Design and Performance Analysis of Thermal Power Coupled Thermal Energy Storage with Integrated Steam Ejector

In this research paper, a deep peaking-regulation system is proposed for a thermal power unit, coupled with thermal energy storage and integrated with a steam ejector. The peak load regulation ability of a 600 MW subcritical thermal power unit is analyzed by using the MHFlow thermal balance calculation software based on self-programming technology. The results demonstrate that the integrated system can achieve a 16 and 11% peaking rate at lows and peaks, respectively. Thereby reducing the minimum operating power of the thermal unit from 150 MW to 50 MW and increasing the maximum operating power from 600 MW to 670 MW. Moreover, the round-trip efficiency of the coupled system can reach up to 75% in a heat storage and release cycle. The extracted main steam flow rate is identified as a critical parameter that affects the peaking rate and round-trip efficiency of the system. It is observed that when the main steam flow rate is less than 200 t/h, any flow variation significantly impacts the efficiency of the coupling system. Furthermore, the exergy losses of the condenser, turbine, and thermal storage system are analyzed in detail, which provides valuable insights into improving the efficiency in future studies.