CoIMBATORE InST ITUTE OF TECHNOLOGIy

DEPARTNENT DF CHEMICAL ENG)NEER)N

B.Teeh. chemical EnpunaoMn

03CH412 Heat Mansfe
Mid Somestes-I Sokon

Part- A.

what as the o ypes

two tube chaet layout
and tulee heal exehagers ? skedch tra Sclhemaic
tube Shaot
cliaqam any
n
twoyeas os tulee shaet afout
Thane ar

isdusial pratea.
Suase PattRs
Tubesheet
ubesAect
Tuto

Tubes

erntens he Counte haat

2 Ahet lud
8o and t loaves hha esceheneaf
at
enhang Same eehange at
fluid entn he
5o'c. old
and
and tt caues he cshange at
30°c
Defermune He LMTD CLog rean Temporatu Dlu~
 Tho 5oe.
Coune Cment
cnd
Gehae. 20°c.
Te
Tao: Goc.

where Thi- Hof fuid temprate at nlat.

Tho - Hot 4id 1emanahne

Tei - Temperaue cotd tlid at wtey .

7emknatun cotd fuidat ott
Tco
7emperahne AT. Ti-Te 8o'e- 6oc - 20
differon at
end
50- 3o =20c.

ditonat
20 - 20
LMTD =
nl) o.

% in delermineti form.
The foe, L-Hopital's eule can lae oppled

LMTO lin 0Ta(

’.

dTAT
LMTD
T,

whil ayig 1. Heptal'sta

ror, (1-V)) o, (or)

LMTD = 20'c. LMTD

 3) State Stefan. bolizmaan taw o% thasmal nadiaticn.
law states had emuse powes
Stefan PBolBzmaan (due hothesmal)
rodia

dngthy sefohcnad
a blauk body cs
Power t tenperahne.
4

4]
Eb

Ensswepower( e)
loo naan contay 567x10
where siefan.

maant ay emesniuy theimaladiahon?

what s
4)
ho raio emusie owerE)

a
ho
esswe powe Oh blat boyt
temperatue.
Game
E
Emihiy (E) =
Eb
how t emits
measue

Emusnity

fempuahe.
ame
at He
flm cuse Conclersahn
5) Disinisk betucc
Condeaten.
doepusa
5.NO
Dropwne condensahon F e n e condenatdn

Tn dopwue conclenietn,
Hae condert does not the iquid Cononab

wets he fae end

Conhuous
)
fovm
These daoplets gw tra Llm conclemat. throgt
whele and then fau trm which thaat renste gake
place . This comlenat

sufaca for funtaflos doun due to ah

|bare
Condenakin rauly. (I MOe)
leat tasfen cocfficats
coeftiueuty Head toaste coeticanb
vengtige houe ho: the welatwaly Rers sue
2)
heat does nos,low hougt |Acat does haoe o
he fln by conolensaho.
condutn
Smoo th and Caa pids
ody
3) tend ho phomot towads
þromotu flmwse ordegh,
dpwe Condensahin
Dsop w e condonan Fmwue condensaton

wnstabl and diblicult ho

ard o deie
ymuntaun, wnommn
not desiad industiay indwtiay. (IMa)
 Mentn any huc asumphent nvclwecd
theoy c cenenahn

Assemphens :
flow Cmmdenale a veial
sutaee
Laminaa.

Flow o heat condensale F n

2)
Conduuton and temperahne duhibuhon s
bo lbe ineas.
assund

rno Shea ves at vapou. liquid

3). Thene

Steam Economy f uafrato.

) Detue
raho numee
detuied
psodua
kilogran vapou
bo He ewapioto .
team ed

Economy (E) =
Riloorams sleam ed.

Econo y (E) =

Boletion (lo. Nal )

An
loocc kalk
fed bo he euaprao with he ale ef
euatto

Concentrated ho preduce hie liqlor

Tt is
3 o . Nal. The
Conumphen 54eam
(ms) Ihis
evaprah,

ms

ms,

overal Mateial
Nateial Bo
Baloe
F
L+v -0.

Nal Balan
poo x0.) (Lxoa) +(Qx o)
3339.33 kg/h.
V loooo- L= 6666-4 ikglh
V 6666- 6
Steam
Econoy ms
-083.

E 082
 Defue hoal exahegen
datuned as Hae yaho atial
maimn oile heat
heat ansfer al o
banter al.
Achual heat trasterat

Nasinm Assisle hat tiatu

Contat hype Beat

what L5 meant by undunet
Lo)
exuhange?
Tndiiect Contat ty aa eauhager
bo th the eics tcow simlteeousy haag
in which Hu wal.
and hat are sefurad by
devces

eam:
Shel anl hulae
Doubl

Pa- B

havi pcsfick heat

3.0 kgl kg-k foung at lahe 20,000 kglk

ente þouallel flw heat CoeekeeA .at l20 'c.

The feu safe cocting uafes. 50,cektl

tempatne yof Doc. The keaf ronsles
nlet
 mnd even all Coc{ficcnf lobo m.k

fud e hoat

temperahne 7 unte
heat

PRrallel Tha:?
tew
Th, 120c
heat ehege" Te:?
Me Sooco kglao.

Chi looo0x3

30o00 lo
3600

Ch 8333.3 w
k.

watu
= Sooo0X -)8Xo
k
3bo0

58o55. 56 w

Ch

Cmen 8323. 89
-0.J43S
Copouty Raho Coan 58055- sb
For cocwsent euhanga
(a) = | amp-NTU Ci4Cn
ttetiomes
|+ C.

where NTO =Nuae t

hanyu Cnin

NTU OA

Cmin 8333-33

126

I - ep-1.26x Il435]
Eßechwenen
Onehenge |+0. 143s

| - 0.2367

|l435

0.6675

Efbeehivenes 6675

emhangen
taa detinton tteehiene

CTh,-h)

Cnia CTh,-T,)

Ghin (Th, -Th)

Gain (Th,-Ta)
120- 1h2
[20 - 20
 Tha 53.25

Ot let 1emperatne o ganic - 53.25.

liauid

Fsom erengy blanee,

(Th, -Tha) = me x a
(120-53. 25)= 50000 x 4-18x (Tc,-20)

> To, = 29.58 c.

29.58 c.
outlet Temporahne
CThy-TA).
Heat Thasfer ya
Ci20-53-25x.

OO00 x Bx
3600

566250

9 - 556.2S kw.

556-2skw.
ral
Heat Tanen
wsed ho
12) A Counter eoo theat
C"= 2.5 kI rom lo5%
Cool

to 3o' by ha

ovnall hoat tras a coetticent

at 15°. 16 the
,esfiate the
to be l·5 kw
espeeted
area Yeqlied.
Sufae
water flow ab , the
h:2-5 kJhk
mn: 20
ol Ti zlo5t Coundo flow
haat nukager.
To ls hter.

Lot
mas
kg/h

mo water pthunal.
ol n t temparat.
Tho ol outlet teferat.
Te wate cilat temperaleu.
Tco watea outlet temberatw.
Enegy Balanea - Had ealaga,
Neat

by wateA.

mh
ToTa)
max 418 x (&o-$5)
(95-3o)
X 2.5× (
200
200 x2.5x f

wate ew
|19.62.

walee flonala
a)
AT, -
Bempenehe DTI
mn
Log
((05- o) -(30-1S)
 UA LMTD
thasfernat

ULMTD

where

2: Heal hansternal

= 200 x 2-5, (1 oS3)

3600

l0. 46t Kw.

Heathet
lo.4164

Ane
Suut vequwed
|:5 x19.5*

O.354 m
A
- 0 . 3 5 y 7 m 2

area e e n d

to coneentrate asoluti
13) An catorae avalable at a,
ho

O.2Mp C Saturahon

Fad hat
 at a veduad uese tho
bolig oint
329 k. The overall heat romafe oe fheal u
2.9 Ken ) Cshnale

he awapra r d
Cqo : 8. 98 kJlg.) u o oteaA
1gnid. The fod
ondalon skam afo,2m
Lalonthaal o
- 220B Lafenf keat os afluiaskon o water

2383 kUIg.
e
at 323 K -

F: 30o00 kg/h

O.2 MPa

boy.soed.

Matorial Balae.
OVerall

s0twent
Conconhakeed
vepouned
kiqu

30000
Solt Balane.

Weigk{o weigt weigat

bolule
Solul Bawe

Psoducd vapouwiat

(Bocoox o.1) (L, xo.5 ) 4 (vxo)

6oo0 kqIh

prodt (Concoatd Ligu)

F -L z 30000- 6000= 24000 kgl.

beigns vafou : 2 400o lyla.

Enengy Balae Enthalpy Balan

Erthaly +
Ertoey
s4eam vopoun pnoc
Shac

Entioy wnd mae Condeneh

He
Hy
Hs

ms Hs L HL 4 VHy +msHc.
FH +
LHL+ VHy.
F$T; t mg Hs-msHe
ms
V Hy.
B0000 x 3.99x 293 +
: Gx 3.98 x323)+ (24c0x 2383)

2202 mg
Cbooox 3.98 A328]+ (24,000 238).
(300c0x3.98x293)

13588. Il K9Jh.
mg

54eam Eonoy mber klograms qvepoun

euapurahs
pooddhad

24400o

13588. |

Sfean

Heas lo b Heat woten neli frm

Seam olig.

(T5 -Te)
x2202 = 2= 2.9 x A x
( 13588.)3600
K lh mix k. )
h

13589.1| x 2202
A 3600

2.9x (393 -323)

m2
40.94. m.

Heat Tnansfu Bunyace ea 40,94 m

129urid
 Asigle efot auaporatrr to be ed with

Soo0 kg/h 6o lutin

condoining o ba
LO .

Conconhated h a
The fad at 313k (40t)

5olut confaun ing 40. solut by caigt lnala

a
Stam anilasa
abiolah bressee of ol.8 k Pa.
ressuee ot 3o8. 975 kAa (3atratin
af the absolut
fo7). The oveall hoat ranle Coethuentia
temperate
Calalal
eqid )
requnid
ania C has skauld be
hat
a)
Haat ransfe
Qvapurator.

Tha
b)
os Rnewatu bthe
Data guen : pnfncalalaha
Enthaly s|enteaps.
Temperahue Entholpyo vapoua
(K) Liudlkolke) CKy)kg).

313 I67.2 2574.4.

Z)9-) 2676
373

401 5b3.4. 2T25-3.

v:?

F: goo kgih.
(0%.50lit.

Te 313k
Overal Mayoae Belenee

wag!
Solent
fad. Concantatd vapou

L + V
6ooo

Balane.
Soute

(5o0ox0) = (Lx04) + (vxoy

wergat % Concantatd 250 lgIh.

Liquot

sclent that is

V: 375 lgIA.

Bolone

Sfam Gortontsaet

fed.

solwet
vapo

mg Hs
 6oce x l67.2) + ms (2725.3 - 563-4): (/2s0x 4g.
(3750 x2676).

82600 co + (mg x 216)-9) =

lo65 8875

9722875
Staar Bowret mg = 4497. 97 ky..

Heat lot
by he
team:
Steam hgu

UA AT
As

A:
I50 A(41a13)

79. 44 m
A
79 44y2.
requnid
Suxtae
8750
The eonomy t O.8338.
euaprahs ms 4uq37

O.e338.
Economy 2
16) Deelop the elahinshp batuen the ofheetienes (E) ad
number ef tensfer wit CNT0) for barallel flw kaat
onhagu.
Consicle olouble pipe haas elanper
Lot s

io uhich ho 4uid
Ke anulaa Sfae laehueen
cold fluid flw thoug
bnel and uterae as shaun in Tgr.

Th, Tha
hotfeuid

Th,t

Hot fucd.
Th

Longtut) hilereH dz
Conyide a gnall elame
the
UdA T
behuee de
Heat honsßer
hof and tmallelantd2

dg
 Nhenc 7h- emporahne o} hot tluid
win e eleme

Temperahu o Cotoa Jluict

As a vesult o hes de Rot lid iss cotlad by Ka
temperahae d+h and old teid iu heokd by
temperaue dTc.
Heat lost ty he hot tlid dq =-m, fa dTh.

Cold feuid. dq :
Heat asd by te

while reaangg equateÝn we get.

4
mnCph.
whele Tcamangg equakin ),0,
de
- 6).
mee
phile Subshakna. ea& om go

dT, - dTc : ds
mhpn
d cTh-Te) :
he khow hat A1:Th -Tc, Thentne the ale equato
Can be
 Ne gef

dar -

UdA aT

the Vaniablay and is hqala

dor

UA

-UA

Let us

Capauty rat teotd Flacd

Achal Head h a n s k u a t .

he etetüene
erhangee Maimwm asible Aeaftatey

CTcl4)
((Th,)

(Tea-TG) (Ta, Tha

Ci CTa, -DG)
Cria (Tby-Te) Cmis

Tha-Tla +
- UA

we
Take Coponetut
 Cc.
L
Case) ChGmin ad Ce : Gnax, hen apuak
Can bc wnten as

Cmis

|- - ECmi (
ran

lot us huo denenonals. deu Ge) TOUA

|-emp

|-ep [-NTUCIHe]
(G)

kan cquaho(
and
Case)
an be

Gna Cmin
(l+
Gnin
Cm
 Cmis
take.

ç(H ) =

Effehienes
(14ca).
Oxprenim ho etinak ral o koat hanf
t6) Develop an
usig MTO
concante
huhehaafehange
Caunen ment
assumphónt.
Butasle
wilh
coneeliehuse
Couta Grent
Let w Coie

aula ece

bahuen inneed
oter puas.

Hof fluid
Ot.

cold Flud i .

Thy

Lengt
 Conide asmall elemet luid
Bo, Le dA be the sunfa
Small eleet.
wiihin he
d : UdAT
Heat Trnsfer withinelenet
fut and Cold Peucd =UdA CTh-Tc), -0
the
hiu dg hof pluid
As ell the tempenaheu
2d cold fluid
s kected
temperaha da
dTe.
hot flui d
Heat lot by

Het gound
Yearmeng eguahin he gf.
while
da

wbids eamangngguahn8, weget

Sunilanly, wbil
dg

behue 9 5 esy.
tha detßenene
whel
fuding
dq de

-d
d cih- ) =
Nhile sbshhg equahon O

dcoT) = - UdA OT
nepe.
hhia reamagng ,weget dA.

d oT
OT

-
la

balane we get.

kleat lo84
celd flud

(Th,-Ih2)
me e p CTa -To) -9

Th,-Th
mhlph 2.

Can be

T2 Th, -Tha T-TG

2.

|-Th, +Tha, + Te-Te

en 2 COns-Ta ) - (Ti, T6))

u
 D12 - UA
2

UA (6T, - 0T)

Heat thansen 9: UA LMTD

Nusett hag t Condenakon, a

mathmahal eprresson b estinae felm hiknew, velouly.

ond loal vale og Gondagkaat afu

dutibuhon corconakon overa Veial.
Coathen Ch) fr a feln
plat keyth t.
let us coniole
a verfhcal þlate oj lergs CL) as.
Sahnaad Sapaa
is mainjaiel atatempratus
whete senpue
wth Hi lplat
Conoloahon
 O ondanahon a vencal
Hhe Case
wese mada.
the folowung asunphons
Plate,

Flew Cordensato
be
linea
assned
þoopertes apo
Thenmophy eal
be constart. vapous l d
sties af lguid
shear
3) Thene

itefau Concdsnata fln

4). heat
distributos s aimedd

by condahön ad. tembrat

b belneas at adiatne
Condenat.

Conider Ihicenes
Let dy ba he
Hhi cenes d e ' Conto
balanee
Condenet
dinetbn F
dnetins
Verhia
volrne

Small
downuands
olekhr
liauid Cordomale

Grauitahinal e.9. dz.oy. ) -ladyde -o

doun wandls

dz.
Shuan foru
 he Corlongak

Lyz

Aeres hepaon west.

while waig Tayaois
d (Tye de) dy
Tyz
(ye dey dy
dn (Tyg dzy dyn
n)
rhe abe qeres tunated o twt
tust cvde
26
the hifen den tormej
derivetie by elinnatig
dz
d (t dz ) dy
dy L4).

Substitue equahon O,,

d
Pa dy dz t ye daly dy
Lyz dz ly
de
Sa dy dz + dTyz dy
condensat oboys, Newton5 Raw o
Vinohy, we get.
 Oquah¡n we ge
substiluh
uaho 6

dve]dy. dz
fg dy dz + dy

whee Yearargement we jet

(on)d2Ve -
dy
We get

d'v

J dy
dvz
dy

B.c1 AE y-0, V
(theu
At y=d
dV
B.c2

eguah => V, 2
 2

founab Condenaat at a distance Z

Mas
as,
be
kop edge
1.
dy

)(o-o

Codensatu.
Mass flow tate ot m e
6

al a difane2 fome hyedge

6.

m
-
3
d o'a)
Grdensat koraig m a n h a t dm
 382

3e

Condansat ladg
as
indiatus Aat
Hiceres
Condea filn
2+dz a n d

mas fow nal qcondenat chnea by

the

Condonsal. yak. bom

small elemay
OVe
balare
hile atpyng
we get
Condensat flm,

dm

dy haat
haat
Rat o
cdueted Ihroush
Aoased.
due to
Condenahon at ha

ligid Vapou
intef
RA
 quahon heget.
hile sulosktukig

- 14)

temperahve
Sune he
an unl.

profle, (15)
a t
b
T= T
At y =O
a t bCo) a

@y a Tw.

at yd. T- T
Sunslay at bf.

T t kbf

Ts - T

22uakos e
a d s vals
while
Ts-T

= T y.

dT
dy
Ts-Tw
) . 1,

dT
 aguahonlo e get.
anahon (%) in
while sulastjuhg

Ts-Tw

-
kb dz.

k dz (is-T)

de

whel integaing,
k u CTs-T

P'gA.
(Ts-Tw)z

4
(T5-Tw) 2.
4k

4ku C+s T) z. ]
Flm thiknes

Rab
Rah oq heat tente. condueted hrauy

frm apous htwnfo

k A TsTw
 ) inc9, wagoy
whle Subrktuhng

4Ru(s-Tu) z|4.

4.u(Ts-T)Z
k

4-1 (Ts-T)z
4

a.
local |4ucG-Tp).Z.

fha dz.
o.elhet

coetha
hs
heat tranfer Jde.
Avenage
dz o
m(Ts-T ZJ

dz
4 -ulis-TN)
 - 1)L

L. L4u CTs-Tw)

Average haat
hansfes coethiuos 4.

4 L
3 4m(Ts-Tw)

4 Cis-Tu ) L.

22L.

4
3. 4M(Ts-Tw

-4
- 44

h
 Ao.5 m Square blale eped

Saherafd s4ean at
a calolaho
þlale s too be mint aned at 18.5, make
hi cúencsloal Aeat tansfer caafhus
ay fem
af 2s n
voloy
awerase Reat anferoafhiue.

b) hansfonval to Hhe plae

heaf ansferate
rate and tofal
condenali
Tsat = 4)-5° and
bar,
fr satunab tempenahu
Sahnatd walr af hen
2qo2 kJg
P=995 |
kJ
K , k=2.2m.h'c
he hafpenhis

ui8.ol X10
plale )a 2:2
225cos,

rom the
f a s t 25 cn

4 k (Is -Tw) 2

(4bS-18s)A0.25

8.olxi0
4x 2.2 xo
3b00 995.)x 9-8)>x2402x g

l.482| X1o m
f-
0. l482
l482 mm
0.
Miuknes t :
 Qol.

loal heat k
thanfer h,oson
Coethuant
2.2
14843.Ao kJ

ocal eaf 4|23.28

Coeshius
Anotheswy
J.A

4A (Ts -T) z
q95-) x 9.8)x 2yo2x1°xa2x10)

3
96oo x 4X g.olx0 (4:S-8-5)x029

4 |23:29
he. moc.

velouy at2:0.25 m
Mean

9.8I% (-4y8 2)xuo)

3x 8-0lxwy

V b. 089

b) Avenage hodt kose

Coetie
 h O.443

: 0 . 443

2.2 Xuoo
ha 8.o1xco y 23x 0.S

0.443x \6-78 10x (0 -l4.

4623. 9s W
m',k

)
x(:sJ8:5)
46 23.s x oSx0.S

Sleann Cordtaho al m -

W.
26 S87.7)

24 02. >x o3