System and method for quantitative verification of flow measurements

Abstract

To provide a flow meter system and method for measuring a fluid flow in a conduit.SOLUTION: A conduit has a conduit axis. A flow meter comprises a sensor configured to provide measurement data relating to the volumetric or mass flow rate though the conduit, and a processor configured to determine a flow per unit time in the conduit using the measurement data, uncertainty measurements per unit time using the measurement data, and an uncertainty quantity using the uncertainty measurements per unit time. The uncertainty quantity is totaled over a certain period of time.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to electronic flow meters or electronic flow measurement devices. Flow meters include, but are not limited to, ultrasonic flow meters, Coriolis flow meters, electromagnetic flow meters, thermal mass flow meters, and differential pressure flow meters. U.S. Patent Nos. 9,304,024, 10,288,462, and 10,393,568, as well as U.S. Patent Application Publication No. 2015 / 0198470 A1, entitled "Self-Checking Flow Meter and Method," describe electronic flow meters and are incorporated herein by reference in their entireties. Electronic flow meters utilize measured sensor parameters to compute flow variables in real time. Some flow meters integrate the flow rate over a measurement cycle and aggregate the integrals to provide a total flow rate in units of volume or mass.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of and priority to U.S. Patent Application No. 17 / 410,463, filed August 24, 2021, which in turn claims the benefit of and priority to U.S. Patent Application No. 63 / 114,407, filed November 16, 2020, by Otto and Brown, which is incorporated by reference in its entirety. [Background technology]

[0003] Electronic flow measurement devices measure parameters and relate these parameters to a measurand, which may be, for example, flow rate, volumetric flow rate, or mass flow rate. In addition to interpreting sensor data to estimate a primary measurement, many electronic flow meters also provide diagnostic functions. These diagnostic functions are typically qualitative in nature, i.e., they are expressed in terms different from the primary measurand. For example, an ultrasonic meter may provide a measure of signal quality, such as amplifier gain or signal-to-noise ratio. While qualitative diagnostics are useful, flow meter users may have difficulty interpreting these diagnostic results because they are not directly related to the measurand. In principle, the sensor diagnostic results could be interpreted in terms of the measurand (e.g., through machine learning), or additional sensors could be incorporated into the measurement device, allowing the measurement device to interpret the uncertainty of the primary measurand quantitatively, i.e., in the same units of measurement as the primary measurand.

[0004] Some electronic flow meters calculate flow rate based on the ultrasonic transit time measurement principle. Transit time ultrasonic flow meters can provide high accuracy performance over a wide range of application conditions. This has led to their adoption in applications such as controlled hydrocarbon transport and nuclear reactor feedwater flow measurement. To achieve high accuracy, transit time ultrasonic flow meters typically employ multiple paired transducers to estimate the velocity over many separate paths. Chordal integration methods are used in transit time ultrasonic flow meters. By selecting the path locations and combining the individual velocity measurements according to numerical integration rules, the result can represent the integrated or averaged velocity over the cross section, and hence the volumetric flow rate, i.e.,

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[0005] Currently, the self-diagnostic capabilities of transit-time ultrasonic instruments are based on the evaluation of parameters such as amplifier gain, signal-to-noise ratio, and velocity distribution descriptors such as flatness, asymmetry, and swirl. [Peterson, S, Lightbody, C, Trail, J, and Coughlan, L (2008), "On-line Condition Based Monitoring of Gas USMs", Proceedings of North Sea Flow Measurement Workshop, Scotland, October 2008; Kneisley, G, Lansing, J, and Dietz, T (2009), "Ultrasonic Meter Condition Based Monitoring - a Fully Automated Solution", Proceedings of the North Sea Flow Measurement Workshop. Workshop), Norway, October 2009. However, because these parameters are difficult to directly relate to the uncertainty of flow measurements, the use of qualitative instrument diagnostics alone is not currently considered to be entirely sufficient as a measure of flow meter verification.For example, the 2003 edition of the Measurement Guidelines for UK Offshore Oil and Gas Measurement and Regulators recognizes the benefits of current diagnostic techniques but points out their drawback: "Diagnosis facilities are currently qualitative rather than quantitative" (Department of Trade and Industry, Licensing and Consents Unit, Guidance Notes for Petroleum Measurement Under the Petroleum (Production) Regulations, December 2003, Issue 7). To address this drawback, two flow meters are sometimes installed in series, that is, one located a short distance downstream of the other. This allows the volumetric flow rates from the two meters to be compared with each other, making the verification quantitative rather than qualitative. Taking this concept a step further, it is also known to calculate two separate and independent flow measurements using two independent subsets of transducers housed within a single meter body.

[0006] One example of such an instrument design is the combination of a four-pass instrument with a single-pass instrument. [Kneisley, G., Lansing, J., and Dietz, T., "Ultrasonic Meter Condition-Based Monitoring - a Fully Automated Solution," Proceedings of the North Sea Flow Measurement Workshop, Norway, October 2009]. The drawback of this design is that the single-pass instrument is much more sensitive to distortions of the flow velocity field than the four-pass instrument. This difference in sensitivity means that, when a difference is detected, the single-pass instrument may be affected by flow field distortions that have negligible effects on the four-pass instrument. When a four-path meter is used as the primary measurement, this can result in false alarms, i.e., the detected difference does not reflect a decrease in the accuracy of the four-path meter. For example, the cited paper found that if a flow conditioner upstream of the meter has a single hole that becomes blocked, the effect on the four-path meter is virtually zero, whereas the effect on a single-path meter can be greater than 0.85%. If an alarm threshold of, say, 0.5% is set for the difference between the four-path and single-path results, the result is effectively an alarm indication that the four-path meter continues to read accurately.

[0007] Another example of this concept is the use of two similar but separate groups of ultrasonic paths. An eight-path configuration may be used where a first set of four paths are all set at a first angle relative to the pipe axis, and a second set of four paths are all set at the negative of that angle, resulting in paths forming a symmetrical X about the pipe axis in a top view. Another configuration may be used where four separate paths (sets) have alternate paths selected relative to the pipe axis. However, both of these configurations share a common weakness: each group of four paths is still affected differently by distortions of the flow velocity field, especially in the presence of complex non-axial flow fields, such as asymmetric rotation. What happens in such cases is that one group of four paths results in an overestimation of the flow rate, while the other group results in an underestimation of the flow meter. While this has been used to some extent in diagnosing flow conditions, this approach complicates the meter validation process because it is difficult to distinguish between errors in the measurement system itself and differences caused by the flow velocity field. More accurate or precise determination of diagnostic information, such as uncertainty information, about flow meters is needed.

[0008] The above-referenced patents and patent applications describe ultrasonic flow meter systems incorporating additional measurements to allow for estimation of uncertainty in flow measurements. Such systems can estimate various components of uncertainty in flow measurements using various measurement parameters, including, but not limited to, uncertainty in the primary velocity measurement, uncertainty in the integral of the axial velocity distribution, and uncertainty in the cross-sectional area used to convert velocity to volumetric load. [Prior art documents] [Non-patent literature]

[0009] [Non-Patent Document 1] Peterson, S., Lightbody, C., Trail, J., and Coughlan, L., "On-line Condition Based Monitoring of Gas USM's," Proceedings of North Sea Flow Measurement Workshop, Scotland, October 2008. [Non-patent document 2] Kneisley, G., Lansing, J., Dietz, T., "Ultrasonic Meter Condition Based Monitoring - a Fully Automated Solution," Proceedings of the North Sea Flow Measurement Workshop, Norway, October 2009. [Non-patent document 3] Department of Trade and Industry, Licensing and Consents Unit, Guidance Notes for Petroleum Measurement Under the Petroleum (Production) Regulations, December 2003, Issue 7 Summary of the Invention

[0010] Some embodiments relate to a flow meter system for measuring a fluid flow rate in a conduit. The conduit has a conduit axis. The flow meter includes a sensor configured to provide measurements related to volumetric or mass flow rate through the conduit, and a processor configured to use the measurement data to calculate a quantity unit flow per unit time in the conduit, use the measurement data to calculate an uncertainty value per unit time, and use the uncertainty value per unit time to calculate an uncertainty quantity. The uncertainty quantities are summed over a period of time.

[0011] Some embodiments relate to a flow meter system for measuring a fluid flow rate in a conduit having a conduit axis. The flow meter system includes a sensor configured to provide measurement data and a processor. The processor is configured to use the measurement data to calculate a flow of quantity units per unit time in the conduit, use the measurement data to calculate at least one uncertainty value of the quantity units per unit time, and use the uncertainty value per unit time to calculate at least one uncertainty quantity. The uncertainty quantities are summed over a period of time.

[0012] Some embodiments relate to an ultrasonic flow meter system for measuring fluid flow rate in a conduit having a conduit axis. The ultrasonic flow meter system includes multiple transducer pairs positioned to form acoustic transfer paths, some of which are co-located in one or more chordal measurement planes. Within each chordal measurement plane, the multiple transducer pairs positioned within the chordal measurement plane are positioned to form an acoustic transfer path that traverses from one side to the other at least once, thereby allowing axial velocity measurements to be made within each chordal plane with at least three traverses within each chordal plane. Each chordal plane is parallel to the conduit axis. The ultrasonic flow meter system further includes a processor configured to calculate a flow rate per unit time in the conduit using the axial velocity measurements, an uncertainty measurement per unit time using the co-located chordal ultrasonic measurements and other inputs, and an uncertainty amount using the uncertainty measurement per unit time. The uncertainty amount is summed over a period of time.

[0013] Some embodiments relate to a method for measuring fluid flow rate in a conduit using a flow meter, the flow meter having multiple transducer pairs for conduit acoustic transfer paths, some of which are co-located in one or more chordal measurement planes. The method includes providing axial velocity measurements for each chordal measurement plane, using the axial velocities for each chordal measurement plane to provide a flow rate per unit time in the conduit, providing uncertainty measurements per unit time for each chordal measurement plane using the co-located measurement paths for each chordal plane, using the uncertainty measurements per unit time to provide an uncertainty for each chordal plane, and providing a total uncertainty per chordal plane over a period of time.

[0014] Some embodiments relate to a self-checking ultrasonic flow meter that provides a flow rate output along with an associated estimate of uncertainty due to changes that may affect the accuracy of the measurement system. The uncertainty estimate is summed as a quantity. In some embodiments, the uncertainty estimate is not affected by asymmetric rotational flow, thus eliminating the need for mechanical flow adjustments. This is achieved by providing redundant measurements of axial velocity in each chordal measurement plane of the flow meter, i.e., by arranging transducers so that multiple axial measurements are made in each chordal measurement plane such that the multiple axial measurements are substantially independent of non-axial or lateral flow effects. This dictates that there should be a minimum of six nodes in each chordal measurement plane, with each node being either a single transducer or a single reflecting point. The resultant axial velocity measurements in each measurement plane are then used in the computation of the flow rate, and a comparison of the individual in-plane axial velocity measurements is used in the uncertainty assessment. In some embodiments, changes in path angle and path length that may occur due to the accumulation of contaminants within the meter body can be detected, and this can be done for each chordal plane without reference to data from another chordal plane. To this end, velocity measurements in each chord plane are made using transducer pairs positioned such that one path has a path length divided by the cosine of the angle relative to the conduit axis that differs from another path in the same plane. Combining these constraints, the flow meter has transducers that make a minimum of three traverses in each chord plane, with at least one path having a different path length or path angle than the other paths in that plane. In some embodiments, other numbers of paths per chord plane can be used, and additional measurements and detections can be utilized.

[0015] In some embodiments, elements of uncertainty from other input measurements can be incorporated. For example, an ultrasonic measurement path that reflects off the bottom of a pipe can be used to check whether liquid is present in the fluid conduit of an ultrasonic gas meter, or a path that reflects off the top of a pipe can be used to determine whether gas is present in the fluid conduit of an ultrasonic liquid flow meter. Data from the reflected path can be used to estimate the uncertainty in the cross-sectional area of ​​the conduit, which can then be converted to an uncertainty expressed in volumetric flow rate, and some embodiments can sum it together with other elements of uncertainty.

[0016] In some embodiments, in addition to the uncertainty from measuring the axial velocity at each chord measurement plane, uncertainty may arise as a result of how well the combination of velocities measured at different planes represents the velocity across the entire cross section of the flow conduit. Another U.S. Patent No. 10,393,568 describes how this component of uncertainty can be estimated by comparing the results of multiple integral methods. Thus, this may be yet another component of uncertainty that is evaluated and summed according to some embodiments.

[0017] Each individual element of uncertainty can be evaluated, converted to units of measure, and individually summed. Furthermore, various elements can be combined to produce an overall uncertainty, and the resulting units of measure can also be summed. By summing the contributing elements of uncertainty and the overall uncertainty, the resulting total uncertainty can be reviewed to determine which sources or elements of uncertainty are the most significant contributors to the overall uncertainty.

[0018] While specific examples of how flow measurement uncertainty data may be obtained are described above, the systems and methods described herein are not limited to such examples. Other flow measurement uncertainty data may be used. In some embodiments, an additional component of uncertainty due to detection of two-phase flow conditions (liquid entrained in gas or gas entrained in liquid) may be evaluated and totaled. In some embodiments, an additional component of uncertainty due to signal loss may be evaluated and totaled.

[0019] Other detection modalities besides ultrasound can also be used. For example, uncertainty estimates from analysis of multiple differential pressure signals can be converted to flow units and summed. Similarly, Coriolis sensor outputs can be combined with other measurements to assess uncertainties that can also be converted to flow units and summed.

[0020] These and other features, aspects, and advantages of the present invention will become apparent from the following description, appended claims, and accompanying exemplary embodiments illustrated in the drawings briefly described below. [Brief explanation of the drawings]

[0021] [Figure 1] 1 is a general block diagram of a flow measurement system including an uncertainty summation module according to some embodiments. [Figure 2] 2 is a flow diagram illustrating an uncertainty sum calculation for the system shown in FIG. 1 according to some embodiments. [Figure 3] 1 is a block diagram of a flow measurement system including a four-chord planar detection system according to some embodiments. [Figure 4] 4 is a flow diagram illustrating an uncertainty sum calculation for the system shown in FIG. 3 according to some embodiments. [Figure 5] 1 is a block diagram of a flow measurement system including a five-chord planar detection system according to some embodiments. [Figure 6]6 is a flow diagram illustrating an uncertainty sum calculation for the system shown in FIG. 5 according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0022] Certain embodiments of the system and method utilize additional data to improve flow calculations. Particularly in areas where accuracy is critical, such as the controlled transfer of liquids or gases, users of flow measurement devices increasingly expect that such devices should be able to provide not only measurement results but also information that allows users to assess the accuracy of those results. While flow measurement diagnostics are monitored in real time or archived for later review, these diagnostics are qualitative in nature and generally provide a relative assessment of measurement uncertainty relative to empirical limits or past records of the same parameter, rather than a quantitative assessment of measurement uncertainty. The incorporation of quantitative self-diagnostics into flow meters is described in U.S. Patent Nos. 9,304,024, 10,288,462, and 10,393,568, which require the processing, recording, and presentation of this information in a practical and meaningful manner, and which are incorporated herein by reference in their entireties. In some embodiments, diagnostic values ​​may be provided in real time, or may be recorded at intervals while real-time information about uncertainty is stored. In some embodiments, post-processing this data presents a potentially large data storage and analytical burden. Conventional condition-based monitoring systems for ultrasound instruments, while sophisticated, lack a clear and practical approach to providing users with an assessment of uncertainty over a given period of time that is of interest.

[0023] Diagnostic techniques in flow measurement devices can be qualitative and transient in nature. For example, the amplification (gain) applied to a pair of ultrasonic transducers in an ultrasonic flow meter may be determined and monitored against alarm limits, or may be recorded at intervals in a database. Thus, when a problem occurs, it is possible to examine the diagnostic data and deduce some information about what the problem was and when it occurred. The question that a user then has is: What was the effect of this event on my measurement? However, the information available from such qualitative diagnostics is not, and generally cannot be, expressed in the same quantitative terms as the flow measurement itself; therefore, the knowledge conveyed by this form of diagnostics falls short in understanding how the problem contributed to uncertainty in the measurement results.

[0024] In some embodiments, systems and methods provide a self-verifying electronic flow meter in which various components of uncertainty are continuously evaluated, combined, and summed in the same terms as the primary flow measurement, i.e., the mass or volume total. In some embodiments, the systems and methods evaluate additional data to derive components of the measurement uncertainty term in units of volumetric or mass flow, and each of these components is integrated and summed. In some embodiments, the accumulated and summed flow rate (in volumetric or mass terms) is provided with a corresponding uncertainty in the overall total. In addition to the overall summed uncertainty, totals may be provided for the individual components of uncertainty, thereby providing insight into how each individual component of uncertainty contributed to the overall uncertainty in the recorded total.

[0025] In some embodiments, the measurement technique is based on measuring the transit time of an ultrasonic pulse, and the uncertainty contribution is determined from a number of sources, including but not limited to: · Signal to noise ratio of the signal. The difference between the computed axial velocities on each chord plane (see, for example, U.S. Pat. No. 9,304,024). The difference between dissimilar chord integral methods (see, for example, US Pat. No. 10,393,568). Area obstruction estimation using ultrasonic ranging techniques to account for the uncertainty in the cross-sectional area used in velocity-to-volume ratio conversion.

[0026] Other measurement techniques can also be employed to estimate individual components of uncertainty. For example, measurement systems using a variety of detection principles can be used to provide uncertainty estimates. For example, a two-component oil and water flow meter can use an ultrasonic instrument, a differential pressure measurement instrument, and a capacitance measurement instrument to estimate the total flow rates of both water and oil in a flowing two-component mixture. The volume rate derived from the differential pressure measurement can be compared to the volume rate derived from the ultrasonic measurement, thereby providing input for estimating one component of uncertainty (uncertainty in the total volumetric flow rate). The oil / water fraction can be estimated from both the measured sound speed from the ultrasonic instrument and the capacitance measurement, and these two pairs of measurements can be used to estimate another component of uncertainty (uncertainty in the oil / water fraction). For water and oil flow rates, the uncertainties for each of the components (i.e., volume rate and oil / water fraction) can be expressed as quantities and summed, and these uncertainties can also be combined to estimate the overall uncertainty in the oil and water quantities, and the overall result can also be summed.

[0027] In some embodiments, the flow measurement systems and methods described herein can calculate, store, and communicate information associated with a measurement parameter as a continuous sum of measurement uncertainties in terms of mass or volume. The uncertainties are estimated in absolute values, which can then be converted into quantitative terms identical to the primary quantity or quantities measured by the flow meter, which can then be summed individually. As provided for summation, component uncertainties are also combined according to uncertainty estimation principles to perform an overall uncertainty summation. As a result, summed values ​​can be stored for both the primary quantity (or quantities, if the instrument can, for example, compute both mass and volume, or compute the quantities of individual components of a flow, e.g., oil and water) and the individual components of uncertainty.

[0028] In some embodiments, the flow meter sensor, e.g., an ultrasonic instrument, is configured to evaluate additional data to derive various components of measurement uncertainty. The flow meter provides measurement uncertainty in units of volumetric or mass flow rate, and each of these components is integrated and summed. While specific types and techniques of flow measurement are described below, the systems and methods, in some embodiments, can be utilized with other types of instruments or sensors in various applications.

[0029] Self-verifying ultrasonic meters using the principles outlined in U.S. Patent Nos. 9,304,024, 10,288,462, and 10,393,568 utilize an electronic signal processing unit and multiple transducers to make multiple measurements of the transit time of an ultrasonic pulse sent along a specific path in a flowing fluid. These paths are arranged so that the meter, in some embodiments, can make multiple axial velocity measurements in each chordal plane of a multi-path ultrasonic flowmeter. The resulting measurements can be used to determine the flow rate and volume, and, in some embodiments, to estimate the uncertainty in the flow rate. For each chordal plane, the difference between the axial velocity results, in some embodiments, is used to determine an uncertainty component, expressed in velocity (e.g., meters per second) for that chordal plane. In some embodiments, this component uncertainty for a given chordal plane can then be converted to an uncertainty in volumetric flow rate by using appropriate weighting and geometric terminology. In some embodiments, multiplying the component measures of volumetric flow rate uncertainty by the corresponding time intervals yields an integrated result expressed in volume uncertainty. During each calculation cycle, the volume uncertainty increment is added to the previous value for that given element of uncertainty, resulting in some embodiments in the overall volume of uncertainty. During each calculation cycle, the overall uncertainty is also calculated in some embodiments by combining the various element uncertainty inputs.

[0030] Referring to FIG. 1 , system 1 includes processor 2, a vessel, conduit, or pipe 3 providing a fluid or fluid / solid mixture (e.g., gas, liquid, sediment-containing fluid, or a mixture thereof) at a flow rate, and sensor 4 configured to provide data for determining the flow rate. Sensor 4, in some embodiments, is a unit that is an assembly of sensor technologies corresponding to flow rate and related measurands. Sensor 4 may be an ultrasonic sensor including multiple transducers, as described below and in U.S. Pat. Nos. 9,304,024, 10,288,462, and 10,393,568. Sensor 4 emits signals that are converted into flow rate data and additional data in processor 2. Sensor 4 may be coupled to processor 2 wirelessly (dashed line) or via a wired connection.

[0031] The processor 2 is configured to determine the flow rate, total mass and / or volume, and flow rate in terms of uncertainty provided through the pipe 3 over time based on the flow data and the additional data. The flow rate, total mass or volume, and uncertainty may be provided on a display 5 or communicated digitally to another system (e.g., via analog or digital inputs and outputs 13). The additional data may be utilized to evaluate various sources of uncertainty in the form of individual component uncertainties, and such additional data may include signal-to-noise ratio measurements and additional transit time measurements to enable evaluation of velocity uncertainty, additional velocity measurements to enable evaluation of flow distribution uncertainty, and ultrasonic evaluation of the cross-sectional area of ​​the pipe.

[0032] Other and various measurements may, in some embodiments, be included in and converted into the element uncertainty in units of volumetric or mass flow rate. Measurement data may be provided by analog or digital inputs and outputs 13. For example, two measurements may be used to estimate two values ​​of density and thus the element uncertainty in units of density, which may then be converted into an uncertainty expressed in mass flow rate by multiplying by the volumetric flow rate. The element uncertainties for density may then be summed on a mass basis. Some available diagnostic methods do not readily accommodate this procedure. For example, in general use, amplifier gain cannot be directly related to uncertainty in terms of flow rate, and can only be used in this manner if the relationship between gain and flow rate uncertainty has been empirically established for a very specific set of circumstances.

[0033] Processor 2 may be any hardware and / or software processor or processing architecture configured to execute instructions and operate on data from sensor 4 and other sources. Processor 2 may include a wired or wireless interface for communicating with sensor 4. Processor 2 may be or include one or more microprocessors, application-specific integrated circuits (ASICs), circuits including one or more processing components, a group of distributed processing components, circuits supporting a microprocessor, or other hardware devices configured to process sensor data. In some embodiments, processor 2 and display 5 are part of a computer, server, mobile computing device, or workstation and are separate from sensor 4. In some embodiments, processor 2 may be integrated into or located in sensor 4 or pipe 3, a network associated with sensor 4, or a remote data center. In some embodiments, display 5 is a liquid crystal display within the flow meter or sensor 4 that provides a totalized uncertainty value. In some embodiments, display 5 is provided on a smartphone or other handheld device or is integral with sensor 4.

[0034] In some embodiments, processor 2 includes a non-transitory medium, such as a memory, that stores software instructions for performing flow and uncertainty determinations. In some embodiments, processor 2 includes flow calculation module 6, uncertainty calculation module 7, flow summation module 8, uncertainty calculation module 9, uncertainty summation module 11, and signal processing module 15. Modules 6, 8, 9, 11, and 15 may be implemented in hardware, software, or a combination thereof and may be integrated with one another. In some embodiments, one or more of modules 6, 8, 9, 11, and 15 are included in sensor 4 or shared between processor 2 and sensor 4.

[0035] In some embodiments, sensor 4 is configured as a multipath ultrasonic flow meter that performs multiple transit time measurements to calculate multiple axial velocities (e.g., two or more) within each chordal plane. The transit time measurements are provided to flow calculation module 6 and flow summation module 8 of processor 2 to determine flow velocity and volume. In some embodiments, signal processing module 15 converts signals from sensor 4 into digital information, and this signal processing module is in communication with processor 2 to provide and receive data and / or instructions. Uncertainty calculation module 9 also, in some embodiments, receives the transit time measurements and additional data to calculate the uncertainty of the flow rate. For each chordal plane, the difference between the axial velocity results is, in some embodiments, used to determine a component uncertainty in terms of measure (e.g., meters per second) for that chordal plane. In some embodiments, the component uncertainty for a given chordal plane may then be converted to an uncertainty in volumetric flow rate by using appropriate weighting and geometric terminology. In some embodiments, multiplying the component measures of volumetric flow rate by the corresponding time intervals results in an integrated result expressed in volume. In some embodiments, the uncertainty summing module 11 adds the volume increment at each calculation cycle to the previous value for a given element of uncertainty, resulting in some embodiments in a total uncertainty volume. During each calculation cycle, the overall uncertainty is calculated by combining the various element uncertainty inputs, which in some embodiments are summed.

[0036] In some embodiments, axial velocities are calculated in five chordal measurement planes. Using two subsets of these axial velocities, for example, one using data from four chordal planes and another using data from all five chordal planes, two estimates of the average velocity across the cross section of the flow conduit can be obtained. This is achieved by using two different sets of weighting factors, one set using four chordal results and the other set using five chordal results. A comparison of the cross-sectional average velocity measurements from the four chordal and five chordal results can be used to determine the component uncertainty associated with the flow velocity distribution. Large differences in the average velocities calculated from the two different velocity measurements result in large values ​​for this component uncertainty. In some embodiments, an additional measurement path (e.g., from top to bottom) is used to estimate another component uncertainty associated with the cross-sectional area value used in the flow measurement calculation. In other words, the component uncertainty for area is estimated using this path. The elemental uncertainties are converted into volumetric velocity uncertainties by multiplication with the average flow velocity over the cross section, which can then be integrated and summed for the volume.

[0037] Examples 1, 2, and 3 are tabular examples of actual implementations, and are provided below. They illustrate the case where three component uncertainties are estimated based on measurements and additional data available for the flow meter. These component uncertainties may be one of the component uncertainties already described or some other component uncertainties. As with the individual component uncertainties, the overall uncertainty is calculated by combining the individual component uncertainties. In Examples 1, 2, and 3, the main flow rate is held constant, and the component uncertainties are varied between two values ​​to facilitate explanation of the principles at work, and such component uncertainties should not be construed as limiting the present invention. In practical cases, the flow rate and uncertainty may vary continuously, as is familiar to those skilled in the art of flow metering and measurement uncertainty.

[0038] Columns 1 and 2 in each of Examples 1-3 indicate the elapsed time and the time interval between successive measurements / calculations. Processor 2, in some embodiments, provides data for Examples 1, 2, and 3 in response to sensor measurements from Sensor 4. Primary flow rate measurements and corresponding total volumes (sum of volumes) are shown in Columns 3 and 4. These are followed by Columns 5, 6, and 7, which indicate uncertainty values, expressed in cubic meters per hour, for three different components that contribute to the overall uncertainty. In some embodiments, each of these three components may be associated with one of three chord planes. In another embodiment, the three components may be uncertainties associated with the axial velocity measurement, velocity distribution effects, and cross-sectional area uncertainty, respectively. While an unlimited number of different and additional components may be utilized relative to the total number of components, the examples use only three components for simplicity of illustration.

[0039] Columns 8, 9, and 10 show the process of summing the component uncertainties, and columns 11 and 12 show the overall uncertainty and its sum. The cubic meter values ​​shown in columns 8, 9, 10, and 12 may be stored as a single value (i.e., only the most recent value available) or are summed results that can be written at intervals to an internal memory within the flow measurement device, e.g., system 1.

[0040] These sums advantageously retain essential information about the measurement uncertainty over the entire interval between recorded results and may be used as a single result at the end of the process, or may be used over relatively long intervals (minutes, days, months, etc.) between recordings. While only 10 seconds are shown in Examples 1, 2, and 3, in practice the summation may continue over a much longer period (e.g., hours, days, weeks, etc.). Examples 1, 2, and 3 demonstrate relevant uncertainty information related to throughput that can be assessed very quickly and easily by reviewing the sums covering the end of the period of interest. Only Example 1 allows the summation of the individual component uncertainties as well as the overall uncertainty to determine the largest component uncertainty, which potentially provides insight into the underlying causes of the uncertainty and techniques for reducing the uncertainty.

[0041] In some embodiments, the summed uncertainty values ​​are compared to corresponding thresholds by summation module 11. If the uncertainty for a given element uncertainty or the overall uncertainty exceeds the threshold associated with that element, an alarm may be issued by processor 2 on display 5 or may be communicated digitally or by an output such as an electronic switch controlling a DC voltage.

[0042] Another advantageous feature of System 1 can be illustrated by comparing the combined root sum of squares of the individual component uncertainties (summed at the end of a 10-second period, or any practical period in question) with the overall total uncertainty summed continuously during the same period according to some embodiments. By comparing Examples 2 and 3, it can be seen that at the end of the 10-second period, the overall total uncertainty is not the same in Examples 2 and 3, yet the sum of the uncertainties for each of the individual components is the same in these examples (compare columns 11 and 12 with columns 8 and 10 in Examples 2 and 3). This illustrates the benefit and usefulness of calculating and recording both the sum of the individual uncertainties and the overall total uncertainty, since recording only the component sums and combining them at the end of the period would produce different (and inherently inaccurate) results for the continuous sum of the overall uncertainty. The underlying cause is that the component uncertainties highlighted in Examples 2 and 3 are not simultaneously calculated over 20 minutes in Example 2. 3 / hr, and in Example 3, 20 min 3 / hr. This shows that the process of summing the component and overall uncertainties considers and preserves certain information that would otherwise be lost at the end of the 10-second period. Examples 1-3 demonstrate the advantage of calculating and summing the overall uncertainty at each period. If the details of what happens in each period are not preserved, it is not possible to look back and consider how the various component uncertainties combine at a particular point in time. It is the summation process that allows information to be preserved without imposing requirements on the system for the retention of large amounts of data. [Table 1] [Table 2] [Table 3]

[0043] The uncertainty values ​​are combined by various mathematical operations according to known practices in uncertainty assessment. In some cases, the uncertainty values ​​represent ranges within which the values ​​are expected to fall, and when combined, not all contributions are expected to simultaneously reside at the extremes of their uncertainty. For example, the uncertainty values ​​can be combined in a manner that can be described (in simplified terms) as taking the square root of the sum of the uncertainties. In such a manner, the component values ​​do not simply add to each other to give the overall uncertainty. In other cases, the component uncertainties can be linearly added to each other. Various mathematical techniques can be used to combine the summed uncertainty values ​​according to known practices.

[0044] Referring to FIG. 2 , the calculation process can be described using a flowchart 200. Flowchart 200 provides a basic uncertainty summation process in some embodiments. The calculations described in flowchart 200 can be adjusted and include various statistical or mathematical operations. In operation 202, the calculation process begins. In operation 204, sensor 4 provides a measurement step (e.g., sending and receiving ultrasonic pulses, measuring transit time, providing velocity data, providing communication data, etc.) that provides measurement data. The measurement data from sensor 4 is recorded in memory and stamped with the time of the sample and other associated data for data processing operations. In operation 204, a primary flow computation is performed. The flow computation may be performed by flow module 6 and flow summation module 8, as described in U.S. Patent Nos. 9,304,024, 10,288,462, and 10,393,568, and examples of such measurements are described below in some embodiments. Flow measurements can be computed at regular or irregular intervals, typically but not necessarily at a relatively fast rate such as once per second, hi some embodiments, flow measurements may be based on velocity inferred from ultrasound transit time measurements.

[0045] In operation 208, the uncertainty calculation module 9, in some embodiments, calculates the uncertainty in units of quantity per unit time (e.g., m 3 The component uncertainty of the flow measurement is determined in units of s / s or kg / s. The component uncertainty can be determined by a variety of means, including, but not limited to, comparing different results from different combinations of measurement data, evaluating signal-to-noise ratios or other diagnostic parameters, or evaluating statistical values ​​derived from the measurement data. The component uncertainty, in some embodiments, can be calculated by processor 2 using uncertainty calculation module 9 according to the techniques described in U.S. Pat. Nos. 10,393,568 and 9,304,024.

[0046] At operation 210, processor 2 determines the time interval (e.g., using a timestamp) between the current measurement and the previous measurement. At operation 212, processor 2 multiplies the uncertainty value by the time interval to determine the uncertainty quantity (e.g., expressed in mass and / or volume). At operation 214, summation module 8 adds each uncertainty quantity value (expressed in quantity units) to the previous value to provide a summed uncertainty result (expressed in quantity units). At operation 216, process 200 returns to operation 204 if more data is available, or exits to stop operation 218. The summed uncertainty result may be recorded, stored, or output periodically—once a day, once an hour, once a minute, etc.—or may be recorded, stored, or output for a specific operation, such as the transfer of an individual batch of fluid, e.g., a tanker loading operation.

[0047] In some embodiments, the total uncertainty can be used to check the validity of the flow meter and identify when inspection or repair is necessary. For example, if the total uncertainty for a given period reaches a predetermined threshold, the meter or sensor 4 can be flagged for subsequent inspection, maintenance, or replacement. The processor 2 can send a message to provide an alert and / or an indication of the amount of total uncertainty. In some embodiments, the total can be divided by the total accumulated period to express it as a flow rate. In some embodiments, the rate of change of the total uncertainty can be used to diagnose problems with the sensor 4 or the pipe 3. In some embodiments, the total uncertainty can be divided by the total flow rate to determine the uncertainty in relative terms, such as a ratio or percentage. The relative uncertainty can be used to indicate when inspection, maintenance, repair, or replacement is necessary. For example, a relative uncertainty of 1 percent or less of total flow indicates that the system 1 is measuring flow properly, while a higher percentage indicates that remedial action is needed.

[0048] Referring to Figure 3, system 25 is similar to system 1 (Figure 1) and includes processor 2, a vessel, conduit, or pipe 3 that provides a fluid (e.g., gas, liquid, sediment-containing fluid, or a mixture thereof) at a flow rate, and sensor 17 configured as an ultrasonic measurement sensor. Sensor 17 includes multiple transducers that form nodes and paths 21A-21D, 22A-22D, and 23A-23D in four chord planes 20A-20D. In the example shown in Figure 3, sensor 17, in some embodiments, has six nodes and three paths in each of chord planes 20A-20D.

[0049] Referring to FIG. 4, system 25 (FIG. 3) may employ a flow rate and uncertainty calculation process 51 utilizing sensor 17, in which multiple axial velocity measurements 52A-52D are made at each of chordal planes 20A-20D. Measurements 52A-52D are measurement data from sensor 17. Measurements / results 54A-54D represent axial velocity results, and measurements / results 56A-56D represent uncertainty values ​​calculated from the measurement data. From the axial velocity results at each of chordal planes 20A-20D, an axial velocity value for that plane (e.g., results 54A-54D) is calculated, and an uncertainty for that axial velocity result (e.g., results 56A-56D) is calculated. The axial velocity results (e.g., results 54A-54D) are combined to compute a flow rate measurement, which is a volumetric flow rate 98. The volumetric flow rate 98 is provided to flow summation module 8 to obtain a volumetric summation result. The uncertainty results 56A-56D for each chord plane 20A-20D may be converted from units of velocity to units of volumetric flow rate. Once expressed in volumetric flow rate, each of the axial velocity uncertainties per chord plane 20A-20D may then be input into uncertainty summation module 9 and summed in units of cubic meters. The individual axial velocity uncertainty results per chord plane 20A-20D (e.g., results 56A-56D) may also be combined to obtain an overall uncertainty, shown as U-chord result 88, which represents the uncertainty of the measurement result by summing the contribution of the uncertainties for each chord. U-chord result 88 is also computed in terms of volumetric flow rate, and this U-chord result is an additional input to the uncertainty summation calculated by uncertainty summation module 11 (FIG. 3). An exemplary end result is the total volume (i.e., measurement result) measured by instrument 17, with five uncertainty results: one uncertainty result for each of the chord measurement planes 20A-20D, and one for the total measurement result (i.e., U-chord 88). By examining these totals, the long-term uncertainty can be easily calculated, including information about the contribution of each of the four measurement chords 20A-20D to the overall measurement uncertainty.

[0050] Referring to FIG. 5, system 81 is similar to systems 1 and 25 (FIGS. 1 and 3) in that system 81 includes processor 2, a vessel, conduit, or pipe 3 that provides a fluid (e.g., gas, liquid, sediment-containing fluid, or a mixture thereof) at a flow rate, and sensor 85 configured as an ultrasonic measurement sensor. Sensor 85 may be similar to sensor 4 (FIG. 1) and have multiple transducers that form nodes and paths 21A-21E, 22A-22E, and 23A-23E within five chordal planes 20A-20E. In the example shown in FIG. 5, sensor 85, in some embodiments, has six nodes and three paths within each of chordal planes 20A-20E, and two nodes associated with a V-path 83 that penetrates planes 20A-20E.

[0051] Referring to FIG. 6, system 81 (FIG. 5) may employ a flow rate and uncertainty calculation process 81 utilizing sensor 85, in which multiple axial velocity measurements 52A-52E are performed at each of chordal planes 20A-20E. Process 91 is similar to process 51 (FIG. 4), in that process 91, in some embodiments, employs additional measurements dedicated to determining additional component uncertainty. Measurements / results 54A-54E are measurement data from sensor 85. Measurements / results 54A-54E represent axial velocity results, and measurements / results 56A-56E represent uncertainty values ​​calculated from the measurement data. From the axial velocity results at each of chordal planes 20A-20D, an axial velocity value for that plane (e.g., results 54A-54D) is calculated, and an uncertainty for the axial velocity results (e.g., results 56A-56D) is calculated. The axial velocity results (e.g., results 54A-54D) are combined to compute a flow measurement result, i.e., a VelFourchord value 81, which is used to provide a volumetric flow rate 98. The axial velocity value for plane 20E (e.g., result 52E) is used to compute a Velfivechord value 78, which in some embodiments allows for the calculation of additional component uncertainties according to the techniques of U.S. Pat. No. 10,393,568.

[0052] The 4th chord combined velocity or Belfour chord value 81 and the 5th chord combined velocity or Belfive chord value 78 are used to compute an additional component uncertainty or U-integral value 80. The U-integral value 80 estimates the uncertainty by integrating or averaging the flow velocity distribution. Additionally, additional sensors and measurements (e.g., sensor 94 for area obstruction estimation) are used in computing another component uncertainty, the cross-sectional area uncertainty or U-area value 84. Such a result can be derived from data obtained from additional measurements, for example, measurements from V-path 83 (FIG. 5). In process 91, an overall uncertainty or U-combined value 96 is computed from the three main component uncertainties, U-area value 84, U-chord value 88, and U-integral value 80, using uncertainty calculation module 72 (FIG. 5). Thus, in this example, process 91 includes flow measurement result or flow value 98 and nine different uncertainties: five uncertainty values ​​for axial velocity (one per chord measurement plane, e.g., results 56A-56E), three major components of the overall uncertainty (e.g., values ​​80, 84, and 88), and an overall uncertainty (e.g., value 96). When these nine uncertainty values ​​and flow value 98 are calculated over time, examining the sum allows for a ready understanding of the overall uncertainty and the factors contributing to that overall uncertainty. For example, the area uncertainty total or U-area value 84 may be significantly larger than the combined chord velocity total (e.g., value 82) or the integral uncertainty total (e.g., value 90) of the chord velocity total, suggesting a process contamination problem. In a different embodiment, the total chord velocity uncertainty (e.g., value 88) may be the largest, and if the axial velocity uncertainty in chord plane 20B (value 56B) is much larger than the total for the other chords, this indicates that there is likely a problem with the measurement on chord plane 20B.

[0053] The volumetric flow rate 98 is input to flow summation module 8 to produce a volumetric flow result. The uncertainty results 56A-56D for each chordal plane 20A-20D and the uncertainty result 56E for plane 20E may be converted from units of velocity to units of volumetric flow rate. Once expressed in volumetric flow rate, each of the axial velocity uncertainties per chordal plane 20A-20E may then be input to uncertainty summation module 9 and summed in units of cubic meters. The individual axial velocity uncertainty results for each chordal plane 20A-20D (e.g., results 56A-56D) are also combined to determine an overall uncertainty representing the uncertainty of the measurement result due to the combined effect of each chordal uncertainty, shown as U-chord result 88. U-chord result 88 is also computed in terms of volumetric flow rate, which is an additional input to the uncertainty summation calculated by uncertainty summation module 72 (FIG. 5).

[0054] While the detailed drawings, specific examples, and specific configurations provided relate to preferred exemplary embodiments, they serve for illustrative purposes only. The disclosed invention is not limited to the specific configuration shown. For example, the method can be implemented in any of a variety of step sequences or according to any of a variety of mathematical formulas. The configurations of the hardware and software shown and described may vary depending on selected performance characteristics and physical properties of the communication devices. For example, the types of system components and their interconnections may vary. The systems and methods shown and described are not limited to the precise details and conditions disclosed. The figures show only preferred example operations. Specific data formats and operations are shown as non-limiting. Furthermore, other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangements of the exemplary embodiments without departing from the scope of the invention as defined by the appended claims.

Claims

1. 1. A flow meter system for measuring a fluid flow rate in a conduit having a conduit axis, the flow meter system comprising: a sensor configured to provide measurement data; using the measured data to calculate the flow in units of volume per unit time in the conduit; determining at least one uncertainty in units of quantity per unit time using the measurement data; and a processor configured to calculate at least one uncertainty using the uncertainty values ​​per unit time, the uncertainty being summed over a period of time.

2. The flow meter system of claim 1 , wherein the quantity units are expressed in mass or volume.

3. 2. The flow meter system of claim 1, wherein the sensor includes ultrasonic transducers located in one or more chord measurement planes, a pair of transducers disposed in each chord measurement plane positioned to form an acoustic transmission path that traverses at least one time from one side of the chord measurement plane to another side of the chord measurement plane, each traverse being either direct from one transducer to another transducer or via one or more reflecting points, and wherein multiple axial velocity measurements are made with a minimum of three traverses in each chord plane, each chord plane being parallel to the conduit axis.

4. 2. The flow meter system of claim 1, wherein the one uncertainty in units of quantity per unit time includes multiple first measurements, each associated with a unique chordal plane.

5. The flow meter system of claim 4 , wherein each of the first measurements is converted to a corresponding first quantity.

6. The flow meter system of claim 5 , wherein the first amounts are summed.

7. 1. An ultrasonic flow meter system for measuring a fluid flow rate in a conduit having a conduit axis, the ultrasonic flow meter system comprising: a number of transducer pairs arranged to form acoustic transfer paths in each of the one or more string measurement planes that are co-located in the string measurement planes; and a processor configured to calculate a flow rate in the conduit per unit time using axial velocity measurements, to calculate uncertainty measurements per unit time using the axial velocity measurements, and to calculate an uncertainty amount using the uncertainty measurements per unit time, wherein the uncertainty amount is summed over a period of time.

8. The ultrasonic flow meter system of claim 7 , wherein the uncertainty measurement is related to a difference between the axial velocity measurements in each chordal plane.

9. 8. The ultrasonic flowmeter system of claim 7, wherein the multiple transducer pairs arranged in the chord measurement planes are positioned to form acoustic transmission paths with at least one traversal from one side, and wherein multiple axial velocity measurements are made in each chord plane with a minimum of three traversals in each chord plane, each chord plane being parallel to the conduit axis, and each chord plane having two paths per chord plane, each path being a reflection path with two traversals of the chord plane and one reflection in each of the two paths.

10. 10. The ultrasonic flow meter system of claim 9, including three paths per chord plane, wherein the transmission on two paths is direct between transducers and one path is a reflected path that includes two crossings of the chord plane and one reflection point.

11. 8. The ultrasonic flow meter system of claim 7, wherein the uncertainty measurement per unit time includes multiple first measurements, each associated with a unique chordal plane.

12. The ultrasonic flow meter system of claim 11 , wherein each of the first measurements is converted to a corresponding first quantity.

13. The ultrasonic flow meter system of claim 12 , wherein the first amounts are summed.

14. 8. The ultrasonic flow meter system of claim 7, wherein the multiple transducer pairs arranged in the chord measurement planes are positioned to form acoustic transmission paths that traverse at least once from one side, and multiple axial velocity measurements are made in each chord plane with a minimum of three traverses in each chord plane, each chord plane being parallel to the conduit axis, and two nodes each being shared by two paths, allowing the total number of nodes to be reduced from six to four or from seven to five.

15. 8. The ultrasonic flow meter system of claim 7, wherein the multiple transducer pairs arranged in the chordal measurement plane are positioned to form acoustic transmission paths, with three nodes each shared by two paths, reducing the total number of nodes from seven to four.

16. 8. The ultrasonic flow meter system of claim 7, wherein the multiple transducer pairs arranged in the chordal measurement plane are positioned to form acoustic transmission paths that traverse at least once from one side, with two nodes each shared by two paths and a third node shared by three paths, reducing the total number of nodes from seven to three.

17. 8. The ultrasonic flow meter system of claim 7, wherein the multiple transducer pairs disposed in the chord measurement planes are positioned to form acoustic transfer paths, the acoustic transfer paths in each chord measurement plane overlapping each other.

18. 1. A method for measuring fluid flow in a conduit using a flow meter, the flow meter having multiple transducer pairs positioned relative to an acoustic transmission path of the conduit, the method comprising: providing an axial velocity measurement; using the axial velocity to provide a flow rate per unit time in the conduit; providing, for each chordal plane, a measurement of uncertainty per unit time using the axial velocity measurements; providing an uncertainty using the uncertainty measurements per unit time; and providing a total uncertainty over a period of time.

19. The method of claim 18 further comprising the step of determining a fluid flow rate in the conduit from the axial velocity measurements.

20. The method of claim 18 , further comprising comparing the total uncertainty or the uncertainty to a threshold to determine a fault.

21. 1. A flow meter system for measuring a fluid flow rate in a conduit, the flow meter system comprising: a sensor configured to provide measurement data; using the measurement data to calculate the flow rate in the conduit; calculating at least one uncertainty value in unit quantity per unit time using the measurement data; and a processor configured to calculate at least one uncertainty using the uncertainty values ​​per unit time, the uncertainty being summed over a period of time.

22. 22. The flow meter system of claim 21, wherein two resultant velocities are calculated using the axial velocity values ​​from multiple chordal planes detected by the sensor, each of the two resultant velocities being calculated using a different chordal integral scheme, and a difference between the first resultant velocity and the second resultant velocity is used in calculating the uncertainty value.

23. 22. The flow meter system of claim 21, wherein the sensor comprises at least one of an ultrasonic sensor, a Coriolis sensor, an electromagnetic sensor, a differential pressure sensor, a thermal sensor, a vortex shedding sensor, a cross-correlation sensor, a capacitance sensor, a microwave sensor, a temperature sensor, a pressure sensor, or a density sensor.

24. 22. The flow meter system of claim 21, wherein the sensor uses a reflected ultrasonic path to calculate an area uncertainty and combines the area uncertainty with the velocity result to produce an uncertainty associated with area in units of volume per unit time, and the area uncertainty is summed in units of volume.

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