Abstract The conceptual design and systematic comparison of S-CO2 coal-fired power generation systems are performed in the viewpoint of the thermodynamic analysis and economic assessment to promote the practical application in the industry. First, the differences between the conventional steam boiler and S-CO2 boiler are pointed out. 3 layouts of the water-cooling wall are compared in the aspect of the hydrodynamic characteristic and structural parameters to select the suitable one coupled to the S-CO2 cycles. Based on the optimized water-cooling wall layout, the energy, exergy and economic analysis models of the integrated S-CO2 coal-fired power systems are further developed. Finally, the mechanism of the inter-cooling thermodynamic process to improve the system performance is investigated and the distribution of the individual irreversibility is given. The systematic comparison is performed among 3 configurations of S-CO2 coal-fired power plants with consideration of the thermo-economic performance. The conceptual design of key components is also provided. The results demonstrate that the S-CO2 boiler is fatter due to 8 times larger mass flow rate of working fluid than the conventional steam boiler. The layout of water-cooling wall with the split flow strategy and vertical tubes is helpful in compacting the scale of the boiler for its less diameter and number of tubes, and its thermal efficiency is higher than that of other layouts. Among the 3 S-CO2 cycle layouts studied, the S-CO2 coal-fired power system with the inter-cooling cycle yields highest efficiency and is the most economic configuration. The thermal efficiency of the S-CO2 coal-fired power plant composing the inter-cooling cycle is 47.69–49.09% with total thermal conductance of recuperators changed from 120 MW·K−1 to 180 MW·K−1 when the turbine inlet parameters are 620 °C/620 °C/30 MPa, and displays an advantage over the ultra-supercritical steam Rankine power plant. The system levelized cost of electricity is 0.0397 $·(kW·h)−1 and shows great commercial potential. The detailed discussion of this study is beneficial to a comprehensive understanding of various S-CO2 coal-fired power systems and provide a clue to establish a practical power plant for the application of coal-fired industry.

中文翻译：

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结合 S-CO2 布雷顿循环的 1000 MW 燃煤电厂的能源、火用和经济 (3E) 评估和概念设计

摘要 从热力学分析和经济评价的角度对S-CO2燃煤发电系统进行概念设计和系统比较，以促进其在工业中的实际应用。首先指出常规蒸汽锅炉与S-CO2锅炉的区别。3种布置方式的水冷壁从水动力特性和结构参数方面进行比较，以选择合适的与S-CO2循环耦合的水冷壁。在优化水冷壁布置的基础上，进一步建立了S-CO2燃煤发电一体化系统的能源、火用和经济分析模型。最后，研究了中冷热力学过程提高系统性能的机理，给出了个体不可逆性的分布。考虑到热经济性能，对S-CO2燃煤电厂的3种配置进行了系统比较。还提供了关键部件的概念设计。结果表明，由于工作流体的质量流量比传统蒸汽锅炉大 8 倍，S-CO2 锅炉更胖。水冷壁采用分流策略和立管布置，管径小、管数少，有利于缩小锅炉规模，热效率高于其他布置方式。在研究的 3 个 S-CO2 循环布局中，带中冷循环的 S-CO2 燃煤发电系统效率最高，是最经济的配置。组成中冷循环的S-CO2燃煤电厂的热效率为47.69%～49.09%，当汽轮机进口参数由120 MW·K-1变为180 MW·K-1时，换热器的总热导率为 620 °C/620 °C/30 MPa，与超超临界蒸汽 Rankine 电厂相比具有优势。系统平准化电力成本为 0.0397 $·(kW·h)-1，显示出巨大的商业潜力。本研究的详细讨论有利于全面了解各种S-CO2燃煤发电系统，为建立适合燃煤工业应用的实用电厂提供线索。