热式微小流量传感器温度场及信号提取分析

Analysis about Temperature Field and Signal Processing of Thermal Micro Mass Flow Sensor

热式流量传感器由于其结构简单、没有机械运动部件等固有的优点,在微小流量测量领域具有明显优势。针对微小气体流量测量领域毛细取样管路及其内部气体流体,进行热力学、流体力学理论分析,配合信号处理电路的分析,提出了消除环境温度影响的电路方法,同时使用MATLAB语言,用数值计算方法,获得了气体流量与毛细取样管路温度场之间的关系,进一步获得了热式流量传感器动态特性的传递函数,并对不同组态模式下的热式传感器在微小流量下的测量性能进行了仿真分析和实验,获得了有益的结果。

Thermal mass flow sensor has obvious advantages in the field of micro-flow measurement because of its simple structure and no mechanical moving parts.As far as the field of micro gas flow measuring capillary pipeline and its internal gas fluid is concerned,thermodynamics and hydrodynamics theoretical analysis were carried out.Combined with the signal processing circuit analysis,the method to eliminate the influence of environmental temperature was proposed.At the same time,the relationship between gas mass flow and temperature field of the capillary pipeline has been obtained by MATLAB language and numerical calculation,and furthermore,the transfer function about the dynamic characteristics of the thermal flow sensor was deduced,the sensor performances with different configuration modes under micro-flow conditions were simulated and tested,and the valuable results have been acquired.