Research On Installation Environment And Pressure Loss Of Vortex Flowmeter With Tiny Diameter And Abnormity Cross Section

Vortex flowmeter is an instrument based on the principle of Karman vortex street.Due to its simple structure,convenient maintenance and wide application range,it is widely used in petroleum,chemical,electric power and other industries.Traditional vortex flowmeter is difficult to meet the measurement requirements when the pipeline diameter is tiny.The vortex flowmeter with abnormity cross section can achieve good measurement performance under the condition of tiny-diameter pipeline due to its own structural characteristics.This topic is studied on the PF3 W series vortex flowmeter provided by SMC Corporation of Japan.The simulation and experimental methods are used to study the pressure loss,installation environment and similarity.Specific work includes:1.Simulation analysis of pressure loss.Through the simulation analysis of the total pressure loss of the PF3 W series pipeline under different transition section angles,the angle value which minimizes the total pressure loss of the pipeline is determined to be 40 degrees.2.Installation environment simulation analysis.The transition section angle is set to 40 degrees.Then the simulation analysis on installation environment of the PF3 W series vortex flowmeter are carried out.According to the stability of the Strauhal number,the length range of the abnormity cross section pipeline is determined.3.Experiment verification.According to the above simulation analysis results,the experimental pipelines are designed to carry out the actual flow experiment.The simulation analysis results are verified by experimental data.4.Similarity analysis.The geometric similarity criterion of the tiny-diameter abnormity cross section pipeline vortex flowmeter is given by simulation analysis.First,the ratio of cross section area of front and rear pipelines is the same,and second,the R/L value of the abnormity cross section pipeline is the same.Then,by analyzing the relationship between Reynolds number corresponding to the upper and lower limits of vortex flowmeter and the pipeline diameter,it is concluded that under the condition of small flow,the lower limit of flow can be expanded by reducing the pipeline diameter.Finally,the influence of physical parameters of fluid medium on the coefficients of PF3 W series vortex flowmeters is analyzed.It is considered that the measurement performance of PF3 W series vortex flowmeters is not affected by physical parameters of fluid medium within a certain range of Reynolds number.