Correcting for Two-Phase Flow in a Digital Flowmeter

• US 20090019947A1
• Filed: 07/14/2008
• Published: 01/22/2009
• Est. Priority Date: 11/22/1999
• Status: Active Grant

• Current Assignee: Schneider Electric Systems USA, Inc. (Schneider Electric SE)
• Original Assignee: Invensys Systems Incorporated (Invensys PLC)
• Inventors: de la Fuente, Maria Jesus, Henry, Manus P.
• Granted Patent: US 7,784,360 B2
• Time in Patent Office: Days
• US Class Current: 73/861.356
• 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 15/024 involving digital counting

Abstract

A flowmeter is disclosed. The flowmeter includes a vibratable conduit, and a driver connected to the conduit that is operable to impart motion to the conduit. A sensor is connected to the conduit and is operable to sense the motion of the conduit and generate a sensor signal. A controller is connected to receive the sensor signal. The controller is operable to detect a single-phase flow condition and process the sensor signal using a first process during the single-phase flow condition to generate a validated mass-flow measurement. The controller is also operable to detect a two-phase flow condition and process the sensor signal using a second process during the two-phase flow condition to generate the validated mass-flow measurement.

Claims

1. A flow measurement system comprising:

an input module operable to receive an analog sensor signal from a sensor connected to a vibratable flowtube, the analog sensor signal related to a process fluid through the flowtube, wherein the process fluid includes a liquid medium and a gas;

a signal processing system operable to determine sensor signal characteristics from a digitized version of the sensor signal, and further operable to determine drive signal characteristics for a drive signal to be applied to the flowtube such that a drive phase of the drive signal substantially matches a sensor phase of the analog sensor signal;

a measurement system operable to determine a property of the process fluid, based on the sensor signal characteristics; and

an output module operable to output the drive signal to the flowtube to maintain an oscillation of the flowtube while the process fluid is contained therein.