Detection method for Coriolis mass flowmeter

Abstract

The present invention discloses a detection method for a Coriolis mass flowmeter. The method includes: collecting vibration signals at the inlet end and the outlet end of the measuring tubes, where the number of measuring tubes is at least two, and at least one vibration detection unit is respectively arranged at the inlet end and the outlet end of each measuring tube; determining at least two mass flow rate data according to the collected vibration signals at the inlet end and the outlet end of the measuring tubes, and determining whether the difference between the at least two mass flow rate data is within a set error range; if the difference between the at least two mass flow rate data is not within the set error range, it is determined that the Coriolis mass flowmeter has a fault. In the present invention, the number of measuring tubes is set to be at least two, and the corresponding mass flow rate is determined by collecting and processing the vibration signals of these at least two measuring tubes, overcoming the drawbacks of relying on the same measuring tube in the prior art and improving the accuracy of the mass flow rate measurement result.

Description

Technical Field

[0001] The present invention relates to the technical field of metering devices, and particularly to a detection method for a Coriolis mass flowmeter. Background Art

[0002] A Coriolis mass flowmeter is a metering device that determines the mass flow by measuring the Coriolis force. It has high precision and stability and a wide range of applications.

[0003] As a metering device, failures are inevitable. In the prior art, various fault detection methods for Coriolis mass flowmeters are provided. The Chinese patent application of CN110514259A discloses a detection method for a high-precision Coriolis flowmeter. At least two pairs of vibration detection elements are arranged on the measuring tube. By detecting the vibration at the inlet and outlet of the measuring tube, at least two time differences are determined, and then at least two mass flows can be determined. Then, by processing at least two mass flows, it can be determined whether there is a fault in the Coriolis mass flowmeter. Although this patent has low cost and high precision, multiple groups of vibration detection elements are installed on the same measuring tube. Affected by factors such as manufacturing process and use environment of the same measuring tube, there will be certain measurement errors in itself. Therefore, the signals obtained by multiple groups of vibration detection elements will all contain the same error data. If the mass flows determined according to these signals are processed, the obtained results will surely also contain the error data of the measuring tube itself, which will have an adverse impact on the measurement accuracy. Summary of the Invention

[0004] The embodiments of the present invention provide a detection method for a Coriolis mass flowmeter to solve the problem in the prior art that installing multiple groups of vibration detection units on the same measuring tube has an adverse impact on the measurement accuracy.

[0005] On the one hand, the embodiments of the present invention provide a detection method for a Coriolis mass flowmeter, including:

[0006] Collect the vibration signals at the inlet end and the outlet end of the measuring tube, where the number of measuring tubes is at least two, and at least one vibration detection unit is respectively arranged at the inlet end and the outlet end of each measuring tube;

[0007] 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 at least two mass flow data is within the set error range;

[0008] If the difference between at least two mass flow data is not within the set error range, it is determined that there is a fault in the Coriolis mass flowmeter.

[0009] In a possible implementation, when determining at least two mass flow rate data, the mass flow rate flowing through the measurement tube is determined according to the vibration signals at the inlet end and the outlet end of the same measurement tube.

[0010] In a possible implementation, when determining at least two mass flow rate data, two vibration detection units are respectively arranged at the inlet end and the outlet end of each measurement tube. Two mass flow rate data are determined according to the vibration signals at the inlet end and the outlet end of the same measurement tube. After averaging the two mass flow rate data, the difference is determined with the average value of the mass flow rate data determined according to the vibration signals of other measurement tubes.

[0011] In a possible implementation, when determining at least two mass flow rate data, the corresponding mass flow rate is determined according to the vibration signal at the inlet end of one measurement tube and the vibration signal at the outlet end of another measurement tube.

[0012] In a possible implementation, when determining at least two mass flow rate data, two vibration detection units are respectively arranged at the inlet end and the outlet end of each measurement tube. Two mass flow rate data are determined according to the vibration signal at the inlet end of one measurement tube and the vibration signal at the outlet end of another measurement tube. After averaging the two mass flow rate data, the difference is determined with the average value of the mass flow rate data determined according to the remaining two mass flow rate data.

[0013] In a possible implementation, when at least two measurement tubes work simultaneously, the work of collecting the vibration signals at the inlet end and the outlet end of the measurement tubes is carried out simultaneously.

[0014] In a possible implementation, when at least two measurement tubes work sequentially, the vibration signals at the inlet end and the outlet end are collected when the measurement tube is in the working state.

[0015] The detection method for the Coriolis mass flowmeter in the present invention has the following advantages:

[0016] The number of measurement tubes is set to at least two. By collecting and processing the vibration signals of these at least two measurement tubes, the corresponding mass flow rate is determined, overcoming the drawback in the prior art that relies on the same measurement tube and improving the accuracy of the mass flow rate measurement result. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to these drawings without creative efforts.

[0018] Figure 1 It is a flowchart of a detection method for a Coriolis mass flowmeter provided by an embodiment of the present invention;

[0019] Figure 2 It is a schematic structural diagram of a detection system for a Coriolis mass flowmeter provided by an embodiment of the present invention;

[0020] Figure 3 It is a schematic structural diagram inside the main pipeline provided by an embodiment of the present invention. Specific embodiments

[0021] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with 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, rather than all 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.

[0022] Figure 1 It is a flowchart of a detection method for a Coriolis mass flowmeter provided by an embodiment of the present invention. The embodiment of the present invention provides a detection method for a Coriolis mass flowmeter, and the method includes:

[0023] S100. Collect vibration signals at the inlet end and the outlet end of the measuring tube 300, where the number of the measuring tubes 300 is at least two, and at least one vibration detection unit is respectively arranged at the inlet end and the outlet end of each measuring tube 300.

[0024] Exemplarily, both ends of the measuring tube 300 are respectively connected to the main pipeline 200, and a stabilizing block 100 is arranged at the connection between the main pipeline 200 and the measuring tube 300 to protect the connection between the main pipeline 200 and the measuring tube 300. The medium flowing through the main pipeline 200 is distributed into at least two measuring tubes 300, and the mass flow rate in each measuring tube 300 is approximately the same.

[0025] In the embodiment of the present invention, the measuring tube 300 is an arc-shaped tube, the vibration detection units are all 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 measuring tube 300. When the number of the vibration detection units at the inlet end and the outlet end is two or more, 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 inside the measuring tube 300.

[0026] S110. Determine at least two mass flow rate data according to the vibration signals collected 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 rate data is within a set error range.

[0027] Exemplarily, when the fluid medium flows in the measuring tube 300, the entire measuring tube 300 is in a vibrating state under the drive of the vibrating unit. However, under the influence of the fluid medium, the vibration conditions at the inlet end and the outlet end of the measuring tube 300 are not exactly the same. Specifically, there is a difference in the vibration phase, and the magnitude of this difference is proportional to the mass flow rate flowing through the measuring tube 300. Therefore, the corresponding mass flow rate data can be directly determined according to the phase difference between the vibration signals at the inlet end and the outlet end of the measuring tube 300.

[0028] S120. If the difference between at least two mass flow rate data is not within the set error range, it is determined that the Coriolis mass flowmeter is faulty.

[0029] Exemplarily, since the physical parameters of multiple measuring tubes 300, including the radian, thickness, etc., are not exactly the same, even if the same mass flow rate flows through, the mass flow rates determined according to the vibration signals of different measuring tubes 300 are not exactly the same, and there is more or less a difference greater than zero. As long as this difference is within the acceptable range, that is, the set error range, it can be determined that the Coriolis mass flowmeter is in a normal state. The above set error range can be a specific mass flow rate difference or a percentage.

[0030] In an embodiment of the present invention, multiple measuring tubes 300 in the same Coriolis mass flowmeter work separately. Therefore, the possibility that these multiple measuring tubes 300 fail simultaneously is very small. As long as one of the measuring tubes 300 is 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 multiple measuring tubes 300 is too large, it indicates that at least one of the measuring tubes 300 has failed. At this time, an alarm message can be sent through the alarm device to remind the maintenance personnel to further check the Coriolis mass flowmeter.

[0031] In a possible embodiment, when determining at least two mass flow rate data, the mass flow rate flowing 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.

[0032] Exemplarily, when determining the mass flow rate 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 provided at each of 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 these two vibration detection units.

[0033] When two vibration detection units are respectively arranged at the inlet end and the outlet end of each measuring tube 300, two mass flow rate data are determined according to the vibration signals at the inlet end and the outlet end of the same measuring tube 300. After averaging the two mass flow rate data, the difference is determined with the average value of the mass flow rate 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 medium flow direction, where vibration detection unit I and vibration detection unit II are located at the inlet end of the measuring tube 300, and vibration detection unit III and vibration detection unit IV are located at the outlet end of the measuring tube 300. At the same time, vibration detection unit I and vibration detection unit IV form a group and are symmetrically located on both sides of the central axis of the measuring tube 300, and vibration detection unit II and vibration detection unit III form a group and are also symmetrically located on both sides of the central axis of the measuring tube 300. When determining the mass flow rate, mass flow rate data I is determined according to the vibration signals collected by vibration detection unit I and vibration detection unit IV, and then mass flow rate data II is determined according to the vibration signals collected by vibration detection unit II and vibration detection unit III. The average value of mass flow rate data I and mass flow rate data II is taken as the mass flow rate data of the medium flowing through a measuring tube 300. The mass flow rate data of the medium flowing through other measuring tubes 300 can be determined in the same way.

[0034] In a possible embodiment, when determining at least two mass flow rate data, the corresponding mass flow rate 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 another measuring tube 300.

[0035] Exemplarily, when determining the mass flow rate according to the vibration signal of the same measuring tube 300, it is inevitable to introduce the error data of the measuring tube 300 itself. Therefore, in this embodiment, the vibration detection units at the corresponding positions of the two measuring tubes 300 are taken as a group, and the corresponding mass flow rate is determined according to the vibration signals collected by the two vibration detection units in a 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 arranged 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 at the inlet end of one measuring tube 300 and the vibration signal at the outlet end of another measuring tube 300.

[0036] When two vibration detection units are respectively arranged at the inlet end and the outlet end of each measuring tube 300, two mass flow rate data are determined according to the vibration signals at the inlet end of one measuring tube 300 and the vibration signals at the outlet end of the other measuring tube 300. After averaging the two mass flow rate data, the difference is determined with the average value of the mass flow rate 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 along the medium flow direction on one measuring tube 300, where vibration detection unit I and vibration detection unit II are located at the inlet end of the measuring tube 300, and vibration detection unit III and vibration detection unit IV are located at the outlet end of the measuring tube 300. Vibration detection unit V, vibration detection unit VI, vibration detection unit VII, and vibration detection unit VIII are sequentially arranged along the medium flow direction on the other measuring tube 300, where vibration detection unit V and vibration detection unit VI are located at the inlet end of the measuring tube 300, and vibration detection unit VII and vibration detection unit VIII are located at the outlet end of the measuring tube 300. In this embodiment, vibration detection unit I and vibration detection unit VIII, vibration detection unit II and vibration detection unit VII, vibration detection unit III and vibration detection unit VI, and vibration detection unit IV and vibration detection unit V are respectively a group.

[0037] When determining the mass flow rate, mass flow rate data I is determined according to the vibration signals collected by vibration detection unit I and vibration detection unit VIII, then mass flow rate data II is determined according to the vibration signals collected by vibration detection unit II and vibration detection unit VII, then mass flow rate data III is determined according to the vibration signals collected by vibration detection unit III and vibration detection unit VI, and finally mass flow rate data IV is determined according to the vibration signals collected by vibration detection unit IV and vibration detection unit V. The average value of mass flow rate data I and mass flow rate data II, and the average value of mass flow rate data III and mass flow rate data IV are obtained. The difference of the mass flow rate data can be determined according to the two averages.

[0038] In a possible embodiment, when at least two measuring tubes 300 work simultaneously, the work of collecting the vibration signals at the inlet end and the outlet end of the measuring tubes 300 is carried out simultaneously.

[0039] Exemplarily, a flow direction switching device is arranged on one side of the main pipeline 200 close to the inlet end of the measuring tube 300, such as Figure 3As shown. The device includes a driving unit 210 and a flow deflector 230. A diverter plate 220 is arranged inside the main pipeline 200. The diverter plate 220 divides the medium flowing through the main pipeline 200 into multiple branches, and the number of branches is the same as the number of measuring tubes 300. Each branch flows into a corresponding measuring tube 300 one by one. The flow deflector 230 is rotatably arranged at the end of the diverter plate 220. The flow deflector 230 rotates under the drive of the driving unit 210 to change the state of the medium flowing into the measuring tube 300.

[0040] In an embodiment of the present invention, the driving unit 210 is a servo motor, and it controls the flow deflector 230 to have three switching states. In two of the states, the end of the flow deflector 230 abuts against the opposite side surfaces of the main pipeline 200, so that the medium flows into two different measuring tubes 300. In these two states, the measuring tubes 300 are in a sequential working state, that is, only one measuring tube 300 is in the working state at the same time. In the remaining one state, the flow deflector 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 the simultaneous working state.

[0041] When multiple measuring tubes 300 work simultaneously, the above method can be directly used to diagnose whether the Coriolis mass flowmeter is faulty. When multiple measuring tubes 300 work sequentially, the vibration signals collected by each measuring tube 300 can be stored. After each measuring tube 300 has worked once, the fault detection work of the Coriolis mass flowmeter is carried out.

[0042] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0043] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. Detection method for Coriolis mass flowmeter, characterized in that, Including: Collecting vibration signals at the inlet end and the outlet end of the measuring tubes (300), where the number of the measuring tubes (300) is at least two, and at least one vibration detection unit is respectively arranged at the inlet end and the outlet end of each measuring tube (300); Determining at least two mass flow rate data according to the collected vibration signals at the inlet end and the outlet end of the measuring tubes (300), and determining whether the difference between the at least two mass flow rate data is within a set error range; If the difference between at least two of the mass flow rate data is not within the set error range, it is determined that the Coriolis mass flowmeter has a fault; Wherein, when determining the at least two mass flow rate data, the corresponding mass flow rate 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 another measuring tube (300); when determining the at least two mass flow rate data, two vibration detection units are respectively arranged at the inlet end and the outlet end of each measuring tube (300), one mass flow rate data 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 another measuring tube (300), and another mass flow rate data is determined according to the vibration signal at the outlet end of one measuring tube (300) and the vibration signal at the inlet end of another measuring tube (300). After taking the average of the two mass flow rate data, the difference is determined with the average value of the mass flow rate data determined according to the average value of the remaining two mass flow rate data.

2. The detection method for a Coriolis mass flowmeter according to claim 1, characterized in that When at least two of the measuring tubes (300) work simultaneously, the work of collecting the vibration signals at the inlet end and the outlet end of the measuring tubes (300) is carried out simultaneously.

3. The detection method for a Coriolis mass flowmeter according to claim 1, characterized in that, When at least two of the measuring tubes (300) work in sequence, the vibration signals at the inlet end and the outlet end are collected when the measuring tube (300) is in the working state.

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