Lamtec FMS 4 - Lag time Parameters 898; 900; P-factor Parameter 899

FMS Commissioning O regulation
2
Commissioning
Lag time
Parameters 898 / 900
Regulation parameter setting
t ___ t = regulation section's lag time
14
Specified via parameters 898 and 900
The calculated value should be input by means of parameter 898.
Factory setting: 15 seconds.
The lag time can be adjusted to the load via parameter 900.
The lag time gets shorter at full load, due to the higher gas velocities.
Lag time shortening of 3 seconds is preset at the factory.
To calculate lag time at full load: proceed as described above.
Guideline for 2 or 3-draught boiler:
Parameter 898 Z 12 seconds
Parameter 900 Z 3 seconds
The P-factor should be so adjusted that a target/actual value deviation of
1...2 vol.% O is corrected within 4...6 steps without overshooting.
2
P-factor Actuation pulse too short Z increase P-factor parameter 899
Parameter 899 Overshooting Z reduce P-factor.
Repeat until the target value is corrected within ca. 4...6 steps.
Check regulator setting at intermediate and full load.
Note: It is possible to achieve optimisation by means of the P-factor
(parameter 899) and the lag time (parameters 898 and 900), that
inter alia also depends on the installation's properties; e.g. one
may set a somewhat shorter lag time if the P-factor is reduced at
the same time.
Recommendation:
Set a slightly longer regulation cycle and smaller P-factor Z safer !!!
New O target value
2
Old O target
2
value
Actuation step
0
4
t
1
1
t
1
t
2
t
3
t
4
3
3
2
2
O
2
[vol.%]
i
60