PENGUJIAN KARAKTERISTIK PERPINDAHAN PANAS DAN FAKTOR GESEKAN PADA PENUKAR KALOR PIPA KONSENTRIK SALURAN ANNULAR DENGAN ALTERNATE CLOCKWISE AND COUNTER CLOCKWISE TWISTED TAPE INSERT
Abstract: This research was conducted to examine the characteristics of heat
transferand friction factor in the
annular channel concentric
tube heat exchangerwith the addition of alternate
clockwise and counter clockwise (C-CC) twisted tape insert with the twist angle
variation (θ) = 30o, 45 o, and 60o. Test
section was the single pass concentric tube heat exchanger with inner tube and
outer tube made of aluminum. Flows in the inner tube and in annulus were
counter flow. Working fluid in the inner tube was hot water which its inlet
temperature was maintained at
60°C, whereas the
working fluid in
the annulus was
cold water with its inlet temperature of ± 28o . Classic
twisted tape insert and C-CC twisted tape inserts with twist angle (θ) = 30o,
45 o and 60o installed in the inner tube of the
concentric tube heat exchanger. For comparison, inner tube tested without
twisted tape insert (plain tube) and with the addition of classic twisted tape
insert. Classic twisted
tape insert and
C-CC twisted tape
insert made of aluminum strip with a thickness of 0.7 mm, width 12.6 mm,
which had a twist ratio of
4.0 and the pitch length
of 50.3 mm. The
research result has showed
that the concentric
tube heat exchanger
with the addition
of C-CC twisted tape insert
with θ = 30o, 45oand 60o into its inner
tube produce Nusselt number,
pressure drop, friction
factor and thermal
performance greater than the classic twisted tape insert. C-CC twisted
tape insert with θ = 60o has produced Nusselt numbers, pressure
drop, friction factor and thermal performance higher than
the C-CC twisted tape insert with
θ = 30o and 45o.
The addition of
C-CC twisted tape
insert has resulted
in enhancement heat transfer
better than the
classic twisted tape
insert. At the
same Reynolds number, the
addition of classic
twisted tape insert,
C-CC twisted tape
insert with θ = 30o,
45oand 60o into the
inner tube increase
the average Nusselt numbers has
been 45.82%, 51.34%,
60.23%, and 70.02%
compared to the plain tube, respectively. At the same
Reynolds number, the addition of classic twisted tape
insert, C-CC twisted tape insert
with θ = 30o, 45oand 60o into inner tube
has produced an
average friction factor
of 3.020; 3.223; 3.473; and
3.737 times than the
friction factor of
plain tube, respectively.
The addition of classic twisted tape insert, C-CC twisted tape insert
with θ = 30o, 45oand 60o into the inner tube
has produced an average thermal performance of 1.001; 1.011; 1.045; and 1.085,
respectively.
Keywords: Nusselt number, Reynolds
number, Friction factor, Alternate
clockwise and counter clockwise
twisted tape insert, Twist angle
Penulis: Sudardi Gus Utama,
Tri Istanto, Wibawa Endra Juwana
Kode Jurnal: jptmesindd120014
