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Experimental research of fluids against icing of overhead wires
Málek, Jan ; Polach, Pavel (referee) ; Galas, Radovan (advisor)
In this thesis, commercially available anti-icing fluids were tested. A methodology of assessment was designed for the effect of anti-icing fluids on the rapidity of ice growth and its development over time. These tests were conducted on a device constructed for the purpose of the thesis. The solutions were tested for their effect on the ice adhesion to a contact wire. The effect of the solutions on the tribological behaviour of the collector strip and contact wire was described. The experiments were supplemented by mensuration of the size of the contact angle of the solutions on the copper surface. However, these fluids anti-icing effect is relatively short-term. On the contrary, the thesis shows that even a small amount of anti-icing solution on the surface of the contact wire can help to significantly lower the ice adhesion.
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Measuring of emissivity of wet and dry surfaces
Brzobohatý, Tomáš ; Janotková, Eva (referee) ; Pavelek, Milan (advisor)
The objective of this thesis is to create summary of emissivity of wet surfaces, emissivity of rime surfaces and emissivity of dry surfaces. The next objective is to create materials for termovision measurement and find the use for this materials for practice. Theoretical part of thesis deals with a theory of ways of heat transfer (radiation mainly), description of emisivity concept, description of emisivity finding ways and the show emissivity of mesuared materials from avaible sources for working hypothesis. Emissivity of dry, wet and rime samples were measured as the experimental part of thesis. Experimental part of thesis consist of experiment description, working hypothesis, measuring instruments and measuring area description, measuring proces description and presentation of measured results. Obtained dependences are benefits for termovision measurent, energy evaluation and the thermal state microclimate simulations.
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Dimensioning of Overhead Line Conductors According to ČSN EN 50341 and ČSN EN 50423
Dostál, Martin ; Novotný, Jan (referee) ; Orságová, Jaroslava (advisor)
Overhead line must be designed to be able to resist variety of influences. These influences are mechanical, which are caused by wind and rime during the normal conditions and electrical influences. Therefore all parts of overhead line have to be designed and built to withstand mechanical and electrical stress. This bachelor’s thesis is focused mainly on electrical parameters of overhead line, climatic stress and calculation of mechanical stress during limit states. There are described formulas and steps of calculation of line straining MV and HV and there are also described examples of calculation in detail.
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Experimental research of fluids against icing of overhead wires
Málek, Jan ; Polach, Pavel (referee) ; Galas, Radovan (advisor)
In this thesis, commercially available anti-icing fluids were tested. A methodology of assessment was designed for the effect of anti-icing fluids on the rapidity of ice growth and its development over time. These tests were conducted on a device constructed for the purpose of the thesis. The solutions were tested for their effect on the ice adhesion to a contact wire. The effect of the solutions on the tribological behaviour of the collector strip and contact wire was described. The experiments were supplemented by mensuration of the size of the contact angle of the solutions on the copper surface. However, these fluids anti-icing effect is relatively short-term. On the contrary, the thesis shows that even a small amount of anti-icing solution on the surface of the contact wire can help to significantly lower the ice adhesion.
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Dimensioning of Overhead Line Conductors According to ČSN EN 50341 and ČSN EN 50423
Dostál, Martin ; Novotný, Jan (referee) ; Orságová, Jaroslava (advisor)
Overhead line must be designed to be able to resist variety of influences. These influences are mechanical, which are caused by wind and rime during the normal conditions and electrical influences. Therefore all parts of overhead line have to be designed and built to withstand mechanical and electrical stress. This bachelor’s thesis is focused mainly on electrical parameters of overhead line, climatic stress and calculation of mechanical stress during limit states. There are described formulas and steps of calculation of line straining MV and HV and there are also described examples of calculation in detail.
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|
|
Measuring of emissivity of wet and dry surfaces
Brzobohatý, Tomáš ; Janotková, Eva (referee) ; Pavelek, Milan (advisor)
The objective of this thesis is to create summary of emissivity of wet surfaces, emissivity of rime surfaces and emissivity of dry surfaces. The next objective is to create materials for termovision measurement and find the use for this materials for practice. Theoretical part of thesis deals with a theory of ways of heat transfer (radiation mainly), description of emisivity concept, description of emisivity finding ways and the show emissivity of mesuared materials from avaible sources for working hypothesis. Emissivity of dry, wet and rime samples were measured as the experimental part of thesis. Experimental part of thesis consist of experiment description, working hypothesis, measuring instruments and measuring area description, measuring proces description and presentation of measured results. Obtained dependences are benefits for termovision measurent, energy evaluation and the thermal state microclimate simulations.
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