Peaking Shaving Performance Study Of Combined-Cycle CHP Plant Coupled With Heat Storage

The capacity of domestic renewable generator assembly machines is increasing,and combined cycle-based combined heating and power(CHP)system need to undertake more peak-shaving tasks.The traditional CHP units with fixed power by heat can not meet the demand for renewable energy consumption.Therefore,it is important to carry out research on the flexibility of combined cycle combined heat and power units and realize the heat-electrolysis coupling for the consumption of renewable energy power.In this paper,aiming at the combined cycle pumped steam heating unit composed of PG9351FA,the heat storage method of extracting the gas exhaust and molten salt heat exchange and the heat release method of pressing unsaturated water in the heating part of the high-temperature molten salt is proposed to improve the peak shaving capacity of the combined cycle combined heat and power unit.In this paper,the combined cycle is modeled by Ebsilon software according to the actual parameters of the unit,and the variable operating conditions model of the combined cycle unit is calculated under two different combustion engine operation strategies.To investigate how the performance of combined cycle units is affected by heat storage systems,a study was conducted,and the maximum heat storage capacity of combined cycle combined heat and power units under different turbine loads was obtained,among which the heat storage capacity of the group was stronger when the gas turbine adopted the T3 adjustment mode.Furthermore,an examination was conducted on the thermal efficiency of the molten salt heat storage system.The findings suggested that when the heat storage and release capabilities of the molten salt system are in equilibrium,the gas consumption rate for power generation by the unit will decrease as the power of the molten salt system increases during a single operational cycle.Finally,the heat storage system’s operational features and maximum capacity were assessed.The results of the study show that for every 10MW increase in the power of the heat storage system after the integration of the heat storage system,the heat supply of the unit increases by approximately 8.55MW.When the heating load exceeds 100MW,the peaking capacity of the heat storage system is significantly improved compared to the reference unit.Taking the heat storage and release power of 50MW as an example,when the heating load is 150MW,the peaking capacity of the unit is increased from 34.84% to 61.5%.