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Grate Biomass Boiler
Dražka, Ondřej ; Křemínský, Pavel (referee) ; Lisý, Martin (advisor)
The aim of the thesis is a design of a grate steam boiler with capacity of 35 t/h and output steam parameters with temperature 430 °C and pressure 4,1 MPa. The first part of the thesis deals with stoichiometric calculations and boiler efficiency. The theses mainly focuses on the heat transfer calculation and the geometric design of individual heat transfer surfaces. The specifics of fuel are taken into consideration. The drawing of the basic boiler scheme is a part of the thesis.
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Study of AlSi protective coating after degradation
Vítková, Gabriela ; Řičánková, Veronika (referee) ; Hutařová, Simona (advisor)
Materials used for high temperature applications works in a very aggressive environment (oxidation, hot corrosion, erosion, fatigue, creep). Demands on these materials are very high. Nickel-based superalloys show the certain stability in this environment. Improved resistance to oxidation and hot corrosion can be achieved by using protective layers such as diffusion barriers. This thesis is focused on changes of microstructure and properties of AlSi layer applied by „slurry“ method on nickel-based superalloy Inconel 713 LC, due to long-term thermal exposition at 800, 900 a 1000 °C.
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High temperature corosion of SiMo type ductile iron
Viskupič, Adam ; Kaňa, Václav (referee) ; Roučka, Jaromír (advisor)
While using iron castings behind temperature of 500 C namely at cyclic heat straining degradation of structure and breaching iron castings. For this purpose introduce cast iron with content of Si and Mo. Focusing on improvement of SiMo51 for increased high-temmperature corrosion-and fatigue life in exhaust-gas temperatures up to 800 C. Thesis set up chemical microheterogeneity, properties, high temperature corosion and microhardness
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Oxide scales damaging evaluation
Audyová, Markéta ; Vejvoda, Stanislav (referee) ; Lošák, Pavel (advisor)
This work is focused on oxide scale failure and characteristics created in high temperature – supercritical processes. The presence of high temperature corrosion in supercritical processes is minimalised by selection of the right material. For this work was selected material X10CrMoVNb9-1, where formulas of present oxidation scales are Fe2O3, Fe3O4 and FeCr2O4. Each oxidation scale has its own mechanical properties thus it is important to notice scale arrangement, thickness and geometry. Oxide scale mechanical properties, scale failure mechanisms and oxidation scale growth is evaluated in this work. Tension and pressure oxide scale failure are determined by critical values, which are mentioned in this work. Thanks to these values there was possibility to verify the authenticity of the finite element model. Oxidation scales created in heat exchangers are badly accessible thus it is difficult to observe them or remove them mechanically. Tube finite element model with oxidation scales was created in this work. There are simulations of scales on selected steel in supercritical conditions (pressure 24 MPa, temperature 500 °C). Simulation and analytic results are compared. Failure operative conditions are searched for scale FeCr2O4 until its compleate delamination and separation from metal. Aim of this work is to create an oxidation scale model with a possibility of futher use.
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Prediction of furnace tubes corrosion using operating data
Kolomazník, Milan ; Kilkovský, Bohuslav (referee) ; Jegla, Zdeněk (advisor)
The thesis deals with the modeling and prediction of corrosion of radiation tube snake in the heating furnace. Specifically it is focused on vertical cylindrical furnace which is included in the catalytic hydrocracking unit and serves for heating aggressive circulation gas which is the cause of high temperature corrosion. An important basis for the creation of computational models are available records about the operation of the furnace and about the corrosion and degradation mechanisms during the lifetime of the tube system in furnace. Such information enables the creation of a computational model which is based on the prediction of high-temperature corrosive damage of radiation tube snake. The computational model involving all relevant factors may serve as the basis for a predictive life management system of radiation snakes in the heating furnace.
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Grate Biomass Boiler
Dražka, Ondřej ; Křemínský, Pavel (referee) ; Lisý, Martin (advisor)
The aim of the thesis is a design of a grate steam boiler with capacity of 35 t/h and output steam parameters with temperature 430 °C and pressure 4,1 MPa. The first part of the thesis deals with stoichiometric calculations and boiler efficiency. The theses mainly focuses on the heat transfer calculation and the geometric design of individual heat transfer surfaces. The specifics of fuel are taken into consideration. The drawing of the basic boiler scheme is a part of the thesis.
|
|
|
High temperature corosion of SiMo type ductile iron
Viskupič, Adam ; Kaňa, Václav (referee) ; Roučka, Jaromír (advisor)
While using iron castings behind temperature of 500 C namely at cyclic heat straining degradation of structure and breaching iron castings. For this purpose introduce cast iron with content of Si and Mo. Focusing on improvement of SiMo51 for increased high-temmperature corrosion-and fatigue life in exhaust-gas temperatures up to 800 C. Thesis set up chemical microheterogeneity, properties, high temperature corosion and microhardness
|
|
|
Oxide scales damaging evaluation
Audyová, Markéta ; Vejvoda, Stanislav (referee) ; Lošák, Pavel (advisor)
This work is focused on oxide scale failure and characteristics created in high temperature – supercritical processes. The presence of high temperature corrosion in supercritical processes is minimalised by selection of the right material. For this work was selected material X10CrMoVNb9-1, where formulas of present oxidation scales are Fe2O3, Fe3O4 and FeCr2O4. Each oxidation scale has its own mechanical properties thus it is important to notice scale arrangement, thickness and geometry. Oxide scale mechanical properties, scale failure mechanisms and oxidation scale growth is evaluated in this work. Tension and pressure oxide scale failure are determined by critical values, which are mentioned in this work. Thanks to these values there was possibility to verify the authenticity of the finite element model. Oxidation scales created in heat exchangers are badly accessible thus it is difficult to observe them or remove them mechanically. Tube finite element model with oxidation scales was created in this work. There are simulations of scales on selected steel in supercritical conditions (pressure 24 MPa, temperature 500 °C). Simulation and analytic results are compared. Failure operative conditions are searched for scale FeCr2O4 until its compleate delamination and separation from metal. Aim of this work is to create an oxidation scale model with a possibility of futher use.
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|
|
Prediction of furnace tubes corrosion using operating data
Kolomazník, Milan ; Kilkovský, Bohuslav (referee) ; Jegla, Zdeněk (advisor)
The thesis deals with the modeling and prediction of corrosion of radiation tube snake in the heating furnace. Specifically it is focused on vertical cylindrical furnace which is included in the catalytic hydrocracking unit and serves for heating aggressive circulation gas which is the cause of high temperature corrosion. An important basis for the creation of computational models are available records about the operation of the furnace and about the corrosion and degradation mechanisms during the lifetime of the tube system in furnace. Such information enables the creation of a computational model which is based on the prediction of high-temperature corrosive damage of radiation tube snake. The computational model involving all relevant factors may serve as the basis for a predictive life management system of radiation snakes in the heating furnace.
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|
|
Study of AlSi protective coating after degradation
Vítková, Gabriela ; Řičánková, Veronika (referee) ; Hutařová, Simona (advisor)
Materials used for high temperature applications works in a very aggressive environment (oxidation, hot corrosion, erosion, fatigue, creep). Demands on these materials are very high. Nickel-based superalloys show the certain stability in this environment. Improved resistance to oxidation and hot corrosion can be achieved by using protective layers such as diffusion barriers. This thesis is focused on changes of microstructure and properties of AlSi layer applied by „slurry“ method on nickel-based superalloy Inconel 713 LC, due to long-term thermal exposition at 800, 900 a 1000 °C.
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