Unigas N880X-FGR, Руководство по установке, использованию и обслуживанию, Страница: 15 / 60

PART II: NOTES FOR THE INSTALLER
15
How to read the burner “Performance curve”
To check if the burner is suitable for the boiler to which it must be install-
led, the following parameters are needed:

furnace input, in kW or kcal/h (kW = kcal/h/860);

backpressure (data are available on the boiler ID plate or in the
user’s manual).
Example:
Furnace input: 600kW
Backpressure: 4 mbar
In the “Performance curve” diagram, draw a vertical line matching the fur-
nace input value and an horizontal line matching the backpressure value.
The burner is suitable if the intersection point A is inside the performance
curve.
Data are referred to standard conditions: atmospheric pressure at 1013
mbar, ambient temperature at 15° C.
Checking the proper gas train size
Matching the burner to the boiler
(
low NOx burners)
The burners described in this manual have been tested with combustion chambers that comply with EN676 regulation and whose
dimensions are described in the diagram . In case the burner must be coupled with boilers with a combustion chamber smaller in dia-
meter or shorter than those described in the diagram, please contact the supplier, to verify that a correct matching is possible, with
respect of the application involved. To correctly match the burner to the boiler verify the type of the blast tube . Verify the necessary
input and the pressure in combustion chamber are included in the burner performance curve; otherwise the choice of the burner must
be revised consulting the burner manufacturer. To choose the blast tube lenght consider the following rule, even if it differs from the
instructions of the boiler manufacturer: Cast-iron boilers, three pass flue boilers (with the first pass in the rear part): the blast tube must
protrude at least 150÷200 mm into the combustion chamber.The length of the blast tubes does not always allow this requirement to be
met, and thus it may be necessary to use a suitably-sized spacer to move the burner backwards.
To check the proper gas train size, it is necessary to the available gas pres-
sure value upstream the burner’s gas valve. Then subtract the backpressure.
The result is called
pgas. Draw a vertical line matching the furnace input
value (600kW, in the example), quoted on the x-axis, as far as intercepitng
the network pressure curve, according to the installed gas train (DN65, in the
example). From the interception point, draw an horizontal line as far as
matching, on the y-axis, the value of pressure necessary to get the reque-
sted furnace input. This value must be lower or equal to the
pgas value, cal-
culated before.
WARNING! Carefully seal the free space between blast tube and the refractory lining with ceramic fibre rope or
other suitable means.
PART II: NOTES FOR THE INSTALLER
Campo di lavoro bruciatori
Tipo P60 Mod. M-xx.x.IT.A.0.50 - M-.xx.x.IT.A.0.65
-1
0
1
2
3
4
5
6
7
8
100 200 300 400 500 600 700 800 900
Potenza kW
Contropressione in camera di
combustione mbar
A
ba
ckpr
essu
re in
co
m
bu
st
ion
ch
am
b
e
r
(m
b
ar
)
Power kW
0
5
10
15
20
25
100 200 300 400 500 600 700 800 900
Potenza / Output (kW)
Minima pressione gas in
rete / Minimum inlet gas
pressure (mbar)
Rp 2" (50)
DN65
Power kW
minimu
m
ga
s pre
ssur
e
in
the net
work mbar
DN65
150÷200 mm
5° MAX
Fig. 1
ceramic fibre
refactory wall
Fig. 2