Solution Found!
For the liquid storage system shown in Fig. E15.4, the
Chapter 15, Problem 15.4(choose chapter or problem)
For the liquid storage system shown in Fig. E15.4, the control objective is to regulate liquid level h2 despite disturbances in flow rates, q1 and q4. Flow rate q2 can be manipulated. The two hand valves have the following flow-head relations: Figure E15.4 Do the following, assuming that the flow transmitters and the control valve have negligible dynamics. Also assume that the objective is tight level control. (a) Draw a block diagram for a feedforward control system for the case where q1 can be measured and variations in q4 are neglected. (b) Design a feedforward control law for case (a) based on a steady-state analysis. (c) Repeat part (b), but consider dynamic behavior. (d) Repeat parts (a) through (c) for the situation where q4 can be measured and variations in q1 are neglected.
Questions & Answers
QUESTION:
For the liquid storage system shown in Fig. E15.4, the control objective is to regulate liquid level h2 despite disturbances in flow rates, q1 and q4. Flow rate q2 can be manipulated. The two hand valves have the following flow-head relations: Figure E15.4 Do the following, assuming that the flow transmitters and the control valve have negligible dynamics. Also assume that the objective is tight level control. (a) Draw a block diagram for a feedforward control system for the case where q1 can be measured and variations in q4 are neglected. (b) Design a feedforward control law for case (a) based on a steady-state analysis. (c) Repeat part (b), but consider dynamic behavior. (d) Repeat parts (a) through (c) for the situation where q4 can be measured and variations in q1 are neglected.
ANSWER:Step 1 of 12
From the problem we know that
A controller is used to control the the liquid level 
The flow-head relations of the valves 
The dynamics of the flow transmitter and the control valves are negligible.
The goal is a tight level control.