thesis - experimental part. In practical part I devote myself to use our new knowledge on a given building. More precisely - I use numerical calculations to present energy use of of given facade in comparison with ETICS on the same building with the same boundary conditions.
|
|
|
Green and blue infrastructure: means of reducing surface temperatures in the urban environment
SEDLÁČEK, Jan
Climate change may accelerate the Urban Heat Island (UHI) effect with many consequences for the well-being of human populations in cities. Green and blue infrastructures (GBI) are presented as a way to mitigate the UHI effect. In our study, the influence of GBI (primarily less studied types) on surface temperature (ST) was tested using a thermal camera. Various types of GBI (e. g. tree shade and lawn) and their combination were compared.
|
|
|
Časové změny vlivu vegetačního krytu na místní klima intravilánu obce pomocí metod dálkového průzkumu Země
NÁROVEC, Václav
The diploma thesis deals with changes in vegetation indices and surface temperatures of previously undeveloped peripheral areas of České Budějovice and its immediate surroundings, which were built up after 1990. Areas that were undeveloped before 1990 and spread over either permanent grassland or arable land with agricultural crops. These areas are divided into four types - industrial areas, service areas, residential areas of multiapartment houses and residential areas of solitary family houses. The work uses Landsat satellite images for the years 1990, 1993, 1999, 2006, 2010, 2015 and 2020. The studied areas were examined in the period before construction, just after construction and with a distance after construction. In the period before the transformation (1990), there were high values of vegetation indices NDVI (Normalized Difference Vegetation Index), SAVI (Soil Adjusted Vegetation Index) a NDMI (Normalized Difference Moisture Index) and low values of surface temperatures in most of the studied areas. However, during the construction, the vegetation decreased and thus the values of vegetation indices decreased and the surface temperatures increased. Subsequent improvements were observed in areas with multi-apartment and family houses, where the vegetation of parks and residential gardens grew after a certain time. In the vicinity of the industrial area and service areas, where vegetation did not grow, the values of the monitored indices remained low.
|
|
|
Tepelný ostrov města - analýza stavu a možnosti zlepšení
CHVOJKOVÁ, Aneta
Increasing surface temperature in urban environments along with the creation of heat islands is one of the most visible phenomena of a worsening climate in general. This phenomenon is inherently linked to the increasing rate of urbanisation and urban development. Heat islands in cities are formed by an accumulation of high surface temperatures and differ significantly from areas in their rural surroundings. The surface temperature depends on several factors. These include, including but not limited to, colour, permeability or material of the surface, as well as the presence of vegetation in the given area or the layout of the streets. Anthropogenic activity caused by fossil fuel combustion or transport also has a significant impact on the temperature in urban environments. One of the most efficient tools to reduce the rise in temperatures is in particular high-quality vegetation and water retention in urban environments and the landscape in general. The area of interest of this work, which deals with the topic described above, is Kardašova Řečice with twelve determined locations. Using satellite data analysis, problematic areas in terms of surface temperature and several smaller heat islands were identified. The results of the spectral vegetation indices analysis showed a mutual correlation between the surface temperature and the presence of vegetation, which was analysed by NDVI and NDMI spectral vegetation indices data. The highest temperatures and the lowest surface humidity were found in areas with the least vegetation (greenery). The situation was the opposite in areas with sufficient vegetation cover and water for evapotranspiration. Since vegetation has been proved to have a significant positive impact on reducing the surface temperature in urban environments, a strategy was suggested to improve the urban living conditions by implementing a suitably selected green and green-blue infrastructure.
|
guest ::
