Riello PRESS GBV, Инструкции по установке, использованию и обслуживанию

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11
20033090
GB
Technical description of the burner
4.5.1 Burner firing rates according to air density
The burner firing rate range provided in this Manual applies to op-
eration at a surrounding temperature of 20°C at an altitude of 100
meters above sea level (atmospheric pressure approx. 1000
mbar).
The burner may be required to operate with comburent 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 altitude conditions. Proceed as follows to check the above:
1 -
Find the correction factor F in the Tab. D for the plant's air
temperature and altitude.
(1) AVERAGE BAROM. PRESS.
Tab. D
2 - Divide the burner's delivery Q by F in order to obtain the
equivalent delivery Qe:
3 - In the firing rate range of the burner (Fig. 4), 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. 4) 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. 4), the burner deliver
the output required.
If H3 is lower than H1, the burner's delivery must be reduced.
A reduction in delivery is accompanied by a reduction of the pres-
sure in the combustion chamber:
Qr = reduced delivery
H1r = reduced pressure
H
1r
= H
1
x (Qr/Q)
2
Example , a 5% delivery reduction:
Qr = Q x 0,95
H
1r
= H
1
x (0,95)
2
Steps 2-5 must now be repeated using the new Qr and H
1r
val-
ues.
Altitude
a.s.l.
(1)
Correction factor F
Air temperature °C
m mbar 0 5 10 15 20 25 30 40
0 1013 1,087 1,068 1,049 1,031 1,013 0,996 0,980 0,948
100 1000 1,073 1,054 1,035 1,017 1,000 0,983 0,967 0,936
200 989 1,061 1,042 1,024 1,006 0,989 0,972 0,956 0,926
300 978 1,050 1,031 1,013 0,995 0,978 0,962 0,946 0,916
400 966 1,037 1,018 1,000 0,983 0,966 0,950 0,934 0,904
500 955 1,025 1,007 0,989 0,972 0,955 0,939 0,923 0,894
600 944 1,013 0,995 0,977 0,960 0,944 0,928 0,913 0,884
700 932 1,000 0,982 0,965 0,948 0,932 0,916 0,901 0,872
800 921 0,988 0,971 0,954 0,937 0,921 0,906 0,891 0,862
900 910 0,977 0,959 0,942 0,926 0,910 0,895 0,880 0,852
1000 898 0,964 0,946 0,930 0,914 0,898 0,883 0,868 0,841
1200 878 0,942 0,925 0,909 0,893 0,878 0,863 0,849 0,822
1400 856 0,919 0,902 0,886 0,871 0,856 0,842 0,828 0,801
1600 836 0,897 0,881 0,866 0,851 0,836 0,822 0,808 0,783
1800 815 0,875 0,859 0,844 0,829 0,815 0,801 0,788 0,763
2000 794 0,852 0,837 0,822 0,808 0,794 0,781 0,768 0,743
Qe = Q : F (kg/h)
H3 = H2 x F (mbar)
CAUTION
The combustion head must be adjusted in respect
to the equivalent delivery Qe.
Qe
kg/h
mbar
Fig. 4
D388