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Specifications in the heat calculation of electrothermal devices
Mikmek, Vladislav ; Foral, Štěpán (referee) ; Lázničková, Ilona (advisor)
This bachelor's thesis deals with the heat calculation of a resistance crucible furnace with emphasis on the influence of selected specifications. The whole process of the heat calculation is described. The calculation used in this thesis requires inputs as the kind of material of the batch or it's weight, the dimensions of the crucible and of the heating elements and others. The output of the calculation is the heat necessary to melt the batch, power needed by the crucible, the dimensions of the resistance spiral, permitted surface load of the spiral and the number of supports in the furnace to hold the heating elements. Parts of the canculation where there is possible to choose different methods to acquire needed values are also mentioned. The last chapter shows on a particular example of crucible furnace the influence of selected specifications on quantities dependent on these specifications. In selected parts of the calculation, that can be done by at least two diffent methods, is shown the influence of the choice on the partial result. In the case of a bigger differences of the results is shown even the influence on the subsequent parts of the calculation and final results. The contribution of the thesis is a summarization of the influences of the selected specifications on the results of the heat calculation. It also shows that some selected specifications have minor and other major influence on the calculation.
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Resistive Heating System for Work Shoes
Pár, Lukáš ; Huták, Petr (referee) ; Vorel, Pavel (advisor)
This bachelor thesis deals with the design of a device for the resistive heating of work-shoes, the circuits of a power converter for a heater and the battery-pack. Two variants of the heater are designed in the first part of thesis. Thesis continues with design of DC/DC converters for both types of the heater. Next part of the thesis deals with a design of the battery-pack with simple BMS circuits. The design of the control circuit for selected DC/DC converter follows. Next part of thesis deals with the construction of the device. Last part is dedicated to measurements and verification.
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Thermal calculation in design of resistance and induction devices
Krčál, Vít ; Foral, Štěpán (referee) ; Lázničková, Ilona (advisor)
This bachelor’s thesis focuses on thermal calculation of electric heating device and related theory. Selected topics in electric heating technology are explained, followed by the calculation in design of a crucible furnace and its automation using a computer program. The theoretical part first deals with the heat transfer mechanisms and their mathematical description. Further on, the thesis describes how heat is created in resistance and induction heating devices and mentions applications of these types of heating. The main part of the thesis focuses on the thermal calculation of the resistance crucible furnace for aluminium melting. The calculation relates to a cylinder-shaped model of the furnace with determined structure and deals mostly with heat loss, electric power input, thermal efficiency and design of heating elements. The calculation is achieved only in general and it is subsequently automated in Microsoft Office Excel® application. The computer program, which is also a part of the thesis, allows user to change input parameters and see how it affects results of the calculation. In the last chapter, an example of calculation for specific numeric data is presented. The main goal of the thesis is to automate the calculation. That can save some time while calculating and designing a crucible furnace.
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DC/DC converter 2,5kW/1500A for resistive heating of iron components
Martiš, Jan ; Knobloch, Jan (referee) ; Vorel, Pavel (advisor)
This thesis deals with the design and construction of a single-phase switching power supply, which is intended for direct resistive heating of iron components. The power supply is especially intended for resistive heating of horse-shoes. The supply is able to deliver an output current of up to 1500 A at a power of up to 2500 W. The first part of this work deals with the design of individual parts of the unit, the second part is focused on construction and testing of the supply and the last part contains technical documentation. The power supply was successfully tested and the required output parameters were met. However some problems do exist, especially with overheating of the output rectifier and with contacting the heated component to the output leads of the supply. These problems will be discussed in the work. The power supply can be used as an alternative solution to classic means of iron heating. The methods and ideas presented in this work can be applied in a design of a similar power supply with high output current, but most of the design rules are valid generally for the given topology.
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|
Specifications in the heat calculation of electrothermal devices
Mikmek, Vladislav ; Foral, Štěpán (referee) ; Lázničková, Ilona (advisor)
This bachelor's thesis deals with the heat calculation of a resistance crucible furnace with emphasis on the influence of selected specifications. The whole process of the heat calculation is described. The calculation used in this thesis requires inputs as the kind of material of the batch or it's weight, the dimensions of the crucible and of the heating elements and others. The output of the calculation is the heat necessary to melt the batch, power needed by the crucible, the dimensions of the resistance spiral, permitted surface load of the spiral and the number of supports in the furnace to hold the heating elements. Parts of the canculation where there is possible to choose different methods to acquire needed values are also mentioned. The last chapter shows on a particular example of crucible furnace the influence of selected specifications on quantities dependent on these specifications. In selected parts of the calculation, that can be done by at least two diffent methods, is shown the influence of the choice on the partial result. In the case of a bigger differences of the results is shown even the influence on the subsequent parts of the calculation and final results. The contribution of the thesis is a summarization of the influences of the selected specifications on the results of the heat calculation. It also shows that some selected specifications have minor and other major influence on the calculation.
|
|
|
Resistive Heating System for Work Shoes
Pár, Lukáš ; Huták, Petr (referee) ; Vorel, Pavel (advisor)
This bachelor thesis deals with the design of a device for the resistive heating of work-shoes, the circuits of a power converter for a heater and the battery-pack. Two variants of the heater are designed in the first part of thesis. Thesis continues with design of DC/DC converters for both types of the heater. Next part of the thesis deals with a design of the battery-pack with simple BMS circuits. The design of the control circuit for selected DC/DC converter follows. Next part of thesis deals with the construction of the device. Last part is dedicated to measurements and verification.
|
|
|
Thermal calculation in design of resistance and induction devices
Krčál, Vít ; Foral, Štěpán (referee) ; Lázničková, Ilona (advisor)
This bachelor’s thesis focuses on thermal calculation of electric heating device and related theory. Selected topics in electric heating technology are explained, followed by the calculation in design of a crucible furnace and its automation using a computer program. The theoretical part first deals with the heat transfer mechanisms and their mathematical description. Further on, the thesis describes how heat is created in resistance and induction heating devices and mentions applications of these types of heating. The main part of the thesis focuses on the thermal calculation of the resistance crucible furnace for aluminium melting. The calculation relates to a cylinder-shaped model of the furnace with determined structure and deals mostly with heat loss, electric power input, thermal efficiency and design of heating elements. The calculation is achieved only in general and it is subsequently automated in Microsoft Office Excel® application. The computer program, which is also a part of the thesis, allows user to change input parameters and see how it affects results of the calculation. In the last chapter, an example of calculation for specific numeric data is presented. The main goal of the thesis is to automate the calculation. That can save some time while calculating and designing a crucible furnace.
|
|
|
DC/DC converter 2,5kW/1500A for resistive heating of iron components
Martiš, Jan ; Knobloch, Jan (referee) ; Vorel, Pavel (advisor)
This thesis deals with the design and construction of a single-phase switching power supply, which is intended for direct resistive heating of iron components. The power supply is especially intended for resistive heating of horse-shoes. The supply is able to deliver an output current of up to 1500 A at a power of up to 2500 W. The first part of this work deals with the design of individual parts of the unit, the second part is focused on construction and testing of the supply and the last part contains technical documentation. The power supply was successfully tested and the required output parameters were met. However some problems do exist, especially with overheating of the output rectifier and with contacting the heated component to the output leads of the supply. These problems will be discussed in the work. The power supply can be used as an alternative solution to classic means of iron heating. The methods and ideas presented in this work can be applied in a design of a similar power supply with high output current, but most of the design rules are valid generally for the given topology.
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