High concentrations of chloride ions in desulfurization wastewater will corrode the equipments and affect normal operation of them. In order to study the effect of spraying desulfurization wastewater to coal on boiler operation

an ash melting point tester was firstly applied to study the effect of adding chlorine salts and desulfurization wastewater into coal on the ash melting points

and the mechanism of ash melting point change was explained by thermodynamic simulation. Secondly

the precipitation characteristics of chlorine in coal combustion process were studied by thermodynamic simulation. Then

according to the simulation results

the corrosion rate of chlorine to metal was calculated. Finally

the chlorine balance of the boiler system of which the feed coal is treated by spraying desulfurization wastewater was analyzed. The results show that

adding the desulfurization wastewater will reduce the ash melting point. During the coal combustion process

chlorine releases mainly in form of HCl(g). When the wastewater spraying flow rate is 7.5 t/h

the volume fraction of HCl(g) in the flue gas can reach 50×10-6. The corrosion rates of T91 and 15 CrMoG metal pipes are different at different heating surface temperatures and different HCl volume fractions. In this way

chlorine mainly releases in form of gas

and most of the chlorine will concentrate in the desulfurization system

which destroys the chlorine balance. Therefore

when spraying the desulfurization wastewater to coal yard

the amount of desulfurization wastewater needs to be strictly controlled to ensure normal operation of the boiler.