PART I: SPECIFICATIONS
10
1.6 How to read the burner “Performance curve”
To check if the burner is suitable for the boiler to which it must be instal-
lled, the following parameters are needed:
z
furnace input, in kW or kcal/h (kW = kcal/h / 860);
z
backpressure (data are available on the boiler ID plate or in the
user’s manual).
Example:
Furnace input: 600kW
Backpressure: 4mbar
In the “Performance curve” diagram, draw a vertical line matching the
furnace input value and an horizontal line matching the backpressure
value. The burner is suitable if the intersection point A is inside the per-
formance curve.
Data are referred to standard conditions: atmospheric pressure at
1013mbar, ambient temperature at 15°C.
1.7 Checking the proper gas train size
1.8 Performance Curves
To get the input in kcal/h, multiply value in kW by 860.
Data are referred to standard conditions: atmospheric pressure at 1013mbar, ambient temperature at 15°C
NOTE:
The performance curve is a diagram that represents the burner performance in the type approval phase or in the laboratory
tests, but does not represent the regulation range of the machine. On this diagram the maximum output point is usually reached by adj-
suting the combustion head to its “MAX” position (see paragraph “Adjusting the combustion head”); the minimum output point is rea-
ched setting the combustion head to its “MIN” position. During the first ignition, the combustion head is set in order to find a
compromise between the burner output and the generator specifications, that is why the minimum output may be different from the Per-
formance curve minimum.
To check the proper gas train size, it is necessary to the available
gas pressure 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 requested furnace
input. This value must be lower or equal to the
pgas
value, calcula-
ted before.
PRESSURE IN
COMBUSTION CHAM
BER
(mbar)
HR75A
kW
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
back
pressure in
comb
ustio
n
ch
amber (mba
r)
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
