Development Of The Correlation Ultrasonic Flowmeter

In many production processes, the flow measurement of two-phase (gas/liquid, gas/solid and liquid/solid) flow is a difficult problem that has not been solved perfectly for a long time. By the introduction of cross-correlation technology and ultrasonic transducer, the ultrasonic flow measurement system can be developed, and the un-contact flow measurement of two-phase flow can be realized, therefore the research of the ultrasonic cross-correlation flowmeter is a subject that has great significance.Based on the principle of the ultrasonic cross-correlation flowmeter, the key factor of the development of cross-correlation flowmeter, namely the design of cross-correlator, is analyzed in the paper. Digital signal processing is introduced to design the flowmeter, the cross-correlation operation of random noise signal is dealt with inside the frequency field, and the digital cross-correlator is designed. Because of a large number of data processing to carry out, TMS320C5402 DSP, electromagnetic ultrasonic transducer, oscillatory source circuit, receive signal disposal circuit, A/D, SRAM, Flash Memory and display circuit are selected to design the prototype of a machine of the real-time measurement system.In the past, piezoelectricity transducer was adopted usually in theultrasonic flowmeter development, so in higher temperature, for example, exceeds 150"C, the measurement was not carried out. For this reason, referred to the application of electromagnetic ultrasonic in high temperature metal measurement, coarse rail of surface measurement, panel flaw detection and material stress measurement, electromagnetic ultrasonic is introduced into flow measurement for the first time, and electromagnetic ultrasonic transducer is developed to gear to flow measurement. By experiment test, this transducer works normal, thus a new kind of solution for high temperature flow measurement is put forward in the paper.In design of prototype of a machine, through to carefully design of hardware, the influence factor in flow measure is reduced. By experiment test, hardware works normal, thus prove that the design of the prototype of a machine is successful.