Siemens 6DR2210, Руководство пользователя, Страница: 69 / 270

Manual 1 Technical Description
1.5 Functional description of the structure switches
1.5.4 Controller types (S1, S49 to S53)
SIPART DR22 6DR2210
C79000-G7476-C154-03
67
The desired adjustment range of
λ
gives:
vA = =1
λ
E
1
1.25 = 0.8
vE = =1
λ
A
1
0.75 = 1.333
vA and vE are set in the structuring mode oFPA. By setting the nominal ratio wv from 0 to 1
the ratio factor v can now be adjusted from 0.8 to 1.33 or the air factor
λ
from 1.25 to 0.75.
0.75
1.2
1.25
0.8
0.9
1
1.1
1.2
0.2 0.6
1.33
1,3
1
0.8 0.4 0
0.8
1.1
0.9
1
wv
v
λ
Figure 1-34 Relationship ratio factor v and air factor
λ
to standardized nominal ratio wv
If the combustion is also to take place at small flow volumes with excess air, the constant c
must be set negative. Figure 1-35 shows the gas/air ratio in the controlled state at different
air factors
λ
and c = 0 as well as at
λ
= 1 and c
<
0, i.e. with excess air.
1)
constant gas/air ratio
2)
gas/air ratio with additional air excess
% mA
Gas
m
3
/h
V=1.33 λ =0,75
Q
L
V=1 λ =1
V=0.8 λ =1.25
1)
V=1, c<0
2)
X2
X2
22
20
18
16
14
12
10
8
6
4
120
110
100
90
80
70
60
50
40
30
20
10
0
3,500
3,000
2,500
2,000
1,500
1,000
500
X
1
X
1
Q
G
0
0 2,000 4,000 6,000 8,000 10,000 12,000 m
3
/h air
4 6 8 10 12 14 16 18 20 mA
0 10 20 30 40 50 60 70 80 90 100 %
Figure 1-35 Display of gas/air ratio in controlled status