In this paper, based on the idea of reducing heat exchanger exergy
destruction and increasing turbine work, a new three-stage cascade Rankine
system and a new four-stage cascade Rankine system is proposed to improve
the cold energy utilization rate during liquefied natural gas(LNG)
gasification on liquefied natural gas-floating storage and regasification
unit. Then compare them with the original cascade Rankine cycle established
under the same conditions. The results show that under the condition of 175
t/h LNG flow, the maximum net output power of the new three-stage cascade
Rankine cycle system is 4593.31 kW, the exergy efficiency is 20.644%. The
maximum net output power of the new four-stage cascade Rankine cycle system
is 5013.93 kW, and the exergy efficiency is 22.509%. Compared with the
original cascade Rankine cycle system, the maximum net output power of the
new three-stage cascade Rankine cycle system and the new four-stage cascade
Rankine cycle system is increased by 9.41% and 11.45%, respectively, and the
system exergy efficiency is increased by 9.29% and 11.28%, respectively.
Progress of liquefied natural gas cold energy utilization
