WET GAS MEASUREMENT

• US 20080257066A1
• Filed: 11/07/2007
• Published: 10/23/2008
• Est. Priority Date: 04/20/2007
• Status: Active Grant

• Current Assignee: Schneider Electric Systems USA, Inc. (Schneider Electric SE)
• Original Assignee: Invensys Systems Incorporated (Invensys PLC)
• Inventors: Henry, Manus P., Tombs, Michael S.
• Granted Patent: US 8,892,371 B2
• Time in Patent Office: Days
• US Class Current: 73/861.356
• CPC Class Codes: G01F 1/8436 signal processing
• CPC Class Codes: G01F 1/8486 with multiple measuring conduits
• CPC Class Codes: G01F 1/849 having straight measuring conduits
• CPC Class Codes: G01N 2009/006 vibrating tube, tuning fork
• 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

Abstract

A first apparent property of a multi-phase process fluid is determined based on the motion of the vibratable flowtube. One or more apparent intermediate values associated with the process fluid are determined based on the first apparent property. One or more corrected intermediate values are determined based on a mapping between the apparent intermediate values and the corrected intermediate values. One or more phase-specific properties of the multi-phase process fluid are determined based on the corrected intermediate values. A measure of wetness of the multi-phase process fluid is determined based on the one or more phase-specific properties that are determined based on the corrected intermediate values. A second apparent property of the multi-phase process fluid is determined using the differential pressure flowmeter. A phase-specific property of a phase of the multi-phase process fluid is determined based on the measure of wetness and the second apparent property.

Claims

1. A method comprising:

passing a multi-phase process fluid through a vibratable flowtube and a differential pressure flowmeter;

inducing motion in the vibratable flowtube;

determining a first apparent property of the multi-phase process fluid based on the motion of the vibratable flowtube;

determining one or more apparent intermediate values associated with the multi-phase process fluid based on the first apparent property;

determining one or more corrected intermediate values based on a mapping between the apparent intermediate values and the corrected intermediate values;

determining one or more estimated phase-specific properties of the multi-phase process fluid based on the corrected intermediate values;

determining a measure of wetness of the multi-phase process fluid based on the one or more estimated phase-specific properties;

determining a second apparent property of the multi-phase process fluid using the differential pressure flowmeter; and

determining a corrected phase-specific property of a phase of the multi-phase process fluid based on the measure of wetness and the second apparent property.

2. The method of claim 1, wherein the mapping is a neural network.

3. The method of claim 1, wherein the multi-phase process fluid is a wet gas.

4. The method of claim 1, wherein:

determining the first apparent property of the multi-phase process fluid includes determining a third apparent property of the multi-phase process fluid based on the motion of the vibratable flowtube; and

determining one or more apparent intermediate values associated with the multi-phase process fluid based on the first apparent property comprises determining one or more apparent intermediate values associated with the multi-phase process fluid based on the first apparent property and the third apparent property.

5. The method of claim 4, wherein the first apparent property of the multi-phase process fluid is an apparent bulk mass flowrate of the multi-phase process fluid and the third apparent property is an apparent bulk density of the multi-phase process fluid.

6. The method of claim 1, wherein determining one or more apparent intermediate values associated with the multi-phase process fluid based on the first apparent property includes determining a volume fraction of the multi-phase process fluid and a volumetric flowrate of the multi-phase process fluid.

7. The method of claim 1, further comprising receiving one or more measurements corresponding to an additional property of the multi-phase process fluid.

8. The method of claim 7, wherein

the additional property of the multi-phase process fluid includes one or more of a temperature of the multi-phase process fluid, a pressure associated with the multi-phase process fluid, or a water-cut of the multi-phase process fluid, and

determining one or more apparent intermediate value associated with the multi-phase process fluid based on the first apparent property includes determining the one or more apparent intermediate values based on the first apparent property and the additional property.

9. The method of claim 1, wherein the measure of wetness is a Lockhart-Martinelli parameter.

10. The method of claim 1, wherein the second apparent property is a mass flowrate of the multi-phase process fluid as a dry gas.

11. The method of claim 1, wherein the differential pressure flowmeter is an orifice plate.

12. The method of claim 1, wherein determining a phase-specific property of the multi-phase process fluid based on the measure of wetness and the second apparent property includes determining a mass flowrate of a gas phase of the multi-phase process fluid.

13. A flowmeter comprising:

a vibratable flowtube, the flowtube being configured to receive a multi-phase process fluid;

a driver connected to the flowtube and configured to impart motion to the flowtube such that the flowtube vibrates;

a sensor connected to the flowtube and configured to sense the motion of the flowtube and generate a sensor signal; and

a controller to receive the sensor signal and configured to;

determine a first apparent property of the multi-phase process fluid based on the motion of the vibratable flowtube;

determine one or more apparent intermediate values associated with the multi-phase process fluid based on the first apparent property;

determine one or more corrected intermediate values based on a mapping between the apparent intermediate values and the corrected intermediate values;

determine one or more estimated phase-specific properties of the multi-phase process fluid based on the corrected intermediate values;

determine a measure of wetness of the multi-phase process fluid based on the one or more estimated phase-specific properties;

receive a second apparent property of the multi-phase process fluid, the second apparent property being determined using a differential pressure flowmeter; and

determine a corrected phase-specific property of a phase of the multi-phase process fluid based on the measure of wetness and the second apparent property.

14. The flowmeter of claim 13, wherein the mapping is a neural network.

15. The flowmeter of claim 13, wherein the multi-phase process fluid is a wet gas.

16. The flowmeter of claim 13, wherein the controller is further configured to:

determine that the first apparent property of the multi-phase process fluid includes determining a third apparent property of the multi-phase process fluid based on the motion of the vibratable flowtube; and

determine that one or more apparent intermediate values associated with the multi-phase process fluid based on the first apparent property comprises determining one or more apparent intermediate values associated with the multi-phase process fluid based on the first apparent property and the third apparent property.

17. The flowmeter of claim 13, wherein to determine one or more apparent intermediate values associated with the multi-phase process fluid based on the first apparent property, the controller is configured to determine a volume fraction of the multi-phase process fluid and a volumetric flowrate of the multi-phase process fluid.

18. The flowmeter of claim 13, wherein the controller is further configured to receive one or more measurements corresponding to an additional property of the multi-phase process fluid.

19. The flowmeter of claim 13, wherein the measure of wetness is a Lockhart-Martinelli parameter.

20. The flowmeter of claim 13, wherein the second apparent property is a mass flowrate of the multi-phase process fluid as a dry gas.

21. The flowmeter of claim 13, wherein to determine a phase-specific property of the multi-phase process fluid based on the measure of wetness and the second apparent property, the controller is configured to determine a mass flowrate of a gas phase of the multi-phase process fluid.

22. A flowmeter transmitter for use with a vibratable flowtube coupled to a differential pressure flowmeter such that a multi-phase process fluid passes through the vibratable flowtube and the differential pressure flowmeter, the flowmeter transmitter comprising:

at least one processing device; and

a storage device, the storage device storing instructions for causing the at least one processing device to;

induce motion in the vibratable flowtube, the vibratable flowtube being configured to receive a multi-phase process fluid;

determine a first apparent property of the multi-phase process fluid based on the motion of the vibratable flowtube;

determine one or more apparent intermediate values associated with the multi-phase process fluid based on the first apparent property;

determine one or more corrected intermediate values based on a mapping between the apparent intermediate values and the corrected intermediate values;

determine one or more estimated phase-specific properties of the multi-phase process fluid based on the corrected intermediate values;

determine a measure of wetness of the multi-phase process fluid based on the one or more estimated phase-specific properties;

receive a second apparent property of the multi-phase process fluid, the second apparent property being determined using a differential pressure flowmeter; and

determine a corrected phase-specific property of a phase of the multi-phase process fluid based on the measure of wetness and the second apparent property.

23. The transmitter of claim 22, wherein the multi-phase process fluid is a wet gas.

24. The transmitter of claim 22, wherein the measure of wetness is a Lockhart-Martinelli parameter.

25. The transmitter of claim 22, wherein the instructions further include instructions for causing the at least one processing device to receive one or more measurements corresponding to an additional property of the multi-phase process fluid.

26. A system comprising:

a vibratable flowtube configured to receive a multi-phase process fluid;

a differential pressure flowmeter coupled to the vibratable flowtube; and

one or more processing devices configured to;

induce motion in the vibratable flowtube;

determine a first apparent property of the multi-phase process fluid based on the motion of the vibratable flowtube;

determine one or more apparent intermediate values associated with the multi-phase process fluid based on the first apparent property;

determine one or more corrected intermediate values based on a mapping between the apparent intermediate values and the corrected intermediate values;

determine one or more estimated phase-specific properties of the multi-phase process fluid based on the corrected intermediate values;

determine a measure of wetness of the multi-phase process fluid based on the one or more estimated phase-specific properties;

receive a second apparent property of the multi-phase process fluid, the second apparent property being determined using the differential pressure flowmeter; and

determining a corrected phase-specific property of a phase of the multi-phase process fluid based on the measure of wetness and the second apparent property.

27. The system of claim 26, wherein:

to determine the first apparent property of the multi-phase process fluid, the one or more processing devices are configured to determine a third apparent property of the multi-phase process fluid based on the motion of the vibratable flowtube; and

to determine one or more apparent intermediate values associated with the multi-phase process fluid based on the first apparent property, the one or more processing devices are configured to determine one or more apparent intermediate values associated with the multi-phase process fluid based on the first apparent property and the third apparent property.

28. The system of claim 26, wherein the one or more processing devices are further configured to receive one or more measurements corresponding to an additional property of the multi-phase process fluid.

29. The system of claim 28, wherein:

the additional property of the multi-phase process fluid includes one or more of a temperature of the multi-phase process fluid, a pressure associated with the multi-phase process fluid, or a water-cut of the multi-phase process fluid, and

to determine one or more apparent intermediate value associated with the multi-phase process fluid based on the first apparent property, the one or more processing devices are configured to determine the one or more apparent intermediate values based on the first apparent property and the additional property.

30. The system of claim 26, wherein to determine a phase-specific property of the multi-phase process fluid based on the measure of wetness and the second apparent property, the one or more processing devices are configured to determine a mass flowrate of a gas phase of the multi-phase process fluid.