Combustion Phenomena of High Temperature Air Combustion - High Temperature Air Combustion: From Energy Conservation to Pollution Reduction - page 137

1500

1400

1300

1200

1100

1000

Wall temperature top
Wall temperature side

900

800

0 1 2 3 4 5 6

Axial distance, m

FIGURE 2.101 Wall temperature (top and side).

FIGURE 2.102 Baseline coal flame.

2.5.3.4.1 Heat and Mass Balance
Detailed heat and mass balances are shown in Figure 2.103 for HTAC97, HTAC98,
and HTAC99 experiments.
The composition of the comburent going into the furnace is similar for the three
cases. During the HTAC97 preheated air was used in the precombustor resulting in
higher NO x concentration in the comburent. The fuel thermal input in the HTAC99
is 580 kW as in the previous trials. The coal burner is operated at 20% excess air,
giving a stoichiometric ratio of λ = 1.2. The furnace efficiency is calculated as:

H
H

η=

ext

× 100

in