Abstract:

During the engineering design and construction of liquefied natural gas(LNG) terminal, the design of flare system is a necessary condition to ensure the safe production of LNG terminal. Taking a LNG terminal as an example, this paper analyzes the generation factors and mechanism of LNG boiled off gas(BOG) and the calculation method of flare emission under six combined working conditions. The results show that under working condition 1, it is in good agreement with the actual production situation, and the corresponding flare gas emission is about 142.7 t/h. On this basis, it is determined that the diameter of BOG branch pipe is DN600 and the diameter of BOG main pipe is DN900; The diameter of the separated droplet shall not be greater than 600 μm; The size of flare knockout drum is ϕ2.5 m×8.0 m; The power of electric heater is 195 kW; The flare is in the form of closed ground flare. The research results can provide theoretical guidance for the processing capacity and equipment configuration of the flare system of LNG terminal project in the future.

Key words: LNG terminal, flare system, design condition, BOG, pipe diameter, knockout drum, electric heater, enclosed ground flare

摘要：

在液化天然气(LNG)接收站工程设计建设过程中，火炬系统的设计是保证LNG接收站安全生产的必要条件。以国内某LNG接收站为例，分析了LNG蒸发气(BOG)产生的因素和机理，及6种工况组合下火炬排放量的计算方法。结果表明：在工况1条件下与实际生产情况吻合良好，其对应的火炬气排放量约为142.7 t/h。在此基础上确定了：BOG支管管径为DN600,BOG总管的管径为DN900;被分离液滴的直径不大于600μm;火炬分液罐尺寸为ϕ2.5 m×8.0 m;电加热器的功率为195 kW;火炬形式为封闭式地面火炬。研究结果可为今后LNG接收站项目火炬系统的处理能力及设备配置提供理论指导。

关键词: LNG接收站, 火炬系统, 设计工况, BOG, 管径, 分液罐, 电加热器, 封闭式地面火炬