渔船LNG动力改造及冷能利用分析

LNG Power Renovation of Fishing Vessels and Analysis on Cold Energy Utilization

针对某渔船进行LNG动力船舶柴油/LNG双燃料系统改造,对LNG冷量进行回收利用。对燃料储存供应系统进行改造,以满足双燃料需求。经计算,LNG储罐中产生的BOG量较小,采用直接燃烧或排空方式进行处理。发动机采用柴油/LNG双燃料模式,选用潍柴6170系列双燃料发动机,燃油与LNG的质量比为3∶7。设计了LNG冷能利用系统,利用LNG冷能进行渔品保鲜。介绍LNG冷能利用系统流程。冷媒采用R717。经计算,利用LNG冷能供冷时,每12 h可冻结的鱼量为1 583.5 kg,满足渔船冷库需求。针对渔船危险区,从消防系统、通风系统、可燃气体报警系统、LNG储罐监控系统、防爆保护系统等方面进行安全控制方案设计。对主要设备LNG储罐进行了设备布置,选用CFW-8/P型高真空多层绝热储罐,布置于驾驶甲板敞开区域,船体安全和稳定性均满足要求。

The LNG powered ship diesel/LNG dual fuel system of a fishing vessel is renovated,and the LNG cooling capacity is recycled.The fuel storage supply system is renovated to meet dual fuel requirements.It is calculated that the amount of BOG produced in the LNG storage tank is small and is treated by direct combustion or emptying.The engine adopts diesel/LNG dual fuel mode,Weichai 6170 series dual fuel engine is selected,and the mass ratio of fuel to LNG is 3:7.The LNG cold energy utilization system is designed to utilize LNG cold energy for fish preservation.The process of LNG cold energy utilization system is introduced.The refrigerant is R717.It is calculated that when LNG cold energy is used for cooling,the amount of fish that can be frozen every 12 h is 1 583.5 kg,which meets the cold storage demand of fishing vessels.For the dangerous area of fishing vessels,the safety control scheme is designed from the aspects of fire protection system,ventilation system,flammable gas alarm system,LNG storage tank monitoring system and explosion protection system.The equipment layout of the main equipment LNG storage tank is carried out.CFW-8/P type high vacuum multi-layer insulation storage tank is selected and arranged in the open area of the driving deck.The safety and stability of the hull meet the requirements.