Biomass as Fuel in Small Boilers (PDF 6.4 - APO Asian Productivity ...

Solution:
Step 1) Find the theoretical air requirement
- 33 -
Performance Evaluation of Biomass Boilers
- Ambient temperature - 30 ºC
- Humidity of air - 0.018 kg/ kg of dry air
[(11.43×C)+{34.5×(H2-02/8)+(4.32×S)}]/100kg/kg of fuel
Step 2) Find the percentage of excess air supplied
Step 3) Find the actual mass of air supplied
Actual mass of Air supplied / Kg of fuel
Note: In order to make the calculation simple, the flue gas mass is taken as
actual mass of air supplied for combustion.
Step 4) Find the losses
i. Dry flue gas loss
= [(11.43×38.5)+{34.5×(5.7-39.8/8)+(4.32×0)}]/100
= 4.65kg of air / kg of rice husk
=
=
% 02
Excess Air Supplied(EA)=
(21-%02)
Excess Air Supplied(EA)=
= 6.97 kg of Air/kg of R.H
= 50%
[1+EA/100]×Theoretical Air
[1+50/100]×4.65
% heat loss due to dry flue gas =
% heat loss due to dry flue gas =
=
7
(21-7)
8.5 %
×100
×100
m×Cp×(Tf-Ta)×100
GCV of Fuel
6.97×0.23×(200-30)×100
3200