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POWER PLANT ENGINEERING
The main characteristic of a grate fired furnaces are the heat liberation
per unit of grate area and
per unit of volume. The heat liberation per unit area of fire grate area is calculated as follows:
H = (W × C)/A
where
H = Heat liberation per unit of fire grate area
W = Rate of fuel consumption (kg/sec)
C = Lower heating value of fuel (kcal/kg)
A = Fire grate area (m
2
)
The heat liberation per unit of furnace volume is given by the following expression:
H = (W × C)/V
where
H = Heat
liberation per unit volume
W = Rate of fuel consumption (kg/sec)
C = Lower heating value of fuel (kcal/kg)
V = Volume of furnace (m
3
).
These two characteristics depend on the following factors :
(
i) Grade of fuel
(
ii)
Design of furnace
(
iii) Method of combustion.
Ash pit
Furnace
Space
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