Essentials of Process Control phần 7 pps
Essentials of Process Control phần 7 pps
... value.
2. Pick a value of
70
and find the value of K, that gives +2-dB
Ly.
3. Repeat step 2 for a whole range of
7~ 1
values, with a new value of K, calculated
at each new value of
70
such that ... RESPONSE OF FEEDBACK CONTROLLERS
Before we give some examples of the design of feedback controllers in the frequency
domain, it would be wise to show what the common
P,
P...
Essentials of Process Control phần 8 ppsx
... 142
-0.8915611
-0.2523 673
-0.0002581
0.0 270 092
0.0 178 741
0.008 976 6
-0.082898 1
-0.0835548
-0.0391486
0.1 473 784
-0.648 279 6
-0.648 279 6
-0.4463 671
-0.245045 1
-0.1182182
(13.3)
(13.4)
(13.5)
0
0.052061
1
VT
II
0 .71 91619 -0.6948426
-0.6948426 ... grounded in the essence of chemical
process control will be capable of understanding the features of model predictive
cont...
Essentials of Process Control phần 6 pps
... unstable.
1.5
-
4. 57
f
3T2
1
=
-
=
1 .75 7
I .75
3
7
1.5
minutes
Note that there are actually two values of
T
that satisfy the equation above, but the lim-
iting one is the larger of the two.
9.3.2 Effects of ...
1
So the IMC controller becomes a PD controller.
GIMC(S)
=
7, s + I
fqw
+
1)
(9 .79 )
I
The IMC structure is an alternative way of looking at controller design....
Essentials of Process Control phần 5 pps
...
ft3
Plugging these into Eqs. (7. 86) and (7. 87) gives
(40)(0.6)(450)%
=
(W9O)(O.W’o
-
TI)
+
QI
(40)(0.6)(90)$
=
(40)(90)(0.6)(&
-
7- z)
(7. 86)
(7. 87)
(7. 88)
(7. 89)
256
PARTTWO:
Laplace-Domain ...
km)
i
71
s+l
ji
72
s+l
73
1 +
k,q
1
+
k2r2
1 +
k3r3
s+l
(7. 77)
G(s)
=
K?J
(70 1s
+
1x702s
+
1) (70 3s +
1)
Let us assume a unit step change in the...
Essentials of Process Control phần 2 ppsx
... example
3.1.3 Control Valves
The interface with the process at the other end of the control loop is made by the
final control element. In a vast majority of chemical engineering processes the
final
control ... or SI units.
Sizing of control valves is one of the more controversial subjects in process con-
trol. The sizing of control valves is a good example of the...
Essentials of Process Control phần 10 ppt
... this process (with
70
=
K,
= 1) with a proportional sampled-data controller and a sampling period of 0.5
minutes, the controller gain that gives a phase margin of 45” is K, = 3.43. The controller
gain ...
PI
controller.
Use r/ values of 0.5 and 2 minutes.
15.3.
Make Nyquist plots for the process of Problem 15.1 and find the value of gain that gives
the following specifica...
Essentials of Process Control phần 9 ppt
... 0
0.2
I
0.8159 2. 176
0.4 2
0.8184
-0.8098
0.6 3
0.8184 3.254
0.8
4 0.8184 -2.310
KC
= feedback controller gain
K, = process steady-state gain
7, )
= process time constant
For the numerical values of K, = ... is one of the reasons
z
transforms are often used.
By definition,
F(z)
=
fro,
+
hr,,z-’
+ h 27; )z-2 +
jj3T,,z-3
+ . . .
If we can get F(:) in terms of an infinite...
Essentials of Process Control phần 4 pptx
... 2
&-/NF
19/12
19112
19/10
&
8.43 13. 17 18.30
DZ
31. 57 36.83
11 .70
Rl 44.0 56.0
67. 85
VZ
75 .6 92.8 109.6
Dcz 1.60
1 .77
1.92
Energy
1.93
2. 17
1.41
costs
Reactor
110.3
134.5 154.8
Column 1 57. 3 57. 9 59.0
Column
2
67. 6 75 .5
82.4
HtEx. ... 0.5548
95.22
96.94
98.85
66.43 82. I2 95.46
265.6 328.3 381 .7
6.50 7. 23
7. 79
8 37. 4
II06
1 376
1256 1659 2064
Column 1
NTIN...
Essentials of Process Control phần 3 pdf
... signals.
4.2
CASCADE CONTROL
One of the most useful concepts in advanced control is cascade control. A cascade
control structure has two feedback controllers, with the output of the primary (or
1
... shutdown of the process.
Override control (or “selective control, ” as it is sometimes called) is a form of
multivariable control in which a vzanipulnted variable can be se...
Essentials of Process Control phần 1 ppt
... knowledge not only of these traditional areas but also
of the fundamentals of process control. For those of us who have been part of this
period of development, the attainment of parity with the ... the
;tem
cess
yben
yben
Essentials of Process Control
Essentials of
Process Control
Michael L. Luyben
Du Pont Central Research and Development
Experimental Station...