Page 155 - Mechanical Engineer's Data Handbook

144 MECHANICAL ENGINEER’S DATA HANDBOOK

Combustion products (YO volume)

Wet analysis sc + vc ’h 100(21R - k) 100( Vn + 79R)
100- 50 -
Y Y Y Y
Dry analysis sc+ vc 100(21R-k) 100( Vn + 79R)
100 - 0
X X X

3.16.8 Calorific value of fuels Liquid (kJ kg-‘; 1YC)
Petrol (gasoline) 47 OOO 43 900
The calorific value of a fuel is the quantity of heat average average
obtained per kilogram (solid or liquid) or per cubic Benzole (crude benzene) 42 OOO 40 200
metre (gas) when burnt with an excess of oxygen in a Kerosene (paraffin) 46 250 43 250
calorimeter. Diesel 46 OOO 43 250
If H,O is present in the products of combustion as a Light fuel oil 44 800 42 100
liquid then the ‘higher calorific value’ (HCV) is Heavy fuel oil 44OOo 41 300
obtained. If the H,O is present as a vapour then the Residual fuel oil 42 100 4oOOO
‘lower calorific value’ (LCV) is obtained.
Gas (MJm-’; 15°C; I bar)
LCV=HCV-207.4%H2 (by mass) Coal gas 20.00 17.85
Producer gas 6.04 6 .00
Calorific value of fuels Natural gas 36.20 32.60
Blast-furnace gas 3.41 3.37
Higher Lower Carbon monoxide 11.79 11.79
calorific calorific Hydrogen 11.85 10.00
value value

Solid (kJkg-’; 15°C) 3.16.9 Boiler emciency
Anthracite 34 600 33 900
Bituminous coal 33 500 32 450 This may be based on either the HCV or the LCV.
Coke 30 750 30 500
Lignite 21 650 20 400 Boiler efficiency E,= ms(hh -hw)
Peat 15 900 14500 m,(HCV or LCV)
where:
ms = mass flow of steam
&=mass flow of fuel
h, = enthalpy of steam
hw = enthalpy of feed water