Pengaruh Airfoil dan Jumlah Sudu pada Perancangan Vertikal Axis Wind Turbine (VAWT) untuk Kecepatan Angin Rendah

AbstrakSelain potensi angin karena bentuk geografisnya, Indonesia juga memiliki potensi angin yang dapat dimanfaatkan dari  pergerakan arus lalu lintas di jalan raya atau jalan tol. Pergerakan kendaraan  berkecepatan tinggi di jalan raya menghasilkan angin lokal, yang  dapat digunakan untuk menghasilkan energi listrik. Angin lokal ini memiliki variabilitas yang lebih kecil, terutama jika lalu lintas  jalan raya  konstan. Tujuan utama dari penelitian ini adalah untuk mendesain Vertical Axis Wind Turbine yang dapat bekerja pada kecepatan angin rendah. Pada pendekatan teoritis, software Qblade digunakan  untuk menganalisa beberapa jenis Airfoil yaitu NACA 0012, NACA 0013, NACA 0014, NACA 0015, NACA 0016 dengan variasi sudu 2, 3 dan 4 angka pada masing-masing konfigurasi aerodinamis. Koefisien performa turbin angin sumbu vertikal yang optimal dapat diperoleh pada simulasi turbin yang menggunakan airfoil NACA 0016 sebesar 1,33 dengan konfigurasi jumlah sudu adalah empat buah pada TSR 3,5 sehingga diperoleh daya sebesar 87,78 watt pada kecepatan angin 5 m/s dan kecepatan putar 300 rpm. Kata kunci: VAWT, Darrieus, Qblade  AbstractApart from wind potential due to its geographical shape, Indonesia also has wind potential which can be exploited from the movement of traffic flow on highways or toll roads. The movement of high-speed vehicles on the highway generates local wind, which can be used to generate electrical energy. These local winds have less variability, especially if road traffic is constant. The main objective of this research is to design a vertical axis wind turbines to operate in low wind speed. In the theoretical approach, Qblade software is used to analyze several types of airfoils, namely NACA 0012, NACA 0013, NACA 0014, NACA 0015, NACA 0016 with 2, 3 and 4 number blade variations on each aerodynamic configuration. The optimal vertical axis wind turbine performance coefficient can be obtained in a turbine simulation that uses a NACA 0016 airfoil of 1.33 with a configuration of four blades at a TSR of 3.5 so that a power of 87.78 watts is obtained at a wind speed of 5 m/s and rotating speed 300rpm. Keywords: VAWT, Darrieus, Qblade 

Techno-economic Analysis of Rooftop Photovoltaic System (RPVS) using Thin-Frameless Solar Panels for Household Customers in Indonesia

The availability of thin-frameless solar panels on the market today makes the installation of rooftop Photovoltaic (RPVS) systems more attractive. The purpose of this research is to analyze financially the use of thinframeless solar panels for on-grid RPVS by household electricity customers in Indonesia. The investment cost, the maintenance costs, and the electricity cost savings were involved for the financial analysis, such as Internal Rate of Return (IRR), Net Present Value (NPV), and Pay Back Period (PBP). The calculation is carried out for ideal conditions, the direction of a non-ideal rooftop and the yearly increase of electricity prices is 15 %. The analysis results show that the minimum available rooftop area is still sufficient for the rooftop area needs for solar panel placement, the thin solar panels are safer than standard solar panels, and savings on electricity payments for the return on investment of the RPVS is to be attractive with the IRR > 12 %. The average investment cost of the non-ideal condition is 8 % higher than the ideal condition. This study provides an overview to the policymakers and developers in exploiting the potential of RPVS, especially in Indonesia. For future research directions, this study needs to analyze the technical and economic feasibility of using hybrid smart-grid technology with batteries

PERANCANGAN GENERATOR MAGNET TETAP DENGAN TORSI HAMBAT RENDAH UNTUK PEMBANGKIT LISTRIK TENAGA BAYU

Generator Magnet Tetap merupakan generator yang sangat umum digunakan pada Pembangkit Listrik    Tenaga    Bayu    sekala   kecil,  Tesis   ini  membahas      upaya   pengurangan      torsi  hambat    yang merupakan salah satu beban parasit terbesar dari generator agar generator dapat menghasilkan listrik pada    kecepatan    angin   yang    rendah   dengan    memanfaatkan      pemasangan      magnet    secara   skew   dan pergeseran posisi magnet. Dari simulasi dengan FEM didapatkan rancangan generator dengan cogging torque maksimum        0.0012Nm dan daya 427 Watt. Kata kunci: Generator, Magnet Tetap, Cogging Torque, Skew, Tenaga Bay

High Performance Cascading Adsorption Refrigeration Cycle with Internal Heat Recovery Driven by a Low Grade Heat Source Temperature

This paper presents the performance of an advanced cascading adsorption cycle that utilizes a driven heat source temperature between 90–130 ºC. The cycle consists of four beds that contain silica gel as an adsorber fill. Two of the beds work in a single stage cycle that is driven by an external heat source, while the other two beds work in a mass recovery cycle that is driven by waste heat of sensible and adsorption heat of the high temperature cycle. The performances, in terms of the coefficient of performance (COP) and the specific cooling power (SCP), are compared with conventional cascading-without-mass-recovery and single-stage cycles. The paper also presents the effect of the adsorbent mass on performance. The results show that the proposed cycle with mass recovery produces as high of a COP as the COP that is produced by the conventional cascading cycle. However, it produces a lower SCP than that of the single-stage cycle

Experimental Investigation of a Three-Bed Adsorption Refrigeration Chiller Employing an Advanced Mass Recovery Cycle

The performance of an advanced three-bed adsorption chiller with a mass recovery cycle has been experimentally investigated in the present study. The temperature and pressure of various components of the chiller were monitored to observe the dynamic behaviour of the chiller. The performances in terms of the coefficient of performance (COP) and specific cooling power (SCP) were compared with a conventional single stage. The results show that the proposed cycle produces COP and SCP values superior to those of the conventional single stage cycle for heat source temperature below 75 °C

Performance Analysis of a Double-effect Adsorption Refrigeration Cycle with a Silica Gel/Water Working Pair

A numerical investigation of the double-effect adsorption refrigeration cycle is examined in this manuscript. The proposed cycle is based on the cascading adsorption cycle, where condensation heat that is produced in the top cycle is utilized as the driving heat source for the bottom cycle. The results show that the double-effect cycle produces a higher coefficient of performance (COP) as compared to that of the conventional single-stage cycle for driving temperatures between 100 °C and 150 °C in which the average cycle chilled water temperature is fixed at 9 °C. Moreover, the COP of the double-effect cycle is more than twice that of the single-stage cycle when the temperature reaches 130 °C. It is also observed that the adsorbent mass ratio of the high temperature cycle (HTC) to the low temperature cycle (LTC) affects the performance of the double-effect adsorption refrigeration cycle

Performance Analysis of a Double-effect Adsorption Refrigeration Cycle with a Silica Gel/Water Working Pair

A numerical investigation of the double-effect adsorption refrigeration cycle is examined in this manuscript. The proposed cycle is based on the cascading adsorption cycle, where condensation heat that is produced in the top cycle is utilized as the driving heat source for the bottom cycle. The results show that the double-effect cycle produces a higher coefficient of performance (COP) as compared to that of the conventional single-stage cycle for driving temperatures between 100 °C and 150 °C in which the average cycle chilled water temperature is fixed at 9 °C. Moreover, the COP of the double-effect cycle is more than twice that of the single-stage cycle when the temperature reaches 130 °C. It is also observed that the adsorbent mass ratio of the high temperature cycle (HTC) to the low temperature cycle (LTC) affects the performance of the double-effect adsorption refrigeration cycle

High performance cascading adsorption refrigeration cycle with internal heat recovery driven by a low grade heat source temperature

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