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SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 1
Sathyabama University
SATHYABAMA UNIVERSITY (Established Under Section 3 Of UGC Act 1956)
DEPARTMENT OF CHEMICAL ENGINEERING Jeppiaar Nagar, Chennai – 119.
SCHX4005 – PROCESS DYNAMICS & CONTROL LAB MANUAL
Register No: _____________________________________________________
Name : ___________________________________________________________
Year:________________________ Section: __________________
Staff in-charge:________________________________________________
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 2
Sathyabama University
Rules to be followed inside the laboratory:
Students should be present on time.
Students must wear Lab coat & shoes.
Students must bring Observation & Record without Fail.
Observation & Record should be neatly covered with laminated brown Sheet.
Students should complete the observation & get it signed on the same day of the
Experiment.
Completed Record should be submitted on the next lab class for correction without
Fail.
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 3
Sathyabama University
Syllabus
1. ON – OFF Control of thermal process
2. Simulation of proportional controller
3. Flow control loop and flow transmitter
4. Level control loop and level transmitter
5. Pressure control loop and pressure transmitter
6. Control valve characteristics
7. Verifying the inherent characteristics of control valve
8. Flow co-efficient of control valve
9. Range ability of control valve
10. Verifying the response of Non-interacting level system
11. Verifying the response of Interacting level system
12. Effect of PI controller on flow control system
13. The effect of P controller on level process for set point and load changes
14. Effect of P, PI, and PID controller on pressure control loop
15. Optimum controller setting using Zeigler Nicholas method
16. Optimum controller tuning on level process station
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 4
Sathyabama University
List of Experiments
1. ON-OFF Controller of Thermal Process
2. Simulation of proportional controller
3. Flow Control loop and Flow transmitter
4. Level Control loop and Level transmitter
5. Pressure Control loop and Pressure transmitter
6. Characteristics of control valve
7. Verifying the response of Non-interacting level system
8. Verifying the response of Interacting level system
9. Control of Process Using Ziegler Nicholas Method
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 5
Sathyabama University
1. On-Off Controller of Thermal Process
Aim:
To obtain the characteristics of ON-OFF controller Thermal Process for the given set point.
Apparatus required:
1. ON-OFF controller set up
2. Stop control
Theory:
ON-OFF position control is a position type of controller action in which controller output is quickly
changed to either maximum or minimum value depending upon whether the controlled variables is greater or
less than the set point.
ON-OFF control system is most widely used type of control for both industrial and domestic service. It
is a control generally employed on some heating systems and domestic water heater.
Procedure:
1. First ON-OFF controller set up is connected to i/p supply and it is switched on
2. A set point is set for heater
3. Heater is switched on and the heater coil begin to heat up and the temperature rises
4. The heater is on until the temperature reaches the set point value. The controller is said to be in ON
condition
5. When temperature increases beyond set point value the heater is switched off by the controller and the
temperature decreases
6. The controller is said to be in the off condition
7. The readings are noted for both the condition
8. The readings are noted for every 15 minutes increase or decrease in temperature output and a graph is
drawn for the time vs. temperature
9. The same experiment is repeated for different set points
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 6
Sathyabama University
Model Graph
Tabulation
Set point=
Time(sec) Temperature(˚C) Controller position
RESULT: Thus the characteristics of ON-OFF controller for the given set point is obtained
OFF
ON
CONTROLLER POSITION
TIME (SECS)
Temp (ºc)
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 7
Sathyabama University
2 .Simulation Of Proportional Controller
Aim:
To design a Proportional controller for first order system with dead time using process reaction curve
Requirements:
System with MATLAB software
Theory:
It is the most empirical tuning methods. Consider the control system which has been opened by disconnecting
the controller from the final control element. Introduce a step change of magnitude A in the variable c which
actuated the final control element. In the case of a valve, c is the stem position. Record the value of the output
with respect to the time. The system is approximated by the response of a first order system with dead time.
GPRC(S)=Ke-tds/(τs+1)
Which has three parameters: static gain K, dead time td, and time constant τ.
K= output (at steady state)/ input (At steady state) =B/A
τ =B/S, where S is the slope of the sigmoidal response at the point of inflection
td= time elapsed until the system responded.
The results of their analysis are summarized below
For proportional controllers
KC=(1/K) ( τ / td) (1+ td/3 τ)
For proportional integral controllers
KC=(1/K) ( τ / td) (0.9+ td/12 τ)
τI = td (30+3 td/ τ) /(9+20 td/ τ)
For proportional integral derivative controllers
KC=(1/K) ( τ / td) (4/3+ td/4 τ)
τI = td (32+6 td/ τ) /(13+8 td/ τ)
τD= td 4/(11+2 td/ τ)
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 8
Sathyabama University
Procedure:
1. Enter the MATLAB package and select SIMULINK
2. Open a new file from the browser window, drag a transfer function block, source block, scope block and
place it in the work place.
3. Define the transfer function for both process and controller by double clicking the transfer function block.
4. Run the system.m
5. Analyse the o/p waveform & trace it in a graph sheet.
6. Repeat the same using MATLAB program.
RESULT: Thus the Proportional controller is designed for first order system with dead time using
process reaction curve
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 9
Sathyabama University
3 .Flow Control loop and Flow transmitter
Aim:
To study the action of controllers for a flow process analyzer using process control software.
Apparatus Required:
1. IBM PC
2. Process Control Software
Theory:
Proportional Integral Control:
Integral or reset action combined with proportional control gives us a controller which will always act to
maintain the controlled variable at its desired value
The proportional control mode provides a stabilizing influence while the integral mode will help to
overcome the offset. Integral controller will provide corrective action as long as there is a deviation in the
controlled variable from the set point value.
Procedure:
1. Ensure that the VPSC cable is connected between IBM PC and flow process.
2. Apply air pressure more than 25psi to the pressure regulator and set regulator output pressure to 20 psi
by varying air regulator, which forms the pneumatic input to I/P convertor.
3. Invoke process control software in the IBM PC and select analyzer.
4. Enter the process parameters into the data entry menu.
5. Check whether the controller output is 100% before switch on the motor.
6. Switch on the pump and select the desired speed by varying the speed control knob.
7. Tune the parameters gain to maintain the controlled variable almost at the set point.
8. View the response for different set points.
Tabulation:
Proportional Integral Control Set point = Kp Ki=
Sl.No Time(in sec) PV (LPH)
RESULT: Thus the action of controllers for a flow process analyzer using process control software is done
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 10
Sathyabama University
4. Level Control loop and level transmitter
Aim:
To study the action of controllers for a level process analyzer using process control software.
Apparatus Required:
1. IBM PC
2. Process Control Software
Theory:
ON OFF Control:
One of the most widely used types of control is the ON/OFF Control. It is also referred as TWO
POSITION control or OPEN AND CLOSE control.
Two position control is a position type of controller action in which the manipulated variable is quickly
changed to either a maximum or minimum value depending upon whether the controlled variables greater or
less than the set point.
If the controlled variable is below the set point the controller output is 100 %( the control valve is fully
opened). If the controlled variable is above the set point controller o/p is 0% when the differential gap is 0.
Differential Gap:
Differential gap is the region in which the control causes the manipulated variable to maintain its
pervious value until the controlled variable has moved slightly beyond the set point.
Time Delay:
The delay given to the controller between successive corrective action
Proportional Control:
It is a controller action in which there is a continuous linear relation between value of the controlled
variable and position of the final control element with in the proportional band.
Proportional Band:
Proportional band or throttling range is defined as the percent deviation in measurement of its full scale
required to give 100% valve deviation.
Proportional Gain:
It is the proportional control factor which is used to determine the proportional band.
Proportional Band= 100% of full scale valve / proportional gain (Kp)
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 11
Sathyabama University
Procedure:
1. Ensure that the VPSC cable is connected between IBM PC and level process.
2. Apply air pressure more than 25psi to the pressure regulator and set regulator output pressure to 20 psi
by varying air regulator, which forms the pneumatic input to I/P convertor.
3. Invoke process control software in the IBM PC and select analyzer.
4. Enter the process parameters into the data entry menu.
5. Check whether the controller output is 100% before switch on the motor.
6. Switch on the pump and select the desired speed by varying the speed control knob.
7. Tune the parameters gain to maintain the controlled variable almost at the set point.
8. View the response for different set points.
Tabulation:
On-Off Control
Set point= Differential Gap=
Sl.No Time(in sec) PV (cm)
Proportional Control
Set point = Kp=
Sl.No Time(in sec) PV (cm)
RESULT: Thus the action of controllers for a level process using process control software is done
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 12
Sathyabama University
5. Pressure Control Loop and Pressure Transmitter
Aim:
To study the pressure control loop and pressure transmitter and to determine the effect of P, PI and PID
controller on pressure control
Apparatus Required:
1. IBM PC
2. Process Control Software
Theory:
On-Off Control:
One of the most widely used type of control is the ON/OFF Control. It is also referred as TWO
POSITION control or OPEN AND CLOSE control.
Two position control is a position type of controller action in which the manipulated variable is quickly
changed to either a maximum or minimum value depending upon whether the controlled variables greater or
less than the set point.
If the controlled variable is below the set point the controller output is 100 %( the control valve is fully
opened). If the controlled variable is above the set point controller o/p is 0% when the differential gap is 0.
Differential Gap:
Differential gap is the region in which the control causes the manipulated variable to maintain its
pervious value until the controlled variable has moved slightly beyond the set point.
Time Delay:
The delay given to the controller between successive corrective action
Proportional Control:
It is a controller action in which there is a continuous linear relation between value of the controlled
variable and position of the final control element with in the proportional band.
Proportional Band:
Proportional band or throttling range is defined as the percent deviation in measurement of its full scale
required to give 100% valve deviation.
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 13
Sathyabama University
Proportional Gain:
It is the proportional control factor which is used to determine the proportional band.
Proportional Band= 100% of full scale valve / proportional gain (Kp)
Proportional Integral Control:
Integral or reset action combined with proportional control gives us a controller which will always act to
maintain the controlled variable at its desired value
The proportional control mode provides a stabilizing influence while the integral mode will help to
overcome the offset. Integral controller will provide corrective action as long as there is a deviation in the
controlled variable from the set point value.
Proportional Derivative Control:
Derivative control action combined with proportional gives us a controller which is good on processes
containing appreciable lag. Because the process lag can be compensated by the anticipatory nature of derivative
action (i.e) derivative action provides the boost necessary to counter act the time delay associated with such
control systems. This is due to the fact that derivative control leads proportional control by 90 deg. Since this
controller combination is most effective where the system lags are high, it could be used on most multi capacity
process applications.
Proportional Integral Derivative Control:
When all three control effects are combined together, we obtain the benefits of each control action and
moreover the effect duplicates the action of a good human operator on a control application. A three mode
controller contains the stability to eliminate offset because of reset control and the ability to provide an
immediate correction for the magnitude of a disturbance because of rate control.
Procedure:
1. Ensure that the VPSC cable is connected between IBM PC and Pressure process
2. Apply air pressure more than 25psi to the pressure regulator and set regulator output pressure to 20 psi
by varying air regulator, which forms the pneumatic input to I/P convertor.
3. Invoke process control software in the IBM PC and select analyzer.
4. Enter the process parameters into the data entry menu.
5. Check whether the controller output is 100% before switch on the motor.
6. Switch on the pump and select the desired speed by varying the speed control knob.
7. Tune the parameters gain to maintain the controlled variable almost at the set point.
8. View the response for different set points.
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 14
Sathyabama University
Tabulation:
On-Off Control
Set point= Differential Gap=
Sl.No Time(in sec) PV (psi)
Proportional Control
Set point= Kp=
Sl.No Time(in sec) PV (psi)
Proportional Integral Control
Set point = Kp= Ki=
Sl.No Time(in sec) PV (psi)
Proportional Derivative Control
Set point = Kp= Kd=
Sl.No Time(in sec) PV (psi)
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 15
Sathyabama University
Proportional Integral Derivative Control
Set point = Kp= Ki= Kd=
Sl.No Time(in sec) PV (psi)
RESULT : Thus the action of controllers for a Pressure Process Analyzer using process control software was
studied.
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 16
Sathyabama University
6. Characteristics of control valve
Aim:
To obtain the characteristics of control valve
Apparatus Required:
1. Control Valve Characteristics Apparatus
Procedure:
1. Start as the setup as explained in “commissioning”. Open the inlet valve of the linear control
Valve. Open the respective hose cock for pressure indication. (Close the inlet valve and hose
Cocks of other control valves)
2. Ensure that the pressure regulator outlet is connected to the valve actuator of the linear control
Valve under study. Keep the control valve fully open by adjusting air regulator. (In case of
Control valve with valve positioner: ensure that the bottom pressure regulator outlet is
Connected to “IN” port at the valve positioner. Adjust the top pressure regulator to 20-25 psi for
Air supply to valve positioner)
3. Adjust the regulating valve and set the flow rate. (Set 400 LPH flow for linear / equal % valve or
600 LPH for quick opening valve). Note for measuring lower flow rates below rotameter
minimum range use measuring jar.
4. For studying other valve (Equal % / quick opening ) remove the air connection connected to the
actuator and connect it to actuator of other valve. (In case of setup with valve positioner remove
connection at the “IN” port of the valve positioner and connect to the actuator of the other
Control valves). Repeat the steps above
Tabulation:
Type of control valve: linear/ equal % / quick opening.
(Fill up the column “valve coefficient” after calculation)
Sl.no Pressure drop Δp (mm of H2O) Flow (LPH) Valve coeff.cv Lift
1
2
3
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 17
Sathyabama University
Calculations:
Cv = 1.16 Q x √ (G/ΔP) where,
Q = flow (m3/h) = Q in LPH/1000
ΔP = pressure drop across valve (bar) = ΔP in mm of H2O x 1.013/(1.33 x 103)
G = specific gravity = 1 for water
Rangeability = maximum controller flow / minimum controllable flow
Model Graph
RESULT:
The characteristics of control valve was obtained
Flow (m3 / h v)
Lift
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 18
Sathyabama University
7. Step response of first order systems arranged in non-interacting mode
Aim:
To obtain the step response of first order systems arranged in non-interacting mode
Apparatus Required:
1. Non-interacting tank setup
2. Watch clock
Procedure:
1. Start up the set up
2. A flexible pipe is provided at the rotameter outlet. Insert the pipe in to the cover of the top tank 1. Keep the
outlet valves (R1 & R2) of both Tank 1 & Tank 2 slightly closed. Ensure that the valve (R3) between Tank 2
and Tank 3 is fully closed.
3. Switch on the pump and adjust the flow to @90 LPH. Allow the level of both the tanks (Tank 1 & Tank 2) to
reach at steady state and record the initial flow and steady state levels of both tanks.
4. Apply the step change with increasing the rotameter flow by @ 10 LPH
5. Record final flow and steady state level of Tank 1
6. Carry out the calculations as mentioned in calculation part and compare the predicted and observed values of
the tank level
7. Repeat the experiment by throttling outlet valve (R1) to change resistance
Formula used:
H (t) observed = (Level at time t – Level at time 0)
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 19
Sathyabama University
Observations:
Diameter of tanks: ID 92mm
Initial steady state level of Tank 1 (cm):
Initial steady state level of Tank 2 (cm):
Final flow rate (LPH):
Final steady state level of Tank 1 (cm):
Final steady state level of Tank 2 (cm):
S. No Time
(sec)
Level of Tank 1
(cm)
Level of Tank 2
(cm)
H(t) observed
(cm)
Model Graph:
RESULT: Thus the step response of first order system arranged in non-interacting mode is obtained
TIME
(SEC)
TANK
LEVEL
(cm)
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 20
Sathyabama University
8. Step response of first order systems arranged in interacting mode
Aim:
To obtain the step response of first order systems arranged in interacting mode
Apparatus Required:
1. Interacting tank setup
2. Watch clock
Procedure:
1. Start up the set up
2. A flexible pipe is provided at the rotameter outlet. Insert the pipe in to the cover of the top tank 3. Keep the
outlet valves (R2) of Tank 2 slightly closed. Ensure that the valve (R3) between Tank 2 and Tank 3 is fully
closed.
3. Switch on the pump and adjust the flow to @90 LPH. Allow the level of both the tanks (Tank 2 & Tank3) to
reach at steady state and record the initial flow and steady state levels of both tanks.
4. Apply the step change with increasing the rotameter flow by @ 10 LPH
5. Record the level of the tank2 at the interval of 30 secs, until the level teaches the steady state
6. Record final flow and steady state level of Tank 3
7. Repeat the experiment by throttling outlet valve (R1) to change resistance
Formula used:
H (t) observed = (Level at time t – Level at time 0)
Observations:
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 21
Sathyabama University
Diameter of tanks: ID 92mm
Initial steady state level of Tank 3 (cm):
Initial steady state level of Tank 2 (cm):
Final flow rate (LPH):
Final steady state level of Tank 3 (cm):
Final steady state level of Tank 2 (cm):
S. No Time
(sec)
Level of Tank 2
(cm)
Level of Tank 3
(cm)
H(t) observed
(cm)
Model Graph:
RESULT: Thus the characteristics of first order system arranged in interacting mode is obtained
TANK
LEVEL
(cm)
TIME
(SEC)
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 22
Sathyabama University
9. Control of Process Using Ziegler Nicholas Method
Aim:
To design a controller using Ziegler Nicholas method for the given transfer function
Requirements:
System with MATLAB software
Theory:
It is based on frequency response analysis and it is closed loop procedure.
Bring the system to the desired operational level.
Using proportional control only and with the feedback loop closed, introduce a set point change and
vary the proportional gain until the system oscillates continuously. The frequency of continuous
oscillation in the crossover frequency wco. Let M be the amplitude ratio of the system’s response at the
crossover frequency.
Compute the following two quantities:
Ultimate gain=Ku= 1/M
Ultimate period of sustained cycling=Pu=2п/wco
Using the values of Ku and Pu, Ziegler Nichols recommended the following settings for feedback
controllers.
Proportional
Kc= Ku/2
Proportional –Integral
Kc= Ku/2.2,
τI=Pu/1.2
Proportional-Integral-Derivative
Kc= Ku/1.7,
τI=Pu/2 ,
τD=Pu/8
SCHX4005 PROCESS DYNAMICS & CONTROL LAB
Department of Chemical Engineering 23
Sathyabama University
Procedure:
1. Enter the MATLAB package and select SIMULINK
2. Open a new file from the browser window, drag a transfer function block, source block, scope block and
place it in the work place.
3. Define the transfer function for both process and controller by double clicking the transfer function block.
4. Run the system.m
5. Analyse the o/p waveform & trace it in a graph sheet.
6. Repeat the same using MATLAB program.
RESULT: Thus the P, PI, & PID controller is designed for the Ziegler Nicholas method and its effect on the
process is studied.
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