Optimization of cascade utilization of LNG cold energy for power generation

Full recovery and utilization of LNG cold energy in the most economical way is an important subject in LNG terminals. Based on thermodynamic principles and application examples at home and abroad, the factors of Organic Rankine Cycle method that affect cold energy utilization efficiency were analyzed and the principle for selecting the working fluids for circulation were proposed. Moreover, single working fluid and mixed working fluid were compared, and the impact of pressure on LNG cold energy recovery was analyzed. Finally, the programs for circulation system optimization based on utilization of multi-level tandem segmented cascade and multi-level complex cascade were provided. Taking Guangxi LNG Terminal as an example, analysis in combination with the actual situations of the local LNG market reveals that LNG cold energy power generation supported with "cold energy + seawater" ice generation program is the optimal solution for Guangxi LNG Terminal. It points out the directions for Guangxi LNG cold energy utilization and has certain guiding significance to cold energy utilization of other coastal LNG terminals in southern China.