a
Co esponding au ho : k acik@ me. u b .cz
S udy o Tempe a u e Fields a Sp inkled Smoo h and Sandblas ed Tube
Bundle
Pe K acík1,a, Ladisla Šnajdá ek1 and JiĜí Pospíšil1
1Ins i u e o Powe Enginee ing, B no Uni e si y o Technology, Facul y o Mechanical Enginee ing, Technická 2896/2,
616 69 B no, The Czech Republic
Abs ac . The pape ocuses on he in luence o sp inkled ube su ace on dis ibu ion o empe a u e ields,
i.e. he hea ans e coe icien on he ubes su ace. Two ypes o ubes ha e been es ed, a smoo h one and
a sandblas ed one in pa icula . A ube bundle comp ises o hi een coppe ubes di ided in o wo ows and
i is loca ed in a low p essu e chambe whe e acuum is gene a ed using an exhaus e ia ejec o . The liquid
es ed was wa e a an absolu e p essu e in a chambe in be ween 97 kPa up o 10 kPa and a he mal g adien
55 o 30 °C. The low o he alling ilm liquid anged be ween ze o and 17 li es pe minu e.
1 In oduc ion
A a ho izon al ube bundle sp inkled by a liquid
o a low low a e, a hin liquid ilm is o med ha
acili a es e ec i e hea ans e . As he liquid lows,
he liquid phase is p omp ly sepa a ed om he apou
phase which inc eases he hea ans e coe icien .
This echnology is applied o ins ance a sea wa e
dis illa ion. This dis illa ion p inciple is based on low
empe a u es ha a y by ens o deg ees Cen ig a e bu i
is necessa y o adequa ely lowe he p essu e o he a ea
in which a ube bundle is posi ioned o enable
e apo a ion. The ad an age o his me hod is ha i can
u ilize low-po en ial was e hea o o he powe -p oducing
p ocesses.
The Eu opean coun ies and he USA emphasize
sa ing he p ima y uel en e ing powe -p oducing
p ocesses. Apa om boos ing e iciency o powe -
p oducing p ocesses and lowe ing ene gy consump ion
i is also possible o use he was e hea o coolness
p oduc ion. The e a e wo p edominan echnologies
o coolness p oduc ion. The i s me hod u ilizes
comp esso cooling de ices which a e, howe e , e y
hea y on elec ic powe . Abso p ion ci cula ion
ep esen s hei easible al e na i e. Al hough being
la ge and mo e expensi e, i consumes app oxima ely
one i h o he elec ic powe . The basic elemen
o a single-s age abso p ion ci cula ion consis s o wo
exchange s ope a ing in a low-p essu e en i onmen –
he abso be and he deso be . The hea ca ying agen 's
s eam is cooled in he abso be , abso bed in o
an abso ben ; excess hea mus be conduc ed away
p ope ly. In a simpli ied way, i is a sp inkled exchange
on he su ace o which he wa e s eam condensa es.
The p ima y hea is supplied o he cycle in deso be , so
he hea is p o ided o he cooling liquid and wa e boils
a ube su ace. And i is he s udy o he modynamic
mechanisms om he pe spec i e o sp inkle modes
when supplying hea o a cooling liquid ha his pape
ocuses on.
2 Sp inkle mode
A liquid lowing h ough a ho izon al ube bundle
may o m h ee basic sp inkle modes isible in Figu e 1.
These a e he D ople mode (a), he Je mode (b) and
he Memb ane (Shee ) mode (c). These h ee modes a e
he eina e e e ed o as he "D", "J" and "S" modes.
Figu e 1 Sp inkle Modes [1]
Wi h an inc easing alling ilm liquid low a e
he ansi ion om he D ople o he Je mode is de ined
by he o ma ion o one s able column o liquid in among
he d ople s ( his ansi ion mode will be he eina e
e e ed o as he "DĺJ" mode). The ansi ion om
he Je o he Memb ane (Shee ) mode is de ined by
he connec ion o wo columns and hei o ma ion o a
small iangula shee (he eina e e e ed o as
This is an Open Access a icle dis ibu ed unde he e ms o he C ea i e Commons A ibu ion License 2.0, which pe mi s un es ic ed use, dis ibu ion, and
ep oduc ion in any medium, p o ided he o iginal wo k is p ope ly ci ed.
DOI: 10.1051/
C
Owned by he au ho s, published by EDP Sciences, 2014
, 02060 (2014)
/201
67
epjcon
EPJ Web o Con e ences
46702060
A icle a ailable a h p://www.epj-con e ences.o g o h p://dx.doi.o g/10.1051/epjcon /20146702060
he "JĺS" mode). In his mode, columns and lea es exis
side by side. Wi h a dec easing alling ilm liquid low
a e he e e se p ocess akes place. Tha means ha
he o ma ion o a s able liquid low among he shee s is
e e ed o as he Shee -Column s a e (he eina e e e ed
o as he "SĺJ" mode) and he disin eg a ion o he i s
column in he Column mode and i s eplacemen
by d ople s changes he s a e o he Je -D ople mode
(he eina e e e ed o as he "JĺD" mode). In case ha
he ansi ion sp inkle mode is desc ibed wi hou
an a ow ma king he di ec ion o he alling ilm liquid
inc ease/dec ease bu wi h a dash, hen he change o
he low a e is no conside ed.
2.1 alling ilm liquid low a e change
A pa icula sp inkle mode is in luenced by
a numbe o ope a ional pa ame e s. The i s o hem is
he in luence o a change in he alling ilm liquid low
a e inc ease/dec ease on he dis ance be ween he d ople
columns, i.e. he equency o d ops, desc ibed in a s udy
conduc ed a he Vic o ia Uni e si y (Aus alia) [4].
An expe imen al se was cons uc ed a his uni e si y
in o de o e i y he nume ical model. I consis ed o
h ee iden ical cylinde s posi ioned in a pa allel way one
below he o he ( h ee diame e s we e es ed: 0.1 m,
0.05 m and 0.02 m). The sp inkle mode i sel was
eco ded by a digi al came a eco de . The Figu e 2
illus a es he dependence o he d op equency (i.e.
he numbe o d ops pe second o all on o he middle
cylinde ) and he dimensionless wa eleng h (i.e.
he wa eleng h desc ibing he dis ance be ween
he d ople columns di ided by su ace ension, also
e e ed o as capilla y cons an ) on he Reynolds
numbe .
Figu e 2 Dependence o d op equency and dimensionless
wa eleng h on he Reynolds numbe [4]
This Figu e shows hese wo quan i ies
o a mono onously inc easing and dec easing low a e.
Measu ing was conduc ed in he Reynolds numbe ange
o 20 – 150 [-] and i was disco e ed ha he dependence
o he equency on he Reynolds numbe is e y simila ,
howe e , when dec easing he low a e he d ops s a ed
o sepa a e in a sligh ly slowe pace in compa ison
wi h he inc easing low a e, which is isible pa icula ly
in he Reynolds numbe ange o app ox. 50 – 100 [-].
The eason o hese sligh ly lowe alues o d ops
sepa a ion can be deduc ed om he dimensionless
wa eleng h whe e a he dec easing low a e he liquid
a he middle cylinde ends o main ain he cu en s a e
as long as possible, i.e. he dis ance be ween he d ople
columns ge s e en sho e which na u ally esul s in
he lowe numbe o d ops. A he Reynolds numbe
o app ox. 70 [-] a u ning poin occu s whe e he low
a e is dec eased o he ex en ha he dis ance be ween
he d ople columns s a s o inc ease apidly, i.e. he d op
equency s a s o dec ease sha ply.
The in luence o he low a e changes a a ious
diame e s o sp inkled ubes was also esea ched
o ins ance by Hu and Jacobi [3]. To conduc hei
esea ch hey ha e c ea ed an ae odynamic unnel
o ac yla e anspa en plas ic o he c oss sec ion
dimensions 203.2 x 304.8 mm whe e he speed o ai
low mo ing in he opposi e di ec ion o he alling ilm
liquid low anged be ween 1.0 and 15.0 mÂs-1. The ube
bundle es ed consis ed o a dis ibu ion ube,
a s abiliza ion ube ha was posi ioned 1.4 mm below he
dis ibu ion ube, a es ed ube, a landing ube and
a collec ing channel. The e we e ape u es o 1.0 mm
diame e d illed in o he dis ibu ion ube a 1.5 mm spans
along he leng h o 229 mm. The ube diame e s es ed
we e 9.5; 12.7; 15.9; 19.0 and 22.2 mm.
Fo he sp inkled ube bundle in a s ill a mosphe e
( lowing ai speed in he ube su oundings comes close
o ze o) Hu and Jacobi [3] e i ied he con enience
o dependence be ween he Reynolds numbe ha
desc ibes a hyd odynamic low mode and he Galilei
numbe ha desc ibes he liquid low esul ing om
g a i a ion, o de ine he ansi ion o indi idual sp inkle
modes. This dependence can be gene ally exp essed
in he o m
Re = Aڄ(Ga)B (1)
whe e bo h dimensionless c i e ia co e se en physical
pa ame e s al oge he ; i.e. he alling ilm liquid low
a e, he alling ilm liquid dynamic iscosi y, he alling
ilm liquid densi y, he alling ilm liquid su ace ension,
he sp inkled ube diame e , he gap be ween
he sp inkled ubes and he g a i a ional accele a ion.
In he s ill mode i was disco e ed ha
he ansi ions be ween he indi idual sp inkle modes
a y wi h an inc easing and dec easing low a e and
c i e ial equa ions we e de e mined o hese modes
acco ding o he equa ion (1) whe e he "A" and "B"
cons an s a e gi en in Table 1 oge he wi h a ela i e
e o o each equa ion
Figu e 3 desc ibes bo de s a inc easing and
dec easing alling ilm liquid low a e acco ding o
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he men ioned equa ions a a mosphe ic p essu e and
wa e empe a u es 30 °C and 55 °C, which co esponds
on he basis o [9] o a modi ied Galilei numbe
Ga0.25 § 476 and 751 [-].
Table 1 Coe icien s o equa ion (1) o de e mine he low
mode acco ding o Hu and Jacobi [3]
a) Inc easing low
D ĺ D-J D-J ĺ J J ĺ J-S J-Sĺ S
A B A B A B A B
0.121 0.284 0.159 0.282 1.880 0.222 2.088 0.220
(8.5 %) (6.6 %) (4.3 %) (4.2 %)
b) Dec easing low
S ĺ S-J S-Jĺ J J ĺ J-D J-Dĺ D
A B A B A B A B
1.004 0.250 1.064 0.244 0.057 0.321 0.045 0.321
(3.9 %) (3.8 %) (8.4 %) (6.2 %)
Figu e 3 Sp inkle mode bo de s a inc easing and dec easing
low a e acco ding o Hu and Jacobi [3]
2.2 In luence o sp inkled ube diame e
In he s udy men ioned abo e [4] he cylinde
diame e in luence on he d op equency and
on he dimensionless wa eleng h in ela ion
o he Reynolds numbe was esea ched, as displayed
in Figu e 4 o he lowe ( hi d) cylinde . The igh
ho izon al axis s ands o he d op equency, i.e. how
many d ops ha e sepa a ed om he middle cylinde pe
second. The da a p esen ed in his Figu e ha e only been
ob ained by measu ing and hey ha e no been compa ed
wi h a nume ical model. The 0.1 m, 0.05 m and 0.02 m
diame e s we e s udied and hey a e ma ked
in he diag am legend as " eq. – exp. D = …". The
measu ed alues demons a e a signi ican mode s abili y
a e he Reynolds numbe alue 100 [-] has been
eached. Howe e , he inc ease p eceding his alue has
been ela i ely s eady despi e he ac ha i amoun s o
app ox. 24% a 0.02 m diame e , app ox. 44%
a he 0.05 m diame e and 38% a he la ges 0.1 m
diame e . The au ho s do no s a e he span and su ace
ype o cylinde s.
Figu e 4 In luence o cylinde diame e on d op equency and
dimensionless wa eleng h [4]
The uppe hal o he Figu e 4 illus a es
he dependences o he dimensionless wa eleng h
on he Reynolds numbe o all h ee s udied diame e s.
The esul s o he expe imen (ma ked in he legend
as "exp. D = ...") and o he nume ical model (ma ked
in he legend as "model D = ...") a e compa ed o each
diame e . The au ho s ound ou ha he di e ence
o esul s be ween he expe imen and he nume ical
model go smalle wi h a dec easing diame e .
The au ho s gi e he de ia ion anging be ween 1% and
2% a he smalles diame e , be ween 1.0% and 4.5%
a he middle diame e and be ween 1.0% and 13.7%
a he la ges diame e . The inal s abili y
o he Reynolds numbe alue 100 [-] achie emen ha
occu ed a hese bo de s as well as a he d op equency
p o es no able, al hough he s abili y a his quan i y has
been much mo e signi ican .
2.3 In luence o sp inkled ubes span
The in luence o he gap be ween he sp inkled
p o iles on he low mode ype was es ed by Wang e al.
[8]. The bundle es ed comp ised o a dis ibu ion ube
ou o which a liquid was lowing ( he subs ances es ed
we e e hylene glycol and wa e ), a ube o ci cula c oss-
sec ion he pu pose o which was o egula e he alling
ilm liquid dis ibu ion and wo la ubes ha c ea ed
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a gap ha demons a ed he low mode. The la ubes
es ed we e made o a polished aluminium
o he dimensions 400 x 25.4 x 3.18 mm (leng h x heigh
x wid h). The measu ing i sel was p eceded by a 2 o
3 hou ube sp inkling in o de o ensu e an ideal
adhe ence o liquid o he su ace (so ha he su ace was
ideally we able). The measu emen p ocedu e was
ollowed o dec ease he low a e om he maximum
and a e he ze o low a e had been eached, i was
again inc eased o he maximum possible a e.
The measu emen was epea ed h ee imes o each
p o ile gap and only a e hese esul s we e ob ained
he Reynolds numbe s o he gi en mode ansi ion and
he ela i e e o o hese alues we e de e mined.
Table 2 Reynolds numbe s o a ious ube pi ches acco ding
o Wang e al. [8]
a) Inc easing low
s-D [mm] D ĺ D-J D-J ĺ J J ĺ J-S J-S ĺ S
4.8 203 259 363 395
6.4 231 293 390 427
9.5 230 298 430 459
14.5 244 320 435 473
19.4 262 336 434 481
24.5 268 348 448 512
RMS% 4.21 1.40 0.84 2.34
b) Dec easing low
s-D [mm] S ĺ S-J S-J ĺ J J ĺ J-D J-D ĺ D
4.8 395 365 268 209
6.4 429 389 289 230
9.5 461 427 297 227
14.5 470 426 328 236
19.4 486 431 335 262
24.5 513 449 341 264
RMS% 0.87 0.77 1.53 4.53
Table 2 p o ides an o e iew o he measu emen
esul s whe e wa e o app oxima ely he same physical
p ope ies ha we e exp essed by he au ho s by means
o he modi ied Galilei numbe Ga0.25 § 450 [-] was used
as he alling ilm liquid. This alue a a mosphe ic
p essu e (101 325 Pa) co esponds wi h he wa e
empe a u e o app ox. 27.4 °C ( ound in [9]).
To achie e he gi en measu emen esul s,
he au ho s se he gap be ween he s abiliza ion ube and
he i s p o ile o 2.0 mm. Thei esul s sugges ha
he la ge he gap be ween he sp inkled p o iles,
he highe he Reynolds numbe o he gi en sp inkle
mode. This inc ease, howe e , did no p o e o be s eady,
i.e. in one case o he gap inc ease he nex Reynolds
numbe was e en lowe by app ox. 1.0% which does no
seem o be a co ec alue as he inc easing gap causes
he ho izon al sp inkled diame e o inc ease as well and
he e o e mo e liquid, i.e. highe low a e, is necessa y
a a la ge gap in o de o achie e he same sp inkle
mode. When compa ing he Reynolds numbe s belonging
o he smalles and he la ges gaps be ween he p o iles
a indi idual modes he inc ease anges be ween app ox.
23% and 32%. The di e ence o he Reynolds numbe s
be ween he inc easing and dec easing low a e
a indi idual s a es equals on a e age 1.1% wi h a
s anda d de ia ion o 1.1%.
2.4 Comp ehensi e de e mina ion o sp inkle mode
a eas
In he abo e men ioned s udy by Hu and Jacobi [3]
he conclusion was eached on he basis
o he measu emen ha nei he he diame e o sp inkled
ubes no he gap be ween hem exe cises any signi ican
in luence on a sp inkle mode. The es ed a io o he gap
be ween ubes and he sp inkled ube diame e anged
app ox. om 0.22 o 5.3 [-]. Fo he pu poses o p ac ical
applica ion and compa ison wi h o he au ho s equa ions
o indi idual modes we e c ea ed wi hou dis inguishing
he inc ease o dec ease o he alling ilm liquid low
a e, while he ela i e e o did no signi ican ly inc ease.
Cons an s o indi idual equa ions de i ed om
he equa ion (1) a e gi en in Table 3, i.e. hey a e
displayed in Figu e 5 in he Reynolds numbe and
he modi ied Galilei numbe ange 0 o 600 [-].
Figu e 5 Sp inkle modes bo de s acco ding o Hu and Jacobi
[3]
Figu e 5 also illus a es h ee Je mode ypes ha
Hu and Jacobi speci ied. The i s one is a so called "in-
line" Je mode ype. This mode ype occu s a low alling
ilm liquid low a es and he liquid alls down
in columns ha a e connec ed in on o he ube and
behind i . I.e. hey c ea e a single ow and hey do no
mo e e ically. The bo de o his mode is de e mined
by he equa ion (2) ha does no dis inguish he inc ease
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o dec ease o he low a e and he ela i e e o
o he equa ion is 12.5%.
Re = 20.53 + 0.256·(Ga)0.25 (2)
The o he wo phases o he Je mode a e s a es whe e
in he i s case he columns pendula e e ically a ound
an imagina y poin and in he second case he way
columns mo e can no longe be p edic ed. The bo de
be ween hese phases is de e mined o inc easing and
dec easing alling ilm liquid low a e in he equa ion
(3), whe e he ela i e e o o he equa ion is se a 8.3%.
Re = 47.42 + 0.600·(Ga)0.25 (2)
O he au ho s who deal wi h expe imen al di ision
o sp inkle modes a e A mb us e and Mi o ic who
published he esul s o hei esea ch o ins ance in [2].
Thei expe imen al de ice consis ed o a dis ibu ion
essel o 260 mm leng h wi h ape u es o 1 mm diame e
a 3 mm span a he bo om, a s abiliza ion ube o 18 mm
diame e posi ioned di ec ly below he ape u es, a es
ube (also o 18 mm diame e ) and a collec ion d ain.
The liquid es ed was dis illed wa e in empe a u e ange
om 15 o 55 °C. The mass low o wa e anged
be ween 0.02 and 0.24 kg/(sÂm) and i was de e mined
by a di e en ial me hod, i.e. by weighing he dis ibu ion
essel bo h be o e and a e he pa icula mode es ing.
F om he alues measu ed o indi idual bo de s
he unc ional dependence was se acco ding
o he equa ion (1) and he inal cons an s a e gi en
in Table 3. Howe e , no ela i e e o is men ioned
a hei equa ions.
Table 3 Reynolds numbe s o a ious ube pi ches acco ding
o Wang e al. [8]
A mb us e
and Mi o ic
[2]
Hu and
Jacobi [3]
Roques e al.
[7]
D –
D-J
A 0.200 0 0.074
(11.0
%)
0.041 7
B 0.250 0 0.302 0.327 8
D-J
– J
A 0.260 0 0.096
(11.2
%)
0.068 3
B 0.250 0 0.301 0.320 4
J –
J-S
A 0.920 0 1.414
(5.8
%)
0.855 3
B 0.250 0 0.233 0.248 3
J-S –
S
A 1.140 0 1.448
(6.6
%)
1.068 0
B 0.250 0 0.236 0.256 3
Table 3 also shows he esul s o Roques e al. [7].
In o de o de e mine sp inkle modes hey c ea ed
an expe imen al de ice consis ing o a dis ibu ion essel
wi h a la bo om o 260 x 10 mm and d illed ape u es
o 1.0 mm diame e a 2.0 mm span along he leng h
o 200 mm. The e we e h ee es ed coppe ubes o 19.04
mm posi ioned below he bo om ha ha e been
sandblas ed be o e he es ing i sel and hus hollows
o app ox. 0.3 ȝm o 2.0 ȝm we e o med a hei su ace.
Figu e 6 Compa ison o sp inkle modes' bo de s by a ious
au ho s
Figu e 6 p esen s a compa ison o indi idual
sp inkle modes' bo de s desc ibed by he abo e
men ioned au ho s and he cons an s de e mined by hem
gi en in Table 3 in o he equa ion (1). Values
in he diag am a e displayed in a loga i hmic scale; i.e.
he Reynolds numbe in he ange om 10 o 1 000 [-]
and he modi ied Galilei numbe in he ange om 50
o 1 000 [-]. The diag am clea ly shows a ce ain
co espondence o he end be ween he Je and he Shee
mode, bu in he case o a ansi ion om he Je
o he D ople mode i is no so e iden . The na owes
ansi ion s ips a e in he case o Hu and Jacobi, which is
30% o 60% compa ed o A mb us e and Mi o ic, bu
hei da a we e ob ained a a smalle expe imen al
sample.
3 Expe imen al de ice
Fo he pu pose o hea ans e a sp inkled ube
bundles esea ch an expe imen al de ice has been
cons uc ed consis ing o a cylinde essel o 1.2 m
leng h wi h a ube bundle posi ioned inside. Vacuum is
gene a ed in he chambe using an exhaus e ia ejec o .
Tube bundle wi h a geome y isible in Figu e 7 consis s
o coppe ubes o 12 mm ou e diame e .
Two geome ically iden ical ube bundles
di e en ia ed by a sp inkled ube su ace we e s udied.
The i s bundle consis ed o smoo h ubes and he second
one o sandblas ed ubes. The di e ence be ween
he indi idual su ace ypes is isible in Figu e 8.
EFM 2013
02060-p.5

Figu e 7 Simpli ied diag am o ube bundle
Figu e 8 Sp inkled ube su ace ypes (smoo h one on he le
and sandblas ed one on he igh )
Fu he de ails on he expe imen al de ice a e
published o ins ance a [5, 6] including pa ial
measu emen esul s.
The calcula ion o he hea ans e coe icien
in his pape is based on he he mal balance acco ding
o he law o conse a ion o ene gy based on a simpli ied
diag am in Figu e 7, he New on's law o hea ans e
and he Fou ie 's law o hea conduc ion.
4 Measu emen esul s
The expe imen s desc ibed in his pape in ol ed
he hea ing o a alling ilm liquid. Tha means ha ho
wa e o he a e age inpu empe a u e 55.2 °C and
he a e age low a e 12.4 l·min was lowing inside
smoo h ubes-1. The a e age alling ilm liquid
empe a u e a he dis ibu ion ube ou le was 29.9 °C
and he es ed alling ilm liquid low a e anged
om 0 o 15.8 l·min-1. In case o sandblas ed ubes ho
wa e o he a e age inpu empe a u e 55.1 °C and
he a e age low a e 13.7 l·min-1 was lowing and
he exchange was sp inkled by cold wa e o a e age
empe a u e a he dis ibu ion ube ou le o 29.8 °C and
he olume ic low a e anged be ween ze o and
16.1 l·min-1. Tes ed ange o an absolu e p essu e
in he chambe anged in bo h cases om 12.3 kPa(a)
o he a mosphe ic p essu e ha was a he ime
o measu emen 96.8 kPa(a) on a e age.
Figu e 9 Images o he mog aphic measu emen
Figu e 8 shows images o he mog aphic
measu emen eco ded by a he mog aphic came a FLIR
SC 660 wi h he esolu ion o 640 x 480 pixels du ing he
whole measu ing p ocess a smoo h and sandblas ed
ubes. The scale o all images anges be ween 25 – 60 °C
and he exchange g adien is he abo e men ioned 55 °C
o 30 °C. The alling ilm liquid ou le om a dis ibu ion
ube is isible a he uppe pa o he images. The i s
image was cap u ed du ing he alling ilm liquid low
a e 3.5 l·min-1 and i is a pu e D ople mode. The second
image eco ds he low a e o 5.5 l·min-1 and due
o a su icien amoun o liquid i s columns can
be dis inguished. This bo de was app oxima ely
he same in smoo h and sandblas ed ubes. The hi d and
ou h image display he low a e 7.5 and 10.2 l·min-1,
EPJ Web o Con e ences
02060-p.6
espec i ely. A g adual inc ease in he numbe
o columns and a co esponding dec ease o d ops can
be obse ed. In spi e o his ac he D ople mode
domina es in he lowe pa o he bundle. The las image
illus a es he low a e 12.4 l·min-1 ha is app oxima ely
he op bo de o he D ople -Je mode.
Figu e 10 Wa e o ms o empe a u e in exchange and o mean
hea ans e coe icien a ube su ace in ela ion o alling ilm
wa e low a e
Figu e 10 depic s he cooling liquid empe a u e
( he liquid lowing inside he ubes) in ela ion o
he alling ilm liquid low a e. The empe a u es we e
measu ed a he beginning ( 5) and a he end
o he bundle ( 6; he bundle's leng h is 12.22 m) and
a e wa ds he empe a u es we e measu ed a 2.86 m ( 13)
and 8.46 m ( 15; conside ed in he di ec ion opposi e
o he cooling liquid low) du ing he sp inkling p ocess.
Full cu es ep esen he smoo h- ube exchange and
he dashed cu es illus a e he sandblas ed- ube
exchange .
The same image also displays he wa e o ms
o he s udied ans e coe icien in smoo h and
sandblas ed ubes wi h a ela i e e o 4.3% ±4.3
in smoo h ubes and 4.7% ±4.3 in sandblas ed ubes.
These wa e o ms we e de e mined om he o al numbe
o 4 487 measu ed poin s.
5 Conclusions
The pape 's objec i e was o b ie ly desc ibe basic
po en ial he modynamic in e connec ions
om he pe spec i e o alling ilm liquid and basic
physical pa ame e s ha exe cise hei in luence
on a sp inkle mode. The e a e a ious s udies dealing
wi h he basic sp inkle modes' phases and hei
ansi ions, howe e , no gene al consensus has been
eached as o which pa ame e s ha e a p ac ical in luence
on a sp inkle mode. The esea ch conduc ed a he B no
Uni e si y o Technology, Ene gy Ins i u e, dep .
o Powe Enginee ing aims o delinea e hese
mechanisms. This pape p esen s he esul s ha ha e
been s udied a wo geome ically iden ical exchange s
di e en ia ed by a su ace ype; in pa icula a smoo h
one and a sandblas ed one.
Due o he ube bundle size and he alling ilm
liquid olume ic low a e only he Je mode (S agge ed)
has been eached a maximum low a e. Based on
a isual obse a ion, he ansi ions co esponding bes
we e hose de ined by A mb us e and Mi o ic (1994).
In ou case, howe e , he e is a eal bundle, no only h ee
ubes posi ioned ho izon ally one below each o he .
The empe a u e in his bundle a ies acco ding
o he heigh and he e o e indi idual modes occu
successi ely and i is di icul o de e mine one speci ic
mode di ec ly.
The main esul s o ou esea ch ac i i y a e
p esen ed in Figu e 10. This Figu e shows ou
empe a u es measu ed inside he exchange .
As he empe a u e change clea ly sugges s, he e is
a smalle he mal g adien in sandblas ed ubes
in compa ison o smoo h ones a low low a es and
consequen ly his pa also p o es a lowe hea ans e
coe icien a ube su ace. A possible eason o his can
be an incomple e wa e w apping o he sandblas ed ube
su ace due o i s oughness. Howe e , he low a e
inc ease makes his di e ence diminish. This can be
caused by an al eady exis ing complex s abilized wa e
ilm ha he main s eam slides along and ha is hicke
han in smoo h ube.
Ou u he esea ch will ocus on o he ypes
o ube su aces and hei in luence on he hea ans e
coe icien and a ious admix u es bo h soluble and
insoluble in wa e which a ec he su ace ension
a dec easing p essu e and we would like o iden i y
he ad an age o low p essu e inside a chambe as he
hea ans e coe icien eac s di e en ly wi h some low
a es a ube bundle han a coe icien measu ed a one,
wo o h ee ubes placed ho izon ally one
abo e he o he .
Acknowledgemen
This pape was c ea ed wi h he inancial suppo
o he Czech Science Founda ion wi hin
he P101/10/1669 g an and he NETME Cen e p ojec
unded by he Ope a ional P og amme Resea ch and
De elopmen o Inno a ions ha is co- unded by ERDF
(Eu opean Regional De elopmen Fund).
EFM 2013
02060-p.7
Re e ences
1. A mb us e , R. J. Mi o ic, Expe imen al The mal
and Fluid Science 18 (3), 183 (1998)
2. A mb us e , R. J. Mi o ic, P oceedings o he 10 h
in e na ional hea ans e con e ence 3, 275 (1994)
3. Hu, X. A. M. Jacobi, Jou nal o Hea T ans e 118
(3), 616 (1996)
4. Ja a , Tho pe and Tu an, Compu a ional luid
dynamics se en h in e na ional con e ence on CFD in he
mine als and p ocess indus ies. (2009)
5. P. K acík, J. Pospíšil, L. Šnajdá ek, Ac a
Poly echnica 52 (3), 48 (2012)
6. P. K acík, L. Šnajdá ek, J. Pospíšil, EPJ Web o
Con e ences 45 (01052), (2013)
7. J.F. Roques, V. Dupon and J. R. Thome. Jou nal o
Hea T ans e [online] 124 (3), 491 (2002)
8. X. Wang, P. S. H njak, S. Elbel, A. M. Jacobi and
M. He, Jou nal o Hea T ans e 124 (2), 1 (2012)
8. X-ENG. X S eam Tables o MS Excel [poþí aþo ý
soubo .xls]. Ve . 2.6. [online].
[ci . 30.11.2010]. F eewa e. <h p://www.x-
eng.com/XS eam_Excel.h m>.
Nomencla u e
A, B [-] cons an s in he equa in (1)
Į [WÂm-2ÂK-1] hea ans e coe icien
D [m] diame e
D d ople mode
D-J d ople – je mode
exp. expe imen
eq. equncy
Ga [-] Galileo numbe
J je mode
J-D je – d ople mode
J-S je – shee mode
p [Pa] p essu e
Re [-] Reynolds numbe
S shee mode
S-J shee – je mode
[°C] empe a u e
V [m3Âs-1] olume ic low
Subsc ip s
1 condi ion o alling ilm liquid in dis ibu ion ube
2 condi ion o alling ilm liquid a essel bo om
5 condi ion o he cooling/hea ing liquid a loop inpu
6 condi ion o he cooling/hea ing liquid a loop
ou pu
o condi ion ou side he ube
V acuum loop
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