The control problem of three impulses – experts, please step in.

In fact, both FV and LV refer to feedwater valves; the only difference lies in their control methods. 1: FV is an actuator used to regulate the flow rate of feedwater. It generally operates as a secondary loop in two-or three-pulse control systems, meaning that minor fluctuations or disturbances are handled by the flow regulator in this secondary loop. Only when the secondary loop regulator FC is unable to adequately adjust the quality factor does the main regulator LC take over to control the opening degree of the control valve, thereby enabling a transition from one equilibrium state to another. 2: LV is an actuator that directly regulates the liquid level; it belongs to a single-pulse or single-loop control system, which is a simple control system in which the liquid level is controlled directly by a control valve. It is generally used in systems where high precision is not required and where there are few disturbances. Most waste heat boilers use single-loop systems, but cascade and triple-pulse systems are also used, with the choice of control system determined by the process requirements. Additionally: There are two control methods for the three impulses – namely, with the adder before and after LC. Both are feedforward-series control systems; however, the signs of the steam flow and feedwater signals at the adder differ depending on whether LC is before or after it. When LC is before, it is conventional control, where Df is negative and Wf is positive ； And at the back, the situation is exactly the opposite: note that each impulse entering the adder has a coefficient, and this coefficient should be related to the system; ultimately, Df and Wf cancel each other out. The three impulses can also be taken into account in the outlet temperature of the superheated steam, but this will not be discussed in detail here.

Could someone upstairs explain in detail the calculation of the three Impulse Control module? For example, when the flow rate fluctuates little, flow regulation is the main approach; what role does the liquid level play in this context? ； When the flow rate fluctuates significantly, level control is the primary method; how should flow rate be utilized in such cases?

If you work in programming, you can use this as a reference; if you’re involved in manufacturing processes, it’s useful to understand that the transition from traditional processes to automated control involves a great deal of knowledge – knowledge of manufacturing processes, equipment, electrical automation, automatic instrumentation, as well as knowledge of metalworking and machining of mechanical parts ! ! P = Pl + C1Pw + C2Ps + C0 (with lc before the adder). P is the output of the adder; PI is the output of the LC regulator. PW represents the flow rate, while PS represents the steam flow rate. C1/C2 are coefficients, and C0 is a constant. Regarding small fluctuations, a negative regulator is sufficient to handle them, so there is no need for a main regulator. The main regulator is used only when the fluctuations are large enough that the negative regulator cannot handle them effectively. In other words, both regulators operate simultaneously. I hope you understand what I mean

How is the range of your small fluctuations determined? After making the calculation, does the final output show the given value of flow rate or the given value of liquid level? I hope an explanation can be provided.

In the boiler three-variable level control system, according to the process requirements, automatic mode is activated and the level is set to 0, which represents the final setpoint. You can view the output curve of the main regulator to see if there are any changes; if no changes occur, it indicates that the main regulator is not performing any regulatory function at this time, serving merely as the setpoint for the secondary regulator. As for the magnitude of the size interference, it is identified by the secondary regulator; it is difficult for humans to draw a conclusion