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Simulation of temperature and airflow in a field distributor with frequency converter
Melechovský, Ondřej ; Maxa, Jiří (referee) ; Ondříček, Adam (advisor)
Presented work deals with heat transfer and its methods. At the beginning thesis describes the theory and the ways of heat transfer with connected quantities and equations. Then it explains the stack effect and impact of temperature on electro technical device. In work is also described ABB driver ACS line and calculation of heat transfer according to IEC 60890 standard. In the practical part there is the calculation of heat transfer in Flow Simulation simulating CFD program solved and finite element method is mentioned. Important part of work is devoted to setting and optimization of simulation. In conclusion are made some changes of construction of driver, dependence on heat transfer is inspected.
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Power - plant
Studený, Jan ; Severa, Zdeněk (referee) ; Mléčka, Jan (advisor)
The "POWER - PLANT" deals with the rehabilitation of the former Central Power Conversion and Dale Schoeller (Nejedly I and III) in the village Libušín Mine. Will be newly designed for building the power plant technology with progressive fluidized bed boiler to biomass steam turbine with an output of 7 MW and absorption (trigeneration) unit producing heat, cooling and electricity, which also will function as a cooler primary circuits. The source of water for the power plant will not only former mining pit Nejedlý I which is currently flooded drinking water at about 12 ° C. This system uses high efficiency embedded fuel (biomass), which is ultimately required less. A greater proportion of electricity generated and part of the heat will be distributed to the public network. In most areas will be proposed publicly accessible greenhouses of steel-aluminum construction filled ETFE foil forming the heat insulating membrane filled with air. The reason is to create conditions for the cultivation of tropical and subtropical plants. Greenhouses will be connected to the absorption unit power (underground meanders through which water will circulate), the ventilation shaft mine and mine water - therefore it will be possible to manage the conditions of the internal environment of the building without the influence of the season and especially without mounting other technological devices. It will provide for cooperation with the absorption unit for cooling the primary circuit - therefore eliminating the need for cooling towers or fans. The project will build a detached departments of the Faculty of Mechanical Engineering in Prague - Institute of progressive technologies and systems for energy and the Faculty of Agronomy and Natural Resources CULS. The reason is to allow students and scientists actively and in practice mainly participate in the operation and especially the development of the issue. The public in the area besides themselves open to the greenhouses indoor and outdoor thermal swimming. Part of the entrance hall is a bistro and foremost lecture hall. The aim is decentralized botanical-energy complex of buildings that produce electricity, heat, cooling, and biomass, and creating recreational, educational and research conditions.
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Study of thermal properties of selected coloids
Křivánková, Kateřina ; Krouská, Jitka (referee) ; Zmeškal, Oldřich (advisor)
The bachelor thesis is focused on the study of the thermal properties of colloidal systems, especially the properties of emulsions (water, oil), which can be used in the cosmetic industry as an essential component of various lotions and creams and in the food industry. In the introduction the first defined thermo-physical processes (conduction, convection and radiation) and temperature measurement (stationary, transient). Furthermore defined physical parameters (heat and thermal conductivity, heat capacity), that are determined using transient methods. The measured data were collected and analyzed by using the EMA (Electrical Measurement Analyser) and the HarFA (Harmonic and Fractal Image Analyser). The results will be used to determine the optimum conditions for the production of cosmetics and dietary supplements.
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Optimalisation of thermal properties of solar cell modules
Dohnalová, Lenka ; Matiašovský, Peter (referee) ; Zmeškal, Oldřich (advisor)
The topic of presented diploma thesis is study of thermal properties structures of photovoltaic cells. The main goal of this thesis is study of ways of heat spreading from volume and planar materials (conduction, convection and radiation). Then it is needed to determine contributions of heat spread from laminated photovoltaic cell and compare them to results measured by transient pulse method, step wise method and with thermo-camera using. At the beginning of this thesis it will be needed to define heat and ways it’s spread. Heat is closely connected with temperature. That is reason why will be there spoken about temperature and methods of its measuring. Than there will be defined basic thermo-physical parameters of materials. Thermo-physical parameters of materials will be measured by transient methods that will be characterized later and by thermo-camera. This thesis deals with photovoltaic cells, so there will be described their structure, properties, utilization and way of their production. Subsequently after the definition of all needed terms the experimental part of this thesis will be introduced. It will be needed to characterize measured volume material and define its thermo-physical parameters. Using the pulse transient method, step wise method and thermo-camera there will be measured the thermal response of PMMA sample, nonlaminated photovoltaic cell and also samples of laminated photovoltaic cells. Findings of all described methods will be finally compared.
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Calculation of the distribution of temperature field of induction machine
Suk, Jiří ; Dostál, Lukáš (referee) ; Janda, Marcel (advisor)
The issue of this bachelor’s thesis is calculation of the distribution of temperature field of induction machine. There is used three different methods of calculating which are compared in the conclusion. First method is lab measuring of surface temperature on different spots on the machine while unloaded without active cooling. Temperature is measured on four spots using different devices. Another way how to calculate temperature field is computer simulation in ANSYS Workbench using finite elements method. In this method is necessary to create real-based model of motor in CAD system. In this case Autodesk Inventor 2015 was used. Last method was simplified analytics calculation using heat circuit of the stator part. Last but not least is comparison of all used methods, results and accuracy of calculation.
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Utilization of absorption systems in the heating systems
Vidlák, David ; Špiláček, Michal (referee) ; Pospíšil, Jiří (advisor)
Main goal of this work is familiarization with basic features of absorption heat pumps and it’s growing importance on the market. In the first part of the work there is a research for clarifying facts associated with such pumps. In the introduction there are descriptions of basic information from the field of heating industry and its connections to our systems. Next there is a brief analysis of price changes in electricity and heat in the last five years. Main part of the analytical section is a description of the used absorption system. Second part of the work is focused on the calculation of the absorption system itself. First there is calculated internal and external part of the device according to the parameters from GE Power s.r.o. After this step there are parametric studies based on changes of key parameters of the default device for a demonstration of the behavior of a heating pump. In the end of the work there is a integration of the unit into the heating cycle for variations including flue gas condenser and using a cooling water from the turbine condenser.
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Energy usage of beer production
Maťa, Jakub ; Tuhovčák, Ján (referee) ; Hejčík, Jiří (advisor)
The bachelor thesis deals with the issue of energy consumption of beer production. The first part focuses on the technology of beer production itself, the understanding of which is a key prerequisite for assessing the possibility of using a heat pump for this process. The main part then describes the individual processes and their energy consumption. Finally, it evaluates the use of a heat pump and shows if it could reduce the energy requirements of beer production.
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Calculation of thermal resistance of finned heatsink
Kyanka, Radim ; Huták, Petr (referee) ; Toman, Marek (advisor)
This bachelor's thesis is focused on the problem with analytical calculations needed to define thermal resistance of finned heat sinks. First it describes how temperature proceeds at different boundary conditions at fin tip. Than it describes different mechanisms of heat transfer, equlation of heat resistance especially of natural and forced convection. To verify the results there is comparison between analytical equlations written in Matlab program and measuring results.
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Trasfer Heat Analysis in Steam Generators in blocks of VVER 440
Roupec, Petr ; Pulec, Jiří (referee) ; Šen, Hugo (advisor)
The aim of this thesis is to analyze the heat transfer in steam generator of blocks in the nuclear power plant VVER 440. The steam generator represents the border between the primary and the secondary circuit. The heat is carried from a warm water from reactor to a cold water. The steam arises after the heat transfer and drives the steam turbine. An important quantity which represents the heat transfer is a heat transfer factor. This thesis is divided into theoretical and a practical part. In the theoretical part is mentioned a principle of the steam generator and the theoretical calculation of the heat transfer factor, which comes first of all from the character of the streaming in the steam generator. The practical part brings a comparison of the heat transfer factor calculated from data measured after the start of the third block of EDU in 1986, with the heat transfer factor which comes from the measurement after the power-increase for 105 % of nominal power of the same block in 2009. Further is shown the prediction of the heat transfer factor for next power-increase and the following service is shown too.
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