Guangxi Vue Hai Zhang Changsui Zhao Zhongyang Luo Proceedings of the 20th International Conference on Fluidized Bed Combustion Guangxi Vue Hai Zhang Changsui Zhao Zhongyang Luo Proceedings of the 20th International Conference on Fluidized Bed Combustion With 1280 figures (~ TSINGHUA ~ UN IVERSITY PRESS ~ Springer Editors Guangxi Vue HaiZhang Department ofThennal Engineering Department ofThennal Engineering Tsinghua University Tsinghua University Beijing, 100084, China Beijing, 100084, China Email: ygx-dte@tsinghua.edu.cn Email: haizhang@tsinghua.edu.cn Changsui Zhao Zhongyang Luo School of Energy and Environment Institute for Thermal Power Engineering Southeast University Zhejiang University Nanjing, 210096, China Hangzhou, 310027, China Email: cszhao@seu.edu.cn Email: zyluo@cmee.zju.edu.cn ISBN 978-7-302-20146-5 Tsinghua University Press, Beijing ISBN 978-3-642-02681-2 Springer Dordrecht Heidelberg London New York e-ISBN 978-3-642-02682-9 Library of Congress Control Number : pending © 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acid-free paper Springer is a part of Springer Science+Business Media (www.springer.com) PREFACE The proceedings of the 20th International Conference on Fluidized Bed Combustion (FBC) collect plenary lectures and 175 peer-reviewed technical papers presented in the conference held in Xi'an China in May 18-21,2009 The conference was the 20th conference in a series, covering the latest fundamental research results, as well as the application experience from pilot plants, demonstrations and industrial units regarding to the FBC science and technology It was co-hosted by Tsinghua University, Southeast University, Zhejiang University, China Electricity Council and Chinese Machinery Industry Federation A particular feature of the proceedings is the balance between the papers submitted by experts from industry and the papers submitted by academic researchers, aiming to bring academic knowledge to application as well as to define new areas for research The authors of the proceedings are the most active researchers, technology developers, experienced and representative facility operators and manufacturers They presented the latest research results, state-of-the-art development and projects, and the useful experience The proceedings are divided into following sections: • CFB Boiler Technology, Operation and Design • Fundamental Research on Fluidization and Fluidized Combustion C02 Capture and Chemical Looping • • Gasification • Modeling and Simulation on FBC Technology • Environments and Pollutant Control • Sustainable Fuels The proceedings can be served as idea references for researchers, engineers, academia and graduate students, plant operators, boiler manufacturers, component suppliers, and technical managers who work on FBC fundamental research, technology development and industrial application The editors would like to take this opportunity to thank our FBC colleagues around the world who devoted much of their time to review the manuscripts to keep the scientific standard of the proceedings Xi' an, China May 2009 GuangxiYUE HaiZHANG Changsui ZHAO Zhongyang LUO II Proceedings ofthe 20th International Conference on Fluidized Bed Combustion Steering Committee Members: Anthony, J Edward Basu, Prabir Bonk, L Donald Bulewicz, M Elzbieta Cabanillas, Andres Chen, Hanping Chyang, Chien-Song DeLallo, R Michael Grace, John Gulyurtlu, Ibrahim Horio, Masayuki Hotta, Arto Hrdlicka, Frantisek Hupa,Mikko Jaud, Philippe Jia, Lufei Kim, Sang Done Leckner,Bo Luo, Zhongyang Maryamchik, Mikhail Miccio, Michele Mustonen, John Newby, A Richard Nowak Wojciech Pham, Hoang Luong Preto, Fernando Rozelle, Peter Rubow, N Lynn Selcuk, Nevin Skowyra, Richard Wedel, von George Werther, Joachim Wietzke, L Donald Winter, Franz Yue, Guangxi Zhao, Changsui CETC-O,Natural Resources, Canada Dalhousie University, Canada National Energy Technology Laboratory, USA Cracow University of Technology, Poland CIEMAT, Spain Huazhong Science and Technology University, China Chung Yuan Christian University, Taiwan, China Parsons Infrastructure & Technology Group,Inc., USA University of British Columbia, Canada INET!, Portugal Tokyo University of Agriculture & Technology, Japan Foster Wheeler Power Group, Inc., Finland CVUT Prague, Czech Republic Abo Akademi University, Finland R&D Division EDF, France CETC-O,Natural Resources, Canada Korea Advanced Institute of Science and Technology, South Korea Chalmers University of Technology, Sweden ZhejiangUniversity, China Babcock & Wilcox, USA University of Salerno, Italy Stone & Webster Consultants, USA Siemens-Westinghouse Power Corp., USA Czestochowa University of Technology ,Poland Hanoi Univeristy of Technology, Vietnam CETC-O,Natural Resources, Canada Department of Energy, USA Parsons Energy and Chemicals Group, USA Middle East Technical University, Turkey Alstom Power, USA Lurgi Energie und Entsorgung, Germany Technical University Hamburg-Harburg, Germany Babcock & Wilcock Company, USA Vienna University of Technology, Austria Tsinghua University, China Southeast University, China Sponsors China National Machinery & Equipment Import & Export Corporation China Power Investment Corporation Dongfang Electric Corporation Foster Wheeler Corporation Harbin Electric Corporation Shanghai Electric Corporation Qingdao Songling Equipment Co., Ltd Power Environmental Taiyuan Boiler Works Wuxi Boiler Works Yixin High Alumina Bricks Company National Nature Science Foundation of China CONTENTS Keynotes LATEST DEVELOPMENT OF CFB BOILERS IN ClllNA G X Yue, H R Yang, J F Lu, H Zhang GASIFICATION OF BIOMASS IN FLUIDISED BED: REVIEW OF MODELLING A G6mez-Barea, B Leckner 13 POTENTIALS OF BIOMASS CO-COMBUSTION IN COAL-FIRED BOILERS J Werther 27 Formation and Reduction of Pollutants in CFBC: From Heavy Metals, Particulates, Alkali, NOx, N 20 , SOx, HC1 Franz Winter 43 LATEST EVOLUTION OF OXY-FUEL COMBUSTION TECHNOLOGY IN CIRCULATING FLUIDIZED BED C S Zhao, L B Duan, X P Chen, C Liang 49 FOSTER WHEELER'S SOLUTIONS FOR LARGE SCALE CFB BOILER TECHNOLOGY: FEATURES AND OPERATIONAL PERFORMANCE OF LAGISZA 460 MWe CFB BOILER Arto Hotta 59 FLUIDIZED COMBUSTION OF LIQUID FUELS: PIONEERING WORKS, PAST APPLICATIONS, TODAY'S KNOWLEDGE AND OPPORTUNITIES M Miccio, F Miccio 71 DIRECT NUMERICAL SIMULATION OF VERTICAL PARTICULATE CHANNEL FLOW IN THE TURBULENT REGIME M Uhlmann, A Pinelli 83 GASIFICATION IN FLUIDIZED BEDS - PRESENT STATUS & DESIGN Prabir Basu, Bishnu Acharya, Animesh Dutta 97 CFB Boiler Technology, Operation and Design RESEARCH AND DEVELOPMENT OF LARGE CAPACITY CFB BOILERS IN TPRI Sun Xianbin, Jiang Minhua EXPERIENCE FROM THE 300 MWe CFB DEMONSTRATION PLANT IN ClllNA P Gauville, J.-C Semedard, S Darling PROJECT MAXAU - FIRST APPLICATION OF HYBRID CFB TECHNOLOGY BY AUSTRIAN ENERGY & ENVIRONMENT Kurt Kaufinann, Herbert Koberl, Thomas Zotter 1300°F 800 MWe USC CFB BOILER DESIGN STUDY Archie Robertson, Steve Goidich, Zhen Fan STRUCTURE AND PERFORMANCE OF A 600MWe SUPERCRITICAL CFB BOILER WITH WATER COOLED PANELS Y Li, L Nie, X K Hu, G X Yue, W K Li, YX Wu, J F Lu, D F Che STARTUP, COMMISSIONING AND OPERATION OF FENYI 100MW CFB BOILER .Zhiwei Wang, Wugao Yu, Shi Bo DESIGN AND OPERATION OF LARGE SIZE CIRCULATING FLUIDIZED BED BOILER FIRED SLURRY AND GANGUE Zhang Man, Bie Rushan, Wang Fengjun PERFORMANCE IMPROVEMENT OF 235 MWe AND 260 MWe CIRCULATING FLUIDIZED BED BOILERS w Nowak, R Walkowiak, T Ozimowski, J Jablonski, T Trybala S B&W IR-CFB: OPERATING EXPERIENCE AND NEW DEVELOPMENTS M Maryamchik,D.L Wietzke NO x EMISSION REDUCTION BY THE OPTIMIZATION OF THE PRIMARY AIR DISTRIBUTION IN THE 235MWe CFB BOILER P Mirek, T Czakiert, W Nowak 107 113 121 125 132 137 143 151 157 162 1168 Proceedings of the 20th International Conference on Fluidized Bed Combustion bottom, around 1400 K As it flows upward, the temperature drops as heat is lost to the cooler walls With the addition of secondary air as the flame passes the phase interface of the furnace, temperature rises again due to continued combustion reactions of the left-over combustible species with the fresh secondary air, and maximum flame temperature reaches around 1350 K in the radiation shaft Figure shows the velocity profile in furnace as x=Omm (range from -2256.5mm to 2265.5mm), it shows that the bulk of the flow out of the burning bed keeps close to the CFB bottom The main flow slowly because the furnace passage section area is large than through hole of air distributor However, There is a distinct difference in the second combustion region, because the fresh secondary air insufflate into the furnace and react intensively with gas which not burnout CO profile is shown in Fig High concentration CO comes from the dense-phase zone and that is consumed in both the fluidized particle combustion and the collision of bed material The high CO region coincides with the main pass of the gas flow and is close to the secondary air inlet In the volume space near the bed bottom, there is only low concentration CO In the dilute-phase zone, temperature reduces to a lower level and any further CO reaction is very slow (a) (b) The paper sludge enter into the furnace from the recycle Fig.5 The CO concentrations profiles of coal inlet, brought a series number water and low caloric value combustion (a) and co-combustion of paper sludge/coal (b) (x=Omm, range from -2256.5mm fuel into the furnace, the temperature of co-combustion to 2265.5mm) (about 135OK, see Fig 3(b)) is low than coal combustion (about 1400K, see Fig (a)) at the CFB bottom At the same time, because of the water's evaporation and fuel mixture, there is much more CO in co-combustion of paper sludge and coal (0.00018 kmol/m", see Fig 5(b)) produced than that in coal combustion (0.00012 kmol/rrr', see Fig (b)) at the CFB bottom It is result in the second combustion of co-combustion is intensively, so that the second combustion temperature (about 1300K) of paper sludge/coal is high than coal combustion temperature (about 1250K) Table The influences of various paper sludge inlet position on the co-combustion of paper sludge and coal in the CFB furnace Furnace Temperature (K) The position of paper sludge inlet Gas outlet Area-Weighted Average Maximum Area-Weighted Average Temperature(K) velocity (m/s) Mixing with coal 1379.2 1078.2 986.4 9.00 Enter in by the recycle inlet 1396.3 1109.6 996.8 9.17 Underside of phase interface 1394.4 1097.4 985.1 9.06 The influences of different paper sludge inlet position on the co-combustion of paper sludge and coal in the CFB furnace Usually, paper sludge contains a large number of water; it is hard to guarantee steady-going combustion of paper sludge with no additional high caloric value fuel When it co-combust with coal, the evaporation and devolatilization of paper sludge processes is different with of coal Therefore, it is necessary to investigate clearly that when and how to put paper sludge into furnace Assume it enter into the CFB by three different mean, for instance mix with coal, enter in through the recycle inlet and spout into at underside of phase interface Take co-combustion of 20 mass% paper sludge and 80 mass% coal as an example; to simulate the three kinds of co-combustion as which mentioned The influences of different paper sludge inlet position on the co-combustion paper and coal in the CFB is shown as Table 3, the predictions indicate that paper sludge spout CFD MODELLING APPLIED TO THE CO-COMBUSTION OF PAPER SLUDGE AND COAL IN ABO T/H 1169 into furnace from the recycle inlet can increase the furnace maximum temperature (1396.3K), area-weighted average temperature (1109.6K) and the furnace gas outlet area-weighted average temperature(996.8K) Mainly, it is decided by the combustion characters of coal and paper sludge, paper sludge need more time and energy to guarantee the evaporation of water, too early and too late can influence the combustion efficiency of paper sludge The gas outlet area-weighted average velocity was determined by the co-combustion efficiency of paper sludge and coal, there is different flue gas species in the furnace Table The influences of mass percentage of paper sludge on the co-combustion of paper sludge and coal in the CFB furnace Furnace Temperature (K) Paper sludge mass fraction Gas outlet Area-Weighted Average (%) Maximum Area-Weighted Average Temperature(K) velocity (m/s) 1371.6 1148.05 998.1 8.91 1361.0 1124.75 982.8 8.97 10 1347.8 1134.65 994.2 9.07 15 1361.8 1121.85 1000.8 9.12 20 1396.3 1109.65 996.8 9.17 The influences of mass percentage of paper sludge on the co-combustion of paper sludge and coal in the CFB furnace Normally, the more paper sludge is disposed, the more energy needs to spend To improve conventional existing CFB, make sure that it is feasible to co-combust with paper sludge But how much paper sludge co-combustion with coal is reasonable? By varying mass percentage of paper sludge from 5% to 20% by mass fraction, and plunge it into furnace at the recycle inlet The predictions result is shown as Table The mathematical modeling predicts that 15 mass% paper sludge co-combustion is the highest temperature at the flue gas outlet, it is 1000.8K CONCLUSIONS The following conclusions have been drawn as results of this study: ( 1) Mathematical methods based on a commercial software FlUENT for DPM combustion was validated for detailed analysis of paper sludge/coal co-combustion processes in the CFB furnace; (2) The predicted results of CFB furnace show that the co-combustion of paper sludge/coal is initially intensively at the bottom of bed; the temperature reaches its maximum in the dense-phase zone, around l400K; (3) The predictions indicate that paper sludge spout into furnace from the recycle inlet can increase the furnace maximum temperature (1396.3K), area-weighted average temperature (1l09.6K) and the furnace gas outlet area-weighted average temperature(996.8K) (4) The mathematical modeling predicts that 15 mass% paper sludge co-combustion is the highest temperature at the flue gas outlet, it is 1000.8K ACKNOWLEDGMENTS This work was supported by Natural Science Foundation of Guangdong Province (China) Research Team (No 003045) and the Doctorate Foundation of South China University of Technology REFERENCES Ahuja, G N and Patwardhan A W.: Chemical Engineering Journal 143 (2008), pp.147-160 Almuttahar, A and Fariborz T.: Chemical Engineering Science 63 (2008), pp.1696-1709 Almuttahar, A and Fariborz T.: Powder Technology 185 (2008), pp.11-23 Caputo, A C and Pacifico M P.: Journal of Hazardous Materials 81 (2001), pp.265-283 Chu, K W and Yu,A B.: Powder Technology 179 (2008), pp.l04-114 FLUENT, 6.2 Manual Fluent Inc USA(2005) Lee, G w., Sung J L., Jurng, J and Hwang, J.: Journal of Hazardous Materials 101 (2003), pp.273-283 Lopes, Rodrigo, J G and Quinta-Ferreira, R M.: Chemical Engineering Journal (2008), doi:lO.1016/j.cej.2008.11.048 Lyngfelt, A and B Leckner: Fuel 78 (1999), pp.1065-1072 Mukadi, L., Guy, C and Robert, L.: Chemical Engineering Science 54 (1999), pp.3071-3078 1170 Proceedings of the 20th International Conference on Fluidized Bed Combustion Pallares, D and Filip J.: Chemical Engineering Science 63 (2008), pp.5663-5671 Shin, D., Jang, S and Hwang, 1.: Waste Management 25 (2005), pp.680-685 Tsai, M Y., Wu,K T Huang C C and Lee, H T.: Waste Management 22 (2002), pp.439-442 Vamvuka, D., Salpigido, N D., Kastanaki, E and Sfakiotakis, S.: Fuel (2008), doi: DOl: IO.lOI6/j.fue1.2008.09.029 Wang, S., Xu, Y, Lu, H., Yu, L., Wan, S., and Ding Y.: Computers & Chemical Engineering(2008), doi: DOl: 10.1016/j.compchemeng.2008.1 0.020 A NEW DRY FLUE GAS DESULFURIZATION PROCESS-UNDERFEED CIRCULATING SPOUTED BED M Tao, B S Jin, Y P Yang School ofEnergy and Environment, Southeast University, Nanjing,210096, China Abstract: Applying an underfeed system, the underfeed circulating spouted bed was designed as a desulfurization reactor The main objective of the technology is to improve the mixing effect and distribution uniformity of solid particles, and therefore to advance the desulfurization efficiency and calcium utility In this article, a series of experimental studies were conducted to investigate the fluidization behavior of the solid-gas two-phase flow in the riser The results show that the technology can distinctly improve the distribution of gas velocity and particle flux on sections compared with the facefeed style Analysis of pressure fluctuation signals indicates that the operation parameters have significant influence on the flow field in the reaction bed The existence of injecting flow near the underfeed nozzle has an evident effect on strengthening the particle mixing Keywords: underfeed circulating spouted bed, desulfurization, solid-gas flow, solid flux, pressure fluctuation INTRODUCTION The underfeed circulating spouted bed is designed as a flue gas desulfurization reactor on the base of conventional circulating fluidizing bed One of the main features of the technology is the uniform solid distribution and intense particles mixing in the riser For the bottom humidifying area is the main zone where desulfurization reaction takes place (Li et al., 2002), the distribution uniformity of agent particles in the area would greatly affect the desulfurization efficiency and calcium utility As the fresh agent is fed to the reactor by the underfeed nozzle, high speed injecting flow exists in the bottom bed and the gas-solid turbulence can be distinctly strengthened This will be of great benefit to physical operation and chemical reaction In this article, the radical distribution of gas velocity was investigated and the solid upflow fluxes were acquired by means of isokinetic sampling with a suction probe (Herb et al., 1992; Aguillon et al., 1996; Zhang et al., 1997; Coronella and Deng, 1998) The sectional distribution of particle fluxes was compared between the two feed styles In order to study the influential factors of the flow characteristic, a wide investment was made on pressure fluctuations at different operation parameters The results have important value and instruction on the optimal design and operation of the underfeed circulating spouted bed EXPERIMENTAL Experimental facility The experiments were conducted in an underfeed circulating spouted bed-flue gas desulfurization (UCSB-FGD) system as shown in Fig.I The height of the bed is 19m, with diameter of 0.6m The whole facility consists of reaction bed, humidifying system, solid-gas separation system, underfeed system, recycling system and measure system For the facefeed style, the fresh agent is added by the screw feeder connected to the loop seal For the underfeed style, the underfeed system is applied The underfeed system includes barrel hopper, upright tube, injector, underfeed nozzle and propeller fan The fresh agent in the barrel hopper was first translated to the injector and then pushed by high speed gas along the pipeline Finally the agent was injected into the bottom bed from the underfeed nozzle and mixed with recycling materiel intensely Figure illustrates the configuration of underfeed system The nozzle served to this investigation contains four orifices of 10 mm The distance from the centre of nozzle to the bottom of divergent cone can be adjusted at O.4m or 0.5 m for the pipeline is connected by the pipe unions which can be taken down and set up easily In this study, the nozzle was located at the height of O.4m from the bottom of divergent cone Test content In order to study the distribution uniformity of solid particles, the mass fluxes in the upflow were acquired by particle collection at each point using a sampling probe Hetero-diameter configuration was applied within the probe in order to advance the velocity of the sampling gas and avoid particle aggradations (Duan et al., 2001) Before solid sampling the rotameter was adjusted by a valve to keep the gas velocity of the probe inlet 1172 Proceedings of the 20th International Conference on Fluidized Bed Combustion equal to the local position The sampling period at each point was 60s The underfeed material used in the experiment was silica sand, with an average diameter of 75~ and the density of 2600kg/m The measuring system of the suction probe is as shown in Fig.3 1- NfJzzle 2~" Retaining shelves 3- Pipe Union 4- Blank cap 5·'- Pipeline - Underfeed nozzle Fig.2 Configuration ofthe underfeed system Sampling probe Disconnecting value t.L2 Reaetlon bed Fill" gas Cyclone separator Recycling matenial S Relay hOPJ)"r (, Exit Barrel hopper Screw feeder \I Feeding air 10 ~'luidizillg air 11 LOQP seal 12 Hiser Adjusting valve Vacuum-pump Rcstdual 13 Fan 14 Bag s epararor Hi Injecting ga$ 16 To Atmosphere Injector J7 lJnderfecdnozlkPi Pressure Probes Fig.3 Fig.l Schematic diagram of the underfeed circulating spouted bed System of iso-kinetic suction probe There are three sampling positions along the axial direction, at the height of 1.17m, 4.87m, and 7.95m from the bottom of divergent cone respectively The sampling points are distributed by method of equiareal annulus The distribution of radical positions and corresponding non-dimensional radius is listed in Table.l Pressure signals of eight positions were measured across the length of the riser The arrangement of the pressure taps is as shown in Fig I The pressure fluctuations of the apparatus were monitored by rapid-response pressure transducers To prevent blockage by fine particles, each port was filled by a filter tip The probe was inserted at the apparatus wall to measure the fluid pressure signals PFS signals were collected by an ADIDA board at a sampling rate of 50Hz The acquisition time was 30s at each point and thus the maximum length of the time series is 1500 points Table Disparity of solid upward fluxes in each annulus with facefeed style Point 5' 4' 3' 2' l' r -0.284 -0.250 -0.211 -0.162 -0.067 0.067 0.162 0.211 0.250 0.284 r/R -0.947 -0.833 -0.703 -0.540 -0.223 0.233 0.540 0.703 0.833 0.947 RESULTS AND DISCUSSION The influence of feed styles on gas velocity Distribution of gas velocities in the X-axis direction was measured by a thermal anemoscope at different heights of the riser The fluidizing velocity was I.2m/s Figure 4(a) shows that the gas velocity is lopsided at the height of 1.17m with facefeed style on account of the existence of recycling system The material returned from the recycling tube on the right side disturbed the gas flow and resulted in the reduction of the gas velocity ANEW DRY FLUE GAS DESULFURIZATION PROCESS-UNDERFEED CIRCULATING SPOUTED BED • -H=1.17m -4) H=4.87m ,A, - H=7.95m 4[ - H=13.05m 40 3.5 A Of 3,5 3,0 "E >- q 4.0 "E 2.5 2.0 >- ~ 1.5 ~1.5 '" c3 1.0 '" (g H=1.17m H=4.87m H=7.95m H=13.05m , 3,0 2,5 1173 ~ ~ o 2.0 o 0,5 1.0 0,5 0,0 -1.0 -0.5 00 -1 -,-_ -, _-, _ -, _ -,-_ 1,0 0.5 -1,0 '" g- '" ~ 0.0 80 0.0 80 0.5 l= E - - riR=O.223 riR=O.540 r/R=O.703 90 - "' ~ § 0.5 :g '" 1.0 g