You need JavaScript to view this

Predictions of NO{sub x} formation in an NH{sub 3}-doped syngas flame using CFD combined with a detailed reaction mechanism

Abstract

The formation of NO{sub x} in a CO/H{sub 2}/CH{sub 4}/NH{sub 3} jet in a co-flowing air stream was modeled by use of CFD combined with a comprehensive detailed reaction mechanism. The comprehensive mechanism involved 340 reversible elementary reactions between 55 species. Three different approaches to include the detailed reaction mechanism were tested. In approach I, all chemistry was described with the comprehensive mechanism. In approaches IIa and IIb the comprehensive mechanism was used in post-processing calculations of the nitrogen chemistry. In approach IIa, the temperatures of the reacting structures obtained in the main calculations were used, whereas in approach IIb, the inlet temperatures to the reacting structures were taken from the main calculation. In approach IIIa and IIIb, empirical reaction mechanisms describing the nitrogen chemistry were tested. The turbulence-chemistry interaction was accounted for with a new model, which combines the Eddy-Dissipation Concept with a model based on the `Exchange by Interaction with the Mean`. There was a clear difference between the computed results and the measured ones. The use of approach I resulted in an obvious overprediction of the lift-off height. The predicted molar NO{sub x} yield with the approaches IIa and IIb were 89 % and 85 %, respectively,  More>>
Authors:
Brink, A; Norstroem, T; Kilpinen, P; Hupa, M [1] 
  1. Aabo Akademi, Turku (Finland). Combustion Chemistry Research Group
Publication Date:
Dec 31, 1997
Product Type:
Conference
Report Number:
TKK-MK-1; CONF-9706306-
Reference Number:
SCA: 014000; 400800; PA: FI-99:003119; EDB-99:068543; SN: 99002078284
Resource Relation:
Conference: 4. international colloquium on process simulation, Espoo (Finland), 11-13 Jun 1997; Other Information: PBD: 1997; Related Information: Is Part Of The 4th international colloquium on process simulation. Proceedings; Jokilaakso, A. [Helsinki Univ. of Technology, Otaniemi (Finland). Dept. of Materials Science and Metallurgy]; PB: 621 p.
Subject:
01 COAL, LIGNITE, AND PEAT; 40 CHEMISTRY; NITRIC OXIDE; CHEMICAL REACTION KINETICS; CARBON MONOXIDE; AMMONIA; METHANE; HYDROGEN; COMPUTERIZED SIMULATION; FLOW MODELS; TURBULENT FLOW; COAL; COMBUSTION; FLAME PROPAGATION
OSTI ID:
357225
Research Organizations:
Helsinki Univ. of Technology, Otaniemi (Finland)
Country of Origin:
Finland
Language:
English
Other Identifying Numbers:
Other: ON: DE99735414; ISBN 951-22-3574-9; TRN: FI9903119
Availability:
OSTI as DE99735414
Submitting Site:
FI
Size:
pp. 359-373
Announcement Date:
Aug 12, 1999

Citation Formats

Brink, A, Norstroem, T, Kilpinen, P, and Hupa, M. Predictions of NO{sub x} formation in an NH{sub 3}-doped syngas flame using CFD combined with a detailed reaction mechanism. Finland: N. p., 1997. Web.
Brink, A, Norstroem, T, Kilpinen, P, & Hupa, M. Predictions of NO{sub x} formation in an NH{sub 3}-doped syngas flame using CFD combined with a detailed reaction mechanism. Finland.
Brink, A, Norstroem, T, Kilpinen, P, and Hupa, M. 1997. "Predictions of NO{sub x} formation in an NH{sub 3}-doped syngas flame using CFD combined with a detailed reaction mechanism." Finland.
@misc{etde_357225,
title = {Predictions of NO{sub x} formation in an NH{sub 3}-doped syngas flame using CFD combined with a detailed reaction mechanism}
author = {Brink, A, Norstroem, T, Kilpinen, P, and Hupa, M}
abstractNote = {The formation of NO{sub x} in a CO/H{sub 2}/CH{sub 4}/NH{sub 3} jet in a co-flowing air stream was modeled by use of CFD combined with a comprehensive detailed reaction mechanism. The comprehensive mechanism involved 340 reversible elementary reactions between 55 species. Three different approaches to include the detailed reaction mechanism were tested. In approach I, all chemistry was described with the comprehensive mechanism. In approaches IIa and IIb the comprehensive mechanism was used in post-processing calculations of the nitrogen chemistry. In approach IIa, the temperatures of the reacting structures obtained in the main calculations were used, whereas in approach IIb, the inlet temperatures to the reacting structures were taken from the main calculation. In approach IIIa and IIIb, empirical reaction mechanisms describing the nitrogen chemistry were tested. The turbulence-chemistry interaction was accounted for with a new model, which combines the Eddy-Dissipation Concept with a model based on the `Exchange by Interaction with the Mean`. There was a clear difference between the computed results and the measured ones. The use of approach I resulted in an obvious overprediction of the lift-off height. The predicted molar NO{sub x} yield with the approaches IIa and IIb were 89 % and 85 %, respectively, whereas a yield of 23 % had been measured. With the empirical mechanisms used in approach IIIa, a similar NO{sub x} yield was predicted as with approaches IIa and IIb. With IIIb the predicted NO{sub x} yield was 40 %. However, in this case 67 % of the NH{sub 3} remained unreacted. The reason for the large difference between the calculated NO{sub x} yield and the measured one reported in the literature is a poor modeling of the initial part of the fuel jet. A possible reason for this is the coarse grid. (author) 15 refs.}
place = {Finland}
year = {1997}
month = {Dec}
}