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Theoretical and Experimental Investigation of Preparation of Distillate Water by Combination of CSP and MED Methods
, M.Sc. Thesis Sharif University of Technology ; Molaee Dehkordi, Asghar (Supervisor)
Abstract
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...
Technical and Economical Potential for Application of Solar Energy in Enhanced Oil Recovery
, M.Sc. Thesis Sharif University of Technology ; Ayatollahi, Shahabodin (Supervisor) ; Soltanieh, Mohammad (Supervisor)
Abstract
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 Numerical Simulation of a Solar Collector for Direct Steam Generation
, M.Sc. Thesis Sharif University of Technology ; Morad, Mohammad Reza (Supervisor)
Abstract
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...
Feasibility Study and Conceptual Design of Solar Energy Source for Surface Train System
, M.Sc. Thesis Sharif University of Technology ; Durali, Mohammad (Supervisor)
Abstract
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 ; 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...
Equipment Hardening Strategies to Improve Electric Distribution System Resilience Against Wildfire
, M.Sc. Thesis Sharif University of Technology ; Vakilian, Mehdi (Supervisor)
Abstract
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...
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) ; Soltanieh, M ; Mansouri Majoumerd, M ; Arild, Ø ; Sharif University of Technology
American Society of Mechanical Engineers
2016
Abstract
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...
Investigation of the performance of modified organic Rankine cycles (ORCs) and modified trilateral flash cycles (TFCs) assisted by a solar pond
, Article Solar Energy ; Volume 182 , 2019 , Pages 361-381 ; 0038092X (ISSN) ; Akbari, A ; Khalilian, M ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Solar pond is a type of solar collector that stores solar energy in the form of heat. The solar pond can be used as a low-temperature heat source for electricity generation. In this paper, to find the most suitable power cycle for power generation from the solar pond, the performance of the Organic Rankine Cycle (ORC), Trilateral Flash Cycle (TFC) and their modified forms with an open feed liquid heater and an internal heat exchanger for different working fluids was investigated. Water was considered as the heat transfer fluid which transfers the stored heat from the solar pond to the working fluid of the cycle. The results indicate that in all cases, the energy and exergy efficiency of the...
Efficient carrier utilization induced by conductive polypyrrole additives in organic-inorganic halide perovskite solar cells
, Article Solar Energy ; Volume 207 , 2020 , Pages 1300-1307 ; Balkan, T ; Solati, N ; Halali, M ; Askari, M ; Kaya, S ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
The morphology of the perovskite layer, the effective extraction of the charge carriers, and their transport are the main factors determining the power conversion efficiency (PCE) of the perovskite solar cells (PSCs). In this work, we demonstrated that the geometric and electronic structures of the PSCs could be modified by using a conductive polymer additive in the lead (Pb) halide layer prepared by a two-step deposition method. Polypyrrole (PPy) as a conductive polymer is used in the perovskite layers which could increase the PCE of CH3NH3PbI3-xClx mixed-halide PSCs. By adding an optimized amount of PPy, PCE has been raised from 10.4 to 13.2%. PPy acts as a conductive channel facilitating...
Enhanced electron transport induced by a ferroelectric field in efficient halide perovskite solar cells
, Article Solar Energy Materials and Solar Cells ; Volume 206 , 2020 ; Askari, M ; Halali, M ; Solati, N ; Balkan, T ; Kaya, S ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Perovskite solar cells have been appearing as a superior photovoltaic device owing to their high photovoltaic performance and low cost of fabrication. The formation of a compact and uniform perovskite layer with large crystal size is a significant factor to get the best device performance. In this work, polyvinylidene difluoride (PVDF) was used as a ferroelectric polymer additive to fabricate high-performance mesoporous CH3NH3PbI3-xClx mixed-halide perovskite solar cells in a sequential deposition method. Power conversion efficiency has been enhanced from 10.4 to 16.51% in an ambient atmosphere in the presence of an optimized amount of PVDF assuring continuous and smooth layers with large...
A Novel, eco-friendly combined solar cooling and heating system, powered by hybrid Photovoltaic thermal (PVT) collector for domestic application
, Article Energy Conversion and Management ; Volume 222 , 2020 ; Liravi, M ; Babaie Rabiee, M ; Ghodrat, M ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
Solar heating and cooling technologies can have a vital role to play in understanding the targets in energy security, economic development, and mitigating climate change. This study aimed to investigate the performance of the combined solar cooling/heating system using a Photovoltaic Thermal collector (PVT) for residential applications. The main advantage of using PVT is the conversion of the maximum amount of solar energy into electricity and thermal energy. In this work, water is used to cool the panel and, consequently, increase the efficiency. The cooling cycle comprises a hybrid ejector-compression refrigeration cycle with two evaporator temperatures. To reduce the effect of the global...
Productivity enhancement of solar stills by nano-coating of condensing surface
, Article Desalination ; Volume 454 , 2019 , Pages 1-9 ; 00119164 (ISSN) ; Soltani Goharrizi, A ; Ayatollahi, S ; Feilizadeh, M ; Sharif University of Technology
Elsevier B.V
2019
Abstract
Wettability is one of the most important factors which significantly influences solar still efficiency. Moreover, it determines the condensation mode, i.e., filmwise or dropwise condensation. In the present study, materials with different wettability were applied as the condensing surface to evaluate the effect of wettability on the distillate production of a single slope solar still. To compare the effects of dropwise and filmwise condensation on the condensate yield, the wettability of the condensing surface was changed by applying a nano-silicon solution according to a dip coating technique. All the experiments were conducted at three surface inclination angles. The results revealed that...
Efficiency improvement of solar stills through wettability alteration of the condensation surface: An experimental study
, Article Applied Energy ; Volume 268 , 2020 ; Soltani Goharrizi, A ; Ayatollahi, S ; Feilizadeh, M ; Dashti, H ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
The condensation process is of great importance in many heat transfer devices in which a large amount of energy must be transferred. Furthermore, condensation is a crucial part of energy conversion and affects the energy efficiency of thermal desalination plants and solar stills. During the condensation process in solar stills, an essential part of the energy is transferred through the condensation surface to produce fresh water. Therefore, the condensation surface plays a significant role in the working efficiency of solar stills. The wettability of the condensation surface influences the condensation mechanism, which, in turn, affects the efficiency of solar stills. This study aims to...
Optimal design and simulation of sensor arrays for solar motion estimation
, Article IEEE Sensors Journal ; Volume 17, Issue 6 , 2017 , Pages 1673-1680 ; 1530437X (ISSN) ; Durali, M ; Jalali, M. A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2017
Abstract
Modern sensors consist of arrays of detectors specially arranged to enhance precision, capabilities, and field of view (FOV). Sensor arrays can have multiple functionalities, such as the simultaneous detection of position and motion. We use a linear sensor model and develop an optimization method to design an array of photodiodes. Our objective function minimizes bias and variance estimations. We introduce a maximum likelihood technique to approximate and determine the bias caused by measurement errors, and verify our theory by statistically complete simulations. We apply our theory to design an optimal sun sensor. The sensor has a predefined conical FOV, and its accuracy is controlled by a...
Greener, nonhalogenated solvent systems for highly efficient Perovskite solar cells
, Article Advanced Energy Materials ; Volume 8, Issue 21 , 25 July , 2018 ; 16146832 (ISSN) ; Mazloum Ardakani, M ; Gholipour, S ; Tavakoli, M. M ; Turren Cruz, S. H ; Taghavinia, N ; Gratzel, M ; Hagfeldt, A ; Saliba, M ; Sharif University of Technology
Wiley-VCH Verlag
2018
Abstract
All current highest efficiency perovskite solar cells (PSCs) use highly toxic, halogenated solvents, such as chlorobenzene (CB) or toluene (TLN), in an antisolvent step or as solvent for the hole transporter material (HTM). A more environmentally friendly antisolvent is highly desirable for decreasing chronic health risk. Here, the efficacy of anisole (ANS), as a greener antisolvent for highest efficiency PSCs, is investigated. The fabrication inside and outside of the glovebox showing high power conversion efficiencies of 19.9% and 15.5%, respectively. Importantly, a fully nonhalogenated solvent system is demonstrated where ANS is used as both the antisolvent and the solvent for the HTM....
Carbon nanoparticles in high-performance perovskite solar cells
, Article Advanced Energy Materials ; Volume 8, Issue 12 , 2018 ; 16146832 (ISSN) ; Mazloum Ardakani, M ; Gholipour, S ; Marinova, N ; Delgado, J. L ; Turren Cruz, S. H ; Domanski, K ; Taghavinia, N ; Saliba, M ; Gratzel, M ; Hagfeldt, A ; Tress, W ; Sharif University of Technology
Wiley-VCH Verlag
2018
Abstract
In the past few years, organic–inorganic metal halide ABX3 perovskites (A = Rb, Cs, methylammonium, formamidinium (FA); B = Pb, Sn; X = Cl, Br, I) have rapidly emerged as promising materials for photovoltaic applications. Tuning the film morphology by various deposition techniques and additives is crucial to achieve solar cells with high performance and long-term stability. In this work, carbon nanoparticles (CNPs) containing functional groups are added to the perovskite precursor solution for fabrication of fluorine-doped tin oxide/TiO2/perovskite/spiro-OMeTAD/gold devices. With the addition of CNPs, the perovskite films are thermally more stable, contain larger grains, and become more...
Elucidation of charge recombination and accumulation mechanism in mixed perovskite solar cells
, Article Journal of Physical Chemistry C ; Volume 122, Issue 27 , 2018 , Pages 15149-15154 ; 19327447 (ISSN) ; Turren Cruz, S. H ; Prochowicz, D ; Tavakoli, M. M ; Pandey, K ; Zakeeruddin, S. M ; Gratzel, M ; Hagfeldt, A ; Saliba, M ; Sharif University of Technology
American Chemical Society
2018
Abstract
Organic-inorganic perovskite solar cells (PSCs) have gained considerable attention owing to their impressive photovoltaic properties and simple device manufacturing. In general, PSC employs a perovskite absorber material sandwiched between an electron and hole selective transport layer optimized with respect to optimal band alignment, efficient charge collection, and low interfacial recombination. The interfaces between the perovskite absorber and respective selective contacts play a crucial role in determining photovoltaic performance and stability of PSCs. However, a fundamental understanding is lacking, and there is poor understanding in controlling the physical processes at the...
Solar energy systems – Potential of nanofluids
, Article Journal of Molecular Liquids ; Volume 289 , 2019 ; 01677322 (ISSN) ; Hassan, A ; Qasim, M. A ; Ali, H. M ; Babar, H ; Sajid, M. U ; Sharif University of Technology
Elsevier B.V
2019
Abstract
Global warming escalation has extended average temperature of earth beyond its safe limit. To avert this environmental-threat, solar energy has acquired substantial attention of remarkable researchers in this century. To effectively utilize solar energy by transforming into thermal and electrical energy, the involvement of nanofluids having intensified thermal, optical and magnetic properties, has become very popular. The foremost objective of this article is to provide a comprehensive review on the applications of nanofluids in solar energy systems like solar collectors, photovoltaic cells, solar stills, and thermal energy storage, which are thoroughly discussed in this paper. The effect of...
Quasi core/shell lead sulfide/graphene quantum dots for bulk heterojunction solar cells
, Article Journal of Physical Chemistry C ; Volume 119, Issue 33 , 2015 , Pages 18886-18895 ; 19327447 (ISSN) ; Aashuri, H ; Simchi, A ; Kalytchuk, S ; Fan, Z ; Sharif University of Technology
American Chemical Society
2015
Abstract
Hybrid nanostructures combining semiconductor quantum dots and graphene are attracting increasing attention because of their optoelectronic properties promising for photovoltaic applications. We present a hot-injection synthesis of a colloidal nanostructure which we define as quasi core/shell PbS/graphene quantum dots due to the incomplete passivation of PbS surfaces with an ultrathin layer of graphene. Simulation by density functional theory of a prototypical model of a nonstoichiometric Pb-rich core (400 atoms) coated by graphene (20 atoms for each graphene sheet) indicates the possibility of surface passivation of (111) planes of PbS with graphene resulting in a decrease in trap states...
Supercritical synthesis and in situ deposition of PbS nanocrystals with oleic acid passivation for quantum dot solar cells
, Article Materials Chemistry and Physics ; Volume 156 , 2015 , Pages 163-169 ; 02540584 (ISSN) ; Simchi, A ; Aashuri, H ; Sharif University of Technology
Elsevier Ltd
2015
Abstract
Colloidal quantum dot solar cells have recently attracted significant attention due to their low-processing cost and surging photovoltaic performance. In this paper, a novel, reproducible, and simple solution-based process based on supercritical fluid toluene is presented for in situ growth and deposition PbS nanocrystals with oleic-acid passivation. A lead precursor containing sulfur was mixed with oleic acid in toluene and processed in a supercritical fluid condition at different temperatures of 140, 270 and 330 °C for 20 min. The quantum dots were deposited on a fluorine-doped tin oxide glass substrate inside the supercritical reactor. Transmission electron microscopy, X-ray diffraction,...