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C.d. Papageorgiou - One of the best experts on this subject based on the ideXlab platform.

  • Floating Solar Chimney Technology
    Solar Energy, 2010
    Co-Authors: C.d. Papageorgiou
    Abstract:

    1.1 Floating Solar Chimney technology description The purpose of this chapter is to present the Floating solar Chimney (FSC) technology, look for the site www.floatingsolarChimney.gr, in order to explain its principles of operation and to point out its various significant benefits. This technology is the advisable one for candidacy for large scale solar electricity generation especially in desert or semi desert areas of our planet and a major technology for the global warming elimination. The solar Chimney power plants are usually referred to as solar updraft towers (http://en.wikipedia.org/wiki/Solar_updraft_tower) and the related solar Chimneys are huge reinforced concrete structures. However due to the high construction cost of the concrete solar Chimneys the solar up-draft tower technology is expensive demanding a high initial investment in comparison to its competitive solar technologies. Their solar up-draft towers are huge structures of high initial investment cost that can not be split into small units. That is possible for the relatively also expensive PV solar technology. Also the solar updraft technology is far more expensive compared to the conventional fossil fueled power plants of similar electricity generation. That is why the solar Chimney technology has not yet been applied although it is a solar technology of many advantages. The Floating Solar Chimney (FSC) is a fabric low cost alternative of the concrete solar Chimney up-draft towers that can make the Floating Solar Chimney technology cost competitive in comparison not only with the renewable electricity generation technologies but also with the conventional fossil fueled electricity generation technologies. Also the FSC technology is cost effective to be split into small units of several MW each. The Floating Solar Chimney Power Plant, named by the author as Solar Aero-Electric Power Plant (SAEP) due to its similarity to the Hydro-Electric power plant, is a set of three major components: • The Solar Collector. It is a large greenhouse open around its periphery with a transparent roof supported a few meters above the ground. • The Floating Solar Chimney (FSC). It is a tall fabric cylinder placed at the centre of the solar collector through which the warm air of the greenhouse, due to its relative buoyancy to the ambient air, is up-drafting. • The Turbo-Generators. It is a set of air turbines geared to appropriate electric generators in the path of up-drafting warm air flow that are forced to rotate generating electricity. The gear boxes are adjusting the rotation speed of the air turbines to the generator rotation speed defined by the grid frequency and their pole pairs. Source: Solar Energy, Book edited by: Radu D. Rugescu, ISBN 978-953-307-052-0, pp. 432, February 2010, INTECH, Croatia, downloaded from SCIYO.COM

  • Floating Solar Chimney versus Concrete Solar Chimney Power Plants
    2007 International Conference on Clean Electrical Power, 2007
    Co-Authors: C.d. Papageorgiou
    Abstract:

    A solar Chimney power plant has three major components: (1) A circular solar collector (Greenhouse) (2) A tall cylinder in the center of the solar collector ( Solar Chimney) (3) A set of air turbines geared to electric generators around the bottom of the solar Chimney The air warms up inside the greenhouse by the solar irradiation and, due to its buoyancy, tends to escape through the Solar Chimney. This warm stream of air is leaving part of its thermodynamic energy to the air turbines placed in the path of the airflow. The solar Chimney power stations were named Solar Aero-Electric Power Plants (SAEPPs) due to their similarity to Hydro Electric Power Plants. The efficiency of the SAEPPs is roughly proportional to the height of their solar Chimneys. Solar Chimneys can be made as reinforced concrete structures (Concrete Solar Chimneys, CFCs), or as lighter than air inflated structures (Floating Solar Chimneys FSCs). These floating solar Chimneys are made by successive balloon tubes, filled with a lighter than air gas. This permits to the FSCs to float in the air and thus to have heights 1.5divide3 Km giving to their SAEPPs higher efficiencies than Concrete Solar Chimney SAEPPs. Using ground thermal storage, or artificial thermal storage in the form of water in closed plastic tubes, it can be proved that the SAEPPs can operate 24 hours per day 365 days per year with a minimum guaranteed power production. This means that the SAEPPs, although renewable by nature, can have a similar operation to conventional power stations and thus can replace them. In the present paper a comparison for construction cost of SAEPPs with Floating Solar Chimneys and Concrete Solar Chimneys is given. It is shown that FSC Technology Power Plants is 5 to 6 times cheaper than CFC Technology Power Plants.

Dennis Y.c. Leung - One of the best experts on this subject based on the ideXlab platform.

  • Mathematical Modelling of the Performance of a Solar Chimney Power Plant with Divergent Chimneys
    Energy Procedia, 2017
    Co-Authors: Dennis Y.c. Leung
    Abstract:

    Abstract Chimney is a critical component influencing the performance of a Solar Chimney Power Plant (SCPP). An enhancement on the power output of SCPPs with divergent Chimneys was observed in a number of experimental and numerical studies using Computational Fluid Dynamic (CFD) models. In this paper, a mathematical model was established to analyse the hydrodynamic features of a series of divergent Chimneys in a SCPP. The importance of estimating the loss from the potential diffuser stall in divergent Chimneys was especially discussed in this study. The result of the mathematical model was compared with those of CFD simulation to evaluate the validity and the performance of this present model. Subsequently, parametric studies were conducted by using this mathematical model. The performance of divergent SCPPs was found to be governed by the area ratio of Chimney entrance over its exit. The result further indicated that the optimal area ratio of divergent Chimneys was different when the Chimney height varied from 100m to 300m. Besides, several shorter divergent SCPPs showed a comparable power output as the cylindrical SCPPs with taller Chimneys, which demonstrated an outstanding advantage of divergent SCPPs for commercial application.

  • Effect of Divergent Chimneys on the Performance of a Solar Chimney Power Plant
    Energy Procedia, 2017
    Co-Authors: Dennis Y.c. Leung, Michael Z.q. Chen
    Abstract:

    Abstract This paper numerically examined the performance of divergent Chimneys in solar Chimney power plants with two shape-controlling parameters, that is, the area ratio of the Chimney exit over the entrance and the divergent angle. Compared with the conventional cylindrical Chimneys, a higher power output in the divergent-Chimney system could be achieved. This enhancement effect, however, increased first and then declined with increasing the area ratio or the divergent angle. Furthermore, subsequent parametric studies indicated that the area ratio and the divergent angle have different impacts on this enhancement effect: the area ratio may dominate the strength of the enhancement effect while the divergent angle may dominate the change rate of the enhancement effect along the varying shape-controlling parameters.

  • Impact of the geometry of divergent Chimneys on the power output of a solar Chimney power plant
    Energy, 2017
    Co-Authors: Dennis Y.c. Leung, John C.y. Chan
    Abstract:

    Divergent Chimney is proposed to be an alternative for Solar Chimney Power Plants (SCPPs) because of their reported remarkable improvement in power output over cylindrical Chimneys. However, the power output of divergent SCPPs in those studies changed from several percentage to >100 times higher than that of cylindrical ones. In our hypothesis, this large deviation was related to the various configurations of the SCPPs examined. Therefore, this paper examined comprehensively the effect of geometry of divergent Chimneys on system performance of SCPPs to further reveal their hydrodynamic features. The geometric parameters under investigation included the area ratio (AR) of Chimney exit over entrance, the divergent angle (DA) of Chimney wall and the size of system. Our numerical simulations indicated a parabolic tendency in the performance of the divergent SCPPs when increasing the ARs (or DAs). Reasons for this tendency were proposed based on its hydro- and thermo-interaction. Furthermore, the normalized power output showed good consistency among the SCPPs with different sizes when geometric similarity was adopted to the entire system geometry. The similar normalized outputs found were almost insensitive to the variations in the solar insolation. These outcomes would be a valuable reference for designing SCPPs with divergent Chimneys.

Roozbeh Sangi - One of the best experts on this subject based on the ideXlab platform.

  • performance evaluation of solar Chimney power plants in iran
    Renewable & Sustainable Energy Reviews, 2012
    Co-Authors: Roozbeh Sangi
    Abstract:

    Abstract The solar Chimney power plant is a simple solar thermal power plant that is capable of converting solar energy into thermal energy in the solar collector. In the second stage, the generated thermal energy is converted into kinetic energy in the Chimney and ultimately into electric energy using a combination of a wind turbine and a generator. The purpose of this study is to evaluate the performance of solar Chimney power plants in some parts of Iran theoretically and to estimate the quantity of the produced electric energy. A mathematical model based on the energy balance was developed to estimate the power output of solar Chimneys as well as to examine the effect of various ambient conditions and structural dimensions on the power generation. The solar Chimney power plant with 350 m Chimney height and 1000 m collector diameter is capable of producing monthly average 1–2 MW electric power over a year.

Alex Stojcevski - One of the best experts on this subject based on the ideXlab platform.

  • Solar Chimney power plant and its correlation with ambient wind effect
    Journal of Thermal Analysis and Calorimetry, 2019
    Co-Authors: Mazdak Arzpeyma, Kazi Md. Salim Newaz, Mehdi Seyedmahmoudian, Naveed Akram, Ben Horan, Saad Mekhilef, Alex Stojcevski
    Abstract:

    The use of solar energy in the present era is necessary and important as well. Solar Chimney technology for power generation is one of the solar energy harvesting techniques where the direct and dispersed solar radiations are absorbed in the solar Chimney power plant. The effectiveness of solar Chimneys has been proven for power generation, and it is a promising approach to future energy generation plans. This article provides a comprehensive scenario of the research and development of solar energy technology as well as the history of solar Chimneys in the last few decades. It describes the state of empirical and theoretical studies and the physical processes for this commonly used technology. Finally, this paper presents some avenues to cover the practical required approaches for solar Chimney power generation plant. In this study, the numerical investigation is also considered to study the stack configuration effect on the performance of a solar Chimney power plant. Numerical simulation of the proposed configuration shows that the speculated geometry can reduce the throttling effect of the deflected plume.

Richard Karl Strand - One of the best experts on this subject based on the ideXlab platform.

  • enhancement of natural ventilation in buildings using a thermal Chimney
    Energy and Buildings, 2009
    Co-Authors: Kwang Ho Lee, Richard Karl Strand
    Abstract:

    A new module was developed for and implemented in the EnergyPlus program for the simulation and determination of the energy impact of thermal Chimneys. This paper describes the basic concepts, assumptions, and algorithms implemented into the EnergyPlus program to predict the performance of a thermal Chimney. Using the new module, the effects of the Chimney height, solar absorptance of the absorber wall, solar transmittance of the glass cover and the air gap width are investigated under various conditions. Chimney height, solar absorptance and solar transmittance turned out to have more influence on the ventilation enhancement than the air gap width. The potential energy impacts of a thermal Chimney under three different climate conditions are also investigated. It turned out that significant building cooling energy saving can be achieved by properly employing thermal Chimneys and that they have more potential for cooling than for heating. In addition, the performance of a thermal Chimney was heavily dependent on the climate of the location.