Problem 1: Plot the adiabatic flame temperature, and equilibrium SO, SO2, NO, and NO2 concentrations for mixtures coal and biomass with biomass fractions ranging from 0 to 1. Assume two cases of air input: 25% theoretical and 20% excess air.
Below are the ultimate analyses for coal and biomass.
Table 1 Ultimate analysis in wt. % and higher heating value of coal and biomass (pine wood) samples
|
|
C
|
H
|
N
|
S
|
O
|
Ash
|
HHV (MJ/kg)
|
|
Coal
|
86.71
|
4.23
|
1.27
|
0.66
|
2.36
|
4.77
|
34.72
|
|
Biomass
|
53.43
|
6.64
|
0.14
|
0.05
|
38.89
|
0.85
|
22.31
|
Please show:
- Balanced chemical equation
- Example calculations
- Final plots
Problem 2: Calculate the time evolution for a population of 1000 burning particles. Assume that the surface area burning rate, f, is 0.5 mm2/min. Assume a diameter interval *Di = 0.2 mm centered around the following diameters di with specified fuel feed rate distribution, Fi, in each size interval:
|
i
|
1
|
2
|
3
|
4
|
|
di (mm)
|
0.1
|
0.3
|
0.5
|
0.7
|
|
Fi (kg/min)
|
0
|
0
|
0
|
1
|
This calculation will require simultaneous solution of 5 differential equations for each mass interval, Mi. Discuss the impact of 30% changes in surface area burning rate, combustion temperature, and particle porosity on the time required to combust all particles (defined as bin 1 containing >95% of particles).
- Combustion equations
- Combustion duration calculations
- Combustion parameter discussion