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.
Photovoltaic Systems
A. Ahmadi; M. A. Ehyaei
Abstract
Entropy generation can be caused by the energy transfer from a high-temperature recourse to a low-temperature resource; this is defined by the second law of thermodynamics. This phenomenon can occur for the Earth by transferring the solar energy from the sun to the earth. The process of entropy generation ...
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Entropy generation can be caused by the energy transfer from a high-temperature recourse to a low-temperature resource; this is defined by the second law of thermodynamics. This phenomenon can occur for the Earth by transferring the solar energy from the sun to the earth. The process of entropy generation of the Earth is an important concept for the life of the earth. This process also has significant effects on the global hydrological cycle, carbon cycle of the Earth’s atmosphere, and global warming. This paper presents an approximate method to estimate the entropy generation of the earth caused by the sun. Application of the heat engine to calculate the entropy generation of the planets has been carried out so far. In this research work, the concept of heat engine is applied to calculate the entropy generation of the earth and the atmosphere surrounding it in a relatively simple model. Based upon this calculation, the rate of entropy generation of the earth and its surrounding atmosphere is . Moreover, by considering this imaginative heat engine, the first and second law efficiencies are equal to 0.11036 % and 0.11546 %, respectively. The results of this research work have also been justified by similar works on this topic.
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
E. Bani-Hani; F. Alkhatib; A. Sedaghat; A, Alkhazzam; F. Al-Dousari; O. Al-Saad
Abstract
Used engine oil is one of the most environment pollutants that is produced in large quantities. Methods of recycling and reuse of the oil are important for sustainable environment. In this work, a new experimental method is proposed for producing diesel-like fuel from the waste engine oil. The study ...
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Used engine oil is one of the most environment pollutants that is produced in large quantities. Methods of recycling and reuse of the oil are important for sustainable environment. In this work, a new experimental method is proposed for producing diesel-like fuel from the waste engine oil. The study proposes new physical and chemical treatment methods to produce diesel-like fuel from the used engine oil. The produced oil is chemically analyzed to characterize the produced engine oil fuel for application in a diesel engine, to calculate the power produced, to measure the gaseous emissions and to compare with the standard diesel fuel. The diesel-like fuel properties are investigated including viscosity, flash point, pour point, energy content, and gaseous emissions. The diesel-like fuel proves to emit less gaseous pollutants such as NOx than the diesel fuel. The diesel-like fuel is tested in a diesel engine which provided the efficiency of 22.4%. The proposed experimental approach proves sustainable for producing diesel-like fuel from waste engine oils and protects the environment from the abundant amount of the waste engine oil.
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.
Wind Energy
H. Berahmandpour; Sh. Kouhsari; H. Rastegar
Abstract
Economic dispatch in the presence of wind farms is of high interest in power system operational planning. Due to the uncertainty of wind speed and wind power, a probabilistic model is needed for application in economic dispatch solution. The weibull probability distribution function is a common tool ...
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Economic dispatch in the presence of wind farms is of high interest in power system operational planning. Due to the uncertainty of wind speed and wind power, a probabilistic model is needed for application in economic dispatch solution. The weibull probability distribution function is a common tool to model wind speed probabilistic behavior, but the main challenge is the nonlinearity of wind power generation with respect to wind speed. This causes complexity in probabilistic economic dispatch, which can lead to numerical and time-consuming solution methods. Therefore, linearization of the wind power curve is in the interest of some methods by simply connecting the first point to end point of power curve by a straight line. In this paper, by developing a conventional objective function for ED solution, two main contributions are made to obtain a suitable method for fast and also good accuracy results in real time purposes. At first, an improved method for linearization of wind power curve with respect to previous works is introduced which increases the performance of modelling with respect to the nonlinear model as the base model. The second contribution is developing an analytical routine for economic dispatch by an acceptable time-consuming calculation suitable for real time purposes. The effectiveness of the new approach has been tested on two test systems. The results show the improvement in relative error in ED cost with respect to real nonlinear curve model which reduces the error about one fifth regard to the conventional linearization model.
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.
Photovoltaic Systems
N.O. Adeniji; J.O. Adeniji; O. Ojeikere
Abstract
Global solar radiation is the sum total of all radiation reaching the earth surface i.e. it includes: the direct and the diffused solar radiation reaching the earth surface. The instrument used for measuring this very important component arriving from the whole hemisphere is the pyranometer. This is ...
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Global solar radiation is the sum total of all radiation reaching the earth surface i.e. it includes: the direct and the diffused solar radiation reaching the earth surface. The instrument used for measuring this very important component arriving from the whole hemisphere is the pyranometer. This is one of the most important parameter for applications, developments and researches related to alternative source of clean and renewable energy. In cases where these data are not available, it is very common to use computational models to estimate the missing data, which are based mainly on the search for relationships between weather variables, such as temperature, humidity, precipitation, cloud cover and sunshine hours, among others. In this research work, the baseline data for mean monthly global solar radiation and sunshine hours for three (3) geopolitical zones of Nigeria (sub-sahara regions of Nigeria) with Sokoto (North-western Nigeria) (12.910N, 5.200E), Maiduguri (North-eastern Nigeria) (11.850N, 13.080E) and Ilorin (North- Central Nigeria) (8.430N, 4.500E) were obtained from the Nigeria Metrological Agency (NIMET), Nigeria which spread from 1996 to 2010. A linear regression correlation model was developed and clearness index estimated for each station in this study. The result shows the Angstrom coefficients and for estimating global solar radiation for zone respectively, using the Angstrom-Prescott model. The average global solar radiation for these stations was estimated, results subjected to statistical tests proven to be good estimates. The study concluded that the Angstrom- Prescott model plays a significant role in predicting and estimating solar energy potentials in these regions
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.
Solar Thermal Engineering
A. Naseri; M. Fazlikhani; M. Sadeghzadeh; A. Naeimi; M. Bidi; Seyyed H. Tabatabaei
Abstract
In this paper, a novel CO2 transcritical power cycle which is driven by solar energy integrated by a cryogenic LNG recovery unit is investigated. In the proposed cycle, the condenser unit of the CO2 power cycle is replaced by a Stirling engine. Thermodynamic and exergy analyses are carried out to evaluate ...
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In this paper, a novel CO2 transcritical power cycle which is driven by solar energy integrated by a cryogenic LNG recovery unit is investigated. In the proposed cycle, the condenser unit of the CO2 power cycle is replaced by a Stirling engine. Thermodynamic and exergy analyses are carried out to evaluate the performance of the presented system. Furthermore, in order to investigate the impact of utilization of Stirling engines instead of conventional condenser units, the proposed cycle is compared with the typical CO2 power cycle. The results show that employing the Stirling engine decrease the exergy destruction from 17% in the typical cycle to 8.85%. In addition, the total generated power of the novel system is considerably boosted up about 15 kW in off-peak times and more than 20 kW in the peak time. Moreover, integration of the Stirling engine also decreases LNG mass flow rate. Therefore, the required heat exchanger area in the LNG heater is also lowered.
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.
Sakhr M. Sultan; C. P. Tso; Ervina Efzan M. N
Abstract
A case study is conducted to evaluate the photovoltaic (PV) performance in a horizontal and in an inclined PV solar thermal collector (PVT) for two different PVT geometries; the series flow and the parallel series flow. It is shown that the series flow gives a better photovoltaic performance at a horizontal ...
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A case study is conducted to evaluate the photovoltaic (PV) performance in a horizontal and in an inclined PV solar thermal collector (PVT) for two different PVT geometries; the series flow and the parallel series flow. It is shown that the series flow gives a better photovoltaic performance at a horizontal PVT surface as compared to the parallel series flow. At mass flow rate of 0.03 kg/s and zero inclination angle (horizontal PVT surface), the PV efficiencies are 14.32 % and 14.25 % for series and parallel series flow, respectively. But for an inclined PVT surface, the parallel series performs better than that of the series flow. At mass flow rate of 0.03 kg/s and inclination angle of 45 °C, the PV efficiencies are 13.76 % and 13.87 % for series and parallel series flow, respectively. It can be concluded that the inclination angle is one of the essential parameters that can be used to evaluate any PVT design and make better comparison between different designs. It is also beneficial for researchers and PVT product designers to know the effectiveness of their collector designs for cooling the PV panel at the early product design stage and to base on the optimum inclination angle of the region.
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.
A. Kumar; K.C. Nikam; A.K. Behura
Abstract
Exergy analysis of a 250 MW power plant is done in this study. Thermal performance analysis using MATLAB calculation tool has been done. Exergy destruction phenomenon and Exergetic efficiency is calculated for various components of 250 MW coal fired subcritical power plant. The calculated overall plant ...
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Exergy analysis of a 250 MW power plant is done in this study. Thermal performance analysis using MATLAB calculation tool has been done. Exergy destruction phenomenon and Exergetic efficiency is calculated for various components of 250 MW coal fired subcritical power plant. The calculated overall plant exergy efficiency is evaluated 34.75%. Besides, results also concluded that exergy destruction takes place in the steam generator 490.76 MW (93.07%) followed by the other components. The comparative study of heat loss ratio with respect to varying plant load is performed out of which condenser contribute to have major heat loss ratio. The outcomes of this research study will be beneficial for future researchers.
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
R. Alayi; F. Jahanbin
Abstract
The purpose of this research is to supply the electricity required by renewable energies used by the photovoltaic cell, in this regard, have been using the type of crystal silicon photovoltaic cells. The used software with this regard is Homer. Homer is capable of simulating renewable energies to monitor ...
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The purpose of this research is to supply the electricity required by renewable energies used by the photovoltaic cell, in this regard, have been using the type of crystal silicon photovoltaic cells. The used software with this regard is Homer. Homer is capable of simulating renewable energies to monitor demand for loads. Electricity is generated by the Pv cell, but the energy produced in DC. While the energy required is alternating after the voltage converter is used for conversion. The storage will be used at times when there is no electricity produced by the PV cell or the production of electricity is higher than the demand, in this study the battery is considered a storage unit. The important results of this study can be attributed to the production of 15339 kW electricity by the Pv cell.
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.
H. Pourderogar; H. Harasii; R. Alayi; Seyed H. Delbari; M. Sadeghzadeh; A.R. Javaherbakhsh
Abstract
This paper aims to determine the optimal performance characteristics of a solar tracking system in order to maximize the power generation through using the MOPSO algorithm. Considering the sun path during a day, the necessity of using solar tracking systems to achieve the maximum power output from photovoltaic ...
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This paper aims to determine the optimal performance characteristics of a solar tracking system in order to maximize the power generation through using the MOPSO algorithm. Considering the sun path during a day, the necessity of using solar tracking systems to achieve the maximum power output from photovoltaic (PV) panels has been investigated. The solar tracking system allows PV arrays to follow sunlight all day long. The unidirectional tracking system follows the sun path, thereby optimizing the angular motion of PV arrays relative to the sun resulting in higher power generation. To evaluate the performance of a PV system, the total solar radiation was calculated first for both fixed and unidirectional tracking systems. Analyzing the results indicates that for June 20th the power generation of the PV module equipped with a unidirectional tracker is 35% higher than the fixed PV module. The optimal value of the declination angle, Azimuth, and arrays’ tilting angles in a unidirectional tracking system calculated using the MOPSO algorithm are , and respectively.
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.
F. Salek; Alireza Eskandary Nasrabad; M. M. Naserian
Abstract
In this paper, a novel thermal driven supercharging system for downsizing of a turbocharged diesel engine is proposed. Furthermore, Kalina cycle has been used as waste heat recovery system to run the mounted supercharging system. The waste heat of air in engine exhaust and intake pipes is converted to ...
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In this paper, a novel thermal driven supercharging system for downsizing of a turbocharged diesel engine is proposed. Furthermore, Kalina cycle has been used as waste heat recovery system to run the mounted supercharging system. The waste heat of air in engine exhaust and intake pipes is converted to cooling and mechanical power by Kalina cycle. The mechanical power produced by Kalina cycle is transferred to an air compressor to charge extra air to the engine for generating more power. This feature can be used for downsizing the turbo-charged heavy duty diesel engine. In addition, the heat rejected from engine intercooler is transferred to Kalina cycle vapor generator component, and part of engine exhaust waste heat is also used for superheating Kalina working fluid before entering engine. Then, first and second law analysis are performed to assess the operation of the engine in different conditions. Moreover, an economic model is provided for the Kalina cycle which is added to engine as supplementary component. Finally, simple payback and Net present value methods are used for economic evaluation of the added supplementary system. According to the results, mounting the novel waste heat driven air charging system has resulted in increment of air mass flow rate which leads to extra power generation (between 9 kW and 25 kW). The payback period and profitability index of the project are approximately 3.81 year and 1.26, consecutively.
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.
M. Ghazvini; S.M. Pourkiaei; F. Pourfayaz
Abstract
Finding a superior evaluation for an irreversible actual heat engine (irreversible Carnot heat engine) can be mentioned as the substantial purpose of this study. To obtain this purpose, the considered criteria are Ecological Coefficient of Performance (ECOP), exergetic performance coefficient thermo-economic, ...
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Finding a superior evaluation for an irreversible actual heat engine (irreversible Carnot heat engine) can be mentioned as the substantial purpose of this study. To obtain this purpose, the considered criteria are Ecological Coefficient of Performance (ECOP), exergetic performance coefficient thermo-economic, ecological-based thermo-economic, and ecologico-economical functions. These criteria are optimized by implementing NSGA II and thermodynamic analysis. Irreversibilities of the system is considered for the study assessment, consequently, two states are specified in the optimization procedure. The findings associated with every scheme are assessed independently. In the first scenario, maximizing the power output, First law efficiency of the system, and dimensionless ecological-based thermo-economic function ( ) is set as the target. In the second scenario, the three objective functions such as power output ( ), efficiency ( ) and dimensionless ecologico-economical ( ) are simultaneously maximized. To be clear, the coupled of multi-objective evolutionary approaches (MOEAs) and non-dominated sorting genetic algorithm (NSGA-II) approach are presented. The comparison of three prominent approaches such as: LINAMP, TOPSIS, and FUZZY performs in decision making. Ultimately, error analyses of results based on Maximum Absolute Percentage Error are carried out. According to the results, in the first scenario, the appropriate results were the result of the decisions made by TOPSIS and LINAMP, with a deviation index equal to 0.322 from the ideal ratio of this scenario. In the second scenario, the best decision-making results were achieved by the TOPSIS method, with a deviation index equal to 0.104 from the ideal state for this scenario.
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%.
Sh. Sham Dol; S. Shahid Pervaiz; M. Uzair; Sh. Khalid Bashir; M. Mustafa Elzughbi
Abstract
The research aims at designing a solar endurance glider for an increased flight time. The constraints for design include reduction in weight compared to a typical glider and improving its aerodynamic performance by application of vortex generators on its wingspan. The design of each component was performed ...
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The research aims at designing a solar endurance glider for an increased flight time. The constraints for design include reduction in weight compared to a typical glider and improving its aerodynamic performance by application of vortex generators on its wingspan. The design of each component was performed through various stages of similitude cases; furthermore, the components, such as solar panels and vortex generators were selected based on a decision matrix design process. This research utilized ANSYS 18.1 K-Omega SST turbulence simulation techniques to successfully simulate the glider at different speeds along with various angle of attacks for aerodynamics optimization. The results show an improvement in lift force from 160 N to 192 N once the vortex generators were installed. 16 solar cells are installed on the glider’s wings providing 57.6 Watts of power. This study faced a limitation on the physical testing using a wind tunnel for validation; therefore, the team relied on CFD simulations verification from published data. This report details the concept of boundary layer, design process, glider simulation as well as glider configuration, such as the wingspan and total length. The glider should be able to maintain a flight time of at least 6 hours with vortex generators and solar panels.
T. Oyegoke; E. Obadiah; Y. S. Sardauna MOHAMMED; O. Alao BAMIGBALA; O. A. Oluwarotimi OWOLABI; T. Tongshuwar GEOFFREY; A. Oyegoke; A. Onadeji
Abstract
Increasing energy demand and fossil fuel dependency have increased interest in bioethanol production in recent years. The use of conventional saccharine and starchy materials for ethanol production is prohibitive as it is a threat to food security. As such, rice husk poses to be of great value, providing ...
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Increasing energy demand and fossil fuel dependency have increased interest in bioethanol production in recent years. The use of conventional saccharine and starchy materials for ethanol production is prohibitive as it is a threat to food security. As such, rice husk poses to be of great value, providing a means to utilize waste. This study assessed the economic viability of bioethanol production from rice husk waste, which entails capital and manufacturing cost estimation, and profitability of this process. Further cost optimization studies were carried to determine the material cost, government subsidy, and tax potential to maximize the overall financial benefit (i.e., ROI and net profit) of the bioethanol production. Findings from this study indicated that transforming rice husk into bioethanol would not be economically feasible due to negative net profit (i.e., a loss on investment) obtained from its profitability analysis. Further studies indicated that the project was susceptible to the raw material cost, subsidy, and tax rate. Result obtained from the optimization studies indicates that if the rice husk sales as low as 1.38 US$/kg, and Government introduced 25% subsidy and tax-free policy on bioethanol production, the project would yield a net worth of US$ 5 million per annum, payback period of 5.5 years, and a return on investment of 16.1%. Therefore, this study recommends introducing a subsidy and tax-waiver policy for biofuels production to encourage investors and promote cleaner fuels in emerging nations.