Study of direct thermal energy storage technologies for effectiveness of concentrating solar power plants

摘要

In this paper, numerical comparisons are devised among different direct thermal energy storage (TES) technologies of concentrating solar power (CSP) plants with possible alternatives in design, plantwide control and global economic considerations and therefore, leading the process up to the sustainable power production through the day and night. The first design is based on the conventional direct double-tank thermal energy storage CSP plant, and afterwards, the modification on the design of this plant is proposed. The modification on the plantwide control is followed by recycling the heat transfer fluid (HTF) through the solar field and decreasing the degradation of temperature of the storage in discharge period. In addition, the analogues analysis is performed towards the solutions of the stable behavior on dynamic of the storage and power production. Owing to the fact that the single-tank storage technology eliminates using an extra storage volume in process design, consequently, it decreases the capital cost of the plant, the dynamic design of the single-tank storage technology is presented. Avoiding the greater degradations of the parameters is considered and improved through the heat exchanger trains as a challenging issue in storage technologies along with the plantwide control. In this work, considerations of process control toimprove the quality of storage, operational issues, and flexibility related to the selected TES technologies are discussed due to making decisions for optimal control and covering the demanded energy generated by CSP plant.