Iranica Journal of Energy & Environment
Volume:13 Issue: 1, Winter 2022

The pandemic scenario caused by Covid-19 generated negative impacts. Covid-19 has made it clear that our daily lives depend to a high degree on access to energy. Therefore, now more than ever, it is necessary to promote new activities such as local food production, but also local energy capture. This article is an attempt to expose and quantify the benefits of a renewable energy transition in Ecuador post Covid-19 and post-oil. The generation, consumption, and reserves of oil in Ecuador were characterized, and the concept of energy transition was applied to evaluate the possibilities of integration of renewables, the progressive exit of thermal power plants, and future energy strategies. The year 2015 was taken as a basis and it was determined that energy use was 154.0 TWh / year, which corresponds to an end-user of approximately 147 TWh / year. The objective was to reduce this end-use demand to 80.0 TWh/year by 2055 through the integration of renewables and energy efficiency, for which 5 transition phases were planned until a 100% renewable system was obtained. It is concluded that the energy transition in Ecuador is technically possible and economically viable, without giving up the energy well-being that we currently enjoy. However, results show that even 100% renewable is not enough to face climate change.

This paper presents an original concept of using high flexible flapping vortex generator in a heat sink for airside heat transfer augmentation. The proposed thin winglet, made with an elastic sheet, is responsible for increasing the cooling rate and mixing quality performance in laminar convection airflow. This study focuses on the excessive bending of the flapping winglet and reducing its blockage effect and pressure drop. This novel concept is demonstrated using a numerical simulation of the flow field with a coupled Fluid-Solid-Interaction technique in transient conditions. The continuity, momentum, and energy equations for forced convection airflow are solved by the finite element method using the COMSOL Multi-physics. Numerical results reveal high amplitude for the flapping vortex generator while under a large deformation and bending. This behavior leads to flow mixing with a small blockage effect due to the deformed aerodynamic shape of the winglet. The present findings show that the high flexible winglet enhances the rejected heat by 100%, with a 33% decrease in pressure drop compared to the rigid vortex generator at the same air velocity.

Proper acoustic design is especially important in some buildings. For example, in concert halls, one of the desirable functional features is the proper transmission of music. In this regard, an indicator that can effectively show the quality of the received sound is the sound intensity, which is the purpose of this study is a way to optimize this indicator. Among the most effective variables that will affect the intensity of the received sound and also the important characteristics of the sound source are the frequency and octave of the sound, as well as the distance between the sound source and the receiver. In this research, a new method was proposed to investigate the effect of these three variables on the received sound intensity. In this regard, ODEON software, one of the most powerful software in acoustic design, was used and data analyses were implemented. Then, using full factorial method (one of the experimental design methods), targeted scenarios based on three independent variables were identified and by using the results of simulated scenarios, the linear relationship between the dependent variable (sound intensity) and independent variables (frequency, octave and distance) were developed. Using this linear relationship, it was found that the octave of sound has the greatest effect on sound intensity, and sound frequency and distance from the sound source were inversely related to the sound intensity.

Most of today's buildings, due to improper imitation of the architecture of buildings in other countries, are forced to use more energy to create conditions of thermal comfort. Building windows affect energy efficiency. So, the aim of this research is to be concerned with Tabriz climate; in selecting the proportion and suitable glazing of the windows, in order to access the best design and execute a model to decrease energy consumption. The research approach is to utilize simulation and Design Builder software as a research tool. So, the annual gas consumed in the Building was received from the National Iranian Gas Company and a case study is modeled and after converting the unit from kWh to kg and kg to m3 and reliability of simulation results. Then, through parametric optimization, eight scenarios in designing windows and through the genetic algorithm, the glazing coating were evaluated. The simulations were performed again and the results index was examined. Eventually, based on the analysis of outputs, according to fixed area, it is more suitable to replace windows with the height of 1.5 to 1.74 meters instead of windows with the height of 1 or 1.2 meters. A window should be replaced with 2, 3, 4 or 5 windows with the same fixed area. I is desired to superseded triple-glazed glazing with low-emissivity filled with argon gas with clear double-glazed glazing filled with air to reduce energy consumption. The amount of heat losses for the window height of 1 to 1.5m, from one window to five windows and for the clear double-glazed glazing filled with air were 2.04%, 11.11%,. and 45.36%, respectively.

One of the crucial issues in early stages of designing process of a building is a lack of architects’ knowledge about the energy consumption in different forms of building with different proportions, especially in central courtyard forms. The purpose of this research is to investigate the effectiveness of the ratio of perimeter to the height of the courtyard (R1) and the ratio of width to length of the courtyard (R2) on energy consumption. In the first step of this research, different proportions of central courtyard with different R1 and R2 were simulated in design builder software. Then, multi linear regression was used to find out the effect of different proportions (R1 and R2) on energy consumption through SPSS software. Finally, the effect of R1 and R 2 ratio on energy consumption was validated through investigating six existing central courtyard forms. The result demonstrated that the effective coefficient of the R1 and R2 ratio on energy consumption were -25.41 and 62.69 respectively. Findings of this research help architects to achieve relative acknowledge about the energy consumption of different proportions of the courtyard forms for creating more energy efficient forms.

The nanofluid-based gas hydrate formation process employing copper oxide (CuO) nanoparticles have been experimentally investigated in this work. Different concentrations of nanofluids are injected into the reactor at the operating condition of 29 bar, 274.15 K, and impeller speed of 100 rpm. It was observed that the kinetics of the carbon dioxide hydrate formation process was greatly affected by the nanoparticles. The remarkable point was that at a very low concentration of 20 ppm, a considerable improvement on the carbon dioxide hydrate formation kinetic without using any surfactant was obtained. At the concentration of 20 ppm, the values of the initial rate of hydrate formation, growth time, and induction time were 0.0495, 194.5, and 4.4 min, respectively, which these results can be of great importance for the use of carbon dioxide hydrate in various industries. The results indicated that the kinetics of gas hydrate formation was also severely influenced by the impeller speed and initial gas pressure. The rate of CO2 captured in the hydrate crystalline lattice is also modeled by the first-order kinetic model. It was seen that this model can be used to predict the rate of hydrate formation with considerable accuracy.

One of the crucial factors for the presence of more people outdoors is to create comfortable conditions. This issue is significant for the elderly due to the different physical conditions. The purpose of this study is to improve the micro-climatic condition around residential complexes considering the elderly in a linear type. For this purpose, two physical indicators, the ratio of the height of buildings to their distance from each other (H/D) and the orientation of them towards the street, were investigated. Regarding H/D, ratios of 0.5, 1, 1.5, and 2, and about the orientation factor, angles of 135° to 200° were examined. This study was conducted outdoors around residential complexes in Iran, Tabriz, with a cold semi-arid climate. Envi-met software model 4.4.5 was used for the simulation. The days June 22 and December 22, 2020 were selected as one of the hottest and coldest day of the year. Two indexes of the Predicted Mean Vote (PMV) and the Universal Thermal Climate Index (UTCI) were examined as essential thermal comfort indexes. Also, for validation, local and field data in six days (21, 22, 23 June in summer and 21, 22, 23 December in winter) were extracted and compared with the data of the software. The results display, the ratio of H/D=1.5 and the angles of 135° and 145° were the most suitable comfort conditions.

Today, air pollution in urban areas is a major issue that have been affecting human health and the environment. Over the years artificial neural network methods has been used for prediction of pollutants concentration in many metropolitans. In the present study data were obtained from department of environment and air quality controlling stations in city of Tehran from March 2012 to October 2013. Prediction of CO and PM10 contaminations during cold and warm seasons under the influence of instability indices and meteorological parameters was done using the artificial neural network. Results of the modeling process showed that the highest correlation coefficient was obtained 0.84 for PM10 in warm season. On the contrary, the highest correlation coefficient of CO in cold season was 0.78. Also, the effect of instability indices on air pollution was investigated. The highest CO concentration occurred during cold seasons (R2= 0.81), while the lowest concentration was in warm season (R2= 0.72). In case of  PM, the highest concentration occurred during warm seasons (R2= 0.84), while the lowest concentration was in cold season (R2=0.75).

The increasing prevalence of water-borne diseases necessitates periodic monitoring of domestic and drinking water sources. The current study assessed the safety of well water in the four emirate zones (Gwandu, Yauri, Argungu, and Zuru) of Kebbi State, Nigeria. Using normal procedures, samples of well water were examined for heavy metals, physicochemical characteristics, and microorganisms, and the results were compared to the World Health Organization (WHO) drinking water criteria. The heavy metals’ chronic daily ingestion (CDI) and hazard quotient (HQ) were also determined. The results showed that well water in the four emirate zones had normal temperature, biochemical oxygen demand (BOD), dissolved oxygen (DO), total suspended solids (TSS), and zinc (Zn). However, non-permissible concentrations of lead (Pb), iron (Fe), cadmium (Cd), chromium (Cr), and pH (Gwandu and Argungu only) were detected in all the water samples. Except for Cd and Cr in children, the CDI and HQ of the heavy metals were normal. The microbiological examinations revealed that the water samples from the four zones had abnormal levels of Bacillus species (bacteria), Escherichia coli (bacteria), Staphylococcus aureus (bacteria), Aspergillus niger (fungi), Mucor racemosa (fungi), and Paecilomyces variotti (fungi). The results obtained suggest that well water in the four zones is not suitable for human consumption unless treated.

Photovoltaic cells are a significant renewable energy source due to their cheap cost and renewability. In both warm sunny and colder and cloudier conditions, a-Si modules outperform c-Si modules on a normalized energy basis. This study investigated 1 m2 of amorphous photovoltaic silicon on curved surfaces. The Taguchi and response surface methods were utilized to expand the model in real terms. Results demonstrated the technology gap in the use of silicon crystal photovoltaics is eliminated. The maximum power in the Taguchi method test is 59.87 W, while the minimum power is 57.84 W when the system is deployed on a flat surface, and the maximum power in the RSM Test is 61.14 W when the system is deployed on a hemispherical surface, and the minimum power is 56.6 W when the system is deployed on a flat surface. The minimal performance was 7.1% on a level surface. The flat surface produced 810 kWh, the cylindrical surface 960 kWh, and the hemisphere 1000 kWh. The NPV at Flat surface is $697.52, with a 34.81%, IRR and an 8.58-year capital return period. Hemisphere and cylindrical surfaces both get $955.18. The investment yield was 39.29% for cylindrical constructions and 40.47% for hemispheres. On the flat surface, doubling fixed investment improved IRR by 21.3%. The cylindrical system increased by 25.59% and the hemisphere by 24.58%. The developed simulation model is empirically evaluated using a MATLAB computer tool; the key findings from the validation procedure are reported in this study.