Abstract S–CO2 (Supercritical-CO2) coal-fired power plant is a promising technology for efficient and clean utilization of coal for power generation. The comparative study between the S–CO2 coal-fired power plant and the power plant with steam Rankine cycle from aspects of energy and exergy balances is conducted. The conversion and transfer of the energy and exergy in the power plants are revealed. With the main gas parameters of 32MPa/620 °C and double-reheat process, the power generation efficiencies of the S–CO2 coal-fired power plant and the power plant with steam Rankine cycle are 49.06% and 48.12%, respectively. The corresponding exergy efficiencies are 48.02% and 47.10%, respectively. The energy-saving mechanism of the S–CO2 coal-fired power plant is revealed: the smaller boiler efficiency and larger exergy efficiency of the boiler system in the S–CO2 coal-fired power plant make the energy level of the energy being transferred to the S–CO2 cycle is higher than that of the energy being transported to the Rankine cycle. The CO2 absorbs the high-level energy and produces more mechanical power through the S–CO2 cycle to obtain higher power efficiency.

中文翻译：

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S-CO2循环与蒸汽-朗肯循环相比燃煤电厂的节能机理

摘要 S-CO2（超临界CO2）燃煤电厂是一种高效清洁利用煤炭发电的有前景的技术。从能量平衡和火用平衡方面对S-CO2燃煤电厂与蒸汽兰金循环电厂进行了对比研究。揭示了发电厂中能量和火用的转换和转移。在主气参数32MPa/620℃和二次再热工艺下，S-CO2燃煤电厂和蒸汽兰金循环电厂的发电效率分别为49.06%和48.12%。相应的火用效率分别为 48.02% 和 47.10%。S-CO2燃煤电厂节能机理揭示：S-CO2 燃煤电厂锅炉系统较小的锅炉效率和较大的火用效率使得转移到 S-CO2 循环的能量的能级高于输送到朗肯循环的能量的能级. CO2 吸收高能级的能量并通过 S-CO2 循环产生更多的机械能，从而获得更高的功率效率。