Design Of Measurement And Control System For Gas-liquid Two-phase Flow Experiment Apparatus

The study of gas-liquid two-phase flow law and its parameter measurement technology has been an active topic for scholars in related fields.Experimental data is the basis of two-phase flow research.At present,in the gas-liquid two-phase flow experiment,the pipeline valve adjustment,the standard meter output signal measurement and the sensor output signal acquisition are generally operated by independent modules.There is no unified software to coordinate and control various departments,the experimental operation is cumbersome and the experiment efficiency is not high.Aiming at the above problems,this paper proposes a design of measurement control system for gas-liquid two-phase flow experimental device.The design integrates dynamic data acquisition,pipeline valve control and host computer human-computer interaction to improve the automation degree of the gas-liquid two-phase flow experimental system,which is conducive to the improvement of gas-liquid two-phase flow experimental efficiency.Combined with the gas-liquid two-phase flow experimental process,it is necessary to measure the output signal of the pipeline temperature,pressure and flow standard table at any time in the experiment;it is necessary to change the pipeline flow pattern by adjusting the valve opening to create different experimental conditions.Different gas-liquid two-phase flow research methods require real-time sampling of sensor output signals.The gas-liquid two-phase flow experimental device measurement control system designed in this paper satisfies the functional requirements of temperature,pressure measurement,high-speed data acquisition,valve control,and pipeline flow regulation in two-phase flow experimental research.The system low-speed sampling module can accurately measure the measurement error of the 0-20 mA signal output from the standard temperature and pressure flow standard table by less than 1.5%.The system is designed with a high-speed signal sampling module that can achieve ±10V voltage,sampling records of any signal with a frequency less than 200 kHz.The system can generate PWM signals with a frequency of 5kHz,resulting in a signal frequency error of less than 0.01%.At the same time,the pulse signal can be counted within 5kHz,and the frequency measurement error is within 0.05%.In the actual flow generation verification experiment,three flow patterns of bubble flow,slug flow and annular flow can be generated in the vertical rise pipeline in the system,which meets the requirements of gas-liquid two-phase flow experiment.This paper completes the demand analysis,scheme design,software and hardware design,and system experiment test of the gas-liquid two-phase flow experimental device measurement control system.It has been verified by experiments that the various parts of the system work in harmony and have stable performance.In general,the system achieves the desired function for use in gas-liquid two-phase flow experiments.