| China’s power supply structure has been constantly adjusted,and the clean power generation technology of combined cycle using natural gas as fuel is gradually widely used.The optimization of steam system of combined cycle units has great practical significance for energy conservation and emission reduction.In this paper,the mathematical model of each main equipment is discussed.Using Aspen Plus simulation software,the combined cycle power station model is established.Under the conditions that the natural gas consumption and the gas tu rbine output electric power are constant values,and the gas inlet parameters of th e waste heat boiler are constant,combined with the actual operating data of the p ower plant,the combined cycle conditions are 65.3%,78%,95.5%,100%load co nditions respectively.The operation optimization of steam system parameters is car ried out,and the optimum curve of steam parameters is obtained,which provides theoretical guidance for the operation optimization of the unit.On the basis of the model of combined cycle power station,a trough solar mirror field is added to form a model of solar-gas steam combined cycle system by using part of the water supply of photothermal evaporation power station,and the process is simulated by using EBILON simulation software to optimize the steam system structure of combined cycle units.Under the condition of the total power generation capacity of 390 MW,the natural gas saving effect of the two steam structures on the combined cycle unit is compared.The results show that both steam structures can achieve the purpose of saving natural gas.After the steam structure of the combined cycle unit is optimized,it has great practical significance for energy saving and emission reduction.Solar heating of feed water at the outlet of medium pressure economizer has better effect on saving natural gas than feed water at the outlet of low pressure economizer.Finally,the influence of solar radiation intensity change on ISCC system evaluation performance was studied,and the utilization and loss of useful energy in solar-gas-steam combined cycle system were analyzed by analysis methods. |
