LNG卫星站冷能制冰工艺优化及模拟分析

Process optimization and simulation of ice-making utilizing cold energy from LNG satellite station

关键词:  LNG卫星站  冷能利用  制冰工艺  HYSYS模拟  相变冷媒 

Key words:  LNG satellite station  cold energy utilization  ice-making process  HYSYS simulation  phase transition refrigerant

摘要:

在现有的利用LNG卫星站冷能制冰的技术中,由于LNG气化量随季节及各时段用气量不同有很大的波动,会出现LNG气化量与冰的需求量不匹配的问题,且制冰量不稳定。针对这一问题,提出了一种新的联合制冰工艺,该工艺把利用相变冷媒(R410A)与LNG换热制冰的方法和蒸气压缩式制冷循环相结合,并采用天然气发动机为压缩机提供动力。除了能解决以上问题,还可缓解电力燃气的季节不平衡性。运用HYSYS软件对该工艺进行了模拟分析,并确定了该工艺的关键运行参数,模拟结果表明:气化量为2×10⁴~10×10⁴ m³/d的小型LNG卫星站,日制冰量约为127 t,相比用普通的制冰方法制取相同的冰最多每天可节约7 332 kW的能量。若按每100 kg冰块8元的批发价计算,年毛收入可达370.36万元,经济效益非常可观。 

Abstract:

Owing to the vaporizing quantity of LNG changing a lot in different seasons and times, some problems occur in the existing ice-making process by utilizing cold energy from LNG satellite station, including the mismatch between LNG vaporizing quantity and ice requirement, with the unstable output of ice-making. To solve these problems, a novel associated ice-making process was proposed. This process combines the ice-making method of utilizing cold energy from LNG with phase transition refrigerant (R410A) and the vapor compression refrigeration cycle, adopting natural gas engine to provide the power for compressor. In addition to solve the above problem, the new process also can alleviate the seasonal imbalance of electricity and gas. Simulations were carried out with the process software HYSYS, and the key operational parameters of the new process have been determined. The simulation results show that the output of ice-making is about 127 t for the small LNG satellite station that vaporizing quantity is 20×10³-100×10³ m³/d. Compared with the ordinary ice-making method, the new process can save energy up to 7 332 kW per day. If the wholesale price of ice is 8 yuan per 100 kg, the annual gross income will amount to 3 703 600 yuan. The new process has considerable economic benefit.