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Pengaruh Fraksi Udara Terhadap Koefisien Perpindahan Kalor Kondensasi Refrigeran Petrozon Rossy-22 Di Dalam Pipa Tegak Sudarja Sudarja; Purnomo Purnomo; Prajitno Prajitno
Semesta Teknika Vol 10, No 2 (2007): NOVEMBER 2007
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/st.v10i2.840

Abstract

Petrozon Rossy-22 is one of hydrocarbon refrigerants which environmentally safe, since there is no effect on either ozone depletion or global warming. In the refrigeration cycle, imperfect vacuuming process or other factors that permit circulation of air taken place in the system predicted influencing heat transfer rate in condenser. Therefore, research on the influence of air fraction against condensation heat transfer coefficient of Petrozon Rossy-22 inside vertical pipe to be done. A modified refrigeration system of vapor compression was applied in this research, where the condensation was done in the 2 meters straight vertical condenser (double pipe heat exchanger, that further called as test section). The diameter of internal and external pipe were ¾” and 1 ¼” respectively. Electric heater was installed on upstream of the test section. Mixture of air- refrigerant was flowed downward inside internal pipe, while cooling water was flowed upward through annulus. The varied parameters were: air fraction, air-refrigerant and cooling water flow rate. The result of the research indicated that condensation heat transfer coefficient significantly decreased when air fraction increased. The proposed empiric equation is :       Nu = 0.0138. (1-w)8.8198. Re0.7941. Pr4.7315with determination coefficient of 0.6927 and average absolute deviation of 17.65 %. The equation was for Re= 6.922-12.953, Pr= 2,008-2,696, and w= (0,25-1)%.
STUDI NUMERIK RANCANGAN ALAT PENYEDOT MERKURI PADA MESIN PEMBUAT BOHLAM DITINJAU BERDASARKAN HEAT TRANSFER Joko Jumiyanto; Sutrisno Sutrisno; Prajitno Prajitno
Jurnal Poli-Teknologi Vol. 18 No. 3 (2019)
Publisher : Politeknik Negeri Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32722/pt.v18i3.2411

Abstract

The purpose of this study is to observe the pattern of fluid flow on a bulb making machine. The design problem of a mercury suction device is some of the mercury and the exhaust heat from the chimney is sucked in imperfectly towards the outlet. These imperfections occur due to the chimney design and power at the outlet fan. Variations in speed at the bulb-making machine outlet are the most effective looking simulation. CFD simulation is done using fluent ansys. The results of the simulation show the heat transfer phenomenon that occurred. At a speed of 6 m/s the maximum heat air produced is 30.5C. The speed variation in the most effective bulb making machine in this study is 15 m/s. because the surrounding air is almost close to initial temperature which is equal to 27.7C. Keep in mind that by increasing the speed value it will reduce the level of efficiency of the tool.
Co-Authors Joko Jumiyanto Purnomo Purnomo Sudarja Sudarja, Sudarja Sutrisno Sutrisno