The Study On Wide-load Operation Scheme Of Boiler Denitrification System For 600MW Supercritical Unit In Wangqu Power Plant

China's thermal power plant nitrogen oxide emissions increased with the total installed capacity increased year by year,in order to prevent the boiler combustion of coal combustion produces too much nitrogen oxides(NOX)pollution of the environment,Wangqu power plant on the two boiler units were The SCR flue gas denitration system adopts the selective catalytic reduction method(SCR).In order to meet the SCR catalytic reduction temperature window,the inlet flue gas temperature is generally above 320 ? in the SCR reactor design process.However,the SCR inlet flue gas temperature will be lower than 320 ? when the boiler is under 50% load,so the SCR denitrification system can not work normally because the unit load is controlled by the grid dispatching,usually under the condition of changing operating conditions,causing the NOx concentration of boiler flue gas emissions can not meet the emission requirements.In order to ensure the normal operation of the SCR denitrification system under the condition of the wide load operation of the boiler and to solve the discharge problem of the standard,this paper presents the reform plan of the boiler and thermal system of the 600 MW supercritical unit boiler of Wangqu Power Plant:economizer flue gas bypass,economizer grading layout,economizer set water supply bypass regulation,the addition of zero-plus high,economizer to install the recirculation pump.According to the actual situation of Wangqu Power Plant,the optimum technical scheme of the boiler unit suitable for this power plant is studied and developed.Through the economizer calculation of boiler economizer,the unit operating parameters after the implementation of the reform plan were calculated and analyzed.The results show that the variable load range of the SCR system can be widened after the retrofitting,and the unit can reach above the minimum 35% load,and the operation condition of the SCR system can be satisfied by the operation adjustment to meet the increasingly stringent requirement of the boiler flue gas NOX emission.