腐蚀对管输CO2压力损失影响分析

目的研究腐蚀对超临界和密相状态下长输CO_2管道压力损失的影响。方法假设新无缝钢管的表面粗糙度为0.1 mm,轻度腐蚀无缝钢管的表面粗糙度为0.25 mm,严重腐蚀无缝钢管的表面粗糙度为0.9 mm,结合输量、管长、环境温度等基础数据,采用HYSYS软件模拟计算腐蚀对不同粗糙度的超临界和密相状态下长输CO_2管道的压力分布,根据压力分布结果总结受粗糙度影响的压力分布规律。结果随着粗糙度的增大,超临界和密相状态下的CO_2在流动过程中的压力损失不断增大,超临界状态下的输送受粗糙度的影响大于密相状态下的输送。受高差影响后,结果发生了变化,密相状态下的压力损失大于超临界状态下的压力损失。结论表面粗糙度对不同相态下的CO_2的输送压力损失影响很大,粗糙度每增大1 mm,压降增大约9%~11.2%。在无高差的条件下,超临界状态的压力损失大于密相状态下的压力损失;受高差影响后,密相状态下的压力损失大于超临界状态下的压力损失。在实际输送管道中,密相状态下的压力损失大于超临界状态下的压力损失。

Effect of Corrosion on Pressure Loss of CO2 Pipeline

Objective To study the effect of corrosion on pressure loss of long-distance CO2 pipeline at supercritical and dense-phase states. Methods Assuming that the surface roughness of new seamless steel tubes was 0.1 mm, that of mild corrosion seamless steel tubes 0.25 mm and that of severe corrosion of seamless steel tubes 0.9 mm, effect of corrosion on the pressure distribution of long-distance CO2 pipeline with different roughness conditions at supercritical and dense-phase states was simulated and calculated by HYSYS software combined with basic data like transmission capacity, tube length and ambient temperature. Then the regulations of distribution influenced by roughness conditions were summarized according to the results of pressure distribution. Results With increasing roughness, pressure loss in flow process of CO2 pipeline at supercritical and dense-phase states increased continuously. Transmission at supercritical state was more affected by roughness than that at dense-phase state. However, subject to height difference, the results changed to that pressure loss at dense-phase state was larger than that at supercritical state. Conclusion Surface roughness has great influence on pressure loss of CO2 pipeline at different phase states. The pressure loss will increase for 9%~11.2% for every 1 mm roughness increases. Under the conditions without height difference, pressure loss at supercritical state is greater than that at dense-phase state. Subject to height difference, that at dense-phase state is bigger than that at supercritical state. For actually used pipelines, pressure loss at dense-phase state is larger than that at supercritical state.