Reactor temperature control scheme
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The company’s temperature control system for the reaction vessel: Circulating water flows through the jacket of the reaction vessel. This circulating water passes through a heating heat exchanger (the heat exchange medium is steam, with a control valve TV_1011 on the steam pipeline) and a cooling heat exchanger (the medium is industrial water, with a control valve TV_1021 on the industrial water pipeline). Before entering the heating and cooling heat exchangers, the circulating water goes through three-way control valves (TV_1012 and TV_1022 respectively), which are used to regulate the flow rate of water into the heat exchangers as well as the flow rate of water flowing around them. Temperature transmitters are installed at the outlets of the heating and cooling heat exchangers (TIC_1011 and TIC_1021 respectively). The current control scheme involves using the temperature sensor TIC_1021 at the outlet of the cooling heat exchanger to control valve TV_1021, and using the temperature inside the vessel, TIC_1031, along with the temperature transmitter TIC_1011 at the outlet of the heating element, to regulate valve TV_1022. Additionally, TIC_1011 is used to control the opening degree of valve TV_1012； Is this solution feasible? What are its shortcomings? TV_1011: Steam control valve for the heating heat exchanger; TV_1012: Control valve for the inlet tee of the circulating water in the heating heat exchanger; TV_1021: Industrial water control valve for the cooling heat exchanger; TV_1022: Control valve for the inlet tee of the circulating water in the cooling heat exchanger. TIC_1011: Temperature at the outlet of the circulating water in the heating heat exchanger; TIC_1021: Temperature at the outlet of the circulating water in the cooling heat exchanger; TIC_1031: Temperature inside the reaction vessel
It would be easier to understand if there were a diagram available
Draw a sketch by hand; it doesn’t look very good
Has the equipment been decided on? Or has it already been installed? If it is still in the design phase, it is not recommended to do this; it’s a bit complicated, debugging will be difficult, and the control lag time is likely to be quite long. It is recommended to add coils to the reaction tank and separate the hot and cold sources.
The equipment has been installed and trial production is complete; currently, temperature control is done manually as automatic control is not satisfactory
The flowchart is really useful; especially, I can’t understand the flow direction of the three-way valve. Could you give some guidance? Also, is it fixed whether the reaction in this reactor releases heat or absorbs heat – sometimes it cools down and sometimes it heats up
During the reaction process, there is indeed both temperature increase and decrease
Can’t we just use program control instead of PID control? Cooling is activated when the temperature rises, and heating when it drops
The reaction vessels I use are mostly controlled by programs; I’ve never seen traditional PID control, zoning control, or cascade control used