scholarly journals Application of the Correlation Measurement Method for Reconstructing of the Velocity Profile with Spatial and Temporal Discretization in Studies of the Hydrodynamics of Turbulent Flows Based on the Matrix Conductometry Method

2021 ◽  
Vol 12 (4) ◽  
pp. 292-300
Author(s):  
S. M. Dmitriev ◽  
A. E. Khrobostov ◽  
D. N. Solncev ◽  
A. A. Barinov ◽  
A. A. Chesnokov ◽  
...  
Keyword(s):  
Data Collection ◽  
Turbulent Flows ◽  
Flow Rate ◽  
Nuclear Power ◽  
Power Plants ◽  
Correlation Method ◽  
Measuring System ◽  
Reliability Of Results ◽  
The Matrix ◽  
Influence Of Noise

The correlation method for measuring of the coolant fl rate is used in the operation of nuclear power plants and is widespread in research practice including study of turbulent fl    hydrodynamics. However the question of its applicability and possibilities in studies using the matrix conductometry method remains open. Earlier the algorithm for determining of the correlation fl rate using a conductometric measuring system was highlighted and the error of the results obtained was estimated and the dependence of the influence of noise and the time of data collection on the reliability of results was investigated. These works were carried out using two independent mesh sensors and the issue of the resolution of local velocity components was not covered. The purpose of this work was to test the correlation method for measuring velocity with temporal and spatial sampling using two-layer mesh conductometric sensors.As the result velocity cartograms were obtained over the cross-section of the experimental model with quasi-stationary mixing and the value of the average flow rate is in good agreement with the values obtained from the standard flow meters of the stand. Also measurements were carried out at a non-stationary setting of the experiment and realizations of the flow rate and velocity components of the flow at the measuring points were obtained.Analysis of the obtained values allows to conclude about the optimal data collection time for correlation measurements, as well as the reliability of results.

scholarly journals Regularization of Feedwater Flow Rate Evaluation for Venturi Meter Fouling Problem in Nuclear Power Plants

2001 ◽  
Vol 134 (1) ◽  
pp. 3-14 ◽  
Author(s):  
Andrei V. Gribok ◽  
Ibrahim K. Attieh ◽  
J. Wesley Hines ◽  
Robert E. Uhrig
Keyword(s):  
Flow Rate ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Rate Evaluation

scholarly journals 1D-3D coupling investigation of hydraulic transient for power-supply failure of centrifugal pump-pipe system

2019 ◽  
Vol 21 (5) ◽  
pp. 708-726 ◽  
Author(s):  
Xiaoqin Li ◽  
Xuelin Tang ◽  
Min Zhu ◽  
Xiaoyan Shi
Keyword(s):  
Turbulent Flows ◽  
Flow Rate ◽  
Power Supply ◽  
Nuclear Power ◽  
Transient Flow ◽  
Internal Flow ◽  
Transition Process ◽  
Pipeline System ◽  
Pipe System ◽  
Rotating Speed

Abstract In the pumping station, the main feedwater system and the reactor system of nuclear power plant, power-supply failure causes strong hydraulic transients. One-dimensional method of characteristics (1D-MOC) is used to calculate the transient process in the pipeline system while three-dimensional (3D) computational fluid dynamics is employed to analyze the turbulent flows inside the pump and to obtain the performance parameters of the pump, and the data exchanges on the boundary conditions of the shared interface between 1D and 3D domains are updated based on the MpCCI platform. Based on the equation of motion of the pump motion parts, the relationship between the external characteristics and the internal flow field in the pump is further investigated because the dynamic behavior of the pump and the detailed fluid field evolutions inside the pump are captured during the transition process, and the transient flow rate, rotating speed, and pressure inside the impeller are comprehensively investigated. Meanwhile, compared with the data gained by experiment and traditional 1D-MOC, the relative errors of rotating speed and the flow rate obtained by 1D-3D coupling method are smaller than those by 1D-MOC. Furthermore, the influences of the main coupling parameters and coupling modes on the calculation results are analyzed, and the cause of the deviation is further explained.

The Effect of Boron on the Sliding Wear Behavior of Iron-Based Hardfacing Alloys for Nuclear Power Plants Valves

2006 ◽  
Vol 510-511 ◽  
pp. 562-565
Author(s):  
Jeng Wan Yoo ◽  
Kwon Yeong Lee ◽  
Ji Hui Kim ◽  
Ki Soo Kim ◽  
Seon Jin Kim
Keyword(s):  
Wear Resistance ◽  
Martensitic Transformation ◽  
Nuclear Power ◽  
Sliding Wear ◽  
Power Plants ◽  
Wear Behavior ◽  
Wear Test ◽  
Wear Loss ◽  
The Matrix ◽  
Iron Based

A new iron-based wear resistance alloy was developed to replace the Co-containing Stellite 6 alloys in nuclear power industry. The effect of B addition on the wear resistance was investigated. Sliding wear tests of Fe-Cr-C-Si-xB (x = 0.0, 0.3, 0.6, 1.0 and 2.0 wt%) alloys were performed in air at the room temperature under a contact stress of 103 MPa. Low-boron alloys containing less than 0.6 wt% boron showed an excellent wear resistance than any other tested alloys. The improvement was associated with the matrix hardening by promotion of the γ→α′straininduced martensitic transformation occurring during the wear test. However, the alloys containing more than 1.0 wt% boron showed slightly increased wear loss compared to the low-boron alloys because of the absence of the strain-induced martensitic transformation and the presence of the brittle FeB particles, aiding crack initiation.

Relationship Between Flow Pattern and Pressure Distribution in Venturi Scrubber

2014 ◽  
Author(s):  
Naoki Horiguchi ◽  
Hiroyuki Yoshida ◽  
Akiko Kaneko ◽  
Yutaka Abe
Keyword(s):  
Flow Rate ◽  
Nuclear Power ◽  
Power Plants ◽  
Gas Flow ◽  
The Self ◽  
Radioactive Materials ◽  
Venturi Scrubber ◽  
Nuclear Disaster ◽  
Severe Accidents ◽  
Main Components

As revealed by Fukushima Daiichi nuclear disaster, countermeasures against severe accidents in nuclear power plants are an urgent need. In particular, from the viewpoint of protecting containment and suppressing diffusion of the radioactive materials, it is most important to install filtered venting devices to release high pressure contaminated gas to the atmosphere with elimination radioactive materials in the gas. A Multi Venturi Scrubber System (MVSS) is one of the filtered venting devices, and used in European reactors [1, 2]. One of the main components of the MVSS is a Venturi Scrubber (VS). It is considered that a dispersed or dispersed annular flow is formed in the VS by a self-priming phenomena. In the self-priming phenomena, the liquid was suctioned from a surrounding region of the VS to the inside of the VS. And a part of the radioactive materials are eliminated through the gas-liquid interface of the dispersed or annular dispersed flow. Therefore, to consider the MVSS operation characteristics, it is important whether to occur the self-priming or not and the liquid flow rate of the self-priming of the VS. The objective of this paper is to understand the self-priming phenomena of the VS for the filtered venting. And theoretical analysis and experiment were conducted. By comparing these results, we discussed about the mechanism of the self-priming phenomena. As results, the self-priming phenomena in the VS was confirmed and, at a high gas flow rate, the suspension of the self-priming is confirmed experimentally and theoretically.

scholarly journals Application of the Correlation Velocity Measurements for Hydrodynamic Investigations of Turbulent Coolant Flow in Nuclear Reactor Elements

2020 ◽  
Vol 11 (3) ◽  
pp. 196-203
Author(s):  
I. A. Konovalov ◽  
A. E. Khrobostov ◽  
M. A. Legchanov ◽  
D. N. Solncev ◽  
A. A. Barinov ◽  
...  
Keyword(s):  
Flow Rate ◽  
Power Plants ◽  
Nuclear Reactor ◽  
Correlation Method ◽  
Coolant Flow ◽  
Wire Mesh ◽  
Coolant Flow Rate ◽  
Test Facility ◽  
Test Model ◽  
Measured Velocity

The method of correlation measurement of the coolant flow rate, widely used for operational diagnostics of nuclear power plants, can be extensively used in research practice. The aim of this work was to apply a correlation method based on the conductometric measurement system with wire-mesh sensors for measuring a coolant flow rate.Insignificant concentration of a salt solution (NaCl or Na2SO4 ) creates a gradient of the conductivity in the flow, which is used as a passive scalar measured by the system. Authors used turbulent pulsations at the interface of two concurrent flows with identical velocities in a square channel as a signal source for the correlation method. The paper presents the methodology of the tests, test facility description, signalto-noise ratio estimation, the results of digital signal processing and comparison of the measured velocities in the model with the flowrate‒averaged velocity determined by the use of flowmeters. The measured velocity values give acceptable agreement for the turbulent flow modes. It was shown that the measurement accuracy drops sharply for low-Reynolds flows.The obtained results were used for flowrate measurements in core-imitator channels of the nuclear reactor test model. The presented paper is an approbation of this approach for its application as part of an test model of a nuclear reactor in order to determine the each duct flow rates in the channels of the core simulator using wire mesh sensors.

scholarly journals A novel tool monitoring approach for diamond wire sawing

2021 ◽  
Author(s):  
Berend Denkena ◽  
Benjamin Bergmann ◽  
Björn-Holger Rahner
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Cutting Speed ◽  
Cutting Process ◽  
Measuring System ◽  
Functional Verification ◽  
Diamond Wire ◽  
Tool Monitoring ◽  
Diamond Wire Sawing ◽  
Machine Operator

AbstractMobile diamond wire sawing is a highly flexible, productive and, versatile cutting process. Accordingly, it is used in many areas, such as the dismantling of nuclear power plants or wind turbines. Despite the widespread use of the process, the cutting process requires continuous manual monitoring by the machine operator. This is due to the continuously changing cutting conditions. A common process error is tool breakage. It is often caused by the displacement of the grinding segments (cutting beads). Due to the cutting speed (up to 30 m/s), these failures cannot be detected and prevented by the machine operator. However, a measuring system or process monitoring does not exist yet. Accordingly, a damaged diamond wire can become hooked, which often results in wire breaks. As a result, grinding segments break away from the wire, which can lead to deadly accidents. Therefore, a new approach for monitoring the tool for diamond wire grinding will be investigated. The paper is divided into five sections. First, the requirements for the sensor system are derived. After the selection of a measuring principle and the functional verification in the grinding process, the monitoring approach is presented and features for monitoring the tool with regard to the displacement of grinding segments are described. It was shown that the developed approach is suitable for monitoring the diamond wire tool during the sawing process. The investigation on a prepared diamond wire tool also demonstrated that the feature allows the detection of displacing grinding segments already from 2 mm.

Sign in / Sign up

Export Citation Format

Share Document