Study of evaporation characteristics of droplets in high-temperature flue gas

摘要

In Selective Non-Catalytic Reduction (SNCR) process, the droplet evaporation of reducing agent solution has an important influence on NOx removal efficiency and ammonia escape control. In this study, based on the evaporation characteristics of liquid droplets, Fluent software was applied to simulate the effect of several parameters on the evaporation process of the droplets in high-temperature airflow, including flow velocity, flow temperature, droplet spraying velocity, droplet spraying amount, and droplet particle size. The results show that the increase of the airflow temperature from 1173 to 1473 K, the airflow velocity from 4 to 8 m/s, and droplet spraying velocity from 15 to 40 m/s can reduce the time of droplet evaporation to 73.0%, 89.6%, and 72.0%, respectively. The increase of the droplet spraying amount from 0.028 to 0.139 kg/s and the droplet particle size from 50 to 300 μm increased the droplet evaporation time by 1.28 and 3.2 times, respectively.