热式气体流量计的研究与应用

The Research and Application of Thermal Gas Flowmeter

介绍了热式气体质量流量计的测量原理,表头电路仿真过程和仪表参数设置。应用两个热电阻传感器,一个测流速,另一个测温。通过电桥电路调整两个探头至恒温差,通过标定不同流速下的电桥加热功率实现热式气体瞬时流量的准确计量。由于仪表电路的复杂性,采用电路仿真的方法对电桥电路进行测试,针对不同测温传感器的工况温度值,仿真不同气体流速下,不同测速探头的实时温度值,验证了不同瞬时流量下测温探头的加热功率并不相同且具有标定可行性。再以美国斯雅乐气体质量流量计为例,详细介绍了热式流量计的仪表计量数据和配置参数。热式气体质量流量计具有高灵敏度、高重复性的工业计量仪表,尤其适用于大管径、低流速的测量场合。

The measuring principle of the thermal gas mass flowmeter,the simulation process of the meter head circuit and the parameter setting of the meter are introduced.Two thermal resistance sensors,one measuring the velocity and the other measuring the temperature,are used to adjust the two probes to the constant temperature difference through the bridge circuit.By calibrating the bridge heating power at different flow rates,the instantaneous flow of hot gas can be accurately measured.Because of the complexity of the instrument circuit,adopt the method of circuit simulation testing bridge circuit,according to different working condition of the temperature,temperature sensor simulation under different gas flow rate and different temperature real-time speed measuring probe,verify the instantaneous flow under different temperature measuring probe the heating power is not the same and calibration of feasibility.Taking Seiler gas mass flowmeter as an example,the meter measurement data and configuration parameters of thermal flowmeter are introduced in detail.Thermal gas mass flowmeter has high sensitivity and high repeatability,especially suitable for measuring occasions with large pipe diameter and low flow rate.