Thermographic Phosphor Sensor for High-Temperature Fluid Measurement
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Solution Overview
Problem
Existing temperature measurement techniques, such as thermocouples, are inadequate for measuring exhaust gas temperatures exceeding 1700 °C in gas turbine systems, leading to inaccurate readings and high replacement costs due to their limited temperature tolerance and durability issues.
Innovation Solution
A thermographic temperature sensor system utilizing a thermographic phosphor probe with a light pipe and optical source, where the phosphor emits phosphorescence in response to optical energy, allowing for direct measurement of fluid temperatures above 1700 °C, using non-metallic refractory materials and an air gap to enhance signal transmission and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If thermocouples are used to measure exhaust gas temperature, then temperature measurement is possible, but the measurement becomes inaccurate and the device fails when temperature exceeds 1700 °C
Solution Approach 1:
The patent replaces the mechanical/electrical thermocouple system with an optical measurement system. A phosphor coating on the probe tip emits phosphorescence when excited by light, and the phosphorescence intensity correlates with temperature. This optical system eliminates the electrical contacts and mechanical wear issues of thermocouples, enabling reliable measurement at temperatures above 1700 °C
Solution Approach 2:
The patent changes the measurement parameter from electrical voltage (thermocouple) to optical phosphorescence intensity. The phosphor material's phosphorescence characteristics change predictably with temperature, providing a reliable measurement mechanism that remains stable at extreme temperatures where thermocouples fail
2Measurement precision
If thermocouples are used in high temperature environments, then temperature measurement is achieved, but replacement costs increase due to frequent failures
Solution Approach 1:
The optical phosphorescence-based measurement system replaces the thermocouple, eliminating the frequent failures and replacements required in high-temperature environments. The phosphor-coated probe tip has no moving parts or electrical contacts that wear out, ensuring continuous operation and eliminating downtime for replacement
3Device complexity
If traditional temperature measurement techniques are used, then simple device structure is maintained, but measurement precision deteriorates at temperatures above 1700 °C
Solution Approach 1:
The patent changes from electrical resistance measurement (thermocouple) to optical phosphorescence measurement. The phosphor coating's phosphorescence intensity is directly correlated with temperature, providing accurate measurements at extreme temperatures. The probe structure remains simple with the phosphor applied as a coating on the tip surface
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 system provides accurate and durable temperature measurements beyond the limits of traditional thermocouples, reducing replacement costs and improving measurement precision in high-temperature environments.
Implementation Method 1
The thermographic phosphor is configured to phosphoresce in response to absorbing light from the optical source
Data Source
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AI summary
A system includes a thermographic temperature sensor 20 that may measure a temperature of a fluid. The thermographic temperature sensor includes a probe 80, an optical source 90 coupled to the probe, and a detector 96 coupled to the probe. The system also includes a housing of the probe; and a light pipe of the probe disposed within the housing and including a thermographic phosphor 86 that may phosphoresce in response to absorbing light from the optical source. The phosphorescence by the thermographic phosphor is representative of a temperature of the fluid within a flow path of the fluid, and the detector may detect the phosphorescence by the thermographic phosphor.