RF Void Fraction Measurement in Geothermal Pipes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for measuring void fraction in geothermal systems disrupt energy production and lack real-time feedback, requiring temporary shutdowns or additional lab work.
Innovation Solution
A system that uses radiofrequency (RF) signal attenuation measurements in a geothermal power plant's transportation unit to estimate void fraction in real-time without disrupting production, employing antennas with aerodynamic and hydrodynamic designs to secure against vibrations and damage, and computing systems to calculate void fraction and enthalpy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional measurement techniques (separator/silencer assembly or pressure-controlled pipe) are used to measure void fraction, then measurement capability is achieved, but energy production is disrupted and operations must be temporarily shut down
Solution Approach 1:
The patent replaces mechanical measurement systems (separator/silencer assemblies, pressure-controlled pipes) with an electromagnetic field-based RF measurement system. The RF signal transmission method eliminates the need for physical flow redirection or pressure control modifications, allowing continuous energy production while achieving void fraction measurement through signal attenuation analysis in the two-phase flow.
2Loss of time
If tracer injection method is used to measure void fraction, then real-time measurement capability is improved, but additional lab work is required and instantaneous feedback is not provided
Solution Approach 1:
The RF measurement system is self-contained and autonomous, requiring no external lab work or sample analysis. The system performs void fraction measurement directly in the field using RF signal transmission through the pipeline, with results computed and provided in real-time without requiring removal of samples for laboratory analysis.
3Productivity
If RF signal attenuation measurement is implemented, then real-time void fraction measurement without production disruption is achieved, but antenna design complexity increases due to vibration and damage concerns
Solution Approach 1:
The patent employs protective coverings or coatings on the antennas that allow the RF signals to pass through while protecting the antenna elements from mechanical damage due to vibrations and two-phase flow conditions. These protective layers enable the antennas to maintain structural integrity in harsh geothermal environments while preserving RF signal transmission capability.
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
Enables real-time void fraction measurement and enthalpy calculation without interrupting geothermal power plant operations, providing instantaneous feedback and improving energy output estimation.
Implementation Method 1
measuring the attenuations of one or more radiofrequency (RF) signals in a fixed span of a transportation unit (e.g., a pipe). Depending on void fraction of the two-phase mixture in the transportation, the RF signals would attenuate differently across the fixed span.
Data Source
AI summary
Several embodiments include a method of computing void fraction in a two-phase mixture in a pipe. A driver and a transmitter antenna can transmit a radio frequency (RF) signal through the pipe. The pipe can convey the two-phase mixture extracted from a geothermal well. The RF signal can pass through the two-phase mixture. A receiver antenna in the pipe can receive the RF signal. A receiver circuit can measure signal strength attenuations of the RF signal at the receiver antenna over a time window. A computation engine can compute an average of the signal strength attenuations over the time window. The computation engine or another computing device can then compute, in real-time, a change in a void fraction of the two-phase mixture based on the average of the signal strength attenuations.