P. Jaud EDF R&D · EDF/CNET CdF Ingenierie Engineering Contact Project Financing advisor Banque...
Transcript of P. Jaud EDF R&D · EDF/CNET CdF Ingenierie Engineering Contact Project Financing advisor Banque...
P. Jaud EDF R&D
Operation of the CFB boiler
Start of the CFB boiler in 1996 operated by SOPROLIF,
4 fuels were burned at Provence 250 MWe CFBProvence Lignite (design fuel, but local mine closed in 2003).
Lean coal (Gard, France), low volatile bituminous coal not far from semi anthracite
Imported coal, low ash and sulfur content, high volatile bituminous coal
Delayed petroleum coke, with a high sulfur content
SNETSNET
Electricity Electricity generation generation
contractcontract
EDF/CNETEDF/CNETCdF IngenierieCdF Ingenierie
Engineering Engineering ContactContact
Project Financing Project Financing advisoradvisor
Banque IndosuezBanque Indosuez
ENDESASNETEDF
EDFEDF
Steam Steam contractcontract
SNETSNET
Operation Operation contractcontract
HBCMHBCM
Coal supply Coal supply contractcontract
SuppliersSuppliers
Equipment Equipment contractscontracts
SOPROLIFSOPROLIF
Shareholders :
SNETSNET
Electricity Electricity generation generation
contractcontract
EDF/CNETEDF/CNETCdF IngenierieCdF Ingenierie
Engineering Engineering ContactContact
Project Financing Project Financing advisoradvisor
Banque IndosuezBanque Indosuez
ENDESASNETEDF
EDFEDF
Steam Steam contractcontract
SNETSNET
Operation Operation contractcontract
HBCMHBCM
Coal supply Coal supply contractcontract
SuppliersSuppliers
Equipment Equipment contractscontracts
SOPROLIFSOPROLIF
Shareholders : -In 2004, ENDESA became majority shareholder of SNET,
- In 2008 SNET took over SOPROLIF and EON bought ENDESA shares in SNET,
- In January 2010 EON took over 100 % of SNET.
Characteristics of the fuels burnt at Provence 250 MWe CFB
Fuel analysis Provence lignite(Gardanne Coal)
Petroleum Cokeat ship unloading
Imported Coal Gard Coal
Moisture 9.9 % 5 to 7 % 9 % 5.7 %
Ash (dry basis) 30.0 % 0.5 to 0.7 % 15.4 % 28.0 %
Volatile matter (dry basis) 43.5 % 9 to 10 % 25.6 % 15.0 %
Carbon (dry basis) 49.5 % 80 to 87 % 71.2 % 63.2 %
Hydrogen (dry basis) 3.2 % 3.1 to 3.4 % 3.9 % 3.9 %
Oxygen (dry basis) 11.9 % 1 to 7 % 7.0 % 2.1 %
Nitrogen (dry basis) 1.3 % 1.3 to 1.7 % 1.7 % 1.8 %
Sulfur (dry basis) 4.2 % 6 to 8 % 0.8 % 1.3 %
Low Heating Value (MJ/kg)(dry) 18.4 31.4 to 32.2 25.1 to 25.4 16.5
Fuels
Very few operation set points have been modified to burnt different fuels
Provence lignite
Petroleum coke
Imported coal
50% Petroleum coke 50% Imported coal
Furnace temperature reference +10°C +10°C +10°C
O2 at boiler outlet (before air heaters)
3% 4.0% 3.7% 3.7%
Temperature for feeding fuel without oil support
reference +30°C +30°C +30°C
Furnace temperature: Objective: reduce unburned loss
O2 at boiler outlet (before air heaters): Objective: compensate for the lower flue gas volume
Operation set points
General behaviour of the boiler
Main performance data
12% lower pressure drop, but satisfactory heat transfer rate in the furnace remains similar since higher temperatureNo need for ballast injectionBoiler efficiency:
- Impact of unburned loss in the fly ash and limestone calcination- Impact of the sulphation credits: good results of Provence lignite and blend of petroleum coke + imported coal
Provence Lignite
Petroleum coke
Imported coal
50% petroleum coke 50% imported coal
Mean furnace temperature difference Reference +47°C +26°C +40°CFurnace upper part pressure drop Reference -10% -15% -12%Boiler efficiency NFE 32.130With sulphation credits
92.6%94.8%
91.0%93.7%
91.6%91.6%
91.3%93.3%
Unburned carbon in fly ash (% of fly ash)
0.5% 3.7% 7.7% 5 to 7 %
Pollutant emissions
Pollutant emissions at stack
Regulation limits: SO2 : 400 mg/Nm3, Nox: 500 mg/Nm3
Desulphurisation
Petroleum coke: very good desulphurisation rate: 97%
Low Ca/S: <2.5
explanation: significant conversion of SO2to SO3 in the presence of Va
Blend: Ca/S higher due to change of limestone, optimisation necessary
Combustion of the blend
CO content: quite low
NOx content: low
Blend: good compromise
Units (dry 6% O2 )
Provence lignite
Petroleum coke
Imported coal
50% petroleum coke 50% imported coal
SO2 mg/Nm3 37 280 to 300 50 140 to 250NOx mg/Nm3 240 160 to 100 280 200 to 160CO mg/Nm3 13.8 28 73 37Ca/S mol/mol ~3 <2.5 <2.5 2.8
Blend allow to cope with the European regulation: 200 mg/Nm3 for SO2 and NOx
Startups/shutdowns
Démarrages programmés
020406080
100120140160180
1996 1997 1998 1999 2000 2001 2002(aout)
Total
Démarrages chauds
Démarrages tièdes+froidsTotal
Démarrages fortuits
020406080
100120140160180
1996 1997 1998 1999 2000 2001 2002(aout)
Total
Démarrages chaudsDémarrages tièdes+froidsTotal
Since beginning of commercial operation up to December 2003
35556 hours of operation
616 start ups
The unit has been used in peak load between 1999 and 2001
Since 2002 new policy: plant operated in base load
Availability
Disponibilité technique chaudière (hors grève)
76.05
94.34
77.3191.0687.78
94.10
0.0010.0020.0030.0040.0050.0060.0070.0080.0090.00
100.00
1997 1998 1999 2000 2001 2002
Année
Disp
onib
ilité
Mode de calcul : Energie produiteEnergie demandée
Unavailability Sources
Bilan 1998/2003Indispos
en hproportion
en %Indispos
en hproportion
en %chaudière PSP 2003 62,1 36 8,1
dont éco 268 8,3 6 1,3dont écrans vaporisateurs 999 31,0 28 6,3dont SMT2 709 22,0 0 0,0alimentation charbon 28 0,9 142 31,8allumage gaz 36 1,1 23 5,1air comburant 50 1,5 52 11,6circulation des cendres 889 27,5 109 24,4dont surpresseurs 113 3,5 44 9,8dont liaison foyer-cyclone 119 3,7 0 0,0dont vannes pointeau 144 4,5 46 10,3dont réfractaires 186 5,8 0 0,0dont joints 156 4,8 0 0,0refroidisseur de cendres 35 1,1 6 1,3autres 221 6,9 85 19,0total 3226 100 447 100
indisponibilités totales indisponibilités partielles
Main location of steam leakages
14
3
2
5 6
During operation, steam leakages occured in several locations mainly in the furnace due to default of welding (location 2), stress induced by refractory fixation (location 3), thermal cycling (locations 4, 5 & 6). The external heat exchangers were also subject to steam leakage due to overheating of the tube buddles (location 1).
Troubles on expansion joints
1
2
3
The expansion joints were subject to numerous blockages due to unappropriate design leading to ash plugging.
Agglomerations of circulating ash
1
2 3
The first ash agglomeration occured in 2002 due to combination of minerals by fusion and crystallizationbecause of the aluminates and silicate contents of the “Gard”
coal used to replace the “Gardanne”
coal. The second agglomeration phenomenon followed a period of frequent change of fuel blend and resulted inthe blockage of one of the 4 circulating loops. It seemed that there is a need for a period of stabilisation ofthe bed material composition before changing fuel.
Refractory problems
213
47
5
6
8
The most sensitive locations for refractory damages are the cyclones (locations 4 & 5), the external heat exchangers (locations 1 & 3) and the loop seals (location 6). Other places (2, 7 & 8) are also subject to regular maintenance.
Other sources of unavaibility
1
234
5
6
Some other components encountered some troubles during operation
like : the cone valves (location 1), the ash coolers (location 2), the compressors (location 3), the blowers (location 4), the fluidization nozzles (location 5) and the wind box under the loop seals (location 6).
Questions
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