Studium chemických procesů v klouzavém obloukovém výboji pomocí optické emisní spektroskopie
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Date
Authors
Maďarová, Štefánia
ORCID
Advisor
Referee
Mark
C
Journal Title
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Volume Title
Publisher
Vysoké učení technické v Brně. Fakulta chemická
Abstract
Cieľom bakalárskej práce je štúdium chemických procesov prebiehajúcich dohasínajúcej plazme v kĺzavom oblúkovom a tlecom výboji. O dohasínajúcej plazme hovoríme vtedy, keď je zo systému odstránený vonkajší zdroj energie a začne v ňom dochádzať k relaxačným procesom. Experimenty v bakalárskej práci prebiehali za rôznych podmienok, pre rôzne tlaky a výkony vo výboji. Teoretická časť práce stručne popisuje štúdium atmosféry Titanu. Popísane sú základné vlastnosti a kinetické procesy prebiehajúce v plazme, opisuje tlecí a oblúkový výboj. V experimentoch bol použitý čistý dusík a plynná zmes dusíka a metánu pri rovnakom prietokovom množstve a rôznych tlakoch. Pri analýze produktov chemických reakcií boli využite: optická emisní spektrometrie (Optical Emission Spectroscopy - OES), plynová chromatografie v kombinácii s hmotnostným spektrometrom ako detektorom (Gas Chromatography-Mass Spectrometry - GC-MS). Výboj bol generovaný jednosmerným zdrojom napätia a meranie prebiehalo v prúdiacom režime. Celkový tlak plynu sa pohyboval v rozmedzí 1 000-4 000 Pa pri prietoku dusíku 400 mln/min a metánu 0.025 mln/min. prúd bol v rozmedzí 85-150 mA. U všetkých experimentálnych podmienok pre tlecí výboj bol dobre viditeľný jav tzv. pink afterglow. Tento jav odpovedá maximálnej intenzite vyžarovania v dohasínajúcom výboji, prejavujúcim sa značným nárastom charakteristického ružového žiarenia. Optické emisné spektra dohasínajúceho výboja boli snímané v rozsahu vlnových dĺžok 540-640 nm. V nameraných spektrách boli identifikované tri spektrálne systémy dusíku (prví a druhý pozitívny a prví negatívni) tie majú maximálne hodnoty v dohasínaní v tzv. „pink-afterglow“. Tieto maxima klesali s rastúcim tlakom a posúvali sa k neskorším časom dohasínania.
The aim of the bachelor thesis is to study the chemical processes of the glow discharge and the sliding arc under the post discharge conditions. The post discharge or afterglow plasma means that the external source of energy is removed from the system and the relaxation process can start. The experiments in bachelor work were performed under the different experimental conditions, for various pressures and gas mixtures. The theoretical part briefly describes term plasma and kinetic processes occurring in plasma generated by electrical discharges. Also there is described the problem of Titan’s atmosphere and possibility of mimic it by the gliding arc discharge. In the experiments, pure nitrogen and a gaseous mixture of nitrogen and methane were used at the same flow rate and different pressures. Optical Emission Spectroscopy (OES) and Gas Chromatography-Mass Spectrometry (GC-MS) were used to analyze chemical reaction products. The glow discharge was generated by a DC voltage source and the measurement was in flow mode. The total gas pressure ranged from 1 000-4 000 Pa at a nitrogen flow rate of 400 ml / min and methane of 0.025 ml / min. The current was in the range of 85-150 mA. In all experimental conditions, a well-known phenomenon called “pink afterglow” was observed. This phenomenon corresponds to the maximum intensity of radiation in a stagnant discharge, exhibiting a significant increase in characteristic pink radiation. The optical emission spectra of the discharging discharge were scanned in the wavelength range 540-640 nm. Three spectral nitrogen systems (the first and the second positive and the first negative ones) have been identified in the measured spectra, they have maximum values in the so-called " "Pink-afterglow". These maxims dropped with increasing pressure and shifted to a later decay time.
The aim of the bachelor thesis is to study the chemical processes of the glow discharge and the sliding arc under the post discharge conditions. The post discharge or afterglow plasma means that the external source of energy is removed from the system and the relaxation process can start. The experiments in bachelor work were performed under the different experimental conditions, for various pressures and gas mixtures. The theoretical part briefly describes term plasma and kinetic processes occurring in plasma generated by electrical discharges. Also there is described the problem of Titan’s atmosphere and possibility of mimic it by the gliding arc discharge. In the experiments, pure nitrogen and a gaseous mixture of nitrogen and methane were used at the same flow rate and different pressures. Optical Emission Spectroscopy (OES) and Gas Chromatography-Mass Spectrometry (GC-MS) were used to analyze chemical reaction products. The glow discharge was generated by a DC voltage source and the measurement was in flow mode. The total gas pressure ranged from 1 000-4 000 Pa at a nitrogen flow rate of 400 ml / min and methane of 0.025 ml / min. The current was in the range of 85-150 mA. In all experimental conditions, a well-known phenomenon called “pink afterglow” was observed. This phenomenon corresponds to the maximum intensity of radiation in a stagnant discharge, exhibiting a significant increase in characteristic pink radiation. The optical emission spectra of the discharging discharge were scanned in the wavelength range 540-640 nm. Three spectral nitrogen systems (the first and the second positive and the first negative ones) have been identified in the measured spectra, they have maximum values in the so-called " "Pink-afterglow". These maxims dropped with increasing pressure and shifted to a later decay time.
Description
Citation
MAĎAROVÁ, Š. Studium chemických procesů v klouzavém obloukovém výboji pomocí optické emisní spektroskopie [online]. Brno: Vysoké učení technické v Brně. Fakulta chemická. 2017.
Document type
Document version
Date of access to the full text
Language of document
cs
Study field
Spotřební chemie
Comittee
prof. Ing. Martina Klučáková, Ph.D. (předseda)
prof. Ing. Michal Veselý, CSc. (místopředseda)
prof. Ing. Ladislav Omelka, DrSc. (člen)
doc. Ing. František Šoukal, Ph.D. (člen)
prof. Mgr. Martin Vala, Ph.D. (člen)
Date of acceptance
2017-06-20
Defence
Klučáková – Co znamenají jednotky průtoku mln/min?
Veselý – Jaké standardní podmínky jste pro experiment zvolila?
Result of defence
práce byla úspěšně obhájena
Document licence
Standardní licenční smlouva - přístup k plnému textu bez omezení