CFB Power Plant Boiler is a high-efficiency, energy-saving and low-pollution boiler product using circulating fluidized bed clean combustion technology. Take one 160t/h sub-high temperature, sub-high pressure, energy-saving and environmentally-friendly CFB boiler as an example.

I. CFB Power Plant Boiler Main Features

  1. The furnace contains large amount of materials, whose circulation brings high heat transfer coefficient, widening the thermal load adjustment range. It has strong adaptability to fuel, improving the combustion energy structure.
  2. The operating temperature of CFB boiler is usually 870-910℃, which is ideal for desulfurization and denitrification. The desulfurization efficiency can reach about 96%, and the SO2 emission can reach 100mg/m3. The circulating fluidized bed uses low-temperature staged air supply combustion, which greatly reduces the generation and emission of NOx. The NOx emissions can reach 100mg/m3.
  3. Circulating fluidized bed boiler features high combustion efficiency, good fuel adaptability, comprehensive use of ash and slag.

II. CFB Power Plant Boiler Design Parameter

Evaporation capacity 160t/h

Rated steam pressure 5.29MPa

Rated steam temperature 485℃

Feed water temperature 104℃

Flue gas temperature 135℃

Blowdown rate ≤1%

Air temperature at air preheater inlet 20℃

Primary air temperature 135℃

Secondary air temperature 135℃

Excess air coefficient at air preheater outlet 1.35

Design thermal efficiency 89.76%

Desulfurizing efficiency (in-furnace, Ca/S ratio 2-2.5) ≥95%

Primary and secondary air ratio 5:5

Boiler fly ash and bottom slag ratio 5:5

Fuel consumption 23.64t/h

Development of CFB Power Plant Boiler

III. CFB Power Plant Boiler Design Fuel

  1. Design coal: AII soft coal, fuel characteristics are as follows:

Car=56.03%, Har=2.69%, Oar=2.11%, Nar=0.92%, Sar=0.54%, Aar=29.75%, War=7.96%, Vnet,ar=25%, Qnet=20934kJ/kg

  1. The particle size of coal: 0-13mm, less than 200μm is less than 10%, and over 13mm is less than 10%.

IV. CFB Power Plant Boiler Desulfurizer

The desulfurizer is limestone, and the composition is below.

Item Formula Unit Value
Calcium Carbonate CaCO3 % 92.6
Magnesium Carbonate MgCO3 % 2.8
Water H2O % 0.82
Other % 3.78

The boiler has an limestone interface at secondary air pipe, and limestone is sprayed into furnace through pneumatic conveying equipment. The particle size of limestone ranges from 0 to 2mm, and 50% cut particle size d50=250μm.

V. CFB Power Plant Boiler Dimension

Furnace width 8610mm

Furnace depth 4530mm

Drum center line elevation 39700mm

Boiler highest point (body) elevation 43800mm

Boiler highest point (roof) elevation 47000mm

Air-distribution plate elevation 5200mm

Operating level elevation 8000mm

Boiler width 10200mm

Boiler depth 19300mm