(552g) Oxy-Gas Combustion for Process Heater Retrofitting: Effect of Scenario Parameters On Velocity and Composition Fields in the near Burner Region

Oxy-fuel combustion has been proposed as a retrofit technology for the power generation, petrochemical, and refining industries. Despite its advantage of providing an effluent stream of concentrated CO2, questions remain about heat transfer, pollutant formation, and flame stability in boilers, process heaters, and other combustion equipment retrofitted with oxy-fuel burners.

The objective of our oxy-gas research is to produce the simulation tools needed for simulating efficient CO2 capture from process heaters. We have specifically focused on (1) creating a Large Eddy Simulation (LES) tool for demonstrating practical oxy-gas combustion in process heaters and (2) using the LES technology to produce predictive capability with quantified uncertainty bounds for a pilot-scale oxy-gas process heater.

We use a rigorous uncertainty quantification (V/UQ) analysis approach to achieve predictive capability, employing the Data Collaboration methods of Michael Frenklach and coworkers at the University of California-Berkeley [1,2]. Data Collaboration requires consistency between simulation results and experimental data. For our Data Collaboration analysis, we employ the ARCHES simulation tool, a three-dimensional, LES code developed by Professor Smith and his research group at the University of Utah. ARCHES uses a low-Mach number (M < 0.3), variable density formulation to simulate heat and mass transfer in reacting flow [3]. The selected experimental data are from the International Flame Research Foundation's (IFRF) oxy-gas experiments, also known as the OXYFLAM experiments [4].

To perform the V/UQ analysis, there are requirements of both the experimental data and the simulations. For the experimental data, the uncertainty range of all measured variables (response quantities of interest) must be determined as precisely as possible. For the simulations, the parameter space that has the greatest effect on the experimentally measured variables must be probed via an experimental design. In the case of the IFRF OXYFLAM experiments,the parameter space that we have probed includes scenario parameters such as O2 and natural gas flow rates, model parameters such as the model for the boundaries of the near burner region, and numerical parameters such as mesh resolution. We examine the effect of the ranges of these parameters on the simulation results and determine the region of consistency between experiment and simulation. This region of consistency defines the uncertainty range of the response quantities of interest.

References [1] Frenklach, M., Packard, A., Seiler, P., and Feeley, R., ?Collaborative Date Processing in Developing Predictive Models of Complex Reaction Systems,? International Journal of Chemical Kinetics, 36, 57?66 (2004). [2] Feeley, R., Seiler, P., Packard, A., and Frenklach, M., ?Consistency of a Reaction Dataset,? Journal of Physical Chemistry A, 108, 9573?9583 (2004). [3] Spinti, J., Thornock, J., Eddings, E., Smith, P., and Sarofim, A., ?Heat Transfer to Objects in Pool Fires,? in Transport Phenomena in Fires, WIT Press, Southampton, U.K., 2008. [4] Lallemant, N., Dugue, J., and Weber, R., ?Analysis of the Experimental Data Collected During the OXYFLAM-1 and OXYFLAM-2 Experiment, Phase 1: 1995-1996. IFRF Doc No F 85/y/4, International Flame Research Foundation, IJmuiden, The Netherlands (1997).