PENGUJIAN KARAKTERISTIK PERPINDAHAN PANAS DAN FAKTOR GESEKAN PADA PENUKAR KALOR PIPA KONSENTRIK DENGAN PERFORATED TWISTED TAPE INSERT

PARINGGA, NOVITA (2015) PENGUJIAN KARAKTERISTIK PERPINDAHAN PANAS DAN FAKTOR GESEKAN PADA PENUKAR KALOR PIPA KONSENTRIK DENGAN PERFORATED TWISTED TAPE INSERT. Other thesis, Universitas Sebelas Maret.

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    Abstract

    This study was conducted to examine the effect of axial spaced-pitch ratio (sx/W) and perforation hole diameter ratio (d/W) on the characteristics of heat transfer and friction factor in a concentric tube heat exchanger fitted with perforated twisted tape insert (PT). In this study, sx/W was varied by 0.56, 0.87, and 1.19, while the d/W varied by 0.16, 0.19, and 0.24. Perforated twisted tape insert was a modification of the typical twisted tape insert (TT) by administering small holes to increase fluid turbulence near the tube wall and the tape edge. For comparison, in this study also tested heat exchanger without insert (plain tube) and with the addition of the TT. The working fluid in the inner tube was hot water and in the annulus was cold water, with the flow direction was counterflow. Tests were conducted at a Reynolds number (Re) 5,400-17,500. The study results showed that the use of insert PT, increasing the Nusselt number (Nu), friction factor (f) and thermal performance () as compared with the use of insert TT. Characteristics of heat transfer, friction factor and thermal performance of the heat exchanger with the use of insert PT increases with a decrease in the value of the sx/W and the increase in the value of d/W. The heat exchanger with the addition of the PT with a value of sx/W = 0.56 and the value of d/W = 0.24 produces the Nusselt number, pressure drop, friction factor, effectiveness and the highest thermal performance. The average Nusselt number in the inner tube (Nui) with the addition of the TT and the PT with sx/W = 0.56, 0.87, and 1.19 increased in the range of 29% - 37%, 70% - 79%, 58% - 67%, and 46% - 55% compared to the plain tube, respectively. The average Nusselt number in the inner tube (Nui) with the addition of the TT and the PT with d/W = 0.16, 0.19, and 0.24 increased in the range of 29% - 37%, 70% - 79%, 79% - 101%, and 89% - 116% compared to the plain tube, respectively. The average friction factor in the inner tube with the addition of the TT and the PT with sx/W = 0.56, 0.87, and 1.19 increased 1.70, 2.95, 2.71, and 2.46 times greater than the friction factor of plain tube, respectively. The average friction factor in the inner tube with the addition of the TT and the PT with d/W = 0.16, 0.19, and 0.24 increased 1 .70, 2.95, 3.18, and 3.45 times greater than the friction factor of plain tube, respectively. Thermal performance of the heat exchanger with the addition of the TT and the PT with sx/W = 0.56, 0.87, and 1.19 in the range of 1.19-0.86, 1.39-0.98, 1.34-0.93, 1.28- 0.88, respectively. Thermal performance of the heat exchanger with the addition of the TT and the PT with d/W = 0.16, 0.19, and 0.24 in the range of 1.19-0.86, 1.39-0.98, 1.55-1.03, and 1.62-1.08, respectively.

    Item Type: Thesis (Other)
    Subjects: T Technology > TJ Mechanical engineering and machinery
    Divisions: Fakultas Teknik > Teknik Mesin
    Depositing User: Minardi Aris
    Date Deposited: 02 Dec 2015 21:04
    Last Modified: 02 Dec 2015 21:04
    URI: https://eprints.uns.ac.id/id/eprint/22296

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