Improvement in Solar Chimney Power Generation by Using a Diffuser Tower

2015 ◽  
Vol 137 (3) ◽  
Author(s):  
Shinsuke Okada ◽  
Takanori Uchida ◽  
Takashi Karasudani ◽  
Yuji Ohya
Keyword(s):  
Power Generation ◽  
Wind Turbine ◽  
Static Pressure ◽  
Solar Chimney ◽  
Generation Efficiency ◽  
High Rise ◽  
Pressure Region ◽  
Computational Fluid Dynamics Cfd ◽  
Inner Diameter ◽  
Power Generation Systems

The solar chimney prototype, operated in Spain from 1982 to 1989, verified the concept of the solar chimney. The power generation mechanism in this system is to turn the wind turbine placed inside a high rise cylindrical hollow tower by an induced thermal updraft. As long as the thermal updraft is induced inside the tower by the solar radiation, this system can produce electricity. The disadvantage of this system is the low power generation efficiency compared to other solar energy power generation systems. To overcome this disadvantage, we improved the mechanism in order to augment the velocity of the air which flows into the wind turbine. By applying a diffuser tower instead of a cylindrical one, the efficiency of the systems power generation is increased. The mechanism that we investigated was the effect of the diffuser on the solar chimney structure. The inner diameter of the tower expands as the height increases so that the static pressure recovery effect of the diffuser causes a low static pressure region to form at the bottom of the tower. This effect induces greater airflow within the tower. The laboratory experiment, as does the computational fluid dynamics (CFD) analysis of the laboratory sized model, shows that the proposed diffuser type tower induces a velocity approximately 1.38–1.44 times greater than the conventional cylindrical type. The wind power generation output is proportional to the cube of the incoming wind velocity into the wind turbine; therefore, approximately 2.6–3.0 times greater power output can be expected from using the diffuser type tower.

Transient Analysis of Power Generation Systems using Wind Turbine-Hybrid on Bakaru System

2021 ◽  
Author(s):  
Andarini Asri ◽  
Marwan ◽  
Musfirah Putri Lukman ◽  
Kurniawati Naim ◽  
Muh.Imran Bachtiar ◽  
...  
Keyword(s):  
Power Generation ◽  
Wind Turbine ◽  
Transient Analysis ◽  
Power Generation Systems

Preliminary Research of a Zero CO2 Emission Power Generation System

2010 ◽  
Author(s):  
Jing-yu Ran ◽  
Chang-lei Qin
Keyword(s):  
Power Generation ◽  
Co2 Emission ◽  
Generation System ◽  
Emission Power ◽  
Generation Efficiency ◽  
Technical Problems ◽  
The Earth ◽  
Emission System ◽  
Power Generation System ◽  
Power Generation Systems

CO2 is a main greenhouse gas fazing the Earth. So countries around the world are actively studying the methods of capturing CO2 to reduce emission. In this paper, firstly a brief review was carried out on the research development and technical problems of three typical near-zero CO2 emission power generation systems. Focus was made on the construction of one possible commercially applied zero emission system, which has new principle but relatively conservative sections. Preliminary analysis and calculation of energy and mass flow have been finished to evaluate its performance. The results showed that apart from zero CO2 emission, a relatively tempting efficiency could be sustained. Theoretically, higher than 90% purity of CO2 and 63% generation efficiency of the whole system can be achieved.

scholarly journals An Experimental Investigation of Wake Characteristics and Power Generation Efficiency of a Small Wind Turbine under Different Tip Speed Ratios

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2113 ◽  
Author(s):  
Yu-Ting Wu ◽  
Chang-Yu Lin ◽  
Che-Ming Hsu
Keyword(s):  
Power Generation ◽  
Wind Turbine ◽  
Power Output ◽  
Estimation Method ◽  
Mechanical Power ◽  
Power Coefficient ◽  
Regulation System ◽  
Generation Efficiency ◽  
Blade Rotation ◽  
Wake Characteristics

We carried out a wind tunnel experiment to examine the power generation efficiency of a stand-alone miniature wind turbine and its wake characteristics at different tip speed ratios (TSRs) under the same mean inflow velocity. Resistors in the electrical circuit were adjusted to control the TSRs to 0.9, 1.5, 3.0, 4.1, 5.2, and 5.9. The currents were measured to estimate the turbine power outputs versus the TSRs and then establish the actual power generation coefficient Cp distribution. To calculate the mechanical power coefficient, a new estimation method of the mechanical torque constant is proposed. A reverse calibration on the blade rotation speed was performed with given electrical voltages and currents that are used to estimate the mechanical power coefficient Cp, mech. In the experiment, the maximum Cp,mech was approximately 0.358 (corresponding to the maximum Cp of 0.212) at the TSR of 4.1. Significant findings indicate that the turbine at the TSR of 5.2 produces a smaller torque but a larger power output compared with that at the TSR of 3.0. This comparison further displays that the turbine at the TSR of 5.2, even with larger power output, still produces a turbine wake that has smaller velocity deficits and smaller turbulence intensity than that at the TSR of 3.0. This behavior demonstrates the significance of the blade-rotation control (i.e., pitch regulation) system to the turbine operation in a large wind farm for raising the overall farm power productivity.

Power Generation From Wind Turbines in a Solar Chimney

2011 ◽  
Author(s):  
Tudor Foote ◽  
Ramesh Agarwal
Keyword(s):  
Power Generation ◽  
Wind Turbine ◽  
Wind Power ◽  
Wind Turbines ◽  
Stokes Equations ◽  
Computational Study ◽  
Boussinesq Approximation ◽  
Navier Stokes ◽  
Solar Chimney ◽  
Wind Speeds

In past several years, several studies have shown that the shrouded wind turbines can generate greater power compared to bare turbines. A solar chimney not only generates an upward draft of the wind inside the solar tower but also creates a shroud around the wind turbine. There is large number of empty silos on farms, especially in mid-western U.S. They can be used as a solar chimney with minor modifications at very modest cost. The objective of this study is to determine the potential of these silos/chimneys in generating wind-power by installing a wind turbine inside the silo. An analytical/computational study is performed to evaluate this potential by employing the well known commercial Computational Fluid Dynamics (CFD) software FLUENT. An actuator disc model is used to model the turbine. Calculations are performed for three cases using the dimensions of a typical silo and assuming Class 3 wind velocity: (a) bare turbine (without enclosing silo), (b) turbine enclosed by a cylindrical silo, and (c) the turbine enclosed by the cylindrical silo with a diffuser at the top of the silo. The incompressible Navier-Stokes equations with Boussinesq approximation and a two equation realizable k–ε model are employed in the calculations. Cp and generated power are calculated for the three cases. It was found that the silo increases the Cp beyond the Betz’s limit significantly and as a result the generated power; this effect is consistent with that found in the recent literature that the shrouded wind-turbines can generate greater power than the bare turbines. The inclusion of a diffuser on top of the silo further increases the generated power and Cp. The results reported here are for typical silo dimensions and wind speeds; the results for silos with different dimensions and wind speeds can be easily generated. This study shows the potential of using abandoned silos in mid-west for wind power generation.

The performance of small wind power generation systems on super high-rise buildings

2014 ◽  
Vol 14 (3) ◽  
pp. 489-499 ◽  
Author(s):  
Seol-Hui Park ◽  
Jeong-Ha Park ◽  
Jin-Chul Park ◽  
Eun-Taik Lee
Keyword(s):  
Power Generation ◽  
Wind Power ◽  
Wind Power Generation ◽  
High Rise ◽  
Power Generation Systems

scholarly journals Development of High Performance Airfoils for Application in Small Wind Turbine Power Generation

2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Emmanuel Yeboah Osei ◽  
Richard Opoku ◽  
Albert K. Sunnu ◽  
Muyiwa S. Adaramola
Keyword(s):  
Power Generation ◽  
Wind Turbine ◽  
High Performance ◽  
Turbine Blades ◽  
Turbine Rotor ◽  
Wind Turbine Blades ◽  
Small Wind Turbine ◽  
Stall Angle ◽  
Power Generation Systems ◽  
Drag Ratio

Small wind turbine power generation systems have the potential to meet the electricity demand of the residential sector in developing countries. However, due to their exposure to low Reynolds number (Re) flow conditions and associated problems, specific airfoils are required for the design of their blades. In this research, XFOIL was used to develop and test three high performance airfoils (EYO7-8, EYO8-8, and EYO9-8) for small wind turbine application. The airfoils were subsequently used in conjunction with Blade Element Momentum Theory to develop and test 3-bladed 6 m diameter wind turbine rotors. The aerodynamic performance parameters of the airfoils tested were lift, drag, lift-to-drag ratio, and stall angle. At Re=300,000, EYO7-8, EYO8-8, and EYO9-8 had maximum lift-to-drag ratios of 134, 131, and 127, respectively, and maximum lift coefficients of 1.77, 1.81, and 1.81, respectively. The stall angles were 12° for EYO7-8, 14° for EYO8-8, and 15° for EYO9-8. Together, the new airfoils compared favourably with other existing low Re airfoils and are suitable for the design of small wind turbine blades. Analysis of the results showed that the performance improvement of the EYO-Series airfoils is as a result of the design optimization that employed an optimal thickness-to-camber ratio (t/c) in the range of 0.85–1.50. Preliminary wind turbine rotor analysis also showed that the EYO7-8, EYO8-8, and EYO9-8 rotors had maximum power coefficients of 0.371, 0.366, and 0.358, respectively.

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