# PTU B.Tech Petroleum Engineering 6th Semester May 2019 74039 PROCESS INSTRUMENTATION and DYNAMIC CONTROL Question Papers

PTU Punjab Technical University B-Tech May 2019 Question Papers 6th Semester Petroleum Engineering

Roll No.
Total No. of Pages : 02
Total No. of Questions : 09
B.Tech.(Petroleum Refinary Engineering) (2013 Batch) (Sem.?6)
PROCESS INSTRUMENTATION & DYNAMIC CONTROL
Subject Code : BTPC-603
M.Code : 74039
Time : 3 Hrs. Max. Marks : 60
INSTRUCTIONS TO CANDIDATES :
1.
SECTION-A is COMPULSORY consisting of TEN questions carrying T WO marks
each.
2.
SECTION-B contains FIVE questions carrying FIVE marks each and students
have to attempt any FOUR questions.
3.
SECTION-C contains T HREE questions carrying T EN marks each and students
have to attempt any T WO questions.
4.
Assume any missing data.

SECTION-A
1.

a) Enlist any four types of pressure measuring instruments.

b) What do you understand by first order and second order system?

c) Compare feedback and feed forward control system.

d) What do you understand by tuning of controller settings?

e) Describe the terms rise time and overshoot with context to a under damped second
order system.

f) Find the Laplace transform of a function f(t) = A cos (t).

g) What do you understand by frequency response?

h) Give the initial value theorem for Laplace transformation.

i) What is a transfer function? Give its physical significance.

j) Define transportation lag. Give its transfer function.

SECTION-B
2.
A mercury thermometer having time constant of 1 minute has been placed in a bath at
200?C and indicating 200?C temperature on achieving steady state. Afterwards the bath
temperature suddenly started increasing linearly at the rate of l?C/min. Plot the response.
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(S2)-681

3.
Derive an expression for the change in head of the second tank to unit step change in the
inlet flow rate of the first tank of a two liquid level tanks in series system connected in a
non-interacting fashion having equal time constant. Assuming, the linear valve resistance
characteristics of the valves installed in the outlet line of first and second tank
respectively.
4.
For close loop system as shown in figure,

Calculate :

a) The value of kc when the closed loop response has = 2

b) Find the offset for a unit step change in U for kc =3
U
+
R +
(s 2)
k
C
c
G
?
+
p
(
s s 3)

Fig.
5.
Find and draw the transient response of controllers in P, PI and PID mode for step error
input.
6.
Two first order systems with time constants, 1 = 10 sec and 2 = 20 sec and gains, Kp1 =
1.2 and Kp2 = 1 respectively are connected in series in a non-interacting manner. Find the
value of kc for proportional controller in the close loop unit feedback system to have a
decay ratio of 0.6.

SECTION-C
7.
a) Sketch the Nyquist diagram for the following open loop transfer function.

i) G(s) = (s + 1)
1

ii) G(s) =

2
s

b) What do you understand by stability of a control system? Discuss the stability

criterion.
8.
a) Describe and compare any two methods for measuring the flow rate of a fluid flowing

through a pipe.

b) With the help of neat diagram, describe principles, features and working of

thermocouple for the measurement of temperature.
9.
a) Explain briefly the various control techniques used in distillation column.

b) Discuss the computer control of chemical processes.

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