Abstract:

Liquefied natural gas(LNG)fueled fishing vessels have a wide horizon of development,in order to improve the LNG cold energy utilization efficiency of them,this paper compared the pros and cons of recycling LNG cold energy through refrigerated warehouse and power generation,and proposed a new LNG cold energy utilization system for LNG-fueled fishing vessels.The utilizing efficiency of cold energy and exergy in different Rankine cycle condensation temperature,evaporation temperature and secondary refrigerant outlet temperature were obtained in this paper.The results show that the utilizing efficiency of cold energy increases significantly when Rankine cycle condensation temperature decreases or evaporation temperature rises.As secondary refrigerant outlet temperature increases,the utilizing efficiency of cold energy increases slightly,but the flow rate of secondary refrigerant increases significantly.In this system,the maximum cold energy utilization efficiency and exergy utilizing efficiency can respectively reach 200.1% and 28.6%,improved significantly and energy-saving effect is remarkable.

Key words: liquefied natural gas, cold energy recovery, exergy, fishing vessel, refrigerated warehouse

摘要：

液化天然气(LNG)动力渔船推广前景广阔,为提高其LNG冷能的利用效率,对比分析了在船舶上利用LNG冷能的冷库和发电两种方案的利弊,并在此基础上提出了一种新的LNG冷能利用系统。通过热力学分析,获得了不同有机朗肯循环(ORC)冷凝温度、蒸发温度和载冷剂出口温度条件下系统的冷能利用率及效率。分析结果表明,系统冷能利用率随朗肯循环冷凝温度的降低、蒸发温度的升高而有显著提高;随载冷剂出口温度升高,系统冷能利用率稍有提高,但载冷剂流量显著增大。该系统冷能利用率及效率最大值分别达200.1%和28.6%,可实现LNG冷能利用率的大幅提升,节能效果显著。

关键词: 液化天然气, 冷能回收, (火用), 渔船, 冷库