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Modeling of a Hybrid Solid Oxide Fuel Cell Microturbine System with Steam Injection
, M.Sc. Thesis Sharif University of Technology ; Morad, Mohammad Reza (Supervisor)
Abstract
Hybrid Solid Oxide Fuel Cell-Micro Gas Turbine systems(SOFC-MGT) present opportunities for improvement over conventional systems, including high efficiency, cogeneration, and the potential for low carbon emmisions. In order to advance toward commercialization, Hybrid systems need to model under design point and off-design situations that maintain safe and efficient operations, also exhibiting favorable exergetic and economic performance. The present work investigates the hybrid SOFC-MGT performance and effects of steam injection, humidity effect, and fuel change in the system. The 1-D model of SOFC stack has been developed in EES Code and then coupled with a microturbine’s components with...
Reliability Centered Maintenance (RCM) Implementation in Thermal and Combined Cycle Power Plants
, M.Sc. Thesis Sharif University of Technology ; Abbaspour Tehrani Fard, Ali (Supervisor) ; Fotuhi-Firuzabad, Mahmoud (Supervisor)
Abstract
Power generation stations, which are commonly called power plants, are treated as the core module of power systems and are in charge of producing power to be transmitted and distributed to the end consumers. As the beating heart of power industry, power plants need to be available and reliable all the time and so do their constituent components since the need for reliable electricity, nowadays, is ever increasingly highlighted. The reason lies in the rapid jump of population growth in one hand and the incredible amount of damages as a consequence to the power interruptions due to the power plant component outages, if happened, on the other one. So, power plants have to be kept within a...
Numerical Simulation to Improve the Performance of Air-cooled Steam Condenser Ejector and Steam Turbine Operation in a Rankine Cycle
, M.Sc. Thesis Sharif University of Technology ; Darbandi, Masoud (Supervisor)
Abstract
Nowadays, widespread needs for creating low pressure ambient in various industries make vacuum systems have different research and industrial applications. One of these applications is in cooling system of Rankine power cycle. In this case, the performance of the vacuum system has a direct and significant effect on the cooling performance of the condenser and consequently, power production of the steam turbine. Also, a considerable part of deration in thermal power plants industry is due to the thermal deration of the cooling systems. This is mostly because of malfunction of the condenser due to ambient temperature rise. Therefore, by providing suitable solutions to improve the efficiency...
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...
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)...
Monitoring of Petrochemical Refinary Process
, M.Sc. Thesis Sharif University of Technology ; Rashtchian, Davoud (Supervisor) ; Sharifzadeh, Mahdi (Supervisor)
Abstract
Due to the replacement of fossil fuel with cleaner products, the reduction of fuel consumption in transportation until 2045, the excessive production of fuel oil in refineries and the growth of feed demand from downstream chemical units, have made countries to upgrade their refineries or construct Petro-refineries. The Petro-refinery is a new generation of refinery and its main purpose is to supply chemicals to downstream units. The products of these units will have more valuable than fuel refineries. Steam cracking unit, aromatic unit and propane dehydrogenation unit are important units that are in Petro-refineries. In this research, all refinery units were technically and economically...
Temporal Analysis of Customer Satisfaction based on Steam Game Review Metadata
, M.Sc. Thesis Sharif University of Technology ; Heydarnoori, Abbas (Supervisor)
Abstract
The length of time a user plays a computer game is one of the most important metrics for a game’s success in the gaming industry. The importance of this metric can be explained from the viewpoint of different actors present in this industry, for example, from the point of view of the game Developer, increasing the duration of the playtime leads to an increase in opportunity for further in-game marketing, gamers value this metric since it entails how long can a game can entertain them. Making sure that a game can be entertaining for a long period of time is one of the most important factors in choosing to buy a game. Also, it’s in every online store’s best interest to always offer games to...
Catalyst deactivation in industrial combined steam and dry reforming of natural gas
, Article Fuel Processing Technology ; Vol. 120 , 2014 , pp. 96-105 ; ISSN: 03783820 ; Baghalha, M ; Sharif University of Technology
Abstract
The catalyst's performance and deactivation in a Midrex® industrial fixed bed reactor were investigated for the combined steam and dry reforming of natural gas using a one-dimensional heterogeneous model. The results demonstrate that there is a strong tendency for the catalyst's deactivation by carbon formation originating from methane decomposition. However, kinetic modelling of the combined reforming process shows that only a fraction of the catalyst in the industrial reactor is required for the reactions to reach an equilibrium state in the reformer. Hence, as the catalyst is deactivated at the reactor entrance area, the reaction zone gradually moves forward and still allows for...
Integration of an absorption chiller in a total CHP site for utilizing its cooling production potential based on R-curve concept
, Article International Journal of Refrigeration ; Volume 35, Issue 5 , 2012 , Pages 1384-1392 ; 01407007 (ISSN) ; Karimkashi, S ; Saidi, M. H ; Sharif University of Technology
Abstract
Total site integration offers energy conservation opportunities across different individual processes. It also helps for design as well as optimization of the central utility system. It gives massive energy-saving opportunities. The large industrial CHP sites generate heat and power simultaneously. These sites have different steam levels at different pressures which are used for power generation via steam turbines and also directly for satisfying process heat demand. There are many sites requiring cooling demand in hot seasons. In this article, integration of a LiBr/water absorption chiller in a CHP site has been investigated until its cooling demand is satisfied. Low pressure steam at 3 bar...
Economic feasibility of CO2 capture from oxy-fuel power plants considering enhanced oil recovery revenues
, Article Energy Procedia, 19 September 2010 through 23 September 2010 ; Volume 4 , September , 2011 , Pages 1886-1892 ; 18766102 (ISSN) ; Soltanieh, M ; Saboohia, Y ; Arab, M ; Sharif University of Technology
2011
Abstract
Considering the dramatic increase of greenhouse gases concentration in the atmosphere, especially carbon dioxide, reduction of these gases seems necessary to combat global warming. Fossil fuel power plants are one of the main sources of CO2 emission and several methods are under development to capture CO2 from power plants. In this paper, CO2 capture from a natural gas fired steam cycle power plant using oxyfuel combustion technology is studied. Oxy-fuel combustion is an interesting option since CO2 concentration in the flue gas is highly increased. The Integrated Environmental Control Model (IECM) developed by Carnegie Mellon University (USA) is used to evaluate the effect of this capture...
Exergy analysis of waste heat recovery section in steam-natural gas reforming process
, Article Energy and Fuels ; Volume 29, Issue 5 , April , 2015 , Pages 3322-3327 ; 08870624 (ISSN) ; Farhadi, F ; Sharif University of Technology
American Chemical Society
2015
Abstract
In this work, an exergy analysis is performed for the waste heat recovery section (WHRS) of the steam-natural gas reforming (SNGR) process as a major energy intensive process. Two alternate conditions are investigated to evaluate the required thermodynamic parameters: normal operating condition and increase of C2 + components in the process feed stream. At normal operating condition, the exergy efficiency of WHRS amounts to 0.58 while some 17.2 kJ energy is destructed for each mole of H2 produced. If heavier than methane components are increased in the feed up to 8.5 mole %, despite the increase of H2 production, the exergy efficiency decreases down to 0.54...
Development of a qualified nodalization for small-break LOCA transient analysis in PSB-VVER integral test facility by RELAP5 system code
, Article Nuclear Engineering and Design ; Volume 240, Issue 10 , October , 2010 , Pages 3309-3320 ; 00295493 (ISSN) ; Jafari, J ; Boroushaki, M ; D'Auria, F ; Sharif University of Technology
2010
Abstract
This paper deals with development and qualification of a nodalization for modeling of the PSB-VVER integral test facility (ITF) by RELAP5/MOD3.2 code and prediction of its primary and secondary systems behaviors at steady state and transient conditions. The PSB-VVER is a full-height, 1/300 volume and power scale representation of a VVER-1000 NPP. A RELAP5 nodalization has been developed for PSB-VVER modeling and a nodalization qualification process has been applied for the developed nodalization at steady state and transient levels and a qualified nodalization has been proposed for modeling of the PSB ITF. The 11% small-break loss-of-coolant-accident (SBLOCA), i.e. rupture of one of the...
Determining the best sequence of load pickup during power system restoration
, Article 2010 9th Conference on Environment and Electrical Engineering, EEEIC 2010, 16 May 2010 through 19 May 2010 ; May , 2010 , Pages 1-4 ; 9781424453719 (ISBN) ; Nourizadeh, S ; Ranjbar, A. M ; Sharif University of Technology
2010
Abstract
The first control action in power system restoration concerns the generation restart. In the initial phase of restoration, operators are often concerned with load pickup problems. One of the important problems during load pickup is keeping frequency response in allowable range. The aim of this paper is to determine the best sequence of load pickup by hydro and steam units during power system restoration based on frequency response of prime movers. Hydro power plants and combustion turbine units have the capability of black start operation and can be used for early stages of power system restoration. This paper considers hydro power plants for evaluating the stability and frequency response...
Component and mode models for the short-term scheduling of combined-cycle units
, Article IEEE Transactions on Power Systems ; Volume 24, Issue 2 , 2009 , Pages 976-990 ; 08858950 (ISSN) ; Shahidehpour, M ; Li, Z ; Fotuhi Firuzabad, M ; Sharif University of Technology
2009
Abstract
We propose a component model for the scheduling of combined-cycle gas turbine (CCGT) units by mixed-integer programming (MIP) in which combustion turbines (CTs) and steam turbines (STs) are modeled as individual units. The hourly schedule of CCGT based on the component model is compared with that of the mode model. The modeling of modes, which includes a combination of CTs and STs, would require certain approximations for representing fuel input-power output curves, ramping rate limits, minimum operating time limits, etc. The approximations can result in sub-optimal schedules. Furthermore, the commitment and dispatch of CCGTs based on the mode model will require a real-time dispatch to...
Developing a mathematical model for reforming of glycerol towards a comparative evaluation of the liquid vs. gas phase medium
, Article International Journal of Hydrogen Energy ; Volume 44, Issue 49 , 2019 , Pages 26764-26772 ; 03603199 (ISSN) ; Kazemeini, M ; Larimi, A ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Glycerol might be converted into hydrogen through a catalytic reforming process. In order to design an effective route, the choice of reaction conditions and in particular its medium considered yet a crucial issue still needing further investigations. In this research, a mathematical model of reforming processes in vapor (i.e., steam reforming (SR) and liquid phase (i.e.; aqueous phase reforming (APR)) were developed. This was performed in terms of understudying effects of parameters including the reactor diameter, catalyst morphology (i.e., particle size) and mass flow rate on the glycerol conversion. Then, a superior reaction medium in terms of these variables was determined. For data...
On the origin of intermediate temperature brittleness in La-based bulk metallic glasses
, Article Journal of Alloys and Compounds ; Volume 770 , 2019 , Pages 535-539 ; 09258388 (ISSN) ; Tavakoli, R ; Aashuri, H ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
The effect of strain rate on the ductility of a La-based bulk metallic glass (BMG) over a wide temperature range, and the correlation between ductility and relaxation processes within this alloy are investigated in the present work. The three point bending test and dynamic mechanical analysis are employed to study these phenomena. It is found that the activation energies of the nearly constant loss (NCL) relaxation and intermediate temperature brittleness are almost identical. This observation reveals that the NCL relaxation, as a locally confined or caged dynamics, contributes as the main source of intermediate temperature brittleness in La-based BMGs. © 2018 Elsevier B.V
Exergy analysis and thermodynamic optimisation of a steam power plant-based Rankine cycle system using intelligent optimisation algorithms
, Article Australian Journal of Mechanical Engineering ; 2019 ; 14484846 (ISSN) ; Assareh, E ; Moltames, R ; Sharif University of Technology
Taylor and Francis Ltd
2019
Abstract
In this paper, exergy analysis of a steam power plant located in southern Iran named Zarand power plant has been studied. In order to optimize the performance of the Rankine cycle and achieve higher exergy efficiency, several parameters have been considered as decision variables. Knowing that there is the ability to change some of the parameters in the specific range in the process of electricity production in power plant, temperature and output pressure of the boiler and output pressure of four steps of extraction turbine have been selected as six decision variables. Also, exergy efficiency has been considered as the objective function. For this purpose, the exergy efficiency of the system...
Hydrogel materials as an emerging platform for desalination and the production of purified water
, Article Separation and Purification Reviews ; 2020 , Pages 1-20 ; Ghannadi Maragheh, M ; Torab Mostaedi, M ; Torkaman, R ; Asadollahzadeh, M ; Sharif University of Technology
Taylor and Francis Inc
2020
Abstract
Water is the most abundant liquid on Earth, but only 2.5% of worldwide water are fresh. It is impossible to ignore the importance of water in almost every process on Earth, from the smallest bacteria life to the formation of the continents. Today, efforts for the desalination of seawater and brackish water are critical to produce drinking water. In recent years, a novel material: hydrogel, was considered in desalination processes. Interesting hydrogel applications were proposed for forward osmosis desalination, solar still, electrodialysis, and capacitive desalination. Simple and inexpensive desalination ways for drinking water production are needed. Hydrogel compounds are one of the leading...
Thermodynamic modeling and optimization of cogeneration heat and power system using Evolutionary algorithm (Genetic Algorithm)
, Article Proceedings of the ASME Turbo Expo, 14 June 2010 through 18 June 2010 ; Volume 3 , 2010 , Pages 745-752 ; 9780791843987 (ISBN) ; Karrabi, H ; Ghadami, S ; Barzegar, H ; Rasoulipour, S ; Kebriyaie, M ; Sharif University of Technology
Abstract
A gas-turbine cogeneration system with a regenerative air preheater and a single-pressure exhaust gas boiler serves as an example for application of CHP Plant. This CHP plant which can provide 30 MW of electric power and 14kg/s saturated steam at 20 bars. The plant is comprised of a gas turbine, air compressor, combustion chamber, and air pre-heater as well as a heat recovery steam generator (HRSG). The design Parameters of the plant, were chosen as: compressor pressure ratio (rc), compressor isentropic efficiency (ηac), gas turbine isentropic efficiency (ηgt), combustion chamber inlet temperature (T3), and turbine inlet temperature (T4). In order to optimally find the design parameters a...
Multi-objective optimization of industrial membrane SMR to produce syngas for Fischer-Tropsch production using NSGA-II and decision makings
, Article Journal of Natural Gas Science and Engineering ; Volume 32 , 2016 , Pages 222-238 ; 18755100 (ISSN) ; Farsi, M ; Eini, S ; Sharif University of Technology
Elsevier
2016
Abstract
Membrane reactors are an advanced technology with vast application capacities for equilibrium limited endothermic reactions. The main propose of this study is to offer an optimized packed-bed membrane steam methane reforming (SMR) tubular reactor for sustainable CH4 conversion by implementing triple-objective optimization model based on optimum H2/CO ratio for low temperature Fischer-Tropsch (F-T) process. In this study a one dimensional pseudo-homogeneous model based on mass, energy, and momentum conservation laws is used to simulate the behavior of a packed-bed membrane reactor for production of syngas by SMR. In the optimization section, the proposed work explores optimal values of...