Effect of spray operation conditions on Nox emission control in a power station

Adequately mixing of reactants is an important factor for efficient deNOx process in power station NOx emission control system. In this study, an experimental validated CFD simulation is conducted to investigate the effect of spray operation conditions on the mixing uniformity of reactant ammonia vapor in deNOx process occurring in a power station's furnace. According to the CFD simulation results, it is found that spray mo-mentum ratio, initial droplet size and initial ammonia concentration all affect the mixing uniformity of ammonia vapor. Overall, a larger spray momentum ratio, larger initial droplet size and lower ammonia concentration contributes positively to the mixing uni-formity. By comparing the same spray momentum ratio but different nozzle inlet velocity and furnace inlet velocity, it is found that the impact of spray momentum ratio mainly comes from furnace inlet velocity not nozzle inlet velocity. In addition, gravity should not be neglected. In the end, the method described in this study could provide a systematic way to study the effects of nozzle operation conditions on deNOx process.(c) 2023 The Authors. Published by Elsevier Ltd on behalf of Institution of Chemical Engineers. This is an open access article under the CC BY license (http://creative-commons.org/licenses/by/4.0/).

Automated summary

The effect of spray operation conditions on the mixing uniformity of reactant ammonia vapor in the deNOx process occurring in a power station's furnace was investigated through experimental validated CFD simulation. The study found that spray momentum ratio, initial droplet size, and initial ammonia concentration all affect the mixing uniformity of ammonia vapor. It was also observed that the impact of spray momentum ratio mainly comes from the furnace inlet velocity rather than the nozzle inlet velocity. Gravity should not be neglected in the analysis. The method described in this study provides a systematic way to study the effects of nozzle operation conditions on the deNOx process.