Trends in Renewable Energy
Not a member yet
143 research outputs found
Sort by
A Review of Low Temperature Combustion Mode of Engine
Get PDFSince the 21st century, people's increasing attention to fuel economy and environmental issues has prompted the engine research community to continuously develop new efficient and clean combustion theories and methods. In terms of combustion technology, many researchers have proposed different new engine combustion methods, such as homogeneous charge compression ignition combustion (HCCI), premixed charge compression combustion (PCCI), and reaction controlled compression ignition (RCCI), which are the three main low-temperature combustion methods. These combustion methods are different from the premixed combustion method of the spark ignition (SI) engine represented by the traditional gasoline engine and the diffusion combustion method of the compression ignition (CI) engine represented by the traditional diesel engine. The flame temperature affects the combustion and emission process of the engine, and realizes the efficient and clean combustion of the engine. This paper first briefly describes the conventional engine combustion method, and then briefly summarizes the comparison between these three low-temperature combustion methods and their respective combustion and emission characteristics as well as advantages and disadvantages, with respect to the conventional combustion method.Citation: Hao, Q. (2023). A Review of Low Temperature Combustion Mode of Engine. Trends in Renewable Energy, 9(2), 180-191. doi:http://dx.doi.org/10.17737/tre.2023.9.2.0016
Artificial Intelligence, Machine Learning and Neural Networks for Tomography in Smart Grid – Performance Comparison between Topology Identification Methodology and Neural Network Identification Methodology for the Distribution Line and Branch Line Length Approximation of Overhead Low-Voltage Broadband over Power Lines Network Topologies
Get PDFUntil now, the neural network identification methodology for the branch number identification (NNIM-BNI) has identified the number of branches for a given overhead low-voltage broadband over powerlines (OV LV BPL) topology channel attenuation behavior [1]. In this extension paper, NNIM-BNI is extended so that the lengths of the distribution lines and branch lines for a given OV LV BPL topology channel attenuation behavior can be approximated; say, the tomography of the OV LV BPL topology. NNIM exploits the Deterministic Hybrid Model (DHM) and the OV LV BPL topology database of Topology Identification Methodology (TIM). By following the same methodology of the original paper, the results of the neural network identification methodology for the distribution line and branch line length approximation (NNIM-LLA) are compared against the ones of the newly proposed TIM-based methodology, denoted as TIM-LLA.Citation: Lazaropoulos, A., & Leligou, H. (2023). Artificial Intelligence, Machine Learning and Neural Networks for Tomography in Smart Grid – Performance Comparison between Topology Identification Methodology and Neural Network Identification Methodology for the Distribution Line and Branch Line Length Approximation of Overhead Low-Voltage Broadband over Power Lines Network Topologies. Trends in Renewable Energy, 9(1), 34-77. doi:http://dx.doi.org/10.17737/tre.2023.9.1.0014
Temperature Forecasting as a Means of Mitigating Climate Change and Its Effects: A Case Study of Mali
Get PDFTemperature forecasts and trend analyzes were carried out for several locations in Mali as an important tool for warning of potentially threatening weather events such as severe heat waves, storms, droughts and floods, which could pose a great risk to humans and their environment. Five locations (Segou, Sikasso, Kayes, Gao and Taoudenni) across Mali (170 00’N – 40 00’W) were chosen for this research work. Satellite data of annual temperature obtained from the European Centre for Medium-Range Weather Forecast (ECMWF) database for 35 years (1985-2019) was used for this work. The Mann-Kendall trend test was carried out for various locations to observe and study the trend. Four Models including Auto Regressive and Integrated Moving Average (ARIMA), Exponential smoothening (ETS), TBATS (Trigonometric seasonality, Box-Cox transformation, ARMA errors, Trend and Seasonal components) and the linear model were employed to forecast average temperature for 10 years for all the locations. The model that produces the best forecast at the 95% confidence level is expected to have the lowest Root Mean Square Error (RMSE) value. The results showed that no significant trends were recorded at the considered locations. The linear model produced the best forecast for Segou, Kayes and Taoudenni, while the TBATS model produced the best forecast for Gao and the ARIMA model produced the best forecast for Sikasso.Citation: Billy, U., Udo, S., Ewona, I., Umoh, M., & Mfongang, A. (2023). Temperature Forecasting as a Means of Mitigating Climate Change and Its Effects: A Case Study of Mali. Trends in Renewable Energy, 9(2), 167-179. doi:http://dx.doi.org/10.17737/tre.2023.9.2.0015
Effects of Angstrom-Prescott and Hargreaves-Samani Coefficients on Climate Forcing and Solar PV Technology Selection in West Africa
Get PDFWe evaluated and compared the performance of simulated Angström-Prescott (AP) and Hargreaves-Samani (HS) models on monthly and annual timescales using generalized datasets covering the entire West African region. The fitted AP model yielded more efficient parameters of a = 0.366 and b = 0.459, whereas the HS model produced a 0.216 coefficient based on an annual timescale, which is more suitable in the region compared to coefficients recommended by the Food and Agriculture Organization (FAO) (a = 0.25 and b = 0.5) and HS (0.17), respectively. Employing the FAO and HS recommended coefficients will introduce a relative percentage error (RPE) of 18.388% and 27.19% compared to the RPEs of 0.0014% and 0.1036% obtained in this study, respectively. When considering time and resource availability in the absence of ground-measured datasets, the coefficients obtained in this study can be used for predicting global solar radiation within the region. According to the AP and HS coefficients, the polycrystalline module (p-Si) is more reliable than the monocrystalline module (m-Si) because the p-Si module has a higher tendency to withstand the high temperatures projected to affect the region due to its higher intrinsic properties based on the AP and HS coefficients assessment in the region.Citation: Agbor, M., Udo, S., Ewona, I., Nwokolo, S., Ogbulezie, J., Amadi, S., & Billy, U. (2023). Effects of Angstrom-Prescott and Hargreaves-Samani Coefficients on Climate Forcing and Solar PV Technology Selection in West Africa. Trends in Renewable Energy, 9(1), 78-106. doi:http://dx.doi.org/10.17737/tre.2023.9.1.0015
Africa's Path to Sustainability: Harnessing Technology, Policy, and Collaboration
Get PDFThis paper explores the significant role of technological advancements, strategic policies, and collaborations in driving Africa towards a more sustainable future. It highlights how the continent's increasing adoption of innovative technologies, such as renewable energy solutions and digital infrastructure, coupled with well-crafted strategic policies and international collaborations, is transforming various sectors and fostering a sustainable future. These advancements have not only improved access to basic services like healthcare and education but have also created new opportunities for economic growth and job creation. The paper emphasizes the importance of ongoing collaborations between African countries and international partners in sharing knowledge, expertise, and resources to accelerate sustainable development efforts across the continent. The paper discusses different international organizations that have collaborated with and assisted Africa in the areas of technical innovation, finance, and knowledge exchange necessary to achieve a full-scale sustainable future. Despite their humanitarian efforts, Africa faces tremendous hurdles in attaining a sustainable future. These challenges range from a lack of access to technology and digital infrastructure in rural areas to difficulties in harnessing technological advancements due to infrastructure and connectivity constraints. These challenges have hindered Africa's ability to fully leverage the potential of technical innovation and digital solutions for a sustainable future. Limited financial resources and investment opportunities have further impeded progress in achieving the necessary infrastructure and connectivity upgrades. The continent is vulnerable to the impacts of climate change, which further hinders its development progress. Therefore, it is crucial for ongoing collaborations between African countries and international partners to address these challenges collectively and work towards long-term solutions for a sustainable future in Africa.Citation: Nwokolo, S., Eyime, E., Obiwulu, A., & Ogbulezie, J. (2024). Africa's Path to Sustainability: Harnessing Technology, Policy, and Collaboration. Trends in Renewable Energy, 10(1), 98-131. doi:http://dx.doi.org/10.17737/tre.2024.10.1.0016
A Review of Research on Emission Characteristics of Ethanol-Diesel Blends in Diesel Engines
Get PDFThis paper reviews research on the emission characteristics of blended ethanol and other fuels. With the rapid development of modern industry, the extensive use of fuel engines has led to increasingly prominent contradictions between energy and the environment. In order to respond to sustainable development and reduce engine emissions in various countries, many scientific research institutions have conducted research on mixed fuels. The research of blended fuel mainly focuses on its sustainability, economy and environmental protection. Compared with gasoline engines, diesel engines have a lower fuel consumption rate and are widely used in heavy industry. But its fuel comes from refining crude oil, which is non-renewable and has poor cleanliness. As an emerging renewable fuel, ethanol is a fuel with good development prospects due to its good cleanliness, wide range of sources and renewable. If ethanol can be used as an alternative fuel for traditional internal combustion engines and diesel engines, it can save some traditional fuels and improve the emission problems of internal combustion engines to a certain extent. This paper introduces the research status of ethanol blended fuels, and the emission characteristics of engines (NOx, HC and CO) under different ethanol ratios and different operating conditions. It can be seen that with the increase of ethanol blending ratio, NOx content will increase, while CO and HC emissions will decrease.Citation: Chen, M. (2023). A Review of Research on Emission Characteristics of Ethanol-Diesel Blends in Diesel Engines. Trends in Renewable Energy, 9(2), 107-119. doi:http://dx.doi.org/10.17737/tre.2023.9.2.0015
Recent Studies on Alternative Fuel of Dimethyl Ether
Get PDFWith the development of industrialization, a large number of non-renewable fuels (such as coal and crude oil) are consumed, and the harmful substances produced in the combustion process of a large number of fossil fuels have caused serious pollution to the atmosphere, and the harmful gases produced by combustion have caused disastrous damage to the ecological balance. Therefore, finding clean energy and exploring alternative fuels are very important in today's society. This paper mainly reviews the studies on the alternative fuels of dimethyl ether (DME). Firstly, the types of alternative fuels currently researched by society and their respective advantages and disadvantages are analyzed, and the preparation of dimethyl ether and its advantages and disadvantages are analyzed in detail. In addition, the physicochemical properties, combustion and emission characteristics of dimethyl ether and diesel are compared and analyzed. The conclusion is that the injection delay angle of dimethyl ether is larger than that of diesel, the ignition delay period is shorter than that of diesel, and the maximum explosion pressure, maximum pressure rise rate and combustion noise of dimethyl ether are lower than that of diesel. The diffusion combustion speed of DME is faster than that of diesel, and the combustion duration is shorter than that of diesel. At the same time, as an alternative energy, dimethyl ether engine has a significant reduction in NOx emission, a very low level of HC and CO emission, and zero soot emission. In conclusion, the DME engine has good performance and emission characteristics.Citation: Zhang, J. (2022). Recent Studies on Alternative Fuel of Dimethyl Ether. Trends in Renewable Energy, 9(1), 1-10. doi:http://dx.doi.org/10.17737/tre.2023.9.1.0014
Study of hydrogen internal combustion engine vehicles based on the whole life cycle evaluation method
Get PDFIn order to better achieve the goal of low carbon emissions from vehicles, a whole life cycle assessment of hydrogen-fueled internal combustion engine vehicles has been conducted in recent years. Based on the study of hydrogen use around the world, we studied the emission and economic performance of hydrogen-fueled internal combustion engine vehicles from the beginning of hydrogen production to the end of use (Well-to-Wheel, WTW) based on the whole life cycle evaluation method. The results show that the overall environmental impact of hydrogen production by steam reforming of natural gas is the smallest, and that the rational use of "abandoned electricity" for hydrogen production from electrolytic water in the western part of China significantly reduces the overall environmental impact and the cost of hydrogen production. In the use phase, the emissions are less, which not only can meet the National 6 emission standard, but also can reach higher emission standard after adding exhaust gas recirculation (EGR). From the whole life cycle point of view, hydrogen-fueled internal combustion engine has a very good development prospect.Citation: Guo, P., Xu, J., Zhao, C., and Zhang, B. (2022). Study of hydrogen internal combustion engine vehicles based on the whole life cycle evaluation method. Trends in Renewable Energy, 8, 27-37. DOI: 10.17737/tre.2022.8.1.0013
Construction of Hydrogen Safety Evaluation Model Based on Analytic Hierarchy Process (AHP)
Get PDFWith the large consumption of traditional primary energy, hydrogen as a clean and renewable energy has been widely studied by scholars around the world. Hydrogen is mainly used in hydrogen internal combustion engine and hydrogen fuel cell. Hydrogen internal combustion engine is the direct combustion of hydrogen as fuel, with the advantages of easy use. Alternatively, hydrogen fuel cell converts the chemical energy of hydrogen into electrical energy by electrochemical reaction, which has the advantages of high efficiency and zero pollution. Regardless of the use method, the safety of hydrogen use needs to be considered. However, in the whole life cycle of hydrogen, the process from hydrogen production to the use of hydrogen in automobiles is extremely complex. There are many factors affecting the safety of hydrogen use, and a single factor cannot be used as an evaluation. In order to make the evaluation of hydrogen safety more complete and accurate, the weight of four primary evaluation indexes and eight secondary evaluation indexes affecting hydrogen safety is determined by analytic hierarchy process, and a reliable hydrogen safety evaluation model is established.Citation: Xu, J., Wang, M., and Guo, P. (2022). Construction of Hydrogen Safety Evaluation Model Based on Analytic Hierarchy Process (AHP). Trends in Renewable Energy, 8(2), 84-95. DOI: http://dx.doi.org/10.17737/tre.2022.8.2.0014
A Review of Engine Emissions Testing Methods for Environmental Sustainability
Get PDFWith the increase of vehicle ownership, vehicle emission pollution has become a major source of air pollution. The control of automobile pollutant emissions is one of the effective methods to reduce air pollution. Domestic and foreign exhaust pollutant testing methods for in-use vehicles have been gradually developed from the original idling method to the double-idling method and the simple working condition method. There are many methods to test the exhaust pollutants of in-use vehicles, but the test operation cycle, gas analysis principle, cost, application occasions and the accuracy level of various testing methods are different. This paper introduces the idling method, the working condition method and the on-board emission testing method for detecting vehicle emission pollutants. Two optimized methods for detecting automotive emission pollutants (namely the double-idle method and the simple transient working condition method) are also introduced.Citation: Wang, M. (2022). A Review of Engine Emissions Testing Methods for Environmental Sustainability. Trends in Renewable Energy, 8(2), 96-106. DOI: 10.17737/tre.2022.8.2.0014