Configuration Optimization and Performance Analysis of Supercritical Carbon Dioxide Power Generation and Energy Storage Integrated System

doi:10.3969/j.issn.1008-0198.2024.04.001

Abstract

Abstract: To synergistically enhance the efficiency and flexibility of coal-fired power system, and promote the transformation of thermal power units, a scheme of using supercritical carbon dioxide (S-CO₂) working fluid to construct a coupling system of coal-fired power generation and pumped thermal electricity storage (“source-storage-integrated” system) is proposed. Based on the first and second laws of thermodynamics, the design and off-design calculation models of the integrated system are developed, and the potential of the flexibility improvement and the energy efficiency of the heat storage-release process are analyzed. The results show that by integrating pumped thermal electricity storage technology on the basis of S-CO₂ coal-fired power system, the minimum output power of the unit can be reduced from the original 30% rated load to zero, which greatly improves the peak regulation depth and operation flexibility. When 75% rated load is selected as the heat release condition, the output power can be increased by 23.59% of the rated load. In addition, the equivalent round-trip efficiency of the heat storage-release process of the integrated system is 78.64%. The sensitivity analysis of heat storage parameters shows that the optimal value range for the molten salt cold tank temperature is 405~420 ℃, and the value range for the atmospheric pressure water hot tank temperature is 70~75 ℃.

Key words: supercritial carbon dioxide, coal-fired power generation, pumped thermal electricity storage, flexibility

CLC Number:

TK116

ZHU Guangming, CHEN Xun, HE Honghao, SUN Ruiqiang, XIE Guohong, YANG Yi, WANG Yangguang. Configuration Optimization and Performance Analysis of Supercritical Carbon Dioxide Power Generation and Energy Storage Integrated System[J]. Hunan Electric Power, 2024, 44(4): 1-10.

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