LNG接收站入口BOG温度对再冷凝器控制的影响

Influence of inlet BOG temperature on recondenser control in LNG terminal

关键词:  LNG接收站  再冷凝器  控制  入口BOG温度  响应

Key words:  LNG terminal  recondenser  control  inlet BOG temperature  response

摘要:

青岛LNG接收站再冷凝器入口LNG流量调节阀灵敏度不高,且不适合频繁动作,导致再冷凝器液位波动较大,难以实现自动控制。通过对现有操作工艺和控制方案的深入分析,提出增加入口BOG温度调节作为辅助控制手段的新思路。为此,进行了入口BOG温度梯度变化下再冷凝器系统的响应实验,定量衡量了入口BOG温度对再冷凝器液位的控制能力。理论和实验数据说明,通过调节入口BOG温度可以改善再冷凝器液位控制的稳定性和精度,减少入口LNG流量调节阀的动作次数。文中提出的方案可以在手动控制下保护入口LNG流量调节阀,减轻操作员的工作强度,同时也有助于再冷凝器液位的自动控制回路设计。 

Abstract:

LNG flow control valve at the inlet of recondenser in Qingdao LNG terminal suffers from low sensitivity and inadequacy of frequent adjustments, which lead to large fluctuations and the difficulty of automatic control of the recondenser. Based on deep analysis of current process flow and control strategy, a new idea of adding inlet BOG temperature regulation as an auxiliary control method is put forward in this paper. To this end, experiments under gradient changes of inlet BOG temperature for the recondenser system are carried out, and the degree of controlling LNG level in recondenser using inlet BOG temperature is measured quantitatively. Both theoretical and experimental data show that the control stability and accuracy of LNG level in the recondenser can be improved by adjusting inlet BOG temperature, thus the regulation frequency of the inlet LNG flow control valve can be reduced. The proposed method can protect the inlet LNG flow control valve and reduce labor intensity of operators while manual control. Meanwhile, it will contribute to the design of practical automatic control strategies for the recondenser.