Perancangan dan Optimasi Turbin Air Vortex untuk Pembangkit Listrik Mikrohidro

Pungkiarto, Irwanda Yuni (2021) Perancangan dan Optimasi Turbin Air Vortex untuk Pembangkit Listrik Mikrohidro. Masters thesis, Institut Teknologi Sepuluh November.

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Abstract

Turbin air vortex adalah salah satu solusi memanfaatkan potensi energi potensial air dengan head rendah untuk dikonversi menjadi energi listrik pada pembangkit listrik tenaga mikrohidro (PLTMH). Turbin vortex bekerja dengan memanfaatkan aliran vortex yang terbentuk di bak intake tanpa menggunakan komponen guide vane sehingga jumlah komponen total turbin dapat direduksi. Hal ini menguntungkan dari sisi proses manufaktur maupun secara ekonomi.
Fokus pembahasan pada studi ini yaitu proses perancangan, analisa dan optimasi turbin air vortex. Perancangan turbin vortex meliputi bak intake, runner dan tailrace. Bak intake dirancang menggunakan profil logaritmik spiral. Proses perancangan runner dimulai dengan penentuan kondisi kerja turbin, penentuan dimensi utama, perhitungan geometri sudu turbin dan pemodelan 3D. Hasil perancangan diuji performa dengan menggunakan simulasi Computational Fluid Dynamics (CFD). CFD dilakukan pada kondisi steady dengan menggunakan model multifasa VOF dengan model turbulensi k-ε standard. Kriteria penilaian performa dari hasil rancangan diantaranya efisiensi, pola aliran dan kavitasi. Runner hasil rancangan dioptimasi untuk memaksimalkan efisiensi turbin. Optimasi dilakukan menggunakan Design of Experiment (DOE) dengan metode Taguchi. Parameter atau faktor yang divariasikan pada proses optimasi yaitu jumlah, panjang, sudut masuk dan sudut keluar dari sudu runner turbin. Masing-masing faktor menggunakan tiga level variasi.
Faktor paling berpengaruh terhadap torsi output runner adalah panjang sudu runner. Faktor berikutnya adalah sudut keluar sudu, kemudian jumlah sudu dan yang terakhir adalah sudut masuk sudu. Kombinasi nilai level faktor yang menghasilkan performa runner paling optimal yaitu jumlah sudu sebanyak 13 buah, panjang sudu 45 derajat, sudut masuk 11o dan sudut keluar sebesar 3 derajat. Efisiensi runner hasil optimasi naik sebesar 21.7% menjadi 58.8% dari 48.3% pada runner perancangan awal. Turbin dengan runner hasil optimasi beroperasi pada head 0.858 meter, debit 0.6 m3/s dan kecepatan putar runner 45 rpm.Tekanan lokal minimum pada runner berada di atas tekanan uap jenuh air sehingga kavitasi tidak akan terjadi.
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The gravitational water vortex turbine (GWVT) is one solution to utilize the
potential energy of water to be converted into electrical energy in a low head micro�hydropower plants (MHPP). The GWVT works by utilizing the vortex flow formed in
the intake basin without the use of a guide vane to direct the flow into runner so that
the overall components can be reduced. This is advantageous in terms of the
manufacturing process and economically.
The main focuses of this study are the process of designing, analyzing, and
optimization a GWVT. The design of the GWVT includes the intake basin, runner, and
tailrace. The intake basin or vortex chamber is designed using a spiral logarithmic
profile. The initial runner design process starts with determining the working
conditions of the turbine, estimating the main dimensions, calculating the runner
blade geometry, and 3D modeling of the runner.. The performance of the initial
turbine design was verified by using Computational Fluid Dynamics (CFD)
simulation. CFD is carried out at a steady-state using a multiphase VOF model with
a standard k-ε turbulence model. Performance assessment criteria from the initial
design are efficiency, flow pattern, and cavitation. The initial runner design is
optimized to maximize turbine efficiency. Optimization was carried out using the
Design of Experiment (DOE) technique by using the Taguchi method. Factors that are
varied in the optimization process are the numbers, length, inlet angle, and outlet
angle of the turbine runner blades with three levels of variation.
The most influential factor on runner output torque is runner blade length.
The next factor is the blade outlet angle, then the number of blades, and the last is the
blade inlet angle. The optimum runner design has 13 pieces of blade, 45 degrees
blade length, 11 degrees of inlet blade angle, and 3 degrees outlet blade angle. The
efficiency of the optimized runner increased by 21.7% to 58.8% from 48.3% (initial
design runner). The turbine with the optimized runner operates at a head of 0.858
meters, a discharge of 0.6 m3/s, and a runner rotational speed of 45 rpm. The
minimum local pressure on the runner is above the saturated steam pressure so that
cavitation will not occur.

Item Type:	Thesis (Masters)
Uncontrolled Keywords:	Turbin vortex, mikrohidro, CFD, optimasi, DOE, metode Taguchi, Vortex turbine, microhydropower, CFD, optimization , DOE, Taguchi method
Subjects:	T Technology > TJ Mechanical engineering and machinery > TJ870 Hydraulic turbines.
Divisions:	Faculty of Industrial Technology and Systems Engineering (INDSYS) > Mechanical Engineering > 21101-(S2) Master Thesis
Depositing User:	Irwanda Yuni Pungkiarto
Date Deposited:	28 Aug 2021 13:27
Last Modified:	28 Aug 2021 13:27
URI:	http://repository.its.ac.id/id/eprint/91075

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