Effect of radiation on nitrogen oxide emissions from nonsooty swirling flames of natural gas
- International Flame Research Foundation, Ijmuiden (Netherlands)
The present study attempts to quantify the effect of radiation on nonpremixed, turbulent diffusion flame temperature and NO{sub x} emissions for flames subjected to different overall heat extraction. Comprehensive in-flame data have been generated for two flames of similar strain field and luminosity in order to facilitate flame comparison. The flame produced in the refractory-lined furnace (flame 1) is shorter than that of the water-cooled confinement (flame 2) by around 30%, and the extent of combustion increases by 20% at a distance 27-mm downstream of the burner outlet. The density-averaged mean flame temperatures were 1,850 and 1,675 K, and furnace NO{sub x} emissions were 49 and 33 ppm for flames 1 and 2, respectively. The total radiative intensities calculated spectrally using the Exponential Wide Band model are in very good agreement with the measurements and indicate that the amount of radiant energy emitted directly by both flames is similar. Radiation plays a crucial role in extracting the energy from the postflame zone, and therefore, it affects the enthalpy of the products entrained from the external recirculation zone. Flame temperatures and NO{sub x} emissions are strongly dependent on the energy of the flow entrained by the jets. It is concluded that the radiant friction cannot be used as an exclusive NO{sub x} scaling parameter to describe the effect of radiation on emissions of confined turbulent diffusion flames. Proper scaling parameters should incorporate the energy entrained (from external recirculation zone) into the flame, and therefore, these parameters have to take into account the amount of energy extracted from the postflame zone.
- OSTI ID:
- 93168
- Report Number(s):
- CONF-940711-; TRN: IM9537%%211
- Resource Relation:
- Conference: 25. international symposium on combustion, Irvine, CA (United States), 31 Jul - 5 Aug 1994; Other Information: PBD: 1994; Related Information: Is Part Of Twenty-fifth symposium (international) on combustion; PB: 1838 p.
- Country of Publication:
- United States
- Language:
- English
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