Flow-Rate Measurement Assembly According to the Differential-Pressure Measurement Principle

• US 20170328750A1
• Filed: 11/18/2015
• Published: 11/16/2017
• Est. Priority Date: 12/19/2014
• Status: Active Grant

• Current Assignee: Endress+Hauser SE+Co. KG (Endress+Hauser AG)
• Original Assignee: Endress + Hauser GmbH + Company KG (Endress+Hauser AG)
• Inventors: Jehle, Max, Parrotto, Davide
• Granted Patent: US 10,006,790 B2
• Time in Patent Office: Days
• CPC Class Codes: G01F 1/363 with electrical or electro-mechanical indication G01F1/37 and G01F1/38 take precedence
• CPC Class Codes: G01F 1/40 Details of construction of the flow constriction devices
• CPC Class Codes: G01F 1/42 Orifices or nozzles
• CPC Class Codes: G01F 25/10 of flowmeters

Abstract

The invention relates to a flow-rate measurement assembly for measuring a flow rate of a medium (2) through a measurement pipe (3), comprising at least one differential-pressure producer (4), which is located in the measurement pipe (3) and which effects a drop in the media pressure, which drop depends upon the flow rate, and comprising a differential-pressure measurement transducer (5) for providing a differential-pressure measurement signal (22), which depends upon the difference between the high-pressure-side media pressure and the low-pressure-side media pressure, wherein the difference is a measure of the flow rate of the medium (2), wherein the evaluating unit (10) is designed to determine a relationship between the differential-pressure measurement signal (22) and a characteristic parameter of a fluctuation of the differential-pressure measurement signal (22), to judge the determination of a monotonically decreasing relationship between the differential-pressure measurement signal (22) and the characteristic parameter to be an indication of a clogged high-pressure line (6), and to judge the determination of a monotonically increasing relationship between the differential-pressure measurement signal (22) and the characteristic parameter, the monotonically increasing relationship of which is significantly stronger than the monotonically increasing relationship of an unclogged flow-rate measurement assembly, as an indication of a clogged low-pressure line (8).

Claims

1. Flow-rate measurement assembly for measuring a flow rate of a medium (2) through a measurement pipe (3), comprising at least one differential-pressure producer (4) located in the measurement pipe (3), which producer especially brings about a reduction of a cross-sectional area through which the medium (2) flows inside the measurement pipe (3) in the region of the differential-pressure producer (4) and thus a drop in the media pressure dependent upon the dimensions of the differential-pressure producer (4) and upon the flow rate, comprising:

a differential-pressure measurement transducer (5) for detecting a difference between a high-pressure-side media pressure and a low-pressure-side media pressure and for providing a differential-pressure measurement signal (22), which depends upon the difference between the high-pressure-side media pressure and the low-pressure-side media pressure, wherein the difference between the high-pressure-side media pressure and the low-pressure-side media pressure is a measure for the flow rate of the medium (2),

a high-pressure line (6), which is connected to a high-pressure inlet (7) of the differential-pressure measurement transducer (5) in order to apply the high-pressure-side media pressure to the differential-pressure measurement transducer (5),

a low-pressure line (8), which is connected to a low-pressure inlet (9) of the differential-pressure measurement transducer (5) in order to apply the low-pressure-side media pressure to the differential-pressure measurement transducer (5), and

an evaluating unit (10) for evaluating the differential-pressure measurement signal (22), wherein the evaluating unit (10) is designed to

determine a relationship between the differential-pressure measurement signal (22) and a characteristic parameter of a noise or of a fluctuation in the differential-pressure measurement signal (22),

judge the determination of a monotonically decreasing relationship between the differential-pressure measurement signal (22) and the characteristic parameter to be an indication of a clogged high-pressure line (6), and

judge the determination of a monotonically increasing relationship between the differential-pressure measurement signal (22) and the characteristic parameter, the monotonically increasing relationship of which is significantly stronger than the monotonically increasing relationship of an unclogged flow-rate measurement assembly, as an indication of a clogged low-pressure line (8).

2. Flow-rate measurement assembly according to claim 1, wherein the monotonically increasing or decreasing relationship between the differential-pressure measurement signal (22) and the characteristic parameter is approximately modeled by a linearly increasing or decreasing function, and wherein the significantly more strongly monotonically increasing relationship is an approximately linearly increasing function, the linear coefficient of which is significantly greater than the error-corrected linear coefficient of a linearly increasing function of an unclogged flow-rate measurement assembly.

3. Flow-rate measurement assembly according to claim 1, wherein the monotonically increasing or decreasing relationship between the differential-pressure measurement signal (22) and the characteristic parameter is approximately modeled by a quadratically increasing or decreasing function, and wherein the significantly more strongly monotonically increasing relationship is an approximately quadratically increasing function, the coefficient of the square term of which is significantly greater than the error-corrected coefficient of the square term of a quadratically increasing function of an unclogged flow-rate measurement assembly.

4. Method for monitoring a flow-rate measurement assembly—

especially, according to claim 1—

comprising the method steps of;

at least temporarily detecting a time curve of the differential-pressure measurement signal (22) and a characteristic parameter of a noise or a fluctuation in the differential-pressure measurement signal (22), determining a relationship between the differential-pressure measurement signal (22) and a characteristic parameter of a noise or a fluctuation in the differential-pressure measurement signal (22), wherein the determination of a monotonically decreasing relationship between the differential-pressure measurement signal (22) and the characteristic parameter is to be judged as an indication of a clogged high-pressure line (6), and the determination of a monotonically increasing relationship between the differential-pressure measurement signal (22) and the characteristic parameter, the monotonically increasing relationship of which is significantly stronger than the monotonically increasing relationship of an unclogged flow-rate measurement assembly, is to be judged as an indication of a clogged low-pressure line (8).