Q3. (6 marks) Consider the liquid blending control system shown in Figure 1 where stream consists of a mixture of two co

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Q3 6 Marks Consider The Liquid Blending Control System Shown In Figure 1 Where Stream Consists Of A Mixture Of Two Co 1 (54.16 KiB) Viewed 9 times

Q3. (6 marks) Consider the liquid blending control system shown in Figure 1 where stream consists of a mixture of two components and stream 2 has x2= 1. An overflow line maintains a constant holdup in the tank. The control objective is to control the blend composition, x, which can be measured online but there is a significant transport time delay associated with the location of the composition measurement, which is downstream of the blending tank. Inlet flow rate W2 can be manipulated but its upstream pressure can vary significantly. The exit flow rate w can also be measured. The chief disturbance variable is inlet flow rate wl, which can exhibit very large and frequent changes. Using the instrument provided, you are required to suggest the following control scheme to solve the control problem of the blending system: a) Cascade control only (2 Marks) b) Feedforward control only (2 Marks) c) Cascade and Feedforward control (2 Marks) Be sure to clearly identify the MV, CV, and DV for each control strategy. Control valve Mixture of A and B 31 Pure A x2 = 1 wi W2 Overflow line 1 X LD