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energy-conversion
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Simulation of Plasma Gasification and Power Generation Based on Solid Waste
, M.Sc. Thesis Sharif University of Technology ; Saboohi, Yadollah (Supervisor)
Abstract
Along with the development of social and economical development and expansion of urban areas the rate of municipal solid waste (MSW) generation has been increased. Waste-to-Energy technologies consist of any waste treatment process that enables generating energy from a waste source. In recent years many studies have shown that plasma gasification has a considerable potential as an effective method for solid waste treatment and energy recovery. Plasma gasification converts MSW to a clean syngas and its application could reduce MSW volume and the environmental risks of waste landfill. In the present study the methods of waste conversion to energy has been reviewed, then plasma gasification of...
Gas and Electrcicity Networks Co-Planning in Microgrid Generations
, M.Sc. Thesis Sharif University of Technology ; Fotuhi-Firuzabad, Mahmud (Supervisor) ; Rajabi-Ghahnavieh, Abbas (Co-Advisor)
Abstract
As a long-established approach, the electricity and natural gas networks have been operated and planned independently. Nevertheless, in recent years there has been a significant progress in energy conversion technologies in microgrids, thus making the electricity and gas networks more connected on the costumers’ side and also enabling users to utilize each of the carriers interchangeably. This increasing correlation between the two networks has led us to a new approach called co-planning of electricity and natural gas networks.This thesis aimed to take a closer look at this new approach and tried to study different aspects of it. Based on the concept of useful energy, a new approach has been...
Degradation Based Framework for Long-term Optimization of Energy Conversion Systems. Case Studies: Solid Oxide Fuel Cell Gas Turbine
, Ph.D. Dissertation Sharif University of Technology ; Roshandel, Ramin (Supervisor)
Abstract
The energy systems efficiency is a great issue confront power plants professionals. Besides using high-tech components in power plants, plant operation optimization can significantly improve energy efficiency and economic performance, as efficiency of plant components generally depends on operating conditions. In addition, system preventive maintenance can reduce plant operation and failure costs, however it is also costly when done frequently. Therefore, optimizing operating conditions and preventive maintenance intervals can minimize the expected total cost of plant due to operation, failures and preventive maintenances. In recent years, the use of optimization models to determine plant...
Multi-Energy Hub System Planning Integrated with Natural Gas and Electricity Networks
, M.Sc. Thesis Sharif University of Technology ; Rajabi-Ghahnavieh, Abbas (Supervisor) ; Fotuhi-Forizabad, Mahmoud (Co-Supervisor)
Abstract
Traditionally, different energy carriers are operated and planned independently. In recent years, with the growth of technology, communication has increased between different energy carrier-systems, in particular within electricity and natural gas networks. The attention to the links between various energy carriers has led to the formation of a new concept called the Energy Hub (EH). In this research, the problem of capacity development planning for gas power plant, CHP and boiler has been studied in a specified time horizon for several energy hubs, so as to meet the demand for electrical and thermal energy. It is worthy to note that the development of electricity and natural gas...
Fault Tolerant AC/DC/AC Converters for Wind Energy Turbine with Doubly-Fed Induction Generator
, Ph.D. Dissertation Sharif University of Technology ; Zolghadri, Mohammad Reza (Supervisor) ; Saadate, Shahrokh (Supervisor)
Abstract
AC/DC/AC converters are widely being used in a variety of power applications. Continuity of service of these systems, as well as their reliability and performance are now of the major concerns. Indeed, the failure of the converter can lead to the total or partial loss of the control of the phase currents and can cause serious system malfunction or even shutdown. Thus, uncompensated faults can quickly endanger the system. Therefore, to prevent the spread of the fault to the other system components and to ensure continuity of service, fault tolerant converter topologies associated with quick and effective fault detection and compensation methods must be implemented. In this thesis, the...
Power System Load Frequency Control in the Presence of Wind Turbines
, M.Sc. Thesis Sharif University of Technology ; Ranjbar, Ali Mohammad (Supervisor)
Abstract
This study presents the application of the doubly fed induction generator (DFIG) to reduce the frequency deviation and improve frequency of a power system. This has been done by proposing a wind turbine model and a new fuzzy controller. The fuzzy controller has been suggested to change the speed of the wind turbine rotor and modify the impacts of wind speed fluctuations on the output power. The fuzzy controller parameters are optimized using the genetic algorithm (GA) to achieve the appropriate transient response. A smart controller is combined with fuzzy controller to optimize the usage of wind turbine’s kinetic energy. Furthermore, the DFIG with the proposed controller participates in the...
Feasibility Study of Re-Design of the Wells Turbine for Small Amplitude Ocean Waves Energy Conversion to Electricity by Analytical Method and Numerical Simulation
, M.Sc. Thesis Sharif University of Technology ; Taeibi Rahni, Mohammad (Supervisor) ; Abbaspour, Madjid (Supervisor)
Abstract
In this research, the feasibility of the usage of the Wells turbine for direct conversion of the hydro-mechanical energy of the surface waves is studied via analytical and numerical methodologies. The results produced, showed for the first time that the Wells turbine can be employed for such waves directly and the performance variables are quite reasonable and even efficient considering low cost of HKWT system and abundant availability of those waves. For the low-frequency waves, the turbine is tested for different wave velocities to discover the best angular velocity of the rotor in terms of performance and the rotational velocity of 300 RPM has been found to be the optimum amount. Further,...
Design of a hybrid Ocean Thermal Energy Conversion with Solar Thermal Energy (OTEC-STE) system for energy production(case study: Oman sea region)
, M.Sc. Thesis Sharif University of Technology ; Abbaspour Tehrani Fard, Majid (Supervisor)
Abstract
The ocean thermal energy conversion system is one of a variety of renewable marine energy that is made up of a thermodynamic cycle, and it uses the difference between the temperature of hot water at the ocean surface and cold water at the depths of the ocean to generate electricity. The closed cycle is one type in which the system uses a working fluid which its boiling point less than the boiling point of water. Increasing the temperature of the fluid inlet in the cycle increases the system efficiency, which has been applied in this study to increase the efficiency of the OTEC system. The required energy to increase this temperature has been achieved by adding a solar collector to this...
Design and Simulation of a Spar_Buoy Wave Energy Converter Using Piezoelectric Materials
, M.Sc. Thesis Sharif University of Technology ; Tabeshpour, Mohammad Reza (Supervisor) ; Abbaspour, Madjid (Supervisor)
Abstract
Nowdays, the world’s need for energy from renewable sources is increasing due to the excessive use of non - renewable resources and the pollution of the environment. Energy converters are classified into three general types: electromagnetic, electrostatic, and piezoelectric, in which piezoelectric materials are used in converters that convert mechanical energy into electrical energy (and vice versa). In the last decade there has been extensive research into the use of these materials for self-charging of low consumption electrically-powered devices such as sensors. For this purpose, in this study, a new method for harvesting electrical energy from the sea using piezoelectric elements is...
Optimal Design of Induction MHD Generator for Electrical Power Generation from Exhaust of the Gas Turbine Power Plants
, M.Sc. Thesis Sharif University of Technology ; Boroushaki, Mehrdad (Supervisor)
Abstract
Today, due to increasing electricity consumption and demand, the use of conventional systems such as thermal, hydro and nuclear power plants is not enough to convert energy. Over the past century, scientists have sought to discover new technologies for exploiting different forms of energy and converting them into high-efficiency electrical energy. One of these ways is to use the phenomenon of magnetohydrodynamics (magnetic fluid dynamics) to convert thermal energy directly into electrical energy. Magnetohydrodynamics is a theoretical field that studies the dynamics of fluids with electrical conductivity. Induction magneto-hydrodynamic generators use ionized hot plasma (a quasi-neutral gas of...
PIDEC Batteries Simulation Accompany with Comparative Study of Key Parameters on its Efficiency
, M.Sc. Thesis Sharif University of Technology ; Moshkbar Bakhshayesh, Khalil (Supervisor) ; Mohtashami, Soroush (Co-Supervisor)
Abstract
Nuclear batteries have been attractive since the beginning of the twentieth century due to their longer life in comparison with other types of batteries. These batteries are produced in different types with different efficiencies depending on the method used to convert their energy. In this study, due to the lack of the resources in the country to study the types of nuclear batteries, first we did an overview of the classification and operation of different types of nuclear batteries, especially on the latest type of nuclear batteries, PIDEC, that has not been studied in the country so far. The most important feature of a PIDEC is that it has an intermediate stage to transmit the maximum...
Study of Ion Transport from the Two-Dimensional Structure of MXene
, M.Sc. Thesis Sharif University of Technology ; Esfandiar, Ali (Supervisor)
Abstract
Reverse electrodialysis-based membranes are one of the most promising approaches to osmotic energy production. However, conventional reverse electrodialysis membranes have high strength and insufficient mass transfer, which leads to low power density and efficiency. In recent decades, the transport of ions at the nanoscale for the manufacture of reverse electrodialysis machines has attracted much attention. Compared to conventional devices, power density and energy conversion efficiency increase dramatically due to space constraints and electrostatic interactions at the nanoscale. Lamellar nanostructures, which can be easily fabricated by stacking two-dimensional nanosheets, may be a...
Estimation of weibull parameters for wind energy application in Iran's cities
, Article Wind and Structures, An International Journal ; Volume 21, Issue 2 , 2015 , Pages 203-221 ; 12266116 (ISSN) ; Hannani, S. K ; Boroushaki, M ; Sharif University of Technology
Techno Press
2015
Abstract
Wind speed is the most important parameter in the design and study of wind energy conversion systems. The weibull distribution is commonly used for wind energy analysis as it can represent the wind variations with an acceptable level of accuracy. In this study, the wind data for 11 cities in Iran have been analysed over a period of one year. The Goodness of fit test is used for testing data fit to weibull distribution. The results show that this data fit to weibull function very well. The scale and shape factors are two parameters of the weibull distribution that depend on the area under study. The kinds of numerical methods commonly used for estimating weibull parameters are reviewed. Their...
Conceptual design of a 5 MW OTEC power plant in the Oman Sea
, Article Journal of Marine Engineering and Technology ; Volume 16, Issue 2 , 2017 , Pages 94-102 ; 20464177 (ISSN) ; Sadeghzadeh, S ; Sharif University of Technology
Taylor and Francis Ltd
2017
Abstract
Developing ocean energy extraction, including ocean thermal energy conversion (OTEC), has been of interest to researchers for many decades. OTEC is a free fuel technology and could be used as a baseline power generation. These advantages plus the engineering challenge have resulted in researchers striving to design and construct prototype devices. Making use of worldwide experience, all sections of a conceptual design including site selection, technical specifications and cost estimation were carried out for an Iranian OTEC power plant. A 5 MW closed cycle floating plant with an annual average temperature difference of 22°C was chosen at a 33 km distance from Chabahar harbour. Deep seawater...
Nanofluid-assisted gas to hydrate (GTH) energy conversion for promoting CO 2 recovery and sequestration processes in the petroleum industry
, Article Petroleum Science and Technology ; Volume 34, Issue 1 , 2016 , Pages 37-43 ; 10916466 (ISSN) ; Montazeri, V ; Sharif University of Technology
Taylor and Francis Inc
2016
Abstract
In this work the enhancement of gas to hydrate conversion employing the nanographene oxide (NGO)-based nanofluid regarding CO2 capture and sequestration recovery is investigated. A new series of experiments are carried out at different pressures, temperatures, agitation intensities and NGO promoter concentrations by using a newly developed fully automated GTH (gas to hydrate) energy converter. According to the presented results at the 3 MPa and 275.15 K and in the presence of 30 ppm NGO, it is possible to reach a CO2 gas to hydrate conversion of 95% at a low impeller speed in less than 2.5 h, which is quite interesting from an energy consumption standpoint. The presented approach can have...
Electromechanical modeling and analytical investigation of nonlinearities in energy harvesting piezoelectric beams
, Article International Journal of Mechanics and Materials in Design ; 2016 , Pages 1-16 ; 15691713 (ISSN) ; Ahmadian, M. T ; Zohoor, H ; Sharif University of Technology
Springer Netherlands
2016
Abstract
Piezoelectric materials are extensively applied for vibrational energy harvesting especially in micro-scale devices where other energy conversion mechanisms such as electromagnetic and electrostatic methods encounter fabrication limitations. A cantilevered piezoelectric bimorph beam with an attached proof (tip) mass for the sake of resonance frequency reduction is the most common structure in vibrational harvesters. According to the amplitude and frequency of applied excitations and physical parameters of the harvester, the system may be pushed into a nonlinear regime which arises from material or geometric nonlinearities. In this study nonlinear dynamics of a piezoelectric bimorph harvester...
Investigation and visualization of surfactant effect on flow pattern and performance of pulsating heat pipe
, Article Journal of Thermal Analysis and Calorimetry ; Volume 139, Issue 3 , 2020 , Pages 2099-2107 ; Kalan, K ; Vandadi, M ; Shafii, M. B ; Saidi, M. H ; Sharif University of Technology
Springer Netherlands
2020
Abstract
Pulsating heat pipes (PHPs) are one of the new devices used for cooling in several applications such as electronic and aerospace systems. Their low cost, effectiveness at various conditions, being equipped for passive energy conversion, and well distribution of temperature compared to conventional heat pipes are among the reasons of their popularity. To investigate the effect of surface tension of the working fluid on the behavior of PHPs, a copper heat pipe is fabricated with inner and outer diameters of 2 mm and 4 mm, respectively. Five different concentrations of cetrimonium bromide (C-Tab) surfactant are dissolved in water and are tested with a filling ratio of 50% (± 1%). A piece of...
Thermal and electrical conductivity of a graphene-based hybrid filler epoxy composite
, Article Journal of Materials Science ; Volume 56, Issue 27 , 2021 , Pages 15151-15161 ; 00222461 (ISSN) ; Kazemi Ranjbar, S ; Sharif University of Technology
Springer
2021
Abstract
The development of polymer-based composites with thermal transport capability has now become essential in response to the efficient thermal management required in electronic and energy conversion devices. In this work, a novel hybrid filler consisting of graphene nanoplatelet (GNP) and boron nitride microparticles (micro-BN) is used to improve the thermal conductivity of epoxy composite. The GNPs with an average lateral size of 8 µm and an average thickness of 5 nm are in the same volume range with the 1 µm size micro-BN particles. According to the results, the thermal conductivity of the composites changes abruptly with increasing micro-BN loading at fixed GNP loading, which is attributed...
Complex modal analysis and coupled electromechanical simulation of energy harvesting piezoelectric laminated beams
, Article Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science ; 2018 ; 09544062 (ISSN) ; Ahmadian, M. T ; Zohoor, H ; Sharif University of Technology
SAGE Publications Ltd
2018
Abstract
In this paper, coupled electromechanical behavior of a vibrational energy harvesting system composed of a unimorph piezoelectric laminated beam with a large attached tip mass is investigated. To achieve this goal, first the electromechanically coupled partial differential equations governing the lateral displacement and output voltage of the harvester are extracted through exploiting the Hamilton’s principle. Considering vibration damping due to mechanical to electrical energy conversion, a complex modal analysis is performed to extract the complex eigenfrequencies and eigenfunctions of the system. Furthermore, an exact analytical solution is presented for the system response to the harmonic...
Complex modal analysis and coupled electromechanical simulation of energy harvesting piezoelectric laminated beams
, Article Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science ; Volume 233, Issue 7 , 2019 , Pages 2526-2537 ; 09544062 (ISSN) ; Ahmadian, M. T ; Zohoor, H ; Sharif University of Technology
SAGE Publications Ltd
2019
Abstract
In this paper, coupled electromechanical behavior of a vibrational energy harvesting system composed of a unimorph piezoelectric laminated beam with a large attached tip mass is investigated. To achieve this goal, first the electromechanically coupled partial differential equations governing the lateral displacement and output voltage of the harvester are extracted through exploiting the Hamilton’s principle. Considering vibration damping due to mechanical to electrical energy conversion, a complex modal analysis is performed to extract the complex eigenfrequencies and eigenfunctions of the system. Furthermore, an exact analytical solution is presented for the system response to the harmonic...