110 / 134 ECO Gold 09/2021
18.2.2 Procedure for setting the control parameters for external control
1. Activating external control ( 16.1).
2. Set the slave controller:
2.1. Parameter to auto ;
Xpf in dependence of:
Check or adjust device type ( 8.2.4).
Select heat transfer liquid with as low-viscosity and with as high a thermal capacity as possible.
Ranking list: Water, water/glycol, oils, Fluorinert®.
Set pump level as high as possible,
Make sure there is adequate circulation,
select the hose length as short as possible, e.g. 2 x 1 m,
select the hose cross-sectional area as large as possible, e.g. ½ inch,
set the throughput through the external consumer as large as possible.
2.2. Set Xpf:
With a tendency to oscillate with a short period of oscillation (e.g. 30 s) Xpf smaller, otherwise larger,
with poor thermal coupling and a large mass to temper large (e.g. 2 – 5, possibly even larger),
with good thermal coupling and a small mass to temper small (e.g. 0.2 – 0.7),
if fast temperature changes are required, external baths should be controlled if possible with internal control. Other-
wise choose Xpf to be very small (0.05 – 0.1).
3. Setting the master controller (PID controller):
First start with Auto, then possibly continue with manual.
3.1. Setting Kpe:
With a tendency to oscillate (long period of oscillation, e.g. 10 min) Kpe larger, otherwise smaller,
3.2. Setting Tne/ Tve/ Tde:
Generally quite high values (Tne = 70 s – 200 s; Tve = 50 s – 150 s),
with smaller values faster transient responses, otherwise slower transient responses and therefore less oscillation,
Tve: To reduce transients increase Tve, otherwise vice versa,
Tde (damping for Tve): generally approx. 10 % of Tve.
4. Correcting quantity limit ( 18.2.1) and temperature limits (Til/Tih) ( 7.4.5).
Set according to the physical boundary conditions.
Example:
Correcting quantity limit
depends on heat transfer liquid and vessel
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