Gaseous Biofuels in Biorefineries: Biomethane
Abstract
1012 6943
Gaseous Biofuels in Biorefineries: Biomethaneby
Abstract
The global production of biomethane is rapidly emerging as a sustainable alternative to fossil fuels for energy generation. Biogas, where methane (CH4) is usually one of the main components, is generated through the anaerobic digestion (AD) of various organic substrates, including animal manure, organic wastes, and wastewater. The efficiency of the AD process depends on key operational parameters and reactor designs that optimize microbial activity and gas yield. However, inhibitory compounds such as heavy metals, [...] 1012 6943 |
Test Site for Small Wind Turbines – Technical and Logistical Issues of a Decade-Long ProjectAbstract
This work addresses the main results of a test site for small wind turbines (SWTs) located in Patagonia, and the development of the measurement systems involved, including the uncertainties calculations according to applicable IEC standards. Due to market evolution for over a decade, the test systems evolved from battery-charging SWTs to grid-connected units. The test site, developed and managed by state-owned INTI (National Institute for Industrial Technology), was established in 2012 and received support from the [...] 799 5354 |
Environmental Impacts of Different Electricity Production Scenarios in FranceAbstract
This study focuses on the environmental impacts of the electricity production scenarios proposed for France for 2060 by the French electricity network manager, RTE. They consider an increasing electricity consumption and a production without fossil fuels, essentially based on wind, photovoltaic, hydraulic, and, for some, nuclear power. The total power to install is significantly higher than the current one; it is higher in the scenarios that rely more on photovoltaic and less on nuclear. Renewable energies require [...] 876 9225 |
Assessment of Water Balance Dynamics and Resource Stress in the Gaza Strip, Palestineby
Abstract
Water scarcity is one of the most pressing global challenges, particularly in arid and semi-arid regions. In this context, the Gaza Strip, where groundwater is the only available natural water resource, faces severe water stress due to overexploitation and drought conditions. This study aimed to review the recent water budget for the Gaza Strip by collecting data for the years (2021-2022) which was analyzed, discussed, and compared with other studies. The results showed a sharp deterioration in the Gaza Strip in te [...] 891 6709 |
A Novel Approach to Carbon Monoxide Removal Using Transition Metal-Doped Boron Nitride Nanosensors for Environmental SustainabilityAbstract
Adsorption of toxic gas of CO molecules by using transition metals of X (X = Ti, V, Cr, Co, Cu, Zn)-doped boron nitride nanocage (B5N10_NC) has been studied by computational chemistry. Based on NQR analysis, X-doped on B5N10_NC has shown the lowest fluctuation in electric potential and the highest negative atomic charge, including 0.2331 (copper), 0.3112 (cobalt), 0.5883 (chromium), 0.6853 (zinc), 0.6893 (vanadium) and 0.7499 coulomb (titanium), respectively, have presented the most tendency for being the electron [...] 754 4020 |
Design and Management of Renewable Energy Systems for Isolated Communities with No Grid ConnectionAbstract
The growing demand for energy and the need to reduce dependence on non-renewable sources have driven the research and application of sustainable technologies. In this context, an integrated solution that combines distributed energy generation from renewable sources, such as wind and hydro, with efficient management of household energy consumption is proposed. This study focuses on the hybrid renewable energy system simulation analysis designed to meet the demand of an off-grid household in a self-consumption mode. [...] 849 5014 |
Experimental Study and Kinetic Modeling of Agro-Industrial Wastes for Conversion to Fuel Gas via the Boudouard ReactionAbstract
Independent parallel reactions (IPR) and distributed activation energy (DAEM) kinetic models were developed and compared for the combined pyrolysis-gasification of two agro-industrial waste materials. The aim was to recycle greenhouse gas carbon dioxide for mitigating emissions, to evaluate the thermal behavior, reactivity, conversion and product composition in terms of structural/chemical characteristics of the fuels, and to provide accurate kinetic parameters useful in the scaling-up of the process. The experimen [...] 934 4758 |
Optimization of Heat Transfer in Parabolic Trough Collectors Using Advanced Turbulator Designs and Nanofluidsby
Abstract
Parabolic trough collectors (PTCs) are essential for solar thermal energy systems, and their thermal efficiency can be significantly enhanced using turbulators and nanofluids. This numerical study introduces three novel fin-spiral turbulator configurations (4, 7, and 10 blades) to enhance heat transfer within the absorber tube. Additionally, three nanofluid types including water-based single-walled carbon nanotubes (SWCNT), cupric oxide (CuO), and a hybrid SWCNT-CuO, at concentrations of 1%, 3%, and 5% were evaluat [...] 1467 9062 |
Acknowledgment to Reviewers of Journal of Energy and Power Technology in 2024Abstract
The editors of Journal of Energy and Power Technology would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2024. We greatly appreciate the contribution of expert reviewers, which is crucial to the journal's editorial process. We aim to recognize reviewer contributions through several mechanisms, of which the annual publication of reviewer names is one. Reviewers can download a certificate of recognition directly from our submission system. Additionally, reviewers can [...] 598 3457 |
Quantification and Comparative Analysis of Environmental Factors to Large-Scale Solar Plant’s Energy Performance via Regression and Linear Correlation Modelsby
Abstract
Performance degradation, including system deterioration, corrosion, and energy loss in solar PV systems, can be caused by environmental conditions such as high humidity, frequent rainfall, and temperature swings in tropical nations. Over the years, photovoltaic energy has been successfully developed to have low production costs and high efficiency. It has been the main reason that solar energy is one of the fastest-growing renewable energies in the world, with a generation of 821 TWh of electricity since 2021, repr [...] 919 9061 |
High Data Rate MWD Mud Pulse Telemetry – From Mysteries to DiscoveryAbstract
Our new approach to MWD mud pulse telemetry offers significant increases over conventional data rates. Using waveguide acoustics, we show that common drilling communications channels support carrier frequencies exceeding several hundred Hertz. Such signals are prone to attenuation over large drill pipe distances. Low power, self-spinning “turbosirens” are designed, providing high torque and rotation rate performance at all flow rates without electric or hydraulic motor drives. The sirens rotate, drawing only on the [...] 2339 15076 |
Post-Combustion CO2 Capture from an Industrial Power Plant Using Five Chemical Solvents: A Comparative TEAAbstract
CO2 capture processes using five chemical solvents were modeled in Aspen Plus V.12.1 for the capture of over 90% CO2 from a 456 ton/hour split flue gas stream containing 12.02 mol% CO2 emitted by the Longview 780 MW power plant (West Virginia, USA). Since the flue gas contained 33.10 ppmv SO2 and 35.47 ppmv NO2, a gas polishing process, using deionized water (DIW), was included in the model for complete scrubbing of SO2 and NO2 from the raw flue gas before the CO2 capture process. The five chemicals used for CO2 ca [...] 2058 11558 |
Stability Improvement of Multimachine System Using Back-To-Back ConvertersAbstract
As the penetration level of inverter-based generators continues to increase, it becomes crucial to reduce power oscillations between inverters and synchronous generators (SG) to improve system stability. This paper uses a multimachine system as the research platform and proposes a grid separation method employing a multi-terminal back-to-back converter. The converter is designed to be placed at the point of common coupling (PCC) in the original multimachine system and can divide the original grid into multiple micr [...] 869 4583 |
The Brazilian Research Scenario in Green Hydrogen: A Brief Contextualizationby
Abstract
Hydrogen is crucial in various industrial sectors and can be obtained through different synthesis routes. However, a significant portion of its production still relies on chemical processes involving fossil fuels, resulting in hydrogen and the generation of greenhouse gases (GHGs) as the final byproduct. In alignment with the goals of the 2030 Agenda, where countries commit to implementing energy transition, hydrogen obtained through a green route has been increasingly explored by governmental and academic entities [...] 1639 8636 |
Nanostructure-Based Solid-State Energy Storage through Hydrogen Trapping in Batteries Using Materials Modelling TechniqueAbstract
A comprehensive investigation on hydrogen grabbing by SiO-GeO was carried out, including DFT computations at the CAM-B3LYP-D3/6-311+G (d,p) level of theory. The data shows that if silicon elements are replaced by germanium, the H-grabbing energy will be ameliorated. Electromagnetic and thermodynamic properties of SiO, GeO, and SiO-GeO nanoclusters have been evaluated. The hypothesis of the hydrogen adsorption phenomenon was confirmed by density distributions of PDOS and LOL for hydrated nanoclusters of H-SiO, H-GeO [...] 896 4547 |
Security Length Associated with the Risk of Ammonia Tank Leak Using CTOA Criterion and ALOHA SoftwareAbstract
Ammonia is a toxic gas and can cause tragic consequences for humans. The damage level depends on concentration and duration of exposure. The security length associated with the risk of a tank leak at the acute exposure level of 30 ppm (AEGL-1) has been computed. Two tools have been combined: the CTOA criterion and the ALOHA software. The CTOA, a measure of fracture resistance against ductile crack propagation, is implemented in Abaqus software to compute the size of a breach in a tank submitted to internal pressure [...] 863 5689 |
An Application of Excess Solar and Storage Capacity Optimization for Grid Servicesby
Abstract
This initiative aims to enhance the efficiency of utility demand response (DR) operations by coordinating and integrating behind-the-meter (BTM) photovoltaic systems (PV) and energy storage (ES) using innovative machine learning software applications embedded in a distributed control architecture. The project is in the process of creating distributed energy resource (DER) learning agents and optimization engine within a hierarchical and layered distributed control architecture (DCA). These components work together [...] 847 5040 |
Grid-Connected Photovoltaic System for Generating Energy to Dairy Farm ActivitiesAbstract
Minas Gerais is the leading milk-producing state in Brazil, and many dairy activities are supplied with electricity by the cable aerial network of the electrical energy state company. Given that the Brazilian energy matrix relies primarily on hydroelectric power, studies on the potential of other renewable energy sources in the context of dairy farms are innovative. Additionally, frequent disturbances and interruptions have motivated the installation of solar energy systems on dairy farms. However, the scarcity of [...] 884 5203 |
Probabilistic Modeling of Cyber-Physical Microgrid Systems to Evaluate the Reliability and Resiliency Implications of Cyber Attacksby
Abstract
The integration of cyber and physical layer of the grid has not only introduced a microscopic spectacle to observe and ensure the efficient flow of electricity but has also exposed the interdependencies of the network. These cyber-physical interdependencies are often exploited in the form of cyber-attacks that can disable a grid introducing substantial financial losses and observable social repercussions. Thus, it is important to address the impending Achilles heel by devising pragmatic approaches to comprehensibly [...] 1260 7736 |
Physical Characterization of Solar Thermal Energy Storage (TES) Materials for Solar Dryers: Case of Volcanic Stone (Pozzolan) in Chadby
Abstract
Many sensible heat storage materials are regularly used as thermal energy storage (TES) systems to improve the efficiency of solar dryers. The present work focuses on the effects of the volume and particle sizes of a volcanic stone (pozzolan) for the same purpose. Samples soaked in matt black and without soaking were also considered. Heat charge and discharge tests were carried out by exposing the pozzolan contained in a solar collector of the direct solar dryer (DSD) and indirect solar dryer (ISD) to the sun. Char [...] 1517 7849 |
Elaboration, Structural and Optical Characterization of the New Ternary Chalcogenide SnSb2S5by
Abstract
In this study, tin antimony sulfide (SnSb2S5) thin films with 200 nm, 312 nm, and 431 nm thicknesses were successfully fabricated using thermal evaporation. These films' structural, optical, and photoanode properties were meticulously characterized to assess their suitability for photovoltaic applications. X-ray diffraction (XRD) analysis confirmed the presence of an orthorhombic symmetry phase within the Pnma space group, ensuring the crystalline quality of the films. Raman spectroscopy further validated the cryst [...] 756 4999 |
The Effect of the Addition of Titanium Dioxide on Silicone Self-Adhesive TapesAbstract
The investigation aimed to delve into the intricate relationship between the presence of titanium dioxide and the resulting alterations in the adhesive's behavior under different conditions. The focus extended beyond mere observation to understand how these additives interact with the adhesive matrix, potentially imparting beneficial attributes. Notably, the study delved into the optimization of thermal stability, the extension of the adhesive's functional lifespan, and the mitigation of shrinkage tendencies. This [...] 1071 7330 |
Building Blocks for an Energy TransitionAbstract
The present need for an energy transition in the wake of a global climate catastrophe led to the “EU green deal” which requires a transition of the energy system in all countries. This study aimis survey aims to identify strategies within such an energy transition based on global trend analyses and reports on available technologies for implementation. Based on a literature analysis of over 300 pieces (of feasibility studies and technology implementation reports with a focus on Central Europe) and a statistical anal [...] 1136 8955 |
Design and Techno-Economic Evaluation of a Hybrid Mini-grid System for an Academic Institutionby
Abstract
Inadequate electricity supply is a global challenge that needs solutions. This situation has compelled the purchasing of fossil fuel-generating units for use in residential, commercial, and industrial sectors to generate electricity. However, using fossil fuel generating units cause greenhouse gas emissions, bringing about environmental pollution and ultimately resulting in climate change. In particular, educational institutions require adequate and reliable power supply to ensure proper learning and teaching, whic [...] 1491 9848 |
Local Authority Waste Management Strategies, the Circular Economy and the Generation of Energy from Waste in Englandby
Abstract
The purpose of this article is to examine the approach to waste management of local authorities in England, to investigate their strategic objectives, and to ascertain to what extent sustainability and circular economy practices are in evidence in this context. A qualitative, inductive research method is used, based on an examination of secondary documentation in three local authorities in England in Birmingham, Bristol and Newcastle upon Tyne. The findings reveal considerable common ground within the three authori [...] 1032 7030 |
Wind Farm Layout Optimization Subject to Cable Cost, Hub Height, and a Feasible 3D Gaussian Wake Model ImplementationAbstract
We address the Wind Farm Layout Optimization (WFLO) problem and tackle the optimal placement of several turbines within a specific (wind farm) area by incorporating additional aspects of an economically driven target function. With this, we contribute three refinements for WFLO research: First, while many research contributions optimize the turbines' locations subject to maximum energy production or energy efficiency, we instead pursue a strategy of maximizing a profit objective. This enables us to incorporate inne [...] 1026 6752 |
A Review of North American Prospects for Power and Hot-Water Generation with Thermal EnergyAbstract
This article outlines an innovative approach to explore thermal energy extraction for power generation or industrial hot water applications. Unlike traditional steady-state models, this approach embraces time-variant scenarios, explicitly incorporating a cyclical fluid circulation strategy to maintain a stable surface fluid temperature or power output. By introducing an increasing and decreasing stepwise rate sequence and an intermittent circulation strategy, the method aims to optimize efficiency in response to va [...] 882 5384 |
Nonlinear Optimal Control for a PMLSG-VSC Wave Energy Conversion Unitby
Abstract
This article aims to treat the nonlinear control problem for the complex dynamics of a wave energy unit (WEC) that consists of a Permanent Magnet Linear Synchronous Generator (PMLSG) and a Voltage Source Converter (VSC). The article has developed a globally stable nonlinear optimal control method for this wave power generation unit. The new method avoids complicated state-space model transformations and minimizes the energy dispersion by the control loop. A novel nonlinear optimal control method is proposed for the [...] 898 5992 |
Floating Oscillating Water Column Wave Energy Converters: A Review of DevelopmentsAbstract
The main challenge in designing offshore renewable energy structures is to ensure their structural integrity on a life cycle basis while operating in harsh environments and, in parallel, being financially competitive and environmentally friendly concerning other types of energy systems. The Oscillating Water Column (OWC) converters are among the first energy converters to be developed and deployed into the sea due to their relative simplicity of operation and relatively small number of moving parts. This review pro [...] 4175 45786 |
Monitoring Energy-Loss-Driven-Cost by Using Earned Value Simulation in Complex SystemsAbstract
The economic impact of energy loss stemming from end-user electricity consumption is a significant concern, with historical trends revealing escalating costs. Effectively managing both peak and off-peak demands remains a formidable challenge due to the unpredictable nature of consumer behaviors, leading to energy wastage. This study delves into the nexus of demand uncertainty, financial repercussions, and potential strategies to mitigate energy losses in the evolving landscape of electricity consumption.that causes [...] 990 6120 |
LFO Damping Enhancement in Multimachine Network Using African Vulture Optimization AlgorithmAbstract
The prolonged presence of low-frequency oscillation (LFO) in power system networks (PSN) poses a significant threat to their stability. Hence, engineers and researchers have continuously developed effective strategies to mitigate the issue and enhance the stability of the PSN. This article proposes a new approach using the African Vultures Optimization Algorithm (AVOA) to design robust Power System Stabilizers (PSS) and enhance the LFO damping in multi-machine networks. The damping ratio-based objective function mi [...] 873 5280 |
Proposal for the Sustainable Electrification of a Primary Healthcare Centre (PHC) Facility in NigeriaAbstract
Energy is a prerequisite to running health facilities and is, therefore, key to the success of the service. Karshi primary healthcare centre (PHC) facility is confronted with an unreliable power supply that leads to a high cost of generating power from diesel to operate its equipment. This facility needs a sustainable and reliable electricity supply and therefore a change in their energy system to enable it improve its quality of healthcare delivery services. A solar energy-based electricity generation system that [...] 1180 9046 |
Acknowledgment to Reviewers of Journal of Energy and Power Technology in 2023Abstract
The editors of Journal of Energy and Power Technology would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2023. We greatly appreciate the contribution of expert reviewers, which is crucial to the journal's editorial process. We aim to recognize reviewer contributions through several mechanisms, of which the annual publication of reviewer names is one. Reviewers can download a certificate of recognition directly from our submission system. Additionally, reviewers can [...] 838 4480 |
Stability Analysis of Autonomous Microgrid Operated at Constant-Frequency with the Consideration of Reactive Power Balanceby
Abstract
Large-scale autonomous microgrids have potential application values as they can increase renewable energy penetration level without compromising the stability of the existing large power systems. Before their widespread implementation, critical issues like stability analysis etc need to be solved. This paper analyses the stability in an autonomous microgrid operated at constant frequency with the consideration of reactive power balance. Difference equations of reactive power for the grid-forming generator are const [...] 1072 6037 |
Array Formation Testing with Multiple Azimuthal and Axial Pressure TransducersAbstract
An early formation tester operating a “sink probe” that extracts fluids from the borehole, also measures pressures at its location; pressures are additionally collected at two passive sensors, one situated 180 deg away and the second about meter axially. These positions are not conducive to accurate permeability predictions, since pressure transient signals used for inverse analysis attenuate very rapidly. Closer probe spacings offer formation evaluation advantages at low mobilities because Darcy pressure dissipati [...] 1118 6510 |
Saving is Losing: Pumping Cost vs. GHG Emissions in Water Distribution SystemsAbstract
Global climate change has necessitated the reduction of GHG emissions. Water distribution system (WDS) pumping adds to these emissions and, therefore, should be reduced. Under electricity hourly cost tariffs, utilities are incentivized to pump during the nighttime hours. This can have a deleterious effect, however, on GHG emissions. To quantify this effect, a modeling study of twelve real WDSs was performed with an electricity tariff. The systems all had the typical tank-level-based pump controls but also time-base [...] 1255 7114 |
Net Zero Corridors: A Case Study Approach from Perth, Australia to Decarbonize Urban Power and Transportby
Abstract
The transition to net zero cities is a pivotal challenge in the face of climate change. This research introduces a novel methodology termed "Net Zero Corridors," which emphasizes a bottom-up approach to decarbonize urban power and transport systems. By focusing on urban corridors, this method integrates distributed power systems with urban transport, offering a localized solution to the broader challenge of urban decarbonization. Drawing from urban fabric theory and urban metabolism data, the study provides insight [...] 1448 9072 |
Efficient Industrial Wastewater and Leachate Evaporation Utilizing Heat Localization in Porous MediaAbstract
In this paper, an efficient industrial wastewater and leachate evaporation method is proposed and tested experimentally. The goal of this study is to investigate whether the addition of a carbon foam (CF) porous layer can lead to energy savings by evaporating more water mass per unit of energy input. The standard boiling evaporator layout was redesigned by placing the heating element in the upper region of the tank and CF underneath the heat source. The CF purposed to localize the energy in an area by the water' [...] 1216 7700 |
An Adsorption-Desorption Heat Engine for Power Generation from Waste HeatAbstract
According to the United States Department of Energy, waste heat recovery would allow up to a 20% reduction in greenhouse gases (GHG) emission. Most of the waste energy is discharged as a low-grade heat at temperatures less than 250°C. Therefore, the development of new technologies and the enhancement of existing ones to convert low-grade heat into electrical or mechanical energy are of great importance. The working principle of adsorption-desorption heat pumps with cyclic switching between adsorption and desorp [...] 1401 8970 |
Technical Analysis of Sawdust-to-Power: A Paradigm Shift in Waste Management in a Typical Developing Economyby
Abstract
The proper management of sawdust is critical to socioeconomic development. In this research, waste-to-energy has been proposed to utilize sawdust in selected timber markets in Port Harcourt, namely, Illoabuchi Timber Market, Marine Base Timber Market, and Mile 3 Timber Market. A quantitative approach has been taken to estimate the sawdust generation, energy potential, power generation capacities, and pollutant reduction of indiscriminate combustion of sawdust. The findings suggest that, annually, 171 ktons, 42 kton [...] 1367 11255 |
Na+ Mobility in PEO-Based Composite Solid-State Electrolytes by NMRby
Abstract
Charge transfer and mobility are essential for electrochemical processes in batteries, which need to be understood in detail for optimization, especially in the case of all-solid-state batteries. Wide line NMR is well-known in solid-state NMR and allows the quantification of ion mobility in ordered crystalline and amorphous structures. Temperature-dependent 23Na-NMR is sensitive to ion mobility via longitudinal relaxation, but also via line analysis and transverse relaxation. As 23Na is a spin 3/2 nucleus, 23Na-NMR [...] 1894 9326 |
Enhancement Techniques for the Reduction of Heating and Cooling Loads in Buildings: A Reviewby
Abstract
The building sector is rated as a big consumer of electric energy and emissions, responsible for about 40% of final electric energy consumption. As a result, the Paris Agreement 2015 set a goal for buildings and the construction sector to reach a nearly zero-carbon stage by 2050. This urged most countries to create regulations for the construction sector and invest in energy efficiency programs. The present paper aims to present an updated review of building energy-saving solutions and techniques to contribute to c [...] 2318 18348 |
Generalized Normal Distribution Optimization Algorithm for Economic Dispatch with Renewable Resources IntegrationAbstract
In an electric power system operation, the main goal of economic dispatch (ED) is to schedule the power outputs of committed generating units efficiently. This involves consideration of relevant system equality and inequality constraints to meet the required power demand at the lowest possible operational cost. This is a challenging optimization problem for power system operators that can be dealt with efficient meta-heuristic algorithms. This article uses a recent meta-heuristic approach named the generalized norm [...] 1197 8563 |
A Comparative Study of R134a and Propane (R290) as Refrigerants in Heat Pump Water Heatersby
Abstract
In the context of decarbonization efforts, heat pump water heaters (HPWHs) offer an attractive solution over conventional electric resistance type hot water systems due to their 2-3 times higher efficiency. However, the high manufacturing costs and taxes associated with using hydrofluorocarbon (HFC) refrigerant make HPWHs expensive. As a means to tackle this issue, this paper explores the use of propane (R290) as a refrigerant in HPWHs. The study involves an experimental comparison of R290 and R134a, with refrigera [...] 2159 42810 |
Overall Reaction Rate Study of Thermal Methane Cracking in Non-Isothermal ConditionsAbstract
The thermal cracking of methane (TMC) is a significant reaction occurring above 850°C, which proceeds in two stages: non-isothermally and isothermally. However, most existing studies have focused on obtaining reaction rates under isothermal conditions [1], limiting their applicability to practical industrial reactor conditions. This novel research aims to determine the overall thermal decomposition rate of methane to hydrogen and carbon in adiabatic conditions, covering the range of unstable industrial reactor temp [...] 1385 7138 |
Exploring the Potential of Phase Change Material for Thermal Energy Storage in Building EnvelopesAbstract
Buildings, with their significant energy consumption, pose a pressing concern for the future. Inadequate heating, ventilation, and air-conditioning (HVAC) systems further exacerbate thermal management difficulties and energy requirements. To address these challenges, Phase Change Materials (PCMs) offer valuable potential for sustainable energy reduction within the building sector, leveraging passive cooling and heating techniques. Numerical study has been conducted to explore the impact of embedding PCM within the [...] 1133 9757 |
Volt-Var Control for Utility-Scale Solar PV Plants to Downsize SVCs and Curtailment EffectsAbstract
One way to increase solar photovoltaic penetration in the grid is the management of voltage fluctuations. This is because a photovoltaic plant cannot be interconnected to the grid if it causes voltage violations. Voltage violation is where voltage exceeds the acceptable range. Often, grid operators request photovoltaic plant owners to regulate voltage sufficiently with expensive and space-consuming static Var compensators. Unfortunately, this sometimes makes the project less feasible. This paper argues that there a [...] 855 9031 |
Study and Characterization of a Spherical Solar Collector. Part II: Comparative Analysis with Flat-Plate DevicesAbstract
The paper analyses the performance of a spherical solar collector compared to the efficiency of a flat-plate solar collector, which is the type of solar collector that does not use a tracking system in collecting solar radiation for energy conversion. Spherical solar collector benefits from a constant value of the angle of incidence, which optimizes the solar radiation that strikes the absorber of the solar device and maximizes the energy collection. Besides, the spherical geometry has a larger area for equal dimen [...] 838 6461 |
Improving the Performance of Solar Thermal Energy Storage SystemsAbstract
In recent times, renewable energy resources have been greatly researched because of the increasing concern to minimize global warming and meet energy demands. Energy storage systems have become useful tools for sustainability and meeting energy needs. Solar energy has proven in recent times to be the primary and most prevalent option due to its environmental friendliness, availability, and minimal pollution. Effective utilization of available energy resources has led to developing new alternative energy devices lik [...] 1463 12564 |
Permeability, Compressibility and Pressure Prediction in Supercharged Wireline and FTWD EnvironmentsAbstract
In conventional wireline and LWD/MWD formation testing, downhole predictions for rock and fluid properties are based on simplified Darcy flow models, but only for mathematical expediency. These require initially constant pressures that are uniform throughout the reservoir. This limitation precludes common applications in overbalanced drilling, so that supercharge or near-well invasion effects - associated with rapidly decreasing pressures at the sandface where pressures are measured - are completely ignored. Such 1 [...] 1163 6931 |
Study and Characterization of a Spherical Solar Collector. I. Efficiency and Thermal Losses CoefficientAbstract
This paper studies and characterizes a solar collector with spherical geometry to produce hot water for sanitary and domestic applications and other facilities. The new geometry enlarges the solar collector surface and allows full sun tracking during the day without needing a solar tracking system. Although this geometry has been in use for some time, its market penetration is low due to the lack of perfect knowledge of solar collector behavior and the benefits compared with conventional solar collectors. The studi [...] 941 6935 |
Effects of Waste Cooking Oil Biodiesel on Performance, Combustion and Emission Characteristics of a Compression Ignition EngineAbstract
With their higher sustainability index, biofuels, environmentally-friendly and renewable nature is a viable alternative energy source in the transportation sector. This study presents the effect of waste cooking oil (WCO) biodiesel on performance, combustion, and emission from a compression ignition engine. The biodiesel was blended with diesel in varying proportions of 5% biodiesel and 95% diesel (designated as B5), 10% biodiesel in diesel (B10), 15% biodiesel in diesel (B15), 20% biodiesel in diesel (B20), 50% bi [...] 1196 12043 |
A Review of Practical Applications of Fluid Flow and Associated Heat Transfer Modeling in WellboresAbstract
Investigations on two-phase gas/liquid flow in pipes have been under study for nearly six decades. These studies have significantly assisted in managing fluid flow in the wellbore and surface networks, leading to the separation of phases and transmission of oil and gas into the market. This study summarizes some of the main lessons learned in flow through wellbores. Besides understanding some of the fundamental principles, we focused on the practical items of interest: Conventional production scenarios for oil and [...] 1333 10494 |
Nonlinear Optimal Control for Six-Phase Induction Generator-Based Renewable Energy SystemsAbstract
The article aims at optimizing six-phase induction generator-based renewable energy systems (6-phase IGs or dual star induction generators) through a novel nonlinear optimal control method. Six-phase induction generators appear to be advantageous compared to three-phase synchronous or asynchronous power generators, in terms of fault tolerance and improved power generation rates. The dynamic model of the six-phase induction generator is first written in a nonlinear and multivariable state-space form. It is proven th [...] 1077 7834 |
Fixed-Switching Frequency Finite-State Model Predictive Thrust and Primary Flux Linkage Control for LIMAbstract
The special design of linear induction machines (LIMs) leads to adverse effects caused by the longitudinal and end effects. These effects make the thrust control of the LIMs most attractive because its value decreases sharply with the speed increase. Thus, finite-state model predictive control (FS-MPC) is developed to increase the performance of the LIMs. However, the variable switching frequency is the main drawback of this control. Consequently, the main objectives of this paper are to propose FS-MPC with a const [...] 1059 7279 |
Non-Isothermal Compressible Flow Model for Analyzing the Effect of High CO2 Inlet Flow Rate on Particle Size in a Supercritical Antisolvent Processby
Abstract
In this work with CFD simulations, the evaluation of the supercritical anti-solvent (SAS) process for producing nanoparticles from an expanded solution of ethanol/solute in carbon dioxide is reported. The influence of the solution and antisolvent flow rates on mean particle size, the flow dynamic, and the supercritical mixture's jet velocity must be well established in the literature and analyzed. The high flow rate of the anti-solvent resulted in increased mean particle sizes for all studied cases. At the lowe [...] 1106 8720 |
Thermodynamic and Structural Optimization of Organic Rankine Cycle Plant for Clean Energy Access Using Artificial Bee Colony and Multi-Criteria Decision-Making Algorithmsby
Abstract
The quest to decarbonize the energy space to avert the negative climate change consequences calls for using low/zero-carbon energy conversion technologies in the energy generation space. The Organic Rankine Cycle is a low/zero-carbon energy conversion technology for recovering waste heat from low to medium-temperature heat sources and for biomass conversion. Therefore, this paper presents the thermodynamic optimization, with an artificial bee colony algorithm, of different ORC configurations, including simple organ [...] 1387 7530 |
The Eastern Australian Floods of February 2022 and Its Relationship with Climate ChangeAbstract
During February 2022 major riverine flooding occurred in an area which has the fastest population growth in Australia. This extended from the Mary River in Southeast Queensland (SEQ) to the Clarence River in Northeast NSW (NENSW). Two centres within this area were devastated by floods unprecedented in living memory. One was the Brisbane Metropolitan area where all-time record daily rainfall in the suburbs flooded creeks. This creek flooding was much worse than that caused by the Brisbane River itself where Wivenhoe [...] 3166 23170 |
Techno-Economic Analysis of Waste-to-Suburban Cooking Energy Critical Infrastructure Development in Southwestern NigeriaAbstract
This study examined the techno-economic specifications for a Waste-to-Suburban Cooking Energy critical infrastructure project in Southwestern Nigeria. Technological and project economic data for the W2E project were obtained from strategic sources and energy project foresight/analysis framework used. The results showed residential upgraded biogas-for-cooking demand of approximately 10,243 m3/month, and municipal solid waste (MSW) input of approximately 80 tonnes/month. The planned biogas plant had estimated costs o [...] 1769 12335 |
Influence of Biogas Digestates on the Composition of Soil Organic MatterAbstract
The increasing number of biogas plants with various digested organic materials and output of digestates calls for more detailed investigations of their suitability as soil amendments. In a trial in Northern Germany two replicate plots each were treated with fresh or prolonged fermented digestate to investigate the influence of digestates on the composition of soil organic matter (SOM). The relative proportions of relevant SOM compound classes were determined by pyrolysis-field ionization mass spectrometry (Py-FIMS) [...] 1205 7627 |
Transfer Learning for Fault Detection with Application to Wind Turbine SCADA DataAbstract
In agreement with the Editor-in-Chief, the editorial office, and the authors, this article has been removed and marked as retracted because its content and data contained plagiarism from an unpublished study. Please refer to the Removal Statement. 870 6000 |
The Liquid-Mediated Synthesis and Performance Evaluation of Li-Zr-F Composite for Ion-Conductionby
Abstract
Crystalline lithium fluoride (LiF) has been intensively pursued as potential alternative solid electrolytes (SEs) owing to its excellent chemical and electrochemical oxidation stability, and good deformability. However, due to its low ion conductivity, LiF is still challenging for practical SE applications. Herein, Li-Zr-F composite-based SE by liquid-mediated synthesis is proposed to be studied. methanol (CH3OH) was mainly evaluated as a liquid-mediated precursor for synthesizing Li-Zr-F composites under the stoic [...] 1846 10059 |
Modeling of Autonomous Microgrid Operated at Medium-Voltage Level and at Constant Frequency and Study of Its Voltage Profileby
Abstract
To increase power level in an autonomous microgrid, higher voltage is necessary. In this paper, detailed Matlab/Simulink modeling of a microgrid operated at medium-voltage level and at constant frequency has been conducted. Modified boost converter and medium-frequency transformer isolated DC/DC converter are adopted for both solar energy and wind energy harnessing in order for them to be connected with the microgrid. This paper further adopted a differential evolution (DE)-based method to carry out load flow analy [...] 1057 6710 |
Prediction of Wind Loadings on Offshore Wind Turbines Using CFDAbstract
Analysing the structural response of offshore wind turbines (OWTs) requires a robust method to estimate environmental loadings associated with extreme weather conditions. This study aimed to accurately predict wind loadings on a non-rotating OWT using a Computational Fluid Dynamics (CFD) code, Ansys Fluent package. The inlet velocity boundary condition was defined as a uniform inlet wind speed and then as a Normal Wind Profile (NWP). Three large wind speeds of 25 m/s, 40 m/s and 50 m/s were tested with the aid of t [...] 1514 11781 |
An 800V End to End SiC Powertrain to Accommodate Extremely Fast Chargingby
Abstract
Widespread adoption of electric vehicles has presented the challenges of short range and prolonged charging time. Going forward, extremely fast charging is the only solution to these problems. However, the typical Silicon power electronics supported 400 V electric vehicle powertrain cannot live up to this challenge. Limitations include the huge cable size, heating of equipment due to high current and user safety, to name a few. In this paper, we have analyzed an 800 V EV powertrain using power electronics based on [...] 2901 18652 |
A Combined Power and Ejector Refrigeration Cycle System for Thermal Energy Recovery from the Waste Heat of Internal Combustion EngineAbstract
In this paper, due to the importance of energy recovery from internal combustion engines and the increasing human growing need for power and refrigeration, a two-cycle power and refrigeration system consisting of an organic Rankine cycle and an ejector refrigeration cycle is investigated analytically. The proposed system with the ability to use the ejector as an effective and economical system, can produce simultaneous power and refrigeration by drawing thermal energy from the exhaust gas and engine coolant in the [...] 1380 9124 |
Co-development of Low-speed Electric Community Buses for Local Area RevitalizationAbstract
This paper describes the development of low-speed electric community buses (LSECBs) designed by the author's group and their spread situation in Japan. LSECBs are electric vehicles that can travel on public roads at speeds of less than 5.56 m/s (20 km/h). The university, local government, local businesses, and residents with a co-design approach developed the LSECBs. They have various advantages such as safety due to low speed and low energy consumption. In particular, the LSECBs have features not found in ordinary [...] 1073 7894 |
Green Energy Sources Reduce Carbon Footprint of Oil & Gas Industry Processes: A ReviewAbstract
In recent years, the oil and gas sector has been moving towards green production methods to achieve net-zero emission goals. Governments and corporations have started large-scale initiatives to deploy advanced technologies to reduce carbon footprints and prevent global warming. Herein, we have explored the emerging techniques and methods used in reducing the effects of gas emissions in the oil and gas industry. The transition process from hydrocarbons to renewable energy resources, including solar thermal applicati [...] 2100 14645 |
Significance of Insulation and Heat Pumps in Decarbonising the UKby
Abstract
This paper examines the economic case for the UK to proceed urgently with the installation of thermal insulation and heat pumps in most UK buildings, in the context of the legal requirement to achieve net-zero carbon emissions by 2050. A recent study by the same authors assumed that such insulation and heat pumps would be in place, and showed how the whole of the UK’s energy demand could be met by low carbon electricity generation and appropriate storage. This paper extends the modelling to consider the risk that i [...] 1394 10055 |
Acknowledgment to Reviewers of Journal of Energy and Power Technology in 2022Abstract
The editors of Journal of Energy and Power Technology would like to express their sincere gratitude to the following reviewers for assessing manuscripts in 2022. We greatly appreciate the contribution of expert reviewers, which is crucial to the journal's editorial process. We aim to recognize reviewer contributions through several mechanisms, of which the annual publication of reviewer names is one. Reviewers receive a voucher entitling them to a discount on their next LIDSEN publication and can download a certifi [...] 771 5005 |
The Effect of Rotor Radius Ratio on The Performance of Hybrid Vertical Axis Wind Turbine Savonius-Darrieus NREL S809Abstract
This research aims to know the effect of the Rotor Radius Ratio on the performance of the hybrid Vertical Axis Wind Turbine Savonius-Darrieus NREL S809 model using the Computational Fluid Dynamics method. Two-bladed Savonius is used as an internal rotor, and three-bladed Darrieus NREL S809 as an external rotor. Turbine model performance is analyzed through the value of the Moment Coefficient and Power Coefficient. The result shows that the increase in the Rotor Radius Ratio value causes an increase in the initial M [...] 1526 13139 |
Traffic NOx Pollution Prediction and Health Cost Estimation Using Machine Learning: A Case Study of Toronto, Canadaby
Abstract
Road traffic is a significant source of air pollution that has a harmful impact on human health. To reduce the health and environmental impacts of fossil fuel consumption in the transportation sector, many countries have implemented policies to promote the deployment of electric vehicles (EVs). A vital factor to consider when designing policies to support EV use is the monetized health impacts of fossil fuel consumption. This research aims to investigate the health benefit of replacing internal combustion engine ve [...] 1203 8756 |
Evaluation of Oxidative Stability and Kinetic Parameters of the Cottonseed and Soybean Biodiesels by Rancimat and Differential Scanning Calorimetry Techniquesby
Abstract
In this study, the oxidative stability of the cottonseed oil biodiesel (CB) and soybean oil biodiesel (SB) was investigated by two methodologies, Rancimat and Differential Scanning Calorimetry (DSC), using samples fresh and aged (mid-term storage condition (100 days)). The biodiesel samples were synthesized by transesterification and characterized by specific mass, kinematic viscosity, acidity value, ester content, viscosity index, and peroxide value. The activation energy (Ea), Arrhenius pre-exponential factor (Z) [...] 1282 8167 |
Net Zero UK – Generation and Energy Storage Requirements for the UK to Become Carbon Neutralby
Abstract
This paper sets out a quantified scenario for the UK to reach net zero carbon emissions. Wind and solar are the main energy sources and their intermittency is accommodated through hydrogen electrolysis, biogas from anaerobic digesters, and their combination into biomethane. Hydrogen and biomethane stocks are tracked. A daily energy balance model is presented, using the most recent recorded weather data-2017 to 2021. Long periods of low wind in 2021 indicated the necessary energy storage capacities, which were adjus [...] 1614 9743 |
Enhancing the Wettability of Polyetheretherketone (Peek) Membrane with Ozone for Improving Fuel Cell Performanceby
Abstract
Ozone was reacted with the aromatic membrane polyetheretherketone (PEEK) to form oxidized functional groups on the surface to enhance the attraction and transport of protons in fuel cells. Ozonation of unsaturated C-C sp2 bonds in PEEK formed a primary ozonide which dissociated to primarily produce O=C-O/O=C-OH moieties, and the root mean squared roughness factor (Rq) decreased from 7.4 nm, for the untreated sample, down to 3.1 nm. The oxidation of the surface and decrease in surface roughness made the surface incr [...] 1035 7098 |
The Design, Development and Assessment of a Novel De-centralised IoT-Based Remote Monitoring of a Small-Scale Anaerobic Digester Networkby
Abstract
The implementation of community-level de-centralised anaerobic digestion (AD) systems offers a sustainable solution for organic waste management and energy provision, but there is currently a need for low-cost methods of system control and management at this scale. The problem becomes accentuated with increasing deployment, as greater complexities are created by the need to both monitor and control a wider network of smaller, community-scale plants. This paper describes research to design, deploy and test such a sy [...] 1510 12951 |
Fabrication of Perovskite Solar Cells by the Smart Stacking ProcessAbstract
The most commonly used process for fabricating perovskite solar cells is based on wet chemistry, which greatly limits the choice of materials suitable for optimizing the performance of the device. We developed a new approach for the fabrication of perovskite-based solar cells. In the smart stacking process, the perovskite solar cell was assembled by stacking two pieces of perovskite films prepared separately. A working perovskite solar cell was developed with PCE = 0.78% and the perovskite layer was analyzed with X [...] 1259 7854 |
The Impacts of Offshore Wind Farms (OWFs) on Local Tourism and Recreation -- Evolving Lessons from PracticeAbstract
The article examines the nature of impacts of the rapidly growing Offshore Wind Farm (OWF) industry on tourism and recreation in coastal communities, especially in the UK. The multi-methods research approach includes reviews of literature, content of OWF Environmental Statements (ESs) for predicted impacts, recent practice for actual impacts, and the use of mitigation and enhancement measures. Findings from literature indicate that the overall impact on tourism appears relatively benign, and sometimes positive. The [...] 1627 16132 |
A Data-Based Reliability Analysis of ESP Failures in Oil Production WellsAbstract
Electrical Submersible Pumps (ESPs) are one of the most widely used artificial lift methods in the petroleum industry. However, ESP failures are unanticipated and common occurrences with significant financial impacts for the operators. Analysis of the ESP performance and failures are essential in its design and optimization. This paper presents a statistical approach for diagnosing and evaluating the root causes of ESP failures. The analysis is based on the field data gathered from the surface and downhole ESP moni [...] 5810 39765 |
Comparing Environmental Impacts Arising from the Use of Electric Two-Wheeler vis-a-vis Gasoline Two-Wheeler in Indiaby
Abstract
Electric vehicles are becoming popular among consumers while BS-VI norms have been introduced and mandated for conventional vehicles in India. In the present study, the environmental impacts from the use phase of electric two-wheeler (EV) and gasoline two-wheeler (GV) have been evaluated and compared using the life cycle assessment (LCA) perspective. The functional unit adopted was 1000 km driven by one vehicle under Indian road and traffic conditions. CML 2001 and ReCiPe 2016 methods were used for the assessment u [...] 1717 11135 |
A Dual-PRF Scan Mode and Adaptive Doppler-Velocity Dealiasing to Increase Radar Clear-Air Velocity Data Coverage and UsabilityAbstract
By using long pulses with extended dwelling time, lowered pulse repetition frequency (PRF) and reduced Nyquist velocity, the radar measurement capability can be enhanced to increase clear-air Doppler velocity data coverage (which is beneficial for radar wind analysis and data assimilation and motivated our previous study). This potential capability is further explored (beyond our previous study) by not only modifying the existing operational clear-air scan mode with a lowered PRF and reduced the Nyquist velocity (t [...] 1037 7675 |
TEA of a Unique Two-Pathways Process for Post-Combustion CO2 CaptureAbstract
A unique two-Pathways process using aqueous sodium glycinate for CO2 capture from a split flue gas stream emitted from 600 MWe post-combustion coal power plant was developed in Aspen Plus v.10. The split gas flow rate used was 44.75 ton/h and contained 0.0023 mol% SO2 and 13.33 mol% CO2. The process includes a washing unit, a CO2 absorption unit, a reverse osmosis unit, and a solvent regeneration unit or an ultrafiltration unit. The washing unit uses deionized water to completely remove SO2 and the CO2 absorption u [...] 1386 8646 |
The Physical Potential for Dutch Offshore Wind Energyby
Abstract
In the Netherlands, an important way to contribute toward achieving climate goals is the large-scale deployment of wind turbines in the North Sea. The North Sea is a unique location for offshore wind power thanks to its strong winds, shallow waters, and proximity to large energy users. Wind turbines generate electricity by extracting kinetic energy from the atmosphere. This kinetic energy is replenished at a finite rate through the mixing of atmospheric layers. The replenishment rate sets a physical limit to the am [...] 1726 21313 |
A Robust Second-Order Conic Programming Model with Effective Budget of Uncertainty in the Optimal Power Flow ProblemAbstract
Integrating large-scale wind energy in modern power systems necessitates high-efficiency mathematical models to address classical assumptions in power systems. In particular, two main assumptions for wind energy integration in power systems have not been adequately studied. First, nonlinear AC power flow equations have been linearized in most of the literature. Such simplifications can lead to inaccurate power flow calculations and result in technical issues. Second, wind power uncertainties are inevitable and have [...] 1113 6997 |
Historical Evolution and Scenarios Up to 2050 of Heating Energy Consumption and CO2 Emissions of Residential Buildings in ViennaAbstract
Today, the building sector poses a major problem concerning fossil fuel energy consumption and the corresponding emissions of local pollutants and global greenhouse gases (GHG). In addition, an increasing number of people are living in urban areas, and it is becoming challenging to provide the necessary living space and energy for heating in fast-growing cities. Currently, urban areas host approximately 50 % of the global population and generate 70 % of GHG. The core objective of this study is to analyze the histor [...] 1145 8744 |
Risks Associated with the Use of Hydrogen as an Energy Carrier or Sourceby
Abstract
Hydrogen is a dangerous gas due to its low ignition energy, wide flammability range, promotion of the embrittlement of steel, and its high coefficient of permeation for polymers. The fracture toughness and failure elongation of pipe steels are strongly impacted by hydrogen embrittlement, whereas yield stress and ultimate strength are moderately impacted. Specific tools are required for the pipe defect assessment used for the transport of hydrogen, which is pure or blended with natural gas. The safety factors associ [...] 2695 17248 |
Study of Hydrogen Embrittlement in Pipelines and Nuclear Power Plants: Estimates for DurabilityAbstract
Due to the increasing need to further develop the world gas and oil industry and the increased public attention to clean energy sources, studying and preventing Hydrogen Induced Cracking is one of the main safety concerns in nuclear power plants, oil pipelines and platforms. In this article, the growth and incubation times for internal Hydrogen Induced Cracks (HIC) are examined. Specifically, these times are modeled in two separate phases - the first phase (I) is a long time approximation, when the crack growth is [...] 1448 10038 |
Artificial Neural Networks and Gradient Boosted Machines Used for Regression to Evaluate Gasification Processes: A ReviewAbstract
Waste-to-Energy technologies have the potential to dramatically improve both the natural and human environment. One type of waste-to-energy technology that has been successful is gasification. There are numerous types of gasification processes and in order to drive understanding and the optimization of these systems, traditional approaches like computational fluid dynamics software have been utilized to model these systems. The modern advent of machine learning models has allowed for accurate and computationally ef [...] 1225 9608 |
Incentivizing Alternative Fuel Vehicle Transactions: Analysis of Cash-for-Clunkers Transactions for New Alternative Fuel VehiclesAbstract
Monetary incentives to accelerate the transition of private vehicle fleets to zero emissions promote sustainability in the transportation sector. Clean Cars for America to incentivize transactions for new battery power vehicles is a program in furtherance of sustainable transportation goals in the United States. Unfortunately, data on transactions for new alternative fuel vehicles (AFVs) are scarce so empirical research to explore the costs and/or the benefits of such programs is also scarce. Analysis of transactio [...] 1012 6617 |
From Food to Foot: The Energy and Carbon Flows of the Human Body at Walking and CyclingAbstract
The carbon footprint of motorized transport modes per unit length traveled encompasses the unit share of the vehicle lifetime emissions, that of the transport infrastructure, and those of the motor energy, considered both from “well to tank” and from “tank to wheel”. In the active modes of transport, i.e., walking and cycling, the counterpart of motor energy is human energy, which is associated with two kinds of carbon flows: the carbon footprint of food intake, – which we call the Food to Body component – and the [...] 1723 13959 |
Numerical Study to Understand the Conservation of Hydrogen Through a Dynamic Fuel Supply System in Proton Exchange Membrane Fuel Cells (PEMFCs)Abstract
Reducing and conserving fuel usage is pivotal for any engineering system for the development of a sustainable energy solution. Proton exchange membrane fuel cells (PEMFCs) are one of the promising renewable energy systems that consume hydrogen as their source of fuel to generate electricity. This paper investigate the necessity of the constant supply of fuel (hydrogen) in the PEMFC system to ensure stable operation. We propose that a dynamic supply of fuel could help achieve similar performance and reduce the amoun [...] 1089 8234 |
Surface Treatment of Flexible Barrier Film for Improved Stability of Organic Photovoltaic Mini Modulesby
Abstract
The lifetime and stability of organic photovoltaics (OPVs) are the key factors that influence the technology used to scale up and commercialize OPVs. High-performing and reliable devices are used to fabricate the devices of choice. Materials and methods that can be used to prevent the degradation of organic materials, enabling better OPV applications, are being increasingly researched in recent years. Herein, we present the surface modification process of a commercial, flexible barrier film based on polyethylene te [...] 1525 10203 |
Analysis of LoRa Transmission Delay on Dynamic Performance of Standalone DC MicrogridsAbstract
One important aspect toward proper and stable functioning of a communication-based controlled microgrid is data transmission. Consequently, an analysis of the effect of data transmission delay is of significance for any chosen communication protocol. This paper focuses on the effect of employing LoRa for data transfer at the secondary control level of a standalone DC microgrid. It analyses the effect of LoRa transmission delay on the dynamic performance of DC microgrids. This paper simulates a community DC microgri [...] 1260 9510 |
Controller Evaluation for Solar-Latent Thermal Energy Applicationsby
Abstract
In this study, the performance of a self-sufficient controller used for a solar-latent heat domestic hot water (DHW) production unit under real-world operating conditions was analyzed. The unit consists of a flat-plate solar collector and a latent heat storage tank. The controller is powered by a small solar panel and governs the charging and discharging of the system, ensuring maximum solar energy absorption, desired hot water temperature, and constant monitoring of the heat-storage tank’s capacity. The system is [...] 1001 7154 |
Improving the Engine Efficiency Using a New Combined Refrigeration Cycle for Low-Temperature Heat Source (Waste Heat Recovery)Abstract
Passenger and commercial internal combustion engines have relatively large dissipated thermal energy sources that can be used for initiating thermodynamic refrigeration cycles at low temperatures while improving engine efficiency. Researchers have focused on combined power-refrigeration cycles in past studies. This paper presents the operation and performance of a new combined refrigeration system driven by waste heat recovery within the internal combustion engines. For this purpose, the effects of several paramete [...] 1168 7421 |
Analysis of Correlations for the Prediction of the Entrainment Fraction of Droplets in Gas-liquid Annular Flowsby
Abstract
In gas-liquid flows, droplets that detach from the liquid film lining the internal walls of a pipe and merge with the gas flowing through the pipe follow an annular flow pattern. This work analyzes correlations for estimating the entrainment fraction of such droplets contained in the literature by comparing their predictions with experimental data also from the literature. The results of this comparative study demonstrate that the analyzed correlations do not accurately reproduce experimental conditions. This is du [...] 1898 11646 |
Non-Newtonian Flow in Bifurcated Piping and Arterial Networksby
Abstract
Flows in multi-branch piping systems are modeled for linear Newtonian and nonlinear Power Law, Bingham Plastic and Herschel-Bulkley fluids. The nonlinear models are often used to describe multiphase fluids consisting of liquid and solid phases, including cement slurries and drilling muds in petroleum engineering. Rheological and heterogeneous multiphase effects are important to blood flows in single and bifurcated arteries, capillaries and veins – biological applications are also emphasized to highlight their incre [...] 1228 9706 |
A Large Eddy Simulation Study of Cyclones: The Effects of Interparticle Collisions on Erosion Predictionby
Abstract
Cyclone separators are widely used in fluid catalytic cracking (FCC) units due to their lack of moving parts and relatively low-pressure drop. However, cyclone separators are prone to erosion-related issues, which is a major drawback. In this paper, a large eddy simulation (LES) of the particle-gas flow in a cyclone separator is investigated using a four-way Euler-Lagrange approach to model inter-particle collisions and the exchange of momentum between particles and fluid. The effects of inter-particle and particle [...] 1603 10833 |
Experimental Study of Lean-burning Limits of Hydrogen-enriched LPG Intended for Domestic UseAbstract
The lean-burning limits of hydrogen-enriched Liquefied Petroleum Gas (LPG) have been studied using a Bunsen burner. The lean-burning limits under different conditions are important design considerations in developing gas-fired domestic appliances. In this study, the lean-burning limits of hydrogen-enriched LPG have been obtained across a wide range of Reynolds numbers (600 to 1800) and H2 volumetric fractions (0% to 25%). The results show that the lean-burning limit is increased, on average, by 4.0% to 7.2% for eve [...] 2202 12153 |
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