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Pellet - Heating value

Pellet - Heating value

   Heat of combustion is the full heat energy (defined in watt) that is released while 1 kg of fuel undergoes complete combustion. One part of full heat energy goes to the vaporization of released water and to warming incombustible components up. The difference of this heat energy and the heat of combustion is called heating energy (or energy value) of fuels, defined in watt and meant under complete combustion of 1kg of fuel. The heating value of 2 kg of wood pellet amounts to the heating value of 1m3 of natural gas (36MJ/m3).

  Wood pellet Energy grass pellet
Heating value (MJ/kg) 18.3 16.5
Heating value (kWh/kg) 5.10 4.58
Ash content (%) 0.5 - 1 7.5 - 11

   Wood pellet is used in pellet stoves and furnaces. Since pelletizing made wood possible to be dissolved, these equipment do not really differ from oil and gas furnaces. Each construction is fitted up with fuel tank, burner head and specific heat exchanger. The temperature of flame released by the burner head in wood pellet furnace is 800-1000 °C, while the temperature of flue-gas is 70-100 °C, which concludes that the system works with 90% efficiency. A family-size pellet bin generally holds 1 m3 of wood pellet. After combustion, the residual cinder on cinder tray is 0.5-1 kg. A furnace with 35 kW capacity combusts 1 m3 of wood pellet in 4 weeks approximately, hence the need of cleaning is rare. Cleaning takes 5 minutes.