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WTE: Combustion Phenomena on Moving Grate

  • J. SwitenbankEmail author
  • V. Sharifi
Reference work entry
Part of the Encyclopedia of Sustainability Science and Technology Series book series (ESSTS)

Glossary

AD

Anaerobic digestion

CFD

Computational fluid dynamics

CHP

Combined heat and power

CHP/DHC

Combined heat and power/district heating and cooling

CV

Calorific value

DEFRA

Department of Environment Food and Rural Affairs

DHC

District heating and cooling

DVC

Depolymerization-vaporization-cross-linking model

EfW

Energy-from-waste

EU

European Union

FG

Functional group

FG-DVC

Functional group model and a depolymerization-vaporization-cross-linking model

GJ

Gigajoule

kWh

Kilowatt hours

kW h

Kilowatt heat

MBT

Mechanical biological treatment

MSW

Municipal solid waste

MRF

Material recovery facility

MW

Megawatt

NO

Nitric oxide

NO x

Nitrogen oxides

PCDD/Fs

Polychlorinated dibenzo-dioxins and furans

RDF

Refuse-derived fuel

ROC

Renewable Obligation Certificate

SRF

Solid-recovered fuel

TEQ

Toxic equivalent

TGA

Thermogravimetric analysis

WID

Waste WTE directive

WTE

Waste-to-energy

Definition of the Subject

Historically, waste materials from cities were simply dumped in huge piles of polluting...

Nomenclature

A

Particle surface area, m2m−3

Ar

Pre-exponent factor in char burning rate, kgm−2s−1

Av

Pre-exponent factor in devolatilization rate, s−1

C

Constant; molar fractions of species

Cfuel

Fuel concentration, kgm−3

Cpg

Specific heat capacity of the gas mixture, Jkg−1K−1

Cmix

Mixing rate constant, 0.5

Cw,g

Moisture mass fraction in the gas phase

Cw,s

Moisture mass fraction at the solid surface

Dig

Dispersion coefficients of the species Y i, m2s−1

dp

Particle diameter, m

Eb

Black body emission, Wm−2

Er

Activation energy in char burning rate, Jkmol−1

Ev

Activation energy in devolatilization rate, Jkmol−1

E0

Effective diffusion coefficient

Hevp

Evaporation heat of the solid material, Jkg−1

Hg

Gas enthalpy, Jkg−1

Hs

Solid-phase enthalpy, Jkg−1

hs

Convective mass transfer coefficient between solid and gas, kgm−2s−1

hs

Convective heat transfer coefficient between solid and gas, Wm−2K−1

Ix+

Radiation flux in positive x direction, Wm−2

Ix

Radiation flux in negative x direction, Wm−2

ka

Radiation absorption coefficient, m−1

kd

Rate constants of char burning due to diffusion, kgm−2s−1

kr

Rate constants of char burning due to chemical kinetics, kgm−2s−1

kv

Rate constant of devolatilization, s−1

ks

Radiation scattering coefficient, m−1

pg

Gas pressure, Pa

Qh

Heat loss/gain of the gases, Wm−3

Qsh

Thermal source term for solid phase, Wm−3

qr

Radiative heat flux, Wm−2

R

Universal gas constant; process rate, kgm−3s−1

Rmix

Mixing rate of gaseous phase in the bed, kgm−3s−1

S

Stoichiometric coefficients in reactions

Ssg

Conversion rate from solid to gases due to evaporation, devolatilization, and char burning, kgm−3s−1

Syig

Mass sources due to evaporation, devolatilization, and combustion, kgm−3s−1

Syis

Source term, kgm−3s−1

t

Time instant, s

T

Temperature, K

U

x velocity, ms−1

V

y velocity, ms−1

VM

Volatile matter in fuel, wt%

x

Coordinate in bed forward-moving direction, m

y

Coordinate in bed height direction, m

Yig

Mass fractions of individual species (e.g., H2, H2O, CO, CO2, CmHn, etc.)

Yis

Mass fractions of particle compositions (moisture, volatile, fixed carbon, and ash)

εs

System emissivity

σb

Stefan-Boltzmann constant, 5.86 × 10−8 Wm−2K−4

υ

Remaining volatile in solid at time, t

υ∞

Ultimate yield of volatile

Φ

Void fraction in the bed

λg

Thermal dispersion coefficient, Wm−1K−1

λg0

Effective thermal diffusion coefficient, Wm−1K−1

λs

Effective thermal conductivity of the solid bed, Wm−1K−1

Subscripts

env

Environmental

g

Gas phase

i

Identifier for a component in the solid

p

Particle

s

Solid phase

Bibliography

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Copyright information

© Springer Science+Business Media LLC, part of Springer Nature 2019

Authors and Affiliations

  1. 1.Energy and Environmental Engineering (EEE)Sheffield UniversitySheffieldUK
  2. 2.EEE Group, Chemical and Biological EngineeringSheffield UniversitySheffieldUK

Section editors and affiliations

  • Athanasios C. Bourtsalas
    • 1
  • Nickolas Themelis
    • 2
  1. 1.Earth Engineering CenterColumbia UniversityNew YorkUSA
  2. 2.Columbia UniversityEarth and Environmental EngineeringNew YorkUSA

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