Performance analysis and optimization of LNG cold energy integrated power generation system coupled with liquefied air energy storage

To increase the utilization efficiency of liquefied natural gas （LNG） cold energy and address the issues that the low round trip efficiency, power generation, utility value of conventional liquefied air energy storage （LAES） system and the continuous operation of LNG regasification process is inconsistent with the peak operation of the energy storage process, the LNG cold energy integrated power generation system coupled with liquefied air energy storage was built. Moreover, the thermodynamic performance and economic feasibility of the system were evaluated. The results showed that using Ethane and Propane as working fluids for reheat organic Rankine cycle （RORC） could significantly improve system performanc. The liquid air pump outlet pressure, liquid air storage pressure, the working fluids gasification pressure of the RORC, LNG outlet temperature of the RORC1 condenser, and the liquefied air flow rate had a significant effect on the system performance. The single objective and multi-objective optimization for the system performance were carried out based on the genetic algorithm （GA） and non-dominated sorting genetic algorithm （NSGA-Ⅱ）, and the multi-objective optimization results were determined. The comprehensive performance of the optimized system was better than that of the system studied in recent years. The net present value （NPV） analysis method proved that the system had certain economic feasibility with the NPV reaching 13.77×10⁶ USD, and the initial investment cost of the system could be recovered in 12.55 years. The research findings provide a reference basis for modeling design and efficient operation of the LAES integrated power generation system driven by LNG cold energy.