Which expert could provide a detailed explanation of this process?

This is a feedforward + feedback control scheme, but the flowchart representation is incorrect. Typical examples are shown below.

This is a complex form of control: both the flow rate of the material being heated and its temperature after heating serve as inputs for determining the steam flow rate required for heating. Based on these flow rates and the desired temperature, factors such as the specific heat of the material and the latent heat of steam are used as bases for calculation, in order to convert these values into a steam flow rate that can be used to adjust the opening degree of the steam valve, thereby achieving control

three element control

:handshake thank you

Thank you {:1_90:} in my innocence

You can take a look at the course materials from Zhejiang University: https://wenku.baidu.com/view/d8ea487dbb1aa8114431b90d6c85ec3a87c28be0.html Page 6 shows a comparison between pure feedforward control and pure feedback control. If the pressure of the inlet steam varies little, the amount of heating steam can be controlled directly using the flow rate/temperature of the material. Page 13: Feedforward + feedback control is used because the material flow rate and temperature at the inlet vary greatly, which affects the control parameters of the outlet temperature T. Additionally, since the vapor pressure also fluctuates significantly, a feedback loop for the outlet temperature TIC is implemented. Feedforward is a separate controller that belongs to the category of \"pre-control\"; it does not require feedback signals, so it is not a closed-loop control system. For example, if the amount of material is too high, the steam valve is opened in advance ； The inlet temperature is too high; reduce the steam first. And a feedback controller must be closed-loop, with a longer control time in a closed-loop system. In your example, there is only a flow rate feedback signal; therefore, it is not necessary to calculate the heat enthalpy of the material, and this constitutes linear feedback. As for the schematic representation, FT-225 should be an adder, while FIC-224 should be a feedforward controller. Its setpoint can be either the setpoint of TIC-226 or the output value of TIC-226; the latter provides stronger control capabilities.

:victory::handshake Okay, thank you!

I think this resembles a cascade control system: flow control constitutes the secondary loop, while temperature is the primary loop. The output of the temperature control serves as the input for flow control, and by regulating the steam flow at the inlet of the heat exchanger, the outlet temperature of the fluid being heated in the heat exchanger can be controlled

This post was last edited by Ku Liang Zhi Le on 2019-12-9 at 18:32. The diagram shows a feedforward cascade control system for the material outlet temperature – based on steam flow rate plus material flow rate. The material outlet temperature is the primary and controlled variable in the cascade control system ； Steam flow rate is the secondary controlled variable in a cascade control system ； Material flow is a feedforward quantity, that is, an disturbance. The image shows an incorrect representation; it should be: https://attach01.hcbbs.com/forum/201912/09/182919qll66b4eee75t7v7.png

The first image sent is correct; I don’t know how to delete the latter two. I'm sorry.