Riello RS 45/E BLU - C Appendix - Gas Supply Pressure

52
GB
Appendix - Gas supply pressure
C
The adjacent tables show minimum load losses along
the gas supply line depending on the maximum burner
output operation.
Column 1
Load loss at combustion head.
Gas pressure measured at the test point 1)(Fig. 36),
with:
• combustion chamber at 0 mbar;
• burner working at maximum output;
• Ring nut 2)(Fig. 15) adjusted as in the diagram of Fig. 16
Column 2
Load loss at gas butterfly valve 2)(Fig. 36) with maxi-
mum opening: 90°.
Column 3
Load loss at train 3)(Fig. 36) including: adjustment
valve VR, safety valve VS (both fully open), pressure
adjuster R, filter F.
The values shown in the tables refer to:
natural gas G 20 PCI 9.45 kWh/Sm
3
(8.2 Mcal/Sm
3
)
With:
natural gas G 25 PCI 8.13 kWh/Sm
3
(7.0 Mcal/Sm
3
) multiply the values of the tables:
- columns 1-2: by 1.5;
- column 3: by 1.35.
To know
the approximate output at which the burner is
operating at its maximum:
- Subtract the combustion chamber pressure from the
gas pressure measured at test point 1)(Fig. 36);
- find, in the table relating to the burner concerned,
column 1, the pressure value closest to the result
you want;
- read the corresponding output on the left.
Example - RS 45/E BLU:
• Maximum output operation
• Natural gas G 20 PCI 9.45 kWh/Sm
3
• Ring nut 2)(Fig.15) adjusted as in the diagram of Fig. 16
• Gas pressure at test point 1)(Fig. 36) = 7.5 mbar
• Pressure in combustion chamber = 2.0 mbar
7.5 - 2.0 = 5.5 mbar
A maximum output of 320 kW shown in Table RS 45/E
BLU corresponds to a pressure of 5.5 mbar, column 1.
This value serves as a rough guide; the effective out-
put must be measured at the gas meter.
To know
the required gas pressure at test point
1)(Fig. 36), set the maximum output required from the
burner operation, then:
- find the nearest output value in the table for the
burner in question.
- read, on the right (column 1) the socket pressure
1)(Fig. 36);
- add this value to the estimated pressure in the com-
bustion chamber.
Example - RS 45/E BLU:
• Maximum output required: 320 kW
• Natural gas G 20 PCI 9.45 kWh/Sm
3
• Ring nut 2)(Fig. 15) adjusted as in the diagram of Fig. 16
• Gas pressure at output of 320 kW, taken from table
RS 45/E BLU, column 1 = 5.5 mbar
• Pressure in combustion chamber = 2.0 mbar
5.5 + 2.0 = 7.5 mbar
gas pressure at test point 1)(Fig. 36)
Fig. 36
2
VS
VR
R
3
1
F
RS 45/E BLU p (mbar)
kW 1 2
3
Ø 3/4”
3970602
Ø 3/4”
3970599
Ø 1”1/4
3970258
Ø 1”1/4
3970256
Ø 1”1/2
3970250
Ø 2”
3970257
190 2.6 0.7 24.7 16.6 8.3 4.2 3.2 3.2
200 2.8 0.8 27.4 18.2 9.1 4.5 3.2 3.2
240 3.7 1.1 38.7 24.8 12.4 6.1 3.5 3.2
280 4.6 1.5 51.5 32.6 16.1 7.8 4.5 3.2
320 5.5 1.9 65.4 41.2 20.0 9.6 5.4 3.7
360 6.4 2.4 81.0 50.5 24.0 11.8 6.4 4.4
400 7.3 3.0 - - 28.3 14.1 7.4 5.2
440 8.4 3.6 - - 33.0 16.4 8.5 5.9
480 9.7 4.3 - - 37.7 18.7 9.6 6.7
520 11.1 5.1 - - 42.4 21.1 10.7 7.5
550 12.1 5.7 - - 45.9 23.2 11.6 8.2
D3790