Research On The Key Techniques Of Transit Time Flowmeters

Ultrasonic flowmeter is a non-contact instrument,it can be used for different diameter media flow measurement,but also can be used for a variety of difficult to contact and observe the media measurement.Ultrasonic measurement method of small pressure loss,high precision,basically not subject to the various parameters of the measured interference,in particular,can be used for strong corrosive,non-conductive,radioactive and flammable and explosive media flow measurement.Reality is applied to oil and gas,petrochemical,water treatment,food and beverage,pharmaceutical,energy,metallurgy,pulp and paper and building materials industries.TDC-GP21 that was launched by ACAM company is a time-digit converter based on transit time,which can measure the flow rate and temperature at the same time.It has high integration,good consistency,good measurement accuracy and higher features.In this article,it is used in the design of ultrasonic flowmeter,so that the flow meter with higher accuracy and greater range.In the process of ultrasonic flow detection theory,firstly,the principle of time difference measurement is studied,and the flow rate measurement principle is analyzed.At the same time,the flow detection model is established and the relevant fluid simulation is carried out;Secondly,several factors influencing the accuracy of flow measurement are analyzed,which mainly affect the ultrasonic velocity,the water density at different temperatures and the material temperature at different temperatures.The correction coefficient compensation algorithm is used to improve the measurement accuracy of the flowmeter,by reducing the minimum flow rate,the measurement range is improved;Finally,the use of TDC-GP21 chip ultrasonic flowmeter prototype design,the use of vacuum potting and other technology breakthrough transducers encapsulation process,by increasing the ultrasonic emission and receive energy,the use of synchronous testing methods to improve the accuracy and improve the stability of the prototype,to guide follow-up study.