Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
  • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
  • G01F1/66—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters
  • G01F1/666—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by measuring frequency, phase shift or propagation time of electromagnetic or other waves, e.g. using ultrasonic flowmeters by detecting noise and sounds generated by the flowing fluid
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
  • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
  • G01F1/704—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow using marked regions or existing inhomogeneities within the fluid stream, e.g. statistically occurring variations in a fluid parameter
  • G01F1/708—Measuring the time taken to traverse a fixed distance
  • G01F1/7082—Measuring the time taken to traverse a fixed distance using acoustic detecting arrangements
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
  • G01M3/00—Investigating fluid-tightness of structures
  • G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
  • G01M3/04—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point
  • G01M3/24—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using infrasonic, sonic, or ultrasonic vibrations
  • G01M3/243—Investigating fluid-tightness of structures by using fluid or vacuum by detecting the presence of fluid at the leakage point using infrasonic, sonic, or ultrasonic vibrations for pipes
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01M—TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR
  • G01M3/00—Investigating fluid-tightness of structures
  • G01M3/02—Investigating fluid-tightness of structures by using fluid or vacuum
  • G01M3/26—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors
  • G01M3/28—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables or tubes; for pipe joints or seals; for valves ; for welds
  • G01M3/2807—Investigating fluid-tightness of structures by using fluid or vacuum by measuring rate of loss or gain of fluid, e.g. by pressure-responsive devices, by flow detectors for pipes, cables or tubes; for pipe joints or seals; for valves ; for welds for pipes
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
  • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
  • G01F1/704—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow using marked regions or existing inhomogeneities within the fluid stream, e.g. statistically occurring variations in a fluid parameter
  • G01F1/708—Measuring the time taken to traverse a fixed distance
  • G01F1/712—Measuring the time taken to traverse a fixed distance using auto-correlation or cross-correlation detection means

Definitions

• the present invention generally relates to monitoring fluid flowing in a pipe and is more specifically directed to a method using sonar-based sensors to aid in the detection of anomalies such as leaks in the pipe.
• the present invention is directed in one aspect to a method for monitoring a flowing fluid in a pipeline wherein a dynamic model of the fluid flowing in the pipeline is provided with a parameter forming part of the dynamic model being a speed of sound of the fluid.
• At least one sonar-based sensor is coupled to the pipeline and is operable to measure the speed of sound of the fluid flowing through the pipeline and to generate signals indicative thereof.
• a controller is provided and is in communication with the sonar-based sensor and associated with the dynamic model. In the preferred embodiment of the present invention, the controller receives the signals generated by the sonar-based sensor and then interprets and compares these signals to the dynamic model. The controller, based on the comparison, then determines when the simulated state of the fluid is sufficiently different from the measured state to indicate an anomaly.
• the method of the present invention also includes the measurement of one or more operational parameters, in addition to the speed of sound, relevant to the fluid flowing in the pipe.
• These operational parameters can include such things as, but arc not limited to, pressure, temperature, pump speed and volumetric flow rate.
• Each of these operational parameters also form part of. the above-described dynamic model.
• the controller interprets and compares the measured operational parameters to the dynamic model to determine if the measured operational parameters deviate from values corresponding to the operational parameters forming part of the dynamic model. Once the comparison is conducted, the controller can perform further analysis, particularly if a deviation between the dynamic model and the measured parameters is detected. This further analysis can take the form of determining where in the pipeline the anomalous behavior originated. The larger the amount of measured data, and thereby the greater the amount of sonar-based or other sensors, the more accurate the determination of the location of any anomalous behavior will be.
• the sonar-based sensors are non-invasive and can be removably clamped onto the pipeline at virtually any desired location. It is also preferable that the at least one sonar-based sensor includes a plurality of sonar-based sensors positioned along the pipeline, each generating signals receivable by the controller indicative of the speed of sound of the fluid flowing through the pipeline adjacent to the particular sonar-based sensor. [OOIOJ In an embodiment of the present invention, stratification within the pipeline is measured and monitored by providing at least one first sensor having a first spatial array of at least two sensors disposed at different axial locations spaced along the pipeline.
• Each of the sensors in the first spatial array generates a first signal indicative of pressure convecting with a portion of the flow passing through an upper portion of the pipeline.
• At least one second sensor having a second spatial array of at least two sensors disposed at different axial locations is provided and is spaced along the pipeline.
• Each of the sensors in the second spatial array generates a second signal indicative of pressure convecting with a portion of the flow passing through a lower portion of the pipeline.
• the controller uses the first signals to determine a first velocity of the flow passing through the upper portion of the pipeline, and the second signals to determine a second velocity of the flow passing through the lower portion of the pipeline. Using the first and second velocities, a level of stratification in the flow is determined.
• the first spatial array is aligned axially along a top portion of the pipeline
• the second spatial array is aligned axially along a bottom portion of the pipeline.
• the at least one first and second sensors described above can include a plurality of first and second sensors with the controller comparing the level of stratification for each of the first and second sensors to the dynamic model.
• the first and second sensors can be used along with the sonar based sensors described above, as well as other sensors and instrumentation to monitor other flow parameters, all of which can be compared by the controller with the dynamic model to determine if any unacceptable deviations from the dynamic model are present in the pipeline. This information can also be used to ascertain the location of anomalies that are causing the deviant behavior in the flowing fluid.
• FIG. 1 is a schematic illustration showing sonar-based sensors coupled to a pipeline and used to monitor fluid flow conditions in the pipeline.
• Attorney Docket No. CC-0932PCT is a schematic illustration showing sonar-based sensors coupled to a pipeline and used to monitor fluid flow conditions in the pipeline.
• FIG. 2 is a schematic diagram of an apparatus for determining at least one parameter associated with a stratified fluid flowing in a pipe.
• FIG. 3 is a cross-sectional schematic view of non-stratified, turbulent, Newtonian flow through a pipe.
• a pipeline monitoring system generally designated by the reference number 10 includes a pipeline 12 having three sonar-based sensors 14 coupled thereto and spaced axially apart from one another along the pipeline.
• Sonar-based sensors 14 of the type described herein are offered by Cidra Corporation of Wallingford, Connecticut under the trademark SONARtrac.
• the sonar-based sensors 14 are configured to measure the speed of sound of fluid flowing in the pipeline 12 and to generate signals indicative thereof, the signals being receivable by a controller 16.
• other operational parameters such as pump speed, fluid pressure, flow rate, flow temperature, and the like can also be monitored with signals indicative of these measured parameters being sent to and received by the controller 16.
• a dynamic model 18 of the fluid flowing in the pipeline 12 is associated with the controller 16.
• the dynamic model 18 is a mathematical representation of the fluid flowing in the pipeline 12 and has stored therein values corresponding to operational parameters, as well as the speed of sound of the fluid flowing in the pipeline. Historically, speed of sound was considered to be constant in a fluid flowing in a pipeline. However, this is not the case as the speed of sound can vary in the pipeline.
• the sonar-based sensors 14 can, during normal operating conditions, be employed to provide data indicative of the speed of sound of the flowing fluid in the pipeline, the data being used in the dynamic model to optimize the model.
• the values corresponding thereto are compared in a comparing step 20, to corresponding values in the dynamic model 18.
• the comparison 20 will provide for a determination of when one or more of the operational Attorney Docket No. CC-0932PCT
• parameters and/or the speed of sound have deviated from the dynamic model, thereby indicating a potentially detrimental condition within the flow and or the pipe comprising the pipeline 12.
• Anomalous behavior can be monitored in this manner.
• the comparison can be employed to aid in the determination of the locations of leaks within the pipeline by analyzing which sensors transmitted the deviant data.
• stratification sensors 20 can also be coupled to the pipeline 12.
• unsteady pressures along a pipe caused by coherent structures (e.g., turbulent eddies and vortical disturbances) that convect with a fluid flowing in the pipe contain useful information regarding parameters of the fluid.
• the present invention provides various means for using this information to measure parameters of a stratified flow, such as, for example, velocity, level/degree of stratification, and volumetric flow rate.
• an apparatus 30 for measuring at least one parameter associated with a flow 32 flowing within a duct, conduit or other form of pipeline 12, is shown.
• the parameter of the flow 32 may include, for example, at least one of: velocity of the flow, volumetric flow rate, and level of stratification.
• the flow 32 is depicted as being stratified, where a velocity profile 34 of the flow 32 is skewed from the top of the pipe 12 to the bottom of the pipe, as may be found in industrial fluid flow processes involving the transportation of a high mass fraction of high density, solid materials through a pipe where the larger particles travel more slowly at the bottom of the pipe.
• the flow 32 may be part of a hydrotransport process.
• the flow 32 is again shown passing through the pipe 12.
• the flow 32 is depicted as a non-stratified, Newtonian flow operating in the turbulent regime at Reynolds numbers above about 100,000.
• the flow 32 of Fig. 3 has a velocity profile 34 that is uniformly developed from the top of the pipe 12 to the bottom of the pipe.
• the coherent structures 36 in the non-stratified, turbulent, Newtonian flow 32 of Fig. 3 exhibit very little dispersion. In other words, the speed of convection of the coherent structures 36 is not strongly dependent on the physical size of the structures.
• dispersion describes the dependence of convection velocity with wavelength, or equivalently with temporal frequency.
• non-dispersive convect at a constant velocity
• dispersion For turbulent, Newtonian flow, there is typically not a significant amount of dispersion over a wide range of wavelength to diameter ratios.
• Sonar-based flow measurement devices such as, for example, the device described in aforementioned U.S. Patent No. 6,609,069 to Gysling, have advantageously applied the non-dispersive characteristic of turbulent, Newtonian flow in accurately determining flow rates.
• stratified flows such as those depicted in Fig. 2, however, some degree of dispersion is exhibited.
• the coherent structures 36 convect at velocities that depend on their size, with larger length scale coherent structures tending to travel slower than smaller length scale structures.
• some of the underlying assumptions associated with prior sonar-based flow measurement devices namely that the speed of convection of the coherent structures 36 is not strongly dependent on the physical size of the structures, are affected by the presence of stratification.
• the apparatus 30 of Fig. 2 accurately measures parameters such as velocity, level of stratification, and volumetric flow rate of a stratified flow 32.
• the apparatus 30 includes a spatial array 38 of at least two sensors 40 disposed at different axial locations X
• Each of the sensors 40 provides a pressure signal P(t) indicative of unsteady pressure created by coherent structures convecting with the flow 32 within the pipeline 12 at a corresponding axial location X
• the pressure generated by the convective pressure disturbances may be measured through strained-based sensors 40 and/or pressure sensors.
• the sensors 40 provide analog pressure time-varying signals P
• the apparatus 30 is shown as including four sensors 40, it is contemplated that the array 38 of sensors 40 includes two or more sensors 40, each providing a pressure signal P(t) indicative of unsteady pressure within the pipeline 12 at a corresponding axial location X of the pipeline.
• the apparatus may include two to twenty four sensors 40.
• the accuracy of the measurement improves as the number of sensors 40 in the array 38 increases.
• the degree of accuracy provided by the greater number of sensors 40 is offset by the increase in complexity and time for computing the desired output parameter of the flow. Therefore, the number of sensors 40 used is dependent at least on the Attorney Docket No. CC-0932PCT
• the outputs 44 of the apparatus 30 can be received by the controller 16 for comparison to the dynamic model 18.
• the signal processor 42 can form part of the above-described controller 16.
• the stratification sensors 40 can be employed to generate signals indicative of normal stratification levels that can be used to optimize the dynamic model 18.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Acoustics & Sound (AREA)
• Electromagnetism (AREA)
• Measuring Volume Flow (AREA)
• Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)

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• 2007
  • 2007-08-01 EP EP07836448A patent/EP2069724A2/de not_active Ceased
  • 2007-08-01 WO PCT/US2007/017290 patent/WO2008016697A2/en active Application Filing
• 2009
  • 2009-03-02 NO NO20090954A patent/NO20090954L/no not_active Application Discontinuation

Non-Patent Citations (1)

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