Multidimensional simulations of both flue gas and fly ash (solid particle) flows with application to erosion prediction in the economisers of coal-fired power utility boilers are reported. A computer code specifically designed for power utility boilers, DS4PUB (Design Software for Power Utility Boilers), was used for the calculations. The major area of erosion often occurs at the economizer of the boiler and depends on the particulate velocity and concentration so that computational results include the economizer inlet distribution of the mean flue gas and particulate velocities, and fly ash concentration. The computer code was validated by comparisons with previously available experimental data and recently performed measurements for flue gas flow velocity, dust burden, and erosion rates at the inlet of economizers in large operating power stations. The results of the multidimensional simulations agreed reasonably well with the experimental measurements. An important finding of this study is that the transverse location of maximum erosion in the economizer tube bank strongly depends on the upstream geometric design of the boiler. For boilers with a shorter turning flow path, the maximum erosion is found to be close to the rear wall of the economizer because both the maximum particulate velocity and concentration occur in this region. For configurations with a long flow path, which includes a splitter plate, the maximum erosion region was found to be closer to the front wall of the economizer, mainly due to the high flow velocity in this region. A relatively high erosion area close to the side and rear wall was also found because of the high concentration of large fly ash particles in this area. Interesting feature of fly ash flow in multidimensional complex boiler geometries such as concentration distributions for different fly ash particle sizes are also discussed.

Issue Section:
Power
Topics:
Boilers, Erosion, Flow (Dynamics), Particulate matter, Fly ash, Flue gases, Computers, Design, Engineering simulation, Simulation, Coal, Computer software, Dust, Power stations
1.
Amoroso, L. A. M., 1990, “Modelling Flow in Boiler Tube Banks,” MEngSci. Thesis, School of Mechanical and Manufacturing Engineering, University of New South Wales, Sydney, Australia.
2.
Bauver, W. P., McGough, T. C., and McGowan, J. G., 1984, “A Facility for the Characterization of Erosion of Heat Transfer Tubing,” Gas-Solids Flow, ASME, pp. 115–122.
3.
Benyon, P. J., 1991, “Economiser Erosion Investigation,” BE Thesis, Department of Mechanical Engineering, The University of Sydney, Sydney, Australia.
4.
Chieng
C. C.
, and
Launder
B. E.
,
1980
, “
On the Calculation of Turbulent Heat Transport Downstream of an Abrupt Pipe Expansion
,”
Numerical Heat Transfer
, Vol.
3
, pp.
189
–
207
.
5.
Cho, N.-H., Fletcher, C. A. J., and Srinivas, K., 1991, “Efficient Computation of Wing Body Flows,” Lecture Notes in Physics, Springer, Vol. 371, pp. 167–191.
6.
Christo, F. C., and Fletcher, C. A. J., 1992, “Erosion Modeling in Vales Point Power Station Using ’ECONEROS’ Code,” Technical Report, Department of Mechanical Engineering, The University of Sydney, Sydney, Australia.
7.
ECNSW (Electricity Commission of New South Wales), 1988, “Liddell Power Station Unit 6: Boiler Rehabilitation,” Specification and contract No. 3824.
8.
Fan
J.
,
Zhou
D.
,
Jin
J.
,
Cen
K.
,
1991
, “
Numerical Simulation of Tube Erosion by Particle Impaction
,”
Wear
, Vol.
142
, pp.
171
–
184
.
9.
Fan
J.
,
Zhou
D.
,
Zeng
K.
, and
Cen
K.
,
1992
, “
Numerical and Experimental Study of Finned Tube Erosion Protection Method
,”
Wear
, Vol.
152
, pp.
1
–
19
.
10.
Fletcher, C. A. J., 1991, Computational Techniques for Fluid Dynamics, Vol. 2: Specific Techniques for Different Flow Categories, 2nd ed., Springer, Heidelberg.
11.
Fletcher
C. A. J.
, and
Bain
J. G.
,
1991
, “
An Approximate Factorisation Explicit Method for CFD
,”
Computers and Fluids
, Vol.
19
, pp.
61
–
74
.
12.
Guzman
M. M.
,
Fletcher
C. A. J.
, and
Hooper
J. D.
,
1994
, “
Computational Investigation of Cobra Probe Operation
,”
Int. J. Num. Meth. Heat Fluid Flow
, Vol.
4
, pp.
425
–
445
.
13.
Hamed
A.
,
1992
, “
An Investigation in the Variance in Particle Surface Interactions and Their Effects in Gas Turbines
,”
Journal of Aircraft for Gas Turbines and Power
, Vol.
114
, pp.
235
–
241
.
14.
Humphrey
J. A. C.
,
1990
, “
Review—Fundamentals of Fluid Motion in Erosion by Solid Particle Impact
,”
Int. J. Heat and Fluid Flow
, Vol.
11
, pp.
170
–
195
.
15.
Jones, P., and Owens, D., 1995, “Wallerawang Power Station Units 7 & 8 Economiser Erosion and Replacement Investigation,” Report No. pp/M/1266/1, Power Engineering Boiler, Fuel & Water Systems, Pacific Power, New South Wales, Australia, Apr.
16.
Jun
Y. D.
, and
Tabakoff
W.
,
1994
, “
Numerical Simulation of a Dilute Particulate Flow (Laminar) Over Tube Banks
,”
ASME Journal of Fluids Engineering
, Vol.
116
, pp.
770
–
777
.
17.
Kitchen, A. N., 1990, “Flyash Erosion Prediction in Economisers,” MEngSci. Thesis, Department Mechanical Engineering, The University of Sydney, Sydney, Australia.
18.
Launder
B. E.
, and
Spalding
D. B.
,
1974
, “
The Numerical Computation of Turbulent Flows
,”
Comp. Methods in Appl. Mech. and Eng.
, Vol.
3
, pp.
269
–
289
.
19.
Orszag, S. A., Yakhot, V., Flannery, W. S., et al., 1993, “Renormalization Group Modeling and Turbulence Simulations,” in: Near Wall Turbulent Flows, So, R. M. C., Speziale, C. G., and Launder, B. E., eds., Elsevier Science Publishers B. V., pp. 1031–1046.
20.
Pacific Power, 1995, “Unit 7 Economiser Air Flow Test in Wallerawang Power Station,” Technical Report No. MTT374, Pacific Power, New South Wales, Australia.
21.
Platfoot, R., 1991, “Internal Flows in Coal Fired Boilers,” PhD. Thesis, Department of Mechanical Engineering, The University of Sydney, Sydney, Australia.
22.
Raask, E., 1988, Erosion Wear in Coal Utilization, Hemisphere Publishing.
23.
Rhie
C. M.
, and
Chow
W. L.
,
1983
, “
Numerical Study of the Turbulent Flow Past an Airfoil With Trailing Edge Separation
,”
AIAA J.
, Vol.
21
, pp.
1525
1525
.
24.
Schuh
M. J.
,
Schuler
C. A.
, and
Humphrey
J. A. C.
,
1989
, “
Numerical Calculation of Particle-Laden Gas Flows Past Tubes
,”
AIChE Journal
, Vol.
35
(
3
), pp.
466
–
480
.
25.
Schweitzer
M. O.
, and
Humphrey
J. A. C.
,
1988
, “
Note on the Experimental Measurement of Particle Flux to One and Two In-Line Tubes
,”
Wear
, Vol.
126
, pp.
211
211
.
26.
Tu
J. Y.
, and
Fletcher
C. A. J.
,
1994
, “
An Improved Model for Particulate Turbulence Modulation in Confined Two-Phase Flows
,”
Int. Comm. Heat and Mass Transf.
, Vol.
21
(
6
), pp.
775
–
783
.
27.
Tu, J. Y., Fletcher, C. A. J., and Behnia, M., 1994, “Computation of Three-Dimensional Fly Ash Flow in Vales Point Power Station,” DS4PUB Technical Report, No. 94–12, CANCES, University of New South Wales, Sydney, Australia.
28.
Tu
J. Y.
and
Fletcher
C. A. J.
,
1995
a, “
Numerical Computation of Turbulent Gas-Solid Particle Flow in a 90° Bend
,”
AIChE Journal
, Vol.
41
(
10
), pp.
2187
–
2197
.
29.
Tu, J. Y., and Fletcher, C. A. J., 1995b, “Computational Analysis of Turbulent Gas-Solid Flows In In-Line Tube Banks,” Gas-Solid Flows, ASME FED-Vol. 228, pp. 309–317.
30.
Van Doormaal
J. P.
, and
Raithby
G. D.
,
1984
, “
Enhancements for the SIMPLE Method for Predicting Incompressible Fluid Flow
,”
Num. Heat Transfer
, Vol.
7
, pp.
147
–
163
.
31.
Zdravistch
F.
,
Fletcher
C. A. J.
, and
Behnia
M.
,
1995
, “
Numerical Laminar and Turbulent Fluid Flow and Heat Transfer Predictions in Tube Banks
,”
Int. J. Num. Meth. Heat Fluid Flow
, Vol.
5
, pp.
717
–
733
.
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