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Modern technological elements for tubular heat exchangers
Plánková, Tereza ; Babička Fialová, Dominika (referee) ; Jegla, Zdeněk (advisor)
The aim of this diploma thesis is to get acquainted with modern technological elements currently used in shell-and-tube heat exchanger in the shell-side and tube-side, thermal-hydraulic calculation of selected elements and comparison of thermal-hydraulic properties with classically used competing technological elements. The work deals mainly with EM baffle in the tube-side and tube inserts like the twisted tape type (and its modifications) and coiled wire in the tube-side. The theoretical part is focused on acquaintance with classical technological elements in shell-and-tube heat exchanger and with basic thermal-hydraulic calculations, practical part then on acquaintance with modern elements and thermal-hydraulic calculation of selected elements. These calculations are then compared with the results of the thermo-hydraulic calculation of similar elements.
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Prediction and experimental evaluation of the performance of a Z-type distribution system
Polcsák, Jakub ; Rebej, Miroslav (referee) ; Babička Fialová, Dominika (advisor)
The purpose of this work was to find a suitable calculation method for predicting the function of distribution systems in the design calculations of process and energy equipment. In particular, it aimed at describing the distribution of the working fluid flow in a dividing distribution system and a combined Z-type distribution system (with nozzles located parallel to opposite sides of the system). Analytical and CFD calculation tools validated by data from the performed physical experiments were used in this work. In the CFD method, the prediction of the dividing flow was performed for full 3D and simplified 2D geometry of Z-type distribution systems. The carried-out analyzes show that the prediction of the distribution system function obtained by both analytical and numerical approaches is accurate enough. The relative difference between the experimental and computational relative standard deviations did not exceed 9 %. The main disadvantage of 3D CFD analysis, especially concerning the purpose of the intended application, i.e., the inclusion of a distribution model in a complex modeling system for the initial design of heat transfer equipment, was the extremely long computational time. Analytical models appear to be a reasonable compromise between the accuracy of the flow distribution prediction and the computational times.
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Analysis of Flow Distribution in Systems with Dense Tube Bundles
Babička Fialová, Dominika ; Dohnal, Miloslav (referee) ; Turek, Vojtěch (advisor)
Considering heat transfer equipment with dense tube bundles, it is essential to ensure as uniform a fluid distribution into the tubes as possible in order to prevent various operating problems. This bachelor’s thesis therefore focuses on tube-side flow analysis in such equipment. CFD simulations were carried out using a diverse set of flow systems with outflow into a constant-pressure environment. The respective tube bundle geometries differed in densities and sizes, arrangements of the tubes, and tube diameters. Air was used as the working fluid in the majority of the cases, however, some of the simulations were also carried out with water. Data obtained from evaluations in the fluid flow modelling software ANSYS Fluent were further analysed and the influence of the mentioned differentiating parameters on flow distribution non-uniformity and pressure drop was investigated. According to the regression model, the dependence of flow distribution non-uniformity on density and size of the bundle and on mass flow rate per unit outflow area cannot be rejected with the standard significance level. As for pressure drop, the only parameter that was not rejected was mass flow rate per unit outflow area.
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Effective utilization of waste heat by intensification of thermal equipment
Cejpek, Ondřej ; Babička Fialová, Dominika (referee) ; Jegla, Zdeněk (advisor)
The main aim of this Bachelors thesis is waste heat and its usage. In theoretical part, there are described sources of waste heat, possible way of its usage and there are described an equipment, which can reduce waste heat, mainly heat exchangers. At the end of the theoretical part of the thesis, intensification elements for heat exchangers are described. The aim of practical section is to design a heat exchanger with plane tube, tube with fins and tube with ribbed fins and select the best variant for our industrial case. In this section the main relationships and practices for heat exchanger design are described. At the end of this thesis the most suitable option for our case is selected.
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Fluid Flow in Nonstandard Process and Power Equipment
Chýlek, Martin ; Babička Fialová, Dominika (referee) ; Turek, Vojtěch (advisor)
Flow distribution has big importance in equipment with limited tube rows because it provides correct operation and sometimes specific flow distribution for technology purposes is needed. This thesis is focusing on flow analysis in these units using computational fluid dynamics (CFD). For analysis of such systems models with varying tube rows and varying perforated segment lengths were created. Analysis showed significant impact of flow manifold layout along with tube layout and number of tubes. Simplified 1D model using static pressure regain coefficient was created which provides much shorter computational times. Comparison of 1D and CFD models was made to determine field of their usage.
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Selection of a solar water heating system for a garden greenhouse
Šplíchal, Jan ; Babička Fialová, Dominika (referee) ; Jegla, Zdeněk (advisor)
The Bachelor thesis deals with selecting a suitable solar water heating system for a garden greenhouse in a specific location in the Czech Republic. The selection of the suitable water heating system itself is carried out based on an overview of commonly used systems of solar heating and by evaluating competitive designs for said garden greenhouse with regards to its layout and location. A part of the thesis focuses on a measured data set showing the real-world behavior of the garden greenhouse in different parts of the year with the purpose of theoretical calculation of essential parameters, which are needed for an indicative calculation of the collector area needed for selected water heating system. The achieved results and parameters are summarized and with them a real potential of the solar water heating system for said garden greenhouse and its value in the sense of prolonging the period of using the garden greenhouse for growing plants in cold spring and autumn months is recognized.
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Using of modern software support in the projection practice of process engineer
Zajíc, Jonáš ; Babička Fialová, Dominika (referee) ; Jegla, Zdeněk (advisor)
The presented MSc. thesis is focused on the introduction and application of PDMS software in the process piping designing area. The introduction to the employing of the PDMS software is elaborated in the first part of the thesis as practical user manual of this software followed by the benefits of this software as a recognized supportive design program are consequently illustrated on partial solved cases from common design practice. The particular benefit of deploying PDMS in design practice is demonstrated in the thesis by economic evaluation of two selected solved industrial projection cases where design optimization of process piping system is solved with the support of this software system. Introduction of new ones broadening possibilities and current trends in the supportive design software systems, specifically using the scanner and supporting Everything3D are also presented as part of the thesis on a concrete example of the reconstruction of the boiler room.
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Determination of fired heater heat duty
Slowik, Roman ; Babička Fialová, Dominika (referee) ; Jegla, Zdeněk (advisor)
The compilation and application of a new alternative method of calculating the heat duty of process tubular furnaces, published in the journal Chemical Engineering Research and Design, is the main objective of this work. The alternative method is processed in a suitable computational environment and the created calculation tool is subsequently applied to the given industrial cases of process tubular furnaces. An assessment of the accuracy of the new alternative method is performed on the basis of a comparison of the results obtained from the industrial cases with available results from commercial simulation software.
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CFD analysis of thermal stress of a tubesheet
Vince, Tomáš ; Babička Fialová, Dominika (referee) ; Rebej, Miroslav (advisor)
This diploma thesis focuses on the phenomena of multiphase flow in a steam generator as a one of probable causes of tubes and tubesheet weld cracking. In the first part of the work, a research was carried out focusing on the boiling and the phenomenon of two-phase flow in technical applications, its characteristics and properties. The thesis continuous with an overview of available numerical multiphase models in the ANSYS Fluent 2021 R1 and a research of previously published works focused on two-phase flow with the presence of boiling. The research is followed by a description of the particular boiler, which is part of the nitric acid production plant in the chemical company DUSLO, a.s., its operating conditions and a more detailed description of the issue that is being addressed in this thesis. The second part of the work continuous with a description of the computational model, including a description of the geometry of the model and used simplifications, the computational mesh and the description of boundary conditions. Important part is the description of calculation setting of steady-state and transient CFD simulations in ANSYS Fluent. Finally, the results of the two-phase flow calculation are presented and then discussed in the conclusions.
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Analysis of heat losses of operated heat exchangers
Sýs, Tomáš ; Babička Fialová, Dominika (referee) ; Jegla, Zdeněk (advisor)
The proposed bachelor’s thesis deals with calculation and analysis of heat losses of operated heat exchangers used for food applications. In the first part of the thesis, general problematics of heat exchangers is introduced, including their use and breakdown by basic categories, as well as problematics of insulation, which is supplemented by a list of the most commonly used types of insulation. Another chapter is devoted both to the assignment and description of the industrial case; drawing documentation and measured input data necessary for the calculation of heat losses are also presented. The last part of the thesis introduces the used method of assessment of heat losses of the heat exchanger network, achieved results and their discussion.
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