China is rich in high-grade coalbed methane resources, accounting for one-third of the total amount of coalbed methane resources. Qinshui Basin is the main high ranking coalbed methane mining basin in China. In the early stage of CBM development, low-production and low-efficiency wells were formed in the process of block development because of an insufficient understanding of reservoir geological conditions. The existence of low-yield and low-efficiency wells with low output and a poor development benefit seriously restricts the efficient development of coalbed methane. In order to improve the overall development efficiency of coalbed methane fields, how to revitalize low-yield and low-efficiency wells is the main problem facing the development process of coalbed methane. With the deepening understanding of the study area geology, the formation of low-yield and low-efficiency wells has been basically identified. With the advancement of development technology, developers have the abilit... [more]

Aviation fuel contamination can seriously affect aircraft flight safety, and the centripetal pump is the core component of aviation fuel purification equipment. The performance of centripetal pumps is highly demanded for purification equipment. The operating parameters of centripetal pumps significantly affect the internal flow characteristics, which affects the performance of centripetal pumps. However, the flow characteristics of a centripetal pump influenced by the operating parameters have not yet been elaborated upon. In this research, a three-dimensional numerical simulation of the air-fuel two-phase flow field inside a centripetal pump was carried out using the VOF/Mixture model to investigate the effects of three relatively independent physical quantities, namely, fuel flow, outlet fuel discharge pressure, and rotational speed, on the operating characteristics of the centripetal pump. The flow law inside the flow channel of a centripetal pump was analyzed based on a rotating fl... [more]

The side-blown smelting process is becoming popular in the modern metallurgical industry due to its large potential for dealing with complex materials. To further enhance its efficiency, it is essential to comprehensively understand the complex gas−liquid flow behavior in the smelting bath. In this study, the volume-of-fluid method is employed to establish computational fluid dynamics modeling on a 1:5 scaled model of a side-blown furnace. The simulation was validated against the experimental results. Notably, the influences of the nozzle’s submerged depth, injection velocity, and angle were systematically investigated. The results show that increasing the injection velocity from 29.44 to 58.88 m/s resulted in 52.97%, 116.67%, 500.00%, and 5.88% increases in the interface area, liquid velocity, liquid turbulent kinetic energy, and gas penetration depth, respectively. The maximum gas−liquid interface area, gas penetration depth, velocity, and turbulence of the liquid were found at an in... [more]

This study examines the geothermal energy extraction potential from the basement rock within the Denver−Julesburg Basin, focusing on the flow performance and heat extraction efficiency of different geothermal well configurations. It specifically compares U-shaped, V-shaped, inclined V-shaped, and pipe-in-pipe configurations against enhanced geothermal system setups. Through numerical modeling, we evaluated the thermal behavior of these systems under various operational scenarios and fracture conditions. The results suggest that while closed-loop systems offer moderate temperature increases, Enhanced geothermal system configurations show substantial potential for high-temperature extraction. This underscores the importance of evaluating well configurations in complex geological settings. The insights from this study aid in strategic geothermal energy planning and development, marking significant advancements in geothermal technology and setting a foundation for future explorations and o... [more]

This review article focuses on applying operation state detection and performance optimization techniques in industrial electrical systems. A comprehensive literature review was conducted using the preferred reporting items for systematic reviews and meta-analyses (PRISMA) methodology to ensure a rigorous and transparent selection of high-quality studies. The review examines in detail how soft sensing technologies, such as state estimation and Kalman filtering, along with hybrid intelligent modeling techniques, are being used to enhance efficiency and reliability in the electrical industry. Specific case studies are analyzed in areas such as electrical network monitoring, fault detection in high-voltage equipment, and energy consumption optimization in industrial plants. The PRISMA methodology facilitated the identification and synthesis of the most relevant studies, providing a robust foundation for this review. Additionally, the article explores the challenges and research opportunit... [more]

An improved fault localization method combining total aggregate empirical modal decomposition (MEEMD) and Teager energy operator (TEO) is proposed to address the fault localization issue of three-terminal multi-segment overhead line−cable hybrid transmission lines. This method solves the fault localization problem caused by wave impedance discontinuity in hybrid lines. First, the MEEMD algorithm, which improves modal aliasing, and the Teager energy operator, which reflects transient energy changes, are combined for the accurate detection of faulty traveling wave heads. The fault line section determination condition within the fault branch is used to determine the overhead line section or cable section where the fault is located after determining the faulty branch line. This condition is based on the time difference between the initial traveling wave of the fault arriving at each end measurement point and the T-node. Ultimately, the fault distance is determined using the double-ended tr... [more]

The productivity and pressure response of the tight sand gas wells are influenced by multiple flow mechanisms, such as threshold pressure gradient, phase-change phenomena, and stress sensitivity. Understanding the sensitivity of these factors is crucial for the effective development of tight sand gas reservoirs. This study aims to clarify the sensitivity of various factors affecting the productivity and pressure response of tight sand gas wells. Based on the percolation theory of tight sand gas reservoirs, we considered stress sensitivity, threshold pressure gradient, and phase-change phenomena to derive an unsteady mathematical model of a fractured well with an infinite boundary, and a point source solution was obtained. The proposed model was solved using series function properties, variable substitution, perturbation technique, Poisson superposition formula, Laplace transform, and numerical inversion. The influence of several important parameters on pressure response and productivit... [more]

This paper is focused on researching the behaviour of heating companies in connection with current developments in the electricity market and flexibility in the context of market behaviour. The work assesses the increase in profitability through the creation of a technical−economic model using an objective function with profit maximization. The objective of the paper is to present the procedure and methodology for creating a model using the basic scheme of production processes integrated into the system platform. The result of the work is a comparative analysis of modelled cases of implemented operation deployment according to a defined period and modelling modes on selected time series. The description of individual outputs demonstrates the economic advantage of using combinations of modes of combined electricity and heat production, and non-combined electricity and heat production, including the use of heat-suppression mode because of overproduction of electricity.

The diffusion behavior of polyurethane slurry in vertical cracks, especially rough cracks, is not clear and needs to be studied to provide an effective reference for grouting design. In this study, the diffusion morphology and characteristics of modified polyurethane slurry in vertical cracks were investigated through modeling tests using the line source grouting method. Based on the viscous time-varying characteristics of the slurry, a numerical model of slurry diffusion was established using the joint FVM-VOF method. The numerical model was found to be accurate and reliable compared to the test results. Finally, building upon the basic theory of three-dimensional structure, a rough surface model with Gaussian distribution, more consistent with reality, was established. A numerical simulation system was then employed to study the diffusion morphology and characteristics of slurry in different rough cracks. The results indicate that the diffusion of modified polyurethane slurry within... [more]

The power sector is the single industry with the largest carbon emission in China, the carbon emission of which accounts for more than 40% of China’s total carbon emissions. In relevant research on the simulation of power system operation, current studies focus more on energy conservation and economical operation, while few consider the low-carbon optimization of the power system from the perspective of carbon emissions. In addition, in relevant research on carbon reduction in the power system, current studies focus more on controlling the direct carbon emission of the source side and less on the indirect carbon emissions of the load side, which focus on the reverse effect of a user’s electricity consumption behavior on the carbon reduction goals of the power system. This article delved into a deterministic simulation model of power system operation based on time series load curves and proposed a carbon reduction mechanism called the low-carbon demand response mechanism, which guides u... [more]

The problem of soil and Chuanxiong tuber congestion on vibrating screens usually exists during the Chuanxiong mechanized harvesting process. To address this problem, the conveyance performance of a crankshaft rocker vibrating screen was studied. By establishing and solving the dynamics and kinematics equations for the crankshaft rocker vibrating mechanism and Chuanxiong soil residue, the acceleration of the vibrating screen and Chuanxiong-soil residue was studied. The sliding speed, motion process, and conveying distance of the Chuanxiong soil residue were also analyzed. The theoretical analysis results indicated that the acceleration of the vibrating screen depends on the rod lengths of the vibrating mechanism and the crank rotational speed and position. The displacement of the Chuanxiong-soil residue along the positive sliding direction in a cycle was more significant than that of the negative sliding direction. The appropriate advancement speed of the harvester was also obtained. Th... [more]

Under casing annulus gas venting, the annulus of the well is in a special state of zero-net liquid flow (ZNLF), leading to gas production without liquid at the wellhead, resulting in significant holdup issues. Therefore, conventional two-phase flow models cannot be used for calculation. To study the flow characteristics of ZNLF in the annulus of the well, this study established a visual experimental device with a total height of 5.4 m, an outer pipe inner diameter of 140 mm, and an inner pipe outer diameter of 72 mm. The flow characteristics of ZNLF were studied by controlling the casing pressure, initial liquid level, and bottom gas injection rate. The experimental results showed that the flow patterns of ZNLF are mainly bubbly flow and churn flow. Bubbly flow occurred at lower gas rates, while churn flow occurred at higher gas rates. In addition, the experiment found that when the gas injection rate and initial liquid column height were controlled to be the same, the liquid holdup de... [more]

The Upper Paleozoic tight sandstone reservoirs on the eastern margin of the Ordos Basin exhibit strong heterogeneity and complex pore structures, leading to poor correlation between porosity and permeability and insufficient accuracy in permeability calculations to meet the requirements of reservoir fine evaluation. Therefore, a new method for high-precision permeability calculation based on flow zone index (FZI) reservoir classification is proposed. This method determines the number of reservoir classifications based on the characteristics of the FZI normal probability distribution plot and establishes FZI division criteria for reservoir types. Classified reservoirs exhibit similar flow characteristics, significantly improving the correlation between permeability and porosity. Based on nuclear magnetic resonance (NMR) combined with mercury injection capillary pressure (MICP) experiments, a modeling method for calculating the flow zone index based on the geometric mean of NMR T2 is pro... [more]

Lipid production using microalgae is challenging for producing low-value-added products. Harnessing microalgae for their fast and efficient CO2 fixation capabilities may be more reasonable since algal biomass can be utilized as a precursor for various products in a biorefinery approach. This study aimed to optimize the productivity and efficiency of Microchloropsis salina biomass production in open thin-layer cascade (TLC) photobioreactors under physical simulation of suitable outdoor climate conditions, using an artificial seawater medium. Continuous operation proved to be the most suitable operating mode, allowing an average daily areal productivity of up to 27 g m−2 d−1 and CO2 fixation efficiency of up to 100%. Process transfer from 8 m2 to 50 m2 TLC photobioreactors was demonstrated, but with reduced daily areal productivity of 21 g m−2 d−1 and a reduced CO2 fixation efficiency, most probably due to increased temperatures at midday above 35 °C. An automated overnight switch-off of... [more]

Kombucha is a traditional, fermented beverage made with an essential biomaterial known as SCOBY (symbiotic culture of bacteria and yeast). Three different tea types, namely black, green, and oolong, were compared in kombucha fermentation in terms of pH dynamics, the formation of SCOBY biomass, and the production of acetic acid. The rational, exponential, and polynomial models described pH dynamics with good fit, R2 > 0.98. The formation of SCOBY biomass and the production of acetic acid were modelled using sigmoidal functions, with three-parameter logistic and Gompertz models and four-parameter Boltzmann and Richards models. The F-test indicated that the three-parameter models were statistically adequate; thus, the Gompertz model was modified to present the biological meaning of the parameters. The SCOBY biomass formation rates ranged from 7.323 to 9.980 g/L-day, and the acetic acid production rates ranged from 0.047 to 0.049% acid (wt/vol)/day, with the highest values from the non-con... [more]

The cylinder liner bears alternating thermal load and mechanical load, and evaluating the cylinder liner deformation is a key issue in the design stage of an engine. In this work, the shape and position tolerance of the cylinder liner to various loads were studied based on the finite element method, the simplex algorithm and the least square method. Firstly, the heat transfer boundary conditions of the cylinder liner were obtained through combustion simulation. Combined with the mechanical load, the transient deformation of the cylinder liner under the thermo-mechanical load was obtained. Subsequently, the out-of-roundness and coaxiality were selected to evaluate the shape and position changes in the cylinder liner. Finally, the transient tolerance analysis of the cylinder liner under alternating thermo-mechanical load was carried out. The results show that the maximum out-of-roundness of the cylinder liner under thermal load, mechanical load and thermos-mechanical load was 15.12, 43.4... [more]

Flexographic printing is widely used in the packaging field, but there are still some problems in the printing of flexographic ink on non-absorbent substrates, such as low precision and unstable quality. In this paper, the printing process of flexographic ink is simulated. The interaction of fluid flow, temperature change, and solid deformation in flexographic printing is studied systematically by using the method of fluid−solid thermal coupling for the first time. The process of ink channel formation under static extrusion and fluid−solid thermal coupling was analyzed. The influences of printing pressure, printing speed, ink layer thickness, and ink viscosity on the ink channel were explored. The results show that the printing speed increases and the temperature in the stamping area increases. The printing speed is nonlinear related to the ink flow channel, the influence on the channel is slow at a low speed, the channel increases sharply at a medium and high speed, and tends to be st... [more]

At Procter and Gamble, innovation is based on a framework of Irresistible Superiority [1] that utilizes five complementary components – Products, Packages, Communication, Retail Execution, and Value. Increasing-ly, the computational techniques heavily leveraged with-in the Process Systems Engineering community are play-ing a leading role in delivering these five vectors, and they become increasingly valuable as we aim to deliver products in more exploratory consumer spaces – where combining high-volume data, advanced modeling, and quantified uncertainty will allow us to discover and deliv-er better products faster than ever before...

Equation-Oriented (EO) modeling techniques have been gaining popularity as an alternative for simulating and optimizing process systems due to their flexibility and ability to leverage state-of-the-art solvers inaccessible to many procedural modeling approaches. Despite these advantages, adopting EO modeling tools remains challenging due to the significant learning curve and effort required to build and solve models. Many techniques are available to help diagnose problems with EO process models and reduce the effort required to create and use them. However, these techniques still need to be integrated into EO modeling environments, and many modelers are unaware of sophisticated EO diagnostic tools. To survey the availability of model diagnostic tools and common workflows, the U.S. Department of Energy’s Institute for the Design of Advanced Energy Systems (IDAES) has conducted user experience interviews of users of the IDAES Integrated Platform (IDAES-IP) for process modeling. The inter... [more]

Equation-oriented (EO) modeling has the potential to enable the effective design and optimization of the operation of advanced energy systems. However, advanced modeling of energy systems results in a large number of variables and non-linear equations, and it can be difficult to search through these to identify the culprit(s) responsible for convergence issues. The Institute for the Design of Advanced Energy Systems Integrated Platform (IDAES-IP) contains a tool to identify poorly scaled constraints and variables by searching for rows and columns of the Jacobian matrix with small L2-norms so they can be rescaled. A further singular value decomposition can be performed to identify degenerate sets of equations and remaining scaling issues. This work presents an EO model of a flowsheet developed for post-combustion carbon capture using a monoethanolamine (MEA) solvent system as a case study. The IDAES diagnostics tools were successfully applied to this flowsheet to identify problems to im... [more]

Ethylene is a crucial precursor for a diverse spectrum of products and services. As global production exceeds 150 million tons annually and is projected to surpass 255 million tons by 2035, the imperative for sustainable and efficient ethylene production becomes increasingly clear. Despite Externally Heated Crackers (EHCs) dominating ethylene production for over a century, they face intrinsic limitations that necessitate transformative solutions, including intense radial thermal gradients, high metal demand, and substantial CO2 emissions. This study employs a robust combination of Computational Fluid Dynamics (CFD) coupled with detailed chemical kinetics to rigorously assess selected configurations of Internally Heated Crackers (IHCs) against the leading EHC designs. Our findings reveal that IHCs exhibit the potential to enhance ethylene output by a factor of 1.66 when compared to EHCs of the same length, diameter, and surface temperature. These results herald a promising era for devel... [more]

Designing a digital twin will be crucial in developing automation-based future manufacturing systems. The design of digital twins involves data-driven modelling of individual manufacturing units and interactions between the various entities. The goals of future manufacturing units such as zero waste at the plant scale can be formulated as a model-based optimal control problem by identifying the necessary state, control inputs, and manipulated variables. The fundamental assumption of any model-based control scheme is the availability of a “reasonable model”, and hence, assessing the goodness of the model in terms of stability and sensitivity around the optimal parameter value becomes imperative. This work analyses the data-driven model of an acetaminophen production plant obtained from SINDy, a nonlinear system identification algorithm using sparse identification techniques. Initially, we linearize the system around optimal parameter values and use local stability analysis to assess the... [more]

Utilizing sustainable energy sources is crucial for expanding the range of solutions available to meet the growing energy demand and reducing reliance on environmentally damaging and depleting conventional fuels. Biosolids, a type of biomass, are generated as secondary effluent during wastewater treatment process in municipal and industrial sites. These solids possess the potential to serve as a sustainable energy source due to their richness of carbon. For an extended period, biosolids have been landfilled, even though it can be considered a wasteful use of a precious resource and a possible mean for contamination to the food supply chain. This has served as an extra impetus to investigate the potential for harnessing the capabilities of these substances. While many research studies have looked at different ways to put biomass waste to use, very little has been written on biosolids, especially those derived from industrial sources. This research assesses the feasibility of transformin... [more]

Some of the most highly trusted and ubiquitous process simulators have solution methods that are incompatible with algorithms designed for equation-oriented optimization. The natively unconstrained Efficient Global Optimization (EGO) algorithm approximates a black-box simulation with kriging surrogate models to convert the simulation results into a reduced-order model more suitable for optimization. This work evaluates several established constraint-handling approaches for EGO to compare their accuracy, computational efficiency, and reliability using an example simulation of an amine post-combustion carbon capture process. While each approach returned a feasible operating point in the number of iterations provided, none of them effectively converged to a solution, exploring the search space without effectively exploiting promising regions. Using the product of expected improvement and probability of feasibility as next point selection criteria resulted in the best solution value and re... [more]

We study the design and optimization of a multicomponent seawater desalination process with zero liquid discharge (ZLD). The designed process is highly integrated with multiple sub processing units that include humidification-dehumidification, Lithium Bromide absorption chiller, multi-effect evaporators, mechanical vapor compression, and crystallization. Aspen Plus software with E-NRTL and SOLIDS thermodynamic packages are used for modeling and simulation of desalination and crystallization units, respectively. In addition to this, we use data-driven optimization to find the best operating condition (i.e., the temperature of the last effect evaporator) that minimizes the overall energy consumption of the designed plant with an output constraint imposed on the mass fraction of salts going to the ZLD system should be greater than 20 wt.% to achieve the ZLD goal. We use a local sample-based data-driven optimizer, Nonlinear Optimization with the Mesh Adaptive Direct Search (NOMAD) algorith... [more]