Measurement Accuracy Improvement Method Of Gas Ultrasonic Flowmeter In Complex Flow Field

China is a large natural gas consuming country,and the need for the development of natural gas metering equipment will grow with the increasing use of natural gas.Gas ultra-sonic flow meter relative to the traditional flow meter,has outstanding advantages,it will certainly be widely used.In the practical application process,due to the installation space is limited,the emergence of elbow or double elbow and other installation,leading to com-plex flow field,flowmeter measurement accuracy is not high.Therefore,it is very im-portant to study the measurement accuracy improvement of gas ultrasonic flowmeter in complex flow field.In this dissertation,the measurement precision of gas ultrasonic flowmeter under complex flow field is mainly studied.The main contents are as follows:(1)Rectifier on gas ultrasonic measurement accuracy.For the Sick Rectifier and Elster Rectifier commonly used in the market numerical simulation study,select the rectification better rectifier.For rectifiers with better rectification effect,the numerical simulations under single-bends and double-bends were carried out,respectively,and the installation positions with smaller installation requirements and better rectification per-formance were explored.(2)The influence of filtering algorithm on gas ultrasonic measurement accuracy.Several commonly used traffic filtering algorithms are programmed by MATLAB.Then SD card module is used for real-time data acquisition.The original traffic data is taken as the input value of each filtering algorithm,and the standard deviation of each filtering algorithm in the same interval is analyzed and compared.Selection of the smallest standard deviation filter algorithm.(3)Instrument coefficient correction algorithm on the gas ultrasonic measurement accuracy.Analyze the current actual instrument coefficient curve,and then analyze the advantages and disadvantages of several correction algorithms.For the specific application environment,propose the corresponding instrument coefficient correction algorithm.After the meter factor correction of the instrument to achieve 1.0 accuracy table requirements.(4)Rapid calibration method of experimental verification.Through the calibration of actual flow,the rationality of the installation position of the rectifier,the effectiveness of the filtering algorithm and the effectiveness of the instrument coefficient correction algo-rithm are verified,and the measurement precision of the gas ultrasonic flowmeter is finally increased.