Laser-Induced Fluorescence Probe for Fuel Dilution Detection

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Solution Overview

Problem

There is a challenge in measuring fuel contamination or dilution in oil, particularly in diesel engines, which affects engine durability and emission control during lean NOx trap regeneration, as existing methods lack precision in detecting fuel presence and concentration in oil samples, especially with particulate-laden samples.

Innovation Solution

The use of laser-induced fluorescence (LIF) spectroscopy with a 532-nm laser diode as an excitation source and a spectrometer for detecting fluorescent light emitted by the oil and dye, allowing for precise analysis of fuel presence and concentration in oil samples, even in the presence of soot and other particulates.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If laser-induced fluorescence spectroscopy is used to detect fuel in oil, then measurement precision and sensitivity are improved, but device complexity increases

Engineering Contradiction:

Improvefuel detection precisionVSAvoiddetection system complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces complex mechanical separation and analysis systems with an optical detection system. A laser excites fluorescent dyes in fuel components, and the emitted fluorescence is detected and analyzed spectrally, eliminating the need for mechanical sample preparation and separation equipment while achieving high measurement precision.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent utilizes fluorescence emission at different wavelengths (colors) to identify and quantify different fuel components in oil. By detecting the characteristic fluorescence spectra emitted when laser-excited fuel molecules return to ground state, the system achieves precise fuel detection through spectral analysis of color changes.

Inventive Principle:

Principle #32Color changes

2Device complexity

If traditional gas chromatography methods are used for fuel dilution measurement, then device complexity is reduced, but measurement precision and sensitivity deteriorate

Engineering Contradiction:

Improvedetection system complexityVSAvoidfuel detection precision

Core Design Contradiction:

Device complexityVSMeasurement precision

Solution Approach 1:

The patent replaces gas chromatography's complex mechanical separation columns and detection systems with a direct optical fluorescence detection system. The laser-induced fluorescence method provides equivalent or superior measurement precision without requiring complex mechanical separation apparatus.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Object-generated harmful factors

If extra fuel injection is increased to regenerate lean NOx trap catalysts, then emission control is improved, but oil dilution by fuel worsens

Engineering Contradiction:

ImproveNOx emissionsVSAvoidoil dilution

Core Design Contradiction:

Object-generated harmful factorsVSLoss of substance

Solution Approach 1:

The patent implements real-time feedback monitoring of fuel dilution in engine oil using laser-induced fluorescence spectroscopy. The measured fuel concentration and dilution rate are fed back to the engine control system, which adjusts injection timing and quantity to maintain optimal catalyst regeneration while preventing excessive oil dilution, thus resolving the contradiction between emission control and oil protection.

Inventive Principle:

Principle #23Feedback

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 method provides high sensitivity and accuracy in detecting fuel dilution in oil, enabling real-time feedback for optimizing engine operation and reducing engine oil dilution, with the ability to measure dilution rates and concentrations effectively, outperforming traditional gas chromatography methods in sensitivity and precision.

Implementation Method 1

laser-induced fluorescence (LIF) spectroscopy with a 532-nm laser diode as an excitation source

Methodology Applied

Scientific EffectLaser-induced fluorescence: Fluorescence

Implementation Method 2

532-nm laser diode

Methodology Applied

Scientific EffectLaser: Laser

Implementation Method 3

detecting fluorescent light emitted by the oil and dye

Methodology Applied

Scientific EffectFluorescence emission: Fluorescence

Data Source

PatentUS7839492B2Laser-induced fluorescence fiber optic probe measurement of oil dilution by fuel

Publication Date: 2010.11.23 UT BATTELLE LLC

AI summary

Apparatus for detecting fuel in oil includes an excitation light source in optical communication with an oil sample for exposing the oil sample to excitation light in order to excite the oil sample from a non-excited state to an excited state and a spectrally selective device in optical communication with the oil sample for detecting light emitted from the oil sample as the oil sample returns from the excited state to a non-excited state to produce spectral indicia that can be analyzed to determine the presence of fuel in the oil sample. A method of detecting fuel in oil includes the steps of exposing a oil sample to excitation light in order to excite the oil sample from a non-excited state to an excited state, as the oil sample returns from the excited state to a non-excited state, detecting light emitted from the oil sample to produce spectral indicia; and analyzing the spectral indicia to determine the presence of fuel in the oil sample.