The Research Of The High-speed Gas Ultrasonic Flowmeter

A lot of energy gas have been widely applied today, people pay close attention to the measure of the energy gas, the way of the gas transmission is pipeline type during the process of gathering, transporting, applying and storing, a lot of flowmeters are needed to monitor the transmission. The non-contact ultrasonic flowmeter has the unique advantage to measure the large-tube, high-speed gas accurately, the way of measuring the flow of the gas by ultrasound waves had been applied early, but because of the effect of the propagation characteristics and measure environment of ultrasound waves, the measuring result is not satisfactory. Especially in the process of high speed gas flow measurement, ultrasonic propagation path has a great influence by gas flow velocity.The paper improves the ultrasonic flow calculation formulthe to eliminate the effect of sound velocity to the measurement of the high-speed gas flow by analyzing the principle of the measurement of the ultrasonic gas flowmeter, and has completed the type selection of the flow measurement system equipment based on the propagation characteristics of ultrasound waves and the technical index of the gas flow measurement. The emphasis of the paper is the designment of the time measurement system based on the MSP430F543 and TDC-GP2, and the ultrasonic automatic calibration system based on TMS320F28335 and stepping motor, which achieves the purpose of navigation by controlling the stepping motor with TMS320F28335.In this paper, the main work include four points: Firstly, analyzes the principle and method of measurement to the ultrasonic high-speed gas flow, and the factors which affect the measurement of the flow, then put forward relevant solutions based on the factors, chooses the method of measurement and the flow measurement system equipment based on the requirements of the flow measurement. Secondly, the establishment and implementation of ultrasonic automatic calibration system based on TMS320F28335 and stepping motor, which is used for adjusting the position of the ultrasonic transducer. Thirdly, the designment of the ultrasonic high-speed gas flow measurement system by using the time-difference method based on TDC-GP2, the system is used for measuring the propagation time of the ultrasound in fair current situation or countercurrent situation in the gas pipe, has the visual man-machine interface and the function of storing data at the same time. At last, the design of the software and the data processing analysis, the system software mainly includes two parts: Stepping motor control module with TMS320F28335 and the time measurement module of TDC-GP2.In this paper, according to study of the time-differenced ultrasonic high-speed gas flowmeter, and builds the whole measuring system to measure the gas flow in the pipeline, displays and stores the measuring results at last. The time-differenced flowmeter based on the ultrasonic automatic calibration has been tested by the experiment, the flowmeter has the characteristic of good stability and accuracy, can monitor the gas flow in pipeline effectively.