Characteristics Of Flowmeters Research Articles

Solid–Liquid Two-Phase Flowmeter Flow-Passage Wall Erosion Evolution Characteristics and Calibration of Measurement Accuracy

Solid–liquid two-phase flowmeters are widely used in critical sectors, such as petrochemicals, energy, manufacturing, the environment, and various other fields. They are indispensable devices for measuring flow. Currently, research has primarily focused on gas–liquid two-phase flow within the flowmeter, giving limited attention to the impact of solid phases. In practical applications, crude oil frequently contains solid particles and other impurities, leading to equipment deformation and a subsequent reduction in measuring accuracy. This paper investigates how particle dynamic parameters affect the erosion evolution characteristics of flowmeters operating in solid–liquid two-phase conditions, employing the dynamic boundary erosion prediction method. The results indicate that the erosion range and peak erosion position on the overcurrent wall of the solid–liquid two-phase flowmeter vary with different particle dynamic parameters. Erosion mainly occurs at the contraction section of the solid–liquid two-phase flowmeter. When the particle inflow velocity increases, the erosion range shows no significant change, but the peak erosion position shifts to the right, primarily due to the evolution of the erosion process. With an increase in particle diameter, the erosion range expands along the inlet direction due to turbulent diffusion, as particles with lower kinetic energy exhibit better followability. There is no significant change in the erosion range and peak erosion position with an increase in particle volume fraction and particle sphericity. With a particle inflow velocity of 8.4 m/s, the maximum erosion depth reaches 750 μm. In contrast, at a particle sphericity of 0.58, the minimum erosion depth is 251 μm. Furthermore, a particle volume fraction of 0.5 results in a maximum flow coefficient increase of 1.99 × 10−3.

Process variability reduction in flow control and wedge flowmeter performance evaluation

In modern flow control settings, a slow controller sampling rate is often much slower than a flowmeter response, and flowmeters are often selected without consideration of the dynamic response characteristics. However, for fast loops which necessitate a high control sampling frequency, negligence in flowmeter selection might result in an undesirable control performance degradation. Such associated research is expected to be critical to design and evaluation of new flowmeters, i.e., wedge flowmeters in this study, but little work has been found in the public domain to address this issue. In this paper, a new way of calculating process variability is proposed to fast-track the evaluation of flow control performance and cost saving. In addition, based on frequency response analysis, a systematic study of how dynamic response characteristics of flowmeters impact flowmeter accuracy and process variability is presented. Moreover, the impact of controller sampling rate on process variability is researched. Last, the closed-loop stability of the flow control loop with new wedge flowmeters is evaluated for a wide range of its targeted applications. The results demonstrate that a flowmeter with a faster response will always lead to process variability reduction for a given controller sampling rate, and that with careful controller set up, a flow loop with wedge flowmeter is still stable despite relatively slow dynamics.

Electrode Polarization Impedance and Its Application in Flow Rate Measurement of Conductive Liquid: A Review

Electrode polarization concept is an old one and has been used in numerous applications. It exists when a metallic electrode comes in contact with the conductive fluid. Basically, in the biomedical field, the concept of electrode polarization is used for measuring biosignals like ECG, EEG, and EMG. Nowadays, its application is not only limited in the biomedical field but also used in general applications such as for measuring the conductivity of the liquid and flow rate. In this article, we make a general review of the fundamental properties of electrode polarization impedance, its dependency on specific parameters. Then, we review certain equivalent circuit models used to describe the physical phenomena in the formation of the ionic double layer. Following this, we enumerate the applications of electrode polarization impedance in the flow rate measurement of conductive liquid and the variation in the polarization impedance-based flowmeter characteristics concerning specific designing parameters such as frequency, electrodes area, space between the electrodes, temperature, and roughness.

Use of Results of Indirect Measurements in Problems of Calculating Total Household Consumption of Hot Water

The use of the results of indirect measurements in calculating the total household consumption of hot water is considered. A method of monitoring the metrological characteristics of different types of flowmeters used for commercial accounting of hot water consumption is considered. The method is based on a determination of a correction to the results of measurements of the difference in flows based on which the influence of the errors of flowmeters may be estimated and, where necessary, special calibration of the flowmeters implemented. An example of a calculation of hot water consumption in an individual residence is presented. The need for reconciling the metrological characteristics of flowmeters in the course of calibration is demonstrated.

Research on collaborative control of double-plunger gas prover based on EtherCAT

Piston prover has been widely used as a gas flow standard for its advantages of high accuracy in standard volume, flow stability and repeatability. It has also been employed as the primary gas flow standard in many countries to calibrate meters. However, it is difficult to ensure the uniformity of the inside dimension of the piston, thus the application of conventional piston provers are limited by the maximum calibration flow generated by the piston cylinder volume. In this paper, an improved piston gas prover that mainly consists of two uniform plungers was proposed. Their external diameter constitutes the flow standard. The plungers are driven by servo motor, and the high speed fieldbus EtherCAT has been introduced as the control unit. Hence the two pistons could work collaboratively and operate in three modes: single-piston mode, double-pistons parallel mode, and double-pistons reciprocating mode. Besides generating steady-flow rate, the double-plunger prover can even produce an unsteady-flow rate which could be used to research the dynamic characteristics of flow meters. The structure and working principle of the three modes were carefully introduced. Then experiments for calibrating critical nozzles were carried out, and the results show that the repeatability of the discharge coefficient could be better than 0.06%, and the pressure fluctuation during the process was less than 50 Pa.

Characteristics of Flow Meters with Sediment Laden Flow – A Review

Measurement of flow is an important aspect in the field of hydraulic engineering, both in case of open channel as well as pipe or conduits. In case of pipe conduits various flow meters are used for flow estimation; out of which venturimeter and orifice meter are most commonly used and conventional means. Pipes or conduit carrying sediment laden flow or slurry-water mixture is very common in most of the industries, sewage carrying system etc. Suitability of flow meters i.e. venturimeter and flow meter need to be analyzed for sediment laden flow. Due to the presence of slurry or sediments, coefficient of discharge of flow meter will vary. In the present paper, various works that have been carried out till now in the analysis of characteristics of venturimeter and orifice meter with sediment laden flow are described.

Some Metrological Characteristics of Flow Meters in Which the Coriolis Force Is Used

The effect of the viscosity of the medium being measured is investigated. It is proved that the readings of a flow meter based on the use of the Coriolis force depend on the viscosity of the medium (the velocity profile) and the measurement error may reach 30%. The effect of a change in the parameters of the gas flow on the readings of such flow meters as a function of the location of the instrument (the longitudinal coordinate) is also considered and a conversion formula is derived.

The Electromagnetic Borehole Flowmeter: Description and Application

AbstractBorehole flowmeters are downhole tools that measure axial flow in a well or borehole. Desirable flowmeter characteristics include low detection limit, a wide range of operation, accuracy, durability, reliable performance, and a small diameter and length. The recently developed electromagnetic (F.M) flowmeter has these trails. The first portion of this paper presents the MM flowmeter design, provides laboratory calibration data, and compares the performance characteristics of MM flowmeters 10 those of impeller and thermal pulse flowmeters. The second portion of the paper discusses applications of the MM flowmeter.

The effect of conducting pipes on electromagnetic flowmeter sensitivity

An analytical expression obtained elsewhere for the change in virtual current due to conducting tubes at the ends of an electromagnetic flowmeter is used to determine corrections to the matrix representing the virtual current in a cutoff volume of the flowmeter interior. As described previously use of matrices to represent the virtual current and magnetic field provides an economical method for calculating electromagnetic flowmeter characteristics. Examples are given of calculated end effects under fully developed flow conditions using a configuration that models manufactured flow tubes. Reasonable agreement with end-effect calculations by another author for quasi-uniform magnetic fields is also demonstrated.

Prediction of electromagnetic flowmeter characteristics

The active fluid volume in an electromagnetic flowmeter is taken as a finite circular cylinder. The magnetic potential and virtual-current potential in this volume are expanded in Fourier series in the variables theta (polar angle) and z (axial coordinate). Any magnetic field and virtual current is thus represented by the matrices anm and bpq respectively (being the coefficients in the double-Fourier series). Expressions for the matrix elements for a four-pole electromagnet and for one or two pairs of point electrodes are derived. A method is given for obtaining the matrix elements representing a magnetic field in terms of values of the normal component of the flux density over a cylinder coaxial with the tube. The axisymmetric weight function (and hence the fully developed flow sensitivity) can be derived by evaluating a double sum involving the elements anm and bpq and the coefficients Wnm(r) which are independent of magnetic field and virtual current. Calculations of the weight function and sensitivity have been made and examples of results given.

Computation of pulsed field electromagnetic flowmeter response to profile change

Pulsed field flowmeters are analysed and the vector potential equation is solved numerically using finite difference approximation and successive over relaxation. The flowmeter characteristics are determined for the two extreme cases of parabolic and uniform velocity profile. The results show that the performance of a flowmeter with one primary and two secondary coils is dependent on the velocity profile and the conductivity of the fluid. A design is proposed which is capable of measuring the magnetic Reynolds number and the conductivity of the fluid and hence its flow rate.

Computation of electromagnetic flowmeter characteristics from magnetic field data

A description is given of a method which may be used to predict the performance of a flowmeter subject to certain constraints. The flow channel is an insulating cylinder of circular cross-section, the contact electrodes are assumed to be mathematical points and the flow is restricted to the rectilinear axisymmetric case. The analysis includes the effect of a concentric annular stationary medium surrounding the liquid, but of different conductivity. The magnetic field may have any form, and this is found experimentally by measuring its normal component at a number of points on the cylindrical surface bounding the flow channel. The mathematical basis of the method is given, together with an outline of the computation and a description of the apparatus used to measure the magnetic field. The method can be used both as a means of 'dry calibrating' a given flowmeter and as an aid to flowmeter design.

Calibration of flowmeters

In the first case the calibration results are used for evaluating the most important characteristics of flowmeters: the static conversion characteristic Q(X) (where Q is the flow and X is the information parameter of ~he flowmeter output signal); the error ~(A); the flow measurement ranges Qmin...Qmax; and the output-signal information parameters XQmin.-. XQma x. Moreover, during calibration as a separate test it is necessary to form an aggregate (or range) of initial influencing-quantity values ZII, ZI2 , .... , Zli , ..., Zlm (i.e., to establish the initial utilization conditions). This aggregate is a most important characteristic for evaluating the influence functions (see GOST 81009-72 "State System for Ensuring Uniform Measurements (GSI). Normalized metrological characteristics of measuring equipment").

Normalization of flowmeter characteristics

Normalization of flowmeter characteristics

A method of generating liquid sloshing to determine dynamic flowmeter characteristics

A method of generating liquid sloshing to determine dynamic flowmeter characteristics