Thermo-economic analysis of steam accumulation and solid thermal energy storage in direct steam generation concentrated solar power plants
Thermo-economic analysis of steam accumulation and solid thermal energy storage in direct steam generation concentrated solar power plants
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DOI：
10.1016/j.enconman.2022.116222
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发表时间：
2022-12
影响因子：
10.4
通讯作者：
Abdullah Al Kindi;P. Sapin;A. Pantaleo;Kai Wang;C. Markides
中科院分区：
文献类型：
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作者：
Abdullah Al Kindi;P. Sapin;A. Pantaleo;Kai Wang;C. Markides
在直接蒸汽发生（DSG）聚光太阳能发电（CSP）厂中，常见的热能存储（TES）选项依赖于蒸汽累积。这种传统的选择受到温度和压力限制的约束，并且在排放期间以降低的压力输送饱和或稍微过热的蒸汽，这对于部分负载涡轮机操作是不期望的。然而，蒸汽积累可以与混凝土中的显热储存相结合，以提供更高压力下的更高温度的过热蒸汽。在本文中，这种传统的蒸汽积聚选项（现有的）和综合混凝土蒸汽TES选项（扩展）进行了描述和分析，并以50兆瓦的Khi Solar One DSG CSP工厂为例，对它们的热经济性能进行了比较研究。结果表明，扩展选项与5个10米长，正方形横截面的混凝土块，每个有3600个等距管，提供了额外的TES容量为177兆瓦时相比，现有的配置作为利用太阳能接收器中的大部分可用的热能的结果。此外，在工商业污水附加费排放模式下，扩展选项提供的电力增加58%，热效率提高13%。估计额外投资为420万美元，Khi Solar One的存储和电力成本与延长的TES选项分别比现有的TES选项低29%和6%。随着延长的TES选项，Khi Solar One的预计净现值增加了73%，从4100万美元增加到7100万美元，平均电价为280美元/兆瓦时。
In direct steam generation (DSG) concentrated solar power (CSP) plants, a common thermal energy storage (TES) option relies on steam accumulation. This conventional option is constrained by temperature and pressure limits, and delivers saturated or slightly superheated steam at reduced pressure during discharge, which is undesirable for part-load turbine operation. However, steam accumulation can be integrated with sensible-heat storage in concrete to provide higher-temperature superheated steam at higher pressure. In this paper, this conventional steam accumulation option (existing) and an integrated concrete-steam TES option (extended) are described and analysed, and their thermo-economic performance are compared taking the 50-MW Khi Solar One DSG CSP plant in South Africa as a case study. The results show that the extended option with five 10-m long, square cross-section concrete blocks, each with 3600 equally spaced tubes, provides an additional TES capacity of 177 MWh compared to the existing configuration as a result of utilising most of the available thermal power in the solar receivers. Moreover, the extended option delivers 58 % more electricity with a 13 % enhancement in thermal efficiency during TES discharging mode. With an estimated additional investment of $4.2M, the levelised costs of storage and electricity for Khi Solar One with the extended TES option are, respectively, 29 % and 6 % lower than those obtained with the existing TES option. With the extended TES option, the projected net present value of Khi Solar One increases by 73 %, from $41M to $71M, at an average electricity price of 280 $/MWh.