Mass flow rate measurement device

Patent metadata

Field	Value
Publication number	US-11644355-B2
Application number	US-201917275072-A
Country	US
Kind code	B2
Filing date	Sep 3, 2019
Priority date	Sep 13, 2018
Publication date	May 9, 2023
Grant date	May 9, 2023

Abstract

A device for measuring the mass flow rate, including a flow pipe; a first set of actuators which are arranged in a first plane including a first transverse cross section of the pipe and perpendicular to the fluid flow path, these being configured to move selectively in the first plane; a control circuit configured to control a movement of the first and second actuators so that the cross-sectional area for flow through the pipe in the first plane remains constant; a measurement sensor measuring a force or a stress in a direction perpendicular to the flow path, in the vicinity of the actuators of the first set along the flow path; a computation device configured to calculate the mass flow rate passing through the flow pipe as a function of the force or stress measured by the sensor.

First claim

The invention claimed is:

1. A device for measuring mass flow rate, comprising:
a flow tube defining a fluid-flow path;
a first group of actuators, including at least first and second actuators placed in a first plane including a first cross section of the tube and perpendicular to the fluid-flow path, the actuators of the first group being configured to move selectively in the first plane;
a control circuit configured to control a movement of the first and second actuators of the first group so that the area of the cross section of the flow through the tube in the first plane remains constant, said actuators of the first group being controlled with acceleration setpoints or with setpoints for an amount of movement in the first plane;
at least one sensor for measuring a force or a stress in a direction perpendicular to the flow path, said measuring sensor being placed in proximity to the actuators of the first group on the flow path and furthermore being configured to measure a force in said direction perpendicular to the flow path;
a computing device configured to compute the mass flow rate passing through the flow tube depending on the force or the stress measured by said sensor,
wherein said actuators of the first group are configured to selectively form a recess or protrusion with respect to the tube, said recess and said protrusion having an area Aa in the first plane, the flow area in the tube level with the first plane being denoted by Ac, the following relationship being respected:
Ac/Aa> 10.

2. The device for measuring mass flow rate as claimed in claim 1 , wherein said mass flow rate is computed using the following relationship,

F
c

=

2
⁢

∂
2

v

∂
x

⁢

∂
t

⁢

q
m

[

Math
.

98

]

with Fc a force measured by the sensor, qm the mass flow rate of fluid passing through the flow tube, v an amplitude of transverse movement of the fluid in the tube, x the longitudinal position of the fluid in the tube, and t time.

3. The device for measuring mass flow rate as claimed in claim 1 , wherein the first group of actuators includes at least two actuators positioned in opposite positions on the first cross section.

4. The device for measuring mass flow rate as claimed in claim 1 , wherein the area of the cross section of the flow in the first plane is at least equal to 5 mm 2 .

5. The device for measuring mass flow rate as claimed in claim 1 , wherein said actuators of the first group are configured to modify the shape of the cross section of the tube in the first plane.

6. The device for measuring mass flow rate as claimed in claim 1 , wherein said sensor is a first sensor, the device furthermore comprising a second sensor placed on the side opposite the first sensor with respect to the flow path.

7. The device for measuring mass flow rate as claimed in claim 6 , wherein said first and second sensors are placed in the same plane perpendicular to the flow path of the flow through the tube.

8. The device for measuring mass flow rate as claimed in claim 7 , wherein the computing device is configured to compute the mass flow rate depending on a difference between the measurements of the first and second sensors.

9. The device for measuring mass flow rate as claimed in claim 6 , wherein said computing device is configured to filter the measurements of the first and second sensors to preserve terms in quadrature with the excitation of the actuators of the first group, and configured to subtract these quadrature terms in order to compute the mass flow rate.

10. The device for measuring mass flow rate as claimed in claim 1 , wherein the distance between said first and second actuators is larger than the distance between the first actuator and the first sensor.

11. The device for measuring mass flow rate as claimed in claim 1 , wherein one of the actuators of the first group comprises a membrane capable of moving so as to become the recess or the protrusion with respect to the tube in the first plane.

12. The device for measuring mass flow rate as claimed in claim 1 , furthermore comprising:
a second group of actuators including at least two actuators placed in a second plane including a second cross section of the tube and perpendicular to the fluid-flow path, the second plane being distant from the first along said flow path, each of the actuators of the second group being configured to move selectively in the second plane;
the control circuit being configured to control a movement of the actuators of the second group so that the area of the cross section of the flow through the tube in the second plane remains constant.

13. The device for measuring mass flow rate as claimed in claim 12 , wherein said control circuit is configured for a movement of the actuators of the first group at a frequency at least equal to 20 KHz.

14. The device for measuring mass flow rate as claimed in claim 13 , wherein said control circuit is configured for a movement of the actuators of the second group at a frequency at least equal to 20 KHz, the frequency of the second group of actuators being different than the frequency of the first group of actuators.

15. The device for measuring mass flow rate as claimed in claim 1 , wherein the computing device is configured to filter the measurements of the sensor to preserve terms in quadrature with the excitation of one at least of the actuators of the first group.

16. The device for measuring mass flow rate as claimed in claim 1 , wherein the flow tube has a flow direction in normal operation, and wherein said sensor is placed downstream, in said flow direction, with respect to the actuators of the first group of actuators.

17. The device for measuring mass flow rate as claimed in claim 1 , wherein the first and second actuators include membranes made of silicon, SiC, silica in amorphous or crystalline form, silicon nitride, diamond or sintered ceramic.

18. The device for measuring mass flow rate as claimed in claim 1 , wherein the first and second actuators include seal-tight membranes and piezoelectric elements that stress the seal-tight membranes.

19. The device for measuring mass flow rate as claimed in claim 1 , wherein the sensor is a piezoelectric sensor or a capacitive sensor.

Assignees

• Commissariat Energie Atomique
• Safran

Inventors

• Palacios Laloy Agustin
• Riou Jean-Christophe

Classifications

• G01F1/8463

  the measuring conduits' cross-section being deformed during measurement, e.g. by periodically deflecting a portion of the conduits' surface · CPC title

• G01F1/8472

  having curved measuring conduits, i.e. whereby the measuring conduits' curved center line lies within a plane (G01F1/8481 takes precedence) · CPC title

• G01F1/8422 Primary

  exciters · CPC title

• G01F1/8431

  electronic circuits · CPC title

• G01F1/8427

  detectors · CPC title