小型橇装LNG装置液化工艺对比分析

Comparative Analysis on Liquefaction Processes of Small-scale Skid-mounted LNG Unit

小型橇装LNG装置具有工艺流程简单、安装搬迁方便、原料气适应性强等特点,对于偏远地区油气回收、海上油气回收、散井气回收以及沼气回收利用等具有重要作用。对目前运行的小型橇装LNG装置所采用的混合冷剂循环制冷(MRC)工艺、N2膨胀制冷工艺、丙烷预冷混合冷剂制冷工艺和高压引射制冷工艺等4种液化工艺,从能耗、核心设备选型、可操作性、可成橇性等方面进行对比分析。通过分析得出,MRC工艺比较适合5×104m3/d及以下规模的橇装天然气液化项目。该研究结果对小型橇装LNG装置液化工艺的选择有借鉴意义。

Small-scale skid-mounted LNG unit has such features as simple technological process, convenient installation and removal, and strong adaptability to feed gas, so it plays an important role in biogas recovery and oil recovery from remote areas, offshore and separate wells. Compared are MRC technology, N2 expansion refrigeration technology, propane pre-cooled mixed refrigerant refrigeration technology and high pressure ejector refrigeration technology in such aspects as energy consumption, key equipment selection, maneuverability and skid-mounted ability. Results show that MRC technology is most suitable for 5×104 Nm3/d(or less than) skid-mounted LNG program. This research result has reference significance for selection of small-scale skid-mounted LNG unit.