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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

Analýza sekundárního okruhu bloku VVER 440 / Analysis of the secondary circuit of the VVER 440 block

Černý, Michal January 2018 (has links)
The main aim of this thesis is the model design and control the secondary circuit block VVER 440. The search part of my work is a description of the secondary circuit. In the first part of the calculation is performed for the rated secondary circuit. The second calculation part focuses on the calculation circuit of the secondary for the reduced, influenced by shutting down one steam generator.
122

Vliv vrstvy oxidů na chlazení ocelových povrchů / Influence of the oxide layer on the cooling of steel surfaces

Resl, Ondřej January 2018 (has links)
This thesis deals with the influence of the oxide layer on the spray cooling of steel surfaces. As part of the work steel samples with oxide layer are made and the thickness, porosity and surface roughness of this layer are characterized. The average thermal conductivity of porous oxide layer is determined for different regimes of oxidation. Further, the influence of the oxide layer on the heat transfer coefficient during the spray cooling is experimentally investigated on created samples and the basic numerical simulation of the cooling is done for selected experiment with oxide layer. The thesis also contains theoretical introduction to given issue.
123

Vliv provedení zateplení rodinného domu v Brodku u Prostějova na výdaje spojené s jeho provozem / Influence of Insulating a House in Brodek u Prostějova on the Expenses Related to its Operation

Soukupová, Veronika January 2018 (has links)
This diploma thesis evaluates the influence of a thermal insulation of a structure on expenses related to its operation. It addresses the issues of a thermal insulation, energy loss, energy consumption, and evaluates the recovery of investments considering the insulation costs. It also monitors the insulation price projection on the total cost of the property.
124

Kvantifikace tepelně-hydraulických charakteristik flexibilního prvku s využitím experimentálních dat / Quantification of the thermohydraulic characteristics of the flexible element using experimental data

Sochorec, Rostislav January 2019 (has links)
The diploma thesis aims to establish thermo-hydraulic properties of a flexible tube described by its Darcy friction factor and film heat transfer coefficient respectively. A flexible tube (corrugated stainless steel tube) is an easily shapeable stainless steel component used to build various piping connections, in a place of more common copper or plastic made tubes. It can also be used to build heat exchangers thanks to its signature properties. The investigated product is the one developed and manufactured by the Czech company Flexira s.r.o. and sold under the brand name xConnect System. Its thermo-hydraulic properties are established by an experiment, which is based on real utilizations by Laboratory of Energy Intensive Processes in NETME (New Technologies for Mechanical Engineering) Centre at Brno University of Technology. The investigated case is a coil-shaped element serving a purpose of a water-to-water heat exchanger. The text contains a literature survey of the chosen flexible tube and a description of a draft and development of the specific experimental test based off the established theory. The obtained results are then analysed, for the purpose of establishing a functional dependence, which can then be used to calculate a film heat transfer coefficient.
125

Vliv zanášení výměníku a součinitel prostupu tepla / Effect of exchanger fouling and heat transfer coefficient

Konopiský, Karel January 2020 (has links)
This diploma thesis covers the influence of fouling in heat exchangers and heat transfer coefficient. In the first part of the thesis are covered the characteristics of fouling and its formation, process, and effects on heat transfer surfaces in exchangers. In the next part of the thesis, chemical analysis of cooling water is performed on an extracted sample and the potential of fouling is determined based on the analysis. In the conclusion part, computational models of fouling in the tube side of the heat exchanger are presented; fouling of an actual heat exchanger is calculated and compared with data captured during the operation of the heat exchanger.
126

Experimentální a výpočtové stanovení součinitelů přestupu tepla pro části průmyslové parní turbíny od firmy Siemens, s.r.o Odštěpný závod Industrial Turbomachinery / Experimental and Numerical Assessment of the Heat Transfer Coeficients for Industrial Steam Turbine for Siemens Industrial Turbomachinery

Hladík, Petr January 2015 (has links)
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.
127

Výrobník ledu s přímým odparem / Ice maker with direct evaporation

Loibl, Jan January 2015 (has links)
The theoretical part of the diploma thesis deals with introduction to the issue of refrigeration systems with thermal energy storage. Possibilities of thermal energy storage with phase change are introduced. The thermodynamic principle of functioning of the particular refrigeration system type is explained here as well as its coefficient of performance and fundamental components. In addition, several examples of ice-making systems are discussed. In the practical part the design of a particular refrigeration system is calculated. The main part of the design is the cold evaporator with direct evaporation and the possibility of ice production and its usage for thermal energy storage. The calculation of the overall two-phase heat transfer is carried out.
128

Vliv provedení zateplení rodinného domu ve Slavicích na výdaje spojené s provozem této nemovitosti. / Influence of insulation of a house in Slavice on expenses related to the operation of the property

Pokorná, Jana January 2015 (has links)
This master´s thesis deals with insulation of the house and it's costs. First part describes the energy performance of building, different methods of thermal insulation and types of thermal isolation. This thesis evaluates the influence of thermal insulation of residential building design for expenses associated with operating the property. This thesis uncludes thermal technical assessment of the condition of the house and then heat the assessment of the options for the thermal insulation on its economic return. In conclusion, the assessment of individual variants insulation is calculated as a simple payback period and the effect on price of this house.
129

Hodnocení přestupu tepla na skrápěném trubkovém svazku / Heat Transfer Evaluation on Falling Film Tube Bundle

Kracík, Petr January 2016 (has links)
Sprinkled tube bundles with a thin liquid film flowing over them are used in various technology processes where it is necessary to separate the vapour and liquid phases quickly and efficiently. The process occurs predominantly at low temperatures with a corresponding decrease of pressure around the tube bundle. Such a technology is represented for instance by an evaporator at absorption units or an evaporator for sea water desalination. In ideal conditions water boils at the whole surface of an exchanger, but in practice it must be considered that in original spots of contact between water and the exchanger wall the water will not boil at the tubes' surface but the cooling liquid will merely be heated-up. The presented dissertation thesis focuses on this issue. The objective of the thesis was to determine the heat transfer coefficient at the surface of sprinkled tube bundles of various geometries at atmospheric pressure as well as low pressure. For this purpose experiments have been carried out at tube bundles consisting of copper tubes of 12,0 mm diameter placed horizontally one above another that were heated by water. Three types of tubes (smooth, sandblasted and grooved) of four various pitches (15,0 to 30,0 mm by 5,0 mm increments) have been tested. Simultaneously individual bundles' geometries consisted of 4, 6, 8 and 10 tubes with identical surface finish. Based on the conducted experiments the mathematical model of heat transfer that involves mainly analogy criteria has been made more accurate. A temperature field at the sprinkled tube bundle surface has been scanned by a thermographic camera during the performed experiments. Influence of geometry and tube surface finish on flow mode and consequently also on heat transfer has been assessed in accordance with the compiled methodology.
130

Projekční návrh ohříváku topné vody / Designing of a hot water heater

Zdražil, Pavel January 2016 (has links)
This thesis processes design of hot water heater. It was done thermal, hydraulic and basic strength calculations in the work and from their outcomes was set up a design of heat exchanger, which was afterwards modelled and drawn. In the beginning of the work is reader introduced to heat exchanger types and characteristics and also to its thermal processes. Then the work continues with thermal design of the heat exchanger, where the most important outcome is heat transfer surface with other geometric parameters, followed by hydraulic design, where pressure loss on water side was calculated. The calculations are finished up by basic strength design, calculating thickness of shell and tube walls. The thesis is ended with evaluation of computed design and description of its basic features.

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