Ahmadi Mahmood, Zirak Saadat
Faculty of Mechanical Engineering, Semnan University, Semnan, Iran.
Sci Rep. 2025 Jul 11;15(1):25124. doi: 10.1038/s41598-025-10469-1.
Supercritical carbon dioxide (sCO₂) is an effective working fluid in closed-loop power conversion cycles, offering significant advantages over traditional steam-based Rankine cycles. These cycles efficiently extract heat from sources such as gas turbine exhaust and industrial waste heat, converting it into usable power. This paper presents a novel approach to enhance the performance of the sCO₂ recuperator cycle by integrating multi-effect desalination (MED) and organic Rankine cycles (ORC). This integration aims to improve both thermal efficiency and operational stability of the sCO₂ cycle. The MED process utilizes waste heat from the sCO₂ cycle to produce fresh water, thereby enhancing overall system efficiency, while the ORC optimizes energy recovery from low-grade heat sources. Through a comprehensive analysis of thermodynamic performance and system integration, this study demonstrates significant improvements in the stability and efficiency of the sCO₂ cycle. Various configurations, including simple, recuperator, and split cycles, are examined, focusing on key parameters such as gas turbine outlet temperature, smoke flow rate, and maximum cycle pressure. Results indicate that the efficiencies of the recuperator cycle, recuperator cycle with MED, recuperator cycle with ORC, and recuperator cycle with MED & ORC cycles are 19.26%, 30.89%, 25.51%, and 24.27%, respectively. The study emphasizes minimizing exergy losses to enhance environmental sustainability, leading to increased exergy efficiency and reduced emissions. The stability index correlates with exergy efficiency, indicating that higher values reflect greater stability and lower pollution levels. The sustainability indices for the different configurations are also reported, demonstrating the potential for improved output power and energy efficiency. In conclusion, this study highlights that advancements in sCO₂ cycles and the implementation of various configurations significantly enhance energy efficiency and environmental sustainability, while reducing pollution. The integration of additional cycles, such as Organic Rankine Cycle and Multi-Effect Desalination, further contributes to these improvements.
超临界二氧化碳（sCO₂）是闭环动力转换循环中一种有效的工作流体，与传统的基于蒸汽的朗肯循环相比具有显著优势。这些循环能有效地从燃气轮机排气和工业废热等热源中提取热量，并将其转化为可用电力。本文提出了一种通过集成多效蒸发淡化（MED）和有机朗肯循环（ORC）来提高sCO₂回热器循环性能的新方法。这种集成旨在提高sCO₂循环的热效率和运行稳定性。MED工艺利用sCO₂循环的废热来生产淡水，从而提高整个系统的效率，而ORC则优化从低品位热源的能量回收。通过对热力性能和系统集成的综合分析，本研究表明sCO₂循环的稳定性和效率有显著提高。研究考察了各种配置，包括简单循环、回热器循环和分流循环，重点关注燃气轮机出口温度、烟气流速和最大循环压力等关键参数。结果表明，回热器循环、带MED的回热器循环、带ORC的回热器循环以及带MED和ORC的回热器循环的效率分别为19.26%、30.89%、25.51%和24.27%。该研究强调将火用损失降至最低以提高环境可持续性，从而提高火用效率并减少排放。稳定性指标与火用效率相关，表明较高的值反映出更高的稳定性和更低的污染水平。还报告了不同配置的可持续性指标，展示了提高输出功率和能源效率的潜力。总之，本研究强调sCO₂循环的进展以及各种配置的实施显著提高了能源效率和环境可持续性，同时减少了污染。有机朗肯循环和多效蒸发淡化等附加循环的集成进一步促进了这些改进。
