High-temperature measurement of ultrasonic wave velocity in refractory materials

2002 ◽  
Vol 34 (2) ◽  
pp. 193-201 ◽  
Author(s):  
Marc Huger ◽  
Dominique Fargeot ◽  
Christian Gault
Keyword(s):  
High Temperature ◽  
Temperature Measurement ◽  
Ultrasonic Wave ◽  
Wave Velocity ◽  
Refractory Materials ◽  
Ultrasonic Wave Velocity ◽  
High Temperature Measurement

scholarly journals Analysis of Platen Superheater Tube Degradation in Thermal Power Plants via Destructive/Non-Destructive Characteristic Evaluation

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 581
Author(s):  
Se-Beom Oh ◽  
Jongbeom Kim ◽  
Soon-Woo Han ◽  
Kyung-Mo Kim ◽  
Dong-Seok Yun ◽  
...  
Keyword(s):  
High Temperature ◽  
Ultrasonic Wave ◽  
Wave Velocity ◽  
Power Plants ◽  
Thermal Power ◽  
Microstructural Analysis ◽  
Electromagnetic Acoustic Transducer ◽  
Ultrasonic Wave Velocity ◽  
Temperature Environment ◽  
High Temperature Environment

Coal-fired power plants operating under Korea’s standard supercritical pressure operate in a high-temperature environment, with steam temperatures reaching 540 °C. A standard coal-fired power plant has a 30-year design life, and lifespan diagnosis is performed on facilities that have operated for more than 100,000 h or 20 years. Visual inspection, thickness measurements, and hardness measurements in the field are used to assess the degree of material degradation at the time of diagnosis. In this study, aging degradation was assessed using an electromagnetic acoustic transducer to measure the change in transverse ultrasonic propagation speed, and the results were compared to microstructural analysis and tensile test results. Based on the experimental results, it was found that the boiler tube exposed to a high-temperature environment during long-term boiler operation was degraded and damaged, the ultrasonic wave velocity was reduced, and the microstructural grains were coarsened. It was also confirmed through tensile testing that the tensile and yield strengths increased with degradation. Our findings prove that the degree of change in mechanical properties as a function of the material’s degradation state is proportional to the change in ultrasonic wave velocity.

Study on characteristics of schottky temperature detector based on metal/n-ZnO/n-Si structures

2020 ◽  
Vol 12 ◽  
Author(s):  
Fang Wang ◽  
Jingkai Wei ◽  
Caixia Guo ◽  
Tao Ma ◽  
Linqing Zhang ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Measurement ◽  
Temperature Response ◽  
Large Temperature ◽  
Mems Devices ◽  
Temperature Range ◽  
Response Characteristics ◽  
High Temperature Measurement ◽  
Temperature Detector ◽  
Schottky Structure

Background: At present, the main problems of Micro-Electro-Mechanical Systems (MEMS) temperature detector focus on the narrow range of temperature detection, difficulty of the high temperature measurement. Besides, MEMS devices have different response characteristics for various surrounding temperature in the petrochemical and metallurgy application fields with high-temperature and harsh conditions. To evaluate the performance stability of the hightemperature MEMS devices, the real-time temperature measurement is necessary. Objective: A schottky temperature detector based on the metal/n-ZnO/n-Si structures is designed to measure high temperature (523~873K) for the high-temperature MEMS devices with large temperature range. Method: By using the finite element method (FEM), three different work function metals (Cu, Ni and Pt) contact with the n-ZnO are investigated to realize Schottky. At room temperature (298K) and high temperature (523~873K), the current densities with various bias voltages (J-V) are studied. Results: The simulation results show that the high temperature response power consumption of three schottky detectors of Cu, Ni and Pt decreases successively, which are 1.16 mW, 63.63 μW and 0.14 μW. The response temperature sensitivities of 6.35 μA/K, 0.78 μA/K, and 2.29 nA/K are achieved. Conclusion: The Cu/n-ZnO/n-Si schottky structure could be used as a high temperature detector (523~873K) for the hightemperature MEMS devices. It has a large temperature range (350K) and a high response sensitivity is 6.35 μA/K. Compared with traditional devices, the Cu/n-ZnO/n-Si Schottky structure based temperature detector has a low energy consumption of 1.16 mW, which has potential applications in the high-temperature measurement of the MEMS devices.

scholarly journals Miniaturized fiber taper reflective interferometer for high temperature measurement

2010 ◽  
Vol 18 (13) ◽  
pp. 14245 ◽  
Author(s):  
Jun-long Kou ◽  
Jing Feng ◽  
Liang Ye ◽  
Fei Xu ◽  
Yan-qing Lu
Keyword(s):  
High Temperature ◽  
Temperature Measurement ◽  
High Temperature Measurement ◽  
Fiber Taper
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