# Study on the Influence of Dust Removal Fan Structure Parameters on Dust Removal Performance
## 4 Numerical Simulation Results and Analysis
### Influence of Outlet Length of Dust Removal Fan on Performance of Dust Removal Fan  
The total length of the original dust removal fan model from inlet to outlet is 3470 mm. To investigate the influence of the length of the dust removal fan outlet section on the dust removal efficiency, four groups of dust removal fan models with different outlet section lengths are established for simulation. The extension of the outlet section of the four sets of dust removal fan models is shown in Table 11.  
Four sets of dust removal fan models with different outlet lengths were simulated. The inlet speed was set to 16.405 m/s, the driving impeller speed was set to 2900 r/min, and the dust particle size was set to 10 \(\upmu\)m when the discrete phase simulation was added. The numerical simulation results of the four groups of dust removal fan models with different outlet lengths are summarized in Table 12.  
The relationship between the total pressure efficiency, static pressure efficiency, and dust removal efficiency in the table, and the extension of the outlet section of the dust removal fan, is drawn into a line chart, as shown in Figure 19.  
From the numerical simulation results, lengthening the outlet section of the dust removal fan will reduce the total pressure efficiency and static pressure efficiency of the dust removal fan, but the dust removal efficiency will increase. This is because lengthening the outlet section of the dust removal fan increases the resistance of the airflow inside the fan, leading to reduced total pressure and static pressure, thereby decreasing the total pressure efficiency and static pressure efficiency. Additionally, extending the outlet section of the dust removal fan allows for more effective capture of dust in the airflow by the water film on the side wall of the dust removal fan, thereby improving dust removal efficiency.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Serial Number** & **1** & **2** & **3** & **4** \\ \hline Extension of outlet section/mm & 0 & 100 & 200 & 300 \\ \hline \hline \end{tabular}
\end{table}
Table 11: The extension of the outlet section of the four dust removal fan models.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Extension of** & **Total** & **Static** & **Driving** & **Total Pressure** & **Static Pressure** & **Dust Removal** \\
**Outlet** & **Pressure/Pa** & **Pressure/Pa** & **Impeller Shaft** & **Efficiency/\%** & **Efficiency/\%** & **Efficiency/\%** \\ \hline
0 & 1546.77 & 1226.94 & 20.526 & 49.71 & 39.43 & 81.31 \\
100 & 1504.38 & 1173.04 & 20.496 & 48.42 & 37.76 & 83.02 \\
200 & 1476.42 & 1129.08 & 20.443 & 47.64 & 36.44 & 84.53 \\
300 & 1409.93 & 1115.17 & 20.411 & 45.57 & 36.04 & 85.42 \\ \hline \hline \end{tabular}
\end{table}
Table 12: Comparison of simulation results of dust removal fan models with different outlet lengths.  
However, extending the outlet section of the dust removal fan increases the overall length of the fan and its footprint. Considering both the extension of the outlet section and the efficiency trends shown in Figure 19, extending the outlet section of the dust removal fan by 200 mm appears reasonable.