فهرست مطالب ahmad hajinezhad

Using ethanol in gasoline is considered one of the most significant goals in the 2030 agenda, which has been set a 15-year plan in order to achieve it since 2015. Appropriately, this project was planned for predicting the value of the most important engine parameters such as the equivalence air-fuel ratio (φ), fuel consumption (ṁf), and brake thermal efficiency nb. th, and brake-specific fuel consumption (BSFC) by regression models. According to the protocol of this project, first, the determined percentages of ethanol were added (0, 20, 40, 60, and 80%) to gasoline at different engine speeds (850, 1000, 2000, 3000, and 4000 rpm and the New European Driving Cycle test). After testing, calculating, mathematical programming, and fitting the regression models for the two SI-engine (TU5 and EF7) with different properties of engine design,12 regression equations have been determined for each of the ‘ (positive linear model), (ṁf) (negative linear model), nb.th (negative second-order polynomial model), and BSFC (positive second-order polynomial model), respectively. Clearly, these 48 regression equations with different line slopes will be able to predict the exact value of the ‘, (ṁf), nb.th, and BSFC for each concentration of ethanol at different engine speeds in order to help automotive industries for trend predicting them in other similar engines.

In this paper, a Rankin cycle-based heat and power generation system is simulated. The input energy of the system is supplied by the combustion of natural gas in the boiler. Condenser heat recovery is used to supply thermal energy and on the other hand, the power generated by the turbine is used to supply electricity demand. The first and second laws of thermodynamics and the law of conservation of mass are used to analyze the energy and exergy performance of the system. Finally, the effect of changing each of the performance parameters on the energy and CO2 emission of the system is investigated. According to the results, the turbine output power, net power production, electrical efficiency, energy efficiency, exergy efficiency, and CO2 production is obtained as 354.63 kW, 353.53 kW, 24.23%, 94.92%, 74.38%, and 81.1 g/s, respectively. Furthermore, the simulation results show that increasing the turbine inlet temperature increases electrical efficiency and exergy. Increasing the condenser outlet temperature also reduces electrical and exergy efficiency. On the other hand, increasing natural gas consumption only increases CO2 production and does not affect electrical, energy, and exergy efficiencies.

Global economic development requires increasing water demand for various purposes. Wastewater treatment in these processes leads to an increase in the volume of sewage sludge. However, a significant amount of renewable energy can be recovered from sludge from wastewater treatment. Biomass is one of the energy sources that has the potential of sustainable replacement for fossil fuels, a significant part of which consists of municipal and industrial wastewater. Anaerobic digestion is used as a strategy to generate energy and biogas from municipal waste and sewage. In this study, the energy production potential of wastewater treatment plants in Khorramabad city has been investigated and evaluated using preliminary data (including BOD) on wastewater treatment performance over one year (2021). The results show that annually 2261728 cubic meters of biogas can be produced using the anaerobic digestion method. Using the combined heat and power system can generate 24879008 MW of thermal energy and 476.34 kWh of electricity. Also, the economic evaluation of the system shows that the annual investment costs and operating costs will be 103251697000 and 14620633 Rials, respectively. On the other hand, the refinery can save 44689938600 Rials annually by saving natural gas consumption, selling fertilizer produced, and selling electricity generated to the network. The rate of return on economic capital for implementing this plan is calculated for 3 years and 6 months. In addition to economic justification, implementing this plan will be able to prevent greenhouse gas emissions significantly.

The increasing emission of greenhouse gases as the most crucial factor in global warming has made this a global concern in recent years. One concept proposed to better understand the amount of greenhouse gas emissions is the carbon footprint. Carbon footprint is the amount of greenhouse gases produced by a particular product or activity in its simplest definition. Since the power generation industry is one of the most highly emitting sectors, the study of carbon footprint has also become significant. This is primarily because fossil fuels are still the number one energy source for electricity generation, and even coal-fired power plants, which have the highest greenhouse gas emissions, will be the number one source in the coming years. They will still have a high share. Therefore, in the present study, while examining the concept of carbon footprint and its calculation method in the electricity industry, in a case study of South Khorasan province, the carbon footprint from steam and combined cycle gas and diesel power plants has been compared with Tabas coal-fired power plant. The obtained results show that the site's elevation according to the air density can have up to 10% impact the carbon footprint of the combined cycle power plant, and sites with low height should be chosen as much as possible. Also, the carbon footprint of the coal-burning power plant with a value of 968 grams per kilowatt hour is far higher than other fossil power plants with a value of 579 grams per kilowatt hour.

The demand increasing for electricity during the peak of the electricity grid led to several blackouts in the summer of 1397 . Reduction of investment in the power plant sector due to unprincipled privatization of power plants, failure to implement the next phases of the plan to target subsidies and non-payment of the difference between the obligatory and cost price leading to government Reduced electricity production. Cooling loads increase network loads in summer compared to other seasons. Considering that 65% of the country's buildings use water coolers, one of the ways to control the growth of the peak load of the national electricity grid is to increase the energy efficiency of water coolers. In this study with the help of bottom-up engineering modeling and behavioral functions, As the efficiency of water coolers increases from G to A, B and C, the peak of Tehran's electricity grid peak decreases by 21.08, 19.83 and 17.72%, respectively. This strategic act is effective in the efficiency of cooling equipment, as much as 2.5 years of the budget for the development of the country's power plant capacity. This study, while investigating the estimation of the effective cooling load in the peak of Tehran's electricity network, has estimated the effect of increasing the efficiency of the most widely used cooling equipment (water cooler) in the peak of Tehran's electricity network. The achievement can be used as a tool for better peak policy and, consequently, to prevent a blackout crisis.

In this research, after reviewing the history of the two pipelines of TAPI and IPI, and examining the conditions of the energy market, especially natural gas in both India and Pakistan, the behavior of these two countries has been analyzed in relation to the two pipelines of TAPI and IPI with the game theory approach. In this section, taking into account the income from natural gas imports and its costs, both economic and political, for both India and Pakistan, by adopting a single-stage, sequential game with complete information, the strategic behavior of the two countries concerning the TAPI and IPI pipeline has been modeled. The final result was explained using the maximin principle and the result of the model is that the choice of both pipelines, TAPI and IPI, for both India and Pakistan is the point of equilibrium. In the coming years, these two countries will need a lot of natural gas to generate economic growth and domestic demand. India, as one of the five emerging economies in the international economy and member of the BRICS group, needs a lot of fossil energy carriers, especially natural gas. The gap between the supply and demand of natural gas in Pakistan is estimated at 40 billion cubic meters in 2020 according to the country's Institute for Petroleum Studies, which is consistent with the model of the choice of both TAPI and IPI pipelines. Another important feature of IPI is its stability in the long time, which can resolve the need for India and Pakistan over the years. Despite the fact that the Western governments, especially the United States, did not support the IPI pipeline and impose political costs on both countries of India and Pakistan, but taking into account these political costs, the IPI pipeline will be a serious option for supplying natural gas for these two countries; Therefore, the Islamic Republic of Iran should stop the Media hegemony of the Western countries by emphasizing the economic overcoming of the IPI pipeline over its political costs.

Human environmental impacts on the earth can be examined in various fields. One of the areas of great importance is carbon dioxide emissions by human. One of the thousands of human activities that lead to carbon dioxide emissions into the environment is the supply of water. This paper examines the amount of carbon dioxide released by the drinking water supply system in Sepidan. This project took place within a year's time. The results of the surveyes show that in Sepidan, from one well with an energy consumption of 81318 kwh, one spring with an energy consumption of 102234 kwh, and the building of water and sewage organization with an energy consumption of 5491 kwh, amounting to 1067, 48,769 and 3293 kilograms of carbon dioxide release per year. Also, the results showed that 38 grams of carbon dioxide is produced for the supply of one liter of drinking water in the Sepidan. The results of study showed that the supply of water from the spring at a higher altitude point than areas of the city due to the specific topography of the Sepidan, Which is in the form of sloping, requires much less energy, and releases less contamination or carbon Dioxide.

In the present work the spray characteristics of bio-ethanol and its blends have been experimentally and theoretically investigated. To have a comprehensive study, the effects of ambient condition and injection pressure on the spray of different blends have been considered. Macroscopic and microscopic characteristics of spray such as tip penetration length, cone angle, projected area, volume, Sauter Mean Diameter (SMD), and Ohnesorge number are investigated precisely. Besides, air entrainment and atomization analysis have been carried out to improve mixture formation process. Using curve fitting and least squares method, theoretical correlations have been suggested in such a way to predict experimental results with the accuracy of 9.9%. To have a good estimation for the calculated parameters, uncertainty analysis has been performed. The results demonstrate enhancing the injection pressure or decreasing the ambient pressure, improve the atomization characteristics of spray. Moreover outcomes of this study indicate, spray tip penetration is enhanced by increasing the injection pressure or bio-ethanol percentage in the blend, while spray cone angle showing opposite behavior.

One of the factors that play a significant role in the contamination of ground water resources, solid waste and urban waste. 200 tons of waste is generated daily in the city Bojnourd and the amount of waste causes the release of 33 million liters of leachate per year. That the lack of proper waste disposal systems and landfills poor design caused concern about the influence of hydrocarbons and heavy metals into groundwater is has been. In this study, 2 wells upstream and 2 wells downstream in the side of landfill were sampled. The average concentration of variables NH3¡ NO3-¡ PO43-¡ SO42-¡ Cl¡ Mg2¡ K æ Na in the upstream wells Is measured respectively, 0.02, 20.27, 0.17, 141.2, 89.8, 38.52, 2.8, 27.6 mg/l and wells downstream, 08.8, 51.25, 0.5, 200.1, 182.2, 71.32, 7.1, 218.8 mg/l. Due to the high concentration of ppllutants of NO3-¡ PO43-¡ Mg2¡ K¡ Na æ TDS to a standard amount can be found that Influence of waste landfill leachate to the of groundwater in the area causes contamination wells surrounding the landfill. In this paper, in addition to examining groundwater pollution in the city of Bojnourd, is recommend that to design and locate the new standard burial place by using fuzzy logic and to found fourth place with ranking criteria for burial or should be used anaerobic digestion instead of waste disposal.

Anzali lagoon is the most important aquatic ecosystems of northern Iran. This lagoon is very important in terms of environmental and economic. Deforestation in the Anzali lagoon is the most important environmental concerns of researchers. One of the polluting factors Anzali lagoon , river pollution is the entrance to the lagoon. By examining the landfill in Rasht , how to manage latex was investigated. As well as improving the existing landfill the amount of methane produced by the new landfill is studied. Latex from the landfill by creating new output will increase from 1.5 % to 20 %. In the case of groundwater pollution will be prevented. Due to the high amount of rainfall in the city of Rasht latex discharge 120 cubic meters per day will be. Methane produced from landfill can be used to produce energy. In 2015, the amount of methane produced more than 10 5 cubic meters per year. Assuming a constant amount of waste entering the landfill, methane production by 2050 is 1.4 * 10 5 . The amount of wastewater produced by the anaerobic digester is 210,000 cubic meters per day.