Records Added in May 2023
Records added in May 2023
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Showing records 26 to 50 of 418. [First] Page: 1 2 3 4 5 6 Last
Perspectives of Using Sewage Sludge Char in CO2 Sequestration on Degraded and Brownfield Sites
Marcin Sajdak, Monika Zajemska, Miloud Ouadi, Walter Mucha, Edyta Misztal, Celina Pieszko, Grzegorz Gałko
May 24, 2023 (v1)
Subject: Materials
Keywords: brownfield sites, char, CO2 sequestration, degraded sites, sewage sludge
One of the greatest challenges humankind currently faces is global warming, mainly caused by greenhouse gas emissions. Here we have attempted to show how thermal conversion products, specifically from the pyrolysis of biomass wastes such as sewage sludge, can be used effectively and equivalently to sequester CO2 in brownfield and degraded areas. Scenarios were devised that showed the significant potential for CO2 sequestration in the form of biochar from sewage sludge deposited on degraded and brownfield areas. With the current amount of sludge production, such sludge could even be used in its entirety as a raw material in pyrolysis processes, where, in addition to the biochar, the heat necessary for drying the sludge could be generated and high-energy gas and liquid fractions could be obtained, which could be used to produce alternative fuels. It is therefore important to consider both the potential for CO2 sequestration on degraded and brownfield sites and the potential for sludge di... [more]
Toward Improved Urban Building Energy Modeling Using a Place-Based Approach
Guglielmina Mutani, Pamela Vocale, Kavan Javanroodi
May 24, 2023 (v1)
Keywords: geo-database, geographic information system, place-based approach, QGIS, sustainable cities and communities, Urban Building Energy Modeling UBEM, Urban Scale Energy Models USEM
Urban building energy models present a valuable tool for promoting energy efficiency in building design and control, as well as for managing urban energy systems. However, the current models often overlook the importance of site-specific characteristics, as well as the spatial attributes and variations within a specific area of a city. This methodological paper moves beyond state-of-the-art urban building energy modeling and urban-scale energy models by incorporating an improved place-based approach to address this research gap. This approach allows for a more in-depth understanding of the interactions behind spatial patterns and an increase in the number and quality of energy-related variables. The paper outlines a detailed description of the steps required to create urban energy models and presents sample application results for each model. The pre-modeling phase is highlighted as a critical step in which the geo-database used to create the models is collected, corrected, and integra... [more]
Holistic Approach for an Energy-Flexible Operation of a Machine Tool with Cooling Supply
Martin Lindner, Benedikt Grosch, Ghada Elserafi, Bastian Dietrich, Matthias Weigold
May 24, 2023 (v1)
Subject: Optimization
Keywords: demand-side management, energy flexibility, machine tool, manufacturing, Optimization
The following paper examines the practicality of a methodical approach for energy-flexible and energy-optimal operation in the field of metal-cutting production. The analysis is based on the example of a grinding machine and its central cooling-supply system. In the first step, an energy-flexibility data model is built for each subsystem, which describes energy flexibility potentials generically. This is then extended to enable combined energy cost-optimal production planning. As a basis for the links between the data model representations, the cold flows between the subsystems are modeled using parameter-estimation methods, which have a mean absolute error of only 2.3 percent, making the subsequent installation of heat meters unnecessary. Based on the presented approach, the results successfully validate the possibility of energy-flexible cost-optimal and sensor-reduced production planning by reducing energy costs by 6.6 percent overall and 1.9 percent per workpiece produced.
An ECMS Based on Model Prediction Control for Series Hybrid Electric Mine Trucks
Jichao Liu, Yanyan Liang, Zheng Chen, Hai Yang
May 24, 2023 (v1)
Keywords: equivalent consumption minimization strategy, Model Predictive Control, recurrent neural network, series hybrid electric mine trucks
This paper presents an equivalent consumption minimization strategy (ECMS) based on model predictive control for series hybrid electric mine trucks (SHE-MTs), the objective of which is to minimize fuel consumption. Two critical works are presented to achieve the goal. Firstly, to gain the real-time speed trajectory on-line, a speed prediction model is established by utilizing a recurrent neural network (RNN). Specifically, a hybrid optimization algorithm based on the genetic algorithm (GA) and the particle swarm optimization algorithm (PSOA) is used to enhance the prediction precision of the speed prediction model. Then, on this basis, an ECMS based on MPC (ECMS-MPC) is proposed. In this process, to improve the real-time and working condition adaptability of the ECMS-MPC, the power-optimal fuel consumption mapping model of the range extender is established, and the equivalent factor (EF) is real-time adjusted by means of the PSOA. Finally, taking a cement mining road as the research ob... [more]
Vehicle Emission Models and Traffic Simulators: A Review
Maksymilian Mądziel
May 24, 2023 (v1)
Keywords: air pollution, emission compounds, emission modelling, traffic simulation, vehicles
Accurate estimations and assessments of vehicle emissions can support decision-making processes. Current emission estimation tools involve several calculation methods that provide estimates of the exhaust components that result from driving on urban arterial roads. This is an important consideration, as the emissions generated have a direct impact on the health of pedestrians near the roads. In recent years, there has been an increase in the use of emission models, especially in combination with traffic simulator models. This is because it is very difficult to obtain an actual measurement of road emissions for all vehicles travelling along the analysed road section. This paper concerns a review of selected traffic simulations and the estimation of exhaust gas components models. The models presented have been aggregated into a group with respect to their scale of accuracy as micro, meso, and macro. This paper also presents an overview of selected works that combine both traffic and emis... [more]
Investigating Thermoelectric Batteries Based on Nanostructured Materials
Svyatoslav Yatsyshyn, Oleksandra Hotra, Pylyp Skoropad, Tetiana Bubela, Mykola Mykyichuk, Orest Kochan, Oksana Boyko
May 24, 2023 (v1)
Subject: Materials
Keywords: metallic glass, nanostructured material, thermocouple, thermoelectric battery, thermoelectric generator
This article discusses the characteristics of the design of thermoelectric generators (TEGs) for cold climates. Since the thermocouples of thermoelectric batteries are produced from different materials, their major properties are studied. Particular attention is given to nanostructured materials regarding the modern class of thermoelectric materials. Two-, three-, and four-component alloys (metallic glasses) of the Fe-Ni(Cu)-P-B system are chosen based on the experience of thermoelectric thermometry. The close chemical composition of two thermoelectrodes enables their compatibility in thermocouple production and satisfactory thermoelectric efficiency of batteries during long-term operation. The improvement of the thermoelectric battery characteristics related to a unit of mass is evaluated. The materials studied are distinguished by the absence of toxic components harmful to the environment at the manufacturing and operating stages.
Sand and Dust Storms’ Impact on the Efficiency of the Photovoltaic Modules Installed in Baghdad: A Review Study with an Empirical Investigation
Miqdam T. Chaichan, Hussein A. Kazem, Ali H. A. Al-Waeli, Kamaruzzaman Sopian, Mohammed A. Fayad, Wissam H. Alawee, Hayder A. Dhahad, Wan Nor Roslam Wan Isahak, Ahmed A. Al-Amiery
May 24, 2023 (v1)
Keywords: photovoltaic modules performance, PM1.0, PM2.5, sand and dust storms, total suspended particles
Airborne dust and dust storms are natural disasters that transport dust over long distances from the source basin, sometimes reaching hundreds of kilometers. Today, Iraq is a basin that produces dust storms that strike all neighboring countries such as Iran, Kuwait and Saudi Arabia. These storms affect the productivity and capacity of the photovoltaic modules and reduce the amount of electricity that is generated clearly. Airborne dust reduces the intensity of solar radiation by scattering and absorbing it. In addition, the dust accumulated on the photovoltaic modules causes a deterioration in their productivity. In this study, an extensive review of wind movement and its sources, especially those that hit the city of Baghdad, the capital of Iraq, was conducted. Practical experiments were also carried out during a storm to measure important variables that had not been measured practically before at this site. The experimental tests were carried out starting from 1 April 2022 and contin... [more]
Seismic Monitoring at the Farnsworth CO2-EOR Field Using Time-Lapse Elastic-Waveform Inversion of 3D-3C VSP Data
Xuejian Liu, Lianjie Huang, Kai Gao, Tom Bratton, George El-Kaseeh, William Ampomah, Robert Will, Paige Czoski, Martha Cather, Robert Balch, Brian McPherson
May 24, 2023 (v1)
Keywords: CO2 monitoring, elastic-waveform inversion, enhanced oil recovery, Farnsworth, geologic carbon storage, time-lapse seismic monitoring, vertical seismic profiling (VSP)
During the Development Phase of the U.S. Southwest Regional Partnership on Carbon Sequestration, supercritical CO2 was continuously injected into the deep oil-bearing Morrow B formation of the Farnsworth Unit in Texas for Enhanced Oil Recovery (EOR). The project injected approximately 94 kilotons of CO2 to study geologic carbon storage during CO2-EOR. A three-dimensional (3D) surface seismic dataset was acquired in 2013 to characterize the subsurface structures of the Farnsworth site. Following this data acquisition, the baseline and three time-lapse three-dimensional three-component (3D-3C) vertical seismic profiling (VSP) data were acquired at a narrower surface area surrounding the CO2 injection and oil/gas production wells between 2014 and 2017 for monitoring CO2 injection and migration. With these VSP datasets, we inverted for subsurface velocity models to quantitatively monitor the CO2 plume within the Morrow B formation. We first built 1D initial P-wave (Vp) and S-wave (Vs) velo... [more]
Hosting Capacity Estimate Based on Photovoltaic Distributed Generation Deployment: A Case Study in a Campus of the University of São Paulo
Igor Cordeiro, Welson Bassi, Ildo Luís Sauer
May 24, 2023 (v1)
Keywords: distributed generation, hosting capacity, photovoltaic, power flow, utility
Distributed generation, which is mainly deployed with PV systems that benefit economically prosumers, has soared in use in Brazil. Despite this, PV capacity in excess may cause technical issues which concern planning engineers who have adopted rules of thumb to screen interconnection requests without any detailed study. Recently, the hosting capacity concept has been employed to assess how much PV capacity a distribution grid can host without deteriorating grid parameters, reliability, or power quality. A steady-state and worst-case-based scenario was used to run deterministic power flow simulations to estimate the hosting capacity of a specific radial circuit at a campus of the University of São Paulo, referred to as “USP-105”. Although the result may be not completely accurate, it was found that USP-105 can accommodate 103% of its peak load or 4970.6 kW of PV power, which reduced the circuit’s annual peak load by 9%. Another finding was that hosting capacity increased when PV-DG depl... [more]
An Easily Scalable Dynamic Wireless Power Transfer System for Electric Vehicles
Jannis Noeren, Nejila Parspour, Lukas Elbracht
May 24, 2023 (v1)
Keywords: dynamic wireless charging, electric vehicles, inductive power transfer, inverters, wireless power transfer
This article deals with a LCC-LCC compensated dynamic wireless power transfer system for electric vehicle charging applications. The presented prototype system allows for a power transfer of about 10 kW at 20 cm coil copper to copper distance. With just one circular pickup coil and a very straightforward control scheme, a new coil arrangement enables a seamless power transfer. Furthermore, the system’s design power level is easily adjustable by the size of the the pickup coil. The hardware architecture as well as the software functionality are described in detail. A 20 m test track was built up according to the outlined principle. By measuring the transmitted power, the efficiency and the interference between the primary segments and its effect on the inverter currents are examined. The results show an effective DC to DC efficiency in the range of 91 to 92% and a power fluctuation of approximately 25%.
Clean Energy Action Index Efficiency: An Analysis in Global Uncertainty Contexts
Rui Dias, Nicole Horta, Mariana Chambino
May 24, 2023 (v1)
Keywords: clean energy, correlation, dirty energy, financial arbitrage, financial turmoil, market efficiency
Climate change, the scarcity of fossil fuels, advances in clean energy, and volatility of crude oil prices have led to the recognition of clean energy as a viable alternative to dirty energy. This paper investigates the multifractal scaling behavior and efficiency of green finance markets, as well as traditional markets such as gold, crude oil, and natural gas between 1 January 2018, and 9 March 2023. To test the serial dependency (autocorrelation) and the efficient market hypothesis, in its weak form, we employed the Lo and Mackinlay test and the DFA method. The empirical findings showed that returns data series exhibit signs of (in)efficiency. Additionally, there is a negative autocorrelation among the crude oil market, the Clean Energy Fuels Index, the Global Clean Energy Index, the gold market, and the natural gas market. Arbitration strategies can be used to obtain abnormal returns, but caution should be exercised as prices may increase above their actual market value and reduce t... [more]
Advances in Climatic Form Finding in Architecture and Urban Design
Francesco De Luca
May 24, 2023 (v1)
Subject: Environment
Keywords: building and urban form generation, climate adaptation, computational design, energy generation, energy use reduction, indoor and outdoor comfort, sustainable built environment
Researchers, architects and planners are increasingly urged to develop and apply sustainable methods and solutions to reduce the impact of the built environment on climate, adapt cities to climate change and reduce or eliminate resource depletion and building-related carbon emissions. In recent years, taking advantage of state-of-the-art computational and environmental design tools, researchers and designers are developing new digital workflows, methods and solutions to investigate climate-optimal and performative buildings and urban forms. This perspective paper analyses state-of-the-art computational methods; form generation processes; and tools, criteria and workflows that present how these are integrated into climatic form finding, allowing the improvement of building and urban environmental performances. Additionally, current challenges and future directions are presented.
Graded-Index Active Layer for Efficiency Enhancement in Polymer Solar Cell
M. A. Morsy, Khalid Saleh
May 24, 2023 (v1)
Keywords: 2D-PhC, FDTD, FF, GI-Active layer, PCE, PSC
In this paper, narrow-bandgap polymer acceptors combining a benzotriazole (BTz)-core fused-ring segment, named the PZT series, were used with a high-absorption-efficiency polymer (PBDB) compound with branched 2-butyl octyl, linear n-octyl, and methyl to be utilized as a graded-index (GI) active layer of the polymer solar cells (PSCs) to increase the photocurrent and enhance solar efficiency compared to the existing PBDB-T:PZT and PBDB-T:PZT-γ. In addition, a two-dimensional photonic crystal (2D-PhC) structure was utilized as a light-trapping anti-reflection coating (ARC) thin film based on indium tin oxide (ITO) to reduce incident light reflection and enhance its absorption. The dimensions of the cell layers were optimized to achieve the maximum power-conversion efficiency (PCE). Furthermore, the design and simulations were conducted from a 300 nm to 1200 nm wavelength range using a finite difference time-domain (FDTD) analysis. One of the most important results expected from the study... [more]
Flow Characteristics of Electrochemical Catalytic Reduction of CO2 in Microchannel
Qingjun Yang, Rizhi Dong, Rui Zhu, Shangru Yang, Wen Xie
May 24, 2023 (v1)
Subject: Materials
Keywords: gas-liquid two-phase flow, microfluidic reaction device, photoelectrocatalysis, transfer coefficient
Human beings need abundant material support and energy supply in their exploration of the universe. The sustainable supply of materials is an important condition for long-term space exploration. In situ resource utilization technology (ISRU) is an important way to realize the sustainable development of space exploration, which uses the abundant raw materials in outer space to transform energy and materials. In this paper, a microfluidic reaction device based on in situ resource utilization is designed, which converts H2O and CO2 into O2 and organic matter through photoelectrocatalysis. The flow and mixing process of gas-liquid two-phase flow was studied, and both the characteristics of mass transfer and the chemical reaction of fluids in the microchannel were studied. The dynamic process of the fluid-in-microchannel chemical reaction was expounded, and a prediction model of the volumetric mass transfer coefficient was proposed. The results show that the mass transfer coefficient of the... [more]
Experimental Validation of Double Paraboloid Reflection for Obtaining Quasi-Homogeneous Distribution of Concentrated Solar Flux
Gonçalo Domingos, José Carlos Garcia Pereira, Pedro Alexandre Rodrigues Rosa, José Rodríguez, Luís Guerra Rosa
May 24, 2023 (v1)
Subject: Environment
Keywords: Cassegrain reflector, double paraboloid reflection, optical modelling, ray tracing simulations, solar flux distribution
This work demonstrates that the quasi-homogeneous distribution of concentrated solar flux is achievable by using double paraboloid reflection, with a primary reflector to concentrate the sunlight, and a secondary reflector to homogenise the radiation flux. For that, three slightly different secondary reflectors were designed and manufactured, matching the specifications of the paraboloid concentrator of the SF60 solar furnace located in PSA—Plataforma Solar de Almería, which was used as primary reflector. Starting from preliminary simulations of the optical apparatus, the secondary geometries were selected and then the reflectors were manufactured from 7075-T6 aluminium alloy, using conventional and CNC machining technologies, with further processing to achieve a mirror-like finish. The results obtained from solar irradiation tests corroborate that the “double paraboloid reflection” methodology proposed in previous theoretical works seems to be technically feasible and can be a solutio... [more]
Toward a Fast but Reliable Energy Performance Evaluation Method for Existing Residential Building Stock
Stefano Converso, Paolo Civiero, Stefano Ciprigno, Ivana Veselinova, Saffa Riffat
May 24, 2023 (v1)
Keywords: BEM input database, decarbonization targets, dynamic simulations, energy assessment, Google Maps geometry extraction, old residential buildings, tabular data
Building a reliable energy model for old residential buildings with insufficient documentation and user assistance is a challenging and time-consuming task. Nevertheless, the ambitious European decarbonization targets require this building stock to be renovated, making energy assessment a key priority. In line with this goal, the following study explores a more simplified and automatic framework to generate a residential building energy model (BEM). The paper’s approach is based on the concept of urban building energy modelling (UBEM) archetypes or building prototypes and is customized according to the principles of dynamic simulations performed in the existing BEM software, Integrated Environmental Solutions Virtual Environment IES VE, and Solemma Open Studio. Therefore, based on three real starting inputs, a prototype database (DB) of assigned inputs is generated, i.e., an input matrix, using Google Maps as a geometry source. Other data are drawn from tabular DB. The proposed approac... [more]
Yaw Optimisation for Wind Farm Production Maximisation Based on a Dynamic Wake Model
Zhiwen Deng, Chang Xu, Zhihong Huo, Xingxing Han, Feifei Xue
May 24, 2023 (v1)
Keywords: dynamic wake model, production maximisation, wind farm, yaw meandering
In recent years, a major focus on wind farm wake control is to maximise the production of wind farms. To improve the power generation efficiency of wind farms through wake regulation, this study investigates yaw optimisation for wind farm production maximisation from the perspective of time-varying wakes. To this end, we first deduce a simplified dynamic wake model according to the momentum conservation theory and backward difference method. The accuracy of the proposed model is verified by simulation comparisons. Then, the time lag of wake propagation and its impact on wind farm production maximisation through wake meandering is analysed. On this basis, a yaw optimisation method for increasing wind farm energy capture is presented. This optimisation method uses the proposed dynamic wake model for wind farm prediction. The results indicate that the optimisation period is critical to the effect of the optimisation method on wind farm energy capture.
Hybrid (Gas and Geothermal) Greenhouse Simulations Aimed at Optimizing Investment and Operative Costs: A Case Study in NW Italy
Jessica Maria Chicco, Leonardo Fonte, Giuseppe Mandrone, Andrea Tartaglino, Damiano Vacha
May 24, 2023 (v1)
Keywords: cost optimization, greenhouse, Modelling, shallow geothermal plant
Generally, greenhouses are high energy-consuming, sometimes accounting for 50% of the cost of greenhouse production. Geothermal energy plays a very important role in maintaining the desired temperature and reducing energy consumption. This work deals with a project of a hybrid heating plant (97% geothermal energy and 3% gas-condensing boiler) for the innovative Plant Phenotyping Greenhouse at the University Campus in Grugliasco (few km West of the city of Turin). The aim of the study is to testify to the energy efficiency of this kind of hybrid plant as well as its economic sustainability. Numerical simulations of a GRT were used to calibrate the system and verify that the software reasonably modeled the real case. They helped to correctly size the geothermal plant, also providing data about the thermal energy storage and production during on and off plant cycles. The results show a thermal power of 50.92 kW over 120 days of plant operation, in line with the expected energy needs to me... [more]
DC Link Voltage Enhancement in DC Microgrid Using PV Based High Gain Converter with Cascaded Fuzzy Logic Controller
Senthilnathan Rajendran, Vigneysh Thangavel, Narayanan Krishnan, Natarajan Prabaharan
May 24, 2023 (v1)
Keywords: Cascaded Fuzzy Logic Controller, DC-link voltage, droop control, Luo converter, virtual inertia and damping control
Renewable-based sources can be interconnected through power electronic converters and connected with local loads and energy storage devices to form a microgrid. Nowadays, DC microgrids are gaining more popularity due to their higher efficiency and reliability as compared to AC microgrid systems. The DC Microgrid has power electronics converters between the DC loads and renewable-based energy sources. The power converters controlled with an efficient control algorithm for maintaining stable DC bus voltage in DC microgrids under various operating modes is a challenging task for researchers. With an aim to address the above-mentioned issues, this study focuses on the DC link voltage enhancement of a DC Microgrid system consisting of PV, DFIG-based wind energy conversion system (WECS), and battery Energy Storage System (ESS). To elevate PV output voltage and minimize the oscillations in DC link voltage, a high-gain Luo converter with Cascaded Fuzzy Logic Controller (CFLC) is proposed. Droo... [more]
The Impact of ICT Capital Services on Economic Growth and Energy Efficiency in China
Huifang E, Shuangjie Li, Liming Wang, Huidan Xue
May 24, 2023 (v1)
Keywords: economic growth decomposition framework, Energy Efficiency, ICT capital services, panel regression
This study aims to investigate the impact of ICT capital services on economic growth and energy efficiency in China at both national and industrial levels during the period 2000−2020. To achieve this aim, this study introduces a measurement method for capital services, explores ICT’s contributions to economic growth, and analyzes the impact of ICT on energy efficiency. The empirical results of this study indicate that although the ICT capital services scale is relatively small, accounting for only 8.87% of the total in 2020, its growth rate is faster than that of non-ICT capital services, and the distribution of ICT capital services varies widely among different industries. Additionally, based on the economic growth decomposition framework, this study finds that the contribution of ICT capital services to economic growth is 6.95% on average. It is significantly higher in certain industries, such as Financial industry; Information transmission, software and information technology servic... [more]
An Optimal Control Method for Greenhouse Climate Management Considering Crop Growth’s Spatial Distribution and Energy Consumption
Kangji Li, Yanhui Mi, Wen Zheng
May 24, 2023 (v1)
Keywords: crop growth, Energy Efficiency, greenhouse climate, optimal control, POD, rolling horizon
The environmental factors of greenhouses affect crop growth greatly and are mutually coupled and spatially distributed. Due to the complexity of greenhouse climate modeling, the current optimal control of greenhouse crop growth rarely considers the spatial distribution issues of environmental parameters. Proper Orthogonal Decomposition (POD) is a technique to reduce the order of a model by projecting it onto an orthogonal basis. In this paper, POD is used to extract environmental features from Computational Fluid Dynamics (CFD) simulations, and a low-dimensional feature subspace is obtained by energy truncation. With multi-dimensional interpolation, fast and low-dimensional reconstruction of the dynamic variation of greenhouse climates is achieved. On this basis, a rolling-horizon optimal control scheme is proposed. For each finite horizon, the external meteorological data are updated, and the response of the greenhouse environment is quickly calculated by the POD model. With the perfo... [more]
Impact on Energy Yield of Varying Turbine Designs under Conditions of Misalignment to the Current Flow
Luke Evans, Ian Ashton, Brian G. Sellar
May 24, 2023 (v1)
Keywords: acoustic doppler profiler, IEC TS 62600-200, marine renewable energy, power curve, power performance, tidal energy, tidal flow asymmetry, turbine yaw misalignment, uncertainty
Tidal energy resource characterisation using acoustic velocimetry sensors mounted on the seabed informs developers of the location and performance of a tidal energy converter (TEC). This work studies the consequences of miscalculating the established flow direction, i.e., the direction of assumed maximum energy yield. Considering data only above the proposed TEC cut-in velocities showed a difference in the estimated flow direction of up to 4°. Using a power weighted rotor average (PWRA) method to obtain the established flow direction resulted in a difference of less than 1° compared with the hub-height estimate. This study then analysed the impact of turbine alignment on annual energy production (AEP) estimates for a non-yawing tidal turbine. Three variants of horizontal axis tidal turbines, which operate in different locations of the water column, were examined; one using measured data, and the other two via modelled through power curves. During perfect alignment to the established fl... [more]
Characteristics of Fracturing Fluid Invasion Layer and Its Influence on Gas Production of Shale Gas Reservoirs
Shijun Huang, Jiaojiao Zhang, Jin Shi, Fenglan Zhao, Xianggang Duan
May 24, 2023 (v1)
Keywords: CT scan, fracturing fluid invasion layer, fracturing fluid retention, numerical simulation, shale gas reservoir
With the increase of shale gas resource exploitation in our country during recent decades, the situations of low gas production, fast production decline rate, and low flowback rate have been appearing in field production. It is an urgent problem to be solved in shale gas production and it is therefore necessary to study the interaction of the shale gas reservoir and the detained fracturing fluid. In this paper, the Longmaxi Formation shale samples of Sichuan Basin were selected for a water invasion experiment. The fracture propagation law, the water invasion front location, and the water invasion thickness of deep and shallow shale reservoirs after water invasion were compared and analyzed by CT scanning technology. Based on the analysis of the experimental mechanism, a numerical simulation model was established. The dimensionless permeability and thickness of the fracturing fluid invasion layer were introduced to analyze the positive and negative effects of fracturing fluid retention... [more]
Exploring Digital Twins in the Transport and Energy Fields: A Bibliometrics and Literature Review Approach
Milena Kajba, Borut Jereb, Tina Cvahte Ojsteršek
May 24, 2023 (v1)
Keywords: bibliometrics, digital twin, energy consumption, literature review, logistics, optimisation, transport
Logistics and transport are major sources of energy consumption that still rely heavily on fossil fuels. Especially in the freight sector, finding means to optimise fuel consumption and energy efficiency are increasingly important. Digital twins’ adaptation in logistics and transport is not as frequent as in production, but their implementation potential is immense. This technology can replicate real environments, allowing verification of various scenarios without real-life application, leading to optimal implementation outcome faster and more efficiently. This paper aims to research digital twins’ use in logistics and transport, focusing on digital twins’ potential and effects to optimise energy consumption. Firstly, previous research on digital twins in specified fields was identified, followed by a quantitative literature review. The latter focused on codifying the selected publications based on criteria such as modality, specific environment, energy consumption, etc. Furthermore, a... [more]
Reducing Soot Nanoparticles and NOX Emissions in CRDI Diesel Engine by Incorporating TiO2 Nano-Additives into Biodiesel Blends and Using High Rate of EGR
Mohammed A. Fayad, Mohammed Sobhi, Miqdam T. Chaichan, Tawfik Badawy, Wisam Essmat Abdul-Lateef, Hayder A. Dhahad, Talal Yusaf, Wan Nor Roslam Wan Isahak, Mohd S. Takriff, Ahmed A. Al-Amiery
May 24, 2023 (v1)
Subject: Materials
Keywords: castor oil, EGR, NOX emissions, soot nanoparticles, TiO2 nano-additives
The developments in the field of nano-additives have increased in the recent years due to the desire to reduce the level of exhaust emissions in diesel engines. The soot characteristics of particulate matter (PM) and nitrogen oxides (NOX) were experimentally investigated using two concentrations of titanium dioxide (TiO2) as nano-additives (25 ppm and 40 ppm) blended with C20D (composed of 20% castor oil methyl ester and 80% diesel fuel) and 30% exhaust gas recirculation (EGR). The combustion of C20D + TiO2 increases brake thermal efficiency (BTE) by 2.8% in comparison with neat C20D, while a significant reduction was obtained in BSFC 6.5% and NOX emissions were maintained at a level parallel with diesel. The results indicated that the technique involving a high EGR rate and the addition of 25 ppm and 40 ppm of TiO2 nanoparticles to the C20D exhibits better reductions in NOX emissions by 17.34% and 21.83%, respectively, compared to the technique comprising the use of C20D + TiO2 and C2... [more]
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