新建350MW超临界机组耦合熔盐储热系统方案研究

Research on non afterburning compressed air energy storage system based on molten salt heat storage

本文设计了一种燃煤机组耦合熔盐储热系统新型技术方案,依托某新建350MW超临界机组灵活性调峰项目,提出采用抽汽+电加热联合式加热熔盐的技术路线。为提高系统效率并最大化利用高温蒸汽携带的热量,抽取的主汽采用部分凝结释放潜热加热熔盐的方案,抽取的主汽未凝结部分与熔盐换热后回到再热器冷段,解决了因抽主汽流量过多导致的再热器壁温超温问题,该方案不需要对现有机组方案做任何改动,在保证系统安全稳定高效运行的同时,能够使机组实现从30%THA负荷降至20%THA负荷的深调目标。

This paper designs a new technical solution for a coal-fired unit coupled molten salt heat storage system.Based on the flexible peak shaving project of a newly built 350MW supercritical unit,the technical route of using a combined steam extraction and electric heating to heat molten salt is proposed.In order to improve system efficiency and maximize the utilization of heat carried by high-temperature steam,the extracted main steam adopts a scheme of partially condensing and releasing latent heat to heat the molten salt.The uncondensed part of the extracted main steam exchanges heat with the molten salt and returns to the cold section of the reheater,solving the problem of overheating of the reheater wall temperature caused by excessive extraction main steam flow.This scheme does not require any modifications to the existing unit scheme,ensuring the safe,stable,and efficient operation of the system,it can enable the unit to achieve the deep adjustment goal of reducing the load from 30%THA to 20%THA.