Xin Feng Classroom | Ventilator Series Fan Parameter Conversion Formulas 2

01

What are the conversion formulas for fan parameters?

The outlet air temperature calculation formula is: 

T = T1 + Medium Temperature

 T1 = P (mmH₂O) / (125.5 × Fan Efficiency)

In the previous lesson, we learned how to calculate the torque for damper selection. So how do we select D-type and F-type fan dampers?

When selecting D-type fan regulating dampers, match them based on the ratio of the inlet area of the standard fan to the inlet area of the impeller. When selecting F-type fan regulating dampers, use the ratio of the inlet area to the inlet area of the impeller.

How do you calculate the single-side clearance between the impeller and the inlet? We installed it without proper calculation before, and it didn't achieve the expected results.

The minimum and maximum single-side clearance of the impeller is 0.0015 and 0.004, respectively. During calculation, multiply the impeller diameter by the minimum and maximum values to determine the minimum and maximum clearances, then adjust using tolerances.

Are there specifications for the dimensions of installed parts? Is it necessary to calculate the lengths of bolts, rivets, and similar fasteners?

Bolt Length Calculation: Total thickness of two flange plates plus bolt size plus 5mm allowance. (e.g., total flange thickness 20mm, M24 bolt: 20+24+5=49, round up to nearest size). Add 5mm for washers. Rivet (Round Head) Length Calculation: L = 1.1ξδ + 1.4d d = Rivet diameter (in mm) ξδ = Thickness of shaft plate + rear plate (in mm)

Even the smallest components require precise calculations. I need to put in more effort on my learning journey with wind turbines. Does environmental altitude affect wind turbines?

Yes, and it has a significant impact. The formula for calculating pressure at altitude is: Pb = 101325 × (1 - 0.0225H)⁵.²⁵⁶ H is in kilometers.

I see. If you don't pay attention to this, the wind turbines you make will indeed have major problems!

Yes, many details require attention. Similarly, the specific speed of the fan must also be calculated using the following formula:

n Fan rotational speed (preliminarily determined based on parameters and application). ρ = Gas density in kg/m³

Thank you, teacher! I've learned so much again this session. Combining it with last session's content, I'll pursue a deeper, systematic study! 

There are still many more formulas for fans to explore. Let's keep striving to learn and grow together!