Capacitance Fuel Water Detector Eliminates Mechanical Jamming
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing water detection devices in fuel systems are prone to jamming due to contaminants and are susceptible to failure from bacterial growth, and they often require the introduction of water for testing, which is undesirable.
Innovation Solution
A contaminant detector with a conductive housing and sliding core, a non-conductive sensor probe, and a circuit board that creates a closed field loop to measure capacitance changes, allowing for water detection without mechanical parts and bacterial interference, and enabling simulated testing without water introduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical buoy detection device is used, then water detection capability is provided, but the device is prone to jamming by contaminants
Solution Approach 1:
The patent replaces the mechanical buoy system with an electrical capacitance-based detection system. The buoy and its mechanical floating motion are substituted by capacitive sensors that measure dielectric constant changes in the fuel, eliminating moving parts that could jam while maintaining water detection capability through electrical field interactions with the fuel-water mixture
2Reliability
If electrical conductivity-based water detection is used, then water detection is achieved, but bacterial growth forms insulating films that render the detector useless
Solution Approach 1:
The patent changes the detection parameter from electrical conductivity to dielectric constant (capacitance). Instead of measuring conductivity which is blocked by bacterial films, the system measures the dielectric properties of the fuel-water mixture, which remain detectable even in the presence of bacterial growth, thus maintaining detection reliability
Solution Approach 2:
The patent introduces capacitance measurement as an intermediary detection method. Rather than directly measuring conductivity that is blocked by bacterial films, the system uses capacitive coupling through the fuel medium to detect water presence, allowing the electrical field to penetrate bacterial barriers that would block direct conductivity measurements
3Ease of operation
If water is introduced into the fuel system for realistic function testing, then detector function can be verified, but this contradicts the requirement to remove water from the fuel system
Solution Approach 1:
The patent creates a simulated testing mode that copies the electrical characteristics of water presence without introducing actual water. By manipulating the capacitive sensor readings through electrical simulation, the system allows realistic function testing while maintaining fuel purity, eliminating the need to introduce contaminating water for validation
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
The solution effectively detects excessive water in fuel systems without mechanical failures and bacterial interference, providing reliable alerts and preventing water passage downstream, while allowing for certification testing without introducing water into the system.
Implementation Method 1
measuring the capacitance of the base fluid in proximity to the sensor probe in the housing
Implementation Method 2
creating a closed field loop through the base fluid
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A contaminant detector disposed within a base fluid for detecting the presence of a contaminating fluid includes a conductive core, a conductive sensor probe extending from the core in non-conductive relation, and a circuit board within the core. The circuit board is electrically connected to the sensor probe and electrically insulated from the core. Electrical power applied to the core creates a closed field loop for measuring the localized capacitance of the base fluid. When sufficient contaminating fluid exists in the base fluid to change the localized capacitance, an alarm is sounded to indicate the presence of the contaminating fluid.