Combustion Modification by Non-Thermal Plasma

Autor :Ali Bourig
Herkunft :OvGU Magdeburg, Fakultät für Verfahrens- und Systemtechnik
Datum :16.07.2009
Dokumente :
Dataobject from HALCoRe_document_00007955
Typ :Dissertation
Format :Text
Kurzfassung :Nowadays it seems that the most promising method for accelerating combustion is the non-equilibrium excitation of the gas mixture components, which allows one to affect the chemical reaction kinetics. To enable more efficient excitation of the electronic and vibrational degrees of freedom, one should use short-duration (nanosecond) pulses with a high reduced electric field. The present work focuses on the application of high frequency high voltage pulse discharges capable of delivering an electric pulse of 20 kV during 20 ns with controlled voltage rise time of 5 ns and at a frequency up to 25 kHz in combustion. This study articulates around two major research axis; that of the generation of excited species and particularly the feasibility to produce excited oxygen species in its singlet electronic states O2(a1Δg) and O2(b1Σg+) by a non-thermal electric discharge, at reduced pressure until atmospheric pressure and its characterization by emission spectroscopy. The second research axis concerns their use for the intensification of combustion. The experimental part of the study concerns investigation of singlet oxygen production in the application of a dielectric barrier discharge in O2/He and O2/Ar binary mixtures. The second discharge is a special crossed discharge plasma-chemical reactor that has been developed. This crossed discharge consists of a hybrid discharge in which short high voltage pulses produce ionization while a comparatively low electric field supports the electric current between ionizing pulses. The gas produced by this installation is intensively studied by emission spectroscopy. This work, indispensable to characterize the installation and to obtain initial conditions necessary for flame calculations, relies on different spectrometers and intensified camera. The first potential in the combustion field is to significantly improve combustion efficiency and reduce pollutant emissions using oxidizer “activation”. Conception and development of hybrid plasma burner prototypes, integrating crossed discharge plasma reactor allows us to validate this application by comparing with a classical flame without plasma activation. Finally, modelling of premixed flame fundamental parameters is undergone with CHEMKIN software. The promoting effect of excited oxygen on hydrogen flame has been characterized.
Schlagwörter :nonequilibrium plasma, pulsed dielectric barrier discharge, combined crossed discharge, electronically excited oxygen species, s
Rechte :Dieser Text ist urheberrechtlich geschützt
Größe :212 S.
Erstellt am :25.02.2010 - 11:07:41
Letzte Änderung :22.04.2010 - 09:35:53
MyCoRe ID :HALCoRe_document_00007955
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