Firing Rate; Procedure To Refer Burner Operating Condition In High Altitude Plants - Riello RS 1200/EV Installation, Use And Maintenance Instructions

3.6

Firing rate

Maximum output must be selected in the hatched area of the dia-
gram.
Minimum output must not be lower than the minimum limit shown
in the diagram.
3.6.1 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. 4), 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 temper-
ature = 68°F, 20°C)
 To get the combined correction in case of different air temper-
ature, a compensation of 1000 ft each 20°F (305 m each
11°C) is applicable (100 ft = 2°F).
Example
Rated capacity = 3000 MBtu/hr - Rated air pressure = 1.5" WC
Real altitude = 5000 ft - Real temperature = 108°F

= 108°F - 68°F (reference temp.) = 40°F
(equivalent 2000 ft variation)
40 : 2 = 20 x 100 = 2000 ft
Proceeding as descripted above and considering a "virtual altitude"
of (5000 + 2000) ft:
– 3000 MBtu/hr at 7000 ft, the corrected capacity is 3847 MBtu/hr
– 1.5" WC at 7000 ft, the corrected burner air pressure is 1.92
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.).
20060897
Technical description of the burner
Burner power output
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
WARNING combustion head adjusted.
20050769
Fig. 3