The thickness measurements showed that boilers of the Shahid Rajaee power plant have a non-uniform thickness in some regions of the final reheater tubes after 80,000 h of operation. Experimental tests on areas such as thickness, hardness, metallography, and recorded temperature showed that high temperature erosion is the most obvious reason for thinning in these tubes. Therefore, two possible reasons for the non-uniform tube thinning (problems due to combustion and steam mal-distribution in the tubes) were explored. This paper presents simulations of combustion, flow distribution in reheater tubes, and heat exchange process in Pass 1 of the boiler using FLUENT software. Combustion simulation results showed temperature distribution and mass flux of combustion products are not uniform at the chamber outlet. But these non-uniformities are not proportional to the tubes’ thickness non-uniformity; whereas, simulations showed steam is mal-distributed in the tubes so that steam maldistribution is proportional to the tubes’ thickness non-uniformities. Because steam maldistribution was due to mal-feeding and offloading of headers (U-type headers), all possible ways of feeding and offloading of headers were studied, and the results showed that the H-type configuration has the most uniform flow distribution.

References

References
1.
Chiou
,
J. P.
, 1978, “
Thermal Performance Deterioration in Crossflow Heat Exchanger Due to the Flow Nonuniformity
,”
ASME J. Heat Transfer
,
100
, pp.
580
587
.
2.
Shah
,
R. K.
, and
London
,
A. L.
, 1980, “
Effects of Nonuniform Passages on Compact Heat Exchanger Performance
,”
J. Eng. Power
,
102
, pp.
653
659
.
3.
Lalot
,
S.
,
Florent
,
P.
,
Lang
,
S. K.
, and
Bergles
,
A. E.
, 1999, “
Flow Mal-Distribution in Heat Exchangers
,”
Appl. Thermal Eng.
,
19
(
8
), pp.
847
863
.
4.
Tondeur
,
D.
, and
Luo
,
L. A.
, 2004, “
Design and Scaling Laws of Ramified Fluid Distributors by the Constructal Approach
,”
Chem. Eng. Sci.
,
59
(
8–9
), pp.
1799
1813
.
5.
Luo
,
L. A.
, and
Tondeur
,
D.
, 2005, “
Optimal Distribution of Viscous Dissipation in a Multi-Scale Branched Fluid Distributor
,”
Int. J. Therm. Sci.
,
44
(
12
), pp.
1131
1141
.
6.
Luo
,
L. A.
, and
Tondeur
,
D.
, 2005, “
Multiscale Optimization of Flow Distribution by Constructal Approach
,”
China Particuol.
,
3
(
6
), pp.
329
336
.
7.
Luo
,
L. A.
,
Fan
,
Y. L.
,
Zhang
,
W. W.
,
Yuan
,
X. G.
, and
Midoux
,
N.
, 2007, “
Integration of Constructal Distributors to a Mini Crossflow Heat Exchanger and Their Assembly Configuration Optimization
,”
Chem. Eng. Sci.
,
62
(
13
), pp.
3605
3619
.
8.
Luo
,
L. A.
,
Fan
,
Z. W.
,
Le Gall
,
H.
,
Zhou
,
X. G.
, and
Yuan
,
W. K.
, 2008, “
Experimental Study of Constructal Distributor for Flow Equidistribution in a Mini Crossflow Heat Exchanger (MCHE)
,”
Chem. Eng. Process.
,
47
(
2
), pp.
229
236
.
9.
Yuan
,
J.
,
Rokni
,
M.
, and
Sunsen
,
B.
, 2001, “
Simulation of Fully Developed Laminar Heat and Mass Transfer in Fuel Cell Ducts with different Cross-Sections
,”
Int. J. Heat/Mass Transfer
,
44
, pp.
4047
4058
.
10.
Jiao
,
K.
,
Zhou
,
B.
, and
Quan
,
P.
, 2006, “
Liquid Water Transport in Straight Micro-Parallel-Channels with Manifolds for PEM Fuel Cell Cathode
,”
J. Power Sources
,
157
, pp.
226
243
.
11.
Jung
,
H. M.
,
Lee
,
W. Y.
,
Park
,
J. S.
, and
Kim
,
C. S.
, 2004, “
Numerical Analysis of a Polymer Electrolyte Fuel Cell
,”
Int. J. Hydrogen Energy
,
29
(
9
), pp.
945
954
.
12.
Chen
,
C. H.
,
Jung
,
S. P.
, and
Yen
,
S. C.
, 2007, “
Flow Distribution in the Manifold of PEM Fuel Cell Stack
,”
J. Power Sources
,
173
(
1
), pp.
249
263
.
13.
Mohan
,
G.
,
Roa
,
B. P.
,
Das
,
S. K.
,
Pandiyan
,
S.
,
Rajalakshmi
,
N.
, and
Dhathathreyan
,
K. S.
, 2004, “
Analysis of Flow Mal-Distribution of Fuel and Oxidant in a PEMFC
,”
ASME J. Energy Resour. Technol.
,
126
, pp.
262
270
.
14.
Kapadia
,
S.
, and
Anderson
,
W. K.
, 2009, “
Sensitivity Analysis for Solid Oxide Fuel Cells Using a Three-Dimensional Numerical Model
,”
J. Power Sources
,
189
(
2
), pp.
1074
1082
.
15.
Boersma
,
R. J.
, and
Sammes
,
N. M.
, 1996, “
Computational Analysis of the Gas Flow Distribution in Solid Oxide Fuel Cell Stacks
,”
J. Power Sources
,
63
(
2
), pp.
215
219
.
16.
Chang
,
P. A. C.
,
St-Pierre
,
J.
,
Stumper
,
J.
, and
Wetton
,
B.
, 2006, “
Flow Distribution in Proton Exchange Membrane Fuel Cell Stacks
,”
J. Power Sources
,
162
, pp.
340
355
.
17.
Koh
,
J. H.
,
Seo
,
H. K.
,
Lee
,
C. G.
,
Yoo
,
Y. S.
, and
Lim
,
H. C.
, 2003, “
Pressure and Flow Distribution in Internal Gas Manifolds of a Fuel Cell Stack
,”
J. Power Sources
,
115
, pp.
54
65
.
18.
Kee
,
R. J.
,
Korada
,
P.
,
Walters
,
K.
, and
Pavol
,
M.
, 2002, “
A Generalized Model of the Flow Distribution in Channel Networks of Planar Fuel Cells
,”
J. Power Sources
,
109
, pp.
148
159
.
19.
Maharudrayya
,
S.
,
Jayanti
,
S.
, and
Deshpande
,
A. P.
, 2005, “
Flow Distribution and Pressure Drop in Parallel-Channel Configurations of Planar Fuel Cells
,”
J. Power Sources
,
144
, pp.
94
106
.
20.
Junye
,
W.
, 2008, “
Pressure Drop and Flow Distribution in Parallel-Channel Configurations of Fuel Cells: U-Type Arrangement
,”
Int. J. Hydrogen Energy
,
33
, pp.
6339
6350
.
21.
Junye
,
W.
, 2010, “
Pressure Drop and Flow Distribution in Parallel-Channel Configurations of Fuel Cells: Z-Type Arrangement
,”
Int. J. Hydrogen Energy
,
35
, pp.
5498
5509
.
22.
Viswanathan
,
R.
, 1995,
Damage Mechanisms and Life Assessment of High-Temperature Components
,
3rd ed.
,
ASM International
,
Metals Park, OH
, Chaps. 3–5.
23.
Poursaeidi
,
E.
, and
Alimadadi
,
M.
, 2008, “
Utilizing the Monte Carlo Simulation in Life Evaluation of Superheater Tubes
,” ICME, Johr Bahru, Malaysia 21–33 May.
24.
Poursaeidi
,
E.
, 2006, “
Remaining Life Evaluation of Boiler and Turbine Critical Components of Shahid Rajaee Powerplant- Unit 1 (report for the Shahid Rajaee powerplant)
,” Shahid Rajaee Powerplant, Archives, Qazvin, Iran.
25.
Versteeg
,
H. K.
and
Malalasekera
,
W.
, 1995,
An Introduction to Computational Fluid Dynamics the Finite Volume Method
,
Pearson Education Limited
,
Harlow, England
.
26.
Launder
,
B. E.
, and
Spalding
,
D. B.
, 1972,
Lectures in Mathematical Models of Turbulence
,
Academic Press
,
London, UK
.
27.
Siegel
,
R.
, and
Howell
,
J. R.
, 1992,
Thermal Radiation Heat Transfer
,
Hemisphere Publication
,
Washington DC
.
28.
FLUENT. Fluent Inc.
, 2007, FLUENT 6.3.26 User Manual.
29.
Swamee
,
P. K.
, and
Jain
,
A. K.
, 1976, “
Explicit Equations for Pipe-Flow Problems
,”
J. Hydraulics Div.
,
102
(
5
), pp.
657
664
.
30.
Niroo Research, Metallurgical and Chemical Center, Fuel and Oil Lab
, 2006, Report No. CF850084, Iran.
31.
Crowe
,
C.
,
Sommerfield
,
M.
, and
Tsuji
,
Y.
, 1998,
Multiphase Flows with Droplets and Particles
,
CRC Press
,
Boca Raton, FL
.
You do not currently have access to this content.