Showing papers on "Ultrasonic flow meter published in 2005"

Ultrasonic liquid flow controller

Abstract: An ultrasonic flow meter includes a conduit, a first ultrasonic transducer, a second ultrasonic transducer, and a controller The first ultrasonic transducer is disposed at a first position about a first portion of the conduit to transmit a first ultrasonic signal and to receive a second ultrasonic signal The second ultrasonic transducer is disposed at a second position about a second portion of the conduit that is spaced apart from the first position along a length of the conduit to transmit the second ultrasonic signal and to receive the first ultrasonic signal The controller is configured to cross-correlate the first and second received ultrasonic signals and generate a resulting time-domain signal, analyze the resulting time-domain signal to determine a difference in transit time between the first and second received ultrasonic signals, and calculate a rate of flow of a fluid in the conduit based upon the determined difference

Fluid mechanics of flow metering

Abstract: Fully Developed Turbulent Pipe Flow. - Decay of Disturbances in Turbulent Pipe Flow. - Optimal Characteristic Parameters for the Disturbances in Turbulent Pipe Flow. - Measurement of Velocity and Turbulence Downstream of Flow Conditioners. - Signal processing of Complex Modulated Ultrasonic Signals. - Vortex-Shedding Flow Metering Using Ultrasound. - Ultrasonic Gas-Flow Measurement Using Correlation Methods. - Ultrasound Cross-Correlation Flow Meter: Analysis by System Theory and Influence of Turbulence. - Effect of Area Changes in Swirling Flow. - Errors of Turbine Meters due to Swirl. - Investigation of Unsteady Three-Dimensional Flow Fields in a Turbine Flow Meter. - How to Design a New Flow Meter from Scratch. - Effects of Disturbed Inflow on Vortex Shedding from a Bluff Body. - Correction of the Reading of a Flow Meter in Pipe Flow Disturbed by Installation Effects. - How to Correct the Error Shift of an Ultrasonic Flow Meter Downstream of Installations.

Ultrasonic flowmeter and ultrasonic flow rate measurement method

Abstract: A flowmeter includes: a transit time method unit having a sensor and a reception signal amplification control unit and a flow rate calculation unit which are connected to the sensor via a sensor selector switch; a pulse Doppler method having a reception signal amplification control unit and an integration calculation unit which are connected to the sensor; a transmission/reception timing control unit common to them; a measurement method selection control unit for controlling switching between the transit time method unit and the pulse Doppler method unit, and parallel operation; and a measurement value output selector switch for selecting the output of the transit time method unit and the pulse Doppler method unit. That is, the single flowmeter can perform flow rate measurement by the transit time method having no restriction on the measurement range as well as by the pulse Doppler method having an upper limit of the measurement range but enabling a highly accurate measurement.

Device for determining and/or monitoring volume and/or mass flow of a medium

Abstract: A device for determining and/or monitoring volume and/or mass flow rate of a medium that flows in a direction of flow through a pipeline/measuring tube of inner diameter. The device comprises at least two ultrasonic transducers that emit and/or receive ultrasonic measuring signals along defined sonic paths and a control/evaluation device which determines the volume flow rate and/or the mass flow rate of the medium to be measured inside said pipeline/measuring tube based on the ultrasonic measuring signals according to the travel-time difference principle. In order to provide a multichannel ultrasonic flowmeter, at least one reflector element is placed in the interior of the pipeline/measuring tube. The reflector element has a defined distance from the inner surface of the pipeline/measuring tube and is placed within the sonic path of the ultrasound measuring signals running through the pipeline/measuring tube.

Transit time ultrasonic flowmeter : velocity profile estimation

Abstract: Over the last years, improvements in acoustics and signal processing allowed to measure the flow rate with ultrasonic flowmeter at a very high accuracy. Transit time ultrasonic method is based on a well known principle: let A and B be 2 locations of transducers on each side of a pipe, then the apparent difference of the sound speed on the path AB and on the path BA is proportional to the fluid velocity averaged over the path. The estimation of the flow rate needs the conversion of this path velocity to a velocity averaged over the entire cross-section of the pipe containing the flowing fluid under investigation. Two phenomena have a particularly important impact on flowmeter performance: on the one hand, swirl which is the whole of nonflowing transverse velocities and on the other hand, the fluid velocity profile which can be asymmetric downstream an elbow for example. To date, the correct estimation of the fluid velocity profile and the compensation of swirl is not satisfactory solved. For these purposes we investigated two main directions. To overcome the problem of swirl, we have developed a geometrical configuration of flowmeter paths, which fully compensates for this phenomenon. Concerning the fluid velocity profile, we have defined a parametric model able to describe both symmetric and asymmetric flow velocity profiles. This theoretical parametric model was tested on numerical simulations and validated on data coming from experimental petroleum set up loop. These results show that our approach is a promising way for performance improvement of existing ultrasonic flowmeter accuracy.

Program product to measure density, specific gravity, and flow rate of fluids

Abstract: Program product to measure fluid flow characteristics in a pipeline is provided. A vortex-shedding body is positioned within the pipeline to form vortices. A vortex meter can include a vortex frequency sensor to measure the frequency of the vortices to determine the volumetric flow rate. A differential pressure meter positioned adjacent the vortex-shedding body can produce a differential pressure meter flow rate signal indicative of the density of fluid when flowing through the pipeline. A thermal flow meter positioned adjacent the vortex-shedding body can produce a mass flow rate signal indicative of the mass flow rate of fluid when flowing through the pipeline. The program product can include instructions for a fluid characteristic determiner to perform the operations of processing measured and sensed signals to produce an output of a volumetric flow rate, a flowing fluid density, and a mass flow rate to be displayed on a fluid characteristic display.

Apparatus and method for measuring a fluid flow rate profile using acoustic doppler effect

Abstract: An apparatus and method for measuring a flow velocity profile of fluid traveling in a pipe or conduit uses an ultrasonic wave transmitted from an ultrasonic wave transducer mounted at an angle on the outside of a pipe using a wedge, and made incident onto the fluid in the pipe to measure the fluid flow velocity profile, using the principle that a frequency of an ultrasonic wave, reflected by a reflector existing in the fluid, is changed depending on a flow velocity due to Doppler effect. The transmission frequency and the angle of incidence onto the pipe can be selected to suppress frequency dependence of a measured value due to Lamb wave and allow the flow velocity or flow rate of fluid to be measured with a greater accuracy.

Ultrasonic flow meter including guide elements

Abstract: The measurement of volume flows or mass flows in the intake system of motor vehicle internal combustion engines plays a significant role in reducing pollutant emissions. Therefore, an ultrasonic flow meter for measuring a flow rate of a fluid flowing in a primary flow direction is described. The ultrasonic flow meter has at least two ultrasonic transducers, the ultrasonic transducers being capable of emitting and/or receiving ultrasonic waves at an angle α to the primary flow direction which is different from 90°. Furthermore, the ultrasonic flow meter has at least one guide element which is entirely or partially situated in the fluid. This guide element diverts at least one part of the flowing fluid in such a way that in the diversion, a velocity component is transferred to at least one part of the flowing fluid perpendicular to the primary flow direction. Guide vanes or displacers in particular are described as guide elements. In addition, turbulators may be provided on the guide elements, the turbulators generating a longitudinal fluid bed along the guide elements and thus causing the flow of the fluid to have a better contact with the guide elements when flowing around them. This reduces turbulences within the ultrasonic flow meter. Compared to the devices known from the related art, the ultrasonic flow meters described are distinguished by an improved signal-to-noise ratio and accordingly by a higher measuring precision.

Ultrasonic Flow Rate Meter Having a Pressure Sensor

Abstract: An ultrasonic flow rate meter and a method for measuring the flow rate with the aid of ultrasound are described, having at least two ultrasonic transducers situated offset in a flow channel in the flow direction for transmitting and receiving ultrasound wave packets, so that ultrasound propagation times from one of the ultrasonic transducers to the other, and vice-versa, can be determined in an electronic part, and having a pressure sensor associated with the flow channel for determining the pressure in the flow channel. Measured values for an engine control that is as accurate as possible are determinable by accurately detecting the incoming air in the intake of a motor vehicle internal combustion engine.

Apparatus and method for measuring a fluid flowing in a pipe using acoustic pressures

Abstract: In industrial sensing applications at least one parameter of at least one fluid in a pipe 12 is measured using a spatial array of acoustic pressure sensors 14,16,18 placed at predetermined axial locations x1, x2, x3 along the pipe 12. The pressure sensors 14,16,18 provide acoustic pressure signals P1(t), P2(t), P3(t) on lines 20,22,24 which are provided to signal processing logic 60 which determines the speed of sound amix of the fluid (or mixture) in the pipe 12 using acoustic spatial array signal processing techniques with the direction of propagation of the acoustic signals along the longitudinal axis of the pipe 12. Numerous spatial array-processing techniques may be employed to determine the speed of sound amix. The speed of sound amix is provided to logic 48, which calculates the percent composition of the mixture, e.g., water fraction, or any other parameter of the mixture, or fluid, which is related to the sound speed amix. The logic 60 may also determine the Mach number Mx of the fluid. The acoustic pressure signals P1(t), P2(t), P3(t) measured are lower frequency (and longer wavelength) signals than those used for ultrasonic flow meters, and thus is more tolerant to inhomogeneities in the flow. No external source is required and thus may operate using passive listening. The invention will work with arbitrary sensor spacing and with as few as two sensors if certain information is known about the acoustic properties of the system. The sensor may also be combined with an instrument, an opto-electronic converter and a controller in an industrial process control system.

Doppler ultrasonic flowmeter, and processor and method thereof with quantization error correction

Abstract: In a Doppler ultrasonic flowmeter, to obtain a precise flow rate a flow rate calculation equation that corrects a quantization error occurring to a spatial resolution is used. An ultrasonic transducer transmits/receives ultrasonic pulses, and subject the resulting received signals to A/D conversion after a predetermined process is applied thereto. A computation control section calculates the flow velocity distribution. Then, the flow rate is calculated based on the flow rate calculation equation, which corrects the quantization error occurring to the spatial resolution.

Ultrasonic cavitating apparatus and ultrasonic doppler flow measurement system

Abstract: Disclosed is an ultrasonic Doppler flow measurment system that achieves flow measurement regardless of the temperature of a fluid. A temperature sensor 7 is combined with a pipe 1 to measure the temperature of a fluid 2. A controller 9 calculates a frequency that will cause cavitation when an ultrasonic transducer 4 exerts an ultrasonic vibration on the fluid 2 on the basis of a temperature measured by the temperature sensor 7 and controls a sinusoidal oscillator 6.

Ultrasonic flow meter including turbulators

Abstract: Measuring volume flows or mass flows in the intake system of motor vehicle internal combustion engines plays an important role in reducing harmful emissions. Therefore, an ultrasonic flow meter for measuring a flow velocity of a fluid flowing in an essentially laminar flow in the main flow direction is described. The ultrasonic flow meter has at least two ultrasonic transducers, the ultrasonic transducers being able to emit and/or receive ultrasonic waves at an angle α to the main flow direction which is different from 90°. Furthermore, the ultrasonic flow meter has at least one turbulator situated upstream from at least one ultrasonic transducer in the main flow direction of the fluid, which generates longitudinal eddies in at least one zone adjacent to the at least one ultrasonic transducer, in particular in a protrusion in a wall of a flow pipe and thus improves the flow of the fluid in this zone in the flow pipe. Wedge-shaped turbulators protruding into the flow of the fluid or flow grooves are provided in particular as turbulators. The ultrasonic flow meter is distinguished, in comparison with devices known from the related art, by improved signal-to-noise ratio and thus by higher measurement accuracy.

Estimation of the flow profile correction factor of a transit-time ultrasonic flow meter for the feedwater flow measurement in a nuclear power plant

Abstract: A new method to estimate the flow profile correction factor (FPCF) for a transit-time ultrasonic flow meter (UFM) having a diametral transducer configuration is introduced in this work. For the adaptation of a diametral UFM for a feedwater measurement, the optimized flow profile correction factor is obtained through experiments and a simulation in actual flow conditions. The log function curve fitting is performed on a combined data set; the velocity ratio of UFM reading versus standard fluid measurement at low flow velocity, UFM reading versus standard fluid measurement at medium flow velocity, and UFM reading versus clean Venturi measurement at high flow velocity. Through an uncertainty analysis, the uncertainty of the FPCF is calculated. The resultant uncertainty of the new FPCF is 0.335%. This value is approximately half the value presented by UFM manufacturers. By adaptation of a diametral UFM with the new FPCF proposed in this work, feedwater flow measurement in nuclear power plants (NPPs) can be easily performed at lower cost than either chordal or cross-correlation UFM.

Ultrasonic flowmeter with triangular cross section

Abstract: The invention pertains to an ultrasonic flowmeter (1) comprising a measuring tube (3), at least two ultrasound transmitting and/or receiving transducers (5, 6) located inside the tube (3). The tube (3) has a triangular cross-section over at least part of its length.

Ultrasonic seepage meter

Abstract: An ultrasonic flow meter has been adapted for such measurements in the submarine environment. Connected to a collection funnel, the meter houses two piezoelectric transducers mounted at opposite ends of a cylindrical flow tube. By monitoring the perturbations of fluid flow on the propagation of sound waves inside the flow tube, the ultrasonic meter can measure both forward and reverse fluid flows in real time. Laboratory and field calibrations show that the ultrasonic meter can resolve groundwater discharges in both the forward and reverse directions on the order of 0.1 μm/s (<1 cm/d), and it is sufficiently robust for deployment in the field for several days. Data collected with the meter elucidate the temporal and spatial heterogeneity of submarine groundwater discharge and its interplay with tidal loading and other driving forces. A negative correlation between the discharge and tidal elevation can be observed.

Coriolis flow measurement in two phase flow

Abstract: The largest problem users have with Coriolis flow meters is that they are sensitive to two phase fluids-primarily gas in liquids ('aeration'). 'Sensitive' means that they can convey the wrong mass flow and/or density reading, or, in the worst case, they could stop measuring all together. We explain this phenomenon in classical U-tube meters and give recommendations on how to handle such applications.

A radically new dynamic response capability for Coriolis flow meters

Abstract: The dynamic response of flow meters is significant in many applications, including fast control operations, e.g. short duration (less than 1 s) batch filling and for tracking the periodic flow fluctuations produced by positive displacement devices. The factors which determine Coriolis dynamic response have been elucidated. It has been shown that the meter flow tube response time cannot be less than the duration of one drive cycle of the tube vibration (i.e. reciprocal of drive frequency). This gives the potential of a response time of order 1 ms for the fastest currently available meters. However, the delay-time and update rates from the user output depend upon flow transmitter technology and design. Flow tube dynamic response has been investigated theoretically (simple straight tube), by finite element simulation (complex flow tube shapes) and experimentally. Commercially available meters were tested to determine the flow tube dynamic response to step changes in flow rate and the response to low frequency (compared with meter drive frequency) flow pulsations. Generally, dynamic flow events have been found to introduce contaminating signal components at one or more frequencies, other than that of the meter drive. The paper also presents details of the signal processing used to extract the required phase-difference and a method for reducing the contaminating signal noise. A new fast-response meter is currently being developed and some of the significant advances in the technology of a novel digital transmitter are described.

Ultrasonic flow velocity distribution meter and flow meter, ultrasonic flow velocity distribution and flow rate measuring method, and ultrasonic flow velocity distribution and flow rate measuring processing program

Abstract: PROBLEM TO BE SOLVED: To measure a flow velocity distribution or flow rate along a measuring line with high accuracy and high reliability by improving the reliability of the correlation between ultrasonic echo signals from an ultrasonic reflector. SOLUTION: This ultrasonic flow velocity distribution meter and flow meter comprises an emission trigger oscillation means 22; an ultrasonic oscillation means 23; an ultrasonic pulse receiving means 24; a signal processing means 25 processing received ultrasonic echo signals; and a signal analysis means 26 analyzing the ultrasonic echo signals to calculate the position and speed of the ultrasonic reflector along the measuring line, and measuring the flow velocity distribution or flow rate of a fluid. The signal processing means includes a filtering processing part 31 extracting the same frequency band as an ultrasonic pulse used for measurement from the received ultrasonic echo signals, and an AD converter 32 digitizing the extracted ultrasonic echo signal. The signal analysis means calculates the correlation of reference wave and search wave which are reflected waves from two ultrasonic pulses obtained at a predetermined time interval by use of a fluctuating search window method using a search window the size of which is set for every trigger oscillating period τ. COPYRIGHT: (C)2005,JPO&NCIPI

Method and system for multi-path ultrasonic flow measurement of partially developed flow profiles

Abstract: A method for determining a velocity of a flowing fluid includes estimating a Reynolds number for the flowing fluid; comparing the estimated Reynolds number with a selected range; and determining the velocity of the flowing fluid based on a flow model selected from a laminar flow model, a turbulent flow model, and a partial laminar flow model. An ultrasonic flow meter includes a plurality pairs of transducers configured to form a plurality of measurement paths in a pipe, wherein the plurality of measurement paths are arranged asymmetrically relative to a centerline of the pipe.

Detection of moving objects and flows in liquids by ultrasonic phase conjugation

Abstract: The possibility for the application of the method of parametric phase conjugation of ultrasonic waves in measuring the velocity of moving objects and flows is investigated. Results of experimental measurements of the Doppler frequency shift are presented for a low-frequency wave (1 MHz) generated by phase-conjugate waves (10 MHz and 11 MHz) propagating in opposite directions in the presence of a moving scatterer. The super high sensitivity of the phase of the low-frequency wave to variations in the spatial position of the scatterer is used to measure the velocity of the object. The presence of flows in the region of propagation of phase-conjugate waves returned leads to an uncompensated Doppler shift of the phase of the phase-conjugate wave at the primary radiation source. The implementation of this feature of ultrasonic phase conjugation for the detection and measurement of the flow velocities in a liquid is demonstrated experimentally.

Wedge and wedge unit for use in ultrasonic doppler flow meter

Abstract: A wedge unit according to the present invention is used for an ultrasonic Doppler flow meter, being mounted on the outer wall of a pipe in which a fluid flows, supplying an ultrasonic wave to the fluid, receives the reflected wave and supplies the reflected wave to a flow rate calculation unit, comprises a wedge with one surface thereof being mounted on a part of the outer circumference of the pipe and on another surface thereof being equipped with an ultrasonic oscillator that generates the ultrasonic wave in response to an electric signal and receives the reflected wave; and an ultrasonic wave attenuation unit being mounted on the outer circumference of the pipe so as to include a position where an ultrasonic wave injected from the ultrasonic oscillator into the pipe by way of the wedge first reaches the outer wall of the pipe after being reflected by the inner wall thereof

Device for determining and/or monitoring the volume, and/or mass, flow rate of a medium

Abstract: The invention relates to a device for determining and/or monitoring the volume and/or mass flow rate of a medium that flows through a pipe/measuring tube (3) having an inner diameter (D) in a direction of flow (S). Said device comprises at least two ultrasonic transducers (14) that emit and/or receive ultrasonic measuring signals along defined sonic paths and a control/evaluation device (4) which determines the volume flow rate and/or the mass flow rate of the medium to be measured (2) inside said pipe/measuring tube (3) based on the ultrasonic measuring signals according to the principle of the propagation time difference. The aim of the invention is to provide a multichannel ultrasonic flowmeter which has at least one reflector element (5, 9, 10, 11, 12, 13) in the inner space (15) of the pipe/measuring tube (3), whereby the reflector element (5, 9, 10, 11, 12, 13) has a defined distance (d) from the inner wall (6) of the pipe/measuring tube (3) and is placed within the sonic path of the ultrasound measuring signals, which passes through the pipe/measuring tube (3).

Fiber optic flow sensing device and method

Abstract: The invention provides an optical flow meter for measuring fluid flow through a pipe which obviates the need for the flow to be seeded with foreign particles. The meter comprises a fiber optic Sagnac interferometer with optical path crossing the flowing fluid. The interferometer measures velocity of the fluid by measuring the phase difference between the two beams propagating in the optical path in opposite directions. Light, which is deflected by the fluid, is collected by optical means at both sides of the optical path for calculation, the scintillating statistics and compensation for light intensity.

Density and calorific value measurement in natural gas using ultrasonic flow meters

Abstract: Multipath ultrasonic transit time flow meters (USMs) are today extensively used by industry for volumetric flow metering of natural gas, for fiscal measurement, check metering, etc. As natural gas is typically sold on basis of mass or energy, the density and/or calorific value (GCV) of the gas is measured in addition. In current fiscal metering stations this is typically made using additional instrumentation like e.g. densitometers, calorimeter or gas chromatographs. In addition to the flow velocity and the volumetric flow rate, USMs give measurement of the velocity of sound (VOS) in the gas. The VOS is a quality parameter which contains valuable information about the gas. For example, under certain conditions the density and GCV of the gas can be derived from the VOS. This provides a potential for mass and energy flow rate measurements by the USM itself. Various approaches in this respect have been presented over the recent years, by various research groups. The present paper describes a new method for calculation of density and GCV of natural gas, from measurements of the pressure, temperature and the VOS only. That is, in the present method, no instrumentation is needed in addition to the USM itself and the pressure and temperature sensors. The method can thus be used on existing USM metering stations with only a software upgrade. Such a feature may be of interest for fiscal metering stations (e.g. for backup and redundancy) as well as simpler metering station (where density and GCV are not measured today, but where such information may be of interest e.g. for monitoring). Results for different real natural gas compositions are presented, and contributions to the measurement uncertainty discussed. The paper is intended to provide insight into the potentials and limitations of methods for calculating gas density and GCV from VOS also on a more general basis. (author) (tk)

Ultrasonic flow sensor using quasi-helical beam

Abstract: A probe type acoustic transit-time flow sensor has paired transducers arranged to generate quasi-helical acoustic beams making a plurality of reflective contacts with a pipe's interior wall. The transducers in each pair are spaced apart along the flow axis so that transit-time measurements can be used both to measure the internal diameter of the pipe and to determine a flow rate. These measurements are combined to yield a volumetric flow rate. Various numbers of pairs of transducers can be put on a single probe or on multiple probes and used to provide a more accurate representation of a flow profile and therefore a more accurate volumetric flow determination.

Method for detecting sleeve fluid-loss point utilizing direct-reading ultrasound flowmete

Abstract: The detection system includes well logging truck, computer, and directly read ultrasonic flow meter. The casing leakage loss location detecting process includes connecting the directly read ultrasonic flow meter to the computer via cable joint, cable of the well logging truck and collector ring; setting the directly read ultrasonic flow meter with the cable of the well logging truck to the upper part of the perforating section inside oil-water well stratum; raising the directly read ultrasonic flow meter gradually to test the flow rate values in different depth; determining the leakage loss section of the casing based on the displayed changing flow rate data; lowering the ultrasonic flow meter to the leakage loss section of the casing and raising slowly for continuous measurement to find out the leakage loss point based on the change in flow rate.

Ultrasonic flowmeter having a pressure sensor

Abstract: The invention relates to an ultrasonic flowmeter (10) and to a method for measuring flow by using ultrasound, comprising at least two ultrasonic transducers (12, 14), which are placed inside the flow channel (16) while being offset in the direction of flow and which serve to emit and receive ultrasonic wave packets so that ultrasound transit times from one of the ultrasonic transducers (12, 14) to the other and vice versa can be determined in an electronics component (24). The ultrasonic flowmeter also comprises a pressure sensor (26), which is assigned to the flow channel (16) and which serves to determine the pressure inside the flow channel (16). By precisely measuring the inflowing air in the induction of a motor vehicle combustion engine, measured values can be determined for an engine control that is as precise as possible.

Bubble suppressing flow controller with ultrasonic flow meter

Abstract: An apparatus for the, delivery of slurry, solution comprising an ultrasonic flow meter (303) positioned between a fluid preparation manifold and a slurry delivery arm, and a shutoff valve (307) positioned between a proportional valve (305) and the slurry delivery arm. Also, an apparatus for the delivery of, slurry solution including an ultrasonic flow meter positioned to receive fluid from a fluid preparation manifold, a proportional valve and stepper motor in communication with the flow meter, and a reverse flow restrictor in communication with the proportional valve and a slurry delivery arm.