cfd burner study for entrained flow gasifiers · 2018-06-27 · cfd burner study for entrained...
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CFD Burner Study for Entrained Flow GasifiersNumerical Study of Different Burner Configurations in an Entrained Flow gasifiers
0.5
0.6
0.7
0.8
0.9
1
0 0.05 0.1 0.15 0.2 0.25 0.3
H/C
mol
arra
tio
O/C molar ratio
CPD
RBC-1
RBC-2
LBC-1
LBC-2
LBC-3CRC-252
CRC-272
CRC-274CRC-299CRC-358
XHLNewland
Thomas Förster1, Andreas Richter1, Bernd Meyer2
Institute of Energy Process Engineering and Chemical Engineering18.05.2018, IEC Seminar
1Center for Innovation Competence Virtuhcon, Germany2 Institute of Energy Process Engineering and Chemical Engineering, TU Bergakademie Freiberg, Germany
Motivation
Burner Development for Entrained Flow Gasification
State of the art
Central jet flows
Swirling and non-swirling jetflows
1 to 3 Distributed jet flows
Subjects of interest
Increasing performance
Shortened flame
Stability of the flame
Higher reaction rates
Bader et. al. 2018, Fuel Proc. Techn. 169
Zhang et. al. 2017, Can. J. of Chem. Eng.
TU Bergakademie Freiberg | T. Förster et al. | CFD Burner Study for Entrained Flow Gasifiers | 18.05.2018 1
Motivation
Different Burner Concepts for Non-Catalytic Partitial Oxidation of Natural Gas
Different burner concepts, Förster et. al. 2017, Fuel 203
Fuel
SteamOxidizer+ Steam
�16
(jet)
FuelOxidizer+ Steam
�77
(plate)
(spherical)
Förster et. al. 2017, Fuel 203
−20
−10
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60
0 50 100 150 200 250 300
H2massflo
w,kg/h
Reactor length,mm
jetjet-swirl
platespherical
mH2, out
0Copyright of reuse by Elsevier/Fuel via RightsLink is obtained for the cited images
TU Bergakademie Freiberg | T. Förster et al. | CFD Burner Study for Entrained Flow Gasifiers | 18.05.2018 2
Outline
Burner Concepts Investigation for Entrained Flow Gasifiers
Fuel and Process Analysis for a Comprehensive CFD Model
Influence of the Burner Concept on the Reactor System
Conclusion and Outlook
TU Bergakademie Freiberg | T. Förster et al. | CFD Burner Study for Entrained Flow Gasifiers | 18.05.2018 3
Burner Concepts Investigation for Entrained Flow Gasifiers
Overview of the Reactor Design
Geometric boundary conditions
Geometry of the reactor
Geometry of the burners1
Velocity profile of fuel inletVelocity profile of the oxidizer inletVelocity profile of the moderator inletCharacteristics of the conveying system
Entrained flow coal gasifier (top fired)
Central jet burner
5.4 m high and � 2.3m
Siemens typegasifier
1Geometry influences the flow fields, Euler-Lagrange vs. real geometry
TU Bergakademie Freiberg | T. Förster et al. | CFD Burner Study for Entrained Flow Gasifiers | 18.05.2018 4
Burner Concepts Investigation for Entrained Flow Gasifiers
Burner Concepts (Inverse Models)
B1, central jet
B3, plate
B2, peripheral jet
B4, spherical
Siemens type reactor
TU Bergakademie Freiberg | T. Förster et al. | CFD Burner Study for Entrained Flow Gasifiers | 18.05.2018 5
Burner Concepts Investigation for Entrained Flow Gasifiers
Mesh
B1 and B2 central jets
Dimension: 2D,axis-symmetric
Size: 30k
Type: structured,quadrilateral
Calculation time:∼ 7 days
B3, plate
Dimension: 3D,symmetry
Size: 900k
Type: structured,hexahedral
Calculation time:∼ 50 days
B4, spherical
Dimension: 3D,symmetry
Size: 800k
Type: structured,hexahedral
Calculation time:∼ 50 days
TU Bergakademie Freiberg | T. Förster et al. | CFD Burner Study for Entrained Flow Gasifiers | 18.05.2018 6
Burner Concepts Investigation for Entrained Flow Gasifiers
CFD Setup
Setup for the CFD setup of the Siemens type gasifier1
Solver ANSYS Fluent
Turbulence realizable k-ε model
Radiation DO model
Turbulence chemical interaction Eddy-Dissipation Concept Model
Homogeneous mechanism reduced GRI 1.22
Gas phase properties kinetic theory
Particle tracking Euler-Lagrange
1Safronov et al. 2017, Fuel Proc. Techn. 1612Kazakov and Frenklach 1995, http://www.me.berkeley.edu/drm/3Badzioch and Hawksley 1970, Ind. Eng. Chem. Proc. Des. and Develop. 9(4)
TU Bergakademie Freiberg | T. Förster et al. | CFD Burner Study for Entrained Flow Gasifiers | 18.05.2018 7
Fuel and Process Analysis for a Comprehensive CFD Model
Input Streams
Necessary operational boundary conditions
Coal inlet mcoal, Tcoal
Oxidizer inlet mox, Tox
Moderator inlet mmod, Tmod
Purge inlet mpurge, Tpurge
Wall temperatures Treactor, Tburner
Remark
Operational experience
Equilibrium approach
Non-equilibrium reduced order models
: Most reliable boundary conditions
Boundary conditions criteria
Min. gas temp. Tgas Tcrit-η + 50K
Fuel-oxygen-ratio λ 0.4 to 0.5
Reactor pressure pop 31 bar(a)
Carb. conv. target Xgoal maximum
Thermal power Hth ∼ 250MW
Fuel HHV ∆hHHV,ar Newlandhard coal
Conveying system εvoid ≈ 0.75
TU Bergakademie Freiberg | T. Förster et al. | CFD Burner Study for Entrained Flow Gasifiers | 18.05.2018 8
Fuel and Process Analysis for a Comprehensive CFD Model
Input Streams Approximation for the Current Setup
General boundary conditions
Fuel stream mcoal,kgs 9.0
mCO2 , kgs 1.0
Tpurge, K 300.0
Gasifying stream mgas,kgs 7.5
xO2 , xCO2 , - 0.95,0.05
Tgas, K 653.0
Wall inlet region Tburner, K 300.0
Wall reactor Treactor, K 1600.0
Reactor pressure pop, bar(a) 31.0
Example of burner boundary conditions
TU Bergakademie Freiberg | T. Förster et al. | CFD Burner Study for Entrained Flow Gasifiers | 18.05.2018 9
Fuel and Process Analysis for a Comprehensive CFD Model
General Fuel Properties
Standard anaylsis
Ultimate analysis
Proximate analysis
Intrinsic surface
Density and porosity
Higher heating value
Particle size distribution
Ash characteristics (e.q. temperature of critical viscosity)
Advanced measurements of the used fuel
Pyrolysis rates and composition
Heterogeneous reaction kinetics (CO2 and H2O)
Remark All data need to be available for the same fuel
TU Bergakademie Freiberg | T. Förster et al. | CFD Burner Study for Entrained Flow Gasifiers | 18.05.2018 10
Fuel and Process Analysis for a Comprehensive CFD Model
Pyrolysis Data
Properties of the pyrolysis process
Based on particle heating rates: Experimental determination as close to the operation conditions as possible
Comprises1. Pyrolysis gas compositions and tar properties2. Devolatilization rates for all participating species3. Swelling index
Goal is to use experimental data (e.q. PYMEQ rig)1
No data set for the desired coal is available: Use of network models is necessary
1Reichel et al. 2015, Fuel 158
TU Bergakademie Freiberg | T. Förster et al. | CFD Burner Study for Entrained Flow Gasifiers | 18.05.2018 11
Fuel and Process Analysis for a Comprehensive CFD Model
Newland Coal1
Proxymate analysis (ar), wt %
FC VM Ash Moist
55.6 27.8 13.4 3.2
Ultimate analysis (daf), wt %
C H O N S
82.50 5.11 10.61 1.36 0.42
Other properties
Density (true), kgm3 1456.0
HHV (ar), MJkg 28.88
Boundaries of the CPD in the van-Krevelendiagram
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0.6
0.7
0.8
0.9
1
0 0.05 0.1 0.15 0.2 0.25 0.3
H/C
mol
arra
tio
O/C molar ratio
CPD
RBC-1
RBC-2
LBC-1
LBC-2
LBC-3CRC-252
CRC-272
CRC-274CRC-299CRC-358
XHLNewland
1Kajitani et al. 2003, Report W02021
TU Bergakademie Freiberg | T. Förster et al. | CFD Burner Study for Entrained Flow Gasifiers | 18.05.2018 12
Fuel and Process Analysis for a Comprehensive CFD Model
Results of the Chemical Percolation Model
Particle temperature over time(CPD vs. SFOM)
Particle temperature over time(CPD vs. C2SM)
Final mass fraction yield, wt.%
H2O 12.00
CH4 6.27
CO 5.40
CO2 3.49
Tar 20.15
Tar
C13.7H21.4N1.01
with Mtar = 200 kgkmol
−dmp
dt= k · [mp − (1− fv,0)(1− fw,0) ·mp,0] with k = A · exp
(− EAT ·Ru
)with A = 13 436 655 1
sand EA = 80 970 J
mol
Vol −−→ 0.4659 H2O + 0.2734 CH4 + 0.1348 CO + 0.0555 CO2 + 0.0705 Tar
TU Bergakademie Freiberg | T. Förster et al. | CFD Burner Study for Entrained Flow Gasifiers | 18.05.2018 13
Fuel and Process Analysis for a Comprehensive CFD Model
Heterogeneous Reaction Kinetics
Literature data
Reliability ⇓Availabiltiy ⇑mainly based on TGAmeasurements
: limited usability
TGA
Fast
Reliable
Several systems availableat the institute
Experience in modelbased data evaluation1
: Advantage indetermining rate inkinetic controlled regime
Drop tube
KIVAN2
Sophisticated andcomplex
Closer to the real process
Reliable for regime I + II
: Best kinetic data forentrained flow gasifiers
Literature data3 are adapted for surface based kinetics4
1Schulze et al. 2017, Fuel 1872Gonzalez et al. 2018, Fuel 2243Kajitani et al. 2002, Fuel 814ANSYS Fluent Manual v172, ch. 7.3
TU Bergakademie Freiberg | T. Förster et al. | CFD Burner Study for Entrained Flow Gasifiers | 18.05.2018 14
Influence of the Burner Concept on the Reactor System
Flow Fields, Velocity Magnitude, vaxial = 0 ms
B1, jet central B1, swirl 60◦ B3, plate B4, spherical
TU Bergakademie Freiberg | T. Förster et al. | CFD Burner Study for Entrained Flow Gasifiers | 18.05.2018 15
Influence of the Burner Concept on the Reactor System
Gas Residence Time
B1, jet central B1, swirl 60◦ B3, plate B4, spherical
TU Bergakademie Freiberg | T. Förster et al. | CFD Burner Study for Entrained Flow Gasifiers | 18.05.2018 16
Influence of the Burner Concept on the Reactor System
Overall Particle Residence Times
B1, jet central
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Residence time, s
B3, plate
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Residence time, s
B1, swirl 60◦
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B4, spherical
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TU Bergakademie Freiberg | T. Förster et al. | CFD Burner Study for Entrained Flow Gasifiers | 18.05.2018 17
Influence of the Burner Concept on the Reactor System
Heterogeneous Burnout, rC+O2 = 0.1 kmolm3 s
B1, jet central B1, swirl 60◦ B3, plate B4, spherical
TU Bergakademie Freiberg | T. Förster et al. | CFD Burner Study for Entrained Flow Gasifiers | 18.05.2018 18
Conclusion and Outlook
Conclusion
State of the art CFD models for detailed conversion analysis are available
Different burner concepts including swirl were investigated for the prove of generalconcept
The burner configuration has a great impact on flow and particle dynamics in a reactor
Findings for single-phase systems cannot be transfered directly to multiphase systems.
Next steps
Additional burner concepts will be studied
Implementation of new fuel datasets based on in-house measurements
Usage of ROMs for a better pre-assessment of boundary conditions for CFD
TU Bergakademie Freiberg | T. Förster et al. | CFD Burner Study for Entrained Flow Gasifiers | 18.05.2018 19
Thank you for your kind attention!This research has been funded as part of ProVirt by the European Social Fund (ESF) and theFree State of Saxony (project number 100231952).
TU Bergakademie Freiberg | T. Förster et al. | CFD Burner Study for Entrained Flow Gasifiers | 18.05.2018 20