I was wondering that in process engineering, people only know that PID control is used for temperature or flow regulation, but who decides what values to set for P and I? Is that also part of process engineering? ?
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I heard that in process engineering, one only knows that PID control is used for temperature or flow regulation, but is it also the engineers who determine the values of P and I? ? Where is the interface for self-control?
There are approximate values for flow rate and liquid level; temperature control requires input from process and automatic control systems, as well as on-site experimentation
Process control engineers carry out PID tuning, and process technicians can also learn this skill – it’s never a bad thing to have multiple skills.
Yes, the process parameters need to be specified, and the instrumentation team will select the appropriate instruments based on those specifications
The process department is responsible for providing the processes; once the conditions for automatic control are established, it handles the selection of instruments and prepares the list of materials needed for their installation
The process parameters are set by the process team; other departments determine the selection of equipment based on these parameter values.
Currently, no one wants to be responsible for tuning PID parameters – it’s too complicated and time-consuming. Usually, the configuration staff assign values based on experience, while no one takes the time to make detailed adjustments. Because PID theory is a bit complicated and not many people understand it, no one uses it.
This post was last edited by Hariky on 2019-4-12 at 13:34. These were not suggested by process designers. If you have on-site operators, they are responsible for controlling the P, I, D parameters of the control loops; they enter these values initially based on experience from previous projects (in the DCS Tuning screen), and then make adjustments gradually according to the actual operating conditions. The parameters for the other non-critical circuits can be set directly according to the manual, with adjustments to be made later. The specific values assigned to the P, I, and D parameters depend on the transfer function of the variable being controlled. Factors such as the selection of field instruments and valves, equipment specifications, pipeline layout, and insulation effectiveness all influence this transfer function. Designers cannot calculate each one individually; instead, they use a fixed method to handle things on-site.