نشریه انرژی ایران
سال بیست و دوم شماره 3 (پیاپی 84، پاییز 1398)

The main share of energy consumption in the country and more than a third of its loss is in residential use. Per capita, household electricity consumption is far from the world standard, and the existence of subsidies for energy carriers in Iran, and consequently their low prices, causes occupants to pay less attention to energy consumption. Due to the policy of eliminating subsidies, the effect of improving buildings and occupant behavior on consumption cannot be ignored. The purpose of this study is to investigate the effect of occupant behavior on energy consumption in residential buildings in Isfahan. The statistical populations are 78 typical retrofitted and non-retrofitted residential buildings. Retrofitted buildings are grouped based on the implemented measures into three categories and compared with non-retrofitted units. In addition, the effect of occupants behavior in the studied cases is assessed through questionnaire surveys and simulations (using Design builder software) to determine the impact of behavior change on reducing energy consumption. According to the results, the implemented retrofit measures reduced electricity consumption by up to 4.6%. While occupants behavior (i.e. electrical appliances and lighting use) could save between three to ten times more than retrofit actions.

Introduction of new technologies such as energy storage systems, electric vehicles, and distributed generation improved the characteristics of networks. On other hand, using these components in distribution systems improves system performances such as power losses. One of effective methods for improving system characteristics is distribution network reconfiguration. In this study, in addition to these effects, the role of reconfiguration in improving system resilience is investigated. Accordingly, a comprehensive model for network reconfiguration in the precense of energy storage systems, electric vehicles, wind turbines, and photovoltaic generation is proposed. Regarding this, the optimal location and capacity for optimal operation of system is obtained for all mentioned components. The effectiveness of model is proved in four case studies, The results of the four modes are compared. The results show the effect of network reconfiguration and storage components on the outputs of the model. The model is implemented on the 33 IEEE network in the GAMS environment with Sbb solver.

A quarter of Iran’s area is made from deserts with radiation exceeding . Also, the solar radiation of many parts of Iran is above the international average. So, the use of solar energy in the power system has increased in recent years. On the other hand, the success or failure of a project relates to the economic fluctuations of the country. In this paper, the effects of currency price sudden increment on the construction of the photovoltaic power plant is evaluated. In this research, several factors including the euro exchange rate, adjustment rate, inflation, taxation, government exchange rate, free exchange rate, and … are considered. A total of 48 cases have been investigated and a comprehensive economic assessment of the construction of photovoltaic power plants in different economic conditions is presented. The results reveal that in addition to the type of dedicated currency, the inflation rate is also effective in the economic evaluation of the photovoltaic power plant.

This paper presents the results of a research into the feasibility of recovering waste heat and determining design parameters of a recovery boiler for a set of medium-speed diesel generators with a capacity of 7 MW (the nominal capacity of all units is 42 MW, which would be a study on a unit). And is used to generate electricity. The main purpose of this study is to design a thermal waste recovery system for motors and to utilize geothermal technology for the power plant cooling system. The maximum theoretical potential of power generation is estimated at about 22 MW, and the pinch analysis model enables this potential to reach 80%. In this paper, the exergy performance and unit economic analysis are also performed for the optimum stage and the results are investigated at different minimum temperature and different pinch points. Finally, a geothermal cooling system is designed to control the thermal pollution of the exhaust gases and the water consumption of the system. Also, combining the power plant cycle has a positive effect on the exergy and unit energy efficiency (17and 14.1%) and increases the power generation of the power plant by 19 MW.

The spectral Direct Normal Irradiance (SDNI) is a basic radiometric quantity from which many other quantities can be derived. It provides not only information about the spectral and distribution of the direct solar radiation reaching a particular location. Accurate knowledge about the spectral direct irradiance shall enable us to gain new scientific results in the: determination of cloud effects, calculation of power yield of solar cells for electricity providers, derivation of aerosol distributions and their impact on the radiation field, determining the UV spectral irradiance for medical applications and in the improvement of our understanding of the radiative transfer in a changing climate. Nevertheless, at present, DNI measurements are not available in many instances. Therefore, the main objectives of this project are the setup, characterization, the calibration, the validation and the application of an operational measurement for the (SDNI) at the Institute of Meteorology and Climatology (IMUK) at the Leibniz University Hannover. With sampling times of less than one second even rapid changes of the SDNI can be recorded with a spectral resolution of about 1 nm in the wavelength range from 300 -800 nm (from UV to NIR). For this purpose three different tracking units were used to precisely track the sun location in the sky and finally based on the measurements and tracking strategy best instrument was selected. Finally the best tracking unit was used and the set-up was tested in the institute of Meteorology and climathology of Hannover (Longitude 52.37◦, Latitude 9.73◦). The comparison between the integrated value of the measurements and Pyranometer observations on the same platform, and during a complete day presented in this paper. It is worth to mention that the technique for setting up such a measurement station is very important as a basis for remote sensing research focused on the solar energy and meteorology applications.

One of the future technologies for energy supply in the electricity and automotive industries is the use of fuel cells. Hydrogen is the main source of fuel in fuel cells. Methane reforming through partial oxidation of methane is one of the methods of hydrogen production. In this paper, this process for the production of hydrogen gas, which is the energy source of these fuel cells, is examined numerically and experimentally. In this paper the thermal partial oxidation process of methane was investigated numerically and experimentally. Thermodynamic calculations and kinetic simulation were performed to determine the practical operating conditions. Experimentally, a porous material-based reactor was built to perform the partial oxidation process. Al2O3 granular with different size selected as porous structures and installed in the reaction zone. Physical parameters include diameter of the rector is considered for other experimental test. As the result the temperature profiles along the reactor central axis and concentration profiles of CO and H2 were measured. Also the effects of equivalence air ratio on the reforming process were investigated. Different equivalence air ratio 1.5 and 2 was considered to perform the partial oxidation process.

This paper attempts to present and compare four solar assisted ground source heat pump combined systems with series and parallel layouts and direct and indirect heat exchange in Zahedan in order to supply part of the electricity demand for equipment and selling surplus electricity to the grid as a source of project financing and revenue generation for residents, moreover, fulfill the region's need for access to natural gas. In the first step, the energy need for a residential building on the 94-square-meter plan with common building materials of the region is designed for a family of four in Design builder software and the hourly heat needed for a year is calculated. Design, modeling and performance control of each proposed system in Polysun software is conducted with utilizing 25 solar photovoltaic-thermal collectors with a total area of 33.25 square meters and 2 vertical geothermal heat exchangers in 100 meters depth. And all four plans are evaluated and compared after supplying energy of the building in terms of the amount of energy consumption, heat pump performance coefficient, the amount of produced electricity and CO2 emissions. The maximum and minimum values of the performance coefficient among the plans for direct heat exchange and series systems are 4.39 and 3.87, respectively , the optimal plan is introduced with 4957 kWh electricity consumption and 10667 kWh electricity production. The period of return on capital is estimated for 7 years. Due to the environmental impacts of fossil fuels and due to environmental assessment, the designed system will prevent 5089/7 kg CO2 emissions annually. The results indicate that the proposed optimal plan for exploiting in the south and southeast of Iran will have economic and environmental benefits.