Firing Rate; Test Boiler - Riello RL 190/M Installation, Use And Maintenance Instructions

RL 190/M
(A)
a.s.l.
(1)
m mbar 0
0 1013 1,087
100 1000 1,073
200 989 1,061
300 978 1,050
400 966 1,037
500 955 1,025
600 944 1,013
700 932 1,000
800 921 0,988
900 910 0,977
1000 898 0,964
1200 878 0,942
1400 856 0,919
1600 836 0,897
1800 815 0,875
2000 794 0,852
(1) AVERAGE BAROM. PRESS.
(B)
mbar
D388
(C)
(D)
Burner output
F
AIR
°C
5 10 15 20
1,068 1,049 1,031 1,013
1,054 1,035 1,017 1,000
1,042 1,024 1,006 0,989
1,031 1,013 0,995 0,978
1,018 1,000 0,983 0,966
1,007 0,989 0,972 0,955
0,995 0,977 0,960 0,944
0,982 0,965 0,948 0,932
0,971 0,954 0,937 0,921
0,959 0,942 0,926 0,910
0,946 0,930 0,914 0,898
0,925 0,909 0,893 0,878
0,902 0,886 0,871 0,856
0,881 0,866 0,851 0,836
0,859 0,844 0,829 0,815
0,837 0,822 0,808 0,794
Qe
D1975
25 30 40
0,996
0,980 0,948
0,983 0,967
0,936
0,972 0,956
0,926
0,962 0,946
0,916
0,950 0,934 0,904
0,939 0,923
0,894
0,928 0,913
0,884
0,916 0,901 0,872
0,906 0,891 0,862
0,895 0,880
0,852
0,883 0,868 0,841
0,863 0,849 0,822
0,842 0,828 0,801
0,822 0,808 0,783
0,801 0,788 0,763
0,781 0,768 0,743
kg/h
D688
4
1 - Spare parts list
FIRING RATE (A)
During operation, burner output varies between:
• MINIMUM OUTPUT: area A;
• MAXIMUM OUTPUT: area B.
The work point may be found by plotting a verti-
cal line from the desired delivery and a horizon-
tal line from the pressure in the combustion
chamber. The intersection of these two lines is
the work point which must lie within area A, for
MIN output, and within area B, for MAX output.
Burner firing rates according to air den-
sity
The FIRING RATE area values have been
obtained considering a surrounding temperature
of 20°C, and an atmospheric pressure of 1000
mbar (approx. 100 m above sea level) and with
the combustion head adjusted as shown on
page 6.
The burner may be required to operate with com-
bustion 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 me-
ter and the fan's head are reduced.
It is therefore important to know if the maximum
output required of the burner at a given combus-
tion chamber pressure remains within the burn-
er's firing rate range even
temperature and altitude conditions. Proceed as
follows to check the above:
1 - Find the correction factor F in the Table (B)
for the plant's air temperature and altitude.
2 - Divide the burner's delivery Q by F in order to
obtain the equivalent delivery Qe:
Qe = Q : F (kg/h)
3 - In the firing rate range of the burner, Fig. (C),
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
Figure (C) and find the maximum pressure H2
of the firing rate.
5 - Multiply H2 by F to obtain the maximum re-
duced pressure H3 of the firing rate.
H = H : F (mbar)
3 2
If H3 is greater than H1, as shown in Fig. (B), the
burner delivers the output required.
If H3 is lower than H1, the burner's delivery must
be reduced. A reduction in delivery is accompa-
nied by a reduction of the pressure in the com-
bustion chamber:
Qr = reduced delivery
H1r = reduced pressure
Qr
( )
H r = H x
1 1
Q
Example, a 5% delivery reduction:
Qr = Q x 0.95
2
H1r = H1 x (0.95)
Steps 2 - 5 must now be repeated using the new
Qr and H1r values.
Important:
the combustion head must be adjusted in re-
spect to the equivalent delivery Qe.
TEST BOILER (D)
The firing rates were set in relation to special
test boilers in accordance with the methods
defined in EN 267 standards.
Figure (D) indicates the diameter and length of
the test combustion chamber.
Example: delivery 200 kg/hour:
diameter = 80 cm; length = 3,5 m.
Whenever the burner is operated in a much
smaller commercially-available
chamber, a preliminary test should be per-
formed.
at different
2
combustion