OSD60 temp. control slow response

[AboFaris]

Dear all
I have GEA HFO OSD60 separator, always tripped due to product temp min when refill buffer tank.. when I open the control valve manually by the D10 controller product rise temperature immediately.. PID setting Kp 0.08 Tn 100sec.. any help to make the controller respond faster

thanks All

[popeye62]

Hello AboFaris. Do you mean the FO settling tank when you refer to the buffer tank? I ask because every ship I have been on, the FO separator will wobble (alarm and come off separation) when the settling tank is topped up even with heating on the bunker tank. The difference in temperature is too great for the small separator heater even with heating on the settling tank and it takes time for the temperature to come up and get the separator back on separation. Before fingering the PID, is the heater clean? Is the condensate trap working efficiently to clear the heater of condensate? Is the fuel flow through the heater steady? Is the valve operation smooth? Does the controller have any problems (sluggish, overshooting, hunting etc.) while operating once the settling tank temperature has come up? Changing P,I, or D may introduce some instability in the system. Can you top up more often and reduce the quantity of cold fuel?
Normally, I would suggest that you don't touch it (I certainly wouldn't mess with the settings of the main engine cooling system cascade control) but in this case you cannot do any damage so long as you can put the settings back to where they were so give it a go.
Re the settings in my D10 manual it gives the proportional gain (Kp) as 2.0 with the note ******The control mode (Kp) is factory-set according to general
practical experience and need not be modified under normal conditions.****** No settings are given for the integral (Ti). Good luck, John