Study On The Plan Of Flue Gas Waste Heat Utilization Of 350MW Boiler

Excessive boiler exhaust temperature will seriously reduce the efficiency of the boiler and affect the safe operation of downstream equipment.Therefore,in order to improve the economics and safety of boiler operation,it is necessary to reduce the boiler exhaust temperature.In view of the problem of excessive exhaust gas temperature in a 350MW boiler,this paper proposes a scheme to install a low-temperature economizer in the flue of the boiler.The composition of the flue gas waste heat utilization system,the main design parameters,the arrangement position of the flue gas cooler and its transformation plan,the layout position of a secondary air air heater and its transformation plan,the system water intake point and its return water point are determined.The primary air air heater heats the cold air to 60?,the secondary air air heater heats the cold air to 70?,and the flue gas cooler reduces the flue gas temperature from 165? to 90?.The program not only increases the amount of power generation,but also improves the combustion effect of the boiler and improves the efficiency of the boiler.The key technologies of flue gas waste heat utilization system are analyzed,and corresponding solutions are proposed for specific problems.The economic benefits of the flue gas waste heat utilization system of the 350MW unit were analyzed.The annual economic benefit under the design conditions was 4.93 million yuan,and the emissions of SO₂,CO₂ and soot were also reduced.The environmental benefits were quite remarkable.The total investment in the installation of flue gas waste heat utilization system is 14.6 million yuan,the static investment recovery period is 2.96 years,and the dynamic investment recovery period is 3.4 years.