杂质对管输CO_2节流过程的影响

Impacts of foreign substances on orificing of CO_2 in pipeline transmission

为了研究杂质对管输CO_2节流过程的影响规律,以含杂质CO_2流体为研究对象,给出了考虑相变的节流后温度的计算方法,分析了杂质对CO_2节流过程的影响,并提出相应操作建议。研究表明:H_2S对节流后温度的影响可以忽略;当入口工况为超临界、密相及液相时,杂质为SO_2有助于提高节流后的温度,杂质为N_2和O_2会降低节流后的温度;当入口工况为低压气相时,杂质为SO_2则会降低节流后的温度,杂质为N_2和O_2会提高节流后的温度;对于不同杂质含量的CO_2,节流后出口温度与纯组分节流后相比产生的偏差是不同的,杂质含量越多相应偏差越大。研究结果对含杂质CO_2流体的节流控制和干冰预防有一定指导意义。

To determine impacts of foreign substances on orificing of COz in pipeline transmission, CO2 fluids containing foreign substances are studied to clarify method for calculation of temperatures after orificing with phase transition considered. Then, impacts of foreign substances on orificing of CO2 in pipeline transmission are analyzed, and relevant operational procedures are proposed. Research results show that impacts of H2S on temperatures after orificing are negligible. Within fluids at the inlet in super-critical, high-density or liquid conditions, SO2 may effectively enhance temperatures after orificing, whereas nitorgen and oxygen may reduce temperatures after orificing. If fluids at the inlet are low-pressure gases, SO2 may reduce temperatures after orificing, whereas nitrogen and oxygen may enhance temperatures after orificing. As for CO2 with different contents of foreign substances, deviations in temperatures after orificing may vary from pure CO2 gas. Generally, higher contents of foreign substances may lead to higher deviations. The research results may provide guidance for control over orificing of CO2 fluids containing foreign substances and prevention of dry ice. （5 Figures, 11 References）