停输及泄放工况下超临界CO_(2)管输瞬态特性研究

Study on Transient Characteristics of Supercritical CO2 Pipeline Transportation under Shutdown and Discharge Conditions

针对超临界CO_(2)管输过程中面临的安全技术问题,在分析含杂质CO_(2)相图和物性的基础上,通过对比实验和模拟工况下泄放参数的变化,对OLGA模型有效性进行了验证,对停输和泄漏工况进行瞬态模拟,考察了不同初始温度、初始压力下管道沿线各节点的参数敏感性,得到了停输过程引发气流脉动和泄漏过程引发相变的时间。结果表明:停输工况下,初始温度分别为45、50、55℃时,安全停输时间分别为14、15、15.5 h,初始压力分别为14 MPa和8.5 MPa时,安全停输时间分别为14 h和13 h;泄漏工况下,初始温度分别为45、50、55、60℃时,泄漏口产生干冰的时间分别为3、3.5、4.1、4.7 h,初始温度越低,干冰的形成时间越短;初始压力分别为14 MPa和8.5 MPa时,产生干冰的时间分别为3 h和4.6 h。研究结果可为CCUS管道的应急抢险和安全运行提供实际参考。

Aiming at the safety technical problems faced in the process of supercritical CO2 pipeline transportation,based on the analysis of the phase diagram and physical properties of CO2 containing im-purities,the effectiveness of the OLGA model is verified by comparing the changes of the discharge pa-rameters under the experimental and simulated conditions,and the transient simulation of the shutdown and leakage conditions is carried out.The parameter sensitivity of each node along the pipeline is investi-gated under different initial temperature and pressure,and the time of gas pulsation caused by shutdown and phase transition caused by leakage are obtained.The results show that under shutdown conditions,the safe shutdown time is 14 h,15 h,and 15.5 h when the initial temperature is 45℃,50℃and 55℃,respectively.The safe shutdown time is 14 h and 13 h when the initial pressure is 14 MPa and 8.5 MPa.Under leakage conditions,when the initial temperature is 45℃,50℃,55℃,and 60℃,the time of dry ice generation at the leak outlet is 3 h,3.5 h,4.1 h,and 4.7 h,respectively.The lower the initial temperature,the shorter the formation time of dry ice.When the initial pressure is 14 MPa and 8.5 MPa,the time of dry ice generation is 3 h and 4.6 h,respectively.The research results can provide practical reference for emergency rescue and safe operation of CCUS pipelines.