Operability TroubleShooting

8/20/2019 Operability TroubleShooting

1/72

TROUBLE SHOOTING IN THE PROCESS

INDUSTRIES

A “bread and butter” skill !r all "#e$i"al en%ineers&

Uses s'ste$ati" TS

$et#!d and builds

te"#ni"al kn!(led%e

t#r!u%# e)*erien"e+

N! s'ste$ati" $et#!d+ N!

(a' t! !"us te"#ni"al

kn!(led%e+


2/72

v1

Hot Oil

v2

v3

L1

v7

v5 v6

Hot Oil

F1 T1 T3

T2

F2

T4

T5

F3 T6

T8

F4

L2

v8

T7

P1

F5

F6T9

v4

T#e 'ield ! ,aluable *r!du"t #as de"reased b' -./

!,er t#e last (eek+ 0i) t#e *r!ble$&

D! (e "all t#is an !**!rtunit'1 a "#allen%e

!r a "risis2


3/72

v1

Hot Oil

v2

v3

L1

v7

v5 v6

Hot Oil

F1 T1 T3

T2

F2

T4

T5

F3 T6

T8

F4

L2

v8

T7

P1

F5

F6T9

v4

T#e 'ield ! ,aluable *r!du"t #as de"reased b' -./

!,er t#e last (eek+ 0i) t#e *r!ble$&

Let3s %uess

4!u $ean t#at t#e rea"t!r

isn3t (ell $i)ed2

5#at "!uld %! (r!n%

(it# a *u$*2

5e need a s'ste$ati" (a'

t! tr!uble s#!!t2


4/72

PROCESS TROUBLESHOOTING

5#at d! (e (ant t! learn2

Attitude 6 5e (ant t! distin%uis# n!r$al ,ariati!n

r!$ a se,ere ault and ind t#e r!!t "ause ! a ault.

Skill6 5e "an

a**l' a

s'ste$ati"

Tr!uble S#!!tin%

7et#!d

8n!(led%e6 5e

understand *r!"ess

*rin"i*les ande9ui*$ent


5/72

5#at is Tr!uble S#!!tin%2

• A**li"ati!n ! Pr!ble$ S!l,in% $et#!ds t! t#e dia%n!sisand i$*r!,e$ent ater de,iati!ns !""ur in a s'ste$+

5e d! t#is in !ur e,er':da' li,es all t#e ti$e

5#' d!esn3t t#e *rint!ut l!!k like t#e s"reen

dis*la'2 5e !nl' #a,e ;. $inutes t! #and

in !ur


6/72

PROCESS TROUBLESHOOTING :

A 5ORTH5HILE EDUCATIONAL TOPIC

Can (e tea"# Tr!uble S#!!tin%2

• Pe!*le i$*r!,e (it# e)*erien"e and edu"ati!n

• Students beneit r!$ a s'ste$ati" $et#!d and

earl' e)*erien"e

• TS $!ti,ates and %uides learnin% ! *r!"ess

*rin"i*les and desi%ns t#at "an be easil' $!nit!red

• TS %i,es ne( insi%#ts !r lie:l!n% skill i$*r!,e$ent


7/72


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

S8ILLS

Tail!r (ell kn!(n Pr!ble$

S!l,in% 7et#!d

-+ Build !n *ri!r PS e)*erien"es

=+ Gi,e '!u a *r!"edure t! ada*t t!

$an' situati!ns

;+ C!nsistent (it# $et#!ds used in

en%ineerin% *ra"ti"e

For more detail, see Woods, D., Successful Trouble Shooting for Process

Engineers, Wiley VCH, Weinheim, 2006.


8/72

Ste* - : En%a%eSte* = : Deine

Ste* ; : E)*l!re

Ste* < : Dia%n!sis

Ste* > : I$*le$ent

Ste* ? : L!!kba"k

TROUBLE SHOOTING APPLIES THE

SI@:STEP PROBLE7 SOLING 7ETHODIt3s a "ir"le1 n!t a linear

$et#!d

1

2

34

5

6

5e l!!k ba"k ater ea"# ste*+ Are t#e results ! *re,i!us ste*s uture

state1 *r!"ess understandin%1+ still a**r!*riate2


9/72

TROUBLE SHOOTING APPLIES THE

SI@:STEP PROBLE7 SOLING 7ETHOD

Ste* - : En%a%eSte* = : Deine

Ste* ; : E)*l!re

Ste* < : Dia%n!sis

Ste* > : I$*le$ent

Ste* ? : L!!kba"k

It3s "ir"ular1 n!t linear

1

2

34

5

6

1

2

34

5

6

I ste* is "!$*le)1 "an a**l' all si) ste*s inside !ne $a!r ste*


10/72

Tr!uble S#!!tin% 5!rks#eet

-+ En%a%e

=+ DeineCurrent, desired,deiation

Desired !inal state" #$%&'#

'he (ro)lem *#+*# -'

;+ E)*l!re

a. Fundamentals

). &eleant Chanes

/. (erien/e !a/tors

d. Data /onsisten/y

e. ounds on )ehaior


11/72


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

C!urse Tr!uble:s#!!tin%

5e (ill intr!du"e t#e $et#!d al!n%

(it# %!!d and *!!r a"ti!ns (#ile

s!l,in% a *r!"ess e)a$*le+

T#en1 (e (ill s!l,e a "!u*le $!re

e)a$*les durin% a (!rks#!*+ T#ese

(ill be !n t#e t(!:t!(er distillati!n

*r!"ess+

Naturall'1 (e (ill #a,e a s#!rt eedba"k

sessi!n t! "#e"k !ur learnin% (e als!

"all a eedba"k sessi!n a 9ui+


12/72

CLASS E@A7PLE6 Let3s dis"uss t#is *r!"ess (it#

*re#eat1 *a"ked bed rea"ti!n1 and eluent "!!lin%

Feed tank

FC

1

P3

V 3 0 0

TC

3

T4

Fuel

oil

F

2T7

Produt

tank

C!"!

F

7

#ir

$ntake

FC

5

L-

L=

P-

P;

T>

T?

0C-

0=

TC-


13/72

CLASS E@A7PLE6 0ired Heater S"enari!

9ou are :or;in at your !irst t loo; usual to you, and she )eliees that it is

/aused )y im(ro(er )ehaior o! the sta/; dam(er.

Fortunately, you learned trou)le?shootin s;ills in uniersity. o:, you /an

/om)ine your s;ills :ith the o(erator>s insihts to sole the (ro)lem.


14/72

Feed tank

FC

1

P3

V 3

0 0

TC

3

T4

Fuel

oil

F

2T7

Produt

tank

C!"!

F

7

#ir

$ntake

FC

5

L-

L=

P-

P;

T>

T?

'ime →

'em(

'C1

Fuel !lo:

F2

Feed rate

FC1

CLASS E@A7PLE6 Tr!uble S#!!tin%

T#e !*erat!r d!es n!t like t#ese trends


15/72

Deal (it# e$!ti!ns

7ana%e stress

0irst e( ti$es (e (!n3t a"#ie,e *ere"ti!n


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate


16/72

'ime →

'em(

'C?1

Fuel !lo:F2

Feed rate

FC1

CLASS

E@A7PLE

T#is is t#e *l!t !sele"ted data t#at

is "!n"ernin% t#e

!*erat!r+


ui"k1 (#at is t#e *r!ble$2


17/72

'ime→

'em(

'C1

Fuel !lo:

F2

Feed rate

FC1

Feedtank

FC

1

P3

V

3

0

0

TC

3

T4

Fuel

oil

F

2T7

Produt

tank

C!"!

F

7

#ir

$ntake

FC

5

T#e *u$* is

"a,itatin%

T#e rea"t!r

is leakin% T#e "!ntr!l

s'ste$ is unstable

Aliens #a,e

landed&

D!n3t %uess&

ENGAGE


18/72

S!$e initialattitudes t#at are

n!t #el*ul+

• 5#at1 (#' #a,en3t '!u d!ne

s!$et#in%2

• I d!n3t understand1 but I better

d! s!$et#in% ast+

• O# dear1 run&&

• JI #!*e n! !ne kn!(s t#at I

d!n3t kn!( t#e ans(er+ I #a,e

n! "!niden"eK


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate


19/72

S!$e initial attitudes

t#at are #el*ul+

• Listen and read "areull'+ D!

n!t e)*e"t t#e ans(er t! be!b,i!us+

• 5!rk (it# !t#ers in s!l,in% t#e

*r!ble$+

• Use t#e standard TS $et#!d&

• A**l' *r!"ess *rin"i*les+


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

I (ant t!1

and I "an&&


20/72


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

TS IS GOAL:DIRECTED

Dra( a sket"# and n!te ke' ,ariables+

5#at s#!uld be is a"tuall' #a**enin%2

T#ere!re1 t#e de,iati!n is6 ))))))))

Current

stateUn*r!itable

and *er#a*s1

unsae

0inal

stateEi"ient1

$a' take

ti$e

Initial

stateSae and

a"#ie,ed

9ui"kl'

Safety, major equipment damage and large $ loss takeprecedence.


21/72


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

Current

stateUn*r!itable

and *er#a*s1

unsae

0inal

stateEi"ient1

$a' take

ti$e

Initial

stateSae and

a"#ie,ed

9ui"kl'

DE0INE STATES6 S7ARTS:M

• S*e"ii" and 7easurable

• Attainable• R eliable• Ti$el' "an be a"#ie,ed in t#e a**r!*riate ti$e• Sael'

• M C!st:Ee"ti,e


22/72

'ime →

-utlet 'em(

Fuel !lo: rate

Feed rate

CLASS E@A7PLE

S#!uld be6

A"tuall'6

Initial state6

0inal State6

Feed tank

FC

1

P3

V 3 0 0

TC

3

T4

Fuel

oil

F

2T7

Produt

tank

C!"!

F

7

#ir

$ntake

FC

5

Let3s "!$*lete t#e

deiniti!n+


23/72

'ime →

-utlet 'em(

Fuel !lo: rate

Feed rate

S#!uld be6 "!ntr!llin% te$*erature

A"tuall'6 te$*erature is allin% ast1 but uel

is in"reasin%2

Initial state6 a"#ie,e sae !*erati!n ast&

0inal State6 Pr!du"e desired a$!unt !

*r!du"t

F e e d t a n k

F C

1

P 3

V

3

0

0

T C

3

T 4

F u e l

o i l

F

2T 7

P r o d u t

t a n k

C ! " !

F

7

# i r

$ n t a k e

F C

5

DE0INE


24/72


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

Ri"# understandin%

• 0unda$entals

• C#e"k in!r$ati!n and data&&&

• Rele,ant "#an%es

• Startu*

• Trends

• ui"k b!unds


25/72

• 0unda$entals: 7FE Balan"es1 Se"!nd La(1 St!i"#i!$etr'

: 5#at ae"ts t#e ke' ,ariables2

: C!uld “n!r$al” *lant ,ariati!n "ause t#is

be#a,i!r2

: Causalit'1 (#at "a$e irst2 5#at (as "ause2

CLASS E@A7PLE

-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate


Let3s deter$ine rele,ant

"ausal relati!ns#i*s+


26/72

22

5#at !t#er "auses

inluen"e t#e ee"t2

-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate


Ti$e

CAUSE E00ECT

0eed

l!(

0eedte$*era:

ture

Heater !utlet te$*erature

↓ 2

5#i"# dire"ti!n (!uld "ause t#e ee"t2


27/72

-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate



: Is t#e te$*erature a"tuall' de"reasin%2: Is uel a"tuall' in"reasin%2

: 5#at *rin"i*les "an be used t! "#e"k data2

• 0unda$ental Balan"es

• Du*li"ate sens!rs !n t#e sa$e ,ariable

• C!nsisten"' in rate *r!"esses

: *ressure and l!(

: te$*eratures in #eat transer

• C!nsisten"' in e9uilibriu$ *r!"ess: te$*erature and *ressure in e9uilibriu$ *r!"ess

• Trends ! related ,ariables

: te$*erature and "!$*!siti!ns in rea"t!r


28/72

-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate





CLASS E@A7PLE

H!( "an (e ,eri' t#e data and in!r$ati!n

in t#e !ri%inal *r!ble$ state$ent2


29/72

-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate





-+ Te$*erature sens!rs !r "!nsisten"'1 es*e"iall'

TC:- and T


30/72

• Rele,ant "#an%es $aintenan"e1 et"+

5e s#!uld "!nsider t#e ti$e se9uen"e in tr!uble

s#!!tin% #!(e,er1 a ti$e se9uen"e d!es n!t *r!,e

"ause:ee"t+

• Startu* e9ui*$ent irst *la"ed in ser,i"e

5e $ust "!nsider a (ider ran%e ! r!!t "auses

(#en e9ui*$ent is bein% started u*+

• Trends:5#at is dire"ti!n and rate ! "#an%e ! ,ariables2

-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate


Let3s e)*l!re t#ese issues in t#e

"lass e)a$*le+


31/72

CLASS E@ERCISE

• Rele,ant "#an%es

a+ Calibrated T and an instru$ent in an!t#er *lant

b+ C#an%ed eed tank re9uired !*enin%"l!sin% bl!"k

,al,es

• Startu* : n!t a**li"able

• Trends

a+ 0!r a l!n% ti$e1 t#e TC:- see$ed t! un"ti!n1

#!ldin% T near its set *!int

b+ T#e eed l!( is in"reasin%+

"+ er' re"entl'1 TC:- is de"reasin% ra*idl'

d+ er' re"entl'1 0= is in"reasin% ra*idl'

-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate



32/72

• 5#at is kn!(n and (#at is !*ini!n2

5e $ust "!nsider t#e state$ents ! !t#ers+ 5e

s#!uld seek ,alidati!n !r t#e state$ents+

• Use %uidelines and e)*erien"e a"t!rs

5e (ill build t#ese t#r!u%#!ut !ur "areers+

: H!( d!es data "!$*are (it# t'*i"al ran%e2

: Is t#at a t'*i"al *u$* !utlet *ressure2

: 5#at is a t'*i"al a**r!a"# te$*erature2: 5#at #a,e (e learned r!$ *ri!r aults2

-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate


Let3s "!$*lete buildin% !ur understandin%

! t#e "lass e)a$*le (it# t#ese issue+


33/72

CLASS E@ERCISE

• 5#at is kn!(n and (#at is !*ini!n28n!(n

Data *l!tted

0eed tank "#an%ed 5as it2 5as it d!ne "!rre"tl'2

T "alibrated

O*ini!ns

An unusual s$ell is *resent

T#e "ause is t#e sta"k da$*er

• Use %uidelines and e)*erien"e a"t!rsa+ Are t#e ,alues ! t#e *r!"ess ,ariables t'*i"al2

b+ H!( l!n% d!es t#e TC:- ,ar' be!re it “settles

d!(n” ater a l!( "#an%e

"+ 5#at is a t'*i"al disturban"e t! TC:-2

-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate



34/72


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

“T#e s!luti!n t! a *r!"ess *r!ble$ isn3t

!und b' sittin% be#ind '!ur desk1 but b'

%!in% t! t#e *lant and "arr'in% !ut tests

and e,aluatin% t#e data+”

b' Laird1 et al1 C#e$+ En%r+ Pr!%ress1 =...

5e #a,e t! anal'e t#e initial data and

!r$ulate (!rkin% #'*!t#eses+ T#ese#'*!t#eses %i,e us a basis !r

in,esti%ati!ns6 t#e' !"us !ur

in,esti%ati!ns+


35/72


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

INITIAL EIDENCE

Su((ort, Dis(roe,

Neutral

DIAGNOSTIC ACTIONS

Su((ort, Dis(roe, NeutralOR8ING H4POTHESES

a ) / d e % C D

Brainst!r$ "auses Su**!rtNeutraldis*r!,e

C!nsider ti$e1 "!st1 and se9uen"e+

Ne(1 dia%n!sti"

a"ti!ns


36/72


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

STEPS IN “PLAN”

A+ Brainst!r$ *!ssible r!!t "auses t#at $i%#t

e)*lain t#e initial e,iden"e

B+ Careull' "!$*are t#e "andidate #'*!t#eses

(it# t#e initial data and dis*r!,e

#'*!t#eses1 i *!ssible+

C+ De,el!* a list ! dia%n!sti" a"ti!ns t#at (ill

#a,e dierent !ut"!$es !r ea"# re$ainin%(!rkin% #'*!t#esis+

D+ Order t#e dia%n!sti" a"ti!ns a""!rdin% t!

!ll!(in%6 - #i%# i$*a"t !r redu"in%

#aards1 = l!( "!st and ; s#!rt ti$e+


37/72


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

GENERATING THE CANDIDATE ROOT

CAUSES

C#allen%e t#e"!n,enti!nal (isd!$

@@@@ ust "!uld n!t#a**en+

• D! n!t be"!nr!ntati!nal

• based !n *rin"i*les

• *r!*!se dia%n!sti"

a"ti!n

• Bl!"ked *i*e• 0alse $easure$ent

• C#an%e in e9ui*$ent

*er!r$an"e

• C#an%e is "!n,ersi!n


38/72


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

INITIAL EIDENCE

Su((ort, Dis(roe,

Neutral

DIAGNOSTIC ACTIONS


a ) / d e % C D



Ne(1 dia%n!sti"

a"ti!ns

H!( d! (e kn!( t#e entries6 #'*!t#eses1 initial e,iden"e

and dia%n!sti" a"ti!ns2

T#e' are based !n t#e understandin% de,el!*ed

durin% t#e “E)*l!re” ste*1 (#i"# is "ru"ial

!r %!!d tr!uble s#!!tin%+


39/72


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

INITIAL EIDENCE

Su((ort, Dis(roe,

Neutral

DIAGNOSTIC ACTIONS


a ) / d e % C D



Ne(1 dia%n!sti"

a"ti!ns

CLASS E@A7PLE

• De,el!* a set ! (!rkin% #'*!t#eses!r t#e ired #eater *r!ble$+

• E,aluate ea"# usin% t#e initial e,iden"e


40/72


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

LIST O0 T4PICAL 5OR8ING H4POTHESESn!t ne"essaril' "!$*lete

• TC:- "!ntr!l l!!* is unstable

• Pa"ked bed rea"t!r is *lu%%ed

• TC:- sens!r is ault' readin% l!(er t#at a"tual T

• 0uel ,al,e ;.. is ault'

• 0eed tank is runnin% dr'1 "ausin% ,!rte)

• Sta"k da$*er is t!! ar "l!sed

• 0eed l!( rate is t!! #i%#

Are t#ese r!!t

"auses2


41/72


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

Use "urrent in!r$ati!n t! dierentiate

a$!n% "andidates

D!es initial e,iden"e su**!rt1 is it neutral1

!r d!es it dis*r!,e2

Re$e$ber t#at initial e,iden"e is sube"t t!

err!rs1 !r e)a$*le1 a sens!r "!uld be ault'

!r an !*ini!n "!uld be (r!n%+

T#is t#!u%#t *r!"ess (ill #el* t! ideni'

dia%n!sti" a"ti!ns t! "!$*lete tr!uble

s#!!tin%+


42/72


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

Dia%n!sti" A"ti!ns t! dierentiate a$!n%

re$ainin% "andidates

G!!d a**r!a"#es

: S*e"ii" and desi%ned t! test #'*!t#esis: C!nir$ data F in!r$ati!n

: C!$*are (it# re"entt'*i"al data

: D! s$all e)*eri$ents

• ariables "an be $easured• Seek "!nir$in% in!r$ati!n• Retrie,e useul #ist!ri"al data• Anal'e "ause:ee"ts


43/72


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

Dia%n!sti" A"ti!ns

P!!r A"ti!ns

: “C#e"k t#e ,al,e”: “5#at is t#e #eat transer "!ei"ient2”

: “5#at is t#e uel te$*erature2”

: “S#utd!(n *lant and !*en rea"t!r”

T#ese a"ti!ns9uesti!ns are t!! ,a%ue !r "ann!t

be d!ne+ H!( (!uld '!u *er!r$ t#e a"ti!n

and *r!,ide t#e results t! an en%ineer2


44/72

Feed tank

FC

1

P3

V 3 0 0

TC

3

T4

Fuel

oil

F

2T7

Produt

tank

C!"!

F

7

#ir

$ntake

FC

5

L-

L=

P-

P;

T>

T?

Hypothesis Initial information Diagnostic ActionTC sens!r drit

0uel ,al,e is stu"k !*en

0eed rate "ausin% T de"rease

TC t!! sl!(

Let3s "!$*lete t#e table !r t#ese

#'*!t#eses


45/72

Hypothesis Initial information Diagnostic ActionT sens!r drit Neutral C#e"k (it# te$*erature at

e)it ! rea"t!r

0uel ,al,e is stu"k !*en Dis*r!,e

Te$*erature (!uldin"rease

Pla"e l!( "!ntr!ller in

$anual and $ake s$all"#an%e t! "!ntr!ller !ut*ut

0eed rate "ausin% T de"rease

TC t!! sl!(

Dis*r!,e

*re,i!us "#an%es (ere

"!ntr!lled

Feed tank

FC

1

P3

V 3 0 0

TC

3

T4

Fuel

oil

F

2T7

Produt

tank

C!"!

F

7

#ir

$ntake

FC

5

L-

L=

P-

P;

T>

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46/72


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

INITIAL EIDENCE

Su((ort, Dis(roe,

Neutral

DIAGNOSTIC ACTIONS


a ) / d e % C D



Ne(1 dia%n!sti"

a"ti!nsCLASS E@A7PLE

• De,el!* a set ! dia%n!sti" a"ti!ns+

• C!ntinue until t#e r!!t "ause #as been identiied+


47/72


5!rkin% #'*!t#esis Initial data SND

'C?1 unsta)le , transient /ould )e start o! lare

os/illation

8a/;ed )ed (lued D, !lo: a((ears normal in F1 and F@'C?1 sensor lo: , a/tual tem(erature /ould )e hih

Vale 300 !aulty D, the !uel !lo: is in/reasin

Feed tan; lo: D, the !eed !lo: is normal

#ta/; dam(er /losed #, /ould a!!e/t the /om)ustion

Feed !lo: rate too hih

'his is not a root /ause. 7et>s assume that

the (ro(osed root /ause is not enouh !uel

, !uel ale not !ully o(ened

EALUATE THE 5OR8ING H4POTHESES

S = Support, N = Neutral, D = Disprove


48/72


EALUATE THE 5OR8ING H4POTHESES

5!rkin% #'*!t#esis Dia%n!sti" data SND

'C?1 unsta)le 8la/e /ontroller 'C?1 in maual andin/rease /ontroller out(ut slo:ly

8a/;ed )ed (lued +%'C?1 sensor lo: Com(are the tem(eratures !rom '4 and '@

Vale 300 !aulty +%

Feed tan; lo: +a

#ta/; dam(er /losed *n/rease the dam(er o(enin

Feed !lo: rate too hih

'his is not a root /ause. 7et>s assume thatthe (ro(osed root /ause is not enouh !uel

+%

S = Support, N = Neutral, D = Disprove


49/72

PARETO PLOT

Esti$ate t#e beneit r!$ ea"# "!rre"ti,e a"ti!n1 and

i$*le$ent t#!se ustiied.

ene!it

Corre/tie a/tion


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

D! it&

7an' a"ti!ns $a' be *!ssible+ 5e sele"t

t#!se ustiied b' beneits+

A Paret! *l!t *r!,ides a ,isual dis*la' !

relati,e beneits+


50/72


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

INITIAL EIDENCE

Su((ort, Dis(roe,

Neutral

DIAGNOSTIC ACTIONS


a ) / d e % C D



Ne(1 dia%n!sti"

a"ti!ns

5e (ill "!ntinue dia%n!sti" a"ti!ns until !nl'

!ne #'*!t#esis re$ains t#at #as n!t been

dis*r!,ed+ At t#at *!int1 (e (ill %enerall'

"!n"lude t#at t#e re$ainin% #'*!t#esis is true+

5e (ill "all it t#e “r!!t "ause”+

N!te t#at (e #a,e n!t *r!,ed t#e #'*!t#esis

(e #a,e n!t dis*r!,ed it+


51/72


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

D! it&

A"#ie,e t#e

Initial state 9ui"kl'

: Return t! sae !*erati!n

: A""e*table *r!du"t 9ualit'

: Pr!te"t *r!"ess e9ui*$ent

0inal state reliabl': Ei"ient*r!itable !*erati!n

: Desired *r!du"ti!n rate1 i easible

: A"#ie,ed (it#!ut undue $!nit!rin%


52/72


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

P!ssible s!luti!n s"!res

7usts 1 AA 4

1. #a!ety 4 9

2. $eet (rodu/tion /ontra/ts 9 9

5ants :eiht1. DCF B 15 10

2. nery E 2 =+; 5 @

'otal :eihted s/ore 115

5e t'*i"all' (ill NOT "!$*lete Paret!

"#arts !r 7ust5ant tables (#en s!l,in%a *lant *r!ble$+

But1 (e need t! use t#ese $et#!ds (it#!ut

!r$al d!"u$entati!n&


53/72

Let3s *re*are t#e ste*s!r a"#ie,in% t#e

desired states+

-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

CLASS E@A7PLE

Feed tank

FC

1

P3

V 3 0 0

TC

3

T4

Fuel

oil

F

2T7

Produt

tank

C!"!

F

7

#ir

$ntake

FC

5

L-

L=

P-

P;

T>

T?

T>


54/72

R!!t "ause

• In"rease eed⇒

l!(er T

• L!(er T⇒

"!ntr!ller in"reases uel

• De"reased airuel air"!nstant

• Insui"ient air⇒

l!(er T

8e' C!n"e*t

T#e *r!"ess %ain in

t#e eedba"k l!!*

"#an%ed si%n&

Feed tank

FC

1

P3

V 3 0 0

TC

3

T4

Fuel

oil

F

2

T7

Produt

tank

C!"!

F

7

#ir

$ntake

FC

5

L-

L=

P-

P;

T>

T?


55/72

PROCESS TROUBLESHOOTINGPROCESS TROUBLESHOOTING

-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

A"#ie,e t#e irst desired state ra*idl'&

• Pla"e TC:- in $anual1 st!* t#e in"rease ! uel t!

#eater

• Cl!se uel ,al,e ,;.. until T:- starts t! in"rease

N!te6 D! n!t in"rease t#e air t! t#e uel ri"#

#eater en,ir!n$ent&

• Ensure t#at !)'%en is in e)"ess in lue %as n!s$!ke1 ,ie( la$e1 sa$*le lue %as t! lab

• Pla"e TC:- in aut!

• C!ntinue t! in"rease eed1 but in"rease air l!(

be!re eed& 7!nit!r sta"k %as+


56/72

PROCESS TROUBLESHOOTINGPROCESS TROUBLESHOOTING

-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

A"#ie,e t#e inal desired state+

• Install !n:strea$ lue %as anal'er

• Set desired e)"ess !)'%en b' e)*erien"e t! be -+>:

=/• Pr!,ide l!( !)'%en alar$ t'*i"al ,alue ! -/

• Train !*erat!rs t! adust air l!( t! a"#ie,e

desired e)"ess !)'%en

• Aut!$ate t#e "!ntr!l ! !)'%en b' adustin% t#eair l!( rate+ T#is (!uld be a "as"ade "!ntr!l

desi%n+

OC SS O S OO G


57/72


-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

Create a “L!!kba"k”

• Did (e s!l,e t#e R!!t Cause2

• Did (e %enerate $!re "!nir$in%

in!r$ati!n2• H!( "an (e *re,ent in t#e uture

: trainin%

: $!nit!rin% *r!%ra$s

: $!dii"ati!ns t! "urrent *lant e9ui*$ent F!r

*r!"edures: desi%n %uidelines !r uture *lants

• En#an"e !ur *ers!nal e)*erien"e a"t!rs

•C#e"k et#i"s and le%al !ne $!re ti$e


58/72

Let3s *re*are a l!!k

ba"k (it# ste*s t!

*re,ent uture in"idents

-+ En%a%e

=+ Deine

;+ E)*l!re

+ I$*le$ent

?+ E,aluate

CLASS E@A7PLE

Feed tank

FC

1

P3

V 3 0 0

TC

3

T4

Fuel

oil

F

2T7

Produt

tank

C!"!

F

7

#ir

$ntake

FC

5

L-

L=

P-

P;

T>

T?



59/72


SO7E T4PICAL STRATEGIES THAT DO NOT 5OR8

-+ I '!u d!n3t understand1 %uess+

=+ C!nuse s'$*t!$s (it# r!!t "ause+

;+ Get tunnel ,isi!n+


60/72

T r ! u b l e s # ! ! t i n %

Attitude C#e"k

I #ate tr!uble s#!!tin%+

T#e !r$s are t!! l!n%1

I d!n3t kn!( en!u%#ab!ut e9ui*$ent1 and

I d!n3t like t#e *ressure+4ea#1 'ea#1 I kn!(

t#at I3ll #a,e t!

tr!uble s#!!t+

I3ll (ait until it

reall' $atters+• N! $e$!riati!n1 '!u (ill #a,e

t#e !r$

• G!!d1 “*r!ble$:based” (a' t!

learn ab!ut e9ui*$ent

•Pressure1 tr' (#en MM $atters&

• 5#en it $atters1 (e #a,e t!

*r!du"e i$$ediatel'+




61/72


8e' additi!nal less!n6 5e $ust build *lants t#at "an be

$!nit!red and dia%n!sed& T#is re9uires $an' e)tra sens!rsl!"al and re$!te1 sa$*le *!ints !r lab!rat!r'1 and

s!$eti$es1 ,isual !bser,ati!n %lass *!rts+

5#at (!uld '!u

add t! t#is desi%n

t! i$*r!,e

tr!ubles#!!tin%2

Feed tank

FC

1

P3

V 3 0 0

TC

3

T4

Fuel

oil

F

2T7

Produt

tank

C!"!

F

7

#ir

$ntake

FC

5

L-

L=

P-

P;

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62/72

0urt#er Ste*s t! Reine Tr!uble S#!!tin% Skills

• Re,ie( atta"#ed table (it# enri"#in% and detra"tin%

be#a,i!rs !r a tr!uble s#!!ter• Ski$ reeren"es !n t#e ne)t slide and l!"ate #ints $!st

#el*ul t! '!u

• Per!r$ t#e (!rks#!*s in"luded in t#is less!n

• Pra"ti"e t#e tr!uble s#!!tin% $et#!d !n *r!ble$s '!u

en"!unter in '!u studies lab!rat!r'1 inde*endent

resear"#1 !*erabilit' *r!e"t in t#is "!urse1 et"+



63/72

Reeren"es !r Tr!uble S#!!tin%

'he !ollo:in three resour/es (roide e/ellent a((roa/hes and use!ul re!eren/es !or !urther

study.

Foler, H. #/ott and #tee 7elan/, Strategies for Creative Problem Solving , 8renti/e Hall 8'&,

G((er #addle &ier, 15.

Ie(ner, Charles and en


64/72

• Deelo( a mental imae o! the (ro)lem

Various leels o! a//ura/y to s/reen ideas, Jsu//essie a((roimationK

For eam(le,

? in(ut+out(ut only, no details o! me/hanisms :ithin system

? order o! manitude on system )ehaior

? limits on )ehaior se/ond la:, euili)rium, et/.

? ty(i/al results !rom similar /al/ulations or data

? sim(li!ied analysis /onstant (ro(erties, (er!e/t eui(ment, et/.

? detailed /al/ulations !lo:sheetin

? thorouh data e(erimentation see Chem. n. 4C03 !or methods

• *nitially, remoe some /onstraints !rom the (ro)lem.

? *! * /ould loo; at the /atalyst sur!a/e, A

? *! * /ould ;no: the a/tual rate o! rea/tion, A

? *! * /ould loo; at the internal !lo:s in the essel, A.

• e o(en to an unli;ely )ut not im(ossi)le root /ause

• Deelo( the Jnothin ha((enedK hy(othesis. Could the situation arise :ithout a (ro)lem )ut :ith a !ault in some dataL *s this

really a (ro)lemL

• 'a;e a ris; :ith a J!ar outK idea

• Don>t


65/72

A**endi) B+ E)tra t!*i"s !r PLAN

#hort term

• to moe ui/;ly to a sa!e and enironmentally a//e(ta)le /ondition

• to aoid damae to eui(ment

• to maintain the (lant in a /ondition to reain o(eration ui/;ly i! (ossi)le

• to !urther eri!y the dianosis i! needed

• to maintain (rodu/t uality i! (ossi)le• to a/hiee as near as (ossi)le the desired (rodu/tion rate

7oner term

• to shutdo:n eui(ment, i! needed !or re(air, sa!ety, et/.

• to (roide time !or detailed analysis and /al/ulations or la)oratory inestiations

• to (er!orm dianosis (ossi)le only on (lant a!ter shutdo:n

• to im(roe the o(eratin (oli/y used )y (lant (ersonnel

• to im(roe the maintenan/e (oli/y o! the (lant

• to (roide im(roed eui(ment !or the (lant

e. Continue to 'rou)le #hoot

• Ho: /an :e monitor the solution to eri!y that the dianosis :as /orre/tL

• Ho: /an :e )e alert !or other (otential (ro)lemsL

!. Communi/ate and see; su((ort and /ritiues !rom others• aturally, this de(ends on the time aaila)le and /ost o! the solution

• Do not relate the history o! your (ro)lem solinM ie a summary o! the situation, dianosis ta)le, )asis !or root /ause dianosis

and (ro(osed solution.• Clearly relate the im(li/ations !or sa!ety, enironment, (rodu/t uality, (rodu/tion and /ost

• e /on/ise

• e honestM e(lain any remainin un/ertainty

. When areement has )een rea/hed and authority ien

• Do/ument the analysis and solution /learly and (re/isely

• 8roide a /lear (lan o! ee/ution :ith measura)le /he/; (oints


66/72

A**endi) C+ E)tra t!*i"s !r EALUATE

a. Did :e sole the (ro)lemL Com(are the results :ith (redi/tions

). What are the )ene!i/ial /ollateral /onseuen/es o! solin the (ro)lemL

? Ho: /an :e )e sure to sustain theseL

/. What are (otential (ro)lems /aused )y your solution ethi/al, leal, sa!ety, (ro!it et/.L

? 8re(are /orre/tie a/tions i! they should o//ur

d. Ho: /an :e (reent this (ro)lem !rom re/urrinL

e. Ho: /an you hel( your /olleaues !rom your learnin e(erien/eL

!. Ho: /an :e add to our e(erien/e !a/torsL

. Ho: /an :e identi!y a similar (otential (ro)lem at an early stae in its deelo(mentL

nineers esta)lish (ro/ess $!nit!rin% and dia%n!sis (ro/edures that are (er!ormed routinely to (roide early indi/ation o!

(lant (er!orman/e. Ho: /an the (ro)lem solin e(erien/e )e used to im(roe monitorin o! this (lantL For eam(le,

• *m(roed trainin o! o(eratin (ersonnel• %dditional sensors or (eriodi/ la)oratory analysis• %dditional /al/ulations to summariNe (lant (er!orman/e yields, enery+;, e!!i/ien/y, heat trans!er eui(ment, et/.

• 7o/al monitorin o! eui(ment

• *m(roed maintenan/e (ro/edures that are (er!ormed immediately u(on a s(e/i!i/ /ondition in the (lant


67/72

TROUBLE SHOOTING 5OR8SHOP

5e (ill i$*r!,e !ur TS skills b' a**l'in% t#e standard

$et#!d t! a *r!"ess (it# (#i"# (e are all a$iliar1

distillati!n+ T#e *r!"ess is %i,en in t#e !ll!(in% i%ure+

N!te t#at t#e distillati!n *r!"ess in"ludes #eat transer1luid l!(1 *r!"ess "!ntr!l and saet' e9ui*$ent+

5e "ann!t "!$*art$entalie !ur kn!(led%e (#en s!l,in%

realisti" *r!ble$s&

0!ur *r!ble$s are *r!,ided+ 4!u (ill (!rk in %r!u*s t!

s!l,e t#ese+ T#e instru"t!r (ill *r!,ide eedba"k t! '!ur

9uesti!ns and dia%n!sti" a"ti!ns+


68/72

T(!:distillati!n

*r!"ess used in t#e

Tr!uble S#!!tin%

5!rks#!*

• De*r!*anier

• Debutanier

See larger co"# in the lecture notes$


69/72

TROUBLE SHOOTING 5OR8SHOP E@ERCISE -

'he ne: t:o?distillation to:er (lant in the !iure :as


70/72

TROUBLE SHOOTING 5OR8SHOP E@ERCISE =

'o )e a)le to sell your (rodu/ts, your (lant must o)tain *#- /erti!i/ation. 'his ensures that the

(lant has /onsistently en!or/ed uality /ontrol (ro/edures. 9our /ustomer seri/e enineerre(orts that one o! the /ustomers is dissatis!ied :ith the )utane (rodu/tM you don>t hae more

details. %s a result, you hae esta)lished a routine /om(osition analysis o! arious streams in the

de(ro(aniNer and de)utaniNer in the t:o?distillation (ro/ess that has )een o(eratin !or years.

'he /om(osition monitorin (roram has )een o(eratin !or one :ee;. 'he la)oratory analyses

indi/ate too mu/h aria)ility in the mole !ra/tion (ro(ane in the )ottoms o! the de(ro(aniNer, C?.

For the last day, the mole !ra/tion (ro(ane has )een a)out 0.04, :hile the taret is 0.015.

e!ore the ne: (ro/edures, :e neer ;ne: that :e :ere o(eratin the (lant (oorly, so no one

/aredO *! you /annot o)tain *#- /erti!i/ation, the /om(any :ill not )e a)le to sell (rodu/ts to the

;ey /ustomers.

eryone is mad at you !or !indin the (ro)lemO 9ou )etter sole this (ro)lem so that the (lant

/an /ontinue to o(erate and you are sa!e at :or;.


71/72

TROUBLE SHOOTING 5OR8SHOP E@ERCISE ;

'he o(eration o! the u(stream (ro/ess, :hi/h (re(ares the !eed to the t:o?distillation to:er

(ro/ess, is )ein modi!ied to a//ommodate a ne: /atalyst and modi!ied ra: material/om(osition. 'he ne: u(stream (ro/ess has )een o(eratin !or nearly a shi!t, and the t:o

distillation to:ers seem to )e !un/tionin :ell. 9ou note that some o! the tray tem(eratures are

di!!erent !rom )e!ore the /hane, )ut the (rodu/t (urities, as measured )y s(e/ial la)oratory

analysis, are ery near their s(e/i!i/ations. 9ou are satis!ied that all is :ell. 9ou return to your

o!!i/e to eat that mu!!in that you (ur/hased on the :ay to :or; this mornin.

ust :hen you hae )re:ed the /o!!ee and heated the mu!!in in the mi/ro:ae, the (lanto(erator /alls you. 'he hih (ressure alarm in the de)utaniNer is on, and the o(erator is :orried

that the sa!ety ale :ill o(en. 9ou are neer sure that it :ill /lose /om(letely, so :e don=t

:ant it to o(en unless needed. He thin;s that the u(stream /hane is the /ause o! the (ro)lem

)ut doesn>t ie you a /lear reason :hy.

9ou hae not )een :or;in in this unit !or lon, so here is your /han/e to ma;e !riends :ith

the o(erator. 7et=s :or; :ith the o(erator to !i this (ro)lemO

TROUBLE SHOOTING 5OR8SHOP E@ERCISE


72/72

TROUBLE SHOOTING 5OR8SHOP E@ERCISE <

'his t:o?distillation to:er (ro/ess :as su//ess!ully started u( in anuary, :hen a /are!ul /he/;

indi/ated that the o(eration :as ery /lose to the desin alues. 9ou are sure o! that )e/ause you

:or;ed 12 hours (er day to /he/; and dou)le /he/; eerythin.

*n %uust, you are assined the res(onsi)ility !or this (ro/ess. 9ou de/ide to ta;e a /are!ul loo; at

the /urrent o(eration. 7a)oratory analysis o! the de(ro(aniNer a(or (rodu/t indi/ates a hih loss o!

(ro(ane to the !uel system, 2.5 times the desin alue.

'his loss o! (rodu/t to !uel is /ostin lots o! moneyO 9ou :ant to !ind the /ause !ast P you :ould

li;e to (roide a solution as :ell as a (ro)lem to the (lant manaer. 'ime to a((ly your trou)leshootin s;illsO

Operability TroubleShooting

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