Segmented Sensor Mount With Gap Thermal Isolation for Cryogenic Surfaces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Sensors in extreme temperature environments, such as cryogenic fuel tanks, are prone to malfunction due to ice buildup when not thermally isolated, leading to reduced functionality and reliability.
Innovation Solution
A thermally-isolated sensor mount with interlocking segments providing high thermal resistance, utilizing natural gaps and surface roughness to maintain sensor operation in extreme temperatures, with configurations including prismatic and cylindrical designs that can be customized for specific applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sensor is mounted directly on a cryogenic fuel tank substrate, then the sensor can be easily installed and structurally simple, but the sensor will be exposed to extreme cold temperatures causing ice buildup and malfunction
Solution Approach 1:
The sensor mount is divided into multiple discrete segments (first segment, second segment, third segment) that can be assembled separately and stacked together. Each segment provides a portion of the total thermal resistance, and the segmented design allows for easier manufacturing, assembly, and maintenance compared to a single monolithic structure.
Solution Approach 2:
The sensor mount segments are arranged in a nested or stacked configuration where the first segment is positioned against the substrate, the second segment is positioned against the first segment, and the third segment is positioned against the second segment. This nested arrangement maximizes thermal isolation within a compact volume while maintaining structural integrity.
2Temperature
If multiple segments are used to increase thermal isolation, then the thermal resistance increases protecting the sensor, but the device complexity and number of components increase
Solution Approach 1:
Each segment is designed with specific local features including roughened mating surfaces, gaps between segments, and potentially different materials or coatings optimized for their specific position in the thermal isolation stack. This local optimization allows each segment to contribute maximally to thermal resistance while maintaining manufacturability.
Solution Approach 2:
The design utilizes controllable parameters such as gap thickness between segments, surface roughness characteristics, and material properties to optimize thermal resistance. By adjusting these parameters, the desired thermal isolation can be achieved with a practical number of segments rather than requiring an excessive number of components.
3Temperature
If gaps are introduced between segments to increase gap thermal resistance, then thermal isolation improves, but manufacturing precision requirements increase to maintain consistent gaps
Solution Approach 1:
The mating surfaces of the segments are designed with roughness features that promote self-alignment and automatic gap formation during assembly. The roughened surfaces create mechanical interlocking and ensure consistent gap spacing without requiring high-precision machining or complex adjustment procedures, allowing the structure to self-regulate the gaps.
4Strength
If the sensor mount is designed to be compact and rugged, then the mount size is reduced and structural strength is improved, but thermal isolation may be compromised
Solution Approach 1:
The sensor mount segments can be constructed from composite materials or combinations of materials with different thermal conductivities and mechanical properties. This allows the outer surfaces to be rugged and strong while internal structures provide thermal isolation, achieving both structural strength and thermal protection in a compact design.
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 ensures proper operation of sensors in extreme temperatures by effectively isolating them from both extremely cold and hot substrates, preventing ice buildup and maintaining sensor functionality across a wide range of applications.
Implementation Method 1
Natural gaps between the interlocking layers due to microscopic surface waviness and asperities increase the thermal resistance between adjoining surfaces. This is known as 'gap thermal resistance.'
Implementation Method 2
A thermally-isolated sensor mount is disclosed herein that is rugged, compact, and has a very high degree of thermal isolation (i.e., high thermal resistance) from an extremely hot or cold substrate.
Implementation Method 3
Mating surfaces can be artificially roughened to increase the gap thermal resistance.
Data Source
AI summary
A thermally-isolated sensor mounting structure, including at least two, nested, interlocking segments, including a lower segment and an upper segment attached to the lower segment, with one or more gaps between the upper and lower segments. The upper segment comprises a passageway for holding a sensor probe. The sensor mount can be a prismatic assembly that uses dovetail joints, or a threaded cylindrical assembly that is screwed together. The sensor mount can be attached to a substrate that is extremely cold or hot. Gap thermal resistance between the upper and lower segments plus optional optical coatings isolates the sensor probe from extreme temperatures. Mating surfaces can be artificially roughened or polished to increase the gap thermal resistance. The sensor probe can be screwed into the sensor mount. A total of four (or more) interlocking segments provides sufficient thermal isolation from a cryogenic substrate to prevent ice buildup on the sensor.