Table of Contents
Advertisement
5.13.2 Gas train
Approved according to standard EN 676 and provided separately
from the burner.
To select the correct gas train model, refer to the supplied "Burn-
er-gas train combination" manual.
5.13.3 Gas train installation
Disconnect the electrical power using the main
switch.
DANGER
Check that there are no gas leaks.
Pay attention when handling the train: danger of
crushing of limbs.
Make sure that the gas train is properly installed
by checking for any fuel leaks.
The operator must use the required equipment
during installation.
The gas train is to be connected on the right of the burner, by
flange 1) (Fig. 30).
D3095
Installation
5.13.4 Gas pressure
Tab. H indicates the pressure drop of the combustion head and
the gas butterfly valve depending on the operating output of the
burner.
kW
3000
3500
4000
4500
5000
5500
6000
6500
6650
The values shown in Tab. H refer to:
–
Natural gas G 20 NCV 9.45 kWh/Sm
–
Natural gas G 25 NCV 8.13 kWh/Sm
Column 1
Combustion head pressure drop.
Gas pressure measured at test point P1)(Fig. 31), with:
•
combustion chamber at 0 mbar;
•
burner working at maximum modulating output;
•
combustion head set as on page 20.
Column 2
Pressure loss at gas butterfly valve P2)(Fig. 31) with maximum
opening: 90°.
To calculate the approximate output at which the burner oper-
ates:
–
subtract the combustion chamber pressure from the gas
pressure measured at test point P1)(Fig. 31).
–
Find, in Tab. H related to the burner concerned, the pressure
value closest to the result of the subtraction.
–
Read off the corresponding output on the left.
Example with natural gas G20:
Operation at maximum modulating output
Gas pressure at test point P1)(Fig. 31)
Pressure in combustion chamber
A pressure of 27.8 mbar, column 1, corresponds in Tab. H to an
output of 6000 kW.
This value serves as a rough guide; the effective output must be
measured at the gas meter.
To calculate the required gas pressure at test point P1)(Fig. 31),
P1
set the maximum modulating output required from the burner op-
eration:
–
find the nearest output value in Tab. H for the burner in ques-
P4
tion.
–
Read, on the right (column 1), the pressure at the test point
Fig. 30
P1) (Fig. 31).
–
Add this value to the estimated pressure in the combustion
chamber.
27
GB
1 p (mbar)
G 20
G 25
G 20
7,2
11,1
10,1
15,8
13,0
20,5
15,8
25,2
19,5
30,6
23,6
36,5
27,8
42,3
10,1
32,0
48,1
11,9
33,2
49,9
12,5
3
(8.2 Mcal/Sm
3
(7.0 Mcal/Sm
32.8 - 5
2 p (mbar)
G 25
2,5
3,7
3,5
5,1
4,5
6,6
5,7
8,4
7,0
10,3
8,5
12,5
14,9
17,5
18,3
Tab. H
3
)
3
)
= 32.8 mbar
=
5 mbar
= 27.8 mbar
20027766
Advertisement
Table of Contents
