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Stress-strain analysis of the process of continuous steel casting
Cabaj, Gabriel ; Petruška, Jindřich (referee) ; Návrat, Tomáš (advisor)
The thesis is focused on the development of a computational model for determination of stress and strain of a round billet in the process of continuous steel casting. The supplied material characteristics, the geometry of the continuous casting machine and the temperature distribution in the billet are applied as input data for stress and strain analysis. The computational model based on the finite element method is developed in the commercial software ANSYS. The thesis can be divided into three parts. The first part includes background information related to the continuous casting of steel and a research analysis of the computational modeling of this process. The second part describes the development of the planar and three-dimensional computational model in detail. Finally, the obtained stress and strain results are analyzed and general conclusions, and recommendations for further development are proposed.
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Approximation of the cooling effects of water nozzles by mathematical functions
Hřibová, Veronika ; Mauder, Tomáš (referee) ; Štětina, Josef (advisor)
The Bachelor thesis deals with a cooling process of full cone water nozzles. It explains the principle of the continuous steel casting which these nozzles are used for. The basics of heat transfer and spray cooling are also described. The thesis then summarizes the way of the experiment with these nozzles. The purpose of the thesis is to choose an appropriate 3D mathematical function which would well characterize the distribution of the heat transfer coefficient under the nozzle and then create an algorithm for finding its parameters. The algorithm is programmed in MATLAB and implemented on the data gained by the experimental way for two types of full cone water nozzles.
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Optimization of Secondary Cooling Parameters of Continuous Steel Casting
Klimeš, Lubomír ; Raudenský, Miroslav (referee) ; Pyszko, René (referee) ; Buček, Pavol (referee) ; Štětina, Josef (advisor)
Continuous casting is a dominant production technology of steelmaking which is currently used for more that 95% of the world steel production. Mathematical modelling and optimal control of casting machine are crucial tasks in continuous steel casting which directly influence productivity and quality of produced steel, competitiveness of steelworks, safety of casting machine operation and its impact on the environment. This thesis concerns with the development and implementation of the numerical model of temperature field for continuously cast steel billets and its use for optimal control of the casting machine. The numerical model was developed and implemented in MATLAB. Due to computational demands the model was parallelized by means of the computation on graphics processing units NVIDIA with the computational architecture CUDA. Validation and verification of the model were performed with the use of operational data from Trinecke zelezarny steelworks. The model was then utilized as a part of the developed model-based predictive control system for the optimal control of dynamic situations in the casting machine operation. The behaviour of the developed control system was examined by means of dynamic model situations that have confirmed the ability of the implemented system to optimally control dynamic operations of the continuous casting machine. Both the numerical model of the temperature field and the model-based predictive control system have been implemented so that they can be modified for any casting machine and this allows for their prospective commercial applications.
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Optimization of Thermal Field with Phase Change
Pustějovský, Michal ; Klimeš, Lubomír (referee) ; Popela, Pavel (advisor)
This thesis deals with modelling of continuous casting of steel. This process of steel manufacturing has achieved dominant position not only in the Czech Republic but also worldwide. The solved casted bar cross-section shape is circular, because it is rarely studied in academical works nowadays. First part of thesis focuses on creating numerical model of thermal field, using finite difference method with cylindrical coordinates. This model is then employed in optimization part, which represents control problem of abrupt step change of casting speed. The main goal is to find out, whether the computation of numerical model and optimization both can be parallelized using spatial decomposition. To achieve that, Progressive Hedging Algorithm from the field of stochastic optimization has been used.
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Stress-strain analysis of the process of continuous steel casting
Cabaj, Gabriel ; Petruška, Jindřich (referee) ; Návrat, Tomáš (advisor)
The thesis is focused on the development of a computational model for determination of stress and strain of a round billet in the process of continuous steel casting. The supplied material characteristics, the geometry of the continuous casting machine and the temperature distribution in the billet are applied as input data for stress and strain analysis. The computational model based on the finite element method is developed in the commercial software ANSYS. The thesis can be divided into three parts. The first part includes background information related to the continuous casting of steel and a research analysis of the computational modeling of this process. The second part describes the development of the planar and three-dimensional computational model in detail. Finally, the obtained stress and strain results are analyzed and general conclusions, and recommendations for further development are proposed.
|
|
|
Optimization of Secondary Cooling Parameters of Continuous Steel Casting
Klimeš, Lubomír ; Raudenský, Miroslav (referee) ; Pyszko, René (referee) ; Buček, Pavol (referee) ; Štětina, Josef (advisor)
Continuous casting is a dominant production technology of steelmaking which is currently used for more that 95% of the world steel production. Mathematical modelling and optimal control of casting machine are crucial tasks in continuous steel casting which directly influence productivity and quality of produced steel, competitiveness of steelworks, safety of casting machine operation and its impact on the environment. This thesis concerns with the development and implementation of the numerical model of temperature field for continuously cast steel billets and its use for optimal control of the casting machine. The numerical model was developed and implemented in MATLAB. Due to computational demands the model was parallelized by means of the computation on graphics processing units NVIDIA with the computational architecture CUDA. Validation and verification of the model were performed with the use of operational data from Trinecke zelezarny steelworks. The model was then utilized as a part of the developed model-based predictive control system for the optimal control of dynamic situations in the casting machine operation. The behaviour of the developed control system was examined by means of dynamic model situations that have confirmed the ability of the implemented system to optimally control dynamic operations of the continuous casting machine. Both the numerical model of the temperature field and the model-based predictive control system have been implemented so that they can be modified for any casting machine and this allows for their prospective commercial applications.
|
|
|
Optimization of Thermal Field with Phase Change
Pustějovský, Michal ; Klimeš, Lubomír (referee) ; Popela, Pavel (advisor)
This thesis deals with modelling of continuous casting of steel. This process of steel manufacturing has achieved dominant position not only in the Czech Republic but also worldwide. The solved casted bar cross-section shape is circular, because it is rarely studied in academical works nowadays. First part of thesis focuses on creating numerical model of thermal field, using finite difference method with cylindrical coordinates. This model is then employed in optimization part, which represents control problem of abrupt step change of casting speed. The main goal is to find out, whether the computation of numerical model and optimization both can be parallelized using spatial decomposition. To achieve that, Progressive Hedging Algorithm from the field of stochastic optimization has been used.
|
|
|
Approximation of the cooling effects of water nozzles by mathematical functions
Hřibová, Veronika ; Mauder, Tomáš (referee) ; Štětina, Josef (advisor)
The Bachelor thesis deals with a cooling process of full cone water nozzles. It explains the principle of the continuous steel casting which these nozzles are used for. The basics of heat transfer and spray cooling are also described. The thesis then summarizes the way of the experiment with these nozzles. The purpose of the thesis is to choose an appropriate 3D mathematical function which would well characterize the distribution of the heat transfer coefficient under the nozzle and then create an algorithm for finding its parameters. The algorithm is programmed in MATLAB and implemented on the data gained by the experimental way for two types of full cone water nozzles.
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