凝汽式机组旁路蓄热调峰方案变工况及经济性研究OA

Applying the molten salt heat storage technology to condensing thermal power units can enhance the flexibility of peak shaving.A bypass two-stage heat-storage peak shaving scheme was proposed and applied in an ultra-supercritical 660 MW unit.Taking 30%THA as the design condition for the thermal storage system,four heat storage capacity schemes were designed.The EBSILON software was used to analyze the peak regulation range,heat storage and release duration,peak regulation cost,and the change of net profit from heat-storage peak-shaving under different market rules.The results show that during off-design operations,there exist feasible domains for both heat charging and discharging.During the charging process,when the initial operating condition is between 40%～50%,the decrease in minimum generation load ratio is most significant,with the high-temperature thermal storage system reaching its design capacity first.During the discharging process,when the initial operating condition is 94.6%,the load ratio equivalent to VWO condition can be achieved,with the high-temperature thermal storage system completing discharge first.Regardless of the implementation approach,peak-shaving through thermal storage achieves maximum electricity revenue growth while minimizing lifespan depreciation costs and overall system expenses.In the peak-shaving ancillary service market,net profit peaks at 40%heat-storage starting condition,whereas in the capacity market scenario,the maximum net profit occurs at 45%heat-storage starting condition.The scheme with the smallest heat storage capacity demonstrates the lowest total cost increase,with both market mechanisms yielding optimal net profits.