Combing the operation of low-NOxcombustion with SCR denitration system in utility boiler can reduce denitrification operation costs of the whole power unit

which is of great significance in ensuring the safety

environmental protection and economic operation of the units.Considering the effects of oxygen content of flue gas

additional air(AA)quantity

over fire air(OFA)quantity and other factors on the denitration economic performance of the unit

the comprehensive cost model was established for the unit combing low-NOxcombustion with the SCR denitration system.Moreover

low-NOxcombustion adjustment tests of the boiler and denitrification characteristics tests of the SCR denitration system were conducted to obtain operating characteristics and model parameters of the unit.An optimal operation system aiming at minimizing the comprehensive variable costs for the unit denitrification operation was developed

and online operation guidance for denitrification operation of the power unit was realized.The field test results show that

the denitration optimization system gives reasonable operation guidance.After the optimization

in slag in power plant A

the average carbon content reduced by 32%

the boiler efficiency increased by 0.28%

the ammonia consumption increased by 23kg/h

and the total cost dropped by 240yuan/h.In power plant B

the boiler efficiency changed little

while the urea consumption decreased by 49kg/h

the total cost reduced by180yuan/yuan.