National Repository of Grey Literature 9 records found  Search took 0.00 seconds. 
Influence of residual stress on pressure vessel part fatigue life
Boleloucký, Václav ; Vincour, Dušan (referee) ; Létal, Tomáš (advisor)
This bachelor’s thesis deals with the impact of a residual stress, caused by an applied cyclic pressure, on fatigue life of a pressure vessel part (flat end–cylinder connection). Bachelor’s thesis includes the design of the pressure vessel according to CSN EN 13 445 regulations, analytical solution in Maple software, from which stresses and deformations are determined. Then the results of the analytical approach are firstly verified by a FEM modelling in ANSYS Workbench software and secondly compared to each other in graphs and discussed. From the values of stresses in FEM, analysis fatigue life expectations are calculated with the respect to CSN EN 13 445 regulations, for two cases. First one, where a pressure test is applied and second one, where the pressure test is not applied before the pressure vessel is put into service. In the conlusion the obtained results are discussed.
Integrity breach analysis of storage tank using FEM
Ševčík, Martin ; Vincour, Dušan (referee) ; Létal, Tomáš (advisor)
This master thesis is focused on computational modelling of critical external as well as internal pressure acting of the repaired tank. During cleaning of pipelines, the gas mixture entered into this storage tank causing loss of integrity in the connection between the roof and the shell. The first part of the thesis is focused on check calculation of the shell in exceptional conditions. The next part describes the repair of the tank including check of the pillar according to ČSN EN 1993 1 1 and ČSN EN 1993-1-6. The main part of the thesis is focused on determination of the buckling resistances of the tank in original as well as repaired state using ANSYS Mechanical software. The results are comparable with original tank, whose buckling resistance was not decreased due to the repair.
Flow Induced Vibration Fatigue Analysis of Tube Bundle
Buzík, Jiří ; Vincour, Dušan (referee) ; Lukavský, Jiří (referee) ; Vejvoda, Stanislav (advisor)
The aim of the dissertation thesis is the control of the tube bundle on the cyclic fatigue caused by the flow past tube bundle. Fatigue due to flow is caused by flow-induced vibrations. Examined vibrations are caused by the mutual interaction of two phases (solid and liquid). The present work is focused mainly on the interaction of tube bundles with fluid. The current level of knowledge in this field allows to predict mainly static respectively quazi-static loading. These predictions are based on methods of comparing key vibration variables such as frequencies, amplitudes or speeds (see TEMA [1]). In this way, it is possible to determine quickly and relatively precisely the occurrence of a vibrational phenomenon, but it is not possible to quantitatively assess the effect of these vibrations on the damage of to the tube beam and to predict its lifespan, which would require the determination of the temperature field and the distribution of forces from the fluid on the beam. The aim of the work is to evaluate the-state-of-the-art, to perform a numerical simulation of the flow of fluids in the area of shell side under the inlet nozzle. Current methods of numerical analyses very well solve this problem, but at the expense of computing time, devices and expensive licences. The benefit of this work is the use of user-defined function (UDF) as a method for simulating interaction with fluid and structure in ANSYS Fluent software. This work places great emphasis on using the current state of knowledge for verifying and validation. Verifying and validation of results include, for example, experimentally measured Reynolds and Strouhal numbers, the drag coefficients and for example magnitude of pressure coefficient around the tube. At the same time, it uses the finite element method as a tool for the stress-strain calculation of a key part on tube such as a pipe-tube joint. Another benefit of this work is the extension of the graphical design of heat exchanger according to Poddar and Polley by vibration damages control according to the method described in TEMA [1]. In this section, the author points out the enormous influence of flow velocity on both the tube side and the shell side for design of the heat exchanger to ensure faultless operation. As an etalon of damage, the author chose a heat exchanger designated 104 from the Heat Exchanger Tube Vibration Data Bank [3]. With this heat exchanger, vibrational damage has been proven to be due to cutting of the tubes over the baffles. The last part outlines the possibilities and limits of further work.
Residual Service Lifetime of Furnaces in Petrochemical Industry
Horsák, Libor ; Vincour, Dušan (referee) ; Lukavský, Jiří (referee) ; Vejvoda, Stanislav (advisor)
The objectives of this work is residual lifetime of heaters in petrochemical industry. There is no comprehensive publication about this theme. This paper lists and describes the most of main phenomena that has to be taken into account in the process of determination of residual lifetime. This paper focuses on creep damage of a real heater based on deformation measurement. It describes some heater failures that could cause unplanned operation interruption however, appropriate intervention made possible safe heater operation until planned heater shutdown. No compact method is given how to determine heater residual lifetime, but a direction is given how a complex method of residual lifetime assessment of refinery heaters could be created.
Nonlinear buckling analysis of a flue gas pipe
Jelínek, Jan ; Vincour, Dušan (referee) ; Létal, Tomáš (advisor)
This thesis deals with the nonlinear analysis of stability loss of flue gas pipe. This pipe is a part of desulphurization line. The thesis describes the creating of a simplified FEM model. It also describes the setting of the boundary conditions of the model for few loading cases. These cases differ by preference for one of the load as dominant. There are proposed several variants of stiffening by light ring stiffener. The work is finished by comparing the resistance to the stability loss of the reinforced variants and unreinforced model of flue gas pipe.
Influence of thermal shocks on fatigue of pressure equipment components
Umlauf, Martin ; Vincour, Dušan (referee) ; Létal, Tomáš (advisor)
This thesis examines influence of thermal shock on fatigue of pressure equipment components. The paper relates to project of IMI CCI Brno, which is a leading manufacturer of valves for the energy and process industries. Analysis concerns the impact of thermal shock concentrating on high pressure part of the steam valve. And proposal for a new valve geometry that reduces machining operations and reduce financial costs of production. First part of the thesis presents a basic review of fatigue damage components concerning mechanical loading and thermal – mechanical loading. Second part of the study creates FEM model of the valve. FEM model simulate temperature field and stress during thermal shock. Influence of thermal shock to fatigue damage was computed on basis of stress tensor obtained from FEM simulation under Chapter 18 of the standard EN 13445-3. Existing valve geometry was verified and the new geometry was proposed that simplified and reduce financial costs of production.
Software Aided Design and Assessment of Shell and Tube Heat Exchangers
Létal, Tomáš ; Klemeš,, Jiří (referee) ; Vincour, Dušan (referee) ; Jegla, Zdeněk (advisor)
Subject of this work is a development of an integrated software environment for mechanical design and check of shell and tube heat exchangers. Processes of mechanical design and checks well as software which perform these processes are broken down to basic methods and parts. Mechanical design is usually performed according to some standards. In this work, ČSN EN 13445 is used. This standard describes mostly design check calculations which can be easily algorithmized. On the contrary, design calculations are described to some extent in few simple cases and mechanical design of shell and tube heat exchanger has not been fully algorithmized yet. Subject of this work is design of software, which will be capable of automatically performing mechanical design from datasheet as an input. Based on breakdown of design and check processes, requirements for key software features are derived. Important part of presented work is design and implementation of key modules – data model of shell and tube heat exchanger, module for mechanical design check according to ČSN EN 13445. These modules form basis of the software which will be developed further in future work.
Design of heat exchanger after ČSN EN 13 445
Lošák, Pavel ; Vincour, Dušan (referee) ; Vincour, Dušan (referee) ; Nekvasil, Richard (advisor)
Diploma thesis is fucused on strength calculation of the heat exchanger according to ČSN EN 13 445. Introductory part introduce problems with the design of heat exchangers. In other parts there are a strength calculation of the heat exchanger according to ČSN EN 13 445, the results of the analysis with their appreciation. Annexes included output logs from the program Sant 'Ambrogio, and drawings documentation.
Non-stacionary thermal field in the nozzle at stream mixing
Vosynková, Jana ; Vincour, Dušan (referee) ; Nekvasil, Richard (advisor)
Nuclear energy is already well known area of energy generation. However, it is necessary to eliminate the potential risks of failure. That places special emphasis on safety in production and operation of nuclear power, especially its primary circuit. This work is focused on thermal damage to the injection nozzle, which is part of the pressurizer in the primary circuit Dukovany plant.The aim was a comparative analysis of two geometries nozzle which were loaded by varying temperature loading trought time and by static preassure loading. Main attention was placed on the thermal shocks in the material.

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