天然气烃露点预测研究进展

Research progress of natural gas hydrocarbon dew point prediction

关键词:  烃露点预测  立方型状态方程  GE-EOS模型  相平衡  天然气体系 

Key words:  hydrocarbon dew point prediction  cubic equation of state  GE-EOS model  phase equilibrium  natural gas system

摘要:

获取准确的天然气烃露点数据,对发展天然气工业的诸多环节(如天然气开采、加工和管输)都具有重要意义。预测方法可快速提供一定精度范围的天然气烃露点数据,是推动天然气工业发展的一种重要手段。首先,梳理了经验关联式、状态方程、超额吉布斯自由能-状态方程(GE-EOS)模型3种预测方法的发展及其在烃露点预测领域的应用。其次,通过对不同天然气体系复杂性的分析,提出了以不同的预测模型深入开展不同天然气体系烃露点预测研究的思路,并结合开展的实验工作,指出目前国内常用的烃露点预测模型(PR方程和SRK方程)的平均预测偏差较大(分别为6.7 ℃、9.2 ℃),不能准确有效地指导天然气工业的工程设计和装置运行。最后,指出针对不同复杂性的天然气体系,开发不同的预测模型,形成系统化的天然气烃露点研究成果的重要性与迫切性。

Abstract:

To obtain accurate hydrocarbon dew point data of natural gas is crucial for development of natural gas mining,processing and transporting, which are all the key aspects of natural gas industry. Prediction method is a kind of important factor to promote the development of natural gas industry because it can predict a relative precise hydrocarbon dew point as quick as possible. Firstly, this paper reviewed the development and application of three major natural gas hydrocarbon dew point prediction models, which are empirical correlations model, equation of state model and Gibbs excess energy-equation of state (GE-EOS) model, respectively. Secondly, based on the complexity analysis of different natural gas system, the research idea utilizing vary model to predict the hydrocarbon dew point of different natural gas system is proposed. In further, through the experimental validation, we found there was big deviation between the experimental and predicted dew points temperature. When the common PR and SRK model in domestic was used, the average absolute deviation could achieve 6.7 ℃ and 9.2 ℃ accordingly, which demonstrated that the common models used in domestic were not suitable for guiding the engineering design and plant operation. At last, this paper pointed out the necessity as well as urgency to start the systematic research on natural gas hydrocarbon dew point prediction.