基于热电堆的新型高温薄膜热流传感器的研制

Development of a New Type of High Temperature Thin Film Heat Flux Sensor Based on Thermopile

精确的热流测量对航空发动机设计至关重要,实时监测和获取发动机涡轮叶片表面精确的热流分布可以为航空发动机热端部件设计提供依据,也可以进行状态监测和故障诊断。薄膜热流传感器具有体积小、响应速度快、对工作环境的流动干扰小等优点。然而,目前能够应用于高温高热流环境中测量的薄膜热流传感器在灵敏度方面仍然存在较大的局限性。设计和制造了基于铂铑热电堆的新型高温薄膜热流传感器。该传感器由Pt/Pt-13Rh薄膜热电堆、底层SiO_(2)/Al_(2)O_(3)热阻层、顶层Al_(2)O_(3)保护层组成,底层SiO_(2)/Al_(2)O_(3)热阻层位于Al_(2)O_(3)陶瓷基底和热电堆之间。传感器分别在0~110 kW/m^(2)的热流和1 000℃的温度下进行了测试。测试结果显示,传感器的输出与施加的热流表现出良好的线性关系,灵敏度为8.04×10^(-6)V/(kW/m^(2)),实验数据与仿真结果相近。具有Al_(2)O_(3)保护层的传感器在1 000℃中保温3 h后电阻、灵敏度及响应特性基本上不受影响。设计的新型高温薄膜热流传感器具有较高的灵敏度和可靠性,将为高温环境中的热流测量提供一种新方法。

Accurate heat flux measurement is crucial for both the design and fault diagnosis of aeroengines. The thin film heat flux sensor has the advantages of small size, fast response and little interference to the operation environment. However, the sensors currently capable of corrying out such measurements in high temperature and high heat flux environments still have significant limitations. A new type of high temperature thin film heat flux sensor based on platinum rhodium thermopiles is designed and manufactured. The sensor consists of Pt/Pt-13 Rh thin film thermopiles, the bottom SiO_(2)/Al_(2)O_(3)thermal resistance layer and top Al_(2)O_(3)protective layer. The bottom SiO_(2)/Al_(2)O_(3)thermal resistance layer is sandwiched between the Al_(2)O_(3)ceramic substrate and the thermopiles. The sensor is inspected at heat flux from 0 to 110 kW/m^(2) and temperature of 1 000 ℃ respectively. The measurement results show that the output of the sensor has a good linear relationship with the applied heat flux, and the sensitivity is 8.04×10^(-6)V/(kW/m^(2)). The experimental data and the simulation results coincide. The resistance, sensitivity and response characteristics of the sensor with Al_(2)O_(3)protective layer are basically unaffected after 1 000 ℃ for 3 hours. The high temperature thin film heat flux sensor shows high sensitivity and reliability, which will supply an innovative method for heat flux measurement in high temperature environments.