Performance Analysis of Superheater Heat Exchanger of Thermal Energy Storage System in Direct Steam Solar Power Plant

The unsteady nature of solar energy is one of its major drawbacks. In this regard, an efficient thermal energy storage system can enhance the performance of a solar power plant, effectively. In this paper, different configurations of a steam super-heater heat exchanger based on phase change materials for thermal energy storage are simulated numerically, and analyzed based on the second law of thermodynamics to identify the best configuration. Also, the performance of a concrete energy storage system is compared with other configurations. The results indicate that by increasing the storage modules of phase change materials from one to three, the thermodynamic irreversibility decreases and the system efficiency increases from one to three percent. The results indicates that increase of steam flow rate and inlet steam temperature leads to decrease of exergy efficiency. By increase of inlet steam flow rate by five times and increase of steam temperature by twenty degree in charging mode, the system efficiency decreases by almost five percent.