Abstract:

In order to obtain the safe shutdown time of supercritical CO₂ pipeline, the commercial software OLGA was used to establish a calculation model of pipeline safety shutdown time under multi-factor synergy. Based on the parameter range of supercritical CO₂ pipeline engineering planned by PetroChina Xinjiang Oilfield Company, the influencing factors of pipeline safety shutdown time, such as pipeline capacity, pipe diameter, pipe length, initial station outlet temperature, soil environment temperature, total heat transfer coefficient, and terminal station inlet pressure, were studied, and sensitive factors such as soil environmental temperature and pipe length were obtained based on the gray correlation analysis method. In order to predict safe shutdown time of pipelines, based on above parametric analysis of 1728 sets of safe shutdown time results, a database of pipeline safety shutdown time was established. Combined with the methods of dimensional analysis, Python fitting was used to obtain a high nonlinear regression calculation formula for mapping seven variable parameters (independent variables) and supercritical CO₂ pipeline safety shutdown time (dependent variable). The results showed that the maximum relative error of prediction results of fitting formula was less than 10%, showing good prediction accuracy, and the method has high computational efficiency.

Key words: supercritical carbon dioxide, safe shutdown time, gray association, formulation, prediction

摘要：

为得到超临界CO₂管道安全停输时间，本文采用商业软件OLGA建立了多因素协同作用下管道安全停输时间计算模型。基于中国石油新疆油田分公司规划的超临界CO₂管道工程参数范围，开展了对输量、管径、管长、首站出站温度、土壤环境温度、总传热系数、末站进站压力等管道安全停输时间影响因素研究，并基于灰色关联度分析方法，得出了土壤环境温度、管长等为敏感因素。为预测管道的安全停输时间，基于以上参数化分析得到的1728组安全停输时间计算结果，建立了管道安全停输时间数据库，结合量纲分析方法，利用Python拟合得到了用于映射七大可变参数（自变量）与超临界CO₂管道安全停输时间（因变量）的高度非线性回归计算公式。结果表明：该拟合公式预测结果的最大相对误差小于10%，预测准确性良好，且该方法具有较高的计算效率。

关键词: 超临界CO₂, 安全停输时间, 灰色关联, 公式化, 预测