Experimental study of the effect of an electric field on thermal exchanges under forced convection with gaseous carbon anhydride in presence of the radiation of the Melusine pile
Description
Previous studies showed that, under free or forced convection, the application of a non-uniform electric field with a sufficient intensity at the neighbourhood of the heating elements resulted in a significant improvement of the thermal exchange coefficient under some flow rate and pressure conditions. But these improvements first required the creation of ions in the gas (shock ionization and existence of a corona effect above a sufficient voltage). This document therefore report further studies performed at the neighbourhood of the Melusine atomic pile which would provide ionizing radiations of much greater intensity. The objectives were, on the one hand, a global verification of work hypotheses imagined for the exchange improvement mechanism, and, on the other hand, to obtain data on the conditions under which this exchange improvement mechanism could be used in channels of a reactor. The authors present the instrumentation (measurement cells, gas circuit, heating circuit, high voltage circuit), describe how physical values are measured (pressure, gas flow rate, temperature of the heating element, gas temperature, high voltage). They describe how they compare powers exchanged under forced convection between dioxide carbon and a heated wire with or without external ionizing radiations, and report the various performed calculations (power supplied to the gas, temperature shift, Nusselt and Reynolds numbers). They report and discuss experimental results obtained outside the pile without ionizing radiations, and within the pile in presence of a ionizing radiation
Abstract (French)
Les essais ont ete effectues dans les conditions suivantes: nombres de Reynolds variant de 20.000 a 80.000, pression de 11 a 21 kg/cm2, temperatures moyennes de l'element chauffant de 200 a 600 deg. C, tension electrique de 0 a 30 kV eff et intensite maximum du rayonnement γ, 3x107 roentgen/h. On a confirme, hors pile, que l'augmentation de la puissance echangee, au dessus du seuil d'ionisation, croit avec le champ electrique superficiel. Cette augmentation peut atteindre, en convection forcee, 70 pc de la puissance transmise en l'absence de champ electrique. Sa valeur diminue lorsque la vitesse du gaz augmente et depend peu de la temperature moyenne de la surface chauffante. En pile, on constate une amelioration notable (jusqu'a 40 pc) de la puissance echangee, a des tensions electriques pour lesquelles aucun effet n'est observe en l'absence d'une source exterieure ionisante. Ce resultat confirme ce que l'on imaginait comme mecanisme d'amelioration des echanges par ce procede et montre que la mise en oeuvre pourrait etre faite avec des tensions relativement faibles dans un canal de reacteur. (auteurs)Files
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Additional details
Additional titles
- Original title (French)
- Etude experimentale de l'effet d'un champ electrique sur les echanges thermiques en convection forcee avec l'anhydride carbonique gazeux en presence du rayonnement de la pile Melusine
Identifiers
Publishing Information
- Imprint Pagination
- 34 p.
- Report number
- CEA-N--0338
INIS
- Country of Publication
- France
- Country of Input or Organization
- France
- INIS RN
- 46012598
- Subject category
- S42: ENGINEERING;
- Descriptors DEI
- ANHYDRIDES; CARBON; CARBON DIOXIDE; ELECTRIC FIELDS; EXCITATION SYSTEMS; HEAT TRANSFER; IONIZING RADIATIONS; MEASURING INSTRUMENTS; MELUSINE-1 REACTOR; NUSSELT NUMBER; REYNOLDS NUMBER; WIRES
- Descriptors DEC
- CARBON COMPOUNDS; CARBON OXIDES; CHALCOGENIDES; DIMENSIONLESS NUMBERS; ELEMENTS; ENERGY TRANSFER; ENRICHED URANIUM REACTORS; IRRADIATION REACTORS; ISOTOPE PRODUCTION REACTORS; NONMETALS; OXIDES; OXYGEN COMPOUNDS; POOL TYPE REACTORS; RADIATIONS; REACTORS; RESEARCH AND TEST REACTORS; RESEARCH REACTORS; THERMAL REACTORS; TRAINING REACTORS; WATER COOLED REACTORS; WATER MODERATED REACTORS
Optional Information
- Notes
- 5 refs.; Available from the INIS Liaison Officer for France, see the 'INIS contacts' section of the INIS website for current contact and E-mail addresses: http://www.iaea.org/inis/Contacts/