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

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.