Coriolis Flow Meter Electronics Phase Detection
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Solution Overview
Problem
Existing Coriolis mass flow meters struggle to accurately and quickly determine phase and frequency measurements, especially in two-phase flows and during rapid frequency transitions, leading to errors in mass flow rate and density calculations due to the slow response of notch filters.
Innovation Solution
The implementation of meter electronics that process sensor signals using a Hilbert transform to derive phase differences and frequencies directly from single sensor signals, eliminating the need for external frequency references and significantly reducing processing time, allowing for faster and more accurate determination of flow characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If notch filters are used to determine frequency in prior art flowmeters, then frequency measurement is achieved under quiescent conditions, but the response speed is slow during rapid frequency transitions
Solution Approach 1:
The patent replaces the mechanical/notch filter-based frequency determination system with a digital signal processing system using Hilbert transforms. This substitution enables instantaneous frequency calculation from sensor signals without the bandwidth limitations of notch filters, achieving both high measurement precision and fast response during rapid frequency transitions.
Solution Approach 2:
The patent changes the fundamental parameter of frequency determination from filter-based spectral analysis to instantaneous phase derivative calculation via Hilbert transform. This parameter change allows the system to track frequency dynamically in real-time, resolving the contradiction between measurement accuracy and response speed.
2Measurement precision
If conventional phase measurement methods are used, then phase difference is determined using external frequency references, but processing time is excessive
Solution Approach 1:
The patent extracts and eliminates the external frequency reference component from the phase measurement system. By using Hilbert transforms to compute instantaneous phase directly from sensor signals, the system removes the time-consuming external reference synchronization step while maintaining phase measurement accuracy.
Solution Approach 2:
The patent substitutes the conventional external reference-based phase measurement mechanism with a direct instantaneous phase calculation method using Hilbert transforms. This substitution dramatically reduces processing time by eliminating multiple signal conditioning and synchronization steps.
3Measurement precision
If notch filters with narrow bandwidth are used, then frequency selectivity is improved, but the filter cannot track rapidly changing frequencies
Solution Approach 1:
The patent introduces dynamic frequency tracking by calculating instantaneous frequency from the time derivative of instantaneous phase obtained via Hilbert transform. This dynamic approach allows the system to adapt to rapidly changing frequencies while maintaining the frequency selectivity benefits of narrow bandwidth through precise instantaneous frequency determination.
Solution Approach 2:
The patent replaces the static notch filter system with a dynamic instantaneous frequency calculation system. This substitution provides both the frequency selectivity of narrow bandwidth filters and the adaptability to track rapidly changing frequencies, as the system computes frequency at each instant without bandwidth constraints.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables the Coriolis mass flow meter to determine phase and frequency measurements up to 40 times faster than prior art, reducing errors and providing real-time, accurate mass flow rate and density calculations even in the presence of anomalies such as air bubbles or solid particles.
Implementation Method 1
a driver applies a force to the flow tube. The force causes the flow tube to oscillate
Implementation Method 2
Each conduit configuration may be viewed as having a set of natural vibration modes including, for example, simple bending, torsional, radial and coupled modes
Implementation Method 3
As a material begins to flow through the flow tube, Coriolis accelerations cause each point along the flow tube to have a different phase with respect to other points along the flow tube
Data Source
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AI summary
Meter electronics (20) and methods for detecting a flow anomaly in a flow material flowing through a flow meter (5) are provided. The meter electronics (20) includes an interface (201) for receiving a vibrational response of the flow material, with the vibrational response including at least a first sensor signal and a second sensor signal, and a processing system (203) in communication with the interface (201). The processing system (203) is configured to receive the vibrational response from the interface (201), generate a ninety degree phase shift from the first sensor signal and generate at least one flow characteristic using at least the first sensor signal and the ninety degree phase shift, compare the at least one flow characteristic to at least one anomaly profile, detect a shift in the vibrational response if the at least one flow characteristic falls within the anomaly profile, and indicate an anomaly condition as a result of the detecting.