Simulation and optimization of liquefied natural gas cold energy power generation system on floating storage and regasification unit

Abstract

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.

Energy, exergy, economic and environmental analysis of a regasification system integrating simple ORC and LNG open power cycle in floating storage regasification units

“…The latter component expands part of the regasified NG to supply the fuel gas consumed in the engines. Regarding cascaded ORCs, Yao et al [22] evaluate two three-stage configurations, while Xu and Lin [23] propose two power cycles: a novel three-stage and a four-stage configuration. Based on the results obtained from these studies, cascade configurations allow higher exergy efficiencies to be achieved than cycles in series.…”

Thermodynamic and Economic Analyses of Zero-Emission Open Loop Offshore Regasification Systems Integrating ORC with Zeotropic Mixtures and LNG Open Power Cycle

“…Research on the application of the ORC with cold energy utilisation in FSRUs has focused on open loop regasification systems with ORC configurations both in series (up to three stages) [23][24][25] and in cascade (maximum four stages) [26,27] and the possible integration of waste heat from engine exhaust gases [28]. A summary of these works is shown in Table 1.…”