FLUIDISED BED COMBUSTION








Fluidised Bed Combustion (FBC) is a very flexible method of electricity production – most combustible material can be burnt including coal, biomass and general waste.

FBC systems improve the environmental impact of coal-based electricity, reducing SOx and NOx emissions by 90%.

In fluidised bed combustion, coal is burned in a reactor comprised of a bed through which gas is fed to keep the fuel in a turbulent state. This improves combustion, heat transfer and recovery of waste products. The higher heat exchanger efficiencies and better mixing of FBC systems allows them to operate at lower temperatures than conventional pulverised coal combustion (PCC) systems. By elevating pressures within a bed, a high-pressure gas stream can be used to drive a gas turbine, generating electricity.

FBC systems fit into two groups, non-pressurised systems (FBC) and pressurised systems (PFBC), and two subgroups, circulating or bubbling fluidised bed.

· Non-pressurised FBC systems operate at atmospheric pressure and are the most widely applied type of FBC. They have efficiencies similar to PCC – 30-40%.

· Pressurised FBC systems operate at elevated pressures and produce a high-pressure gas stream that can drive a gas turbine, creating a more efficient combined cycle system – over 40%.

· Bubbling uses a low fluidising velocity – so that the particles are held mainly in a bed – and is generally used with small plants offering a non-pressurised efficiency of around 30%

· Circulating uses a higher fluidising velocity – so the particles are constantly held in the flue gases – and are used for much larger plant offering efficiency of over 40%

The flexibility of FBC systems allows them to utilise abandoned coal waste that previously would not be used due to its poor quality.

Comments

Post a Comment

Popular posts from this blog

INDIAN MINING & CONSTRUCTION EQUIPMENT INDUSTRY

Image
BACKGROUND & HISTORICAL TRENDS Construction and mining equipment cover a variety of machinery such as hydraulic excavators, wheel loaders, backhoe loaders, bull dozers, dump trucks, tippers, graders, pavers, asphalt drum / wet mix plants, breakers, vibratory compactors, cranes, fork lifts, dozers, off-highway dumpers (20T to 170T), drills, scrapers, motor graders, rope shovels etc. They perform a variety of functions like preparation of ground, excavation, haulage of material, dumping/laying in specified manner, material handling, road construction etc. These equipments are required for both construction and mining activity. With a wide production capacity base, India is perhaps the only developing country, which is totally self-reliant in such highly sophisticated equipment. India has only a few, mainly medium and large companies in the organized sector who manufacture these. The technology barriers are high, especially with respect to mining equipment and therefore the role of SM
Read more

MISSION AND VISION OF CIL

The MISSION of Coal India is to produce & market planned quantity of coal & coal products efficiently & Economically with due regards to safety, conservation & quality. The VISION of Coal India is to emerge as a global player in the primary energy sector committed to provide energy security to the country by attaining environmentally and socially sustainable growth through best practices from mine to market.
Read more

Questionare on CMR & CMA

Questionare on CMR & CMA   Q1. Which cut is used for solid blasting in Indian coal Mines a)  Fan cut  b) burn cut  c) wedge cut d) drag cut   Q2. Permitted explosives are safe to use because a) They have less strength b) they have low velocity of detonation c) they do not produce much noise during blasting d) special chemical are used to extinguish the spark produced during blasting.   Q3. Burden is the distance between a)      Two blast holes in same row b)      distance between two rows c)       distance between first row of blast holes and bench d)      d) none of the above   Q4. Which of the following explosive have maximum strength a)      ANFO b) TNT c) RDX d) Nitroglycerine   Q5. To measure the performance of blasting which factor is calculated a)   Tonnage factor  b) space factor c) stripping ratio d) Powder factor   Q6.  What is the formula for blast ability? a) B = c / t      b)B=t / c     c) B = c + t    d) B=  c X t  
Read more