CHEMICAL ENGINEERING PROCESS DYNAMICS AND CONTROL HW MATLAB
A tank chemical reactor system is shown in the figure. A liquid stream enters a tank at a volumetric flow rate F (cfm) and contains reactant A at a concentration of c0 (mol A/ft). Reactant A decomposes in the tank according to the irreversible chemical reaction:
A -> products
The reaction is first order and proceeds at a rate r = -k*c.
The reaction is carried out in a CSTR reactor. The volume of the tank is V and it is maintained at temperature T.
In addition, a portion of the liquid leaving the tank is continuously withdrawn through the sample line, containing a measuring element, at a rate of 0.1 (cfm). The measuring element must be remotely located from the process because rigid ambient conditions must be maintained for accurate concentration measurements. The sample line has a length of 50 (ft), and the cross-sectional area of the line is 0.001 (ft^2).
Variables: V, T, c0, k
Numerical values for the process:
MW = 100 (lb/lb mol A)
PA = 0.8 (lb mol/ft^3)
c0s = 0.1 (lb mol A/ft^3)
k = min^-1
ms = 1.0 (lb mol/min)
F = 100 (cfm)
V = 300 (ft^3)
p [=] volume/flow rate
a) Draw the block diagram for the reactor control system.
b) When a 0.05 (mol A/ft^3) step input is given to the set point, plot the concentration of the tank vs. time according to the controller settings given below. Write/draw all the necessary MATLAB/Simulink model/program/command. Plot all the results on the same graph and compare them.
i) Kc = 230, 430, 630. Use a value of 1.5 (min) for ti.
ii) ti = 0.5 (min), 1 (min), 1.5 (min). Use a value of 230 for Kc.
c) When a 0.05 (mol A/ft^3) step input is given to the feed concentration (ce), plot the concentration of the tank vs. time according to the controller settings given below. Write/draw all the necessary MATLAB/Simulink model/program/command. Plot all the results on the same graph and compare them.
i) Kc = 150, 250, 350. Use a value of 2 (min) for ti.
ii) ti = 1 (min), 2 (min), 3 (min). Use a value of 350 for Kc.