Optimal Band Selection for the Calculation of Planck Mean Absorption Coefficients

Authors

  • M. Gnybida Eaton European Innovation Center, Borivojova 2380, 252 63 Roztoky
  • Ch. Rümpler Eaton, 1000 Cherrington Pkwy Moon Township, PA 15108
  • V. R. T. Narayanan Eaton European Innovation Center, Borivojova 2380, 252 63 Roztoky

DOI:

https://doi.org/10.14311/ppt.2017.1.70

Keywords:

radiation, thermal plasma, circuit breaker, SF6

Abstract

Radiative heat transfer is a major heat loss mechanism in thermal plasmas generated during arc flashes/faults in switchgear applications or during high current interruption in low voltage circuit breakers. A common way to calculate the radiation balance is by means of approximate non-gray radiation models like P1 or discrete ordinates (DOM), where the frequency dependent absorption and emission are described in a number of frequency intervals (bands) using a constant absorption coefficient in each band. Current work is focused on finding the optimal number of bands as well as band interval boundaries that provide a reasonable level of accuracy in comparison to a full spectral solution. An optimization procedure has been applied to different SF6 and copper vapor gas mixtures for an assumed temperature profile. Radiation model results using optimized band averaged absorption coefficients as well as spectral values are provided and discussed for the exemplary temperature profile.

References

A. Gleizes, J. J. Gonzalez, and P. Freton. Thermal plasma modelling. Journal of Physics D: Applied Physics, 38(9):R153, 2005. doi:10.1088/0022-3727/38/9/R01.

Ch. Rümpler and V.R.T Narayanan. Arc modeling challenges. Plasma Physics and Technology, 2(3):261–270, 2015.

Ch. Rümpler, H. Stammberger, and A. Zacharias. Low-voltage arc simulation with out-gassing polymers. In 2011 IEEE 57th Holm Conf. on El. Contacts (Holm), pages 1–8, Sept 2011. doi:10.1109/HOLM.2011.6034770.

Michael F. Modest. Radiative Heat Transfer. Third edition. Academic Press, 2013.

P. Kloc, V. Aubrecht, M. Bartlova, O. Coufal, and Ch. Rümpler. On the selection of integration intervals for the calculation of mean absorption coefficients. Plasma Chem Plasma Process, 35:1097–1110, 2015. doi:10.1007/s11090-015-9648-3.

L. Fagiano and F. Gati. On the order reduction of the radiative heat transfer model for the simulation of plasma arcs in switchgear devices. J Quant Spec Rad Trans, 169:58–78, 2016. doi:10.1016/j.jqsrt.2015.10.002.

P. Kloc, V. Aubrecht, and M. Bartlova. Effective plasma radius for planck mean absorption coefficient. In Proceedings of 21st International Conference on Gas Discharges and their Applications, pages 89–92, 2016.

H. Nordborg and A. Iordanidis. Self-consistent radiation based modelling of electric arcs: I. efficient radiation approximations. J Phys D: Appl Phys, 41(13):135205, 2008. doi:10.1088/0022-3727/41/13/135205.

Downloads

Published

2017-10-15

Issue

Section

Articles