【作者】 余道丞；

【导师】 耿艳峰；

【作者基本信息】 中国石油大学（华东） ， 控制科学与工程， 2013， 硕士

【摘要】 凝析天然气的计量问题属于高含气率气液两相流的计量问题，是多相流计量的一个分支，至今仍未很好地得到解决，是制约我国天然气工业发展一个因素，是当下石油天然气工业迫切需要解决的问题之一。本文基于课题组采用槽式孔板计量凝析天然气的方案，根据课题组的前期研究结论和大量实验数据，研究槽式孔板的气液两相流计量特性，改善计量模型的准确性，扩大流量计的测量范围并提高计量精度，为基于槽式孔板的凝析天然气计量算法的完善奠定基础。本文的研究可分为三个部分，第一部分对槽式孔板压差数据的消噪方法进行了研究，第二部分为研究的主要部分，从理论机理的角度研究了针对环状流的槽式孔板压降并建立了半经验模型，第三部分对槽式孔板的压降倍率特性进行了研究。根据压差数据的非平稳性、具有分形特征、难以获取噪声先验知识的特点，本文选择基于EMD分解的阈值处理新型消噪方法，以分形高斯噪声为噪声模型进行了测试研究，并根据结果对算法进行了优化，使其对分型高斯噪声的处理效果更好，为压差数据的消噪提供了一种方法。采用槽式孔板测量凝析天然气，计量精度的进一步提高依赖于计量模型的准确性，而缺乏理论模型的支持是制约计量模型准确性的一个决定性因素。本文从环状流通过槽式孔板的运动机理出发，对槽式孔板的压降进行了分析，将压降分为加速压降、摩阻压降、局部压降三部分，并根据实验数据获得了环状流的槽式孔板压降半经验模型，取得了良好的效果，为计量模型精度的提高奠定基础。压降倍率一直是采用差压式流量计计量气液两相流的重要研究方向，但计算式的推广性问题仍未得到解决。本文对已有的标准节流件压降倍率计算式和槽式孔板计算式进行了总结，以实际实验数据位基础分析压降倍率的规律特性，得出了以L-M参数、气相Froude数和孔径比为关联因子的计算式，取得了良好的效果。更多还原

【Abstract】 Metering Technology for Condensate Natural Gas belongs to the metering problem forhigh gas content gas-liquid two phase flow, and this problem has not been well solved yet.The lack of reasonable metering technology of Condensate Natural Gas has restricted thedevelopment of the natural gas industry, and this problem is urgent to be solved. This thesis isbased on the idea of using the slotted orifice to meter condensate natural gas, and study thecharacteristics of slotted orifice applied to Condensate Natural Gas metering according to thepreliminary study of the research group and a large number of experimental data. The study isaiming at improving measurement model to expand the measuring range of the flowmeter andto improve measurement accuracy, and lay the foundation for the improvement of condensatenatural gas metering algorithm based on the slotted orifice.This study can be divided into three parts. In the first part the de-noising problem ofpressure drop data has been studied to improve the signal. And the second part is the mainpart of the study, which explored pressure drop structure of slotted orifice for annular flowfrom the point of mechanism, and established a semi-empirical model. In the third part,characteristics of two-phase pressure drop multiplier for slotted orifice were studied.According to the non-stationary and fractal characteristics of the pressure drop data, andthe difficulty to obtain the priori knowledge of noise, a new de-noising method based on thethreshold of EMD was selected in this article to solve this problem. The fractal Gaussiannoise is adopted as the noise model in the test study, and the algorithm was optimized basedon the test results to make it better in handling fractional Gaussian noise.To further improve measurement accuracy of slotted orifice depends on the accuracy ofthe measurement model. But the lack of support from the theoretical model is a decisivefactor in restricting the accuracy of the measurement model. This thesis explored themovement mechanism of the annular flow through the slotted orifice, and divided pressuredrop into acceleration pressure drop, frictional pressure drop and the partial pressure drop.And a pressure drop semi-empirical model was obtained according to the theory andexperimental data, which turned out to be successful. The research of pressure drop multiplier has been an important direction for themeasurement technology of gas-liquid two-phase flow with differential pressure flowmeter,but the replicability issue of the correlations remains unresolved. This thesis summarized theexisting pressure drop multiplier correlations of standard throttling component and slottedorifice, and the characteristics of pressure drop multiplier for slotted orifice has been analyzedbased on the actual experimental data. A new correlation was obtained which is correlated byLM parameters, gas Froude number and the beta ratio, and the correlation achieved goodresults.更多还原