Energy
Masoomeh Bahramisamani; Mehdi Jahangiri
Articles in Press, Accepted Manuscript, Available Online from 03 April 2024
Abstract
Using wind energy for hydrogen production in Iran can be important for reasons such as abundant wind resources in Iran, reducing dependence on fossil fuels, ensuring clean energy supply, the potential for hydrogen exports, technology development and job creation. Therefore, this study signifies the first ...
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Using wind energy for hydrogen production in Iran can be important for reasons such as abundant wind resources in Iran, reducing dependence on fossil fuels, ensuring clean energy supply, the potential for hydrogen exports, technology development and job creation. Therefore, this study signifies the first exploration into the potential for generating electricity and producing hydrogen in ten wind-rich cities in Iran. HOMER V.2.81 software was used for simulations, and the wind data used are averaged over a 25-year period. The results show that in Iran, the price range for wind power is $0.515-$0.620 per kWh in the top 10 stations. Bandar Abbas, Parsabad, and Khalkhal had the best economic and environmental performance, respectively. The highest percentage of renewable electricity production is 71% in Bandar Abbas. Finally, the amount of hydrogen produced based on four common electrolyzer types in Iran was investigated. The total annual hydrogen production per ton for SOE, MCE, AE, and PEME electrolysis method at the examined stations is 131.29, 93.43, 40.99, and 30.69, respectively. According to the results, the highest hydrogen production with a value of 16.87 tons per year is related to the Bandar Abbas station and the SOE electrolysis method. The lowest hydrogen production, with a value of 2.36 tons per year, is related to the Alvand station and the PEME electrolysis method.
Energy
M. Jahangiri; O. Nematollahi; H. Saghaei; A. Haghani
Abstract
Providing sustainable energy to achieve favorable economic development has attracted the attention of many governments in recent years. Renewable energies, especially wind energy, have gained considerable media attention recently due to challenges with the use of fossil fuels, including difficulty in ...
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Providing sustainable energy to achieve favorable economic development has attracted the attention of many governments in recent years. Renewable energies, especially wind energy, have gained considerable media attention recently due to challenges with the use of fossil fuels, including difficulty in accessing and devastating environmental impacts. Extensive efforts have been made in Asia to benefit wind energy regionally, all of which have made Asia a leader in this field. There are a few simulation results in this area, given the importance and need to compile infrastructural strategies and programs that require a thorough understanding of the current state of wind energy usage and determining its potential in different regions. Therefore, this study reports for the first time on surveys conducted on average of 20-year wind speed data collected from 2892 stations in 49 Asian countries and wind speed and power density maps obtained using Geographic Information System (GIS) software and the Boolean method. Besides assessing the problems and issues of energy consumption in countries with high potential wind energy in Asia, in this paper, we try to explore the benefits and requirements of using wind energy in these countries as well as the possibility of maximally using wind energy. According to the results, east and north of Russia, as well as west and southwest Asia are optimal regions for establishing large-scale wind plants; there is no significant potential for the use of wind energy in other regions, especially in the majority of China, ASEAN countries, and their neighboring countries.
Energy
Y. Xu; H. Jiang; K. Chen; Z. Jiang
Abstract
In this paper, a new type of wind collection device that can generate rotating wind for wind power generation has been designed to address the shortcomings of current wind power generation devices. This device can collect wind energy from different directions by changing the direction of the wind. Firstly, ...
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In this paper, a new type of wind collection device that can generate rotating wind for wind power generation has been designed to address the shortcomings of current wind power generation devices. This device can collect wind energy from different directions by changing the direction of the wind. Firstly, the simulation model for this wind collection device had been designed by the software SolidWorks. Secondly, the internal flow field of the model was modeled and simulated using Computational Fluid Dynamics, and the k-ω SST model was selected in Fluent for flow field analysis. The results showed that this device could generate an outlet wind speed of 3.8 m/s at a wind speed of 4 m/s, which verified the wind collection effect of the device. Thirdly, the outlet wind speed was taken as the optimization objective, and orthogonal optimization design was carried out on the guide convex groove in the model, and the optimal design parameters of the guide convex groove were determined. The results showed that when the width of the diversion convex groove is 47.35mm and the height is 10.65mm, the outlet wind speed is the highest, about 3.89m/s. Finally, to verify the analysis results of numerical simulation, the experimental verification of the wind collection device was carried out through physical prototypes. The results indicated that the simulation results are consistent with the physical results The design of this device can provide theoretical support for the subsequent design of a full-direction wind collection device to cope with the complex wind direction conditions.
Energy
A. Jabbari; M. Basaki; M. R. Sheykholeslami
Abstract
In this paper, an axial flux permanent magnet generator for a 30 kW direct drive wind turbine is designed and the design parameters were optimized with the aim of achieving high efficiency. In order to reduce the cogging torque and electromagnetic torque ripple components, the air core topology has been ...
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In this paper, an axial flux permanent magnet generator for a 30 kW direct drive wind turbine is designed and the design parameters were optimized with the aim of achieving high efficiency. In order to reduce the cogging torque and electromagnetic torque ripple components, the air core topology has been used, and with the aim of increasing the power capacity of the generator, a modular structure has been used. The advantage of the modular design is that each module can be considered as a generator unit and depending on the wind speed conditions, the number of units corresponding to the wind speed can be placed in the circuit and the generator will always work with maximum efficiency. First, by using the governing equations, the dimensions and performance characteristics of the generator are determined, and then a generator prototype is fabricated based on the electromagnetic design. In order to evaluate the output performance of the generator, machine simulation was performed in Maxwell finite element analysis software and the characteristic curves of voltage, current and ohmic losses were extracted. In order to evaluate the accuracy of the results, the outcomes of the analytical method have been compared with the experimental tests results.
Energy
P. Hedayati; A. Ramiar; N. Hedayati
Abstract
Wind energy is a prominent renewable energy source, and Vertical Axis Wind Turbines (VAWTs) offer distinct advantages, including adaptability to changing wind directions and reduced noise levels. This paper conducts a numerical investigation into the impact of flat and curved stator blades on VAWTs, ...
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Wind energy is a prominent renewable energy source, and Vertical Axis Wind Turbines (VAWTs) offer distinct advantages, including adaptability to changing wind directions and reduced noise levels. This paper conducts a numerical investigation into the impact of flat and curved stator blades on VAWTs, specifically the Savonius turbine, under 2D, viscous, turbulent, and steady flow conditions. Four stator blade configurations were examined, including no stator blades, smooth stator blades, twisted stator blades (Case A), and both blades being concave (Case B). The study reveals that curved stator blades enhance VAWT performance, with Case B exhibiting the most efficient performance. The results show pressure distribution on the turbine blades is non-uniform, with high and low-pressure zones, predominantly on the windward side. The presence of stator blades enhances pressure on all turbine blades, with Case B exhibiting the most optimal pressure distribution. Detailed observation of streamline and velocity distribution reveals improved flow lines for Case B, leading to more effective turbine blade performance. Case B consistently produces the highest turbine torque, with a maximum value of approximately 2.1 N·m achieved at Re = 15750. The torque demonstrates a positive correlation with increasing Reynolds numbers. The study further introduces a non-dimensional torque ratio analysis, where Case B attains 7.59 times higher torque than the reference case at Reynolds number 15750. The sensitivity of torque increase with respect to Reynolds number change highlights that Case B (with a slope of torque increase at around 4.5e-04) is the most responsive within the studied Reynolds number range.
Energy
M. Bagheri; I. Mirzaee; M. Khalilian; V. Mousapour
Abstract
The present study simulates Invelox in a three-dimensional and stable way. The flow regime is turbulent flow and an unorganized grid with 350000 cells was utilized. This work has studied the modeling of invelox with conventional dimensions and four different sizes in the form of four modes for use in ...
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The present study simulates Invelox in a three-dimensional and stable way. The flow regime is turbulent flow and an unorganized grid with 350000 cells was utilized. This work has studied the modeling of invelox with conventional dimensions and four different sizes in the form of four modes for use in a residential building. The numerical data with an error of less than 6% are in good agreement with the available experimental and analytical data. The results show that considering the average velocity of mode 2 with a velocity of 6.54 m/s and a 5% difference from the other two modes, it can be operated in a residential building. It is worth noting that in this investigation, in addition, the effect of dust on the turbine performance was evaluated. The results represent that the oscillation frequency of the blades increases with the increase of the rotational speed. In the case of not considering dust particles on blades, this amount increases by 25%, while considering dust particles with an amount of 0.1%, it increases up to 300%, and this can cause irreparable damage to the turbine as well as the power generation system.
Energy
A. Bozorgi; M. J. Zarei
Abstract
Noise pollution is one of the biggest problems of wind turbines, especially when these turbines are located near residential areas. In this article, the effect of blade thickness is numerically investigated on the noise pollution of an H-type Darrieus wind turbine. The flow is first simulated using the ...
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Noise pollution is one of the biggest problems of wind turbines, especially when these turbines are located near residential areas. In this article, the effect of blade thickness is numerically investigated on the noise pollution of an H-type Darrieus wind turbine. The flow is first simulated using the unsteady Reynolds averaged Navier-Stokes equations and the SST-kω model at the tip speed ratio of 2.64. Then, the noise is calculated using Ffowcs Williams-Hawkings equations. Blade thickness is changed using NACA airfoils from NACA 0008 up to NACA 0024. It is concluded that noise calculation at only one point, known as a routine method in noise investigation of wind turbines, is insufficient to investigate the noise of this turbine. Here, maximum noise in directivity is defined as the criterion of noise pollution. The results show that changing the blade profile of the benchmark turbine from NACA 0021 to NACA 0015 increases the power coefficient from 0.318 to 0.371 and reduces the maximum noise from 95.67 dB (76.35 dB) to 90.19 dB (71.01 dB) at R = 2 m (8m). For NACA 0018, the power coefficient is 0.353, and the maximum noise is 89.78 dB (70.47 dB) at R = 2 m (8m). Overall, the highest output power is for NACA 0015, and the lowest noise pollution is for NACA 0018.
Energy
A. A. Sheikh Aleslami; H. Sadeghi
Abstract
Tall buildings are subject to wind loads as one of the effective lateral loads. An analysis of the effect of wind on Milad Tower is presented in this research. The wind tunnel testing results and numerical modelling implemented in computational fluid dynamics (CFD) using ANSYS software. For the numerical ...
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Tall buildings are subject to wind loads as one of the effective lateral loads. An analysis of the effect of wind on Milad Tower is presented in this research. The wind tunnel testing results and numerical modelling implemented in computational fluid dynamics (CFD) using ANSYS software. For the numerical simulation, the K-epsilon model has been used. The study evaluated the flow around the tower in several deformation states and compared it with a model where the tower is modeled rigidly in the wind tunnel. The maximum coefficient of negative pressure (suction) at the top of the tower structure equals to -1.95, which occurs at q =90o, and the maximum coefficient of the positive pressure equals +1. Since the buildings near the tower are located a short distance from the tower, the shed's structure, which is located near the tower, has also been investigated. With the aid of Tecplot software. The wind pressure coefficients obtained from the wind tunnel test were plotted. As part of the wind loading analysis in the single-span and two-span shed models, the model is rotated with a step of 5o relative to the direction of wind application, and wind pressure is recorded.
Energy
P. A. Ayoubi; M. E. Yazdi; I. Harsini
Abstract
The development of models that predict power production of wind farms (WFs) by considering the interacting wakes is important; because wakes of the turbines exert a significant influence on power production of turbines, and hence on the layout of wind turbines in WFs. Thus, the purpose of present study ...
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The development of models that predict power production of wind farms (WFs) by considering the interacting wakes is important; because wakes of the turbines exert a significant influence on power production of turbines, and hence on the layout of wind turbines in WFs. Thus, the purpose of present study was to provide an innovative analytical method for the prediction of power generation of the WFs that have a flat terrain and are consisted of horizontal-axis wind turbines (HAWTs) with the same hub height. The methodology employed utilized an analytical Gaussian model of HAWT wake to develop an analytical model that calculates the effective wind velocity acting on the downstream HAWT(s), which is further used for reading its generated power from the turbine’s catalog; thus, providing the generated power of the WF as the output. The results of presented model were validated by the field measurements data of Horns Rev WF and also were compared to two analytical models for predicting the generated power. The results were compared with two numerical simulations of the literature, and the output data of three commercial software. Moreover, the error analysis revealed that the presented model mostly showed superior accuracy in predicting the field measurements data.
