Taishan Group CFB boiler
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Technical Review Technical Characteristics Structural Features After-sale Service

I Technical Review On the basis of absorbing domestic and foreign experience in designing, manufacturing, installing and operating CFB, and in combination with own features, Taishan Group cooperates with Institute of Thermal Physics of Chinese Academy of Sciences, insists on technical innovation and continuous product perfection, thus designs high-performance, environmentalprotecting and high-efficiency CFB. This boiler features good coal adaptation, safe and reliable operation, high performance and energy saving. The ash may be used as the admixture of cement, decreasing environmental...

Rated evaporation Rated steam pressure Rated steam temperature Feed-water temperature Exhaust gas temperature Design fuel Applicable fuel Fuel particle size Operation level of boiler Steel frame size Thermal efficiency Limestone particle size 35 t/h 5.29 MPa 485 ℃ 105 ℃ 150 ℃ soft coal lignite , lean coal, anthracite , gangue 0~10mm 6m

Space Diagram cyclone separator refeeder membrane wall fluidized bed Ignition system Boiler proper arrangement 1. Natural circulation 2. Omniseal hightemperature cyclone separator (with water jacket) Boiler includes three parts: First is furnace and drum; furnace adopts full membrane wall, and the bottom is water cooled air chamber bended with water wall tube. Second is hightemperature cyclone separator and refeeder. To meet current denitration requirement, SNCR spray gun port in reserved at the entrance of separator. Third is tail flue duct, including superheater, economizer and air...

Steam-water flow Drum → low temperature superheater→ high temperature superheater→header ↗ ↓↑ economizer water-cooling ↑ feed water    Boiler feed water enters economizer inlet header, then to outlet header along the economizer tube, and enters the drum via the outlet pipe. Drop to water wall lower header via centralized downcomer, through membrane wall, and enters the drum for steam-water separation. The saturated steam is imported into roof tube inlet header via the connecting pipe, enter low temperature superheater piping system, then desuperheater, and then high temperature...

Flue gas process cold air → primary air preheater cyclone separat Tail silo ↓ dust collector ↓ Chimney

energy saving strong load regulation environmental protection

High efficiency

1. High thermal efficiency Thermal efficiency η=100%-（q2+q3+q4+q5+q6）      Q2: heat loss due to exhaust gas, mainly relevant to flue gas amount and exhaust gas temperature Q3: heat loss due to chemical unburned gas, generally 0.5% Q4: heat loss due to mechanical unburned gas, relevant to the carbon content of big slag and fly ash Q5: heat loss due to radiation, generally 0.5% Q6: heat loss due to sensible heat in slag, relevant to slag temperature and slag amount, generally no more than 1% Thermal efficiency mainly depends on q2

Two factors affecting Q2 (heat loss due to exhaust gas) Exhaust gas temperature: the lower, the smaller the heat loss is; yet blind lowering of exhaust gas temperature not only cause low temperature corrosion of air preheater, but also the area of air preheater is too big, the duct resistance rises, fan power consumption increases, so for factory and user, the loss outweights the gain. Optimized design:  Big heating surface increases heat absorption capacity.  Design best exhaust gas temperature, seek a balance point between lowering exhaust gas temperature and preventing tail low...

Two factors affecting Q2 (heat loss due to exhaust gas) Flue gas amount: mainly relevant to excess air coefficient, air leakage coefficient; the smaller, the less the flue gas amount is, the less the loss is. Optimized design:  Select low excess air coefficient 1.15～1.2  Mature sealing technology lowers air leakage coefficient.

Two factors affecting Q4 (heat loss due to mechanical unburned gas): Carbon content of big slag and fly ash Design fly ash/big slag=6/4, if the coal is confirmed, the ash content is certain, in order to lower the two items, it is necessary to improve burning efficiency.  • • • Measures to lower the carbon content of big slag: Adopt water-cooled distributor to reduce ash leakage Bell windcap labyrinth layout, well-distributed without dead point Secondary air arrangement, stronger penetrating power, better combustion-supporting effect Measures to lower the carbon content of fly ash:...

Mature sealing technology ensures small air leakage coefficient, reduces flue gas amount and resistance, thus lowers ID fan power consumption. Low bed pressure lowers bed depth, fluidized height, wind chamber pressure and primary air power consumption. Primary and secondary air adopt staged combustion, select big secondary air distribution proportion as 55:45, reduce the primary air distribution proportion to reduce primary air power consumption. Smart underbed ignition system, mature sealed heat insulation technology, shortens starting time, reduces starting consumption and boiler proper’s...

II. Environmental protection Nox emission control SO2 emission control Environmental protection Comprehensive utilization of ash Combustible low grade fuel

At present, with frequent occurrence of haze, environmental protection policy is more and more strict, emission index is smaller and smaller. Our company improves original CFB boiler, adopts new fluidized bed combustion technique, ensures low emission of Nox, original emission is less than 200mg/Nm3, after SNCR denitration technology, it can meet the emission index.

Boiler proper adopts specific design to restrain the generation of NOx  Low bed temperature combustion technique Original CFB’s bed temperature is 900～950℃, we increase the furnace heat absorption area by 15%, adopt high-efficiency separation technology to control the bed temperature to 830～ 860℃, realizing low-temperature combustion, restraining the generation of Nox under the premise of ensuring good combustion performance. Staged combustion technique Primary and secondary air staged combustion enable main combustion area in anoxic reducing atmosphere, restrain the generation of Nox,...