一种LNG卫星站冷能制冰工艺的改进优化

Improvement and optimization of an ice-making process utilizing cold energy from LNG satellite station

关键词:  LNG卫星站  冷能制冰  低品位冷能  Aspen  工艺优化  压缩机能耗  经济效益 

Key words:  LNG satellite station  cold energy to ice-making  low-grade cold energy  Aspen  process optimization  energy consumption of compressor  economic benefit

摘要:

通过分析发现,目前一种新的LNG卫星站冷能制冰工艺(文中工艺流程一)仍存在一些不足:其仅能回收利用LNG高品位冷能,而不能有效回收利用低品位冷能。为此,对该工艺作了进一步改进,在其基础上提出了两套更加节能的LNG卫星站冷能制冰工艺(文中工艺流程二、三),并对其工艺参数作了模拟优化。对于气化量为(2～10)×10⁴ m³/d的小型LNG卫星站,在给定的几种工况下,通过Aspen软件模拟计算,并对比分析发现,改进优化后的工艺流程二、三较工艺流程一,压缩机能耗最高分别降低了26.51%、28.75%；在制冰经济效益上,日收益额最少可分别高出107元、119元,最高可达307元、489元,年收益额则最多可分别高出11.2万元、17.8万元；此外,在设备初投资及运行维护费用上,工艺流程三较工艺流程二更经济。由此可见,在LNG冷能制冰上,改进优化后的两套新工艺较改进前的工艺更具经济优势,且随着气化量的增大,其优势越来越明显,其中工艺流程三优势更突出,更适合LNG卫星站冷能制冰项目。 

Abstract:

Analysis results show that there are still some shortcomings in the latest ice-making processes of utilizing cold energy from LNG satellite station (the first process in this paper):only the high-grade cold energy of LNG can be recycled while the low-grade cold energy is wasted. So, improvements have been made, and two more efficient energy saving ice-making processes (the second process and the third process in this paper) are proposed on the basis of the first process, and the process parameters are optimized. Simulation and analysis for the ice-making process of utilizing cold energy from LNG satellite station, whose vaporizing quantity is(2-10)×10⁴ m³/d ,are made by the application of Aspen software. The results show that the energy consumption of compressor in the second and third process can reduce 26.51% and 28.75% respectively than that of the first process. For the first investment of equipment and operation cost, the third process has more advantages than the second process. Obviously, the two modified processes have more advantages than the first processes, and the advantages become more obviously with the increase of vaporizing quantity and the advantages of the third process is most apparent, and it is more suitable for ice-making project of LNG satellite station.