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CFD Modeling Overview

Benefits of CFD Modeling

  • Reduces costs—CFD modeling allows designers to predict results before installation, avoiding costly errors

  • Saves time—CFD modeling eliminates time consuming on-site trial and error situations

  • Provides detailed insights—CFD modeling gives insight into furnace operation that cannot be obtained through testing/measurement

Our Experience

CFD modeling is used to: 1) validate the baseline furnace combustion performance and 2) facilitate design of the air pollution control system for a particular unit.


We have developed our own modeling team and capabilities. The types of models include: 1) non-reacting flow; 2) fuel combustion and reacting flow; and 3) pollutant formation (i.e., NOx, SOx, LOI, CO, etc), with fuel ranging from coal, biomass, oil to natural gas. We have also analyzed a wide range of boiler types from pulverized fuel (p.f.) boilers (tangential or wall-fired) with a wide range of burners to fluidized bed and stoker units. Our models have addressed a variety of chemical-reacting flows associated with fuel combustion and reacting flow:

  • Solid fuel combustion chemistry (devolatilization, char oxidation kinetics)

  • Gas volatiles (i.e. gaseous fuel) combustion

  • CO finite rate chemistry

  • Soot formation chemistry (heavy oil combustion)

  • NOx formation chemistry (thermal NOx, fuel-N conversion chemistry)

  • SOx formation chemistry (SO2 and SO3) and reduction by limestone (CaO+SO2)

  • Urea and ammonia chemistry to reduce NOx

  • Sorbent chemistry for SO2, Mercury, and HCl capture.

RAS’s PhD level experts have modeled over 100 models on a wide variety of boiler configurations:

  • Circulating fluidized bed (CFB)

  • Tangential-fired

  • Wall-fired

  • Cyclone

  • Stoker/grate fired

  • Kilns

  • Various burner types

and fuel types:

  • Variety of coals

  • Biomass

  • Biomass co-fired with coal

  • Waste products

  • Oil

  • Natural Gas

  • Waste and landfill gases

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