Complex Technological Processes Research Articles

Principles and stages of creation of automatic control systems with a model of complex technological processes

The object of this study is an effective approach to designing automatic control systems with a model of complex technological processes, which include interrelated and complementary stages from the formulation of the task to the implementation of the control system at the facility. It includes a set of measures, starting with the analysis of the process in its hardware design with the construction of an information and logical scheme to the development of all types of security and commissioning. The main problem in the implementation of a control system with a technological process model is the limited ranges of adequacy of mathematical models. Therefore, when changing the load on the unit, changing external and internal perturbations, it is necessary to constantly ensure the necessary level of adequacy of the models. It is proposed to use a combined model as a mathematical model of the control object, combining the advantages of analytical and experimental-statistical models. This makes it possible to significantly expand the information base of the resulting model. A simple and effective iterative algorithm for calculating this model is also proposed. It includes sequential steps to determine the parameters of the model by basic dependences (the deterministic part of the model), followed by clarifying them according to the current data from the object (experimental statistical part of the model). The effectiveness of the approach is confirmed by the example of ASC TP of the ammonia synthesis column. By improving the accuracy of determining the control parameters and narrowing the range of their change around the optimal value, the volume of ammonia release increases by 5–8 %. The application of the described approach on the example of the development of an automatic control system for the technological process of ammonia synthesis confirmed the economic feasibility of implementing the proposed solutions

Scenario-Driven Methodology for Cascading Disasters Risk Assessment of Earthquake on Chemical Industrial Park

With the increase in industrial accidents induced by natural disasters, the study of earthquake risk assessment has been widely considered by scholars. However, the cascade evolution of Natech (natural–technological) disasters has not been thoroughly studied, especially in chemical parks with complex technological processes. From the perspective of scenario deduction, combined with cross-impact analysis and a damping interpretation structural model, this paper analyzes the evolution process of cascade disaster in a chemical industrial park after the Wenchuan earthquake. At the same time, a visual network risk assessment model is constructed to identify the impact of earthquake cascade disasters on the park. The simulation results show that the scenario-driven risk assessment method proposed in this paper can directly reflect the coupling relationship and propagation path among the derived events and realize dynamic, intuitive and structured disaster expression to deal with the earthquake Natech (natural–technological) disaster scenario effectively and quickly.

Exploring global attention mechanism on fault detection and diagnosis for complex engineering processes

Considering about slow drift and complicated relationships among process variables caused by corrosion, fatigue, and so on in complex chemical engineering processes, an Industrial Process Optimization ViT (IPO-ViT) method was proposed to explore the global receptive field provided by self-attention mechanism of Vision Transformer (ViT) on fault detection and diagnosis (FDD). The applications on data sampled from both a real industrial process and the Tennessee Eastman (TE) process showed superior performance of the global attention-based method (IPO-ViT) over other typical local receptive fields deep learning methods without increasing sample and computation requirements. Moreover, results on six different variants in combing local, shallow filtering and global receptive field mechanisms unravel that the local attention explosion, the information alignment, and the expression capability are three major challenges for further improving on industrial applications of complex deep learning network structures.

The influence of gamma irradiation on the storability and biochemical parameters of potato tubers

Potato storage is a complex technological process aimed at reducing weight losses and maintaining the biochemical and consumer indicators of tubers at an appropriate level. Depending on the storage temperature, the amount of losses on sprouts in the overall structure of waste can be a significant. Currently, in most European countries, the use of a classic potato tuber germination inhibitor based on the active ingredient chlorprofam is prohibited for environmental reasons. In this regard, an alternative method of restraining the germination of ware and intended for industrial processing potatoes based on the use of gamma irradiation is of interest. Studies on gamma irradiation of tubers using 60Co were conducted in 2019-2021 at the Russian Institute of Radiology and Agroecology (Obninsk), followed by storage of potatoes in cold storage chambers of the Russian Potato Research Centre at two temperatures - 6-7 °C and 9-10 °C. The studied radiation doses were 15, 25 and 50 Gy. It was found that potato weight losses during storage depended mainly on temperature (influence of factor 42.2%) and gamma irradiation (influence of factor 42.2%). For ware potatoes (6-7 °C), gamma irradiation doses of 15 and 25 Gy were optimal; for potatoes intended for processing into fried products (9-10 °C), - 50 Gy. Irradiation at these doses significantly reduced the germination of tubers and the amount of total losses during storage. At a storage temperature of 9-10 °C and irradiation dose of 50 Gy, there was also noticed a decrease in reducing sugars content in tubers by 2-2.5 times, which made it possible to obtain the final product when frying of higher quality in terms of color. There was no significant effect on the content of dry matter, starch, nitrates and vitamin C in tubers. After irradiation doses of 25 and 50 Gy a slight decrease in protein content was noticed.

A Direct Patient-Provider Relationship With the Medical Physicist Reduces Anxiety in Patients Receiving Radiation Therapy

The complex technological processes involved in radiation therapy can be intimidating to patients, causing increased treatment-related anxiety and reduced satisfaction. An intervention was implemented to provide direct consultations between patients and medical physicists to reduce patient anxiety and improve patient satisfaction. A randomized clinical trial was conducted to test the intervention's effect on anxiety, distress, treatment adherence, technical understanding, and satisfaction in patients receiving radiation therapy. Eligible patients were recruited into "intervention" and "standard of care" arms within a phase 2 screening randomized trial. Intervention-arm patients met with a medical physicist who provided technical information and addressed patient questions or concerns at the time of treatment simulation and before the first treatment. In addition to baseline information collected before randomization, participants were surveyed (1) before simulation, (2) before the first treatment, and (3) before the completion of treatment to evaluate the study endpoints. Primary endpoints included patient anxiety and distress. Secondary endpoints included patient treatment adherence, overall satisfaction, and technical understanding of treatment. Patients in the intervention arm were surveyed before and after each physicist meeting. Participant anxiety was significantly reduced in the intervention arm (difference, -0.29; 95% confidence interval, -0.57 to -0.02; P=.038). No differences in distress or treatment adherence were observed between groups. Although measures of technical understanding and satisfaction were evaluated as exploratory objectives, participants in the intervention group were more likely to feel that technical aspects of treatment were adequately explained (difference, 0.78; 95% confidence interval, 0.03-1.54), and all measures of technical understanding and satisfaction were considerably higher in the intervention group at the time of the first visit. The establishment of a direct patient-provider relationship with the medical physicist reduced anxiety in patients receiving radiation therapy. In addition, increases in patient understanding of the technical aspects of care and in satisfaction were observed at the initiation of treatment.

Decision Support Tool for the Agri-Food Sector Using Data Annotated by Ontology and Bayesian Network

The scientific literature is a valuable source of information for developing predictive models to design decision support systems. However, scientific data are heterogeneously structured expressed using different vocabularies. This study developed a generic workflow that combines ontology, databases and computer calculation tools based on the theory of belief functions and Bayesian networks. The ontology paradigm is used to help integrate data from heterogeneous sources. Bayesian network is estimated using the integrated data taking into account their reliability. The proposed method is unique in the sense that it proposes an annotation and reasoning tool dedicated to systematic analysis of the literature, which takes into account expert knowledge of the domain at several levels: ontology definition, reliability criteria and dependence relations between variables in the BN. The workflow is assessed successfully by applying it to a complex food engineering process: skimmed milk microfiltration. It represents an original contribution to the state of the art in this application domain.

Effect of Chemical Composition of Clay on Physical-Mechanical Properties of Clay Paving Blocks

Clay paving blocks made of natural, environmentally friendly materials have their own originality and colorful authenticity, but due to the complex technological production process, they are also relatively expensive products; therefore, their environmental resistance properties are strictly defined and controlled by the standards. The physical and mechanical properties of clay paving blocks are the key factors aiming to ensure the longevity of products and their long-term success in the market. Therefore, ensuring high physical and mechanical properties of clay paving blocks have become a most crucial challenge for the manufactures. This article considers the parameters of the technological production process of clay paving blocks manufacturing and evaluates the influence of the chemical composition of three different types of clay on the physical and mechanical properties of the paving blocks. Water absorption, linear shrinkage, freeze/thaw, acid resistance, and transverse breaking load of clay paving blocks are investigated. This study reveals the importance of raw material selection in the production process of clay paving blocks and provides the concept of main quality factors of clay.

Kinetic and technological regularities of the filtration process of suspensions using excipients in the production of baker’s yeast

Optimal design and management of baker’s yeast production should be based on an in-depth analysis of individual technological processes. Filtration of suspensions using excipients refers to complex technological processes and depends on a large number of factors. In this paper, the kinetic and technological regularities of the process of filtration of suspensions using excipients are considered. The main kinetic regularities of the filtration process are revealed depending on the thickness of the sediment, the pressure drop, concentration, temperature and microbiological purity of the suspension. The effect of the suspension temperature on the main qualitative indicators of yeast: lifting force, acidity and persistence has been established. The performed experimental studies of the filtration process on an industrial continuous vacuum filter and the analysis of the obtained patterns allowed us to formulate a number of recommendations aimed at effective management of the process, reducing losses during the processing of baker’s yeast. Recommendations have also been developed to reduce starch consumption and increase the cycle of operation of the vacuum filter.

Features of Machine Grinding of Surfaces with a Flap Wheel

In order to obtain the necessary shape of long panels and sheaths, the aircraft industry successfully uses a complex technology of shaping. Grinding, as an operation in a complex technological process, is provided after the operation of shot-peen forming before hardening. It is designed to ensure that the roughness and final aerodynamic shape of the surface meet the requirements established by the drawing of the part. To implement this technology, a special installation UDF-4 (shot-impact forming unit) was designed and manufactured at the Irkutsk National Research Technical University. The version of this installation was equipped with a CNC system and a revolver stripping head with 4-flap wheels. The possibility of choosing the necessary flap wheels in the process of grinding, depending on the curvature and width of the treated surface, significantly expanded the technological capabilities of the installation. The elastic abrasive flap wheels of a straight profile used in production have proven themselves well both in terms of grinding performance and tool durability. However, practice has shown that due to the complex impact of abrasive petals during contact with the treated surface, a special zone of uneven impact along the length of the contact of the petals is formed during grinding. The results of experimental studies have shown that the roughness of the treated surface is significantly improved when the direction of movement of the flap wheels feed in the contact zone is changed from oncoming to passing. The paper presents experimental data on studies of changes in surface roughness in the contact zone with the abrasive flap wheels during grinding, depending on the processing modes, as well as the results of an experimental study of the quality of the treated surface with counter and passing feed.

SELF-STARTING OF SYNCHRONOUS MOTORS WITH COMPENSATION INERTION OF THE EXCITATION CONTOUR

The actual scientific problem is solved in the work, which consists in the development, theoretical and experimental researches of devices for self - starting of synchronous motors with compensation of inertia of excitation circuit. The aim of the work is to increase the reliability of the self-starting mode of synchronous motors of responsible mechanisms to maintain the continuity of complex technological processes. In the event of natural disasters and natural disasters, power outages can cause long-term disruptions of technological processes, large material losses, and in some cases fires and explosions, which can lead to human casualties and significant economic damage.
 Under these conditions, the mode of restarting synchronous motors must be used to power the responsible electric drives of mechanisms, such as mine fans, water pumping stations.
 To limit the dynamic loads, it is necessary to have the smallest possible value of e.r.s. stator SD in order to limit the switching current, which can be achieved by using various methods and means of extinguishing the field, increasing the time of introduction of automatic re-inclusion or automatic inclusion of the reserve. The calculated dependences of the self-starting modes of SD when extinguishing the magnetic field due to the inclusion of capacitive energy storage devices are obtained. The developed device for self-starting of SD with a capacity of 1000 kW of the drive unit of the pump unit with ENE was implemented at the pumping station of the Dnieper Metallurgical Plant. The efficiency of the developed device does not depend on the presence of voltage that supplies the excitation system in the self-starting mode. The use of ENE in the excitation circuit provides compensation for the inertia of the OZ and increase the input coin and intensive quenching of the magnetic field. The developed devices provide reliable self-starting of synchronous electric drives of mechanisms with continuous technological processes regardless of the presence of voltage in the power supply system of the exciter.

Analysis and Valuation of the Energy-Efficient Residential Building with Innovative Modular Green Wall Systems

The installation of green wall systems on the residential buildings is a complex technological process, the parameters of which vary depending on design solutions, methods of performing work, instrumental and technical support, professional skills of the work performers and many other factors. The authors used the life cycle approach for the assessment of the energy-efficient residential building with integrated greening systems. The aim of the study was to evaluate an energy-efficient residential building with an innovative modular green wall system and to compare it with existing technological solutions. We show that the life cycle approach provides the choice of a decision that is also optimal in conditions of risk, which indicates the effective use of the green wall system. The results of the work are presented by the development of technology with modular green systems, which will expand the practice of technological design, experimental construction and the renovation of buildings, to improve the quality of the urban environment by implementing rational construction and technological solutions and appropriate work methods. This study will be helpful for researchers in green construction to develop their future research studies and for various residential green building owners.

Reliability Testing of Wind Power Plant Devices with the Use of an Intelligent Diagnostic System

This paper introduces the issue of reliability simulation studies of wind farm equipment in the process of an operation. By the improvement, retrofitting and insertion of new (optimal) solutions to change the quality and terms of the use of wind farm equipment, an evaluation of their impact on reliability under real conditions can be carried out over a long period of time. Over a brief period, testing the reliability of a technical facility is only possible in a simulation. The aspect of evaluating the reliability of wind farm equipment after the application of intelligent systems, including the Wind Power Plant Expert System (WPPES), can be tested in the manner of a simulation. It was accepted in this article that the operation of the wind farm equipment is detailed based on Markov processes. The results of such research activities are the development of reliable and appropriate strategies and an exploitation policy of PE facilities. The above-mentioned issues in such a comprehensive approach have not been fully presented in the literature. The process of exploitation of complex technical objects such as PE devices is a complex random technical and technological process.

Application of agent-based approach for heat conduction processes simulation

Heat transfer processes are the basis of the most technological processes of the energy sector. Thus, the development of modern approaches for computer simulation and visualization of the phenomena of thermal energy transfer in various objects are of great importance and is relevant. Classical models in the form of differential equations of various types describe processes in continuous space and time. So, it is difficult to apply classical models to study nonlinear phenomena, and processes in inhomogeneous media in the presence of discontinuous solutions at the boundaries. In these cases, simplifying assumptions are used, thus, the adequacy of the models is reduced. It is of great interest to apply fundamentally different approaches to describe transfer processes, which include discrete dynamic models. The purpose of this project is to study the possibilities to apply discrete approaches to simulate nonlinear heat transfer processes under conditions of material inhomogeneity and the presence of volume sources of variable power. The paper studies the possibilities to apply the agent-based approach to simulate models of complex systems. This approach allows us to consider a continuum as a set of interacting elements (agents). The behavior of the elements is completely described by local dependencies. At the same time, the laws of functioning of individual elements are accepted as deterministic and they correspond to the fundamental principles of the theory of heat transfer. The possibility to apply a discrete approach for simulating the process of heat transfer by the molecular mechanism has been studied. The general methodology to develop an agent-based deterministic model is described. Its applicability to describe quasi-linear and nonlinear heat conduction processes is considered. The examples of simulation of combustion processes complicated by exothermic and endothermic effects are considered. The advantages and disadvantages of the proposed method are indicated. The results of the study have shown that discrete agent models are a good alternative to classical continuum approaches to study heat transfer processes in inhomogeneous media. The results obtained do not contradict modern approaches to the description of thermal processes. It has also been found that the simulation algorithms used in the agent-based approach are quite universal and easily adapt to changes under the conditions of problem setting. The analysis of the results makes it possible to recommend a discrete agent-based approach to develop simulation models of complex technological processes and systems.

Theory of Movement of Machine-Tractor Unit with Trailer Haulm Harvester Machine

Harvesting sugar and fodder beet tops is a complex technological process that requires the use of special harvesting machines. Trailed harvesters of different rows, which together with aggregate tractors form symmetric or asymmetric machine-tractor units, the movement of which in the horizontal plane is not always stable, are widely used. The purpose of this study is to determine the parameters of stable plane-parallel motion of asymmetric harvester machine-tractor unit based on numerical computer simulation of the obtained analytical dependencies. According to the results of the analytical study, the values of the amplitude and phase-frequency characteristics of the turning angle tractor’s oscillations were obtained. They reflect the reproduction by the angle rotation fluctuations of the haulm harvester machine in the horizontal plane. Calculations have shown that reducing the value of the input resistance coefficient of pneumatic tires of the driving wheels of the aggregating tractor increases its sensitivity to the action of disturbing influences. The greater the sensitivity, the closer the wheels of the power tool are to the attachment point of the trailed haulm harvester. In qualitative terms, increasing the speed of the machine-tractor unit from 1.5 to 2.5 m∙s−1 leads to an undesirable increase in the amplitude-frequency response and desired increase in the phase-frequency response when reproducing its external disturbing effects in the form of oscillations of the angle of rotation of the harvester.

Assessment of the Harmonics Influence on the Power Consumption of an Electric Submersible Pump Installation

Oil production is a complex technological process that requires significant electricity consumption. The main electricity consumers in oil and gas production workshops are artificial lift facilities. Currently, among the objects of mechanized mining, installations of electric submersible pumps are widespread. When planning technological modes, it is necessary to be able to assess the change in the power consumption parameters when changing the technological process parameters. The paper proposes a typical replacement scheme for the electrical complex element. The power consumption calculation of electric submersible pump installations has been carried out. The error in the power consumption modeling results of electric submersible pump installations in comparison with the results of instrumental measurements is no more than 10%. The estimation of additional losses of electric energy caused by the influence of harmonics is carried out. The proposed technique makes it possible to estimate the power consumption of an electric submersible pump installation when changing the parameters of the technological process and equipment. The results of the work can be used for planning material support and optimization of warehouse stocks within the framework of integrated logistics support for the technological process of industrial enterprises.

Mathematical Models for an Energy Intensive Multistage Roasting Process of Pelletized Industrial Waste from Apatite-Nepheline Ores

In this article, we describe mathematical and computer models for the complex, energy-consuming, multistage, integrated chemical and power engineering processes of calcination and sintering of pelletized industrial waste from apatite-nepheline ores, accumulated in the dumps of mining and processing plants. The models take into account the negative effect of vitrification and the subsequent destruction of pellets in case the operating temperature condition in the high-temperature roasting zone of indurating conveyor furnaces is violated during the implementation of these thermally activated processes. Experimental and analytical methods have been developed for the analysis of integrated, thermally activated processes in a dense multilayer mass of pellets obtained from apatite-nepheline ores waste, taking place in indurating furnaces. The possibility of complex phenomena accounting for polymorphic transformations, chemical reactions in solid phases, reactions involving a liquid phase, as well as the formation of new phases and solid solutions as a result of reactions, must be considered when modeling these processes. This analysis makes it possible to increase the strength of pellets during sintering and the degree of calcination as a result of carbonates dissociation, as well as to detect and use the potential of increasing energy and resource efficiency in a complex, environmentally safe, chemical and power engineering system for the processing of industrial waste of apatite-nepheline ores from dumps of mining and industrial plants.

Assessment of the influence of key factors of the rapeseed drying process using electric radiant film heaters on germination ability and germination energy

Drying of any crop is a complex technological process, accompanied by a change in the content of not only the amount of moisture in them, but also useful substances and properties. The improvement of the drying technology of small-seeded crops should be aimed at preserving the sowing qualities of seeds (germination ability and germination energy), therefore, the assessment of the quality of rape plant seeds after the drying process in a conveyor-cascade type drying unit is an important and integral part of the work, and the use of modern mathematical methods is an integral part of the processing and interpretation of the results of field experiments. The experiment and analysis of the results of the work were carried out according to the methodology of the state variety testing of agricultural crops. The results were processed using two-factor analisys.

Организационно-технологические мероприятия по экономии ресурсов и энергосбережению в процессе проектирования и строительства в зимний период

This article considers the problems of obtaining construction products in winter, along with complex technological processes, in the light of scientific achievements and analysis of influencing factors when solving thermophysical problems, as well as evaluating the results on production indicators, especially those related to economics. The accumulated domestic and foreign experience reflects years of intensive work carried out by scientists and engineers, which continues to this day. In Eastern Siberia and neighbouring regions characterised by a prolonged winter period, construction works are carried out all year round. Special attention should be paid to planning construction activities in winter and developing working documentation in view of the seasonality of work. The material and technical resources of the construction contractor should be taken into account, mainly the feasibility of the operational plans for construction and installation activities and the financing schedule. The paper includes examples of winter construction demonstrating the existing limitations, in particular the increased energy consumption. Some recommendations are given aimed at improving the quality of project documentation.

Моделирование вентиляции угольных шахт с учетом выработанных пространств

Mine ventilation network models are widely used in underground coal mining in Russia. The models cover a variety of practical problems ranging from simple air distribution in active mine workings to changes in the static air pressure gradient associated with complex technological or hazardous processes occurring in mines. Isolated gob areas are integral parts of ventilation networks in coal mines. The most commonly used underground coal extraction technology in Russia is the longwall mining. A gob forms when a coal seam is extracted, and the upper layers of the rock cave in. Gobs are isolated from active mine entries with seals, but there is always air leakages from active faces inducing the air circulation in isolated areas. Gobs join different coal seams and often become the sources of underground fires. Therefore, the inclusion of gobs in mine ventilation network models would help contain accidents and eliminate the caused damage. The study uses the method of representative elementary volumes to incorporate a porous medium into mine ventilation network models. Quadratic resistances are assigned to the edges of the model, where Kirchhoffs laws are valid. The aerodynamic resistances of the gob edges are calculated using the Ergun equation. The proposed method has been used to evaluate pressure gradients in the gob area of the Raspadskaya mine. Several scenarios of the aerodynamic resistance variation in the active mine workings surrounding the gob area, such as partial flooding and drilling of boreholes from the surface, have been simulated, and the corresponding changes in pressure gradients have been analyzed.

Design and analysis of an electric bike chassis

Development of any vehicle, be it a two wheeler or a four wheeler, is a complex and detailed engineering process. For its progress, designers have to prepare concept sketches on 2D platforms (on sheets and graphic tablets), model them on 3D softwares and carry out a bunch of simulations and tests on various computer aided engineering softwares. The aim of this paper is to design and analyze an electric bike chassis and hence prove its stability by performing static structural test. Solidworks was used for modeling the chassis and ANSYS was utilized to analyze it. The frame presented in this study is an original concept and dissimilar to the conventional IC engine chassis. Aspects like the weight of the chassis, its strength, rigidness, and storage space available to the consumer were considered while designing it. Initially, three different frames were modeled and after brainstorming session with experts, the best one out of the three was finalized considering all the above mentioned parameters in mind. In total, four materials were applied on the skeleton for its analysis. These included carbon steel AISI 1018, alloy steel AISI 4130, aluminum alloy 2018, and aluminum alloy AISI 7068 T6. The simulations were completed in true scale. Later on the results were compared and the deformations were thoroughly revised by the team. Considering the cost, weight and the final results of the deformations, the best material was picked up.