摘要
为了探究管输CO_2节流放空过程中的压力、温度响应及相态变化,基于Joule-Thomson效应搭建了橇装实验装置,分别进行了超临界态、液态、气态及含杂质气态CO_2多级节流放空实验。通过实验发现:(1)超临界态及气态实验出口温度先上升后下降,而液态实验出口温度先下降后上升并最终与主管温度变化一致;(2)主管内CO_2的压力、温度随着实验的进行而不断下降,且各截面之间参数差异明显,表明压力扰动传播速度受密度影响;(3)含杂质N2的CO_2放空时出口温度低于纯气态CO_2放空,主管内压力随时间变化速率大于纯CO_2实验主管压力变化速率;(4)管外气云逐渐收缩为气锥,气锥随管内压力下降、温度上升逐渐减弱并最终消失。实验结果表明:(1)在单级节流相同压降下,液态实验产生的温降明显小于超临界态及气态节流温降,但液态CO_2全节流过程会因发生相变而使平均节流效应增强;(2)密度影响内能对外耗散的程度,进而影响节流系数,即密度增大,节流系数降低。进而建议,通过增大泄放速率、节流入口增温、节流出口整流等措施来实现对CO_2放空过程的安全控制。
In order to investigate the temperature and pressure responses and phase change during the throttling and blowdown of pipe- line CO2, we set up a skid-mounted experimental device based on the Joule-Thomson effect. And this device was used for multistage CO2 throttling and blowdown experiments at supercritical state, liquid state, gaseous state and gaseous state with impurities, respectively. The following results are obtained. First, the outlet temperature increases and then decreases in the experiment under supercritical state and gaseous state, while it decreases, then increases and finally complies with the temperature change of the main pipeline under liquid state. Second, the pressure and temperature of CO2 in the main pipeline decrease continuously in the process of the experiment, and the parameter differences between sections are large, indicating that the propagation velocity of pressure disturbance is affected by the den- sity. Third, the outlet temperature during the blowdown of CO2 with N2 was lower than that of pure COs, and the pressure change rate of the experiment with N2 is higher than that of pure CO2 experiment. And fourth, the gas cloud outside the pipeline shrinks into gas coning gradually, and the gas coning diminishes and ultimately disappears with the decrease of pressure and f temperature inside the pipeline. It is indicated that, with the same pressure drop of single-stage throttling, the temperature drop in liquid state is much less than that in su- percritical state and gaseous state. Due to the phase change in the whole throttling process of liquid CO2, however, the average throttling effect is enhanced. The density affects the degree of internal energy dissipation, and then affects the throttling coefficient. It means that the throttling coefficient decreases with the increasing of the density. Finally, it is recommended to fulfill the safety control on CO2 throt- tling process by taking some measures, such as increasing the discharge rate, increasing the temperature at the throttlin
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2016年第10期126-136,共11页
Natural Gas Industry
基金
国家自然科学基金项目"含杂质超临界CO2管道输送安全控制关键技术研究"(编号:51374231)
中央高校基本科研业务费专项资金"超临界CO2管道泄漏扩散机理及安全评价研究"(编号:16CX06005A)
国家科技支撑计划项目"大规模燃煤电厂烟气CO2捕集纯化
输送及安全控制技术研究"(编号:2012BAC24B01)
关键词
CO2管道
CCS
节流
放空
相态实验
超临界态
节流效应
气云变化
安全控制
CO2 pipeline
CCS
Throttling
Blowdown
Phase experiment
Supercritical state
Throttling effect
Gas cloud change
Safety control
