PENGUJIAN KARAKTERISTIK PERPINDAHAN PANAS DAN FAKTOR GESEKAN PADA PENUKAR KALOR PIPA KONSENTRIK SALURAN PERSEGI DENGAN FAKULTAS TEKNIK UNIVERSITAS SEBELAS MARET CLASSIC TWISTED TAPE DAN PERFORATED TWISTED TAPE INSERT

KUNCORO, BROTO (2011) PENGUJIAN KARAKTERISTIK PERPINDAHAN PANAS DAN FAKTOR GESEKAN PADA PENUKAR KALOR PIPA KONSENTRIK SALURAN PERSEGI DENGAN FAKULTAS TEKNIK UNIVERSITAS SEBELAS MARET CLASSIC TWISTED TAPE DAN PERFORATED TWISTED TAPE INSERT. Other thesis, Universitas Sebelas Maret.

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    Abstract

    The research was conducted to examine the characteristics of heat transfer and friction factor in the rectangular channel heat exchanger with a classic twisted tape inserts and perforated twisted tape insert. Test section was the single pass concentric tube heat exchanger with inner tube and outer tube made of aluminum. The dimensions of the outer tube were 23.05 mm x 23.05 mm for the outer side and 21.75 mm x 21.75 mm for the inner side, whereas the dimensions of the inner tube were 18.50 mm x 18.50 mm for the outer side and 17.20 mm x 17.20 mm for the inner side. The length of heat exchanger was 1,998 mm and the length of pressure difference measurement in the inner tube was 2,018 mm. Flows in the inner tube and in annulus were in opposite directions. Working fluid in the inner tube was hot water which its inlet temperature was maintained at 60°C, whereas in the annulus was cold water at ± 28oC. Both of classic twisted tape insert and perforated twisted tape insert with a twist ratio of 4.0 were made of aluminum strips with a thickness of 0.76 mm and width of 12.61 mm which it was twisted so forming twist with the length of pitch was 50.35 mm. Perforated twisted tape inserts I and II were punched with hole diameter of 4 mm and 6.5 mm, respectively, where the distance between the center hole of 4 mm. Twisted tape insert installed in the inner tube of the concentric tube heat exchanger. The results showed that at the same Reynolds number, the addition of classic twisted tape insert, perforated twisted tape insert I and perforated twisted tape insert II in the inner tube increasing the average Nusselt numbers were 40.83 %, 16.80%, and 31% than the inner tube without a twisted tape insert (plain tube), respectively. At the same pumping power, the average Nusselt number in the inner tube with classic twisted tape insert, perforated twisted tape insert I, and perforated twisted tape insert II increased 27.21%, 12.41%, and 15.07% than the plain tube, respectively. At the same Reynolds number, the addition of classic twisted tape inserts, perforated twisted tape insert I and perforated twisted tape insert II in the inner tube increased the average friction factor 3.19, 1.89, and 2.71 times than plain tube, respectively. At the same pumping power , the addition of classic twisted tape inserts, perforated twisted tape insert I and perforated twisted tape insert II the average friction factor increased 4.51, 1.85, and 3.41 times than plain tube, respectively. The average thermal performance of inner tube with the addition of classic twisted tape inserts, perforated twisted tape insert I and perforated twisted tape insert II were 1.26, 1.13, and 1.11, respectively. Keywords : Nusselt number, Reynolds number, classic twisted tape, friction factor, perforated twisted tape

    Item Type: Thesis (Other)
    Subjects: T Technology > TJ Mechanical engineering and machinery
    Divisions: Fakultas Teknik > Teknik Mesin
    Depositing User: Ayu Purnama Sari
    Date Deposited: 15 Jul 2013 16:51
    Last Modified: 15 Jul 2013 16:51
    URI: https://eprints.uns.ac.id/id/eprint/4479

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