A. Beiranvand; M.A. Ehyaei; A. Ahmadi; Jose Luz Silvaria
Abstract
The high potential of solar energy in Iran, as well as the problem of air pollution, makes it increasingly inevitable that solar energy is used. In this study, the solar-powered Organic Rankine cycle (ORC) has been investigated. The solar-type collector is a flat plate collector. The energy, exergy, ...
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The high potential of solar energy in Iran, as well as the problem of air pollution, makes it increasingly inevitable that solar energy is used. In this study, the solar-powered Organic Rankine cycle (ORC) has been investigated. The solar-type collector is a flat plate collector. The energy, exergy, and economic analyses of the hybrid system with the MOPSO algorithm have been carried out for Tehran., the capital of Iran. The working fluid of the solar collector has assumed water and the working fluid of the ORC cycle is R123. The MATLAB software is used for simulation and to compute the R123 fluid properties, the Refprop software is used. The exergy investigation shows that the most exergy destruction is related to the evaporator. Two objective functions consist of exergy efficiency and the price of electricity are considered. The decision variables for this optimization are considered as; the number of solar collector panels, the pump, and turbine isentropic efficiencies, and the pressure of condenser and evaporator. The Pareto diagram shows that the exergy efficiency of the system can vary as 7.5 % to 10.5 %, as well as the price of produced electricity can vary from 0.2 to 0.26 to $/kWh.
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.
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.