Coriolis mass flowmeter amplitude self-adaptation control method based on fluid state detecting

Abstract

The invention discloses a Coriolis mass flowmeter amplitude self-adaptation control method based on fluid state detecting. An ultrasonic transducer is arranged at an inlet end of a Coriolis mass flowmeter detecting pipe, through the attenuation effect on ultrasonic signals from impurities such as air bubbles, whether the amplitude value of received signals is changed suddenly is detected and judged via a threshold value comparer, whether impurities exist at a fluid state is obtained, and then switching of fixed PID and fuzzy PID amplitude controllers is carried out. According to the method, by detecting on the fluid state and self-adaptation controller switching, high-precision stable state control performance can be kept, system dynamic response speed can be improved, measuring pipe vibration stopping is avoided, stable vibration is reestablished quickly, the self adaptability of Coriolis mass flowmeter measuring pipe amplitude control is enhanced, and the reliability and the metering performance of a Coriolis mass flowmeter under a complex working condition are improved.

Description

technical field [0001] The invention relates to a Coriolis flowmeter control method, in particular to a Coriolis flowmeter amplitude adaptive control method based on fluid state detection. Background technique [0002] The Coriolis flowmeter has the characteristics of high precision, wide range ratio, and good repeatability. It represents the highest level of direct mass flow measurement technology and is widely used in petroleum, chemical, pharmaceutical, food, trade measurement and other industrial fields. Its working principle is to directly measure the mass flow rate by using the Coriolis force which is proportional to the mass flow rate generated when the fluid flows in the vibrating pipeline. [0003] The Coriolis flowmeter works based on the vibration of the measuring tube. It is generally believed in the industry that the amplitude stability of the measuring tube vibration has an important impact on the accurate measurement of the Coriolis flowmeter. It is also foun...

AI Technical Summary

Problems solved by technology

However, when the parameters of the vibration system of the measuring tube are stable, the fuzzy PID control, compared with the fixed PID control, will cause frequent jumps in the PID parameters on the one hand, reduce the steady-state performance of the amplitude control, and have a negative impact on the measurement of the Coriolis flowmeter. , which weakens its high-precision advantages; on the other hand, the fuzzy PID control method needs to calculate and adjust the PID parameters in real time, which requires high data calculation and data storage capabilities of the system, and long-term operation will significantly increase system power consumption and improve Application cost of flow meter

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