Riello RLS 28/E, Инструкции по установке, использованию и обслуживанию

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20059594 10 GB
Technical description of the burner
3.9 Firing rate
The burner can work in two ways: low and high fire.
–
MAXIMUM OUTPUT must be selected in area A (Fig. 5).
– MINIMUM OUTPUT must not be lower than the minimum limit
shown in the diagram:
Tab. F
NOTE:
the firing rate areas given in Fig. 5 have been reduced by 10% with
respect to the maximum range that can be reached.
Consult “Procedure to refer burner operating condition in high alti-
tude plants”.
3.9.1 Procedure to refer burner operating condition
in high altitude plants
The firing rate area values have been obtained considering a sur-
rounding temperature of 68°F (20°C), and an atmospheric pres-
sure of 398” W.C. and with the combustion head adjusted as
shown on page 21.
The burner may be required to operate with combustion air at a
higher temperature and/or at higher altitudes.
Heating of air and increase in altitude produce the same effect: the
expansion of the air volume, i.e. the reduction of air density.
The burner fan’s delivery remains substantially the same, but the
oxygen content per cubic meter and the fan's head are reduced.
It is therefore important to know if the maximum output required of
the burner at a given combustion chamber pressure remains within
the burner's firing rate range even at different temperature and al-
titude conditions.
Proceed as follows to check the above:
1 - Find the correction factor F in the Tab. G for the plant's air tem-
perature and altitude.
2 - Divide the burner’s delivery Q by F in order to obtain the equiv-
alent delivery Qe:
3 - In the firing rate range of the burner (Fig. 6) indicate the work
point defined by:
Qe = equivalent delivery
H1 = combustion chamber pressure
The resulting point A must remain within the firing rate range.
4 - Plot a vertical line from Point A as shown in (Fig. 6) and find the
maximum pressure H2 of the firing rate.
5 - Multiply H2 by F to obtain the maximum reduced pressure H3
of the firing rate.
If H3 is greater than H1, as shown in (Fig. 6), the burner delivers
the output required.
If H3 is lower than H1, the burner's delivery must be reduced. A re-
duction in delivery is accompanied by a reduction of the pressure
in the combustion chamber:
Qr = reduced delivery
H1r = reduced pressure
Example, a 5% delivery reduction:
Qr = Q x 0.95
H1r = H1 x (0.95)
2
Model MBtu/hr GPH
RLS 28/E 378 2.7
WARNING
The firing rate area values have been obtained con-
sidering an ambient temperature of 68 °F (20 °C),
and an atmospheric pressure of 394” WC and with
the combustion head adjusted as shown on
page 21.
Fig. 5
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Burner output
Qe = Q : F (MBTU/h)
H3 = H2 x F (“ W.C.)
H1r = H1 x
( )
Qr
Q
2