The flame characteristics of a pilot-scale swirl burner for air and oxy-fuel combustion of pulverized coal are investigated. The local burner air (or oxygen) ratio λ and the oxygen concentration have been systematically varied. The investigated flames were characterized recording UV emissions originating from OH* chemiluminescence indicating the reaction zone in the gas phase, measuring the axial and tangential velocities using an laser Doppler velocimetry (LDV) system and analyzing the composition of the flue gas. A change of the flame structure was revealed from the conducted measurement: the “regular” flame for the investigated burner is characterized by a cone-shaped swirling combustion zone with a distinct inner recirculation zone. Reducing the oxidizer flows through the burner leads to a breakdown of the inner recirculation zone and a significant change of the flame pattern. This change was identified by the LDV measurements as well as from the chemiluminescence images, and it was found to be closely related to the momentum flow through the burner into the main combustion zone.

References

References
1.
Liu
,
H.
,
Zailani
,
R.
, and
Gibbs
,
B.
,
2005
, “
Comparisons of Pulverized Coal Combustion in Air and in Mixtures of O2/CO2
,”
Fuel
,
84
(7–8), pp.
833
840
.
2.
Hjärtstam
,
S.
,
Andersson
,
K.
,
Johnsson
,
F.
, and
Leckner
,
B.
,
2009
, “
Combustion Characteristics of Lignite-Fired Oxy-Fuel Flames
,”
Fuel
,
88
(
11
), pp.
2216
2224
.
3.
Wall
,
T.
,
Liu
,
Y.
,
Spero
,
C.
,
Elliott
,
L.
,
Khare
,
S.
,
Rathnam
,
R.
,
Zeenathal
,
F.
,
Moghtaderi
,
B.
,
Buhre
,
B.
,
Sheng
,
C.
,
Gupta
,
R.
,
Yamada
,
T.
,
Makino
,
K.
, and
Yu
,
J.
,
2009
, “
An Overview on Oxyfuel Coal Combustion—State of the Art Research and Technology Development
,”
Chem. Eng. Res. Des.
,
87
(
8
), pp.
1003
1016
.
4.
Chen
,
L.
,
Yong
,
S. Z.
, and
Ghoniem
,
A. F.
,
2012
, “
Oxy-Fuel Combustion of Pulverized Coal: Characterization, Fundamentals, Stabilization and CFD Modeling
,”
Prog. Energy Combust. Sci.
,
38
(
2
), pp.
156
214
.
5.
Scheffknecht
,
G.
,
Al-Makhadmeh
,
L.
,
Schnell
,
U.
, and
Maier
,
J.
,
2011
, “
Oxy-Fuel Coal Combustion—A Review of the Current State-of-the-Art
,”
Int. J. Greenhouse Gas Control
,
5
(
Suppl. 1
), pp.
S16
S35
.
6.
Toporov
,
D.
,
Bocian
,
P.
,
Heil
,
P.
,
Kellermann
,
A.
,
Stadler
,
H.
,
Tschunko
,
S.
,
Förster
,
M.
, and
Kneer
,
R.
,
2008
, “
Detailed Investigation of a Pulverized Fuel Swirl Flame in CO2/O2 Atmosphere
,”
Combust. Flame
,
155
(
4
), pp.
605
618
.
7.
Heil
,
P.
,
Toporov
,
D.
,
Stadler
,
H.
,
Tschunko
,
S.
,
Förster
,
M.
, and
Kneer
,
R.
,
2009
, “
Development of an Oxycoal Swirl Burner Operating at Low O2 Concentrations
,”
Fuel
,
88
(
7
), pp.
1269
1274
.
8.
Tigges
,
K.-D.
,
Klauke
,
F.
,
Bergins
,
C.
,
Busekrus
,
K.
,
Niesbach
,
J.
,
Ehmann
,
M.
,
Kuhr
,
C.
,
Hoffmeister
,
F.
,
Vollmer
,
B.
,
Buddenberg
,
T.
,
Wu
,
S.
, and
Kukoski
,
A.
,
2009
, “
Conversion of Existing Coal-Fired Power Plants to Oxyfuel Combustion: Case Study With Experimental Results and CFD Simulations
,”
Energy Procedia
,
1
(
1
), pp.
549
556
.
9.
Habermehl
,
M.
,
Toporov
,
D.
,
Erfurth
,
J.
,
Förster
,
M.
, and
Kneer
,
R.
,
2012
, “
Experimental and Numerical Investigation on a Swirl Oxycoal Flame
,”
Appl. Therm. Eng.
,
49
, pp.
161
169
.
10.
Hardalupas
,
Y.
, and
Orain
,
M.
,
2004
, “
Local Measurements of the Time-Dependent Heat Release Rate and Equivalence Ratio Using Chemiluminescent Emission From a Flame
,”
Combust. Flame
,
139
(
3
), pp.
188
207
.
11.
Weidmann
,
M.
,
Verbaere
,
V.
,
Boutin
,
G.
,
Honoré
,
D.
,
Grathwohl
,
S.
,
Goddard
,
G.
,
Gobin
,
C.
,
Dieter
,
H.
,
Kneer
,
R.
, and
Scheffknecht
,
G.
,
2015
, “
Detailed Investigation of Flameless Oxidation of Pulverized Coal at Pilot Scale (230 kW)
,”
Appl. Therm. Eng.
,
74
, pp.
96
101
.
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