带膨胀机液化流程优化及膨胀机关键运行参数研究分析

Optimization and key operation parameters analysis of expander in different expansion liquefaction process

带膨胀机液化流程由于流程简单、安全性高等优点,在小型边际气田以及FPSO-LNG具有广阔的市场前景。对传统氮气膨胀液化流程进行创新与优化,以提高能量利用效率,是液化流程研究的关键点。采用HYSYS软件以比功耗作为目标函数,对不同带膨胀机液化流程中膨胀机的关键运行参数进行优化研究,给出不同膨胀机液化流程中膨胀机的关键运行参数对流程性能的影响。研究结果表明,在换热器压力承受范围内提高膨胀机的出口压力对于降低能耗具有显著作用,合理选取双循环膨胀流程中的制冷剂有益于节能。

As the expander liquefaction process deserves broad market prospects in small marginal gas fields and FPSO - LNG, innovation and optimization of traditional nitrogen expansion liquefaction process in order to improve the energy efficiency are the key point of liquefaction process research. In this paper, key operation parameters to accomplish huge energy saving in different expander liquefaction process were discussed using the software Aspen Hysys. The research indicates that improving the expander outlet pressure shows a significant effect on the reduction of energy consumption, as long as the LNG heat exchanger in the scope of pressure bearing capacity. Furthermore, reasonable selection of dual cycle refrigerant is good for energy saving in the process.