Page 126 - New Trends In Coal Conversion

Coal and biomass cofiring: CFD 4

modeling

Chungen Yin
Department of Energy Technology, Aalborg University, Aalborg East, Denmark

Chapter Outline

4.1 Introduction 90
4.2 An overview of coal and biomass cofiring 90
4.3 CFD modeling of coal and biomass cofiring: the basic and generic modules 90
4.3.1 Turbulent mixing 91
4.3.2 Fuel particle motion 92
4.3.3 Radiation heat transfer 92
4.3.4 Heterogeneous reactions 94
4.3.4.1 Pyrolysis 94
4.3.4.2 Char reactions 94
4.3.5 Homogeneous reactions 95
4.3.6 Pollutant formation 96
4.3.6.1 Thermal NO x 96
4.3.6.2 Fuel NO x 97
4.3.7 Ash behavior 98
4.4 Suspension cofiring of coal and biomass: CFD modeling 100
4.4.1 Biomass preparation for suspension-firing and overall modeling strategy 100
4.4.2 Special modeling issue: motion of large, nonspherical biomass particles 102
4.4.3 Special modeling issue: conversion of large biomass particles 103
4.5 Grate cofiring and fluidized bed cofiring of coal and biomass: CFD
modeling 104
4.5.1 Overall modeling strategy 104
4.5.2 Special modeling issue: solid fuel conversion in a dense fuel bed 105
4.6 Coal and biomass cofiring under oxy-fuel conditions: special modeling
issues 107
4.6.1 Modeling of gaseous radiative properties under oxy-fuel conditions 107
4.6.2 Modeling of combustion chemistry under oxy-fuel conditions 109
4.7 Concluding remarks 110
References 112

New Trends in Coal Conversion. https://doi.org/10.1016/B978-0-08-102201-6.00004-2
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