Modification of the Mixed Fluid Cascade cycle with heat recovery of the working fluid reverse flows and optimised natural gas flow pressure

Objective. The paper investigates the feasibility of heat recovery from reverse flows in the Mixed Fluid Cascade cycle, highlighting its positive impact on specific energy consumption for liquefied natural gas (LNG) production. Method . The study employs mathematical modeling to analyze both the basic and modified cycle operations. The modified version incorporates heat exchangers in the liquefaction and subcooling stages, allowing reverse flows to be heated by direct flow heat. Additionally, a booster compressor for the feed natural gas flow is introduced to enhance energy efficiency. Result . The numerical experiments assess how variations in feed flow pressure, heat under-recovery in heat exchangers, and their configuration affect specific energy consumption and mass flow rates in the cycle's external cooling stages. Results indicate that thermal load can be redistributed towards high-temperature stages, leading to a reduction in specific energy consumption for LNG production. Conclusion . Overall, the research demonstrates the potential benefits of implementing heat recovery strategies in the Mixed Fluid Cascade cycle, contributing to more efficient LNG production processes.