Riello RLS 800/EV MX, Installation, Use And Maintenance Instructions

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25
20010950
GB
Installation
5.12.3 Gas pressure
The table show minimum pressure losses along the gas supply line depending on the maximum burner output operation.
The values shown in the table refer to:
•
Natural gas G 20 PCI 9.45 kWh/Sm
3
(8.2 Mcal/Sm
3
)
•
Natural gas G 25 PCI 8.13 kWh/Sm
3
(7.0 Mcal/Sm
3
)
Column 1
Pressure loss at combustion head.
Gas pressure measured at the test point 1) (Fig. 26), with:
•
Combustion chamber at 0 mbar;
• Burner working at maximum output;
• Combustion head adjusted as in the diagram of Fig. 18.
Column 2
Pressure loss at gas butterfly valve 2) (Fig. 26) with maximum
opening: 90°.
Column 3
Pressure loss of gas train 3)(Fig. 26) includes:
•
adjustment valve (VR)
• safety valve (VS) (both fully open)
• pressure adjuster (R)
• filter (F)
Calculate the approximate maximum output of the burner in this
way:
–
subtract the combustion chamber pressure from the gas
pressure measured at test point 1) (Fig. 26).
– Find, in the table relating to the burner concerned, the pres-
sure value closest to the result of the subtraction.
– Read off the corresponding output on the left.
Example with natural gas G 20:
Maximum output operation
Gas pressure at test point 1) (Fig. 26)
= 32.2 mbar
Pressure in combustion chamber = 2 mbar
32.2 - 2 = 30.2 mbar
A pressure of 30.2 mbar, column 1, corresponds in the table A to
an output of 6000 kW.
This value serves as a rough guide, the effective delivery must be
measured at the gas meter.
To calculate the required gas pressure at test point 1) (Fig. 26),
set the maximum output required from the burner operation:
–
find the nearest output value in the table for the burner in
question.
– Read off the pressure at test point 1) (Fig. 26) on the right in
column 1.
– Add this value to the estimated pressure in the combustion
chamber.
Example with natural gas G 20:
Required burner maximum output operation: 6000 kW
Pressure of the gas at an output of 6000 kW = 30.2 mbar
Pressure in combustion chamber
= 2 mbar
30.2 + 2 = 32.2 mbar
pressure required at test point 1) (Fig. 26).
kW
1

p (mbar)
2

p (mbar)
3

p (mbar)
MBC 1200 SE MBC 1900 SE MBC 3100 SE MBC 5000 SE
G 20 G 25 G 20 G 25 G 20 G 25 G 20 G 25 G 20 G 25 G 20 G 25
3500 11..5 16.5 2.7 3.5 61.0 91.8 32.6 44.3 15.6 21.0 7.8 10.1
4000 15.2 22.3 3.6 4.6 80.6 119.3 40.0 54.4 19.1 25.7 9.2 12.2
4500 19.0 28.1 4.5 5.8 101.5 47.9 65.8 22.8 31.4 10.8 14.8
5000 22.7 33.9 5.5 7.2 124.8 56.3 78.5 26.7 38.0 12.7 17.5
5500 26.4 39.7 6.7 8.7 65.8 91.7 31.4 44.8 14.8 20.3
6000 30.2 45.5 8.0 10.3 76.2 105.4 36.9 51.7 17.0 23.2
6500 35.4 51.3 9.4 12.1 87.0 120.1 42.4 59.6 19.4 26.6
7000 38.9 57.9 10.9 14.0 97.9 136.1 48.0 68.5 21.6 30.6
7500 44.8 66.6 12.5 16.1 109.4 152.9 53.7 77.9 24.1 34.9
8000 50.6 75.4 14.2 18.3 121.7 170.4 60.4 88.0 26.9 39.5
Fig. 26
MBC 1200 SE
MBC 1900-3100-5000 SE
D3734