Vibrating Meter Static Pressure Control for Outgassing Prevention

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Solution Overview

Problem

Vibrating meters, particularly Coriolis flow meters, face challenges in accurately measuring fluid flow in custody transfer situations due to outgassing or flashing of liquids when the fluid pressure falls below its saturation pressure, especially in systems with reduced cross-sectional areas, leading to measurement difficulties.

Innovation Solution

A fluid flow system that includes a pipeline with a pressure sensor and a vibrating meter, where a system controller determines the static pressure of the fluid based on pressure and flow characteristics, adjusting the fluid flow rate if the pressure falls below the saturation pressure to maintain it above the fluid's saturation pressure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the fluid pressure is reduced below saturation pressure to enable flow measurement, then flow measurement capability is improved, but outgassing and flashing occur causing measurement inaccuracies

Engineering Contradiction:
Improveflow measurement accuracyVSAvoidoutgassing and flashing
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The system performs preliminary detection of fluid static pressure using a pressure sensor before flow measurement occurs. By detecting the pressure condition in advance, the system can identify when pressure approaches saturation pressure and take preventive actions to avoid outgassing and flashing during measurement.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors fluid static pressure and provides feedback to the control system. When the pressure is detected to be at or near saturation pressure, the feedback mechanism triggers corrective actions such as adjusting flow rate or pressure control valves to maintain pressure above saturation level, thereby preventing outgassing while enabling accurate flow measurement.

Inventive Principle:
Principle #23Feedback

2Productivity

If the fluid flow rate is increased to improve productivity, then measurement throughput is improved, but static pressure drops below saturation pressure causing phase change

Engineering Contradiction:
Improvemeasurement throughputVSAvoidfluid phase stability
Core Design Contradiction:
ProductivityVSStability of the object's composition

Solution Approach 1:

Before increasing flow rate for higher productivity, the system preliminarily detects the current static pressure using the pressure sensor. This advance detection allows the system to calculate the safe maximum flow rate that will maintain pressure above saturation pressure, preventing phase change while maximizing measurement throughput.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system continuously monitors static pressure and provides real-time feedback during flow measurement. When pressure approaches saturation pressure during high-rate measurement, the feedback mechanism automatically adjusts the flow rate or pressure control to maintain phase stability, enabling sustained high productivity without causing outgassing.

Inventive Principle:
Principle #23Feedback

3Measurement precision

If a pressure sensor is installed in the pipeline to monitor pressure, then pressure detection capability is improved, but the system complexity increases

Engineering Contradiction:
Improvepressure detection accuracyVSAvoidsystem component count
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The pressure sensor serves multiple functions within the system: it detects fluid static pressure for outgassing prevention, provides data for flow rate calculation, enables saturation pressure determination, and supports both flow measurement and phase stability monitoring. This multi-functionality reduces the need for separate dedicated components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent combines the pressure detection function with the existing flow measurement system by integrating the pressure sensor into the same measurement apparatus. The pressure sensor data is merged with flow rate data from the vibrating meter to jointly determine fluid characteristics and prevent outgassing, reducing overall system complexity compared to separate independent systems.

Inventive Principle:
Principle #5Merging (Combining)

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 system ensures accurate fluid flow measurement by maintaining the fluid above its saturation pressure, preventing outgassing and flashing, thereby improving measurement reliability and accuracy in custody transfer situations.

Implementation Method 1

a first pressure sensor located within the pipeline and determining a first pressure within the pipeline

Methodology Applied
Scientific EffectPressure sensing:

Implementation Method 2

a vibrating meter including: a sensor assembly located within the pipeline proximate to and in fluid communication with the first pressure sensor; and a meter electronics in electrical communication with the sensor assembly and configured to receive one or more sensor signals and measure one or more flow characteristics

Methodology Applied
Scientific EffectVibration: Vibration

Implementation Method 3

determine a static pressure of the fluid based on the pressure of the fluid within the pipeline and the one or more flow characteristics

Methodology Applied
Scientific EffectHydrodynamic pressure relationship:

Data Source

PatentEP2718678B1Method and apparatus for determining and controlling a static fluid pressure through a vibrating meter
Publication Date: 2021.01.27 MICRO MOTION INC
  • EP2718678B1 patent drawingFigure 1
  • EP2718678B1 patent drawingFigure 2
  • EP2718678B1 patent drawingFigure 3

AI summary

A method for operating a fluid flow system (300) is provided. The fluid flow system (300) includes a fluid flowing through a pipeline (301), a first pressure sensor (303) located within the pipeline (301), and a vibrating meter (5). The vibrating meter (5) includes a sensor assembly (10) in fluid communication with the first pressure sensor (303). The method includes steps of measuring a pressure of the fluid within the pipeline (301) using the first pressure sensor (303) and measuring one or more flow characteristics of the fluid using the vibrating meter (5). The method further includes a step of determining a static pressure of the fluid based on the pressure of the fluid within the pipeline (301) and the one or more flow characteristics. The method further includes a step of determining if the fluid contains at least some gas based on the static pressure of the fluid.