*3.2. Effect of Flue Gas Temperature on the Evaporation Performance*

Figure 7 shows the turbulence kinetic energy under different flue gas temperatures. By increasing the flue gas temperature, the turbulence kinetic energy in the mixing zone of the flue gas and the droplets changes slightly, which indicates the slight difference in the mixing intensity between flue gas and droplets. Figure 8 displays temperature under different flue gas flow rates. Higher flue gas temperature corresponds to higher temperature and more heat in the mixing zone of flue gas and droplets, which is advantageous to evaporate the droplets.

**Figure 6.** Effect of flue gas flow rate on evaporation performance.

**Figure 7.** Turbulence kinetic energy under different flue gas temperatures (m2/s2).

**Figure 8.** Temperature under different flue gas temperatures (K).

Figure 9 shows the effect of flue gas temperature on the droplet evaporation performance in the spray drying tower. It can be seen that increasing the flue gas temperature is beneficial for reducing the droplet residence time in the spray drying tower and improving droplet evaporation performance. This is because the higher flue gas temperature increases the temperature difference between the flue gas and the droplets, enhancing the diffusion and thermophoretic force effects. As a result, heat and mass transfer become more vital, and the droplet evaporation speed is accelerated and reduces the complete evaporation distance.
