Thermopile Sensor for High Temperature Thermal Measurements
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Solution Overview
Problem
Existing temperature and heat flux measurement instruments are not suitable for high-temperature environments due to their limited durability and reliability, making it challenging to accurately monitor and analyze thermal data in applications like rocket engines and gas turbines.
Innovation Solution
A thermopile sensor with a uniform substrate and refractory metal thermopile junctions, connected in series, along with a thermocouple component, is designed to operate effectively in high-temperature environments by utilizing a substrate with a varying elevation and an anti-oxidation layer, allowing for accurate temperature and heat flux measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional temperature sensors (thermocouples, resistance temperature detectors, thermistors) are used in high temperature environments, then measurement capability is provided, but reliability and durability deteriorate due to oxidation and material degradation
Solution Approach 1:
The sensor employs a composite structure combining refractory metal strips (tungsten, molybdenum) with a ceramic substrate (sapphire, silicon carbide). This composite design enables the sensor to withstand temperatures exceeding 1000°C while maintaining structural integrity and measurement accuracy, directly resolving the contradiction between reliability and temperature limit.
Solution Approach 2:
The patent employs thin-film deposited refractory metal strips that can be rapidly replaced if degraded. The thin-film nature allows for cost-effective batch fabrication and replacement, maintaining system reliability without requiring long-lived individual sensor components.
2Adaptability or versatility
If existing instrumentation options are used, then temperature measurement is achieved, but adaptability to harsh high temperature environments deteriorates
Solution Approach 1:
The sensor implements local quality through differentiated substrate sections: a first section with elevated thermopile junctions for heat flux measurement and a second section at lower elevation for temperature reference. This local differentiation enables simultaneous measurement of multiple thermal parameters in harsh environments, enhancing both adaptability and reliability.
Solution Approach 2:
The patent changes the physical state and properties of materials to adapt to high temperature environments. Refractory metals maintain structural stability at temperatures where conventional metals would oxidize or deform, while ceramic substrates provide thermal stability. This parameter change enables operation in previously inaccessible temperature regimes.
3Measurement precision
If thermopile junctions are placed on a flat substrate surface, then manufacturing is simplified, but measurement precision deteriorates due to insufficient thermal gradient detection
Solution Approach 1:
The patent transitions from a two-dimensional flat substrate to a three-dimensional structure with elevated sections. The thermopile junctions are positioned on a first section that rises vertically from the substrate, creating a stepped configuration. This dimensional change enhances thermal gradient detection by positioning junctions in regions of higher thermal stress while maintaining manufacturability through standard deposition techniques.
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 sensor provides reliable and accurate measurements of temperature and heat flux up to 1000°C, with continuous operation demonstrated for over ten hours, and offers a cost-effective, minimally invasive solution for high-temperature applications.
Implementation Method 1
a first strip of a first conductive material, extending from the first section to the second section, and a second strip of a second conductive material, forming an electrical junction with the first strip on the second section
Implementation Method 2
a third strip of a third conductive material connecting with a fourth strip of a fourth conductive material on the first surface of the substrate to form an electrical junction
Data Source
AI summary
A thermopile sensor including a uniform substrate having a first surface with a first section and a second section at an elevation varying relative to the first section by between about 5 micrometers and about 500 micrometers. The sensor further includes a plurality of thermopile junctions, with each junction having (i) a first strip of a first conductive material, extending from the first section to the second section, (ii) a second strip of a second conductive material, forming an electrical junction with the first strip on the second section and extending to the first section, and (iii) with the thermopile junctions being connected in series. A first contact pad on the substrate is connected to an initial thermopile junction and a second contact pad on the substrate is connected to a last thermopile junction, with conductors connecting to the first and second contact pads and extending off of the substrate.