0
Research Papers: Gas Turbines: Combustion, Fuels, and Emissions

CFD Prediction of Partload CO Emissions Using a Two-Timescale Combustion Model

[+] Author and Article Information
Bernhard Wegner1

Energy Sector, Siemens AG, 45478 Mülheim/Ruhr, Germanybernhard.wegner@siemens.com

Uwe Gruschka, Werner Krebs

Energy Sector, Siemens AG, 45478 Mülheim/Ruhr, Germany

Y. Egorov, H. Forkel, J. Ferreira

 ANSYS Germany, 83624 Otterfing, Germany

Kai Aschmoneit

EKT, Darmstadt University of Technology, 64287 Darmstadt, Germany

1

Corresponding author.

J. Eng. Gas Turbines Power 133(7), 071502 (Mar 17, 2011) (7 pages) doi:10.1115/1.4002021 History: Received April 21, 2010; Revised May 16, 2010; Published March 17, 2011; Online March 17, 2011

Today’s and future electric power generation is characterized by a large diversification using all kind of sources, including renewables resulting in noncoherent fluctuations of power supply and power usage. In this context, gas turbines offer a high operational flexibility and a good turn down ratio. In order to guide the design and down select promising solutions for improving partload emissions, a new combustion model based on the assumption of two separate timescales for the fast premixed flame stabilization and the slow post flame burnout zone is developed within the commercial computational fluid dynamics (CFD) code ANSYS CFX. This model enables the prediction of CO emissions generally limiting the turn down ratio of gas turbines equipped with modern low NOx combustion systems. The model is explained and validated at lab scale conditions. Finally, the application of the model for a full scale analysis of a gas turbine combustion system is demonstrated.

FIGURES IN THIS ARTICLE
<>
Copyright © 2011 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Sketch of CO emission as function of adiabatic flame temperature

Grahic Jump Location
Figure 2

Species and temperature profiles of a premix flame

Grahic Jump Location
Figure 3

YCO profiles obtained from the reaction progress c∗YCO,ff, the transport Eqs. 9,11 by setting cff=0.99

Grahic Jump Location
Figure 4

Sketch of burner and combustor of the atmospheric rig (8)

Grahic Jump Location
Figure 5

Aeordynamic boundary conditions selected at the burner inlet–color coded is the mixture fraction

Grahic Jump Location
Figure 6

Thermal boundary conditions for the atmospheric test rig

Grahic Jump Location
Figure 7

Reference planes used for model validation

Grahic Jump Location
Figure 8

Temperature distribution for the standard setup and the optimized parameter set; z denotes coordinate along lines presented in Fig. 7

Grahic Jump Location
Figure 9

CO prediction for the atmospheric combustor rig—using the BVM, the TSS model, and the chemical equilibrium assumption; z denotes coordinate along lines presented in Fig. 7

Grahic Jump Location
Figure 10

Calculated nondimensional CO emissions as function of the Zimont factor A

Grahic Jump Location
Figure 11

Comparison of calculated and measured CO emissions versus primary zone temperature (all data are nondimensional)

Grahic Jump Location
Figure 12

Scatter plot of CO versus equivalence ratio on the combustor outlet plane

Grahic Jump Location
Figure 13

Flame surface based on an isosurface of reaction progress c=0.98 colored with equivalence ratio

Grahic Jump Location
Figure 14

Timescale of postflame CO oxidation as a function of equivalence ratio obtained from laminar 1D premixed flames using detailed kinetics

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In