PENGARUH KETEBALAN SUDU RODA JALAN TERHADAP EFISIENSI TURBIN ALIRAN SILANG (TURBIN CROSS FLOW)

AGUS SUGIRI, ST, Muhammad Sulaiman, S.T., M.T., D.Eng.,

2011 | Tesis | S2 Mag.Sistem Teknik

Perancangan dan fabrikasi roda jalan (runner) turbin aliran silang mempunyai pengaruh yang besar terhadap efisiensinya. Hal-hal yang harus dipertimbangkan dalam perancangan dan kontruksi roda jalan ( runner) turbin aliran silang diantaranya adalah jumlah sudu, ketebalan sudu, kelengkungan sudu dan bentuk profil sudu. Penelitian ini bertujuan untuk mengetahui pengaruh ketebalan sudu roda jalan terhadap efisiensi turbin aliran silang. Hasil penelitian diharapkan dapat dijadikan bahan pertimbangan dalam menentukan ketebalan sudu roda jalan yang cocok agar kerja turbin menjadi optimal. Penelitian dilakukan dengan studi eksperimental menggunakan roda jalan berdiameter 80 mm, panjang 130 mm, jumlah sudu 20 dengan ketebalan sudu 1,5 mm, 2 mm, dan 2,5 mm. Pengujian dilakukan pada sistem Pembangkit Tenaga Mikrohidro Model Drum (PTMMD). Ketinggian air yang digunakan pada pengujian adalah 2,1 m, 2,3 m dan 2,5 m. Putaran roda jalan diukur menggunakan tachometer, daya keluaran diukur menggunakan powermeter dan torsi turbin diukur dengan timbangan pengukur torsi. Hasil penelitian menunjukkan bahwa ketebalan sudu berpengaruh pada efisiensi turbin. Pengujian dengan head/tinggi muka air 2,1 m,2,3 m dan 2,5 m menunjukkan efisiensi turbin terbesar terjadi pada ketebalan sudu 2 mm. Efisiensi tertinggi terjadi pada pengujian dengan tinggi muka air/head turbin 2,5 m, ketebalan sudu 2 mm sebesar 89 %. Daya yang dibangkitkan generator terbesar pada ketinggian turbin 2,5 m, ketebalan sudu 2 mm sebesar 70 watt.

Design and fabrication runner of cross-flow turbine had significant effects on the efficiency. Things must be considered in the designing and constructing runner of cross-flow turbine were the blade quantity, blade thickness, blade curvature, and profile form of blade. This study was conducted to know the effect of blade thickness to the efficiency of the cross-flow turbine. It was expected that the study results could be used as consideration matters to determine the blade thickness of the suitable runner in order to reach the works of turbine optimally. The study was performed by applying the experimental study using the runner of 80 mm in diameter, 130 mm in length, 20 blades with the thickness of 1.5 mm; 2 mm; and 2.5 mm. The test was performed in the system of power generator of microhydro model drums (PTMMD: Pembangkit Tenaga Mikrohidro Model Drum). The applied water high in the test were 2.1 m; 2.3 m; and 2.5 m. Rotation of runner was measured by tachometer, output electric power was measured by powermeter, and torsion was measured torquemeter. The study results showed that the blade thickness had the significant effect to the efficiency. Tests using head/high of water surfaces of 2.1 m; 2.3 m; and 2.5 m showed the biggest efficiency of turbine that was occurred in the blade of 2 mm thickness. The highest efficiency of 89%, was occurred in the test using the high of water surface or head of 2.5 m; and the blade thickness of 2 mm. The power generated by generator with head 2.5 m and the blade thickness of 2 mm was 70 watt.

Kata Kunci : Sudu roda jalan, Putaran, Daya keluaran, Efisiensi.