Apparatus And Method For Augmenting A Coriolis Meter

• US 20090013799A1
• Filed: 10/15/2007
• Published: 01/15/2009
• Est. Priority Date: 07/15/2003
• Status: Active Grant

• Current Assignee: Expro Meters, Inc. (Umbrellastream LP, Inc.)
• Original Assignee: Cidra Sarl (Nordic Cultural & Educational Foundation)
• Inventors: Gysling, Daniel L.
• Granted Patent: US 7,793,555 B2
• Time in Patent Office: Days
• US Class Current: 73/861.355
• CPC Class Codes: G01F 1/7082 using acoustic detecting arrangements
• CPC Class Codes: G01F 1/712 using auto-correlation or cross-correlation detection means
• CPC Class Codes: G01F 1/74 Devices for measuring flow of a fluid or flow of a fluent solid material in suspension in another fluid
• CPC Class Codes: G01F 1/8413 means for influencing the flowmeter's motional or vibrational behaviour, e.g., conduit support or fixing means, or conduit attachments
• CPC Class Codes: G01F 1/8477 with multiple measuring conduits
• CPC Class Codes: G01F 15/024 involving digital counting
• CPC Class Codes: G01F 25/10 of flowmeters
• CPC Class Codes: G01N 2009/006 vibrating tube, tuning fork
• CPC Class Codes: G01N 2291/0215 Mixtures of three or more gases, e.g. air
• CPC Class Codes: G01N 2291/02818 Density, viscosity
• CPC Class Codes: G01N 2291/02836 Flow rate, liquid level
• CPC Class Codes: G01N 2291/02872 Pressure
• CPC Class Codes: G01N 2291/0422 Shear waves, transverse waves, horizontally polarised waves
• CPC Class Codes: G01N 2291/0427 Flexural waves, plate waves, e.g. Lamb waves, tuning fork, cantilever
• CPC Class Codes: G01N 29/024 by measuring propagation velocity or propagation time of acoustic waves
• CPC Class Codes: G01N 9/002 using variation of the resonant frequency of an element vibrating in contact with the material submitted to analysis G01N9/34 takes precedence
• CPC Class Codes: G01N 9/24 by observing the transmission of wave or particle radiation through the material

Abstract

A correction system provides at least one of a compensated mass flow rate measurement and a compensated density measurement of a coriolis meter. The correction system includes a gas volume fraction (GVF) meter, which may include an array of strained-based or pressure sensors, to measure the speed of sound propagating through the fluid passing through the coriolis meter to calculate at least the GVF of the fluid and/or the reduced natural frequency. The calculated gas volume fraction and/or reduced frequency is provided to a processing unit for determining an improved mass flow rate and/or density for the coriolis meter. The improved density is determined using analytically derived or empirically derived density calibration models (or formulas derived therefore), which is a function of the measured natural frequency and at least one of the determined GVF, reduced frequency and speed of sound, or any combination thereof.

Claims

1. A correction system for correcting a coriolis output signal of a coriolis meter, the coriolis meter being configured to measure a parameter of a fluid flowing in a pipe, and the output signal being indicative of the parameter of the fluid flow, the correction system comprising:

a flow measuring device measuring the speed of sound propagating through the fluid passing through the coriolis meter, the measuring device providing a correction signal in response to the measured speed of sound; and

a processing unit responsive to the coriolis output signal and the correction signal for providing a corrected coriolis output signal.

2. The correction system of claim 1, wherein said correction signal is at least one of an SOS signal indicative of the speed of sound propagating through the fluid, a GVF signal indicative of the gas volume fraction of the fluid and a reduced frequency indicative of the reduced frequency of the fluid.

3. The correction system of claim 1, wherein the coriolis output signal is a mass flow rate measurement of the fluid flow.

4. The correction system of claim 2, wherein the coriolis output signal is a mass flow rate measurement of the fluid flow.

5. The correction system of claim 1, wherein the coriolis output signal is a density of the fluid flow.

6. The correction system of claim 2, wherein the coriolis output signal is a density of the fluid flow.

7. The correction system of claim 1, wherein the coriolis meter includes a pair of vibrating tubes wherein fluid flows therethrough, the tubes having an inward flow portion and an outward flow portion, and wherein said flow measuring device comprises a first array of sensors arranged on the outward portion of one of the tubes and a second array of sensors arranged on the inward portion of the one of the tubes for determining the speed of sound measurement of the fluid flowing in each respective inward and outward portion of the one of the tubes.

8. The correction system of claim 7, wherein the first and second array of sensors includes strain based sensors.

9. The correction system of claim 1, wherein said flow measuring device comprises a first speed of sound sensing device arranged on the pipe at the input end of the coriolis meter and a second speed of sound sensing device arranged on the pipe at the output end of the coriolis meter, said first and second speed of sound sensing devices performing the speed of sound measurement of the fluid flowing therethrough.

10. A method for correcting a coriolis output signal of a coriolis meter, the coriolis meter being configured to measure a parameter of a fluid flowing in a pipe, and the output signal being indicative of the parameter of the fluid flow, the method comprising:

measuring the speed of sound propagating through the fluid passing through the coriolis meter

providing a correction signal in response to the measured speed of sound; and

determining a corrected coriolis output signal in response to the coriolis output signal and the correction signal.

11. The method of claim 10, wherein providing a correction signal includes providing at least one of an SOS signal indicative of the speed of sound propagating through the fluid, a GVF signal indicative of the gas volume fraction of the fluid and a reduced frequency indicative of the reduced frequency of the fluid.

12. The method of claim 10, wherein the coriolis output signal is a mass flow rate measurement of the fluid flow.

13. The method of claim 11, wherein the coriolis output signal is a mass flow rate measurement of the fluid flow.

14. The method of claim 10, wherein the coriolis output signal is a density of the fluid flow.

15. The method of claim 11, wherein the coriolis output signal is a density of the fluid flow.

16. The method of claim 10, wherein the coriolis meter includes a pair of vibrating tubes wherein fluid flows therethrough, the tubes having an inward flow portion and an outward flow portion, and wherein the measuring the speed of sound includes providing a first array of sensors arranged on the outward portion of one of the tubes and providing a second array of sensors arranged on the inward portion of the one of the tubes for determining the speed of sound measurement of the fluid flowing in each respective inward and outward portion of the one of the tubes.

17. The method of claim 10, wherein the measuring the speed of sound includes providing a first speed of sound sensing device arranged on the pipe at the input end of the coriolis meter and providing a second speed of sound sensing device arranged on the pipe at the output end of the coriolis meter, said first and second speed of sound sensing devices performing the speed of sound measurement of the fluid flowing therethrough.