Pub Date : 2021-10-28DOI: 10.20998/2078-774x.2021.01.07
Subotovich Subotovich, A. Lapuzin, Y. Yudin
To smooth the parameters of the three-dimensional flow behind the nozzle cascade new methods were suggested that allow us to sustain the flow rate, stagnation enthalpy and the axial projection of the moment of momentum for initial-, nonuniform and averaged flows. It was shown that the choice of the fourth integral characteristic (the kinetic energy, the entropy and the quantity of motion) has no particular significance because it has no effect on the complex criterion of the cascade quality, i.e. the velocity coefficient-angle cosine product that characterizes the level of the radial component of velocity. The minimum values of the velocity coefficient and the cosine angle satisfy the method that allows us to sustain the quantity of motion during the smoothing and the maximum values of the specified nozzle characteristics satisfy method 2 that enables the entropy maintenance. To evaluate the aerodynamic efficiency of the nozzle cascade the preference should be given to method 1 that enables the kinetic energy conservation and the velocity coefficient allows for the precise determination of the degree of loss of the kinetic energy that is equal to 3.6 % as for the example given in the scientific paper. As for method 1, the kinematic losses in the cascade are defined by the angle cosine that characterizes the level of the radial component of the velocity behind the cascade. For the example in question, kinematic losses are equal to 1.9 % and the complex criterion of quality equal to 0.972 corresponds to the overall losses of 5.5 %. It was suggested to use the velocity coefficient and the two angles of flow as integral cascade characteristics. The use of these characteristics enables the correct computations of the efficiency factor for the stage within the one-dimensional computation. The incisive analysis was performed for different methods used for the averaging of the parameters of the axially asymmetric flow behind the nozzle cascade. It was suggested to neglect the flow rate factor in the case of thermal computations done for the turbine stage.
{"title":"New Methods Used for the Smoothing of the Three-Dimensional Flow Behind the Turbine Nozzle Cascade","authors":"Subotovich Subotovich, A. Lapuzin, Y. Yudin","doi":"10.20998/2078-774x.2021.01.07","DOIUrl":"https://doi.org/10.20998/2078-774x.2021.01.07","url":null,"abstract":"To smooth the parameters of the three-dimensional flow behind the nozzle cascade new methods were suggested that allow us to sustain the flow rate, stagnation enthalpy and the axial projection of the moment of momentum for initial-, nonuniform and averaged flows. It was shown that the choice of the fourth integral characteristic (the kinetic energy, the entropy and the quantity of motion) has no particular significance because it has no effect on the complex criterion of the cascade quality, i.e. the velocity coefficient-angle cosine product that characterizes the level of the radial component of velocity. The minimum values of the velocity coefficient and the cosine angle satisfy the method that allows us to sustain the quantity of motion during the smoothing and the maximum values of the specified nozzle characteristics satisfy method 2 that enables the entropy maintenance. To evaluate the aerodynamic efficiency of the nozzle cascade the preference should be given to method 1 that enables the kinetic energy conservation and the velocity coefficient allows for the precise determination of the degree of loss of the kinetic energy that is equal to 3.6 % as for the example given in the scientific paper. As for method 1, the kinematic losses in the cascade are defined by the angle cosine that characterizes the level of the radial component of the velocity behind the cascade. For the example in question, kinematic losses are equal to 1.9 % and the complex criterion of quality equal to 0.972 corresponds to the overall losses of 5.5 %. It was suggested to use the velocity coefficient and the two angles of flow as integral cascade characteristics. The use of these characteristics enables the correct computations of the efficiency factor for the stage within the one-dimensional computation. The incisive analysis was performed for different methods used for the averaging of the parameters of the axially asymmetric flow behind the nozzle cascade. It was suggested to neglect the flow rate factor in the case of thermal computations done for the turbine stage.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121491779","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 : 2021-10-28DOI: 10.20998/2078-774x.2021.01.05
O. Yefimov, B. Ilchenko, L. Tiutiunyk, Tetyana Yesipenko, A. Motovilnik, T. Harkusha
The materials of the article consider the optimization of certain parameters and characteristics of the equipment of NPP power units, which are closely related to the processes of their design and construction. Modern NPP power units are complex technical systems. They include a set of interconnected equipment for different technological purposes, which ensures the performance of power units of a complex function of electricity production and heat of the specified quality and according to a given load schedule. Complete mathematical models of the functional state of steam turbine power units are characterized by a large number of nonlinear connections and contain implicit functions. This complicates their widespread use to solve problems of systematic analysis of the quality of operation of power units. The aim of the work is to analyze the basic theoretical foundations, methods and approaches to the calculation and optimization of the parameters of the equipment of NPP power units by methods of mathematical modeling. The solution of the problem of optimization of NPP power unit parameters includes the following stages: selection of optimality criteria (objective functions); development of a system of interconnected mathematical models in accordance with the required hierarchical level of optimization research; selection of computational methods and optimization algorithms. Taking into account the above methodological provisions and approaches increases the efficiency of mathematical modeling to solve problems of calculations and optimization of NPP power unit parameters.
{"title":"Basic bases of calculations and optimization of NPP power unit equipment parameters methods of mathematical modelling","authors":"O. Yefimov, B. Ilchenko, L. Tiutiunyk, Tetyana Yesipenko, A. Motovilnik, T. Harkusha","doi":"10.20998/2078-774x.2021.01.05","DOIUrl":"https://doi.org/10.20998/2078-774x.2021.01.05","url":null,"abstract":"The materials of the article consider the optimization of certain parameters and characteristics of the equipment of NPP power units, which are closely related to the processes of their design and construction. Modern NPP power units are complex technical systems. They include a set of interconnected equipment for different technological purposes, which ensures the performance of power units of a complex function of electricity production and heat of the specified quality and according to a given load schedule. Complete mathematical models of the functional state of steam turbine power units are characterized by a large number of nonlinear connections and contain implicit functions. This complicates their widespread use to solve problems of systematic analysis of the quality of operation of power units. The aim of the work is to analyze the basic theoretical foundations, methods and approaches to the calculation and optimization of the parameters of the equipment of NPP power units by methods of mathematical modeling. The solution of the problem of optimization of NPP power unit parameters includes the following stages: selection of optimality criteria (objective functions); development of a system of interconnected mathematical models in accordance with the required hierarchical level of optimization research; selection of computational methods and optimization algorithms. Taking into account the above methodological provisions and approaches increases the efficiency of mathematical modeling to solve problems of calculations and optimization of NPP power unit parameters.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114941190","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 : 2020-12-30DOI: 10.20998/2078-774x.2020.02.03
Pavel Petrovich Gontarovskiy, N. Garmash, A. A. Glyadya
{"title":"Analyzing the Vibrations of the Critical Components in the Power Generating Unit of 200MW under Kinematic Loadings","authors":"Pavel Petrovich Gontarovskiy, N. Garmash, A. A. Glyadya","doi":"10.20998/2078-774x.2020.02.03","DOIUrl":"https://doi.org/10.20998/2078-774x.2020.02.03","url":null,"abstract":"","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115626384","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 : 2020-12-30DOI: 10.20998/2078-774x.2020.01.08
O. Avdieieva, Oleksandr Usatyi, I. Palkov, Sergii Andrijovich Palkov, O. Ishchenko
The article describes the effectiveness of the application of a comprehensive methodology in the modernization of the flow parts of steam turbines. The above methodology makes it possible to increase the absolute efficiency by 0.83%, and the turbine power by 1.87% due to the use of an object-oriented approach. The use of recursive traversal of various optimization levels for information exchange between objects allows finding an optimal solution for a large number of design parameters.
{"title":"Application of a comprehensive methodology to optimize the flow paths of steam turbines","authors":"O. Avdieieva, Oleksandr Usatyi, I. Palkov, Sergii Andrijovich Palkov, O. Ishchenko","doi":"10.20998/2078-774x.2020.01.08","DOIUrl":"https://doi.org/10.20998/2078-774x.2020.01.08","url":null,"abstract":"The article describes the effectiveness of the application of a comprehensive methodology in the modernization of the flow parts of steam turbines. The above methodology makes it possible to increase the absolute efficiency by 0.83%, and the turbine power by 1.87% due to the use of an object-oriented approach. The use of recursive traversal of various optimization levels for information exchange between objects allows finding an optimal solution for a large number of design parameters.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121389990","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 : 2020-12-30DOI: 10.20998/2078-774x.2020.02.01
O. Zhyrkov, Oleksandr Usatyi, O. Avdieieva, Yuri Torba
{"title":"Numerical Investigation of the Streamlining of Nozzle Arrays Equipped with Grid Valves","authors":"O. Zhyrkov, Oleksandr Usatyi, O. Avdieieva, Yuri Torba","doi":"10.20998/2078-774x.2020.02.01","DOIUrl":"https://doi.org/10.20998/2078-774x.2020.02.01","url":null,"abstract":"","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132157196","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 : 2020-12-30DOI: 10.20998/2078-774x.2020.01.04
A. Pereselkov, Olga Krugliakova
Consideration is given to the possibility of the control of the structure of the trickle flow by using flat-plate jet nozzles for the elliptic shape of the surface of the spray zone. This research paper gives consideration to the data of experimental investigations of the water-air dispersed water during the internal mixture formation in the flat-plate nozzle as applied to the cooling of the ingot between the rollers in continuous steel casting machines. In this case, the water flow rate per nozzle and the water concentration can be reduced ten times. As a result, the ingot cooling intensity is reduced and the probability of the crack nucleation on the ingot surface is decreased. This research paper gives also the data of the experimental research carried out for a more efficient use of flat-plate nozzles when cooling the casting roller before its polishing and when heating it before charging the mill stand. It was shown that the intercrossing of trickle flows produced by two flat-plate jet nozzles arranged at an angle relative to each other results in the four-time increase in the spray zone surface area and the surface spray density is reduced two times. The analogous problem was solved using the kinetic energy of the disintegrating water film and the drops after these leave the flat-plate nozzle for the additional splitting when passing through the metal gauze. It turned out that the spray zone was increased threefold and the surface spray density was decreased two times. The trickle flow structure control options in question with the use of flat-plate nozzles contribute to the improved quality of the ingots, decreased water consumption, reduced number of the nozzles and their simplified arrangement on the collectors.
{"title":"Some Methods of a Change in the Trickle Flow Structure during the Water Dispersion by Flat-Plate Jet Nozzles","authors":"A. Pereselkov, Olga Krugliakova","doi":"10.20998/2078-774x.2020.01.04","DOIUrl":"https://doi.org/10.20998/2078-774x.2020.01.04","url":null,"abstract":"Consideration is given to the possibility of the control of the structure of the trickle flow by using flat-plate jet nozzles for the elliptic shape of the surface of the spray zone. This research paper gives consideration to the data of experimental investigations of the water-air dispersed water during the internal mixture formation in the flat-plate nozzle as applied to the cooling of the ingot between the rollers in continuous steel casting machines. In this case, the water flow rate per nozzle and the water concentration can be reduced ten times. As a result, the ingot cooling intensity is reduced and the probability of the crack nucleation on the ingot surface is decreased. This research paper gives also the data of the experimental research carried out for a more efficient use of flat-plate nozzles when cooling the casting roller before its polishing and when heating it before charging the mill stand. It was shown that the intercrossing of trickle flows produced by two flat-plate jet nozzles arranged at an angle relative to each other results in the four-time increase in the spray zone surface area and the surface spray density is reduced two times. The analogous problem was solved using the kinetic energy of the disintegrating water film and the drops after these leave the flat-plate nozzle for the additional splitting when passing through the metal gauze. It turned out that the spray zone was increased threefold and the surface spray density was decreased two times. The trickle flow structure control options in question with the use of flat-plate nozzles contribute to the improved quality of the ingots, decreased water consumption, reduced number of the nozzles and their simplified arrangement on the collectors.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"155 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114514010","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 : 2020-12-30DOI: 10.20998/2078-774x.2020.01.03
A. Tarasov, O. Lytvynenko, Irina Myhaylova, S. Naumenko
Thermophysical experiments became a very rare phenomenon due to their expensiveness and rather complicated and time-consuming preparation and carrying out. Very often the teachers tend to prefer the computer simulation of these and those technological processes for the in-depth formation of detailed knowledge in students. The reason for such a preference is evident; this approach provides visual aspects and relatively fast attainment of the goal. A negative side of such a choice is that the future specialists are not able to judge the reliability of these and those experimental relationships between the physical parameters of the processes that are used for the machinery design. To remove this drawback of the teaching and learning process, a small-size aerodynamic tunnel was created and the detailed technique for the running of experiment and experimental data processing was elaborated. The length of the working section of this tunnel was equal to 0.5 m. The rectangular cross-section of the tunnel bore was equal to 0.35´0.15 m2. The heat loss was studied at the lower wall of aerodynamic tunnel that was equipped with three heating elements arranged longitudinally to the air stream. The heating elements were the strips made of konstantan with the cross-section of 10´0.11 mm2 and the thermocouples were fixed to the lower surface. A maximum value of the local Reynolds number was Rex < 105, i.e. the laminar boundary layer was actually in progress on the entire surface. When processing the obtained experimental data we took into account radiation heat losses and the heat losses caused by thermal conductivity along heating elements. Nevertheless, heat transfer intensity values turned out to be 3 to 4 times higher in comparison to those of the laminar flow mode. The numerical analysis of the thermal state of the experimental plate enabled the determination of the heat losses that were not taken into account earlier. Hence, we managed to achieve actually full coincidence of the experimental values of the intensity of heat transfer that were derived from a reliable similarity equation. The research done is required for the formation of the competence in students that study for the Master’s degree to get their specialty.
{"title":"The Thermophysical Experiment Carried out for the Education of the Students Studying for the Master’s Degree to Get Heat Engineering Specialties","authors":"A. Tarasov, O. Lytvynenko, Irina Myhaylova, S. Naumenko","doi":"10.20998/2078-774x.2020.01.03","DOIUrl":"https://doi.org/10.20998/2078-774x.2020.01.03","url":null,"abstract":"Thermophysical experiments became a very rare phenomenon due to their expensiveness and rather complicated and time-consuming preparation and carrying out. Very often the teachers tend to prefer the computer simulation of these and those technological processes for the in-depth formation of detailed knowledge in students. The reason for such a preference is evident; this approach provides visual aspects and relatively fast attainment of the goal. A negative side of such a choice is that the future specialists are not able to judge the reliability of these and those experimental relationships between the physical parameters of the processes that are used for the machinery design. To remove this drawback of the teaching and learning process, a small-size aerodynamic tunnel was created and the detailed technique for the running of experiment and experimental data processing was elaborated. The length of the working section of this tunnel was equal to 0.5 m. The rectangular cross-section of the tunnel bore was equal to 0.35´0.15 m2. The heat loss was studied at the lower wall of aerodynamic tunnel that was equipped with three heating elements arranged longitudinally to the air stream. The heating elements were the strips made of konstantan with the cross-section of 10´0.11 mm2 and the thermocouples were fixed to the lower surface. A maximum value of the local Reynolds number was Rex < 105, i.e. the laminar boundary layer was actually in progress on the entire surface. When processing the obtained experimental data we took into account radiation heat losses and the heat losses caused by thermal conductivity along heating elements. Nevertheless, heat transfer intensity values turned out to be 3 to 4 times higher in comparison to those of the laminar flow mode. The numerical analysis of the thermal state of the experimental plate enabled the determination of the heat losses that were not taken into account earlier. Hence, we managed to achieve actually full coincidence of the experimental values of the intensity of heat transfer that were derived from a reliable similarity equation. The research done is required for the formation of the competence in students that study for the Master’s degree to get their specialty.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134455024","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 : 2020-12-30DOI: 10.20998/2078-774x.2020.01.07
V. Voloshchuk, O. Nekrashevych, S. Liubytskyi
The paper demonstrates the importance of taking into account the accumulation of exergy in a control volume of a thermal storage during transient modes for evaluation of exergy-based parameters. The investigations are based on the exergy balance equation and mathematical model of the mode of simultaneous thermal energy addition and removal. It is found that for the specified parameters of the unit, when the exergy accumulation is not included, the error of estimation of exergy-base parameters can be large: in case of calculation of fuel of exergy and exergy efficiency this error can reach 80 %, the exergy destruction values are received with 130 % error. It is shown that these errors depend on the ratio of rates of cold and hot working fluids and decrease with increasing this ratio, but almost do not depend on the storage volumes and the initial temperatures of working fluids. Including accumulation of exergy within the control volumes during dynamic modes of thermal systems is necessary for implementation of exergy-based control strategies.
{"title":"Exergy Analysis of Transiant Modes in Hot Water Storage Tanks","authors":"V. Voloshchuk, O. Nekrashevych, S. Liubytskyi","doi":"10.20998/2078-774x.2020.01.07","DOIUrl":"https://doi.org/10.20998/2078-774x.2020.01.07","url":null,"abstract":"The paper demonstrates the importance of taking into account the accumulation of exergy in a control volume of a thermal storage during transient modes for evaluation of exergy-based parameters. The investigations are based on the exergy balance equation and mathematical model of the mode of simultaneous thermal energy addition and removal. It is found that for the specified parameters of the unit, when the exergy accumulation is not included, the error of estimation of exergy-base parameters can be large: in case of calculation of fuel of exergy and exergy efficiency this error can reach 80 %, the exergy destruction values are received with 130 % error. It is shown that these errors depend on the ratio of rates of cold and hot working fluids and decrease with increasing this ratio, but almost do not depend on the storage volumes and the initial temperatures of working fluids. Including accumulation of exergy within the control volumes during dynamic modes of thermal systems is necessary for implementation of exergy-based control strategies.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114774954","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 : 2020-12-30DOI: 10.20998/2078-774x.2020.02.04
A. Yerofieieva, V. Artemchuk, N. Mukhina, O. Karasov
Topicality. The presented work is devoted to the urgent task of increasing the energy efficiency of chamber furnaces.The purpose is to solve the problem connected with optimizing the parameters of the non-stationary mode of the applied electric field in order to increase the efficiency of the chamber furnaces. Methodology. According to well-known methods of experiment planning, we obtained a set of Paretoincomparable solutions of the chamber furnace, taking into account the voltage between the burner and the metal charge, which is the basis of the algorithm. Findings. The work proposes an innovative system acting the process of metal heating in a chamber furnace. The result is a developed chamber furnace control system, in which the optimal values of control actions at each step of the heating cycle are determined according to the created algorithm. The proposed control system is universal, because after miscalculations it produces the dynamics, according to which one needs to change the value of direct-current voltage and gas supply with a step in time to perform any given mode of metal heat treatment. The experimental studies conducted on a real chamber furnace with a bogie hearth at Zaporozhye Titanium and Magnesium Combine confirmed this. The analysis of the obtained metal annealing temperature curve showed that the implementation of the optimal values of the control actions, obtained using the developed algorithm, provides a high uniformity and better quality heating of the metal. The dynamics of gas consumption by the chamber furnace during the heating cycle in the basic mode, without voltage supply, and under the condition of its use in accordance with the performed optimization testify to the possibility of significant energy efficiency improvement of the considered furnaces. Conclusions. For the first time we proved the possibility and efficiency of using a non-stationary electric field in the furnace chamber as a control action, which confirms the originality of the obtained results. The practical value of the research is that the developed control algorithm is universal in terms of metal heat treatment and can be used in chamber furnaces of any industrial enterprise, while one heating cycle reduces the consumption of natural gas by more than 10 %.
{"title":"Optimization of Non-Stationary Electric Field Parameters in Order to Increase the Efficiency of Chamber Furnaces","authors":"A. Yerofieieva, V. Artemchuk, N. Mukhina, O. Karasov","doi":"10.20998/2078-774x.2020.02.04","DOIUrl":"https://doi.org/10.20998/2078-774x.2020.02.04","url":null,"abstract":"Topicality. The presented work is devoted to the urgent task of increasing the energy efficiency of chamber furnaces.The purpose is to solve the problem connected with optimizing the parameters of the non-stationary mode of the applied electric field in order to increase the efficiency of the chamber furnaces. Methodology. According to well-known methods of experiment planning, we obtained a set of Paretoincomparable solutions of the chamber furnace, taking into account the voltage between the burner and the metal charge, which is the basis of the algorithm. Findings. The work proposes an innovative system acting the process of metal heating in a chamber furnace. The result is a developed chamber furnace control system, in which the optimal values of control actions at each step of the heating cycle are determined according to the created algorithm. The proposed control system is universal, because after miscalculations it produces the dynamics, according to which one needs to change the value of direct-current voltage and gas supply with a step in time to perform any given mode of metal heat treatment. The experimental studies conducted on a real chamber furnace with a bogie hearth at Zaporozhye Titanium and Magnesium Combine confirmed this. The analysis of the obtained metal annealing temperature curve showed that the implementation of the optimal values of the control actions, obtained using the developed algorithm, provides a high uniformity and better quality heating of the metal. The dynamics of gas consumption by the chamber furnace during the heating cycle in the basic mode, without voltage supply, and under the condition of its use in accordance with the performed optimization testify to the possibility of significant energy efficiency improvement of the considered furnaces. Conclusions. For the first time we proved the possibility and efficiency of using a non-stationary electric field in the furnace chamber as a control action, which confirms the originality of the obtained results. The practical value of the research is that the developed control algorithm is universal in terms of metal heat treatment and can be used in chamber furnaces of any industrial enterprise, while one heating cycle reduces the consumption of natural gas by more than 10 %.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125259337","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 : 2020-12-30DOI: 10.20998/2078-774x.2020.01.02
Y. A. Oleynik, S. A. Saprykin, S. Naumenko
Formulas for drive power of centrifugal supercharger of natural gas are obtained, where efficiency factor (EF) of centrifugal supercharger is equal to product of three EF of centrifugal supercharger: mechanical, polytropic, gas-dynamic. The gas dynamic EF of the centrifugal supercharger is usually not taken into account and is taken equal to one. Gas dynamic EF takes into account the pressure loss of the centrifugal supercharger pumped in the stages and the energy loss due to friction of the centrifugal supercharger impellers in the gas medium. Also in the formula of calculation of drive power of the operated centrifugal supercharger the presence of condensate and water vapors in the natural gas is taken into account, which affects the accuracy of measuring the flow rate of pumped gas in the diaphragm flowmeter. Pumping of pure natural gas is impossible in reality and there are always impurities in natural gas, which must be taken into account to estimate the mass flow rate of gas. For formulas of practical (operated) and theoretical calculations of the drive power of the centrifugal natural gas blower received constant (equal to 0.004) for daily standard gas flow, which simplifies the calculation. The paper presents both precise and simplified formulas for the drive power of a centrifugal natural gas blower.
{"title":"Determination of Fuel Gas Flow Rate in Gas Pumping Unit and Compressor Station","authors":"Y. A. Oleynik, S. A. Saprykin, S. Naumenko","doi":"10.20998/2078-774x.2020.01.02","DOIUrl":"https://doi.org/10.20998/2078-774x.2020.01.02","url":null,"abstract":"Formulas for drive power of centrifugal supercharger of natural gas are obtained, where efficiency factor (EF) of centrifugal supercharger is equal to product of three EF of centrifugal supercharger: mechanical, polytropic, gas-dynamic. The gas dynamic EF of the centrifugal supercharger is usually not taken into account and is taken equal to one. Gas dynamic EF takes into account the pressure loss of the centrifugal supercharger pumped in the stages and the energy loss due to friction of the centrifugal supercharger impellers in the gas medium. Also in the formula of calculation of drive power of the operated centrifugal supercharger the presence of condensate and water vapors in the natural gas is taken into account, which affects the accuracy of measuring the flow rate of pumped gas in the diaphragm flowmeter. Pumping of pure natural gas is impossible in reality and there are always impurities in natural gas, which must be taken into account to estimate the mass flow rate of gas. For formulas of practical (operated) and theoretical calculations of the drive power of the centrifugal natural gas blower received constant (equal to 0.004) for daily standard gas flow, which simplifies the calculation. The paper presents both precise and simplified formulas for the drive power of a centrifugal natural gas blower.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133684885","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：