PENGUJIAN KARAKTERISTIK PERPINDAHAN PANAS DAN FAKTOR GESEKAN PADA PENUKAR KALOR PIPA KONSENTRIK SALURAN PERSEGI DENGAN TWISTED TAPE INSERT WITH CENTRE WING
Abstract: This research was conducted to examine the characteristics of heat
transferand friction factor in a
square channel concentric
tube heat exchanger with the addition
of twisted tape insert
with centre wing.
The test section
was a single pass
concentric tube heat
exchanger with inner
tube and outer
tube made of aluminum.
The length of
heat exchanger was 2,170
mm and the length of pressure drop measurement in the inner
tube was 2,255 mm. Flows in
the inner tube
and annulus were
counter flow. Working
fluid in the
inner tube was hot
water. The temperature
of hot water
in the inner
tube was maintained at 60°C,
where as the working fluid in the annulus was cold water and maintained at ± 28oC.
Inner tube without twisted tape insert (plain tube) and inner tube with twisted
tape insert were also analyzed for comparison. All twisted tapes
were made of
aluminum strip with
a thickness of
0.7 mm and 12.6 mm width, which had a twist ratio of
4.0 and the pitch length of 59.3 mm. While the twisted tape inserts with centre
wing was varied with wings angle of 20°,
40° and 60°.
Classic twisted tape
insert and twisted
tape inserts with centre wing
were installed in
the inner tube
of the concentric
tube heat exchanger. The results
showed that the inner tube with the addition of twisted tape insert
with centre wing
produced Nusselt number,
friction factor and thermal performance that was greater than
the addition of classic twisted tape insert
and plain tube.
Values of Nusselt
number, friction factor
and thermal performance is
also increased with
increasing angle of
attack. At the
same Reynolds number, the
addition of classic twisted tape insert
and twisted tape insert with a
wings angle 20°,
40° and 60°
at centre wing
showed the increasing of average
Nusselt number in the inner
tube at 25.91%;
53.88%; 69.67% and 76.86%,
the friction factor
at 2.55; 3.28;
3.77 and 4.05
times, the average thermal
performance at 1.105; 1.293;
1.372 and 1.403
when compared to the
plain tube, respectively. At the
same pumping power,
the addition of classic
twisted tape insert
and twisted tape
insert with a
wings angle 20°, 40° and 60° at centre wing showed the increasing
average Nusselt number in the
inner tube at
14.53%; 24.76%; 34.78%
and 37.81%, the friction
factor at 2.9; 3.88;
4.41 and 4.78,
the average thermal
performance at 1.104; 1.13;
1.28 and 1.30
times when compared to
the plain tube, respectively.
Penulis: Anang Fatkhur R,
Wibawa Endra J, Tri istanto
Kode Jurnal: jptmesindd120002
