LNG接收站大管径管道冷却方式探索

LNG接收站管道冷却是接收站调试的一个重组成部分,大管径管道由于冷却过程中可能会发生巨大应力变化,对设施造成严重损坏。为此,对大管径管道冷却的吹扫、置换、BOG预冷、LNG冷却填充等主步骤、合格标准及其注意事项进行了分析,认为12 in以上大管径管道必须采用先BOG预冷、再LNG冷却填充的方式进行冷却。

LNG接收站新增储罐及其卸料管线冷却方式探讨

目前,国内已建LNG接收站普遍存在新建储罐的投用问题,需对新建储罐进行预冷及调试。为此,简述了新建储罐及其卸料连接管线预冷的原则,提出了利用LNG船进行冷却、利用原有储罐及设施进行冷却和外置蒸发器冷却卸料管线3种冷却方式,并分析了其优缺点,认为LNG接收站新增储罐及其卸料管线应根据接收站的生产设备情况,选择一个最简便、安全、经济的预冷方式。

LNG接收站卸料管路冷却方案

目前LNG接收站卸料系统的冷却方式有两种，其一是直接采用船上的LNG，使用船上的气化器将LNG气化冷却卸料管路；其二是先使用低温氮气将卸料管路冷却至一定温度后，再采用船上的LNG冷却或直接进液。对比了两种方法的优缺点，计算了不同长度卸料管路和保冷管路显热利用率分别为60％、50％、40％、30％4种情况下，冷却消耗的冷却介质的量和冷却时间，进而比较使用LNG冷却和使用液氮冷却的经济性。结果表明：使用液氮冷却卸料管路比使用LNG冷却卸料管路更经济，费用约可节省一半，但使用液氮冷却前期投资比较大。

Process Study and Exergy Analysis of a Novel Air Separation Process Cooled by LNG Cold Energy

In order to resolve the problems of the current air separation process such as the complex process, cumbersome operation and high operating costs, a novel air separation process cooled by LNG cold energy is proposed in this paper, which is based on high-efficiency heat exchanger network and chemical packing separation technology. The operating temperature range of LNG cold energy is widened from 133K-203K to l13K-283K by high- efficiency heat exchanger network and air separation pressure is declined from 0.5MPa to about 0.35MPa due to packing separation technology, thereby greatly improve the energy efficiency. Both the traditional and novel air separation processes are simulated with air handling capacity of 20t＇h-1. Comparing with the traditional process, the LNG consumption is reduced by 44.2%, power consumption decrease is 211.5 kWh per hour, which means the annual benefit will be up to 1.218 million CNY. And the exergy efficiency is also improved by 42.5%.