U2 COMBINATION VIEWING HEAD AND SIGNAL PROCESSORS
66-2071—02
14
After all burners are in service and boiler load is above 90%,
perform the following for discrimination tests and adjustments.
a. Turn off the burner
b. Check if background signal is below “Flame Off”
threshold. If not, increase Flame Off threshold so
the background count is below set point. If the back-
ground flame signals are too high, increase IR filter
setting to a higher value starting with 2
3
4
5, until background count is below Flame Off thresh-
old point.
NOTE: With IR sensor, two adjustments are available: gain
and flicker set point. Both may require adjustment to
obtain the required discrimination. In general, flicker
filter adjustment works better for discrimination than
gain adjustment.
c. After 1 minute, re-start burner on pilot and main oil
burner.
d. Check that U2 recognizes the pilot and main flames.
If the flame signal is below Flame On threshold,
lower Flame On threshold below flame on signal.
e. Repeat all tests if any changes are made to Gain,
Flicker set point, Flame On and Flame Off Thresh-
old.
NOTE: Above is simplified version of adjustment. Ves-
sels equipped with a large number of burners,
“T” fired units and cross fired boilers will require
several adjustments including use of multiple
files for obtaining the required discrimination.
Manual Configuration for Coal Firing
Applications with Multiple Burners
In general, coal firing units are equipped with several coal
mills. Each coal mill may supply pulverized coal to several
burners.
For units equipped with a gas igniter and gas warm-up
burners, two dedicated files for each U2 are highly
recommended. One file should be dedicated to the gas igniter
and warm-up gas burners, and the other to main coal.
For units equipped with a gas igniter and oil warm-up burners,
two files are recommended; one file for the gas igniter and the
other for the oil warm-up burners and main coal firing.
NOTE: Alternately, 3 files may be used, however, only
two files may be selected via the “File Select” 0/
24 Vdc input on the U2. The third file must be
selected via a Modbus RTU interface. Refer to
Table 3 and the “FILE” section of this document.
CAUTION
ALL ADJUSTMENTS SHOULD BE CARRIED OUT
BY A QUALIFIED PERSON.
BMS interlock(s) may require temporary bypass during
configuration. This operation should be carried out
under supervised conditions and limited to minimum
time. Remove bypasses as soon as configuration and
setup is completed.
For vessels equipped with gas igniters, follow setup procedure
described above. For best discrimination, two to three files
may be required to accommodate three different fuel firings.
1.
Establish igniter flame as described above.
2.
Start warm-up oil burner.
3.
Go to IR menu and adjust gain setting to 50.
4.
If equipped with UVSS sensor adjust gain to 0
5.
Adjust IR filter to 1 and UVSS filter to 9
6.
Go to milliamp output gain and adjust to 50
7.
Go to Flame ON and adjust to 1200
8.
Go to Flame off and adjust to 800
9.
Go To FFRT and adjust to 3 seconds
10.
Go to Time Delay and adjust to zero “0” seconds
11.
With oil firing at the minimum on the first burner - adjust
gain up or down to be just above 1200
12.
One by one light-off the remaining burners and adjust
gain as necessary.
13.
When all mill burners are firing oil, start pulverizer sys-
tem.
14.
Adjust mill output to minimum coal flow as recommend
by the manufacturer.
15.
If the signal is still above Flame On for all burners asso-
ciated with the mill, no further adjustment will be neces-
sary.
16.
Repeat for at least one more mill by establishing gas
igniters and oil burners for the mill.
17.
When first Mill is established, turn off the warm-up burn-
ers - one by one. If the signal falls below the Flame Off
point, adjust gain to higher value so that signal remains
above Flame Off point.
18.
After all oil burners and igniters are off, adjust mill coal
flow as per manufacturer recommendations.
19.
Repeat for all mills.
20.
Go back to first mill - reduce coal flow to minimum.
21.
Establish igniter and oil burners.
22.
Stop the mill as per manufacturer's recommendations.
23.
Sweep the mill of coal and then shutdown oil burners; if
igniters are in service, turn off igniters.
24.
If the flame signal from the back ground is above the
Flame Off point - increase Flame Off set point and/or
increase filter frequency set point.
25.
Make adjustment to all units associated with this mill.
26.
RE-ESTABLISH THE MIL AND REPEAT THE ABOVE
FOR THE REMAINING MILLS - ONE AT A TIME.
NOTE: Above is simplified version of adjustment. Ves-
sels equipped with a large number of burners,
“T” fired units and cross fired boilers will require
several adjustments including use of multiple
files for obtaining the required discrimination.
AUTOMATIC SETUP
NOTE: For single burner systems only. Multiple burners
require several manual adjustments to obtain the
proper discrimination.
