1 Introduction
2 Experimental methodology
2.1 Laboratory-scale coal burner
Proximate analysis | wt% | |
---|---|---|
Volatile matter | 34.80 | |
Fixed carbon | 50.80 | |
Moisture | 5.80 | |
Ash | 8.60 |
Ultimate analysis | wt% | |
---|---|---|
Carbon | 69.20 | |
Hydrogen | 4.40 | |
Oxygen | 9.98 | |
Nitrogen | 1.42 | |
Sulfur | 0.58 |
Sieve pitch (μm) | Cum. mass% | Mass% |
---|---|---|
500 | 100 | 10 |
210 | 90 | 28 |
150 | 62 | 12 |
75 | 50 | 22 |
<75 | 28 | 28 |
Lower heating value (MJ/kg) | 27.12 |
2.2 Test conditions
Parameter | Carrier | Pilot | Coflow |
---|---|---|---|
Volume flow rate (m3/h, STPa) | 6.0 | 4.0 | 14.4 |
Mass flow rate (g/s) | 1.9–2.6 | 1.25 | 4.74 |
Bulk equivalence ratio (–) | 1.2–2.3 | 1.0 | |
Reynolds number (Re) | 6200 | 1518 | 1944 |
Temperature (K) | 293 | 293 | 293 |
Thermal input (kW) | 4.9b–17.4 | 3.4 |
Case | Flow rate coal mass (g/s) | Volume flow rate \((\hbox {m}^3/\hbox {h},\hbox { STP})\)
| Composition (vol. %) | Carrier
\(\phi _{CH_4}\) (–) | Bulk
ϕ (–) | Adiabatic flame temperaturea (K) | |
---|---|---|---|---|---|---|---|
\(\hbox {O}_2/\hbox {CO}_2/\hbox {N}_2/\hbox {CH}_4\)
|
\(\hbox {O}_2/\hbox {CO}_2/\hbox {N}_2\)
| Gas only | Gas + coal | ||||
A1 | 0.15 | 1.6/0.0/3.8/0.5 | 30/0/70 | 0.66 | 1.28 | 2095 | 2561 |
A2 | 0.31 | 1.6/0.0/3.8/0.5 | 30/0/70 | 0.66 | 1.97 | 2095 | 2097 |
A3 | 0.46 | 1.6/0.0/3.8/0.5 | 30/0/70 | 0.66 | 2.63 | 2095 | 1575 |
O1 | 0.46 | 1.6/3.5/0.3/0.5 | 30/64/6 | 0.66 | 2.63 | 1713 | 1269 |
O2 | 0.46 | 2.2/3.0/0.3/0.5 | 40/54/6 | 0.50 | 1.91 | 1738 | 2142 |
O3 | 0.46 | 2.5/2.7/0.3/0.5 | 45/49/6 | 0.44 | 1.68 | 1833 | 2516 |