22-05-2012, 01:12 PM
FUels and Combustion
FUels and Combustion .ppt.ppt (Size: 2.51 MB / Downloads: 54)
Introduction
Solar energy is converted to chemical energy through photo-synthesis in plants
Energy produced by burning wood or fossil fuels
Fossil fuels: coal, oil and natural gas
Calorific value
Calorific value is the total quantity of heat liberated when a unit mass of fuel burn completely.
Measured at 25˚C.
Heat or energy produced
Gross calorific value (GCV): vapour is fully condensed
Net calorific value (NCV): water is not fully condensed.
NCV = GCV – (mass %hydrogen)(9)(λv)kJ/kg
λv –latent heat of water vapour at reference temperature, normally at 298.15K.
λv at 298.15K = 2442.5kJ/kg.
Liquid Fuels
Usage
Used extensively in industrial applications
Examples
Furnace oil
Light diesel oil
Petrol
Kerosine
Ethanol
LSHS (low sulphur heavy stock)
Specific gravity
Ratio of weight of oil volume to weight of same water volume at a given temperature
Specific gravity of water is 1 at 4˚C.
Hydrometer used to measure