梯级火储集成系统设计及其调频基础研究OA

[Objective]Driven by the global energy transition and the"dual-carbon"goals,enhancing the operational flexibility of coal-fired units has become pivotal for improving the grid's renewable energy accommodation capacity.To enhance the frequency-regulation flexibility of coal-fired units and address the pinch-point bottleneck in molten-salt/steam heat exchange,this study proposes a three-tank cascaded thermal energy storage(TES)system integrated with a subcritical unit.[Methods]A steady-state model of a 330 MW unit was developed in EBSILON.It incorporated high-,intermediate-,and low-temperature molten-salt loops,and achieved partial boiler-turbine decoupling via main-steam and feedwater bypass circuits.[Results]The simulation results indicate that the cycle electric efficiency reached 63.51%at 100%THA;the heat rate increase of the integrated system was about 1%in hot standby working state of each working condition,and 13.2%at 40%THA with a 5%Pe regulation depth;the coal consumption penalty grew exponentially with regulation depth,providing a basis for defining an economic dead band.[Conclusion]The cascaded TES structure preserves steam exergy while significantly improving load-response rate and frequency-regulation capability,offering both theoretical insights and a practical design paradigm for flexibility retrofits of coal-fired units in power systems with high renewable penetration.