BOILER ACCESSORIES

BOILER ACCESSORIES:
Boiler can fail by explosion as a results of either faulty construction or improper operation .To minimize the danger of failure the following are added to the boiler:
1-Pressure gage for saturated steam pressure recording.
BOILER AUXILIARIES:
1-Superheater 2-Air preheater

BOILER HEAT BALANCE:
1-Usefuel (heat absorbed by steam) =m ?(h_f+xh_fg-h_w)
2-Heat absorbed in boiler fluids
a-preheater b-superheater c- reheater d-economizer
3- Heat loss to dry gases.
4-Heat loss to moisture content .
5-heat loss due to evaporation of moisture.
6- heat loss due to co formation.
7- heat loss due to unburned fuel .
8- heat loss due to exhaust gases.
9- heat loss by radiation.( Hgained -Hlosses)

HEAD LOSSES AND BOILER EFFICIENCY:
Conversion of energy from fuel to potential energy of steam is accompanied by heat losses.
?f =(heat generated from 1 kg fuel by furnce)/(lower calorific value of fuel)

?f =Q_f/H_L
HL > Qf
Heat surface (?h):
?h=h_s/Q_f < 1
?h: involves heat losses from the hot gases to the steam

?h=0.61- 087