Showing posts with label calorific values. Show all posts
Showing posts with label calorific values. Show all posts

Monday 23 May 2016

Calorific values

Calorific values

The calorific value of a fuel is the quantity of heat produced by its combustion - at constant pressure and under "normal" ("standard") conditions (i.e. to 0oC and under a pressure of 1,013 mbar).

The combustion process generates water vapor and certain techniques may be used to recover the quantity of heat contained in this water vapor by condensing it.
  • Higher Calorific Value (or Gross Calorific Value - GCV, or Higher Heating Value - HHV) -  the water of combustion is entirely condensed and that the heat contained in the water vapor is recovered
  • Lower Calorific Value (or Net Calorific Value - NCV, or Lower Heating Value - LHV) - the products of combustion contains the water vapor and that the heat in the water vapor is not recovered
FuelHigher Calorific Value
(Gross Calorific Value - GCV)
Lower Calorific Value
(Net Calorific Value - NCV)
kJ/kgBtu/lbkJ/kg
Acetone29000
Alcohol 96%30000
Anthracite32500 - 3400014000 - 14500
Bituminous coal17000 - 232507300 - 10000
Butane495102090045750
Carbon34080
Charcoal2960012800
Coal (Lignite - Anthrasite)15000 - 270008000 - 14000
Coke28000 - 3100012000 - 13500
Diesel fuel448001930043400
Ethane5190047800
Ethanol2970012800
Ether43000
Gasoline473002040044400
Glycerin19000
Hydrogen14179061000121000
Kerosene4620043000
Lignite163007000
Methane55530 50000
Methanol23000
Oil, heavy fuel43000
Oil, light distillate48000
Oil, light fuel44000
Oils vegetable39000 - 48000
Paraffin4600041500
Peat13800 - 205005500 - 8800
Pentane45350
Petrol48000
Petroleum43000
Propane50350 46350
Semi anthracite26700 - 3250011500 - 14000
Sulfur9200
Tar36000
Turpentine44000
Wood (dry)14400 - 174006200 - 7500
kJ/m3Btu/ft3
Acetylene56000
Butane C4H101330003200
Hydrogen13000
Natural gas43000950 - 1150
Methane CH439820 
Propane C3H81010002550
Town gas18000
kJ/lBtu/Imp gal
Gas oil38000164000
Heavy fuel oil41200177000
Kerosene35000154000
  • 1 kJ/kg = 1 J/g = 0.4299 Btu/ lbm = 0.23884 kcal/kg
  • 1 Btu/lbm = 2.326 kJ/kg = 0.55 kcal/kg
  • 1 kcal/kg = 4.1868 kJ/kg = 1.8 Btu/lbm
  • 1 dm3 (Liter) = 10-3 m3 = 0.03532 ft3 = 1.308x10-3 yd3 = 0.220 Imp gal (UK) = 0.2642 Gallons (US)

Difference between stress and strain

What is the difference between stress and strain? Answer: Stress is the internal resistance force per unit area that opposes deformation, w...