PENGUJIAN KARAKTERISTIK ALIRAN FASA TUNGGAL ALIRAN AIR VERTIKAL KE ATAS PADA PENUKAR KALOR SALURAN RECTANGULAR BERCELAH SEMPIT
Abstract: This research
was conducted to
investigate the flow
characteristics of single phase
vertical upward water
flow with/without heat
exchange in narrow
gap rectangular channel heat
exchanger. Test section
was a concentric
tube heat exchanger. The
inner tube was
made of aluminium
with inner side
and outer side lengths of 17. 4
mm and 18.4 mm. The outer tube was made of aluminium with inner side and outer
side lengths of 23.68 mm and 24.68 mm. The pressure measuring length was 1,200
mm. Hydraulic diameter of the narrow rectangular channel was 5.28 mm. Flows in the inner tube and in
annulus were in opposite directions.
Working fluid used
in this research
was water. For
the flow with heat exchange, the water temperature at
the inlet of inner tube was maintained at 60oC. In the research, the
mass flow rate and pressure drop across narrow annulus were measured at steady states.
Results of the research were compared with predictions from conventional flow
theory. Results of the research shown that
the flow characteristics of
water through the
narrow annulus were different from those in conventional
pipes. For the flow without heat exchange in
narrow annulus, the
flow transition from
laminar to turbulent
flow was initiated earlier
than that in
normal pipes at
a Reynolds number
range from 1,850 to 2,333. The
flow transition with heat exchange occurred for a Reynolds number in the range
of 1,657 to 2,245. Flow friction factor of the
downward flow with heat
exchange was larger
than that without
heat exchange at the
Reynolds number was
lower than 734.
The flow friction
characteristics in narrow annulus
had relations to the liquid
temperature difference at the inlet and
outlet of the
annulus. Their influences
on the flow
friction were concentrated in the
laminar flow area.
Penulis: Wibawa Endra J, Tri
Istanto, Ahmad Khusaeni
Kode Jurnal: jptmesindd100002
