大型LNG接收站冷能的综合利用

INTEGRATED UTILIZATION OF COLD ENERGY FROM LARGE-SCALE LNG RECEIVING TERMINALS

越来越多的人已经意识到,LNG冷能是一笔宝贵的财富。为此,运用低温制冷效率工程数据和火用经济学方法,计算了LNG冷能的价值与气化过程中压力和温度变化范围的关系,结果指出:300×104t/a规模的LNG项目在8.0MPa下气化时可利用的冷功率为65MW,折合电能约为10×108kWh。还介绍了采用丙丁烷和乙二醇水溶液冷媒循环储存系统来解决LNG气化与冷能用户的运行在时间和空间上不同步的问题,以实现冷能集成和梯级利用的方案。最后指出了在中国目前的能源形势下,LNG冷能集成和梯级利用的必要性和可能性,以及实现方式:首先应着眼于煤化工、油气勘探开发、轻烃分离等大规模冷能产业市场;通过在国内外成熟可靠单项技术基础上的集成优化,有可能实现70%以上的冷能回收率。实施的关键是冷能产业链与LNG接收站同步规划建设,并在循环经济园区范围内按照市场机制统筹协调。

LNG cold energy has been realized as an alternative energy with great potential.Therefore,this study estimated the value of available energy related to the gasifying pressure and temperature range,in terms of the exergo-economics.The potential cold energy of a 3 mmt/a LNG terminal when re-gasified at 8 MPa is up to 65 MW,or 1 billion kWh/a electricity.An engineering method,applying propane/butane and other cold media inventory/recycling system to solve the issue of non-synchronization both in time and space,which realize the integrated and cascaded use of LNG cold energy,has been described.The necessity and possibility of integrated utilization of LNG cold energy has been emphasized;the priority are in the air separation market for coal-based chemistry,proving up and exploitation of oil and gas,C2+ separation from natural gas,and other large scope cold industry.More than 70% LNG cold energy should have been utilized,through integrated creation and optimization based on a series of mature technologies.A huge energy saving and economic benefit could be expected.The key to realize this target is the synchronized plan and construction of LNG terminal with cold industry chain,as well as the coordination according to the marketing economy mechanism within the circle economic region.