CN114910142A - Detection method for Coriolis mass flowmeter - Google Patents

Abstract

The invention discloses a detection method for a Coriolis mass flowmeter, which comprises the following steps: collecting vibration signals of the inlet end and the outlet end of each measuring tube, wherein the number of the measuring tubes is at least two, and the inlet end and the outlet end of each measuring tube are respectively provided with at least one vibration detection unit; determining at least two mass flow data according to the collected vibration signals at the inlet end and the outlet end of the measuring pipe, and determining whether the difference value of the at least two mass flow data is within a set error range; if the difference between at least two mass flow data is not within the set error range, a failure of the coriolis mass flow meter is determined. The invention sets the number of the measuring tubes as at least two, and the corresponding mass flow is determined by collecting and processing the vibration signals of the at least two measuring tubes, thereby overcoming the defect of relying on the same measuring tube in the prior art and improving the precision of the mass flow measurement result.

Description

Detection method for Coriolis mass flow meters

technical field

The invention relates to the technical field of metering equipment, in particular to a detection method for a Coriolis mass flowmeter.

Background technique

Coriolis mass flowmeter is a metering device that determines mass flow by measuring Coriolis force. It has high accuracy and stability and has a wide range of applications.

As a metering device, failure is inevitable, and a variety of failure detection methods for detecting Coriolis mass flowmeters are provided in the prior art. The Chinese invention patent application CN110514259A discloses a detection method for a high-precision Cordial flowmeter, wherein at least two pairs of vibration detection elements are arranged on the measuring tube. At least two mass flow rates can be determined, and then whether the Coriolis mass flowmeter is faulty can be determined by processing the at least two mass flow rates. Although this patent has lower cost and higher accuracy, multiple sets of vibration detection elements are installed on the same measuring tube, and the same measuring tube itself will have certain effects under the influence of manufacturing process, use environment and other factors. Therefore, the signals obtained by multiple groups of vibration detection elements will contain the same error data. If the mass flow rate determined from these signals is processed, the obtained result must also contain the error data of the measuring tube itself, which will adversely affect the measurement accuracy.

SUMMARY OF THE INVENTION

Embodiments of the present invention provide a detection method for a Coriolis mass flowmeter, so as to solve the problem of adversely affecting measurement accuracy existing in the prior art when multiple groups of vibration detection units are installed on the same measurement tube.

In one aspect, an embodiment of the present invention provides a detection method for a Coriolis mass flowmeter, including:

Collecting vibration signals at the inlet end and the outlet end of the measurement tube, wherein the number of measurement tubes is at least two, and at least one vibration detection unit is respectively provided at the inlet end and the outlet end of each measurement tube;

Determine at least two mass flow data according to the collected vibration signals at the inlet end and the outlet end of the measuring tube, and determine whether the difference between the at least two mass flow data is within the set error range;

If the difference of at least two mass flow data is not within the set error range, it is determined that the Coriolis mass flow meter is faulty.

In a possible implementation manner, when at least two pieces of mass flow data are determined, the mass flow rate flowing through the measuring tube is determined according to the vibration signals at the inlet end and the outlet end of the same measuring tube.

In a possible implementation manner, when at least two mass flow data are determined, two vibration detection units are respectively provided at the inlet end and the outlet end of each measuring tube, according to the vibration signals at the inlet end and the outlet end of the same measuring tube Determine the two mass flow data, take the average value of the two mass flow data, and then determine the difference with the average value of the mass flow data determined according to the vibration signals of other measuring tubes.

In a possible implementation manner, when the at least two mass flow data are determined, the corresponding mass flow is determined according to the vibration signal at the inlet end of one measuring tube and the vibration signal at the outlet end of the other measuring tube.

In a possible implementation manner, when at least two mass flow data are determined, two vibration detection units are respectively provided at the inlet end and the outlet end of each measuring tube, according to the vibration signal at the inlet end of one measuring tube and the other measuring The vibration signal at the outlet end of the pipe determines two mass flow data, and after averaging the two mass flow data, the difference is determined with the average mass flow data determined according to the average determined by the remaining two mass flow data.

In a possible implementation manner, when at least two measuring tubes work simultaneously, the work of collecting vibration signals at the inlet end and the outlet end of the measuring tubes is performed simultaneously.

In a possible implementation manner, when at least two measuring tubes work in sequence, the vibration signals at the inlet end and the outlet end are collected when the measuring tubes are in a working state.

The detection method for Coriolis mass flowmeter in the present invention has the following advantages:

The number of measuring tubes is set to at least two, and the corresponding mass flow rate is determined by collecting and processing the vibration signals of the at least two measuring tubes, which overcomes the disadvantage of relying on the same measuring tube in the prior art and improves the mass flow rate. The accuracy of the measurement results.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained according to these drawings without creative efforts.

1 is a flowchart of a detection method for a Coriolis mass flowmeter provided by an embodiment of the present invention;

2 is a schematic structural diagram of a detection system for a Coriolis mass flowmeter provided by an embodiment of the present invention;

FIG. 3 is a schematic structural diagram of the interior of a main pipeline provided by an embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

FIG. 1 is a flowchart of a detection method for a Coriolis mass flowmeter provided by an embodiment of the present invention. An embodiment of the present invention provides a detection method for a Coriolis mass flowmeter, the method comprising:

S100. Collect vibration signals at the inlet end and the outlet end of the measuring tube 300, wherein the number of the measuring tubes 300 is at least two, and at least one vibration detection unit is respectively provided at the inlet end and the outlet end of each measuring tube 300.

Exemplarily, both ends of the measuring pipe 300 are respectively connected to the main pipe 200, and a stabilizing block 100 is provided at the connection between the main pipe 200 and the measuring pipe 300, so as to protect the connection between the main pipe 200 and the measuring pipe 300. . The medium flowing in the main pipe 200 is distributed to at least two measuring tubes 300, and the mass flow in each measuring tube 300 is approximately equal.

In the embodiment of the present invention, the measuring tube 300 is an arc-shaped tube, the vibration detection units are arranged inside the arc-shaped tube, and the vibration detection units at the inlet end and the outlet end are symmetrically arranged on both sides of the central axis of the measurement tube 300 . When the number of vibration detection units at the inlet end and the outlet end are two or more, then one vibration detection unit at the inlet end and one vibration detection unit at the outlet end form a group, and the two vibration detection units in a group are respectively located at Two symmetrical positions on the inside of the tube 300 are measured.

S110. Determine at least two mass flow data according to the collected vibration signals at the inlet end and the outlet end of the measuring tube 300, and determine whether the difference between the at least two mass flow data is within a set error range.

Exemplarily, when the fluid medium flows in the measuring tube 300, the entire measuring tube 300 is in a vibrating state under the driving of the vibration unit, and the vibration of the inlet end and the outlet end of the measuring tube 300 is not complete under the influence of the fluid medium. same. Specifically, there is a difference in the vibration phase, and the magnitude of this difference is proportional to the mass flow through the measuring tube 300. Therefore, the corresponding mass can be directly determined according to the phase difference of the vibration signals at the inlet end and the outlet end of the measuring tube 300. traffic data.

S120. If the difference between at least two mass flow data is not within the set error range, determine that the Coriolis mass flowmeter is faulty.

Exemplarily, since the physical parameters of the plurality of measuring tubes 300, including radian, thickness, etc., are not exactly the same, even if the same mass flow flows through, the mass flow determined according to the vibration signals of different measuring tubes 300 will not be completely the same. The same, more or less there is a difference greater than zero, as long as the difference is within an acceptable range, that is, the set error range, it can be determined that the Coriolis mass flowmeter is in a normal state. The above-mentioned setting error range may be a specific mass flow difference value or a percentage.

In the embodiment of the present invention, the multiple measuring tubes 300 in the same Coriolis mass flowmeter work independently, so the possibility of the multiple measuring tubes 300 failing at the same time is very small, as long as one of the measuring tubes 300 In a normal working state, the mass flow rate determined by this measuring tube 300 can be used as a reference to judge whether the working states of other measuring tubes 300 are normal. If the difference between the mass flow rates determined according to the vibration signals of the plurality of measuring tubes 300 is too large, it means that at least one measuring tube 300 is faulty. At this time, an alarm message can be sent through the alarm device to remind the maintenance personnel of the problem. Oli mass flowmeter for further inspection.

In a possible embodiment, when at least two pieces of mass flow data are determined, the mass flow through the measuring tube 300 is determined according to the vibration signals at the inlet end and the outlet end of the same measuring tube 300 .

Exemplarily, when the mass flow rate is determined according to the vibration signals at the inlet end and the outlet end of the same measuring tube 300, the vibration signals collected by two vibration detection units in the same group need to be used. If only one vibration detection unit is set at the inlet end and the outlet end of the measuring tube 300, the corresponding mass flow rate is determined according to the vibration signals collected by the two vibration detection units.

When two vibration detection units are respectively provided at the inlet end and the outlet end of each measuring tube 300, the two mass flow data are determined according to the vibration signals at the inlet end and the outlet end of the same measuring tube 300, and the two mass flow data are taken as After the average value, the difference value is determined with the average value of the mass flow data determined according to the vibration signals of other measuring tubes 300 . For example, vibration detection unit I, vibration detection unit II, vibration detection unit III and vibration detection unit IV are sequentially arranged on a measuring tube 300 along the flow direction of the medium, wherein the vibration detection unit I and vibration detection unit II are located at the entrance of the measuring tube 300 The vibration detection unit III and the vibration detection unit IV are located at the outlet end of the measuring tube 300 . At the same time, the vibration detection unit I and the vibration detection unit IV are a group, and are symmetrically located on both sides of the central axis of the measuring tube 300, and the vibration detecting unit II and the vibration detecting unit III are a group, and are also symmetrically located on the central axis of the measuring tube 300. sides. When determining mass flow, determine mass flow data I according to the vibration signal collected by vibration detection unit I and vibration detection unit IV, then determine mass flow data II according to the vibration signal collected by vibration detection unit II and vibration detection unit III, and obtain The average value of the mass flow data I and the mass flow data II is taken as the mass flow data of the medium flowing in one measuring tube 300 . The mass flow data of the medium flowing in other measuring tubes 300 can be determined in the same way.

In a possible embodiment, when the at least two mass flow data are determined, the corresponding mass flow is determined according to the vibration signal at the inlet end of one measuring tube 300 and the vibration signal at the outlet end of the other measuring tube 300 .

Exemplarily, when the mass flow rate is determined by the vibration signal of the same measuring tube 300, the error data of the measuring tube 300 itself will inevitably be brought in. Therefore, in this embodiment, the vibration detection units at the corresponding positions of the two measuring tubes 300 are used as In one group, the corresponding mass flow rate is determined according to the vibration signals collected by the two vibration detection units in the group. In this way, the information of multiple measuring tubes 300 can be integrated together to avoid introducing fixed error data. If only one vibration detection unit is provided at the inlet end and the outlet end of each measuring tube 300, the corresponding mass flow rate is determined according to the vibration signal of the inlet end of one measuring tube 300 and the vibration signal of the outlet end of the other measuring tube 300.

When two vibration detection units are respectively provided at the inlet end and the outlet end of each measuring tube 300, two mass flow data are determined according to the vibration signal at the inlet end of one measuring tube 300 and the vibration signal at the outlet end of the other measuring tube 300. After the mass flow data is averaged, the difference is determined with the average mass flow data determined according to the vibration signals of other measuring tubes 300 . For example, vibration detection unit I, vibration detection unit II, vibration detection unit III and vibration detection unit IV are sequentially arranged on a measuring tube 300 along the flow direction of the medium, wherein the vibration detection unit I and vibration detection unit II are located at the entrance of the measuring tube 300 The vibration detection unit III and the vibration detection unit IV are located at the outlet end of the measuring tube 300 . Another measuring tube 300 is sequentially provided with vibration detection unit V, vibration detection unit VI, vibration detection unit VII and vibration detection unit VIII along the flow direction of the medium, wherein the vibration detection unit V and vibration detection unit VI are located at the inlet end of the measurement tube 300. , the vibration detection unit VII and the vibration detection unit VIII are located at the outlet end of the measuring tube 300 . In this embodiment, the vibration detection unit I and the vibration detection unit VIII, the vibration detection unit II and the vibration detection unit VII, the vibration detection unit III and the vibration detection unit VI, and the vibration detection unit IV and the vibration detection unit V are respectively one group.

When determining mass flow, determine mass flow data I according to the vibration signal collected by vibration detection unit I and vibration detection unit VIII, then determine mass flow data II according to the vibration signal collected by vibration detection unit II and vibration detection unit VII, then according to The vibration signal that vibration detection unit III and vibration detection unit VI collect determines mass flow data III, finally determine mass flow data IV according to the vibration signal collected by vibration detection unit IV and vibration detection unit V, obtain mass flow data I and quality The average of flow data II, and the average of mass flow data III and mass flow data IV. The difference value of the mass flow data can be determined according to the two averages.

In a possible embodiment, when at least two measuring tubes 300 work simultaneously, the work of collecting vibration signals at the inlet end and the outlet end of the measuring tubes 300 is performed simultaneously.

Exemplarily, a flow direction switching device is provided on the side of the main pipe 200 close to the inlet end of the measuring pipe 300 , as shown in FIG. 3 . The device includes a driving unit 210 and a deflector 230 . A dividing plate 220 is arranged inside the main pipe 200 . The dividing plate 220 divides the medium flowing through the main pipe 200 into a plurality of tributaries, and the number of the tributaries is the same as that of the measuring pipes 300 . , each branch flows into a measuring tube 300 in a one-to-one correspondence. The deflector 230 is rotatably disposed at the end of the dividing plate 220 , and the deflector 230 is rotated under the driving of the driving unit 210 to change the state of the medium flowing into the measuring tube 300 .

In the embodiment of the present invention, the driving unit 210 is a servo motor, which controls three switching states of the deflector 230 . In two states, the ends of the deflector 230 abut on opposite sides of the main pipe 200 . , so that the medium flows into two different measuring tubes 300. In these two states, the measuring tubes 300 are in a state of working in sequence, that is, only one measuring tube 300 is in a working state at the same time. In the remaining one state, the baffle plate 230 is parallel to the flow direction of the medium, so the medium can flow into the two measuring tubes 300 at the same time. In this state, the measuring tubes 300 are in a simultaneous working state.

When a plurality of measuring tubes 300 work at the same time, the above method can be directly used to diagnose whether the Coriolis mass flowmeter is faulty. When a plurality of measuring tubes 300 work in sequence, the vibration signals collected by each measuring tube 300 can be stored, and after each measuring tube 300 works once, the fault detection of the Coriolis mass flowmeter can be performed. .

Although preferred embodiments of the present invention have been described, additional changes and modifications to these embodiments may occur to those skilled in the art once the basic inventive concepts are known. Therefore, the appended claims are intended to be construed to include the preferred embodiment and all changes and modifications that fall within the scope of the present invention.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Thus, provided that these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims (7)

1. A sensing method for a coriolis mass flowmeter, comprising:

collecting vibration signals of an inlet end and an outlet end of a measuring pipe (300), wherein the number of the measuring pipes (300) is at least two, and the inlet end and the outlet end of each measuring pipe (300) are respectively provided with at least one vibration detection unit;

determining at least two mass flow data according to the acquired vibration signals at the inlet end and the outlet end of the measuring pipe (300), and determining whether the difference value of the at least two mass flow data is within a set error range;

and if the difference value of at least two mass flow data is not within a set error range, determining that the Coriolis mass flowmeter has a fault.

2. The sensing method for a coriolis mass flowmeter of claim 1, characterized in that the mass flow through said measurement tube (300) is determined from vibration signals at the inlet end and the outlet end of the same measurement tube (300) when determining said at least two mass flow data.

3. The sensing method for a coriolis mass flowmeter of claim 2, wherein in determining said at least two mass flow rate data, two vibration sensing units are provided at each of said inlet and outlet ends of said measurement tube (300), and wherein said two mass flow rate data are determined from vibration signals at said inlet and outlet ends of the same measurement tube (300), and wherein said two mass flow rate data are averaged and then a difference is determined from an average of said mass flow rate data determined from vibration signals of other said measurement tubes (300).

4. The sensing method for a coriolis mass flowmeter of claim 1, characterized in that in determining said at least two mass flow data, the corresponding mass flow is determined based on a vibration signal at an inlet end of one of said measurement tubes (300) and a vibration signal at an outlet end of the other of said measurement tubes (300).

5. The sensing method for a coriolis mass flowmeter of claim 4, wherein in determining said at least two mass flow rate data, two vibration sensing units are provided at each of an inlet end and an outlet end of said measuring tube (300), two mass flow rate data are determined from a vibration signal at the inlet end of one of said measuring tubes (300) and a vibration signal at the outlet end of the other of said measuring tubes (300), and after averaging two of said mass flow rate data, a difference is determined from an average of the mass flow rate data determined from the remaining two mass flow rate data.

6. The sensing method for a coriolis mass flowmeter of claim 1, wherein the operation of acquiring vibration signals at the inlet end and the outlet end of said measurement tubes (300) is performed simultaneously when at least two of said measurement tubes (300) are operating simultaneously.

7. The sensing method for a coriolis mass flowmeter of claim 1 characterized in that said vibration signals at said inlet end and said outlet end are collected while said measurement tubes (300) are operating while at least two of said measurement tubes (300) are operating in sequence.

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