17 research outputs found
Studi Eksperimen Performa Helical Darrieus Turbin Farming
Get PDFMengadopsi potensi aliran air bawah laut, turbine farm dapat diterapkan pada saluran irigasi pertanian. Hal tersebut memiliki potensi dan realisasi yang lebih memungkinkan mengingat jumlah area pertanian di Indonesia masih sangat luas. Tujuan dari penelitian ini adalah untuk mengetahui performa turbin. Penelitian ini menggunakan rancang bangun Helical Darrieus Turbine Farm yaitu berupa saluran aliran air dan pembuatan beberapa turbin. Turbin arus laut dengan tipe helical darrieus sebanyak tiga buah diletakkan di dalam water flume. Kondisi dan geometri water flume dilakukan pendekatan sesuai dengan kondisi aktual saluran irigrasi pertanian yaitu kecepatan air 0.4 m/s. Penelitian dilakukan secara eksperimen di dalam laboratorium. Hasil penelitian menunjukkan pada kecepatan putar terbesar yaitu sebesar 22 rpm, didapatkan nilai torsi 0.035 Nm. Hubungan antara tip speed ratio dengan koefisien torsi menunjukkan tren yang meningkat. Nilai tertinggi koefisien torsi hasil pengujian adalah 0.065. Pada TSR maksimal nilai Cp juga maksimal. Koefisien performa maksimal pada turbin sebesar 0.051. Berdasarkan hasil tersebut desain turbin memerlukan modifikasi dengan memperpanjang jarak antar turbin sehingga menghasilkan performa yang lebih tinggi
Studi Eksperimen Karakteristik Shell-And-Tube Heat Exchanger Dengan Variasi Jenis Baffle Dan Jarak Antar Baffle
Get PDFShell-and-Tube Heat Exchanger merupakan jenis penukar kalor yang banyak digunakan di pembangkit dan pengolahan minyak. Namun, peningkatan performa penukar kalor ini perlu dilakukan dengan cermat karena alirannya yang kompleks didalam shell. Penelitian ini mengkaji peningkatan performa dalam bentuk koefisien perpindahan panas total dan efektivitas dengan melakukan variasi jenis baffle (single segmental dan triple segmental) dan baffle spacing (5 cm dan 10 cm) menggunakan pendekatan eksperimen dan numerik. Penukar kalor diuji pada laju massa 0,033; 0,066; 0,099; 0,133; dan 0,166 kg/s. Pada variasi jenis baffle, hasil eksperimen menunjukkan single segmental menghasilkan koefisien perpindahan panas total dan efektivitas yang lebih baik dari pada triple segmental dengan nilai koefisien perpindahan panas total maksimal 301 W/m2.K pada 0,166 kg/s dan efektivitas maksimal 0,5 pada 0,033 kg/s. Sedangkan, pada variasi baffle spacing, hasil eksperimen menunjukkan baffle spacing 5 cm menghasilkan koefisien perpindahan panas maksimal 651 W/m2.K saat laju massa 0,166 kg/s sedangkan baffle spacing ini hanya munjukkan performa yang lebih besar dari baffle spacing 10 cm ketika laju massa 0,133 kg/s. Hasil simulasi menunjukkan turbulensi aliran yang besar pada sisi shell mengakibatkan distribusi temperatur merata sehingga mempengaruhi koefisien perpindahan panas total. Kata Kunci : Shell-and-Tube Heat Exchanger , baffle spacing, jenis baffle, koefisien perpindahan panas total, efektivitas, CFD.Â
KARAKTERISASI MEMBRAN KOMBINASI NATA DE COCO DAN LERI DALAM APLIKASI DESALINASI LARUTAN NACL BERBASIS ELEKTRODIALISIS
No full textABSTRAKPenelitian ini bertujuan untuk mengkarakterisasi membran kombinasi nata de coco dan leri sertauntuk mengetahui efisiensi dari pengurangan kadar garam pada larutan NaCl dengan metodedesalinasi berbasis elektrodialisis (ED) menggunakan membran kombinasi nata de coco dan leri.Sintesis membran kombinasi nata de coco dan leri dilakukan dengan mencampurkan air kelapadan air limbah cucian beras (leri) sebanyak 500 mL dan bahan tambahan lain, kemudiandifermentasi selama 10-12 hari. Membran dikarakterisasi dengan uji gugus fungsi, uji swelling, danuji tarik regang. Efisiensi hasil ED larutan NaCl (2000, 2500, 3000, 3500, dan 4000 mg/L) padamasing-masing konsentrasi ditetapkan dengan metode titrasi Argentometri.Hasil penelitian menunjukkan bahwa pada membran kombinasi nata de coco dan leri terdapatgugus O-H pada panjang gelombang 3371,57 m-1 untuk membran sebelum elektrodialisis dan3410,15 cm-1 untuk membran setelah elektrodialisis. Hasil uji swelling pada membran yaitusebesar 97,85%.Uji tarik regang menunjukkan bahwa membran sebelum diaplikasikan untukelektrodialisis memiliki daya tarik sebesar 24,78 MPa dan 24,81 MPa Untuk daya reganganmembran yaitu 3,35 % dan 2,92%. Efisiensi elektrodialisis larutan NaCl tertinggi pada konsentrasi2000 mg/L pada waktu 90 menit sebesar 33,35%. Namun penelitian yang dilakukan oleh Pinem(2008 menunjukan bahwa efisiensi yang dihasilkan sebesar 90% pada tekanan 7 bar pada larutanumpan 2000 mg/L. Sedangkan penelitian yang dilakukan oleh Winata (2016) menunjukan bahwaefisiensi yang dihasilkan dapat mencapai 95-99% melalui EDM (Electrodialysis Metathesis.Kata Kunci : Nata de coco, leri, elektrodialisis, titrasi Argentometr
Experimental Study of Heat Transfer Characteristics in The Hair-Pin Heat Exchanger
Get PDFThe heat transfer characteristics in the horizontal Hair-pin heat exchanger are investigated experimentally. Heat transfer coefficients were calculated and plotted with the experimental data. The inner and outer diameters of the inner tube are 10.67 and 12.09 mm. The inner tube is made from stainless steel with thickness 0.71 mm and the length of 500 mm with conductivity thernal 14.4 W/m.K. The outer tube is made from PPMA(polymethyl methacrylate) with thickness 2.27 mm and the length of 450 mm. Cold and hot water are used as working fluids in outer tube and inner tube, respectively. Flows in the inner tube and outer tube were counter flow. The mass flow rates were varied of cold water are 0.0167, 0.0194, 0.0222, 0.025 and 0.0278 kg/s. Reynolds number were got between of 1667 and 2776 in laminar flow to turbulent flow. Then, the results data of cold water are heat transfer 139,67 Watt for the lowest flowrate and 348,78 Watt for the highest flowrate. From the experimental results obtained heat transfer characteristics in Hair-pin heat exchanger, can be increased by varied the mass flow rate in cold sid
Experimental Study of Heat Transfer Characteristics in The Hair-Pin Heat Exchanger
Get PDFThe heat transfer characteristics in the horizontal Hair-pin heat exchanger are investigated experimentally. Heat transfer coefficients were calculated and plotted with the experimental data. The inner and outer diameters of the inner tube are 10.67 and 12.09 mm. The inner tube is made from stainless steel with thickness 0.71 mm and the length of 500 mm with conductivity thernal 14.4 W/m.K. The outer tube is made from PPMA(polymethyl methacrylate) with thickness 2.27 mm and the length of 450 mm. Cold and hot water are used as working fluids in outer tube and inner tube, respectively. Flows in the inner tube and outer tube were counter flow. The mass flow rates were varied of cold water are 0.0167, 0.0194, 0.0222, 0.025 and 0.0278 kg/s. Reynolds number were got between of 1667 and 2776 in laminar flow to turbulent flow. Then, the results data of cold water are heat transfer 139,67 Watt for the lowest flowrate and 348,78 Watt for the highest flowrate. From the experimental results obtained heat transfer characteristics in Hair-pin heat exchanger, can be increased by varied the mass flow rate in cold sid
Numerical Study of Shell-And-Tube Heat Exchanger Characteristicsin Laminar Flow with Single Segmental Baffle
Get PDFShell-and-tube heat exchangers (STHEs) are one of the most popular heat exchanger due its flexibility to allow wide range pressure and temperature. The shell-sideperforms very complex flow which result in the difficult of analysis. This paper examines the characteristic of shell-side which obtained by adjusting vary of mass flow rates to gain laminar flow condition. A certain STHE with single segmental baffle used in this analysis that run by the stream analysis method developed by Heat Transfer Research Inc. (HTRI). The result shows that the increase value of mass flow rate will increase the shell-side heat transfer coefficient, pressure drop, and heat exchanger effectiveness. The increase value of mass flow rate from 0.1065 kg/s to 0.1775 kg/s will increase the shell-side heat transfer coefficient about 37.56% where minimum and maximum values are 1557.58 and 2142.76 W/m2.K. The shell-side pressure drop also increase from 0.325 kPa to 0.898 kPa or up to 176.31% increase. The heat exchanger effectiveness increase with the lower number of 7.02% from 0.276 to 0.295. From this experiment, it can be inferred that the increase value of mass flow rate in shell-side will be good to the heat exchanger performance, but the increase value of pressure drop must be in consideration too
Numerical Study of Shell-And-Tube Heat Exchanger Performance with Various Baffle Spacing
Get PDFHeat exchanger is the instrument used to exchange the heat from one system to another that can be used as a heater or cooler. One of those types is shell-and-tube heat exchanger which is mostly used in many factories. Shell-and-tube heat exchanger consist of shell, which there are many tube inside it with baffles arranged along the shell-side. This study examines the effect of baffle spacing towards shell-and-tube heat exchanger performance which geometry have been specified first. This study used a simulation method developed by Heat Transfer Research Inc. (HTRI) to determine heat exchanger performances. Baffle spacing is set to various values: 30 mm, 60 mm, and 90 mm which one of each conditions also vary the mass flow rate to various number: 0.8333 kg/s, 0.1667 kg/s, and 0.25 kg/s. The simulation will generate outlet temperature of each fluid, overall heat transfer coefficient, and pressure drop. Baffle spacing 30 mm generates pressure drop 0.011 kPa while the increase of mass flow rate from 0.1660 kg/s to 0.250 kg/s also increase the value of pressure drop 0.030 kPa to 0.045 kPa. From those three variation of baffle spacing, baffle spacing 60 mm generates a stable value: 0.003 kPa, 0.007 kPa, and 0.015 kPa that is the optimum condition to gain the good performance of shell-and-tube heat exchanger
The experimental study of twisted tape effect on heat transfer performance of hairpin heat exchanger
No full textExperimental study of double pipe heat exchanger performance equipped with perforated twisted tape considering various twist ratio
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