Scheme design and performance analysis for a 670 MW coal-fired unit coupled with molten salt energy storage system
To address the challenges posed by the reverse peak shaving characteristics of new energy generation units to the smooth operation of the power grid,coal-fired units urgently need to improve their flexible operation and deep peak shaving capabilities.This article proposes three schemes of molten salt heat storage and heat release for a 670 MW reheating unit,including using a steam ejector to allocate the steam inlet flow rate of the reheater.By using Ebsilon to establish the thermal model,this article analyzes the performance of the coupled system.The results show that all schemes can effectively expand the peak shaving range of the unit.Under energy-storage conditions,the thermal economy of steam-extraction is better than using electrical heating at the same peak shaving depth.The heat-storage scheme of integrating steam ejector to allocate extraction steam to compensate for reheat inlet flow can effectively solve the problem of reheater over temperature caused by a large amount of extracted main steam.Under heat-release conditions,using molten salt to heat high pressure feed water can acquire better thermal and economic benefits.In the combination scheme of heat storage and release,C1-S2 exhibits the best economic performance,with an upward peak shaving depth of 76.89 MW,and a cyclic thermal efficiency and thermal efficiency of 42.48%and 41.31%,respectively.
molten salt energy storagethermal power unit renovationdeep peak shavingflexible operation
国家科技期刊平台
NSTL
万方数据
