稳态自热型对流换热系数传感器研究

Research of Heat Transfer Coefficient Sensor in Thermal-Steady and Active Mode

关键词:  稳态  自热型  对流换热系数  比例系数  阶跃加热  传感器  测量

Key words:  Thermal-steady  Active mode  Heat transfer coefficient  Correlation factor  Step change in heat flux  Sensor  Measurement

摘要:

为解决旋转固体表面对流换热系数测试难题，设计并研发了一款基于稳态方法的自热型对流换热系数传感器。进行了管道标定实验，分别与经典经验公式以及自制的标定端进行了对比，结果发现传感器的测试存在一个稳定的比例系数，经修正后相对误差小于5%。采用数值模拟方法进一步从机理方面探究了该比例系数存在的合理性，发现在阶跃加热的情况下存在一个“热调整区”，会导致对流换热的阶跃性变化，这种变化类似于“入口效应”，同时这种效应不受加热段温度的影响，定性地验证了传感器测量的准确性。

Abstract:

An innovative heat transfer coefficient sensor in thermal-steady and active mode is designed and developed in order to measure the heat transfer coefficients on rotating solid surface. Compared with the results of two heat transfer correlations and the self-developed calibration apparatus， the heat transfer coefficient sensor had a constant correlation factor during the calibration experiments in a rectangular pipe. The relative error was less than 5% after correction. The rationality of the correlation factor was investigated with numerical simulation method. The results showed that there was a thermal adjustment zone which could cause the step change in convective heat transfer when the heat flux had a step change. Similar with the entrance effect， the step change is not affected by the temperature of the heating zone. So， the accuracy of the sensor measurement is verified by the qualitative research.