Eco-friendly Horizontal High Pressure CFB Boilers for Power Plant
1.What is CFB Boiler?
- Circulating fluidized bed boiler adopts clean coal combustion technology with the highest degree of industrialization.
- Circulating fluidized bed boiler adopts fluidized combustion.
- Its main structure consists of combustion chamber (dense phase zone and dilute phase zone) and recycling furnace (including high temperature gas-solid separator and recycling system). Compared with bubbling fluidized bed combustion technology, the biggest difference is that the operation wind speed is high, which strengthens the heterogeneous reaction process of combustion and desulfurization.
- The boiler capacity can be expanded to a large capacity acceptable to the power industry (600 MW or above).
- The circulating fluidized bed boiler has solved the basic problems of thermology, mechanics, materials, expansion, wear and overheating, etc. well, and has become an engineering problem.
- Advanced technologies for energy utilization of non-flammable solid fuels such as coal gangue, oil shale, municipal waste, sludge and other wastes.
2.What is fluidization of CFB Boiler?
- When the solid particles in the fluid through, as the fluid velocity increases gradually, solid particles began to exercise, and the friction between solid particles is becoming more and more big, when the velocity reaches a certain value, the friction between solid particles and their gravity is equal, each particle can freedom of movement, all solid particles showed similar flow state of the phenomenon, this phenomenon is called fluidization.
- For solid particles with fluidized liquid and solid, the particles are uniformly distributed in the bed, which is called "loose fluidization".
- For gas-solid fluidized solid particles, the gas does not flow through the bed uniformly, the solid particles are divided into groups for turbulent movement, the void in the bed varies with the position and time, this fluidization is called "clustering" fluidization.
- Circulating fluidized bed boiler belongs to fluidization of "cluster type".
- Solid particles (bed material), fluid (fluidized air) and equipment to complete the fluidization process are called fluidized beds.
3.What is the structure of CFB Boiler?
- Boiler adopts single drum and natural circulation mode. Generally, it is divided into two shafts, the front and the tail. The front shaft is the main suspension structure and is surrounded by a membrane water wall. From bottom to top, the sequence is primary air chamber, dense phase zone and dilute phase zone, and from top to bottom, the tail flue is high temperature superheater, low temperature superheater, economizer and air preheater. The tail shaft adopts a supporting structure. The two shafts are connected by a vertical cyclone separator, and the lower part of the separator is connected with a return device and a ash cooler. There are anti-wear lining inside the combustion chamber and separator, pipe-laying furnace wall for the front shaft, external metal guard plate, light furnace wall for the tail shaft, and all the weight of the boiler is borne by eight steel pillars.
- Boiler uses under-bed ignition (oil or gas), staged combustion, primary air ratio accounts for 50-60%, fly ash circulation is low rate, medium temperature separation of ash and slag discharge is dry, respectively by water-cooled screw slag discharger, ash cooler and dust collector ash bucket discharge. Furnace is the key to ensure full combustion of fuel. Turbulent bed is used to make fluidization rate 3.5-4.5 m/s, and appropriate furnace cross section is designed. Thin lining (high alumina brick) is laid on the furnace membrane wall tube. Even when the boiler burns different fuels, the combustion efficiency can be maintained above 98-99%.
- The inlet flue gas temperature of the high temperature separator is about 800 C. The inner diameter of the cyclone is smaller and the structure is simplified. Only a thin anti-wear lining (silicon nitride brick) is needed in the cyclone. Its service life is longer. The circulation rate is about 10-20.
- The circulating ash conveying system is mainly composed of return pipe, return device, overflow pipe and ash cooler.
- The adjustment process of the bed temperature control system is automatic. In the whole load range, a constant value of dense phase bed temperature between 850 and 950 C is maintained, which is the optimum desulfurization temperature. When the automatic control is not put into operation, the constant bed temperature can be maintained manually.
- Protecting the environment and saving energy are the most important considerations in the long-term development of various countries. Circulating fluidized bed boilers are developed on the basis of this point. Their high reliability, high stability, high utilization rate, best environmental protection characteristics and extensive fuel adaptability, especially for inferior fuels, have attracted more and more attention and are fully suited to China's national conditions and development advantages.
4.What are the benefits of CFB Boiler?
Greatest Fuel Flexibility
• Best overall solution for high moisture fuels.
• Ability to burn fuels containing mid-level amounts of alkali.
• Proficient at combusting fuels from the extreme low-end to extreme high-end moisture contents.
• Lowest excess oxygen required for complete combustion.
• Lowest unburned carbon.
Highest Allowable Outputs
• Highest Pressure.
• Highest Temperature.
• Steam Flow (up to 1,000,000 PPH).
|Rated steam pressure
|Rated steam temperature
|Feed water temperature
||Anthracite, lean coal, bituminous coal, lignite, petroleum coke, breeze, etc.
|Number of coal feeder
|Super heater thermostat mode
|Pre-heater air temperature
|Exhaust gas temperature
6.Why should you choose CFB Boiler?
- 1100 employees, 400,000 ㎡ with fixed assets amounting to USD 110,000,000, 34 years experience, ISO9001, SO3834, EN12952 certificated, 150km expressway to Shanghai,60km state road to Suzhou or Wuxi, this is how we keep superior quality and competitive offers for global valued customers.
- Our main products cover Utility Boiler, HRSG Boiler, coal-fired , oil(gas) -fired, coal-water-slurry-fired and garbage-fired steam/hot water boilers, organic heat carrier boilers, etc., and Boiler spare parts (Economizer, Finned tube, Header, Steam drum, Superheater, Water wall panel, Air preheater, Cyclone separator, etc., which are widely used in power generation, heat supply, chemical engineering, textile, food, paper, road building, plastic, rubber and wood working industries.
7.How to contact us?