GE P&W FuelSolv - Slag Control Treatment Program at a Southeastern Utility - Manual (Page 5)

Technical Paper Page 5
Figure 3: Key Dates of Trial and Results Summary (for Gross Load >700 MW)
The data below (Figure 3) presents average parame-
ter values from the trial, implies that chemical
treatment does not adversely impact the boiler. A
longer trial could indicate if boiler operation signifi-
cantly improvers with chemical treatment while
burning the opportunity coal.
Infrared Photography
The trial team used port inspection and photog-
raphy to monitor boiler slagging conditions in the
furnace. The team developed a standardized nam-
ing convention for referencing boiler ports at vari-
ous elevations. For example, port “3A4E” refers to
Unit 3, Alpha side, Level 4, Port E. This ensured that
slagging conditions were properly recorded, since
more than a dozen trial team members viewed,
photographed, and commented on the visual condi-
tions during the trial.
Visual and infrared (IR) photos of conditions at the
various boiler elevation ports (Figure 4) were made
with an Olympus brand “point-and-click” digital
camera and a Mikron Lumasense brand infrared
camera.
Slag conditions inside the boiler were recorded with
a portable, battery-operated Lumasense Mikron-
brand model 7604F infrared camera.
The camera’s integral flame filter and high tem-
perature range covered the boiler’s operating
range throughout the trial and its multi-spot tem-
perature measurement capability enabled final
images to include reference temperature profiles,
(Mikron 2011). Thermal photos of the boiler slag
conditions were recorded at the boiler ports
throughout the trial.
Not only were visual observations of these condi-
tions important, they were, arguably, the best way
to measure the impact of chemical treatment on
boiler slag, since instantaneous changes in many
variables (such as sootblower activity, number of
pulverizers in operation, load changes, etc.) make
it difficult to compare with other parameters in
isolation (such as FEGT).
Several photos of the slagging conditions in the
boiler on November 23 and 30 (Figures 5 and 6)
clearly show the bottom of the superheater (SH)
pendant and no or minimal slag accumulation.
There was some initial concern about the under-
side of the tubes at Level 3; however, the slag was
removed with a firm push of a spade. Overall
slagging was considered minor at this point, and
noticeably worsened as the inspection continued
down the boiler. (The worst slag was near the
burners.)
PARAMETERS
(start – end dates)
10/18 –
11/14 11/15 –
11/23 11/30 –
12/3 12/4 –
12/8 12/10 –
12/12 12/17 12/18 –
12/20
NAPP Coal, % 0 16 33 33 50 50 50
Magnesium product, lbs/ton 0 3.0 2.0 1.5 1.5 1.0 1.1
Metal oxide product, lbs/ton 0 0 0 0.25 0.25 0.25 0.275
# of Pi data points 4,118 342 634 391 699 123 771
Avg # of sootblows/day 36 57 63 82 104 94 157
Avg Heat Input, MMBtu/hr 7,003 7,060 6,278 6,216 6,892 6,953 6,986
Avg Coal to Boiler, ton/hr 336 321 325 327 327 332 331
U3A Avg Max FEGT, o F 2,318 2,683 2,602 2,496 2,468 2,561 2,627
U3B Avg Max FEGT, o F 2,497 2,536 2,464 2,486 2,521 2,479 2,511