熔盐储热系统对火电机组热经济性和调峰性能的影响

The effect of molten salt thermal storage scheme on thermal economy and peaking performance of thermal power units

为了研究耦合熔盐储热系统在同时供应工业蒸汽和供暖蒸汽的情况下对火电机组热经济性和调峰性能的影响,采用Ebsilon软件对耦合熔盐储热系统300 MW亚临界机组进行建模,聚焦机组同时供应工业蒸汽和供暖蒸汽工况,对比研究了8种储/放热方案的循环热效率、调峰容量和熔盐流量等指标。结果表明:在储热过程中,方案3和方案6的循环热效率最高,达到25.77%;方案7和方案8的调峰容量最大,为50 MW;在放热过程中,放热方式采用预热给水时机组的循环热效率和调峰容量最高,分别为33.50%和16.85 MW;在储/放热循环过程中,方案3的循环热效率最高,达到29.64%;方案7的调峰容量最大,达到66.85 MW。综合各方案的指标,方案7为该机组在同时供应工业蒸汽和供暖蒸汽工况下的最优储/放热方案。该研究可为耦合熔盐储热系统的火电机组调峰过程提供理论指导。

In order to study the effect of coupled molten salt thermal storage system on thermal economy and peaking performance of thermal power units under the condition of simultaneous supply of industrial steam and heating steam,Ebsilon software was used to model a 300 MW subcritical unit with coupled molten salt thermal storage system,focusing on the unit supplying industrial steam and heating steam simultaneously.The cycle thermal efficiency,peaking capacity,and molten salt flow rate of eight thermal storage/release scenarios were comparatively investigated.The results show that during the thermal storage process,Scenario 3 and Scenario 6 have the highest cycle thermal efficiency of 25.77%,and Scenario 7 and Scenario 8 have the highest peaking capacity of 50 MW.During the thermal release process,the highest cycle thermal efficiency and peaking capacity of the unit are achieved when the thermal release method uses preheated feedwater,which is 33.50%and 16.85 MW,respectively.During the thermal storage/release cycle,Scenario 3 has the highest cycle thermal efficiency of 29.64%and Scenario 7 has the largest peaking capacity of 66.85 MW.Combining indicators across programs,Scheme 7 is the optimal thermal storage/release scheme for this unit under the condition of supplying industrial steam and heating steam at the same time.This study can provide theoretical guidance for the peaking process of thermal power units coupled with molten salt thermal storage system.