Firing Rate; Procedure To Refer Burner Operating Condition In High Altitude Plants - Riello RS 120/EV BLU Installation, Use And Maintenance Instructions

3.7

Firing rate

The maximum output is chosen within area A) and B)(Fig. 3) of
the diagram.
To use area B) as well, the pre-calibration of the
combustion head is necessary, as explained in the
paragraph "Pre-calibration of combustion head"
at page 19.
WARNING
3.7.1 Procedure to refer burner operating condition
in high altitude plants
Find the CORRECTED BURNER CAPACITY for the plant's alti-
tude in chart 1 and the CORRECTED PRESSURE in chart 2.
Check in the firing rate graph of the burner (Fig. 3), if the working
point defined by the values above is within the range limits. If not,
higher burner size is needed.
Note
 Charts are based only on altitude variation (reference tem-
perature = 68°F, 20°C)
 To get the combined correction in case of different air tem-
perature, a compensation of 1000 ft each 3.6°F (305 m each
2°C) is applicable (100 ft = 0.36°F).
Example
– Rated Capacity = 2517 MBtu/hr
– Rated Air Pressure = 1.39" WC
– Reference Altitude = 328 ft
– Reference Temperature = 20°C = 68°F
– Real Altitude = 3000 ft
– Real Temperature = 17°C = 62.6°F
– Temperature Difference = 68°F - 62.6°F = 5.4°F
– Virtual Altitude Increment = 5.4°F/3.6°F x 1000 ft = 1500 ft
– Virtual Altitude = (Real Altitude) + (Virtual Altitude Increment) =
3000 ft + 1500 ft = 4500 ft
– Corrected Capacity = (2585 + 2607)/2 = 2596 MBtu/hr
– Corrected Pressure = (2.76 + 3.19)/2 = 2.98" WC
Reference conditions:
– Ambient Temperature 68 °F (20 °C)
– Barometric Pressure 394" WC (1000 mbar)
– Altitude 328 ft a.s.l. (100 m a.s.l.)
20102152
Technical description of the burner
The minimum output must not be lower than the minimum limit of
the diagram.
Thermal power
8 GB
The firing rate was obtained considering a room
temperature of 68 °F and an atmospheric pressure
of 394 "WC (approx. 0 ft above sea level), with the
combustion head adjusted.
WARNING
20061167
Fig. 3