Wet gas measurement

• US 9,234,780 B2
• Filed: 09/09/2014
• Issued: 01/12/2016
• Est. Priority Date: 08/28/2006
• 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.
• Primary Examiner(s): Desta, Elias
• Application Number:
  US14/481,616
• Publication Number:
  US 20140373639A1
• Time in Patent Office: 490 Days
• Field of Search: 702/12, 702/45, 702/48, 702/100, 73/542.4, 731/524.7, 738/613.56, 738/613.55
• US Class Current: 1/1
• 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 1/8409 constructional details
• CPC Class Codes: G01F 1/8431 electronic circuits
• CPC Class Codes: G01F 1/8436 signal processing
• CPC Class Codes: G01F 1/8481 having loop-shaped measuring conduits, e.g. the measuring conduits form a loop with a crossing point
• CPC Class Codes: G01F 1/8486 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 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 multi-phase process fluid is passed through a vibratable flowtube. Motion is induced in the vibratable flowtube. A first apparent property of the multi-phase process fluid based on the motion of the vibratable flowtube is determined, and an apparent intermediate value associated with the multi-phase process fluid based on the first apparent property is determined. A corrected intermediate value is determined based on a mapping between the intermediate value and the corrected intermediate value. A phase-specific property of a phase of the multi-phase process fluid is determined based on the corrected intermediate value.

Claims

1. A method of measuring a multi-phase fluid, the method comprising:

passing the multi-phase fluid through a flowtube;

vibrating the flowtube;

using sensors to sense motion of the flowtube, each sensor generating a signal indicative of the motion of a different portion of the flowtube;

determining, by a controller, an apparent mass flow rate of the multi-phase process fluid based on a phase difference between the signals from the sensors;

determining, by the controller, an apparent intermediate value associated with the multi-phase fluid using the apparent mass flow rate;

determining, by the controller, a corrected intermediate value based on a mapping between the apparent intermediate value and the corrected intermediate value; and

determining, by the controller, a phase-specific mass flow rate of a phase of the multi-phase fluid based on the corrected intermediate value.

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

3. The method of claim 2, further comprising:

determining that the apparent intermediate value is within a first defined region of values prior to determining the corrected intermediate value; and

determining that the corrected intermediate value is within a second defined region of values prior to determining the phase-specific mass flow rate.

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

5. The method of claim 4, wherein the multi-phase fluid includes a first phase and a second phase, the first phase includes a non-gas fluid, and the second phase includes a gas.

6. The method of claim 4, wherein the multi-phase fluid includes a first phase including a first non-gas fluid, and a second phase including a second non-gas fluid, and a third phase including a gas.

7. The method of claim 1, further comprising determining an apparent density of the multi-phase fluid based on the signals from the sensors.

8. The method of claim 7, further comprising determining a phase-specific density of the multi-phase fluid.

9. The method of claim 1 further comprising receiving one or more measurements corresponding to an additional property of the fluid.

10. The method of claim 9 wherein the additional property of the multi-phase fluid includes one or more of a temperature of the multi-phase fluid, a pressure associated with the multi-phase fluid, and a watercut of the multi-phase fluid;

and wherein determining an apparent intermediate value associated with the multi-phase fluid includes determining the intermediate value based on the apparent mass flow rate and the additional property.

11. The method of claim 1, wherein determining an apparent intermediate value associated with the multi-phase fluid based on the mass flow rate includes determining a volume fraction associated with an amount of non-gas fluid in the multi-phase fluid and a volumetric flow rate of the multi-phase fluid.

12. The method of claim 1, wherein determining an apparent intermediate value associated with the multi-phase fluid based on the apparent mass flow rate includes determining a first Froude number corresponding to a non-gas phase of the multi-phase fluid and a second Froude number corresponding to a gas phase of the multi-phase fluid.

13. The method of claim 1, wherein determining a phase-specific mass flow rate of a phase of the multi-phase fluid comprises determining a mass flow rate of a non-gas phase of the multi-phase fluid.

14. A flowmeter comprising:

a flowtube for containing a multi-phase fluid;

a driver connected to the flowtube and configured to vibrate the flowtube;

a pair of sensors connected to the flowtube at different locations on the flowtube and configured to output sensor signals indicative of the flowtube motion at said locations; and

a controller configured to;

receive the sensor signals;

determine an apparent mass flow rate of the multi-phase fluid based on a phase difference between the sensor signals;

determine an apparent intermediate value associated with the multi-phase fluid based on the apparent mass flow rate;

determine a corrected intermediate value based on a mapping between the apparent intermediate value and the corrected intermediate value; and

determine a phase-specific mass flow rate of a phase of the multi-phase fluid based on the corrected intermediate value.

15. The flowmeter of claim 14 wherein the mapping is a neural network configured to determine an error in the intermediate value resulting from the presence of the multi-phase fluid.

16. The flowmeter of claim 14, wherein the controller is further configured to:

determine that the apparent intermediate value is within a first defined region of values prior to determining the corrected intermediate value; and

determine that the corrected intermediate value is within a second defined region of values prior to determining the phase-specific mass flow rate of a phase of the multi-phase fluid.

17. The flowmeter of claim 14, wherein the multi-phase fluid is a wet gas.

18. The flowmeter of claim 14, wherein determining the apparent mass flow rate of the multi-phase fluid includes determining an apparent density of the multi-phase fluid.

19. The flowmeter of claim 14, wherein determining an apparent intermediate value associated with the multi-phase fluid based on the first apparent property includes determining a first Froude number corresponding to a non-gas phase of the multi-phase fluid and a second Froude number corresponding to a gas phase of the multi-phase fluid.

20. A transmitter for a Coriolis flowmeter of the type having a flowtube for containing a multi-phase fluid, a driver connected to the flowtube and configured to vibrate the flowtube, and a pair of sensors connected to the flowtube at different locations on the flowtube and configured to output sensor signals indicative of the flowtube motion at said locations, the transmitter comprising:

a controller configured to;

receive the sensor signals;

determine an apparent mass flow rate of the multi-phase fluid based on a phase difference between the sensor signals;

determine an apparent intermediate value associated with the multi-phase fluid based on the apparent mass flow rate;

determine a corrected intermediate value based on a mapping between the apparent intermediate value and the corrected intermediate value; and

determine a phase-specific mass flow rate of a phase of the multi-phase fluid based on the corrected intermediate value.