scholarly journals Розробка стенду для вимірювання метрологічних характеристик електродвигунів

2021 ◽  
pp. 104-111
Author(s):  
Володимир Павлович Квасніков ◽  
Дмитро Михайлович Квашук ◽  
Марія Олександрівна Катаєва
Keyword(s):  
Power Plants ◽  
Operating Conditions ◽  
Metrological Characteristics ◽  
Normal Operation ◽  
Strain Gauges ◽  
Measuring Instruments ◽  
Electric Motors ◽  
Number Of Factors ◽  
The Moment

The problems of accurate measurement of the forces transmitted to the rotating shafts of electric motors have been solved for more than one century. At the same time, they have not lost their relevance, which is due to the wide development and variety of electric motors and power plants, the specific operating conditions of which require the use of a wide arsenal of measuring instruments. An important aspect in the process of using high-precision electric motors in such areas as medicine, vehicles, military-industrial complex is the improvement of the metrological characteristics of measuring equipment. In such conditions, power measurements at high-speed installations, where in some cases conventional measurement systems are either unsuitable or have low accuracy, are of particular importance. At the same time, in the absence of means of accurate determination of the error, attempts are made to predict them, which makes it possible to determine the influence of subtle factors on the efficiency of power plants. Even under optimal conditions for the functioning of measuring instruments, due to the influence of a number of factors, gross errors may appear. Such errors are unpredictable, and their significance is difficult to predict. To prevent the impact of negative factors on the operation of measuring instruments, additional sensors are often used, for example, to identify unnecessary vibrations, vibrometers are used in parallel with strain gauges. In the absence of such additional measuring sensors, in order to identify gross errors in diagnosing the characteristics of the moment of force, it is advisable to use machine learning tools, factor analysis techniques, simulation modeling, and other forecasting tools. With the help of such methods, among the sampling of data obtained from strain gauges, or other sensors, for measuring the moment of force, it is possible to identify deviations from normal operation, through certain frequency patterns of such influences. Among the many works describing the characteristics of errors in measuring physical quantities, there are not many that are devoted to predicting the accuracy of measuring sensors. Thus, when the measured conditions change, gross errors occur that negate the process of controlling electric motors, which is often the cause of an emergency condition. To solve this problem, you need simple and affordable tools that will allow you to form a classification of deviations in measurement errors. However, taking into account a significant number of factors of influence on the measuring medium, this can be realized only under the condition of an individual approach to the construction of measuring instruments. For this purpose, a stand was developed for measuring the metrological characteristics of electric motors. It was tested in conditions of increased vibration. The results of such tests made it possible to determine the deviations from the nominal error value of the strain gauge sensor.And also highlight a number of features of such a deviation caused by the frequency characteristics of the pulse source. The structure of the software and technical characteristics of the proposed stand and its comparison with existing analogs, as well as the functional and electrical circuit are presented. As a result of testing the proposed stand, a classification of factors influencing the accuracy of strain gauges was developed. 

Environmental Fatigue Test of CF8M With a Small Autoclave Simulating PWR Conditions

2008 ◽  
Author(s):  
Il-Seok Jeong ◽  
Gag-Hyeon Ha ◽  
Tae-Ryoung Kim
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Low Cycle Fatigue ◽  
Test Procedure ◽  
Cyclic Strain ◽  
Fatigue Tests ◽  
Operating Conditions ◽  
Measuring Instruments ◽  
Pressurized Water Reactor ◽  
Pressurized Water

To develop a fatigue design curve of cast stainless steel CF8M used in primary piping material of nuclear power plants, low-cycle fatigue tests have been conducted by Korea Electric Power Research Institute (KEPRI). A small autoclave simulated the environment of a pressurized water reactor (PWR), 15 MPa and 315 °C. Fatigue life was measured in terms of the number of cycles with the variation of strain amplitudes at 0.04%/s strain rate. A small autoclave of 1 liter and cylindrical solid fatigue specimens were used for the strain-controlled low cycle environmental fatigue tests to make the experiments convenient. However, it was difficult to install displacement measuring instruments at the target length of the specimens inside the autoclave. To mitigate the difficulty displacement data measured at the shoulders of the specimen were calibrated based on the data relation of the target and shoulder length of the specimen during hot air test conditions. KEPRI developed a test procedure to perform low cycle environmental fatigue tests in the small autoclave. The procedure corrects the cyclic strain hardening effect by performing additional tests in high temperature air condition. KEPRI verified that the corrected test result agreed well with that of finite element method analysis. The process of correcting environmental fatigue data would be useful for producing reliable fatigue curves using a small autoclave simulating the operating conditions of a PWR.

On-Site Evaluation of Bending Stresses at the Root of Small Bore Pipes by Accelerometric Measurements

2003 ◽  
Author(s):  
J. Guillou ◽  
L. Paulhiac
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Numerical Models ◽  
Operating Conditions ◽  
Strain Gauges ◽  
Bending Stress ◽  
Piping Systems ◽  
Bending Stresses ◽  
Site Evaluation

Several vibration-induced failures at the root of small bore piping systems occurred in French nuclear power plants in past years. The evaluation of the failure risk of the small bore pipes requires a fair estimation of the bending stress under operating conditions. As the use of strain gauges is too time-consuming in the environmental conditions of nuclear power plants, on-site acceleration measurements combined with numerical models are easier to handle. It still requires yet a large amount of updating work to estimate the stress in multi-span pipes with elbows and supports. The aim of the present study is to propose an alternate approach using two accelerometers to measure the local nozzle deflection, and an analytical expression of the bending stiffness of the nozzle on the main pipe. A first formulation is based on a static deformation assumption, thus allowing the use of a simple analog converter to get an estimation of the RMS value of the bending stress. To get more accurate results, a second method is based on an Euler Bernoulli deformation assumption: a spectral analyzer is then required to get an estimation of the spectrum of the bending stress. A better estimation of its RMS value is then obtained. An experimental validation of the methods based on strain gauges has been successfully performed.

scholarly journals SOURCE TERM ASSESSMENT FOR 100 MWE PRESSURIZED WATER REACTOR

2020 ◽  
Vol 22 (2) ◽  
pp. 61
Author(s):  
Pande Made Udiyani ◽  
Muhammad Budi Setiawan
Keyword(s):  
Power Plants ◽  
Public Perception ◽  
Source Term ◽  
Fission Products ◽  
Operating Conditions ◽  
Normal Operation ◽  
Pressurized Water Reactor ◽  
Pressurized Water ◽  
Water Reactor ◽  
Starting Point

One of the barriers on the implementation of nuclear energy in Indonesia is public perception towards the safety of nuclear power plants (NPPs). Therefore, it is necessary to perform a study about the radiation impact of normal and abnormal operations of an NPP. In accordance to the program of Ministry of Research and Technology period 2020-2024, concerning the plan to build a small modular reactor (SMR)-type NPP, a radiation safety study has been performed for the 100 MWe Pressurized Water Reactor (PWR-100MWe). Source term release of radioactive substances into the environment from PWR-100MWe is a starting point in the study of the radiological consequences of reactor operation. Therefore, this paper will examine the PWR-100MWe source term under normal and abnormal operating conditions, according to the design and the design basis accident (DBA). The initial trigger of the DBA is Lost of Coolant Accident (LOCA) such as Small LOCA and Large LOCA.  Due to the limitations of available SMR data, the study of PWR-100MWe source term refers to the assumption of the release fraction of fission products per subsystem in a larger 1000MWe PWR. It is expected from this assumption that pessimistic source term will be obtained. The study begins with calculation of PWR-100MWe core inventory using ORIGEN2 code based on PWR-100MWe reactor parameters. Through the mechanistic source term model and PWR-1000MWe release parameters, source terms will be obtained for normal operation and abnormal conditions i.e. DBA. Normal source term is used to calculate the consequences of normal operation, which will be used for environmental monitoring and environmental safety analysis of the site. Whereas accident source term is the basis for calculating the radiological consequences of accidents used for SAR documents and nuclear preparedness.Keywords: SMR, PWR-100MWe, normal operation, source term, accident

Could biomass-fueled boilers be operated at higher steam temperatures? Part 3: Initial analysis of costs and benefits

TAPPI Journal ◽  
2014 ◽  
Vol 13 (8) ◽  
pp. 65-78 ◽  
Author(s):  
W.B.A. (SANDY) SHARP ◽  
W.J. JIM FREDERICK ◽  
JAMES R. KEISER ◽  
DOUGLAS L. SINGBEIL
Keyword(s):  
Flue Gas ◽  
Power Plants ◽  
Superheated Steam ◽  
Black Liquor ◽  
Simulation Software ◽  
Operating Conditions ◽  
Costs And Benefits ◽  
Steam Generation ◽  
Fireside Corrosion ◽  
Corrosion Resistant

The efficiencies of biomass-fueled power plants are much lower than those of coal-fueled plants because they restrict their exit steam temperatures to inhibit fireside corrosion of superheater tubes. However, restricting the temperature of a given mass of steam produced by a biomass boiler decreases the amount of power that can be generated from this steam in the turbine generator. This paper examines the relationship between the temperature of superheated steam produced by a boiler and the quantity of power that it can generate. The thermodynamic basis for this relationship is presented, and the value of the additional power that could be generated by operating with higher superheated steam temperatures is estimated. Calculations are presented for five plants that produce both steam and power. Two are powered by black liquor recovery boilers and three by wood-fired boilers. Steam generation parameters for these plants were supplied by industrial partners. Calculations using thermodynamics-based plant simulation software show that the value of the increased power that could be generated in these units by increasing superheated steam temperatures 100°C above current operating conditions ranges between US$2,410,000 and US$11,180,000 per year. The costs and benefits of achieving higher superheated steam conditions in an individual boiler depend on local plant conditions and the price of power. However, the magnitude of the increased power that can be generated by increasing superheated steam temperatures is so great that it appears to justify the cost of corrosion-mitigation methods such as installing corrosion-resistant materials costing far more than current superheater alloys; redesigning biomassfueled boilers to remove the superheater from the flue gas path; or adding chemicals to remove corrosive constituents from the flue gas. The most economic pathways to higher steam temperatures will very likely involve combinations of these methods. Particularly attractive approaches include installing more corrosion-resistant alloys in the hottest superheater locations, and relocating the superheater from the flue gas path to an externally-fired location or to the loop seal of a circulating fluidized bed boiler.

Improving management as a way to increase labour productivity

Upravlenie ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 24-30
Author(s):  
A. O. Ivanov
Keyword(s):  
Productivity Growth ◽  
Labour Productivity ◽  
Production Costs ◽  
Managerial Practices ◽  
Industrial Enterprises ◽  
Labour Productivity Growth ◽  
Period 2 ◽  
Main Factors ◽  
The Moment

The article gives an overview, performs analysis and classification of successful managerial practices applied at Russian industrial enterprises in the framework of the national project “Labour productivity and employment support”. The paper emphasizes the main factors of labour productivity growth as follows: investment policy, growth of human capital, and efficient use of managerial capital of enterprise. In order to determine the need of enterprises to increase labour productivity, the author proposes four universal criteria that signal the existing inefficiency even before the loss of competitiveness: 1) the dynamics of labour productivity in the company is not positive during a given period; 2) the company is behind competitors by labour productivity indicator; 3) the company is behind competitors by labour productivity growth rates indicator for a certain period; 4) unit production costs rise. These criteria allow you to take into account the situation both within the enterprise and in comparison with other enterprises. Each criteria can be considered separately or in combination with the others, applied to enterprises of different industries, specialization, and scale. Criteria indicate the direction of development in which the company is experiencing difficulties at the moment, or may experience them in the future.

Field Methods for Studying the Radiation Situation in the Area of the Belarusian NPP in the Pre-Operational Period

ANRI ◽  
2020 ◽  
pp. 31-44
Author(s):  
Aleksey Ekidin ◽  
Aleksey Vasil'ev ◽  
Maksim Vasyanovich ◽  
Evgeniy Nazarov ◽  
Mariya Pyshkina ◽  
...  
Keyword(s):  
Dose Rate ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Field Studies ◽  
Radiation Monitoring ◽  
Normal Operation ◽  
Construction Site ◽  
External Radiation ◽  
Field Methods

The article presents the results of field studies in the area of the Belarusian NPP in the pre-operational period. The «background» contents of gamma-emitting radionuclides in individual components of the environment are determined. The main array of dose rate measurements in the area of the NPP construction site is in the range 0.048 ÷ 0.089 μSv/h. External radiation in the surveyed area is formed at 96% due to 40K, 226Ra and 232Th. The information obtained can be used to correctly interpret the data of future radiation monitoring during normal operation of nuclear power plants.

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