Modeling and dynamic simulation of thermal energy storage system for concentrating solar power plant

• Published in: Energy (Oxford) 2020-05, Vol.198, p.117183, Article 117183
• Main Authors: Yu, Qiang, Li, Xiaolei, Wang, Zhifeng, Zhang, Qiangqiang
• Format: Article
• Language: English
• Subjects: Charging; Computer simulation; Concentrating solar power; Design; Disturbance; Dynamic characteristics; Electric power generation; Energy management; Energy storage; Experimental data; Irradiation; Lumped parameter method; Mass flow; Model accuracy; Molten salts; Oil; Power plants; Radiation; Solar energy; Solar power; Step disturbance; Storage systems; Systems design; Temperature; Thermal energy; Thermal energy storage; Thermal simulation
• ISSN: 0360-5442; 1873-6785
• DOI: 10.1016/j.energy.2020.117183

Thermal energy storage system in concentrating solar power plants can guarantee sustainable and stable electricity output in case of highly unstable solar irradiation conditions. In this paper, the lumped parameter method is used to develop the models of different thermal energy storage systems. In order to improve the reliability as well as the prediction accuracy of developed models, the charging/discharging process is firstly simulated, and then the dynamic characteristics of thermal energy storage systems are fully tested by imposing 15% step disturbance of mass flow. The results show that the charging/discharging characteristics of the three different thermal energy storage systems are almost the same, which have little to do with the storage mediums used in the systems. Besides, for the representative 1MWe solar parabolic trough power plant, a 15% step up disturbance of oil mass flow will result in a small increase (1.8% and 1.3% respectively) on the outlet temperature of oil and molten salt. On the other side, a 15% step down disturbance of oil mass flow will lead a 2.7% and 2.2% decrease on the outlet temperature of oil and molten salt respectively. In order to verify the validity of the proposed models, the simulation results are compared with both the design points and representative experimental data from the 1MWe solar parabolic trough power plant. The results show that the maximum relative error is not more than 1% when comparing with the design points and the maximum relative error is not more than 12% when comparing with the representative experimental data. Conclusions of this paper are good references for system design, control and commissioning of concentrating solar power plants. •Thermal energy storage can provide sustainable and stable electricity output.•Lumped parameter method is used to build the model of thermal energy storage.•The dynamic characteristics are tested by a 15% step disturbance of mass flow.•A 15% step-up will result in a 1.3% increase in molten salt outlet temperature.•A 15% step down will result in a 2.2% decrease in molten salt outlet temperature.