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    Feasibility Study and Conceptual Design of Solar Energy Source for Surface Train System

    , M.Sc. Thesis Sharif University of Technology Maleki, Sina (Author) ; Durali, Mohammad (Supervisor)
    Advancements in solar powered systems bring about the possibility for today’s transportation systems to be operated and driven by such a clean and renewable source of energy. The challenging point of this combination is to draw high power levels from such a low power density source of energy. As a result, employing an efficient power storage and management system becomes inventible. The subjects of this research are to design a grid connected system and evaluate its performance and feasibility in a real application (Tehran- Mehrshahr surface train – Tehran 5th Metro Line). The task includes sixteen pairs of DC transmission lines which are powered by CIGS solar module technology and four... 

    Modeling and Optimal Design of a Solar Chimney Power Plant

    , M.Sc. Thesis Sharif University of Technology Gharagozlou, Ali (Author) ; Boroushaki, Mehrdad (Supervisor)
    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... 

    Theoretical and Numerical Simulation of a Solar Collector for Direct Steam Generation

    , M.Sc. Thesis Sharif University of Technology Mehrabi, Pouria (Author) ; Morad, Mohammad Reza (Supervisor)
    Direct steam generation (DSG) process using linear FRESNEL collectors has been developed widely in recent years and is one of the most promising solar technologies for thermal power generation, Industrial processes and domestic usage. In this process water as heat transfer fluid (HTF) is heated through a solar field. Continuous breakthroughs are being achieved on improvement of these collectors. A multi-phase CFD model is developed to calculate the wall temperature of linear Fresnel absorber tubes and fluid properties including temperature, velocity, and pressure. In order to design the collector field and identify the critical condition such as overheating of the absorber tubes, modeling of... 

    Equipment Hardening Strategies to Improve Electric Distribution System Resilience Against Wildfire

    , M.Sc. Thesis Sharif University of Technology Talebi, Amir Hossein (Author) ; Vakilian, Mehdi (Supervisor)
    The severe wildfires in California, Australia, Canada, and Iran have interrupted the power system operation, caused multiple blackouts, took many lives, and caused damages to power grid infrastructure to the extent of millions and billions of dollars. Most of the recent wildfires occur in the distribution system. Therefore, enhancing power system distribution resilience against wildfire is crucial.To this end, two groups of measures are proposed: the hardening of the power network and the operational measures. The past published papers mainly studied the resilience enhancement strategies against wildfire from an operational perspective. There is a considerable gap between the past works... 

    Technical and Economical Potential for Application of Solar Energy in Enhanced Oil Recovery

    , M.Sc. Thesis Sharif University of Technology Najafi, Homayoun (Author) ; Ayatollahi, Shahabodin (Supervisor) ; Soltanieh, Mohammad (Supervisor)
    In this thesis, the application of solar energy in the steam injection as a thermal enhanced oil recovery (TEOR) is evaluated. The motivations of this project are using a renewable energy, suitable solar potential of Iran, successful experience in the world, undeveloped heavy oilfield reservoirs in Iran. This application is investigated by three aspects which are:Reservoir Engineering aspect: the heavy oilfield are determined and then screening for selection good candidate of steam injection are done. One of the reservoirs is analyzed by simulation and optimization the steam injection to determine how much it’s production will be improved by using steam injection (contionous and cyclic)... 

    Theoretical and Experimental Investigation of Preparation of Distillate Water by Combination of CSP and MED Methods

    , M.Sc. Thesis Sharif University of Technology Najafi Sani, Mohammad Ali (Author) ; Molaee Dehkordi, Asghar (Supervisor)
    With the depletion of fossil resources, price of these energy careers increases. Therefore, researchers investigate for other alternative choices. One of the most interesting choice is the renewable energies. These sources of energies are attractive due to either they are permanent resources or they are environmentally friendly. The most important renewable energy resource is solar energy that in fact is the source of other renewable energies. The most important and economic method of solar energy absorption is the thermal method. Common technology in thermal method is the Parabolic-Trough. But, recently a new technology have been developed called Compact Linear Fresnel Reflector (CLFR) that... 

    Year-round outdoor experiments on a multi-stage active solar still with different numbers of solar collectors

    , Article Applied Energy ; Volume 152 , 2015 , Pages 39-46 ; 03062619 (ISSN) Feilizadeh, M ; Karimi Estahbanati, M. R ; Jafarpur, K ; Roostaazad, R ; Feilizadeh, M ; Taghvaei, H ; Sharif University of Technology
    Elsevier Ltd  2015
    The present work investigated the outdoor performance of a basin type multi-stage solar still as well as the effect of collector over basin area (CBA) ratio on the distillate production. The effect of CBA was studied in outdoor experiments for the first time. The system consisted of a still coupled with one, two or three flat-plate solar collectors. In order to study the effect of CBA more accurately, the experiments were conducted in both winter and summer. In these experiments, the distilled water production of the multi-stage still was measured during the whole 24. h of a day on an hourly basis. The results revealed that in the winter, the basin coupled to one solar collector (CBA. =... 

    Visible light switchable bR/TiO2 nanostructured photoanodes for bio-inspired solar energy conversion

    , Article RSC Advances ; Volume 5, Issue 24 , Jan , 2015 , Pages 18642-18646 ; 20462069 (ISSN) Naseri, N ; Janfaza, S ; Irani, R ; Sharif University of Technology
    Royal Society of Chemistry  2015
    Today, regarding the limitation and environmental side effects of fossil fuel resources, solar hydrogen production is one of the main interests in the energy research area. The development of visible light sensitized semiconductors based on non-toxic components, low cost and available bio-species is an ongoing approach for H2 generation based on water splitting reactions. Here, two different morphologies of TiO2 photoanodes, nanoparticulated and nanotubular, have been modified with simply extracted bacteriorhodopsin (bR) without any linker. Achieving a significant enhancement in photoconversion efficiency of TiO2 photoanodes, η% was increased from 2.9 to 16.5 by bR addition to the TiO2... 

    TiO 2 fibers enhance film integrity and photovoltaic performance for electrophoretically deposited dye solar cell photoanodes

    , Article ACS Applied Materials and Interfaces ; Volume 3, Issue 3 , February , 2011 , Pages 638-641 ; 19448244 (ISSN) Shooshtari, L ; Rahman, M ; Tajabadi, F ; Taghavinia, N ; Sharif University of Technology
    Nanoparticulated TiO 2 fibers as one-dimensional long structures were introduced into TiO 2 P25 nanoparticle films using coelectrophoretic deposition. This prevented the usual crack formation occurring in wet coatings, and resulted in less porosity and higher roughness factor of the films that provided more favorable conditions for electron transport. The films used as the photoanode of a dye solar cell (DSC) produced 65% higher photovoltaic efficiency. TiO 2 fibers can be excellent binders in single-step, organic-free electrophoretic deposition of TiO 2 for DSC photoanode  

    Thermo-economic analysis and multi-objective optimization of a solar dish Stirling engine

    , Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; 2020 Rostami, M ; Assareh, E ; Moltames, R ; Jafarinejad, T ; Sharif University of Technology
    Bellwether Publishing, Ltd  2020
    Stirling engines operate in a variety of temperatures and the electric power production via dish Stirling systems could be considered as an appropriate alternative for high-temperature solar concentrator energy harvesting systems. To this end, by performing various studies and analyses on the engine, Stirling cycle, and heat exchangers while utilizing the solar energy as the input thermal energy of the Stirling engine, parameters with the highest effect on the output power and engine stability are detected and considered as optimization variables. In this case, output power, thermal efficiency, and economic evaluation are taken to be the three suitable objective functions for multi-objective... 

    Thermo-economic analysis and multi-objective optimization of a solar dish Stirling engine

    , Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; Volume 43, Issue 22 , 2021 , Pages 2861-2877 ; 15567036 (ISSN) Rostami, M ; Assareh, E ; Moltames, R ; Jafarinejad, T ; Sharif University of Technology
    Taylor and Francis Ltd  2021
    Stirling engines operate in a variety of temperatures and the electric power production via dish Stirling systems could be considered as an appropriate alternative for high-temperature solar concentrator energy harvesting systems. To this end, by performing various studies and analyses on the engine, Stirling cycle, and heat exchangers while utilizing the solar energy as the input thermal energy of the Stirling engine, parameters with the highest effect on the output power and engine stability are detected and considered as optimization variables. In this case, output power, thermal efficiency, and economic evaluation are taken to be the three suitable objective functions for multi-objective... 

    Thermal residual stresses in silicon thin film solar cells under operational cyclic thermal loading: A finite element analysis

    , Article Solar Energy ; Volume 135 , 2016 , Pages 366-373 ; 0038092X (ISSN) Namvar, A ; Dehghany, M ; Sohrabpour, S ; Naghdabadi, R ; Sharif University of Technology
    Elsevier Ltd  2016
    In manufacturing amorphous silicon solar cells, thin films are deposited at high temperatures (200-400 °C) on a thick substrate using sputtering and plasma enhanced chemical vapor deposition (PECVD) methods. Since the thin films and substrate have different thermal expansion coefficients, cooling the system from deposition temperature to room temperature induces thermal residual stresses in both the films and substrate. In addition, these stresses, especially those having been induced in the amorphous silicon layer can change the carrier mobility and band gap energy of the silicon and consequently affect the solar cell efficiency. In this paper, a 2D finite element model is proposed to... 

    The impact of climate condition on the optimal size of direct coupled photovoltaic-electrolyzer systems

    , Article Simulation Series, 26 July 2015 through 29 July 2015 ; Volume 47, Issue 10 , July , 2015 , Pages 224-229 ; 07359276 (ISSN) Sayedin, F ; Maroufmashat, A ; Sattari khavas S ; Elkamel, A ; Aladwani, S ; Sharif University of Technology
    The Society for Modeling and Simulation International  2015
    Solar energy exists extensively in all parts of the world. However the intermittency of solar energy presents critical challenges to PV system. The intermittency can be covered by storing solar energy in chemical bonds such as hydrogen. This process can be performed by photovoltaic powered electrolysis of water. The energy transfer efficiency between PV and electrolyzer is subject to the distance between maximum power points (MPP) of PV module and operating points. The operating points can be adjusted by optimizing the design parameters of the electrolyzer but the maximum power points are function of PV module characteristics, solar radiation and ambient temperature. Therefore the weather... 

    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) Jafarifar, N ; Behzadi, M. M ; Yaghini, M ; Sharif University of Technology
    Elsevier Ltd  2019
    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... 

    The effect of lithium doping in solution-processed nickel oxide films for perovskite solar cells

    , Article ChemPhysChem ; Volume 20, Issue 24 , 2019 , Pages 3322-3327 ; 14394235 (ISSN) Saki, Z ; Sveinbjornsson, K ; Boschloo, G ; Taghavinia, N ; Sharif University of Technology
    Wiley-VCH Verlag  2019
    The effect of substitutional Li doping into NiOx hole transporting layer (HTL) for use in inverted perovskite solar cells was systematically studied. Li doped NiOx thin films with preferential crystal growth along the (111) plane were deposited using a simple solution-based process. Mott-Schottky analysis showed that hole carrier concentration (NA) is doubled by Li doping. Utilizing 4 % Li in NiOx improved the power conversion efficiency (PCE) of solar devices from 9.0 % to 12.6 %. Photoluminescence quenching investigations demonstrate better hole capturing properties of Li:NiOx compared to that of NiOx, leading to higher current densities by Li doping. The electrical conductivity of NiOx is... 

    Techno-economic comparative study on hydrogen and electricity cogeneration systems with CO2 capture

    , Article ASME 2016 10th International Conference on Energy Sustainability, ES 2016, collocated with the ASME 2016 Power Conference and the ASME 2016 14th International Conference on Fuel Cell Science, Engineering and Technology, 26 June 2016 through 30 June 2016 ; Volume 1 , 2016 ; 9780791850220 (ISBN) Zohrabian, A ; Soltanieh, M ; Mansouri Majoumerd, M ; Arild, Ø ; Sharif University of Technology
    American Society of Mechanical Engineers  2016
    In order to achieve the international climate goals and to keep the global temperature increase below 2 °C, carbon capture and storage in large point sources of CO2 emissions has received considerable attention. In recent years, mitigation of CO2 emissions from the power sector has been studied extensively whereas other industrial point source emitters such as hydrogen industry have also great potential for CO2 abatement. This study aims to draw an updated comparison between different hydrogen and power cogeneration systems using natural gas and coal as feedstock. The goal is to show the relative advantage of cogeneration systems with respect to CO2 emission reduction costs. Accordingly, the... 

    Techno-economic and environmental analysis of an integrated standalone hybrid solar hydrogen system to supply CCHP loads of a greenhouse in Iran

    , Article International Journal of Green Energy ; Volume 14, Issue 3 , 2017 , Pages 295-309 ; 15435075 (ISSN) Homayouni, F ; Roshandel, R ; Hamidi, A. A ; Sharif University of Technology
    The techno-economic and environmental performance of hybrid solar hydrogen energy systems was investigated to provide combined cooling, heating and power (CCHP) demands of a standalone greenhouse in Iran to achieve sustainable agriculture based on an optimization procedure. From the environmental point of view, by deploying hybrid energy systems, 83%, to 100% of emissions can be avoided. Also a sensitivity analysis was performed on the hybrid energy systems in order to study the effect of major parameter variation on the systems justification. It was concluded that hybrid solar systems are economically competitive with conventional systems, for high solar intensity locations with high diesel... 

    Techno-economic analysis of a modified concentrating photovoltaic/organic Rankine cycle system

    , Article International Journal of Ambient Energy ; 17 February , 2020 Moltames, R ; Roshandel, R ; Sharif University of Technology
    Taylor and Francis Ltd  2020
    The combination of concentrating photovoltaic (CPV) and organic Rankine cycle (ORC) systems not only leads to a reduction of photovoltaic (PV) operating temperature, but also leads to an additional electric power production. Increase in the temperature of the PV decreases its operating efficiency, while increases the ORC efficiency. Therefore, there is an optimum temperature in which the total electricity produced by the combined system will be maximum. In this study, a modified CPV/ORC system is simulated and the optimum operating temperature of the PV panel is determined for different PV efficiencies. The most striking result is that increase in the PV nominal efficiency will result in the... 

    Sustainable starfish like cobalt electrocatalyst grown on optimized CNT-graphene hybrid host for efficient water oxidation

    , Article Applied Surface Science ; Volume 524 , 15 September , 2020 Naseri, N ; Ghasemi, S ; Pourreza, M ; Moshfegh, A. Z ; Sharif University of Technology
    Elsevier B.V  2020
    Solar energy generation is one of the most efficient approach to solve emerging environment and energy challenges. In this context, solar assisted dissociation of water into oxygen and hydrogen utilizing scalable and high performance electrocatalysts plays key role since the produced hydrogen is a clean energy carrier. Here, cobalt based nanoflakes with metallic core and oxidized surface were grown on the designed carbonaceous layer for anodic oxygen evolution reaction (OER) using an electrochemical approach. Carbonaceous layers containing proper amount of carbon nanotubes (CNT) and reduced graphene oxide (rGO) species were used to optimize the system. Although higher weight percent of rGO... 

    Surface passivation of titanium dioxide via an electropolymerization method to improve the performance of dye-sensitized solar cells

    , Article RSC Advances ; Volume 6, Issue 15 , 2016 , Pages 12537-12543 ; 20462069 (ISSN) Mazloum Ardakani, M ; Khoshroo, A ; Taghavinia, N ; Hosseinzadeh, L ; Sharif University of Technology
    Royal Society of Chemistry  2016
    In dye-sensitized solar cells recombination reactions at the TiO2 photoanode with the electrolyte interface plays a critical role in cell efficiency. Recombination of injected electrons in the TiO2 with acceptors in the electrolyte usually occurs on uncovered areas of TiO2 surfaces. In this work, we report electropolymerization of polymer films on nanoporous TiO2 electrode surfaces using an ionic liquid as the growth medium. The choice of ionic liquid as the growth medium for this study is based on the insolubility of dye N719 in this electrolyte, thus avoiding dye molecule detachment from the TiO2 photoanode surface over the entire potential range investigated during the...