Analysis On Performance Of Solar Aided Coal-fired Generation System

With the Energy structure adjustment,the proportion of clean energy increases,solar thermal power generation has developed in recent years.Solar aided coal-fired power generation not only brings coal consumption but also reduces pollutant emissions.Coal-fired power generation occupies a large proption,solar aided coalfired power generation has positive meaning.The research is mainly focused on trough solar assisted coal-fired power generation.Besides,the research on the impact of boiler in solar aided coal-fired power generation is rare.In this paper,a new type of solar aided coal-fired power generation system is proposed,tower solar energy is used to heat the steam extraction instead of the heating surface of boiler.Overtemperature that is caused by extraction is regulated by flue gas recirculation(FGR).Boiler heating surface and thermodynamic cycle of the 600 MW subcritical and 1000 MW supercritical unit is builded by EBSILON professional software.The reliability of model is analysed by comparing design values,which can meet the requirements of the calculation.the parameters of different load and different draw ratio are obtained under off-design conditions.And the performance of boiler under the maxmium of steam extcation is studied.For the exemple of 1000 MW unit,the change of boiler performance and economic are analyzed with the increase of the ratio of steam extraction.The result shows that FGR can meet the need of temperature regulation,the absorption share of boiler heating surface changes,the boiler efficiency is decreased,the exhaust gas temperature increases.But the thermaleconomics of overall integration system is good,and coal saving is large.