This paper presents the results of material tests, experimental tests and statistical analysis of the thermal performance of three types of heat accumulators containing an organic phase-change material and two materials of a higher thermal conductivity: a copper mesh and porous coke recyclate. The aim of the research was to empirically and statistically compare the increase in the PCM heat distribution through a copper conductor and coke recyclate. The research was conducted in accordance with an incomplete central compositional experimental design and using the Statistica software. The studies of the structure and chemical composition of the coke recyclate used and the empirical testing of the finished heat accumulators confirmed an improvement in the distribution and storage of heat by the accumulator with the phase-change material and coke recyclate compared to the pure phase-change material and copper-conductor accumulators, as the holding time of a temperature of 20 °C was extende... [more]

The mechanical recycling of solid plastic waste on a small-scale level can be accomplished with the correct approaches. Thermoplastics are the types of plastic mostly considered for mechanical recycling because of their physical properties and ease of reprocessing. This paper reviews the mechanical reprocessing techniques of selected thermoplastics (polyethylene terephthalate and polyolefins), since they constitute a significant proportion of the plastics used commercially. Furthermore, necessary considerations for the effective operation of small-scale plants, including energy requirements of machinery and optimisation in order to improve efficiency and product quality, are discussed. A clearer understanding and addressing of the process-related challenges will lead to the successful establishment and management of small-scale mechanical recycling facilities to benefit communities. Efficient small-scale mechanical reprocessing establishments have become essential in reducing the envir... [more]

This paper reviews analytical solutions for the accelerated flow of an incompressible Newtonian fluid in a pipeline. This problem can be solved in one of two ways according to the (1) imposed pressure gradient or (2) flow rate. Laminar accelerated flow solutions presented in a number of publications concern cases where the two driving mechanisms are described by simple mathematical functions: (a) impulsive change; (b) constant change; (c) ramp change, etc. The adoption of a more complex and realistic description of the pressure gradient or flow rate will be associated with a profound mathematical complexity of the final solution. This is particularly visible with the help of the universal formula derived by several researchers over the years and discussed in this paper. In addition to the solutions strictly defined for laminar flow, an interesting extension of this theory is the theory of underlying laminar flow for the analysis of turbulent accelerated pipe flows (TULF model developed... [more]

In order to help Energy Internet (EI) enterprises develop sustainably, promote the transformation and upgrading of energy systems and achieve the goal of carbon peaking and carbon neutrality, a study on the influencing factors of green technology innovation (GTI) in EI enterprises was conducted using the Decision-making Trial and Evaluation Laboratory-Adversarial Interpretive Structure Modeling Method (DEMATEL-AISM). Through a literature review and field research, the DEMATEL-AISM-based model of the GTI influencing factors of EI enterprises was constructed on the basis of summarizing the system of GTI influencing factors of EI enterprises, visualizing the interrelationship and hierarchical structure among GTI influencing factors of EI enterprises and finally proposing relevant countermeasures and suggestions. This study shows that the proximity-level factors such as R&D investment and external cooperation directly affect the GTI of EI enterprises; the essential-level factors such as en... [more]

Nowadays, the Internet of Things (IoT) has a wide impact on many potential applications. The impact of IoT on performing demand-side management (DSM) in an Indian educational institution has not been researched in depth before. In this research work, an IoT-enabled SDSMS (Smart DSM System) has been deployed with the main objective of minimizing electricity tariff and also to tweak the quality of user comfort. It can be feasible by prioritizing available renewable PV solar energy during peak hours in an Indian educational institution. DSM has been performed using day-ahead load shifting and rescheduling the different classes of institutional loads by applying hybrid BPSOGSA (Binary Particle Swarm Optimization and Gravitational Search Algorithm). The BPSOGSA performance on DSM has been evaluated based on electricity tariff, peak demand range, and PAR and compared with the outcomes of both binary conventional algorithms BPSO and BGSA, respectively. The proposed method enhances the degree... [more]

The smart grid concept is introduced to accelerate the operational efficiency and enhance the reliability and sustainability of power supply by operating in self-control mode to find and resolve the problems developed in time. In smart grid, the use of digital technology facilitates the grid with an enhanced data transportation facility using smart sensors known as smart meters. Using these smart meters, various operational functionalities of smart grid can be enhanced, such as generation scheduling, real-time pricing, load management, power quality enhancement, security analysis and enhancement of the system, fault prediction, frequency and voltage monitoring, load forecasting, etc. From the bulk data generated in a smart grid architecture, precise load can be predicted before time to support the energy market. This supports the grid operation to maintain the balance between demand and generation, thus preventing system imbalance and power outages. This study presents a detailed revie... [more]

Longwall shearers’ haulage system of the Eicotrack type, used most often nowadays, is presented in this article. Its disadvantages, causing problems with a correct operation of mechanized longwall shearer systems, are discussed. The concept of the innovative Flextrack, which should reduce the occurrence of the disadvantages mentioned above, is described. A course and research results, connected with rig tests of the Flextrack haulage system functionality, are presented. Measurement results of wear and stresses, obtained for the Eicotrack and Flextrack haulage systems, are compared and presented. Based on an analysis of the obtained results, a modified version of the Komtrack haulage system was suggested and manufactured. This haulage system was tested in the field conditions, similar to underground conditions in a mine coal longwall. The obtained results confirmed its full functionality and lack of problems experienced in the case of the Eicotrack and Flextrack systems. At present, the... [more]

Achieving clean energy goals will require significant advances in regard to addressing the computational needs for next-generation renewable-dominated power grids. One critical obstacle that lies in the way of transitioning today’s power grid to a renewable-dominated power grid is the lack of a faster-than-real-time stability assessment technology for operating a fast-changing power grid. This paper proposes an artificial intelligence (AI) -based method that predicts the system’s stability margin information (e.g., the frequency nadir in the frequency stability assessment and the critical clearing time (CCT) value in the transient stability assessment) directly from the system operating conditions without performing the conventional time-consuming time-domain simulations over detailed dynamic models. Since the AI method shifts the majority of the computational burden to offline training, the online evaluation is extremely fast. This paper has tested the AI-based stability assessment me... [more]

Low-salinity surfactant nanofluids have recently shown promising results in the wettability alteration of reservoir rocks from oil-wet state towards more water-wet state. However, the investigation of pore-level interactions of nanofluids injection in real oil carbonate rocks at reservoir conditions, which determines the overall fluid dynamics, is lacking. Therefore, in this work, we studied the effect of nanoparticles augmented low-salinity surfactant flooding on the wettability alteration of hydrophobic carbonate rocks with harsh reservoir conditions via X-ray micro-tomography. The designed experiment scheme involved core flooding with an X-ray transparent core-holder developed for studying the flow properties of fluids at the micro level (pore scale). The wettability was quantified by measuring the differences in contact angles after the injection of low salinity, low-salinity surfactant, and low-salinity surfactant nanofluid. The findings illustrate that surfactant flooding with si... [more]

Information technologies possess the significant potential to improve the efficiency of resources and optimize energy usage, as well as make a significant contribution to the sustainable circular economy (CE). The concept of digital sufficiency provides a framework for understanding how information technology can be part of significant achievements in the circular economy, especially when embraced by business companies. Moreover, the possibility of the implementation of closed-loop resources has become possible with the development of digital manufacturing technologies. However, the research of establishing the CE in SMEs, especially in fossil-energy-abundant countries, such as the Russian Federation, is quite limited. Our paper fills in this gap by studying the adoption of CE practices as well as the investments for promoting CE in Russian SMEs through such factors as the existence of R&D, bank loans, and access to grants at the national and international level. It achieves this based... [more]

The International Accounting Standards Board (IASB) and the International Sustainability Standards Board (ISSB) of the IFRS Foundation support the integrated reporting of companies’ financial and sustainability performance to stakeholders. This paper aims to investigate whether financial and environmental, social, and corporate governance (ESG) practices have a real impact on the success of the companies in the European renewable energy equipment and services industry. Using the Granger test, the causality between the market capitalization and financial indicators was established, whereas no causality was identified between the market capitalization and ESG performance. The research led to the conclusion that the investment decision is mainly based on the information provided by the financial statements of the companies, the early stages of sustainability reporting regulation, and the need for increasing the quality and availability of corporate social responsibility information for in... [more]

Chemical compounds dissolved in insulating oil, as indicators can excellently monitor the paper aging condition, which has attracted increasing interest in areas of transformer condition monitoring and fault diagnosis. Because of their outstanding features, such as good correlation with the degree of polymerization of cellulose paper and the aid of non-destructive online monitoring, chemical indicators have been effectively used for transformer condition assessment. In this study, a comprehensive, in-depth insight into the indicators of the aging of insulating paper from aging characteristics, physico-chemical characteristics, shortcomings of various compounds, generation pathways and mechanisms, and monitoring technologies are provided. It is expected that these chemical indicators can provide better guidance for the evaluation of paper insulation performance and transformer aging. In addition, the latest research progress, as well as current challenges and future prospects are also o... [more]

Despite the enormous efforts put into practice by governmental entities, most of the energy consumption worldwide proceeds from fossil fuels. In this regard, there is a clear need to advance toward the use of cleaner energies. This situation is especially critical in developing countries, where a high population, increased commercial and industrial activities, and rising greenhouse gas (GHG) emissions are major concerns. This paper focuses on reviewing the current energy map in Jordan, one of the developing countries in the Southwest Asia area. Jordan generates 2.7 million tons of municipal solid waste annually, which can cause a variety of environmental problems rather than benefit the energy industry or the country’s economy. Jordan uses biomass energy to provide just 0.1% of its overall energy needs. Presently, produced energy comprises logs, chips, bark, and sawdust is made up of around 44% wood. Jordan has a high potential for producing biomass in the future. About 96% of the biom... [more]

This paper aims to provide a quantitative assessment of the effect of driver action and road traffic conditions in the real implementation of eco-driving strategies. The study specifically refers to an ultra-efficient battery-powered electric vehicle designed for energy-efficiency competitions. The method is based on the definition of digital twins of vehicle and driving scenario. The models are used in a driving simulator to accurately evaluate the power demand. The vehicle digital twin is built in a co-simulation environment between VI-CarRealTime and Simulink. A digital twin of the Brooklands Circuit (UK) is created leveraging the software RoadRunner. After validation with actual telemetry acquisitions, the model is employed offline to find the optimal driving strategy, namely, the optimal input throttle profile, which minimizes the energy consumption over an entire lap. The obtained reference driving strategy is used during real-time driving sessions at the dynamic driving simulato... [more]

This article presents a new model of a dedicated air transformer for computer analyses of wireless power transfer systems. This model includes a form of subcircuit for SPICE. It takes into account the electric, magnetic and thermal properties of the modeled device. The form of the elaborated model is presented and the results of its experimental verification are shown. Some results from measurements and computations of an air transformer and a wireless power transfer system containing this transformer are shown and discussed. The structure of the tested system and the measuring setup used are also described. The results of measurements and computations illustrating the influence of the distance between the windings of the air transformer and the displacement between its windings on the output voltage of the power transfer system are presented and discussed. The influence of load resistance on the properties of the considered system is analyzed.

In the past few decades, the machine learning (or data-driven) approach has been broadly adopted as an alternative to scientific discovery, resulting in many opportunities and challenges. In the oil and gas sector, subsurface reservoirs are heterogeneous porous media involving a large number of complex phenomena, making their characterization and dynamic prediction a real challenge. This study provides a comprehensive overview of recent research that has employed machine learning in three key areas: reservoir characterization, production forecasting, and well test interpretation. The results show that machine learning can automate and accelerate many reservoirs engineering tasks with acceptable level of accuracy, resulting in more efficient and cost-effective decisions. Although machine learning presents promising results at this stage, there are still several crucial challenges that need to be addressed, such as data quality and data scarcity, the lack of physics nature of machine lea... [more]

Energy security affects the functioning of countries politically, economically, and socially. Energy is an important factor in sustainable development efforts. Hence, countries are assessing their energy systems for compatibility with sustainable development goals by creating new concepts for energy development. Combining the concepts of energy security and sustainable energy consumption, an analysis of the differentiation of EU countries in terms of selected indicators indicated in Goal 7 of Agenda 2030 was carried out in dynamic terms. Two groups of indicators were distinguished. One group of indicators was selected to represent the changes in energy demand reported by final consumers, taking into account the use of energy obtained from renewable sources. The second group of indicators represents those relating to the security of supply of raw materials, i.e., energy dependency indicators broken down by major energy commodities and an energy productivity indicator. The analysis uses... [more]

Firewood stoves are widespread and popular for renewable heat supply in Europe. Several new technological measures have been developed recently that aim at improving the appliance performance in terms of emissions and efficiency. In order to support the trend towards “(nearly) zero-emissions technologies”, the objective of this study was to provide a profound overview of the most relevant technical primary and secondary measures for emission reduction and to analyze their functionality, the relevant framework conditions for their application and their costs. Since user behavior is essential for emission and efficiency performance, the state of knowledge about user behavior is summarized and the latest measures for its optimization are evaluated as non-technical primary measures. Primary and secondary measures were analyzed separately, but also potentially promising combinations of primary and secondary optimization were evaluated using SWOT analysis. The results showed that complementa... [more]

The (Cu,Mn,Co)3O4 (CMC) spinel layer is useful in inhibiting Cr vaporization that deteriorates the solid oxide fuel cell performance. The effectiveness of the spinel layer in suppressing volatile Cr species from the metallic interconnects is strongly dependent on layer density, which is influenced by particle size distributions and agglomerations of the spinel powders. Considering that the material properties were influenced by the synthesizing conditions, this study elucidated the influences of citric acid (fuel) on the structure, morphology, and electrical properties of sol−gel derived CMC spinel powders. Dual-phase CMC spinel powders, consisting of cubic CuMnCoO and tetragonal Mn2CoO4, were successfully synthesized at citrate-to-nitrate (CA/MN) ratios of 0.8, 1.0, and 1.2. An undesired CuCo2O4 phase was observed in spinel powders synthesized at a low CA/MN ratio of 0.5. The CA/MN ratio has influenced not only the phase formation of CMC spinel, but also the particle size distribution... [more]

In January 2019, the Canadian province of Alberta enacted limits on crude oil and bitumen production. These production controls, a policy referred to as curtailment, represent a shift for a government that historically avoided market intervention. The policy was designed to shrink a growing and prolonged price differential between the Western Canadian Select price of oil, the key benchmark for Alberta’s heavy oil production, and the West Texas Intermediate benchmark. The curtailment created artificial scarcity, shrinking the price differential from more than $40 USD per barrel in November 2018 to less than $15 USD per barrel in February 2019. In the process, this policy transferred market surplus from refiners, mainly those in the US Midwest, to producers in Alberta. We review this large-scale market intervention and calculate the magnitude of the economic transfer. We find the curtailment increased producer surplus by $659M CAD per month and reduced consumer surplus by $763M per month... [more]

This study addresses the issue of energy optimization by investigating solutions for the reduction of energy consumption in the diagnostics and monitoring of technological processes. The implementation of advanced process control is identified as a key approach for achieving energy savings and improving product quality, process efficiency, and production flexibility. The goal of this research is to develop a cost-effective system with a minimal number of ultrasound sensors, thus reducing the energy consumption of the overall system. To accomplish this, a novel method for obtaining high-resolution reconstruction in transmission ultrasound tomography (t-UST) is proposed. The method involves utilizing a convolutional neural network to take low-resolution measurements as input and output high-resolution sinograms that are used for tomography image reconstruction. This approach allows for the construction of a super-resolution sinogram by utilizing information hidden in the low-resolution m... [more]

The IEEE 1459 standard states that: “There is a need to quantify correctly the distortions caused by the nonlinear and parametric loads …” The paper undertakes this problem. The article includes an analysis of selected steady-state properties of a single-phase AC circuit containing a series connection of a resistance, an inductance, and a nonlinear element described by a signum function. The circuit is supplied from a sinusoidal voltage source. The mathematical model of this circuit is described using dimensionless variables. Based on the harmonic balance, a description of the circuit for the fundamental harmonic and the circuit for the remaining harmonics was separated. On the basis of the relationship between the current and voltage waveforms, the solution for all harmonics, the harmonic content coefficients, and the elements of the equivalent scheme of the nonlinear load, were estimated symbolically. Based on the circuit equations, a circuit model and measurement systems were develo... [more]

The Mobile Ad-hoc Network is a self-configuring decentralized network, where the network topology is dynamically modifiable. The IoT (Internet of Things) based Wireless Sensor Network contains more sensors and shares information over the Internet to a cloud server. However, the IoT-based wireless sensor network channel has moderate security is poor compared to MANET and packet loss is increased due to attackers. In IoT, all the sensors forward the detected data frequently to the internet gateway, so the energy saving in the network is low compared to MANET. In this work, the smart environment of IoT, Wireless Sensor Networks (WSN) and MANET make a great heterogeneous network in IT Technology; the combination of this heterogeneous network has new challenging issues. In this heterogeneous network, MANET provides a trusted route between the sensor to gateway nodes into the IoT environment using Energy Saving Optimization Techniques [MANET-ESO in IoT]. It saves energy for each node and red... [more]

An intermediate fluid vaporizer (IFV) is a typical vaporizer of liquefied natural gas (LNG), which is used in a large number of LNG terminals. Since it requires a large supply of seawater during its operation, it generates a lot of energy consumption. In this study, to reduce the seawater consumption in the regasification system, the heat transfer process was first numerically calculated, and the heat transfer coefficient of the IFV was determined for different seawater inlet temperatures, seawater flow rates, and LNG flow rates. The calculation results of the heat transfer coefficient were integrated into the numerical model in HYSYS, and the minimum seawater flow of the IFV under different working conditions was obtained. For receiving terminals using multiple IFVs, this study programmed calculations based on optimization software. The operating configuration of the IFVs under different operating conditions was optimized to reduce the consumption of seawater in the regasification sys... [more]

With a view to reducing harmonic content in electrical power systems, and, consequently, improving power quality level, filters and other harmonic compensation devices are widely used. In the category of filters, they can be distinguished into two classes that are related to the operating mode, active or passive, both widely known and applied in electrical power grids and in the most diverse industry sectors. In this sense, taking into account the use of compensating devices in four-wire electrical systems feeding single-phase, non-linear loads, this paper presents a new hybrid arrangement of harmonic compensation that incorporates both active and passive filtering, which performs all functions concerning the harmonic compensation of a four-leg shunt active power filter. In this hybrid arrangement, the harmonic filtering of positive and negative sequence components is performed by a three-leg shunt active power filter, while the filtering of zero-sequence harmonics is attributed to the... [more]