The Sichuan Basin is a significant region for exploration and development of shale gas in China, and it is essential to clarify the impact of deep shale gas reservoir parameters on cost-effective development at scale to ensure national energy security. Rock physics modeling is a significant means of communicating the physical and elastic parameters of rocks. A rock physics modeling method applicable to fractured shale gas reservoirs is proposed for the current situation of complex fluid relationships in shale gas reservoirs and unclear characteristics of gas identification seismic response. In this paper, based on the Self Consistent Approximation (SCA) model and the differential effective medium (DEM) model, the anisotropic source of shale is used as a starting point to add bound water, kerogen, clay, and brittle minerals, the Schoenberg linear slip theory is used to add fracture disturbance effects, and then the Brown−Korringa model is used to perform fluid replacement under anisotro... [more]

To solve the problem of the common unsteady inverse heat conduction problem in the industrial field, a real-time solution method of improving the whale optimization algorithm (IWOA) and parameter-adaptive proportional-integral-differential (PID) is proposed in the paper. A feedback control system with IWOA-PID, which can inversely solve the boundary heat flux, is established. The deviation between the calculated temperature and the measured temperature of the measured point obtained by solving the direct heat conduction problem (DHCP) is used as the system input. The heat flux which is iteration-solved by IWOA-PID is used as system output. The method improves the initial solution distribution, global search capability and population diversity generalization of the traditional whale optimization algorithm (WOA), which effectively improves the parameter-adaptive capability of PID. The experimental results show that the solution method of inverse heat transfer proposed in the paper can ac... [more]

Countercurrent flow limitation (CCFL) refers to an important class of gravity-induced hydrodynamic processes that impose a serious restriction on the operation of gas−liquid two-phase systems. In a nuclear power plant, CCFL may occur in the liquid level measurement system where an orifice is applied in the pipeline, which may introduce error into the level measurement system. CCFL can occur in horizontal, vertical, inclined, and even much more complicated geometric patterns, and the hot-leg channel flow passage has been widely investigated; however, a pipeline with variable cross-sections, including an orifice, has not yet been investigated. An experimental investigation has been conducted in order to identify the phenomenon, pattern, and mechanism of CCFL onset in this type of geometry. Both visual and quantified experiments were carried out. A high-speed camera was applied to capture the flow pattern. Visual experiments were implemented at atmospheric pressure, while quantified press... [more]

The electrification of vehicles is considered to be the means of reducing the greenhouse gas (GHG) emissions of the transport sector, but “range anxiety” makes most people reluctant to adopt electric vehicles (EVs) as their main method of transportation. Workplace charging has been proven to counter range anxiety and workplace charging is becoming quite common. A workplace parking lot can house hundreds of EVs. In this paper, a program has been developed in MATLAB that uses the well-known evolutionary optimization algorithm, the genetic algorithm (GA), to optimize the charging schedule of fifty EVs that aims at achieving three goals: (a) keeping the electricity demand low, (b) reducing the cost of charging and (c) applying load shifting. Three schedules were developed for three scenarios. The results demonstrate that each schedule was successful in achieving its goal, which means that scheduling the charging of a fleet of EVs can be used as a method of demand-side management (DSM) in w... [more]

Because reliance on gas for electricity generation rises over time, the natural gas and electricity markets are highly connected. However, both of them are susceptible to various risk factors that endanger energy security. The intricate interactions among multiple risks and between the two markets render risk assessment more challenging than for individual markets. Taking a systematic perspective, this study first undertook a thorough analysis of the evolution mechanism that indicated the key risk factors and dual interactions, with real-world illustrative examples. Subsequently, a system dynamics model was constructed for understanding the causal feedback structures embedded in the operation of a coupled natural gas−electricity market in the face of risks. Quantitative experiments were conducted by using data from China’s Energy Statistical Yearbook, China’s Statistical Yearbook and other reliable sources to assess the effects of individual risks, depict the evolutionary behavior of c... [more]

China has developed a preliminary policy system for the development of new energy vehicles regarding the law, electricity price, grid-connected standards, project management, and financial support, however, defects remain in the policy and market environment, market mechanism, control technology, infrastructure, etc. We analyze new energy vehicles based on the analysis of basic data such as the number of electric vehicles and charging facilities, focusing on industrial development strategies, related subsidies, and tax policies. First, this paper summarizes the development status of China’s new energy vehicles in different scenarios. In 2021, China’s new energy vehicle production was 3545 thousand, and sales amounted to 3521 thousand. According to preliminary estimates, the number of new energy vehicles will exceed 15 million in 2030. The research route for the development of new energy vehicle bottlenecks is proposed. Secondly, we analyze foreign and Chinese policies on different stag... [more]

The perspective of the emerging environmentally friendly and economically efficient detonation gun technology for the high-temperature gasification of organic wastes with ultra-superheated mixture of steam and carbon dioxide is discussed. The technology is readily scalable and allows the establishment of a highly reactive atmospheric-pressure environment in a compact water-cooled gasifier due to very high local temperature (above 2000 °C), intense in situ shock-induced fragmentation of feedstock, and high-speed vortical convective flows enhancing interphase exchange processes. These unique and distinctive features of the technology can potentially provide the complete conversion of solid and liquid wastes into syngas, consisting exclusively of hydrogen and carbon monoxide; microparticles, consisting of environmentally safe simple oxides and salts of mineral residues, as well as aqueous solutions of oxygen-free acids such as HCl, HF, H2S, etc., and ammonia NH3. A small part of the synga... [more]

The article describes an approach to expanding the methodology for applying hydraulic fracturing in oil fields by adding the possibilities of 3D modeling with color imaging of the pore structure of the productive intervals of wells. As an applied example, the geological and geophysical section of the productive level of one of the wells of the Moscudinskoye oil field, with known data on the integrated interpretation of the results of well-logging and microcomputer tomography, was chosen. According to well-logging data, the productive reservoir in the analyzed section of the section is characterized by a high degree of heterogeneity. Tomographic studies of a full-size core made it possible to identify four lithotypes here with different pore structure features. Accounting for the identified reservoir heterogeneity, as well as data on the thickness and other characteristics of reservoir properties of individual lithotypes that make up the section, made it possible to significantly increa... [more]

This paper presents an improved topology for a DC−DC converter suitable for PV applications. The proposed converter has the ability to be energized from multiple DC sources. Hence, it can be energized from two, three or a higher number of sources according to the number of modules adopted in its design. The proposed converter can supply a single load with DC power at a voltage lower or higher than the summation of all excitation DC voltages with a non-reversed voltage polarity at its output. Moreover, it provides a more reliable operation compared to other DC−DC converters due to its ability for operation with partial failures in its exciting sources. In this paper, the theoretical discussion of the proposed converter is presented considering its construction and its principle of operation. The performance of the proposed converter is theoretically evaluated using simulation based on power simulation (PSIM) software at different conditions. The performance of the converter is theoretic... [more]

In the current study, plain and lignin loaded with Zeolite Y, hydrogen was decomposed in a pyrolysis chamber. The reaction parameters were optimized and 390 °C, 3% catalyst with a reaction time of 40 min were observed as the most suitable conditions for better oil yield. The bio-oil collected from the catalyzed and non-catalyzed pyrolytic reactions was analyzed by gas chromatography mass spectrometry (GCMS). Catalytic pyrolysis resulted in the production of bio-oil consisting of 15 components ranging from C3 to C18 with a high percentage of fuel range benzene derivatives. Non-catalytic pyrolysis produced bio-oil that consists of 58 components ranging from C3 to C24; however, the number and quantity of fuel range hydrocarbons were lower than in the catalyzed products. The pyrolysis reaction was studied kinetically for both samples using thermogravimetry at heating rates of 5, 10, 15 and 20 °C/min in the temperature range 20−600 °C. The activation energies and pre-exponential factors wer... [more]

The development of the electric power industry needs to be understood against the current backdrop of the transition to technological platforms facilitating the adoption of smart grids. Smart grids can be made up of separate clusters (microgrids) consisting of power consumers, power grids, and distributed generation (DG) units. To improve energy efficiency, DC microgrids can be integrated into smart grids to deliver power to consumers within a building (or several buildings) and at the sites of C&I facilities. It is advisable to carry out integrations of DC and AC microgrids with DG and energy storage units on the basis of power routers used to couple grids of different voltage classes. This study outlines a computer model of power router-based integration of DC and AC microgrids with distributed generation and energy storage units. The model was developed in the MATLAB environment. The paper also features the results of a study of the proposed methods as applied to voltage control und... [more]

Dump load (DL) utilization at low demand hours in highly penetrated islanded microgrid is of great importance to offer voltage and frequency regulation. Additionally, load flow (LF) convergence is vital to optimize the working states of the DL allocation problem. Hence, more analysis is necessary to highlight the significance of DL in power regulation while observing the influence of LF on solution accuracy. This article proposes two LF techniques derived from backward/forward sweep (BFS), viz., general BFS (GBFS) and improved special BFS (SBFS-II). The latter is based on global voltage shared between generating units, while the former has a more general approach by considering generating bus’s local voltage. The optimal sizing and sitting of DL with optimum droop sets are determined using the mixed-integer distributed ant colony optimization (MIDACO) with the two new LF methods. The optimization problem was formulated to minimize voltage and frequency deviations as well as power losse... [more]

The energy sector is one of the most important pollutants in the atmosphere and causes significant emissions of greenhouse gases. In Russia, coal is the main contributor to the fossil fuel consumption of thermal power plants and boilers, thus affecting atmospheric air pollution by releasing particulate matter and nitrogen oxides, which are strongly associated with a negative impact on human health. This problem is especially acute for the resource regions of Yenisei, Siberia, a 2.5+ mln sq km macro-region in the very heart of Russia. In this paper, we analyze the impact of the structure of electricity and heat generation on emissions of pollutants and climate-active gases in Yenisei, Siberia, and give an overview of their social, ecological, and economic effects. More than 75% of electricity in Yenisei, Siberia, is produced by hydroelectric power plants that do not pollute the atmosphere. The rest of the electricity is generated in the cogeneration mode by thermal power plants, which a... [more]

The need for higher capacity battery cells has increased significantly during the past years. Therefore, the subject of this study is to investigate the behavior of high performance 21700 Lithium-Ion cylindric battery cells under several abuse conditions, represented by high mechanical loads with different velocities and states of charge (SoC), and to develop a finite element analysis (FEA) model, using the OpenRadioss’ explicit solver capabilities. The present study is focused on the investigation of the behavior of these cells under high mechanical loads with different loading velocities and different states of charge. The aim of the study is to provide a tool to predict the point of an internal short circuit in FEA, with a very good approximation. Experiments were completed using a hydraulic flat-compression test, set up at four different states of charge, 40%, 60%, 80% and 100%, and three different loading velocities of 10 mms−1, 100 mms−1 and 1000 mms−1. A homogenized FEA model is... [more]

This paper presents the development and use of benchmarking grey-box models for the detection and diagnosis of multiple-dependent faults (MDFDD) of a water-cooled centrifugal chiller. Models are developed using data recorded by a Building Automation System (BAS) from a central cooling plant of an institutional building. The forward residual-based fault detection model identifies a fault symptom, when the difference between the measured value of target variable and benchmarking value exceeds the corresponding threshold. For the fault diagnosis, most publications start from a known single fault and establish the impact on following variables in the system. This paper presents a rule-based backward approach. The proposed method identifies if (i) the fault symptom is correct (i.e., a variable has abnormal values), or (ii) the fault symptom is incorrect (i.e., the symptom of target variable is caused by impacts generated by other faulty variables due to the dependency between variables), or... [more]

The main aim of this work is to propose a new algorithm of reliability assessment for steel civil engineering structures subjected to fire temperatures. This new algorithm is based upon the relative probabilistic entropy concept elaborated by Bhattacharyya, and this probabilistic distance is sought in-between extreme and admissible deformations of some structural beam subjected to higher temperatures. Similar to the First Order Reliability Method, this approach uses the first two probabilistic characteristics of the structural response, when structural output may be modelled with the use of Gaussian distribution. The probabilistic structural response is found here using hybrid computational technique−the Finite Element Method system ABAQUS with its fully coupled thermo-elastic analysis with 3D solid elements and probabilistic modules implemented in the computer algebra system MAPLE. The probabilistic response is determined via a triple stochastic analysis, which is based on the classic... [more]

Protonic ceramic fuel cells (PCFCs) are one of the promising and emerging technologies for future energy generation. PCFCs are operated at intermediate temperatures (450−750 °C) and exhibit many advantages over traditional high-temperature oxygen-ion conducting solid oxide fuel cells (O-SOFCs) because they are simplified, have a longer life, and have faster startup times. A clear understanding/analysis of their specific working parameters/processes is required to enhance the performance of PCFCs further. Many physical processes, such as heat transfer, species transport, fluid flow, and electrochemical reactions, are involved in the operation of the PCFCs. These parameters are linked with each other along with internal velocity, temperature, and electric field. In real life, a complex non-linear relationship between these process parameters and their respective output cannot be validated only using an experimental setup. Hence, the computational fluid dynamics (CFD) method is an easier... [more]

Hydraulic fracturing utilizes pressurized liquid typically consisting of water, proppants, and a multitude of chemical additives, in order to fracture petroliferous strata to extract natural gas and oil. In this process, a vast amount of wastewater is produced. This water is heavily contaminated, which renders it unusable outside of direct reuse, without extensive treatment being performed. Typically, various sophisticated analytical techniques are involved in the characterization of both waste and treated waters, increasing the cost and the complexity of the management efforts. The article discusses the constituents found in oilfield wastewater, the methods used to identify and quantify these constituents, and the present management methods. Additionally, we introduce total organic carbon and conductivity analyses as surrogate measurements of overall water quality. Total organic carbon and conductivity are established bulk measurements, which can be used to facilitate rapid decisions... [more]

Electric vehicle (EV) disposition may challenge serious environmental issues such as excessive dependence on oil, especially in the transport sector. Despite this understanding, the adoption intention has been disappointing to date. This review tries to present a comprehensive overview of the methodologies, theories, and variables used in 57 peer-reviewed articles published between 2015 and 2022 covering the main forms of consumer adoption of EVs, consisting of purchase as well as behavioral and usage intentions. Governments may stimulate consumer adoption of EVs with exemptions on roadway tolls, convenient access to charging infrastructures, and tax and economic incentives considering energy trading and vehicle sharing. Second, it is important to create intensive awareness revolving around the EV segment. Furthermore, respecting and understanding consumer preferences would also pave the way for the success of EV acceptance. Finally, consumers’ risk−benefit belief while adopting new te... [more]

A wave energy converter features the ability to convert wave energy into the electrical energy required by unmanned devices, and its energy-conversion efficiency is an essential aspect in practical applications. This paper proposes a novel point-absorption wave energy converter with passive morphing blades to meet the demand for improved energy-conversion efficiency. We first introduce its concept and design, with its blades forming their shape by adaptive changes with the direction of the water flow. Next, the three-dimensional geometrical-morphing model, energy-conversion model, and energy-conversion-efficiency model of the wave energy converter were established. Then, the CFD model was built to optimize the design parameters, and the simulation results revealed that the maximum conversion efficiency can be obtained at 90% solidity with 10 blades, a 40−60% load, and 20~25 degrees for the external deflection angle. The simulations also showed that the passive morphing-blade group prov... [more]

We experimentally studied the air−water pressure drop characteristics with inner diameters of 20 mm under stable and transverse vibration conditions in the horizontal circular channel. We experimented with the status of the gas-phase conversion flow velocity Jg at 0.1−20 m/s, and the liquid-phase conversion flow velocity Jw at 0.1−3.0 m/s. In this paper, we discuss the effect of flow velocity, amplitude, and frequency on the transverse vibration pressure drops. With increasing frequency and amplitude, the vibration performance of pressure drops become more intense. Thus, with increasing frequency and amplitude, the frictional pressure drop increases. Moreover, the frictional pressure drop increases linearly with the increasing flow velocity. We compared the experimental results of air−water pressure drop with the calculated results of previous empirical correlations. Based on Chisholm-C correlation, we obtained a modified correlation for factor C in horizontal channels under transverse... [more]

The study presents the research results on the rejected water generated in dewatering sludge stabilised in Autothermal Thermophilic Aerobic Digestion (ATAD) technology. The research was carried out in three municipal wastewater treatment plants (WWTPs), with a capacity of 1500 to 3260 m3 d−1 and a sludge node capacity of 835 to 2000 kg DM d−1. The mean content of Kjeldahl nitrogen (TKN) in the rejected water samples taken from each object ranged from 485 to 1573 mg N L−1, ammonium nitrogen 318 to 736 mg N L−1, and the average concentration of total phosphorus ranged from 96 to 281 mg P L−1. The average content of organic matter expressed as five-day biological oxygen demand (BOD5) ranged from 205 to 730 mg O2 L−1, while chemical oxygen demand (COD) ranged from 767 to 4884 mg O2 L−1. The study determined the kinetics of the biochemical decomposition of organic matter, assuming that it follows the first-order equation. The average reaction rate constant k in subsequent treatment plants w... [more]

Classification is one of the most common methods of supervised learning, which is divided into a process of data acquisition, data mining, feature analysis, machine learning algorithm selection, model learning and validation, as well as prediction of the result, which was done in the current work. The data that were analyzed concerned ionizing radiation signals generated by partial discharges, recorded by a method using the phenomenon of scintillation. It was decided to check if the data could be classified and if it was possible to determine the defect of an electrical power device. It was possible to find out which classifier (algorithm) worked best for the task, and that the data obtained can be classified, as well as that it is possible to determine the defect. In addition, it was possible to check what effect changing the default values of the classifier’s parameters has on the effectiveness of classification.

Reuse and recycling are preferred strategies in waste management to ensure the high position of waste resources in the waste management hierarchy. However, challenges are still pronounced in many developing countries, where disposal as a final solution is prevalent, particularly for municipal solid waste. On the other hand, refuse-derived fuel as a means of energy recovery provides a sustainable option for managing mixed, contaminated and residual municipal solid waste (MSW). This study provides one of the earliest assessments of refuse-derived fuel (RDF) from MSW in Ghana through a case study in the cities of Accra and Kumasi. The residual/reject fractions (RFs) of MSW material recovery were characterized for thermochemical energy purposes. The studied materials had the potential to be used as RDF. The combustible portions from the residual fractions formed good alternative fuel, RDF, under the class I, II-III classification of the EN 15359:2011 standards. The RDF from only combustibl... [more]

In this paper, the role of soft open point (SOP) is investigated with and without system re-configuration (SR) in reducing overall system power losses and improving voltage profile, as well as the effect of increasing the number of SOPs connected to distribution systems under different scenarios using a proposed hybrid water cycle algorithm (HWCA). The HWCA is formulated to enhance the water cycle algorithm (WCA) search performance based on the genetic algorithm (GA) for a complex nonlinear problem with discrete and continuous variables represented in this paper by SOP installation and SR. The WCA is one of the most effective optimization algorithms, however, it may have difficulty striking a balance between exploration and exploitation due to the nature of the proposed nonlinear optimization problem, which mostly causes slow convergence and poor robustness. Consequently, the HWCA proposed in this paper is an efficient solution to improve the balance between exploration and exploitatio... [more]