关键词: 凝汽机组, 灵活性改造, 熔盐储热, 600MW, 仿真模拟, 经济性分析

Abstract: In order to achieve the deep peak regulation and flexible operation of thermal power units under the "dual - carbon" goals and enhance the adaptability of high - power pure condensing units to the power grid, this paper focuses on a 600MW condensing unit and conducts a coupling design and economic analysis of a molten salt thermal energy storage system. The aim is to propose a technical transformation plan that takes into account both peak - shaving capabilities and thermal economy. Based on the EBSILON software, a simulation model of the unit's thermodynamic system is established, and its accuracy is verified. Two steam extraction and thermal energy storage schemes are put forward: Scheme 1 involves extracting reheated steam, and Scheme 2 involves extracting main steam. Under the rated operating conditions, with a thermal energy storage load of 90MW as the basis, a coupled model of thermal energy storage and release system is established. A comparative analysis is carried out from five aspects: peak - shaving capacity, overall plant thermal efficiency, absolute electrical efficiency, system cycle efficiency, and engineering applicability. Combined with the peak - valley electricity price policy in Hebei Province, the average daily revenue and static investment payback period of the system are estimated. The simulation results show that the peak - shaving capacities of Scheme 1 and Scheme 2 are 38.85 MW and 54.70 MW, respectively; the system cycle efficiencies are 84.6% and 60.1% respectively. Under typical peak - valley electricity prices, the average daily net revenues of Scheme 1 and Scheme 2 are 98,100 yuan and 70,500 yuan respectively; the static investment payback periods are 2.08 years and 3.53 years respectively. Scheme 1 demonstrates more excellent performance in terms of system cycle efficiency, absolute electrical efficiency, and economy. Regarding the molten salt thermal energy storage transformation of high - power condensing units, the scheme of extracting reheated steam can ensure significant peak - shaving capabilities while possessing better thermal economy and a shorter investment payback period. With better comprehensive performance, it can be recommended as a technical route for the flexibility transformation of similar units.

Key words: condensing unit, flexibility transformation, molten salt thermal storage, 600MW, simulation, economic analysis