Sharif Digital Repository

The objective of the present research work has been the development of a model of optimal distribution electrical energy which may include distributed generators. Electrical distribution company has the option of receiving electric power from distributed generators owned by customers (Private Companies), DGs belonging to the electrical distribution company and purchase of power from market (high voltage network). The electrical distribution company would alternatively be able to sell surplus of its generation to the power market (high voltage network). The model of distribution system depicts the flow of electricity in each hour interval. The restrictions and bounds are the flows in each... 

The development of natural gas supply systems and its transmission networks are vitally important to achieve a natural gas economy. Development and planning of natural gas transmission networks as multidisciplinary projects have crucial impact on the economy of gas-rich countries like Iran. The nvestment costs and operation expenses of pipeline networks are so large that even small improvements in system utilization and planning can involve substantial amounts of money. A large number of technological options exist for development in conversion, distribution levels and …, which cause various pathways for supplying natural gas. In addition there are many energy recovery technologies along... 

In a single chemical plant, the operation of each unit operation is not independent of each other. In the other hand, the main operations are performed in reactors following by several separation steps including distillation and purification units. The total energy requirements are sullied by the heat exchanger networks. The performance of these systems is improved by integration and intensification of the reactor and distillation column in a single unit. The main objective of the present work is to provide an effective design approach to intensify the reactor and distillation column. In a reactive distillation column, the reaction and separation is done in a single unit. Increasing... 

This report models the electricity supply network by means of the ESM software. In this model, the distribution company obtains its final users’ electricity demand from three sources: distributed generation plants owned by private sector, distributed generation plants owned by the distribution company and buying from electricity market (Over distribution network). According to the model, the optimum point of operating the network is a point with maximum profit, minimum waste and environmental effects. The optimum point of supply minimizes the network wastes to an optimum extent. In this model, the distribution company can supply the extra electricity to the electricity market, provided that... 

The economic activities in a country involved with depletion of natural resources and emission of pollutants and gases to the environment. Depletion of exhaustible resources and environmental pollutions are two determinants of sustainability of development. The present research work is aimed at studying the sustainability of Iranian economy in 2009. The analysis of sustainable development of economy is based the concept of exergy, exergy efficiency and ecological exergy efficiency. Exergy efficiency is the ratio of the exergy of a product in economic activity to the exergy of input streams to that section of economy. Ecological exergy efficiency is defined as the ratio of exergy of product... 

In this project, a comprehensive model is developed for energy and exergy analysis in refineries. By studying Tehran’s North Refinery unit as a case study, the Reference Energy System as the conceptual model of the thesis and also Energy & Exergy Balance table is prepared. Through the exergy balance table, the Exergy efficiency defined. These factors help to settle priority for efficiency improvement investment. Then, the economic and technical relations and costraints are formulized using linear programming model. In this model, the CO2 emission and exergy destruction costs are intended. Using Energy System Model (ESM) software, the thesis model is advanced as RESM stands for Refinery... 

Nowadays, cement has become the cornerstone of any modern society especially in developing countries. But, cement production process is highly energy intensive and emits significant volumes of carbon dioxide.According to the latest reports, Iranian cement industry accounts for about 14.5% of total industrial sector’s energy consumption and this indicates the importance of sustainable development for cement industry concerning national energy and environmental constraints.Based on these facts, current study assesses the technology improvement opportunities particularly waste heat recovery power generation (WHRPG) technology for Iranian cement industry. This needs identifying optimized mass... 

Structural changes in the energy sector, including the need to diversify sources of energy supply, security of supply, energy consumption growth in developing countries, rising oil prices and the exhaustibility of fossil fuel reserves, environmental issues, increased consumption of petrochemical products etc., has led to increased share of natural gas in primary energy supply. Iran has a wide range of options to use natural gas endowment. The present research aims to develop a model for optimal allocation of natural gas to various applications.The gas distribution system is modeled in the present study. Technical onstraints together with economic characteristics are considered in the model.... 

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... 

Depletion of fossil energy reserves and rapid growth of energy demand have been challenging issues in the energy sector. Proper solution of these issues requires development of an integrated and comprehensive approaches. Such conceptual framework could provide an appropriate means for studying energy problems and anlysing the development of efficient technologies which could improve the economic viability and reduce the impact of energy system on the environmental. Therefore, analytical tools need to be developed further and they could be applied for systematic analysis of impact of new energy technologies on the economical efficiency and environmental compatibility of energy... 

High pressure natural gas is transported from processing plants to end users via a network of natural gas system. Pressure reduction along the transport system is compensated in compressor stations. High pressure natural gas flows in to distribution network in demand center which operates at medium pressure. Medium pressure gas is transferred to end users who can use natural gas with low pressure. Therefore, pressure of natural gas is reduced consequently when gas flows from transport systems to distribution network and end users. Work is dissipated during pressure reduction which otherwise could be converted in to power.A technology that could be utilized for conversion of pressure work in... 

Different disadvantages associated with using fossil fuels as the main energy source including crisis of wells’ depletion and serious environmental problems, causing by the emission of large quantities of greenhouse gases (GHG), especially carbon dioxide (CO2), has increased attention to replacing them with renewable and clean fuels such as wind, solar, and geothermal energy sources. Hydrogen, as a clean energy carrier, is one of the best fuels in terms of the environment and cost. So, it is recently receiving increasing attention and it may one day replace fossil fuels for various applications such as in automobiles and power stations. The main subject of this thesis was surveying the... 

Hydro power is a clean energy resource which has numerous advantages over other renewable energy systems including competitiveness with fossil fuel systems, high reliability, considerable potential, and availability of technology. These advantages have drawn attention to hydropower systems. Small Hydro Power (SHP) systems can be used for supplying the demand of rural and remote areas where electricity network rarely exists. SHP may also provide an investment opportunity. Comprehensive analysis of design features and operation of SHP and management of risks involved requires development and application of reliable analytical tools. The present research aims at developing a model for optimal... 

Steel in Iran is mainly produced by EAFs. One of the most fundamental issues in the field of electric arc furnace is to foresight methods to reduce energy consumption and emissions. A model is presented in the present research work that avails itself to analysis of mass and energy recovery simultaneously. The proposed model includes three major elements: scrap pre-heating, sponge iron pre-heating and inert gases pre-heating. An important feature of this approach is to preheat sponge iron. Mathematical model for preheating scrap has been developed on the basis of CONSTEEL technology. Also the model for sponge iron and inert gases preheating has been formulated based on the literature review.... 

The purpose of this study is to investigate and analyse the technological transition of a new clean energy technology in the market. The agent-based modeling is used in national innovation chain to describe knowledge spillover between main actors in innovation procedure in order to attain renewable energy technology (RET) from basic research to commercial stage. Government’s expenditure on training human resource and R&D activities is modeled as a tool to analyse the development of innovation chain in order to increase diffusion rate of the new technology. Application of the knowledge flow model is demonstrated through analysis of introduction of solar PV in the energy system of Iran and... 

Regarding the reduction of high qualified and accessible resources, the waste water treatments are accounted as one of the main challenges in environmental context. Surprisingly, with or without consideration of this issue can lead to play the crucial key in whether development or society retardation. With developing and being more sophisticated of waste water treatment technology and also rising the stringency of environmental constraint, approaching the optimum technology basis economics of scale is time consuming and complicated.Behind this concept, contribution of this study is twofold. The general approach of treatment is identified using AHP methodology in primary stage. After that, it... 

Waste management is one of the essential and basic utility services in 21st century, especially in rural areas. It includes different environmental, technical, economic, legal and social aspects which need to be considered in levels of waste generation, transport, treatment and disposal. Therefore, considering economic criterion in waste management programs, as the only one criterion, will result in environmental impacts in long-term and impose high costs to the society and the economy overall. The main purpose of this study is to develop a multi-criteria mathematical model, which take into account both economic and environmental criteria in order to present an integrated municipal solid... 

Thermal energy and water in flue gases varies with the type of fuel and thermal conversion system. Flue gas temperature is maintained in the range of 140 (℃) to 200 (℃) and it is subject to the sulfur content of the fuel. Vapor content of the flue gas is in the range of 10%_20% of volumetric flow. Considerable part of vapor may be recovered which can be used as cooling water make up. There are various means and methods for water capture and heat recovery which includes shell-tube heat exchanger among others. Selection of appropriate material and heat exchanger is conditioned by corrosion, temperature of flue gas and it’s economic feasibility. Identification of an optimal design of... 

The iron and steel industry has faced several challenges during the recent years. There has always been an aspiration towards higher economic profitability for the system. During the mid 1970s and 1980s the energy crises caused a dramatic rise in energy costs, which led to an increased awareness in energy conservation. In recent years, climate change issues have become more important for the industry. The operating practices for an industrial system are often affected by external restrictions concerning the economical, energy and environmental efficiency of the system. There are a large number of ways to increase the system efficiency, e.g. installation of new process equipment, and practice... 

The study presents a comprehensive electric arc furnace model for simulation and control application to predict chemical processes, heat and mass transfer. The model consists of arc module, chemical – slag module and heat transfer sector to observe fundamental phenomena affecting on energy consumption. Two modules act independently of each other and the two module calculations apply in the heat transfer sector. Arc module predicts the amount of energy dissipated from the arcs using arc currents and arc lengths; chemical and slag module calculates chemical energy, changes of elements/compounds, slag height and slag quality; while the heat-transfer sector uses calculations of the other two...