Method for measuring a speed of a fluid

Patent metadata

Field	Value
Publication number	US-2020232829-A1
Application number	US-201816605451-A
Country	US
Kind code	A1
Filing date	Mar 30, 2018
Priority date	Apr 25, 2017
Publication date	Jul 23, 2020
Grant date	—

Abstract

Method for measuring a speed of a fluid, implemented by an ultrasonic flow meter comprising a reflector mirror positioned between two transducers, the measuring method comprising measurement phases in which: one of the two transducers emits an ultrasonic measurement signal; the other of the two transducers receives the ultrasonic measurement signal after it has completed a measurement trip; the processing means evaluate the speed of the fluid depending on a measurement trip time; the measurement method furthermore comprising compensation phases in which: one of the two transducers emits an ultrasonic compensation signal; said transducer receives the ultrasonic compensation signal after it has completed a compensation trip during which it was reflected by the reflector mirror; the processing means compensate for a measurement drift of said transducer by adjusting the measurement trip time depending on a compensation trip time.

First claim

1 . A method of measuring a speed of a fluid, the method being performed by an ultrasonic fluid meter having two transducers, a reflector mirror positioned between the two transducers, and processor means, the measurement method comprising measurement stages, each comprising measurement steps, during which:
one of the two transducers emits an ultrasound measurement signal; the other one of the two transducers receives the ultrasound measurement signal after it has travelled along a measurement path; the processor means evaluate the speed of the fluid as a function of a measured time of flight taken by the ultrasound measurement signal to travel along the measurement path; the measurement method further comprising compensation stages, each comprising compensation steps, during which: one of the two transducers emits an ultrasound compensation signal; said transducer receives the ultrasound compensation signal after it has travelled along a compensation path during which it is reflected by the reflector mirror; the processor means compensate any measurement drift of said transducer by adjusting the measured time of flight as a function of a compensation time of flight taken by the ultrasound compensation signal to travel along the compensation path.

2 . The measurement method according to claim 1 , wherein the ultrasonic fluid meter also includes a temperature sensor, and wherein the processor means also adjust the measured time of flight as a function of a measured temperature of the fluid during the measurement stage.

3 . The measurement method according to claim 2 , wherein the ultrasonic fluid meter further includes a memory storing a reference table comprising reference temperature values, and together with each reference temperature value, a reference time taken by an ultrasound reference signal to travel along the compensation path when the ageing of the transducers is negligible, and wherein the adjustment of the measured time of flight consists in extracting a reference time from the reference table corresponding to a reference temperature identical to the measured temperature, and in adding to or subtracting from the measured time of flight a difference between the compensation time of flight and the reference time.

4 . The measurement method according to claim 3 , wherein the compensation stages include training stages, during which:
the temperature sensor measures the temperature of the fluid and produces reference temperatures; for each reference temperature, the processor means measure the reference time taken by the ultrasound reference signal to travel along the compensation path, and incorporate the reference temperature and the reference time in the reference table.

5 . The measurement method according to claim 4 , wherein the training stages are performed during a preliminary period of predetermined duration that begins after installing the ultrasonic fluid meter.

6 . The measurement method according to claim 3 , wherein the reference table is filled in prior to installing the ultrasonic fluid meter.

7 . An ultrasonic fluid meter comprising a duct incorporating two transducers and a reflector mirror positioned between the two transducers, and processor means arranged to perform the measurement method according to claim 1 .

8 . The ultrasonic fluid meter according to claim 7 , including two reflector mirrors, each reflector mirror being positioned in the proximity of a respective one of the transducers.

9 . The ultrasonic fluid meter according to claim 7 , wherein the transducers are piezoelectric transducers.

10 . The ultrasonic fluid meter according to claim 7 , wherein each of the transducers and the reflector mirror is annular in shape and fits closely to an inside wall of the duct.

11 . The ultrasonic fluid meter according to claim 10 , wherein the width of each transducer lies in the range 8% to 12% of an inside diameter of the duct, and wherein the width of the reflector mirror lies in the range 3% to 5% of the inside diameter of the duct.

12 . A computer program including instructions for enabling an ultrasonic fluid meter to perform the measurement method according to claim 1 .

13 . Storage means wherein they store a computer program including instructions for enabling an ultrasonic fluid meter to perform the measurement method according to claim 1 .

Assignees

• Sagemcom Energy & Telecom Sas

Inventors

• Teboulle Henri

Classifications

• G01F1/7082 Primary

  using acoustic detecting arrangements · CPC title

• G01F25/10

  of flowmeters · CPC title

• G01F1/668

  Compensating or correcting for variations in velocity of sound · CPC title

• G01F15/02

  Compensating or correcting for variations in pressure, density or temperature · CPC title

• G01F1/662 Primary

  Constructional details · CPC title