Original Article
Wind Energy
N. Mishra; A. Jain; A. Nair; B. Khanna; S. Mitra
Abstract
As the energy demand is growing and fossil fuel based energy resources are getting depleted, there has been an increased focus on the use of renewable energy resources. Wind energy is a highly suitable energy resource that can be harvested for the purpose. This research deals with the design and fabrication ...
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As the energy demand is growing and fossil fuel based energy resources are getting depleted, there has been an increased focus on the use of renewable energy resources. Wind energy is a highly suitable energy resource that can be harvested for the purpose. This research deals with the design and fabrication of novel designs as a mean to harness wind energy using a ‘Savonius’ Turbine. It is generally employed to harvest the low to very low wind speed potentials. The paper introduces a novel concept about a Ducted Savonius wind turbine where power generation can increase more than 10 folds. The paper provides experimental validation of the effect of using a converging ducted structure with a single stage and double stage configurations of a Savonius wind turbine. The paper also compares the turbine’s performance with and without endplates and compares Single Stage and Double Stage Turbine. The experiment results show that around 15% increase in tangential blade velocity in single stage rotor when end plates are used. The results of the study proves that power coefficient increases with the addition of a converging ducted structure with the Savonius wind turbine, and also with the use of endplates.
Original Article
Wind Energy
RSR Gorla; M. K. Pallikonda; G. Walunj
Abstract
In the developed world, energy is one of the major factors and research is focusing on renewable energy. The global warming, CO2, NOX and limited fossil fuel are the research areas that are important. Renewable energy may be generated by wind, water, wave, solar and biomass. In this article, we are studying ...
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In the developed world, energy is one of the major factors and research is focusing on renewable energy. The global warming, CO2, NOX and limited fossil fuel are the research areas that are important. Renewable energy may be generated by wind, water, wave, solar and biomass. In this article, we are studying the wind energy availability for Cleveland, Ohio area. A statistical method using the Rayleigh probability distribution function is used to estimate the mean wind speed and thus calculate the annual energy output from a windmill. Furthermore, the annual energy output calculated from Rayleigh PDF is compared with the actual energy output from the observed historical data for the period 2009-2018
Original Article
Ocean Thermal Energy
R. Kaushal; R. Kumar
Abstract
The paper deals with falling film heat transfer across horizontal copper tubes at different tube surface geometries, mass flow rates, heat fluxes and weight percentage of salt in water salt solution at atmospheric pressure. The falling film heat transfer coefficient is significantly affected by heat ...
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The paper deals with falling film heat transfer across horizontal copper tubes at different tube surface geometries, mass flow rates, heat fluxes and weight percentage of salt in water salt solution at atmospheric pressure. The falling film heat transfer coefficient is significantly affected by heat flux, film Reynolds number and water salt solution for three types of augmented tubes viz. spiral, splined and smooth. This paper considers the influence of operating parameters on heat transfer coefficient using Fuzzy-Topsis applications. The experimental results reveal that falling film heat transfer has been greatly enhanced in case of spiral tube when compared with splined and smooth tubes. The spiral tube shows significant heat transfer performance than other two tubes for a given heat flux and Reynolds number as heat flux increases surface temperature also increases and increment in surface temperature of smooth tube is greater than spiral and spline tube for given heat flux and Reynolds number. As mass flow rate increases, surface temperature of all three tubes decreases but for a given heat flux and Reynolds number smooth tube has more surface temperature than other two tubes.
Research Note
Electricity Generation by Green Energy Sources
A. Ahmadi; F. Esmaeilion; A. Esmaeilion; M. A. Ehyaei; J. L. Silveira
Abstract
Until 2026, the annual rate of municipal solid waste production will increase and the per capita waste generation in Iran will be 0.6 kg/person.day. In this paper, the process of conversion of waste-to-energy in Iran is investigated and the future situation is estimated. Also, the trend of waste management ...
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Until 2026, the annual rate of municipal solid waste production will increase and the per capita waste generation in Iran will be 0.6 kg/person.day. In this paper, the process of conversion of waste-to-energy in Iran is investigated and the future situation is estimated. Also, the trend of waste management methods and energy production are evaluated. At the end, the benefits of the waste-to-energy process at the capital of Iran (Tehran) are observed. Waste-to-Energy (WTE) facilities in waste management are used within 3 regions of 22 metropolitan areas of Tehran and serve 950,000 citizens. With manufacturing new WTE plants in Iran, it would be possible to prevent the burning of about 15 million barrels of oil or 255⨯107 cubic meters of natural gas annually and use these fossil fuels to produce petrochemicals and export them. The associated overall expenses of WTE is also estimated in different countries at a rate of GDP between 300 and 3,000 $ per ton of MSW. By substituting WTE plants instead of oil basic plants, can reduce about 0.13 kg/kWh CO2 emissions. While most of the power plants are gas basic, that will have an increase of CO2 emissions of about 0.19 kg / kWh.
Review Paper
Photovoltaic Systems
M. Lak Kamari; H. Isvand; M. Alhuyi Nazari
Abstract
Renewable energies are noticeably developing due to their various advantages such as low greenhouse gases emission, availability and their reducing cost trend. In order to achieve the favorable objectives in energy projects, it is crucial to consider all the related parameters affecting the decision ...
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Renewable energies are noticeably developing due to their various advantages such as low greenhouse gases emission, availability and their reducing cost trend. In order to achieve the favorable objectives in energy projects, it is crucial to consider all the related parameters affecting the decision making. Multi Criteria Decision Making (MCDM) methods are reliable and efficient tool for policy making and achieving the most appropriate solution. These approaches consider the influential factors and their relative importance in prioritizing the alternatives. Since the outcome of the MCDM approaches depend on the employed algorithm and the used criteria, this article focuses on the studies related to the applications of these methods in renewable energy technology selection. The aim of the present paper is extracting the criteria which are necessary to be used in decision making for renewable energy systems. In addition, the approaches employed for improving the performance of MCDM methods as decision making aids are represented. According to this review study, technical, economic and environmental criteria are utilized in the majority of decision making researches. Moreover, some of the studies have considered other criteria such as social and risk to achieve more reliable decision. Some ideas are represented in the reviewed researches such as integrating different methods and using fuzzy sets, instead of crisp sets, to improve the performance of the MCDM methods and reduce the uncertainties.
Original Article
Fuel Cells
M. Beigzadeh; F. Pourfayaz; S.M. Pourkiaei
Abstract
The use of green buildings is increasing these days and many activities in order to improve the efficiency of this type of constructions have been done by the advancement of technology. Fuel cells are one of equipment which have been used to generate power and heat for residential buildings in recent ...
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The use of green buildings is increasing these days and many activities in order to improve the efficiency of this type of constructions have been done by the advancement of technology. Fuel cells are one of equipment which have been used to generate power and heat for residential buildings in recent years. For this purpose, a building in a cold region has been studied. In this study, the fuel of the fuel cell is provided from renewable fuel reforming, which is fermentation of waste and wastewater. First, a SOFC modeling has been carried out which is fed by biogas from a building waste. The modeling results of renewable-fuel fuel cell of this building have showed that 72% of electricity and 13% of the required heating could be provided using its wastes. All in all, by using biogas which has been produced from building waste, most required power and a part of required hot water could be provided and the environmental pollution is reduced by utilizing waste and trash. This will utilize all waste of the building for biofuels production and also provides major of the electricity and heating demand of the building.
Technical Note
Systems with Low Energy Consumption
Seyyed M. Mirlohi; M. Sadeghzadeh; R. Kumar; Mehdi Ghassemieh
Abstract
In this research, a plan to implement a zero-energy building (ZEB) for a hot and dry climate region of Iran (Yazd) is introduced and a comparison with a typical house of that climate is performed. Based on climate conditions, several active or passive methods are available in order to create a balance ...
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In this research, a plan to implement a zero-energy building (ZEB) for a hot and dry climate region of Iran (Yazd) is introduced and a comparison with a typical house of that climate is performed. Based on climate conditions, several active or passive methods are available in order to create a balance between energy supply and demand, namely improving wall insulations by using efficient heating/cooling devices, using solar energy, utilizing energy storage devices, and etc. Here, the SketchUp software is employed to present the plot of the selected building. In addition, one of the interfaces of Energy plus software called "BEOpt" is used for performing energy and economic analyses on the fast-constructed and pre-fabricated schemes. Considering the equipment’s world price, the results demonstrate that the zero-energy building scheme in selected climate conditions is applicable and the payback period is estimated to be about 5.5 years. In addition, replacing the typical buildings with a ZEB will decrease carbon dioxide emissions by about 27.4 metric tons/yr.
Original Article
Electricity Generation by Green Energy Sources
M. Farzaneh-Gord; H. Hajializadeh; A. H. Sarabandi
Abstract
There has been an increasing interest in the enhancement the efficiency and functionality of engines, particularly petrol ones, in recent years. In this paper, four stroke spark ignition internal combustion engine cycle has been simulated based on first law of thermodynamics. The second law analysis ...
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There has been an increasing interest in the enhancement the efficiency and functionality of engines, particularly petrol ones, in recent years. In this paper, four stroke spark ignition internal combustion engine cycle has been simulated based on first law of thermodynamics. The second law analysis has also been conducted to analyse the effects of ignition timings, combustion duration as well as engine speed upon engine efficiency and performance. The availability (exergy) balance equations of the engine cylinder has been considered in detail. Moreover, total availability fractions and process irreversibilities have been evaluated. By considering the results for brake and indicated mean effective pressure, it is shown that they behave in an opposite way in terms of increasing engine speeds. After perusing the figures, a conclusion is made, revealing that exergetic efficiency rises by increasing engine speed, whereas the opposite is true for brake thermal efficiency. Furthermore, The optimum point in which total efficiency ( both thermal and exergetic) shows the highest possible level happens at the speed of 2500 rpm
Original Article
Energy Policy
Seyed M. Mortazavi; S. Garoosi
Abstract
Energy plays an essential role in the economic and social development of all countries around the world, and its consumption is rising considerably due to the fast industrial development and increasing the standards of living. However, due to the high dependency on fossil fuel resources by all the developed ...
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Energy plays an essential role in the economic and social development of all countries around the world, and its consumption is rising considerably due to the fast industrial development and increasing the standards of living. However, due to the high dependency on fossil fuel resources by all the developed and developing countries around the world to cover their energy supply needs, fluctuations in supply and demand of energy as well as the energy prices would definitely lead to considerable macro- and micro-economic effects for both the energy exporter and importer countries. Therefore, the necessity of stability of economy and its understanding is becoming more and more popular among policy-makers and researchers around the world. As many energy consuming industries in Iran such as services and products are highly dependent on energy prices, understanding the economic robustness relationships with the supply and demand fluctuations of fossil fuel resources is important for the researchers and also policy-makers. In this paper, the effect of oil price fluctuations on several macro-economic parameters as well as energy sector’s resilience and electricity market as the main Iranian energy economics issues are discussed.
Original Article
Fuel Cells
Haleh Sadeghi; I. Mirzaee; Sh. Khalilarya; N. Ahmadi
Abstract
In present research, a three-dimensional, single phase proton-exchange membrane fuel cell has been simulated numerically. The governing equations have been solved using finite volume scheme and the obtained results have been validated against famous published data which showed proper conformity. The ...
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In present research, a three-dimensional, single phase proton-exchange membrane fuel cell has been simulated numerically. The governing equations have been solved using finite volume scheme and the obtained results have been validated against famous published data which showed proper conformity. The basic target is an investigation of the gas channel shape effect on cell performance and mass transport phenomenon. First, the besides walls of gas channels have been converted from straight condition to sinusoidal form with two different steps and in continue, the membrane electrode assembly has been bended in four states, but the gas channel cross section area has been kept 1 mm2. The results revealed that, the spiral models because of curved construction, prepare the long pathway for incoming gases and also much mass diffusion to the reaction area. So for model M1, the produced current density for V=0.6 [V], increased about 7.5% and consequently more oxygen and hydrogen consumed. The pressure drop of spiral models has been studied and results showed that the base model has the less pressure drop but model M2 because of higher performance and nearly same pressure drop can be a best choice for user. Also, for new bended models, the best choice is a model with δ=0.4, which has produced more current density, while its reaction area is about 19.64 mm2 larger than the conventional model with δ=0.
Original Article
Geothermal Energy Systems
H. Mohamed; E. Bani-Hani; M. EL Haj Assad
Abstract
A thermodynamic analysis based on first law of thermodynamics of organic Rankine cycle (ORC) was presented to find out effect of organic fluid selection on the cycle efficiency and power output.Different configurations of ORCs with and without Internal Heat Exchanger (IHE) were used. The criteria for ...
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A thermodynamic analysis based on first law of thermodynamics of organic Rankine cycle (ORC) was presented to find out effect of organic fluid selection on the cycle efficiency and power output.Different configurations of ORCs with and without Internal Heat Exchanger (IHE) were used. The criteria for choosing the optimum working fluid were discussed and many different organic fluids were compared in terms of thermal efficiency and power output. The results showed that higher efficiencies were obtained for ORCs with IHE configuration, and the organic fluid R123 had the most favorable performance for which the thermal efficiency of ORC was 14.2 and 13.28 with and without IHE, respectively. Moreover, the work output of ORC cycle was about 50 kJ/kg which was the highest when using R123 as an organic fluid.
Original Article
Low-carbon Technologies
M. Jalili; R. Cheraghi; M. M. Reisi; R. Ghasempour
Abstract
Cement plants are one of the massive energy consumers and greenhouse gas producers. Processes that are carried out in a cement factory have considerable energy losses which are mostly happening because of exhausted gases and airflow for cooling the clinker. Energy consumption in a regular plant is 25% ...
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Cement plants are one of the massive energy consumers and greenhouse gas producers. Processes that are carried out in a cement factory have considerable energy losses which are mostly happening because of exhausted gases and airflow for cooling the clinker. Energy consumption in a regular plant is 25% electrical and 75% thermal. Therefore, the main goal of this study is to represent a thermal recycling system in cement plants to generate power from high-temperature exhaust gases from the preheater and cooler’s high-temperature air. Thermodynamic analysis has been carried out by EES software and exergy efficiency and exergy destruction of each component of the system have been obtained. Moreover, a parametric study on the suggested cycle has been used which obtained results shows that if the input temperature and pressure of turbines get closer to the critical point of the expanded working fluid in turbines, the rate of net output work increases which lead to increasing of exergy efficiency of the whole system. The increased network of the cycle was almost 20% which would rise from 3497 kW to 4186 kW and exergy efficiency would rise from 38% to 45.94%.