Chen Hao, Liu Tao, Feng Nanming, Shi Yeming, Zhou Zigang, Dai Bo
The State Key Laboratory of Environment-Friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China.
School of Materials and Chemistry, Southwest University of Science and Technology, Mianyang 621010, China.
Micromachines (Basel). 2023 Jul 20;14(7):1458. doi: 10.3390/mi14071458.
Aiming at the shortcomings of the traditional engineering experience in designing thin-film heat flow meters, such as low precision and long iteration time, the finite element analysis model of thin-film heat flow meters is established based on finite element simulation methods, and a double-type thin-film heat flow sensor based on a copper/concentrate thermopile is made. The influence of the position of the thermal resistance layer, heat flux density and thickness of the thermal resistance layer on the temperature gradient of the hot and cold ends of the heat flow sensor were comprehensively analyzed by using a simulation method. When the applied heat flux density is 50 kW/m and the thermal resistance layer is located above and below the thermopile, respectively, the temperature difference between the hot junction and the cold junction is basically the same, but comparing the two, the thermal resistance layer located above is more suitable for rapid measurements of heat flux at high temperatures. In addition, the temperature difference between the hot and cold contacts of the thin-film heat flux sensor increases linearly with the thickness of the thermal resistance layer. Finally, we experimentally tested the response-recovery characteristics of the sensors, with a noise of 2.1 μV and a maximum voltage output of 15 μV in a room temperature environment, respectively, with a response time of about 2 s and a recovery time of about 3 s. Therefore, the device we designed has the characteristic of double-sided use, which can greatly expand the scope of use and service life of the device and promote the development of a new type of heat flow meter, which will provide a new method for the measurement of heat flow density in the complex environment on the surface of the aero-engine.
针对传统工程经验设计薄膜热流计存在精度低、迭代时间长等缺点，基于有限元模拟方法建立了薄膜热流计的有限元分析模型，并制作了基于铜/浓缩物热电堆的双型薄膜热流传感器。利用模拟方法综合分析了热阻层位置、热流密度和热阻层厚度对热流传感器冷热端温度梯度的影响。当施加的热流密度为50kW/m且热阻层分别位于热电堆上方和下方时，热端和冷端的温差基本相同，但相比之下，位于上方的热阻层更适合高温下热流的快速测量。此外，薄膜热流传感器的热冷接触温差随热阻层厚度呈线性增加。最后，对传感器的响应-恢复特性进行了实验测试，在室温环境下，噪声分别为2.1μV，最大电压输出为15μV，响应时间约为2s，恢复时间约为3s。因此，我们设计的装置具有双面使用的特点，可大大扩大装置的使用范围和使用寿命，推动新型热流计的发展，为航空发动机表面复杂环境下热流密度的测量提供新方法。
