Sharif Digital Repository

Despite the abundant renewable energy sources, the Iranian energy sector relies almost entirely on fossil fuel energy resources. Power sector is dominant source of CO2 emissions and responsible for about 35% of total CO2 emissions in the country. Additionally, long-term electricity demand of Iran is expected to grow quickly, which in turn requires extensive investment to meet the growing demand over the next decades. On the other hand, increasing domestic fossil fuel consumption had been a serious challenge due to high costs of oil and gas. Current study pays particular attention to the possible penetration rates of renewable electricity technologies and their implications for fossil fuel... 

After a brief review of the global gas flaring and venting in oil industries including the emission of air pollutants and greenhouse gases and the amount of energy resources wasted, the focus is on Iran as a major oil producing and the world's third largest gas flaring country. Gas flaring is also practiced in natural gas industries, petroleum refining and petrochemical plants, although the level of emission is very low compared with emissions from oil production. The historical emission of these gases globally and Iran specifically, geographic location of emission sources, composition of gases, environmental impacts of gas flaring and the current and future projects to mitigate emissions... 

Purpose: Dams require high-volume of construction materials and operations over the life cycle. This paper aims to select a proper type of dam structure that can significantly contribute to the sustainability of dam projects. Design/methodology/approach: This research proposes a complementary fuel consumption and carbon dioxide (CO2) emission assessment method for the alternate dam structure types to assist decision-makers in selecting sustainable choices. Related equations are developed for two common earthen and rock-fill dam structures types in Iran. These equations are then successfully applied to two real dam project cases where the significance of the achieved results are assessed and... 

Energy and economy play a substantial role in environmental issues such as the emission of greenhouse gases. CO2 is one of the greenhouses that is hugely produced in industrial processes and other human being activities. The major share of CO2 emission is related to the energy-related activities. As a result, modeling the amount of produced CO2 by utilization of different energy sources must be considered. Moreover, by considering economic indicators such as gross domestic product, the accuracy of the model could be improved. In the present work, artificial neural network (ANN) with two transfer functions including normalized radial basis and tansig is used to model CO2 production of... 

Plug-in Hybrid Electric Vehicles (PHEV) have the potential to limit emissions and reduce the cost of transportation. Although wide scale adoption of plug-in vehicles is still a few years away, politicians, electric utilities, and auto companies are eagerly awaiting the opportunities that may arise from reduction of emissions and gasoline and oil consumption, new services and increased revenues, and new markets that would create new jobs. For consumers, plug-in vehicles will significantly lower operational costs when compared with traditional gasoline cars. The savings are potentially high, in average, as electricity cost mile work out to about one forth of gasoline. But it is noticeable to... 

One of the most prominent hybrid solar devices is the photovoltaic thermal system (PVTS), which is able to provide simultaneous electricity and thermal energy. The thermal energy is the heat absorbed by the photovoltaic (PV) module and transferred to the attached thermal collector and finally to the heat transfer fluid. Utilizing a proper heat transfer fluid is an effective means to increase in obtained thermal and electrical powers and enhance PV thermal management. Over the past decade, employing nanofluids thanks to their superior thermophysical properties became a proved strategy to improve the efficiency of the PVTS. This paper covers cutting-edge researches on nanofluid-based PVTS via... 

The aim of this paper is to investigate the application of solid oxide fuel cell (SOFC) as the prime mover of a combined heat and power (CHP) system. In this paper, four hybrid systems are proposed to improve the performance of CHP and compare with baseline condition. Capacity design and operation strategy of hybrid systems are applied to a case study of a greenhouse located in Mahabad, Iran and optimized by using technical, economic and environmental objective functions. Levelized cost of energy (LCOE) and CO2 emission rate are considered as the objective functions. For LCOE optimization, three scenarios are considered to evaluate the impacts of future energy prices and CO2 tax. In scenario... 

Purpose: Dams require high-volume of construction materials and operations over the life cycle. This paper aims to select a proper type of dam structure that can significantly contribute to the sustainability of dam projects. Design/methodology/approach: This research proposes a complementary fuel consumption and carbon dioxide (CO2) emission assessment method for the alternate dam structure types to assist decision-makers in selecting sustainable choices. Related equations are developed for two common earthen and rock-fill dam structures types in Iran. These equations are then successfully applied to two real dam project cases where the significance of the achieved results are assessed and... 

Considerable portion of energy losses in a vehicle traced to tire. Energy losses in a tire are due to tire longitudinal slip as well as rolling resistance. Hence, both of aforementioned factors must take into the consideration to study the tire energy loss. Present paper aims to investigate the power losses in tires and to examine influence of road conditions and tire inflation pressure on them. To cover the real-world conditions, experiments were done on a gasoline-fueled passenger vehicle on an urban highway along two routes with same length and opposite gradients to comprise the change of road conditions. Then, by use of engine performance model which is prepared in dynamometer... 

One of the most prominent hybrid solar devices is the photovoltaic thermal system (PVTS), which is able to provide simultaneous electricity and thermal energy. The thermal energy is the heat absorbed by the photovoltaic (PV) module and transferred to the attached thermal collector and finally to the heat transfer fluid. Utilizing a proper heat transfer fluid is an effective means to increase in obtained thermal and electrical powers and enhance PV thermal management. Over the past decade, employing nanofluids thanks to their superior thermophysical properties became a proved strategy to improve the efficiency of the PVTS. This paper covers cutting-edge researches on nanofluid-based PVTS via... 

New concepts and strategies are continually being investigated to meet fuel efficiency targets for new generations of internal combustion engines. Thermal management methods can reduce fuel consumption by up to 4%. One approach for thermal management is a map-controlled thermostat. In the current work, this concept is investigated through a benchmarking approach and a methodology for deriving the response time curve for this type of thermostat. To better explore the benchmarking idea, characteristics of map-controlled thermostats for two different engines are identified, analyzed, and compared. Finally, the effects of two separate map-controlled thermostats on the average fuel consumption of... 

This paper aims to analyze Iran's long-term power sector development from economic, environmental, social, and sustainable perspectives. For this purpose, a linear programming model is developed, which includes three objective functions: minimization of costs, minimization of CO2 emissions, and maximization of created jobs. To provide a sustainable plan, analytical hierarchy process is employed to allocate expert-based weights to the objective functions. Moreover, to support the decision-makers, Pareto-optimal alternatives are explored by varying the weights of objectives. The multi-objective model is solved by applying a weighted method based on fuzzy membership functions. The results show... 

Today, the interest on distributed generation has been increasing, especially due to technical development on generation systems that meet environmental and energy policy concerns. One of the most important distributed energy technologies is Combined Heat and Power (CHP). CHP is small and self-contained electric generation plan that can provide power for household applications, commercial or industrial facilities and hence its applications are overtly increasing. It can reduce power loss and enhance service reliability in distribution systems. One of the influential factors for the users is the purchasing cost of CHP which is largely dependent on its type, capacity and efficiency. Therefore... 

Today, the interest on distributed generation has been increasing, especially due to technical development on generation systems that meet environmental and energy policy concerns. One of the most important distributed energy technologies is Combined Heat and Power (CHP). CHP is small and self-contained electric generation plan that can provide power for household applications, commercial or industrial facilities and hence its applications are overtly increasing. It can reduce power loss and enhance service reliability in distribution systems. One of the influential factors for the users is the purchasing cost of CHP which is largely dependent on its type, capacity and efficiency. Therefore... 

After a brief review of the global gas flaring and venting in oil industries including the emission of air pollutants and greenhouse gases and the amount of energy resources wasted, the focus is on Iran as a major oil producing and the world's third largest gas flaring country. Gas flaring is also practiced in natural gas industries, petroleum refining and petrochemical plants, although the level of emission is very low compared with emissions from oil production. The historical emission of these gases globally and Iran specifically, geographic location of emission sources, composition of gases, environmental impacts of gas flaring and the current and future projects to mitigate emissions... 

The techno-economic and environmental performance of hybrid solar hydrogen energy systems was investigated to provide combined cooling, heating and power (CCHP) demands of a standalone greenhouse in Iran to achieve sustainable agriculture based on an optimization procedure. From the environmental point of view, by deploying hybrid energy systems, 83%, to 100% of emissions can be avoided. Also a sensitivity analysis was performed on the hybrid energy systems in order to study the effect of major parameter variation on the systems justification. It was concluded that hybrid solar systems are economically competitive with conventional systems, for high solar intensity locations with high diesel...