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Scientific Publications Year 2006 for Solar Updraft Chimneys SUP SCPP SCPT

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Maximum fluid power condition in solar chimney power plants – An analytical approach
Solar Energy, Volume 80, Issue 11, November 2006, Pages 1417-1423
Theodor W. von Backström, Thomas P. Fluri

2006 Theodor W. von Backstrôm, Thomas P. Fluri: Maximum fluid power condition in solar chimney power plants – An analytical approach

PDF Document of 0.2Mo Abstract
Main features of a solar chimney power plant are a circular greenhouse type collector and a tall chimney at its centre. Air flowing radially inwards under the collector roof heats up and enters the chimney after passing through a turbo-generator.
The objective of the study was to investigate analytically the validity and applicability of the assumption that, for maximum fluid power, the optimum ratio of turbine pressure drop to pressure potential (available system pressure difference) is 2/3. An initial power law model assumes that pressure potential is proportional to volume flow to the power m, where m is typically a negative number between 0 and −1, and that the system pressure drop is proportional to the power n, where typically n = 2. The analysis shows that the optimum turbine pressure drop as fraction of the pressure potential is (n − m)/(n + 1), which is equal to 2/3 only when m = 0, implying a constant pressure potential, independent of flow rate. Consideration of a basic collector model proposed by Schlaich leads to the conclusion that the value of m is equal to the negative of the collector floor-to-exit efficiency. A more comprehensive optimization scheme, incorporating the basic collector model of Schlaich in the analysis, shows that the power law approach is sound and conservative.
It is shown that the constant pressure potential assumption (m = 0) may lead to appreciable underestimation of the performance of a solar chimney power plant, when compared to the analyses presented in the paper. More important is that both these analyses predict that maximum fluid power is available at much lower flow rate and much higher turbine pressure drop than predicted by the constant pressure potential assumption. Thus, the constant pressure potential assumption may lead to overestimating the size of the flow passages in the plant, and designing a turbine with inadequate stall margin and excessive runaway speed margin. The derived equations may be useful in the initial estimation of plant performance, in plant performance analysis and in control algorithm design. The analyses may also serve to set up test cases for more comprehensive plant models.
Article Outline
Nomenclature
1. Introduction
2. Power law model
2.1. Maximum fluid power condition
3. Value of m for simple solar collector model
3.1. Power law vs. constant pressure potential model
4. Effect of variable collector efficiency
5. Conclusions
References


Critical evaluation of solar chimney power plant performance
Solar Energy, Volume 80, Issue 5, May 2006, Pages 535-544
J.P. Pretorius, D.G. Kröger

2006 J.P. Pretorius, D.G. Kröger: Critical evaluation of solar chimney power plant performance

PDF Document of 0.3Mo Abstract
This paper evaluates the influence of a recently developed convective heat transfer equation, more accurate turbine inlet loss coefficient, quality collector roof glass and various types of soil on the performance of a large scale solar chimney power plant. Results indicate that the new heat transfer equation reduces plant power output considerably. The effect of a more accurate turbine inlet loss coefficient is insignificant, while utilizing better quality glass enhances plant power production. Models employing Limestone and Sandstone soil produce virtually similar results to a Granite-based model. The plant collector height is found to differ from previously obtained optimal values.
Article Outline
Nomenclature
1. Introduction
2. Convective heat transfer equation
2.1. Convection to ambient
2.2. Convection from roof to collector air
2.3. Convection from ground to collector air
2.4. Simulation and results
3. Turbine inlet loss coefficient
3.1. Simulation and results
4. Collector roof glass quality
4.1. Simulation and results
5. Various ground types
5.1. Simulation and results
6. Optimizing the collector roof shape and inlet height
6.1. Simulation and results
7. Conclusion
Appendix A
References


The potential of solar chimney for application in rural areas of developing countries
Fuel, Volume 85, Issues 17-18, December 2006, Pages 2561-2566
Frederick N. Onyango, Reccab M. Ochieng
Abstract
Solar chimney electric power generation is one of the concepts in renewable energy technology (RET) application. The power station is based simply on the principle that warm air rises. Air underneath a glass ceiling is heated by solar radiation and rises through a chimney. The warm air which has just risen is replaced by air from the edge of the glass ceiling which flows inward, and will then itself begin to heat up. In this way the Sun’s heat radiation is converted into kinetic energy of constantly rising air to drive turbine built into the chimney. The turbine then converts the wind power by means of a generator into electrical energy. We have considered the appropriateness of a solar chimney to rural villages and highlight some features of such a power generating plant. The calculations carried out show that the power that can be generated by a solar chimney of specific dimension exhibit a minimum threshold value of τ = 2.9, the temperature ratio of the difference between the collector surface temperature and the temperature at the turbine (Ts–TH) to the difference between the air mass temperature under the roof and the collector surface temperature (Tm–Ts). Our calculations show that for τ = 2.9, an appreciable electric power ( 103 W) can be generated by a sturdy and physically viable solar chimney whose dimension has been determined to be L = 150 m, H = R = 1.5 m. Thus the minimum dimension of a practical solar chimney electric power station would serve approximately fifty (50) households in a typical rural setting.
Article Outline
Nomenclature
1. Introduction
2. Solar chimney
3. Theory
4. Discussion
5. Conclusion
References


Counter-rotating turbines for solar chimney power plants
Renewable Energy, Volume 31, Issue 12, October 2006, Pages 1873-1891
F. Denantes, E. Bilgen
Abstract
An efficiency model at design performance for counter-rotating turbines is developed and validated. Based on the efficiency equations, an off-design performance model for counter-rotating turbines is developed. Combined with a thermodynamic model for a solar chimney system and a solar radiation model, annual energy output of solar chimney systems is determined. Two counter-rotating turbines, one with inlet guide vanes, the other without, are compared to a single-runner system. The design and off-design performances are weighed against in three different solar chimney plant sizes. It is shown that the counter-rotating turbines without guide vanes have lower design efficiency and a higher off-design performance than a single-runner turbine. Based on the output torque versus power for various turbine layouts, advantageous operational conditions of counter-rotating turbines are demonstrated.
Article Outline
Nomenclature
1. Introduction
2. Counter-rotating turbines
2.1. Mathematical model
2.2. Profile loss model
2.2.1. Constant profile loss model
2.2.2. Profile loss model by Lewis
2.2.3. Profile loss model using lift/drag ratio
2.3. Validation and comparison of the loss models
2.3.1. Single-runner turbine
2.3.2. Counter-rotating turbine
2.3.3. Comparison of the three profile loss models
2.4. Design performance model
3. Solar chimney model
3.1. Thermodynamics
4. Solar radiation
5. Results and discussion
5.1. Scenarios
5.2. Mechanical considerations
5.3. Torque comparison with SRT, CRT, and CRTa turbines
5.4. Nominal turbine efficiency
5.5. Off-design performance
5.6. Efficiency
5.7. Annual energy output
6. Conclusions
Acknowledgements
References


Available energy of the air in solar chimneys and the possibility of its ground-level concentration
Solar Energy, Volume 80, Issue 7, July 2006, Pages 804-811

2006 N. Ninic: Available energy of the air in solar chimneys and the possibility of its ground-level concentration

PDF Document of 0.3Mo Abstract
Solar chimneys are defined as low temperature solar thermal power plants, which use the atmospheric air as a working fluid, where only one part of the thermodynamic cycle within the plant is utilized. The available work potential that atmospheric air acquires while passing through the collector has been determined and analyzed. The dependence of the work potential on the air flowing into the air collector from the heat gained inside the collector, air humidity and atmospheric pressure as a function of elevation are determined. Various collector types using dry and humid air have been analyzed. The influence of various chimney heights on the air work potential are established. The possibly higher utilization factors of the available hot air work potential without the use of high solid chimneys are discussed. It has been shown that the vortex motion flowing downstream of the turbine can be maintained under pressure and can possibly take over the role of the solid structure chimney. Thus, a part of the available energy potential acquired in the collector would be used to maintain the vortex flow in the air column above the ground-level turbine. Basic conditions for the maintenance of such a vortex flow are described and compared to the tornado phenomenon.
Article Outline
Nomenclature
1. Introduction
2. Available energy of the collector air
3. Height potential in the standard atmosphere
4. The role of the solid chimney
5. The impact of humidity on the height potential
6. The possibility of ground-level concentration of the height potential
7. Conclusion
Acknowledgements
References

2006 Horace Heffner: Energy Costs and References

PDF Document of 0.1Mo

2006 Timothy M. VanReken, Athanasios Nenes: Cloud Formation in the Plumes of Solar Chimney Power Generation Facilities: A Modeling Study

PDF Document of 0.6Mo

2006 Xinping Zhou, Jiakuan Yang, Bo Xiao, Guoxiang Hou: Experimental study of the temperature field in a solar chimney power setup

PDF Document of 1.4M0

2006 EnviroMission Solar Tower

PDF Document of 0.3Mo / http://www.enviromission.com.au

2006 Frederick N. Onyango, Reccab M. Ochieng: The potential of solar chimney for application in rural areas of developing countries

PDF Document of 0.3Mo

2006 Christos Papageorgiou: Floating Solar Chimney Technology

PDF Document of 1.7Mo / www.floatingsolarchimney.gr

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Scientific Publications in Chinese

2006
集热棚对太阳能烟囱发电系统效率的影响
Analyses on collector influence on efficiency of solar chimney power plant
【作者】 毛宏举; 李戬洪;
【Author】 MAO Hong-ju 1,2, LI Jian-hong 1
(1. Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China;
2. Graduate School of the Chinese Academy of Science, Beijing 100039, China)
【机构】 中国科学院广州能源研究所; 中国科学院广州能源研究所 广东广州510640 中国科学院研究生院; 北京100038; 广东广州510640;
【摘要】 采用计算流体动力学(CFD)方法对太阳能烟囱发电装置进行数值模拟,得到装置内部的温度场、速度场、压力场等分布情况。对集热棚的各种几何和物理参数进行研究和分析。结果表明,集热棚直径、太阳辐照强度、覆盖材料的透明度等诸多参数对系统效率有直接而重要的影响。 更多还原
【Abstract】 Some influence factors on efficiency in solar chimney power plant are studied by using the Computational Fluid Dynamics (CFD) method in the paper. The temperature, velocity, pressure of the air are obtained. The study shows the diameter of chimney, solar radiation, transparency of the cover are the most important influence factors. The purpose is to deliver some advice for application and development of solar chimney generation system in future.
【关键词】 太阳能烟囱; 计算流体动力学; 系统效率; 影响因素;
【Key words】 solar chimney; CFD; system efficiency; influence factor;
【文献出处】 可再生能源, Renewable Energy, 编辑部邮箱 , 2006年06期

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2006
太阳能热气流电站系统的研究进展
Progress of Researches on the Solar Chimney Power Plant System
【作者】 黄素逸;
【Author】 HUANG Su-yi (School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China)
【机构】 华中科技大学 能源与动力工程学院 湖北武汉 430074;
【摘要】 太阳能热气流电站系统是一种将太阳能转换为电能的装置,近年来对太阳能热气流电站系统的研究非常活跃。简要概括了关于太阳能热气流电站系统的国内外研究现状,总结了太阳能热气流发电系统的优势,介绍了其商用电站的建设进展,分析了在我国建设太阳能热气流电站的可行性。 更多还原
【Abstract】 The solar chimney power plant system is one that accomplishes the task of converting solar energy into kinetic energy, and many researchers have shown great interest in this subject in recent years. This paper is a detailed review of the progress of researches in the past few decades on solar chimney power plant system, including the advantages of this system over the conventional power plant system. Furthermore, the progress of the large-scale solar chimney power plant and the possibility of building up such a power plant in China are discussed in this paper.
【关键词】 太阳能热气流电站; 集热棚; 透平; 烟囱; 蓄热层;
【Key words】 solar chimney power plant; collector; turbine; chimney; storage;
【基金】 教育部重点基金资助专案(104127)。
【文献出处】 东莞理工学院学报, Journal of Dongguan University of Technology, 编辑部邮箱 , 2006年04期

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2006
太阳能热气流电站透平布置位置研究
Research on the position of turbine in the solar chimney power plant system
【作者】 明廷臻; 刘伟; 高敏; 许国良; 潘垣;
【Author】 MING Ting-zhen 1, LIU Wei 1, GAO Min 2, XU Guo-liang 1, PAN Huan 1
(1. Huazhong University of Science and Technology, Wuhan 430074, China;
2. Tianjin Datang International Panshan Power Generation Company Limited, Tianjin 301900, China)
【机构】 华中科技大学; 天津大唐国际盘山发电有限责任公司; 华中科技大学 湖北武汉430074; 湖北武汉430074; 天津蓟县301900;
【摘要】 基于相对压力概念,建立了太阳能热气流电站系统的新数学模型,并通过数值模拟得到系统内的相对压力分布。根据系统相对压力的分布特点确定了透平布置的最佳位置:在烟囱的底部区域,相对压力最小,压力梯度最大,最适于布置透平;在技术容许的情况下,为实现能量转换效率最高,不宜采用能量梯级利用方案。 更多还原
【Abstract】 Based on the concept of relative static pressure,a new mathematical model has been set up to analyze the solar chimney power plant systems. The relative static pressure profiles in the system have been obtained by numerical simulation. The most appropriate position of the turbine has been found in accordance with the characteristic of the relative static pressure profiles, which gives a theoretical reference to the design and utilization of the solar chimney power plant.
【关键词】 太阳能热气流电站; 相对压力; 透平;
【Key words】 solar chimney power plant systems; relative static pressure; turbine;
【基金】 教育部重点基金资助项目(104127); 国家重点基础研究发展规划项目(G2000026303)
【文献出处】 可再生能源, Renewable Energy, 编辑部邮箱 , 2006年05期

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2006
烟囱性状对太阳能烟囱发电系统效率的影响
Analyses on influence factor of efficiency in solar chimney power plant
【作者】 毛宏举; 李戬洪;
【Author】 MAO Hong-ju 1,2, LI Jian-hong 1
(1. Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510640, China;
2. Graduate School of the Chinese Academy of Science, Beijing 100039, China)
【机构】 中国科学院广州能源研究所; 中国科学院广州能源研究所 广东广州510640; 中国科学院研究生院; 北京100038; 广东广州510640;
【摘要】 采用计算流体动力学(CFD)方法分析了烟囱对太阳能烟囱发电系统效率的影响。通过对烟囱高度、烟囱形状、烟囱内表面粗糙度和温度对系统的影响分析表明:在其它条件不变的情况下,烟囱高度和直径对系统效率影响最为显著,其次是形状,最后是烟囱内表面粗糙度和温度。 更多还原
【Abstract】 Some influence factors of efficiency in solar chimney power plant are studied by using the Computational Fluid Dynamics(CFD) method in the paper. The study shows the height and diameter of chimney are the most important influence factors, next is the shape of chimney, the least influence factors are the roughness and temperature of the chimney inner surface.The purpose of this paper is to deliver some advice for application and development of solar chimney generation system in future.
【关键词】 太阳能烟囱; 计算流体动力学(CFD); 系统效率; 影响因素;
【Key words】 solar chimney; CFD; system efficiency; influence factor;
【文献出处】 可再生能源, Renewable Energy, 编辑部邮箱 , 2006年05期

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2006
太阳能热气流电站系统研究
A STUDY OF THE SOLAR CHIMNEY POWER PLANT SYSTEMS【作者】 明廷臻; 刘伟; 许国良; 范爱武;
【Author】 MING Ting-Zhen LIU Wei XU Guo-Liang FAN Ai-Wu
(School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China)
【机构】 华中科技大学能源与动力工程学院; 华中科技大学能源与动力工程学院 武汉 430074; 武汉 430074;
【摘要】 由于现有模型不足以准确描述太阳能热气流发电系统的物理机制,本文提出一个更完善的数学模型去分析太阳能热气流电站系统的相对压力分布和系统抽力.模型中考虑了太阳辐射和系统尺寸参数对系统相对压力和系统抽力的影响。以西班牙试验电站为例进行数值模拟,探索系统尺寸参数和太阳辐射对系统相对压力和系统抽力的影响。数值计算结果与理论分析具有良好的一致性. 更多还原
【Abstract】 As the existing models are insufficient to accurately describe the mechanism, a comprehensive model is advanced in this paper to evaluate the relative static pressure and driving force of the solar chimney power plant systems, in which the effects of various parameters on the relative static pressure and driving force have been further investigated. Using the solar chimney prototype in Spain as an example, the numerical studies are performed to explore the effect of the geometric modifications and solar radiation on relative static pressure and driving force of the system, which show reasonable agreement with the analytical model.
【关键词】 太阳能热气流电站; 相对压力; 抽力; 数值模拟;
【Key words】 solar chimney power plant system; relative static pressure; driving force; numerical simulation;
【基金】 教育部重点基金资助项目(No.104127)
【文献出处】 工程热物理学报, Journal of Engineering Thermophysics, 编辑部邮箱 , 2006年03期

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