Acoustic Flow Rate Determination in Pressurized Pipelines
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Solution Overview
Problem
Existing methods for measuring flow rate in pressurized pipelines are inadequate, particularly for unsteady flows and turbulent regimes, as they are either invasive, costly, or prone to significant errors due to factors like air entrainment and hydraulic elements, and lack accuracy in field applications.
Innovation Solution
A method that generates a transient fluid wave and measures pressure at multiple locations using sensors to determine wave speed and flow regime, allowing for precise flow rate calculation based on wave speed, pressure measurements, and resistance terms specific to laminar or turbulent flows, with adjustments for hydraulic elements and pipe characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electromagnetic flow meters are used to measure flow rate, then flow rate can be measured in conductive fluids, but the method is intrusive and limited by fluid conductivity
Solution Approach 1:
The patent replaces electromagnetic flow measurement with an acoustic wave-based method. Instead of using electromagnetic fields that require conductive fluids, the invention uses acoustic waves propagating through the fluid to determine flow rate. This substitution allows measurement of both conductive and non-conductive fluids (like gasoline) without the limitations of Faraday's law of induction.
Solution Approach 2:
The patent introduces acoustic waves as an intermediary to measure flow rate. Rather than directly measuring fluid properties with intrusive sensors, the method uses sound wave propagation characteristics (velocity, frequency, wavelength) as a mediator to indirectly determine flow rate. This intermediary approach enables non-intrusive measurement that doesn't depend on fluid conductivity.
2Measurement precision
If Laser Doppler Velocimetry (LDV) is used to measure flow rate, then local flow velocity can be measured, but the apparatus is expensive and requires transparent pipe sections
Solution Approach 1:
The patent replaces expensive LDV apparatus with simpler, lower-cost acoustic sensors and signal processing equipment. Instead of using complex laser systems and transparent pipe sections, the invention employs affordable acoustic transducers that can be installed in standard opaque pipelines, dramatically reducing system cost and complexity while maintaining measurement capability.
Solution Approach 2:
The patent substitutes optical measurement (LDV) with acoustic measurement. Instead of using laser beams and optical interferometry that require transparent pipes, the method uses acoustic wave propagation through the fluid and pipe walls. This substitution eliminates the need for transparent pipe sections and complex optical equipment, making the system suitable for field installations in existing pipelines.
3Measurement precision
If hot-wire method is used to measure flow rate, then flow velocity can be measured, but the method is intrusive and requires costly maintenance
Solution Approach 1:
The patent uses acoustic waves as an intermediary to measure flow velocity without direct contact with the fluid. Instead of inserting hot wires into the flow path, the method places acoustic sensors on or near the pipe exterior. The acoustic waves propagate through the pipe wall and fluid, allowing velocity measurement without intrusive elements that require maintenance.
Solution Approach 2:
The patent replaces the thermal convection-based hot-wire method with an acoustic wave-based measurement system. Instead of heating wires and measuring convective cooling, the invention uses acoustic transducers to generate and detect sound waves. This substitution eliminates the need for heated elements in contact with the fluid, removing maintenance requirements associated with wire replacement and calibration.
4Ease of operation
If pressure transducers are flush mounted to be non-intrusive, then disturbance to fluid flow is minimized, but accurate flow rate determination in turbulent flow requires additional considerations
Solution Approach 1:
The patent applies dynamic signal processing techniques to handle turbulent and unsteady flow conditions. Instead of using static pressure measurements, the method employs time-varying acoustic wave analysis, including frequency domain transformation (FFT), wave velocity calculation, and dynamic correlation between upstream and downstream sensor signals. This dynamic approach enables accurate flow rate determination in turbulent flows by capturing transient flow characteristics.
Solution Approach 2:
The patent uses feedback from multiple sensor measurements to refine flow rate calculation. By comparing acoustic wave characteristics from upstream and downstream sensors, including wave velocity, frequency, and amplitude variations, the system iteratively determines flow rate while compensating for turbulent flow effects. This feedback mechanism improves measurement accuracy in complex flow regimes.
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 provides accurate and non-invasive flow rate determination in both laminar and turbulent flows, minimizing errors and adapting to various pipeline conditions, thus enhancing measurement precision and reliability in field applications.
Implementation Method 1
generating a transient fluid wave using a generator
Implementation Method 2
measuring a pressure of the fluid wave at at least two locations in the pipe, the pressure being measured by sensors that are positioned on or in the pipe
Implementation Method 3
determining a wave speed of fluid based on the measured pressure of the fluid wave at the at least two locations in the pipe
Data Source
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AI summary
A method 100 of determining a flow rate of a fluid flowing in a pipe. The method 100 includes measuring a pressure of fluid at at least two locations in the pipe 101, the pressure being measured by sensors that are positioned on or in the pipe. A wave speed of fluid is determined 102 based on measured pressure of fluid at a location in the pipe. The flow rate of fluid is determined 106 based on the determined wave speed and based on the measured pressures at two locations in the pipe. An apparatus for determining a flow rate of fluid flowing in a pipe is configured to perform the method 100.