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Research Papers: Fuel Combustion

The Impact of Predried Lignite Cofiring With Hard Coal in an Industrial Scale Pulverized Coal Fired Boiler

[+] Author and Article Information
Halina Pawlak-Kruczek

Department of Boilers,
Combustion and Energy Processes,
Faculty of Mechanical and Power Engineering,
Wroclaw University of Science and Technology,
27 Wybrzeze Wyspianskiego,
Wroclaw 50-370, Poland
e-mail: halina.pawlak@pwr.edu.pl

Robert Lewtak

Institute of Power Engineering,
Department of Thermal Processes,
Augustowka 36,
Warsaw 02-981, Poland
e-mail: robert.lewtak@ien.com.pl

Zbigniew Plutecki

Faculty of Production Engineering and Logistics,
Opole University of Technology,
ul. Ozimska 75,
Opole 45-370, Poland
e-mail: z.plutecki@po.opole.pl

Marcin Baranowski

Department of Boilers,
Combustion and Energy Processes,
Faculty of Mechanical and Power Engineering,
Wroclaw University of Science and Technology,
27 Wybrzeze Wyspianskiego,
Wroclaw 50-370, Poland
e-mail: marcin.baranowski@pwr.edu.pl

Michal Ostrycharczyk

Department of Boilers,
Combustion and Energy Processes,
Faculty of Mechanical and Power Engineering,
Wroclaw University of Science and Technology,
27 Wybrzeze Wyspianskiego,
Wroclaw 50-370, Poland
e-mail: michal.ostrycharczyk@pwr.edu.pl

Krystian Krochmalny

Department of Boilers,
Combustion and Energy Processes,
Faculty of Mechanical and Power Engineering,
Wroclaw University of Science and Technology,
27 Wybrzeze Wyspianskiego,
Wroclaw 50-370, Poland
e-mail: krystian.krochmalny@pwr.edu.pl

Michal Czerep

Department of Boilers,
Combustion and Energy Processes,
Faculty of Mechanical and Power Engineering,
Wroclaw University of Science and Technology,
27 Wybrzeze Wyspianskiego,
Wroclaw 50-370, Poland
e-mail: michal.czerep@pwr.edu.pl

Jacek Zgora

Department of Boilers,
Combustion and Energy Processes,
Faculty of Mechanical and Power Engineering,
Wroclaw University of Science and Technology,
27 Wybrzeze Wyspianskiego,
Wroclaw 50-370, Poland
e-mail: jacek.zgora@pwr.edu.pl

Lukasz Niedzwiecki

Department of Boilers,
Combustion and Energy Processes,
Faculty of Mechanical and Power Engineering,
Wroclaw University of Science and Technology,
27 Wybrzeze Wyspianskiego,
Wroclaw 50-370, Poland
e-mail: lukasz.niedzwiecki@pwr.edu.pl

1Corresponding author.

Contributed by the Advanced Energy Systems Division of ASME for publication in the JOURNAL OF ENERGY RESOURCES TECHNOLOGY. Manuscript received August 15, 2017; final manuscript received March 30, 2018; published online May 7, 2018. Assoc. Editor: Ronald Breault.

J. Energy Resour. Technol 140(6), 062207 (May 07, 2018) (14 pages) Paper No: JERT-17-1439; doi: 10.1115/1.4039907 History: Received August 15, 2017; Revised March 30, 2018

The paper presents the experimental and numerical study on the behavior and performance of an industrial scale boiler during combustion of pulverized bituminous coal with various shares of predried lignite. The experimental measurements were carried out on a boiler WP120 located in CHP, Opole, Poland. Tests on the boiler were performed during low load operation and the lignite share reached over to 36% by mass. The predried lignite, kept in dedicated separate bunkers, was mixed with bituminous coal just before the coal mills. Computational fluid dynamic (CFD) simulation of a cofiring scenario of lignite with hard coal was also performed. Site measurements have proven that cofiring of a predried lignite is not detrimental to the boiler in terms of its overall efficiency, when compared with a corresponding reference case, with 100% of hard coal. Experiments demonstrated an improvement in the grindability that can be achieved during co-milling of lignite and hard coal in the same mill, for both wet and dry lignite. Moreover, performed tests delivered empirical evidence of the potential of lignite to decrease NOx emissions during cofiring, for both wet and dry lignite. Results of efficiency calculations and temperature measurements in the combustion chamber confirmed the need to predry lignite before cofiring. Performed measurements of temperature distribution in the combustion chamber confirmed trend that could be seen in the results of CFD. CFD simulations were performed for predried lignite and demonstrated flow patterns in the combustion chamber of the boiler, which could prove useful in case of any further improvements in the firing system. CFD simulations reached satisfactory agreement with the site measurements in terms of the prediction of emissions.

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References

Weigl, K. , Schuster, G. , Stamatelopoulos, G. N. , and Friedl, A. , 1999, “Increasing Power Plant Efficiency by Fuel Drying,” Comput. Chem. Eng., 23(Suppl. 1), pp. S919–S922. [CrossRef]
Reid, I. A. B. , 2016, Retrofitting Lignite Plants to Improve Efficiency Performance, IEA Clean Coal Centre, London.
Xu, C. , Xu, G. , Zhao, S. , Dong, W. , Zhou, L. , and Yang, Y. , 2016, “A Theoretical Investigation of Energy Efficiency Improvement by Coal Pre-Drying in Coal Fired Power Plants,” Energy Convers Manage., 122, pp. 580–588. [CrossRef]
Xu, C. , Xu, G. , Zhu, M. , Dong, W. , Zhang, Y. , Yang, Y. , and Zhang, D. , 2016, “Thermodynamic Analysis and Economic Evaluation of a 1000 MW Bituminous Coal Fired Power Plant Incorporating Low-Temperature Pre-Drying (LTPD),” Appl. Therm. Eng., 96, pp. 613–622. [CrossRef]
Pawlak-Kruczek, H. , 2017, Low-Rank Coals Power Generation, Fuel and Chemical Production, Woodhead Publishing, Cambridge, UK, pp. 23–40. [CrossRef]
Nikolopoulos, N. , Violidakis, I. , Karampinis, E. , Agraniotis, M. , Bergins, C. , Grammelis, P. , and Kakaras, E. , 2015, “Report on Comparison Among Current Industrial Scale Lignite Drying Technologies (A Critical Review of Current Technologies),” Fuel, 155, pp. 86–114. [CrossRef]
Karthikeyan, M. , Zhonghua, W. , and Mujumdar, A. S. , 2009, “Low-Rank Coal Drying Technologies—Current Status and New Developments,” Dry Technol., 27(3), pp. 403–415. [CrossRef]
Xu, C. , Bai, P. , Xin, T. , Hu, Y. , Xu, G. , and Yang, Y. , 2017, “A Novel Solar Energy Integrated Low-Rank Coal Fired Power Generation Using Coal Pre-Drying and an Absorption Heat Pump,” Appl. Energy, 200, pp. 170–179. [CrossRef]
Xu, C. , Xu, G. , Zhao, S. , Zhou, L. , Yang, Y. , and Zhang, D. , 2015, “An Improved Configuration of Lignite Pre-Drying Using a Supplementary Steam Cycle in a Lignite Fired Supercritical Power Plant,” Appl. Energy, 160, pp. 882–891. [CrossRef]
Atsonios, K. , Violidakis, I. , Agraniotis, M. , Grammelis, P. , Nikolopoulos, N. , and Kakaras, E. , 2015, “Thermodynamic Analysis and Comparison of Retrofitting Pre-Drying Concepts at Existing Lignite Power Plants,” Appl. Therm. Eng., 74, pp. 165–173. [CrossRef]
Han, X. , Yan, J. , Karellas, S. , Liu, M. , Kakaras, E. , and Xiao, F. , 2017, “Water Extraction From High Moisture Lignite by Means of Efficient Integration of Waste Heat and Water Recovery Technologies With Flue Gas Pre-Drying System,” Appl. Therm. Eng., 110, pp. 442–456. [CrossRef]
Xu, C. , Xu, G. , Yang, Y. , Zhao, S. , Zhang, K. , and Zhang, D. , 2015, “An Improved Configuration of Low-Temperature Pre-Drying Using Waste Heat Integrated in an Air-Cooled Lignite Fired Power Plant,” Appl. Therm. Eng., 90, pp. 312–321. [CrossRef]
Han, X. , Liu, M. , Wu, K. , Chen, W. , Xiao, F. , and Yan, J. , 2016, “Exergy Analysis of the Flue Gas Pre-Dried Lignite-Fired Power System Based on the Boiler With Open Pulverizing System,” Energy, 106, pp. 285–300. [CrossRef]
Xu, C. , Xu, G. , Fang, Y. , Zhou, L. , Yang, Y. , and Zhang, D. , 2014, “A Novel Lignite Pre-Drying System Incorporating a Supplementary Steam Cycle Integrated With a Lignite Fired Supercritical Power Plant,” Energy Procedia, 61, pp. 1360–1363. [CrossRef]
Wang, J. , Fan, W. , Li, Y. , Xiao, M. , Wang, K. , and Ren, P. , 2012, “The Effect of Air Staged Combustion on NOx Emissions in Dried Lignite Combustion,” Energy, 37(1), pp. 725–736. [CrossRef]
Han, X. , Liu, M. , Zhai, M. , Chong, D. , Yan, J. , and Xiao, F. , 2015, “Investigation on the Off-Design Performances of Flue Gas Pre-Dried Lignite-Fired Power System Integrated With Waste Heat Recovery at Variable External Working Conditions,” Energy, 90(Pt. 2), pp. 1743–1758. [CrossRef]
Agraniotis, M. , Koumanakos, A. , Doukelis, A. , Karellas, S. , and Kakaras, E. , 2012, “Investigation of Technical and Economic Aspects of Pre-Dried Lignite Utilisation in a Modern Lignite Power Plant Towards Zero CO2 Emissions,” Energy, 45(1), pp. 134–141. [CrossRef]
Atsonios, K. , Violidakis, I. , Sfetsioris, K. , Rakopoulos, D. C. , Grammelis, P. , and Kakaras, E. , 2016, “Pre-Dried Lignite Technology Implementation in Partial Load/Low Demand Cases for Flexibility Enhancement,” Energy, 96, pp. 427–436. [CrossRef]
Agraniotis, M. , Stamatis, D. , Grammelis, P. , and Kakaras, E. , 2010, “Dry Lignite Cofiring in a Greek Utility Boiler: Experimental Activities and Numerical Simulations,” Energy Fuels, 24(10), pp. 5464–5473. [CrossRef]
Agraniotis, M. , Stamatis, D. , Grammelis, P. , and Kakaras, E. , 2009, “Numerical Investigation on the Combustion Behaviour of Pre-Dried Greek Lignite,” Fuel, 88(12), pp. 2385–2391. [CrossRef]
Drosatos, P. , Nikolopoulos, N. , Nikolopoulos, A. , Papapavlou, C. , Grammelis, P. , and Kakaras, E. , 2017, “Numerical Examination of an Operationally Flexible Lignite-Fired Boiler Including Its Convective Section Using as Supporting Fuel Pre-Dried Lignite,” Fuel Process Technol., 166, pp. 237–257. [CrossRef]
Drosatos, P. , Nikolopoulos, N. , Agraniotis, M. , and Kakaras, E. , 2016, “Numerical Investigation of Firing Concepts for a Flexible Greek Lignite-Fired Power Plant,” Fuel Process Technol., 142, pp. 370–395. [CrossRef]
Agraniotis, M. , Grammelis, P. , Papapavlou, C. , and Kakaras, E. , 2009, “Experimental Investigation on the Combustion Behaviour of Pre-Dried Greek Lignite,” Fuel Process Technol., 90(9), pp. 1071–1079. [CrossRef]
Lewtak, R. , Pawlak-Kruczek, H. , and Ostrycharczyk, M. , 2015, “Experimental and Numerical Study of Pulverized Lignite Combustion in Air and Oxy-Fuel Conditions—Part1: Experimental Setup and the Mathematical Model,” 40th International Technical Conference on Clean Coal and Fuel Systems, Clearwater, FL, May 31–June 4, pp. 241–253.
Pawlak-Kruczek, H. , Lewtak, R. , and Ostrycharczyk, M. , 2015, “Experimental and Numerical Study of Pulverized Lignite Combustion in Air and Oxy-Fuel Conditions. Part 2: Experimental and Numerical Results,” 40th International Technical Conference on Clean Coal and Fuel Systems, Clearwater, FL, May 31–June 4, pp. 254–265.
Zhao, H. , Geng, X. , Yu, J. , Xin, B. , Yin, F. , and Tahmasebi, A. , 2016, “Effects of Drying Method on Self-Heating Behavior of Lignite During Low-Temperature Oxidation,” Fuel Process Technol., 151, pp. 11–18. [CrossRef]
PKN, 2002, “Paliwa stałe - Oznaczanie zawartości popiołu metodą wagową,” Polski Komitet Normalizacyjny, Warsaw, Poland, Standard No. PN-G-04512:1980/Az1:2002.
ISO, 2009, “Solid Mineral Fuels—Determination of Gross Calorific Value by the Bomb Calorimetric Method and Calculation of Net Calorific Value,” International Organization for Standardization, Geneva, Switzerland, Standard No. ISO 1928:2009 https://www.iso.org/standard/41592.html.
PKN, 2007, “Paliwa stałe—Oznaczanie całkowitego węgla, wodoru i azotu—Metody instrumentalne,” Polski Komitet Normalizacyjny, Warsaw, Poland, Standard No. PKN-ISO/TS 12902:2007.
PKN, 2000, “Sita kontrolne—Wymagania techniczne i badania—Sita kontrolne z tkaniny z drutu,” Polski Komitet Normalizacyjny, Warsaw, Poland, Standard No. PN-ISO 3310-1:2000.
Pronobis, M. , 2005, “Evaluation of the Influence of Biomass Co-Combustion on Boiler Furnace Slagging by Means of Fusibility Correlations,” Biomass Bioenergy, 28(4), pp. 375–383. [CrossRef]
BSI, 1987, “Methods for Assessing Thermal Performance of Boilers for Steam, Hot Water and High Temperature Heat Transfer Fluids—Part 1: Concise Procedure,” British Standards Institute, London, Standard No. BS 845-1:1987. https://shop.bsigroup.com/ProductDetail/?pid=000000000000923110
CEN (European Committee for Standardisation), 2003, “Shell Boilers—Part 11: Acceptance Tests,” British Standards Institute, London, Standard No. BS EN 12953-11:2003. https://shop.bsigroup.com/ProductDetail/?pid=000000000030011361
CEN (European Comitte for Standardisation), 2003, “Water-Tube Boilers and Auxiliary Installations—Part 15: Acceptance Tests,” British Standards Institute, London, Standard No. BS EN 12952-15:2003. https://shop.bsigroup.com/ProductDetail/?pid=000000000030011352
Baum, M. M. , and Street, P. J. , 1971, “Predicting the Combustion Behaviour of Coal Particles,” Sci. Technol., 3(5), pp. 231–243.
Magnussen, B. F. , and Hjertager, B. H. , 1977, “On Mathematical Modeling of Turbulent Combustion With Special Emphasis on Soot Formation and Combustion,” Symp. Combust., 16(1), pp. 719–729. [CrossRef]
Rokni, E. , Hsein Chi, H. , and Levendis, Y. A. , 2017, “In-Furnace Sulfur Capture by Cofiring Coal With Alkali-Based Sorbents,” ASME J. Energy Resour. Technol., 139(4), p. 042204. [CrossRef]

Figures

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Fig. 1

The feeding system of the WP 120 boiler with adjustments for the addition of lignite

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Fig. 2

Fuel hopper arrangement of the feeding systems for the WP 120 boiler

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Fig. 3

Firing arrangement for WP120 boiler (after an upgrade to Low NOx burners)

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Fig. 4

The heating load for the WP 120 boiler during the heating season corresponding with the performed suite of tests

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Fig. 5

Measurement and sampling points at the WP120 boiler

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Fig. 6

Sampling points on the pulverized coal ducting (three-dimensional diagram of the boiler)

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Fig. 7

Geometric model of the WP-120 boiler applied in numerical simulations

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Fig. 8

Temperature distribution over the central, horizontal axis, parallel to the front wall of the boiler (height equal to the height of auxiliary oil burners)

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Fig. 9

Particle size distribution for reference and cofiring test using wet and predried lignite; weighted averages for all four corners at two levels for each test

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Fig. 10

Emissions of NO, SO2, and CO from the boiler, during reference tests and cofiring test with dry and wet lignite

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Fig. 11

PM emissions during reference tests and cofiring test with dry and wet lignite (measured at the stack)

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Fig. 12

Unburned combustibles in fly ash and bottom ash for reference and coburning test with the use of wet and dry lignite

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Fig. 13

Selected numerical results describing the combustion process of 100% bituminous coal in the WP120 boiler at the thermal power of 55 MW: (a) velocity, m/s, (b) temperature, °C, (c) O2 mole fraction, %, (d) CO mole fraction, ppm, (e) NOx emission, mg/m3n 6% O2 dry, and (f) selected particle trajectories colored by temperature, °C

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Fig. 14

Selected numerical results describing the combustion process of bituminous coal (85%m) and lignite in the WP120 boiler at the thermal power of 58 MW: (a) velocity, m/s, (b) temperature, °C, (c) O2 mole fraction, %, (d) CO mole fraction, ppm, (e) NOx emission, mg/m3n 6% O2 dry, and (f) selected particle trajectories colored by temperature, °C

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