不同管径和温压条件下的CO_2管道输送特性

为深入研究CO_2管输特性,以输量为100×104 t/a的CO_2管道工程为例,采用Pipephase仿真软件建模,分别对气相、液相和超临界相3种相态的CO_2在不同管径和温压条件下的输送过程进行模拟。结果表明:气相、液相、超临界相3种管输方式在不同管径下的压降均不大,压降基本只受输送距离的影响;管输CO_2的密度和黏度以气相输送时基本不受输送距离、温度及压力的影响,以液相和超临界相输送时主要受温度影响。管道以气相输送时,应避免在高压和准临界区域运行;以液相输送时,应选择在较高压力下运行;以超临界相输送时,应避免温度压力到达临界点。中长距离、沿线人烟稀少的CO_2管道优先采用超临界相输送;中短距离、沿线人口密度高的CO_2管道优先采用气相输送。

CO_2 pipeline transportation characteristics with different pipe diameters under different pressures & temperatures

In order to study CO2 pipeline transportation technology further,the CO2 transportation project of 100×104 t/a was taken as an example,the simulation software Pipephase was adopted for modeling to simulate the transportation process of CO2 in gas phase,liquid phase and supercritical phase under the conditions of different pipe diameters,temperatures and pressures.It is indicated that in three pipeline transportation modes(i.e.,gas phase,liquid phase and supercritical phase),the pressure drop is seldom affected by the pipe diameter,but only affected by the transportation distance.The density and viscosity of pipeline CO2 are not affected by transportation distance,temperature or pressure in the transportation mode of gas phase while it is mainly affected by the temperature in the transportation modes of liquid phase and supercritical phase.It is necessary to avoid high pressure and pseudocritical regions during the transportation of gas phase,to operate under higher pressure during the transportation of liquid phase,and to prevent temperature and pressure from reaching critical points during the transportation of supercritical phase.It is shown from comprehensive comparison and analysis that as for CO2 transportation projects with the capacity of million tons,the transportation mode of supercritical phase is preferred for moderate-and long-distance CO2 transportation pipelines in sparsely populated regions,and the transportation mode of gas phase is preferred for moderate-and short-distance CO2 transportation pipelines in highly populated areas.