pm36j6b10-01e_25 yokogawa electric corporation 2-9-32 nakacho, musashino-shi tokyo, 180-8750 japan...

PM36J6B10-01E_25

Yokogawa Electric Corporation 2-9-32 Nakacho, Musashino-shiTokyo, 180-8750JAPAN

Public Relations Dept., Yokogawa Electric CorporationCopyright © by Yokogawa Electric Corporation<date/time>

AOAAdvanced Operation Assistance

Solutions

July, 2003

PM36J6B10-01E_25Public Relations Dept., Yokogawa Electric CorporationCopyright © by Yokogawa Electric Corporation <date/time>

1. What is AOA ?


What is the AOA ?

Upper solution of process operation done by operatorsTo assist daily work of production people to realize safer and more cost-effective operation. For example,– In desk work

• Support to prepare an operation report• Support to turn up operation related problems• Support to standardize operation know-how

– In normal operation• Suppress unnecessary DCS alarms to notify only important DCS alarms• Notify an early sign of abnormality faster than it is detected by DCS

alarms• Prevent miss-operation

– In transition operation (e.g. startup/load change/reactor switchover)

• Give an adequate instruction to the operator in a sequential order• Prevent miss-step/miss-procedure

Process

CONTROL domain OPERATION domain

MES, ERP

Process Control (DCS)

Advanced Process Control Advanced Operation Assistance

Process Operation (Operators)


Difference between APC and AOA

APC (Advanced Process Control)– Position: Additional function of DCS– Purpose: Improvement of controllability– Configuration: Runs on additional PC– Main user: Engineering people– Approach: Based on mathematical process model– Benefit: More cost-effective control

AOA (Advanced Operation Assistance)– Position: Additional function of DCS– Purpose: Improvement of operation work– Configuration: Runs on operator’s console or additional

PC– Main user: Production people (operator/process

engineer)– Approach: Based on knowledge and experiences of

skillful operator/process engineer– Benefit: Safer and more cost-effective operation


System architecture

Run on HIS or Additional PCSupports Windows2000/XPproServer/client configurationComponent software– Exaopc

(OPC interface package)– Exaplog

(Event reporting/analysis package)– Exapilot

(Operation efficiency improvement package)• Exapilot Professional or Standard• Advanced alarm function• MS Excel link icon

Support all DCS via OPCinterface

HISENG

FCS

V net

AOA Client

Ethernet

PC

PC

FCS

HF bus

ABC Busconverter

Setting

AOA Server

Gathering

Setting

Gathering

CENTUM-XL, VMicro XL

Event message

Gathering

(max. 4)

AOA Client

CENTUM CS 1000CENTUM CS 3000

Exaopc is required

System architecture(In case of additional PC)


2. ExaplogEvent reporting and analysis package

2.1 Operation event viewer/analyzer2.2 Operation event reporter


Assist desk work of production Dept.– Reporting of operational event– Monitoring of operational event– Analysis of operational event

Utilize a DCS alarm and event message which is less frequently used

Exaplog

Message Printer

HugeRunning Cost

HugeStorage Space

SpecialisticManual Work

Exaplog (Software Printer)

MinimumRunning Cost

MinimumStorage Space

Semi-automaticWork


2.1 Operation event viewer/analyzer

5 viewers– Event balance trend (EBT)– Monthly/Weekly EBT– Category sort– Point ID (Tag) sort– Message summary

(same as DCS printer)

5 filters– Scope in– Exclude– Character– Process unit– User defined

Event balance trend (EBT) Category sort

Point ID sortMessage summary

Character/Process unit

User defined

Monthly/Weekly EBT


Event balance trend (EBT)

Process Requests

Operator’s Actions

X-axis : Time (24hours)Y-axis : Number of events

Display the balance between– Process requests (+)

• System alarm• Process alarm• Annunciator message• Operation guidance, etc.

– Operators actions (-)• Tag data entry• Tag mode change, etc.

No. Pattern Type EBT Pattern Suspected Problem Countermeasure

Long term analysis about seasonal change

Long term analysis about erosion/corrosion

Unnecessary alarms/messages Retuning of alarm set valuesIntegration of redundant alarms/messagesMasking of low priolity alarms/messages

Low automation rate Automation using DCSManual operation according to know-how Automation using ExapilotComplex operation sequence Simplify operation sequence

Lack of support function Navigation using Exapilot

Insufficient Operator capability Operator training

Human error Error detection using Exapilot

Unstable process Introduction of advanced process control

Excessive Operation

Operator Work Overflow

Inadequate Operation

I

II

III

IV

V

No urgent problem

Redundant alarms/messages

Balanced

Excessive Nortification


Category sort, Point ID sort

Category sort– Type– Sub type– Detail– Batch ID– Station

Point ID (Tag) sort– Tag– Tag + Detail


2.2 Operation event reporting

Various reports can be exported to CSV file– Tag list which notifies many alarms

• Per detail (e.g. HH/HI/LO/LL/VEL/DEV/IOP)• Per priority (e.g. High/Medium/Low)• Per process unit (e.g. station#, process unit filter)

– Tag list which alarm set point have been changed

– AOF (alarm off) tag list– Manual control tag list, and more

Additional editing can be done using MS-ExcelUser defined report can be registered


(4)

(1)Select “Sub Type” tub(2)Select “Tag Alarm”(3)Press “Scope in filter” button(4)Select “Tool\Export Result” to save a result of analysis as CSV file(5)Edit a report file using MS-Excel function

(1)

(2)

(3)

(5)

e.g. Tag list which notifies many alarms


(1)Select “Detail” tub(2)Select “MAN”(3)Press “Scope in filter” button(4)Select “Tool\Export Result” to save a result of analysis as CSV file(5)Edit a report file using MS-Excel function

(1)

(2)

(3)

(4)

(5)

e.g. Tag list which controlled manually


Benefits of Exaplog

Hidden problem can be revealed– Field related problem

• Failure of field instrumentation/equipment• Mismatch of field instrumentation/equipment• Range over of field instrumentation

– Control related problem• Mismatch of PID parameters

– Alarm related problem• Unnecessary HI/LO alarm caused by mismatched alarm thresho

ld/hysteresis• Unnecessary IOP alarm caused by range over• Nuisance Annunciator message related to DI/SW

– Operation related problem• Complex manual operation• Miss-operation


Pharmaceutical plant, USA

The background– Large batch chemical plant– Legacy system was replaced to CS3000– Over 10,000 I/O

The problem– 50,000 alarms per day– Audible alarms were disabled

• Operators where missing critical alarms• Alarms were disappearing from display in 10

minutes• Lost production• Increased safety hazards• Increased production cost


The approach– Use Six Sigma methodology– Set overall goal of 10 alarms/day– Use Exaplog to measure and analyze alarms

The result– Cut the alarming rate by a 98%

• Field improvement– Improvement of field instrumentations (re-ranging)

• Alarm optimization and management– Elimination of nuisance Opeguide messages– Retuning of alarm threshold

– Two of the four operator stations back on-line– Operator mistakes have decreased– Productivity has increased by notification of adequate

alarms– Operating issues around several pieces of equipments

have been resolved by systematic alarm analysis


PTA, Southeast Asia

Benefits– Eliminate unnecessary DCS alarm events and

operation for 40%– Improve inefficient operation sequences– Operator can concentrate on only necessary alarm

events– Lower miss-operation

Process AlarmDaily

Average (Before)

TI-xxxx, HH alarm 73 30

TI-xxxx, Hi alarm 145 Change to proper HI alarm setting 50

LC-xxxx, Auto mode 27 PID tuning 0

LC-xxxx, Man mode 26 PID tuning 0

Change to proper HH alarm setting

CountermeasureDaily

Average (After)


3. ExapilotOperation efficiency improvement package


Exapilot

Additional DCS function for– Knowledge-based process control– Knowledge-based process monitoring

Application can be programmed as flow chart or logic chart– Specialist programming skill is not needed– High usability– High understandability– High maintainability

Existing application in DCS is no need to modify

Various usages– Automation of transient operation– Alarm management– Operator training


Flow chart programming tool (Standard)

Visible iconsfor flow chart program

Application example

Application example


Logic chart programming tool (Option)

Application example

Grammar of logic chart

Visible iconsfor logic chart program


Ready-made templates

For flow chart

For logic chart


3.1 Automation of transient operation


Builder function

<Condition icon>Check LI100.PV>=50

<Block mode setting icon>P101.MODE to AUTO

<Condition icon>Check P101.PV = 2

<Output to DCS icon>P101.CSV to 2 (Start)

<Confirmation icon>HV100 Open

<Guidance message icon>P101 start finished

<Condition icon>Check P101.ALRM = NR(NR means Normal)

<Output to DCS icon>P101.CSV to 0 (Stop)

<Alarm message icon>P101 start error

<Pause icon>Pause this sequence

<Alarm message icon>Preparation error

<Output to DCS icon>FIC100.SV to 20t/h

<Timer icon>Wait 10 minutes

YES YES

NONO

NOYES

Typical paper SOP

Know-how

Know-how

(1) Check base tank level LI100.PV >= 50%(2) Start pump P-101(3) Check answer back flag(4) open field hand valve HV100

Typical paper SOP (too much simplified)

If tank level is lower than 50%, announce it and open inlet valve of base tank (FIC100.SV = 20t/h), and wait for 10 minutes. If answerback is not ‘2’ and alarm status (P101.ALRM) is not “NR”, stop pump (P101.CSV = 0), announce it, and pause operation till field operator solves the problem.

Operation know-how of veteran operator/engineer

An automation program can be easily created as flow chart diagram including a veteran operator’s/engineer’s know-how.


Operation function

1. Icons’ color means the condition. Green:Now executing Gray:Finished White:Unexecuted Yellow:Paused

1 2 3 4

1 2 3 4 5 6 7 8

Flow chart diagram can be executed automaticallyInteractive operation between Exapilot and operators can be doneVarious kinds of messages makes operators right judgmentOperational status can be confirmed visuallyManual interposition by operators can be done according to need

2. Four kinds of messages display. 1)Confirm 2)Guide 3)Alarm 4)System

3. Manual operation is available. 1)Start all 2)Start icon 3)Stop icon 4)Pause (all/icon) 5)Initialize icon 6)Break icon 7)Skip icon 8)Stop all


Benefits

Safety improvement– Prevention of miss-operation– Prevention of hazardous situation by the early

detection of process abnormality

Productivity improvement– Improvement of product quality– Increase of production by shortening of operation

time– Reduction of transient (off-specification) product

Cost saving– Utility saving (steam, fuel gas, electricity,

instrumentation air)– Saving of inventory management cost– Reduction of operator’s workload– Reduction of engineering workload


Application examples1. Crude unit, Japan2. BTX, Japan3. Polyethylene/Polypropylene, Japan4. Olefin, Japan5. Ethylene, Japan6. PTA, Southeast Asia7. ABS/AS, Taiwan8. Soda ash, USA9. High purified alcohol, Japan10. Ethyl-benzene, Japan


(1) Crude unit, Japan

Problems– Operator’s workload is higher than in a normal

operation• Twice or three times a week• 130 DCS manipulations/switchover

– Operation time and product quality depends on a skill of assigned operator

• Three hours difference• Utility was also wasted

Engineering– 4 applications

• Adjust process load before switchover• Switch crude oil from LGO to HGO• Switch crude oil from HGO to LGO• Heat up, Air in

– Skilful operator:2 man-months for making main procedure

Automation of crude switchover operation


Difference of ramping technique

Junior operators– Ramps up SV of feed temperature linearly in a same rate

Veteran operators– Changes the ramping rate according to the zone of

temperature• From 40 degree to 45 degree (First stage)

– Change “MODE” from “AUT” to “MAN”– Change “MV”– Return “MODE” from “MAN” to “AUT” (Repetition)

• From 180 degree to 185 degree (Final stage)– Control in “AUT” mode mainly– Change “MV” in case a deviation between SV and PV is remaining for

long time– Desensitize (change) PID parameters to prevent the over shoot

45-50yrs 42%

41-45yrs 20%

36-40yrs 9%

31-35yrs 6%

26-30yrs 17%21-25yrs 6%

Veteran operators


Benefits

90% of manual operations were automatedAll monitoring works were automated2000 unnecessary alarms were suppressed– Operators can do another work during crude switchover

operation– Miss-step and miss-procedure were prevented from

occurring– Safer operation was achieved

0

50

100

150

200

250

Crude switch 151 116 106

Normal 50 50 50

LGO to HGO HGO to LGO LGO to HGO

31March 2April 5April

0

50

100

150

200

250

Crude switch 15 15 15

Normal 50 50 50

LGO to HGO HGO to LGO LGO to HGO

31March 2April 5April

Done by operator Done by Exapilot

Number of DCS tough operation by operators


Benefits

Operating time was shortenedProduct quality was improved– Operation cost was reduced

Adjust process load4:00-9:30

(Manual operation)

Switchover9:30-12:30(Manual)

Switchover9:30-11:30

(Automatic)

Crude Charge (A train)

Crude Charge (B train)

Separator Level

Separator Flow

Stripper LevelStripper Extract Flow

Dryer Bottom Level

Product Flow

LGO to HGO Operator comes to work at 8:30to do another work

Operator comes to work at 4:00to start the preparation work

Done by operator (manual) Done by Exapilot (automatic)

Adjustprocess load

7:00-9:30(Automatic)


(2) BTX plant, Japan

Process– BTX (Benzene, Toluene, Xylene) plant

• Mixture of law material (Crude gas oil)• Distillation (Extraction of impurities)• Hydro treating• Extraction (Dissolution of BTX)• Recovery• Distillation (Constituent separation of BTX)

System configuration– CENTUM-XL with ABC– Exapilot on HIS

Automation of heuristics control in Benzene tower


Target operation– Process load control– NA density control in intermediate tank– Ratio control of solvent in case of

composition fluctuation– Temperature monitoring of air fin– Specific productivity monitoring of utility

• Fuel gas, steam, electric power

Engineering– 1 veteran operator– 2 months (July to August in 2002)


Benefits– Reduction of operator’s workload

• From 34 times/day to 3 times/day

– Improvement of product quality

Before use (SD = 0.0011)

After use (SD = 0.0008)

Density of Benzene (%)

Upper limit

Lower limit


(3) Polyethylene plant, Japan

Purpose of introduction– Reduction of operator’s workload

• Three hours everyday• 200 DCS manipulations/operation• Process monitoring is required continuously

– Shortening of operation time– Reduction of transient products

• Operating time depends on assigned operator• Quantity of transient products depends on assigned

operator– In case of junior operator: +50% of average– In case of skilful operator: -20% of average

– Standardization of control method• Overshoot control is required to shorten operation time

Automation of grade changeover operation

Ukishima factory (CENTUM CS 3000)• PP (Bulk polymerization) 70,600 ton/year (KPP1)• PP (Bulk polymerization) 67,000 ton/year (KPP2)

Chidori factory (CENTUM-XL) PP (Vapor phase polymerization) 89,100 ton/year (KPP3) HDPE (Slurry polymerization) 45,000 ton/year (KHD1) HDPE (Slurry polymerization) 50,200 ton/year (KHD2)


Why not automated using DCS function ?– Difficulty of programming

• Only skilful operators and process engineers know the best procedure experientially

• It is difficult for DCS engineers to import all of their know-how into DCS program

– Frequent modification of program is required• Addition of new experiences is often necessary

– Inheritance of operation know-how is required• DCS program is difficult for operators to understand


Engineering– 8 months/200 applications-plant– Skilful operator inputs his experiences into Exapilot– Process engineer temporary supports operators



• Operation was fully automated• Any miss-operation was prevented

– Operating time was optimized• 10% shortened on the average

– Transition products were reduced• 20% reduced on the average

– Engineering workload was reduced• 90% reduced in comparison with that for DCS

– Operation know-how was shared


(4) Olefin plant, Japan

Problems– Periodical stop/purge/restart operation is required

• Once a month, for three days• 530 hours/year-operator for DCS monitoring/manipulation

– Many confirmation works between board operator and field operator

• 15 sheets of check list, including 263 confirmation items– Time required depends on a skill of assigned operator

• This operation causes a load fluctuation more than 20%• Sensitive operation for load adjustment is required before/after the

purge operation to avoid abnormal reaction of other reactors• 3 hours difference

– Skilful operators will reach mandatory retirement age in a few years

Automation of reactor switchover operation

19-2526-30

31-35

36-40

41-45

46-50

51-55

56-604%

11%

7%

11%

7%15%

26%

19%

Age compositionin Olefin plant

Cleaningliquid

Ma

teria

l

Reactor #1_

#2_

#3_

#4_

#5_

Cru

de

reco

very

Pu

rificatio

n

Re

actio

n

Olefin plantprocess flow 0

50

100

150

200

8/17 8/18 8/19 Date

Tim

es/d

ay

Stop/Purge/Startof reactor

Load adjustmentof distillation tower

Normal operation

Number of manipulationson DCS in August 1997

90

25

45

1510

70

130

25

45

Pu

rificatio

n


Buying motivation of Exapilot– More flexible than DCS

• Changeover of operational procedure can be done online depending on a situation (pause, restart, bypass)

• Interactive operation can be done• Combination with existing DCS program

– Easier than DCS• Special skill for engineering is not necessary• Operator/process engineer can directly input their know-

how• Frequent modification is possible

Schedule– Decision of introduction in December 1997– Beginning of operation in June 1998

Engineering– DCS engineer: 0.8 man-months for making user-defined

procedure modules– Chief operator: 1.3 man-months for making main

procedure– Efficiency of engineering is 1/10 in comparison with DCS


Application example– Automation of reactor depressurisation

• Extract liquid/gas to downstream in order to reduce inlet pressure when reactor is stopped

• In case of junior operator, it takes long time to depress inlet pressure for fear of process fluctuation

• In case of skilful operator, he can immediately depress inlet pressure by monitoring pressure and flow of downstream so that process load of downstream becomes upper limitation constantly

• Operation time was reduced from 5 hours to 2.5 hours– Automation of reactor pressurisation

• Operation time was reduced 30 minutes– Automation of feed control during start up operation

• Feed flow of other reactors is fluctuated according to the fluctuation of header pressure while operator ramps up load of feed compressor to start up purged reactor, and it causes mental distress to the operators due to the possibility of abnormal reaction

• Stable control was realized



• Full automation of board operation was achieved• 290 manipulations were reduced in each purge operation• 410 hours/year were reduced including monitoring work

– Increase of productivity• 3 hours shortened in each purge operation

(150hours/year)• Productivity was increased 200 ton/year

– Prevention of miss-operation• Check list was eliminated

– Reduction of mental distress– Succession of operation know-how

0

50

100

150

200

250

8/17 8/18 8/19Num

ber

of

Op

era

tion

s o

n D

CS

pe

r D

ay

Before automation(August 1997)

0

50

100

150

200

250

7/14 7/15 7/16

After automation(July 1998)

BeforeAutomation

600

500

400

300

200

100

0

Tim

e / M

an Y

ear

AfterAutomation

Operating Timeon DCS

Operating Time on DCS

Monitoring Timeon DCS

Monitoring Time on DCS

530

120


(5) Ethylene plant, Japan

Process– Ethylene plant

• 374,000 ton/year

System configuration– CENTUM-V with ABC (Bus converter)

Target operation– Naphtha Evaporation

• Stabilization Control– Naphtha Cracking Furnace

• Decoking Operation– Naphtha Cracking Furnace

• Oil Combustion Start/Stop– GT Hot Wash Operation– EMG Secondary Operation

Automation of decoking related operation


Process– Ethylene plant

• 374,000 ton/year

System configuration– CENTUM-V with ABC (Bus

converter)

Target operation– Naphtha Splitter

• FRN Tank Switchover Operation• Start Up/Shut Down Operation• Charge Control

– BT Unit• Start Up/Shut Down

– Ethylene• Start Up/Shut Down

Automation of Naphtha switchover operation


(6) PTA plant, Southeast Asia

Process– Purified Terephthalic Acid– 800,000 ton/year

System configuration– CENTUM CS

Benefits– Reduce work load of unusual state operation– Standardise plant start up operation– 200 field activities are confirmed by Exapilot– 500 DCS parameters are monitored by Exapilot– 420 DCS parameters are automatically adjusted– Prevent miss-step or miss-procedure– Ensure timing of Plant Start Up operation

Automation of plant startup operation


Many DCS parameters are monitored and adjusted by Exapilot

Heating by junior operator Heating by Exapilot


(7) ABS plant, Taiwan

Process– AS plant– 50% Polymer of acrylic nitrile and styrene monomer– Low material of ABS– 12 hours startup/shutdown

System configuration– CENTUM-XL via ABC

Objectives– Full automation for plant startup and shutdown– Shorter, safer startup and shut down– Better quality control in startup and shutdown

Automation of plant startup/shutdown operation


Implementation approach– Smart ramp and soak design for feed– Model based temperature control to treat

long dead time characters– Adaptive gain to handle changing process

gain– Optimum switchover of PID algorithm to

avoid startup overshoot• i.e. PI to PD to PID

– Polymer reaction temperature profile setting

– Set point swift to avoid temperature run away

– Nonlinear valve plug compensation


Engineering– Manpower: 4 supervisors and engineers

from customer 4 engineers from vender– Term: 6 months

Benefits– Reduction of operator’s work load

• From 400 DCS manipulations to 3 Exapilot operations

– Improvement of process performance– Shortening of startup/shutdown time


(8) Sodium carbonate decahydrate, USA

Process– Sodium carbonate decahydrate

• Two crystallizers• Refrigeration system• Vacuum controls for barometric condenser• Pusher centrifuge• Crystallizer heating system• Numerous pump and tanks

– New process and new operators– Many field operations

System configuration– CENTUM CS 3000

• FCS x 1, HIS x 2• 162 control loops• 2 operators/shift



Engineering– Manpower: 1.5 man-month– Term: 1 month

Application– 300 icons– 24 sub-procedures– 5 seconds– 52 field activities are confirmed– 44 DCS parameters are monitored– 90 DCS parameters are automatically

adjusted

Builder window

Operation window


Benefits– Guides the operator through every step of the procedure. Ver

y user friendly.– Much easier to implement the procedure than in the DCS– Expect reduction in operating time, operator work load, and

miss-operation.– Procedures are fully documented as part of the development

process.– Easy to update and optimize the procedure as the process k

nowledge improves.i.e. the best operating knowledge is retained.

– Operator training for both off-line and on-line

Future application– 6 Calciner refractory cure procedures– 4 MVR Crystallizer startup procedures– 2 Boiler Startup & Shutdown Procedures


(9) High purified alcohol plant, Japan

Process– High purified alcohol plant– Different 9 distillation towers

System configuration– CENTUM CS 3000

Problems– Two different start up procedures

due to the season changes– High frequency operation (every 3 weeks)– Start up procedure depends on each

distillation tower– Many manual operation to control pressure

and temperature



Engineering– Manpower: 8 man-month

• 2 veteran operators (1.5 man-month)• 2 process engineers (0.5 man-month)

– Term: 6 weeks

Benefits– Reduce manual operation– Reduce engineering workload– Prevent miss-step or miss-procedure– Operation know-how is standardized


(10) Ethyl-benzene plant, Japan

Process– Ethyl-benzene– Frequency: 2-3 times/year

System configuration– CIEMAC via Exaopc (OPC interface)

Problems– High intensity work

• Takes for 2 weeks• 2,300 DCS manipulations• Operated with normal operation in parallel

– Typical heuristics operation

Automation of regeneration operation of alkylation catalyst


Engineering– Mid-level operator

Benefits– Reduction of operator’s work load

• 90% reduction of DCS manipulations done by operator

– Standardization of complex operation know-how


3.2 Alarm Management

(1) Masking of unnecessary DCS alarm(2) Dynamic alarm setting(3) Addition of pre-alert(4) Replacement to advanced alarm(5) Prevention of miss-operation

Under development (will be released in Feb. 2004)


What is required to the alarm system ?

For safer and more cost-effective operation of industrial systems– To help the operator to correct potentially dangerous

situations before the ESD is forced to intervene– To recognize and act to avoid hazardous situations– To identify deviations from desired operating conditions

that could lead to financial loss– To better understand complex process conditions

An effective alarm system

TargetNormalUpsetShutDown

Key Alarm Information

X X

XX X X X X X

XXXXXXXX

X X

XX X X X X X

XXXXXXXX

X XPlant State

ESDneeded

Operatorinterventionneeded

Minor operatingadjustmentneeded

X = Alarm

EEMUA No.191


20152 alarms/day

Refinery Phenol plant

5274 alarms/day

Unnecessary alarms notified despite safe or efficient operationNecessary alarms not notified despite unsafe or inefficient operation(it’s not general because alarm must be set narrowly for safety reasons)

However, in fact…

Demand to additional alarm management function

5471 alarms/day

PTA plant

An ineffective alarm system

TargetNormalUpsetShutDown

Key Alarm Information

X XXX X X

X

X

XX

XXXX

XX

X

XX

XX

XX

X XX

X

X XX

XX

X

XX X

Plant StateESD

needed

Operatorinterventionneeded

Minor operatingadjustmentneeded

X = Alarm

EEMUA No.191


(1) Masking of unnecessary DCS alarm

Masking of unnecessary HI/LO alarm– Because alarm threshold is unmatched

Masking of longstanding false HI/LO alarm– Because alarm hysteresis parameter is unmatched

Re-activation of longstanding true HI/LO alarm– Because still function of CENTUM is not used

Masking of oscillation HI/LO alarm– Because PID parameters are unmatched

Masking of repeating annunciator message– Because appropriate DCS sequence (delay timer) is not prepared

Masking of unnecessary IOP/IOP- alarm– Because tag range is unmatched (range over)

Fault diagnosis for necessary IOP/IOP- alarm– Because field transmitter is failed– Because wire is come down

1. Detect and suppress unnecessary DCS alarms automatically2. Display the reason of occurrence as countermeasure3. Report a suppressed alarms list


A) Repeating HI/LO alarm (masking logic)

Monitoring period

Note) Mean: PV moving average, Dev: PV standard deviation, SH: Scale HI, SL: Scale LO, A: parameter (default=2)

(1) IF New_PH = Mean - 3 x Dev >= Original_PL + 0.1 x (SH - SL) & |New_PH - Mean| >= |Original_PH - Mean|

THEN New_PH = Mean - 3 x Dev

(2) IF New_PH = Mean - 3 x Dev <= Original_PL + 0.1 x (SH - SL) & |New_PH - Mean| >= |Original_PH - Mean|

THEN New_PH = Mean - A x Dev

SL

SH

Original_PH

Original_PL

Start monitoring

1 2 3

New_PH

Number of occurrence

HI HI HI

Time

PV

Start

masking

Purpose

This logic can mask an unnecessary HI/LO alarm which is slowly oscillating near PH/PL.

Logic

This logic consists of “monitoring” logic, “masking” logic and “recovery” logic. Monitoring logic is started when first HI/LO alarm is occurred, and then monitors the number of occurrence while ordered monitoring period. In case the number reaches an ordered times, masking logic is run.

Masking logic

PH/PL is automatically changed so that new PH/PL is not announced. The reason of suppression is displayed as a countermeasure.

Reason of occurrence: Alarm threshold is unmatched


A) Repeating HI/LO alarm (recovery logic)

Recovery logic

Condition 1:

IF Mean + 3 x Dev < Original_PH or Original_PH < Mean – 3 x Dev

THEN Return to Original_PH

Condition 2:

IF New_PH >= Mean


(In case the maximal value of oscillation is greater than Original_PH, HI alarm will be notified again)

Condition 3:

IF |Original_PH – Mean| >= |New_PH – HYS x (SH – SL) – Mean| (HYS=0.02)


(In case the maximal value of oscillation is greater than Original_PH, HI alarm will be notified again)

SL

SH

Original_PH

Original_PL

New_PH

Time

PV

Mean Mean Mean

|Original_PH - Mean|

|New_PH – Hys x (SH – SL) – Mean|

Hys x (SH-SL)

3 x Dev

3 x Dev

Condition 1 Condition 2 Condition 3

Mean


B) Long standing false alarm

Monitoring period

SL

SH

Original_PH

Start monitoring

New_PH

HYS x (SH - SL)

HI NR

Time

PV

Start

masking

Purpose

This logic can mask unnecessary HI/LO alarm which is lower/higher than PH/PL but still in the band of hysteresis.

Masking logic

In case PV is in the band of hysteresis for monitoring period, PH/PL will be changed to higher/lower vale momently.

3 x Dev

Mean

HYS x (SH - SL)

3 x Dev

2sec

Reason of occurrence: Hysteresis parameter is unmatched

Note) Mean: PV moving average, Dev: PV standard deviation, SH: Scale HI, SL: Scale LO, HYS: parameter (default=0.02)

IF PH/PL is in activation AND

Mean + 3 x Dev < Original_PH & Mean + 3 x Dev > Original_PH – HYS x (PH – PL)

THEN New_PH = Original_PH + HYS x (PH – PL) for 2 seconds


THEN New_PH = Mean - 3 x Dev

Stop

masking


C) Long standing true alarm

Monitoringperiod

IF HI/LO is activated for ordered period & Mean + 3 x Dev >= Original_PH

THEN New_PH/New_PL= SH/SL, 2 seconds later, Return to Original PH/PL

SL

SH

Original_PH

Start

monitoring

New_PH

HI NR

Time

PV

Re-notification

Purpose

This logic re-notifies longstanding true HI/LO alarm.

Re-notification logic

In case true HI/LO alarm is activated for monitoring period, PH/PL is changed momently to SH/SL, so that PH/PL is announced again.

HINR HI

Monitoringperiod

2Sec

Mean3 x Dev

HH

Reason of occurrence: Still function of CS3000 is not used


D) Oscillation alarm

Monitoring period

SL

SH

PL

Start

monitoring

PH

Time

PV

Start

masking

Purpose

This logic masks unnecessary HI/LO alarms by setting AOF in case PV is oscillated due to the mismatch of PID parameters.

Masking Logic

In case HI/LO alarms are notified one after the other for ordered times, Exapilot sets AOF. (Select HH or HI, LO or LL)

Recovery Logic

In case HI/LO alarms are not notified for ordered period, Exapilot sets AON.

(In case PID is not retuned, HI/LO alarms

are continuously masked)

AOF

Monitoring period

1 2

AON AON

Occurrence number

Stop

masking

1 2

LL

HH

HI HI

LO LO

PID is retuned

Reason of occurrence: PID parameter is unmatched


E) Repeating Annunciator message

Monitoring period

Start

monitoring

Purpose

This logic masks an unnecessary annunciator which announced repeatedly.

Masking logic

In case annunciator is announced ordered times in monitoring period, AOF is set to target annunciator (%AN). Then target tag is registered as habitual.

ON

%ANN

OFF

AON

Monitoringperiod

TimeMonitoringperiod

1 2 3

Occurrencenumber

Start

masking

Recovery logic

In case annunciator is not announced for monitoring period, AON is set to target annunciator (%AN).

Masking logic (After learning)

In case registered tag announced annunciator again, AOF is set without waiting.

Reason of occurrence: DCS sequence is not prepared

Stop

masking

AOF


F) Fault diagnosis and suppression of IOP alarm

Monitoring period

SL

SH

Judgment

HI IOPRAW

Purpose

This logic detects true IOP/IOP- alarms which announced due to range over.

Detection Logic

In case IOP/IOP- is happened after HI/HH or LO/LL alarm is notified, and is recovered after ordered period, this logic shows the reason of IOP/IOP- alarm (range over). Also target tag is registered as habitual.

Exclude logic

In case registered tag announces IOP/IOP- alarm again, target tag is excluded from watch list.

HHNR HH

HH

PH

HI

IOP

Start

monitoringMonitoring periodfor IOP detection

Reason of occurrence: Range over (engineering problem)


Startmonitoring

(0%)SL

(100%)SH

IOP IOPRAW

Purpose

This logic masks unimportant IOP/IOP- alarm which announced due to range over.

Masking logic

In case registered tag is in AON, and RAW data of registered tag is greater than SH or smaller than SL for monitoring period, AOF is set.

Recovery logic

RAW is returned between SL and SH, AON is set.

Normal Range

IOP-

IOP

Normal Range

Normal Range

Time

AON

Stopmonitoring

Startmasking

Stopmasking

AOF


SL

IOP

Judgment 5Sec

IOPRAWPurpose

This logic detects true IOP/IOP- alarm which notified due to the failure of field transmitter.

Detection logic

In case IOP/IOP- is happened even though HI/HH or LO/LL alarm is not notified, or IOP/IOP- is happened immediately (within 5 seconds) after HI/HH or LO/LL alarm is notified, this logic shows the reason of IOP/IOP- alarm (failure of field transmitter). Also target tag is registered as habitual.

Masking logic

In case registered tag announces IOP/IOP- alarm again, AOF is set continuously.

NRNR NR

HH

PH

IOP

JudgmentStart

monitoringStart

monitoring

SH

Monitoringperiod

Monitoring period

HI

AON

Reason of occurrence: Failure of field transmitter

AOF

HH


SL

SH

Judgment

IOPRAWPurpose

This logic announces the reason of true IOP/IOP- (breaking of wire) alarms.

Detection Logic

In case IOP/IOP- is notified even though HI/HH or LO/LL alarms are not notified, and IOP/IOP- is not recovered for ordered period, this logic shows the reason of alarm notification.

NR

LL

PL

IOP-

Monitoring periodStart

monitoring

Reason of occurrence: Breaking of wire


(2) Dynamic alarm setting

Alarm threshold (PH/PL) should be changed dynamically according to the drastic changes of set point (e.g. load change, grade change)

Exapilot Excel Link icon (option) reads optimum alarm threshold (PH/PL) to FCS automatically when SV is drastically changed

Exapilot Correlation Diagnosis icon (Advanced Alarm option) can monitor the correlation between elapsed time and process variable (PV) online

Start up Grade A Grade B

GradeChange

Shut down

PH=100

PL=80PH=SV + 5

PL=SV - 10

PH=SV + 10

PL=SV - 12

PH=200

PL=180 PH=SV + 4

PL=SV – 6

PH=SV + 4

PL=SV - 2 TIME

PV


Case Branch icon

In case ofGrade A

Repetition

Out put toDCS icon

A B C D E

GRADE A Grade A Grade B Grade C Grade D


For the transient condition

Correlation diagnosis icon


(3) Addition of pre-alert

SL

SH

PL

Start

monitoring

PH

Time

PV

Start

monitoring

Purpose

This logic announces pre-process alert in case;

-PH/PL is announced

-PV is increasing/decreasing

-PV will reach HH/LL within ordered period (e.g. within 5 minutes)

HH LO

LL

HH

NR HI NR LL

NotifyHH pre-alert

NotifyLL pre- alert

Period of

notification

Period of

notification

Pre-alert function predicts an indication of HH/LL alarm before HH/LL is announced, and displays alert message to operators to prevent ESD.


(4) Replacement to advanced alarm

Various kinds of diagnosis templates (Standard/Option)– Fault diagnosis

• Field transmitter (e.g. Failure, Breaking of wire)• Control valve (e.g. Sticking, Leakage, Clogging of strainer)• Pump (e.g. Trip)• Pipe (e.g. Clogging, Leakage)• Storage tank (e.g. Leakage)

– Overload monitor• Pump• Compressor• Turbine• Centrifuge• Blower• Agitator

– Operation efficiency monitor• Heat exchanger (e.g. Energy effectiveness)• Distillation tower (e.g. tray performance, Temp. distribution)• Reactor

– Quality monitorDetect an early sign of abnormality faster than it’s detected by DCS alarmsNotify the reason of alarm and adequate countermeasure to operatorsSend e-mail to relevant peopleExecute countermeasure automatically if necessary


Standard logic templates

Monitoring Failure of Field Instrumentation– Detect Invariant Indicated Value (A01)– Detect Continuously Increasing Indicated Value (A02)– Detect Continuously Decreasing Indicated Value (A03)– Detect Deviation Alarm between 2-instruments (A04)– Detect Deviation Alarm between 3-instruments (A05)

Monitoring Process Abnormalities– Detect Hunting S Type (Standard deviation type) (B01)– Detect Hunting DS Type (Deviation of standard deviation) (B02)– Detect Deviation Alarm between Theoretical Value and Raw Value (B03)

Preventing Miss-operation– Detect Neglected Alarm (C01)– Detect Neglected MODE (C02)– Detect Neglected CAL (C03)

Monitoring Failure/Overload of Field Equipments– Monitoring Control Valve (EXA01)– Monitoring Pressure Gauge (EXA02)– Monitoring Reciprocating Compressor Abnormalities (EXA03)– Monitoring Clogging in Process Units (EXA04)

Monitoring Process Abnormalities– Monitoring Reactor Temperature Distribution (EXB01)– Monitoring Heat Balance Abnormality in the Furnace (EXB02)


Application examples

This logic detects the abnormality of cylinder valve in reciprocating compressor by comparing the difference between estimated outlet temperature and measured outlet temperature.In case cylinder valve is broken or quantity of cooling water is insufficient, the outlet temperature will be risen due to back flow inside of cylinder.

Example1: Reciprocating compressor diagnosis

Example2: Correlation diagnosis

Correlation diagnosis icon

T TTI101.PV TI102.PV


Exapilot can define pre-alert which can detect early sign of process abnormality before it is detected by process HI/LO alarms.

Example3: Reactor temperature distribution diagnosis

TI102.PH

TI102.PV1 hour

5 degrees


P

P

PI101.PV

PI103.PV

PPI102.PV

Low pressure steam

(-0.1 MPa <= PI101.PV-P102.PV <= 0.1 MPa)

(-0.1 MPa <= PI101.PV-P103.PV <= 0.1 MPa)

Guidance message

Example4: Pressure indicator diagnosis This logic detects the abnormality of pressure indicator by checking the difference of three pressures.

Furnace

FI103.PV

FI101.PV

FI102.PV

TI100.PV

TI200.PVLowMaterial A

LowMaterial B

FuelGas

XI103.PV

Example5: Furnace incomplete combustion diagnosis

This logic detects early sign of incomplete combustion in furnace unit before DCS HI alarm detects it, by monitoring the difference between “Fuel gas calorie” calculated using fuel gas flow & gravity and “Furnace duty” calculated using flow & temperature of furnace unit.


(5) Prevention of miss-operation

Incorrect action must be detected ASAP to prevent serious troubleExapilot Advanced Alarm can detect various kinds of miss-operation by monitoring operator’s behavior

Example: Miss of tag mode change

IF FIC100.MODE is changed to “MAN” 3 minutes lapsed FIC100.MODE is still in “MAN”THENExapilot changes tag mode to “AUT”


3.4 Operator training system


Training system

Use Exapilot and CS 3000 test function (WDA)No need to modify existing DCS applicationLow cost systemSimple process model can be made in Exapilot– Dead time– Time lag– Material balance, etc.

General training using HIS windowsTraining for transition operation using Exapilot window


Simulate the material balancebetween valve positionand tank level

Simulate the material balancebetween valve positionand tank level

FIC

FIC

Level

TICFieldcontroller

Hot water

CENTUM CS 3000 Test function

Simulate a fieldtemp. controllerSimulate a fieldtemp. controller

Temp

ExapilotRead PV/MV/SVWrite RAWRead PV/MV/SVWrite RAW

Dead timeTime lagDead timeTime lag

Exapilot application for process simulation

Exapilot application for automation of transition operation

Read PV/MV/SV/PH/PL/ALRMWrite SV/MV/PH/PLRead PV/MV/SV/PH/PL/ALRMWrite SV/MV/PH/PL

pm36j6b10-01e_25 yokogawa electric corporation 2-9-32 nakacho, musashino-shi tokyo, 180-8750 japan...

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