Renewable Energy Resources and Technologies
Mahdi Shahmari; Payam Zarafshan; Shahriar Kouravand; Morteza Khashehchi
Abstract
Renewable energies as a clean replacement resource of fossil fuels have many advantages, among which wind has the potential to be the very applicable source in the world. To use wind energy, two kinds of turbines have been developed; the Vertical Axis Wind Turbine (VAWT) and Horizontal Axis Wind Turbine ...
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Renewable energies as a clean replacement resource of fossil fuels have many advantages, among which wind has the potential to be the very applicable source in the world. To use wind energy, two kinds of turbines have been developed; the Vertical Axis Wind Turbine (VAWT) and Horizontal Axis Wind Turbine (HAWT). In small scale applications, using a VAWT has some advantages such as low cost and noise, simple mechanism, and the low sensitivity to the wind direction. In this paper, the design and analysis of a combined wind turbine, consist of the Savonius-Darrieus rotor, are performed to use in irrigation applications. To predict the output power, a series of experiments were conducted using the Computational Fluid Dynamics (CFD) method. For this purpose, ANSYS fluent and Q-Blade software programs are used. To design the rotor performance, NACA symmetric airfoils are considered. Next, this combined turbine was made and experimental tests were performed. Finally, the output power is computed and so, the water flow rate for irrigation purposes such as water pumping is obtained. The results indicate that the self-starting of the turbine is improved using the considered design. This could be useful in regions with low wind speed.
Advanced Energy Technologies
Mohammad Sajjad Rostami; Morteza Khashehchi; Payam Zarafshan; Mohammad Hossein Kianmehr; Ehsan Pipelzadeh
Abstract
Capacitive deionization (CDI) is an emerging energy efficient, low-pressure and low-cost intensive desalination process that has recently attracted experts’ attention. The process is to explain that ions (cations and anions) can be separated by a pure electrostatic force imposed by a small bias ...
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Capacitive deionization (CDI) is an emerging energy efficient, low-pressure and low-cost intensive desalination process that has recently attracted experts’ attention. The process is to explain that ions (cations and anions) can be separated by a pure electrostatic force imposed by a small bias potential. Even at a rather low voltage of 1.2 V, desalinated water can be produced. The process can be well operational by a professional cell design. Although various processes have been manufactured before, in this study, membrane was removed and a new unit was designed and manufactured (Using CFD Simulation). In this case, the combination of activated carbon powder (with an effective surface area of 2600 m2 per gram), carbon black, and polyvinyl alcohol with a ratio of 35/35/30 coated on carbon paper as electrode materials was considered for tests. The weight was 1.41 grams for each material, and the thickness was 0.44 mm. CDI system was tested, and the results of charge-discharge cycles, cyclic voltammetry, and impedance spectroscopy were evaluated. It can be implied that there is no need for a strong pump and, also, pressure drop can be reduced due to such a noticeable space between two electrodes. Preliminary experimental results showed high specific capacitance (2.1 Farad) and ultra-high salt adsorption capacity, compared with similar cases.
