Help, please! Control scheme needed

The top control scheme for a distillation tower generally includes temperature control and level control. For temperature control, a PID algorithm can be used to regulate the top temperature of the tower. Specifically, a temperature sensor can be installed to measure the temperature at the top of the tower, and then the temperature at that location can be controlled by adjusting the opening degree of the reflux valve. In practical operation, it is necessary to adjust the PID parameters according to the actual conditions in order to improve control performance. At the same time, to avoid control instability caused by the reflux valve opening being too large or too small, it is recommended to set a certain threshold to limit the valve opening. For level control, a PID algorithm can be used to control the liquid level in the reflux tank. Specifically, a level sensor can be installed to measure the liquid level in the reflux tank, and the level can then be controlled by adjusting the opening degree of the feed valve. It is also necessary to adjust the PID parameters according to the actual conditions in order to improve control performance. It should be noted that since there is only one flow of material, level control and temperature control influence each other, requiring comprehensive consideration. For example, when the top temperature rises, the opening degree of the feed valve needs to be reduced appropriately to keep the liquid level in the reflux tank from becoming too high, thereby preventing excessive flow rates that could cause the temperature to rise too quickly. The same is true in reverse. Furthermore, since the top condenser and reflux tank are vertical, issues such as sensor delay or unstable signals may arise, requiring experiments for tuning in order to ensure stable and reliable control performance. .

This post was last edited by CHANGBAISHI on 2023-5-25 06:54. This control scheme should be set based on the process conditions required by the distillation tower. As long as it meets the temperature required for the reflux liquid in the tower, and this temperature should be achieved by controlling the temperature of the condenser. Controlling the flow rate into the tower is achieved using FIC0201-----LI0201. As can be seen from the diagram, the liquid flowing into the tower as part of this backflow should be a saturated liquid; it seems that some saturated gas also needs to be extracted from the storage tank for use as a product or for other purposes. From the diagram, it doesn’t seem to be a discussion on a \"control scheme\"; rather, it appears to be an issue related to understanding a mature process flow. It is recommended to approach this by considering the requirements of the distillation tower, for reference only.