spreadsheet - gas blanketed tanks - outbreathing process calculations & control valve sizing - rev2

8/17/2019 Spreadsheet - Gas Blanketed Tanks - Outbreathing Process Calculations & Control Valve Sizing - Rev2

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Process and Physca! Para"e#ers

Para"e#er

Ser$ce (Tan%)

&!'d (S#ored n Tan%)s

Ser$ce (PCV)

&!'d (Thro'h PCV)

Vo!'"e o Tan% (V#%)

O*era#n Press're o Tan%

O*era#n Te"*era#'re o Tan%

+o!ec'!ar ,eh# o Gas (&or Ar ./0121 3"o!)

Co"*ress4!#y &ac#or o Gas (I dea! en#er 5)

S#andard 6ens#y o Gas (&or Ar aro'nd 50.. K3"7)Gas Re!ease Press're 6o8ns#rea" o O'#!e# PCV

S#e +n"'" A"4en# Te"*era#'re

S#e +a9"'" A"4en# Te"*era#'re

6esn :ac%ro'nd ; This spreadsheet focuses on Design Calculation of O%nlet li/uid 0owrates are considered and the Tank $ir Outbreathing Flowrates

gi#en C# is selected and the calculated C# re/uired is copared against it,


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:!an%e# Gas &!o8n Cond#ons (In!e# #o PCV)

6ens#y o Tan% In!e# Iner# C'shon Gas a# &!o8n Cond#ons

S*ec


3/33

D-&ac#or (As Per API .??? #h Ed#on)

Nor"a! Te"*

Nor"a! Press're

S#d0 Te"*

S#d0 Press're

Ac#'a! Te"*0Ac#'a! Press're

To#a! O'#4rea#hn Gas &!o8 Ra#e Re@'red

Tan% O'#!e# PCV Process Para"e#ers

In!e# &!'d (Iner# Gas) +ass &!o8 Ra#e

6esn &!o8 +arn (Ty*ca!!y 507)

6esn +ass &!o8 Ra#e (8)

Ra#o o S*ec


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In!e# &##n =ead Loss Coe>cen# (K)

O'#!e# PCV SnF

Va!$e +an'ac#'rer

Va!$e +ode! Se!ec#ed

Se!ec#ed Va!$e Ra#ed +a9"'" (&!o8 Coe>cen#) CV5

P*n Geo"e#ry &ac#or (&*)

+odcen# (O'#!e#Red'cer) (K:.)

O$era!! Press're Loss Coe>cen# ( K H K5K.K:5-K:.)

NOTE ; Sizing has been done based on English 1nits )Psi2 3b4ft52 inch etc,+ since Cis the sae since the re/uired answers are in "atios or percentages, 7here#er re/

Se!ec#ed Va!$e Ra#ed Press're 6ro* Ra#o &ac#or(&ro" +an'ac#'rer or #he Ta4!e) (X#)

Se!ec#ed Va!$e Cr#ca! &!o8 Cond#on Press're 6ro* Ra#o &ac#or(X")

Press're 6ro* across Va!$e or Va!$e Press're 6Jeren#a! (P5-P. or

P)


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EJec#$e Press're 6ro* Ra#o (X EJ)

Gas E9*anson &ac#or (D)Ca!c'!a#ed Ca*ac#y &ac#or Re@'red (CV.)

Ra#ed Ca*ac#y &ac#or o Va!$e (CV5)

Va!$e O*enn Re@'red (CV.3CV5)

Is Va!$e Se!ec#ed S'#a4!e B

Cr#ca!#y :y

Genera! G'de!ne Chec%s

50 Is Va!$e O*enn A4o$e 5? B

50 Is Va!$e O*enn :e!o8 /? B

.0 Is Va!$e End Se S"a!!er #han or E@'a! #o Lne Se B

70 Is 6esn &!o8 +arn a#!eas# 507 B

NOTES

Cr#ca! or S'4-Cr#ca! &!o8 B (Cho%ed or No# Cho%ed) To help deterine E8ecti#e Pressure Drop "atio

Conc!'sons ;a, The Outbreathing "e/uireents are calculated as per the new $P% (etho There is an alternati#e ethod for snall sized tanks that satisf! speci6c crite4, %n general2 Val#es can also be allowed to operate under Choked Flow Con

possible is the rated #al#e critical pressure drop ratio, %n non choked );on9crc, For Val#e Openings which are too low2 #erif! the acceptabilit! and whethe.enerall! ne#er select a #al#e greater than the line size,d, %f the 3i/uid stored in the Tank is #olatile2 the outbreathing re/uireents


6/33


7/33

EXPANSION TANK -

Un#s Va!'e

Cushion .as %nlet for PCV

$ir

5 '

psia

kpaa ?' @+Solution


8/33

oC 55,55

oF BB,'*

oC ,*'

g45 50??/

lb4ft5 ?0?7

50???

74&, B,''

',''

74, oC

kPa ','''

g ','''kPa ','>'

g ',5*>

;O

B',>?

-elow B&

B,'''


9/33

',5&'

.705

kpaa 5?507.

.//0

kpaa 5?507.

.10/

kpaa /50???

;54hr ?02.

S54hr ?0221

54hr ?02

g4hr ?021

$54hr ?02

g4hr ?021

g4hr ',>BA

lb4hr


10/33

','''

','''

?0???

Carraro

','5<

',*''


11/33

Uncho%ed or S'4-Cr#ca! &!o8

?077

',AA?0???/1

?0?75??

.0/

S'#a4!e

:'# Ta%e Care d'e #o Very Lo8 In!e# &!o8

No Cr#ca!#y

NO Very Acce*#a4!#y NO

DES Good DES

DES Good DES

DES Good DES

as stated in $P% &'''2 *th Edition2 5,5,&,ria gi#en in $nnex $ of the $P% std, The newer ethod isitions, %f #al#es operate at higher pressure drop ratios th

itical+ 0ows2 the pressure drop is deterined b! the gener the #al#e opens or not for that 0owrate and pressure,

hange2 but that has been accounted for in the Outbreath


12/33

r 4s


13/33

UTLET CONTROL VALVE SIZING (GAS)

Va!'e Va!'e

Cushion .as %nlet for PCV Cushion .as %nlet for PCV

$ir $ir

' '

?


14/33

55,55 55,55

BB,'* BB,'*

,*' ,*'

50??/ 50??/

?0?7 ?0?7

50??? 50???

B,'' B,''

','' ',''

;O ;O

B',>? B',>?

-elow B& -elow B&

B,''' B,'''


15/33

',5&' ',5&'

.705 .705

5?507. 5?507.

.//0 .//0

5?507. 5?507.

.10/ .10/

/50??? /50???

?02. ?02.

?0221 ?0221

?02 ?02

?021 ?021

?02 ?02

?021 ?021

',>BA ',>BA


16/33

',''' ','''

',''' ','''

?0??? ?0???

Carraro Carraro

','5< ','5<

',*'' ',*''


17/33

Uncho%ed or S'4-Cr#ca! &!o8 Uncho%ed or S'4-Cr#ca! &!o

?077 ?077

',AA ',AA?0???/1 ?0???/1

?0?75?? ?0?75??

.0/ .0/

S'#a4!e S'#a4!e

No Cr#ca!#y No Cr#ca!#y

Very Acce*#a4!#y NO Very Acce*#a4!#y

Good DES Good

Good DES Good

Good DES Good

eneral in nature and ore conser#ati#e than the Old ethod with the introan critical 0ow conditions2 then the e8ecti#e pressure drop ratio becoes th

ral pressure drop )1pstrea9downstrea+ across the #al#e,

ing "e/uireents )due to 0ow+ forula,


18/33


19/33

Va!'e

Cushion .as %nlet for PCV

$ir

'

?' @+Solution


20/33

55,55

BB,'*

,*'

50??/

?0?7

50???

B,''

',''

oC

','''

','''','>'

',5*>

;O

B',>?

-elow B&

B,'''


21/33


22/33

','''

','''

?0???

Carraro

','5<

',*''


23/33

Uncho%ed or S'4-Cr#ca! &!o8

?077

',AA?0???/1

?0?75??

.0/

S'#a4!e

No Cr#ca!#y

NO Very Acce*#a4!#y

DES Good

DES Good

DES Good

uction of new paraeters such as 3atitude2 Ccritical pressure drop ratio since at Choked


24/33


25/33

:ass o Ca!c'!a#on

if ;& then &?,'


26/33

Tank Operating Teperature

Calculated

Sec, 5,5,&,B2 $P% &''' )* Ed,+

Sec, 5,5,&,B2 $P% &''' )* Ed,+

Sec, 5,5,&,&2 $P% &''' )* Ed,+

$ssued sae as Tank Op, Tep

Sec, 5,5,&,52 $P% &''' )* Ed,+

$ssuing ;o %nsulation is conser#ati#esince adding insulation reduces 0ow

re/nt

$bo#e


27/33

Sec, 5,5,&,52 $P% &''' )* Ed,+

Sec, 5,5,&,5,52 $P% &''' )* Ed,+

STP at , oC2 < at

;TP at 'oC2 < at

For Val#e Selected -elow

(asoneilan Control Val#e andbook and%S$ "eference


28/33

Fro Val#e (anufacturer

See -lackonk "eference


(asoneilan "eference )Table+

Val#e Setpoint Decided b! us

$bient Outside 4 Exit Pressure

See Table attached orCrane or -lackonk reference


Fro Val#e (anufacturer orthe %S$ "eference table2 Sec, ?




29/33

$ll "eferences$ll "eferences


Depends on .uidelines below

(argin b! which 0ow is Choked

See Carl -ranan "eference





%n Choked 0ow2 ax P Drop is CriticalVal#e P "atio2 else it is

e/ual to Val#e P Drop

9Factor2 :9Factor etc,low2 the highest pressure drop ratio


30/33


31/33

VPMH=EXANE (Non Vo!a#!e)

-elow &> oC $bo#e and E/ual &> oC

-elow B& B ,>

-etween B& and >? 5 >

$bo#e >? &,> B

VP=EXANE (Vo!a#!e)

-elow &> oC $bo#e and E/ual &> oC

-elow B& ,> ,>

-etween B& and >? > >

$bo#e >? B B

Nor"a! Cond#ons

S#andard Cond#ons


32/33

Ty*ca! X# Va!'es (Ra#ed Press're 6ro

' oC2 < at

, oC2


33/33

Ra#o &ac#or)

spreadsheet - gas blanketed tanks - outbreathing process calculations & control valve sizing - rev2

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