Gliwice, 2020
Hierarchical Control
Laboratory
Exercise 1
Stirred-tank continuous-flow reactor
Obaid Ba Geri
AshishKumar Sutariya
1. Introduction:
The aim of this lab
The aim of the exercise is modeling of a stirred-tank continuous-flow reactor, finding its static
characteristics, and designing control system for the reactor.
Task. 1
We have created a model of the reactor for the mentioned state equations:
Matlab code:
function dy=f(t,y)
e=exp(1); Fa=1.5;
Fb=0.5;
Fd=2;
Ta=300; Tb=300; c=5000;
h=500;
H=10^6;
k=0.2*(1-e^(1-(y/173)));
dy(1)=Fa+Fb-Fd;
dy(2)=(((1-y(2))/y(1))*Fa)-((y(2)/y(1))*Fb)-(y(2)*k);
dy(3)=(((Ta-y(3))/y(1))*Fa)+(((Tb-y(3))/y(1))*Fb)+(H/(c*y(1)))-((h/c)*y(2)*k);
dy=dy';
end
plots of the system we used following Matlab code:
time=150; v =
[500,1,300];
[t2, y2] = ode45(@f,0:time,v);
dW=y2(1:time+1,
1); dCa=y2(1:time+1,
2); dT=y2(1:time+1,
3);
figure;
plot(0:time, dW)
xlabel('Time')
ylabel('W')
figure;
plot(0:time, dCa)
xlabel('Time')
ylabel('Ca')
figure;
plot(0:time, dT)
xlabel('Time')
ylabel('T')
We obtained following plots:
As now we can observe from the plot the characteristics of the model. According, to the plots we
can conclude the following:
1. The mass of the mixture is constant
2. We can observe that the plots start
3. The temperature of the reactor is increasing during the whole simulation
4. Concentration of substance A is decreasing.
Task 2
Design and apply a diagonal controller with signal assignments: F W A →, F C D → A and H →T, which stabilize state
variables on desired levels.
In the function blocks we used the same formulas as in the previous example. We
obtained the following results:
So now we can observe that both of the methods provide us with the same results. So, we can
conclude that the results are correct.