多声道超声流量计在弯管段安装的适应性研究

Adaptability study of multi-path ultrasonic flowmeter installed in a bend pipe

针对在不具备直管段安装条件时,如何合理地选取多声道超声流量计的声道数量、测量断面及安装角度,本文从数学建模、误差分析、数值计算仿真与试验分析等方面,对DN400多声道超声流量计在弯管中的适应性进行了综合研究。利用高斯-雅克比数值积分法,给出了试验数据处理与数值仿真的数学模型,并分析了模型误差及横流的影响,提出利用双断面测量可减小横流的影响,并在数值仿真和试验中得到了验证。通过对声道数量、测量断面、安装角度进行数值仿真和试验表明,安装角度对低流速测量影响显著,最佳安装角应为0°;高流速测量应选用双断面,可根据测量精度的要求选用8声道或18声道。仿真结果与试验结果得到了很好的吻合,为进一步指导试验奠定了理论基础。

Aiming at the problem of how to select number of acoustic paths,measurement planes and installation angle when installing straight pipe is impossible,the performance of DN400 multi-path ultrasonic flowmeter for bend pipe measurement was studied from mathematical modeling,error analysis,numerical simulation and experiment analysis.According to Gauss-Jacobi numerical integration method,a mathematical model for simulation and experiment is given,and model errors and the effect of cross flow are analyzed.A two symmetric plane measurement method is proposed to decrease the effect of cross flow,which is verified in numerical simulation and experiment.Numerical simulation and experiment results indicate that the installation angle has significant effect on low flow rate measurement,the optimum installation angle is 0°;and the two plane measurement method should be used for high flow rate measurement.According to the measurement precision requirement,8 or 18 acoustic paths could be selected.Simulation results are consistent well with the experimental results,which establishes a theoretical foundation for subsequent experiment study.