Table of Contents
Advertisement
5.9
Combustion air adjustment
Fuel/combustion air synchronisation is done with the relevant
servomotors (air and gas) by logging a calibration curve by
means of the electronic cam.
It is advisable, to reduce the loss and for a wide calibration field,
to adjust the servomotors to the maximum of the output used, the
nearest possible to the maximum opening (90°).
On the gas butterfly valve, fuel step according to the burner
output required, with servomotor completely open, is carried out
by the pressure stabiliser placed on the gas train.
The values indicated in Tab. M and Table N on page 33 can be a
reference for a good combustion calibration.
5.9.1
Air / gas adjustment and output modulation
The burner system for air/fuel adjustment and power modulation
performs - in one single control device - a series of integrated
functions to obtain optimal energy/operating efficiency from the
burner, both for single operation and when combined with other
units (e.g. double furnace boiler or several generators working in
parallel).
The basic system functions control:
1
the dosage of the air and fuel through positioning, using
direct servo-commands, of the relevant valves eliminating
the possible play in the calibration systems with mechanical
cam lever mechanisms, used on traditional modulating
burners;
2
the modulation of the burner output in accordance with the
load required by the system, with maintenance of the
pressure or temperature of the boiler at the operating values
set;
3
the fine correction, in continuous mode, of the air flow rate
according to the flue gas analysis performed at the flue
(O2); this function is associated with the presence of the O2
Kit containing the PLL module and the QGO2 sensor;
4
the measurement of the combustion yield (this function
requires the O2 kit);
5
the sequence (cascade adjustment) of several boilers,
suitably connected.
Further interfaces and communication functions with computers,
for remote control or integration in central supervision systems
are available on the basis of the configuration of the system.
The first start up and every further internal setting
operation of the adjustment system or the
expansion of the base functions require access by
means of password and are to be carried out by
ATTENTION
service personnel who are especially trained for
the internal programming of the instrument and
the specific application created with this burner.
The first start-up and curve synchronisation manual is supplied
with the burner.
At request, the complete manual for the control and setting of all
parameters is available.
Start-up, calibration and operation of the burner
5.9.2
Pressure switch adjustment
Being that the values of the reference pressures cannot be
determined before starting the calibration, the following
operations must be performed (with burner off):
•
open the manual valves upstream of the gas train;
•
adjust the minimum gas pressure switch (Fig. 33, on
page 30) on the gas train, to the start of the scale;
•
adjust the maximum gas pressure switch (Fig. 32, on
page 30) on the butterfly valve to the end of the scale;
•
adjust the air pressure switch (Fig. 31, on page 30), on the air
box of the burner, to the start of the scale.
29
GB
20184914
Advertisement
Table of Contents
