CHAPTER 4: INITIAL START-UP
PR2: 04/22/13 Page
45
of
158
Benchmark 2.0LN Dual-Fuel Low NOx Boiler
Operation and Maintenance Manual
OMM-0052_0E
GF-127
AERCO International, Inc.
•
100 Oritani Dr.
•
Blauvelt, NY 10913
•
Ph: 800-526-0288
Figure 4-4: Gas Pressure Adjustment Screw Location
9. Set the
ON/OFF
switch to the
ON
position.
10.
Change the valve position to 34% using the ▲ arrow key. The unit should begin its start
sequence and fire.
11. Next, verify that the gas pressure downstream of the SSOV is 7.3” W.C. for both FM and
DBB (IRI) gas trains. If gas pressure adjustment is required, remove the brass hex nut
on the Natural Gas SSOV actuator containing the gas pressure adjustment (Figure 4-4).
Make gas regulator adjustments using a flat-tip screwdriver to obtain 7.3” W.C.
12. Increase the valve position to 100% and verify that the gas pressure downstream of the
SSOV remains at 7.2” W.C. Readjust pressure if necessary.
13. With the valve position at 100%, insert the combustion analyzer probe into the flue probe
opening and allow enough time for the combustion analyzer to settle.
14. Compare the measured oxygen level to the oxygen range for the inlet air temperature
shown in Table 4-1. Also, ensure that the carbon monoxide (CO) and nitrogen oxide
(NOx) readings do not exceed the values shown.
Table 4-1: Combustion Oxygen Levels for a
100%
Air/Fuel Valve Position
Inlet Air Temp
Oxygen %
± 0.2
Carbon Monoxide
NOx
>100°F
5.5 %
<100 ppm
<20 ppm
90°F
5.7 %
<100 ppm
<20 ppm
80°F
5.9 %
<100 ppm
<20 ppm
<70°F
6.0 %
<100 ppm
<20 ppm
15. If necessary, adjust the iris air damper shown in Figure 4-5 until the oxygen level is
within the range specified in Table 4-1.
16. Once the oxygen level is within the specified range at 100%, lower the valve position to
80%.
