Pub Date : 2022-12-28DOI: 10.17588/2072-2672.2022.6.058-068
A. Popov
Currently, materials with a random pore arrangement are mainly used as thermal insulation. Such materials, as a rule, have low strength. To solve a number of structural tasks, a heat-insulating material with a high specific strength is required.To date, for these purposes sandwich panels with layers of honeycomb cells filled with air are applied. In this regard, the current goal is to develop more efficient materials with an ordered structure, which will have greater thermal resistance and strength. For numerical simulation of thermal conductivity in a porous material with an ordered structure, the Steady-State Thermal module of the ANSYS software package has been used. Polymers that are often used in 3D printing, such as PETG plastic and Phrozen photopolymer, are chosen as materials for a porous medium with the Neovius TFMT structure. As a result of the study of thermal conductivity in an elementary cell of the Neovius surface in the ANSYS software package, the values of the effective thermal conductivity coefficient are obtained for various characteristic of geometric parameters (cell wall thickness, length of the edge of the cube in which the cell of the Neovius surface is inscribed). Based on the results obtained, it has been found that the dependence of the coefficient of effective thermal conductivity on the cell wall thickness (as well as on the relative cell thickness) is linear. It has been also determined that the geometry under study has a quasi-isotropic thermal conductivity, since it has cubic symmetry. Based on these results, the corresponding graphical and analytical dependencies are designed. The developed heat-insulating material with an ordered structure based on Neovius TPMT is proposed to be used as thermal insulation. The obtained graphical and analytical dependences make it possible to determine the coefficient of effective thermal conductivity of a material with a structure based on the Neovius TFMT with known characteristic geometric parameters (cell wall thickness, cube edge length). The results obtained can be used to design thermal insulation for several tasks when, in addition to thermal insulation properties, structural strength is also important. The porous structure can be produced using modern 3D printing methods, such as selective laser sintering (SLS), laser stereolithography (SLA), etc.
{"title":"Development of thermal insulation with ordered structure based on Neovius TPMS","authors":"A. Popov","doi":"10.17588/2072-2672.2022.6.058-068","DOIUrl":"https://doi.org/10.17588/2072-2672.2022.6.058-068","url":null,"abstract":"Currently, materials with a random pore arrangement are mainly used as thermal insulation. Such materials, as a rule, have low strength. To solve a number of structural tasks, a heat-insulating material with a high specific strength is required.To date, for these purposes sandwich panels with layers of honeycomb cells filled with air are applied. In this regard, the current goal is to develop more efficient materials with an ordered structure, which will have greater thermal resistance and strength. For numerical simulation of thermal conductivity in a porous material with an ordered structure, the Steady-State Thermal module of the ANSYS software package has been used. Polymers that are often used in 3D printing, such as PETG plastic and Phrozen photopolymer, are chosen as materials for a porous medium with the Neovius TFMT structure. As a result of the study of thermal conductivity in an elementary cell of the Neovius surface in the ANSYS software package, the values of the effective thermal conductivity coefficient are obtained for various characteristic of geometric parameters (cell wall thickness, length of the edge of the cube in which the cell of the Neovius surface is inscribed). Based on the results obtained, it has been found that the dependence of the coefficient of effective thermal conductivity on the cell wall thickness (as well as on the relative cell thickness) is linear. It has been also determined that the geometry under study has a quasi-isotropic thermal conductivity, since it has cubic symmetry. Based on these results, the corresponding graphical and analytical dependencies are designed. The developed heat-insulating material with an ordered structure based on Neovius TPMT is proposed to be used as thermal insulation. The obtained graphical and analytical dependences make it possible to determine the coefficient of effective thermal conductivity of a material with a structure based on the Neovius TFMT with known characteristic geometric parameters (cell wall thickness, cube edge length). The results obtained can be used to design thermal insulation for several tasks when, in addition to thermal insulation properties, structural strength is also important. The porous structure can be produced using modern 3D printing methods, such as selective laser sintering (SLS), laser stereolithography (SLA), etc.","PeriodicalId":23635,"journal":{"name":"Vestnik IGEU","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88046541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-28DOI: 10.17588/2072-2672.2022.6.005-017
D. Saponenko, O. Y. Kuleshov
Research in the field of alternative energy sources use is of relevance due to the limited reserves of fossil fuels, the constant cost increase and flue gas emissions generated by power plants along with fuel combustion. The use of low-grade ground energy with the help of geothermal heat pump stations makes it possible to save fossil fuel and reduce environmental pollution. Since about 50 % of the one-time capital investment is spent on the construction of ground loop, the issues on improving the efficiency of ground heat abstraction are of particular relevance. However, until now there is no unified normative technique to calculate ground probes and to create ground loops of optimal constructions. The absence of calculation methods and intelligible practical dependencies does not allow one to quantify the influence of various factors on the heat extraction process, the intensity of which varies significantly over time. The authors have applied two analytical methods in the developed mathematical model. The first one is a source-sink method adapted to the non-stationary process of heat abstraction away from the soil mass. And the second one is the superposition method which made it possible to quantify the effect of the interaction of temperature fields in the well. The mathematical model has been developed, and calculated dependences have been obtained. The authors have presented a calculation method and the results of mathematical modeling of the non-stationary process of soil heat abstraction by a vertical U-shaped geothermal probe and the internal interaction of the temperature fields of the downcomer and riser pipes. The results of the computational experiment are presented in the form of graphs. The authors have determined three key particular cases of the operation of a ground probe and formulas to define the maximum allowable increment of the temperature of the heated coolant under the condition of maximum efficient use of the heat-receiving surface applicable to various types of soil. The analysis of the obtained results makes it possible to identify the main factors affecting the heat-absorption efficiency (actual heat transfer coefficients and specific heat inflows) for each of the pipes and for the entire probe, considering the interaction of temperature fields around the downcomer and riser pipes during the heating period.
{"title":"Interaction of temperature fields in soil massif during abstraction of low-grade heat by U-shaped probes of geothermal heat pump units","authors":"D. Saponenko, O. Y. Kuleshov","doi":"10.17588/2072-2672.2022.6.005-017","DOIUrl":"https://doi.org/10.17588/2072-2672.2022.6.005-017","url":null,"abstract":"Research in the field of alternative energy sources use is of relevance due to the limited reserves of fossil fuels, the constant cost increase and flue gas emissions generated by power plants along with fuel combustion. The use of low-grade ground energy with the help of geothermal heat pump stations makes it possible to save fossil fuel and reduce environmental pollution. Since about 50 % of the one-time capital investment is spent on the construction of ground loop, the issues on improving the efficiency of ground heat abstraction are of particular relevance. However, until now there is no unified normative technique to calculate ground probes and to create ground loops of optimal constructions. The absence of calculation methods and intelligible practical dependencies does not allow one to quantify the influence of various factors on the heat extraction process, the intensity of which varies significantly over time. The authors have applied two analytical methods in the developed mathematical model. The first one is a source-sink method adapted to the non-stationary process of heat abstraction away from the soil mass. And the second one is the superposition method which made it possible to quantify the effect of the interaction of temperature fields in the well. The mathematical model has been developed, and calculated dependences have been obtained. The authors have presented a calculation method and the results of mathematical modeling of the non-stationary process of soil heat abstraction by a vertical U-shaped geothermal probe and the internal interaction of the temperature fields of the downcomer and riser pipes. The results of the computational experiment are presented in the form of graphs. The authors have determined three key particular cases of the operation of a ground probe and formulas to define the maximum allowable increment of the temperature of the heated coolant under the condition of maximum efficient use of the heat-receiving surface applicable to various types of soil. The analysis of the obtained results makes it possible to identify the main factors affecting the heat-absorption efficiency (actual heat transfer coefficients and specific heat inflows) for each of the pipes and for the entire probe, considering the interaction of temperature fields around the downcomer and riser pipes during the heating period.","PeriodicalId":23635,"journal":{"name":"Vestnik IGEU","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79288791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-28DOI: 10.17588/2072-2672.2022.6.026-036
M. Koskov, A. Ivanov
Today, a physical problem of engineering design of inertial magnetic fluid accelerometers to measure dynamic processes is relevant. The main drawback of modern sensors is the nonlinear characteristic of the forced response, which limits the application area of the sensors to the case of quasi-static action (tilt angle sensor). The reason of nonlinearity is the design of the magneto-mechanical system of the elastic suspension of the inertial mass made in the form of a pair of permanent ring magnets. This drawback can be eliminated by designing an axisymmetric electromagnetic system that generates a magnetic field with a linear intensity gradient along the symmetry axis. Thus, the paper is devoted to this problem and experimental approvement of the results on a laboratory sensor prototype. The Monte Carlo algorithm is used to calculate electromagnetic system containing permanent magnets and magnetizing coils. The algorithm is implemented using the C++ programming language. Measurements of the most important parameters of the magnetic field from the point of view of the purpose of the study are carried out on the assembled model of the electromagnetic system of the accelerometer. The calculation of electromagnetic system that generate permanent magnetic field with linear intensity gradient along the symmetry axis is carried out. The applicability of the Monte Carlo method to solve similar engineering problems is shown. The measurements of the magnetic field strength of a given configuration have been made. The force of the magnetic field acting on the test sensitive element with a constant magnetic moment is measured. A comparison of the calculated magnetic field with the field of a real system is carried out. It shows satisfactory agreement between the calculated data and the real ones. A linear dependence of the restoring force on the displacement coordinate of a body with a constant magnetic moment from the equilibrium position is shown. The linearization of the response of the mechanical part of the magnetic fluid accelerometer is achieved by choosing the desired configuration of its electromagnetic system, which allows making reliable measurements of both static and dynamic quantities.
{"title":"Magnetic system of uniaxial inertial ferrofluid accelerometer","authors":"M. Koskov, A. Ivanov","doi":"10.17588/2072-2672.2022.6.026-036","DOIUrl":"https://doi.org/10.17588/2072-2672.2022.6.026-036","url":null,"abstract":"Today, a physical problem of engineering design of inertial magnetic fluid accelerometers to measure dynamic processes is relevant. The main drawback of modern sensors is the nonlinear characteristic of the forced response, which limits the application area of the sensors to the case of quasi-static action (tilt angle sensor). The reason of nonlinearity is the design of the magneto-mechanical system of the elastic suspension of the inertial mass made in the form of a pair of permanent ring magnets. This drawback can be eliminated by designing an axisymmetric electromagnetic system that generates a magnetic field with a linear intensity gradient along the symmetry axis. Thus, the paper is devoted to this problem and experimental approvement of the results on a laboratory sensor prototype. The Monte Carlo algorithm is used to calculate electromagnetic system containing permanent magnets and magnetizing coils. The algorithm is implemented using the C++ programming language. Measurements of the most important parameters of the magnetic field from the point of view of the purpose of the study are carried out on the assembled model of the electromagnetic system of the accelerometer. The calculation of electromagnetic system that generate permanent magnetic field with linear intensity gradient along the symmetry axis is carried out. The applicability of the Monte Carlo method to solve similar engineering problems is shown. The measurements of the magnetic field strength of a given configuration have been made. The force of the magnetic field acting on the test sensitive element with a constant magnetic moment is measured. A comparison of the calculated magnetic field with the field of a real system is carried out. It shows satisfactory agreement between the calculated data and the real ones. A linear dependence of the restoring force on the displacement coordinate of a body with a constant magnetic moment from the equilibrium position is shown. The linearization of the response of the mechanical part of the magnetic fluid accelerometer is achieved by choosing the desired configuration of its electromagnetic system, which allows making reliable measurements of both static and dynamic quantities.","PeriodicalId":23635,"journal":{"name":"Vestnik IGEU","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89701964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-31DOI: 10.17588/2072-2672.2022.5.063-071
I. Polyuschenkov
Various computational algorithms to perform automatic control of motion are widely used in microprocessor control systems of electric drives. The requirements for such algorithms are the minimum execution time, the minimum amount of calculations, the compactness of the software, the convergence in the statics and dynamics of the control system. It ensures the stability and accuracy of coordinates control. The above-mentioned issues are applicable to the computational algorithm to develop a S-shaped trajectory of the electric drive by the position master unit. The position master unit based on the well-known mathematical model has some disadvantages that limit its use. They are incorrect calculation of the trajectory depending on the speed, acceleration, and sampling interval, as well as the self-oscillatory processes in case of the output and intermediate coordinates. As a result, it leads to a decrease of the accuracy of the electric drive control. Despite the standard solutions, such position master unit require improvement. In this regard, upgrading such a position master unit is relevant. The aim of upgrading is to eliminate these shortcomings by introducing corrective calculations and logical sequences that transfer the position master unit into a stable state as soon as it reaches a given value of the output coordinate. To control the motion of the electric drive when we develop a mathematical model and software based on it, it is necessary to use computational algorithms and numerical methods of calculation that are the least costly in terms of execution time. A modernized mathematical model of the S-shaped trajectory of position master unit is proposed. Restrictions of the parameters of this master unit have been eliminated. They may lead to incorrect path generation, as well as self-oscillations of the output and intermediate coordinates during the path generation, which reduces the accuracy of the electric drive control and cause vibration and noise. The software of the modernized position master unit, in comparison with its original form, does not contain cumbersome arithmetic that is costly in terms of execution time. The software has been successfully implemented into the microprocessor control system of the electric drive. At the same time, it is necessary to observe a time-stable execution of computational sequences and to consider the influence of the values of the numerical parameters used in the calculations.
{"title":"Mathematical model of position master unit of electric drive and development of its software","authors":"I. Polyuschenkov","doi":"10.17588/2072-2672.2022.5.063-071","DOIUrl":"https://doi.org/10.17588/2072-2672.2022.5.063-071","url":null,"abstract":"Various computational algorithms to perform automatic control of motion are widely used in microprocessor control systems of electric drives. The requirements for such algorithms are the minimum execution time, the minimum amount of calculations, the compactness of the software, the convergence in the statics and dynamics of the control system. It ensures the stability and accuracy of coordinates control. The above-mentioned issues are applicable to the computational algorithm to develop a S-shaped trajectory of the electric drive by the position master unit. The position master unit based on the well-known mathematical model has some disadvantages that limit its use. They are incorrect calculation of the trajectory depending on the speed, acceleration, and sampling interval, as well as the self-oscillatory processes in case of the output and intermediate coordinates. As a result, it leads to a decrease of the accuracy of the electric drive control. Despite the standard solutions, such position master unit require improvement. In this regard, upgrading such a position master unit is relevant. The aim of upgrading is to eliminate these shortcomings by introducing corrective calculations and logical sequences that transfer the position master unit into a stable state as soon as it reaches a given value of the output coordinate. To control the motion of the electric drive when we develop a mathematical model and software based on it, it is necessary to use computational algorithms and numerical methods of calculation that are the least costly in terms of execution time. A modernized mathematical model of the S-shaped trajectory of position master unit is proposed. Restrictions of the parameters of this master unit have been eliminated. They may lead to incorrect path generation, as well as self-oscillations of the output and intermediate coordinates during the path generation, which reduces the accuracy of the electric drive control and cause vibration and noise. The software of the modernized position master unit, in comparison with its original form, does not contain cumbersome arithmetic that is costly in terms of execution time. The software has been successfully implemented into the microprocessor control system of the electric drive. At the same time, it is necessary to observe a time-stable execution of computational sequences and to consider the influence of the values of the numerical parameters used in the calculations.","PeriodicalId":23635,"journal":{"name":"Vestnik IGEU","volume":"14 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90763402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-31DOI: 10.17588/2072-2672.2022.5.044-053
V. Saveliev, G. Filatova, T. Shadrikova, V. Tyutikov, V. Shuin
As a rule, electrical values of the transient process that occurs during insulation breakdown are considered to determine the fault location in case of short-term self-eliminating and arc intermittent single-phase earth faults in distribution cable networks of 6–10 kV. The known methods for remote earth fault location based on monitoring the parameters of transient currents and voltages, do not always provide sufficient accuracy to determine the fault location. It is due to the influence of various random factors (the value of the total capacitive current that depends on the network operation mode, the moment the fault occurs, etc.). Thus, the task to improve the accuracy of the remote fault location algorithm under the influence of these factors, as well as the speed to determine the fault location is relevant. Considering the complexity of transient processes in case of single-phase earth faults in 6–10 kV cable networks, simulation in Matlab software package is carried out to study the effectiveness of the algorithm of the operation of a device for remote earth fault location based on the above method. A method to determine remotely the location of an earth fault is proposed. It makes possible to ensure sufficient accuracy and speed based on the analysis of the factors that affect the measurement accuracy and in-depth studies on simulation models of 6–10 kV cable networks in Matlab. It is shown that the total effect of various factors that distort the measurement in case of remote fault location using a controlled line model can cause errors in measuring the distance up to the point of the fault equals to 10–15 % with close earth faults (about hundreds of meters away the busbars of the power source) and no more than 5–10 % at the distances a few kilometers away. The method to determine remotely the fault location using the models of a controlled transmission line provides an increase in the accuracy and speed of measuring the distance to the earth fault location in 6–10 kV cable networks. It is more promising to apply when one develops devices for remote earth fault location.
{"title":"Remote earth fault location at 6–10 kV cable line using its models","authors":"V. Saveliev, G. Filatova, T. Shadrikova, V. Tyutikov, V. Shuin","doi":"10.17588/2072-2672.2022.5.044-053","DOIUrl":"https://doi.org/10.17588/2072-2672.2022.5.044-053","url":null,"abstract":"As a rule, electrical values of the transient process that occurs during insulation breakdown are considered to determine the fault location in case of short-term self-eliminating and arc intermittent single-phase earth faults in distribution cable networks of 6–10 kV. The known methods for remote earth fault location based on monitoring the parameters of transient currents and voltages, do not always provide sufficient accuracy to determine the fault location. It is due to the influence of various random factors (the value of the total capacitive current that depends on the network operation mode, the moment the fault occurs, etc.). Thus, the task to improve the accuracy of the remote fault location algorithm under the influence of these factors, as well as the speed to determine the fault location is relevant. Considering the complexity of transient processes in case of single-phase earth faults in 6–10 kV cable networks, simulation in Matlab software package is carried out to study the effectiveness of the algorithm of the operation of a device for remote earth fault location based on the above method. A method to determine remotely the location of an earth fault is proposed. It makes possible to ensure sufficient accuracy and speed based on the analysis of the factors that affect the measurement accuracy and in-depth studies on simulation models of 6–10 kV cable networks in Matlab. It is shown that the total effect of various factors that distort the measurement in case of remote fault location using a controlled line model can cause errors in measuring the distance up to the point of the fault equals to 10–15 % with close earth faults (about hundreds of meters away the busbars of the power source) and no more than 5–10 % at the distances a few kilometers away. The method to determine remotely the fault location using the models of a controlled transmission line provides an increase in the accuracy and speed of measuring the distance to the earth fault location in 6–10 kV cable networks. It is more promising to apply when one develops devices for remote earth fault location.","PeriodicalId":23635,"journal":{"name":"Vestnik IGEU","volume":"11 suppl_1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90275706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-31DOI: 10.17588/2072-2672.2022.5.054-062
A. Anisimov, M. E. Sorokovnin, S. Tararykin, E.S. Tselischev
Currently, the problem to develop the optimality criterion in terms of parametric synthesis of state regulators of mechatronic systems is truly relevant. The optimality criteria developed earlier are based on the use of indirect quality indicators of automatic control systems. These criteria are mostly focused on providing an analytical solution of the synthesis problem than on the real properties of the systems. To consider all the requirements for the system, it is necessary to transfer from indirect optimality criteria to direct ones. It provides a compromise between the main requirements considering the specific features of the system. In this regard, to optimize electromechanical systems it is proposed to use a complex optimality criterion based on the mathematical apparatus of fuzzy logic. As part of the study, state space methods are used to develop a vector-matrix model of an object and synthesize a state controller. The calculation of the optimality criterion according to the determinable quality indicators is based on the mathematical apparatus of fuzzy logic. Development of a fuzzy model is conducted by means of the modeling tools of the Matlab software package. To find the optimal parameters of the regulator search optimization methods are used. A new optimality criterion for mechatronic systems has been developed and studied. It is based on the use of fuzzy logic apparatus, which makes it possible to more fully consider the set of specified technical requirements for their design. The results of the conducted computational experiments have proved the effectiveness of the developed criterion and optimization algorithms. Designers can effectively use the obtained results for parametric optimization to enhance diverse types of mechatronic systems with state controllers.
{"title":"Development of optimality criteria for mechatronic systems using fuzzy logic apparatus","authors":"A. Anisimov, M. E. Sorokovnin, S. Tararykin, E.S. Tselischev","doi":"10.17588/2072-2672.2022.5.054-062","DOIUrl":"https://doi.org/10.17588/2072-2672.2022.5.054-062","url":null,"abstract":"Currently, the problem to develop the optimality criterion in terms of parametric synthesis of state regulators of mechatronic systems is truly relevant. The optimality criteria developed earlier are based on the use of indirect quality indicators of automatic control systems. These criteria are mostly focused on providing an analytical solution of the synthesis problem than on the real properties of the systems. To consider all the requirements for the system, it is necessary to transfer from indirect optimality criteria to direct ones. It provides a compromise between the main requirements considering the specific features of the system. In this regard, to optimize electromechanical systems it is proposed to use a complex optimality criterion based on the mathematical apparatus of fuzzy logic. As part of the study, state space methods are used to develop a vector-matrix model of an object and synthesize a state controller. The calculation of the optimality criterion according to the determinable quality indicators is based on the mathematical apparatus of fuzzy logic. Development of a fuzzy model is conducted by means of the modeling tools of the Matlab software package. To find the optimal parameters of the regulator search optimization methods are used. A new optimality criterion for mechatronic systems has been developed and studied. It is based on the use of fuzzy logic apparatus, which makes it possible to more fully consider the set of specified technical requirements for their design. The results of the conducted computational experiments have proved the effectiveness of the developed criterion and optimization algorithms. Designers can effectively use the obtained results for parametric optimization to enhance diverse types of mechatronic systems with state controllers.","PeriodicalId":23635,"journal":{"name":"Vestnik IGEU","volume":"94 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80656274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-31DOI: 10.17588/2072-2672.2022.5.072-079
K. N. Bubnov, V. Zhukov, S. D. Gorshenin, E. Barochkin
A large number of generating equipment installed at thermal power plants (TPPs) operate at the limit of their fleet life resource or beyond it. Malfunctions and defects occur during the entire period of operation of steam turbine plant (STP) of TPPs. It causes performance degradation of efficiency, reliability, and maneuverability of STP. Thus, the methods to provide monitoring over the technical position of the elements and/or functional units of steam turbine plant are to be applied. Hence, special attention is to be paid to the development of methods to monitor the technical position and diagnostics of generating equipment of TPPs. The methods are based on a mathematical model of flow characteristics of steam turbine plants. It allows us to consider the effect of changes in the open flow area of the individual compartments of a steam turbine on the pressure distribution over the flow path. To develop the model, the authors have applied mathematical modeling methods and the balance relations of mass and energy methods. The solution of the equations of the obtained linear and nonlinear systems is carried out by methods of computational mathematics. Calculation of thermodynamic parameters of the coolant is carried out based on tables of properties of water and water vapor and software for their description. A mathematical model of a steam turbine plant has been developed. It represents a set of linear and nonlinear algebraic equations that consider the flow discharge characteristics of the steam turbine compartments. Also, it makes possible to assess the technical position and it considers the effect of defects on the pressure distribution over the flow path of the steam turbine. The results of the statistical analysis prove that the model has been recognized adequate under the variation range in the electrical load. The results of the development of mathematical steam turbine plant model can be used to develop intelligent systems to monitor and diagnose power generating equipment of TPPs. Application of these systems allow the management of the TPP to change over from the system of preventive maintenance of equipment to the system of the repair of equipment according to technical position.
{"title":"Mathematical model of flow characteristics of steam turbine plant","authors":"K. N. Bubnov, V. Zhukov, S. D. Gorshenin, E. Barochkin","doi":"10.17588/2072-2672.2022.5.072-079","DOIUrl":"https://doi.org/10.17588/2072-2672.2022.5.072-079","url":null,"abstract":"A large number of generating equipment installed at thermal power plants (TPPs) operate at the limit of their fleet life resource or beyond it. Malfunctions and defects occur during the entire period of operation of steam turbine plant (STP) of TPPs. It causes performance degradation of efficiency, reliability, and maneuverability of STP. Thus, the methods to provide monitoring over the technical position of the elements and/or functional units of steam turbine plant are to be applied. Hence, special attention is to be paid to the development of methods to monitor the technical position and diagnostics of generating equipment of TPPs. The methods are based on a mathematical model of flow characteristics of steam turbine plants. It allows us to consider the effect of changes in the open flow area of the individual compartments of a steam turbine on the pressure distribution over the flow path. To develop the model, the authors have applied mathematical modeling methods and the balance relations of mass and energy methods. The solution of the equations of the obtained linear and nonlinear systems is carried out by methods of computational mathematics. Calculation of thermodynamic parameters of the coolant is carried out based on tables of properties of water and water vapor and software for their description. A mathematical model of a steam turbine plant has been developed. It represents a set of linear and nonlinear algebraic equations that consider the flow discharge characteristics of the steam turbine compartments. Also, it makes possible to assess the technical position and it considers the effect of defects on the pressure distribution over the flow path of the steam turbine. The results of the statistical analysis prove that the model has been recognized adequate under the variation range in the electrical load. The results of the development of mathematical steam turbine plant model can be used to develop intelligent systems to monitor and diagnose power generating equipment of TPPs. Application of these systems allow the management of the TPP to change over from the system of preventive maintenance of equipment to the system of the repair of equipment according to technical position.","PeriodicalId":23635,"journal":{"name":"Vestnik IGEU","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80900698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-31DOI: 10.17588/2072-2672.2022.5.024-032
V. Tyutikov, Y. Kutumov, T. Shadrikova, V. Shuin
To improve the reliability of power supply of consumers, a significant part of 6–10 kV cable networks (in Russia about 20 %) operate with resonant neutral grounding via arc suppression coil (ASC) (single-phase earth fault capacitive current compensation). This neutral grounding mode provides suppression of arcing earth faults accompanied by dangerous overvoltage and reduction of current at the point of fault by compensating the capacitive component of the elementary frequency. Field experience of operation of 6–10 kV compensated cable networks has shown that the reason of the decrease of the efficiency of the neutral grounding mode is an increase of the residual current at the point of fault. It happens due to the active component of the elementary frequency and higher harmonic components that are not compensated via ASC up to the values when long time arc duration and transition of the earth fault to the short circuit become possible. The existing solutions of the problem of full compensation of the current of a single-phase earth fault are not sufficiently developed and substantiated. Thus, the solution of the problem to increase the efficiency of grounding the neutral of the network via ASC can be achieved by developing and implementing methods and devices of the full compensation of the earth fault current, including the active component of the elementary frequency and higher harmonic components. To achieve the terms and conditions of full compensation of the current components of a single-phase earth fault, the classical theory of electrical circuits has been used. To verify the validity of the results obtained, simulation modeling in the Matlab software package has been carried out. For an electrical network with neutral grounding via ASC, the authors have obtained a general mathematical description of the terms and conditions of full current compensation at the point of earth fault, including higher harmonic components and transient components. The authors have defined the requirements for accuracy to determine the moment of a single-phase earth fault and the voltage value of the damaged phase when insulation fault occurs. Possible options of algorithms to compensate higher harmonics in the current of stable earth fault are proposed. The obtained general mathematical description of the terms and conditions of full current compensation at the point of a single-phase earth fault in 6–10 kV compensated cable networks allows us to substantiate existing methods and develop new ones to compensate both the total current at the point of fault and its components.
{"title":"Terms and conditions of single phase to earth fault current full compensation in 610 kV cable networks with neutral point grounded via arc suppression coil","authors":"V. Tyutikov, Y. Kutumov, T. Shadrikova, V. Shuin","doi":"10.17588/2072-2672.2022.5.024-032","DOIUrl":"https://doi.org/10.17588/2072-2672.2022.5.024-032","url":null,"abstract":"To improve the reliability of power supply of consumers, a significant part of 6–10 kV cable networks (in Russia about 20 %) operate with resonant neutral grounding via arc suppression coil (ASC) (single-phase earth fault capacitive current compensation). This neutral grounding mode provides suppression of arcing earth faults accompanied by dangerous overvoltage and reduction of current at the point of fault by compensating the capacitive component of the elementary frequency. Field experience of operation of 6–10 kV compensated cable networks has shown that the reason of the decrease of the efficiency of the neutral grounding mode is an increase of the residual current at the point of fault. It happens due to the active component of the elementary frequency and higher harmonic components that are not compensated via ASC up to the values when long time arc duration and transition of the earth fault to the short circuit become possible. The existing solutions of the problem of full compensation of the current of a single-phase earth fault are not sufficiently developed and substantiated. Thus, the solution of the problem to increase the efficiency of grounding the neutral of the network via ASC can be achieved by developing and implementing methods and devices of the full compensation of the earth fault current, including the active component of the elementary frequency and higher harmonic components. To achieve the terms and conditions of full compensation of the current components of a single-phase earth fault, the classical theory of electrical circuits has been used. To verify the validity of the results obtained, simulation modeling in the Matlab software package has been carried out. For an electrical network with neutral grounding via ASC, the authors have obtained a general mathematical description of the terms and conditions of full current compensation at the point of earth fault, including higher harmonic components and transient components. The authors have defined the requirements for accuracy to determine the moment of a single-phase earth fault and the voltage value of the damaged phase when insulation fault occurs. Possible options of algorithms to compensate higher harmonics in the current of stable earth fault are proposed. The obtained general mathematical description of the terms and conditions of full current compensation at the point of a single-phase earth fault in 6–10 kV compensated cable networks allows us to substantiate existing methods and develop new ones to compensate both the total current at the point of fault and its components.","PeriodicalId":23635,"journal":{"name":"Vestnik IGEU","volume":"338 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85444142","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-31DOI: 10.17588/2072-2672.2022.5.012-017
V. Murko, V. Bukhmirov, E. Bushuev, A. K. Dzhundubaev, M. Sultanaliev, E. N. Temlyantseva
Brown coals are valuable natural resource. Brown coals of the Kara-Keche deposit are most of all ready for industrial development in the Kyrgyz Republic. To solve the problems of effective development of brown coal of this deposit, it is necessary to study the issues of direct combustion of water-coal fuel (WCF) without thermal stabilization of the flame with additional sources of heat release. Experimental studies of WCF combustion have been conducted at the experimental industrial technological stand of Siberian State Industrial University, Novokuznetsk city. Structural-rheological and thermal characteristics of a pilot batch of brown coal of the Kara-Keche deposit, as well as data on the organization of efficient combustion of WCF, have been obtained. Brown coal of the Kara-Keche deposit meets the requirements of pipeline transportation and direct combustion in the furnaces of boilers of thermal power plants and boiler houses. The resulted water-coal fuel of brown coal is effectively burned in a vortex adiabatic furnace and the combustion process is like the combustion of WCF of hard coals of “G” type.
{"title":"Technological assessment of processes of water-coal fuel combustion of brown coal of Kara-Keche deposit of Kyrgyz Republic","authors":"V. Murko, V. Bukhmirov, E. Bushuev, A. K. Dzhundubaev, M. Sultanaliev, E. N. Temlyantseva","doi":"10.17588/2072-2672.2022.5.012-017","DOIUrl":"https://doi.org/10.17588/2072-2672.2022.5.012-017","url":null,"abstract":"Brown coals are valuable natural resource. Brown coals of the Kara-Keche deposit are most of all ready for industrial development in the Kyrgyz Republic. To solve the problems of effective development of brown coal of this deposit, it is necessary to study the issues of direct combustion of water-coal fuel (WCF) without thermal stabilization of the flame with additional sources of heat release. Experimental studies of WCF combustion have been conducted at the experimental industrial technological stand of Siberian State Industrial University, Novokuznetsk city. Structural-rheological and thermal characteristics of a pilot batch of brown coal of the Kara-Keche deposit, as well as data on the organization of efficient combustion of WCF, have been obtained. Brown coal of the Kara-Keche deposit meets the requirements of pipeline transportation and direct combustion in the furnaces of boilers of thermal power plants and boiler houses. The resulted water-coal fuel of brown coal is effectively burned in a vortex adiabatic furnace and the combustion process is like the combustion of WCF of hard coals of “G” type.","PeriodicalId":23635,"journal":{"name":"Vestnik IGEU","volume":"71 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90950985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-10-31DOI: 10.17588/2072-2672.2022.5.005-011
V. Bukhmirov, M.H. Suleimanov, E. Bushuev, O. Kolibaba, N.P. Gusenkova
Experiments are often considered as the way to find rational heating modes at manufacturing enterprises. Unlike experimental methods, modern calculation methods use mathematical modeling of physical and chemical processes in heating furnaces. It allows to reduce the time of the research and it is less resource intensive. A mathematical model is proposed to find rational operation modes of thermal furnaces according to the specified criterion. The model considers the porosity of the heated material and the flow of the furnace atmosphere through it. Finite difference method and the zonal method to calculate complex heat transfer is used for numerical implementation of the model. A mathematical model of the thermal operation of a thermal furnace to heat bulk cages has been developed, considering the filtration of combustion products. The developed mathematical model is designed to find new modes of thermal operation of the heating furnace, which provide a specified quality of the final product with a minimum fuel consumption or maximum furnace productivity according to the given fuel consumption rate.
{"title":"Development of modern method to calculate thermal performance of chamber heating furnace","authors":"V. Bukhmirov, M.H. Suleimanov, E. Bushuev, O. Kolibaba, N.P. Gusenkova","doi":"10.17588/2072-2672.2022.5.005-011","DOIUrl":"https://doi.org/10.17588/2072-2672.2022.5.005-011","url":null,"abstract":"Experiments are often considered as the way to find rational heating modes at manufacturing enterprises. Unlike experimental methods, modern calculation methods use mathematical modeling of physical and chemical processes in heating furnaces. It allows to reduce the time of the research and it is less resource intensive. A mathematical model is proposed to find rational operation modes of thermal furnaces according to the specified criterion. The model considers the porosity of the heated material and the flow of the furnace atmosphere through it. Finite difference method and the zonal method to calculate complex heat transfer is used for numerical implementation of the model. A mathematical model of the thermal operation of a thermal furnace to heat bulk cages has been developed, considering the filtration of combustion products. The developed mathematical model is designed to find new modes of thermal operation of the heating furnace, which provide a specified quality of the final product with a minimum fuel consumption or maximum furnace productivity according to the given fuel consumption rate.","PeriodicalId":23635,"journal":{"name":"Vestnik IGEU","volume":"91 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78353242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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