Optimisation électrique et géométrique d'un électrofiltre à barrière diélectrique en configuration fil-tube carré. Application aux particules submicroniques

L'objectif de ce travail est l'étude de l'efficacité de collecte des particules submicroniques d'un électrofiltre deconfiguration fil-tube carré en utilisant une Décharge à Barrière Diélectrique (DBD). Les expériences sont faites avec desparticules de fumée d'encens ayant une taille moyenne d'environ 0,32 pm. La répartition en taille des particules à la sortie del'électrofiltre est mesurée grâce à un spectromètre d'aérosols à lumière blanche. L'efficacité de collecte est estimé pour diversestensions et fréquences appliquées (gammes : 4-30 kV, de 0,3 à 1000 Hz) à un débit d'air fixe.Le premier volet de l'analyse a consisté en une caractérisation électrique et granulomètrique de l'électrofiltre de configurationcarré dit de référence. Les résultats obtenus ont montré que le comportement électrique de l'électrofiltre de géométrie carré estsimilaire à celui de géométrie cylindrique. Aussi, l'utilisation de la DBD pour la précipitation donnait de très bons résultats enconfiguration fil-tube carré (plus de 99% d efficacité). Le second volet de notre étude a été consacré à l'optimisation géométrique de l'électrofiltre de référence. Les résultats ont montré que le diamètre du fil, le nombre des faces collectrices ont une influence minime sur la précipitation. Tandis que, la section du tube et la largeur de la contre électrode et sa discrétisation ont une influence importante. L'analyse de l'effet de la présence d'une deuxième Barrière Diélectrique (BD) a montré qu'à la différence de la simple BD ou le mode de décharge est assez homogène, la décharge a un comportement filamentaire dans le cas de la double BD. Aussi, l'efficacité de collecte des particules pour les deux conThe objective of this work is the study of the collection efficiency of submicron particles with wire-to-square tubeElectroStatic Precipitator (ESP) using a Dielectric Barrier Discharge (DBD). The experiments are performed with incense smokeparticles having a mean size of about 0.32 m. An aerosol spectrometer is employed for characterizing the size distribution ofthese particles at the outlet of the ESPs. The collection efficiency is estimated for various applied voltages and frequencies(ranges: 4 30 kV, 0.3 1000 Hz) at a fixed air flow rate.The first step of our study consisted of an electrical characterization of the reference precipitator and the evaluation of itscollection efficiency performances. The results have shown that electrical behavior of the wire-to-square tube configuration issimilar to the wire-to- cylinder configuration. Furthermore, it reveals that the square configuration charged with a DBD gives verygood results (more than 99% of efficiency). The second step of the study was devoted to the geometrical optimization of thesquare ESP. The obtained results have established that the wire diameter, the number of faces has a minimal effect on electrostatic precipitation. However, the tube section, the width of the ground electrode and its discretization have an important effect. Also, the analysis of the effect of the presence of a second Dielectric Barrier (DB) has shown that in the case of the single DB, the discharge mode is rather homogeneous. In contrast, the discharge has a filamentary behavior in the case of the double DB. Results show that the particle collection efficiency of both ESPs is higher at high applied voltages and within a certaiPOITIERS-SCD-Bib. électronique (861949901) / SudocSudocFranceF

A Fast and Straightforward Solver for Generation Allocation Problem Including Losses using A Hopfield Network

Abstract In this paper, a fast solver for generation allocation problem including transmission losses using a Hopfield Neural Network (HNN) approach is presented. The proposed HNN is distinguished by a direct computation method mapped to the generation allocation problem of thermal generators commonly known as economic dispatch (ED). The developed HNN employs a linear input-output model for the transfer function of neurons. Formulations for solving the ED problem are explored, through the application of these formulations; direct computation instead of iterations for solving the problem without losses becomes possible. Not like the usual Hopfield methods, which select the weighting factors of the energy function by trials, the proposed method determines the corresponding factors only by calculations. To include the transmission losses, a dichotomy method is combined to the Hopfield Neural Network iteratively. The effectiveness of the developed method is identified through its application to the 15-unit system. Computational results manifest that the method has a lot of excellent performances

Analysis of Pulsed electric field pre-treatment for beet juice extraction: Evaluation of treatment chambers configuration effects

The major challenge today for the application of PEF in the industry has interest to increase the production capacity and improve the quality of food products. PEF pre-treatment is a multifactorial process. In addition to the electric field intensity, pulses number and the capacitor value, the configuration of the treatment chamber now presents a significant parameter in this process.Cylindrical and square parallelipedic treatment chambers (TC) are compared and their effect is studied with variation of electric field, number of pulses and capacitor value at frequency of 1Hz. The results show that the cylindrical treatment chamber showed higher beet juice yield with all studied parameters. The quality of extracted juice estimated in terms of absorbance at 530 nm wavelength were determined for each sample and results show that using a cylindrical treatment chamber configuration in PFE technology  gives a  good juice quality compared with square parallelipedic treatment chamber. The energy consumption during PEF treatment is reduced in the cylindrical treatment chamber due to the low values of the electric field, pulses number and capacitor value compared with square parallelipedic treatment chamber

Study of the electrostatic separation of a metal/polymer mixture based on electro-adhesive force

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