Calderas de Lecho Fluidizado - T&E Calderas y...
Transcript of Calderas de Lecho Fluidizado - T&E Calderas y...
Calderas de Lecho Fluidizado
Calderas de Lecho Fluidizado
TIPO
- ACUATUBULARES PARA VAPOR
- HÍBRIDAS PARA VAPOR
- ACUATUBULARES PARA AGUA CALIENTE
- HÍBRIDAS PARA AGUA CALIENTE
- PARA FLUIDO TÉRMICO
COMBUSTIBLES
- CARBÓN
- RESIDUOS DE PALMA
- CACARILLA DE ARROZ
- DESPERDICIOS DE MADERA
Caldera Acuatubular
Background
• German design• Developed by Dr. Heinrich
Vorkauf in 1944• Robust and distinc design
natural circulation boiler• Built to the ASME 1 approved by
Depnaker• Performance Values- Steam rating: from 0.4 to 290 t/h- Steam Pressure: from 8 to 136 bar- Steam temperature: to 535°C- Hot Water Boiler: to 174MW
Desempeño
•Steam rating: from 0.4 to 290 t/h
•Steam Pressure: from 8 to 136 bar
•Steam temperature: to 535°C
•Hot Water Boiler: to 174MW
Potente
Confiable
Caldera Acuatubular
Design Principle
1.Unheated return tubes
2.Header
3.Mixture tubes
4.Riser tubes/evaporator
5.Overflow tubes
6.Unheated steam drum
7.Unheated down comers
Caldera Acuatubular
Advantages1. High water circulation an quick
start up2. High steam Purity3. High efficiency4. Reduce response time with
varying steam demand5. Low pressure variations at turn
down6. Low water side pressure loss7. Self supporting construction8. Small foot Print9. Simple erection with few site
welds
Caldera Acuatubular
Construction1. Tube cage with all welded or separately
supported heating surfaces is self-supported by downcomers in the corners of the boiler (2, 7).
2. No complicated connections between boiler and cold frame.
3. The compact tube system will be manufactured in the workshop under good conditions and sharp quality surveillance.
4. Eckrohr-Boilers can be cut longitudinally or cross wise into several stable pieces for transportation.
Caldera Acuatubular
Simulation10 t/hr 26 barg, Boiler with Fluidized bed Combustor
Factory assembled boiler delivered to site
Boiler pressure part installation
Caldera Acuatubular
Lecho Fluidizado BurbujeanteBFB – Blubling Fludized Bed
El mejor sistema de combustión para calderas entre 4 y 100 t/h que usan
carbón como combustible.
Combustión
Cámara de Combustión de Lecho Fluidizado Burbujeante
Main features– Fluid bed consisting of
350 mm layer of silica sand
– Sand of size between 0.5 to 1.5 mm used
– High pressure forced draft fan used for fluidization
Combustor del lecho
Cámara de Combustión de Lecho Fluidizado Burbujeante
Main features– Special construction
stainless steel nozzles – Fluid bed maintained at 700
to 900 °C during operation
Boquillas de aire de acero inox
View of Fluidized bed combustor
Cámara de Combustión de Lecho Fluidizado Burbujeante
Main features
– Sand is fluidized by passing air through nozzles located at bottom of the bed.
– Fuel fed by over-bed screw feeder
– Fluid bed maintained at 700 to 900 °C during operation
Boquillas de aire de acero inox
Cámara de Combustión de Lecho Fluidizado Burbujeante
Advantage of Fluidized Bed Boiler
• Cheaper coal fines used as fuel thus costing about 50 % less. Size of coal required is 100 % below 15 mm.
• 100 % capacity of the boiler can be obtained with nearly all types of coals. No capacity reduction for lower heating value.
Ventajas de las calderas deLecho Fluidizado
Advantage of Fluidized Bed Boiler
• The capacity of boiler is specified at the working pressure with feed water at 30 °C.
Not on F&A 100 °C basis.
Ventajas de las calderas deLecho Fluidizado
Advantage of Fluidized Bed Boiler
• Large external furnace with large volume causes complete combustion of volatile matter. No fouling of boiler due to tar.
• Low Furnace temperature. Causes no fouling of refractory
Ventajas de las calderas deLecho Fluidizado
Advantage of Fluidized Bed Boiler
• Fuel flexibility. Fluid bed furnace can burn a variety of fuels without reduction of boiler output
• Materials like sludge and waste can be incinerated along with the coal
Ventajas de las calderas deLecho Fluidizado
Advantage of Fluidized Bed Boiler
• The combustor can be started immediately after up to 4 hours shut down without any pre heating as the sand bed retains heat
• Very quick turndown is possible and thus very quick load response.
Ventajas de las calderas deLecho Fluidizado
Advantage of Fluidized Bed Boiler The best attributes
• Produces very low NOx and Sox emissions
• Very reliable as the only moving part is the fans which are outside the hot zone
• Higher combustion efficiency (95-99%)
Ventajas de las calderas deLecho Fluidizado
Expected emissions for fluidized bed combustor
• Test parameter • result • limit • Units
• Dust particulate
• bag house filter
• Ventury scrubber
• ESP
• 50
• 100
• 100
• 50 • mg/Nm3
• Nitrogen oxides
• 30 • 300 • mg/Nm3
• Sulphur • 150 • 300 • mg/Nm
Emisiones de las calderas deLecho Fluidizado
Limitations of various dust collector systems
• Cyclone separators - 350 mg/Nm3
• Ventury scrubber - 150 mg/nm3
• Electro static Precipitator - 100 mg/nm3
• Bag filter - 50 mg/Nm3
Control de emisiones calderas Lecho Fluidizado
BOILER SYSTEM• Water tube boiler
• In – bed tube assembly
• Fluidized bed combustor
• Forced draft fans
• Induced draft fans
• Feed water pumps
• Controls
• Cyclone separator
• Ventury scrubber
• Bag Filter
• Chimney
• Deaerator
• Fuel feeding and storage
system
• Feed water Plant
• Ash disposal system
• Economize
• Super Heater
Sistema de generación de vapor
Fluidized bed boiler schematic diagram
Fluidized bed combustor
Stainless steel air nozzles
Stainless steel air nozzles
Fluid bed cooling tube bundle construction
Coal Screw feeder
Belt conveyor for feeding coal to hopper
Dust collection system including cyclone separator and scrubber
Ventury scrubber
Ash removal systemsManual ash lever
Ash removal systemAutomatic ash screw
Control panel
Control panel - Touch screen with mimic diagram
Control panel – Display of Boiler parameters
Control panel - Daily log sheet
Control panel – Graph of Boiler parameters
Furnace draft control
Fluidized bed temperature control
40 t/hr 45 barg rice husk fired boiler
Bubbling fluidized bed boiler
• Uses low furnace gas velocity of 2.5 m/s
• Furnace height is normally 5
meters
• Easy to control due to in-bed tube
bundle
• Suitable for boiler of capacity
below 100 t/hr. There are more
than 200 bubbling fluidized bed
boilers using coal in Indonesia.
• Low Forced draft fan pressure(800
mm Wg) and power consumption
BFB vs CFB
Circulating fluidized bed boiler
• Operates at higher furnace Gas velocity of 7 m/s. This carries most of the bed solids upwards with the gas.
• Solids separated from gas in a refractory lined cyclone separator and returned to the fluid bed.
• Gives higher combustion efficiency
BFB vs CFB
Circulating fluidized bed boiler Disadvantages• Needs very tall furnace to get adequate
residence time for carbon. Normal furnace height is 15 meters
• Needs very high Forced draft fan pressure of nearly 2000 mm Wg. This means very high power consumption
• Used for boilers above 100 t/hr capacity• The boiler is difficult to control due to
unstable bed temperature. Needs very sophisticated control
• The hot cyclone is refractory lined and needs lot of maintenance causing plant shut down
• The Chinese CFB of 20 – 50 t/hr capacity has shown lot of operation problems in Indonesia and customers have shut down most of these boilers
• Operates at higher furnace Gas velocity of 7 m/s. This carries most of the bed solids upwards with the gas.
• Solids separated from gas in a refractory lined cyclone separator and returned to the fluid bed.
• Gives higher combustion efficiency
BFB vs CFB
Problems of Bad Fluidized Bed Boiler
• Frequent erosion of Bed tubes• Fluidizing nozzles of wrong design
– Air nozzle of 150 mm dia. with large size holes– Large distance between nozzles
• Bed temperature is higher than 1000 °C since the in-bed cooling tubes are not adequate
• Unable to achieve 100 % load• Pressure part made in China• Difficult to change in bed tubes
Problemas de calderas deficientes de
Lecho Fluidizado
In – Bed tubes in Hamada Boiler
In – Bed tubes in Hamada Boiler
Hamada air nozzle Basuki air nozzle
Hamada air nozzle New After use
www.calderasyenergia.com
Ing. Daniel de los Rí[email protected](57) 3214493924
FIN DE PRESENTACION Calderas de Lecho Fluidizado