A major difference between the two-element and the three-element feedwater regulator control systems, is that a three-element system will additionally measure and incorporate the __________.
• Two-element vs. three-element feedwater control in boiler operations • The typical three measured variables in an automatic drum level control system • Difference between load change (steam demand) and drum level as control inputs
• Ask yourself: In a basic two-element system, which two process variables are normally used to control drum level? • When load changes quickly, which additional measurement helps the control system anticipate and stabilize drum level more effectively? • Of the choices given, which variable directly represents the incoming water side of the balance between steam leaving and water entering the drum?
• Be clear on what the two elements are in a two-element system before adding the third. • Identify which option represents an independent flow measurement rather than a variable already implied by drum level or firing rate. • Confirm which variable directly indicates the feedwater entering the drum, not the steam or fuel going out.
No comments yet
Be the first to share your thoughts!