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Building Technologies
Basic Documentation LMV5...
CC1P7550en
19 O2 trim control with LMV52 and PLL52
22.05.2018
19.12 Setting notes
(Summary of the most important rules for setting O2 trim control)
19.12.1 Parameterizations
Parameterize all truly air-regulating actuators as such
If the parameter settings are changed, O
2
trim control must be readjusted.
19.12.2 Setting fuel-air ratio control
Caution!
Set sufficient excess O2
Set the amount of excess air of the ratio control curve such that, whatever the
environmental conditions (combustion chamber and fuel pressure, temperature and
pressure of the combustion air), the set residual O2 content will lie above the O2
setpoints required by O2 trim control.
Example:
Figure 123: Setting fuel-air ratio control
∂
Parameterized load proportional to the fuel rate
The burner load parameterized at the curvepoints must be proportional to the
actual burner load. To make the correct setting, determine the burner load with
the help of the fuel meter.
∂
Curvepoint 1
The first curvepoint should have an adequate distance below curvepoint
‚
.
This means that the curve for reducing the air rate is also defined below point
‚
. As a guide value, point
•
should lie at about half the load of point
‚
.
Point
‚
should be smaller than or equal to the low-fire load.
Ι
Note!
The following values can be entered at the AZL52 from software version V05.00 for
the LMV52.2 and software version V10.10 for the LMV52.4:
∂
Χ
(O2 ratio control - O2 setpoint)
″
0.1%
∂
Χ
(O2 setpoint -
O2 min value
)
″
0.1%
