变传感器设定值的科氏质量流量管控制方法

在科氏质量流量计中,流量管的稳幅振动是准确测量的前提。当两相流发生时,科氏质量流量管无法维持在最佳幅值下振动,导致传感器输出信号幅值波动大。针对两相流下流量管幅值控制面临的问题,分析影响流量管振动幅值大小和稳定性的因素,提出跟踪传感器信号幅值、变传感器信号设定值的控制方法,在研制的数字式科氏质量流量变送器上实时实现,并在气-液两相流实验装置上进行2种设定值方法的对比实验。实验结果表明,在不同含气量和控制及时性的情况下,变传感器设定值的控制方法均具有良好的信号跟踪和幅值控制的性能,流量管振动较平稳,传感器信号幅值波动范围小,极大地减小了两相流测量过程中的波动性。

Variable sensor setting value based control method for Coriolis Mass flowtube flowmeter

Stable vibration of flowtube is the premise of accurate measurement for Coriolis mass flowmeter. Optimal vibration amplitude of flowtube cannot be maintained when two phase flow occurs, which leads to a large fluctuation of the sensor output signal. Aiming at the problem of flowtube amplitude control, the factors affecting its vibration amplitude and stability are analyzed. And variable sensor setting value control method is proposed to track the sensor amplitude variation. The method is realized on the developed digital Coriolis mass flow transmitter in real time. The comparative experiments of two kinds of setting value methods are performed in a liquid gas two phase flow rig. The experimental results show that the variable sensor setting value method has a better performance both in signal tracking and amplitude controlling under the situations of different gas volume fractions and control responses. The flowtube can be maintained relatively stable vibration, and the fluctuation range of the sensor signal amplitude is small, which reduces the volatility significantly in the process of two phase flow measurement.