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Energies, Volume 16, Issue 4 (February-2 2023) – 523 articles

Cover Story (view full-size image): There has been an increase in research studies on large-scale floating offshore wind turbine systems in recent years due to favorable factors such as highly stable generator power, which further enables applications in deeper waters and yields stable wind energy. This study entailed a load evaluation for the tower design of a large floating offshore wind turbine system according to wave conditions. In the correlation analysis, the tower-top deflection had the highest correlation, and this further affects nacelle acceleration. In the correlation between significant wave height and wave peak period and tower pitch moment, the wave peak period is more dominant than the significant wave height. In addition, the tower pitch moment is reduced even if the shape is changed to have the same mass, which shows the possibility of economical tower redesign. View this paper
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32 pages, 6254 KiB  
Review
Applications of Supercritical Water in Waste Treatment and Valorization: A Review
by Nadjiba Benmakhlouf, Nawel Outili, Belén García-Jarana, Jezabel Sánchez-Oneto, Juan R. Portela, Mejdi Jeguirim and Abdeslam-Hassen Meniai
Energies 2023, 16(4), 2081; https://doi.org/10.3390/en16042081 - 20 Feb 2023
Cited by 1 | Viewed by 2562
Abstract
The present review deals with water applications in sub and supercritical conditions with a focus on supercritical water oxidation process (SCWO) as an example of high temperature and pressure technologies. It starts by presenting the advantages of water properties near and beyond the [...] Read more.
The present review deals with water applications in sub and supercritical conditions with a focus on supercritical water oxidation process (SCWO) as an example of high temperature and pressure technologies. It starts by presenting the advantages of water properties near and beyond the critical point and the major applications exploiting them. Then, it presents a review on SCWO from the description of the process, the reaction mechanism and kinetics to reactor design and modeling. It also presents the main problems and difficulties that delay the SCWO industrial application, and summarizes the main efforts and research to overcome them for a safe, efficient and economic process. Full article
(This article belongs to the Section A4: Bio-Energy)
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31 pages, 800 KiB  
Article
Customised Multi-Energy Pricing: Model and Solutions
by Qiuyi Hong, Fanlin Meng and Jian Liu
Energies 2023, 16(4), 2080; https://doi.org/10.3390/en16042080 - 20 Feb 2023
Viewed by 1954
Abstract
With the increasing interdependence among energies (e.g., electricity, natural gas and heat) and the development of a decentralised energy system, a novel retail pricing scheme in the multi-energy market is demanded. Therefore, the problem of designing a customised multi-energy pricing scheme for energy [...] Read more.
With the increasing interdependence among energies (e.g., electricity, natural gas and heat) and the development of a decentralised energy system, a novel retail pricing scheme in the multi-energy market is demanded. Therefore, the problem of designing a customised multi-energy pricing scheme for energy retailers is investigated in this paper. In particular, the proposed pricing scheme is formulated as a bilevel optimisation problem. At the upper level, the energy retailer (leader) aims to maximise its profit. Microgrids (followers) equipped with energy converters, storage, renewable energy sources (RES) and demand response (DR) programs are located at the lower level and minimise their operational costs. Three hybrid algorithms combining metaheuristic algorithms (i.e., particle swarm optimisation (PSO), genetic algorithm (GA) and simulated annealing (SA)) with the mixed-integer linear program (MILP) are developed to solve the proposed bilevel problem. Numerical results verify the feasibility and effectiveness of the proposed model and solution algorithms. We find that GA outperforms other solution algorithms to obtain a higher retailer’s profit through comparison. In addition, the proposed customised pricing scheme could benefit the retailer’s profitability and net profit margin compared to the widely adopted uniform pricing scheme due to the reduction in the overall energy purchasing costs in the wholesale markets. Lastly, the negative correlations between the rated capacity and power of the energy storage and both retailer’s profit and the microgrid’s operational cost are illustrated. Full article
(This article belongs to the Special Issue Challenges and Research Trends of Computational Intelligence)
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17 pages, 4520 KiB  
Article
Research on Hierarchical Control Strategy of ESS in Distribution Based on GA-SVR Wind Power Forecasting
by Linlin Yu, Gaojun Meng, Giovanni Pau, Yao Wu and Yun Tang
Energies 2023, 16(4), 2079; https://doi.org/10.3390/en16042079 - 20 Feb 2023
Cited by 3 | Viewed by 1356
Abstract
In recent years, the world has been actively promoting the development of wind power, photovoltaic, and other new energy. The inherent randomness and intermittency of wind power output have led to the reduction of supply-side controllability and stability, and the power system is [...] Read more.
In recent years, the world has been actively promoting the development of wind power, photovoltaic, and other new energy. The inherent randomness and intermittency of wind power output have led to the reduction of supply-side controllability and stability, and the power system is facing severe challenges. Aiming at the irregular fluctuation of wind power output and the restriction between the charge and discharge depth and service life of hybrid energy storage equipment, a hierarchical control strategy for a hybrid energy storage system based on improved GA-SVR wind power prediction is proposed. First of all, the short-term prediction of wind power output is carried out using Support Vector Regression (SVR), and the improved genetic algorithm is used for optimization. Then, the result obtained from the prediction calculation is used as the wind power output, and the internal initial power of each energy storage element is obtained through the hybrid energy storage capacity configuration method and further controlled through hierarchical control regulation. Finally, a simulation experiment is carried out on the proposed control strategy. The simulation algorithm shows that the proposed method can not only enhance the effective output of new energy but also extend the service life of energy storage and ensure the safe and stable operation of the power system. Full article
(This article belongs to the Special Issue Volume II: Situation Awareness for Smart Distribution Systems)
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17 pages, 4157 KiB  
Article
Kernel Function-Based Inverting Algorithm for Structure Parameters of Horizontal Multilayer Soil
by Min-Jae Kang, Chang-Jin Boo, Byeong-Chan Han and Ho-Chan Kim
Energies 2023, 16(4), 2078; https://doi.org/10.3390/en16042078 - 20 Feb 2023
Viewed by 1061
Abstract
A multilayer soil structure model is fundamental to design grounding systems. A new method is presented to invert the structure parameters of horizontal multilayer soil. The structure parameters of soil are determined by analyzing the kernel function of the integral equation of the [...] Read more.
A multilayer soil structure model is fundamental to design grounding systems. A new method is presented to invert the structure parameters of horizontal multilayer soil. The structure parameters of soil are determined by analyzing the kernel function of the integral equation of the apparent resistivity. The essence of the proposed method avoids the difficulties encountered in general optimization methods; namely, the calculation of the apparent resistivity and its derivative. Full article
(This article belongs to the Section F1: Electrical Power System)
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29 pages, 3513 KiB  
Article
Forging Local Energy Transition in the Most Carbon-Intensive European Region of the Western Balkans
by Jasminka Young and Aleksandar Macura
Energies 2023, 16(4), 2077; https://doi.org/10.3390/en16042077 - 20 Feb 2023
Cited by 3 | Viewed by 1881
Abstract
To close an existing literature gap, we explore the conditions critical for the enactment of local energy transition and the shift to decarbonized renewable heating systems in the public sector of the most carbon-intensive European region of the Western Balkans. We select and [...] Read more.
To close an existing literature gap, we explore the conditions critical for the enactment of local energy transition and the shift to decarbonized renewable heating systems in the public sector of the most carbon-intensive European region of the Western Balkans. We select and then analyze the municipality of Priboj, which stands out among 150 municipalities in Serbia due to its effective promotion of local energy transition. The analysis provides a rich empirical illustration of a specific path that enables the local level to embark on a tailor-made energy transformation in an underdeveloped and path-dependent national policy framework. By linking a multi-level perspective of sustainability transitions to accounts of path dependency, we advance the understanding of the critical determinants and frameworks of local energy transition. Our analysis is enhanced with an investigation of the role of key actors and governance modes. A shared understanding of innovative solutions and existing local heating regime problems, and a shared vision of economically and environmentally viable opportunities based on available and unutilized local biomass, encouraged the local leaders to embark on a long and novel journey to decarbonize the local heating system. These observed factors coalesced with local political stability anchored in both the local- and national-level contexts. The effective coordination and cooperation across national- and local-level decision makers, financial institutions, and utilities was facilitated by a specific geographical and political context out of the reach of powerful gas network advocates. With these factors present, the synchronized entrepreneurial multi-level efforts served as the vehicles to develop and implement a shared vision of energy transition that became a learning platform for other regional actors. Full article
(This article belongs to the Section C: Energy Economics and Policy)
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27 pages, 3798 KiB  
Article
Electric Vehicle Charging Hub Power Forecasting: A Statistical and Machine Learning Based Approach
by Francesco Lo Franco, Mattia Ricco, Vincenzo Cirimele, Valerio Apicella, Benedetto Carambia and Gabriele Grandi
Energies 2023, 16(4), 2076; https://doi.org/10.3390/en16042076 - 20 Feb 2023
Cited by 2 | Viewed by 2280
Abstract
Electric vehicles (EVs) penetration growth is essential to reduce transportation-related local pollutants. Most countries are witnessing a rapid development of the necessary charging infrastructure and a consequent increase in EV energy demand. In this context, power demand forecasting is an essential tool for [...] Read more.
Electric vehicles (EVs) penetration growth is essential to reduce transportation-related local pollutants. Most countries are witnessing a rapid development of the necessary charging infrastructure and a consequent increase in EV energy demand. In this context, power demand forecasting is an essential tool for planning and integrating EV charging as much as possible with the electric grid, renewable sources, storage systems, and their management systems. However, this forecasting is still challenging due to several reasons: the still not statistically significant number of circulating EVs, the different users’ behavior based on the car parking scenario, the strong heterogeneity of both charging infrastructure and EV population, and the uncertainty about the initial state of charge (SOC) distribution at the beginning of the charge. This paper aims to provide a forecasting method that considers all the main factors that may affect each charging event. The users’ behavior in different urban scenarios is predicted through their statistical pattern. A similar approach is used to forecast the EV’s initial SOC. A machine learning approach is adopted to develop a battery-charging behavioral model that takes into account the different EV model charging profiles. The final algorithm combines the different approaches providing a forecasting of the power absorbed by each single charging session and the total power absorbed by charging hubs. The algorithm is applied to different parking scenarios and the results highlight the strong difference in power demand among the different analyzed cases. Full article
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19 pages, 3490 KiB  
Article
Value-Driven System Design of Utility-Scale Airborne Wind Energy
by Rishikesh Joshi, Michiel Kruijff and Roland Schmehl
Energies 2023, 16(4), 2075; https://doi.org/10.3390/en16042075 - 20 Feb 2023
Cited by 1 | Viewed by 1751
Abstract
In the current auction-based electricity market, the design of utility-scale renewable energy systems has traditionally been driven by the levelised cost of energy (LCoE). However, the market is gradually moving towards a subsidy-free era, which will expose the power plant owners to the [...] Read more.
In the current auction-based electricity market, the design of utility-scale renewable energy systems has traditionally been driven by the levelised cost of energy (LCoE). However, the market is gradually moving towards a subsidy-free era, which will expose the power plant owners to the fluctuating prices of electricity. This paper presents a computational approach to account for the influence of time-varying electricity prices on the design of airborne wind energy (AWE) systems. The framework combines an analytical performance model, providing the power curve of the system, with a wind resource characterisation based on ERA5 reanalysis data. The resulting annual energy production (AEP) model is coupled with a parametric cost model based on reference prototype data from Ampyx Power B.V. extended by scaling laws. Ultimately, an energy price model using real-life data from the ENTSO-E platform maintained by the association of EU transmission system operators was used to estimate the revenue profile. This framework was then used to compare the performance of systems based on multiple economic metrics within a chosen design space. The simulation results confirmed the expected behaviour that the electricity produced at lower wind speeds has a higher value than that produced at higher wind speeds. To account for this electricity price dependency on wind speeds in the design process, we propose an economic metric defined as the levelised profit of energy (LPoE). This approach determines the trade-offs between designing a system that minimises cost and designing a system that maximises value. Full article
(This article belongs to the Special Issue Airborne Wind Energy Systems)
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33 pages, 4640 KiB  
Review
Site Selection of Combined Offshore Wind and Wave Energy Farms: A Systematic Review
by Shabnam Hosseinzadeh, Amir Etemad-Shahidi and Rodney A. Stewart
Energies 2023, 16(4), 2074; https://doi.org/10.3390/en16042074 - 20 Feb 2023
Cited by 10 | Viewed by 2871
Abstract
Growing energy demand worldwide and onshore limitations have increased interest in offshore renewable energy exploitation. A combination of offshore renewable energy resources such as wind and wave energy can produce stable power output at a lower cost compared to a single energy source. [...] Read more.
Growing energy demand worldwide and onshore limitations have increased interest in offshore renewable energy exploitation. A combination of offshore renewable energy resources such as wind and wave energy can produce stable power output at a lower cost compared to a single energy source. Consequently, identifying the best locations for constructing combined offshore renewable energy farms is crucial. This paper investigates the technical, economic, social, and environmental aspects of Combined Offshore Wind and Wave Energy Farm (COWWEF) site selection. Past literature was evaluated using a systematic review method to synthesize, criticize, and categorize study regions, dataset characteristics, constraints, evaluation criteria, and methods used for the site selection procedure. The results showed that most studied regions belong to European countries, and numerical model outputs were mainly used in the literature as met-ocean data due to the limited coverage and low spatiotemporal resolution of buoy and satellite observations. Environmental and marine usage are the main constraints in the site selection process. Among all constraints, shipping lanes, marine protected areas, and military exercise areas were predominately considered to be excluded from the potential sites for COWWEF development. The technical viability and economic feasibility of project deployment are emphasized in the literature. Resource assessment and distance to infrastructures were mostly evaluated among techno-economic criteria. Wind and wave energy power are the most important criteria for evaluating feasibility, followed by water depth, indicators of variability and correlation of the energy resources, and distance to the nearest port. Multi-Criteria Decision-Making (MCDM) methods and resource-based analysis were the most-used evaluation frameworks. Resource-based studies mainly used met-ocean datasets to determine site technical and operational performance (i.e., resource availability, variability, and correlation), while MCDM methods were applied when a broader set of criteria were evaluated. Based on the conducted review, it was found that the literature lacks evaluation of seabed conditions (seabed type and slope) and consideration of uncertainty involved in the COWWEF site selection process. In addition, the market analysis and evaluation of environmental impacts of COWWEF development, as well as impacts of climate change on combined exploitation of offshore wind and wave energy, have rarely been investigated and need to be considered in future studies. Finally, by providing a comprehensive repository of synthesized and categorized information and research gaps, this study represents a road map for decision-makers to determine the most suitable locations for COWWEF developments. Full article
(This article belongs to the Special Issue Wind and Wave Energy Resource Assessment and Combined Utilization)
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12 pages, 2475 KiB  
Article
Examination of the Structure and Definition of the Mechanism of Formation of Products by Pyrolysis of Tarim Crude Oil
by Yue Ma, Fan Shao, Jing Wang, Han Yang and Changtao Yue
Energies 2023, 16(4), 2073; https://doi.org/10.3390/en16042073 - 20 Feb 2023
Cited by 1 | Viewed by 1327
Abstract
Pyrolysis of crude oil is an important way to generate natural gas. However, the current analysis of pyrolysis gas carbon isotopes and the study of gas generation dynamics are not unified, and the genesis and accumulation of gas reservoirs are needed to conduct [...] Read more.
Pyrolysis of crude oil is an important way to generate natural gas. However, the current analysis of pyrolysis gas carbon isotopes and the study of gas generation dynamics are not unified, and the genesis and accumulation of gas reservoirs are needed to conduct in-depth discussions. Therefore, Tarim crude oil samples in China were selected to perform thermal simulation experiments using an autoclave. The pyrolysis hydrocarbon production yield, carbon isotope characteristics and gas-generation process of crude oil samples in Tarim Basin were studied by GC-MS, FT-IR and carbon isotope analysis, respectively. The compositions of the Tarim Oilfield were determined, including the 83.69% content of hydrocarbons, the 14.08% content of aromatic compounds, and lower than 3% content of heteroatom compounds. The non-monotonic linear relationship of C2-5 isotopes may be due to the complexity of crude oil, and the formation of gaseous hydrocarbons can be divided into three stages. The results showed that the δ13C distribution range of C2-5 hydrocarbons was −40.5% to −10.5%, and the δ13C distribution of methane was −53.3% to −27.4%. The lowest δ13C value for methane occurs at 350 °C, and the corresponding carbon isotope value is −53.3%. When the pyrolysis temperature range is 250–300 °C, crude oil undergoes volatilization and preliminary pyrolysis, and the C4-5 output exceeds 95%. When the temperature rises to 300–500 °C, the aliphatic hydrocarbon chain in crude oil begins to crack, the side and branch chains of aromatic and heteroatomic compounds are broken, and C4-5 begins to crack to form C1-3. Finally, the temperature rises to 500–600 °C, and C3-5 begins to deeply crack into C1-2, and eventually all is converted to methane. Full article
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27 pages, 5368 KiB  
Article
Development and Upstream Integration of the Photovoltaic Industry Value Chain in Mexico
by Mariano O. Birlain-Escalante, Jorge M. Islas-Samperio, Ángel de la Vega-Navarro and Arturo Morales-Acevedo
Energies 2023, 16(4), 2072; https://doi.org/10.3390/en16042072 - 20 Feb 2023
Viewed by 2334
Abstract
Several countries are focusing their efforts on diversifying electricity generation to promote the transition towards a sustainable low-carbon energy system through the strategic development of the value chains related to renewable energy industries. In this way, the development of a national industry that [...] Read more.
Several countries are focusing their efforts on diversifying electricity generation to promote the transition towards a sustainable low-carbon energy system through the strategic development of the value chains related to renewable energy industries. In this way, the development of a national industry that helps to ensure a clean and affordable electricity supply and that also generates important socio-economic benefits, has gained relevance worldwide. This article proposes a methodology and economic model that considers technological progress and economies of scale to analyze a potential upstream development and integration of the value chain of the photovoltaic industry in Mexico. The results show that the upstream development of a national photovoltaic industry is financially viable and sustainable, and with which the national demand for photovoltaic technology could be satisfied by 76% and imports reduced by 47%, both compared to a reference scenario. This enables the generation of more than 447,000 jobs and an added value of more than 12,000 M USD. This would increase the national value content to 89% by 2040 and contribute to the national goal of generating 35% of its electricity through clean energy technologies, fulfilling the commitment established in its nationally determined contributions. Furthermore, it would enable the transition towards a sustainable energy future in Mexico. Full article
(This article belongs to the Section A2: Solar Energy and Photovoltaic Systems)
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17 pages, 6668 KiB  
Article
Transient Hydrodynamic Behavior of a Pump as Turbine with Varying Rotating Speed
by Jianxin Hu, Wenfeng Su, Ke Li, Kexin Wu, Ling Xue and Guolei He
Energies 2023, 16(4), 2071; https://doi.org/10.3390/en16042071 - 20 Feb 2023
Cited by 5 | Viewed by 1483
Abstract
The working condition of a centrifugal pump as a turbine (PAT) is often unsteady. The rotating speed of a PAT constantly varies as the flow and load change, resulting in transient hydrodynamic behaviors between different working conditions. During the transition, the PAT undergoes [...] Read more.
The working condition of a centrifugal pump as a turbine (PAT) is often unsteady. The rotating speed of a PAT constantly varies as the flow and load change, resulting in transient hydrodynamic behaviors between different working conditions. During the transition, the PAT undergoes a severe change in performance and complicated internal flow structures. In previous work, the fixed rotating speed of a PAT was mostly considered using computational fluid dynamics. To investigate the transient behavior of a PAT, relevant simulation tools are developed to depict transient flow conditions, and the corresponding transient speed of the impeller is calculated. Both large and small fluctuation transitions are simulated for the practical application of the PAT. The simulated results are first verified by experiments. The results show that the rotating speed significantly affects the performance and stability of the PAT. The rapid increment in flow rate and rotating speed lead to large energy dissipation in the internal flow field of the PAT. The range of high efficiency of the PAT expands and migrates to the high flow rate range. The efficiency in the transition condition started a cyclic growth after the flow reached 60 m3/h, and it reached a peak at around 80 m3/h, which was about 5% lower than the calculated value in a quasi-steady state. In the range of high rotating speeds, the rotating speed of the impeller and the operational stability are sensitive to flow fluctuation. The internal flow fields during transition conditions are analyzed as well. The obtained results can be utilized as a reference for studying the hydrodynamic characteristics and stability of fluid machinery in the transition under transient flow conditions. Full article
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16 pages, 5797 KiB  
Article
Simulation and Protection of Reignition Overvoltage in Wind Farm Considering Microscopic Dielectric Recovery Process of Vacuum Circuit Breaker
by Ziheng Pu, Hao Liu, Yaoqiang Wang, Xinyun Yu and Tian Wu
Energies 2023, 16(4), 2070; https://doi.org/10.3390/en16042070 - 20 Feb 2023
Cited by 4 | Viewed by 1442
Abstract
The high amplitude and steep overvoltage generated by the breaking of the vacuum circuit breaker in the wind farm damages the inter-turn insulation of the transformer. There is a certain difference between the simulation results of the traditional reignition model and the measured [...] Read more.
The high amplitude and steep overvoltage generated by the breaking of the vacuum circuit breaker in the wind farm damages the inter-turn insulation of the transformer. There is a certain difference between the simulation results of the traditional reignition model and the measured overvoltage. It is necessary to improve the simulation model to simulate the overvoltage condition of the transformer more accurately and then select appropriate overvoltage protection measures. In this paper, based on the physical process of dielectric recovery during the opening process of the vacuum circuit breaker, a model of dielectric strength recovery is built to simulate the arc reignition of the vacuum circuit breaker. The model was applied to compare the overvoltage protection effects of RC snubbers, surge arresters, and choke coils. The simulation results show that the overvoltage amplitude and reignition times calculated by the model proposed in this paper are closer to the measured values. Compared with the traditional linear curve reignition model, the accuracy was increased by 24% and 51.2%, respectively. The parameter value of RC snubbers, the connection mode of surge arresters, and the combination mode of choke coil have an influence on overvoltage suppression. Finally, a suitable suppression scheme is proposed by installing a combined arrester on the high-voltage side of the transformer and connecting a choke coil in series, which can limit the phase-to-ground voltage and the phase-to-phase voltage to 2.43 p.u and 3.24 p.u, respectively, and reduce the steepness from 157.2 kV/μs to 22.3 kV/μs. Full article
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27 pages, 21380 KiB  
Article
Design and Integration of the EU-DEMO Water-Cooled Lead Lithium Breeding Blanket
by Pietro Arena, Gaetano Bongiovì, Ilenia Catanzaro, Cristiano Ciurluini, Aldo Collaku, Alessandro Del Nevo, Pietro Alessandro Di Maio, Matteo D’Onorio, Fabio Giannetti, Vito Imbriani, Pietro Maccari, Lorenzo Melchiorri, Fabio Moro, Rocco Mozzillo, Simone Noce, Laura Savoldi, Simone Siriano, Alessandro Tassone and Marco Utili
Energies 2023, 16(4), 2069; https://doi.org/10.3390/en16042069 - 20 Feb 2023
Cited by 8 | Viewed by 1707
Abstract
The water-cooled lead lithium breeding blanket (WCLL BB) is one of two BB candidate concepts to be chosen as the driver blanket of the EU-DEMO fusion reactor. Research activities carried out in the past decade, under the umbrella of the EUROfusion consortium, have [...] Read more.
The water-cooled lead lithium breeding blanket (WCLL BB) is one of two BB candidate concepts to be chosen as the driver blanket of the EU-DEMO fusion reactor. Research activities carried out in the past decade, under the umbrella of the EUROfusion consortium, have allowed a quite advanced reactor architecture to be achieved. Moreover, significant efforts have been made in order to develop the WCLL BB pre-conceptual design following a holistic approach, identifying interfaces between components and systems while respecting a system engineering approach. This paper reports a description of the current WCLL BB architecture, focusing on the latest modifications in the BB reference layout aimed at evolving the design from its pre-conceptual version into a robust conceptual layout. In particular, the main rationale behind design choices and the BB’s overall performances are highlighted. The present paper also gives an overview of the integration between the BB and the different in-vessel systems interacting with it. In particular, interfaces with the tritium extraction and removal (TER) system and the primary heat transfer system (PHTS) are described. Attention is also paid to auxiliary systems devoted to heat the plasma, such as electron cyclotron heating (ECH). Indeed, the integration of this system in the BB will strongly impact the segment design since it envisages the introduction of significant cut-outs in the BB layout. A preliminary CAD model of the central outboard blanket (COB) segment housing the ECH cut-out has been set up and is reported in this paper. The chosen modeling strategy, adopted loads and boundary conditions, as well as obtained results, are reported in the paper and critically discussed. Full article
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10 pages, 787 KiB  
Article
Speed of Sound Measurements of Biogas from a Landfill Biomethanation Process
by José Juan Segovia, Alejandro Moreau, Xavier Paredes, Teresa E. Fernández-Vicente, David Vega-Maza and María Carmen Martín
Energies 2023, 16(4), 2068; https://doi.org/10.3390/en16042068 - 20 Feb 2023
Viewed by 1122
Abstract
Biogas is drawing attention as it can be a solution both to increase the renewable energy for heat or power supply and to help achieve a decarbonized economy. In this work, the measurements of the speed of sound of three mixtures of biogas [...] Read more.
Biogas is drawing attention as it can be a solution both to increase the renewable energy for heat or power supply and to help achieve a decarbonized economy. In this work, the measurements of the speed of sound of three mixtures of biogas from the biomethanation plant of the municipal waste of Valdemingómez, Madrid (Spain), are presented. The measurements were performed using an acoustic resonator, which is able to measure the speed of sound of gas mixtures with a relative expanded uncertainty of approximately 0.08%. A virial-type equation was also applied to fit the experimental values of the speed of sound, and the heat capacities as perfect gas were derived with uncertainties below 0.8%. In addition, the experimental results were compared with those calculated with the reference equations of state for natural gas mixtures such as GERG-2008 and AGA8-DC92. For both equations, the average relative deviations were less than 0.02% and 0.2% for the speed of sound and the heat capacities, respectively. These values are less than the uncertainties of these equations, demonstrating their reliability in predicting the thermodynamic behavior of biogas. Full article
(This article belongs to the Special Issue Thermodynamics for Net-Zero Energy Systems)
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28 pages, 14220 KiB  
Article
An Unmanned Helicopter Energy Consumption Analysis
by Marcin Żugaj, Mohammed Edawdi, Grzegorz Iwański, Sebastian Topczewski, Przemysław Bibik and Piotr Fabiański
Energies 2023, 16(4), 2067; https://doi.org/10.3390/en16042067 - 20 Feb 2023
Cited by 1 | Viewed by 1996
Abstract
The number of operations incorporating E-VTOL aircrafts is increasing each year, and the optimization of the energy consumption of such vehicles is a major problem. In this paper, a small-scale ARCHER helicopter’s energy consumption is analyzed, wherein different flight conditions, main rotor revolutions, [...] Read more.
The number of operations incorporating E-VTOL aircrafts is increasing each year, and the optimization of the energy consumption of such vehicles is a major problem. In this paper, a small-scale ARCHER helicopter’s energy consumption is analyzed, wherein different flight conditions, main rotor revolutions, and flight control system settings are considered. The helicopter dynamic model was developed in the FLIGHTLAB environment and was then validated based on flight test data. The model used for the calculation of energy consumption was developed using the electric and dynamic characteristics of the main rotor, electric motor, and transmission system. The main part of this work concerns the analysis of electric energy consumption during the vehicle’s flight via the use of an automatic flight control system (AFCS) that ensures repeatable flight conditions. The AFCS was designed such that it includes both path and attitude control to provide hover and cruise control modes. The helicopter’s energy consumption was analyzed during different phases of flight, when executing maneuvers, and using different main rotor angular velocities to perform - a given task. The results show that the level of energy consumption significantly depends on the helicopter’s main rotor revolutions, flight speed, and the maneuvers performed. The proposed methodology can be used in prospective energy-efficient mission planning and UAV helicopter design. Full article
(This article belongs to the Special Issue Modeling for Energy Consumption Analysis)
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25 pages, 6011 KiB  
Review
Application of Biogas and Biomethane as Maritime Fuels: A Review of Research, Technology Development, Innovation Proposals, and Market Potentials
by George Mallouppas, Elias Ar. Yfantis, Constantina Ioannou, Andreas Paradeisiotis and Angelos Ktoris
Energies 2023, 16(4), 2066; https://doi.org/10.3390/en16042066 - 20 Feb 2023
Cited by 5 | Viewed by 6332
Abstract
This review paper examines the applicability of biogas and biomethane as potential maritime fuels and examines issues of these fuels from a supply chain perspective (from production to end use). The objectives are to identify: (1) the latest research, development, and innovation activities; [...] Read more.
This review paper examines the applicability of biogas and biomethane as potential maritime fuels and examines issues of these fuels from a supply chain perspective (from production to end use). The objectives are to identify: (1) the latest research, development, and innovation activities; (2) issues and key barriers related to the technology readiness to bring biogas/biomethane to market; and (3) commercialisation issues, including cost parity with natural gas (the main competitor). A survey of the literature was carried out based on research articles and grey literature. The PESTEL and SWOT analyses identified opportunities for these fuels due to the relevant regulations (e.g., Fit for 55; the recent inclusion of the Mediterranean Sea as a SECA and PM control area; MPEC 79), market-based measures, and environmental, social, and governance strategies. The potential of biomass feedstock is estimated to have a substantial value that can satisfy the energy needs of the maritime industry. However, production costs of biomethane are high; estimated to be 2–4 times higher compared to natural gas. The market is moving in the direction of alternative drop-in fuels, including liquefied and compressed biomethane (LBM and CBM) and biogas. In terms of potential market penetration, LBM can be used as a marine drop-in fuel for the existing fleet that already combust LNG and LPG due to similar handling. Currently, these vessels are LNG and LPG tankers. However, in newly built vessels, LBM can be also supplied to container ships, vehicle carriers, and bulk carriers (about 20% of newly built vessels). Provided that compressed natural gas infrastructure exists, CBM can be exploited in vessels with low energy needs and low space requirements and shore-side electrification, because investments in retrofits are lower compared to constructing new infrastructure. Full article
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27 pages, 11382 KiB  
Article
Comparative Performance Evaluation of Gas Brayton Cycle for Micro–Nuclear Reactors
by Sungwook Choi, In Woo Son and Jeong Ik Lee
Energies 2023, 16(4), 2065; https://doi.org/10.3390/en16042065 - 20 Feb 2023
Viewed by 1714
Abstract
Gas Brayton cycles have been considered the next promising power cycles for microreactors. Especially the open-air and closed supercritical CO2 (S-CO2) Brayton cycles have received attention due to their high thermal efficiency and compact component sizes when compared to the [...] Read more.
Gas Brayton cycles have been considered the next promising power cycles for microreactors. Especially the open-air and closed supercritical CO2 (S-CO2) Brayton cycles have received attention due to their high thermal efficiency and compact component sizes when compared to the steam Rankine cycle. In this research, the performances of the open-air and closed S-CO2 Brayton cycle at microreactor power range are compared with polytropic turbomachinery efficiency. When optimizing the cycle, three different optimization parameters are considered in this paper: maximum efficiency, maximum cycle specific work, and maximum of the product of both indicators. For the air Brayton cycle, the maximum of the product of both indicators allows to consider both efficiency and specific work while optimizing the cycle. However, for the S-CO2 Brayton cycle, the best performing conditions follow either maximum efficiency or the maximum cycle specific work conditions. In general, the S-CO2 power cycle should be designed and optimized to maximize the cycle specific work for commercial-scale application. The results show that the air Brayton cycle can achieve near 45% efficiency when it can couple with a microreactor with a core outlet temperature higher than 700 °C. However, the S-CO2 power cycle can still achieve above 30% efficiency when it is coupled with a microreactor with a core outlet temperature higher than 500 °C, whereas the air Brayton cycle cannot even reach breakeven condition. Full article
(This article belongs to the Special Issue New Challenges in Nuclear Energy Systems)
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18 pages, 4419 KiB  
Article
Coal Gangue Classification Based on the Feature Extraction of the Volume Visual Perception ExM-SVM
by Murad S. Alfarzaeai, Eryi Hu, Wang Peng, Niu Qiang and Maged M. A. Alkainaeai
Energies 2023, 16(4), 2064; https://doi.org/10.3390/en16042064 - 20 Feb 2023
Cited by 2 | Viewed by 1456
Abstract
Computer-vision-based separation methods for coal gangue face challenges due to the harsh environmental conditions in the mines, leading to the reduction of separation accuracy. So, rather than purely depending on the image features to distinguish the coal gangue, it is meaningful to utilize [...] Read more.
Computer-vision-based separation methods for coal gangue face challenges due to the harsh environmental conditions in the mines, leading to the reduction of separation accuracy. So, rather than purely depending on the image features to distinguish the coal gangue, it is meaningful to utilize fixed coal characteristics like density. This study achieves the classification of coal and gangue based on their mass, volume, and weight. A dataset of volume, weight and 3_side images is collected. By using 3_side images of coal gangue, the visual perception value of the volume is extracted (ExM) to represent the volume of the object. A Support Vector Machine (SVM) classifier receives (ExM) and the weight to perform the coal gangue classification. The proposed system eliminates computer vision problems like light intensity, dust, and heterogeneous coal sources. The proposed model was tested with a collected dataset and achieved high recognition accuracy (KNN 100%, Linear SVM 100%, RBF SVM 100%, Gaussian Process 100%, Decision Tree 98%, Random Forest 100%, MLP 100%, AdaBosst 100%, Naive Bayes 98%, and QDA 99%). A cross-validation test has been done to verify the generalization ability. The results also demonstrate high classification accuracy (KNN 96%, Linear SVM 100%, RBF SVM 96%, Gaussian Process 96%, Decision Tree 99%, Random Forest 99%, MLP 100%, AdaBosst 99%, Naive Bayes 99%, and QDA 99%). The results show the high ability of the proposed technique ExM-SVM in coal gangue classification tasks. Full article
(This article belongs to the Special Issue Intelligent Coal Mining Technology)
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23 pages, 6669 KiB  
Review
Energy Efficiency of Tall Buildings: A Global Snapshot of Innovative Design
by Mir M. Ali, Kheir Al-Kodmany and Paul J. Armstrong
Energies 2023, 16(4), 2063; https://doi.org/10.3390/en16042063 - 20 Feb 2023
Cited by 1 | Viewed by 5640
Abstract
Design priorities for tall and supertall buildings have for some time shifted to achieving more energy efficiency to address the energy needs of the increasing global population. Engineers and architects aim to achieve energy conservation through active and passive approaches, pursuing technological innovations [...] Read more.
Design priorities for tall and supertall buildings have for some time shifted to achieving more energy efficiency to address the energy needs of the increasing global population. Engineers and architects aim to achieve energy conservation through active and passive approaches, pursuing technological innovations and adopting climate-responsive design. Because of the green movement currently dominating the building industry, tall buildings that need a massive amount of energy to build and operate, and the practical desire to switch from non-renewable to clean renewable energy resources, intense attention has been given to the energy efficiency of tall buildings in the recent past. Due to the vast array of energy-efficient design features, equipment, and applications available now, it is timely to examine the pros and cons of these issues. This review paper is an attempt to comprehensively present and deliberate these issues. It illustrates and discusses the concepts and applications through a few case studies from several continents worldwide. The review shows that the design of tall buildings focusing on energy conservation is an evolutionary process and there is a need for further research about how to face the associated challenges to improve energy efficiency by developing creative solutions and strategies, as well as applying additional innovative technologies. Full article
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29 pages, 6357 KiB  
Article
Energetic, Economic and Environmental (3E) Analysis of a RES-Waste Gasification Plant with Syngas Storage Cooperation
by Jacek Roman, Robert Wróblewski, Beata Klojzy-Karczmarczyk and Bartosz Ceran
Energies 2023, 16(4), 2062; https://doi.org/10.3390/en16042062 - 20 Feb 2023
Cited by 2 | Viewed by 1578
Abstract
Today, the increasing amount of waste is a growing ecological and financial problem. Another issue is the need to limit the share of controllable sources powered by fossil fuels. A hybrid generation system (HGS) is proposed to solve both problems. The system consists [...] Read more.
Today, the increasing amount of waste is a growing ecological and financial problem. Another issue is the need to limit the share of controllable sources powered by fossil fuels. A hybrid generation system (HGS) is proposed to solve both problems. The system consists of renewable energy sources (RES) and a waste gasification system. Contrary to many papers, it is proposed to include syngas storage and use gas turbines as balancing sources. The HGS was modeled, and electricity generation, capacity factors, and efficiencies were calculated. The economic (LCOE and PP) and environmental parameters (CO2 emission and reduction) were analyzed and calculated for different RES capacities. The results show that the proposed HGS covered 45.7–80% of municipal demand. The HGS was characterized by high CO2 emissions, due to the low efficiency of gasification-gas turbine installation and the need to compress syngas. However, the HGS can be environmentally beneficial due to the reduction in waste disposal in landfills. The LCOE was EUR 174–191 with a minimum at the RES capacity of 14 MW. Any change in waste disposal costs and emission allowances would cause significant changes in the LCOE. It was found that it can be beneficial to use a gasification system as a balancing source in a HGS. Full article
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16 pages, 4226 KiB  
Article
The Experimental Study of an R744 Heat Pump System for an Electric Vehicle for Cabin Cooling or Heating and Battery Fast Charging Cooling
by Xilong Wang, Keke Xu, Linjie Huang, Feng Cao and Yulong Song
Energies 2023, 16(4), 2061; https://doi.org/10.3390/en16042061 - 20 Feb 2023
Cited by 2 | Viewed by 2523
Abstract
In this paper, a new R744 heat pump system is studied. The gas cooler, evaporator, indoor heat core, and indoor gas cooler are all micro-channel heat exchangers. The R744 high pressure system adopts a combination of an accumulator and internal heat exchanger (ACCU/IHX). [...] Read more.
In this paper, a new R744 heat pump system is studied. The gas cooler, evaporator, indoor heat core, and indoor gas cooler are all micro-channel heat exchangers. The R744 high pressure system adopts a combination of an accumulator and internal heat exchanger (ACCU/IHX). In addition, an electronic reversible regulating valve is added before the outdoor gas cooler, making the outdoor heat exchanger able to be used as a gas cooler or evaporator. The water-cooled condenser can improve the performance in the cooling or heating mode. The research contents contain the performance and optimal pressure under extreme conditions as a result of the experiments. The results show that the cooling capacity can reach 8.2 kW with a COP of 1.87, under a 40 °C external circulation intake. The cooling capacity on the battery side can reach 11 kW under an ambient temperature of 40 °C, which can provide a sufficient cooling capacity. Under an ambient temperature of −20 °C, the maximum heating capacity can reach 6.86 kW with a COP of 1.67. Under an ambient temperature of −15 °C, the heating capacity reaches 5.07 kW with a COP of 1.78, when the indoor air volume flow rate is 200 m3/h. Obviously, R744 heat pumps show a huge advantage, compared with the traditional PTC heating or R134a heat pumps at extremely low temperatures. Full article
(This article belongs to the Special Issue Current Status on the Thermal Management of Electric Vehicles)
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14 pages, 1211 KiB  
Article
Inverter-Less Integration of Roof-Top Solar PV with Grid Connected Industrial Drives
by M. Ryyan Khan, Intekhab Alam and M. Rezwan Khan
Energies 2023, 16(4), 2060; https://doi.org/10.3390/en16042060 - 20 Feb 2023
Cited by 2 | Viewed by 2116
Abstract
Green energy from Solar PV is getting increased attention in the industries due to the falling price of solar panels in the world market. A grid-tied inverter is one of the major components in such a system, where the DC energy from PV [...] Read more.
Green energy from Solar PV is getting increased attention in the industries due to the falling price of solar panels in the world market. A grid-tied inverter is one of the major components in such a system, where the DC energy from PV is converted to AC and synchronized with the grid to obtain power sharing between the PV and the grid for the industrial drives. In this paper, a DC link has been proposed instead of an AC link for interconnection between the solar PV system and the grid to run those industrial drives. In most modern industrial applications, induction motors are driven by VVVF (Variable Voltage and Variable Frequency) inverters to achieve efficient speed control. The inverters commonly have a rectifier section at the front end that rectifies the input AC to DC and the DC is then used in PWM mode to generate the required voltage and frequency for the induction motor operating under variable speed and load conditions. Such an inverter can use both AC or DC as the input so long the supply voltage has the right value for the inverter to operate. In our proposition, we eliminate the grid-tied inverter and use a DC link, created from the rectified AC and the regular Solar PV, to obtain the power-sharing between the PV output and the grid. Using the DC link output directly to energize the VVVF inverter has an impact on the performance of the inverter. In the proposed system, the solar PV array is designed in such a way that the grid remains as the supplementary power source only to supplement any shortfall in the PV output due to variable sunshine conditions. The control circuit used in this novel technique is inexpensive, efficient, and simple in design when compared to the grid-tied inverters. The proposed system has been implemented at Niagara Textiles in Gazipur, Bangladesh. The experimental/practical results are presented to validate the basic concept. Around a 20% reduction in the cost of energy has been reported in this paper, with a more than 90% efficient system. This will definitely make solar PV energy more competitive with regular energy and attractive to industries for its simplicity. Full article
(This article belongs to the Topic Advanced Energy Harvesting Technology)
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16 pages, 3652 KiB  
Article
The Collaborative Optimization of the Discharge Pressure and Heat Recovery Rate in a Transcritical CO2 Heat Pump Used in Extremely Low Temperature Environment
by Zhongkai Wu, Feifei Bi, Jiyou Fei, Zecan Zheng, Yulong Song and Feng Cao
Energies 2023, 16(4), 2059; https://doi.org/10.3390/en16042059 - 20 Feb 2023
Cited by 1 | Viewed by 1112
Abstract
Considering the excellent environmental properties and heating capability under wide running conditions of the natural fluid CO2, the transcritical CO2 heat pump system has widely been used in the application of water heaters, commercial heating and cooling, electric vehicle thermal [...] Read more.
Considering the excellent environmental properties and heating capability under wide running conditions of the natural fluid CO2, the transcritical CO2 heat pump system has widely been used in the application of water heaters, commercial heating and cooling, electric vehicle thermal management, etc. Since the performance was highly affected by the discharge pressure and heat recovery rate in a transcritical CO2 system, the collaborative optimization of these two parameters was analyzed in detail in this study. The results showed that the optimal value of the system heating COP, which was the ration of heating capacity to power consumption, was better under a higher heat recovery rate and relatively lower discharge pressure, which is why these kinds of operating conditions are highly recommended from the perspective of collaborative optimization. Additionally, the heat recovery rate had a positive effect on the system performance when the discharge pressure was lower than its optimal value, while the heat recovery rate would present a passive effect on the system performance when the discharge pressure was higher than its optimal value. The relevant conclusions of this study provide a good theoretical basis for the efficient and stable operation of the transcritical CO2 heat pump technology under the conditions of a wide ambient temperature range. Full article
(This article belongs to the Special Issue Current Status on the Thermal Management of Electric Vehicles)
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24 pages, 5320 KiB  
Review
The Use of Plants from the Lemnaceae Family for Biofuel Production—A Bibliometric and In-Depth Content Analysis
by Małgorzata Krzywonos, Zdzisława Romanowska-Duda, Przemysław Seruga, Beata Messyasz and Stanisław Mec
Energies 2023, 16(4), 2058; https://doi.org/10.3390/en16042058 - 20 Feb 2023
Cited by 2 | Viewed by 2328
Abstract
Plants of the Lemnaceae family are becoming increasingly popular among researchers. The goal of the study was to characterize trends in scientific research related to the use of aquatic plants from the Lemnaceae family for energy purposes, especially for the production of biogas, [...] Read more.
Plants of the Lemnaceae family are becoming increasingly popular among researchers. The goal of the study was to characterize trends in scientific research related to the use of aquatic plants from the Lemnaceae family for energy purposes, especially for the production of biogas, bioethanol, and other biofuels. These plants fit perfectly into the concept of a circular economy. This study performed a bibliometric and in-depth content analysis to review the use of plants from the Lemnaceae family for biofuel production. A set of 666 articles published from 2008 to 2022 was identified from the Scopus and Web of Science databases. Different analytical scientometric tools (topic mapping and overlay visualization networks) were used to analyze 141 articles; the most influential countries, institutions, authors, journals, and articles were identified. Depth content analysis reveals five research areas: (i) development of duckweed growth and starch accumulation; (ii) development of the pretreatment techniques; (iii) development of ethanol fermentation; (iv) hydrothermal liquefaction and bio-oil production; and (v) anaerobic digestion and biogas production. Full article
(This article belongs to the Special Issue Sustainable and Circular Systems for Biofuel Production and Usage)
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28 pages, 6622 KiB  
Review
Current Trends in Electric Vehicle Charging Infrastructure; Opportunities and Challenges in Wireless Charging Integration
by Konstantina Dimitriadou, Nick Rigogiannis, Symeon Fountoukidis, Faidra Kotarela, Anastasios Kyritsis and Nick Papanikolaou
Energies 2023, 16(4), 2057; https://doi.org/10.3390/en16042057 - 20 Feb 2023
Cited by 19 | Viewed by 15301
Abstract
Nowadays, the imperative need for the reduction of Greenhouse Gas (GHG) emissions leads to the wider adoption of environmentally friendly transportation means. As a result, various policies underpinning the Electric Vehicle (EV) deployment are legislated globally, and several technical advances contributing to the [...] Read more.
Nowadays, the imperative need for the reduction of Greenhouse Gas (GHG) emissions leads to the wider adoption of environmentally friendly transportation means. As a result, various policies underpinning the Electric Vehicle (EV) deployment are legislated globally, and several technical advances contributing to the electrification of the transportation sector are pursued. In this paper, a comprehensive overview of the current status of the infrastructure utilized for the realization of both conductive and contactless (wireless) charging of an EV battery is conducted. Furthermore, the issue of EV integration in conventional distribution networks, as well as in future power system architectures, is discussed in detail. Particular focus is given to wireless (i.e., inductive) charging. A detailed presentation of the respective standards and charging levels, as well as the magnetic couplers and the compensation network configurations, is carried out. Moreover, innovative concepts such as dynamic and quasi-dynamic wireless charging, as well as future challenges and opportunities, are presented and discussed. Finally, smart control and communication techniques applicable to EV charging are presented in the context of the future Internet of Energy (IoE) concept. Full article
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13 pages, 439 KiB  
Article
Media Coverage of Carbon Capture and Storage: An Analysis of Established and Emerging Themes in Dutch National Newspapers
by Emma ter Mors, Esther van Leeuwen, Christine Boomsma and Renate Meier
Energies 2023, 16(4), 2056; https://doi.org/10.3390/en16042056 - 20 Feb 2023
Cited by 2 | Viewed by 1946
Abstract
Policymakers in several European countries are considering the implementation of carbon capture and storage (CCS) technology as part of a strategy to prevent further climate change. Successful CCS implementation requires societal support but planned CCS projects have encountered significant opposition. In this study, [...] Read more.
Policymakers in several European countries are considering the implementation of carbon capture and storage (CCS) technology as part of a strategy to prevent further climate change. Successful CCS implementation requires societal support but planned CCS projects have encountered significant opposition. In this study, we examine the CCS coverage in Dutch national newspapers from 2017 to 2019, a period during which the Dutch CCS landscape underwent several substantial changes, and compare the results to those of earlier media analyses conducted between 1991 and 2011. Most of the 324 articles identified discussed CCS in a neutral (36.4%) or balanced (24.4%) manner, and more critical articles than supportive ones were found (23.1% vs. 16.0%). Consistent with the earlier media analyses, the potential of CCS to reduce carbon dioxide emissions was a major theme in the positive portrayal of CCS, while the argument that CCS implementation is needed for the prompt reduction in emissions gained prominence. High CCS deployment costs and the perception that CCS is an unproven technology have remained major themes in the negative portrayal of CCS. The availability of and preference for alternative solutions was a more prominent theme in the conversation compared to earlier years, whereas the subject of CCS safety was discussed less than before. The study illustrates how media coverage can shed light on the evolving relationships between society and CCS, and on the established and emerging themes in arguments used for and against the technology. Full article
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13 pages, 4053 KiB  
Article
Influence of Catalytic Additive Application on the Wood-Based Waste Combustion Process
by Błażej Gaze, Paulina Wojtko, Bernard Knutel, Przemysław Kobel, Kinga Bobrowicz, Przemysław Bukowski, Jerzy Chojnacki and Jan Kielar
Energies 2023, 16(4), 2055; https://doi.org/10.3390/en16042055 - 20 Feb 2023
Cited by 1 | Viewed by 1224
Abstract
The furniture industry is one of the most dynamically developing sectors of the Polish economy. Unfortunately, due to national law, it involves producing a significant amount of wood-based waste, which can only be incinerated in installations that meet the requirements for waste incineration [...] Read more.
The furniture industry is one of the most dynamically developing sectors of the Polish economy. Unfortunately, due to national law, it involves producing a significant amount of wood-based waste, which can only be incinerated in installations that meet the requirements for waste incineration or co-incineration plants. This is due to the presence of various types of chemical additives in post-production residues, which increases the emission of hazardous compounds into the atmosphere during combustion. This article presents an analysis of the impact of the use of catalytic additives on the amount of emissions produced from the combustion of wood-based waste. For this purpose, the analyzed material was pelletized by mixing it with the DESONOX catalyst or by spraying the fuel with the DESONOX + H2O solution in a 1:1 ratio. Catalytic substances were introduced into the fuel until a concentration of 0.1% of its mass was obtained. The use of catalysts has significantly reduced CO and NOX emissions into the atmosphere. In the case of carbon monoxide, the most effective was Ad2 (reduction by 44%), and in the case of nitrogen oxides, Ad1 (reduction by 31%) achieved the best outcome. The results from this analysis may be an indication for Polish legislation encouraging furniture plants to burn this waste in their own units using catalytic substances. Full article
(This article belongs to the Special Issue Advanced Technologies for Wastewater and Solid Waste Treatment)
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27 pages, 860 KiB  
Review
Non-Hardware-Based Non-Technical Losses Detection Methods: A Review
by Fernando G. K. Guarda, Bruno K. Hammerschmitt, Marcelo B. Capeletti, Nelson K. Neto, Laura L. C. dos Santos, Lucio R. Prade and Alzenira Abaide
Energies 2023, 16(4), 2054; https://doi.org/10.3390/en16042054 - 20 Feb 2023
Cited by 2 | Viewed by 1606
Abstract
Non-Technical Losses (NTL) represent a serious concern for electric companies. These losses are responsible for revenue losses, as well as reduced system reliability. Part of the revenue loss is charged to legal consumers, thus, causing social imbalance. NTL methods have been developed in [...] Read more.
Non-Technical Losses (NTL) represent a serious concern for electric companies. These losses are responsible for revenue losses, as well as reduced system reliability. Part of the revenue loss is charged to legal consumers, thus, causing social imbalance. NTL methods have been developed in order to reduce the impact in physical distribution systems and legal consumers. These methods can be classified as hardware-based and non-hardware-based. Hardware-based methods need an entirely new system infrastructure to be implemented, resulting in high investment and increased cost for energy companies, thus hampering implementation in poorer nations. With this in mind, this paper performs a review of non-hardware-based NTL detection methods. These methods use distribution systems and consumers’ data to detect abnormal energy consumption. They can be classified as network-based, which use network technical parameters to search for energy losses, data-based methods, which use data science and machine learning, and hybrid methods, which combine both. This paper focuses on reviewing non-hardware-based NTL detection methods, presenting a NTL detection methods overview and a literature search and analysis. Full article
(This article belongs to the Section F: Electrical Engineering)
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17 pages, 2991 KiB  
Review
A Review of Electric Motors with Soft Magnetic Composite Cores for Electric Drives
by Youguang Guo, Xin Ba, Lin Liu, Haiyan Lu, Gang Lei, Wenliang Yin and Jianguo Zhu
Energies 2023, 16(4), 2053; https://doi.org/10.3390/en16042053 - 19 Feb 2023
Cited by 10 | Viewed by 4604
Abstract
Electric motors play a crucial role in modern industrial and domestic applications. With the trend of more and more electric drives, such as electric vehicles (EVs), the requirements for electric motors become higher and higher, e.g., high power density with good thermal dissipation [...] Read more.
Electric motors play a crucial role in modern industrial and domestic applications. With the trend of more and more electric drives, such as electric vehicles (EVs), the requirements for electric motors become higher and higher, e.g., high power density with good thermal dissipation and high reliability in harsh environments. Many efforts have been made to develop high performance electric motors, such as the application of advanced novel electromagnetic materials, modern control algorithms, advanced mathematical modeling, numerical computation, and artificial intelligence based optimization design techniques. Among many advanced magnetic materials, soft magnetic composite (SMC) appears very promising for developing novel electric motors, thanks to its many unique properties, such as magnetic and thermal isotropies, very low eddy current loss, and the prospect of low-cost mass production. This paper aims to present a comprehensive review about the application of SMC for developing various electric motors for electric drives, with emphasis on those with three-dimensional (3D) magnetic flux paths. The major techniques developed for designing the 3D flux SMC motors are also summarized, such as vectorial magnetic property characterization and system-level multi-discipline robust design optimization. Major challenges and possible future work in this area are also discussed. Full article
(This article belongs to the Topic Future Generation Electric Machines and Drives)
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17 pages, 3931 KiB  
Article
Dynamic Response Difference of Hydraulic Support under Mechanical-Hydraulic Co-Simulation: Induced by Different Roof Rotation Position and Hysteresis Effect of Relief Valve
by Qingliang Zeng, Chen Ma, Zhaosheng Meng, Jiantao Wang, Penghui Xu and Xiaowan Lei
Energies 2023, 16(4), 2052; https://doi.org/10.3390/en16042052 - 19 Feb 2023
Viewed by 1373
Abstract
As key supporting equipment in coal mining, hydraulic supports are vulnerable to impact pressure from roof movement and deformation. In this paper, a mechanical-hydraulic co-simulation platform for hydraulic supports is established. Moreover, the rationality of the simulation platform is verified. Based on this [...] Read more.
As key supporting equipment in coal mining, hydraulic supports are vulnerable to impact pressure from roof movement and deformation. In this paper, a mechanical-hydraulic co-simulation platform for hydraulic supports is established. Moreover, the rationality of the simulation platform is verified. Based on this platform, the rigid-flexible coupling impact dynamics model of hydraulic support is built. Finally, by delaying the opening time of the relief valve, the energy dissipation problem of the relief valve hysteresis effect on the hydraulic support system under the rotary impact is discussed. The results indicate that the rotary load acting on the hydraulic support decreases gradually with the backward movement of the roof rotary position, which causes the peak pressure in the column to decrease (by 69 MPa). The hinge point load of different parts shows different load transfer laws. The hysteresis effect of the relief valve prolongs the energy release time of the system, increasing the pressure in the column by 23 MPa. The instantaneous opening speed of the relief valve spool reaches 15.7 m/s, and the hinge point between the top beam and the column is most sensitive to the hysteresis effect (impact coefficient increases by 0.63). Full article
(This article belongs to the Topic Mining Safety and Sustainability)
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