Sparking-induced decomposition of 10% SF6-90% N-2 mixtures: effect of a solid organic insulator, oxygen and water

Citation
I. Coll et al., Sparking-induced decomposition of 10% SF6-90% N-2 mixtures: effect of a solid organic insulator, oxygen and water, J PHYS D, 33(11), 2000, pp. 1348-1359
Citations number
18
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
JOURNAL OF PHYSICS D-APPLIED PHYSICS
ISSN journal
00223727 → ACNP
Volume
33
Issue
11
Year of publication
2000
Pages
1348 - 1359
Database
ISI
SICI code
0022-3727(20000607)33:11<1348:SDO1SN>2.0.ZU;2-B
Abstract
The chemical stability of 10% SF6-90% N-2 mixtures (100 kPa pressure) has b een studied under sparking in the presence or absence of an organic insulat or (teflon, kel'F, polyethylene, polypropylene. nylon. megelit), and/or add ed impurities (0.2%; O-2 or H2O). The study was carried out experimentally and numerically. The production rates of the main decomposition products of SF6: (SF4 + SOF2 ), S2F10, etc, and of products containing nitrogen, NF3, N2O, were evaluate d. The results from the model led to trends similar to those observed exper imentally concerning the effects on gas phase composition, of the presence of atoms such as O, H, C, etc, from the vaporized Insulator and/or the adde d impurities. A comparison of the chemical stability of the SF6-N-2 mixture with that of pure SF6 has also been made. The results can be summarized as follows: in all cases, the major byproducts formed were (SF4 + SOF2) and S2F10; the use of the SF6-N-2 mixture instead of SF6 led to the decreased formatio n of degradation products: vaporization of an organic insulator caused an increase in the production o f degradation products which was less intense for the mixture than for pure SF6; the study carried our with nitrogen-diluted SF, showed the importance of fo reign atoms (C. H. O. etc) on the proportion of SF6 that is not regenerated . Owing to their tendency to trap fluorine atoms. the impurity atoms preven t SF6 from recombining and can thus lead to the deterioration of the dielec tric qualities of the gas mixture.