| Gas-liquid two-phase flow of Low-containing liquid exists in modern industrial production widely, whose flow pattern identification and flow measurement technology is always a technical problem. In recent years, many domestic and foreign research institutions and researchers are committed to the technology research. Department of automation in China University of Petroleum is committed to developing a new type of low-cost gas-liquid two-phase flow meter,has designed instrument hardware and obtained a large amount of experimental data by means of the indoor and field experiments. In this paper, algorithm for the two-phase flow pattern recognition and flow measurement is provided by analyzing experimental data.ICA's applied research in the two-phase flow is discussed in the first part. Firstly, mathematical description,basic assumptions,basic principles,as well as classical analytical methods and criteria of ICA technology are introduced. Fast ICA algorithm is emphasized and simulation signal is decomposed. It turns out that ICA can decompose linear mixed-signal of some Non-Gaussian signal into simple Non-Gaussian signal. Then ICA technology is applied to decompose upriver and downriver mixed-signal into relatively simple independent signals respectively, transit time is got through the use of estimation of delay and then related flow rate is got. At the same time, because this method has a filter effect at a certain extent, it could reject interference noises from two-phase flow measurement signal and maintain basic characteristics of two-phase flow measurement signal. In view of the above, in this paper the independent components with the strongest non Gaussian from two differential pressure signals in Vortex precession flowmeter and Slotted orifice are extracted and a comparison of their characteristics is made. The change of two differential pressures is explored when every phase flow changes.two-phase measurement characteristics of vortex precession flowmeter is explored by analyzing vortex precession signal in the second part. On the one hand, relationship between the frequency and flow of vortex precession signal is researched in single-phase measurement.firstly, explores Physical meaning of main frequency and Minor Frequency of vortex precession,explores the relationship between frequency and quality flow. On base of this ,summarizes the offset law of main frequency of vortex precession in gas-liquid two-phase flow of low-containing liquid,researches the relationgship between main frequency of vortex precession and quality flow. On the other hand,relationship between the amplitude of vortex precession signal and quality flow is researched. firstly, explores the relationship between the amplitude of vortex precession signal and quality flow in single-phase measurement. On base of this , explores the chenges law of he amplitude of vortex precession signal,explores the relationship between the amplitude of vortex precession signal and Frg parameter and L-M parameter in two-phase measurement.
|
PDF Full Text Request