卸料期间储罐压力变化影响因素

Influencing Factors of Tank Pressure Variation during Unloading

LNG接收站在卸料过程储罐压力变化很大,船方LNG进入接收站LNG储罐内后,随着储罐液位上升,气相空间减少,船舱补气等,储罐压力随之产生变化。并且在卸料过程中,储罐压力存在上升速度快,上升幅度大的特点,而储罐压力的波动直接影响着储罐的使用安全。文章通过分析卸船期间影响储罐压力波动的各种因素,对卸船各阶段控制方法进行总结,提出在LNG船靠泊前降低卸料总管温度,加速阶段卸料选择靠近码头储罐等方式控制卸船期间储罐压力,并依据船方LNG物态信息预判卸货后储罐的平衡压力。

During unloading,the pressure of LNG storage tank changes greatly.After the ship’s LNG enters the LNG storage tank of the receiving station,as the liquid level of the storage tank rises,the gas phase space decreases,and the BOG return to ship,etc.,and the pressure of the storage tank along with the change.During unloading,the pressure of the storage tank has the characteristics of rapid rise and large increase,the fluctuation of the pressure of the storage tank directly affects the safety of the storage tank.This article analyzes the factors that affect the pressure fluctuation of the storage tank,summarizes the control methods of each stage of the unloading.It is proposed to reduce the temperature of the unloading main pipe,select the initial feeding storage tank and other methods to control the pressure of the storage tank during unloading,and predict the pressure of the storage tank after unloading based on the ship’s LNG physical information.