Pub Date : 2021-12-30DOI: 10.20998/2078-774x.2021.02.03
Pavlo Chishkala, D. Meshkov, O. Bozhko
The analysis of diagnostic methods of diesel engines is given. The principle of diagnostics by certain methods, parameters, by which the diagnostics of fuel injection equipment is conducted, as well as disadvantages of one or another method are considered. The main causes of derangements in the nodes of the fuel injection equipment of diesel engines are determined. The examples have proved that the direct diagnostics methods are the most effective in determining correlation dependencies, for example, indicating the workflow in a diesel cylinder. It is particularly established that the methods of technical diagnostics do not require dismantling of the fuel injection equipment and have proven themselves to be versatile and operative, allowing to comprehensively evaluate the condition of the diesel. The methods of non-separable diagnostic of the condition of a diesel engine are described in detail, the features of such indirect diagnostic methods as vibration, acoustic, indirect indicating by determining the voltage in the cylinder head studs, estimation of the wear rate of component parts with a metal content in engine oil, as well as diagnosing with uneven rate speed of the crankshaft. The vibro-acoustic diagnostic method of a diesel engine can be used to determine the technical condition of such elements as a diesel fuel injection pump , nozzles, and a fuel-priming pump. In addition, the characteristics of motor testers, highly specialized testers and auto scanners are given. A diagnostic feature using a computer auto scanner is that it allows evaluating the condition of nodes in a comprehensive manner, that is, taking into account the mutual influence of derangements on each other. It is noted that the methods that do not require disassembling can be considered the most effective, and the most accurate assessment of the technical condition of the diesel fuel system can be given using the diagnostic method according to the parameters of work processes.
{"title":"Formation of a Flow-Line Technical Diesel Engine by the Method of Safety-Free Diagnostics","authors":"Pavlo Chishkala, D. Meshkov, O. Bozhko","doi":"10.20998/2078-774x.2021.02.03","DOIUrl":"https://doi.org/10.20998/2078-774x.2021.02.03","url":null,"abstract":"The analysis of diagnostic methods of diesel engines is given. The principle of diagnostics by certain methods, parameters, by which the diagnostics of fuel injection equipment is conducted, as well as disadvantages of one or another method are considered. The main causes of derangements in the nodes of the fuel injection equipment of diesel engines are determined. The examples have proved that the direct diagnostics methods are the most effective in determining correlation dependencies, for example, indicating the workflow in a diesel cylinder. It is particularly established that the methods of technical diagnostics do not require dismantling of the fuel injection equipment and have proven themselves to be versatile and operative, allowing to comprehensively evaluate the condition of the diesel. The methods of non-separable diagnostic of the condition of a diesel engine are described in detail, the features of such indirect diagnostic methods as vibration, acoustic, indirect indicating by determining the voltage in the cylinder head studs, estimation of the wear rate of component parts with a metal content in engine oil, as well as diagnosing with uneven rate speed of the crankshaft. The vibro-acoustic diagnostic method of a diesel engine can be used to determine the technical condition of such elements as a diesel fuel injection pump , nozzles, and a fuel-priming pump. In addition, the characteristics of motor testers, highly specialized testers and auto scanners are given. A diagnostic feature using a computer auto scanner is that it allows evaluating the condition of nodes in a comprehensive manner, that is, taking into account the mutual influence of derangements on each other. It is noted that the methods that do not require disassembling can be considered the most effective, and the most accurate assessment of the technical condition of the diesel fuel system can be given using the diagnostic method according to the parameters of work processes.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130873506","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 : 2021-12-30DOI: 10.20998/2078-774x.2021.02.06
Yevgenij Zaytsev
At the present stage of the development of technology, it is necessary to ensure the strength, reliability and durability of the structure that successfully functions under conditions of high-temperature heat exchange as maximum as possible. In this regard, graphite structural elements are widely used, and they are also applied for parts of space and aircraft, jet and rocket engines. The transversely isotropic graphite cylinder used in this work has a unique set of qualities that make it indispensable for problems in nuclear physics and power engineering; however, in the calculation of thermal engineering practice, it has not been studied enough, since it contains a large scatter of thermophysical characteristics for various grades of graphite. The aim of the study, including the basis of the developed method for solving boundary value problems of doubly nonlinear unsteady thermal conductivity, is to consider the effect of temperature dependences of the thermophysical characteristics of the material on temperature, zonal radiative-convective heat transfer and anisotropy on the distribution of temperature fields along the length, at the center and surface of a semi-infinite solid cylinder. The essence of this method is that the Goodman’s and Kirchhoff’s transformations are applied to the problem posed converted to a dimensionless form, then the relative temperature and functions from it, are expanded in the series of sines on the a priori interval, then the superposition principle is applied, after which the original setting is converted to a set of linearized problems with reduced thermophysical characteristics. Linear problems are solved by the method of integral transformations, which are summed up. The upper limit of the priori interval is determined from the condition that the relative temperature obtained from the solution of the problem Fo ® ¥ takes the value of the upper limit of the a priori interval. A large number of numerical calculations in the Matlab environment graphically show changes in the relative temperature on the axis and surface of the cylinder in a wide range of Fourier criteria. It is found that with an increase in the Fourier criterion, the character of heating changes qualitatively from the axis to the surface of the cylinder, both in terms of nonlinearities and anisotropy. For the case of double nonlinearity, the location of the temperature fields at different anisotropies in comparison with an isotropic material is shown graphically.
{"title":"The Calculation of Double Nonlinearity and Material Anisotropy Influence on the Temperature Distribution in the Cylinder Under High Temperature Heat Exchange","authors":"Yevgenij Zaytsev","doi":"10.20998/2078-774x.2021.02.06","DOIUrl":"https://doi.org/10.20998/2078-774x.2021.02.06","url":null,"abstract":"At the present stage of the development of technology, it is necessary to ensure the strength, reliability and durability of the structure that successfully functions under conditions of high-temperature heat exchange as maximum as possible. In this regard, graphite structural elements are widely used, and they are also applied for parts of space and aircraft, jet and rocket engines. The transversely isotropic graphite cylinder used in this work has a unique set of qualities that make it indispensable for problems in nuclear physics and power engineering; however, in the calculation of thermal engineering practice, it has not been studied enough, since it contains a large scatter of thermophysical characteristics for various grades of graphite. The aim of the study, including the basis of the developed method for solving boundary value problems of doubly nonlinear unsteady thermal conductivity, is to consider the effect of temperature dependences of the thermophysical characteristics of the material on temperature, zonal radiative-convective heat transfer and anisotropy on the distribution of temperature fields along the length, at the center and surface of a semi-infinite solid cylinder. The essence of this method is that the Goodman’s and Kirchhoff’s transformations are applied to the problem posed converted to a dimensionless form, then the relative temperature and functions from it, are expanded in the series of sines on the a priori interval, then the superposition principle is applied, after which the original setting is converted to a set of linearized problems with reduced thermophysical characteristics. Linear problems are solved by the method of integral transformations, which are summed up. The upper limit of the priori interval is determined from the condition that the relative temperature obtained from the solution of the problem Fo ® ¥ takes the value of the upper limit of the a priori interval. A large number of numerical calculations in the Matlab environment graphically show changes in the relative temperature on the axis and surface of the cylinder in a wide range of Fourier criteria. It is found that with an increase in the Fourier criterion, the character of heating changes qualitatively from the axis to the surface of the cylinder, both in terms of nonlinearities and anisotropy. For the case of double nonlinearity, the location of the temperature fields at different anisotropies in comparison with an isotropic material is shown graphically.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131308258","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 : 2021-12-30DOI: 10.20998/2078-774x.2021.04.08
Yu. I. Martynov, O. Petrenko, B. Liubarskyi
Contemporary tendencies relentlessly dictate the conditions for the appearance of a more qualitative, reliable and comfortable elevator chain for the rolling stock of a vertical motion. At the same time, the issues of energy saving and cost-effective use of resources gain currency against the background of rising prices for energy carriers and market prices for various elements that play an essential role in the availability of many electromechanical systems. Unfortunately, attention was paid to the availability of above problems in the elevator sector when the majority of the elevators (about 60% of them) outlived their technical service life that ensured the reliable operation. As a matter of fact, an amazingly important issue is relating to the embedment of reliable, durable and economically substantiated components of electromechanical systems into contemporary Ukrainian elevators. The purpose of the research done was to define the main parameters and performances of the asynchronous elevator motor of an ADB180M6 type. The motor is powered from the industrial network of 50 Hz and the frequency converter with the frequency of 50Hz and 16.6 Hz. This scientific paper uses the methods of physical investigations. The elevator motor test data satisfy the reliability parameters that make any elevator user feel comfortable. The main measurement data obtained for the engine No43886 of an ADB180M6 type powered from the frequency converter “Altivar” of 22kW with the motor speed of 910 rpm and 289 rpm satisfy the requirements of the regulatory documentation. The noise level is within satisfactory margins.
{"title":"Defining the Main Parameters and Performances of the Elevator Motor","authors":"Yu. I. Martynov, O. Petrenko, B. Liubarskyi","doi":"10.20998/2078-774x.2021.04.08","DOIUrl":"https://doi.org/10.20998/2078-774x.2021.04.08","url":null,"abstract":"Contemporary tendencies relentlessly dictate the conditions for the appearance of a more qualitative, reliable and comfortable elevator chain for the rolling stock of a vertical motion. At the same time, the issues of energy saving and cost-effective use of resources gain currency against the background of rising prices for energy carriers and market prices for various elements that play an essential role in the availability of many electromechanical systems. Unfortunately, attention was paid to the availability of above problems in the elevator sector when the majority of the elevators (about 60% of them) outlived their technical service life that ensured the reliable operation. As a matter of fact, an amazingly important issue is relating to the embedment of reliable, durable and economically substantiated components of electromechanical systems into contemporary Ukrainian elevators. The purpose of the research done was to define the main parameters and performances of the asynchronous elevator motor of an ADB180M6 type. The motor is powered from the industrial network of 50 Hz and the frequency converter with the frequency of 50Hz and 16.6 Hz. This scientific paper uses the methods of physical investigations. The elevator motor test data satisfy the reliability parameters that make any elevator user feel comfortable. The main measurement data obtained for the engine No43886 of an ADB180M6 type powered from the frequency converter “Altivar” of 22kW with the motor speed of 910 rpm and 289 rpm satisfy the requirements of the regulatory documentation. The noise level is within satisfactory margins.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"94 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116073166","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 : 2021-12-30DOI: 10.20998/2078-774x.2021.04.07
O. Voinov, Yu. V. Elkin
The mankind created the global production that has an increasingly harmful effect on the natural environment. The present-day condition of natural environment causes much concern. A global environmental problem has inevitably emerged and now it requires a decrease in the intensity of the harmful action of available productive facilities. The purpose of the research done was to substantiate and find a potential opportunity for the use of a new approach to an increase in the level of ecological compatibility due to a partial renewal of the worn-out equipment. A substantial portion of the domestic energy equipment has a low level of the process-related functioning efficiency (including ecological efficiency). A global practice shows that the problems of the improvement of technological parameters can be solved in a different way to provide failure –free functioning of power facilities. The analysis of the circumstances existing nowadays in the field of the interaction of domestic power engineering and natural environment gives us an opportunity to adhere to the opinion that the use of the method of partial renewal is objectively affordable and it is a highly efficient tool for the reduction of the degree of harmful action on the part of power equipment. The purpose of this research paper was to show technological opportunities of the method of a partial renewal of worn-out engineering facilities (first of all power equipment and especially boiler plants) as an affordable tool for a decrease of the degree of their harmful action on the environment. Among the branches of the domestic industry, the power engineering branch needs badly a partial renewal and in the first turn these are boiler plants. This type of renewal is of vital importance for Ukraine that possesses a huge fleet of completely worn-out boiler plants. It is advisable to perform an integrated partial renewal. The partial renewal can involve all or individual parts of the entire chain of process elements. A successful fulfillment of the program of partial renewal is defined by a high quality control of the system of scientific and organizational-&-engineering problems relating to the renewal arrangement and realization. An issue relating to an index of the estimation of the extent of renewal of engineering facilities is of great importance. The capital inputs into the partial renewal are always justified for all intents and purposes. As for the conception of the renewal of the worn-out equipment the partial renewal can become an important launching low-cost step that will simplify the expected realization of the program of complete renewal.
{"title":"Partial Renewal is a Tool for an Increase in the Environmental Efficiency of the Worn-out Power Facilities","authors":"O. Voinov, Yu. V. Elkin","doi":"10.20998/2078-774x.2021.04.07","DOIUrl":"https://doi.org/10.20998/2078-774x.2021.04.07","url":null,"abstract":"The mankind created the global production that has an increasingly harmful effect on the natural environment. The present-day condition of natural environment causes much concern. A global environmental problem has inevitably emerged and now it requires a decrease in the intensity of the harmful action of available productive facilities. The purpose of the research done was to substantiate and find a potential opportunity for the use of a new approach to an increase in the level of ecological compatibility due to a partial renewal of the worn-out equipment. A substantial portion of the domestic energy equipment has a low level of the process-related functioning efficiency (including ecological efficiency). A global practice shows that the problems of the improvement of technological parameters can be solved in a different way to provide failure –free functioning of power facilities. The analysis of the circumstances existing nowadays in the field of the interaction of domestic power engineering and natural environment gives us an opportunity to adhere to the opinion that the use of the method of partial renewal is objectively affordable and it is a highly efficient tool for the reduction of the degree of harmful action on the part of power equipment. The purpose of this research paper was to show technological opportunities of the method of a partial renewal of worn-out engineering facilities (first of all power equipment and especially boiler plants) as an affordable tool for a decrease of the degree of their harmful action on the environment. Among the branches of the domestic industry, the power engineering branch needs badly a partial renewal and in the first turn these are boiler plants. This type of renewal is of vital importance for Ukraine that possesses a huge fleet of completely worn-out boiler plants. It is advisable to perform an integrated partial renewal. The partial renewal can involve all or individual parts of the entire chain of process elements. A successful fulfillment of the program of partial renewal is defined by a high quality control of the system of scientific and organizational-&-engineering problems relating to the renewal arrangement and realization. An issue relating to an index of the estimation of the extent of renewal of engineering facilities is of great importance. The capital inputs into the partial renewal are always justified for all intents and purposes. As for the conception of the renewal of the worn-out equipment the partial renewal can become an important launching low-cost step that will simplify the expected realization of the program of complete renewal.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133251154","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 : 2021-12-30DOI: 10.20998/2078-774x.2021.03.03
M. Lohvyniuk, Ye.V. Novakivskyy
The purpose of this scientific paper was to analyze the mathematical model built for the staged arrangement of the fuel combustion system and calculate the formation of nitrogen oxides throughout the boiler furnace height for the different distributions of thermal loadings along the full vertical extent of the combustion chamber. The obtained results enable the determination of the overall amount of nitrogen oxides formed in the boiler and it allows us to provide appropriate ecological indices for the boiler when regulating the air concentration in the burner rows. In practice, to suppress the formation of nitrogen oxides we often use such basic methods as low-toxic burners, staged fuel combustion, flue gas recirculation, etc. The analysis of the computations done allows us to draw a conclusion that the operation of the boiler with ecological indices that satisfy standard values of the European Directive 2010/75/EU is only possible for the load below 40 %. After reconstruction of the burner system and adjustment of the air supply system with the observation of above ecological norms the boiler power can be increased up to 80 % using the staged fuel burning with the ensurance of environmental performances during its operation. Computational and experimental data errors varied in the range of 8 % to 12 %. With the increase in the overall chemical incomplete combustion by 40 % to 60 % (q3) these losses are compensated by a decrease in absolute losses due to the boiler aggregate load and the losses through external walls (q5) due to an increase in the boiler power.
{"title":"Decreasing NOx Emissions by Way of the Staged Fuel Combustion","authors":"M. Lohvyniuk, Ye.V. Novakivskyy","doi":"10.20998/2078-774x.2021.03.03","DOIUrl":"https://doi.org/10.20998/2078-774x.2021.03.03","url":null,"abstract":"The purpose of this scientific paper was to analyze the mathematical model built for the staged arrangement of the fuel combustion system and calculate the formation of nitrogen oxides throughout the boiler furnace height for the different distributions of thermal loadings along the full vertical extent of the combustion chamber. The obtained results enable the determination of the overall amount of nitrogen oxides formed in the boiler and it allows us to provide appropriate ecological indices for the boiler when regulating the air concentration in the burner rows. In practice, to suppress the formation of nitrogen oxides we often use such basic methods as low-toxic burners, staged fuel combustion, flue gas recirculation, etc. The analysis of the computations done allows us to draw a conclusion that the operation of the boiler with ecological indices that satisfy standard values of the European Directive 2010/75/EU is only possible for the load below 40 %. After reconstruction of the burner system and adjustment of the air supply system with the observation of above ecological norms the boiler power can be increased up to 80 % using the staged fuel burning with the ensurance of environmental performances during its operation. Computational and experimental data errors varied in the range of 8 % to 12 %. With the increase in the overall chemical incomplete combustion by 40 % to 60 % (q3) these losses are compensated by a decrease in absolute losses due to the boiler aggregate load and the losses through external walls (q5) due to an increase in the boiler power.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129144451","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 : 2021-12-30DOI: 10.20998/2078-774x.2021.04.05
Mykhaylo Bozhenko, Tatiana Izhevska
A promising trend in air conditioning systems is the use of indirect evaporative cooling, but in the classic version it is effective in dry and hot climates. For the need to maintain comfortable air parameters in public buildings, it is not possible to fully implement such a process in the conditions of Ukraine (the relative humidity of the outside air ranges from 63 to 75 %). The aim of the work is to increase the energy efficiency of air conditioning systems with standard equipment through partial evaporative cooling and use for cooling water in cooling towers of the air removed from the rooms during the warm season, and in the cold season - use of the exhaust air for preheating the supply air in heat exchanger. A corresponding system diagram was developed and computational studies of a direct-flow circuit and a circuit with recirculation were carried out for one of the educational buildings of the Igor Sikorsky Kyiv Polytechnic Institute. According to the results of calculating the direct-flow circuit in the warm period, the energy efficiency of indirect evaporative cooling was 23.5 %. The annual amount of recovered heat of ventilation emissions for this scheme in the cold period was 3731 GJ / year, and the economic effect - 1473185 UAH / year. For a circuit with recirculation during a warm period, the greatest effect of indirect evaporative cooling is achieved with a recirculation rate of 10 %, and for the overall decrease in the cooling capacity of the air conditioner during this period the greatest impact is not indirect evaporative cooling, but recirculation. In the cold season, the greatest utilization effect is also achieved with a 10 % recirculation rate.
{"title":"Central Air Conditioning Systems with Partial Indirect Evaporative Cooling and Utilization of Cold and Heat of Ventilation Emissions","authors":"Mykhaylo Bozhenko, Tatiana Izhevska","doi":"10.20998/2078-774x.2021.04.05","DOIUrl":"https://doi.org/10.20998/2078-774x.2021.04.05","url":null,"abstract":"A promising trend in air conditioning systems is the use of indirect evaporative cooling, but in the classic version it is effective in dry and hot climates. For the need to maintain comfortable air parameters in public buildings, it is not possible to fully implement such a process in the conditions of Ukraine (the relative humidity of the outside air ranges from 63 to 75 %). The aim of the work is to increase the energy efficiency of air conditioning systems with standard equipment through partial evaporative cooling and use for cooling water in cooling towers of the air removed from the rooms during the warm season, and in the cold season - use of the exhaust air for preheating the supply air in heat exchanger. A corresponding system diagram was developed and computational studies of a direct-flow circuit and a circuit with recirculation were carried out for one of the educational buildings of the Igor Sikorsky Kyiv Polytechnic Institute. According to the results of calculating the direct-flow circuit in the warm period, the energy efficiency of indirect evaporative cooling was 23.5 %. The annual amount of recovered heat of ventilation emissions for this scheme in the cold period was 3731 GJ / year, and the economic effect - 1473185 UAH / year. For a circuit with recirculation during a warm period, the greatest effect of indirect evaporative cooling is achieved with a recirculation rate of 10 %, and for the overall decrease in the cooling capacity of the air conditioner during this period the greatest impact is not indirect evaporative cooling, but recirculation. In the cold season, the greatest utilization effect is also achieved with a 10 % recirculation rate.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131603353","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 : 2021-12-30DOI: 10.20998/2078-774x.2021.04.02
V. Gnesin, L. Kolodyazhnaya, Yu. G. Bykov, I. Kravchenko, Oleksii Petrov, V. Donchenko
Aeroelasticity problems arise in the different fields of technology. The accident-free operation of the airborne machines is one of the most important factors that should be taken into account during their designing and upgrading. The solution of this problem involves the implementation of many measures to provide the system reliability on the whole, including its individual elements, in particular aircraft engine, its fan whose wide-chord blades can be exposed to the wreckage due to different reasons including the aeroelastic effects, i.e. self-excited vibrations. As a result, the origination of the aeroelastic phenomenon (flutter) in design and off-design modes should be eliminated at the stage of the design and operational development of the rotor wheel that would result in a considerable increase of the level of reliability of the aircraft engine. Based on the analysis of the available methods used for the flutter prediction we can draw a conclusion that the most promising approach to the analysis of the aeroelastic behavior of the blade ring of fan is the use of the method based on the three-dimensional model of the aerodynamics and dynamics (the method used for the solution of the coupled aeroelastic problem). By solving the coupled aeroelastic problem of the nonstationary aerodynamics and elastic vibrations of the blades we can get the amplitude –frequency blade vibration spectrum for the three-dimensional gas flow, including forced vibrations and self-excided vibrations in order to increase the reliability of the blade row of turbine machines. The developed numerical method was used for the analysis of the aeroelastic behavior of the blade ring of the fan mounted in the airborne engine for the operation mode of 3520 rmp with appropriate boundary conditions at the inlet and outlet behind the ring. The computation data confirmed the origination of self-vibrations for the given fan operation mode.
{"title":"Flutter of Fan Blades in the Aircraft Engine in the Three-Dimensional Subsonic Gas Flow","authors":"V. Gnesin, L. Kolodyazhnaya, Yu. G. Bykov, I. Kravchenko, Oleksii Petrov, V. Donchenko","doi":"10.20998/2078-774x.2021.04.02","DOIUrl":"https://doi.org/10.20998/2078-774x.2021.04.02","url":null,"abstract":"Aeroelasticity problems arise in the different fields of technology. The accident-free operation of the airborne machines is one of the most important factors that should be taken into account during their designing and upgrading. The solution of this problem involves the implementation of many measures to provide the system reliability on the whole, including its individual elements, in particular aircraft engine, its fan whose wide-chord blades can be exposed to the wreckage due to different reasons including the aeroelastic effects, i.e. self-excited vibrations. As a result, the origination of the aeroelastic phenomenon (flutter) in design and off-design modes should be eliminated at the stage of the design and operational development of the rotor wheel that would result in a considerable increase of the level of reliability of the aircraft engine. Based on the analysis of the available methods used for the flutter prediction we can draw a conclusion that the most promising approach to the analysis of the aeroelastic behavior of the blade ring of fan is the use of the method based on the three-dimensional model of the aerodynamics and dynamics (the method used for the solution of the coupled aeroelastic problem). By solving the coupled aeroelastic problem of the nonstationary aerodynamics and elastic vibrations of the blades we can get the amplitude –frequency blade vibration spectrum for the three-dimensional gas flow, including forced vibrations and self-excided vibrations in order to increase the reliability of the blade row of turbine machines. The developed numerical method was used for the analysis of the aeroelastic behavior of the blade ring of the fan mounted in the airborne engine for the operation mode of 3520 rmp with appropriate boundary conditions at the inlet and outlet behind the ring. The computation data confirmed the origination of self-vibrations for the given fan operation mode.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127632541","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 : 2021-12-30DOI: 10.20998/2078-774x.2021.03.08
V. Mel’nick, Olha Vorobyova, N. Ostapenko
Analysis of literature sources suggests that the use of anaerobic treatment methods is especially effective for high concentrations of contaminants in wastewater, as well as for large volumes of water supplied for treatment, which is typical for industrial wastewater. In biotechnological production and food industry, waste water has a high level of pollution with organic compounds, it is advisable to use anaerobic treatment methods. Anaerobic wastewater treatment processes are characterized by low energy consumption and the ability to recover energy through the combustion of methane. To ensure the required temperature regime for the operation of the bioreactor, a new design of the heat exchange device of the anaerobic bioreactor with immobilized microorganisms has been developed. This design of the bioreactor can provide the required degree of wastewater purification at significantly lower costs for construction, operation, and material and energy resources. For clarity, the design features were designed bioreactor with a plane load of bundled software SOLIDWORKS and a mathematical model of the processes of anaerobic wastewater treatment.
{"title":"Modernization of Anaerobic Bioreactor for Waste Water Purification Plant","authors":"V. Mel’nick, Olha Vorobyova, N. Ostapenko","doi":"10.20998/2078-774x.2021.03.08","DOIUrl":"https://doi.org/10.20998/2078-774x.2021.03.08","url":null,"abstract":"Analysis of literature sources suggests that the use of anaerobic treatment methods is especially effective for high concentrations of contaminants in wastewater, as well as for large volumes of water supplied for treatment, which is typical for industrial wastewater. In biotechnological production and food industry, waste water has a high level of pollution with organic compounds, it is advisable to use anaerobic treatment methods. Anaerobic wastewater treatment processes are characterized by low energy consumption and the ability to recover energy through the combustion of methane. To ensure the required temperature regime for the operation of the bioreactor, a new design of the heat exchange device of the anaerobic bioreactor with immobilized microorganisms has been developed. This design of the bioreactor can provide the required degree of wastewater purification at significantly lower costs for construction, operation, and material and energy resources. For clarity, the design features were designed bioreactor with a plane load of bundled software SOLIDWORKS and a mathematical model of the processes of anaerobic wastewater treatment.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"192 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134500962","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 : 2021-12-30DOI: 10.20998/2078-774x.2021.04.03
S. Kravchenko, O. Linkov, M. Shelestov, Alexander Bekaryuk, Eduard Bozhko
Simulation of the working process of an internal combustion engine is the basis for all further calculations and studies of the engine. Of particular relevance is the availability of an adequate mathematical model of the engine process due to the fact that due to the trend of continuous improvement of engine performance, it is necessary to take into account many influencing factors to obtain a satisfactory result. The most complex and dependent on many physicochemical parameters is the process of combustion of fuel in the engine. Models of combustion in diesel engines can be divided into three groups: detailed models; empirical and semipemirical models. The analysis of world experience in research and mathematical modeling of combustion process in internal combustion engines is performed in the work. The advantages and disadvantages of different mathematical models are indicated. It is proposed to use a semi-empirical mathematical model of combustion which describes the differential characteristic of the combustion rate by two curves corresponding to the periods of the first flash and diffusion combustion. Use of such model simplifies performance of calculations and at the same time allows to receive qualitative results considering many factors of influence.
{"title":"Mathematical Modeling of the Working Process of a Two-Stroke Engine with Countermoving Pistons","authors":"S. Kravchenko, O. Linkov, M. Shelestov, Alexander Bekaryuk, Eduard Bozhko","doi":"10.20998/2078-774x.2021.04.03","DOIUrl":"https://doi.org/10.20998/2078-774x.2021.04.03","url":null,"abstract":"Simulation of the working process of an internal combustion engine is the basis for all further calculations and studies of the engine. Of particular relevance is the availability of an adequate mathematical model of the engine process due to the fact that due to the trend of continuous improvement of engine performance, it is necessary to take into account many influencing factors to obtain a satisfactory result. The most complex and dependent on many physicochemical parameters is the process of combustion of fuel in the engine. Models of combustion in diesel engines can be divided into three groups: detailed models; empirical and semipemirical models. The analysis of world experience in research and mathematical modeling of combustion process in internal combustion engines is performed in the work. The advantages and disadvantages of different mathematical models are indicated. It is proposed to use a semi-empirical mathematical model of combustion which describes the differential characteristic of the combustion rate by two curves corresponding to the periods of the first flash and diffusion combustion. Use of such model simplifies performance of calculations and at the same time allows to receive qualitative results considering many factors of influence.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132474367","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 : 2021-12-30DOI: 10.20998/2078-774x.2021.04.01
Riza Sherfedinov, Oleksandr Usatyi, O. Avdieieva, Mykhailo Daludin, Illia Yenin
This scientific paper gives the main research data obtained during the solution of the search problem to define optimal parameter values for the thermal circuit of the К-540-23.5 turbine unit that would provide the most efficient operation both for the optimal version of the high pressure cylinder (HPC) as part of the turbine unit and the turbine unit on the whole. The effect of the distribution of heat differences in the stages of the optimal flow part of the high pressure cylinder used by the К-540-23.5 turbine on the integral quality factors of the turbine unit has been assessed. The calculation studies of the thermal circuit of the turbine unit with the optimal flow section of the high-pressure cylinder showed that the temperature of the underheated feed water in the high pressure heater (HPH) arranged near the steam generator has the most critical effect on the power and economical efficiency of the high pressure cylinder and entire turbine unit. The two-criterion Pareto problem for the upgrading of the turbine unit was formulated and solved to define optimal underheating temperature values. Consideration was given to the two variants of the solution of the optimization problem for the feed water underheating temperature in the high pressure heater. Comparison and analysis of the two variants of solution for the two-criterion optimization problem showed the identity of the obtained data and it confirms the correctness of the problem formulation and the algorithms used for its solution.
{"title":"Specific Features of the Replacement of the Available Flow Path by the Optimal Flow Path when Upgrading the Steam Turbine High-Pressure Cylinder","authors":"Riza Sherfedinov, Oleksandr Usatyi, O. Avdieieva, Mykhailo Daludin, Illia Yenin","doi":"10.20998/2078-774x.2021.04.01","DOIUrl":"https://doi.org/10.20998/2078-774x.2021.04.01","url":null,"abstract":"This scientific paper gives the main research data obtained during the solution of the search problem to define optimal parameter values for the thermal circuit of the К-540-23.5 turbine unit that would provide the most efficient operation both for the optimal version of the high pressure cylinder (HPC) as part of the turbine unit and the turbine unit on the whole. The effect of the distribution of heat differences in the stages of the optimal flow part of the high pressure cylinder used by the К-540-23.5 turbine on the integral quality factors of the turbine unit has been assessed. The calculation studies of the thermal circuit of the turbine unit with the optimal flow section of the high-pressure cylinder showed that the temperature of the underheated feed water in the high pressure heater (HPH) arranged near the steam generator has the most critical effect on the power and economical efficiency of the high pressure cylinder and entire turbine unit. The two-criterion Pareto problem for the upgrading of the turbine unit was formulated and solved to define optimal underheating temperature values. Consideration was given to the two variants of the solution of the optimization problem for the feed water underheating temperature in the high pressure heater. Comparison and analysis of the two variants of solution for the two-criterion optimization problem showed the identity of the obtained data and it confirms the correctness of the problem formulation and the algorithms used for its solution.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"83 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131219194","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：