高温高压对超声流量计表体变形量及测量精度的影响

Influence of High Temperature and High Pressure on Deformation and Measurement Accuracy of Ultrasonic Flowmeter

在国内尚无高温高压标准水流量检定装置的情况下,为了保证超声波流量计在核电站主给水流量测量误差在0.3%以内,该文基于有限元分析与高温高压静态实验相结合的方法对高温高压引入的表体结构参数变形量及产生的流量测量误差进行分析。研究结果表明,设计的高温高压静态实验装置具有较高的变形量测量精度和测量稳定性。在无高温高压水流量标准装置的情况下,对提高超声波流量计在高温高压状态的测量精度具有积极作用;温度是影响表体结构参数变形的主要因素,压力影响可以忽略。表体结构参数变形量与温度之间呈线性关系,随温度的升高而增大;在P=7.8 MPa,T=226℃工况下,超声波流量计结构参数变形量引入的误差为0.64%,无法满足核电站主给水流量测量误差为0.3%的要求。

In the absence of a high temperature and high pressure standard water flow verification device in China,in order to ensure that the measurement error of the ultrasonic flowmeter in the main feedwater flow of the nuclear power plant is within 0.3%,this paper analyzes the deformation of the meter body structure parameters introduced by high temperature and high pressure and the resulting flow measurement error based on the combination of finite element analysis and high temperature and high pressure static experiment.The research results show that the high temperature and high pressure static experimental device designed has high deformation measurement accuracy and measurement stability,which would play a positive role in improving the measurement accuracy of ultrasonic flowmeter in the absence of high temperature and high pressure water flow standard device.Temperature is the main factor affecting the deformation of the structural parameters of the meter body,and the influence of pressure can be ignored.There is a linear relationship between the deformation of the structure parameters of the meter body and the temperature,which increases with the increase of temperature.Under the working conditions of P=7.8 MPa,T=226℃,the error introduced by the deformation of the structural parameters of the ultrasonic flowmeter is 0.64%,which cannot meet the requirement that the main feedwater flow measurement error of the nuclear power plant is less than 0.3%.