Multiphase Coriolis flowmeter

• US 7,207,229 B2
• Filed: 02/01/2006
• Issued: 04/24/2007
• Est. Priority Date: 02/10/2003
• Status: Active Grant

• Current Assignee: Schneider Electric Systems USA, Inc. (Schneider Electric SE)
• Original Assignee: Invensys Systems Incorporated (Invensys PLC)
• Inventors: Mattar, Wade M., Henry, Manus P., Duta, Mihaela D., Tombs, Michael S.
• Primary Examiner(s): THOMPSON, JEWEL VERGIE
• Application Number:
  US11/344,140
• Publication Number:
  US 20060161366A1
• Time in Patent Office: 447 Days
• Field of Search: 738/610.4, 738/613.56, 738/613.57, 73/614.1
• US Class Current: 73/861.354
• 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 1/8436 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: G01F 25/10 of flowmeters
• CPC Class Codes: G01N 2009/006 vibrating tube, tuning fork
• CPC Class Codes: G01N 33/2823 Raw oil, drilling fluid or polyphasic mixtures

Abstract

A flowmeter is disclosed. The flowmeter includes a vibratable flowtube, and a driver connected to the flowtube that is operable to impart motion to the flowtube. A sensor is connected to the flowtube and is operable to sense the motion of the flowtube and generate a sensor signal. A controller is connected to receive the sensor signal. The controller is operable to determine a first flow rate of a first phase within a two-phase flow through the flowtube and determine a second flow rate of a second phase within the two-phase flow.

Claims

1. A flowmeter comprising:

a vibratable flowtube;

a driver connected to the flowtube and operable to impart motion to the flowtube;

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

a controller connected to receive the sensor signal, the controller being operable to determine a first flow rate of a first phase within a two-phase flow through the flowtube and determine a second flow rate of a second phase within the two-phase flow.

2. The flowmeter of claim 1 wherein the first phase includes a gas and the second phase includes a liquid.

3. The flowmeter of claim 1 wherein the controller is operable to input an apparent density of the two-phase flow detected by the flowmeter and output a corrected density of the two-phase flow.

4. The flowmeter of claim 3 wherein the controller is operable to correct the apparent density based on a theoretical relationship between the apparent density and the corrected density.

5. The flowmeter of claim 3 wherein the controller is operable to correct the apparent density based on an empirical relationship between the apparent density and the corrected density.

6. The flowmeter of claim 3 wherein the controller is operable to correct the apparent density based on a table storing relationships between the apparent density and the corrected density.

7. The flowmeter of claim 1 wherein the controller is operable to input an apparent mass flow rate of the two-phase flow detected by the flowmeter and output a corrected mass flow rate of the two-phase flow.

8. The flowmeter of claim 7 wherein the controller is operable to correct the apparent mass flow rate based on a theoretical relationship between the apparent mass flow rate and the corrected mass flow rate.

9. The flowmeter of claim 7 wherein the controller is operable to correct the apparent mass flow rate based on an empirical relationship between the apparent mass flow rate and the corrected mass flow rate.

10. The flowmeter of claim 1 wherein the controller is operable to input an apparent first phase fraction of the two-phase flow detected by the flowmeter that defines an amount of the first phase in the two-phase flow and output a corrected first phase fraction of the two-phase flow.

11. The flowmeter of claim 1 wherein the controller is operable to input a first phase fraction of the two-phase flow detected by a phase fraction sensor that is external to the flowmeter.

12. The flowmeter of claim 1 wherein the controller is operable to determine the first flow rate and the second flow rate based on corrected values for a detected density and detected mass flow rate of the two-phase flow.

13. The flowmeter of claim 12 wherein the controller is operable to determine the first flow rate and the second flow rate based on a corrected value for a detected first phase fraction that defines an amount of the first phase in the two-phase flow.

14. The flowmeter of claim 1 wherein the controller is operable to determine the first flow rate and the second flow rate based on densities of the first phase and the second phase, respectively.

15. The flowmeter of claim 1 wherein the controller is operable to determine a first superficial velocity of the first phase and a second superficial velocity of the second phase, based on the first flow rate and the second flow rate, respectively.

16. The flowmeter of claim 15 wherein the controller is operable to determine a flow regime of the two-phase flow, based on the first superficial velocity and the second superficial velocity.

17. The flowmeter of claim 16 wherein the controller is operable to determine a slip velocity between the first phase and the second phase, based on an average velocity of the first phase and an average velocity of the second phase.

18. The flowmeter of claim 17 wherein the controller is operable to provide corrections to the first flow rate and the second flow rate, based on the first and second superficial velocities, the determined flow regime, or the slip velocity, to thereby obtain a corrected first flow rate and a corrected second flow rate.

19. A method comprising:

determining a bulk density of a two-phase flow through a flowtube, the two-phase flow including a first phase and a second phase;

determining a bulk mass flow rate of the two-phase flow; and

determining a first mass flow rate of the first phase, based on the bulk density and the bulk mass flow rate.

20. A flowmeter controller comprising:

a density correction system operable to input an apparent density of a two-phase flow and output a corrected density of the two-phase flow, the two-phase flow including a first phase and a second phase;

a mass flow rate correction system operable to input an apparent mass flow rate of the two-phase flow and output a corrected mass flow rate of the two-phase flow; and

a flow component mass flow rate determination system operable to determine a first mass flow rate of the first phase, based on the corrected density and the corrected mass flow rate.

21. A method comprising:

passing a two-phase flow through a vibratable flowtube, the two-phase flow having a first phase and a second phase;

imparting motion to the flowtube using a driver;

sensing the motion of the flowtube using a sensor;

determining a first flow rate of the first phase within the two-phase flow passing through the flowtube; and

determining a second flow rate of the second phase within the two-phase flow passing through the flowtube.

22. The method of claim 21 wherein the first phase includes a gas and the second phase includes a liquid.

23. The method of claim 21 further comprising correcting an apparent density of the two-phase flow to obtain a corrected density of the two-phase flow.

24. The method of claim 21 further comprising correcting an apparent mass flow rate of the two-phase flow to obtain a corrected mass flow rate of the two-phase flow.

25. The method of claim 21 further comprising correcting an apparent first phase fraction of the two-phase flow that defines an amount of the first phase in the two-phase flow to obtain a corrected first phase fraction of the two-phase flow.

26. The method of claim 21 further comprising detecting a first phase fraction of the two-phase flow using a phase fraction sensor.

27. The method of claim 21 wherein determining the first flow rate includes determining the first flow rate based on corrected values for a detected density and detected mass flow rate of the two-phase flow.

28. The method of claim 27 wherein determining the first flow rate includes determining the first flow rate based on a corrected value for a detected first phase fraction that defines an amount of the first phase in the two-phase flow.

29. The method of claim 21 determining the first flow rate includes determining the first flow rate based on densities of the first phase and the second phase, respectively.

30. The method of claim 21 further comprising determining a first superficial velocity of the first phase and a second superficial velocity of the second phase based on the first flow rate and the second flow rate, respectively.

31. The method of claim 30 further comprising determining a flow regime of the two-phase flow, based on the first superficial velocity and the second superficial velocity.

32. The method of claim 31 further comprising determining a slip velocity between the first phase and the second phase, based on an average velocity of the first phase and an average velocity of the second phase.

33. The method of claim 32 further comprising providing corrections to the first flow rate and the second flow rate, based on the first and second superficial velocities, the determined flow regime, or the slip velocity, to thereby obtain a corrected first flow rate and a corrected second flow rate.

34. A flowmeter comprising:

a vibratable flowtube;

a driver connected to the flowtube and operable to impart motion to the flowtube;

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

a controller connected to receive the sensor signal, the controller being operable to determine a bulk density of a two-phase flow through a flowtube, the two-phase flow including a first phase and a second phase, determine a bulk mass flow rate of the two-phase flow, and determine a first mass flow rate of the first phase, based on the bulk density and the bulk mass flow rate.

35. A method comprising:

correcting an apparent density of a two-phase flow to obtain a corrected density of the two-phase flow, the two-phase flow including a first phase and a second phase;

correcting an apparent mass flow rate of the two-phase flow to obtain a corrected mass flow rate of the two-phase flow; and

determining a mass flow rate of the first phase, based on the corrected density and the corrected mass flow rate of the two-phase flow.