The Effect of Inlet Notch Variations on Turbine Speed in Pico-hydro Power Plants

Abstract

Energy is an important element in the continuity of human activities. Indonesia has the potential to produce 94.3GigaWatt of electricity in the hydropower sector, but only a few can be utilized, which is only 4.2GigaWatt [1]. This study aims to utilize renewable energy that has not been utilized optimally, especially in Indonesia. This study exploits the potential of water flow from the Coban Wonoasri River, Bangun Village, Munjungan District, Trenggalek Regency which has a low head but has a fairly heavy discharge. The basin cone for making vortex flow has a canal length of 1450mm, a canal width of 231.5mm, and a canal height of 500mm with a basin cone diameter of 560mm, a basin cone height of 700mm, and a water outlet diameter of 90mm. A vortex turbine with a diameter of 270mm and a height of 210mm with a total of 8 blades, a blade curvature of 30°, and a blade tilt of 22.5° was used for research on this low head river. The inlet notch variations that will be used are angles of 0°, 17.82°, 19.30°, and 19.98°. The inlet notch with a width of 0° and a discharge of 8.81l/s cannot produce turbine rotation because the vortex flow is not formed properly. Inlet notch with a width of 17.82° and 19.30° produces an average turbine speed of 157.2 rpm and 159.2 rpm. The variation of the inlet notch with a width of 19.98° produces the best turbine speed of 162.7 rpm with a flowrate of 7.72l/s.