Thermodynamic Performance Analysis of Integrating Multi-heat Source Molten Salt Heat Storage System into Coal-fired Power Plant
To further reduce the electric load rate of coal-fired power plants(CFPPs)under the mini-mum stable combustion load of the boiler,the coal-fired power system models for molten salt heat storage integrated with multi-heat sources of flue gas and main steam were established by Ebsilon software,and the thermodynamic performance of the integrated system was analyzed through a case of a 660 MW super-critical CFPP.In addition,the performance of integrated system under different discharging benchmark conditions was analyzed.Calculation results show that during the charging process,the minimum electric load rate of CFPP can be reduced from 30％to 11.75％due to the maximum split mass flow rate of the main steam at 88.40 kg/s.During the discharging process,the output power of CFPP increases by 88.50 MW,accounting for 13.40％of turbine heat acceptance condition(THA).The maximum equiva-lent cycle efficiency of the integrated system under the condition of 30％THA for charging and 75％THA for discharging is up to 85.89％.The additional exergy loss of the integrated system is negative during the charging process,while it is positive during the discharging process.The integrated system has the largest additional exergy loss at 41.96 MW under 100％THA for discharging and the lowest exergy loss at 12.40 MW under 50％THA for discharging.Overall,the integrated system shows the best performance under the condition of 30％THA for charging and 50％THA for discharging with the maximum equiva-lent cycle efficiency of 94.35％.
operation flexibilitymultiple heat sourcesmolten salt heat storageexergy analysise-quivalent cycle efficiency
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维普
