Original Article
Solar Thermal Engineering
Mahdi Rezaei Rad; Rouzbeh Shafaghat; Amirhossein Aghajani afghan; Behrad Alizadeh Kharkeshi
Abstract
This experimental study introduces a solar humidifier-dehumidifier desalination model as a type of open-air-open water (OAOW) system; also, a new condenser with thermoelectric modules is applied in the dehumidifier unit. The experimental tests were done by considering climate conditions in the north ...
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This experimental study introduces a solar humidifier-dehumidifier desalination model as a type of open-air-open water (OAOW) system; also, a new condenser with thermoelectric modules is applied in the dehumidifier unit. The experimental tests were done by considering climate conditions in the north of Iran (Mazandaran province, Babol), and the effect of the inlet air's temperature and flow rate on the system's functional characteristics and condenser was investigated to improve the performance. Sensors measured the data related to the fluid temperature and humidity of the cycle at different points; other data was also gathered by psychrometric chart and EES software. The results section investigates water generation rate, GOR, coefficient of performance (COP), and condenser efficiency. The results showed that the highest water production is 420 g/hr, and the highest GOR is 0.19. Also, the water production rate and COP increase as the inlet air temperature rises. At temperatures lower than 75o Celsius, due to the air saturation, the maximum point of the water production and COP occurs at a flow rate of 0.022 kg/s. at high temperatures, increasing the flow rate raises water production, and on the other hand, the COP in the condenser is 0.8 at the highest point. According to the economic analysis done for the proposed model, the freshwater cost is 0.098-0.049 $/year for one liter.
Original Article
Mojtaba Ghiyasi
Abstract
Data envelopment analysis (DEA) is a mathematical programming approach for the performance basement of the production units from a production economic view. In this paper, we analyze the performance of Iranian wind power plants (IWPP) using DEA. In the second phase of the study, we utilize the inverse ...
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Data envelopment analysis (DEA) is a mathematical programming approach for the performance basement of the production units from a production economic view. In this paper, we analyze the performance of Iranian wind power plants (IWPP) using DEA. In the second phase of the study, we utilize the inverse DEA approach as a valuable method for the future planning of the IWPPs. In this step, we considered five different scenarios from a short-run up to a long-run planning for electricity production by renewable energy. In the short-run we just need more capacity factor rather than capital. Although in the mid-run we did not presume capital extension, the result suggested this. In the end, in the long-run planning extension in not only capacity factor but also more investment in the higher technologies is a requirement for reaching the desired electricity production.
Original Article
Biomass Energy Sources
G PRAVEEN KUMAR YADAV; DIN BANDHU; K.JAYASIMHA REDDY; R. Meenakshi Reddy; Chadaram Srinivasu; Ganesh Babu Katam
Abstract
Recycling plastics into energy sources is the most promising method for cutting down on pollution and trash. In this regard, predictions of adiabatic engines using pistons with thermal barrier coatings (TBCs) were made to reduce in-cylinder heat rejection, safeguard the underlying metallic surfaces from ...
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Recycling plastics into energy sources is the most promising method for cutting down on pollution and trash. In this regard, predictions of adiabatic engines using pistons with thermal barrier coatings (TBCs) were made to reduce in-cylinder heat rejection, safeguard the underlying metallic surfaces from thermal cracking, and indeed reduce engine emissions. This study compares the predicted thermal and physical parameters of Plastic Waste Oil (WP) with its diesel blends in fixed proportions of WP10D90 (10% plastic oil, 90% diesel), WP20D80, WP30D70, WP40D60, and WP50D50 to diesel values. The study further explores the concept of the utility function to evaluate the best-ranked fuel blend in each category of various performance characteristics namely BTE, BSFC, UHC, CO, and NOx. Additionally, the effect of the thermal barrier piston coating on CI engine performance metrics and emissions was studied and compared to those achieved with regular diesel oil. When compared to diesel, the results state that the WP40D60 blend has the highest brake thermal efficiency, i.e., 31.62% at 80% load, and the lowest NOx emissions at all load conditions. In addition, it was further observed that the WP20D80 has lower hydrocarbon (HC) emissions at 20% load and an increment in CO emissions for all blends and load combinations. Overall, WP30D70 has come up with the best fuel as per the Utility function.
Original Article
Photovoltaic Systems
Pankaj Verma; Bharat Gangal; Gaurav Jain; Ravi Hada
Abstract
Most of the partial shading maximum power point tracking methods have been designed for the static shading pattern of the partial shading conditions, however, the irradiance pattern may change further when in partial shading mode. Therefore, to cover this research gap, a global maximum power point control ...
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Most of the partial shading maximum power point tracking methods have been designed for the static shading pattern of the partial shading conditions, however, the irradiance pattern may change further when in partial shading mode. Therefore, to cover this research gap, a global maximum power point control under varying irradiance (GCVI) algorithm is proposed in this paper. The algorithm does not use any sensors to detect the change in the irradiance, instead, the change in the current values of the modules are continuously monitored to detect the change. The reference voltages across which the peaks on the power curve are scanned are obtained from the reference voltage generation process, the consideration of these reference points avoids the excessive power losses in the system. The verification of the working of the proposed algorithm is carried out by simulating the photovoltaic system model on SIMULINK in MATLAB software. Simulations are carried out in various scenarios to show the effectiveness of the control. The simulation results illustrate that with the change in the global maximum under partial shading, the system successfully retunes to the new maximum point; the maximum point retunes from 10 kW to 9.2 kW and from 13.8 kW to 11.5 kW for two different case scenarios. Further, the comparisons are also carried out with the previously reported methods.
Review Paper
Biomass Energy Sources
Madhurjya Saikia; Pranjal Sarmah; Partha P Borthakur
Abstract
Biodiesel, derived from biomass, offers significant environmental advantages by reducing CO2 and CO emissions and promoting energy self-sufficiency. Currently, biodiesel remains limited to DG sets used by a small number of farmers in India, with minimal adoption in the transportation sector. Numerous ...
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Biodiesel, derived from biomass, offers significant environmental advantages by reducing CO2 and CO emissions and promoting energy self-sufficiency. Currently, biodiesel remains limited to DG sets used by a small number of farmers in India, with minimal adoption in the transportation sector. Numerous challenges impede biodiesel's acceptance. This research focuses on identifying challenges connected to India's biofuel policy, supply chain inefficiencies, and vehicle technology. In terms of cultivation, land management, and the delivery of high yielding varieties to farmers, biofuel policies have failed to encourage indigenous feedstock. Instead, the Biofuel Policy 2022 encourages the imported palm oil sterain. Inconsistencies in the supply chain caused by policies impair the cost effectiveness of biodiesel. Diesel engines in automobiles have compatibility concerns owing to corrosiveness and high fuel consumption due to the fuel's low calorific value. Furthermore, biodiesel causes substantial NOx emissions. This study offers policy-level solutions, such as encouraging the production of domestic feedstocks through efficient management of wastelands. In this approach, farmers may receive high yielding seeds at a reduced cost until the industry is self-sufficient. In addition, Policy Linked Incentive (PLI) scheme can be given to biodiesel producers. A policy like ethanol blending can also be implemented. The biodiesel supply chain, like that of Germany, the United States, Malaysia, and Indonesia, must be optimized. For the technological challenges in diesel engines, the government must use policy intervention, to incorporate engine components suitable for biodiesel, as well as upgrade diesel engines by calibrating electronic control units and with exhaust gas recirculation systems.
Original Article
Applications of Machine Learning Algorithms in Renewable Energies
Kossoko Babatoundé Audace DIDAVI; Richard Gilles AGBOKPANZO; Bienvenu Macaire AGBOMAHENA
Abstract
In this work, the photovoltaic power forecast for the next 24 hours by combining a time series forecasting model (LSTM) and a regression model (XGBoost) from direct irradiation only is performed. Several meteorological parameters such as irradiance, ambient temperature, wind speed, relative humidity, ...
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In this work, the photovoltaic power forecast for the next 24 hours by combining a time series forecasting model (LSTM) and a regression model (XGBoost) from direct irradiation only is performed. Several meteorological parameters such as irradiance, ambient temperature, wind speed, relative humidity, sun position, dew point were identified as influencing parameters of PV power variability. Thanks to the parameter extraction and selection techniques of the XGBoost model, only the direct irradiation could be kept as input parameters. The LSTM model was used to predict the direct irradiation for the next 24 hours and the XGBoost model to estimate the future power from the predicted irradiation. These models were developed under Python 3, the exploited data were downloaded in the PVGIS database for the city of Abomey-Calavi in Benin and the prediction was carried out on a panel of 1000W of peak power. An experimental validation was then performed by comparing the predicted irradiance values to the measured values on site. It was obtained for the LSTM model a root mean square error of 3.66 W/m2 and for the XGBoost model a root mean square error and a regression coefficient of 1.72 W and 0.992129 respectively. These results were compared to the LSTM-XGBoost performances with irradiation, temperature, sun position and wind speed as inputs. It was found that the use of irradiation alone as input did not as such impair the forecast performance. The proposed method was also found to be more efficient than LSTM and CNN models used alone.
Original Article
Fuel Cells
Amarnath Gundalabhagavan; Veeresh Babu Alur; Ganesh Babu Katam; Kshitij Bhosale
Abstract
Fuel cells have been identified as a promising technology to meet future electric power requirements. Out of various fuel cells, Proton Exchange Membrane Fuel Cells (PEMFC) has been staged up as they can operate at low temperatures and also have high power density. In this article, the flow field design ...
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Fuel cells have been identified as a promising technology to meet future electric power requirements. Out of various fuel cells, Proton Exchange Membrane Fuel Cells (PEMFC) has been staged up as they can operate at low temperatures and also have high power density. In this article, the flow field design of a Single Serpentine Flow Field (SSFF) has been modified to L-Serpentine Flow Field (LSFF) in order to reduce thermal and water management problems in PEMFC. A numerical study was conducted on 441 mm2 active area at 700C and 3 atm operating conditions, to evaluate various flow characteristics by comparing LSFF with SSFF, and it was observed that temperature and species flux distribution in LSFF enhanced significantly. The modification of the flow field yielded remarkable improvements in various aspects. These enhancements included a more uniform distribution of membrane water content, an impressive 8% increase in O2 consumption, a remarkable 22% improvement in product evacuation demonstrated by the H2O species profile, attributed to a 40% reduction in product travel distance. Additionally, a noteworthy 10% increase in power density was achieved. Despite a slight increase in pressure drop due to the additional bends and turns in the modified flow field, the impact on power density remained insignificant. These findings highlight the immense potential of the modified flow field to significantly enhance performance.