فهرست مطالب

Journal of Renewable Energy and Environment
Volume:8 Issue: 2, Spring 2021

  • تاریخ انتشار: 1400/02/22
  • تعداد عناوین: 9
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  • Somayeh Naserpour, Hasan Zolfaghari *, Parviz Zeaiean Firouzabadi Pages 1-12
    One of the most important characteristics of site selection for solar energy system installations and optimum solar energy harvesting in the hilly or mountainous terrains is knowledge about the amount and duration of solar radiation within such topographic terrains. Solar radiation data are not readily available for most mountain terrains because of their rugged topography. For these areas, solar radiation data can be obtained through alternative methods such as the Hemispherical Viewshed Algorithm in which spatial and temporal variations of radiation are calculated in terms of elevation, slope, and terrain. In this study, this algorithm was used to estimate and model solar radiation in the Paraw Mountain in Kermanshah. The inputs for this method were ASTER Digital Elevation Model (DEM) with a spatial resolution of 30 m and meteorological parameters that affect solar radiation. The slope and aspect maps were created from ASTER DEM and layers for monthly direct, diffuse, global, and radiation periods were generated for the year 2016. The results showed that in the Paraw Mountain, the amount of solar radiation received was dependent on the slope orientation, as the north and northeast-facing slopes received the lowest and the south and southwest-facing slopes and the flat areas received the highest direct and global radiation (i.e., in terms of this factor, these landscapes can be recommended as the best site for solar energy system installations and optimum solar energy harvesting). The sum annual radiation period varies from 382.67 to 4310.9 hours, the total radiation received annually varies between 1005.56 and 7467.3 MJ/m2, and the sum monthly solar radiation is the highest in July (181.49-842.26 MJ/m2) and lowest in December (25.42-319.90 MJ/m2). Statistical error comparisons between station-based measurements and model-based estimates were performed via R2, measures. As a result, this model was recommended for solar radiation estimation with acceptable accuracy, especially in high areas with rugged topography where solar radiation data are not readily available.
    Keywords: Solar Radiation, Kermanshah province, GIS, Satellite Imagery, Paraw Mountain
  • Sajad Saberi, Behrooz Rezaie * Pages 13-20
    This paper presents a sensorless speed control algorithm based on Finite Control Set Model Predictive Control (FCS-MPC) for Permanent Magnet Synchronous Motor (PMSM) fed by a 3-level Neutral-Point Clamped (NPC) converter. The proposed scheme uses an anti-windup Proportional-Integral (PI) controller concept to generate the reference electromagnetic torque using the error of speed. Then, FCS-MPC uses this torque reference and other parameters such as a current limitation, neutral point voltage unbalance, and switching frequency to control the converter gate signals. Also, an Adaptive Nonsingular Fast Terminal Sliding Mode Observer (ANFTSMO) was employed to estimate rotor position precisely in positive (clockwise) and negative (counterclockwise) speed to eliminate the encoder. The proposed algorithm has fast dynamics and low steady-state error. Moreover, torque fluctuation and current distortion reduced compared with Space Vector Pulse Width Modulation (SVPWM) based speed control and Direct Predictive Speed Control (DPSC). Simulation results using MATLAB/SIMULINKÒ demonstrate the performance of the proposed scheme.
    Keywords: Finite control set model predictive control, Electromagnetic torque, Sensorless speed control, Permanent Magnet Synchronous Motor
  • Selfa Zwalnan *, Nanchen Caleb, Mahan Mangai, Nantim Sanda Pages 21-30
    The effect of solar collector configurations on the thermal efficiency of an active solar water heater was investigated using TRNSYS in this study. Two versions of a solar heater were formulated on the basis of serpentine and riser-header flat plate configurations. Both models were simulated based on the same parameters and weather conditions. Besides, in accordance with clear sky and cloudy sky conditions, a parametric analysis was performed to determine the impact of varying parameters on the thermal efficiency of the two models. The results showed that the serpentine-based device model provided about 2.62 % more usable thermal energy than the riser-header configuration. In addition, both models demonstrated the same response and sensitivity to changes in the collector area and the volume of the tank. However, on a cloudy day, the efficiency of serpentine showed a significant improvement and sensitivity to flow variance with an efficiency gap of about 30 % to the riser header configuration.
    Keywords: Simulation, TRNSYS software, Flat plate, Serpentine, Parametric Studies
  • Nima Amani *, Abdul AmirReza Soroush Pages 31-38

    Traditionally, building energy model is created in isolation from the architectural building information model and energy analyses have relied on a single analysis tool. The building energy model can be generated more quickly by leveraging existing data from the BIM. The impacts of energy consumption are significant in the building usage phase, which can last several decades. Due to the large share of the final energy consumption in the building sector, accurate analysis of thermal and cooling loads of a building and the efforts to reduce energy losses represent an effective way to reduce energy consumption. Therefore, it is essential to analyze the building energy performance in the design phase, which is when critical decisions are made. This study aims to investigate the impact of the building components and construction materials on building energy efficiency using Building Information Modeling (BIM) technology in a mild climate zone. After reviewing the proposed designs, the main building form was chosen for energy modeling and analysis. Then, building energy consumption analysis was performed based on the basic parameters of the building energy model. Eventually, the most optimal mode was selected by examining different energy consumption forms. This study showed that the building HVAC system always had the largest share of energy consumption. Finally, the results of parametric studies on alternative schemes of energy use intensity optimization showed that 22.59 % savings could be achieved as compared to the base building model in a 30-year time horizon

    Keywords: Building energy efficiency, Software simulation, Building Information Modeling (BIM), Mild climate, Energy performance assessment (EPA)
  • Tuhid Pashaee Golmarz, Sajadollah Rezazadeh *, Maryam Yaldagard, Narmin Bagherzadeh Pages 39-53
    In the present work, a Proton-Exchange Membrane Fuel Cell (PEMFC) as a three-dimensional and single phase was studied. Computational fluid dynamics and finite volume technique were employed to discretize and solve a single set of flow fields and electricity governing equations. The obtained numerical results were validated with valid data in the literature and good agreement was observed between them. The main purpose of this paper is to investigate the effect of deformation of the geometric structure of a conventional cubic fuel cell into a cylindrical one. For this purpose, some important parameters indicating the operation of the fuel cell such as oxygen distribution, water, hydrogen, proton conductivity of the membrane, electric current density, and temperature distribution for two voltage differences between the anode and cathode and the proposed models were studied in detail. Numerical results showed that in the difference of voltages studied, the proposed new model had better performance than the conventional model and had a higher current density, in which at V = 0.4 [V], about a 10.35 % increase in the amount of electric current density was observed and the average increment in generated power was about 8 %, which could be a considerable value in a stack of cells. Finally, the discussion of critical parameters for both models was presented in more detail. The core idea of the results is that the Oxygen and Hydrogen utilization, water creation, and heat generation are greater in the new model.
    Keywords: PEM fuel cell, Geometry, Mass Transport, performance
  • Abubakari Zarouk Imoro *, Moses Mensah, Richard Buamah Pages 54-60
    This study was conducted to improve the voltage production, desalination, and COD removal efficiencies of a five-chamber Microbial Desalination Cell (MDC). To do this, rhamnolipid was added to anolytes only and catholytes stirred to determine the effects of these factors on the MDC activity. This was followed by a factorial study to investigate the effects of the interactions of rhamnolipid and stirring on the voltage production, desalination, and COD removal efficiencies of the MDC. Increasing the concentration of rhamnolipid to 240 mg/L improved the peak voltage produced from 164.50 ± 0.11 to 623.70 ± 1.32 mV. Also, the desalination efficiency increased from 20.16 ± 1.97 % when no rhamnolipid was added to 24.89 ± 0.50 % at a rhamnolipid concentration of 240 mg/L, and COD removal efficiency increased from 48.74 ± 8.06 % to 64.17 ± 5.00 % at a rhamnolipid concentration of 400 mg/L. In the stirring experiments, increasing the number of stirring events increased peak voltage from 164.50 ± 0.11 to 567.27 ± 18.06 mV. Similarly, desalination and COD removal efficiencies increased from 20.16 ± 1.97 % and 48.74 ± 8.06 % to 24.26 ± 0.97 % and 50.23 ± 1.60 %, respectively, when the number of stirring events was more than twice a day. In the factorial study, voltage production, desalination, and COD removal efficiencies were 647.07 mV, 25.50 %, and 68.15 %, respectively. However, the effect of the interaction between rhamnolipid and stirring was found to be insignificant (p>0.05). Thus, the addition of only rhamnolipid or the stirring of catholytes only can improve the performance of the five-chamber MDC.
    Keywords: Voltage, COD, Exoelectrogens, Rhamnolipid, interaction effect
  • MohammadReza Shekari, Seyed Mohammad Sadeghzadeh, Mahdi Golriz * Pages 61-73

    In recent decade, Perovskite Solar Cells (PSCs) have received considerable attention compared to other photovoltaic technologies. Despite the improvement of Power Conversion Efficiency (PCE) of PSCs, the chemical instability problem is still a matter of challenge. In this study, we have fabricated two kinds of PSCs based on gold and carbon electrodes with the optimal PCE of about 15 % and 10.2 %, respectively. We prepared a novel carbon electrode using carbon black nanopowder and natural graphite flaky powder for Hole Transport Material (HTM) free carbon-based PSC (C-PSC). Current density-voltage characteristics over time were measured to compare the stability of devices. Scanning Electron Microscope (SEM) and Energy-dispersive X-ray Spectroscopy (EDS) analyses were carried out to study applied materials, layer, and surface structures of the cells. The crystal structure of perovskite and its association with the stability of PSCs were analyzed using an obtained X-ray diffraction (XRD) pattern. As a result, the constructed HTM-free C-PSC demonstrated high stability against air, retaining up to 90 % of its optimal efficiency after 2000 h in the dark under ambient conditions (relative humidity of (50 ± 5); average room temperature of 25 °C) in comparison to constructed gold-based PSCs (Gold-PSC) which are not stable at times. The experimental results show that novel low-cost and low-temperature carbon electrode could represent a wider prospect of reaching better stability for PSCs in the future.

    Keywords: Stability, Efficiency, Perovskite, Electrode, Carbon, Solar Cell
  • Mahnoosh Eghtedari, Abbas Mahravan * Pages 74-80
    Increasing fossil fuel consumption in the building, especially in the air-conditioning sector, has increased environmental pollution and global warming. In this research, a zero-energy passive system was designed to ventilate the building and provide comfortable conditions for people in the summer. A hybrid passive system was designed for indoor cooling to minimize fossil energy use. This research was done experimentally- and analytically and by simulation. An experimental study comprising a test chamber and simulation using Builder Design software was carried out to evaluate the cooling and ventilation potential of a hybrid passive system functioning. In the experimental section, air temperature, humidity, and airflow for the outdoor environment and the output of the evaporative cooling channel were measured. These measurements were tested in August from 9:00 AM to 3:00 PM for six consecutive days. The obtained experimental data were given to Design Builder software as an input parameter, and then, the comfort conditions inside the chamber, the dimensions, and location of the air inlet valve into the chamber were examined. The findings showed that the proposed system could reduce the air temperature by an average of 10 oC and increase the air humidity by 33 %. The findings showed that the air inside the chamber was comfortable during the hottest hours of the day. Raising the valve location, increasing the area, and increasing the volumetric flow rate of the air increased the percentage of dissatisfaction. The findings showed that in addition to wind speed and air temperature, the geometrical shape of the air inlet opening contributes to indoor air comfort conditions.
    Keywords: Hybrid system, Passive cooling, Evaporative Cooling, Solar Chimney
  • Ali Khatibi, MohammadHossein Jahangir *, Fatemeh Razi Astaraiea Pages 81-90

    Land-use change is one of the most important spatial phenomena that can affect the usage of energy technologies. In this study, land-use change in barren and residential areas in Alborz province in Iran was modeled using the cellular automata combined with the Markov Chain from 2001 to 2031. Due to adaptability to the environmental considerations, all protected areas were removed from the study area. Then, an economical and performance-based optimization model was developed; then, by using the status of the two land-use classes in 2031, an optimum scenario was identified for generating solar electricity. Based on the results, the optimum scenario involves installing distributed photovoltaic modules in 18.37 % of residential areas and setting up concentrated solar systems in 0.74 % of barren areas, simultaneously. Economic investigation of the optimum scenario showed that although there were some environmental and political benefits for using the solar electricity such as reduction of air pollutants and more energy safety, the optimum scenario will be costly and non-economical without the government’s financial supports.

    Keywords: sustainable development, Solar Electricity, Landuse Changes, Cellular Automata, Future Study