Method and device for detecting additives, abrasion or corrosion on wall of vibrating tube of Coriolis mass flowmeter

Abstract

The invention relates to all application fields of a Coriolis mass flowmeter for fluid density measurement and mass measurement. The invention discloses a method for detecting additives, abrasion or corrosion on the wall of a vibrating tube wall of the Coriolis mass flowmeter, which comprises the following steps of: presetting the threshold low value and the threshold high value of the three-order resonant frequency of the vibrating tube; periodically measuring the three-order resonant frequency of the vibrating tube; and comparing the measured three-order resonant frequencies with the threshold values and analyzing the variation rule of the measured three-order resonant frequencies at the same time. The invention relates to a device for realizing the method, which comprises a zero point judgment assisting device for controlling fluid flowing or stopping in the vibrating tube, a control device for controlling the zero point judgment assisting device and a resolving device for the statistic analysis of the three-order resonant frequencies and variation thereof. The method of the invention can be used for more accurately judging the abnormal working state the vibrating tube of the Coriolis mass flowmeter has additives, abrasion or corrosion.

Description

【Technical field】 [0001] The invention relates to all fields of application of Coriolis mass flowmeters for density measurement and mass measurement of industrial process fluids such as petroleum, chemical industry, natural gas, etc., and particularly relates to online monitoring, online calibration and fault diagnosis of Coriolis mass flowmeters for working conditions. . 【Background technique】 [0002] Coriolis mass flow meters are used to measure mass flow and other information of substances flowing through pipes. As in US Patent Re. 31450, issued February 11, 1982 to J.E. Smith et al., US Patent No. 4,491,025, issued January 1, 1985 to J.E. Smith et al., and November 21, 2006, to Sicong Ren As disclosed in Chinese Patent No. ZL200410073046.2, such a flowmeter has one or more vibrating tubes of the same configuration, and each vibrating tube configuration can be regarded as having a set of natural vibration modes, such as simple bending, torsion, diameter, etc. direction...

AI Technical Summary

Problems solved by technology

Therefore, when there are multiple abnormal working conditions in the vibrating tube of the Coriolis mass flowmeter, such as cracks, attachments and wear, etc., the Coriolis mass flowmeter can be judged by the change trend of the driving power and the first-order resonance frequency. It is inaccurate that the vibrating tube of the Oli mass flowmeter is in an abnormal working state with cracks, the abnormal working state of the vibrating tube with attachments, or the abnormal working state of the vibrating tube being worn out

Or it is simply impossible to confirm which abnormal working state the vibrating tube of the Coriolis mass flow meter is in

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