The paper presents the method of fouling degree evaluation of the heating surfaces in pulverized coal-fired boiler during coal combustion and biomass co-combustion. The fouling processes have a negative impact on the boiler operation by reducing the steam outlet temperature, increasing the mass flow rate of cooling spray water, and may be the reason for overheating of the superheater (SH) tube material. This leads to a reduction of the boiler efficiency and can cause shortening of a lifetime as well as damage of boiler heat exchangers, in particular, the steam SH. The basis of fouling degree assessment method are the dimensionless coefficients, which represent current values of heat absorbed by an individual heat exchanger in comparison to the value for a clean surface. The coefficients are determined based on the calculated heat power of individual heat exchanger taking into account the adjustment resulting from the flue gas temperature inside a combustion chamber. The results of the analysis showed a significant reduction of the amount of heat absorbed by the convection SH during continuous boiler operation. The next important conclusion is a large increase of the heat amount transferred to the radiant SH, which may result in exceeding the permissible temperature of the tube material. The proposed method together with on-line monitoring system installed on the boiler is used to calculate the fouling degree of individual heating surfaces. Accurate monitoring of boiler heating surface conditions can be used to optimize soot blowers operation and finally to improve process efficiency.

References

1.
Buhre
,
B. J. P.
,
Hinkley
,
J. T.
,
Gupta
,
R. P.
,
Nelson
,
P. F.
, and
Wall
,
T. F.
,
2006
, “
Fine Ash Formation During Combustion of Pulverized Coal–Coal Property Impacts
,”
Fuel
,
85
(2), pp.
185
193
.
2.
Mishra
,
V.
,
Bhowmick
,
T.
,
Chakravarty
,
S.
,
Kumar Varma
,
A.
, and
Sharma
,
M.
,
2016
, “
Influence of Coal Quality on Combustion Behaviour and Mineral Phases Transformations
,”
Fuel
,
186
, pp.
443
455
.
3.
Tomeczek
,
J.
, and
Palugniok
,
H.
,
2002
, “
Kinetics of Mineral Matter Transformation During Coal Combustion
,”
Fuel
,
81
(
10
), pp.
1251
1258
.
4.
Van Dyk
,
J. C.
,
Benson
,
S. A.
,
Laumb
,
M. L.
, and
Waanders
,
B.
,
2009
, “
Coal and Coal Ash Characteristics to Understand Mineral Transformations and Slag Formation
,”
Fuel
,
88
(
6
), pp.
1057
1063
.
5.
Wee
,
H. L.
,
Wu
,
H.
,
Zhang
,
D.-K.
, and
French
,
D.
,
2005
, “
The Effect of Combustion Conditions on Mineral Matter Transformation and Ash Deposition in a Utility Boiler Fired With a Sub-Bituminous Coal
,”
Combust. Inst
,
30
(
2
), pp.
2981
2989
.
6.
Panagiotidis
,
I.
,
Vafiadis
,
K.
,
Tourlidakis
,
A.
, and
Tomboulides
,
A.
,
2015
, “
Study of Slagging and Fouling Mechanisms in a Lignite-Fired Power Plant
,”
Appl. Therm. Eng.
,
74
, pp.
156
164
.
7.
Vassilev
,
S.
,
Baxter
,
D.
, and
Vassileva
,
C.
,
2013
, “
An Overview of the Behaviour of Biomass During Combustion—Part I: Phase-Mineral Transformations of Organic and Inorganic Matter
,”
Fuel
,
112
, pp.
391
449
.
8.
Pronobis
,
M.
,
2006
, “
The Influence of Biomass Co-Combustion on Boiler Fouling and Efficiency
,”
Fuel
,
85
(
4
), pp.
474
480
.
9.
Lundmark
,
D.
,
Mueller
,
C.
,
Backman
,
R.
,
Zevenhoven
,
M.
,
Skrifvars
,
B.-J.
, and
Hupa
,
M.
,
2010
, “
CFD Based Ash Deposition Prediction in a BFBC Firing Mixtures of Peat and Forest Residue
,”
ASME J. Energy Resour. Technol.
,
132
(
3
), p.
031003
.
10.
Modliński
,
N.
,
2014
, “
Computational Modeling of a Tangentially Fired Boiler With Deposit Formation Phenomena
,”
Chem. Process Eng.
,
35
(
3), pp. 361–368
.
11.
Balakrishnan
,
S.
,
Nagarajan
,
R.
, and
Karthick
,
K.
,
2014
, “
Mechanistic Modeling, Numerical Simulation and Validation of Slag-Layer Growth in a Coal-Fired Boiler
,”
Energy
,
81
, pp.
462
470
.
12.
Vessakosol
,
P.
, and
Charoensuk
,
J.
,
2010
, “
Numerical Analysis of Heat Transfer and Flow Field Around Cross-Flow Heat Exchanger Tube With Fouling
,”
Appl. Therm. Eng.
,
30
(10), pp.
1170
1178
.
13.
Trojan
,
M.
, and
Taler
,
D.
, 2015, “
Thermal Simulation of Superheaters Taking Into Account the Processes Occurring on the Side of the Steam and Flue Gas
,”
Fuel
,
150
(10), pp.
75
87
.
14.
Madejski
,
P.
,
Taler
,
D.
, and
Taler
,
J.
,
2016
, “
Numerical Model of a Steam Superheater With a Complex Shape of the Tube Cross Section Using Control Volume Based Finite Element Method
,”
Energy Convers. Manage.
,
118
, pp.
179
192
.
15.
Shi
,
Y.
,
Wang
,
J.
, and
Liu
,
Z.
,
2015
, “
On-Line Monitoring of Ash Fouling and Soot-Blowing Optimization for Convective Heat Exchanger in Coal-Fired Power Plant Boiler
,”
App. Therm. Eng.
,
78
, pp.
39
50
.
16.
Kalisz
,
S.
, and
Pronobis
,
M.
,
2005
, “
Investigations on Fouling Rate in Convective Bundles of Coal-Fired Boilers in Relation to Optimization of Sootblower Operation
,”
Fuel
,
84
(
7–8
), pp.
927
937
.
17.
Pena
,
B.
,
Teruel
,
E.
, and
Diez
,
L. I.
,
2013
, “
Towards Soot-Blowing Optimization in Superheaters
,”
App. Therm. Eng.
,
61
(2), pp.
737
746
.
18.
Sheikh
,
A. K.
,
Zubair
,
S. M.
,
Haq
,
M. U.
, and
Budair
,
M. O.
,
1996
, “
Reliability-Based Maintenance Strategies for Heat Exchangers Subject to Fouling
,”
ASME J. Energy Resour. Technol.
,
118
(
4
), pp.
306
312
.
19.
Sciubba
,
E.
, and
Zeoli
,
N.
,
2006
, “
A Study of Sootblower Erosion in Waste-Incinerating Heat Boilers
,”
ASME J. Energy Resour. Technol.
,
129
(
1
), pp.
50
53
.
20.
Madejski
,
P.
, and
Taler
,
D.
,
2013
, “
Analysis of Temperature and Stress Distribution of Superheater Tubes After Attemperation or Sootblower Activation
,”
Energy Convers. Manage.
,
71
, pp.
131
137
.
21.
Benato
,
A.
,
Stoppato
,
A.
,
Mirandola
,
A.
,
Destro
,
N.
, and
Bracco
,
S.
,
2016
, “
Superheater and Drum Lifetime Estimation: An Approach Based on Dynamic Analysis
,”
ASME J. Energy Resour. Technol.
,
139
(
3
), p.
031001
.
22.
Taler
,
J.
,
Trojan
,
M.
, and
Taler
,
D.
,
2012
,
Monitoring of Ash Fouling and Internal Scale Deposits in Pulverized Coal Fired Boilers
,
Nova Science Publishers
,
New York
, Chap. 1.
23.
Zhang
,
S.
,
Shen
,
G.
,
An
,
L.
, and
Li
,
G.
,
2015
, “
Ash Fouling Monitoring Based on Acoustic Pyrometry in Boiler Furnaces
,”
App. Therm. Eng.
,
84
, pp.
74
81
.
24.
Valero
,
A.
, and
Cortes
,
C.
,
1996
, “
Ash Fouling in Coal-Fired Utility Boilers. Monitoring and Optimization of On-Load Cleaning
,”
Prog. Energy Combust. Sci.
,
22
(2), pp.
189
200
.
25.
Taler
,
J.
,
Wᆚglowski
,
B.
,
Taler
,
D.
,
Trojan
,
M.
,
Sobota
,
T.
,
Dzierwa
,
P.
,
Pilarczyk
,
M.
,
Madejski
,
P.
, and
Nabagło
,
D.
,
2015
, “
Method of Determination of Thermo-Flow Parameters for Steam Boiler
,”
J. Power Technol.
,
95
(
4
), pp.
309
316
.
26.
Torres
,
C.
,
Valero
,
A.
,
Serra
,
L.
, and
Royo
,
J.
,
2002
, “
Structural Theory and Thermoeconomic Diagnosis—Part I: On Malfunction and Dysfunction Analysis
,”
Energy Convers. Manage.
,
43
(9–12), pp. 1503–1518.
27.
Verda
,
V.
,
Serra
,
L.
, and
Valero
,
A.
,
2005
, “
Thermoeconomic Diagnosis: Zooming Strategy Applied to Highly Complex Energy Systems—Part 1: Detection and Localization of Anomalies
,”
ASME J. Energy Resour. Technol.
,
127
(
1
), pp.
42
49
.
28.
Saravanamuttoo
,
H. I. H.
, and
MacIsaac
,
B. D.
,
1983
, “
Thermodynamic Models for Pipeline Gas Turbine Diagnostics
,”
ASME J. Eng. Power
,
105
(4), pp.
875
884
.
29.
Stamatis
,
A.
,
Mathioudakis
,
K.
, and
Papailiou
,
K. D.
,
1990
, “
Adaptive Simulation of Gas Turbine Performance
,”
ASME J. Eng. Gas Turbines Power
,
112
(2), pp.
168
175
.
30.
Verda
,
V.
,
2006
, “
Accuracy Level in Thermoeconomic Diagnosis of Energy Systems
,”
Energy
,
31
(15), pp.
3248
3260
.
31.
López
,
C.
,
Unterberger
,
S.
,
Maier
,
J.
, and
Hein
,
K. R. G.
,
2003
, “
Overview of Actual Methods for Characterization of Ash Deposition
,”
ECI Heat Exchanger Fouling and Cleaning: Fundamentals and Applications
, Santa Fe, NM, May 18–22, pp. 279–290.
32.
Kline
,
S. J.
, and
McClintock
,
F. A.
,
1953
, “
Describing Uncertainties in Single-Sample Experiment
,”
Mech. Eng.
,
75
(1), pp.
3
8
.
33.
Kim
,
J. H.
,
Simon
,
T. W.
, and
Viskanta
,
R.
,
1993
, “
Transfer Policy on Reporting Uncertainties in Experimental Measurements and Results
,”
ASME J. Heat Transfer.
,
115
(1), pp. 5–6.
34.
Coleman
,
H. W.
, and
Steele
,
W. G.
,
2009
,
Experimentation, Validation, and Uncertainty Analysis for Engineers
, 3rd ed.,
Wiley
,
Hoboken, NJ
.
35.
Taler
,
J.
,
Taler
,
D.
, and
Ludowski
,
P.
,
2014
, “
Measurements of Local Heat Flux to Membrane Water Walls of Combustion Chambers
,”
Fuel
,
115
, pp.
70
83
.
You do not currently have access to this content.