燃用韩国烟煤的20OMWe流化床机组(Tonghae)运行经验-英文

1、,Operating Experience of the 200MW Tonghae CFB Plant Using Korean Anthracite,Combustion & Thermal Engineering Group Power Generation Laboratory, KEPRI, KEPCO Jae-Sung Kim, Jong-Min Lee, Dong-Won Kim,July 10 14, Kunming, China,Contents (2/22),Introduction Tonghae CFB Boiler Characteristics of Korean

2、Anthracite Initial Experience of the Boiler and System Modification Current Status of the Tonghae CFB Boiler Work for FBAC Stable Fluidization Conclusion,Introduction (3/22),Need to activate a domestic coal industry,Electric Power Generation Capacity with Energy Source,Consumption of Imported and Do

3、mestic Coal for Power Generation,Tonghae Circulating Fluidized Bed Boiler - Electric Power Generation : 1, 2 units 200 MWe (693 Steam t/h) - Using Korean Anthracite - The First and Largest CFB boiler using Low Quality Coal,Plan of the Tonghae Thermal Power Plant CFB (4/22),Unit # #1 Unit #2 Unit Sta

4、rt Engineering 1994. 12 1994. 12 Start Site Excavation 1995. 2 1996. 4 Start Steam Generator 1995. 10 1996. 12 Steel Erection Initial Firing 1997. 10 1999. 3 Synchronization 1998. 1 1999. 7 Commercial Operation 1998. 10 1999. 10,Participants in the Tonghae CFB Project,KEPCO : End User - (Korea East-

5、West Power Co.) KOPEC : Project Architectural Design ABB-CE : Basic Design DOOSAN : Boiler Equipment Fabrication and Procurement,Commercial CFB Boiler Location in Korea (5/22),Complete View of the Tonghae Power Plant (6/22),Main Office,CFB Power Block,Ash Pond,Indoor Coal Yard,Power Generation Proce

6、ss of the Tonghae CFB (7/22),Tonghae CFB boiler (8/22),Type - CFB, Indoor - Natural Circulation - Balanced Draft System Leading Specification - Steam Flow : 693 T/H - Max. Operating P T: 169.6 kg/cm2, 541oC Emission Control - SO2 (O2:6%) : 150ppm - NOx(O2: 6%) : 350ppm Ash Distribution - Fly Ash : 5

7、0% - Bottom Ash : 50% Rectangular Furnace Design - More than 2:1 Aspect Ratio : to Allow for Good Fuel Mixing - Size : 32m (H) x 19m (W) x 7m (L) - Start-up Burner (Side Wall) : 4 - Lance Burner : Side-2, Rear-3,Circulating Fluidized Bed Combustion (9/22),Solid Fluidization - Lower part of furnace :

8、 dense phase - Upper part of furnace : dilute phase - Annulus and core structure - Furnace Cyclone Loopseal (FBHE) Furnace Emission Control - Desulfurization in combustor : CaCO3(fed) + SO2 + 1/2O2 CaSO4 + CO2 - Low operation temperature (900oC) : low NOx emission - Without additional emission contr

9、ol system Advantage - Fuel flexibility - Wide size distribution of fuel - Easy to handle solid particles - High heat transfer rate - Stable for external thermal shock,Backpass,Analysis of Korean Anthracite (10/22),Size Distribution of Korean Anthracite (11/22),Size Change of Korean Anthracite,Effect

10、 of heating rate and particle size on fragmentation,Devolatilization & Combustion,Combustion Characteristics of Korean Anthracite (12/22),Ignition T : 500 - 600oC - very low combustion reactivity Chemical reaction control regime : 3-10 times lower than bituminous,anthracite,bituminous,anthracite,bit

11、uminous,Low Volatile content - VM : 3.7-5.0% High Ash content - Ash : 27 - 42% Low heating value - 4,500-5,000 kcal/kg Relatively high HGI - about 90 - 110,Korean anthracite,Very low combustion reactivity High content of fine particles (0.1mm :10 - 20%) high content of coarse particles High degree o

12、f fragmentation,Low combustion efficiency due to short residence time High temperature in freeboard and cyclones due to post-combustion,Characteristics of Korean Anthracite (13/22),Initial Experience of the Tonghae CFB Boiler (14/22),High temperature and Longer time during bed material heat up : in

13、sealpots, cyclone inlet and outlet (1,0001,100 oC) : in combustor (880920 oC) Formation of clinkers, Fouling of fine particles Low circulation rate (upper P 100mmH2O design : 170190mmH2O ) : higher temperature and unstable bed condition ( 900oC) : higher SOx emission (Ca/S mole ratio 3.03.5 (150ppm)

14、 Defluidization and clinker formation : due to nozzle back sifting and plugging in the combustor : unstable fluidization and particles segregation in FBAC, FBHE Low combustion efficiency : about 1820% unburned carbon in fly ash,Technical approach to solve the problems,Modification of the System - Cy

15、clone, Nozzle, FBAC drain line, etc Optimization of the Operation Cold CFB Reactor, IEA-FBC simulation Characterization of the Coal Lab. Scale CFB Combustor, TGA,Current Status of the Tonghae CFB boiler (15/22),Bed Temperature Design : 900oC Before : 900oC After : 850 - 870oC Cyclone inlet Temperatu

16、re Design : 900oC Before : 960 - 1020oC After : 910 - 930oC Cyclone outlet Temperature Design : 927oC Before : 980 - 1020oC After : 940 - 960oC Sealpot Temperature Before : 960 - 1000oC After : 900 - 930oC Bed Temperature Difference Somewhat decrease,before ash reinjection,after ash reinjection,Curr

17、ent Status of the Tonghae CFB boiler (16/22),SO2 emission : decrease Ca/S mole ratio (150ppm) : Before : 3.5 After : 2.5-3.0,Current Emission Level - SO2 (150) : 110 ppm - NOx (350) : Detecting and Clearing up Poor Fluidization - Increase Availability : Fuel Diversification (Co-combustion with low q

18、uality coal),Work for FBAC Stable Fluidization (18/22) - Experimental,Experiment apparatus of the FBAC,FBAC (Lab-scale) Main Reactor : 500mm (H) x 1,000mm (L) x 500mm(W) Distributor System : 50-distributor nozzles (8mm-4 hole/Nozzle) : 10-air headers Particle Feeder : 1-hopper (350 liter) : a variab

19、le rotary feeder Gas inlet system : 10-Flow Meter, 4-Pressure Tap Exit Gas treatment System : a bag-filter Experimental Variables : particles feed rate, fluidizing velocity in steady state Feed rate : 510kg/min Mixing characteristics : observe with the eyes : sample particles at the exit of the FBAC

20、 classify the particle size distribution Pressure fluctuation measurement : good fluidization & poor fluidization Observation of cleaning up defluidization : with variation of gas velocity,Work for FBAC Stable Fluidization (19/22) - Observation of poor fluidization,Observation of Defluidization,FBAC

21、 defluidization characteristics,Before fluidization,Good fluidization,Occurrence of defluidization,Bridge at the bed surface,Work for FBAC Stable Fluidization (20/22) - Detection of poor fluidization,Good Fluidization,Poor Fluidization,the value, ss : decreased and got out of a certain fluctuation r

22、ange,the value, ss : decreased and got out of a certain fluctuation range,Accumulated standard deviation error for a given period of time, ss,sj : standard deviation,xj : mean,Where,Initial state of pressure fluctuation at good fluidization,Detection and clearing up of defluidization Overall airflow

23、 control,Detection and clearing up of poor fluidization affected by air distributor system : detected by change of a local pressure fluctuation : control the local air flow rate for breaking the defluidization,Detection and clearing up of defluidization local airflow control,Poor fluidization,Clearing up,Overall airflow control,Work for FBAC Stable Fluidization (21/22) - Clearing up poor fluidization,