克服热惯性的气流温度动态测量方法

Dynamic measuring method for airflow temperature with overcoming thermal inertia

针对热敏式温度传感器动态响应速度难以适应快速变化的热流测量的问题,在建立温度传热模型以及对模型参数实测的基础上,提出采用微分预测补偿的方法,提高温度测量的响应速度。应用交流调制激励的方法与电阻串联分压的方式实现热敏电阻的高精度测量,同时采用设定了适当的阻尼系数与固有频率的二阶低通数字滤波方法抑制随机误差的影响,并充分利用数字滤波的中间结果完成温度预测的计算。实验表明:提出的方法极大地提高了热敏电阻测温的响应速度,能够完成气流温度的实时捕捉。

Aiming at the measurement problem that the dynamic response speed of thermosensitive sensors is difficult to fit rapidly changing heat flux, a new method based on differential prediction and compensation is proposed, on the basis of construction of heat transfer model and actual measurement of model parameters.The AC modulation excitation method and voltage dividing are applied to achieve high-precision measurement of thermistor, a second-order low-pass digital filtering method with suitable damping factor and natural frequency is used to decrease the influence of random error, and the temperature prediction is completed with the intermediate result of digital filtering.Experiments show that the proposed method can improve response speed of thermistor and can real-time measure the airflow temperature.