NTU "KhPI" Bulletin: Power and heat engineering processes and equipment最新文献

{"title":"The Method of Determining Total Losses in the Nozzle Cascades of Turbomachines","authors":"A. Lapuzin, V. Subotovich, Y. Yudin, S. Naumenko","doi":"10.20998/2078-774x.2023.01.02","DOIUrl":"https://doi.org/10.20998/2078-774x.2023.01.02","url":null,"abstract":"To assess the level of aerodynamic efficiency of the nozzle cascades of steam and gas turbines, the method was suggested to determine the total loss coefficient instead of kinetic energy loss coefficient that takes into account both kinetic energy losses and kinematic losses. This method allows us to transform the original non-uniform spatial flow behind the cascade into an axisymmetric cylindrical flow. In the tested annular cascade with cylindrical meridional boundaries, the total loss coefficient is approximately 0.02 higher than the kinetic energy loss coefficient. By taking into account kinematic losses when performing thermal calculations for the turbines we eliminate the need for an unjustified correction of the kinetic energy loss coefficient of the nozzle cascade by 0.01–0.03, increasing thus the accuracy of calculations. To analyze the operation of individual sections of the nozzle cascade and to determine the relationship between kinetic energy losses and kinematic losses, it is advisable to use the averaging method proposed in 2021 that enables the transformation of the initial non-uniform spatial flow behind the cascade into an axisymmetric conical flow. The aerodynamic characteristics of this flow are the widely used kinetic energy loss factor and two averaged flow angles.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"38 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126715275","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}

{"title":"Searching for Possible Design Solutions to Extend the Service Life of the HPC of a Powerful NPP Turbine after Damage to the Rotor Blades","authors":"Oleksandr Usatyi, O. Chernousenko, V. Peshko","doi":"10.20998/2078-774x.2023.01.01","DOIUrl":"https://doi.org/10.20998/2078-774x.2023.01.01","url":null,"abstract":"The aim of this research was to analyze and evaluate possible design solutions for the flow path of the high-pressure cylinder (HPC) of the K-1000-60/3000 turbine and the possibility of their short-term implementation in a nuclear power plant after an accidental destruction of the working blades of the last stage of the HPC in conditions of the shortage of generating capacities and a tense operation state of the power system. To achieve the set goals, an appropriate methodology was developed; a mathematical model of thermo-and gas dynamic processes in the flow path of a steam turbine was improved. To make appropriate decisions on changing the design of the turbine, the necessary computational studies of the HPC of the K-1000-60/3000 turbine of the designed structure, the structure without rotor blades of the 5th stage and the structure with four first stages (without the fifth stage) were carried out for both turbine steam flows. The results of the study of thermo- and gas dynamic parameters of the flow showed the presence of differences in the operating conditions of all turbine stages, and these are the most significant for the 4th and 5th stages. A significant redistribution of thermal differences in the stages, and a decrease in the internal power of the HPC of the turbine by 35.5 MW and 6.6 MW respectively, as well as a decrease in their internal efficiency by 11.8 % and 2.1 %, respectively, were noted. Taking into account all the aspects related to the operation of the power unit, the most successful solution for the rapid resumption of operation of a powerful turbine plant used by a nuclear power plant after an accidental damage to the working blades is a HPC design without the working blades of the fifth stage. It is planned to carry out additional studies of the HPC design by replacing the nozzle apparatus of the fifth stage with an appropriate simulator.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117027629","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}

{"title":"Effect of the Specific Features of the Torch Aerodynamics on the Integrated Efficiency of the Multifuel Boiler","authors":"Olexander Efimov, V. Kavertsev, Vadym Dyahiliev","doi":"10.20998/2078-774x.2022.03.04","DOIUrl":"https://doi.org/10.20998/2078-774x.2022.03.04","url":null,"abstract":"This scientific paper gives the literature review emphasizing that the overwhelming majority of the operated boilers are equipped with vortex burners. These burners are characterized by an increased NOx formation, low operation reliability of screen tubes and convective heating surfaces, small maneuverability range and insufficient economical indicators. The defining role of the aerodynamic organization of the furnace processes affecting the operation efficiency of the boilers was shown for the case of the combustion of the energy fuels of a different type. Hence, the problems of an increased reliability, maneuverability, environmental safety and economical operation of the boilers are rather topical. The above problems faced by Ukraine today have been essentially exacerbated due to the fact that most boilers of the thermal power plants have a depleted resource and the production of new boilers (especially high power boilers) was actually stopped. The use of vortex burners with the traditional counter layout on the two opposite furnace walls is peculiar for the overwhelming majority of modern high power boilers in Ukraine and abroad. In this case, the central zone of the furnace is designed to provide the collision of the burner torches of opposite walls and a high-temperature burning core is created. In the case of gas –oil boilers, the availability of the high-temperature core results in an intensified formation of the thermal nitrogen oxides and a decreased operation reliability of the metal of furnace screens. The torch throw onto the side furnace walls during the combustion of fuel oil results in an essential decrease of the operation reliability of the screen tubes due to a high-temperature hydrogen sulfide corrosion. This paper highlights the issues of the effect of the specific features of the torch aerodynamics on the integrated efficiency of the boiler operation and the optimization of the layouts for the combustion of energy fuels in the multifurnace boilers for further reconstruction of the boilers to reduce the emission of harmful substances, increase reliability and economicity of their operation and enlarge the steam load carrying range.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"220 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122364276","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}

{"title":"Features of Replacement of the ТГМП-314 Boiler Heating Installation","authors":"T. Rymar, M. Zayats","doi":"10.20998/2078-774x.2022.03.06","DOIUrl":"https://doi.org/10.20998/2078-774x.2022.03.06","url":null,"abstract":"Thermal power stations play the main role not only in carrying the base load, but also in ensuring the coverage of peak and semi-peak loads of electricity consumption. Improving the operational maintenance of energy equipment gives a greater economic effect, since the costs of modernization of regenerative air heaters, which improve their density and thermal efficiency, are repaid in a short time. The efficiency and cost-effectiveness of the operation of regenerative air heaters was increased by the reconstruction of the heating installation. The results of the reconstruction of the design heaters of the TГМП-314 boilers with sections of sanitary-technical heaters КФСО -II and КФБО -II with replacement by sections of energy heaters (СО-110) are presented. The improved heating installation is installed in front of each regenerative air heater of the ТГМП-314 boiler and is made of two walls placed sequentially according to the air movement, in each of which 12 sections of reconstructed CO-110 heaters with a downward movement of the heating steam flow are installed. An important advantage of the proposed sequential installation of radiators is an increase in the uniformity of the temperature field in the box in front of the regenerative air heater due to two-stage air heating. Sequential installation of radiator walls increases the heat transfer coefficient approximately 1.6 times compared to parallel connection, which makes it possible to double the air speed in the radiators for the same number of sections. The possibility of formation of stagnant zones of sections of CO-110 heaters is excluded. In this case, it is recommended to reconstruct single-pass radiators with the installation of a pipe board and heating steam condensate removal chambers. The high efficiency of the improved heating installation made it possible to carry out all boiler ignitions with the possibility of supplying flue gases immediately through the RAH.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117093871","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}

{"title":"Predicting the Heat-Exchange Intensity in the Biogas Production","authors":"S. Tkachenko, Olha Vlasenko","doi":"10.20998/2078-774x.2022.03.09","DOIUrl":"https://doi.org/10.20998/2078-774x.2022.03.09","url":null,"abstract":"The intensity of the heat exchange between the internal thin-wall vessel and the experimental liquid medium has been studied. The mixture of the distilled glycerol, the substrate from the operating biogas plant, the fresh chicken manure with the moisture content of W = 90 %, chicken manure with the moisture content of W = 90 % aged for 5 days and the chicken manure with the moisture content of W = 90 % aged for 13 days was used as the experimental liquid medium. The experimental-calculative method was suggested to define the coefficient of the heat loss between the internal thin-wall vessel and the experimental liquid medium using the method of regular thermal mode. The main problems peculiar for the methods of the definition of the heat-exchange intensity in the multi-phase and multi-component media in the food industry and in the biogas production have been analyzed. The heat-exchange intensity prediction methods available for the food industry are of great importance for heat and power computations. These methods refute the characteristics of the media and it has a great effect on the computation of their thermal and physical properties. Food products subjected to the thermal processes of sublimation, evaporation, heating and crystallization have the properties of solid, liquid and gaseous bodies and transform from one aggregate state to another and it has a substantial effect on a change of their thermal and physical properties. Biogas technologies are used by the multi-tonnage production. These technologies use huge volumes of the substrate with unknown thermal and physical properties. Contemporary development of biogas technologies raises the problems relating to the thermal stabilization of the process and prediction of the heat-exchange intensity. The productions pay much attention to the problems of the stable temperature mode in the bioreactor. The operation of the biogas plant requires a stable temperature mode at different ambient temperatures. The main requirement to the bioreactor is that the temperature fluctuations should be within certain ranges. The waste treatment of different productions, in particular heating, cooling, thermal stabilization results in the anthropogenic load on the environment due to use of the outdated and not upgraded heat process equipment. It is rather difficult to solve this problem because the thermal and physical properties of the mixtures, liquids, substrates and their chemical compositions and molecular structure are limitedly known or unknown. It is also unknown how these are changed during the thermal treatment and how environmental factors affect their change. Relative errors of the main values, in particular the heat loss coefficient, heat transfer coefficient, specific heat capacity, heat exchange surface area, cooling (heating) rate, nonuniform temperature distribution factor, heat flow, temperature rush, temperature difference, mass of the experimental liquid media, experiment duration and tabl","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"705 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132912903","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}

{"title":"Studying the Effect of the Tangential Nonuniformity of Flow Parameters on Gas Dynamic Performances of the Nozzle Cascades of Turbine Machines","authors":"A. Lapuzin, V. Subotovich, Y. Yudin, S. Naumenko, Ivan Malymon","doi":"10.20998/2078-774x.2022.01.03","DOIUrl":"https://doi.org/10.20998/2078-774x.2022.01.03","url":null,"abstract":"Aerodynamic efficiency of the nozzle cascades of steam and gas turbines is defined by many factors and one of them is the tangential and radial nonuniformity degree of the parameters of a spatial flow behind the cascades. The averaging of these parameters enables the determination of the integral parameters of the cascades, in particular two flow angles and the velocity angle or the kinetic energy loss coefficient. The angle that takes into account the level of the averaged radial component of the velocity defines the level of kinematic losses in the cascade. Even in the case of the cylindric boundaries of the cascade this angle differs from zero and kinematic losses decrease the cascade efficiency by 30 to 50 percent. This scientific paper gives the results of experimental investigations of the effect of the circumferential nonuniformity of the velocity and the angles of the spatial flow on kinematic losses at different radii of the nozzle cascade of the last stage of the steam turbine and the nozzle cascade of the first stage of the gas turbine. The kinetic energy loss coefficient and the coefficient of total losses were suggested as the integral characteristics of the cascades. In the case of cylindric boundaries of the stage the total loss-to-kinetic energy loss ratio is noticeably decreased during the transition from the average zone to the zone of end losses. However, in the peripheral zone of the nozzle cascade of the last stage of steam turbine total losses are three times higher than kinetic energy losses due to the fact that the radial component of the velocity behind the cascade is much higher than the flow rate component and the level of the losses of kinetic energy is not high.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"181 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133934008","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}

{"title":"Aeroelastic Behavior of Long Blades of Last Stage of a 220 MW Steam Turbine","authors":"L. Kolodyazhnaya, Yu. G. Bykov","doi":"10.20998/2078-774x.2022.03.03","DOIUrl":"https://doi.org/10.20998/2078-774x.2022.03.03","url":null,"abstract":"The phenomenon of flutter in steam turbines is quite rare, but when it occurs, the risk of damaging the blades and putting the whole unit out of service increases significantly. Currently, there is a tendency to increase the length of the blades of the last stages of powerful steam turbines, as a result of which the amplitude-frequency characteristics of the blade oscillations change, which can lead to the occurrence of uncontrolled self-excited oscillations. The paper presents the results of a numerical analysis of the aeroelastic characteristics of blade row of the last stage rotor of a 200 MW steam turbine, in which, during modernization, the length of the blades increased to 1200 mm, which made it necessary to check the resistance to flutter in operating modes. The analysis used the method of solving the coupled problem of unsteady aerodynamics and elastic blade vibrations, which allows to predict the amplitude-frequency spectrum of unsteady loads and blade vibrations in a viscous gas flow. The results of the calculations showed the absence of flutter and self-oscillations on the first five natural forms of blade oscillations in the nominal mode of operation of the steam turbine.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123968448","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}

{"title":"Approach to the Selection of Optimal Characteristics for Low Pressure Turbines Using a Single Gas Generator","authors":"S. Khomylyev, I. Kravchenko, Andriy Popuga","doi":"10.20998/2078-774x.2022.03.01","DOIUrl":"https://doi.org/10.20998/2078-774x.2022.03.01","url":null,"abstract":"An approach to the conceptual design of the low pressure turbine for the aviation turbopropeller engine has been shown. The engine is created on the basis of the single gas generator for the two-engine power plant intended for the average transport aircraft. This approach is of great interest because in addition to the efficiency factor, the mass of the designed turbine, the fuel mass and the number of aerodynamic profile were used as optimal design criteria. The designed turbine includes the two stages and the interturbine transition channel of a diffuser type arranged in front of them. Consideration was given to the four flow parts of the turbine that differ by the diameter and the height selected in the preset limitation range. The gas dynamic efficiency of the interturbine transition channel, gas dynamic efficiency of the after-turbine channel, the strength of the turbine blade of the last stage were taken as the limitations. The dependences of the efficiency factor, the turbine mass and the number of turbine blades on the turbine aerodynamic load factor were obtained for the four turbine options. The turbine efficiency factor was determined using our own method of one-dimensional gas-dynamic computation. The fuel flow rate was determined using the mathematical engine model. The turbine mass was determined using the parametric method as a function of the aerodynamic load factor and the turbine flow rate factor. The number of aerodynamic profiles was defined using the Zweifel parameter. It was shown that the use of heavy loaded and less loaded low pressure turbines can reduce the take-off weight of the aircraft in spite of an increased fuel flow rate.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129537792","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}

{"title":"Investigation of the resource indicators of the intermediate pressure rotor of the K-200-130 turbine of power unit No. 11 of DTEK Burshtyn TPP","authors":"O. Chernousenko, D. Rindyuk, V. Peshko","doi":"10.20998/2078-774x.2022.01.02","DOIUrl":"https://doi.org/10.20998/2078-774x.2022.01.02","url":null,"abstract":"The Burshtyn TPP is separated from the unified energy system of Ukraine, operates as part of the \"Burshtynskii Ostriv\" in parallel with the Union for the Co-ordination of Transmission of Electricity (UCTE). Work within the \"Burshtynskii Ostriv\" requires the loading of up to nine power units of the station, whereas before that, no more than six power units worked at the station. On the one hand, joining the UCTE opened opportunities for increasing export supplies of electricity from Ukraine. On the other hand, the maneuvering mode of operation of the power plant in \"Burshtynskii Ostriv\" has an extremely negative effect on the condition of the equipment, as it leads to frequent start-stops of units. As a result of this regime, the accident rate of TPPs has increased significantly. Therefore, it is important to determine the individual resource of Burshtyn TPP power units and assess the possibility of continuing the operation. According to calculations, the total damage of the metal of the intermediate pressure rotor of the K-200-130 turbine unit of power unit No. 11 of DTEK Burshtyn TPP is 107%, with the coefficients of the safety margin for the number of cycles and for deformations at the level of 5 and 1.5, as well as at the permissible metal working time 370 thousand hours. If the total damage of the rotor metal is more than 100%, then further operation of the equipment is impossible according to regulatory documents and the resource is considered to be exhausted. According to experimental data, with the coefficients of safety margin for the number of cycles and deformations at the level of 3 and 1.25, as well as the allowable working time of the metal of 450 thousand hours, the total damage of the metal of the rotor is 83%. The residual resource of the intermediate pressure rotor of the K-200-130 turbine of power unit No. 11 of DTEK Burshtyn TPP will be 58 908 hours. Thus, with the positive decision of the expert commission in accepting the reduced coefficients of safety margin, the allowable service life of the intermediate pressure rotor of the K-200-130 turbine of power unit No. 11 of DTEK Burshtyn TPP can be extended by 50,000 hours. with additional number of starts of no more than 400.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128873955","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}

{"title":"Thermal and Stress State of the Intermediate Pressure Rotor of the Power Unit № 11 of Burshtyn TPP","authors":"O. Chernousenko, D. Rindyuk, V. Peshko","doi":"10.20998/2078-774x.2022.01.01","DOIUrl":"https://doi.org/10.20998/2078-774x.2022.01.01","url":null,"abstract":"Thermal power plants produce about a third of the total electricity generation in the United Energy System of Ukraine and provide maneuvering capacity. The work presents the results of research aimed at analyzing the reliability of thermal power equipment. The thermal and stress state of the medium-pressure rotor of power unit No. 11 of the Burshtyn TPP was investigated. When conducting calculation experiments, both the design geometry and samples of the rotor metal in the places where cracks appeared were taken into account. The temperature distribution and their gradients were calculated to solve the problem of the stress-strain state. The highest values ​​of stress intensity amplitudes are observed in the zone of end seals, which is explained by the more significant influence of the accumulation of low-cycle fatigue as a mechanism of destruction, compared to the exhaustion of the long-term strength of the metal in the stationary mode of operation.","PeriodicalId":416126,"journal":{"name":"NTU \"KhPI\" Bulletin: Power and heat engineering processes and equipment","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133218024","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}