scholarly journals Vertical steam generators tube bundles vibrations

2020 ◽  
Author(s):  
С.М. Каплунов ◽  
Г.Б. Крыжевич ◽  
Т.Н. Фесенко ◽  
Е.А. Дронова
Keyword(s):  
Experimental Studies ◽  
Power Equipment ◽  
Dynamic Stresses ◽  
Spacer Grids ◽  
Equipment Operation ◽  
Contact Loads ◽  
Operational Characteristics ◽  
Tube Bundles ◽  
Equipment Failures ◽  
Vibration Parameters

Представлена реализация расчетного метода для определения и анализа параметров вибрации трубных пучков парогенераторов (ПГ), обтекаемых поперечным турбулентным потоком жидкого теплоносителя. В связи с известными случаями выхода из строя энергетического оборудования вследствие истирания труб ПГ в дистанционирующих решетках, решение данной задачи весьма актуально в настоящее время. Экспериментальные исследования конструкций такого типа чрезвычайно дороги и трудоемки. В связи с этим целью работы является разработка и создание современных математических моделей вибрации трубных пучков. Достижение такой цели представляется весьма прогрессивным и важным для повышения ресурса и безопасности эксплуатации современного энергетического оборудования. Полученные в результате последующих исследований зависимостей параметров вибрации, а именно амплитуды, частотного состава, динамических напряжений, контактных нагрузок и пути скольжения труб в дистанционирующих решетках от конструкционных и эксплуатационных характеристик и параметров ПГ были подробно исследованы. Приведенный анализ подтвердил предполагаемое существенное влияние данных параметров на повышение вибропрочности многокомпонентной конструкции ПГ. The paper presents implementation of a computing method for determination and analysis of vibration parameters of steam generator tube bundles (SG) streamlined by cross liquid coolant turbulent flow. Due to frequent power equipment failures caused by abrasion of SG tubes in spacer grids, this problem is very relevant at the present time. Experimental studies of this type of structures are extremely expensive and time-consuming. The purpose of this paper consists in creation and generation of modern mathematical models of tube bundles vibration. Achievement of this purpose could result in increase of resource and safety of modern power equipment operation. Vibration parameters dependencies obtained in the subsequent research, including amplitudes, frequency composition, dynamic stresses, contact loads and tube sliding paths in spacer grids, depending on structural and operational characteristics of SG were carefully studied. The above analysis confirmed the expected significant Influence of these parameters on increase of multi-component SG structure vibration resistance.

scholarly journals DYNAMICS OF TWO-PHASE FLOW ACROSS HORIZONTAL TUBE BUNDLES - A REVIEW

2005 ◽  
Vol 4 (2) ◽  
Author(s):  
G. Ribatskia ◽  
J. R. Thome
Keyword(s):  
Void Fraction ◽  
Two Phase Flow ◽  
Experimental Studies ◽  
Horizontal Tube ◽  
Prediction Methods ◽  
Phase Flow ◽  
Two Phase ◽  
Pressure Drops ◽  
Frictional Pressure Drop ◽  
Tube Bundles

This paper presents a state-of-the-art review of the hydrodynamic aspects of two-phase flow across horizontal tube bundles. The review covers studies related to the evaluation of void fraction, two-phase flow behaviors and pressure drops on the shell side of staggered and in-line tube bundles for upward, downward and side-to-side flows. This study of the literature critically describes the proposed flow pattern maps and semi-empirical correlations for predicting void fraction and frictional pressure drop. These predicting methods are generally based on experimental results for adiabatic air-water flows. A limited number of experimental studies with R-11 and R-113 were also carried out in the past. The review shows noticeable discrepancies among the available prediction methods. Finally, this study suggests that further research focusing on the development of representative databanks and new prediction methods is still necessary.

Reducing the Impact of Source Information Uncertainty in Intelligent Automated Thermal Process Control Systems in Ensuring Reliable Operation of Power Equipment

Vestnik MEI ◽  
2021 ◽  
Vol 3 (3) ◽  
pp. 78-87
Author(s):  
Edik K. Arakelyan ◽  
◽  
Ivan A. Shcherbatov ◽  
Keyword(s):  
Control System ◽  
Process Control ◽  
Control Systems ◽  
Process Control System ◽  
Power Equipment ◽  
Source Information ◽  
Equipment Operation ◽  
Process Control Systems ◽  
Automated Process ◽  
The Impact

The uncertainty of the source information is used to solve key tasks in an intelligent automated thermal process control system affects the calculation of control actions, the implementation of equipment optimal operating modes and, as a result, leads to degraded reliability. As a rule, this type of information can be qualitative (the use of expert knowledge) or quantitative in nature. In this regard, it is extremely important to reduce the impact of uncertainty. The aim of the study is to identify the types and origins of uncertainty in the source information used by an intelligent automated process control system and to develop approaches to reduce its impact on the reliability of power equipment operation. The approaches used to ensure the specified indicators of reliability, efficiency and environmental friendliness in modern intelligent automated process control systems are based on predictive strategies, according to which the technical condition of equipment and specific degradation processes are predicted. This means that various types of uncertainty can have a significant negative impact. To reduce the influence of uncertainty of the initial information that affects the reliability of power equipment operation, the use of artificial neural networks is proposed. Their application opens the possibility to predict the occurrence of equipment defects and failures based on retrospective data for specified forecast time intervals. A method for reducing the impact of anomalies contained in the source information used in an intelligent process control system for energy facilities is demonstrated. Data omissions and outliers are investigated, the elimination of which reduces the impact of uncertainty and improves the quality of solving key problems in intelligent automated process control systems. Experimental studies were carried out that made it possible to identify the mathematical methods for removing omissions and anomalies in the source information in the best way. Methodological aspects of eliminating various types of uncertainty that exist in managing of power facilities by means of intelligent automated process control systems at the key stages of the power equipment life cycle are described.

scholarly journals Formation of Incrustations during the Cocombustion of Biomass in Fluidised Bed Boilers

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
Petr Buryan
Keyword(s):  
Raw Materials ◽  
Combustion Process ◽  
Power Equipment ◽  
Fluidised Bed ◽  
Boiler Furnace ◽  
Repeated Heating ◽  
Equipment Operation ◽  
Heating And Cooling ◽  
First Pass ◽  
Pass Through

In this article, we focus on causes of formation of incrustations in fluidised bed boilers that result from combustion of biomass-containing energy-producing raw materials and can significantly limit the efficiency of the respective power equipment operation. We applied laboratory procedures followed for assessment of characteristic eutectics of mixtures of coal ashes, desulphurisation components (dolomite and limestone), and woodchip ashes. Our analysis proved that combustion of these (or similar) raw materials, accompanied by repeated heating and cooling of combustion and flue gas desulphurisation products, leads to the formation of unfavourable incrustations. These incrustations can grow up to several tens of centimetres in size, thereby significantly restricting the power equipment functionality. They arise due to incrust reheating that results in the formation of eutectics, which have lower melting temperatures than that during their first pass through the combustion process. The same holds for desulphuriation components themselves. Formation of these new eutectics can be attributed both to recycling of substances produced during the first pass through the furnace as well as to mixtures formed both from recycled materials and from components initially combusted in the boiler furnace.

scholarly journals Experimental studies and numerical modelling of heat and mass transfer process in shell-and-tube heat exchangers with compact arrangements of tube bundles

2018 ◽  
Vol 240 ◽  
pp. 02006 ◽  
Author(s):  
Valery Gorobets ◽  
Yurii Bohdan ◽  
Viktor Trokhaniak ◽  
Ievgen Antypov
Keyword(s):  
Mass Transfer ◽  
Numerical Modelling ◽  
Heat And Mass Transfer ◽  
Heat Exchangers ◽  
Experimental Studies ◽  
Mass Transfer Process ◽  
Experimental Investigations ◽  
Transfer Processes ◽  
Tube Bundles ◽  
Shell And Tube

Shall-and-tube heat exchangers based on the bundles with in-line or staggered arrangements have been widely used in industry and power engineering. A large number of theoretical and experimental works are devoted to study of hydrodynamic and heat transfer processes in such bundles. In that, works the basic studies of heat and mass transfer for these bundles are found. However, heat exchangers of this type can have big dimensions and mass. One of the ways to improve the weight and dimensions of the shell-and-tube heat exchangers is to use compact arrangement of tube bundles. A new design of heat exchanger is proposed, in which there are no gaps between adjacent tubes that touch each other. Different geometry of these tube bundles with displacement of adjacent tubes in the direction of transverse to the flow is considered. Numerical modelling and experimental investigations of hydrodynamic, heat and mass transfer processes in such tube bundles has been carried out. The distribution of velocities, temperatures, and pressure in inter-tube channels have been obtained.

Experimental studies of load characteristics of bogie frames for 350 km/h EMUs

2011 ◽  
Vol 226 (2) ◽  
pp. 216-227 ◽  
Author(s):  
Z Ren ◽  
S Sun ◽  
Q Li ◽  
Z Liu
Keyword(s):  
High Speed ◽  
Experimental Studies ◽  
Lateral Force ◽  
Load Spectrum ◽  
Dynamic Stresses ◽  
Dynamic Coefficients ◽  
Sample Data ◽  
Load Characteristics ◽  
Amplitude Level ◽  
Track Irregularities

In this paper,methods to measure the axle spring load, trailing arm seat lateral force and dynamic stresses of powered and non-powered bogies of a 350 km/h electrical-multi-unit (EMU) are presented. The dynamic amplitude and Hilbert transform of the sample data are used to investigate the characteristics of the forces and the stresses for the EMU running on typical sections including high-speed division, turnout zone, curves, and depot entrance. The load spectrum is then introduced to survey the amplitude level and the number of occurrence of the loads and stresses. Dynamic coefficients of the loads are compared with the recommended values in the Code UIC615-4. The effects of track irregularities and vibrations of gear boxes and motors on the loads and stresses are investigated and the measured loads are classified into six types according to effects of forces on the bogie's movement. The characteristics of the measured loads are useful to establish load conditions for laboratory tests of bogie’s fatigue assessment.

scholarly journals Experimental and numerical studies of heat and mass transfer in low-temperature heat accumulator with phase transformations of accumulating material

2018 ◽  
Vol 240 ◽  
pp. 01009 ◽  
Author(s):  
Valery Gorobets ◽  
Ievgen Antypov ◽  
Viktor Trokhaniak ◽  
Yurii Bohdan
Keyword(s):  
Mass Transfer ◽  
Phase Transformations ◽  
Heat And Mass Transfer ◽  
Thermal Energy ◽  
Experimental Studies ◽  
Experimental Plant ◽  
Chemical Transformations ◽  
Heat Accumulator ◽  
Tube Bundles ◽  
Melting And Crystallization

Accumulation of thermal energy is produced with the aim of storing at certain times, when there is an overabundance of this energy and its further use in other periods of time when there is a deficit thermal energy. Thermal energy storage may be carried out under heating of any material (water, solid materials etc.) or by using the phase or chemical transformation of the material (melting and crystallization processes, direct and reverse chemical reaction). Thermal accumulators with phase or chemical transformations are allowed to concentrate a large amount of energy in a relatively small volume of accumulating material. In this paper an experimental study and numerical modeling of heat and mass transfer in the heat accumulator during phase transformations of the accumulating material are presented. The experimental plant consists of a chamber filled with paraffin. In experimental studies, the changes of the temperature distribution in heat accumulating material and tube bundles have investigated. Numerical simulation of melting and solidification of heat accumulating material during the heated and cooled of tube bundles were performed. As the results of research, the basic laws of melting and crystallization processes in heat accumulator during phase transformations of heat accumulating material were determined.

Research and Application on Fault Diagnosis for Steam Turbine Using Multi-Parameter Fusion

2014 ◽  
Vol 543-547 ◽  
pp. 1068-1073
Author(s):  
Xiao Wen Deng ◽  
Zhen Yu Zhou ◽  
Lei Song ◽  
Peng Li ◽  
Yu Jiong Gu
Keyword(s):  
Fault Diagnosis ◽  
Steam Turbine ◽  
Comprehensive Evaluation ◽  
Mechanical Equipment ◽  
Operational Parameters ◽  
Multiple Parameters ◽  
Equipment Operation ◽  
State Evaluation ◽  
Fault Mode ◽  
Vibration Parameters

For the running situation of supercritical and ultra-supercritical steam turbine unit, a fault diagnosis method of steam turbine based on multiple parameters fusion is proposed. The association of the fault mode with the vibration parameters, the thermodynamic parameters and the operational parameters is built, according to fault development mechanism, equipment operation data and professional experience. The overall state evaluation of mechanical equipment is given, the reliability of fault diagnosis is improved, and the need of the steam turbine fault diagnosis is met, by means of comprehensive evaluation of multiple parameters. Example applications verify this method.

Theoretical and Experimental Study of Operation of the Tank Equipment for Ultrasonic Purification of the Internal Combustion Engine Exhaust Gases

2021 ◽  
Vol 23 (3) ◽  
pp. B219-B226
Author(s):  
Adil Kadyrov ◽  
Aleksandr Ganyukov ◽  
Igor Pak ◽  
Bahtiyar Suleyev ◽  
Kyrmyzy Balabekova
Keyword(s):  
Experimental Data ◽  
Internal Combustion Engines ◽  
Combustion Engine ◽  
Experimental Studies ◽  
Internal Combustion ◽  
Rate Of Change ◽  
Motor Vehicles ◽  
Engine Exhaust ◽  
Exhaust Gases ◽  
Equipment Operation

The article presents results of scientific and experimental studies of the authors on operation of the tank equipment for ultrasonic purification of exhaust gases of internal combustion engines designed to reduce environmental pollution. The scheme of the experimental device implementing the principle of the tank equipment operation for ultrasonic cleaning of the motor vehicles exhaust gases is presented; the obtained experimental data of ultrasonic coagulation processes were processed and analyzed. Empirical relationships of the coagulation coefficient and its rate of change are derived from experimental data.

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