scholarly journals Influence of wind energy utilization potential in urban suburbs: a case study of Hohhot

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wang Wenxin ◽  
Chen Kexin ◽  
Bai Yang ◽  
Xu Yun ◽  
Wang Jianwen

AbstractGiven the increasing trend of using wind energy in cities, the utilization of distributed wind energy in cities has been widely concerned by researchers. The related research on the micro-site selection of wind turbines, a sub-project of the Task27 project of the International energy agency, was continued in this paper. The wind speed data of an observation station near Hohhot, Inner Mongolia, with a range of 10–19 m were collected. The evaluation included wind direction, Weibull parameter characteristics, and turbulence intensity. The potential energy output in 10 different heights was estimated using commercial horizontal and vertical axis wind turbines of the same power. Results showed that the following: the three-parameter Weibull distribution model can well describe the statistical properties of the wind speed in this site. The wind speed distribution model constructed from extrapolation parameters reflects the wind speed statistical properties out of detection positions to a certain extent. The wind energy density of the vertical axis wind turbine is slightly lower than that of the horizontal axis wind turbine. Furthermore, more power can be generated from March to May.

2020 ◽  
Author(s):  
wang Wenxin ◽  
Bai Yang ◽  
Chen Kexin ◽  
Wang Jianwen ◽  
Qin Chaofan

Abstract Background:Given the increasing trend of using wind energy in cities, the utilization of distributed wind energy in cities has been widely concerned by researchers. The related research on the micro-site selection of wind turbines, a sub-project of the Task27 project of the International energy agency, was continued in this paper.Methods:The wind speed data of an observation station near Hohhot, Inner Mongolia, with a range of 10-19 m were collected. The evaluation included wind direction, Weibull parameter characteristics, and turbulence intensity. The potential energy output in 10 different heights was estimated using commercial horizontal and vertical axis wind turbines of the same power.Results:The three-parameter Weibull distribution model can well describe the statistical properties of the wind speed in this site. The wind speed distribution model constructed from extrapolation parameters reflects the wind speed statistical properties out of detection positions to a certain extent.Conclusions:The wind energy density of the vertical axis wind turbine is slightly lower than that of the horizontal axis wind turbine. Furthermore, more power can be generated from March to May.


2020 ◽  
Vol 14 (1) ◽  
pp. 120-132
Author(s):  
Li Zheng ◽  
Zhang Wenda ◽  
Han Ruihua ◽  
Tian Yongsheng

Background: The wind turbine is divided into a horizontal axis and a vertical axis depending on the relative positions of the rotating shaft and the ground. The advantage of the choke wind turbine is that the starting torque is large and the starting performance is good. The disadvantage is that the rotation resistance is large, the rotation speed is low, the asymmetric flow occurs when the wind wheel rotates, the lateral thrust is generated, and the wind energy utilization rate is lowered. How to improve the wind energy utilization rate of the resistance wind turbine is an important issue to be solved by the wind power technology. Objective: The nautilus isometric spiral wind turbines studied in this paper have been introduced and analyzed in detail, preparing for the further flow analysis and layout of wind turbines, improving the wind energy utilization rate of wind turbines, introducing patents of other structures and output characteristics of its generator set. Methods: Combined with the flow field analysis of ANSYS CFX software, the numerical simulation of the new wind turbine was carried out, and the aerodynamic performance of the new vertical axis wind turbine was analyzed. The mathematical model and control model of the generator were established by the maximum power control method, and the accuracy of the simulation results was verified by the measured data. Results: The basic parameters of the new wind turbine tip speed ratio, torque coefficient and wind energy utilization coefficient are analyzed. Changes in wind speed, pressure and eddy viscosity were investigated. Three-dimensional distribution results of wake parameters such as wind speed and pressure are obtained. By simulating the natural wind speed, the speed and output current of the generator during normal operation are obtained. Conclusion: By analyzing the wind performance and power generation characteristics of the new wind turbine, the feasibility of the new wind turbine is determined, which provides reference and reference for the optimal design and development of the wind turbine structure.


2021 ◽  
Vol 926 (1) ◽  
pp. 012093
Author(s):  
Y Kassem ◽  
H Çamur ◽  
M A H A Abdalla ◽  
B D Erdem ◽  
A M R Al-ani

Abstract The grid-connected system can be an attractive solution to reduce electricity consumption, dependence on utility power, and increase electricity generation from renewable energy resources like wind energy for residential electricity users. Based on 33-year wind data (1983-2020), this study investigates the potential of wind energy at different locations ((Akkar, Baalbek, Beirut, Zahlé, Baabda, Nabatieh, Tripoli, and Sidon) in Lebanon using the Weibull distribution function. Monthly NASA wind speed data during the period (1983-2020) were used to estimate the wind energy potential. The result showed that the averaged wind speeds at the selected regions are varied from 3.695m/s to 4.457m/s at the height of 10m. Furthermore, the annual wind power density was estimated at various heights (10m, 30m, and 50m). The results demonstrated that small-scale wind turbines are recommended to be used for generating electricity from wind in the selected regions. Finally, the performance of WRE.060 / 6 kW (vertical axis wind turbine) and Proven WT 6000 (horizontal axis wind turbine) was done based on the monthly NASA wind speed database.


Author(s):  
B. P. Khozyainov

The article provides the analysis of performance efficiency of various designs of wind turbines with a horizontal and vertical axis of rotation and reveals the advantages and disadvantages of each design and possibility of each of them to work effectively in the conditions of the wind mode of Russia. As a result, we have concluded that the wind turbines with a vertical axis of rotation using the principle of the differential front resistance are most adapted for the further development of wind energy since these wind turbines are capable to work at very small wind speeds and are more adapted for further improvement. Moreover, we have made the recommendations for removal of disadvantages and development of advantages of these wind turbines. The article offers a number of patents which can regulate the angular speed of rotation of the wind turbine, the size of the rotating moment and, accordingly, its power depending on the natural wind speed. In particular, there is a patent for a design of the blade with varying dimensions depending on the air stream; the introduction of such device will increase the aerodynamic characteristics of the blade. The use of the wind guide screens allows us to start the wind turbine at wind speed from 0.5 m/s. It promotes the effective performance in the range of wind speed from 0.5 m/s to 4.5 m/s, and the wind guide screens regulate the air stream velocity in the wind turbine volume at speed from 4.5 m/s to 15.0 m/s. At gale-force winds, the wind guide screens are capable of cover the wind turbine preventing its destruction. The use of such wind turbines will positively affect the development of wind energy in Russia.


2015 ◽  
Vol 733 ◽  
pp. 493-496 ◽  
Author(s):  
Chun Mei Wu ◽  
Chun Yu Xiong ◽  
Yong Zhao

Wind turbines is one of the most important components of the wind turbine, design for wind turbines with good wind turbines is the basis of high wind energy utilization coefficient and large economic benefits. Using the theory of Wilson pneumatic designed 100 W horizontal axis wind turbine, in the process of design and design parameters on the vibration performance correction. Finally on rotor vibration modal experiment and pneumatic external characteristic experiment, the experimental results show that the design of the wind turbine at low wind speed can meet the design of the wind energy utilization coefficient, and the wind machine to avoid the resonance region speed at run time, extend the life of the rotor, so as to reduce the design cost.


2019 ◽  
Vol 13 ◽  
Author(s):  
Li Zheng ◽  
Zhang Wenda ◽  
Han Ruihua ◽  
Qi Weiqiang

Background: In a wind farm, the wind speed of the downstream wind turbine will be lower than the wind speed of the upstream wind turbine due to the influence of the wake. Therefore, the wake of wind turbines is one of the uncertain factors predicting the annual power generation of wind farms. The study of the wake can effectively improve the efficiency of power generation. The arrangement of vertical axis wind turbines in wind farms is rarely studied. Therefore, it is important to study the vertical layout of wind turbines under the influence of wakes to obtain the best layout and unit spacing. Objective: To obtain the optimal layout and unit distance of wind turbines in Senegal wind turbines by studying the arrangement of Senegal vertical axis wind turbines in wind farms. Method: Based on the ANSYS CFX flow field calculation module, the fluid dynamics model of the Senegal fan was established and the flow field simulation analysis was carried out. Based on the Jensen wake model and its improved model, three layout methods for wind farm wind turbines are proposed: two units are arranged in series, two units are arranged in parallel, and three units are staggered. Through the simulation model, the wind energy utilization coefficient and wind speed of the wind turbine in the wind farm are obtained. Results: The optimal separation distance between the units was analyzed from four different angles: wind energy utilization coefficient, torque analysis, downstream tail flow and wind speed cloud contour. Finally, based on the optimal arrangement and unit distance, a triangular staggered wind farm composed of 10 units is established, and the integrated flow field characteristics of the whole wind farm are simulated and analyzed. The integrated flow field wake characteristics of the wind farm are obtained. Conclusion: In all three arrangements, the optimum distance between the units should be three times the diameter of the wind turbine. This arrangement ensures that most of the units are unaffected by the wake, the area affected by the low velocity wake of the wind farm is small, and the area affected by the high speed wake is large.


Author(s):  
S. G. Ignatiev ◽  
S. V. Kiseleva

Optimization of the autonomous wind-diesel plants composition and of their power for guaranteed energy supply, despite the long history of research, the diversity of approaches and methods, is an urgent problem. In this paper, a detailed analysis of the wind energy characteristics is proposed to shape an autonomous power system for a guaranteed power supply with predominance wind energy. The analysis was carried out on the basis of wind speed measurements in the south of the European part of Russia during 8 months at different heights with a discreteness of 10 minutes. As a result, we have obtained a sequence of average daily wind speeds and the sequences constructed by arbitrary variations in the distribution of average daily wind speeds in this interval. These sequences have been used to calculate energy balances in systems (wind turbines + diesel generator + consumer with constant and limited daily energy demand) and (wind turbines + diesel generator + consumer with constant and limited daily energy demand + energy storage). In order to maximize the use of wind energy, the wind turbine integrally for the period in question is assumed to produce the required amount of energy. For the generality of consideration, we have introduced the relative values of the required energy, relative energy produced by the wind turbine and the diesel generator and relative storage capacity by normalizing them to the swept area of the wind wheel. The paper shows the effect of the average wind speed over the period on the energy characteristics of the system (wind turbine + diesel generator + consumer). It was found that the wind turbine energy produced, wind turbine energy used by the consumer, fuel consumption, and fuel economy depend (close to cubic dependence) upon the specified average wind speed. It was found that, for the same system with a limited amount of required energy and high average wind speed over the period, the wind turbines with lower generator power and smaller wind wheel radius use wind energy more efficiently than the wind turbines with higher generator power and larger wind wheel radius at less average wind speed. For the system (wind turbine + diesel generator + energy storage + consumer) with increasing average speed for a given amount of energy required, which in general is covered by the energy production of wind turbines for the period, the maximum size capacity of the storage device decreases. With decreasing the energy storage capacity, the influence of the random nature of the change in wind speed decreases, and at some values of the relative capacity, it can be neglected.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Hashwini Lalchand Thadani ◽  
Fadia Dyni Zaaba ◽  
Muhammad Raimi Mohammad Shahrizal ◽  
Arjun Singh Jaj A. Jaspal Singh Jaj ◽  
Yun Ii Go

PurposeThis paper aims to design an optimum vertical axis wind turbine (VAWT) and assess its techno-economic performance for wind energy harvesting at high-speed railway in Malaysia.Design/methodology/approachThis project adopted AutoCAD and ANSYS modeling tools to design and optimize the blade of the turbine. The site selected has a railway of 30 km with six stops. The vertical turbines are placed 1 m apart from each other considering the optimum tip speed ratio. The power produced and net present value had been analyzed to evaluate its techno-economic viability.FindingsComputational fluid dynamics (CFD) analysis of National Advisory Committee for Aeronautics (NACA) 0020 blade has been carried out. For a turbine with wind speed of 50 m/s and swept area of 8 m2, the power generated is 245 kW. For eight trains that operate for 19 h/day with an interval of 30 min in nonpeak hours and 15 min in peak hours, total energy generated is 66 MWh/day. The average cost saved by the train stations is RM 16.7 mil/year with battery charging capacity of 12 h/day.Originality/valueWind energy harvesting is not commonly used in Malaysia due to its low wind speed ranging from 1.5 to 4.5 m/s. Conventional wind turbine requires a minimum cut-in wind speed of 11 m/s to overcome the inertia and starts generating power. Hence, this paper proposes an optimum design of VAWT to harvest an unconventional untapped wind sources from railway. The research finding complements the alternate energy harvesting technologies which can serve as reference for countries which experienced similar geographic constraints.


2021 ◽  
Author(s):  
Moshe Zilberman ◽  
Abdelaziz Abu Sbaih ◽  
Ibrahim Hadad

Abstract Wind energy has become an important resource for the growing demand for clean energy. In 2020 wind energy provided more than 6% of the global electricity demand. It is expected to reach 7% at the end of 2021. The installation growth rate of small wind turbines, though, is relatively slow. The reasons we are interested in the small vertical axis wind turbines are their low noise, environmentally friendly, low installation cost, and capable of being rooftop-mounted. The main goal of the present study is an optimization process towards achieving the optimal cost-effective vertical wind turbine. Thirty wind turbine models were tested under the same conditions in an Azrieli 30 × 30 × 90 cm low-speed wind tunnel at 107,000 Reynolds number. The different types of models were obtained by parametric variations of five basic models, maintaining the same aspect ratio but varying the number of bucket phases, the orientation angles, and the gaps between the vanes. The best performing turbine model was made of one phase with two vanes of non-symmetric bipolynomial profiles that exhibited 0.2 power coefficient, relative to 0.16 and 0.13 that were obtained for symmetrical polynomial and the original Savonius type turbines, respectively. Free rotation, static forces and moments, and dynamic moments and power were measured for the sake of comparison and explanation for the variations in performances of different types of turbines. CFD calculations were used to understand the forces and moment behaviors of the optimized turbine.


2018 ◽  
Vol 64 ◽  
pp. 06010
Author(s):  
Bachhal Amrender Singh ◽  
Vogstad Klaus ◽  
Lal Kolhe Mohan ◽  
Chougule Abhijit ◽  
Beyer Hans George

There is a big wind energy potential in supplying the power in an island and most of the islands are off-grid. Due to the limited area in island(s), there is need to find appropriate layout / location for wind turbines suited to the local wind conditions. In this paper, we have considered the wind resources data of an island in Trøndelag region of the Northern Norway, situated on the coastal line. The wind resources data of this island have been analysed for wake losses and turbulence on wind turbines for determining appropriate locations of wind turbines in this island. These analyses are very important for understanding the fatigue and mechanical stress on the wind turbines. In this work, semi empirical wake model has been used for wake losses analysis with wind speed and turbine spacings. The Jensen wake model used for the wake loss analysis due to its high degree of accuracy and the Frandsen model for characterizing the turbulent loading. The variations of the losses in the wind energy production of the down-wind turbine relative to the up-wind turbine and, the down-stream turbulence have been analysed for various turbine distances. The special emphasis has been taken for the case of wind turbine spacing, leading to the turbulence conditions for satisfying the IEC 61400-1 conditions to find the wind turbine layout in this island. The energy production of down-wind turbines has been decreased from 2 to 20% due to the lower wind speeds as they are located behind up-wind turbine, resulting in decreasing the overall energy production of the wind farm. Also, the higher wake losses have contributed to the effective turbulence, which has reduced the overall energy production from the wind farm. In this case study, the required distance for wind turbines have been changed to 6 rotor diameters for increasing the energy gain. From the results, it has been estimated that the marginal change in wake losses by moving the down-stream wind turbine by one rotor diameter distance has been in the range of 0.5 to 1% only and it is insignificant. In the full-length paper, the wake effects with wind speed variations and the wind turbine locations will be reported for reducing the wake losses on the down-stream wind turbine. The Frandsen model has been used for analysing turbulence loading on the down-stream wind turbine as per IEC 61400-1 criteria. In larger wind farms, the high turbulence from the up-stream wind turbines increases the fatigues on the turbines of the wind farm. In this work, we have used the effective turbulence criteria at a certain distance between up-stream and down-stream turbines for minimizing the fatigue load level. The sensitivity analysis on wake and turbulence analysis will be reported in the full-length paper. Results from this work will be useful for finding wind farm layouts in an island for utilizing effectively the wind energy resources and electrification using wind power plants.


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