Sharif Digital Repository

Condition monitoring and operation optimization framework of water and energy hybrid systems has been developed in the present research work, by taking into account the variation in behavior of the system over time under changing environmental conditions. System modeling is performed using the physical laws governing the behavior hybrid energy-water system. In addition, machine learning has been used to estimate the deviation of the mathematical model from system operation, which may be due to the effect of depreciation of machinery parts and other uncertain parameters. Using machine learning and mathematical modeling together results in increased accuracy in predicting system behavior over... 

Increased exploitation of energy resources has led to growing attention to the CHP systems due to their high efficiency. High energy loss in power transmission network, which is about 20 %, is an additional reason for growing attention to CHP. In addition to that, utilization of small scale CHP systems has provided ground for growing competition with distributed generators based on renewable energy resources. Selection of optimal technology based on economical and environmental criteria requires application of analytical tool. An analytical tool could avail itself of identifying optimal program for operation of cogeneration systems. The present research work has been implemented to develop... 

The power supply system is one of the most important and complex systems. Various factors affect this system. Climate change affects different parts of the power supply system. In this study, the effect of climate change on electricity demand and electricity supply system has been investigated by considering the limited water resources. The amount of water withdrawal and GHG emissions in different scenarios. Scenarios are considered in such a way that assess the probable rising prices of fuels and water, and carbon taxes at three levels. Also, scenarios of rising water prices have been considered to evaluate the effect of this policy alone. It is worth noting that power plants are modeled... 

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... 

Energy is a production factor and its availability and accessibility contributes to the improvement of the social welfare. Sustainable supply of energy is a prerequisite to the social and economical development. Over-exploitation of exhaustible energy resources along with the destruction caused by human activities has caused the environmental degradation. Therefore sustainable economic growth and improvement of the social welfare depend upon efficient supply of energy which ought to be compatible with the environment. Sustainable development is a concept which depicts a compromise between three aspects of development which are economical, social and environmental compatibility.
The... 

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... 

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... 

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... 

Energy industries in many countries have initiated the process of privatization. Restructuring of energy systems is usually started with dividing the vertically integrated national systems into regional companies. Due to the geographical dimension of energy systems and natural monopoly in many activities, the process of privatization has started with segmentation of the vertically integrated national systems into regional companies. Thus, regional independent companies are formed that include a collection of producers and consumers of energy in their geographic area. These regional companies are economic entities who are pursuing a policy of maximize profit. On the other hand, exchange of... 

One of the ways to solve the problem of water scarcity in the agricultural sector is the development of the greenhouse. Using greenhouse and control of its internal conditions can increase productivity and reduce water consumption. But the issue that needs to be noted is higher energy consumption in greenhouses in comparison to traditional agriculture. The purpose of the present research is to evaluate the various technologies of supplying water and energy with a view to the climate, type of equipment and economic parameters. An analytical tool for designing and operation of the greenhouse have been developed and presented that may be applied in greenhouse sector. It is possible to evaluate... 

Rapid population growth and increasing and rapid consumption of natural resources in the ecosystem leads to the destruction of resources and thus increases the entropy in the earth, and this increase in entropy in the ecosystem changes the environment and has adverse effects on it. As all components in nature interact with each other by action and reaction, therefore, any change in the environment must be adjusted by other sectors and approached a reversible process to enable sustainable ecosystem changes. On the other hand, there is evidence that the world's physical capacity is inadequate to meet the requirements of sustainable development. The reason for this fact is that the ecological... 

Environmental and economic scarcity of resources are the most important challenges of industry sector. Iran confronted with lack of sufficient water resources and proper management and faces with drought and its environmental and economic consequences. It is a complicated challenge to provide the water demand without any damage to the ecosystem and it needs to do social, economic and environmental assessments. Wastewater treatment (water recycling) is an alternative option for supplying water demand. Wastewater treatment system (collecting, transportation to the treatment plant, wastewater treatment, and discharge) designed in order to solve hygienic and health issues in first place, but it... 

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.... 

Given the population growth in the world and in dire need of electricity and to reduce pollution and moving toward sustainable development, renewable energy has special importance in the world. Iran, with 300 days of sunshine a year is one of the countries with high potential in the field of solar energy but for various reasons, solar energy has no significant role in our energy portfolio. Considering the purchase of solar power by the government, reduce solar electricity costs and payback time of the factors that could make greater use of this energy. In this projects using light splitting method, in addition to reducing cell area used, by removing a significant portion of the sun's rays... 

As producing and consuming of natural gas has increased in recent years, improving natural gas distribution and transfer network systems has become vital. Pressure reduction station (PRS) is an important part of the natural gas network. Common PRSs are facing two issues: first is the pressure reduction technology, which is throttling valve that destroys the exergy of the high pressure flow. The solution is to utilize turbo-expander instead which can recover the energy. Second is the preheating technology which is boiler and water bath heater in the common systems that cause environmental problems. Using solar collectors is one of the best solution based on the literature. Since the solar... 

Due to the growth of energy consumption the use of new technologies and efficient energy conversion is necessary. An example of efficient energy conversion technology is CCHP (Combined Cooling, Heating and Power). The aim of the present research work is to develop a model that could be applied for optimal design of a hybrid CCHP system which would be Solar Combined Cooling, Heating and Power (SCCHP). In order to do so,microturbine power system, cooling and heating equipment’s such as absorption system and heat exchanger and also solar collector have been considered as an integral part of the system. The objective of the application of the model has been to identify proper sizing of all... 

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... 

Emission of CO2 and its diffusion into atmosphere is associated with negative effects on the environmental such as Green House Gases effect. Various techniques of CO2 Capture in energy conversion and processing plant are investigated. A method of CO2 Capture could be based on utilization of solar energy for producing methanol. Basic design of such a system and feasibility analysis of developing that system has been considered on the subject of the present research work. Basic design and commercial feasibility of the system producing methanol through capturing CO2 from exhaust gases of a power plant and hydrogen produced by using solar energy have done such an integrated system. The main... 

In this research work an analytical instrument has been developed for assessment of energy technologies, R&D resource allocation and technology development. Development of new technologies has been considered according to the specific conditions of developing countries. The analytical instrument includes two models interlinked with each other: energy technology assessment and optimal control of innovation activities. Energy technology assessment and prioritization of new energy technologies are provided by the model of the energy supply system that contains a detailed representation of current and emerging technologies characterized in terms of their technical indices. The results of this... 

The exit flue gas temperature of conventional gas fired boiler is generally high and considerable energy is lost to environment. Therefore, new methods are needed to recover water and heat from boiler flue gas in order to reduce overall plant water consumption as well as to increase energy efficiency and mitigate detrimental emissions. This project involved design of a heat and water recovery system including condensing heat exchangers to be used in residential buildings. In this project based on simulation of heat and water recovery system the recoverable amount of heat and efficiency improvement potential at various conditions such as different exit flue gas temperatures and different...