Sharif Digital Repository

The advantages of using solar energy, including absence of environmental pollution, renewability, availability, ease of installation and use, and has attracted much attention of researchers. Expanding the use of solar energy in remote areas where national grid coverage is weak, makes off-grid inverter vital role clear. The swinging nature of solar energy requires the use of electrical energy storage and battery charger for optimum energy extraction in a technically and economically manner. The aim of this project is to develop a Smart Charger in Standalone Solar Inverter. Charger circuit design has been done in order to accommodate a 4kW inverter. Selected Charger topology is the... 

All over the world availability of electrical power is an important matter. Electrical power is a basic requirement in each country so with increasing the demand, supply system should be adjusted.Compressed Air Energy System (CAES) stores the excessive produced energy as compressed air and will inject it to gas turbine to produce energy in peak load hours.This project aim is modeling and analyzing of CAES considering reliability. In this project some of failure mechanisms have been identified and modeled and then the performance effect on system failure have been surveyed. This project innovation is incorporating operational models with reliability to determine the best performance for... 

Today's electric power industry is unthinkable without high-power electronic converters. Statcom is one of the critical equipment; which is known for its quick response in reactive power compensation/supply. Losses in a high-power system are considerable. Most of these losses are caused by switching. In a conventional system, the cooling system is used only to control the temperature and stable operation of the switches. In this project, an attempt is made to evaluate the temperature of the outlet fluid for use in the Rankine cycle with organic materials by modeling the heat-generating parts in the Statcom equipment. Also, the unification of the Stacom cooling system with the Rankine cycle... 

Energy and environment crisis in past decades raised concerns about fossil fuels use and has accelerated renewable energy application in terms of solar electric, solar thermal and wind turbines. Due to the fluctuating nature in renewable resources, renewable electric power generation has a stochastic nature that makes it difficult to use by the electricity consumers. Energy storage plays a key role to put more control on renewable power generation.Lead-acid battery is a storage technology that is widely used in photovoltaic systems. Battery investment and maintenance costs account for a big part of photovoltaic system costs. Charging and discharging profiles of the battery has a great impact... 

The potential future use of hydrogen as a transportation fuel must be evaluated from a supply chain perspective. However, the main challenge in motivating the hydrogen supply chain network is the lack of existing hydrogen infrastructure. Strategic decisions for planning sustainable infrastructure can be analyzed hierarchically in time-related stages (2025-2030-2035). Meanwhile, a time- and location-based design has been specifically applied to a few selected ports in southern Iran, with limited focus on a national or countrywide scale. This study proposes a mixed-integer linear programming (MILP) optimization model to logically design the hydrogen supply chain, considering primary energy... 

Nowadays, electricity generation technology from renewable resources, especially solar energy has been very popular; specifically off-grid systems which have the ability of decentralized electricity generation. Dish/Stirling system is one of the most efficient technologies with capability of decentralized electricity generation from solar energy. The purpose of this study is design, optimization and analysis of a 10 KW Dish/Stirling system for different working location in Iran.
A mathematical model is introduced to analyze all the heat losses in different system components including parabolic dish, cavity receiver and Stirling engine. All the calculations are done with MATLABTM... 

This thesis represents a comprehensive view of electric vehicles from the macroeconomic policy in the energy sector perspective. In fact, in this thesis all the efficient factors in the presence of electric vehicles in the transport sector have been completely proceed. Environmental, economic, social and political factors, power grids and infrastructure are considered as the impressive factors. In order to check all factors comprehensively, Systems thinking based on dynamic system method is used. The causal relationships between all the variables which are involved in the presence of electric vehicles and related models to this thesis are simulated in VENSIM software. To investigate this... 

Energy supplement for various demands, including industrial demands, has been human being's challenge over years therefore infrastructures have been developed to generate and transmit energy, gradually. These infrastructures are planned and operated mostly individually so they have less efficiency. Energy hub is a concept that considers energy supplement infrastructures and technologies together. Energy storages play a key role in energy hub. This research intends to provide a framework for industrial load supplement using energy hub concept emphasizing on energy storage role, developing energy supplement optimal size and operation methods. Regarding this method, after introducing main... 

Smart consumers have a major role in the development of the smart grid. On the other hand, increasing need for more flexibility in DGs highlights the consumer’s role. This is possible with the development of smart appliance and appropriate communications infrastructure to active consumers. Today, with the development of smart grids, it is possible to control different parts of home energy systems and manage energy consumption. In this project a comprehensive model has been developed to optimize energy consumption in smart home. In the next phase of the thesis, due to the random nature of solar energy and electric vehicles, stochastic model of smart home energy system is discussed. At this... 

Aerodynamical design of backward swept for a horizontal axis wind turbine blade has been carried out to produce more power. Computational Fluid Dynamics (CFD) calculations were used for solving the conservation equations in one outer stationary reference frame and one inner rotating reference frame, where the blades and grids were fixed in reference to the rotating frame. The Reynolds Averaged Navier-Stokes (RANS) solver was validated in a test case, the National Renewable Energy Laboratory (NREL) VI blades. Simulation results show considerable agreement with the measurements. Three different turbulence models have been compared: Spalart-Allmaras, the Standard K-ε, and Shear Stress Transport... 

In this study, membrane distillation process was used for treatment of high salinity waters. The focus of this study is to simulate and build a setup of membrane distillation process. Since the membrane distillation process is based on the driving force of the temperature difference, the required temperature is provided by both the use of heaters and the use of solar energy. To increase the feed temperature by solar energy, a black polymer coating on the main membrane is used. The main membrane used in this process is PVDF polymer and the polymer coated on the surface is the PAN polymer. After simulating and constructing the laboratory setup, the influence of a variety of parameters on the... 

Distributed generation (DG) and its utilization have some benefits and risks for its owner and power network. From owner perspective, benefits of DG include selling energy, reducing costs related to fuel, and other economic benefits. However, there are some risk factors for the owner including risk of supplying fuel, risk of selling generated power, and other risk factors related to establishment of the DG unit. Utilizing risk-reduction tools such as signing agreements for selling power, purchasing fuel, and related economic tools are necessary for risk management of the owners of DG units. The purpose of this thesis is to investigate the economic situation of the DG units and optimize the... 

Hard disk drives are the main component of computers for permanent data storage. The security of the stored data is related closely to the air gap between the read-write head and the surface of disk. This gap which is created by the aerodynamic force between head and the disk is altered continually by lateral oscillations of disk. In the extreme condition of zero gap and contact between the protective coating layer and subsequently the magnetic material of the disk with the head, the disk will be scratched and damaged. Therefore, the active or passive control of these vibrations has a particular importance in the technology of manufacturing of hard disks. The first step in active control... 

Due to the energy crisis in recent years, much of which is due to excessive energy consumption in the air conditioning of buildings, many studies have been conducted from the perspective of engineering sciences on the subject of insulation and optimization of buildings. This study aims to investigate the conditions of thermal comfort from the mental and psychological perspective of human beings, which is the basis of the individual's decision to accept thermal adaptation behavior in the standard temperature range. In this study, the thermal adaptation model was designed on the theory of programmed behavior, which can explain the adaptation of individuals to the comfort temperature region.... 

Restructuring energy systems for increasing the competence and improving the efficiency has been regarded by energy policy makers. Also, the emerging of new technologies and also the district generation has increased the competence in energy industry. Planning and exploiting the energy system in a restructured environment, has basic differences with integrated systems. Models that can assess the behavior of independent players are needed to assess energy systems in a restructured space.The goal of the present study is to present a model to optimally develop the energy system in a restructured environment. The concept of energy hub was applied to model multicarrier systems. Three steps were... 

Increasing global final energy demand and the use of fossil fuels to meet this amount of energy demand have raised concerns about environmental impacts of fossil fuel consumption and the reduction of fossil energy reserves. Among the energy consumer sectors including industry, transport activities, agriculture, and households, the household sector is one of the most important sectors, regarding its share of total final energy consumption. Heating and cooling systems, which mainly use fossil fuels, are the biggest energy consumers in the household sector. Hence, optimal management of the heating and cooling systems can play an effective role in reducing energy costs in buildings. In this... 

Due to the world's reliance on fossil fuels, the climate change situation has become more severe and has presented major challenges. One of the most promising growth avenues to address these issues in the medium to long term is widespread electrification based on renewable sources. However, this is only feasible if the energy infrastructure can support distributed and renewable energy sources without affecting the performance of the power grid. A grid is also necessary for energy systems in order to connect various technologies and guarantee proper integration of supply and demand for maximum efficiency. A novel idea called Energy Internet (EI) has been put forth to accomplish these goals,... 

Today, financial exchanges have taken on a new form and cryptocurrencies were able to have a special place in these exchanges. Cryptocurrencies have attracted a lot of attention due to their decentralized nature. One of these cryptocurrencies is called Bitcoin and has the largest share of cryptocurrency exchanges. Due to the high volume of Bitcoin exchanges, a lot of energy is needed to supply this decentralized network to confirm transactions and extract it. In order for people in this industry to continue mining Bitcoin, they need to maintain their profitability. Therefore, choosing low consumption and profitable miners is one of the requirements of this industry. The aim of the thesis is... 

This study focuses on the analysis and optimization of smart heating garments in office environments with the aim of improving individual thermal comfort. The primary objective of this research is to answer the question of how integrating a human body thermal model with heating garment systems can contribute to optimizing the garment and, consequently, enhancing individual thermal comfort. The thermal model used in this research is JOS-3, which simulates the thermal behavior of the human body under various environmental conditions. This model, combined with heating garment technology, allows for more precise control of body temperature. In this study, two types of smart heating garments are... 

In the past due to the lack of mechanical systems for air conditioning in the interior spaces, the buildings were designed to be able to maximize the use of natural forces such as solar and wind power. Natural ventilation is an old method of using natural forces. For example, wind tower is one of the traditional elements for using natural ventilation in the warm seasons for benefiting from wind and sun energy. In our country, Iran, in cities like Yazd, which are located in a warm and dry climate, the use of wind towers is very common and our predecessors were pioneer in this field. With the passage of time and the development of mechanical air conditioning systems, the use of natural...