Development An Ultrasonic Gas Flowmeter With Low Power Consumption

In recent decades,gas ultrasonic flowmeter has been developed rapidly,it has a lot of advantages such as non-contact between sensors and gas,no pressure loss,wide measuring range,no requirement of gas properties,etc.At present,the large and medium diameter of gas ultrasonic flowmeter has been widely used in natural gas trade settlement.On the basis of predecessors' study of ultrasonic flow meter,small diameter and low pressure of gas ultrasonic flowmeter based on time-difference method has been researched in this paper.Firstly,automatic compensation algorithm of time-difference measurement is put forward because of the instrument accuracy changed by the influence of temperature,pressure,delay time of electronic circuit,and the corresponding program was designed;Secondly,embedded the transducer in the pipe wall by Z-type installation method in the design and installation of primary instrument,there's no built-in components in the pipe section of the instrument;Thirdly,the signal processing circuit collect and amplify signal adopted the combination of multi-level amplifier and bandpass filter,than by the threshold value method filter the ultrasonic signal;The design of the instrument hardware and software adopt modular approach which according to low power consumption,use low voltage pulsed transducer and intermittent power supply,all of these achieved the purpose of reduce power consumption.After making the sample and finishing debugging,using the standard meter method does flow experiment to test the level of accuracy and stability.Finally,the uncertainty analysis of experimental data is shown and the expanded uncertainty of the instrument is given.The experimental results show that the sample has a good stability and all the parameters meet the design requirements.