NIR Fluid Composition Analyzer with Wavelength Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional near-infrared (NIR) spectrometry techniques face challenges in accurately determining the water fraction in oil-water mixtures due to broadband variations in optical transmission caused by Mie and Rayleigh scatter from particulates and bubbles, leading to high background noise and significant measurement errors.
Innovation Solution
A device employing a broadband radiation source and post-spectral division of wavelengths, using dichroic beam splitters and Rugate filters to separate radiation into absorption and reference bands, allowing for accurate baseline interpolation and improved precision in measuring the water and oil fractions, while also incorporating a variable-gain amplifier to manage signal dynamic range and extend radiation source lifetime.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional DOAS techniques with single wavelength measurement are used, then the device complexity is reduced, but the measurement precision deteriorates due to high background noise from Mie and Rayleigh scatter
Solution Approach 1:
The patent divides the broadband radiation spectrum into multiple wavelength bands using dichroic beam splitters and Rugate filters. The spectrum is segmented into at least three bands: first absorption band (e.g., 1400-1500nm for water), second absorption band (e.g., 1700-1800nm for hydrocarbons), and reference band (e.g., 1500-1600nm). This segmentation allows simultaneous measurement of multiple components while compensating for scatter effects through ratio calculations.
Solution Approach 2:
The patent transitions from single-wavelength measurement to multi-wavelength spectral measurement, adding the wavelength dimension to the measurement process. By measuring radiation intensity across multiple wavelength bands and calculating ratios between absorption bands and reference bands, the system eliminates the need for absolute intensity calibration and compensates for broadband scatter effects.
2Measurement precision
If broadband radiation source operates at high intensity continuously, then the measurement precision is improved, but the duration of action of the radiation source deteriorates
Solution Approach 1:
The patent implements periodic measurement cycles where the broadband radiation source is activated only when needed for measurements. The system can operate in alternating measurement and standby modes, reducing cumulative operating hours and extending source lifetime while maintaining measurement capability when required.
Solution Approach 2:
The patent optimizes the operating parameters of the broadband radiation source by adjusting intensity levels based on measurement requirements. The source can operate at reduced intensity for routine measurements and only increase power when higher signal levels are needed, thereby reducing overall energy consumption and extending component life.
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 precise determination of water and oil fractions with reduced errors, even at high water cuts, and extends the lifespan of radiation sources by optimizing power usage, thus providing reliable and cost-effective monitoring of fluid compositions in oil pipelines and wells.
Implementation Method 1
a broadband radiation source for illuminating the mixture with radiation having a range of wavelengths that extends over an absorption band in each of the fluids
Implementation Method 2
the attenuation of radiation at a wavelength of an absorption band characteristic of one component of the mixture
Implementation Method 3
near infrared (NIR) absorption
Implementation Method 4
using dichroic beam splitters and Rugate filters to separate radiation into absorption and reference bands
Implementation Method 5
a device for separating the radiation into a wavelength band corresponding to an absorption band of one of the fluids, a wavelength band corresponding to an absorption band of another of the fluids, and at least one reference wavelength band substantially adjacent to each of the absorption bands
Implementation Method 6
a detector for detecting radiation that has been attenuated by the mixture
Implementation Method 7
a variable-gain amplifier to manage signal dynamic range
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A device for determining the composition of a mixture of fluids that flow along a pipe, which comprises: a radiation source for illuminating the mixture with radiation; a detector for detecting radiation that has been attenuated by the mixture; a device for monitoring the flow rate of fluid along the pipe and outputting a signal indicative of the flow rate. The device includes a device for adjusting the intensity of radiation emitted by the radiation source in response to the signal indicative of the flow rate so that the intensity of the radiation source is reduced if the flow rate reduces.