KANE905 Operators Manual
Page 44
Since the fuel air mixture is never consistent there is the possibility of
unburned/partially unburned fuel passing through the flue. This is
represented by the unburned carbon loss.
Losses due to combustible matter in ashes, riddlings, dust and grit,
radiation, convection and conduction are not included.
Efficiency Calculation:
Known Data - Fuel: Qgr = Gross Calorific Value (kJ/kg)
Qnet = Net Calorific Value (kJ/kg)
K1 = Constant based on Gross or Net Calorific
Value:
K1g = ( 255 x %Carbon in fuel )/Qgr
K1n = ( 255 x %Carbon in fuel )/Qnet
K2 = % max theoretical CO2 (dry basis)
K3 = % Wet Loss
H
2
= % Hydrogen
H
2
O = % Water
Measured Data:
Tf
= Flue Temperature
Ti
= Inlet Temperature
O
2
m = % Oxygen in flue gas
O
2
r = Oxygen reference %
Calculated data:
Tnet = Net Temperature
% CO2 content in flue gas
% Dry Flue Gas losses
% Wet losses
% Unburned carbon loss
% Efficiency
Tnet
= Flue Temperature - Inlet Temperature
Dry flue gas loss
%
= 20.9 x K1 x (Tnet) / K2 x (20.9 - O2m)
Wet loss %
= 9 x H2 + H2O / Qgr x [2488 + 2.1Tf - 4.2
Ti]
simplified
= [(9 x H2 + H2O) / Qgr] x 2425 x [1 + 0.001
Tnet]
Wet loss %
= K3(1+0.001xTnet)
