摘要
为研究某LNG接收站蒸发气(BOG)再冷凝控制系统的平稳性和适用性,对接收站工艺流程及关键参数作了阐述,依据运行参数和控制方案,利用Aspen Hysys软件建立接收站BOG再冷凝系统的动态模型。在实际生产运行中考虑并分析了包括关停低压泵、外输量增大、BOG处理量频繁波动等出现不同扰动情况时再冷凝器系统参数的动态响应,结果表明:低压泵关停时再冷凝器压力迅速升高至压力报警值,再冷凝器放空阀打开,应先停BOG压缩机,以避免再冷凝器迅速超压带来的危险;BOG处理量波动时,进入再冷凝器的冷凝LNG流量变化滞后于进入再冷凝器BOG流量的变化。当前系统控制方案可以较精确得实现对进出再冷凝器物料的控制,但存在比值控制方式滞后性及总物料量不受控制的不足。
In order to maintain stable operation of BOG recondensation system at a LNG receiving terminal, we analyzed the technological flow and key parameters, and developed a dynamic model by means of Aspen Hysys software. Moreover, some dynamic responses to system parameters containing low-pressure valve shutdown, increase of output volume, and frequent fluctuation of BOG processing volume, which possibly appear under different situations, were taken into consideration. Results show that(1) when the low-pressure valve shutdown, the recondensor's pressure increases at first and then reaches an alarm value. BOG compressor should be closed before release valve open to avoid some dangerous caused by fast overpressure of recondensor; and(2) when BOG processing volume fluctuates, the variation of BOG flowing rate is earlier than that of LNG flowing rate entering into recondensor. Generally, this system can more accurately control material getting in and out of the recondensor; however, there are some shortcomings such as hysteresis of ratio control and inconstant total material amount.
出处
《天然气技术与经济》
2017年第5期39-42,共4页
Natural Gas Technology and Economy
关键词
LNG接收站
BOG再冷凝
动态模型
比值控制
储罐
LNG receiving terminal
BOG recondesation
dynamic model
ratio control
storage tank
