Temperature Sensing Array for Freeboard Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing freeboard sensing technologies fail to reliably operate in extreme weather conditions, particularly freezing temperatures, due to issues with float switches freezing, acoustic and laser range finders being obstructed by ice, and pressure transducers experiencing long-term drift and false readings from wave and acoustic noise.
Innovation Solution
An electronic device with a tubular member housing a printed circuit board assembly featuring an array of temperature sensors at equally spaced locations, measuring temperature differentials between air and water to determine the freeboard distance, which is immune to cold temperatures, acoustic noise, and wave dynamics, with no moving parts exposed to the elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If float switches are used for freeboard detection, then the device can be simple in structure, but it freezes in place when submerged in cold water
Solution Approach 1:
The patent replaces the mechanical float switch system with an electronic temperature sensing array. Instead of using a mechanical float that moves with water level changes, the invention uses temperature sensors arranged vertically to detect temperature differentials between air and water, thereby determining freeboard electronically without moving mechanical parts that can freeze.
Solution Approach 2:
The invention changes the measurement parameter from mechanical position to temperature differential. By measuring temperature differences along the vertical axis and identifying where the transition from air temperature to water temperature occurs, the system determines freeboard based on thermal parameters rather than mechanical displacement.
2Measurement precision
If acoustic or laser range finders are used for freeboard detection, then measurement capability is provided, but ice blocks the detection path
Solution Approach 1:
The patent replaces optical/acoustic detection systems with thermal sensing. Instead of using acoustic waves or laser beams that can be blocked by ice, the invention uses temperature sensors that passively detect thermal fields. Ice cannot block thermal conduction through the sensor housing, eliminating the blockage problem.
Solution Approach 2:
The tubular housing acts as an intermediary that protects the temperature sensors from direct exposure to ice and water while still allowing thermal energy to reach the sensors. The housing conducts thermal energy from the environment to the sensors without being blocked by ice accumulation on its exterior.
3Measurement precision
If pressure transducers are used for freeboard detection, then pressure differential measurement is achieved, but long term drift and false readings occur due to wave activity and acoustic noise
Solution Approach 1:
The patent replaces pressure-sensitive transducers with temperature-based sensing. Instead of measuring pressure differentials that are affected by waves and acoustic noise, the system measures temperature differentials along the vertical axis. Temperature is a scalar quantity not affected by mechanical disturbances like waves or sound waves, providing stable readings.
Solution Approach 2:
The invention changes the measured parameter from pressure to temperature. By detecting the vertical temperature gradient and identifying the transition point between air and water temperatures, the system determines freeboard based on thermal parameters that are insensitive to wave activity and acoustic noise.
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 provides accurate and reliable freeboard sensing in any weather condition, including freezing temperatures, without being affected by ice buildup, wave activity, or acoustic noise, and does not suffer from long-term drift, ensuring continuous monitoring of a vessel's structural integrity.
Implementation Method 1
A plurality of temperature differential values are calculated. Each temperature differential value corresponds to electrical signals received from at least two temperature sensors. At least one maximum temperature differential value is indicative of a freeboard location with respect to the vessel.
Data Source
AI summary
An exemplary inventive freeboard detection system includes a tubular watertight temperature-sensing device and a computer. The temperature-sensing device includes a printed circuit board assembly (PCBA), a potting compound, and a hollow rigid tube. Inside the tube the potting compound encapsulates the PCBA, which includes a printed circuit board (PCB) and multiple temperature sensors closely and equidistantly arrayed along the length of the tube. The temperature-sensing device is vertically secured in a partially submerged state to a vessel with the expectation that some of the vertically arrayed temperature sensors will sense air temperature and others will sense water temperature. On an ongoing basis, the computer receives signals from the temperature sensors and processes the signals to monitor freeboard values, which the computer calculates based on differences in temperature measurements corresponding to pairs of consecutive (and/or nonconsecutive) temperature sensors. A maximum calculated difference in temperature measurements is indicative of the location of the water surface.