The Research On The Effect Of The Oxy-fuel Combustion On Heat Economy Of The 350MW Unit

Coal was the main energy in China.CO₂ released from coal combustion was considered to be the main reason of climate change.The largest emission source of CO₂ was the coal-fired power plant.The effective method of reduction plans was CO₂ mitigation from coal-fired power plant.Oxy-fuel combustion which can increase combustion efficiency and reduce pollutant emission was an important clean coal power generation technology.It was necessary to know the effect of oxy-fuel combustion on coal-fired power plant.In this work,the experiment on the boiler of the unit was done and the heat efficiency of boiler under different load was calculated.An thermodynamic calculation model of coal-fired power plant was developed and was verified through the experimental results on the unit.The operation characteristics of coal-fired power plant based on oxy-fuel combustion was studied through the model.The effect of flue gas recycled on coal-fired power plant based on oxy-fuel combustion was studied and the effects of oxygen concentration,unit load,atmosphere temperature on the performance of the system were investigated.Researches show that the boiler heat efficiency can raise 0.5%based on oxy-fuel condition;the boiler heat efficiency is maximum when oxygen concentration 27%-28%;as starting point of flue gas recycled devices was close to filter,heat efficiency is better.The heat efficiency was increased with the increase of atmospheric temperature.Compared conventional generators,the heat efficiency of oxy-fuel was raised in off-design condition,and was increased with the boiler load increasing.