Heat Loss Insulated Pipe

7/24/2019 Heat Loss Insulated Pipe

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Heat Loss From An Insulated PipeDate

Tips & Tricks for Chemical Engineers By

Pipe Inside Diameter (D1) 23.6 mm

Outside Diameter (D2) 25.4 mmOperating Temperature 4.0

Ambient Temperature -15.0

ind !peed 3.50 m"s

Insu#ati$n Insulated Pipe

T%pe &a#'ium !i#i'ate !ura'e Temperature

!ura'e mmisi*it% 0.04 +eat ,$ss

Ti'ness 3/.1 mm Bare Pipe

Outside Diameter D3 101.6 mm !ura'e Temperature

+eat ,$ssCalculation for Insulated Pipe

Iterati$ns 1 2

!ura'e Temperature tsura'e -14 -14.5/ -14

Intera'e Temperature tintera'e 3.0 4.00 4

Air Properties

A*erage i#m Temperature ta*erage -14.5 -14. -14

25/.65 25/.36 25/

Terma# &$ndu'ti*it% "m. 0.022 0.022 0.02

is'$sit% 7 1.64-05 1.64-05 1.64

Prandt# 8umber Pr 0.1/ 0.1 0.

9pansi$n &$e:'ient ; 1" 0.003/66 0.003/1 0.003/

Air Densit% < 1.3664 1.36 1.36

inemati' is'$sit% = m2"s 1.22-05 1.22-05 1.22

!pe'i>' +eat &p ?"g. 1.00 1.00 1

a#pa @ 1.6-05 1.6/-05 1.6/

e%n$#dBs 8umber e 2140 21/ 21

a%#eig 8umber a 13440 /2152 /21

Air Film Resistance

adiati$n radiati$n 0.16 0.16 0

&$n*e'ti$n$r'ed &$n*e'ti$n 8u$r'ed 146.5 146./ 14

$r'ed 33.0/ 33.0 33

ree &$n*e'ti$n 8uree .2/ .40

ree 2.0 1.6 1

&$mbined &$n*e'ti$n 8u&$mbined 146.5 146./ 14

'$n*e'ti$n 33.0/ 33.0 33

O*era## air side +T& air 33.23 33.25 33

Pipe Resistance

Pipe Terma# '$ndu'ti*it% pipe "m. 64./ 64./ 64

Pipe Ca## resistan'e rpipe 0.00006 0.00006 0.000Insulation Resistance

A*erage Insu#ati$n temperature 26 65 26 /60/ 26 /6

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Insu#ati$n Terma# '$ndu'ti*it% insu#ati$n "m. 0.05322 0.05323 0.053

Insu#ati$n resistan'e rinsu#ati$n 1.32 1.32 1Overall Resistance r$*era## 1.353 1.353 1.3

+eat #$C F 14.04 14.04 14

Intera'e Temperature Tintera'e 4.0 4.0

!ura'e Temeperature Tsura'e -14.5/ -14.5/ -14

+eat ,$ss per Gnit ,engt "m 4.4/ 4.4/ 4

m."m."

"m

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Calculation for Bare PipeIterati$ns 1 2

!ura'e Temperature tsura'e -14.0 4.0

Hare Pipe missi*it% 0./ 0./

Air Properties

A*erage i#m Temperature ta*erage -14.5 -5.51 -5

25/.65 26.64 26

Terma# &$ndu'ti*it% "m. 0.022 0.023 0.02

is'$sit% 7 1.64-05 1.6-05 1.6

Prandt# 8umber Pr 0.1/ 0.16 0.

9pansi$n &$e:'ient ; 1" 0.003/66 0.00336 0.003Air Densit% < g"m3 1.3664 1.3205 1.32

inemati' is'$sit% = 1.22-05 1.30-05 1.30

!pe'i>' +eat &p ?"g. 1.00 1.00 1

a#pa @ 1.6-05 1./0-05 1./0

e%n$#dBs 8umber e 2/5 6/51 6/

a%#eig 8umber a 3022 4/5 4/

Air Film Resistance

adiati$n radiati$n 3.13 3.30 3

&$n*e'ti$n

$r'ed &$n*e'ti$n 8u$r'ed 55. 53.5 5

$r'ed 50.31 4./3 4

ree &$n*e'ti$n 8uree 3.32 6.4 6

ree 3.00 6.03 6

&$mbined &$n*e'ti$n 8u&$mbined 55. 53.5 5

'$n*e'ti$n 50.31 4./3 4

O*era## air side +T& air 53.44 53.13 53

Pipe Resistance

Pipe Terma# '$ndu'ti*it% pipe "m. 64./ 64./ 64

Pipe Ca## resistan'e rpipe 0.00001 0.00001 0.000

Overall Resistance r$*era## 0.01 0.01 0.0+eat #$C F 1014.61 100/.0 100/

Intera'e Temperature Tintera'e 4.0 4.0

+eat ,$ss per Gnit ,engt "m /0.6 /0.4 /0

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23-Jan-15

ChemS!

-14.6

4.5 "m

4.0

/0.5 "m

4 5

-14.5/ -14.5/

4.00 4.00

-14. -14.

25/.36 25/.36

0.022 0.022

1.64-05 1.64-05

0.1 0.1

0.003/1 0.003/1

1.36 1.36

1.22-05 1.22-05

1.00 1.00

1.6/-05 1.6/-05

21/ 21/

/2121 /2121

0.16 0.16

146./ 146./

33.0 33.0

.40 .40

1.6 1.6

146./ 146./

33.0 33.0

33.25 33.25

64./ 64./

0.00006 0.00006

26 /60 26 /60

&

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D1 D2 D3


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23-Jan-15

ChemS!

0.05323 0.05323

1.32 1.321.353 1.353

14.04 14.04

4.0 4.0

-14.5/ -14.5/

4.4/ 4.4/


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ChemS!

4 5

4.0 4.0

0./ 0./

-5.51 -5.51

26.64 26.64

0.023 0.023

1.6-05 1.6-05

0.16 0.16

0.00336 0.003361.3205 1.3205

1.30-05 1.30-05

1.00 1.00

1./0-05 1./0-05

6/51 6/51

4/5 4/5

3.30 3.30

53.5 53.5

4./3 4./3

6.4 6.4

6.03 6.03

53.5 53.5

4./3 4./3

53.13 53.13

64./ 64./

0.00001 0.00001

0.01 0.01100/.0 100/.0

4.0 4.0

/0.4 /0.4


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Thermophysical properties of AirDate


Literature Values Calculated Values

T &p .103 Pr &p .1

?"g. 8.s"m2 m2"s C"m. m2"s ?"g. 8.s"m2 m2"s C

100 1.032 1.1 2.00 .34 2.54 0./6 1.02 1.2 1.5

150 1.012 103.4 4.43 13./0 5./4 0.5/ 1.016 103.2 4.45 1

200 1.00 132.5 .5 1/.10 10.30 0.3 1.00 132.6 .64 1250 1.006 15.6 11.44 22.30 15.0 0.20 1.005 15. 11.4/ 2

300 1.00 1/4.6 15./ 26.30 22.50 0.0 1.005 1/4./ 15.1 2

350 1.00 20/.2 20.2 30.00 2.0 0.00 1.00/ 20/.2 20./ 3

400 1.014 230.1 26.41 33./0 3/.30 0.60 1.014 230.0 26.3 3

450 1.021 250. 32.3 3.30 4.20 0.6/6 1.021 250.5 32.34 3

500 1.030 20.1 3/. 40.0 56.0 0.6/4 1.030 26. 3/.4 4

550 1.040 2//.4 45.5 43.0 66.0 0.6/3 1.041 2//.4 45.55 4

600 1.051 305./ 52.6 46.0 6.0 0.6/5 1.052 305. 52.4 4

650 1.063 322.5 60.21 4.0 /.30 0.60 1.063 322./ 60.2 4

00 1.05 33/./ 6/.10 52.40 /.00 0.65 1.05 33/. 6/.1/ 5

50 1.0/ 354.6 6.3 54.0 10.00 0.02 1.0/ 354.5 6.3 5

/00 1.0 36./ /4.3 5.30 120.00 0.0 1.0/ 36.6 /4.1 5

/50 1.110 3/4.3 3./0 5.60 131.00 0.16 1.110 3/4.1 3.3 5

00 1.121 3/.1 102.0 62.00 143.00 0.20 1.121 3/.1 102./4 650 1.131 411.3 112.20 64.30 155.00 0.23 1.131 411.5 112.24 6

1000 1.141 424.4 121.0 66.0 16/.00 0.26 1.141 424.3 121.3 6

So"rce # !"n$amentals of %eat an$ ass Transfer '2(()*+ !rank , ncropera

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7.10 =.106 @.106 7.10 =.106


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3-Jan-15

hemS!

Pr

m2"s

2.6 0./4

5.6 0.5

10.10 0.3/15.6 0.21

22.4/ 0.0

30.0 0.6

3/.43 0.60

4.3 0.6/5

56./1 0.6/3

66.64 0.6/4

6. 0.6/6

/.22 0.61

.// 0.66

10/./ 0.02

11.2 0.0/

131.33 0.14

143.06 0.20

155.1/ 0.24

16./ 0.26

@.106


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th Order Polynomial Fittin!

"peci#c Heat Curve Fittin!

&1.T4 &2.T3 &3.T2 &4.T &5

3.032336-013 -1.11315-00 1.443/223-006 -0.00056533//1.0223/301

1.0101361-013 2.234/3//-010 1.6/0506-00 4./4240-005 0.004603615

0.042213 0.001631331 J8"A J8"A J8"A

Viscosity Curve Fittin!

&1.T4 &2.T3 &3.T2 &4.T &5

-1.5/6-10 5.115-0 -.246-04 ./-01 -1./50K00

1.0541/345-011 2.3322/625-00/ 1.6062246-005 0.005206/64 0.4/40103/0./0602 0.10/5155 J8"A J8"A J8"A

$inematic Viscosity Curve Fittin!

&1.T4 &2.T3 &3.T2 &4.T &5

2.25/52005-011 -/.3202/4-00/ 0.00012632 0.010632/02 -0.610/351

3.4322/2/4-012 .536104-00 5.323554-006 0.001653264 0.15/6136

0./3/0/ 0.055621526 J8"A J8"A J8"A

Thermal Conductivity Curve Fittin!

&1.T4 &2.T3 &3.T2 &4.T &5

3.116340-011 -0.00000005 4.5/530/60-006 0.0///6//60.52002234

3.221206-012 /.234/4402-00 6.2164326-006 0.001/3/40 0.12023055

0.10 0.0603246 J8"A J8"A J8"A

Alpha Curve Fittin!

&1.T4 &2.T3 &3.T2 &4.T &5

1.3556/636-010 -3./05/6/-00 0.0004464/25 -0.0353552 2.2544/1641

1.15144/-011 0.000000026 1.6264351-005 0.005/04454 0.54332434

0.01606 0.10456206 J8"A J8"A J8"A

Prandtl %um&er Curve Fittin!

&1.T4 &2.T3 &3.T2 &4.T &5


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-2.0/43/6-013 -1.2/234-011 /.0062424-00 -0.000646050./45/121/

/.6312/14-014 1.055/00-010 1.4415363-00 0.000042633 0.003061

0.30204 0.0013//6 J8"A J8"A J8"A


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Thermophysical properties of AirDate


Thermal Conductivity of Plain Car&on "teel

T &a#'u#ated 'rd Order Polynomial Curve Fitti "m. "m. &1.T3 &2.T2 &3.T

400 5/. 5/.0 2.0/-0 /.15-1 -5.11-02

600 4/./ 4/./0 0 0 0

/00 3.2 3.20 1 0 J8"A

1000 30.0 30.00

Thermal Conductivity of Calcium "ilicate

T &a#'u#ated

"m. "m. th Order Polynomial Curve Fitti

310 0.055 0.0551 &1.T4 &2.T3 &3.T2365 0.05 0.05/ 3.1511-013 --010 .366-00

420 0.063 0.0633 .11501-013 1.-00 1.46-006

530 0.05 0.04/ 0./63/005 0.0005 J8"A

645 0.0/ 0.0/1

50 0.104 0.1040

So"rce # !"n$amentals of %eat an$ ass Transfer '2(()*+ !rank , ncropera

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23-Jan-15

ChemS!

!&4

0

J8"A

!

&4.T &5-0.000225 0.033360404

0.0004/36 0.05/5561

J8"A J8"A


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Heat Loss from Insulated Pipe

23-?an-15

+eat #$ss"gain taes p#a'e r$m a pipe 'arr%ing $tter" '$#der Luid tan ambient tempe

. 3/ Car0on steel pipe is carrying hot oil at 1(C an$ ins"late$ ith 5( mm thick calci

O*era## eat transer '$e:'ient $ an insu#ated pipe is de>ned as $##$Cing.

eatured es$ur'esN

Is Critten $r engineering pr$essi$na#s C$ bu% and spe'i% pr$'ess euip

ta*erage S ( tsura'e K tambient )" 2

stimate term$d%nami' pr$perties $ air #ie terma# '$ndu'ti*it% ()M *is'$sit% ()M e

h(radiation

+eat transer '$e:'ient due t$ radiati$n is 'a#'u#ated using $##$Cing re#ati$n.

Cere U is !tean H$#tmann '$ei'ient and V is emissi*it% $r '#added sura'e.

h(convection

&$n*e'ti*e eat transer '$e:'ient '$mprises $ $r'ed and ree '$n*e'ti$n. $r'ed '

CereM PIP

M I8!G,ATIO8

are terma# '$ndu'ti*ities $ pipe and insu#ati$n. inis eat trans

Air "ide Heat Transfer Coe)cient* hAIR

Air side eat transer is due t$ '$mbined eWe't $ '$n*e'ti$n and radiati$n. Assume a

radiati$n S U V (ta*erage4- tambient4)" (ta*erage - tambient)


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$r'ed S 8u.air " D3

ree '$n*e'ti$n is 'a#'u#ated based $n '$rre#ati$n b% &ur'i## and &u.

ree S 8u.air " D3

&$mbined eat transer '$e:'ient due t$ $r'ed and ree '$n*e'ti$n is 'a#'u#ated usin

'$n*e'ti$n S 8u'$mbined.air " D3

Air side eat transer '$e:'ient is 'a#'u#ated as $##$Cing.

air S radiati$n K '$n*e'ti$n

Overall Heat Transfer Coe)cient* +

Terma# '$ndu'ti*it% $r insu#ati$n materia# and pipe is a*ai#ab#e in #iterature and depe

rpipe S D3.#n(D2"D1) " 2.pipe

rinsu#ati$n S D3.#n(D3"D2) " 2.insu#ati$n

O*era## eat transer '$e:'ient is 'a#'u#ated as.

r$*era## S rpipe K rinsu#ati$n K 1"air

G S 1"r$*era##

+eat L$Cing tr$ug insu#ati$n is estimated.

F S (t$perating - tambient)"r$*era##

A re*ised estimate $r intera'e and sura'e temperature is made.

tintera'e S t$perating - F.rpipe

tsura'e S tintera'e - F.rinsu#ati$n

Ab$*e steps are repeated Cit tese neC estimates ti## tere is neg#igib#e diWeren'e in

+eat #$ss per unit #engt $ pipe is estimated as $##$Cing.

8u'$mbined S ( 8u$r'ed 4K 8uree 4) 0.25

+eat,$ss

S XD3 F


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Bare Pipe

$r eat #$ss r$m bare pipe a## ab$*e steps are repeated Cit resistan'e due t$ insu#at

rpipe S D2.#n(D2"D1) " 2.piper$*era## S rpipe K 1"air

$r tis e9amp#e sura'e temperature and eat #$ss are as $##$Cing.

!preadseet $r +eat ,$ss r$m Insu#ated Pipe
http://www.chemsof.com/assets/sheet/Heat_Loss_Insulated_Pipe.xlsxhttp://www.chemsof.com/assets/sheet/Heat_Loss_Insulated_Pipe.xlsx


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rature. Insu#ati$n redu'es te eat #$ss t$ surr$undings. +eat #$ss depends up$n numb

"m silicate ins"lation4 ns"lation is cla$$e$ ith a sheet ith s"race emissiity of (464

ent t$ '$$#M 'i## $r reee pr$du'tQ measureM m$nit$r $r... RR

pansi$n '$ei'ient (; S 1"ta*erage)M air densit% (


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g $##$Cing re#ati$n.

nds up$n temperature. It 'an be >tted int$ a p$#%n$mia# euati$n using ,I8!T un'ti$

temperature.


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i$n n$t '$nsidered.


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er $ a't$rs #ie insu#ati$n ti'nessM ambient temperatureM Cind speed et'. Tis arti'#

m0ient temperat"re is 2C an$ in$ elocity is 345 m7s4 Calc"late s"rface temperat"

eat (&p) and terma# diusi*it% (@) at a*erage air i#m temperature. Tese pr$perties a

ng $utside te pipe. Te >rst tC$ terms $ den$minat$r in ab$*e euati$n are genera##

a*erage air >#m temperature as $##$Cing.


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n in e9'e#. +eat transer resistan'e due t$ pipe and insu#ati$n is 'a#'u#ated using $##$C


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e s$Cs $C t$ 'a#'u#ate eat #$ss r$m an insu#ated pipe and a bare pipe t$ surr$undi

re an$ heat loss from ins"late$ an$ 0are pipe4

re a*ai#ab#e in #iterature in $rm $ tab#esM tese 'an be itted int$ a p$#%n$mia# $rm u

sma##er '$mpared t$ remaining terms and 'an be neg#e'ted. $r tis e9amp#e >rst ter


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ing re#ati$n.


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gs.

ing e9'e#Bs ,I8!T un'ti$n. e%n$#dsBs number (e)M Prandt# number (Pr) and a%#eig

m due t$ pipe Luid is ign$red.


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number (a) are 'a#'u#ated based $n ab$*e pr$perties.


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Heat Loss Insulated Pipe

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