Electromagnetic Flowmeter Based On Quantitative Evalution Of Flow Fieldresearch On Flow Field Error Compensation Method

In the fields of petrochemical,water conservancy and other liquid transportation,flow measurement and other fields,the measurement accuracy of flow meter is very important.However,the symmetry state of the flow field inside the pipeline has a significant impact on the measurement results of the flow field-sensitive flow meter,while the symmetry state of the flow field inside the pipeline is affected by the insufficient measurement method,the influence of temperature coupling and the complex measurement conditions,which is difficult to accurately quantify and evaluate.In this paper,the quantitative evaluation method of flow field based on multi-channel ultrasonic flowmeter is studied by taking electromagnetic flowmeter as the research object,and the flow error caused by the asymmetric flow field is compensated on the basis of eliminating the influence of temperature coupling.The main research contents of the paper are as follows.(1)Based on the principle of multi-channel ultrasonic flow velocity measurement,the quantitative evaluation method of flow field in closed pipeline was studied,the flow field asymmetry coefficient and its calculation method were designed,and the law of flow field asymmetry coefficient changing with flow field was studied through CFD simulation experiment,and verified by real flow experiment.(2)The measurement mechanism model of electromagnetic flowmeter is established,the influence law of ambient temperature and medium temperature on the measurement results of the flowmeter is studied,and the coupling influence of temperature is eliminated on this basis,which provides a basis for separately studying the influence of flow field asymmetry on the measurement results of the flowmeter.(3)A real flow experiment platform was built,the correspondence between the flow field asymmetry coefficient and the flow field error was established through the flow field influence experiment,and the flow field error compensation model of the support vector machine was established to compensate for the flow field error caused by the flow field asymmetry.