Wednesday, December 3, 2008

Calculate fuel flow

Fuel flow to a boiler is calculated as,

Fuel flow = (Heat duty x 1000 x 3.6) / (4.2 x GCV x Efficiency /100)

Thursday, September 4, 2008

Dulongs formula for GCV calculation

If we know the ultimate analysis of fuel, we can easily calculate its GCV.
The basic principle is that there are only 3 components in a fuel which generate heat. These are:
Carbon, Hydrogen and Sulphur.
According to Dulong's formula gross calorific value of a fuel is;
GCV = ((35.5 x C + 114.8 x H + 9.5 x S – 14.5 x O) x 1000) / (100 x 4.1868)
Each multiple of carbon, hydrogen and sulphur represents heat generated by its one mole.
The formula gives GCV in kcal/kg. Simple isnt it !

Boiler Heat Duty

Boiler heat duty = Tonnes per hour of steam generated x (Enthalpy of main steam - Enthalpy of feed water)

Various systems of a coal fired power plant

Coal Handling System: Consisting of crushers, conveyors, belts etc.
•Water treatment plant: Consisting of RO system, cation and anion exchangers, DM system, mixed bed system.
•Boiler package: PF, AFBC, CFBC etc.
•Turbine package: Consisting of turbine, generator, condensor (Air cooled or water cooled)
•Condensate system: With water cooled or air cooled condensor.
•Plant air system: Consisting of compressors, receivers
•Ash handling system: Slurry system or dense phase pneumatic ash handling system
•Electrical system including generation and distribution: Consisting of busbars, transformers, circuit brakers, MCC etc.
•Control and instrumentation along with DCS.: Consisting of transmitters, guages, PLC, DCS with the associated communication cables.
•Civil: With or without piling
•BOP package ( Air conditioning, ventilation, fire fighting, Public address system, plant illumination)

Types of steam Generators


Steam Generator Basics

Steam Generator is based on Rankine cycle

Definition: Equipment which produces steam from water with heat from fuel. Steam generator is also conventionally known as boiler.

Fuel analysis:
•a) Proximate analysis: Includes Fixed carbon, Volatile matter, Moisture and Ash %ages by mass.
•B) Ultimate analysis: Gives respective C, H, O, N, S, M, Ash %ages by mass.