【作者】 徐朋霞；

【导师】 耿艳峰；

【作者基本信息】 中国石油大学 ， 控制科学与工程， 2011， 硕士

【摘要】 凝析天然气是一种低含液率的气液两相流,其流量计量属于多相计量的一个分支,是石油天然气工业迫切需要解决的问题之一。目前,结合新型的信号处理技术,基于差压等常规测量信号通过软件的方法解决计量问题,是凝析天然气流量计量发展的一个重要方向。本文基于课题组自行开发的凝析天然气流量计样机和大量的实验数据,从信号分离的角度对槽式孔板差压信号进行处理。通过采用盲分离范畴内的两种基本方法——时频分析盲分离(TF-BSS)和独立成分分析(ICA),来提取与两相流参数相关的特征量,而后进行必要的分析与处理,完整地实现气液两相流量计量。论文主要分为三部分,第一部分阐述了基于时频分析盲分离方法的两相流量计量过程;第二部分描述了基于独立成分分析的两相流量计量方法;第三部分对两种分离方法的运用进行对比和分析,以总结出更好的处理方式。课题组开发的凝析天然气流量计属于双差压组合测量方式,针对上、下游槽式孔板差压信号DP1、DP2,利用时频分析盲分离方法和独立成分分析方法两种方式,均可分离出表征液相作用的分量,同时得到分离分量方差与液相折算速度的定量关系,关系式准确度较高。而后分别基于通过分离方法得到的液相流量,利用槽式孔板相关式计算得到气相流量,其计量准确度也较理想。结果表明,对于从气液两相流槽式孔板差压信号中提取单相信息,时频分析盲分离和独立成分分析都是较有效的分离方法,同时为凝析天然气各相流量计量提供了一种新的思路。更多还原

【Abstract】 Wet gas flow is a typical two-phase flow with low liquid fractions. Wet gas metering is a subset of multiphase flow metering, and it is one of the major unsolved problems for oil and gas industry. Recently, more and more signal processing technologies have been used in the data processing of wet gas flow, and it is an important issue for wet gas flow metering.Based on a self developed prototype of wet gas meter and an experimental data set, differential pressure (DP) signals from slotted orifices have been processed from a view of signal separating. Two Blind Source Separation (BSS) techniques, which are BSS based on Time-Frequency analysis (TF-BSS) and Independent Component Analysis (ICA), have been used to extract characteristic quantity of wet gas flow. Gas and liquid flow are acquired at last.This thesis consists of three parts. The first part mainly focuses on the two-phase flow metering based on TF-BSS method; The second part elaborates the metering process based on ICA method; The third part is a comparison and an analysis of these two ways, and a conclusion is given in the end.Based on DP signals from a couple of slotted orifices, TF-BSS (TIFROM algorithm) and ICA (FastICA algorithm) are used to separate different effects respectively. A good relationship between the liquid flow rate and the characteristic quantity of the separated signal is established, and a differential pressure correlation for slotted orifice is applied to calculate the gas flow rate. The calculation results are good with 90% relative errors less than±10%.The results show that BSS is an effective method to extract the effect of the liquid flow from DP signals of wet gas flow, and this provides a new approach of wet gas flow metering.更多还原