Method for operating a flowmeter and respective flowmeter

Patent metadata

Field	Value
Publication number	US-10215607-B2
Application number	US-201615150854-A
Country	US
Kind code	B2
Filing date	May 10, 2016
Priority date	May 11, 2015
Publication date	Feb 26, 2019
Grant date	Feb 26, 2019

Abstract

Described and shown is a method for operating a flowmeter (1) having a measuring tube (2), wherein the flow (d) of a medium (4) through the measuring tube (2) is measured. A continuous dwell time of the measured flow (d) greater than or equal to a flow threshold (ds) is assigned to a flow interval (ΔtD,1, ΔtD,2) and a flow volume (V1, V2) is determined from the measured flow (d) in the flow interval (ΔtD,1, ΔtD,2). In each case, a continuous dwell time of the measured flow (d) less than the flow threshold (ds) is assigned to a zero flow interval (ΔtN,1). In each case, a deviation volume of the flow volume (V1, V2) in one of the flow intervals (ΔtD,1, ΔtD,2) from a reference flow volume is determined and the deviation volume is compared to a threshold deviation volume. If the deviation volume in one of the flow intervals (ΔtD,1, ΔtD,2) is less than the threshold deviation volume, a zero flow through the measuring tube (2) is determined and compensated using the measured flow (d) in the zero flow interval (ΔtN,1) directly preceding the flow interval (ΔtD,1, ΔtD,2).

First claim

What is claimed is:

1. A method for operating a flowmeter having a measuring tube,
wherein the flow (d) of a medium through the measuring tube is measured,
wherein
in a first flow interval (Δt D,1 ), a first continuous dwell time of the measured flow (d) greater than or equal to a flow threshold (d s ) is assigned to the first flow interval (Δt D,1 ) and a first flow volume (V 1 ) is determined from the measured flow (d) in the first flow interval (Δt D,1 ),
in a zero flow interval (Δt N,1 ), a continuous dwell time of the measured flow (d) less than the flow threshold (d s ) is assigned to the zero flow interval (Δt N,1 ),
in a second flow interval (Δt D,2 ), a second continuous dwell time of the measured flow (d) greater than or equal to a flow threshold (d s ) is assigned to the second flow interval (Δt D,2 ) and a second flow volume (V 2 ) is determined from the measured flow (d) in the second flow interval (Δt D,2 ),
a first deviation volume of the first flow volume (V 1 ) in the first flow interval (Δt D,1 ) and a second deviation volume of the second flow volume (V 2 ) in the second flow interval (Δt D,2 ), from a reference flow volume are determined and the first deviation volume and the second deviation volume are compared to a threshold deviation volume,
when the first deviation volume is less than the threshold deviation volume, a zero flow through the measuring tube is determined and compensated using the measured flow (d) in the zero flow interval (Δt N,1 ) directly preceding the first flow interval (Δt D,1 ), and
when the second deviation volume is less than the threshold deviation volume, a zero flow through the measuring tube is determined and compensated using the measured flow (d) in the zero flow interval (Δt N,1 ) directly preceding the second flow interval (Δt D,2 ).

2. The method according to claim 1 , wherein the reference flow volume is determined from at least one of the first flow volumes (V 1 ) or the second flow volume (V 2 ).

3. The method according to claim 2 , wherein the reference flow volume is determined in that one of the first flow volumes (V 1 ) or the second flow volume (V 2 ) is assigned to the reference flow volume.

4. The method according to claim 2 , wherein the reference flow volume is determined in that an average value of at least two of the flow volumes is determined and assigned to the reference flow volume.

5. The method according to claim 1 , wherein the first flow volume (V 1 ) is determined in a first sub-interval of the first flow interval (Δt D,1 ), and the second flow volume (V 2 ) is determined in a second sub-interval of the second flow interval (Δt D,2 ).

6. The method according to claim 1 , wherein the measured flow (d), in each case, is used in a sub-interval (Δt′ N,1 ) of a zero flow interval (Δt N,1 ).

7. The method according to claim 1 , wherein, when the first deviation volume is less than the threshold deviation volume, a continuous dwell time of the measured volume (d) less than the flow threshold (d s ) is assigned to the zero flow interval (Δt N,1 ), wherein the zero flow interval (Δt N,1 ) directly precedes the first flow interval (Δt D,1 ), and when the second deviation volume is less than the threshold deviation volume, a continuous dwell time of the measured volume (d) less than the flow threshold (d s ) is assigned to the zero flow interval (Δt N,1 ), wherein the zero flow interval (Δt N,1 ) directly precedes the second flow interval (Δt D,2 ).

8. The method according to claim 1 , wherein the zero flow is determined using the measured flow (d) of at least two zero flow intervals (Δt N,1 ), in that a moving average is formed from the measured flow (d) in the at least two zero flow intervals (Δt N,1 ) or in that a median filter is used on the measured flow (d) in the at least two zero flow intervals (Δt N,1 ).

9. A flowmeter having a measuring tube and a controller,
wherein the controller measures the flow (d) of a medium through the measuring tube during operation,
wherein, during operation, the controller
stores a flow threshold (d s ), a reference flow volume and a threshold deviation volume,
assigns, in a first flow interval (Δt D,1 ), a first continuous dwell time of the measured flow (d) greater or equal to the flow threshold (d s ) to the first flow interval (Δt D,1 ) and determines a first flow volume (V 2 ) from the measured flow (d) in the first flow interval (Δt D,2 ),
assigns a continuous dwell time of the measured flow (d) less than the flow threshold (d s ) to the zero flow interval (Δt N,1 ),
assigns, in a second flow interval (Δt D,2 ), a second continuous dwell time of the measured flow (d) greater or equal to the flow threshold (d s ) to the second flow interval (Δt D,2 ) and determines a second flow volume (V 2 ) from the measured flow (d) in the second flow interval (Δt D,2 ),
determines a first deviation volume of the first flow volume (V 1 ) in the first flow intervals (Δt D,1 ) and a second deviation volume of the second flow volume (V 2 ) in the second flow interval (Δt D,2 ), from the reference flow volume and compares the first deviation volume and the second deviation volume to the threshold deviation volume,
when the first deviation volume is less than the threshold deviation volume, determines and compensates the zero flow through the measuring tube using the measured flow (d) in the zero flow interval (Δt N,1 ) directly preceding the first flow interval (Δt D,1 ), and
when the second deviation volume is less than the threshold deviation volume, determines and compensates the zero flow through the measuring tube using the measured flow (d) in the zero flow interval (Δt N,1 ) directly preceding the second flow interval (Δt D,2 ).

10. A method of operating a flowmeter, the flowmeter comprising a measuring tube and a controller, the method comprising:
using the measuring tube and the controller, measuring a first measured flow and a first continuous dwell time of the first measured flow during a first flow interval when the first measured flow is greater than or equal to a flow threshold;
by the controller, determining a first flow volume based on the first measured flow and the first continuous dwell time;
using the measuring tube and the controller, measuring a measured zero flow and a zero flow continuous dwell time of the measured zero flow during a zero flow interval when the measured zero flow is less than the flow threshold;
using the measuring tube and the controller, measuring a second measured flow and a second continuous dwell time of the second measured flow during a second flow interval when the second measured flow is greater than or equal to the flow threshold;
by the controller, determining a second flow volume based on the second measured flow and the second continuous dwell time;
by the controller, determining a deviation volume of the second flow volume based on a reference flow volume, and comparing the deviation volume to a threshold deviation volume;
when the deviation volume is less than the threshold deviation volume, compensating, by the controller, the second measured flow based on the measured zero flow,
wherein the zero flow interval directly precedes the second flow interval.

11. The method according to claim 10 , wherein the reference flow volume is the first flow volume.

12. The method according to claim 10 , wherein the reference flow volume is an average of a plurality of preceding flow volumes determined by the controller.

13. The method according to claim 10 , wherein determining the deviation volume comprises subtracting the second flow volume from the reference flow volume.

Assignees

• Krohne Messtechnik Gmbh

Inventors

• Brockhaus Helmut
• Dabrowski Markus
• Florin Wilhelm

Classifications

• G01F1/00

  Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow (measuring a proportion of the volume flow G01F5/00) · CPC title

• G01F1/72

  Devices for measuring pulsing fluid flows · CPC title

• G01F25/0084 Primary

  for measuring volume · CPC title

• G01F15/001 Primary

  Means for regulating or setting the meter for a predetermined quantity · CPC title

• G01F11/00

  Apparatus requiring external operation adapted at each repeated and identical operation to measure and separate a predetermined volume of fluid or fluent solid material from a supply or container, without regard to weight, and to deliver it · CPC title