Lab Module

Process Control & Instrumentation Laboratory BKF4791

Faculty of Chemical & Natural Resources Engineering

BKF4791

Process Control & Instumentation Laboratory

Name

Matric No.

Group

Program

Section

Date

Sem. I - Session 2010/2011


Vision

To be a center in producing professionals in the area of chemical and natural resources engineering,

with emphasis on industrial practices and applications.

Mission

To provide for the study of chemical and natural resources engineering in an industrial context

through outstanding education, research, and development.

Program Educational Objective (PEO)

PEO 1: Our graduates will demonstrate effective communications, leadership and teaming skills

PEO 2: Our graduates will demonstrate the foundation and breadth to obtain, apply, and transfer

knowledge across disciplines and into emerging areas of chemical engineering and

related fields

PEO3: Our graduates will demonstrate the foundation and depth for successful chemical

engineering careers in industry, academia, or government

PEO 4: Our graduates will demonstrate that they have a sense of responsibility are ethical in the

conduct of their profession, and have an appreciation for the impact of their profession on

society.

Program Outcomes (PO) for Laboratory

The students are expected to attain the following;

PO 2: ability to communicate effectively, in verbal and written forms, with both

technical and non-technical groups. (S)

PO 3: acquired in-depth technical competence in chemical engineering and related

disciplines (K)

PO 8: ability to function effectively as an individual and in a group with the

capacity to be a leader or manager (A)


CONTENTS

A. Teaching Plan

B. Laboratory Report Format & Evaluation

B1. Laboratory Report Format

B2. Report Evaluation

B3. Laboratory Front page

C. Occupational Safety & Health (OSH)

C1. FKKSA Occupational Safety & Health

C2. General Laboratory Procedures

C3. Emergency Notification & Response

D. Experiment

Exp 1: Density Measurement

Exp 2: Measurement and Analysis of Liquid Flow System

Exp 3: Measurement and Control of Air Flow System

Exp 4: Study on Dynamics of First Order and Second Order Systems

Exp 5: Study on Dynamics of First Order System using Furnace

Exp 6: Steady State and Dynamic Studies of Distillation Column

Exp 7: Gas Temperature Control Using PID Controller

Exp 8: Single Loop PID Level Control Using DCS

Exp 9: Gas Pressure Control Using PID Controller

Exp 10: Dynamic Studies of Simulated Gas Mass Flow Process

IPBL 1: Open Loop Studies of Simulated Gas Mass Flow Process

IPBL 2: PID controller Tuning of Simulated Gas Mass Flow Process


TEACHING PLAN

1 Course Code and Name BKF4791 Process Control & Instrumentation Laboratory

2 Semester and Year Taught Semester 1 Year 4

3 Program Level/Category Degree/Process Control & Instrumentation

4 Unit 1 Credit

5 Prerequisite Course

6 Contact HoursLecture:Tutorial:Laboratory:

0 unit0 unit3 units

(0 hours X 14 weeks)(0 hours X 14 weeks)(3 hour X 14 weeks)

7 Course Synopsis

This laboratory have been developed to address the key engineering educational challenge of realistic problem solving within the constraints of a typical lecture-style course in process dynamics and control. Students will conduct experiments based on two major process operations which are based on computer simulation and plant experimental works. In computer simulation, students will simulate a case study using Matlab environment software and also operate a system on Distributed Control System (DCS). While the students also run the experiment using pilot plant available in this laboratory. This application will encourage students to apply their process control theories into practical term and inculcate the critical thinking among the group members.

8 Course Outcomes

By the end of semester, students should be able to:CO1

CO2

CO3

CO4

CO5

To apply the process instrumentation and control hardware of the control system

To implement control strategies manually and automatically using software packages and plant

To perform scan, control, alarm and data acquisition (SCADA) functions and operate a system using DCS

To develop convenient graphical interface for students that allowed them to interact in real-time with the evolving virtual experiment

Function effectively as an individual and in a group throughout the semester based on tasks/modules assigned

9 Assessment Methods

Distribution (%) CO1 CO2 CO3 CO4 CO5Report 50 % XIndustrial Problem Based Learning (IPBL)

10 % X X X X X

Test 20 % XMentor Mentee 15 % XPeer Evaluation 5% XTotal 100 %

10 Learning References

1. Syntech Process Control Module2. Marlin, T.E., Process Control: Designing Processes and Control Systems

for Dynamic Performance, 2nd Edition, Mc Graw Hill, USA, 2000.3. F.J. Doyle III Process Control Modules, Prentice Hall4. Seborg, D.E., Edgar, T.F. and Mellichamp., Process Dynamic and Control,

John Wiley 2004.5. Stephanopoulos, G., Chemical Process Control: An Introduction to

Theory and Practice, Prentice-Hall 1984.6. D.R. Coughnowr, S.LeBlance., Process Systems, Analysis and Control,

Mc-Graw Hill, 2008.


B. LABORATORY REPORT FORMAT & EVALUATION

B1. Laboratory Report Format

1. Front page

2. Abstract

3. Introduction

4. Literature Review

5. Experiment Objective

6. Methodology

7. Result and Discussion/Questions

8. Conclusions & Recommendations

9. References

10. Appendices

B2. Report Evaluation:

Part A : 55%

(Inclusive of Front Page/Format; Abstract; Introduction; Literature Review; Experiment

Objective; Methodology; Conclusions & Recommendations; References; Appendices; Grammar

& Spelling; Timeliness)

Part B : 45%

(Inclusive of Result and Discussion/Questions)


Report Evaluation for Part A

Instruction: Please assess each item using the given scales. Fractional marks will be given for each category.

Item AssessedUnacceptable

(1)Acceptable

(2)Good

(3)Very Good

(4)Excellent

(5)Score

Organization and Format

Not follow FKKSA laboratory report format. Not well organized. Contents show lack of knowledge.

Partially follow FKKSA laboratory report format. Contents show enough of knowledge but still a few concept and ideas are loosely connected.

Follow FKKSA laboratory report format of writing; all needed sections present. Well organized. Contents show enough knowledge of subject.

Follow FKKSA laboratory format of writing; all needed sections present. Well organized and easily followed. Contents show full knowledge of subject.

Follow FKKSA laboratory report format of writing; all needed sections present. Tables and figures are correctly drawn and numbered. Excellent organized and easily followed. Contents show full excellent knowledge of subject.

Keywords: Front page, Content, Page No., Total page >8, Arrangement

Abstract Several major aspects of laboratory report are missing. Incomplete description of experiment.Student displays a lack of understanding about how to write an abstract.

Abstract misses one or more major aspects of laboratory report.

Abstract contains most major aspects of laboratory report.Abstract may be too technical and only understood by specialist in the discipline.

Abstract contains all major aspects of laboratory report i.e. main purpose of the experiment, its importance, methodology/ approach, most significant results or findings, main conclusions and/or recommendation.

Abstract contains references to all major aspects of laboratory report i.e. main purpose of the experiment, its importance, methodology/ approach, most significant results or findings, main conclusions and/or recommendation.General audience easily understands abstract.

Keywords: Introduction, Objective, Method, Result, Conclusion, Suggestion, 1 page



(1)Acceptable

(2)Good

(3)Very Good

(4)Excellent

(5)Score

Introduction Very little background information or information is incorrect OR, does not give any information about what to expect in the laboratory report

Some introductory information, but still missing some major points. OR, gives little information

Introduction is nearly complete, missing some minor points.

Introduction is complete and well written but theory may not be backed up to concise lead-in to the laboratory experiment.

Introduction is complete and well written; provides all necessary background principles and theory for the experiment. Present a concise lead-in to the laboratory experiment.

Keywords: Related Theory, Principles, Process Background

Literature Review Poor understanding of topic experiment, inadequate information or very little information regarding experiment topic.No external literature review.

Acceptable understanding of topic, adequate information evident, sources cited.Insufficient literature review or may contain unrelated materials.

Good understanding of topic, adequate information evident, sources cited.Sufficient literature review.

Good understanding of topic, adequate information evident, sources cited.Sufficient and relevant literature review.

Complete understanding of topic, topic extensively well-informed and variety of sources are cited.Literature review contains information relevant and directly related to experiment topic.

Keywords: Experiment Topic Information

Experiment Objective

No objective or objective missing the important points.

Objective is partially defined.

Objective is relevant but not elaborated.

Objective is clear, relevant and elaborated but missing some point on relevant explanation.

Objective is precise, clear, relevant and well elaborated with relevant explanation.

Keywords: Objective Elaboration

Methodology Missing several important

Materials and methodology nearly

Materials and methodology are





(1)Acceptable

(2)Good

(3)Very Good

(4)Excellent

(5)Score

explanations of materials and/or methodology. Not sequential. Most steps are missing or are confusing. Some procedural components generally described but are not replicable.

complete but still missing some important experimental details. Others may have difficulties following procedures; some steps are understandable; but most are confusing and lack detail. Can replicate experiment if reader makes some inferences.

explained with sufficient detail; some lack detail or are confusing. Mostly easy to follow. Description of procedure makes it likely that the work can be reliably replicated.

complete. Mostly easy to follow. Description of procedure can be replicated.

complete and adequately detailed. Logical and easily followed. Description of procedure is complete, ensuring that it can be replicated.

Keywords: Experiment Procedure, List of Equipment

Conclusions and recommendations

No conclusions or conclusion missing the important points. No recommendation given to improve the experiment.

Conclusions regarding major points are drawn, but many are misstated, indicating a lack of understanding.Conclusion is too general. Several recommendations have been given but they are too general and not contributing to the experiment’s improvement.

All the important conclusions are drawn could be better stated.Conclusion is related to general interest. Several recommendations have been stated and they are partially contributed to the experiment’s improvement.

All the important conclusions have been made.Conclusion is precisely stated.Conclusion and recommendation relates the study to general interest and other studies that have been conducted.

All the important conclusions have been clearly made. Conclusion is precisely stated and relates the study to general interest, other studies that have been conducted. Recommendations given are significantly contribute to the experiment’s improvement.

Keywords: Experiment Summary, Recommendation



(1)Acceptable

(2)Good

(3)Very Good

(4)Excellent

(5)Score

References Some citations in text are not available in list of reference.

A few citations in text are not available in list of reference.

All citations in text are available in list of reference but list of reference is less than 3.

All citations in text are available in list of reference and list of reference is more than 3.

All citations in text are available in list of reference. List of reference is more than 3 and variety source.

Keywords: Book Reference, Journal Reference, Website Reference

Appendices Appendices not available in laboratory report.

Only a few appendices available in laboratory report.

Appendices available in laboratory report but poorly constructed

Appendices available in laboratory report in structured manners

Appendices available in laboratory report in structured manners, clearly and precise

Keywords: List of Formulas, Tables, Figures, Calculation

Grammar and Spelling

Numerous spelling and/or grammar errors. Transitions confusing and unclear.

Still many spelling and/or grammar errors. Few or weak transitions, often wanders and jumps around.

Occasional grammar/spelling errors. May have a few unclear transitions.

Occasional grammar/spelling mistakes. Spell checked and proofed throughout. Good sentence and paragraph structure and transitions.

Minimal to no spelling mistakes. Spell checked and proofed throughout. Good sentence and paragraph structure and transitions.

Keywords: Language

Timeliness Laboratory report handed in more than one week late

Up to one week late Up to three days late Handed in one day late

Laboratory report handed in on time

Keywords: Punctuality

Total Assessment Marks (55%)


B3. LABORATORY REPORT FRONTPAGE

PROCESS CONTROL & INSTRUMENTATION LABORATORY

(BKF4791)

2010/2011 Semester I

Title of Experiment :

Date of Experiment :

Date of Submission :

Instructor’s Name :

Group of Member :

Name ID

1.

2.

3.

4.

5.

Group No. :

Section :

Marks :

FACULTY OF CHEMICAL AND NATURAL RESOURCES ENGINEERING

UNIVERSITI MALAYSIA PAHANG

Part A 55

Part B 45

TOTAL 100


C. OCCUPATIONAL SAFETY & HEALTH (OSH)

C1. FKKSA OCCUPATIONAL SAFETY AND HEALTH POLICY

In our mission to disseminate knowledge, stimulate teaching and learning, and inculcate soft-skill, FACULTY OF CHEMICAL AND NATURAL RESOURCES ENGINEERING is fully committed in practising safety and health with the aim of achieving the highest standards of Occupational Safety and Health (OSH).

In line with UMP OSH policy, FKKSA will preserve the safety and health of its associates, students, and related parties in accordance with safe system of work and best practice.

It is our policy to:

1. Facilitate our associates and related parties with sufficient information and effective training related to Safety and Health.

2. Comply with all the relevant legislations, regulations and procedures in the conduct of the operation.

3. Achieve zero lost time injury record by having a competent Safety and Health Management Team and a self-motivated trained workforce.

4. Nourish OSH as our highest core values in organisational goal.5. Review safety management systems periodically or continuously in

order to achieve safe system of work and best practice. 6. Establish systems and procedures to maintain the laboratory and pilot

plant facilities as scheduled and to implement safe system of work.

The OSH policy shall be subjected to periodical review to cater for likely variations in the course of the operations and shall be made available to all interested parties.

“STRIVE TOWARDS ZERO LOST TIME INJURY”

______________________________Assoc. Prof Zulkafli B. Hassan

Dean of FKKSA

Dated: AUGUST 2008


C2. General Laboratory Procedures

DO Know the potential hazards of the materials used in the laboratory. Review the Chemical Safety Data

Sheet (CSDS) and container label prior to using a chemical.

Know the location of safety equipment such as emergency showers, eyewashes, fire extinguishers,

fire alarms, spill kits and first aid kits.

Review emergency procedures to ensure that necessary supplies and equipment for spill response and

other accidents are available.

Practice 5S to minimize unsafe work conditions such as obstructed exits and safety equipment,

cluttered benches and hoods, and accumulated chemical waste.

Wear personal protective equipment when working with chemicals. This includes eye protection, lab

coat, gloves, and appropriate foot protection (no sandals). Gloves should be made of a material known

to be resistant to permeation by the chemical in use.

Wash skin promptly if contacted by any chemical, regardless of corrosivity or toxicity at least 15

minutes.

Label and store chemicals properly. All chemical containers should be labeled to identify the

container contents (no abbreviations or formulas) and hazard information. Chemicals should be stored

by hazard groups and chemical compatibilities.

Use fume hoods when processes or experiments may result in the release of toxic or flammable

vapors, fumes, or dusts.

DON’T

Eat, drink, chew gum, or apply cosmetics in areas where chemicals are used and stored.

Perform unauthorized experiment.

Store food in laboratory freezer or ovens.

Drink water from laboratory water sources.

Use laboratory glassware to prepare or consume food.

Smell or taste chemicals.

Pipette by mouth.

Leave potentially hazardous experiments or operations unattended without prior approval

from the lab instructor.

Use chipped, cracked or dirty glassware.

Work alone in the laboratory after office hour.

Dispose chemical waste into sink drains.

Immerse hot glassware in cold water. The glassware may shatter.

Look into a container that is being heated.


C3. Emergency Notification & Response











EXPERIMENT 1: DENSITY MEASUREMENT

OBJECTIVES

1. To study the fundamental principles (hydrostatic) of density measurement

2. To compare the density measurements by two different density transmitters of different

process applications and measurement techniques

3. To study the effect of pressure on the density measurement.

INTRODUCTION

Model DMS 212 is carried out in Model DLT912 Density Level Temperature Measurement / Site

Calibration Plant. Model DLT912 plant is a scale-down real INDUSTRIAL PROCESS PLANT

built on 5ft x 5ft steel platform, complete with its own dedicated control panel. The process

equipment and process instrumentation are real INDUSTRIAL PROCESS type. The plant is

constructed in accordance to industrial process plant standards and practices, with fail-safe

features. For example , the pump (P1) will be automatically switched off unless the liquid level is

above a predetermined low level limit detected by a level switch LS. The process flowrates are at

COMMERCIAL PRODUCTION flowrates, using pipes and not tubings.

PLANT DESCRIPTION

PART A: PLANT INSTRUMENTATION

1. Tank T1

It is a stainless steel cylindrical vessel with a pressure relief valve (PRV), vent (V), overflow and

manual discharge valves i.e. gate valve and globe valve located at the bottom of tank T1. A

pressure gauge (PG) and temperature gauge (TG1) are also mounted at tank T1. Tank T1 can be

operated as an open or closed tank by pressuring with compressed air. A Different Pressure /

Density / Level Transmitter (DT1/LT1) is mounted to measure the density of the liquid or level

in tank T1. A sight glass with millimeter scale (LG1) is also provided to observe the tank level.


2. Tank T2

It is a rectangular tank made of plastic transparent material for internal visibility. A Differential

Pressure / Density / Level Transmitter (DT2/LT2) of bubble tube arrangement is mounted to

measure the density of the liquid or level in tank T2. A temperature gauge (TG2) is also mounted

at tank T2.

3. Tank T3

It is a stainless steel rectangular tank mounted at the platform (below tank T1) with bottom drain

and overflow drain. The water in tank T3 is pumped to tank T1 or T2 using a pump (P1),

complete with its pump suction valve, pump discharge valves (including MV1), pump by-pass

valve (BV1) and pressure relief valve (PRV1). The water in the tank can be heated but the water

temperature is controlled using a RTD element (TE1), a temperature digital indicator TIC1 with

an ON/OFF alarm, set at say 60°C maximum. If the water temperature in the tank exceeds its

high temperature limit, set at temperature ON/OFF controller TIC2, the annunciator TAH will be

activated. A level switch (LS) will automatically switch off the pump P1 if the water is below the

predetermined low-level limit. A stirrer is provided for better mixing in tank T3. The experiment

can also be conducted using sugar water instead of water.

PART B: FIELD INSTRUMENTATION

At Tank T1:

PG : Pressure Gauge

TG1 : Temperature Gauge, bimetal, 0-100°C.

LG1 : Sight Glass with millimeter scale.

DT1 : Differential Pressure / Density transmitter.

PRV : Pressure Relief Valve

AR1 :Air supply regulator to pressurize tank T1.

At Tank T2:

TG2 : Temperature Gauge bimetal 0-100°C

LG2 : Level millimeter scale

DT2 : Differential Pressure / Density transmitter


Immersed in the tank T3 are the following:

TE1 : RTD (PT100) element.

TE2 : Type K Thermocouple element.

TG : Temperature Gauge, bimetal, 0-100°C

LS : Level Switch

- : Stirrer

PART C: PANEL INSTRUMENTATION

Mounted at the control panel are the following:

DIA1 : Digital Density Indicator, from DT1, with ON/OFF alarm to Annunciator

DAL.

Actual density (S.G.) reading = Reading in DIA1, % x its maximum

calibrated density (S.G.)

DI2 : Digital Density Indicator, from DT2.

: Actual density (S.G.) reading = Reading in DI2, % x its maximum

calibrated density (S.G.)

TIC1 : Digital Temperature Indicator, RTD (PT100) input with ON/OFF alarm

to control the tank Heaters ON/OFF

TIC2 : Digital Temperature Indicator, Type K Thermocouple input, from TE2,

with ON/OFF alarm to Annuncator TAH

DLTR : Recorder with four analog pen/bar graph display, as well as display in

engineering units. The ANALOG displays are in % of their maximum upper

range values.

*Red pen (Channel 1) :DT1, 0-100%

*Green pen (Channel 2) :DT2, 0-100%

*Blue pen(Channel 3) :TE1/TIC1, 0-100°C

*Purple pen (Channel 4) :TE2/TIC2, 0-100°C

* An external selector switch is provided to select either LT1/DT1 and LT2/DT2

or TIT3 and TIT4 to be recorded by the Red and Green pens or displayed at

channel 1 and 2, in % of their respective upper range values.


: ANALOG display in the form of horizontal cloured bar or pen-chart

paper are to be read as follows:-

: Analog display x Maximum (calibrated) = Actual reading,

in % range values, engineering, engineering units

units

:Digital display in engineering units are 0-100°C for Channels 1 and 2, and 0-

100°C for Channels 3 and 4.

: The chart drive is set for fast speed (500mm/h).

The recorder chart drive is started or stopped by pressing the RCD button

with the front swing cover opened

Annunciators (TAH, DAL/LAL) with Test and Acknowledge buttons.

TAH : The liquid temperature in tank T3, as measured by the temperature

element TE2 (thermocouple type-K) exceeds the preset High Limit of say 60°C,

set at TIC2

DAL : The density of liquid in tank T1, as measured by the Density Transmitter

DT1 is below its Low limit, set at DIA1

A buzzer will come on and the respective alarm window will lit up when the above abnormal

or alarm conditions occur. Pressing the Acknowledge button will silence the buzzer sound. The

dedicated alarm window remains lit as long as its process variable is still in the alarm condition.

The alarm window light will go off when the process variable is restored to normal.

The Test button is to test if the Annunciator alarm window light is working.

PART D: MEASUREMENT / INSTRUMENTATION:

DT1 : Differential Pressure / Density transmitter, diaphragm-seals

DT2 : Differential Pressure / Density transmitter , bubble tube arrangement


PROCEDURES

1. Fill up water in tank T3 to the marked level. Make sure its drain valve is fully shut.

2. Make sure there is air supply connected and available in the Lab. Do not adjust the air

regulators.

3. At the front panel, switch ON the main power supply. The panel instruments are all lit up.

Make sure the heaters, Pump (P1) and stirrer are switch OFF, from the front panel.

4. Check that the pump suction valve is fully open. The pump discharge valve (MV1) is one

turn open.

5. Open one turn pump by-pass valve (BV1). Let this BV1 open throughout the experiment

for better mixing. If BV1 has a hose connected to it, make sure it is discharge back to the

tank.

6. Decide on which tank (T1 or T2) to be operated for the density measurement, say tank

T1. Thus shut fully MV2 and the interconnecting manual valve MV4. Open one turn

MV3.

7. At tank T1, make sure its top vent (V) and overflow valve are fully open. Also check that

its manual discharge valve i.e. bottom GLOBE valve is fully open but its gate valve is

fully close.

8. Locate the air inlet manual isolation valve located next to AR located at the top tank of

tank T1 and make sure its valve handle is 90° to the air supply inlet tubing. The top space

of tank T1 is at atmospheric pressure as monitored by the pressure gauge (PG).

9. During the experiment, if the water level in Tank T3 is below the preset low level limit,

the level switch (LS) will automatically switch off the Pump (P1). In this case, top up

more water into tank T3 from the external water supply.

EXPERIMENT: DENSITY MEASUREMENT (AMBIENT WATER)

1-9. Please refer to the above Start -Up Procedures.

10. Start Pump (P1) by pressing the green pushbutton at the front panel.

11. Switch ON the stirrer from the front panel. Check that it is turning, otherwise turn

clockwise the knob at air speed controller located next to the stirrer.

12. Do not switch on the Heaters yet.

13. At the sight glass with millimeter scale (LG1), observe the level in tank T1 rising until it

overflows. Let the water circulate throughout tank T1 and tank T3 until the temperature


gauge (TG1) reading is close to the reading at the temperature indicator (T1C1) at the

front panel.

14. Shut the manual discharge GLOBE valve at tank T1.

15. At the front panel, switch off the pump (P1)

RUN I

16. RUN I is done as follows:

a) Scoop out about 500ml of water from T3 and pour into measuring cylinder. Read

the Specific Gravity of water from tank T3 using the hydrometer provided. Pour

the water back into T3.

b) Note that, three consecutive (3) sets of readings are taken for every RUN.

Each set of density readings consists of two readings to be taken simultaneously:

Actual Density (S.G) read from density indicator (DIA1) i.e. Reading in DIA1, % x

its max calibrated S.G.

Actual temperature in tank T1 read from temperature gauge (TG1).

Take down the readings in TABLE 1A, RUN I.

RUN II

17. Continue with RUN II as follows:

a) Set tank T1 to close tank i.e. top space of tank T1 is pressurized.

b) Shut fully the overflow valve and vent (V) valve.

c) Shut fully the bottom gate and globe valves.

d) Let air flow into the top space of tank T1 by turning the air inlet manual

isolation valve handle parallel to the air supply inlet tubing.

Take down readings in RUN II. Three consecutive (3) sets of readings are taken.

18. Set tank T1 back to open tank.

a) Shut the air inlet manual isolation valve. Its handle should be 90° to the air supply

inlet tubing.

b) Then open fully the overflow valve and vent (V) valve.

19. The next test is to use DT1 to verify the density Hydrostatic principle that the density

is proportional to the pressure difference between two elevations in a tank i.e.

Density, ρ = DP where DP is the pressure difference

g H

a) Take the density (S.G) and pressure difference (DP) readings as follows:


- Density (S.G) read from density indicator (DIA1) i.e:

Reading in DIA1, % x its max calibrated density (S.G)

- Pressure difference reading in mmH2O read at the density transmitter DT1.

As this pressure difference reading (DP) has not been processed or filtered yet by

the DP transmitter, it is noisy (fluctuating). Take a nominal mean or average value

for DP.

b) Refer to the RESULT section for a simple calculation to verify that

RUN III

20. Verify the density measured from DT1 with another density measurement from DT2

located at tank T2. Note that both DT1 and DT2 are of different measurement application.

a) Open the connecting manual valve MV4.

b) Starts pump (P1). Note that the stirrer is still on.

c) Let the water circulate throughout tank T1, T2 and tank T3 until the temperature

gauge (TG2) reading is close to the reading at the temperature indicator (TIC 1) at

the front panel.

d) Stop pump (P1)

Notice the bubbles flowing out from the copper tube. Otherwise quickly check that the air

supply is connected and adjusts AR2 until bubbles is flowing. To measure density

accurately, always allow the liquid to reach its overflow pipe but not more.

e) Note that, three consecutive (3) sets of readings are taken for every RUN.

Each set of density readings consists of two readings to be taken simultaneously:

Density (S.G) read from density indicator (DI2) i.e. Reading in DI2, % x

its max calibrated density (S.G)

Actual temperature in tank T2 read from temperature gauge (TG2)

f) Take down the readings in TABLE 1A, RUN III.

g) Drain out all the water in tank T2 by opening its bottom drain valve. Shut the

connecting manual valve MV4. Drain out all the water in tank T1 by opening its

bottom GLOBE valve

21. Repeat the experiment procedure for sugar.

RESULT


TABLE 1A:DENSITY MEASUREMENT (AMBIENT WATER)

MEDIUM : WATER

HEATER :OFF

SPECIFIC GRAVITTY (S.G) read from hydrometer : _________(use hydrometer with scale

0.900-1.000)

RUN I: OPEN TANK T1 Set 1 Set 2 Set 3 Average

A Temperature (TG1),°C

B Actual Density (DIA1),%

Actual Density (S.G)

C Deviation with hydrometer

D Calculated Density,kg/m3

E Density from table, kg/m3

F Deviation D from E, kg/m3

RUN II: CLOSE TANK T1 Set 1 Set 2 Set 3 Average








RUN III: OPEN TANK T2 Set 1 Set 2 Set 3 Average


B Actual Density (DI2),%






TABLE 1B:DENSITY MEASUREMENT (SUGAR)


MEDIUM : SUGAR

HEATER :OFF

SPECIFIC GRAVITTY (S.G) read from hydrometer : _________(use hydrometer with scale

0.900-1.000)

RUN I: OPEN TANK T1 Set 1 Set 2 Set 3 Average








RUN II: CLOSE TANK T1 Set 1 Set 2 Set 3 Average








RUN III: OPEN TANK T2 Set 1 Set 2 Set 3 Average


B Actual Density (DI2),%






Remarks:


A: Read from the Temperature Gauge (TG1,TG2) mounted at tank T1 or T2. Take the average

value for further calculation.

B: Read from the Digital Density Indicator (DIA1 or DI2). Take the average value for further

calculation.

Actual Measured Density (S.G) at T1 = Reading in DIA1,% x 1.182

Actual Measured Density (S.G) at T2 = Reading in DI2,% x 1.182

C: Calculate from equation Deviation = | (B-hydrometer) |

D: Calculate from equation

ρw at operating temperature TG1 or TG2 = S.G. x ρw at reference temperature 15.6°C

Note: Density of water at 15.6°C i.e. ρw,ref =999.007 kg/m3

E: Read from the Table 2-28, Perry’s VII at temperature (TG1, TG2)

F: Calculate from equation Deviation = | (D-E) |

QUESTIONS

1. VERIFICATION OF THE LEVEL/HYDROSTATIC PRINCIPLE,

The following are the test readings taken at Procedure 19, Experiment 1A and 1B:

a) Density (S.G.), at DIA1 : __________ % x 1.182 = __________(S.G.)

100 = __________kg/m3

b) Pressure difference, DP at the density transmitter DT1 : ____________mmH2O.

Note that the pressure difference DP displayed at DT1 is the pressure difference between

the top and bottom tapping points and has NOT been processed yet (i.e. has not been

filtered yet). The display may be fluctuating due to the turbulence inside the pipeline, thus

take a nominal mean or average reading for DP.

These two readings shall be used to verify the density hydrostatic principle,

as follows:

The Density Transmitter DT1 has been calibrated as follows:


Pressure Difference (DP) Output Transmission Signal

-557mmH2O

148.6 mmH2O

4mA, equivalent to density (S.G.) 0

20mA, equivalent to the full-scale density (S.G.) of

1.182

Since

Say at maximum SG= 1.182, i.e. ρ = 1.182 x 999.007kg/m3 = 1180.826 kg/m3

Ρref at 15.6°C = 999.007 kg/m3

1180.826 kg/m3 = (148.6 +557) mmH2O

g h

g h = 0.59755

SG = _________DP ________

0.59755(999.007)

SG = (Measured DP + 557), mmH2O “the density equation for DT1”

596.95

2. Use the pressure difference (DP) reading question 1(b) and substitute into “density

equation for DTI”. Calculate ρ or S.G., based on this pressure difference (DP) reading. Is

the calculated S.G. equal to the S.G. reading taken at the above (a)? Is the calculated ρ in

kg/m3 equal to the density (ρ) reading taken at the above 1(a)?

3. Explain the function of globe valve and gate valve located at the bottom of tank T1? What

is the significant both of the valves compared to other type of valve?

4. The calculated density is based on pressure difference (DP) reading. In your opinion, how

far the accuracy of calculated density? Suggest the way to improve the accuracy?

5. Describe the important of density measurement compared to temperature or flowrate

measurement in term of chemical process?


EXPERIMENT 2: MEASUREMENT AND ANALYSIS OF LIQUID FLOW

SYSTEM

Objective: To study the volumetric Flow Measurement using the Variable Area (FI31),

Orifice / DP (FE31/FT31) and Electromagnetic flow meters (FT32)

Flow PATH :T32 FI31 FT31 LCV31 T31 FT32 T32

Special Remark: Theoretically, FI31 = FE31/FT31 = FT32, if the Level at T31 is controlled.

START-UP CHECK LIST AND PRELIMINARY EXERCISE

Get familiar with the equipment, instrumentation, piping system and various manual valves. The

following preliminary procedures are recommended for familiarization.

1) The tank T32 should be filled with water up to almost the level of its overflow drain pipe.

Excess water will overflow into the common drain. Check that the Instrument Air Supply

(IAS) is connected (32psi).

2) Locate the pump :

At P32

Suction Valve fully OPEN

Discharge valve fully OPEN

By-pass valve BV32 fully OPEN

At P31Suction Valve fully OPEN

Both Discharge valve fully OPEN

At T31 Both Gate and Globe valve fully SHUT

Check that the two adjacent manual valves at the control valve LCV31 are fully open

while the by-pass valve fully shut.

Make sure the T32 Drain valve is fully shut.

3) Turn ON the power supply at the front of the cubicle, to provide power to the pumps,

Recorder and Controller.

4) Get the RECORDER (LFR31) ready as follows but do not start the pump yet.

The Recorder (LFR31) is ON (open it front swing cover and locate its ON/OFF push –

in type switch at the bottom right side below the push button keyboard. Press in to

switch ON )


When the ‘RCD’ display is lit up at the Recorder, its chart drive is running. The

Recorder chart drive can be switched ON/OFF from the ‘RCD’ pushbutton at the front

of the Recorder (with its front swing cover opened).

Learn how to access data from the Recorder (LFR31). In particular, note the digital

indication of the various flow rates.

- the pen trend record is analog 0-100% of 3m³/h

- the indicator is in engineering units, 0 to 3.0m³/h for flow rates. Flow

rates (in m³/h) are displayed at Channels 2 &3. Channel 1 is for Level

(0 to 800mm)

5) Get the Controller (LIC31) ready as follows:

The Controller (LIC31) should be in MANUAL (M) mode with its control output

MV=100%. Check at LCV31 that it is fully open.

Access its PID1 page and set PB1 = 10%, TI1 = 15 sec, TD1 = 0 sec, set point

SV1 = 400mm

Make sure the Controller selector switch is at Position 1: LIC31.

6) Always make sure the pump P32 suction valve and by-pass valve BV32 are always

opened before starting the pump.

7) Start the pump P32. When the pump is started ad flow is verified (check return water

discharge back into the tank via the appropriate pipelines), shut gradually the pump

manual by-pass valve BV32 until FI31 reads about 2 m³/h.

8) When the Level at T31 is near its Set point 400mm (see at PV), start pump P31 and

switch the controller LIC31 to Auto (A) mode.

9) To vary the flow rate, regulate one of the discharge valve at P31 and note the flow rates at

the Recorder display at Channel 2 & 3 and FI31 as per TABLE 1A

Is FI31 = FT31 = FT32 approximately (when the level in tank T31 is controlled)?

Otherwise there is flow ‘leakage’ or ‘by-pass’, OR the instrumentation in inaccurate and

requires calibration check.

10) Stop the pumps P32 and P31.

EXPERIMENT PROCEDURE

1) Please refer to the Section ‘Start-up Check List and Preliminary Exercise’ and follow

the procedures from 1 to 10.

2) Locate the various flow meters and learn how to read the volumetric flow rates as

follows:


FI31 :Variable area flow meter: Read directly at the flow meter FI31 (m³/h) near the

pump discharge.

FE31 / FT31 : Orifice-Differential Pressure: Read LFR31,Green Pen (%) (DP) flow

meter and Channel 2 (m³/h)

FT32 : Electromagnetic flow meter :Read at LFR31, Blue Pen (%) & Channel 3(m³/h).

Note the result in TABLE 1A (see RESULT SECTION). Also read the flow rate

indicator LOCALLY at the flow meter FT32 and compare it with Channel 3 at the

Recorder LFR31. They should be similar.

3) The next test is to use FE31/FT31 to verify the Orifice/DP flow meter principle that the

flow rate is proportional to the square root of the pressure drop i.e.

Volumetric Flowrate, Fv = k¹√h, where h is the pressure drop across the Orifice plate

FE31 measured by FT31

- Open the pump P31 manual discharge valve fully.

- Take the flowrate and pressure drop reading as follows:

a) Flowrate (Fv) in m³/h at the Recorder Channel 2.

b) Orifice plate (FE31) pressure drop, h, in mmH2O at the DP transmitter FT31.

As this pressure drop reading (h) has not been processed or filtered yet by the DP

transmitter, it is noisy (fluctuating). Take a nominal mean or average value for h.

- Refer to IV at the RESULT section for a simple calculation to verify that;

Fv = k¹√h.

4) Reduce the flow rate by gradually shutting the pump P31 manual discharge valve (locate

before the strainer) so that the flow rate (read FT32) is reduced. Note the results in

TABLE 1A.

5) Repeat Procedure 4 at two (2) other flow rates at approximately 1.0 m³/h (33.3%) and

0.8 m³/h (26.71%) of the full scale flow rate of 3 m³/h.

See Procedure 2, 3 and 4. Record the reading in TABLE 1A similarly.

Repeat procedures with increasing flow rates and record the reading in TABLE 1A.

6) Experiment completed. SHUT DOWN the plant:

Switch off the pump P31, P32 at the front panel/Cubicle.

Switch off the Recorder (LFR31) chart drive by pressing its RCD pushbutton with its

swing cover opened.

Switch the Controller LIC31 to Manual (M) mode with its output MV = 0%. Make

sure the Selector Switch is at position 1:LIC31.

Open fully the pump manual by-pass valve BV32.


Switch off the main power supply switch at the front of the cubicle.

Shut fully the manual valve for instrument air supply (IAS). No need to regulate its air

regulator.

RESULT

I. Note the volumetric flow rate readings in TABLE 1A below at four (4) decreasing and four (4)

increasing flow rates.

Regulate the manual discharge valves at P31 to desired flow rate. Shut one of the pump manual

discharge valve (P31) to reduce flow further.

II. Reading in % and Engineering Units at Recorder LFR31 (Channel 2, 3)

% Reading x Max. Calibrated Range value = Reading in engineering units

% Reading x 3 m³/h = reading in m³/h

III. Theoretically, FI31 = FE31/FT31 = FT32, if Level is kept constant

Using FT31 as the reference, note down the various flow rate reading deviations from FI31,

FT32 using the last Column in TABLE 1A.

For FI31 Deviation % = FI31 – FT31 x 100%

FT31

For FT32 Deviation % = FT32 – FT31 x 100%

FT31

IV. Verification of the Orifice / DP flowmeter principle, Fv = k¹√h.

The following are the test readings taken at Procedure 5:

a) Flow rate, Fv at the Recorder Channel 2:____________m³/h.

b) Pressure drop, h at the orifice/DP flowmeter FT31 : ___________mmH2O.

Note that the pressure drop, h displayed at FT31 is the pressure drop across the orifice

plate FE31 and has NOT been processed yet. As the display is fluctuating due to the

turbulence inside the pipeline, take a nominal mean or average reading for h.

There for:

Fv (m³/Hr) = 0.03√h (mmH2O)

the flowrate equation for FE31/FT31

Use the pressure drop (h) reading mentioned at the above IV (b) and substitute into the

flowrate equation for Fe31/FT31. Calculate Fv in m³/h, based on this pressure drop (h)

reading.

* Is the calculated Fv in m³/h equal to the Flowrate Fv reading taken at above IV (a)?


TABLE 1A

Reading

no.

Flow

rate

m³/h

VOLUMECTRIC FLOW RATE READINGCalculate the %

Deviation from

PT31

At FI31 At the Recorder LFR31, panelAt FT31 local indicator

FI31FE31/FT31 FT32

Green Pen Channel 2 Blue Pen Channel 3 H Fv = k¹√h Compare

with

Channel 2

SAME

OR NOT

m³/h % m³/h % m³/h mmH2O m³/h For FI31 For FT32

1 1.2

2 1.0

3 0.8

4 0.5

5 1.5

6

7

8

QUESTIONS

1. Based on volumetric flow rate reading, discuss comparison data Channel 2 FE31/FT31 and at FT31 local indicator? Explain why

the data is different?

2. Based on % deviation data FI31 and FT32, what is your observation? Suggest a solution to minimize the deviation?

3. Give a brief conclusion for overall volumetric flow rate reading.


EXPERIMENT 3: MEASUREMENT AND CONTROL OF AIR FLOW SYSTEM

PLANT MODEL : AFPT921 Air Flow Pressure Temperature Process

Control Training System

OBJECTIVE

Part 1

1. To study gas volumetric flow rate (Fv) measurement using the orifice plate-pressure drop (h)

method, assuming the gas pressure/temperature (i.e. density) remain unchanged and at the

values used in the sizing of the orifice.

2. To study gas mass flow rate (Fm) measurement using the orifice plate-pressure drop (h)

method, using the Perfect Gas Law to compute the gas density from the flowing pressure

and temperature.

Part 2

1. To study gas mass flow rate (Fm) control using PID control mode.

INTRODUCTION

Experiment system AFMS211 is carried out in Model AFPT921 Gas Flow Pressure Temperature

Process Control Training System. This Model AFPT921 plant is a scale-down Real Industrial

Process Plant built on 5ft X 10ft steel platform, complete with its own dedicated control panel. The

process equipment and process instrumentation are real Industrial Process type. The plant is

constructed in accordance to industrial process plant standard and practices, with fail-safe features.

For example, the air heater cannot be turned ON unless there is enough air flow in the pipeline. The

process flow rates are at COMMERCIAL PRODUCTION flow rates, using pipes and not tubings.

PLANT DESCRIPTION

PART 1: INSTRUMENTATION

1. Pipelines PL1

a. This is the ½” process pipeline connecting the air heater and the cooling vessel C90

in Model AFPT921. Pipeline is also lagged.

2. Field Instrumentation

At the process pipeline PL1 are:

a. FT91 : multivariable air mass flow transmitter, with

i. Integral orifice plate FE91


ii. Differential Pressure transmitter DPT911

iii. Absolute pressure transmitter PT911

iv. RTD/Temperature Transmitter (TE911/TT911)

b. FI911 : Variable Area Flow meter (or Rotameter)

The calibration Temperature and Pressure is tagged at the flow meter.

3. Panel instrumentation

Mounted at the control panel are the following:

a. Air heater ON/OFF switch

b. TIC91 : Microprocessor-based Panel Controller (Multifunction) for Temperature

Controls.

c. FIC91 : Microprocessor-based Panel Controller (Programmable) for Flow Control

d. FPTR91: Recorder with four analog pen/bar graph display, as well as display in

engineering units. However, only the green pen/Channel 2 and purple

pen/Channel 4 shall be used for this experiment. The analog displays are in

% of their maximum upper range values.

Green pen (Channel 2) : Fm, 0-50 kg/h

Purple pen (Channel 4) : f, % of 0-6.165 kg/m3

: ANALOG display in the form of horizontal coloured bar or pen-chart paper is to be

read as follows:-

Analog display X Maximum (calibrated) = Actual reading

in % range values, engineering

units

engineering

units

: Digital display in engineering unit is 0-50 kg/h for Channels 2

: The chart drive is set for fast speed (500mm/h).

The recorder chart drive is started or stopped by pressing the RCD button

with the front swing cover opened

e. Annunciators (TAH911, FAL90, FAL91) with Test and Acknowledge buttons.

TAH911 : The process air temperature in pipeline PL1, as measured by the

RTD sensor/transmitter TE911/TT911exceeds the preset High Limit

of say 200 oC.

FAL90 : The flow rates as detected by FS90 are below its Low limit.

FAL91 : The mass flow rate is below its Low limit.


A buzzer will come on and the respective alarm window will lit up when the above

abnormal or alarm condition occur. Pressing the Acknowledge button will silence

the buzzer sound. The dedicated alarm window remains lit as long as its process

variable is still in the alarm condition. The alarm window light will go off when the

process variable is restored to normal. The test button is to test if the Annunciator

alarm window light is working.

INSTRUMENTATION SYSTEM

1. FIC91/PIC911/FIC90: Microprocessor-based Panel Controller (Programmable).

Display h measurement input in % at the I/O as X4.

X4 : h, from DPT911, % of 0-10,000mm H2O

: compute Fv = k1 √ h and display at PT Register as P15, in m3/h

2. FIC91/PIC911/FIC90: Microprocessor-based Panel Controller (Programmable).

Display measurement inputs in % at the I/O Data as follows:

X1 : Computed Fm, from FT91, % of 0-50 kg/h

X2 : Temperature (T), from TT911, % of 0-200 oC.

X3 : Absolute pressure (P), from PT911, % of 0-70 psia

X4 : Differential Pressure (h), from DPT911, % of 0-10,000mm H2O

PV1 : Computed Fm, from FT91, kg/h

PROCESS VARIABLES

1. : Volumetric flow rate, Fv, m3/h = 0.237 √ h (mmH2O), P and T uncompensated

: Volumetric flow rate at actual flowing condition

Fvf, m3/h = 0.0703 √h (mmH2O) √T(K) , P and T uncompensated

√P (psia)

: Volumetric flow rate at Normal condition (1 atm, 0 oC)

Fvb, Nm3/h = 1.305 √h (mmH2O) √P (psia) , P and T uncompensated

√T(K)

2. Mass Flow rate, Fm, kg/h = 1.688 √h (mmH2O) √P (psia)

√T(K)


PART 2: CONTROL SYSTEM

The PID mass flow control system consists of the following in feedback:

Fm-FIC91-FCY91/PP/FCV91

Where

Fm, kg/h = km √(hP) Computed in Multivariable Flow Transmitter FT91

√T

FIC91 : Flow PID Controller

FCY91: Current-to-Air Converter

PP : Pneumatic Positioner, with By-pass

FCV91: Flow Control Valve, Air-to-Close (ATC)

FPTR91: 4-pen Recorder

Green pen (Channel 2) : Fm, Range: 0 to 50 kg/h

PROCESS VARIABLES

Mass flow rate Fm under PID control by FIC91.

Display at recorder: Green pen (Channel 2)

SPECIAL REMARK

The 1-2 Position Selector Switch for controller FIC91/PIC911/FIC90 must be in Position 1, for

FIC91 controller output MV1 to throttle FCV91.

EXPERIMENTAL PROCEDURES

PART 1

1. Switch ON the main power supply. Check that the Process Air and Instrument Air Supply

(IAS) are available at the lab.

2. Make sure the ‘Process Air Inlet’ switch is at its ‘OPEN’ position, and ‘Air Heater’ switch is

at its ‘OFF’ position, at this instance.

3. Shut pipeline PLII by shutting the manual valve (MVII) just before FCV90 so that the air

can only flow via the mass flow meter FT91, in PLI. Remember to re-open it after this

experiment 1.

4. Check that the Pneumatic Positioner (PP) of the control valve FCV91 is connected and not

by-passed. With the PID flow controller FIC91 in manual (M) mode, set FCV91 at 100%


open with its controller output MV=-6.3%. For confirmation, check the stem indicator of

control valve FCV91. Note that FCV91 is Air-To-Close (ATC)

5. Check that the Pneumatic Positioner (PP) of the control valve PCV91 is connected and not

by-passed. With the PID flow controller FIC91 in manual (M) mode, set PCV91 at 100%

open with its controller output MV=-6.3%. For confirmation, check the stem indicator of

control valve PCV91. Note that PCV91 is Air-To-Close (ATC)

6. Set-up the maximum Pressure and Flow rate of the Model Plant. Please follow these

procedures.

a. Set the maximum process pressure.

Check that compressed air is available as process air and is connected to the Model

Plant at the Air Regulator AR90 (Check that it is upstream process air supply manual

valve (PASV) is fully opened). With the manual downstream valve MV90A fully

shut, set the pressure at AR90 to the pressure indicated. Then open MV90A by 1

turn and shut again. Recheck that the pressure at AR90 is correctly set. Once AR90

is set, it need no further adjustment.

b. Set the maximum process air flow rate

To set the maximum process flow rate, adjust MV90A at the process inlet so that

PVI (i.e. Fm) at FIC91 reads from 40 to 50 kg/h. Note that AR90 is used to set the

maximum pressure and MV90A is used to set the maximum flow rate. Once AR90

and MV90A are set, they need no further adjustment.

7. Concentrate on the flow PID controller FIC91 and the recorder FPTR91 and learn to access

and read the following data shown in the table. Also note the variable area flow meter

FI911.

CONTROLLER: FIC911/PIC911/FIC90 RECORDER

REMARKSFIC91: I/O DATA

FIC91: PT

REGISTERFPTR91

Case 1

X4: h, % of 0-10,000 mmH2O P15:Fv

-

h is from FE91/DPT911

Fv=K1√h is computed in

FIC91

Case 11

X1: Air Mass Flow (Fm), % of

0-50 kg/h

X2: Air Temperature (T), % of

-

-

-

-

Fm=Km √(hP)

√T

Computed in FT91

From TE911/TT911


0-200 OC

X3: Air Absolute Pressure (P),

% of 0-70 psia

X4: h, 0-10,000 mmH2O

-

-

-

-

From PT911

From DPT911

Others

See above X1,X2,X3,X4 P16: Fvf Fvf = Kvf √(hT)

√P

P17: Fvb Fvf = Kvf √(hP)

√T

P18: f f=Fm/Fvf

P15,P16,P17,P18 are

computed in FIC91

FIC91: main face plate

PV1: Fm (kg/h)-

Green Pen

Channel 2

Fm is computed in FT91

Note: X1,X2,X3,X4 are in % and are at the I/O Data of FIC91/PIC91/FIC90

P15,P16,P17,P18 are at the PT register of FIC91/PIC91/FIC90

8. Both the following temperature and pressure are to be changed as the experiment progresses,

to get various air flow rates, flowing air temperature (TT911) and pressure (PT911). Refer

to the result section to see the datas required of this experiment. Get ready to collect the

reading for column I, II and III.

PART 2

1. Please refer to the section “START-UP CHECK LIST AND PRELIMINARY

EXERCISES”. (1-14)

2. Please refer to Experiment No. 1 and follow the Procedure 1-6.

3. Concentrate on the unit panel controller FIC91/PIC911/FIC90 in particular FIC91.

4. With FIC91 still in Manual (M) mode, adjust its set point SV1 to 30 kg/h. Access the PID

parameters of FIC91 and set the following first (I) trial PID values:


First (I) trial PID values for FIC91

PB1= 200%

TI1 = 6 secs

TD1 = 0 secs

5. Check that recorder FPTR91 is at fast chart speed (i.e. 500 mm/h) on the occasional print-

out on the recorder chart. If the recorder chart drive has been preset at 500 mm/h but has

been stopped temporarily, press the “RCD” button at the front of the recorder with its swing

cover opened.

6. Transfer FIC91 to Auto (A) mode and watch the recorder response until the flow Fm (Green

Pen) is fairly steady at its set point SV1 to within ± 0.1 kg/h. Introduce a sharp pulse load

disturbance by quickly opening by one turn and then shutting fully the manual by-pass

valve around FCV91. Remember that this by-pass valve must be always shut.

7. Repeat with a second (II) and third (III) set of trial values, using the same sharp pulse load

disturbance as in procedure 6. Flow process is generally high gain and oscillatory and will

require a higher PB% (low gain) controller for damping. Too large PB% however slow

down the response and its recovery to the set point SV.

First (II) trial PID values for FIC91 First (III) trial PID values for FIC91

PB1= 100% PB1= 150%

TI1 = 6 sec TI1 = 10 sec

TD1 = 0 sec TD1 = 0 sec

The recorder Green pen records the flow (Fm) in %, for example 30 kg/h is 60% of 50 kg/h.

Note down the corresponding PID values and set point on the chart paper beside its chart

trend response.

8. The air mass flow control experiment is now completed. Transfer FIC91 to manual (M)

mode with its MV1=-6.3% for maximum air mass flow.


RESULT

Table 1

INSTRUMENT

READINGS

CONTROLLER

FIC911/PIC911/FIC90 I** II** III**

At the PANEL I/O Data

FT91, Fm X1*, % of 0-50 kg/h kg/h kg/h kg/h

TT911, T X2*, % of 0-200 OC oC oC oC

K K K

PT911, P X3*, % of 0-70 psia psia psia psia

DPT911, h X4*, % of 0-

10,000mmH2O

mmH2O mmH2O mmH2O

PT Register

Fv P15*, m3/h m3/h m3/h m3/h

Fvf P16*, m3/h m3/h m3/h m3/h

Fvb P17*, Nm3/h Nm3/h Nm3/h Nm3/h

f P18*, kg/m3 kg/m3 kg/m3 kg/m3

Main Face Plate

Fm PV1*, kg/h kg/h kg/h kg/h

Recorder FPTR91

Recorder

Channel 2

Fm, kg/h kg/h kg/h kg/h

Recorder

Channel 4

Density, f, % of 0-

6.165 kg/m3

kg/m3 kg/m3 kg/m3

At the PLANT

FI911, Nm3/h Nm3/h Nm3/h Nm3/h

PG911A, psig psig psig psig

*Note: X1, X2, X3, X4 are in % and are at the I/O Data of FIC91/PIC91/FIC90

P15, P16, P17, P18 are at the PT register, Fv, m3/h

PV1 is at the main face plate display of FIC91, Fm, kg/h

X1: % of 0 to 50 kg/h or % of 50 kg/h

X2: % of 0 to 200 oC or % of 200 oC


X3: % of 0 to 70 psia or % of 70 psia

X4: % of 0 to 10,000 mmH2O or % of 10,000 mmH2O

The Fm value at the Recorder FPTR91 is computed at the multivariable air mass flow transmitter FT91 then

retransmitted to the Recorder.

**Column I: Maximum air flow rate: FIC91, MV=-6.3%, TIC91, MV1=-6.3%, Switch OFF Heater, PIC91,

MV=-6.3

Column II: Higher Air Temperature: FIC91, MV1=-6.3%, TT911 at least 100 oC, TIC91 Auto (A) mode

with SV1= 150 oC, PB1=10%, TI1=100 sec, TD1=25 sec, Switch ON Heater, PIC91=-6.3%.

Column III: Different Pressure/Flowrate/Temperature: FIC91, MV1=70%, TT911 at least 100 oC, TIC91

Auto (A) mode with SV1= 150 oC, PB1=10%, TI1=100 sec, TD1=25 sec, Switch ON Heater, PIC91=-6.3%.

QUESTIONS

1. What is your observation based on data I, II and III? What is the relationship between these

three data?

2. What is the significant the introduction a sharp pulse load disturbance?

3. Why PI controller is used instead of PID controller in this process? From your own

understanding, how far the performance of the process if PID controller is applies on the

process?


EXPERIMENT 4: STUDY ON DYNAMICS OF FIRST ORDER AND SECOND ORDER

SYSTEMS

OBJECTIVE

1. To demonstrate the properties of a first order system for various values of the system gain

and time constant and also to demonstrate the dynamic properties of a second order system

for various values of the system gain, natural period and damping coefficient.

2. To illustrate the dynamic response of a first order and second order system to different input

signals.

EXPERIMENT PROCEDURES

PART A: FIRST ORDER SYSTEM

1. To start the first order system, click once on the First and Second Order Systems button

from the Main Menu then select the First Order System button. The two windows will be

display; the first is the system window and the second is the input/output window.

2. First, set the system gain Kp (numerator coefficient) and the system time constant τP

(denominator coefficient) both to 10.0 by clicking once on the first order system block. Now

set the step time to 10.0, initial value of the step function to 0.0 and the final value of the

step function to 1.0 by clicking once on the step function block. Click OK after you have

done.

3. To start the simulation, select Start from the Simulation menu. Record the new steady state

value and the length of time it takes for the output to reach the new steady state (sec). Use

the Pointer button to take several points along the response curve in your analysis.

4. Now increase the value of Kp to 40.0 and repeat step 3. How does this response differ from

the response in step 3?

5. Set Kp back to 10.0 and now try increasing the value τP of to 20.0. Repeat the simulation.

How does this response differ from the response in step 3?

6. Now decrease the value of the Kp to 5.0 and decrease the value of τP to 5.0. Repeat the

simulation. Record the new steady state value and the length of time it takes for the output to

reach the new steady state (sec) in Table 1.


Table 1

Kp τP Time Output

10 10

40 10

10 20

5 5

SYSTEM IDENTIFICATION PROBLEM

From the Main Menu, select the System Identification Problem 1 button. Using a step input, run the

simulation to generate output data that can be used to determine the system gain (Kp) and the system

time constant (τP). Remember to use the Pointer button and to take several points along the response

curve in your analysis of the system output.

QUESTION

1. What is the slope of initial response?

2. Calculate the final output value minus the initial output value.

3. Fill in the following table with the parameter values you calculated:

Table 2

Kp

τP

4. Give the first order transfer function of this unknown system.

EXERCISE

1. What effect does increasing the gain have on the system output?

2. What is meant physically by a system with a large gain?

3. What effect does decreasing the time constant have on the system output?

4. What is meant physically by a system with a small time constant?

5. Is it possible for a system to have a negative gain? What is the expected behavior?

6. Is it possible for a system to have a negative time constant? What is the expected behavior?

7. What is the expected response from a first order system driven by a sinusoidal input?


PART B: SECOND ORDER SYSTEM

1. To start the second order system, click once on the First and Second Order Systems button

from the Main Menu then select the Second Order Systems button. The two windows will be

display; the first is the system window and the second is the input/output window.

2. The system under consideration is described by the following transfer function:

3. Set the system gain (Kp) to 10.0 (numerator coefficient), the value of A to 40.0 and the value

of B to 14.0 (denominator coefficient) by clicking Second Order System block.

4. Now set the initial value of the Step Function to 0.0 and the final value of the Step Function

to 1.0 by clicking once on the Step Function block.

5. To start the simulation, select Start from the Simulation menu. Is the system overdamped,

underdamped or critically damped? If the system is underdamped, what is the overshoot,

decay ratio, rise time, settling time and the period of oscillation?

6. Change the value of A to 18 and the value of B to 2. Repeat the simulation. Is the system

overdamped, underdamped or critically damped? If the system is underdamped, what is the

overshoot, decay ratio, rise time, settling time and the period of oscillation?

7. Change the value of A to 42.25 and the value of B to 13. Repeat the simulation. Is the

system overdamped, underdamped or critically damped? If the system is underdamped, what

is the overshoot, decay ratio, rise time, settling time and the period of oscillation?

Table 3

Kp A B Type Overshoot Decay

Ratio

Rise

Time

Settling

Time

Period

10 40 14

10 18 2

10 42.25 13

SYSTEM IDENTIFICATION PROBLEM

1. Close the two windows by clicking the left mouse button on the upper left hand box of both

windows and selecting Close. From the First and Second Order Systems Menu, select the

System Identification Problem 2 button.

2. Using a step input, run the simulation to generate data that can be used to determine the

system gain (), the system time constant () and the damping coefficient ().


QUESTION

1. What is the overshoot in the response?

1. What is the period of the oscillatory response?

2. Calculate the final output value minus the initial output value.

3. Fill in the following table with the parameter values you calculated:

Table 4

Kp

τP

Ξ

4. Derive the second order transfer function for this unknown system.

EXERCISE

Consider the following values for the damping coefficient for a second order dynamic system.

Region I Region II Region III

Ξ<1 Ξ=1 Ξ>1

1. What types of poles does this system have? What types of response would be expected for a

system with a damping coefficient in Region I, II and III?

2. Sketch the corresponding response of the output variable to a step input in Region I, II and

III.

3. How does a decrease in the damping coefficient affect the speed of response?

4. Which of the three responses would be expected to have a shorter response time and

sluggish?

5. What is the trade-offs from a control perspective of the different responses?


EXPERIMENT 5: STUDY ON DYNAMICS OF FIRST ORDER SYSTEM USING

FURNACE

OBJECTIVE

The purpose of this module is to demonstrate the properties of a first order system for various

values of the system gain and time constant. This module also illustrates the dynamic response of a

first order to different input signals.

INTRODUCTION

The unit operation in this module represents a furnace fueled by natural gas which is used to preheat

a high molecular weight hydrocarbon feed (C16 – C26) to a cracking unit at a petroleum refinery. The

furnace model consists of energy and component mass balances which result in coupled nonlinear

differential equations. The furnace model has seven inputs and four outputs as listed below:

Inputs Outputs

Hydrocarbon Flow Rate Hydrocarbon Outlet Temperature

Hydrocarbon Inlet Temperature Furnace Temperature

Air Flow Rate Exhaust Gas Flow Rate

Air Temperature Oxygen Exit Concentration

Fuel Gas Flow Rate

Fuel Gas Temperature

Fuel Gas Purity

The combustion of the fuel is assumed to occur via the following reaction mechanism:

There are two major objectives for operation of the furnace. First, in order to minimize fuel costs,

the furnace must be operated with proper oxygen composition to ensure complete combustion of the

fuel (carbon monoxide is an undesired product). Second, the hydrocarbon feed stream must be

delivered to the cracking unit at the desired temperature.

The furnace has the following manipulated and controlled variables:

Manipulated Variables Controlled Variables


Air Flow Rate Hydrocarbon Outlet Temperature

Fuel Gas Flow Rate Oxygen Exit Concentration

The system also has the following load (or disturbance) variables:

Load Variables

Hydrocarbon Flow Rate

Fuel Gas Purity

PROCEDURE

1. Start by selecting the Furnace from the Main Menu. This is done by clicking the left mouse

button once on the Furnace button. This opens the menu window for the furnace modules.

Click the left mouse button on the Furnace button. Two additional windows should open,

one for the input and output graphs and one for the furnace process flowsheet.

2. Under the Simulation menu, select Start. This command should be executed once during a

lab session. It is the simulated equivalent to a perfect process startup. The process output

graphs are located on the window labeled Furnace Process Monitor. Notice how the outputs

remain unchanged with time.

3. Next, try decreasing the fuel gas purity. This will act as a disturbance to the system. By

double clicking on the Fuel Gas Purity box, change the value from 1.0 to 0.95 by clicking on

the value box and using the backspace key to erase the old value. When you have entered a

new value, click on the Close button. Again, notice how the outputs on the process monitor

are changing with time. Now return the Fuel Gas Purity to 1.0 by double clicking on Fuel

Gas Purity box and adjusting the value as done before.

4. Start the furnace. Record the initial steady state values for each of the inputs and outputs of

the furnace:

Inputs

Hydrocarbon Flow Rate m3/min

Hydrocarbon Inlet Temperature K

Air Flow Rate m3/min

Air Temperature K


Fuel Gas Flow Rate m3/min

Fuel Gas Temperature K

Fuel Gas Purity mol CH4/mol total

Outputs

Hydrocarbon Outlet Temperature K

Furnace Temperature K

Exhaust Gas Flow Rate m3/min

Oxygen Exit Concentration mol O2/min

5. Make the following sequence of increases in the air flow rate by double clicking the left

mouse button on the Air Flow Rate box. The remaining inputs (the six other inputs) should

be kept at their initial steady state values. After each change in the air flow rate, allow the

system to reach a new steady state (approximately 40 simulation minutes) and then record

the values of the output variables obtained using the pointers on the output graphs. Record

the steady state values:

Air Flow Rate Hydrocarbon Outlet

Temperature

Oxygen Exit Concentration

17.9 (nominal)

18.1

18.3

18.5

18.7

Return the Air Flow Rate to its initial value allows the furnace to reach steady state.

6. Make the following sequence of increases in the fuel gas flow rate by double clicking the

left mouse button on the Fuel Gas Flow Rate box. The remaining inputs (the six other

inputs) should be kept at their initial steady state values. After each change in the fuel gas

flow rate, allow the system to reach a new steady state (approximately 40 simulation

minutes) and then record the values of the output variables obtained using the pointers on

the output graphs. Record the steady state values:

Fuel Gas Flow Hydrocarbon Outlet Oxygen Exit Concentration


Rate Temperature

1.21 (nominal)

1.22

1.23

1.24

1.25

Return the Fuel Gas Flow Rate to its initial value allows the furnace to reach steady state.

7. Make the following sequence of increases in the hydrocarbon flow rate by double clicking

the left mouse button on the Hydrocarbon Flow Rate box. The remaining inputs (the six

other inputs) should be kept at their initial steady state values. After each change in the

hydrocarbon flow rate, allow the system to reach a new steady state (approximately 40

simulation minutes) and then record the values of the output variables obtained using the

pointers on the output graphs. Record the steady state values:

Hydrocarbon Flow

Rate

Hydrocarbon Outlet

Temperature

Oxygen Exit Concentration

0.0350 (nominal)

0.0355

0.0360

0.0365

0.0370

Return the Hydrocarbon Flow Rate to its initial value allows the furnace to reach steady

state.

8. Make the following sequence of increases in the fuel gas purity by double clicking the left

mouse button on the Fuel Gas Purity box. The remaining inputs (the six other inputs) should

be kept at their initial steady state values. After each change in the fuel gas purity, allow the

system to reach a new steady state (approximately 40 simulation minutes) and then record

the values of the output variables obtained using the pointers on the output graphs. Record

the steady state values:

Fuel Gas Purity Hydrocarbon Outlet Oxygen Exit Concentration


Temperature

1.00 (nominal)

0.99

0.98

0.97

0.95

Return the Fuel Gas Purity to its initial value allows the furnace to reach steady state.

9. Increase the nominal Air Flow Rate by 20% and repeat Procedure 4-8.

10. To end the session, stop the simulation by selecting Stop under the Simulation menu, then

select Yes under the Quit menu from the Main Menu window. This will return you to the

MATLAB prompt. At this prompt, type quit to exit MATLAB.

QUESTIONS

1. Using the information from Procedure 5-8, calculate the steady state gain for each of the

following input-output pairings. This can be accomplished by graphically by plotting the

output versus input values from the tables and calculating the best linear fit to the data.

*Hint: There are 8 steady state gain

2. Compared with results from (1), is the nonlinear behavior of the furnace apparent? How this

behavior manifested?

3. Using the gains obtained in (1), determine the values of the Air Flow Rate and Fuel Gas

Flow Rate that are necessary to increase the Hydrocarbon Outlet Temperature by 7 ºC and

decrease the Oxygen Exit Concentration by 0.05 mol O2/m3 by assuming the load variables

remain constant. Calculate the new value of the Fuel Gas Flow Rate and Air Flow Rate.


EXPERIMENT 6: STEADY STATE AND DYNAMIC STUDIES OF DISTILLATION

COLUMN

OBJECTIVE

The purpose of this module is to demonstrate the properties of a first order system for various

values of the system gain and time constant and also to demonstrate the dynamic properties of a

second order system for various values of the system gain, natural period and damping coefficient.

This module also illustrates the dynamic response of a first order and second order system to

different input signals.

INTRODUCTION

The process under consideration in this unit is a binary distillation column which separates a

mixture of methanol and ethanol. Distillation is a very important unit operation in the chemical and

petroleum industries. Increasing demand for high quality products coupled with the demand for

more efficient energy utilization has highlighted the role of the process control for distillation

columns.

The particular column studied in this unit has 27 trays, a reboiler on the bottom tray and a total

condenser on the overhead stream. A 50%-50% mixture of methanol and ethanol is fed at the

fourteenth tray. This column was originally modeled by K. Weischedel and T.J. McAvoy in 1980. It

represents a benchmark that has been studied by a number of researchers for the purpose of

controller design. The specific control objective is to achieve an 85% methanol stream at the top

and an 85% ethanol stream at the bottom of the column. This is referred to as dual composition

control.

This column is modeled with component mass balances and steady state energy balances which

result in coupled nonlinear differential algebraic equations. The column model has four inputs and

four outputs as listed below.

Inputs Outputs

Reflux Ratio Overhead Methanol Composition

Vapor Flow Rate Overhead Flow Rate

Feed Methanol Composition Bottom Methanol Composition

Feed Flow Rate Bottom Flow Rate


The column has the following manipulated and controlled variables:

Manipulated Variables Controlled Variables

Reflux Ratio Overhead Methanol Composition

Vapor Flow Rate Bottom Methanol Composition

The system also has the following load (or disturbance) variables:

Load Variables

Feed Flow Rate

Feed Methanol Composition

PROCEDURE

1. Start by selecting the distillation column from the Main Menu. This is done by clicking the

left mouse button once on the Distillation Column button. This opens the menu window for

the distillation column modules. Click the left mouse button on the Distillation Column

button. Two additional windows should open, one for the distillation column process

monitor and one for the distillation column flowsheet.

2. Double click on the box Vapor Flow Rate. Use the backspace key to delete the existing

value and enter 0.045 m3/sec. Close the box and start the simulation. Click on the window

showing the monitor to bring it to the front of your screen. It gives information about the

system outputs. These graphs give both the current and the nominal process values.

3. Changes in the values of Reflux Ratio, Feed Flow Rate and Feed Methanol Composition can

be given in a similar manner. Increase the value of Reflux Ratio to 3.0. Observe the effect

on the outputs. Once the system has reached a new steady state, increases the Feed Methanol

Composition to 0.55. Again, observe the effect on the outputs.

4. When the column has reached the new steady state, return all of the input values to their

nominal values and allow the system to return to its initial steady state.

5. Start the column. Record the initial steady state values for the inputs and outputs.

Inputs

Reflux Ratio

Vapor Flow Rate mol/sec

Feed Methanol Composition mol MeOH/mol total


Feed Flow Rate mol/sec

Outputs

Overhead Methanol

Composition

mol MeOH/mol total

Bottom Methanol

Composition

mol MeOH/mol total

6. Make the following sequence of moves in the reflux ratio by double clicking the left mouse

button on the Reflux Ratio box. The remaining inputs (the three other inputs) should be kept

at their initial steady state values. After each change in the reflux ratio, allow the system to

reach a new steady state (approximately 40 simulation minutes) and then record the values

of the output variables obtained using the pointers on the output graphs. Record the steady

state values:

Reflux Ratio Overhead Methanol

Composition

Bottom Methanol

Composition

1.75 (nominal)

1.85

1.95

1.65

1.55

Return the Reflux Ratio to its initial value allows the column to reach steady state.

7. Make the following sequence of changes in the vapor flow rate by double clicking the left

mouse button on the Vapor Flow Rate box. The remaining inputs (the three other inputs)

should be kept at their initial steady state values. After each change in the vapor flow rate,

allow the system to reach a new steady state (approximately 40 simulation minutes) and then

record the values of the output variables obtained using the pointers on the output graphs.

Record the steady state values:

Vapor Flow Rate Overhead Methanol

Composition

Bottom Methanol

Composition

0.033 (nominal)


0.040

0.036

0.034

0.032

Return the Vapor Flow Rate to its initial value allows the column to reach steady state.

8. Make the following sequence of moves in the feed flow rate by double clicking the left

mouse button on the Feed Flow Rate box. The remaining inputs (the three other inputs)

should be kept at their initial steady state values. After each change in the feed flow rate,




Feed Flow Rate Overhead Methanol

Composition

Bottom Methanol

Composition

0.025 (nominal)

0.026

0.024

Return the Feed Flow Rate to its initial value allows the column to reach steady state.

9. Make the following sequence of moves in the feed composition by double clicking the left

mouse button on the Feed Composition box. The remaining inputs (the three other inputs)

should be kept at their initial steady state values. After each change in the feed composition,




Feed Composition Overhead Methanol

Composition

Bottom Methanol

Composition

0.50 (nominal)

0.53

0.47


Return the Feed Composition to its initial value allows the column to reach steady state.

10. To end the session, stop the simulation by selecting Stop under the Simulation menu, then

select Yes under the Quit menu from the Main Menu window. This will return you to the

MATLAB prompt. At this prompt, type quit to exit MATLAB.

QUESTION

1. Using the information from Procedure 6-9, calculate the steady state gain for each of the

following input-output pairings. This can be accomplished by graphically by plotting the

output versus input values from the tables and calculating the best linear fit to the data.

*Hint: There are 8 steady state gain

2. Using the gains obtained in (1), determine the values of the Reflux Ratio and Vapor Flow

Rate that are necessary to increase the Overhead Methanol Composition to 0.88 and the

Bottom Methanol Composition to 0.17. Assume that the load variables remain constant.

Calculate the new value of the Reflux Ratio and Vapor Flow Rate.

3. Implement this manipulated variable change in the column and record the values of the

output variables. How close do the outputs come to the desired values? Record the actual

values. Return the Reflux Ratio and Vapor Flow Rate to their initial values and allow the

column to reach steady state.


EXPERIMENT 7: GAS TEMPERATURE CONTROL USING PID CONTROLLER

OBJECTIVE

To study the Gas temperature control using PID control.

INTRODUCTION

Model AFPT921 is a process control training system (PCTS) that uses only air to simulate gas,

vapour or steam. Air is readily available from a compressor. (It is deemed unsafe for students

without any industrial experience and safety training to deal with steam or gas). It provides the

simple gas physical processes where the measurement and control of their important variables of

flow, temperature and pressure can be studied.

The inlet air is heated at the electric heater and the heated air flows into pipeline PLI (or

automatically into pipeline PLII if the air flowrate through PLI is too low). Heated air from the

heater can flow into pipeline PLI (or pipeline PLII) via two flow paths:-

1. Via the Flow control valve (FCV91), cooling vessel C90, vessel T91 and vessel T92A.

2. Via a parallel pipeline (pipeline PLII) from the heater directly into pipeline PLI, by-passing

flow control valve (FCV91), cooling vessel C90, vessel T91 and vessel T92A.

There are three basic process control systems found in this plant for air temperature control:

1. Single Loop PID Temperature Control: TE91/TT91 - TIC91 - TCY90/Heater

2. Single Loop PID Temperature Control: TE92/TT92 - TIC92 - TCY90/Heater

3. ON/OFF Temperature Control: TE92/TT92 - TIC910 – Power Supply to Heater

4. Temperature Auto-Selector Control:TE91/TT91 - TIC91 - TCY90/Heater

TE92/TT92 - TIC92 - TCY90/Heater

PROCEDURE

1. Switch ON the operator workstation. (Press the Acknowledge button to silence the alarm

buzzer sound).

2. Select the Gas Temperature Process.

3. Make sure the TIC91A and TIC92A are set to “PID” control mode throughout this

experiment.


4. Call up the TIC91 faceplate. Set the TIC91 to Manual mode and make sure its Output is 0%.

5. Call up the TIC92 faceplate. Set the TIC92 to Manual mode and make sure its Output is 0

%.

6. Call up the TIC92 faceplate. Set the TIC92 to Auto mode and set its Setpoint (SP) to

200°C . Set the subsequent PID trials of

Gain (100/P) = 10

Reset (I) = 22 s

Rate (D) = 5 s

7. Call up the TIC91 faceplate. Set the TIC91 to Auto mode and set its Setpoint (SP) to 80°C .

Set the first PID trials values:

Gain (100/P) = 10

Reset (I) = 100 s

Rate (D) = 25 s

8. Observe patiently the control response in Process View History. Wait till the response is

steady at its set point SV1 to within ±0.2 to ±0.3 OC or shows oscillatory response even after

3 cycles of oscillation.

9. When the response is steady or shows oscillatory response even after 3 cycles of oscillation,

apply Load Step Disturbance. Switch the controller TIC91faceplate to Manual (M) mode

and step increase the control output MV by about 20%. Quickly switch TIC91 back to Auto

(A) mode. The set point SV1 remains unchanged at the previous SV1 value.

10. When the response is steady or shows oscillatory response even after 3 cycles of oscillation,

apply Set Point Disturbance. Step-increase the temperature set point SV1 at TIC91 to 100 OC. Wait till the response is steady at its set point SV1 to within ±0.2 to ±0.3 OC or shows

oscillatory response even after 3 cycles of oscillation.

11. Repeat procedure no. 4 and 5.


12. Make sure both temperature on TIC91 and TIC92 are cooling down to room temperature.

This process will take about 30-40 minutes.

13. Repeat procedure no 6.

14. Call up the TIC91 faceplate. Set the TIC91 to Auto mode and set its Setpoint (SP) to 80°C .

Set the second PID trials values:

Gain (100/P) = 5

Reset (I) = 70 s

Rate (D) = 18 s

15. Repeat procedure no 8-10.

16. Before shutdown the process, please ensure controller TIC91 and TIC92 are switched to the

manual mode and MV are reset to 0%.

RESULTS

PID TIC91 Setpoint

Gain (100/P

)

Reset (I)

Rate (D) Observation

Sec SecI

II

III

DISCUSSION

1. Discus on your observation based on the temperature response at Process History View and the

overshoot value of the temperature response for each PID setting?

2. From the experiment, which is the best PID for this process? Why?

3. Why controller TIC92 didn’t achieve their set point? Explain the factors that influence the

process.

4. What do you learn from this experiment?


EXPERIMENT 8: SINGLE LOOP PID LEVEL CONTROL USING DCS

Plant Model : WLF922 / DCS (Distributed Control System)

Objective : To study Single Loop PID Level Control (LIC31)

PLANT START-UP CHECK LIST

1) Tank T32 should be filled with water up to and just below the level of the shortest level

probe of the Level Switch LS32 which is slightly below the tank T32 overflow pipe outlet.

Top up the water later whenever necessary.

2) Pump P33 in Auto/Manual control mode. Leave it in Manual mode.

3) Quickly check the various manual valve as follows:

Locate the Inflow pump P32. Manual suction, discharge and by-pass valve are fully

Opened.

Pump P31: Manual suction valve = Open Fully

Two (2) manual parallel discharge valve = Shut Fully


Pump P33: Manual suction & by-pass valve = Open Fully

Manual discharge valve MV-T and MV-D = Shut Fully

Operate T31 as an Open Tank with the top vent (V) and overflow drain valves

FULLY OPENED. The pressurizing air inlet to T31 is isolated at its inlet manual valve

(with the valve handle at 90º to the air supply inlet tubing), locate next to the preset Air

Regulator AR31.

Operate T31 as a Self Regulating process. Open only the manual GATE valve at the

gravity discharge pipe at the tank bottom. The second manual GLOBE valve at the

second gravity discharge pipe must remain SHUT.

The bottom manual drain valve of Tank T32 is always SHUT.

Compressed air is required to operate the control valve system LCY31/PP/LCV31 and to

pressurize tank T31.

Check that the pressure is in accordance to the pressure indicated at the air pressure

regulator (IAS). There is no need to adjust this pressure (IAS) too frequently.

4) Note the following switches and pushbuttons but do not switch ON any pump yet.

PANEL, SCADA/DDC : Switch to ‘DDC’ position for DCS control.

EXPERIMENT PROCEDURES

1) Call up the DCS graphic display for ModelWLF922. Make sure LIC31 controller selected to

‘PID’ control mode as shown.

2) Switch the LEVEL-FLOW CONTROL selector switch to position 2 “at LIC31 position”.

Note that the LIC31 shall be in AUTO (AUT) mode and FIC31 shall be in MANUAL

(MAN) mode.


3) Call up the LIC31 Detail faceplate from the DCS graphic display and set the First (I) trial

PID Tuning Parameters (Gain, Reset and Rate) values for LIC31 as follow:

Tank T31 Level Control

Controller : LIC31

Set point : 400mm

First (I) Trial PID Tuning Parameters

Gain (100/P) : 30

Reset (I) : 30 secs

Rate (D) : 0 sec

4) Start the pump P32 and shut its by-pass manual valve BV32.

5) Call up the Historical Trend for LIC31 from its Detail faceplate. Observe the level

response for the level.

6) Apply the Level Load Disturbance to Level of Tank T31 when the level response is

within ±2mm of its Set point (SP). Perform the Level Load Disturbance as follows:

Switch the LIC31 controller to Manual (MAN) mode and decrease its manipulated

(MV) Output (OUT) by 10% for 20 sec.

Switch LIC31 controller back to Auto (AUT) mode

At the LIC31 Process Historical Trend, observe the Tank T31 level response similarly.

7) Repeat the above procedures 3 and 6 for next PID trial Tuning Parameters values in Table

8.0

TABLE 8.0: Single Loop PID Level control at Independent Operation mode

SINGLE LOOP PID LEVEL CONTROL : LIC31

Trial

PID

Set point

(mm)

Gain

(100/P)

Reset

(I)

Rate

(D) Remarks: Test disturbance

sec sec

I 400 30 30 0 Set the recommended PID trial tuning parameters

value and set point. Perform the Load Disturbance

step change as described in procedure 6.II 400 5 30 20


Observe the level response from the Process

Historical Trend to see if damp out to its set point

within 3 cycle to ±2mm of its set point (SP) OR it

III 400 5 30 0

IV 400 0.5 30 0

V 400 5 3 0

Experiment Observation

Single Loop PID Level control (LIC31) at Independent Operation mode

SINGLE LOOP PID LEVEL CONTROL : LIC31

Trial

PID

Set point

(mm)

Gain

(100/P)

Reset

(I)

Rate

(D)Observation

sec sec

I 400 30 30 0

II 400 5 30 20

III 400 5 30 0

IV 400 0.5 30 0

V 400 5 3 0

Enclose the LIC31 level trend response for the above PID values and compare the response with the

different PID setting and comment in the observation column.


EXPERIMENT 9: GAS PRESSURE CONTROL USING PID CONTROLLER

OBJECTIVES

1. To study the gas pressure single capacity control using PIC91A PID single control loop.

2. To study the gas pressure single capacity control using PIC92A PID single control loop.

INTRODUCTION

Model AFPT921 is a process control training system (PCTS) that uses only air to simulate gas,

vapour or steam. Air is readily available from a compressor. (It is deemed unsafe for students

without any industrial experience and safety training to deal with steam or gas). It provides the

simple gas physical processes where the measurement and control of their important variables of

flow, temperature and pressure can be studied.

The gauge pressures at vessels T91 and T92 OR its discharge Pipeline are measured by their

respective gauge pressure transmitters PT91 and PT92. Note that PT92 can be connected to either

ONE of the following tapping points viz at T92 OR at the discharge Pipeline of T92. The vessel

T92 and T92A are interconnected with a large interconnecting pipe so that their pressure and

pressure response are usually the same. Hence T92 + T92A behave like a 1-Capacity process of

double tank volume.

There are five basic process control loops found in this plant for Air Pressure Control system.

1. ON/OFF Air Pressure Control: PT92-PIC90-PSV90/PCV90

2. PID Air Pressure Control, Single Loop: PT911-PIC911-FCY91/PP-FCV91

3. PID Air Pressure Control, Single Loop, Single Capacity or Pipeline:

PT92-PIC92-PCY91/PP-PCV91

4. PID Air Pressure Control, Single Loop, Multi-capacities: PT91-PIC91-PCY91/PP-PCV91

5. PID Air Pressure Control, Cascade: PT91-PIC91-PIC92-PCY91/PP-PCV91

(PT92)


PROCEDURES:

1. Please refer to the Section “PLANT START-UP CHECK LIST”. It is assumed that the

readers have already performed Start-up Check List Procedures.

2. Check that compressed air is available as process air and is connected to the Model plant at

the process Air Regulator AR90. (Check that its upstream process air. Supply manual valve

(PASV) is fully opened). With the manual downstream valve MV90A fully shut, set the

pressure at AR90 to the pressure indicated. Then open MV90A by 1 turn and shut it again.

Recheck that the pressure at AR90 is correctly set. Once AR90 is set, it needs no further

adjustment.

3. To set the maximum process flowrate, adjust the manual valve MV90A at the process inlet

so that PV1 (i.e. Fm) at FIC91 panel controller reads from 40 to 50 kg/h.

4. Switch on the main power supply. The main switch is at the front of the cubicle. Make sure

the PANEL, SCADA/DDC selector switch is at the “PANEL, SCADA” position. All the

panel instruments will lit up.

5. Switch the “PANEL, SCADA/DDC” selector switch to “DDC” position.

6. Call up the Model AFPT921 DCS graphic display on one of the DCS workstation.


7. Always select the PIC91A controller to PID control mode by pressing the “PID” soft button

on the Model AFPT921 graphic display as shown below:

8. Call up the TIC91A faceplate. Set the TIC91A to Manual mode and make sure its Output is

0%.

9. Call up the TIC92A faceplate. Set the TIC92A to Manual mode and make sure its Output is

0%.

10. Call up the FIC91A faceplate and set the FIC91A to Auto mode. Set its PID values as

follow:

Mass Gas Flow controller

Controller : FIC91A

Setpoint : 35 kg/h

11. Call up the SV90A faceplate from the Model AFPT921 graphic display and open the

SV90A valve by switching its faceplate to ON or OPEN position.

12. Switch OFF the Heater (Thyristor, TCY90A) in Manual (MAN) mode i.e. ‘MAN’ from the

DCS graphic of Model AFPT921. These experiments do not require heating element, hence;

make sure that the Heater remains OFF throughout this experiment.


EXPERIMENT 9.1: STUDY GAS PRESSURE CONTROL USING PID SINGLE CONTROL LOOPS

13. For the T91 tank pressure single capacity control, make sure the bypass valves B92B and

B92 shall be opened. To enable the PIC91A single loopPID control, switch the selector

switch to “PIC91” position as shown below:

14. Call up the PIC91A faceplate. Set the subsequent trials of PID parameters values Gain

(100/P), Reset (I) and Rate (D) values as shown in the Table 3a. Observe the IC91A flow

response from its Process History View.


EXPERIMENT 9.2 MULTI-CAPACITY T92 TANK PRESSURE (PIC92A) PID CONTROL

15. To control the T92 tank pressure using the PIC92A single PID loop, switch the selector

switch to “PIC92” position as shown below:

16. Setup the Multi-Capacity T92 Tank Pressure system by manipulating the following manual

valves:

Manual valves between tanks (MV92A2, T92A and T92) = OPENED

Bypass Valves (B92A and B92) = CLOSED

Manual valve TP-T = OPENED

Manual valve TP-P = CLOSED


17. Call up the PIC92A faceplate and switch to Auto mode. Set the subsequent trials of Gain

(100/P), Reset (I) and Rate (D) values as shown in the Table 3b. Observe the PIC92A flow

response from its Process History View.


RESULTS

EXPERIMENT 9.1: STUDY GAS PRESSURE CONTROL USING PID SINGLE CONTROL

LOOPS

EXPERIMENT 9.2: STUDY GAS PRESSURE CONTROL USING PID SINGLE CONTROL

LOOPS


DISCUSSION

1. Based on your observation in experiment 9.1 & 9.2, discuss briefly for each process that was

occurred.

2. Which is the best PID for each experiment?

3. Give an example for every process that is used in industry.

4. Is it possible to use PI controller in both cases? Explain briefly either yes or no?


EXPERIMENT 10: DYNAMIC STUDIES OF SIMULATED GAS MASS FLOW PROCESS

INTRODUCTION

Model SPC211 is developed to study the application of Single Loop controls of some

common simulated processes (Flow and Level). The key topics are how to identify and characterize

some real plant processes available at some physical Plants and how to tune their control loops

using the Ziegler- Nichols, Cohen-Coon and IMC etc Tuning techniques for Quarter Decay Ratio

(QDR) or other performance criteria. Model SPC211 was developed to help teach these key topics

in Process Control and to provide the hands-on opportunity for controller tuning skills to be

acquired.

The Simulated Gas Flow Process consists of a main pipeline where process air

representing gas/vapour flows and then discharge to atmosphere via the process vent manual valve

VF. The process air that flows into the system is conditioned to have air temperature of 100°C.

With reference to the dynamic graphic of the Simulated Gas Mass Flow Process at Model

SPC211, for PID control, mass flowrate measured by Gas Mass Flowmeter (FE91/FT91), is the

measurement input into PID Flow controller FIC91A which in turn throttles the Control valve

FCV91, via a Current-to-Air Converter (I/P), FCY91, and a Positioner (PP).

Table 1: Instrumentation and control configuration for gas mass flow process

Measurement FE91/ FT91 FT91 represents the gas mass

flowmeter

Control Type FIC91A PID Controller configured at DCS

Control Output FCY91 Current-to-Air Converter (I/P)

PP Pneumatic Position

FCV91 Air Mass Flow Control Value.

Air-to-close (ATC) type


Figure 1: Simulated gas mass flow process diagram

OBJECTIVE

1. To analyze the behaviour of the gas mass flow process by simulation

METHODOLOGY (PRELIMINARY EXERCISES)

1. Switch ON the operator workstation. (Press the Acknowledge button to silence the alarm

buzzer sound).

2. Select the Gas Mass Flow Process.

3. The following Preliminary Exercises are for Dynamic Graphic check for the Simulated

Gas Mass Flow Process.

a) Familiarize and identify the single loop simulated plant process at Model SPC211.

Single Loop Simulated Process Simulated Process at Syntek

MODEL SPC211

Gas Mass Flow Process Simulated Gas Mass Flow Process

b) For the Single Loop Simulated process, identify its control loop (i.e. measuring

instrument, controller and final control element with the tag name).

c) Next, check for the engineering units for the measured variable (PV), setpoint (SP) and

controller output (MV (OUT)) for the process at the DCS Controller.


4. The following Preliminary Exercises are for dynamic behaviour of the process when the

controller output is changed (Operating Data Check) at the Simulated Gas Mass Flow Process.

a) View the dynamic graphic of the Simulated Gas Mass Flow Process at the operator

workstation of Model SPC211.

b) ‘OPEN’ solenoid valve SV90 at the dynamic graphic page. It should be green in colour.

c) Select the PID control scheme; call up the controller FIC91A Faceplate. Switch the

controller FIC91A to Manual (MAN) mode. Quickly step change the controller output,

MV (OUT) to 100%.

d) Call up the Process History View from the FIC91A Faceplate to observe the gas mass

flow response (red trend). Wait till the flow response reaches a new steady state (check

the PV value). Note the steady state air mass flowrate.

e) Then, step change MV (OUT) to 50%. Note that FIC91A is still in Manual (MAN)

mode. At the Process History View, observe that the gas mass flowrate (red trend)

increases. Note the steady state air mass flowrate.

f) Step change the controller output, MV(OUT) further to 0% with FIC91A still remain in

Manual (MAN) mode. At the Process History View, observe that the gas mass flowrate

(red trend) increases. Note the steady state gas mass flowrate.

g) ‘Print screen’ the observed gas mass flow response and enclose together with the results

sheets.

h) With FIC91A in Manual (MAN) mode, step change the controller output, MV(OUT)

back to 100%.

5. Observations and Results of Experiments.

The DCS trending records at the Process History View of each respective controller constitute

the results of the experiments. During any experiments, note down the observations

corresponding to the obtained response. Check the OBSERVATIONS AND RESULTS

SECTION for the types of results to observe collect and submit them as results of your

exercise and experiments.


6. To Shut down Model SPC211

a) Close all the windows (including DeltaV Operate page) at the operator workstation.

b) Log Off from the operator workstation.

c) Shut down the operator workstation.

OBSERVATIONS AND RESULTS

Dynamic Graphic Check (Visual and Static Check) for the Simulated Gas Mass Flow Process

(Refer to Methodology in step 3)

Single Loop Simulated

PlantProcess

Process Control Loop Engineering units

Gas Mass Flow Process Tag

Name

Process

Parameter

Units

Measuring

Instrument

PV

Controller SP

Final Control

Element

MV(OUT)

Dynamic Behaviour of the process (Operating Datas Check) at the Simulated Gas Mass Flow

Process (Refer to Methodology in step 4)

Actions Observations Remarks

With FIC91A in Manual (MAN) mode,

i) at MV (OUT) = 100% What is the current air

mass flowrate at steady

state?

1. ______kg/h

2. Is the control value

FCV91 fully shut?

______

ii) at MV (OUT) = 50% What is the air mass

flowrate at steady state?

3. ______kg/h

iii) at MV (OUT) = 0% What is the air mass

flowrate at steady state?

4. ______kg/h

5. Is the control value

FCV91 fully open?

______

Note: Enclose the trend response for the Simulated Gas Mass Flow Process


QUESTIONS

1. From the result obtained, discuss the dynamic behavior of the process (i.e order of the

response)

2. Give suggestions to improve the process performance.


INDUSTRIAL PROBLEM BASED LEARNING 1: OPEN LOOP STUDIES OF

SIMULATED GAS MASS FLOW PROCESS

INTRODUCTION









flowmeter



PP Pneumatic Positione






OBJECTIVE

1. To perform open loop test at the Simulated Gas Mass Flow process.

2. To determine process parameters such as steady state gain (Kp), dead time (tD), response rate

(RR) and time constant ( ).

METHODOLOGY (OPEN LOOP TEST)

1. View the dynamic graphic of the Simulated Gas Mass Flow Process at the operator

workstation.

2. ‘OPEN’ the solenoid valve SV90 at the dynamic graphic page. It should be green in colour.

3. Select the PID control scheme. Then, call up the FIC91A Faceplate and its Detail Faceplate.

4. Practice changing the controller setpoint SP = 18kg/h to 25kg/h to 35kg/h. Switch the

controller to Manual (MAN) mode, practice changing the controller output MV(OUT) = 0%

to 50% to 100%.

5. Next, switch the controller to Auto (AUTO) mode. Practice changing the Gain, Reset and

Rate values from the detail faceplate of FIC91A. Then, set the following Gain, Reset and

Rate (PID) values:

FIC91A: Gain = 0.40, Reset = 3 sec, Rate = 0 sec

Use a setpoint of 25kg/h for the flow controller FIC91A.

User may refer to the “DCS Quick Reference Manual” for more practice.

6. Call up the Process History View from FIC91A to view the flow response (red trend).

NOTE: At the Process History View window, click at the “Chart” menu to select the

“Configure Chart”option and change the “Time Scale” span to 00:02

7. When the response is fairly steady, switch FIC91A to Manual (MAN) mode and step

decrease its MV (OUT) by about 5%. The flow response will rise and then gradually flattens

out exponentially. Wait till the response is fairly steady at the new steady state flowrate

(about 28.10kg/h).

“Print screen” and “save” the observed flow response to be enclosed together with the results

sheets.

8. Use the obtained response curve (for 25kg/h) to determine the process parameters i.e. process

gain, Kp, dead time, tD, response rate, RR and time constant, . Refer to Appendix for the

technique applied to determine these parameters.


9. Next, switch the controller to Auto (AUTO) mode, with a setpoint of 18kg/h. View the flow

response (red trend) at the Process History View page. When the response is fairly steady,

switch FIC91A to Manual (MAN) mode and step decrease its MV(OUT) by about 5%. Wait

till the response is fairly steady at the new steady state flowrate (about 22.60kg/h).

“Print screen” and “save” the observed flow response to be enclosed with the results sheets.


gain, Kp, dead time, tD, response rate, RR and time constant, .

11. Next, switch the controller to Auto (AUTO) mode, with a setpoint of 35kg/h. View the flow

response (red trend) at the Process History View page. When the response is fairly steady,

switch FIC91A to Manual (MAN) mode and step decrease its MV(OUT) by about 5%. Wait

till the response is fairly steady at the new steady State flowrate (about 35.90kg/h). “Print

screen” and “save” the observed flow response to be enclosed with the results sheets.


gain, Kp, dead time, tD, response rate, RR and time constant, .

Note: The process parameters obtained from this experiment will be used later in PID tuning

experiment.


1. Show detailed calculation of the Process Parameters obtained for the Simulated Gas Mass

Flow Process at different operating flow setpoints.

2. Summarise the Process Parameters at the Table below.

Process Parameters Setpoints (SP)

18kh/h 25kg/h 35kg/h

Process gain, Kp

Dead time, tD (sec)

Response Rate, RR

(sec-1)

Time constant, (sec)

3. Enclose the trend response of the Open Loop Test at different operating flow setpoint.

QUESTION


1. For the different operating setpoints of gas mass flow, check whether the process parameters

remain constant or vary. Comment on the process variability if the process parameter varies

for different operating gas mass flow setpoints.

APPENDIX

Open Loop Test (Process Reaction Curve)

Process Parameter Equations1. Steady State Gain, Kp

2. Response Rate, RR

3. Dead time, tD

4. Time constant,

B2

B1

to t1 t2

M2

M1

Range for input variable: M∞ - Mo

Range for output variable: B∞ - Bo

B3


INDUSTRIAL PROBLEM BASED LEARNING 2: PID CONTROLLER TUNING OF

SIMULATED GAS MASS FLOW PROCESS

INTRODUCTION









flowmeter



PP Pneumatic Positione






OBJECTIVE

To control the Simulated Gas Mass Flow Process, using PID controller parameters determined

manually from the following Controller Tuning techniques:

i) Ziegler-Nichols using the Process Reaction Curve Method

ii) Cohen-Coon (C-C) Method

iii) Internal Model Control (IMC Method)

METHODOLOGY (PID TUNING)

1. View the dynamic graphic of the Simulated Gas Mass Flow Process at the operator

workstation. ‘OPEN’ the solenoid valve SV90. It should be green in colour. Select PID

control scheme for FIC91A.

2. Call up the FIC91A faceplate and its Detail Faceplate. Then, set the following Gain, Reset

and Rate (PID) values:

FIC91A: Gain = 0.40, Reset = 3 sec, Rate = 0 sec

Use a setpoint SP of 18 kg/h for the flow controller FIC91A.

Switch the controller to Auto (AUTO) mode.

Call up the Process History View from FIC91A to view the flow response trend.

NOTE:

At the Process History View window, click at the “Chart” menu to select the “Configure Chart” option and

change the “Time Scale” span to 00:02

3. PID Tuning for the flow setpoint 18 kg/h:

a) Using the process parameters [process gain, Kp, dead time, tD, response rate, RR and

time constant, ] determined for flow setpoint of 18kg/h from Experiment Open Loop

Test, calculate its PID Tuning parameters using first the “Ziegler-Nichols Tuning

Relations (Process Reaction Curved Method)”.

* The PID Tuning Parameters determined for SP = 18 kg/h is PID1

Refer to the ‘PID CONTROLLER TUNING TECHNIQUES’ in the Appendix for the

appropriate formulae to establish the approximate Kc, and values for the flow

setpoint.

NOTE: Flow is generally a fast process. A PI Controller should be used when the

Proportional control alone cannot provide sufficient small steady state errors (offset). It is

satisfactory because it eliminates offset and retains acceptable speed of the flow response.

Adding Derivative control action will actually destabilize the flow process system.


b) When the response is fairly steady at its setpoint SP = 18 kg/h, change PID setting; the

Gain (Kc), Reset ( ) and Rate ( ) values at the Detail Faceplate to the PID1 values

calculated for flow setpoint 18 kg/h.

c) Load Step Test:

When the flow response is fairly steady at SP = 18 kg/h, switch FIC91A to Manual

(MAN) mode and quickly step increase its MV(OUT) by about 5% for about 5 sec.

Then, quickly switch FIC91A back to Auto (AUTO) mode.

Observe the flow response (red trend) at the Process History View.

Again when the flow response is fairly steady at SP = 18 kg/h, repeat the above

steps for the step increase MV(OUT) by about 10% for about 5 sec.

Observe the flow response (red trend) similarly.

“Print screen” and “save” the observed flow responses and enclose together with the

results sheets.

Analyze the PID Control responses obtained for both the load step tests respectively.

d) Setpoint Step Test :

When the flow response is fairly steady at SP = 18 kg/h, with the

Controller FIC91A remaining in Auto (AUTO) mode, step increase the setpoint SP

to 23 kg/h.


When the flow response is fairly steady at SP = 23 kg/h, step decrease the setpoint

SP back to 18 kg/h. Wait till the flow response is steady at SP =18 kg/h and then

step increase the setpoint to 28 kg/h.

Observe the flow response/trend (red trend) similarly.

With the controller FIC91A remaining in Auto (AUTO) mode at SP =28 kg/h, step

decrease the setpoint SP to 25 kg/h.

Observed the flow response (red trend) similarly.


results sheets.

Comment on the PID control responses obtained for both the setpoint step tests

respectively.

4. PID Tuning for the flow setpoint 25 kg/h:

a) Using the process parameters [process gain, Kp, dead time, tD, response rate, RR and

time constant, ] determined for flow setpoint of 25 kg/h from Experiment Open Loop


Test, calculate its PID Tuning parameters using first the “Ziegler-Nichols Tuning

Relations (Process Reaction Curved Method)”.

* The PID Tuning Parameters for SP = 25 kg/h is PID2

b) When the response is fairly steady at its setpoint SP = 25kg/h, change the Gain (Kc),

Reset ( ) and Rate ( ) values at the Detail Faceplate to the PID2 values calculated for

flow setpoint 25 kg/h.

c) Load Step Test:

When the flow response is fairly steady at SP = 25 kg/h, switch FIC91A to Manual


Then, quickly switch FIC91A back to Auto (AUTO) mode.


Again when the flow response is fairly steady at SP = 25 kg/h, repeat the above

steps for the step increase of its MV(OUT) by about 10% for about 5 sec.



results sheets.


respectively.

d) Set Point Step Test:

When the flow response is fairly steady at SP = 25 kg/h, with the controller

FIC91A remaining in Auto (AUTO) mode, step increase the setpoint to 30 kg/h.


When the flow response is fairly steady at SP = 30 kg/h, then, step decrease the

setpoint SP back to 25 kg/h. Wait till the flow response is steady at SP =25 kg/h and

then step increase the setpoint to 35 kg/h.



results sheets.


respectively.

5. PID tuning parameters robustness check:

a) With the controller FIC91A remaining in Auto (AUTO) mode at

SP = 35 kg/h at the previously set PID2 values, step decrease the setpoint to 18 kg/h.

At the Process History View, wait till the flow response is steady at SP = 18kg/h.


b) When the flow response is fairly steady at SP = 18 kg/h, switch FIC91A to Manual


Then quickly switch FIC91A back to Auto (AUTO) mode.

c) Observe the flow response (red trend) at the Process History View.

d) Print out the observed flow responses to be enclosed together with the results sheets.

Compare the flow control responses of SP = 25 kg/h and SP = 18kg/h for the same load

step tests respectively.

e) Comment on the robustness of PID2 tuning parameters in controlling

other flow setpoints of the Simulated Gas Mass Flow process.

6. Repeat the above steps 3 to 5 for other controller tuning techniques like Cohen-Coon (C-C)

Method, and Internal Model Control (IMC) Method. Compare the effectiveness of the

PID values determined from each of the tuning methods to control the process.

Take note that these methods actually provide approximate PID values for controller settings which

can be used as the starting point for fine tuning.


1. Show detailed calculation of the PID parameters obtained from each of the tuning methods.

2. Summarise the PID values at the Table below.

Tuning

Methods

SP = 18 kg/h SP = 25 kg/h

Gain

(Kc)

Reset (

)

Rate (

)

Gain

(Kc)

Reset (

)

Rate (

)

Z-N Process ReactionCurve

Cohen-CoonInternal Model Control

3. Enclose the trend response of the Open Loop Test at different operating

flow setpoint.


QUESTION

1. For the different operating setpoints of gas mass flow, check whether the process parameters

remain constant or vary. Comment on the process variability if the process parameter varies

for different operating gas mass flow setpoints.

2. For flow setpoint of 18kg/h, enclose the observed Simulated Gas Mass Flow Process

responses of the load step tests carried out for each of the PID tuning methods. Comment on

the control responses obtained.


responses of the setpoint step tests carried out for each of the PID tuning methods. Comment

on the control responses obtained.


responses of the load step tests carried out for each of the PID tuning methods. Comment on

the control responses obtained.


responses of the setpoint step tests carried out for each of the PID tuning methods. Comment

on the control responses obtained.

6. Enclose the observed Simulated Gas Mass Flow Process responses of the PID robustness

check carried out for each of the PID tuning methods. Comment on the robustness of the

PID tuning parameters for flow setpoint SP = 25kg/h in controlling other setpoints of the air

mass flow process.

APPENDIX

Cohen-Coon Tuning Relations

Controller Type Gain (Kc) Reset ( ) Rate ( )


P - -

PI -

PID

Zeigler and Nichols Tuning Relations

Controller Type Gain (Kc) Reset ( ) Rate ( )

P - -

PI -

PID

Internal Model Control Tuning Relation

Controller Type Gain (Kc) Reset ( ) Rate ( )PI

when

12

121

D

D

c

p

t

t

K

-

PID

when

Documents

Lab Module