A comparison of three radiation models for the calculation of nozzle arcs

Abstract

Three radiation models, the semi-empirical model based on net emission coefficients (Zhang et al 1987 J. Phys. D: Appl. Phys. 20 386–79), the five-band P1 model (Eby et al 1998 J. Phys. D: Appl. Phys. 31 1578–88), and the method of partial characteristics (Aubrecht and Lowke 1994 J. Phys. D: Appl. Phys. 27 2066–73; Sevast'yanenko 1979 J. Eng. Phys. 36 138–48), are used to calculate the radiation transfer in an SF6 nozzle arc. The temperature distributions computed by the three models are compared with the measurements of Leseberg and Pietsch (1981 Proc. 4th Int. Symp. on Switching Arc Phenomena (Lodz, Poland) pp 236–40) and Leseberg (1982 PhD Thesis RWTH Aachen, Germany). It has been found that all three models give similar distributions of radiation loss per unit time and volume. For arcs burning in axially dominated flow, such as arcs in nozzle flow, the semi-empirical model and the P1 model give accurate predictions when compared with experimental results. The prediction by the method of partial characteristics is poorest. The computational cost is the lowest for the semi-empirical model.

PTFE Vapor Contribution to Pressure Changes in High-Voltage Circuit Breakers

“…This temperature corresponds to C 2 F 4 coming from PTFE wall ablation. Indeed, at the initial time t = 0 s, the total HVCB domain contains SF 6 . Then due to the high temperature and to radiation mechanisms, the PTFE walls are eroded and the medium is mainly composed of PTFE gas as observed in Fig.…”

Improvements of radiative transfer calculation for SF6 thermal plasmas

“…Only partial experimental validations on the limited part of the spectrum [16] and on the absorption by cold SF 6 [17] have been performed. Among the works including a comparison of simplified methods for radiative transfer calculation, we may refer to the papers of Verite et al [18] and Dixon et al [19], both including the NEC and PCM methods (MAC also in [19]). The indirect validation with temperature, voltage and pressure measurements, allows to define an uncertainty of the order of a factor of 2 for the divergence of the flux in the hottest regions (comparison with temperature in the hottest regions) and for the absorbed radiation (comparison with pressure).…”

Investigation of SLF Interruption Capability of Gas Circuit Breaker with CFD and a Mathematical Arc Model

“…The spectrum of SF 6 is divided into five bands and the average absorption coefficients are calculated as a function of temperature for each band. These averaged absorption coefficients can be used to solve five DO equations, one for each band [11,12].…”