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    Study On Performance Of Ic Engines Using Hydrogen As Fuel

    , M.Sc. Thesis Sharif University of Technology Kavianpour, Maziar (Author) ; Mozafari, Ali Asghar (Supervisor)
    Hydrogen is one of the favorite substitute for fossil fuels due to various properties including the flammability, ubiquity, and easy extraction from plain water. These properties have made it an appropriate alternative source of energy that can be used in internal combustion engines. Compared with fossil fuel energy, in addition to much lower emissions, hydrogen has proved to be much more efficient when applied as a clean source of energy. The main purpose of the present project is to study the effect of applying hydrogen on performance of compression - ignition as internal combustion engines as an alternative fuel. These studies encompass the results derived from the experiment of using... 

    Modifying TiO2 Photoanodes by Co-Pi Electrocatalyst for Solar H2 Production

    , M.Sc. Thesis Sharif University of Technology Forouzandeh, Mojtaba (Author) ; Naseri, Naimeh (Supervisor)
    Currently, fossil fuels are the primary source of energy in the world. The increasing human need for energy and the limited resources of fossil fuels and their environmental side effects necessitate the search for other sources of energy. Considering its abundance and eco-compatibility, using solar energy is one of the best candidates for future. One of the methods to use solar energy is to convert and store it as hydrogen fuel by photoelectrochemical cells. In recent years, the main challenge with the production of hydrogen fuel in photoelectrochemical is optimizing them to increase efficiency. For this purpose, various approaches have been proposed such as the fabrication and use of... 

    Experimental study of continuous h2/air rotating detonations

    , Article Combustion Science and Technology ; 2020 Dehghan Nezhad, S ; Fahim, M ; Farshchi, M ; Sharif University of Technology
    Taylor and Francis Inc  2020
    An experimental study of a lab scale rotating detonation combustor (RDC) has been conducted to identify and classify its modes of operation under different feeding conditions. The chamber uses air as oxidizer and hydrogen as fuel. The stability diagram of the RDC has been determined based on the detonation chamber Reynolds number and reactants mixture equivalence ratio values. The Reynolds number is based on the air volume flow rate, chamber annulus size, and the reactants mixture feeding slot area. Hence the effects of geometrical parameters and operational parameters on the detonation wave stability can be presented in a single stability map. This diagram identifies different zones in... 

    A model for investigation of optimal hydrogen pathway, and evaluation of environmental impacts of hydrogen supply system

    , Article International Journal of Hydrogen Energy ; Volume 33, Issue 24 , 2008 , Pages 7314-7325 ; 03603199 (ISSN) Qadrdan, M ; Saboohi, Y ; Shayegan, J ; Sharif University of Technology
    Elsevier Ltd  2008
    In order to achieve a hydrogen economy, developing widespread hydrogen supply systems are vitally important. A large number of technological options exist and are still in development for hydrogen production, storage, distribution., which cause various pathways for supplying hydrogen. Besides the technical factors, there are other effective parameters such as cost, operability, reliability, environmental impacts, safety and social implications that should be considered when assessing the different pathways as optimal and viable long-term alternatives. To aid this decision-making process, we have developed a generic optimization-based model for the long-range energy planning and design of... 

    Effect of sinusoidal splitter on mixing performance of co-flow jets of hydrogen and air inside dual-combustor ramjet

    , Article Acta Astronautica ; Volume 180 , 2021 , Pages 211-217 ; 00945765 (ISSN) Sun, C ; Sharifi Rayeni, N ; Moghimihanjani, M ; Moradi, R ; Li, Z ; Sharif University of Technology
    Elsevier Ltd  2021
    In this study, the existence of a sinusoidal splitter on the formation and distribution of hydrogen and air co-jets are investigated in a dual-combustion ramjet engine. The main scope of this research is to analyze the comprehensive flow structure and flame features directly downstream of the sinusoidal splitter. In this work, shockwave/shear-layer interactions behind the sinusoidal splitter are thoroughly studied through a computational fluid dynamic approach. Two different splitter profiles are compared with a simple splitter to demonstrate the main effects of multi shock wave interactions on fuel distribution and penetrations. To simulate co-air jet, Reynolds Average Navier-Stocks... 

    Performance of a standalone wind-hydrogen power system for regions with seasonal wind profile: A case study in Khaf region

    , Article Sustainable Energy Technologies and Assessments ; Vol. 7 , September , 2014 , pp. 265-278 ; ISSN: 22131388 Ahmadi, S ; Rezaei Mirghaed, M ; Roshandel, R ; Sharif University of Technology
    The present study was aimed at performance and energy analysis of a hybrid wind-hydrogen power system. Such system consists of wind turbines, batteries for the short time energy storage, electrolyzer, fuel cell and hydrogen tank for long time energy storage. The proposed configuration is used to supply energy demand of a region with discrete seasonal wind speed regime. Temporary wind energy profiles restrict using batteries for electricity storage as they lose much electrical stored energy for the long time. Based on direct wind turbine usage, batteries and hydrogen storage, different energy supply strategies are introduced and analyzed to power the household electricity demand. The energy... 

    Mixed integer linear programing based approach for optimal planning and operation of a smart urban energy network to support the hydrogen economy

    , Article International Journal of Hydrogen Energy ; Volume 41, Issue 19 , 2016 , Pages 7700-7716 ; 03603199 (ISSN) Maroufmashat, A ; Fowler, M ; Sattari Khavas, S ; Elkamel, A ; Roshandel, R ; Hajimiragha, A ; Sharif University of Technology
    Elsevier Ltd  2016
    The future of urban energy systems relies on the transition to "smart energy networks" which incorporate energy storage with renewable energy sources such as wind and solar. Hydrogen provides a desirable energy vector for both energy storage and exchange of energy between energy hubs within a smart energy network. This paper aims to develop a generic mathematical model for the optimal energy management of future communities where hydrogen is used as an energy vector. An energy hub is a novel concept that systematically and holistically considers the energy requirements of both mobility and stationary loads. In order to perform optimization studies, the minimization of capital cost of... 

    Development of a mathematical methodology to investigate biohydrogen production from regional and national agricultural crop residues: A case study of Iran

    , Article International Journal of Hydrogen Energy ; Volume 42, Issue 4 , 2017 , Pages 1989-2007 ; 03603199 (ISSN) Asadi, N ; Karimi Alavijeh, M ; Zilouei, H ; Sharif University of Technology
    Elsevier Ltd  2017
    This study aims to construct a quantitative framework to assess biological production of hydrogen from agricultural residues in a country or region. The presented model is able to determine proper crops for biohydrogen production, its possible applications and use as well as environmental aspects. A multiplicative decomposition method was designed to forecast future production and Monte Carlo simulation was employed in the model to evaluate the risk of estimations. From 2013 to 2050, the hydrogen production capacity could increase from 53.59 to 164.41 kilotonnes (kt) in Iran. The highest contribution to biohydrogen production (52.1% in 2013 and 73.3% in 2050) belongs to cereal crops... 

    Optimal design of renewable integrated heat and electricity supply systems with genetic algorithm: household application in Iran

    , Article International Journal of Environmental Science and Technology ; Volume 17, Issue 4 , 2020 , Pages 2185-2196 Rezaei Mirghaed, M ; Saboohi, Y ; Sharif University of Technology
    Springer  2020
    The objective of the present study is the development of an optimization model for identifying the best configuration of renewable-based integrated energy systems. The system includes a combination of renewable energy systems such as wind, solar, hydropower and hydrogen production, storage facilities and conventional fossil-fuel generators. The developed tool consists of various modules where water heating assumes the utilization of waste energy as an option. Furthermore, the application, which is demonstrated for a case study in Tehran, has been considered. The power exchange with the distribution network and injection of hydrogen produced from excess renewable sources into gas network are... 

    Economic assessment of hydrogen fueling station, a case study for Iran

    , Article Renewable Energy ; Volume 33, Issue 12 , 2008 , Pages 2525-2531 ; 09601481 (ISSN) Qadrdan, M ; Shayegan, J ; Sharif University of Technology
    In recent years there have been many efforts to develop a hydrogen energy system in Iran. For instance, the Iranian fuel cell steering committee conducted a project and determined some targets to implement hydrogen in different sectors, especially transportation. In this paper, the costs of building stations and the levelized cost of hydrogen for two types of stations, SMR and electrolysis, with various sizes and capacity factors have been investigated. Also, in the case of electrolysis, hydrogen cost sensitivity to the price of electricity has been examined. According to the cost analysis conducted here, it is understandable that hydrogen costs ($/kg) vary considerably based on station... 

    Applicability of membrane reactor technology in industrial hydrogen producing reactions: Current effort and future directions

    , Article Journal of Industrial and Engineering Chemistry ; Volume 104 , 2021 , Pages 212-230 ; 1226086X (ISSN) Mamivand, S ; Binazadeh, M ; Sohrabi, R ; Sharif University of Technology
    Korean Society of Industrial Engineering Chemistry  2021
    Potent carbon-neutral energy carriers bring a vital solution for sustained industrialization and environmental protection. Hydrogen as a novel zero-emission energy carrier offers more than twice energy per unit mass compared to other fuels. Membrane reactor technology transforms gray hydrogen to blue by selective hydrogen separation and carbon dioxide capture from the product mixture. Moreover, improved reactant conversion during reversible steam reforming of methane, methanol, and ethanol; water gas-shift; and dehydrogenation of cyclic and aliphatic hydrocarbons as well as enhanced hydrogen yield are results of selective and distributed hydrogen separation from membrane reactor. In this... 

    Full-core reactor physics analysis for accident tolerant cladding in a VVER-1000 reactor

    , Article Annals of Nuclear Energy ; Volume 155 , 2021 ; 03064549 (ISSN) Safarzadeh, O ; Qarani tamai, M ; Sharif University of Technology
    Elsevier Ltd  2021
    Advanced accident tolerant cladding materials have brought up the potential to delay the deleterious consequences of loos of coolant accidents related to slowing down hydrogen formation from reaction of zirconium with steam in order to minimize the additional heat generation and improve fuel and cladding retention of fission products. The performance improvement offered by these advanced materials may expand the operating envelope of existing light water reactors. This paper examines the neutronic performance of the VVER-1000 light water reactor for the application of accident tolerant cladding in order to realize the endurance of severe accident conditions. This study includes a detailed...