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Exergy and economic analysis of solar chimney in iran climate: tehran, semnan, and bandar abbas
, Article Mathematical Modelling of Engineering Problems ; Volume 7, Issue 1 , 2020 , Pages 55-67 ; Mohammadi, O ; Sadeghzadeh, M ; Pourfayaz, F ; Kumar, R ; Lorenzini, G ; Sharif University of Technology
International Information and Engineering Technology Association
2020
Abstract
Solar chimney is one of the attractive approaches to produce power from a clean source of renewable energy. In this investigation, a potentiometric study is carried out to find out a best location for construction of a solar chimney in different climates of Iran, in the Middle East. With this objective, three locations with different weather climates were chosen, i.e. Tehran, Semnan, and Bandar Abbas. These locations were chosen due to their different climatic conditions and solar irradiation. The used weather conditions are extracted for the middle day of summer, 6th August. The output power of the solar chimney plant was assessed as a function of various thermo-physical properties such as...
Performance optimization of solar chimney power plant using electric/corona wind
, Article Journal of Electrostatics ; Volume 78 , 2015 , Pages 22-30 ; 03043886 (ISSN) ; Kasaeian, A ; Ghalamchi, M ; Ghalamchi, M ; Sharif University of Technology
Elsevier
2015
Abstract
The effect of the corona wind on the natural convection at absorber of a solar chimney power plant pilot was investigated experimentally. The aim of the study is to improve the efficiency of SCPP through enhanced the heat transfer coefficient of absorber with corona wind. The results show that corona wind enhanced the absorber convective heat transfer coefficient leading to increment in air the velocity and the output power of the SCPP. The amount of heat transfer of pilot increased more than 14.5% when applying voltage of 15 KV and the speed in chimney experienced about 72% amelioration
CFD simulation of natural draught cooling tower wind-covering
, Article Applied Mechanics and Materials, Dubai ; Volume 307 , 2013 , Pages 279-284 ; 16609336 (ISSN) ; 9783037856598 (ISBN) ; Salemkar, H ; Behrouzifar, A ; Abrar, B ; Sharif University of Technology
2013
Abstract
Past experiences have shown that a local wind can considerably affect the performances of powerplant cooling towers and factory chimneys. In thermal powerplants, the performance of Rankin cycles would reduce if the temperature of its condenser increases. This issue is very important to powerplants located in countries with strong local winds. To remedy the malperformance of a natural cooling tower in windy conditions, it is required to understand the physics of flow around cooling towers more clearly. One adverse physics is known as the wind covering problem which can drastically affect the natural draught through a cooling tower in windy conditions. In this paper, we focus on wind-covering...
ANN and ANFIS models to predict the performance of solar chimney power plants
, Article Renewable Energy ; Volume 83 , November , 2015 , Pages 597-607 ; 09601481 (ISSN) ; Nasirivatan, S ; Kasaeian, A. B ; Hajinezhad, A ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
A precise model of the behavior of complex systems such as solar chimney power plants (SCPP) would be much beneficial. Also, such a model would be quite contributing to the control of solar chimney operation. In this paper, the identification and modeling of SCPP utilizing ANN and Adaptive Neuro Fuzzy Inference System (ANFIS) are discussed. The modeling is based on the data of three working days which were taken of a built pilot in University of Zanjan, Iran. The input parameters are time, radiation and ambient temperature, while the output is the air velocity at the inlet of the chimney. The results of ANN model and ANFIS model were compared; it was found that ANFIS model exhibited better...
Damped spectral element method for global dynamic analysis of chimneys
, Article Advances in Structural Engineering ; Volume 7, Issue 1 , 2004 , Pages 33-47 ; 13694332 (ISSN) ; Safi, M ; Asadpour, N ; Sharif University of Technology
Multi-Science Publishing Co. Ltd
2004
Abstract
Conventional finite element method has been used successfully in linear and nonlinear analyses in tall chimney structures. The method can be performed by subdividing the large structure with small uniform elements having approximate shape functions. Although this replaces a single complicated structural system with the number of simple uniform elements, in cases of tall concrete chimney structures with cracking and crushing behavior in concrete material and yielding in the reinforcement, the computer time and memory can be large. Hence, it is desirable to search for a procedure requiring lesser number of elements and also less computer time and effort to model a structure. In this respect,...
Computational study on design parameters of a solar chimney
, Article International Conference on Sustainable Mobility Applications, Renewables and Technology, 23 November 2015 through 25 November 2015 ; 2015 ; 9781467395298 (ISBN) ; Raveshi, S ; Shahsavari, M ; Sedaghat, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
Abstract
Today, the production of energy and electricity is one of the major concerns of mankind. Electricity generation by solar energy is considered as one of the alternatives to fossil fuels. Solar chimneys mechanism is based on a natural phenomenon. In this process the solar energy heat up the earth's surface and the surrounding air. Due to the density difference between cold air and warm air, heated air ascends and causes air circulation. In this study, mathematical modelling of solar chimney and governing equations of this system will be discussed. In order to validate the numerical results, upwind velocity in chimney has been compared with a reliable reference results. As well as, the...
The Study of the Effects of Different Parameters on Solar Chimneys Used in Ventilation
, M.Sc. Thesis Sharif University of Technology ; Kazemzadeh Hannani, Siamak (Supervisor)
Abstract
The purpose of present work is to study the effect of different parameters on the solar chimney used in ventilation. Experimental model and numerical model were used to achieve this goal. First, the model was numerically analyzed by Fluent software using Boussinesq approximation. The results of numerical modeling were validated by the empirical model. Finally, the numerical model can be used to investigate the effects of parameters which modeling is not possible by the empirical model for any reason. Experimental modeling was performed on a chimney with height and width of 180 and 62 cm, respectively. The thickness and angle of chimney in both experimental and numerical methods varied from 5...
On the performance of inclined rooftop solar chimney integrated with photovoltaic module and phase change material: A numerical study
, Article Solar Energy ; Volume 211 , 2020 , Pages 1159-1169 ; Ashouri, M ; Hakkaki Fard, A ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
In an attempt to prolong the performance of the conventional Solar Chimney (SC) and enhance its efficiency, this contribution presents a kind of novel compound SC with the Photovoltaic (PV) module and Phase Change Material (PCM) called the SC-PV-PCM system. Using PCM not only improves the PV module performance but also extends the productive period of the SC. A three-dimensional quasi-steady computational fluid dynamics (CFD) model of the proposed system is developed. The developed model is used to investigate the effect of using PCMs with different melting points on the performance of the proposed system. It is demonstrated that the RT-50 provides superior performance among the studied...
Using nucleators to control freckles in unidirectional solidification
, Article Experimental Thermal and Fluid Science ; Volume 33, Issue 8 , 2009 , Pages 1209-1215 ; 08941777 (ISSN) ; Alavi Dehkordi, E ; Esmaily Moghadam, M ; Mohseni Koochesfahani, M ; Sharif University of Technology
2009
Abstract
Buoyancy-induced fluid flow, which is responsible for most forms of macro-segregation and channel-type segregates in castings, is not directly controllable. If left uncontrolled, natural convection will contribute to non-uniform distribution of alloy constituents and grain structure during solidification of a casting. Non-uniform distribution of chemical composition and physical structure in an alloy casting can significantly affect the reliability of mechanical components. Therefore, materials with acceptable defects can be produced only by trial-and-error and their acceptability is determined by costly inspections. We present a novel technique to control the formation of chimneys and...
Development of Guidance and Control System of Environmental Pollution Aerial Inspection System Focusing on Industrial Chimneys
, M.Sc. Thesis Sharif University of Technology ; Banazadeh, Afshin (Supervisor)
Abstract
In this research, first the use of an aerial system for the inspection of industrial chimneys has been investigated. Then, a series of typical requirements are set for the mission of the flying vehicle, and then a suitable multi-rotor for inspection of industrial chimneys has been designed. After determining the aircraft, among the large number of controllers that have been implemented on the multi-rotors since 2008 , the ADRC controller is selected and based on it a control system for the aircraft has been designed. Finally, this controller is tested in 5 different scenarios to evaluate and show its performance and robustness
The effect of strong ambient winds on the efficiency of solar updraft power towers: A numerical case study for Orkney
, Article Renewable Energy ; Volume 136 , 2019 , Pages 937-944 ; 09601481 (ISSN) ; Behzadi, M. M ; Yaghini, M ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Solar updraft tower (SUT) is a simple power plant in which ventilation of heated air inside a channel drives a turbine. This system is recognised as suitable for areas with abundant solar radiation. As a result, there is no extensive research on the performance of SUTs under mild solar radiation. Studies show that strong ambient crosswinds can affect the performance of a SUT. In this paper, the efficiency of SUTs in areas which benefit from strong winds, despite low solar radiation, is investigated through numerical modelling. Comparison is made between the efficiency of a commercial-scale SUT in Manzanares (Spain) with intensive solar radiation, and one of the same size potentially located...
Modeling and Optimal Design of a Solar Chimney Power Plant
, M.Sc. Thesis Sharif University of Technology ; Boroushaki, Mehrdad (Supervisor)
Abstract
The power generation system of this type of power plants operates on the air flowing through the power plant’s chimney and colliding with the turbine blades within the chimney. When the solar collector warms the nearby air and thus expands the air by absorbing the sunlight, a difference is created in the density. Then, this difference in the density creates the phenomenon of buoyancy, making the air pass to the top of the chimney through the collector.This study simulated and optimized a solar chimney power plant. The simulation and optimization were performed based on the information of Manzanares Solar Chimney Power Plant in Spain (located in 150 km from the south of Madrid). It was...
Improving the performance of the finned absorber inclined rooftop solar chimney combined with composite PCM and PV module
, Article Solar Energy ; Volume 228 , 2021 , Pages 562-574 ; 0038092X (ISSN) ; Hakkaki Fard, A ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
Solar Chimney (SC) can play a significant role in energy consumption reduction of ventilation applications. The primary purpose of this study is to ameliorate the performance of an inclined rooftop SC integrated with the Phase Change Material (PCM) and Photovoltaic (PV) module, called the SC-PCM-PV system. To this aim, the effects of using finned absorbers and composite PCMs on the performance of the SC-PCM-PV system are investigated for the first time. A 3D-CFD model is developed via the finite volume method to examine the impact of various design parameters, including fin number, fin thickness, PCM type, and PCM mass on natural ventilation duration, ventilation capacity, and power output....
A systematic review of land use regression models for volatile organic compounds
, Article Atmospheric Environment ; Volume 171 , 2017 , Pages 1-16 ; 13522310 (ISSN) ; Yunesian, M ; Hosseini, V ; Schindler, C ; Henderson, S. B ; Künzli, N ; Sharif University of Technology
Abstract
Various aspects of land use regression (LUR) models for volatile organic compounds (VOCs) were systematically reviewed. Sixteen studies were identified published between 2002 and 2017. Of these, six were conducted in Canada, five in the USA, two in Spain, and one each in Germany, Italy, and Iran. They were developed for 14 different individual VOCs or groupings: benzene; toluene; ethylbenzene; m-xylene; p-xylene; (m/p)-xylene; o-xylene; total BTEX; 1,3-butadiene; formaldehyde; n-hexane; total hydro carbons; styrene; and acrolein. The models were based on measurements ranging from 22 sites in El Paso (USA) to 179 sites in Tehran (Iran). Only four studies in Rome (Italy), Sabadell (Spain),...