科里奥利质量流量计传感器零点模型研究及应用

科里奥利质量流量计以其直接测量质量流量的特点,成为近年来发展最为迅速的流量仪表之一,已经成为贸易结算的首选计量器具。虽然科里奥利质量流量计的测量精度很高,但是其存在零点漂移的缺陷,降低了仪表的长期稳定性。本文以典型的U型振动管传感器为例,基于振动管的幅频和相频特性,分析了传感器的各阶模态对于工作频率的响应,以此建立了传感器的初始相位模型。通过样机实验证明,该理论模型在应用于薄壁振动管时具有较高的计算精度和适用性,并将科里奥利质量流量计在低温介质测量中的测量误差降低到±0.3%以内,也为抑制科里奥利质量流量计零点漂移提供了理论依据。

Research and application of the zero-point model of the sensor in Coriolis mass flowmeter

Due to the virtue of directly measure mass flow, the Coriolis mass flowmeter is the first choice of international trade settlement in recent years. It has become one of the most rapidly developing flowmeters. Although the accuracy of Coriolis mass flowmeter is relatively high, it has the weakness of zero-point drift, which could result in long-term instability. Based on the characteristics of amplitude-frequency and phase-frequency of the classic U tube in the sensor, this article analyzes the responses of each order to the working vibration frequency. The model of the initial phase of the sensor is formulated. By prototypes testing, this zero-point model is suitable for thin-walled pipe structure and can be widely used. It reduces the error of Coriolis mass flowmeter in cryogenic flow measurement to be within ±0. 3% , and also provides a theoretical foundation to reduce the zero-point drift of Coriolis mass flowmeter.