Research of Oxy-fuel CFB Combustion at IET/CAS. Qinggang LU. Institute of Engineering Thermophysics(IET) Chinese Academy of Sciences(CAS)

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1 64 th IEA Fluidized Bed Conversion Meeting Presentation Research of Oxy-fuel CFB Combustion at IET/CAS Qinggang LU Institute of Engineering Thermophysics(IET) Chinese Academy of Sciences(CAS) June 3, 2012 Naples, Italy 中国科学院工程热物理研究所 INSTITUTE OF ENGINEERING THERMOPHYSICS,CHINESE ACADEMY OF SCIENCES

2 Contents 1. Background 2. IET s Activity 1 on 30kW Oxy-fuel CFBC in past 3. IET s Activity 2 on 0.15MWOxy-fuel CFBC at present 4. IET s Activity 3 on 1MW Oxy-fuel CFBC in near future 2

3 Background Coal is main energy resources in China. CFBC is promoted due to advantages of fuel flexibility and low emissions. IET/CAS undertake R&D work on CFB boiler technology supported by industry and Government.

4 IET s CFBC technology in 30 years First Unit in China with diferent capacities 2.8MWt CFBC hot-water boiler was operated in t/h (6MW) CFBC boiler was operated in t/h (12MW) CFBC boiler was operated in MWth CFB boiler t/h CFBC boiler t/h CFBC boiler1992

5 IET s CFBC technology in 30 years First Unit in China with domestic technology 130t/h CFB boiler was operated in t/h (150MW) CFB boiler was in operation in t/h(25MW)CFB boiler t/h (150MW)CFB boiler 2005

6 IET s CFBC technology in 30 years Scale-up R & D works with domestic technology 690t/h (200MW) CFB boiler was in operation t/h (300MW) CFB boiler was in operation t/h(600MW) CFB boiler will be in operation in future 690t/h (200MW) CFB boiler 2007

7 Advantages of oxygen-fuel CFB combustin Keep the advantages of air-fuel CFB combustion With more extended heat surface ( wing wall and EHE) With high heat diffution and gooding mixing in furnace With uniform heat flux in furnace With high oxygen concentration compared with PC boiler Boiler size can be reduced greatly (50%) Easy to apply with the exsiting boiler and new boiler design

8 Research Program on Oxy-fuel CFBC at IET Suppored by CAS STEP ONE 30 kw, 35% O 2 ( ) STEP TWO 0.15MW, 50% O 2 ( ) STEP THREE 1 MW, 50% O 2 ( ) Fuel Cooling water 燃烧 EHE Purific ation Flue Gas Coolin g (CO 2 > 90%) RFG (CO2>9 0%) O 2

9 IET s Activities on Oxy-fuel CFB Combustion 9

10 (1) 30 kw oxy-fuel CFB combustion system ( ) Test rig Size: 3 m Heigh & 100 mm in Diameter O 2 Concentration: ~ 35 %; Local O 2 : ~ 58 % 10

11 Tests were conducted under enriched-air combustion mode. Range of Operating Conditions Heat input : - 30 kw Combustion atmosphere : O 2 /N 2 Combustion temperature: o C O 2 in primary gas : - 35% O 2 in secondary gas : - 58% Excess O 2 :2.0% - 7.9% Primary air ratio: 55% - 68% Secondary air ratio: 32%-45% Superificial velocity: m/s Gas analyzer: Gasmet DX4000, Kane 11

12 Ultimate and proximate analysis of coals ITEMS UNITS Lignite1 Longkou(LK) Lignite2 Shuozhou(SZ) Ultimate analysis C ar % H ar % O ar % S ar % N ar % Proximate analysis M ar % A ar % V ar % FC ar % Q net,ar MJ/kg

13 Test condition Case Coal Type O 2 /N2 O 2 in PA/% O 2 in SA% T1, 100mm / T2, 550mm / T3, 2950mm / 6 LK 33/ LK 32/ LK 33/ LK 32/ SZ 34/ Emissions LK Case 8 LK Case 9 SZ Case 10 H 2 O vol. % CO 2 vol. % CO mg/nm N 2 O mg/nm NOx mg/nm

14 Temperatures Profile Case 7 (Lignite1 LK ) Case 10 (Lignite2 SZ ) o C) o C) Temperature( Height above distributor 100 mm 550 mm 2950 mm Temperature( Height above distributor 100 mm 550 mm 2950 mm 0 17:15 17:23 17:31 17:40 17:48 17:56 Time(h:m) 0 13:30 13:40 13:50 14:00 Time(h:m) 14

15 Emission 30 Case 7 (Liginite 1 LK) CO 2 O 2 浓度 /% CO 2 /% CO/(mg/MJ) N 2 O/(mg/MJ) NO X /(mg/mj) O 2 /% CO N 2 O NO X 浓度 /(mg/mj) 0 17:31 17:33 17:35 17:37 17:39 17:41 17:43 17:45 17:47 17:49 17:51 0 CO 2, O 2, CO, N 2 O and NO X emission 15

16 16 (2) 0.15 MW oxy oxy-fuel CFB combustion fuel CFB combustion system (2010 system ( ) 2012) AircompressorCoolingWaterFeederASUCO2GasTankFlueGasCoolerBFFluegasanalysisFlyashToStackFeederSecondaryAirCoolingwaterGasMixerCoolingWaterCFBGasMixerPrimaryAir1 Furnace: Riser: 6m H, 140mm D 12 water pipes embed in the refractory wall 2 Cyclone: 280 mmd, 1120 mm H; 18 pipes embed in the refractory wall, Cooled by water or air 3 Standpipe: Heat insulation 4 Loop seal: Heat insulation / water cooling

17 5 Fuel feed rate: kg/h 6 Oxygen generation unit: Oxygen generator 30 Nm3/h Purity: 90% 7 CO 2 unit: 48 gas cyclinders Purity: 99% 17

18 Tests were conducted under enriched-air combustion mode. Range of Operating Conditions Heat input : up to 0.15MWth Combustion atmosphere : O 2 /Air Combustion temperature: up to 910 o C O 2 in primary gas : up to 55% O 2 in secondary gas : up to 50% Excess O 2 :2.0% - 10% Primary air ratio: 50% - 100% Secondary air ratio: 0-50% Superificial velocity: 3-6 m/s Gas analyzer: Gasmet DX4000, Kane 18

19 Analysis of coals ITEM UNIT Lignite Shigouyi(SG) Bituminous Coal1 Datong(DT) Bituminous Coal2 Shenmu(SM) Ultimate nalysis C ar % H ar % O ar % S ar % N ar % Proximate analysis M ar % A ar % V daf % FC ar % Q net,ar MJ/kg

20 Effect of O 2 Concentration on combustion characteristics Temperature profiles (including 8 test cases; Bituminous Coal2 (SM)) Continue test time: up to 24 hours; Fuel feeding point: above distributor 800 mm; 20

21 Temperature Vs. Time O 2 concentration in primary gas: 55% Institute of Engineering Thermophysics, Chinese Academy of Sciences Lignite (SG) Bituminous Coal1 (DT)

22 Combustion Efficiency Institute of Engineering Thermophysics, Chinese Academy of Sciences

23 Effect of O 2 Concentration in primary gas on emission CO concentration Vs. O 2 concentration in primary gas SO 2 concentration Vs. O 2 concentration in primary gas 23

24 NO concentration Vs. O 2 concentration in primary gas N 2 O concentration Vs. O 2 concentration in primary gas 24

25 Effect of total O 2 Concentration on SO 2 emission Lignite (SG) Air mode Total O 2 concentration: 50% Test Case O 2 in primary gas Tatal O 2 concentration Primary gas/second gas K /40 SG-1,SG-2,SG-3 45%,50%,55% 50% 60/40 SG-4,SG-5,SG-6 50% 50% 50/50,70/30,100/0 25

26 Effect of total O 2 Concentration on SO 2 emission Bituminous Coal (DT) Air mode Total O2 concentration: 50% Test Case O 2 in primary gas Tatal O 2 concentration Primary gas/second gas K /40 DT-1, DT-2, DT-3 45%,50%,55% 50% 60/40 DT-4, DT-5, DT-6 50% 50% 50/50,70/30,100/0 26

27 Effect of total O 2 Concentration on NOx emission 27

28 Effect of total O 2 Concentration on NOx emission 28

29 Effect of total O 2 Concentration on N conversion Air mode Air mode Total O2 concentration: 50% Total O2 concentration: 50% Lignite (SG) Bituminous Coal (DT) 29

30 Effect of O 2 staging on combustion characteristics 30

31 Effect of O 2 staging on emission 31

32 Effect of second gas feeding height on combustion characteristics 32

33 Effect of second gas feeding height on emission 33

34 Effect of second gas feeding height on emission 34

35 Research work to be continued on 0.15MW system Commission tests in O 2 /CO 2 and O 2 /RFG atmosphere in 40-50% O 2 concentration; Focus on: combustion characteristics, operational strategies, heat transfer, hydrodynamics of solid circulation, emissions, ash characteristics high oxygen concentration (50%, or higher ) 35

36 Build 1 MW th pilot scale CFB facility Heat input: 1 MW O 2 concentration: 50% Expected time:

37 Thank You for Your Attention 37